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Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux
[GitHub/mt8127/android_kernel_alcatel_ttab.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 IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_redirect_number __read_mostly = 9;
121 static int ip_rt_redirect_load __read_mostly = HZ / 50;
122 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
123 static int ip_rt_error_cost __read_mostly = HZ;
124 static int ip_rt_error_burst __read_mostly = 5 * HZ;
125 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
126 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
127 static int ip_rt_min_advmss __read_mostly = 256;
128
129 /*
130 * Interface to generic destination cache.
131 */
132
133 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
134 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
135 static unsigned int ipv4_mtu(const struct dst_entry *dst);
136 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
137 static void ipv4_link_failure(struct sk_buff *skb);
138 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb, u32 mtu);
140 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
141 struct sk_buff *skb);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
143
144 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
145 int how)
146 {
147 }
148
149 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
150 {
151 WARN_ON(1);
152 return NULL;
153 }
154
155 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
156 struct sk_buff *skb,
157 const void *daddr);
158
159 static struct dst_ops ipv4_dst_ops = {
160 .family = AF_INET,
161 .protocol = cpu_to_be16(ETH_P_IP),
162 .check = ipv4_dst_check,
163 .default_advmss = ipv4_default_advmss,
164 .mtu = ipv4_mtu,
165 .cow_metrics = ipv4_cow_metrics,
166 .destroy = ipv4_dst_destroy,
167 .ifdown = ipv4_dst_ifdown,
168 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
174 };
175
176 #define ECN_OR_COST(class) TC_PRIO_##class
177
178 const __u8 ip_tos2prio[16] = {
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BESTEFFORT,
182 ECN_OR_COST(BESTEFFORT),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_BULK,
186 ECN_OR_COST(BULK),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE,
190 ECN_OR_COST(INTERACTIVE),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK),
193 TC_PRIO_INTERACTIVE_BULK,
194 ECN_OR_COST(INTERACTIVE_BULK)
195 };
196 EXPORT_SYMBOL(ip_tos2prio);
197
198 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
199 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
200
201 #ifdef CONFIG_PROC_FS
202 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
203 {
204 if (*pos)
205 return NULL;
206 return SEQ_START_TOKEN;
207 }
208
209 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
210 {
211 ++*pos;
212 return NULL;
213 }
214
215 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
216 {
217 }
218
219 static int rt_cache_seq_show(struct seq_file *seq, void *v)
220 {
221 if (v == SEQ_START_TOKEN)
222 seq_printf(seq, "%-127s\n",
223 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
224 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
225 "HHUptod\tSpecDst");
226 return 0;
227 }
228
229 static const struct seq_operations rt_cache_seq_ops = {
230 .start = rt_cache_seq_start,
231 .next = rt_cache_seq_next,
232 .stop = rt_cache_seq_stop,
233 .show = rt_cache_seq_show,
234 };
235
236 static int rt_cache_seq_open(struct inode *inode, struct file *file)
237 {
238 return seq_open(file, &rt_cache_seq_ops);
239 }
240
241 static const struct file_operations rt_cache_seq_fops = {
242 .owner = THIS_MODULE,
243 .open = rt_cache_seq_open,
244 .read = seq_read,
245 .llseek = seq_lseek,
246 .release = seq_release,
247 };
248
249
250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
251 {
252 int cpu;
253
254 if (*pos == 0)
255 return SEQ_START_TOKEN;
256
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
259 continue;
260 *pos = cpu+1;
261 return &per_cpu(rt_cache_stat, cpu);
262 }
263 return NULL;
264 }
265
266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
267 {
268 int cpu;
269
270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
272 continue;
273 *pos = cpu+1;
274 return &per_cpu(rt_cache_stat, cpu);
275 }
276 return NULL;
277
278 }
279
280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
281 {
282
283 }
284
285 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
286 {
287 struct rt_cache_stat *st = v;
288
289 if (v == SEQ_START_TOKEN) {
290 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");
291 return 0;
292 }
293
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
297 st->in_hit,
298 st->in_slow_tot,
299 st->in_slow_mc,
300 st->in_no_route,
301 st->in_brd,
302 st->in_martian_dst,
303 st->in_martian_src,
304
305 st->out_hit,
306 st->out_slow_tot,
307 st->out_slow_mc,
308
309 st->gc_total,
310 st->gc_ignored,
311 st->gc_goal_miss,
312 st->gc_dst_overflow,
313 st->in_hlist_search,
314 st->out_hlist_search
315 );
316 return 0;
317 }
318
319 static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
324 };
325
326
327 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
328 {
329 return seq_open(file, &rt_cpu_seq_ops);
330 }
331
332 static const struct file_operations rt_cpu_seq_fops = {
333 .owner = THIS_MODULE,
334 .open = rt_cpu_seq_open,
335 .read = seq_read,
336 .llseek = seq_lseek,
337 .release = seq_release,
338 };
339
340 #ifdef CONFIG_IP_ROUTE_CLASSID
341 static int rt_acct_proc_show(struct seq_file *m, void *v)
342 {
343 struct ip_rt_acct *dst, *src;
344 unsigned int i, j;
345
346 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
347 if (!dst)
348 return -ENOMEM;
349
350 for_each_possible_cpu(i) {
351 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
352 for (j = 0; j < 256; j++) {
353 dst[j].o_bytes += src[j].o_bytes;
354 dst[j].o_packets += src[j].o_packets;
355 dst[j].i_bytes += src[j].i_bytes;
356 dst[j].i_packets += src[j].i_packets;
357 }
358 }
359
360 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
361 kfree(dst);
362 return 0;
363 }
364
365 static int rt_acct_proc_open(struct inode *inode, struct file *file)
366 {
367 return single_open(file, rt_acct_proc_show, NULL);
368 }
369
370 static const struct file_operations rt_acct_proc_fops = {
371 .owner = THIS_MODULE,
372 .open = rt_acct_proc_open,
373 .read = seq_read,
374 .llseek = seq_lseek,
375 .release = single_release,
376 };
377 #endif
378
379 static int __net_init ip_rt_do_proc_init(struct net *net)
380 {
381 struct proc_dir_entry *pde;
382
383 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
384 &rt_cache_seq_fops);
385 if (!pde)
386 goto err1;
387
388 pde = proc_create("rt_cache", S_IRUGO,
389 net->proc_net_stat, &rt_cpu_seq_fops);
390 if (!pde)
391 goto err2;
392
393 #ifdef CONFIG_IP_ROUTE_CLASSID
394 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
395 if (!pde)
396 goto err3;
397 #endif
398 return 0;
399
400 #ifdef CONFIG_IP_ROUTE_CLASSID
401 err3:
402 remove_proc_entry("rt_cache", net->proc_net_stat);
403 #endif
404 err2:
405 remove_proc_entry("rt_cache", net->proc_net);
406 err1:
407 return -ENOMEM;
408 }
409
410 static void __net_exit ip_rt_do_proc_exit(struct net *net)
411 {
412 remove_proc_entry("rt_cache", net->proc_net_stat);
413 remove_proc_entry("rt_cache", net->proc_net);
414 #ifdef CONFIG_IP_ROUTE_CLASSID
415 remove_proc_entry("rt_acct", net->proc_net);
416 #endif
417 }
418
419 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
420 .init = ip_rt_do_proc_init,
421 .exit = ip_rt_do_proc_exit,
422 };
423
424 static int __init ip_rt_proc_init(void)
425 {
426 return register_pernet_subsys(&ip_rt_proc_ops);
427 }
428
429 #else
430 static inline int ip_rt_proc_init(void)
431 {
432 return 0;
433 }
434 #endif /* CONFIG_PROC_FS */
435
436 static inline bool rt_is_expired(const struct rtable *rth)
437 {
438 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
439 }
440
441 void rt_cache_flush(struct net *net)
442 {
443 rt_genid_bump(net);
444 }
445
446 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
447 struct sk_buff *skb,
448 const void *daddr)
449 {
450 struct net_device *dev = dst->dev;
451 const __be32 *pkey = daddr;
452 const struct rtable *rt;
453 struct neighbour *n;
454
455 rt = (const struct rtable *) dst;
456 if (rt->rt_gateway)
457 pkey = (const __be32 *) &rt->rt_gateway;
458 else if (skb)
459 pkey = &ip_hdr(skb)->daddr;
460
461 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
462 if (n)
463 return n;
464 return neigh_create(&arp_tbl, pkey, dev);
465 }
466
467 /*
468 * Peer allocation may fail only in serious out-of-memory conditions. However
469 * we still can generate some output.
470 * Random ID selection looks a bit dangerous because we have no chances to
471 * select ID being unique in a reasonable period of time.
472 * But broken packet identifier may be better than no packet at all.
473 */
474 static void ip_select_fb_ident(struct iphdr *iph)
475 {
476 static DEFINE_SPINLOCK(ip_fb_id_lock);
477 static u32 ip_fallback_id;
478 u32 salt;
479
480 spin_lock_bh(&ip_fb_id_lock);
481 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
482 iph->id = htons(salt & 0xFFFF);
483 ip_fallback_id = salt;
484 spin_unlock_bh(&ip_fb_id_lock);
485 }
486
487 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
488 {
489 struct net *net = dev_net(dst->dev);
490 struct inet_peer *peer;
491
492 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
493 if (peer) {
494 iph->id = htons(inet_getid(peer, more));
495 inet_putpeer(peer);
496 return;
497 }
498
499 ip_select_fb_ident(iph);
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 struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
569 {
570 struct fib_nh_exception *fnhe, *oldest;
571 struct rtable *orig;
572
573 oldest = rcu_dereference(hash->chain);
574 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
575 fnhe = rcu_dereference(fnhe->fnhe_next)) {
576 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
577 oldest = fnhe;
578 }
579 orig = rcu_dereference(oldest->fnhe_rth);
580 if (orig) {
581 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
582 rt_free(orig);
583 }
584 return oldest;
585 }
586
587 static inline u32 fnhe_hashfun(__be32 daddr)
588 {
589 u32 hval;
590
591 hval = (__force u32) daddr;
592 hval ^= (hval >> 11) ^ (hval >> 22);
593
594 return hval & (FNHE_HASH_SIZE - 1);
595 }
596
597 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
598 u32 pmtu, unsigned long expires)
599 {
600 struct fnhe_hash_bucket *hash;
601 struct fib_nh_exception *fnhe;
602 int depth;
603 u32 hval = fnhe_hashfun(daddr);
604
605 spin_lock_bh(&fnhe_lock);
606
607 hash = nh->nh_exceptions;
608 if (!hash) {
609 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
610 if (!hash)
611 goto out_unlock;
612 nh->nh_exceptions = hash;
613 }
614
615 hash += hval;
616
617 depth = 0;
618 for (fnhe = rcu_dereference(hash->chain); fnhe;
619 fnhe = rcu_dereference(fnhe->fnhe_next)) {
620 if (fnhe->fnhe_daddr == daddr)
621 break;
622 depth++;
623 }
624
625 if (fnhe) {
626 if (gw)
627 fnhe->fnhe_gw = gw;
628 if (pmtu) {
629 fnhe->fnhe_pmtu = pmtu;
630 fnhe->fnhe_expires = expires;
631 }
632 } else {
633 if (depth > FNHE_RECLAIM_DEPTH)
634 fnhe = fnhe_oldest(hash);
635 else {
636 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
637 if (!fnhe)
638 goto out_unlock;
639
640 fnhe->fnhe_next = hash->chain;
641 rcu_assign_pointer(hash->chain, fnhe);
642 }
643 fnhe->fnhe_daddr = daddr;
644 fnhe->fnhe_gw = gw;
645 fnhe->fnhe_pmtu = pmtu;
646 fnhe->fnhe_expires = expires;
647 }
648
649 fnhe->fnhe_stamp = jiffies;
650
651 out_unlock:
652 spin_unlock_bh(&fnhe_lock);
653 return;
654 }
655
656 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
657 bool kill_route)
658 {
659 __be32 new_gw = icmp_hdr(skb)->un.gateway;
660 __be32 old_gw = ip_hdr(skb)->saddr;
661 struct net_device *dev = skb->dev;
662 struct in_device *in_dev;
663 struct fib_result res;
664 struct neighbour *n;
665 struct net *net;
666
667 switch (icmp_hdr(skb)->code & 7) {
668 case ICMP_REDIR_NET:
669 case ICMP_REDIR_NETTOS:
670 case ICMP_REDIR_HOST:
671 case ICMP_REDIR_HOSTTOS:
672 break;
673
674 default:
675 return;
676 }
677
678 if (rt->rt_gateway != old_gw)
679 return;
680
681 in_dev = __in_dev_get_rcu(dev);
682 if (!in_dev)
683 return;
684
685 net = dev_net(dev);
686 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
687 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
688 ipv4_is_zeronet(new_gw))
689 goto reject_redirect;
690
691 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
692 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
693 goto reject_redirect;
694 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
695 goto reject_redirect;
696 } else {
697 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
698 goto reject_redirect;
699 }
700
701 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
702 if (n) {
703 if (!(n->nud_state & NUD_VALID)) {
704 neigh_event_send(n, NULL);
705 } else {
706 if (fib_lookup(net, fl4, &res) == 0) {
707 struct fib_nh *nh = &FIB_RES_NH(res);
708
709 update_or_create_fnhe(nh, fl4->daddr, new_gw,
710 0, 0);
711 }
712 if (kill_route)
713 rt->dst.obsolete = DST_OBSOLETE_KILL;
714 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
715 }
716 neigh_release(n);
717 }
718 return;
719
720 reject_redirect:
721 #ifdef CONFIG_IP_ROUTE_VERBOSE
722 if (IN_DEV_LOG_MARTIANS(in_dev)) {
723 const struct iphdr *iph = (const struct iphdr *) skb->data;
724 __be32 daddr = iph->daddr;
725 __be32 saddr = iph->saddr;
726
727 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
728 " Advised path = %pI4 -> %pI4\n",
729 &old_gw, dev->name, &new_gw,
730 &saddr, &daddr);
731 }
732 #endif
733 ;
734 }
735
736 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
737 {
738 struct rtable *rt;
739 struct flowi4 fl4;
740 const struct iphdr *iph = (const struct iphdr *) skb->data;
741 int oif = skb->dev->ifindex;
742 u8 tos = RT_TOS(iph->tos);
743 u8 prot = iph->protocol;
744 u32 mark = skb->mark;
745
746 rt = (struct rtable *) dst;
747
748 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
749 __ip_do_redirect(rt, skb, &fl4, true);
750 }
751
752 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
753 {
754 struct rtable *rt = (struct rtable *)dst;
755 struct dst_entry *ret = dst;
756
757 if (rt) {
758 if (dst->obsolete > 0) {
759 ip_rt_put(rt);
760 ret = NULL;
761 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
762 rt->dst.expires) {
763 ip_rt_put(rt);
764 ret = NULL;
765 }
766 }
767 return ret;
768 }
769
770 /*
771 * Algorithm:
772 * 1. The first ip_rt_redirect_number redirects are sent
773 * with exponential backoff, then we stop sending them at all,
774 * assuming that the host ignores our redirects.
775 * 2. If we did not see packets requiring redirects
776 * during ip_rt_redirect_silence, we assume that the host
777 * forgot redirected route and start to send redirects again.
778 *
779 * This algorithm is much cheaper and more intelligent than dumb load limiting
780 * in icmp.c.
781 *
782 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
783 * and "frag. need" (breaks PMTU discovery) in icmp.c.
784 */
785
786 void ip_rt_send_redirect(struct sk_buff *skb)
787 {
788 struct rtable *rt = skb_rtable(skb);
789 struct in_device *in_dev;
790 struct inet_peer *peer;
791 struct net *net;
792 int log_martians;
793
794 rcu_read_lock();
795 in_dev = __in_dev_get_rcu(rt->dst.dev);
796 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
797 rcu_read_unlock();
798 return;
799 }
800 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
801 rcu_read_unlock();
802
803 net = dev_net(rt->dst.dev);
804 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
805 if (!peer) {
806 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
807 rt_nexthop(rt, ip_hdr(skb)->daddr));
808 return;
809 }
810
811 /* No redirected packets during ip_rt_redirect_silence;
812 * reset the algorithm.
813 */
814 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
815 peer->rate_tokens = 0;
816
817 /* Too many ignored redirects; do not send anything
818 * set dst.rate_last to the last seen redirected packet.
819 */
820 if (peer->rate_tokens >= ip_rt_redirect_number) {
821 peer->rate_last = jiffies;
822 goto out_put_peer;
823 }
824
825 /* Check for load limit; set rate_last to the latest sent
826 * redirect.
827 */
828 if (peer->rate_tokens == 0 ||
829 time_after(jiffies,
830 (peer->rate_last +
831 (ip_rt_redirect_load << peer->rate_tokens)))) {
832 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
833
834 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
835 peer->rate_last = jiffies;
836 ++peer->rate_tokens;
837 #ifdef CONFIG_IP_ROUTE_VERBOSE
838 if (log_martians &&
839 peer->rate_tokens == ip_rt_redirect_number)
840 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
841 &ip_hdr(skb)->saddr, inet_iif(skb),
842 &ip_hdr(skb)->daddr, &gw);
843 #endif
844 }
845 out_put_peer:
846 inet_putpeer(peer);
847 }
848
849 static int ip_error(struct sk_buff *skb)
850 {
851 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
852 struct rtable *rt = skb_rtable(skb);
853 struct inet_peer *peer;
854 unsigned long now;
855 struct net *net;
856 bool send;
857 int code;
858
859 net = dev_net(rt->dst.dev);
860 if (!IN_DEV_FORWARD(in_dev)) {
861 switch (rt->dst.error) {
862 case EHOSTUNREACH:
863 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
864 break;
865
866 case ENETUNREACH:
867 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
868 break;
869 }
870 goto out;
871 }
872
873 switch (rt->dst.error) {
874 case EINVAL:
875 default:
876 goto out;
877 case EHOSTUNREACH:
878 code = ICMP_HOST_UNREACH;
879 break;
880 case ENETUNREACH:
881 code = ICMP_NET_UNREACH;
882 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
883 break;
884 case EACCES:
885 code = ICMP_PKT_FILTERED;
886 break;
887 }
888
889 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
890
891 send = true;
892 if (peer) {
893 now = jiffies;
894 peer->rate_tokens += now - peer->rate_last;
895 if (peer->rate_tokens > ip_rt_error_burst)
896 peer->rate_tokens = ip_rt_error_burst;
897 peer->rate_last = now;
898 if (peer->rate_tokens >= ip_rt_error_cost)
899 peer->rate_tokens -= ip_rt_error_cost;
900 else
901 send = false;
902 inet_putpeer(peer);
903 }
904 if (send)
905 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
906
907 out: kfree_skb(skb);
908 return 0;
909 }
910
911 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
912 {
913 struct dst_entry *dst = &rt->dst;
914 struct fib_result res;
915
916 if (dst_metric_locked(dst, RTAX_MTU))
917 return;
918
919 if (dst->dev->mtu < mtu)
920 return;
921
922 if (mtu < ip_rt_min_pmtu)
923 mtu = ip_rt_min_pmtu;
924
925 if (!rt->rt_pmtu) {
926 dst->obsolete = DST_OBSOLETE_KILL;
927 } else {
928 rt->rt_pmtu = mtu;
929 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
930 }
931
932 rcu_read_lock();
933 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
934 struct fib_nh *nh = &FIB_RES_NH(res);
935
936 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
937 jiffies + ip_rt_mtu_expires);
938 }
939 rcu_read_unlock();
940 }
941
942 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
943 struct sk_buff *skb, u32 mtu)
944 {
945 struct rtable *rt = (struct rtable *) dst;
946 struct flowi4 fl4;
947
948 ip_rt_build_flow_key(&fl4, sk, skb);
949 __ip_rt_update_pmtu(rt, &fl4, mtu);
950 }
951
952 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
953 int oif, u32 mark, u8 protocol, int flow_flags)
954 {
955 const struct iphdr *iph = (const struct iphdr *) skb->data;
956 struct flowi4 fl4;
957 struct rtable *rt;
958
959 __build_flow_key(&fl4, NULL, iph, oif,
960 RT_TOS(iph->tos), protocol, mark, flow_flags);
961 rt = __ip_route_output_key(net, &fl4);
962 if (!IS_ERR(rt)) {
963 __ip_rt_update_pmtu(rt, &fl4, mtu);
964 ip_rt_put(rt);
965 }
966 }
967 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
968
969 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
970 {
971 const struct iphdr *iph = (const struct iphdr *) skb->data;
972 struct flowi4 fl4;
973 struct rtable *rt;
974
975 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
976 rt = __ip_route_output_key(sock_net(sk), &fl4);
977 if (!IS_ERR(rt)) {
978 __ip_rt_update_pmtu(rt, &fl4, mtu);
979 ip_rt_put(rt);
980 }
981 }
982
983 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
984 {
985 const struct iphdr *iph = (const struct iphdr *) skb->data;
986 struct flowi4 fl4;
987 struct rtable *rt;
988 struct dst_entry *dst;
989 bool new = false;
990
991 bh_lock_sock(sk);
992 rt = (struct rtable *) __sk_dst_get(sk);
993
994 if (sock_owned_by_user(sk) || !rt) {
995 __ipv4_sk_update_pmtu(skb, sk, mtu);
996 goto out;
997 }
998
999 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1000
1001 if (!__sk_dst_check(sk, 0)) {
1002 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1003 if (IS_ERR(rt))
1004 goto out;
1005
1006 new = true;
1007 }
1008
1009 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1010
1011 dst = dst_check(&rt->dst, 0);
1012 if (!dst) {
1013 if (new)
1014 dst_release(&rt->dst);
1015
1016 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1017 if (IS_ERR(rt))
1018 goto out;
1019
1020 new = true;
1021 }
1022
1023 if (new)
1024 __sk_dst_set(sk, &rt->dst);
1025
1026 out:
1027 bh_unlock_sock(sk);
1028 }
1029 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1030
1031 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1032 int oif, u32 mark, u8 protocol, int flow_flags)
1033 {
1034 const struct iphdr *iph = (const struct iphdr *) skb->data;
1035 struct flowi4 fl4;
1036 struct rtable *rt;
1037
1038 __build_flow_key(&fl4, NULL, iph, oif,
1039 RT_TOS(iph->tos), protocol, mark, flow_flags);
1040 rt = __ip_route_output_key(net, &fl4);
1041 if (!IS_ERR(rt)) {
1042 __ip_do_redirect(rt, skb, &fl4, false);
1043 ip_rt_put(rt);
1044 }
1045 }
1046 EXPORT_SYMBOL_GPL(ipv4_redirect);
1047
1048 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1049 {
1050 const struct iphdr *iph = (const struct iphdr *) skb->data;
1051 struct flowi4 fl4;
1052 struct rtable *rt;
1053
1054 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1055 rt = __ip_route_output_key(sock_net(sk), &fl4);
1056 if (!IS_ERR(rt)) {
1057 __ip_do_redirect(rt, skb, &fl4, false);
1058 ip_rt_put(rt);
1059 }
1060 }
1061 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1062
1063 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1064 {
1065 struct rtable *rt = (struct rtable *) dst;
1066
1067 /* All IPV4 dsts are created with ->obsolete set to the value
1068 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1069 * into this function always.
1070 *
1071 * When a PMTU/redirect information update invalidates a
1072 * route, this is indicated by setting obsolete to
1073 * DST_OBSOLETE_KILL.
1074 */
1075 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1076 return NULL;
1077 return dst;
1078 }
1079
1080 static void ipv4_link_failure(struct sk_buff *skb)
1081 {
1082 struct rtable *rt;
1083
1084 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1085
1086 rt = skb_rtable(skb);
1087 if (rt)
1088 dst_set_expires(&rt->dst, 0);
1089 }
1090
1091 static int ip_rt_bug(struct sk_buff *skb)
1092 {
1093 pr_debug("%s: %pI4 -> %pI4, %s\n",
1094 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1095 skb->dev ? skb->dev->name : "?");
1096 kfree_skb(skb);
1097 WARN_ON(1);
1098 return 0;
1099 }
1100
1101 /*
1102 We do not cache source address of outgoing interface,
1103 because it is used only by IP RR, TS and SRR options,
1104 so that it out of fast path.
1105
1106 BTW remember: "addr" is allowed to be not aligned
1107 in IP options!
1108 */
1109
1110 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1111 {
1112 __be32 src;
1113
1114 if (rt_is_output_route(rt))
1115 src = ip_hdr(skb)->saddr;
1116 else {
1117 struct fib_result res;
1118 struct flowi4 fl4;
1119 struct iphdr *iph;
1120
1121 iph = ip_hdr(skb);
1122
1123 memset(&fl4, 0, sizeof(fl4));
1124 fl4.daddr = iph->daddr;
1125 fl4.saddr = iph->saddr;
1126 fl4.flowi4_tos = RT_TOS(iph->tos);
1127 fl4.flowi4_oif = rt->dst.dev->ifindex;
1128 fl4.flowi4_iif = skb->dev->ifindex;
1129 fl4.flowi4_mark = skb->mark;
1130
1131 rcu_read_lock();
1132 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1133 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1134 else
1135 src = inet_select_addr(rt->dst.dev,
1136 rt_nexthop(rt, iph->daddr),
1137 RT_SCOPE_UNIVERSE);
1138 rcu_read_unlock();
1139 }
1140 memcpy(addr, &src, 4);
1141 }
1142
1143 #ifdef CONFIG_IP_ROUTE_CLASSID
1144 static void set_class_tag(struct rtable *rt, u32 tag)
1145 {
1146 if (!(rt->dst.tclassid & 0xFFFF))
1147 rt->dst.tclassid |= tag & 0xFFFF;
1148 if (!(rt->dst.tclassid & 0xFFFF0000))
1149 rt->dst.tclassid |= tag & 0xFFFF0000;
1150 }
1151 #endif
1152
1153 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1154 {
1155 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1156
1157 if (advmss == 0) {
1158 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1159 ip_rt_min_advmss);
1160 if (advmss > 65535 - 40)
1161 advmss = 65535 - 40;
1162 }
1163 return advmss;
1164 }
1165
1166 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1167 {
1168 const struct rtable *rt = (const struct rtable *) dst;
1169 unsigned int mtu = rt->rt_pmtu;
1170
1171 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1172 mtu = dst_metric_raw(dst, RTAX_MTU);
1173
1174 if (mtu)
1175 return mtu;
1176
1177 mtu = dst->dev->mtu;
1178
1179 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1180 if (rt->rt_uses_gateway && mtu > 576)
1181 mtu = 576;
1182 }
1183
1184 if (mtu > IP_MAX_MTU)
1185 mtu = IP_MAX_MTU;
1186
1187 return mtu;
1188 }
1189
1190 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1191 {
1192 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1193 struct fib_nh_exception *fnhe;
1194 u32 hval;
1195
1196 if (!hash)
1197 return NULL;
1198
1199 hval = fnhe_hashfun(daddr);
1200
1201 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1202 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1203 if (fnhe->fnhe_daddr == daddr)
1204 return fnhe;
1205 }
1206 return NULL;
1207 }
1208
1209 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1210 __be32 daddr)
1211 {
1212 bool ret = false;
1213
1214 spin_lock_bh(&fnhe_lock);
1215
1216 if (daddr == fnhe->fnhe_daddr) {
1217 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth);
1218 if (orig && rt_is_expired(orig)) {
1219 fnhe->fnhe_gw = 0;
1220 fnhe->fnhe_pmtu = 0;
1221 fnhe->fnhe_expires = 0;
1222 }
1223 if (fnhe->fnhe_pmtu) {
1224 unsigned long expires = fnhe->fnhe_expires;
1225 unsigned long diff = expires - jiffies;
1226
1227 if (time_before(jiffies, expires)) {
1228 rt->rt_pmtu = fnhe->fnhe_pmtu;
1229 dst_set_expires(&rt->dst, diff);
1230 }
1231 }
1232 if (fnhe->fnhe_gw) {
1233 rt->rt_flags |= RTCF_REDIRECTED;
1234 rt->rt_gateway = fnhe->fnhe_gw;
1235 rt->rt_uses_gateway = 1;
1236 } else if (!rt->rt_gateway)
1237 rt->rt_gateway = daddr;
1238
1239 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1240 if (orig)
1241 rt_free(orig);
1242
1243 fnhe->fnhe_stamp = jiffies;
1244 ret = true;
1245 }
1246 spin_unlock_bh(&fnhe_lock);
1247
1248 return ret;
1249 }
1250
1251 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1252 {
1253 struct rtable *orig, *prev, **p;
1254 bool ret = true;
1255
1256 if (rt_is_input_route(rt)) {
1257 p = (struct rtable **)&nh->nh_rth_input;
1258 } else {
1259 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1260 }
1261 orig = *p;
1262
1263 prev = cmpxchg(p, orig, rt);
1264 if (prev == orig) {
1265 if (orig)
1266 rt_free(orig);
1267 } else
1268 ret = false;
1269
1270 return ret;
1271 }
1272
1273 static DEFINE_SPINLOCK(rt_uncached_lock);
1274 static LIST_HEAD(rt_uncached_list);
1275
1276 static void rt_add_uncached_list(struct rtable *rt)
1277 {
1278 spin_lock_bh(&rt_uncached_lock);
1279 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1280 spin_unlock_bh(&rt_uncached_lock);
1281 }
1282
1283 static void ipv4_dst_destroy(struct dst_entry *dst)
1284 {
1285 struct rtable *rt = (struct rtable *) dst;
1286
1287 if (!list_empty(&rt->rt_uncached)) {
1288 spin_lock_bh(&rt_uncached_lock);
1289 list_del(&rt->rt_uncached);
1290 spin_unlock_bh(&rt_uncached_lock);
1291 }
1292 }
1293
1294 void rt_flush_dev(struct net_device *dev)
1295 {
1296 if (!list_empty(&rt_uncached_list)) {
1297 struct net *net = dev_net(dev);
1298 struct rtable *rt;
1299
1300 spin_lock_bh(&rt_uncached_lock);
1301 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1302 if (rt->dst.dev != dev)
1303 continue;
1304 rt->dst.dev = net->loopback_dev;
1305 dev_hold(rt->dst.dev);
1306 dev_put(dev);
1307 }
1308 spin_unlock_bh(&rt_uncached_lock);
1309 }
1310 }
1311
1312 static bool rt_cache_valid(const struct rtable *rt)
1313 {
1314 return rt &&
1315 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1316 !rt_is_expired(rt);
1317 }
1318
1319 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1320 const struct fib_result *res,
1321 struct fib_nh_exception *fnhe,
1322 struct fib_info *fi, u16 type, u32 itag)
1323 {
1324 bool cached = false;
1325
1326 if (fi) {
1327 struct fib_nh *nh = &FIB_RES_NH(*res);
1328
1329 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1330 rt->rt_gateway = nh->nh_gw;
1331 rt->rt_uses_gateway = 1;
1332 }
1333 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1334 #ifdef CONFIG_IP_ROUTE_CLASSID
1335 rt->dst.tclassid = nh->nh_tclassid;
1336 #endif
1337 if (unlikely(fnhe))
1338 cached = rt_bind_exception(rt, fnhe, daddr);
1339 else if (!(rt->dst.flags & DST_NOCACHE))
1340 cached = rt_cache_route(nh, rt);
1341 if (unlikely(!cached)) {
1342 /* Routes we intend to cache in nexthop exception or
1343 * FIB nexthop have the DST_NOCACHE bit clear.
1344 * However, if we are unsuccessful at storing this
1345 * route into the cache we really need to set it.
1346 */
1347 rt->dst.flags |= DST_NOCACHE;
1348 if (!rt->rt_gateway)
1349 rt->rt_gateway = daddr;
1350 rt_add_uncached_list(rt);
1351 }
1352 } else
1353 rt_add_uncached_list(rt);
1354
1355 #ifdef CONFIG_IP_ROUTE_CLASSID
1356 #ifdef CONFIG_IP_MULTIPLE_TABLES
1357 set_class_tag(rt, res->tclassid);
1358 #endif
1359 set_class_tag(rt, itag);
1360 #endif
1361 }
1362
1363 static struct rtable *rt_dst_alloc(struct net_device *dev,
1364 bool nopolicy, bool noxfrm, bool will_cache)
1365 {
1366 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1367 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1368 (nopolicy ? DST_NOPOLICY : 0) |
1369 (noxfrm ? DST_NOXFRM : 0));
1370 }
1371
1372 /* called in rcu_read_lock() section */
1373 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1374 u8 tos, struct net_device *dev, int our)
1375 {
1376 struct rtable *rth;
1377 struct in_device *in_dev = __in_dev_get_rcu(dev);
1378 u32 itag = 0;
1379 int err;
1380
1381 /* Primary sanity checks. */
1382
1383 if (in_dev == NULL)
1384 return -EINVAL;
1385
1386 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1387 skb->protocol != htons(ETH_P_IP))
1388 goto e_inval;
1389
1390 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1391 if (ipv4_is_loopback(saddr))
1392 goto e_inval;
1393
1394 if (ipv4_is_zeronet(saddr)) {
1395 if (!ipv4_is_local_multicast(daddr))
1396 goto e_inval;
1397 } else {
1398 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1399 in_dev, &itag);
1400 if (err < 0)
1401 goto e_err;
1402 }
1403 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1404 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1405 if (!rth)
1406 goto e_nobufs;
1407
1408 #ifdef CONFIG_IP_ROUTE_CLASSID
1409 rth->dst.tclassid = itag;
1410 #endif
1411 rth->dst.output = ip_rt_bug;
1412
1413 rth->rt_genid = rt_genid(dev_net(dev));
1414 rth->rt_flags = RTCF_MULTICAST;
1415 rth->rt_type = RTN_MULTICAST;
1416 rth->rt_is_input= 1;
1417 rth->rt_iif = 0;
1418 rth->rt_pmtu = 0;
1419 rth->rt_gateway = 0;
1420 rth->rt_uses_gateway = 0;
1421 INIT_LIST_HEAD(&rth->rt_uncached);
1422 if (our) {
1423 rth->dst.input= ip_local_deliver;
1424 rth->rt_flags |= RTCF_LOCAL;
1425 }
1426
1427 #ifdef CONFIG_IP_MROUTE
1428 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1429 rth->dst.input = ip_mr_input;
1430 #endif
1431 RT_CACHE_STAT_INC(in_slow_mc);
1432
1433 skb_dst_set(skb, &rth->dst);
1434 return 0;
1435
1436 e_nobufs:
1437 return -ENOBUFS;
1438 e_inval:
1439 return -EINVAL;
1440 e_err:
1441 return err;
1442 }
1443
1444
1445 static void ip_handle_martian_source(struct net_device *dev,
1446 struct in_device *in_dev,
1447 struct sk_buff *skb,
1448 __be32 daddr,
1449 __be32 saddr)
1450 {
1451 RT_CACHE_STAT_INC(in_martian_src);
1452 #ifdef CONFIG_IP_ROUTE_VERBOSE
1453 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1454 /*
1455 * RFC1812 recommendation, if source is martian,
1456 * the only hint is MAC header.
1457 */
1458 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1459 &daddr, &saddr, dev->name);
1460 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1461 print_hex_dump(KERN_WARNING, "ll header: ",
1462 DUMP_PREFIX_OFFSET, 16, 1,
1463 skb_mac_header(skb),
1464 dev->hard_header_len, true);
1465 }
1466 }
1467 #endif
1468 }
1469
1470 /* called in rcu_read_lock() section */
1471 static int __mkroute_input(struct sk_buff *skb,
1472 const struct fib_result *res,
1473 struct in_device *in_dev,
1474 __be32 daddr, __be32 saddr, u32 tos)
1475 {
1476 struct rtable *rth;
1477 int err;
1478 struct in_device *out_dev;
1479 unsigned int flags = 0;
1480 bool do_cache;
1481 u32 itag;
1482
1483 /* get a working reference to the output device */
1484 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1485 if (out_dev == NULL) {
1486 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1487 return -EINVAL;
1488 }
1489
1490 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1491 in_dev->dev, in_dev, &itag);
1492 if (err < 0) {
1493 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1494 saddr);
1495
1496 goto cleanup;
1497 }
1498
1499 do_cache = res->fi && !itag;
1500 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1501 (IN_DEV_SHARED_MEDIA(out_dev) ||
1502 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res)))) {
1503 flags |= RTCF_DOREDIRECT;
1504 do_cache = false;
1505 }
1506
1507 if (skb->protocol != htons(ETH_P_IP)) {
1508 /* Not IP (i.e. ARP). Do not create route, if it is
1509 * invalid for proxy arp. DNAT routes are always valid.
1510 *
1511 * Proxy arp feature have been extended to allow, ARP
1512 * replies back to the same interface, to support
1513 * Private VLAN switch technologies. See arp.c.
1514 */
1515 if (out_dev == in_dev &&
1516 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1517 err = -EINVAL;
1518 goto cleanup;
1519 }
1520 }
1521
1522 if (do_cache) {
1523 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1524 if (rt_cache_valid(rth)) {
1525 skb_dst_set_noref(skb, &rth->dst);
1526 goto out;
1527 }
1528 }
1529
1530 rth = rt_dst_alloc(out_dev->dev,
1531 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1532 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1533 if (!rth) {
1534 err = -ENOBUFS;
1535 goto cleanup;
1536 }
1537
1538 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1539 rth->rt_flags = flags;
1540 rth->rt_type = res->type;
1541 rth->rt_is_input = 1;
1542 rth->rt_iif = 0;
1543 rth->rt_pmtu = 0;
1544 rth->rt_gateway = 0;
1545 rth->rt_uses_gateway = 0;
1546 INIT_LIST_HEAD(&rth->rt_uncached);
1547
1548 rth->dst.input = ip_forward;
1549 rth->dst.output = ip_output;
1550
1551 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1552 skb_dst_set(skb, &rth->dst);
1553 out:
1554 err = 0;
1555 cleanup:
1556 return err;
1557 }
1558
1559 static int ip_mkroute_input(struct sk_buff *skb,
1560 struct fib_result *res,
1561 const struct flowi4 *fl4,
1562 struct in_device *in_dev,
1563 __be32 daddr, __be32 saddr, u32 tos)
1564 {
1565 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1566 if (res->fi && res->fi->fib_nhs > 1)
1567 fib_select_multipath(res);
1568 #endif
1569
1570 /* create a routing cache entry */
1571 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1572 }
1573
1574 /*
1575 * NOTE. We drop all the packets that has local source
1576 * addresses, because every properly looped back packet
1577 * must have correct destination already attached by output routine.
1578 *
1579 * Such approach solves two big problems:
1580 * 1. Not simplex devices are handled properly.
1581 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1582 * called with rcu_read_lock()
1583 */
1584
1585 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1586 u8 tos, struct net_device *dev)
1587 {
1588 struct fib_result res;
1589 struct in_device *in_dev = __in_dev_get_rcu(dev);
1590 struct flowi4 fl4;
1591 unsigned int flags = 0;
1592 u32 itag = 0;
1593 struct rtable *rth;
1594 int err = -EINVAL;
1595 struct net *net = dev_net(dev);
1596 bool do_cache;
1597
1598 /* IP on this device is disabled. */
1599
1600 if (!in_dev)
1601 goto out;
1602
1603 /* Check for the most weird martians, which can be not detected
1604 by fib_lookup.
1605 */
1606
1607 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1608 goto martian_source;
1609
1610 res.fi = NULL;
1611 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1612 goto brd_input;
1613
1614 /* Accept zero addresses only to limited broadcast;
1615 * I even do not know to fix it or not. Waiting for complains :-)
1616 */
1617 if (ipv4_is_zeronet(saddr))
1618 goto martian_source;
1619
1620 if (ipv4_is_zeronet(daddr))
1621 goto martian_destination;
1622
1623 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1624 * and call it once if daddr or/and saddr are loopback addresses
1625 */
1626 if (ipv4_is_loopback(daddr)) {
1627 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1628 goto martian_destination;
1629 } else if (ipv4_is_loopback(saddr)) {
1630 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1631 goto martian_source;
1632 }
1633
1634 /*
1635 * Now we are ready to route packet.
1636 */
1637 fl4.flowi4_oif = 0;
1638 fl4.flowi4_iif = dev->ifindex;
1639 fl4.flowi4_mark = skb->mark;
1640 fl4.flowi4_tos = tos;
1641 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1642 fl4.daddr = daddr;
1643 fl4.saddr = saddr;
1644 err = fib_lookup(net, &fl4, &res);
1645 if (err != 0)
1646 goto no_route;
1647
1648 RT_CACHE_STAT_INC(in_slow_tot);
1649
1650 if (res.type == RTN_BROADCAST)
1651 goto brd_input;
1652
1653 if (res.type == RTN_LOCAL) {
1654 err = fib_validate_source(skb, saddr, daddr, tos,
1655 LOOPBACK_IFINDEX,
1656 dev, in_dev, &itag);
1657 if (err < 0)
1658 goto martian_source_keep_err;
1659 goto local_input;
1660 }
1661
1662 if (!IN_DEV_FORWARD(in_dev))
1663 goto no_route;
1664 if (res.type != RTN_UNICAST)
1665 goto martian_destination;
1666
1667 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1668 out: return err;
1669
1670 brd_input:
1671 if (skb->protocol != htons(ETH_P_IP))
1672 goto e_inval;
1673
1674 if (!ipv4_is_zeronet(saddr)) {
1675 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1676 in_dev, &itag);
1677 if (err < 0)
1678 goto martian_source_keep_err;
1679 }
1680 flags |= RTCF_BROADCAST;
1681 res.type = RTN_BROADCAST;
1682 RT_CACHE_STAT_INC(in_brd);
1683
1684 local_input:
1685 do_cache = false;
1686 if (res.fi) {
1687 if (!itag) {
1688 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1689 if (rt_cache_valid(rth)) {
1690 skb_dst_set_noref(skb, &rth->dst);
1691 err = 0;
1692 goto out;
1693 }
1694 do_cache = true;
1695 }
1696 }
1697
1698 rth = rt_dst_alloc(net->loopback_dev,
1699 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1700 if (!rth)
1701 goto e_nobufs;
1702
1703 rth->dst.input= ip_local_deliver;
1704 rth->dst.output= ip_rt_bug;
1705 #ifdef CONFIG_IP_ROUTE_CLASSID
1706 rth->dst.tclassid = itag;
1707 #endif
1708
1709 rth->rt_genid = rt_genid(net);
1710 rth->rt_flags = flags|RTCF_LOCAL;
1711 rth->rt_type = res.type;
1712 rth->rt_is_input = 1;
1713 rth->rt_iif = 0;
1714 rth->rt_pmtu = 0;
1715 rth->rt_gateway = 0;
1716 rth->rt_uses_gateway = 0;
1717 INIT_LIST_HEAD(&rth->rt_uncached);
1718 if (res.type == RTN_UNREACHABLE) {
1719 rth->dst.input= ip_error;
1720 rth->dst.error= -err;
1721 rth->rt_flags &= ~RTCF_LOCAL;
1722 }
1723 if (do_cache)
1724 rt_cache_route(&FIB_RES_NH(res), rth);
1725 skb_dst_set(skb, &rth->dst);
1726 err = 0;
1727 goto out;
1728
1729 no_route:
1730 RT_CACHE_STAT_INC(in_no_route);
1731 res.type = RTN_UNREACHABLE;
1732 if (err == -ESRCH)
1733 err = -ENETUNREACH;
1734 goto local_input;
1735
1736 /*
1737 * Do not cache martian addresses: they should be logged (RFC1812)
1738 */
1739 martian_destination:
1740 RT_CACHE_STAT_INC(in_martian_dst);
1741 #ifdef CONFIG_IP_ROUTE_VERBOSE
1742 if (IN_DEV_LOG_MARTIANS(in_dev))
1743 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1744 &daddr, &saddr, dev->name);
1745 #endif
1746
1747 e_inval:
1748 err = -EINVAL;
1749 goto out;
1750
1751 e_nobufs:
1752 err = -ENOBUFS;
1753 goto out;
1754
1755 martian_source:
1756 err = -EINVAL;
1757 martian_source_keep_err:
1758 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1759 goto out;
1760 }
1761
1762 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1763 u8 tos, struct net_device *dev)
1764 {
1765 int res;
1766
1767 rcu_read_lock();
1768
1769 /* Multicast recognition logic is moved from route cache to here.
1770 The problem was that too many Ethernet cards have broken/missing
1771 hardware multicast filters :-( As result the host on multicasting
1772 network acquires a lot of useless route cache entries, sort of
1773 SDR messages from all the world. Now we try to get rid of them.
1774 Really, provided software IP multicast filter is organized
1775 reasonably (at least, hashed), it does not result in a slowdown
1776 comparing with route cache reject entries.
1777 Note, that multicast routers are not affected, because
1778 route cache entry is created eventually.
1779 */
1780 if (ipv4_is_multicast(daddr)) {
1781 struct in_device *in_dev = __in_dev_get_rcu(dev);
1782
1783 if (in_dev) {
1784 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1785 ip_hdr(skb)->protocol);
1786 if (our
1787 #ifdef CONFIG_IP_MROUTE
1788 ||
1789 (!ipv4_is_local_multicast(daddr) &&
1790 IN_DEV_MFORWARD(in_dev))
1791 #endif
1792 ) {
1793 int res = ip_route_input_mc(skb, daddr, saddr,
1794 tos, dev, our);
1795 rcu_read_unlock();
1796 return res;
1797 }
1798 }
1799 rcu_read_unlock();
1800 return -EINVAL;
1801 }
1802 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1803 rcu_read_unlock();
1804 return res;
1805 }
1806 EXPORT_SYMBOL(ip_route_input_noref);
1807
1808 /* called with rcu_read_lock() */
1809 static struct rtable *__mkroute_output(const struct fib_result *res,
1810 const struct flowi4 *fl4, int orig_oif,
1811 struct net_device *dev_out,
1812 unsigned int flags)
1813 {
1814 struct fib_info *fi = res->fi;
1815 struct fib_nh_exception *fnhe;
1816 struct in_device *in_dev;
1817 u16 type = res->type;
1818 struct rtable *rth;
1819 bool do_cache;
1820
1821 in_dev = __in_dev_get_rcu(dev_out);
1822 if (!in_dev)
1823 return ERR_PTR(-EINVAL);
1824
1825 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1826 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1827 return ERR_PTR(-EINVAL);
1828
1829 if (ipv4_is_lbcast(fl4->daddr))
1830 type = RTN_BROADCAST;
1831 else if (ipv4_is_multicast(fl4->daddr))
1832 type = RTN_MULTICAST;
1833 else if (ipv4_is_zeronet(fl4->daddr))
1834 return ERR_PTR(-EINVAL);
1835
1836 if (dev_out->flags & IFF_LOOPBACK)
1837 flags |= RTCF_LOCAL;
1838
1839 do_cache = true;
1840 if (type == RTN_BROADCAST) {
1841 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1842 fi = NULL;
1843 } else if (type == RTN_MULTICAST) {
1844 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1845 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1846 fl4->flowi4_proto))
1847 flags &= ~RTCF_LOCAL;
1848 else
1849 do_cache = false;
1850 /* If multicast route do not exist use
1851 * default one, but do not gateway in this case.
1852 * Yes, it is hack.
1853 */
1854 if (fi && res->prefixlen < 4)
1855 fi = NULL;
1856 }
1857
1858 fnhe = NULL;
1859 do_cache &= fi != NULL;
1860 if (do_cache) {
1861 struct rtable __rcu **prth;
1862 struct fib_nh *nh = &FIB_RES_NH(*res);
1863
1864 fnhe = find_exception(nh, fl4->daddr);
1865 if (fnhe)
1866 prth = &fnhe->fnhe_rth;
1867 else {
1868 if (unlikely(fl4->flowi4_flags &
1869 FLOWI_FLAG_KNOWN_NH &&
1870 !(nh->nh_gw &&
1871 nh->nh_scope == RT_SCOPE_LINK))) {
1872 do_cache = false;
1873 goto add;
1874 }
1875 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1876 }
1877 rth = rcu_dereference(*prth);
1878 if (rt_cache_valid(rth)) {
1879 dst_hold(&rth->dst);
1880 return rth;
1881 }
1882 }
1883
1884 add:
1885 rth = rt_dst_alloc(dev_out,
1886 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1887 IN_DEV_CONF_GET(in_dev, NOXFRM),
1888 do_cache);
1889 if (!rth)
1890 return ERR_PTR(-ENOBUFS);
1891
1892 rth->dst.output = ip_output;
1893
1894 rth->rt_genid = rt_genid(dev_net(dev_out));
1895 rth->rt_flags = flags;
1896 rth->rt_type = type;
1897 rth->rt_is_input = 0;
1898 rth->rt_iif = orig_oif ? : 0;
1899 rth->rt_pmtu = 0;
1900 rth->rt_gateway = 0;
1901 rth->rt_uses_gateway = 0;
1902 INIT_LIST_HEAD(&rth->rt_uncached);
1903
1904 RT_CACHE_STAT_INC(out_slow_tot);
1905
1906 if (flags & RTCF_LOCAL)
1907 rth->dst.input = ip_local_deliver;
1908 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1909 if (flags & RTCF_LOCAL &&
1910 !(dev_out->flags & IFF_LOOPBACK)) {
1911 rth->dst.output = ip_mc_output;
1912 RT_CACHE_STAT_INC(out_slow_mc);
1913 }
1914 #ifdef CONFIG_IP_MROUTE
1915 if (type == RTN_MULTICAST) {
1916 if (IN_DEV_MFORWARD(in_dev) &&
1917 !ipv4_is_local_multicast(fl4->daddr)) {
1918 rth->dst.input = ip_mr_input;
1919 rth->dst.output = ip_mc_output;
1920 }
1921 }
1922 #endif
1923 }
1924
1925 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1926
1927 return rth;
1928 }
1929
1930 /*
1931 * Major route resolver routine.
1932 */
1933
1934 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1935 {
1936 struct net_device *dev_out = NULL;
1937 __u8 tos = RT_FL_TOS(fl4);
1938 unsigned int flags = 0;
1939 struct fib_result res;
1940 struct rtable *rth;
1941 int orig_oif;
1942
1943 res.tclassid = 0;
1944 res.fi = NULL;
1945 res.table = NULL;
1946
1947 orig_oif = fl4->flowi4_oif;
1948
1949 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1950 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1951 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1952 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1953
1954 rcu_read_lock();
1955 if (fl4->saddr) {
1956 rth = ERR_PTR(-EINVAL);
1957 if (ipv4_is_multicast(fl4->saddr) ||
1958 ipv4_is_lbcast(fl4->saddr) ||
1959 ipv4_is_zeronet(fl4->saddr))
1960 goto out;
1961
1962 /* I removed check for oif == dev_out->oif here.
1963 It was wrong for two reasons:
1964 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1965 is assigned to multiple interfaces.
1966 2. Moreover, we are allowed to send packets with saddr
1967 of another iface. --ANK
1968 */
1969
1970 if (fl4->flowi4_oif == 0 &&
1971 (ipv4_is_multicast(fl4->daddr) ||
1972 ipv4_is_lbcast(fl4->daddr))) {
1973 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1974 dev_out = __ip_dev_find(net, fl4->saddr, false);
1975 if (dev_out == NULL)
1976 goto out;
1977
1978 /* Special hack: user can direct multicasts
1979 and limited broadcast via necessary interface
1980 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1981 This hack is not just for fun, it allows
1982 vic,vat and friends to work.
1983 They bind socket to loopback, set ttl to zero
1984 and expect that it will work.
1985 From the viewpoint of routing cache they are broken,
1986 because we are not allowed to build multicast path
1987 with loopback source addr (look, routing cache
1988 cannot know, that ttl is zero, so that packet
1989 will not leave this host and route is valid).
1990 Luckily, this hack is good workaround.
1991 */
1992
1993 fl4->flowi4_oif = dev_out->ifindex;
1994 goto make_route;
1995 }
1996
1997 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1998 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1999 if (!__ip_dev_find(net, fl4->saddr, false))
2000 goto out;
2001 }
2002 }
2003
2004
2005 if (fl4->flowi4_oif) {
2006 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2007 rth = ERR_PTR(-ENODEV);
2008 if (dev_out == NULL)
2009 goto out;
2010
2011 /* RACE: Check return value of inet_select_addr instead. */
2012 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2013 rth = ERR_PTR(-ENETUNREACH);
2014 goto out;
2015 }
2016 if (ipv4_is_local_multicast(fl4->daddr) ||
2017 ipv4_is_lbcast(fl4->daddr)) {
2018 if (!fl4->saddr)
2019 fl4->saddr = inet_select_addr(dev_out, 0,
2020 RT_SCOPE_LINK);
2021 goto make_route;
2022 }
2023 if (fl4->saddr) {
2024 if (ipv4_is_multicast(fl4->daddr))
2025 fl4->saddr = inet_select_addr(dev_out, 0,
2026 fl4->flowi4_scope);
2027 else if (!fl4->daddr)
2028 fl4->saddr = inet_select_addr(dev_out, 0,
2029 RT_SCOPE_HOST);
2030 }
2031 }
2032
2033 if (!fl4->daddr) {
2034 fl4->daddr = fl4->saddr;
2035 if (!fl4->daddr)
2036 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2037 dev_out = net->loopback_dev;
2038 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2039 res.type = RTN_LOCAL;
2040 flags |= RTCF_LOCAL;
2041 goto make_route;
2042 }
2043
2044 if (fib_lookup(net, fl4, &res)) {
2045 res.fi = NULL;
2046 res.table = NULL;
2047 if (fl4->flowi4_oif) {
2048 /* Apparently, routing tables are wrong. Assume,
2049 that the destination is on link.
2050
2051 WHY? DW.
2052 Because we are allowed to send to iface
2053 even if it has NO routes and NO assigned
2054 addresses. When oif is specified, routing
2055 tables are looked up with only one purpose:
2056 to catch if destination is gatewayed, rather than
2057 direct. Moreover, if MSG_DONTROUTE is set,
2058 we send packet, ignoring both routing tables
2059 and ifaddr state. --ANK
2060
2061
2062 We could make it even if oif is unknown,
2063 likely IPv6, but we do not.
2064 */
2065
2066 if (fl4->saddr == 0)
2067 fl4->saddr = inet_select_addr(dev_out, 0,
2068 RT_SCOPE_LINK);
2069 res.type = RTN_UNICAST;
2070 goto make_route;
2071 }
2072 rth = ERR_PTR(-ENETUNREACH);
2073 goto out;
2074 }
2075
2076 if (res.type == RTN_LOCAL) {
2077 if (!fl4->saddr) {
2078 if (res.fi->fib_prefsrc)
2079 fl4->saddr = res.fi->fib_prefsrc;
2080 else
2081 fl4->saddr = fl4->daddr;
2082 }
2083 dev_out = net->loopback_dev;
2084 fl4->flowi4_oif = dev_out->ifindex;
2085 flags |= RTCF_LOCAL;
2086 goto make_route;
2087 }
2088
2089 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2090 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2091 fib_select_multipath(&res);
2092 else
2093 #endif
2094 if (!res.prefixlen &&
2095 res.table->tb_num_default > 1 &&
2096 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2097 fib_select_default(&res);
2098
2099 if (!fl4->saddr)
2100 fl4->saddr = FIB_RES_PREFSRC(net, res);
2101
2102 dev_out = FIB_RES_DEV(res);
2103 fl4->flowi4_oif = dev_out->ifindex;
2104
2105
2106 make_route:
2107 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2108
2109 out:
2110 rcu_read_unlock();
2111 return rth;
2112 }
2113 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2114
2115 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2116 {
2117 return NULL;
2118 }
2119
2120 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2121 {
2122 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2123
2124 return mtu ? : dst->dev->mtu;
2125 }
2126
2127 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2128 struct sk_buff *skb, u32 mtu)
2129 {
2130 }
2131
2132 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2133 struct sk_buff *skb)
2134 {
2135 }
2136
2137 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2138 unsigned long old)
2139 {
2140 return NULL;
2141 }
2142
2143 static struct dst_ops ipv4_dst_blackhole_ops = {
2144 .family = AF_INET,
2145 .protocol = cpu_to_be16(ETH_P_IP),
2146 .check = ipv4_blackhole_dst_check,
2147 .mtu = ipv4_blackhole_mtu,
2148 .default_advmss = ipv4_default_advmss,
2149 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2150 .redirect = ipv4_rt_blackhole_redirect,
2151 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2152 .neigh_lookup = ipv4_neigh_lookup,
2153 };
2154
2155 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2156 {
2157 struct rtable *ort = (struct rtable *) dst_orig;
2158 struct rtable *rt;
2159
2160 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2161 if (rt) {
2162 struct dst_entry *new = &rt->dst;
2163
2164 new->__use = 1;
2165 new->input = dst_discard;
2166 new->output = dst_discard;
2167
2168 new->dev = ort->dst.dev;
2169 if (new->dev)
2170 dev_hold(new->dev);
2171
2172 rt->rt_is_input = ort->rt_is_input;
2173 rt->rt_iif = ort->rt_iif;
2174 rt->rt_pmtu = ort->rt_pmtu;
2175
2176 rt->rt_genid = rt_genid(net);
2177 rt->rt_flags = ort->rt_flags;
2178 rt->rt_type = ort->rt_type;
2179 rt->rt_gateway = ort->rt_gateway;
2180 rt->rt_uses_gateway = ort->rt_uses_gateway;
2181
2182 INIT_LIST_HEAD(&rt->rt_uncached);
2183
2184 dst_free(new);
2185 }
2186
2187 dst_release(dst_orig);
2188
2189 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2190 }
2191
2192 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2193 struct sock *sk)
2194 {
2195 struct rtable *rt = __ip_route_output_key(net, flp4);
2196
2197 if (IS_ERR(rt))
2198 return rt;
2199
2200 if (flp4->flowi4_proto)
2201 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2202 flowi4_to_flowi(flp4),
2203 sk, 0);
2204
2205 return rt;
2206 }
2207 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2208
2209 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2210 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2211 u32 seq, int event, int nowait, unsigned int flags)
2212 {
2213 struct rtable *rt = skb_rtable(skb);
2214 struct rtmsg *r;
2215 struct nlmsghdr *nlh;
2216 unsigned long expires = 0;
2217 u32 error;
2218 u32 metrics[RTAX_MAX];
2219
2220 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2221 if (nlh == NULL)
2222 return -EMSGSIZE;
2223
2224 r = nlmsg_data(nlh);
2225 r->rtm_family = AF_INET;
2226 r->rtm_dst_len = 32;
2227 r->rtm_src_len = 0;
2228 r->rtm_tos = fl4->flowi4_tos;
2229 r->rtm_table = RT_TABLE_MAIN;
2230 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2231 goto nla_put_failure;
2232 r->rtm_type = rt->rt_type;
2233 r->rtm_scope = RT_SCOPE_UNIVERSE;
2234 r->rtm_protocol = RTPROT_UNSPEC;
2235 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2236 if (rt->rt_flags & RTCF_NOTIFY)
2237 r->rtm_flags |= RTM_F_NOTIFY;
2238
2239 if (nla_put_be32(skb, RTA_DST, dst))
2240 goto nla_put_failure;
2241 if (src) {
2242 r->rtm_src_len = 32;
2243 if (nla_put_be32(skb, RTA_SRC, src))
2244 goto nla_put_failure;
2245 }
2246 if (rt->dst.dev &&
2247 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2248 goto nla_put_failure;
2249 #ifdef CONFIG_IP_ROUTE_CLASSID
2250 if (rt->dst.tclassid &&
2251 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2252 goto nla_put_failure;
2253 #endif
2254 if (!rt_is_input_route(rt) &&
2255 fl4->saddr != src) {
2256 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2257 goto nla_put_failure;
2258 }
2259 if (rt->rt_uses_gateway &&
2260 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2261 goto nla_put_failure;
2262
2263 expires = rt->dst.expires;
2264 if (expires) {
2265 unsigned long now = jiffies;
2266
2267 if (time_before(now, expires))
2268 expires -= now;
2269 else
2270 expires = 0;
2271 }
2272
2273 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2274 if (rt->rt_pmtu && expires)
2275 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2276 if (rtnetlink_put_metrics(skb, metrics) < 0)
2277 goto nla_put_failure;
2278
2279 if (fl4->flowi4_mark &&
2280 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2281 goto nla_put_failure;
2282
2283 error = rt->dst.error;
2284
2285 if (rt_is_input_route(rt)) {
2286 #ifdef CONFIG_IP_MROUTE
2287 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2288 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2289 int err = ipmr_get_route(net, skb,
2290 fl4->saddr, fl4->daddr,
2291 r, nowait);
2292 if (err <= 0) {
2293 if (!nowait) {
2294 if (err == 0)
2295 return 0;
2296 goto nla_put_failure;
2297 } else {
2298 if (err == -EMSGSIZE)
2299 goto nla_put_failure;
2300 error = err;
2301 }
2302 }
2303 } else
2304 #endif
2305 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2306 goto nla_put_failure;
2307 }
2308
2309 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2310 goto nla_put_failure;
2311
2312 return nlmsg_end(skb, nlh);
2313
2314 nla_put_failure:
2315 nlmsg_cancel(skb, nlh);
2316 return -EMSGSIZE;
2317 }
2318
2319 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2320 {
2321 struct net *net = sock_net(in_skb->sk);
2322 struct rtmsg *rtm;
2323 struct nlattr *tb[RTA_MAX+1];
2324 struct rtable *rt = NULL;
2325 struct flowi4 fl4;
2326 __be32 dst = 0;
2327 __be32 src = 0;
2328 u32 iif;
2329 int err;
2330 int mark;
2331 struct sk_buff *skb;
2332
2333 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2334 if (err < 0)
2335 goto errout;
2336
2337 rtm = nlmsg_data(nlh);
2338
2339 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2340 if (skb == NULL) {
2341 err = -ENOBUFS;
2342 goto errout;
2343 }
2344
2345 /* Reserve room for dummy headers, this skb can pass
2346 through good chunk of routing engine.
2347 */
2348 skb_reset_mac_header(skb);
2349 skb_reset_network_header(skb);
2350
2351 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2352 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2353 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2354
2355 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2356 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2357 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2358 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2359
2360 memset(&fl4, 0, sizeof(fl4));
2361 fl4.daddr = dst;
2362 fl4.saddr = src;
2363 fl4.flowi4_tos = rtm->rtm_tos;
2364 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2365 fl4.flowi4_mark = mark;
2366
2367 if (iif) {
2368 struct net_device *dev;
2369
2370 dev = __dev_get_by_index(net, iif);
2371 if (dev == NULL) {
2372 err = -ENODEV;
2373 goto errout_free;
2374 }
2375
2376 skb->protocol = htons(ETH_P_IP);
2377 skb->dev = dev;
2378 skb->mark = mark;
2379 local_bh_disable();
2380 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2381 local_bh_enable();
2382
2383 rt = skb_rtable(skb);
2384 if (err == 0 && rt->dst.error)
2385 err = -rt->dst.error;
2386 } else {
2387 rt = ip_route_output_key(net, &fl4);
2388
2389 err = 0;
2390 if (IS_ERR(rt))
2391 err = PTR_ERR(rt);
2392 }
2393
2394 if (err)
2395 goto errout_free;
2396
2397 skb_dst_set(skb, &rt->dst);
2398 if (rtm->rtm_flags & RTM_F_NOTIFY)
2399 rt->rt_flags |= RTCF_NOTIFY;
2400
2401 err = rt_fill_info(net, dst, src, &fl4, skb,
2402 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2403 RTM_NEWROUTE, 0, 0);
2404 if (err <= 0)
2405 goto errout_free;
2406
2407 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2408 errout:
2409 return err;
2410
2411 errout_free:
2412 kfree_skb(skb);
2413 goto errout;
2414 }
2415
2416 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2417 {
2418 return skb->len;
2419 }
2420
2421 void ip_rt_multicast_event(struct in_device *in_dev)
2422 {
2423 rt_cache_flush(dev_net(in_dev->dev));
2424 }
2425
2426 #ifdef CONFIG_SYSCTL
2427 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2428 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2429 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2430 static int ip_rt_gc_elasticity __read_mostly = 8;
2431
2432 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2433 void __user *buffer,
2434 size_t *lenp, loff_t *ppos)
2435 {
2436 if (write) {
2437 rt_cache_flush((struct net *)__ctl->extra1);
2438 return 0;
2439 }
2440
2441 return -EINVAL;
2442 }
2443
2444 static ctl_table ipv4_route_table[] = {
2445 {
2446 .procname = "gc_thresh",
2447 .data = &ipv4_dst_ops.gc_thresh,
2448 .maxlen = sizeof(int),
2449 .mode = 0644,
2450 .proc_handler = proc_dointvec,
2451 },
2452 {
2453 .procname = "max_size",
2454 .data = &ip_rt_max_size,
2455 .maxlen = sizeof(int),
2456 .mode = 0644,
2457 .proc_handler = proc_dointvec,
2458 },
2459 {
2460 /* Deprecated. Use gc_min_interval_ms */
2461
2462 .procname = "gc_min_interval",
2463 .data = &ip_rt_gc_min_interval,
2464 .maxlen = sizeof(int),
2465 .mode = 0644,
2466 .proc_handler = proc_dointvec_jiffies,
2467 },
2468 {
2469 .procname = "gc_min_interval_ms",
2470 .data = &ip_rt_gc_min_interval,
2471 .maxlen = sizeof(int),
2472 .mode = 0644,
2473 .proc_handler = proc_dointvec_ms_jiffies,
2474 },
2475 {
2476 .procname = "gc_timeout",
2477 .data = &ip_rt_gc_timeout,
2478 .maxlen = sizeof(int),
2479 .mode = 0644,
2480 .proc_handler = proc_dointvec_jiffies,
2481 },
2482 {
2483 .procname = "gc_interval",
2484 .data = &ip_rt_gc_interval,
2485 .maxlen = sizeof(int),
2486 .mode = 0644,
2487 .proc_handler = proc_dointvec_jiffies,
2488 },
2489 {
2490 .procname = "redirect_load",
2491 .data = &ip_rt_redirect_load,
2492 .maxlen = sizeof(int),
2493 .mode = 0644,
2494 .proc_handler = proc_dointvec,
2495 },
2496 {
2497 .procname = "redirect_number",
2498 .data = &ip_rt_redirect_number,
2499 .maxlen = sizeof(int),
2500 .mode = 0644,
2501 .proc_handler = proc_dointvec,
2502 },
2503 {
2504 .procname = "redirect_silence",
2505 .data = &ip_rt_redirect_silence,
2506 .maxlen = sizeof(int),
2507 .mode = 0644,
2508 .proc_handler = proc_dointvec,
2509 },
2510 {
2511 .procname = "error_cost",
2512 .data = &ip_rt_error_cost,
2513 .maxlen = sizeof(int),
2514 .mode = 0644,
2515 .proc_handler = proc_dointvec,
2516 },
2517 {
2518 .procname = "error_burst",
2519 .data = &ip_rt_error_burst,
2520 .maxlen = sizeof(int),
2521 .mode = 0644,
2522 .proc_handler = proc_dointvec,
2523 },
2524 {
2525 .procname = "gc_elasticity",
2526 .data = &ip_rt_gc_elasticity,
2527 .maxlen = sizeof(int),
2528 .mode = 0644,
2529 .proc_handler = proc_dointvec,
2530 },
2531 {
2532 .procname = "mtu_expires",
2533 .data = &ip_rt_mtu_expires,
2534 .maxlen = sizeof(int),
2535 .mode = 0644,
2536 .proc_handler = proc_dointvec_jiffies,
2537 },
2538 {
2539 .procname = "min_pmtu",
2540 .data = &ip_rt_min_pmtu,
2541 .maxlen = sizeof(int),
2542 .mode = 0644,
2543 .proc_handler = proc_dointvec,
2544 },
2545 {
2546 .procname = "min_adv_mss",
2547 .data = &ip_rt_min_advmss,
2548 .maxlen = sizeof(int),
2549 .mode = 0644,
2550 .proc_handler = proc_dointvec,
2551 },
2552 { }
2553 };
2554
2555 static struct ctl_table ipv4_route_flush_table[] = {
2556 {
2557 .procname = "flush",
2558 .maxlen = sizeof(int),
2559 .mode = 0200,
2560 .proc_handler = ipv4_sysctl_rtcache_flush,
2561 },
2562 { },
2563 };
2564
2565 static __net_init int sysctl_route_net_init(struct net *net)
2566 {
2567 struct ctl_table *tbl;
2568
2569 tbl = ipv4_route_flush_table;
2570 if (!net_eq(net, &init_net)) {
2571 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2572 if (tbl == NULL)
2573 goto err_dup;
2574
2575 /* Don't export sysctls to unprivileged users */
2576 if (net->user_ns != &init_user_ns)
2577 tbl[0].procname = NULL;
2578 }
2579 tbl[0].extra1 = net;
2580
2581 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2582 if (net->ipv4.route_hdr == NULL)
2583 goto err_reg;
2584 return 0;
2585
2586 err_reg:
2587 if (tbl != ipv4_route_flush_table)
2588 kfree(tbl);
2589 err_dup:
2590 return -ENOMEM;
2591 }
2592
2593 static __net_exit void sysctl_route_net_exit(struct net *net)
2594 {
2595 struct ctl_table *tbl;
2596
2597 tbl = net->ipv4.route_hdr->ctl_table_arg;
2598 unregister_net_sysctl_table(net->ipv4.route_hdr);
2599 BUG_ON(tbl == ipv4_route_flush_table);
2600 kfree(tbl);
2601 }
2602
2603 static __net_initdata struct pernet_operations sysctl_route_ops = {
2604 .init = sysctl_route_net_init,
2605 .exit = sysctl_route_net_exit,
2606 };
2607 #endif
2608
2609 static __net_init int rt_genid_init(struct net *net)
2610 {
2611 atomic_set(&net->rt_genid, 0);
2612 get_random_bytes(&net->ipv4.dev_addr_genid,
2613 sizeof(net->ipv4.dev_addr_genid));
2614 return 0;
2615 }
2616
2617 static __net_initdata struct pernet_operations rt_genid_ops = {
2618 .init = rt_genid_init,
2619 };
2620
2621 static int __net_init ipv4_inetpeer_init(struct net *net)
2622 {
2623 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2624
2625 if (!bp)
2626 return -ENOMEM;
2627 inet_peer_base_init(bp);
2628 net->ipv4.peers = bp;
2629 return 0;
2630 }
2631
2632 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2633 {
2634 struct inet_peer_base *bp = net->ipv4.peers;
2635
2636 net->ipv4.peers = NULL;
2637 inetpeer_invalidate_tree(bp);
2638 kfree(bp);
2639 }
2640
2641 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2642 .init = ipv4_inetpeer_init,
2643 .exit = ipv4_inetpeer_exit,
2644 };
2645
2646 #ifdef CONFIG_IP_ROUTE_CLASSID
2647 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2648 #endif /* CONFIG_IP_ROUTE_CLASSID */
2649
2650 int __init ip_rt_init(void)
2651 {
2652 int rc = 0;
2653
2654 #ifdef CONFIG_IP_ROUTE_CLASSID
2655 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2656 if (!ip_rt_acct)
2657 panic("IP: failed to allocate ip_rt_acct\n");
2658 #endif
2659
2660 ipv4_dst_ops.kmem_cachep =
2661 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2662 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2663
2664 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2665
2666 if (dst_entries_init(&ipv4_dst_ops) < 0)
2667 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2668
2669 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2670 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2671
2672 ipv4_dst_ops.gc_thresh = ~0;
2673 ip_rt_max_size = INT_MAX;
2674
2675 devinet_init();
2676 ip_fib_init();
2677
2678 if (ip_rt_proc_init())
2679 pr_err("Unable to create route proc files\n");
2680 #ifdef CONFIG_XFRM
2681 xfrm_init();
2682 xfrm4_init();
2683 #endif
2684 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2685
2686 #ifdef CONFIG_SYSCTL
2687 register_pernet_subsys(&sysctl_route_ops);
2688 #endif
2689 register_pernet_subsys(&rt_genid_ops);
2690 register_pernet_subsys(&ipv4_inetpeer_ops);
2691 return rc;
2692 }
2693
2694 #ifdef CONFIG_SYSCTL
2695 /*
2696 * We really need to sanitize the damn ipv4 init order, then all
2697 * this nonsense will go away.
2698 */
2699 void __init ip_static_sysctl_init(void)
2700 {
2701 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2702 }
2703 #endif
kernel source for telekom puls (alcatel/mediatek)