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backing-dev: Handle class_create() failure
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blobd9b40248b97feb4a1e3e4dd01c9ec789b4494842
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 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.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/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #endif
110
111 #define RT_FL_TOS(oldflp) \
112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
113
114 #define IP_MAX_MTU 0xFFF0
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_max_size;
119 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
120 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
121 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
122 static int ip_rt_redirect_number __read_mostly = 9;
123 static int ip_rt_redirect_load __read_mostly = HZ / 50;
124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
125 static int ip_rt_error_cost __read_mostly = HZ;
126 static int ip_rt_error_burst __read_mostly = 5 * HZ;
127 static int ip_rt_gc_elasticity __read_mostly = 8;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131 static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 static struct delayed_work expires_work;
135 static unsigned long expires_ljiffies;
136
137 /*
138 * Interface to generic destination cache.
139 */
140
141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
143 static void ipv4_dst_ifdown(struct dst_entry *dst,
144 struct net_device *dev, int how);
145 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
146 static void ipv4_link_failure(struct sk_buff *skb);
147 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
148 static int rt_garbage_collect(struct dst_ops *ops);
149
150
151 static struct dst_ops ipv4_dst_ops = {
152 .family = AF_INET,
153 .protocol = cpu_to_be16(ETH_P_IP),
154 .gc = rt_garbage_collect,
155 .check = ipv4_dst_check,
156 .destroy = ipv4_dst_destroy,
157 .ifdown = ipv4_dst_ifdown,
158 .negative_advice = ipv4_negative_advice,
159 .link_failure = ipv4_link_failure,
160 .update_pmtu = ip_rt_update_pmtu,
161 .local_out = __ip_local_out,
162 .entries = ATOMIC_INIT(0),
163 };
164
165 #define ECN_OR_COST(class) TC_PRIO_##class
166
167 const __u8 ip_tos2prio[16] = {
168 TC_PRIO_BESTEFFORT,
169 ECN_OR_COST(FILLER),
170 TC_PRIO_BESTEFFORT,
171 ECN_OR_COST(BESTEFFORT),
172 TC_PRIO_BULK,
173 ECN_OR_COST(BULK),
174 TC_PRIO_BULK,
175 ECN_OR_COST(BULK),
176 TC_PRIO_INTERACTIVE,
177 ECN_OR_COST(INTERACTIVE),
178 TC_PRIO_INTERACTIVE,
179 ECN_OR_COST(INTERACTIVE),
180 TC_PRIO_INTERACTIVE_BULK,
181 ECN_OR_COST(INTERACTIVE_BULK),
182 TC_PRIO_INTERACTIVE_BULK,
183 ECN_OR_COST(INTERACTIVE_BULK)
184 };
185
186
187 /*
188 * Route cache.
189 */
190
191 /* The locking scheme is rather straight forward:
192 *
193 * 1) Read-Copy Update protects the buckets of the central route hash.
194 * 2) Only writers remove entries, and they hold the lock
195 * as they look at rtable reference counts.
196 * 3) Only readers acquire references to rtable entries,
197 * they do so with atomic increments and with the
198 * lock held.
199 */
200
201 struct rt_hash_bucket {
202 struct rtable *chain;
203 };
204
205 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
206 defined(CONFIG_PROVE_LOCKING)
207 /*
208 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
209 * The size of this table is a power of two and depends on the number of CPUS.
210 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
211 */
212 #ifdef CONFIG_LOCKDEP
213 # define RT_HASH_LOCK_SZ 256
214 #else
215 # if NR_CPUS >= 32
216 # define RT_HASH_LOCK_SZ 4096
217 # elif NR_CPUS >= 16
218 # define RT_HASH_LOCK_SZ 2048
219 # elif NR_CPUS >= 8
220 # define RT_HASH_LOCK_SZ 1024
221 # elif NR_CPUS >= 4
222 # define RT_HASH_LOCK_SZ 512
223 # else
224 # define RT_HASH_LOCK_SZ 256
225 # endif
226 #endif
227
228 static spinlock_t *rt_hash_locks;
229 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
230
231 static __init void rt_hash_lock_init(void)
232 {
233 int i;
234
235 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
236 GFP_KERNEL);
237 if (!rt_hash_locks)
238 panic("IP: failed to allocate rt_hash_locks\n");
239
240 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
241 spin_lock_init(&rt_hash_locks[i]);
242 }
243 #else
244 # define rt_hash_lock_addr(slot) NULL
245
246 static inline void rt_hash_lock_init(void)
247 {
248 }
249 #endif
250
251 static struct rt_hash_bucket *rt_hash_table __read_mostly;
252 static unsigned rt_hash_mask __read_mostly;
253 static unsigned int rt_hash_log __read_mostly;
254
255 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
256 #define RT_CACHE_STAT_INC(field) \
257 (__raw_get_cpu_var(rt_cache_stat).field++)
258
259 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
260 int genid)
261 {
262 return jhash_3words((__force u32)(__be32)(daddr),
263 (__force u32)(__be32)(saddr),
264 idx, genid)
265 & rt_hash_mask;
266 }
267
268 static inline int rt_genid(struct net *net)
269 {
270 return atomic_read(&net->ipv4.rt_genid);
271 }
272
273 #ifdef CONFIG_PROC_FS
274 struct rt_cache_iter_state {
275 struct seq_net_private p;
276 int bucket;
277 int genid;
278 };
279
280 static struct rtable *rt_cache_get_first(struct seq_file *seq)
281 {
282 struct rt_cache_iter_state *st = seq->private;
283 struct rtable *r = NULL;
284
285 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
286 if (!rt_hash_table[st->bucket].chain)
287 continue;
288 rcu_read_lock_bh();
289 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
290 while (r) {
291 if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
292 r->rt_genid == st->genid)
293 return r;
294 r = rcu_dereference_bh(r->u.dst.rt_next);
295 }
296 rcu_read_unlock_bh();
297 }
298 return r;
299 }
300
301 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
302 struct rtable *r)
303 {
304 struct rt_cache_iter_state *st = seq->private;
305
306 r = r->u.dst.rt_next;
307 while (!r) {
308 rcu_read_unlock_bh();
309 do {
310 if (--st->bucket < 0)
311 return NULL;
312 } while (!rt_hash_table[st->bucket].chain);
313 rcu_read_lock_bh();
314 r = rt_hash_table[st->bucket].chain;
315 }
316 return rcu_dereference_bh(r);
317 }
318
319 static struct rtable *rt_cache_get_next(struct seq_file *seq,
320 struct rtable *r)
321 {
322 struct rt_cache_iter_state *st = seq->private;
323 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
324 if (dev_net(r->u.dst.dev) != seq_file_net(seq))
325 continue;
326 if (r->rt_genid == st->genid)
327 break;
328 }
329 return r;
330 }
331
332 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
333 {
334 struct rtable *r = rt_cache_get_first(seq);
335
336 if (r)
337 while (pos && (r = rt_cache_get_next(seq, r)))
338 --pos;
339 return pos ? NULL : r;
340 }
341
342 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
343 {
344 struct rt_cache_iter_state *st = seq->private;
345 if (*pos)
346 return rt_cache_get_idx(seq, *pos - 1);
347 st->genid = rt_genid(seq_file_net(seq));
348 return SEQ_START_TOKEN;
349 }
350
351 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
352 {
353 struct rtable *r;
354
355 if (v == SEQ_START_TOKEN)
356 r = rt_cache_get_first(seq);
357 else
358 r = rt_cache_get_next(seq, v);
359 ++*pos;
360 return r;
361 }
362
363 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
364 {
365 if (v && v != SEQ_START_TOKEN)
366 rcu_read_unlock_bh();
367 }
368
369 static int rt_cache_seq_show(struct seq_file *seq, void *v)
370 {
371 if (v == SEQ_START_TOKEN)
372 seq_printf(seq, "%-127s\n",
373 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
374 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
375 "HHUptod\tSpecDst");
376 else {
377 struct rtable *r = v;
378 int len;
379
380 seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
381 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
382 r->u.dst.dev ? r->u.dst.dev->name : "*",
383 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
384 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
385 r->u.dst.__use, 0, (unsigned long)r->rt_src,
386 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
387 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
388 dst_metric(&r->u.dst, RTAX_WINDOW),
389 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
390 dst_metric(&r->u.dst, RTAX_RTTVAR)),
391 r->fl.fl4_tos,
392 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
393 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
394 dev_queue_xmit) : 0,
395 r->rt_spec_dst, &len);
396
397 seq_printf(seq, "%*s\n", 127 - len, "");
398 }
399 return 0;
400 }
401
402 static const struct seq_operations rt_cache_seq_ops = {
403 .start = rt_cache_seq_start,
404 .next = rt_cache_seq_next,
405 .stop = rt_cache_seq_stop,
406 .show = rt_cache_seq_show,
407 };
408
409 static int rt_cache_seq_open(struct inode *inode, struct file *file)
410 {
411 return seq_open_net(inode, file, &rt_cache_seq_ops,
412 sizeof(struct rt_cache_iter_state));
413 }
414
415 static const struct file_operations rt_cache_seq_fops = {
416 .owner = THIS_MODULE,
417 .open = rt_cache_seq_open,
418 .read = seq_read,
419 .llseek = seq_lseek,
420 .release = seq_release_net,
421 };
422
423
424 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
425 {
426 int cpu;
427
428 if (*pos == 0)
429 return SEQ_START_TOKEN;
430
431 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
432 if (!cpu_possible(cpu))
433 continue;
434 *pos = cpu+1;
435 return &per_cpu(rt_cache_stat, cpu);
436 }
437 return NULL;
438 }
439
440 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
441 {
442 int cpu;
443
444 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
445 if (!cpu_possible(cpu))
446 continue;
447 *pos = cpu+1;
448 return &per_cpu(rt_cache_stat, cpu);
449 }
450 return NULL;
451
452 }
453
454 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
455 {
456
457 }
458
459 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
460 {
461 struct rt_cache_stat *st = v;
462
463 if (v == SEQ_START_TOKEN) {
464 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");
465 return 0;
466 }
467
468 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
469 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
470 atomic_read(&ipv4_dst_ops.entries),
471 st->in_hit,
472 st->in_slow_tot,
473 st->in_slow_mc,
474 st->in_no_route,
475 st->in_brd,
476 st->in_martian_dst,
477 st->in_martian_src,
478
479 st->out_hit,
480 st->out_slow_tot,
481 st->out_slow_mc,
482
483 st->gc_total,
484 st->gc_ignored,
485 st->gc_goal_miss,
486 st->gc_dst_overflow,
487 st->in_hlist_search,
488 st->out_hlist_search
489 );
490 return 0;
491 }
492
493 static const struct seq_operations rt_cpu_seq_ops = {
494 .start = rt_cpu_seq_start,
495 .next = rt_cpu_seq_next,
496 .stop = rt_cpu_seq_stop,
497 .show = rt_cpu_seq_show,
498 };
499
500
501 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
502 {
503 return seq_open(file, &rt_cpu_seq_ops);
504 }
505
506 static const struct file_operations rt_cpu_seq_fops = {
507 .owner = THIS_MODULE,
508 .open = rt_cpu_seq_open,
509 .read = seq_read,
510 .llseek = seq_lseek,
511 .release = seq_release,
512 };
513
514 #ifdef CONFIG_NET_CLS_ROUTE
515 static int rt_acct_proc_show(struct seq_file *m, void *v)
516 {
517 struct ip_rt_acct *dst, *src;
518 unsigned int i, j;
519
520 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
521 if (!dst)
522 return -ENOMEM;
523
524 for_each_possible_cpu(i) {
525 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
526 for (j = 0; j < 256; j++) {
527 dst[j].o_bytes += src[j].o_bytes;
528 dst[j].o_packets += src[j].o_packets;
529 dst[j].i_bytes += src[j].i_bytes;
530 dst[j].i_packets += src[j].i_packets;
531 }
532 }
533
534 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
535 kfree(dst);
536 return 0;
537 }
538
539 static int rt_acct_proc_open(struct inode *inode, struct file *file)
540 {
541 return single_open(file, rt_acct_proc_show, NULL);
542 }
543
544 static const struct file_operations rt_acct_proc_fops = {
545 .owner = THIS_MODULE,
546 .open = rt_acct_proc_open,
547 .read = seq_read,
548 .llseek = seq_lseek,
549 .release = single_release,
550 };
551 #endif
552
553 static int __net_init ip_rt_do_proc_init(struct net *net)
554 {
555 struct proc_dir_entry *pde;
556
557 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
558 &rt_cache_seq_fops);
559 if (!pde)
560 goto err1;
561
562 pde = proc_create("rt_cache", S_IRUGO,
563 net->proc_net_stat, &rt_cpu_seq_fops);
564 if (!pde)
565 goto err2;
566
567 #ifdef CONFIG_NET_CLS_ROUTE
568 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
569 if (!pde)
570 goto err3;
571 #endif
572 return 0;
573
574 #ifdef CONFIG_NET_CLS_ROUTE
575 err3:
576 remove_proc_entry("rt_cache", net->proc_net_stat);
577 #endif
578 err2:
579 remove_proc_entry("rt_cache", net->proc_net);
580 err1:
581 return -ENOMEM;
582 }
583
584 static void __net_exit ip_rt_do_proc_exit(struct net *net)
585 {
586 remove_proc_entry("rt_cache", net->proc_net_stat);
587 remove_proc_entry("rt_cache", net->proc_net);
588 #ifdef CONFIG_NET_CLS_ROUTE
589 remove_proc_entry("rt_acct", net->proc_net);
590 #endif
591 }
592
593 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
594 .init = ip_rt_do_proc_init,
595 .exit = ip_rt_do_proc_exit,
596 };
597
598 static int __init ip_rt_proc_init(void)
599 {
600 return register_pernet_subsys(&ip_rt_proc_ops);
601 }
602
603 #else
604 static inline int ip_rt_proc_init(void)
605 {
606 return 0;
607 }
608 #endif /* CONFIG_PROC_FS */
609
610 static inline void rt_free(struct rtable *rt)
611 {
612 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
613 }
614
615 static inline void rt_drop(struct rtable *rt)
616 {
617 ip_rt_put(rt);
618 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
619 }
620
621 static inline int rt_fast_clean(struct rtable *rth)
622 {
623 /* Kill broadcast/multicast entries very aggresively, if they
624 collide in hash table with more useful entries */
625 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
626 rth->fl.iif && rth->u.dst.rt_next;
627 }
628
629 static inline int rt_valuable(struct rtable *rth)
630 {
631 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
632 rth->u.dst.expires;
633 }
634
635 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
636 {
637 unsigned long age;
638 int ret = 0;
639
640 if (atomic_read(&rth->u.dst.__refcnt))
641 goto out;
642
643 ret = 1;
644 if (rth->u.dst.expires &&
645 time_after_eq(jiffies, rth->u.dst.expires))
646 goto out;
647
648 age = jiffies - rth->u.dst.lastuse;
649 ret = 0;
650 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
651 (age <= tmo2 && rt_valuable(rth)))
652 goto out;
653 ret = 1;
654 out: return ret;
655 }
656
657 /* Bits of score are:
658 * 31: very valuable
659 * 30: not quite useless
660 * 29..0: usage counter
661 */
662 static inline u32 rt_score(struct rtable *rt)
663 {
664 u32 score = jiffies - rt->u.dst.lastuse;
665
666 score = ~score & ~(3<<30);
667
668 if (rt_valuable(rt))
669 score |= (1<<31);
670
671 if (!rt->fl.iif ||
672 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
673 score |= (1<<30);
674
675 return score;
676 }
677
678 static inline bool rt_caching(const struct net *net)
679 {
680 return net->ipv4.current_rt_cache_rebuild_count <=
681 net->ipv4.sysctl_rt_cache_rebuild_count;
682 }
683
684 static inline bool compare_hash_inputs(const struct flowi *fl1,
685 const struct flowi *fl2)
686 {
687 return (__force u32)(((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
688 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) |
689 (fl1->iif ^ fl2->iif)) == 0);
690 }
691
692 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
693 {
694 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
695 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
696 (fl1->mark ^ fl2->mark) |
697 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
698 *(u16 *)&fl2->nl_u.ip4_u.tos) |
699 (fl1->oif ^ fl2->oif) |
700 (fl1->iif ^ fl2->iif)) == 0;
701 }
702
703 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
704 {
705 return net_eq(dev_net(rt1->u.dst.dev), dev_net(rt2->u.dst.dev));
706 }
707
708 static inline int rt_is_expired(struct rtable *rth)
709 {
710 return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev));
711 }
712
713 /*
714 * Perform a full scan of hash table and free all entries.
715 * Can be called by a softirq or a process.
716 * In the later case, we want to be reschedule if necessary
717 */
718 static void rt_do_flush(int process_context)
719 {
720 unsigned int i;
721 struct rtable *rth, *next;
722 struct rtable * tail;
723
724 for (i = 0; i <= rt_hash_mask; i++) {
725 if (process_context && need_resched())
726 cond_resched();
727 rth = rt_hash_table[i].chain;
728 if (!rth)
729 continue;
730
731 spin_lock_bh(rt_hash_lock_addr(i));
732 #ifdef CONFIG_NET_NS
733 {
734 struct rtable ** prev, * p;
735
736 rth = rt_hash_table[i].chain;
737
738 /* defer releasing the head of the list after spin_unlock */
739 for (tail = rth; tail; tail = tail->u.dst.rt_next)
740 if (!rt_is_expired(tail))
741 break;
742 if (rth != tail)
743 rt_hash_table[i].chain = tail;
744
745 /* call rt_free on entries after the tail requiring flush */
746 prev = &rt_hash_table[i].chain;
747 for (p = *prev; p; p = next) {
748 next = p->u.dst.rt_next;
749 if (!rt_is_expired(p)) {
750 prev = &p->u.dst.rt_next;
751 } else {
752 *prev = next;
753 rt_free(p);
754 }
755 }
756 }
757 #else
758 rth = rt_hash_table[i].chain;
759 rt_hash_table[i].chain = NULL;
760 tail = NULL;
761 #endif
762 spin_unlock_bh(rt_hash_lock_addr(i));
763
764 for (; rth != tail; rth = next) {
765 next = rth->u.dst.rt_next;
766 rt_free(rth);
767 }
768 }
769 }
770
771 /*
772 * While freeing expired entries, we compute average chain length
773 * and standard deviation, using fixed-point arithmetic.
774 * This to have an estimation of rt_chain_length_max
775 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
776 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
777 */
778
779 #define FRACT_BITS 3
780 #define ONE (1UL << FRACT_BITS)
781
782 /*
783 * Given a hash chain and an item in this hash chain,
784 * find if a previous entry has the same hash_inputs
785 * (but differs on tos, mark or oif)
786 * Returns 0 if an alias is found.
787 * Returns ONE if rth has no alias before itself.
788 */
789 static int has_noalias(const struct rtable *head, const struct rtable *rth)
790 {
791 const struct rtable *aux = head;
792
793 while (aux != rth) {
794 if (compare_hash_inputs(&aux->fl, &rth->fl))
795 return 0;
796 aux = aux->u.dst.rt_next;
797 }
798 return ONE;
799 }
800
801 static void rt_check_expire(void)
802 {
803 static unsigned int rover;
804 unsigned int i = rover, goal;
805 struct rtable *rth, **rthp;
806 unsigned long samples = 0;
807 unsigned long sum = 0, sum2 = 0;
808 unsigned long delta;
809 u64 mult;
810
811 delta = jiffies - expires_ljiffies;
812 expires_ljiffies = jiffies;
813 mult = ((u64)delta) << rt_hash_log;
814 if (ip_rt_gc_timeout > 1)
815 do_div(mult, ip_rt_gc_timeout);
816 goal = (unsigned int)mult;
817 if (goal > rt_hash_mask)
818 goal = rt_hash_mask + 1;
819 for (; goal > 0; goal--) {
820 unsigned long tmo = ip_rt_gc_timeout;
821 unsigned long length;
822
823 i = (i + 1) & rt_hash_mask;
824 rthp = &rt_hash_table[i].chain;
825
826 if (need_resched())
827 cond_resched();
828
829 samples++;
830
831 if (*rthp == NULL)
832 continue;
833 length = 0;
834 spin_lock_bh(rt_hash_lock_addr(i));
835 while ((rth = *rthp) != NULL) {
836 prefetch(rth->u.dst.rt_next);
837 if (rt_is_expired(rth)) {
838 *rthp = rth->u.dst.rt_next;
839 rt_free(rth);
840 continue;
841 }
842 if (rth->u.dst.expires) {
843 /* Entry is expired even if it is in use */
844 if (time_before_eq(jiffies, rth->u.dst.expires)) {
845 nofree:
846 tmo >>= 1;
847 rthp = &rth->u.dst.rt_next;
848 /*
849 * We only count entries on
850 * a chain with equal hash inputs once
851 * so that entries for different QOS
852 * levels, and other non-hash input
853 * attributes don't unfairly skew
854 * the length computation
855 */
856 length += has_noalias(rt_hash_table[i].chain, rth);
857 continue;
858 }
859 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
860 goto nofree;
861
862 /* Cleanup aged off entries. */
863 *rthp = rth->u.dst.rt_next;
864 rt_free(rth);
865 }
866 spin_unlock_bh(rt_hash_lock_addr(i));
867 sum += length;
868 sum2 += length*length;
869 }
870 if (samples) {
871 unsigned long avg = sum / samples;
872 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
873 rt_chain_length_max = max_t(unsigned long,
874 ip_rt_gc_elasticity,
875 (avg + 4*sd) >> FRACT_BITS);
876 }
877 rover = i;
878 }
879
880 /*
881 * rt_worker_func() is run in process context.
882 * we call rt_check_expire() to scan part of the hash table
883 */
884 static void rt_worker_func(struct work_struct *work)
885 {
886 rt_check_expire();
887 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
888 }
889
890 /*
891 * Pertubation of rt_genid by a small quantity [1..256]
892 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
893 * many times (2^24) without giving recent rt_genid.
894 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
895 */
896 static void rt_cache_invalidate(struct net *net)
897 {
898 unsigned char shuffle;
899
900 get_random_bytes(&shuffle, sizeof(shuffle));
901 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
902 }
903
904 /*
905 * delay < 0 : invalidate cache (fast : entries will be deleted later)
906 * delay >= 0 : invalidate & flush cache (can be long)
907 */
908 void rt_cache_flush(struct net *net, int delay)
909 {
910 rt_cache_invalidate(net);
911 if (delay >= 0)
912 rt_do_flush(!in_softirq());
913 }
914
915 /* Flush previous cache invalidated entries from the cache */
916 void rt_cache_flush_batch(void)
917 {
918 rt_do_flush(!in_softirq());
919 }
920
921 /*
922 * We change rt_genid and let gc do the cleanup
923 */
924 static void rt_secret_rebuild(unsigned long __net)
925 {
926 struct net *net = (struct net *)__net;
927 rt_cache_invalidate(net);
928 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
929 }
930
931 static void rt_secret_rebuild_oneshot(struct net *net)
932 {
933 del_timer_sync(&net->ipv4.rt_secret_timer);
934 rt_cache_invalidate(net);
935 if (ip_rt_secret_interval) {
936 net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
937 add_timer(&net->ipv4.rt_secret_timer);
938 }
939 }
940
941 static void rt_emergency_hash_rebuild(struct net *net)
942 {
943 if (net_ratelimit()) {
944 printk(KERN_WARNING "Route hash chain too long!\n");
945 printk(KERN_WARNING "Adjust your secret_interval!\n");
946 }
947
948 rt_secret_rebuild_oneshot(net);
949 }
950
951 /*
952 Short description of GC goals.
953
954 We want to build algorithm, which will keep routing cache
955 at some equilibrium point, when number of aged off entries
956 is kept approximately equal to newly generated ones.
957
958 Current expiration strength is variable "expire".
959 We try to adjust it dynamically, so that if networking
960 is idle expires is large enough to keep enough of warm entries,
961 and when load increases it reduces to limit cache size.
962 */
963
964 static int rt_garbage_collect(struct dst_ops *ops)
965 {
966 static unsigned long expire = RT_GC_TIMEOUT;
967 static unsigned long last_gc;
968 static int rover;
969 static int equilibrium;
970 struct rtable *rth, **rthp;
971 unsigned long now = jiffies;
972 int goal;
973
974 /*
975 * Garbage collection is pretty expensive,
976 * do not make it too frequently.
977 */
978
979 RT_CACHE_STAT_INC(gc_total);
980
981 if (now - last_gc < ip_rt_gc_min_interval &&
982 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
983 RT_CACHE_STAT_INC(gc_ignored);
984 goto out;
985 }
986
987 /* Calculate number of entries, which we want to expire now. */
988 goal = atomic_read(&ipv4_dst_ops.entries) -
989 (ip_rt_gc_elasticity << rt_hash_log);
990 if (goal <= 0) {
991 if (equilibrium < ipv4_dst_ops.gc_thresh)
992 equilibrium = ipv4_dst_ops.gc_thresh;
993 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
994 if (goal > 0) {
995 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
996 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
997 }
998 } else {
999 /* We are in dangerous area. Try to reduce cache really
1000 * aggressively.
1001 */
1002 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1003 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
1004 }
1005
1006 if (now - last_gc >= ip_rt_gc_min_interval)
1007 last_gc = now;
1008
1009 if (goal <= 0) {
1010 equilibrium += goal;
1011 goto work_done;
1012 }
1013
1014 do {
1015 int i, k;
1016
1017 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1018 unsigned long tmo = expire;
1019
1020 k = (k + 1) & rt_hash_mask;
1021 rthp = &rt_hash_table[k].chain;
1022 spin_lock_bh(rt_hash_lock_addr(k));
1023 while ((rth = *rthp) != NULL) {
1024 if (!rt_is_expired(rth) &&
1025 !rt_may_expire(rth, tmo, expire)) {
1026 tmo >>= 1;
1027 rthp = &rth->u.dst.rt_next;
1028 continue;
1029 }
1030 *rthp = rth->u.dst.rt_next;
1031 rt_free(rth);
1032 goal--;
1033 }
1034 spin_unlock_bh(rt_hash_lock_addr(k));
1035 if (goal <= 0)
1036 break;
1037 }
1038 rover = k;
1039
1040 if (goal <= 0)
1041 goto work_done;
1042
1043 /* Goal is not achieved. We stop process if:
1044
1045 - if expire reduced to zero. Otherwise, expire is halfed.
1046 - if table is not full.
1047 - if we are called from interrupt.
1048 - jiffies check is just fallback/debug loop breaker.
1049 We will not spin here for long time in any case.
1050 */
1051
1052 RT_CACHE_STAT_INC(gc_goal_miss);
1053
1054 if (expire == 0)
1055 break;
1056
1057 expire >>= 1;
1058 #if RT_CACHE_DEBUG >= 2
1059 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1060 atomic_read(&ipv4_dst_ops.entries), goal, i);
1061 #endif
1062
1063 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1064 goto out;
1065 } while (!in_softirq() && time_before_eq(jiffies, now));
1066
1067 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1068 goto out;
1069 if (net_ratelimit())
1070 printk(KERN_WARNING "dst cache overflow\n");
1071 RT_CACHE_STAT_INC(gc_dst_overflow);
1072 return 1;
1073
1074 work_done:
1075 expire += ip_rt_gc_min_interval;
1076 if (expire > ip_rt_gc_timeout ||
1077 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
1078 expire = ip_rt_gc_timeout;
1079 #if RT_CACHE_DEBUG >= 2
1080 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1081 atomic_read(&ipv4_dst_ops.entries), goal, rover);
1082 #endif
1083 out: return 0;
1084 }
1085
1086 /*
1087 * Returns number of entries in a hash chain that have different hash_inputs
1088 */
1089 static int slow_chain_length(const struct rtable *head)
1090 {
1091 int length = 0;
1092 const struct rtable *rth = head;
1093
1094 while (rth) {
1095 length += has_noalias(head, rth);
1096 rth = rth->u.dst.rt_next;
1097 }
1098 return length >> FRACT_BITS;
1099 }
1100
1101 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1102 struct rtable **rp, struct sk_buff *skb)
1103 {
1104 struct rtable *rth, **rthp;
1105 unsigned long now;
1106 struct rtable *cand, **candp;
1107 u32 min_score;
1108 int chain_length;
1109 int attempts = !in_softirq();
1110
1111 restart:
1112 chain_length = 0;
1113 min_score = ~(u32)0;
1114 cand = NULL;
1115 candp = NULL;
1116 now = jiffies;
1117
1118 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1119 /*
1120 * If we're not caching, just tell the caller we
1121 * were successful and don't touch the route. The
1122 * caller hold the sole reference to the cache entry, and
1123 * it will be released when the caller is done with it.
1124 * If we drop it here, the callers have no way to resolve routes
1125 * when we're not caching. Instead, just point *rp at rt, so
1126 * the caller gets a single use out of the route
1127 * Note that we do rt_free on this new route entry, so that
1128 * once its refcount hits zero, we are still able to reap it
1129 * (Thanks Alexey)
1130 * Note also the rt_free uses call_rcu. We don't actually
1131 * need rcu protection here, this is just our path to get
1132 * on the route gc list.
1133 */
1134
1135 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1136 int err = arp_bind_neighbour(&rt->u.dst);
1137 if (err) {
1138 if (net_ratelimit())
1139 printk(KERN_WARNING
1140 "Neighbour table failure & not caching routes.\n");
1141 rt_drop(rt);
1142 return err;
1143 }
1144 }
1145
1146 rt_free(rt);
1147 goto skip_hashing;
1148 }
1149
1150 rthp = &rt_hash_table[hash].chain;
1151
1152 spin_lock_bh(rt_hash_lock_addr(hash));
1153 while ((rth = *rthp) != NULL) {
1154 if (rt_is_expired(rth)) {
1155 *rthp = rth->u.dst.rt_next;
1156 rt_free(rth);
1157 continue;
1158 }
1159 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1160 /* Put it first */
1161 *rthp = rth->u.dst.rt_next;
1162 /*
1163 * Since lookup is lockfree, the deletion
1164 * must be visible to another weakly ordered CPU before
1165 * the insertion at the start of the hash chain.
1166 */
1167 rcu_assign_pointer(rth->u.dst.rt_next,
1168 rt_hash_table[hash].chain);
1169 /*
1170 * Since lookup is lockfree, the update writes
1171 * must be ordered for consistency on SMP.
1172 */
1173 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1174
1175 dst_use(&rth->u.dst, now);
1176 spin_unlock_bh(rt_hash_lock_addr(hash));
1177
1178 rt_drop(rt);
1179 if (rp)
1180 *rp = rth;
1181 else
1182 skb_dst_set(skb, &rth->u.dst);
1183 return 0;
1184 }
1185
1186 if (!atomic_read(&rth->u.dst.__refcnt)) {
1187 u32 score = rt_score(rth);
1188
1189 if (score <= min_score) {
1190 cand = rth;
1191 candp = rthp;
1192 min_score = score;
1193 }
1194 }
1195
1196 chain_length++;
1197
1198 rthp = &rth->u.dst.rt_next;
1199 }
1200
1201 if (cand) {
1202 /* ip_rt_gc_elasticity used to be average length of chain
1203 * length, when exceeded gc becomes really aggressive.
1204 *
1205 * The second limit is less certain. At the moment it allows
1206 * only 2 entries per bucket. We will see.
1207 */
1208 if (chain_length > ip_rt_gc_elasticity) {
1209 *candp = cand->u.dst.rt_next;
1210 rt_free(cand);
1211 }
1212 } else {
1213 if (chain_length > rt_chain_length_max &&
1214 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1215 struct net *net = dev_net(rt->u.dst.dev);
1216 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1217 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1218 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1219 rt->u.dst.dev->name, num);
1220 }
1221 rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
1222 }
1223 }
1224
1225 /* Try to bind route to arp only if it is output
1226 route or unicast forwarding path.
1227 */
1228 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1229 int err = arp_bind_neighbour(&rt->u.dst);
1230 if (err) {
1231 spin_unlock_bh(rt_hash_lock_addr(hash));
1232
1233 if (err != -ENOBUFS) {
1234 rt_drop(rt);
1235 return err;
1236 }
1237
1238 /* Neighbour tables are full and nothing
1239 can be released. Try to shrink route cache,
1240 it is most likely it holds some neighbour records.
1241 */
1242 if (attempts-- > 0) {
1243 int saved_elasticity = ip_rt_gc_elasticity;
1244 int saved_int = ip_rt_gc_min_interval;
1245 ip_rt_gc_elasticity = 1;
1246 ip_rt_gc_min_interval = 0;
1247 rt_garbage_collect(&ipv4_dst_ops);
1248 ip_rt_gc_min_interval = saved_int;
1249 ip_rt_gc_elasticity = saved_elasticity;
1250 goto restart;
1251 }
1252
1253 if (net_ratelimit())
1254 printk(KERN_WARNING "Neighbour table overflow.\n");
1255 rt_drop(rt);
1256 return -ENOBUFS;
1257 }
1258 }
1259
1260 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1261
1262 #if RT_CACHE_DEBUG >= 2
1263 if (rt->u.dst.rt_next) {
1264 struct rtable *trt;
1265 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1266 hash, &rt->rt_dst);
1267 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1268 printk(" . %pI4", &trt->rt_dst);
1269 printk("\n");
1270 }
1271 #endif
1272 /*
1273 * Since lookup is lockfree, we must make sure
1274 * previous writes to rt are comitted to memory
1275 * before making rt visible to other CPUS.
1276 */
1277 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1278
1279 spin_unlock_bh(rt_hash_lock_addr(hash));
1280
1281 skip_hashing:
1282 if (rp)
1283 *rp = rt;
1284 else
1285 skb_dst_set(skb, &rt->u.dst);
1286 return 0;
1287 }
1288
1289 void rt_bind_peer(struct rtable *rt, int create)
1290 {
1291 static DEFINE_SPINLOCK(rt_peer_lock);
1292 struct inet_peer *peer;
1293
1294 peer = inet_getpeer(rt->rt_dst, create);
1295
1296 spin_lock_bh(&rt_peer_lock);
1297 if (rt->peer == NULL) {
1298 rt->peer = peer;
1299 peer = NULL;
1300 }
1301 spin_unlock_bh(&rt_peer_lock);
1302 if (peer)
1303 inet_putpeer(peer);
1304 }
1305
1306 /*
1307 * Peer allocation may fail only in serious out-of-memory conditions. However
1308 * we still can generate some output.
1309 * Random ID selection looks a bit dangerous because we have no chances to
1310 * select ID being unique in a reasonable period of time.
1311 * But broken packet identifier may be better than no packet at all.
1312 */
1313 static void ip_select_fb_ident(struct iphdr *iph)
1314 {
1315 static DEFINE_SPINLOCK(ip_fb_id_lock);
1316 static u32 ip_fallback_id;
1317 u32 salt;
1318
1319 spin_lock_bh(&ip_fb_id_lock);
1320 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1321 iph->id = htons(salt & 0xFFFF);
1322 ip_fallback_id = salt;
1323 spin_unlock_bh(&ip_fb_id_lock);
1324 }
1325
1326 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1327 {
1328 struct rtable *rt = (struct rtable *) dst;
1329
1330 if (rt) {
1331 if (rt->peer == NULL)
1332 rt_bind_peer(rt, 1);
1333
1334 /* If peer is attached to destination, it is never detached,
1335 so that we need not to grab a lock to dereference it.
1336 */
1337 if (rt->peer) {
1338 iph->id = htons(inet_getid(rt->peer, more));
1339 return;
1340 }
1341 } else
1342 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1343 __builtin_return_address(0));
1344
1345 ip_select_fb_ident(iph);
1346 }
1347
1348 static void rt_del(unsigned hash, struct rtable *rt)
1349 {
1350 struct rtable **rthp, *aux;
1351
1352 rthp = &rt_hash_table[hash].chain;
1353 spin_lock_bh(rt_hash_lock_addr(hash));
1354 ip_rt_put(rt);
1355 while ((aux = *rthp) != NULL) {
1356 if (aux == rt || rt_is_expired(aux)) {
1357 *rthp = aux->u.dst.rt_next;
1358 rt_free(aux);
1359 continue;
1360 }
1361 rthp = &aux->u.dst.rt_next;
1362 }
1363 spin_unlock_bh(rt_hash_lock_addr(hash));
1364 }
1365
1366 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1367 __be32 saddr, struct net_device *dev)
1368 {
1369 int i, k;
1370 struct in_device *in_dev = in_dev_get(dev);
1371 struct rtable *rth, **rthp;
1372 __be32 skeys[2] = { saddr, 0 };
1373 int ikeys[2] = { dev->ifindex, 0 };
1374 struct netevent_redirect netevent;
1375 struct net *net;
1376
1377 if (!in_dev)
1378 return;
1379
1380 net = dev_net(dev);
1381 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1382 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1383 ipv4_is_zeronet(new_gw))
1384 goto reject_redirect;
1385
1386 if (!rt_caching(net))
1387 goto reject_redirect;
1388
1389 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1390 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1391 goto reject_redirect;
1392 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1393 goto reject_redirect;
1394 } else {
1395 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1396 goto reject_redirect;
1397 }
1398
1399 for (i = 0; i < 2; i++) {
1400 for (k = 0; k < 2; k++) {
1401 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1402 rt_genid(net));
1403
1404 rthp=&rt_hash_table[hash].chain;
1405
1406 rcu_read_lock();
1407 while ((rth = rcu_dereference(*rthp)) != NULL) {
1408 struct rtable *rt;
1409
1410 if (rth->fl.fl4_dst != daddr ||
1411 rth->fl.fl4_src != skeys[i] ||
1412 rth->fl.oif != ikeys[k] ||
1413 rth->fl.iif != 0 ||
1414 rt_is_expired(rth) ||
1415 !net_eq(dev_net(rth->u.dst.dev), net)) {
1416 rthp = &rth->u.dst.rt_next;
1417 continue;
1418 }
1419
1420 if (rth->rt_dst != daddr ||
1421 rth->rt_src != saddr ||
1422 rth->u.dst.error ||
1423 rth->rt_gateway != old_gw ||
1424 rth->u.dst.dev != dev)
1425 break;
1426
1427 dst_hold(&rth->u.dst);
1428 rcu_read_unlock();
1429
1430 rt = dst_alloc(&ipv4_dst_ops);
1431 if (rt == NULL) {
1432 ip_rt_put(rth);
1433 in_dev_put(in_dev);
1434 return;
1435 }
1436
1437 /* Copy all the information. */
1438 *rt = *rth;
1439 rt->u.dst.__use = 1;
1440 atomic_set(&rt->u.dst.__refcnt, 1);
1441 rt->u.dst.child = NULL;
1442 if (rt->u.dst.dev)
1443 dev_hold(rt->u.dst.dev);
1444 if (rt->idev)
1445 in_dev_hold(rt->idev);
1446 rt->u.dst.obsolete = 0;
1447 rt->u.dst.lastuse = jiffies;
1448 rt->u.dst.path = &rt->u.dst;
1449 rt->u.dst.neighbour = NULL;
1450 rt->u.dst.hh = NULL;
1451 #ifdef CONFIG_XFRM
1452 rt->u.dst.xfrm = NULL;
1453 #endif
1454 rt->rt_genid = rt_genid(net);
1455 rt->rt_flags |= RTCF_REDIRECTED;
1456
1457 /* Gateway is different ... */
1458 rt->rt_gateway = new_gw;
1459
1460 /* Redirect received -> path was valid */
1461 dst_confirm(&rth->u.dst);
1462
1463 if (rt->peer)
1464 atomic_inc(&rt->peer->refcnt);
1465
1466 if (arp_bind_neighbour(&rt->u.dst) ||
1467 !(rt->u.dst.neighbour->nud_state &
1468 NUD_VALID)) {
1469 if (rt->u.dst.neighbour)
1470 neigh_event_send(rt->u.dst.neighbour, NULL);
1471 ip_rt_put(rth);
1472 rt_drop(rt);
1473 goto do_next;
1474 }
1475
1476 netevent.old = &rth->u.dst;
1477 netevent.new = &rt->u.dst;
1478 call_netevent_notifiers(NETEVENT_REDIRECT,
1479 &netevent);
1480
1481 rt_del(hash, rth);
1482 if (!rt_intern_hash(hash, rt, &rt, NULL))
1483 ip_rt_put(rt);
1484 goto do_next;
1485 }
1486 rcu_read_unlock();
1487 do_next:
1488 ;
1489 }
1490 }
1491 in_dev_put(in_dev);
1492 return;
1493
1494 reject_redirect:
1495 #ifdef CONFIG_IP_ROUTE_VERBOSE
1496 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1497 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1498 " Advised path = %pI4 -> %pI4\n",
1499 &old_gw, dev->name, &new_gw,
1500 &saddr, &daddr);
1501 #endif
1502 in_dev_put(in_dev);
1503 }
1504
1505 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1506 {
1507 struct rtable *rt = (struct rtable *)dst;
1508 struct dst_entry *ret = dst;
1509
1510 if (rt) {
1511 if (dst->obsolete) {
1512 ip_rt_put(rt);
1513 ret = NULL;
1514 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1515 rt->u.dst.expires) {
1516 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1517 rt->fl.oif,
1518 rt_genid(dev_net(dst->dev)));
1519 #if RT_CACHE_DEBUG >= 1
1520 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1521 &rt->rt_dst, rt->fl.fl4_tos);
1522 #endif
1523 rt_del(hash, rt);
1524 ret = NULL;
1525 }
1526 }
1527 return ret;
1528 }
1529
1530 /*
1531 * Algorithm:
1532 * 1. The first ip_rt_redirect_number redirects are sent
1533 * with exponential backoff, then we stop sending them at all,
1534 * assuming that the host ignores our redirects.
1535 * 2. If we did not see packets requiring redirects
1536 * during ip_rt_redirect_silence, we assume that the host
1537 * forgot redirected route and start to send redirects again.
1538 *
1539 * This algorithm is much cheaper and more intelligent than dumb load limiting
1540 * in icmp.c.
1541 *
1542 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1543 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1544 */
1545
1546 void ip_rt_send_redirect(struct sk_buff *skb)
1547 {
1548 struct rtable *rt = skb_rtable(skb);
1549 struct in_device *in_dev;
1550 int log_martians;
1551
1552 rcu_read_lock();
1553 in_dev = __in_dev_get_rcu(rt->u.dst.dev);
1554 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1555 rcu_read_unlock();
1556 return;
1557 }
1558 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1559 rcu_read_unlock();
1560
1561 /* No redirected packets during ip_rt_redirect_silence;
1562 * reset the algorithm.
1563 */
1564 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1565 rt->u.dst.rate_tokens = 0;
1566
1567 /* Too many ignored redirects; do not send anything
1568 * set u.dst.rate_last to the last seen redirected packet.
1569 */
1570 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1571 rt->u.dst.rate_last = jiffies;
1572 return;
1573 }
1574
1575 /* Check for load limit; set rate_last to the latest sent
1576 * redirect.
1577 */
1578 if (rt->u.dst.rate_tokens == 0 ||
1579 time_after(jiffies,
1580 (rt->u.dst.rate_last +
1581 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1582 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1583 rt->u.dst.rate_last = jiffies;
1584 ++rt->u.dst.rate_tokens;
1585 #ifdef CONFIG_IP_ROUTE_VERBOSE
1586 if (log_martians &&
1587 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1588 net_ratelimit())
1589 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1590 &rt->rt_src, rt->rt_iif,
1591 &rt->rt_dst, &rt->rt_gateway);
1592 #endif
1593 }
1594 }
1595
1596 static int ip_error(struct sk_buff *skb)
1597 {
1598 struct rtable *rt = skb_rtable(skb);
1599 unsigned long now;
1600 int code;
1601
1602 switch (rt->u.dst.error) {
1603 case EINVAL:
1604 default:
1605 goto out;
1606 case EHOSTUNREACH:
1607 code = ICMP_HOST_UNREACH;
1608 break;
1609 case ENETUNREACH:
1610 code = ICMP_NET_UNREACH;
1611 IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
1612 IPSTATS_MIB_INNOROUTES);
1613 break;
1614 case EACCES:
1615 code = ICMP_PKT_FILTERED;
1616 break;
1617 }
1618
1619 now = jiffies;
1620 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1621 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1622 rt->u.dst.rate_tokens = ip_rt_error_burst;
1623 rt->u.dst.rate_last = now;
1624 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1625 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1626 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1627 }
1628
1629 out: kfree_skb(skb);
1630 return 0;
1631 }
1632
1633 /*
1634 * The last two values are not from the RFC but
1635 * are needed for AMPRnet AX.25 paths.
1636 */
1637
1638 static const unsigned short mtu_plateau[] =
1639 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1640
1641 static inline unsigned short guess_mtu(unsigned short old_mtu)
1642 {
1643 int i;
1644
1645 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1646 if (old_mtu > mtu_plateau[i])
1647 return mtu_plateau[i];
1648 return 68;
1649 }
1650
1651 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1652 unsigned short new_mtu,
1653 struct net_device *dev)
1654 {
1655 int i, k;
1656 unsigned short old_mtu = ntohs(iph->tot_len);
1657 struct rtable *rth;
1658 int ikeys[2] = { dev->ifindex, 0 };
1659 __be32 skeys[2] = { iph->saddr, 0, };
1660 __be32 daddr = iph->daddr;
1661 unsigned short est_mtu = 0;
1662
1663 for (k = 0; k < 2; k++) {
1664 for (i = 0; i < 2; i++) {
1665 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1666 rt_genid(net));
1667
1668 rcu_read_lock();
1669 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1670 rth = rcu_dereference(rth->u.dst.rt_next)) {
1671 unsigned short mtu = new_mtu;
1672
1673 if (rth->fl.fl4_dst != daddr ||
1674 rth->fl.fl4_src != skeys[i] ||
1675 rth->rt_dst != daddr ||
1676 rth->rt_src != iph->saddr ||
1677 rth->fl.oif != ikeys[k] ||
1678 rth->fl.iif != 0 ||
1679 dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
1680 !net_eq(dev_net(rth->u.dst.dev), net) ||
1681 rt_is_expired(rth))
1682 continue;
1683
1684 if (new_mtu < 68 || new_mtu >= old_mtu) {
1685
1686 /* BSD 4.2 compatibility hack :-( */
1687 if (mtu == 0 &&
1688 old_mtu >= dst_mtu(&rth->u.dst) &&
1689 old_mtu >= 68 + (iph->ihl << 2))
1690 old_mtu -= iph->ihl << 2;
1691
1692 mtu = guess_mtu(old_mtu);
1693 }
1694 if (mtu <= dst_mtu(&rth->u.dst)) {
1695 if (mtu < dst_mtu(&rth->u.dst)) {
1696 dst_confirm(&rth->u.dst);
1697 if (mtu < ip_rt_min_pmtu) {
1698 mtu = ip_rt_min_pmtu;
1699 rth->u.dst.metrics[RTAX_LOCK-1] |=
1700 (1 << RTAX_MTU);
1701 }
1702 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1703 dst_set_expires(&rth->u.dst,
1704 ip_rt_mtu_expires);
1705 }
1706 est_mtu = mtu;
1707 }
1708 }
1709 rcu_read_unlock();
1710 }
1711 }
1712 return est_mtu ? : new_mtu;
1713 }
1714
1715 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1716 {
1717 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1718 !(dst_metric_locked(dst, RTAX_MTU))) {
1719 if (mtu < ip_rt_min_pmtu) {
1720 mtu = ip_rt_min_pmtu;
1721 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1722 }
1723 dst->metrics[RTAX_MTU-1] = mtu;
1724 dst_set_expires(dst, ip_rt_mtu_expires);
1725 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1726 }
1727 }
1728
1729 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1730 {
1731 return NULL;
1732 }
1733
1734 static void ipv4_dst_destroy(struct dst_entry *dst)
1735 {
1736 struct rtable *rt = (struct rtable *) dst;
1737 struct inet_peer *peer = rt->peer;
1738 struct in_device *idev = rt->idev;
1739
1740 if (peer) {
1741 rt->peer = NULL;
1742 inet_putpeer(peer);
1743 }
1744
1745 if (idev) {
1746 rt->idev = NULL;
1747 in_dev_put(idev);
1748 }
1749 }
1750
1751 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1752 int how)
1753 {
1754 struct rtable *rt = (struct rtable *) dst;
1755 struct in_device *idev = rt->idev;
1756 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1757 struct in_device *loopback_idev =
1758 in_dev_get(dev_net(dev)->loopback_dev);
1759 if (loopback_idev) {
1760 rt->idev = loopback_idev;
1761 in_dev_put(idev);
1762 }
1763 }
1764 }
1765
1766 static void ipv4_link_failure(struct sk_buff *skb)
1767 {
1768 struct rtable *rt;
1769
1770 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1771
1772 rt = skb_rtable(skb);
1773 if (rt)
1774 dst_set_expires(&rt->u.dst, 0);
1775 }
1776
1777 static int ip_rt_bug(struct sk_buff *skb)
1778 {
1779 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1780 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1781 skb->dev ? skb->dev->name : "?");
1782 kfree_skb(skb);
1783 return 0;
1784 }
1785
1786 /*
1787 We do not cache source address of outgoing interface,
1788 because it is used only by IP RR, TS and SRR options,
1789 so that it out of fast path.
1790
1791 BTW remember: "addr" is allowed to be not aligned
1792 in IP options!
1793 */
1794
1795 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1796 {
1797 __be32 src;
1798 struct fib_result res;
1799
1800 if (rt->fl.iif == 0)
1801 src = rt->rt_src;
1802 else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
1803 src = FIB_RES_PREFSRC(res);
1804 fib_res_put(&res);
1805 } else
1806 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1807 RT_SCOPE_UNIVERSE);
1808 memcpy(addr, &src, 4);
1809 }
1810
1811 #ifdef CONFIG_NET_CLS_ROUTE
1812 static void set_class_tag(struct rtable *rt, u32 tag)
1813 {
1814 if (!(rt->u.dst.tclassid & 0xFFFF))
1815 rt->u.dst.tclassid |= tag & 0xFFFF;
1816 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1817 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1818 }
1819 #endif
1820
1821 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1822 {
1823 struct fib_info *fi = res->fi;
1824
1825 if (fi) {
1826 if (FIB_RES_GW(*res) &&
1827 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1828 rt->rt_gateway = FIB_RES_GW(*res);
1829 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1830 sizeof(rt->u.dst.metrics));
1831 if (fi->fib_mtu == 0) {
1832 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1833 if (dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1834 rt->rt_gateway != rt->rt_dst &&
1835 rt->u.dst.dev->mtu > 576)
1836 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1837 }
1838 #ifdef CONFIG_NET_CLS_ROUTE
1839 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1840 #endif
1841 } else
1842 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1843
1844 if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
1845 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1846 if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
1847 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1848 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
1849 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1850 ip_rt_min_advmss);
1851 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40)
1852 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1853
1854 #ifdef CONFIG_NET_CLS_ROUTE
1855 #ifdef CONFIG_IP_MULTIPLE_TABLES
1856 set_class_tag(rt, fib_rules_tclass(res));
1857 #endif
1858 set_class_tag(rt, itag);
1859 #endif
1860 rt->rt_type = res->type;
1861 }
1862
1863 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1864 u8 tos, struct net_device *dev, int our)
1865 {
1866 unsigned hash;
1867 struct rtable *rth;
1868 __be32 spec_dst;
1869 struct in_device *in_dev = in_dev_get(dev);
1870 u32 itag = 0;
1871
1872 /* Primary sanity checks. */
1873
1874 if (in_dev == NULL)
1875 return -EINVAL;
1876
1877 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1878 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1879 goto e_inval;
1880
1881 if (ipv4_is_zeronet(saddr)) {
1882 if (!ipv4_is_local_multicast(daddr))
1883 goto e_inval;
1884 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1885 } else if (fib_validate_source(saddr, 0, tos, 0,
1886 dev, &spec_dst, &itag, 0) < 0)
1887 goto e_inval;
1888
1889 rth = dst_alloc(&ipv4_dst_ops);
1890 if (!rth)
1891 goto e_nobufs;
1892
1893 rth->u.dst.output= ip_rt_bug;
1894
1895 atomic_set(&rth->u.dst.__refcnt, 1);
1896 rth->u.dst.flags= DST_HOST;
1897 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1898 rth->u.dst.flags |= DST_NOPOLICY;
1899 rth->fl.fl4_dst = daddr;
1900 rth->rt_dst = daddr;
1901 rth->fl.fl4_tos = tos;
1902 rth->fl.mark = skb->mark;
1903 rth->fl.fl4_src = saddr;
1904 rth->rt_src = saddr;
1905 #ifdef CONFIG_NET_CLS_ROUTE
1906 rth->u.dst.tclassid = itag;
1907 #endif
1908 rth->rt_iif =
1909 rth->fl.iif = dev->ifindex;
1910 rth->u.dst.dev = init_net.loopback_dev;
1911 dev_hold(rth->u.dst.dev);
1912 rth->idev = in_dev_get(rth->u.dst.dev);
1913 rth->fl.oif = 0;
1914 rth->rt_gateway = daddr;
1915 rth->rt_spec_dst= spec_dst;
1916 rth->rt_genid = rt_genid(dev_net(dev));
1917 rth->rt_flags = RTCF_MULTICAST;
1918 rth->rt_type = RTN_MULTICAST;
1919 if (our) {
1920 rth->u.dst.input= ip_local_deliver;
1921 rth->rt_flags |= RTCF_LOCAL;
1922 }
1923
1924 #ifdef CONFIG_IP_MROUTE
1925 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1926 rth->u.dst.input = ip_mr_input;
1927 #endif
1928 RT_CACHE_STAT_INC(in_slow_mc);
1929
1930 in_dev_put(in_dev);
1931 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1932 return rt_intern_hash(hash, rth, NULL, skb);
1933
1934 e_nobufs:
1935 in_dev_put(in_dev);
1936 return -ENOBUFS;
1937
1938 e_inval:
1939 in_dev_put(in_dev);
1940 return -EINVAL;
1941 }
1942
1943
1944 static void ip_handle_martian_source(struct net_device *dev,
1945 struct in_device *in_dev,
1946 struct sk_buff *skb,
1947 __be32 daddr,
1948 __be32 saddr)
1949 {
1950 RT_CACHE_STAT_INC(in_martian_src);
1951 #ifdef CONFIG_IP_ROUTE_VERBOSE
1952 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1953 /*
1954 * RFC1812 recommendation, if source is martian,
1955 * the only hint is MAC header.
1956 */
1957 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1958 &daddr, &saddr, dev->name);
1959 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1960 int i;
1961 const unsigned char *p = skb_mac_header(skb);
1962 printk(KERN_WARNING "ll header: ");
1963 for (i = 0; i < dev->hard_header_len; i++, p++) {
1964 printk("%02x", *p);
1965 if (i < (dev->hard_header_len - 1))
1966 printk(":");
1967 }
1968 printk("\n");
1969 }
1970 }
1971 #endif
1972 }
1973
1974 static int __mkroute_input(struct sk_buff *skb,
1975 struct fib_result *res,
1976 struct in_device *in_dev,
1977 __be32 daddr, __be32 saddr, u32 tos,
1978 struct rtable **result)
1979 {
1980
1981 struct rtable *rth;
1982 int err;
1983 struct in_device *out_dev;
1984 unsigned flags = 0;
1985 __be32 spec_dst;
1986 u32 itag;
1987
1988 /* get a working reference to the output device */
1989 out_dev = in_dev_get(FIB_RES_DEV(*res));
1990 if (out_dev == NULL) {
1991 if (net_ratelimit())
1992 printk(KERN_CRIT "Bug in ip_route_input" \
1993 "_slow(). Please, report\n");
1994 return -EINVAL;
1995 }
1996
1997
1998 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1999 in_dev->dev, &spec_dst, &itag, skb->mark);
2000 if (err < 0) {
2001 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2002 saddr);
2003
2004 err = -EINVAL;
2005 goto cleanup;
2006 }
2007
2008 if (err)
2009 flags |= RTCF_DIRECTSRC;
2010
2011 if (out_dev == in_dev && err &&
2012 (IN_DEV_SHARED_MEDIA(out_dev) ||
2013 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2014 flags |= RTCF_DOREDIRECT;
2015
2016 if (skb->protocol != htons(ETH_P_IP)) {
2017 /* Not IP (i.e. ARP). Do not create route, if it is
2018 * invalid for proxy arp. DNAT routes are always valid.
2019 *
2020 * Proxy arp feature have been extended to allow, ARP
2021 * replies back to the same interface, to support
2022 * Private VLAN switch technologies. See arp.c.
2023 */
2024 if (out_dev == in_dev &&
2025 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2026 err = -EINVAL;
2027 goto cleanup;
2028 }
2029 }
2030
2031
2032 rth = dst_alloc(&ipv4_dst_ops);
2033 if (!rth) {
2034 err = -ENOBUFS;
2035 goto cleanup;
2036 }
2037
2038 atomic_set(&rth->u.dst.__refcnt, 1);
2039 rth->u.dst.flags= DST_HOST;
2040 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2041 rth->u.dst.flags |= DST_NOPOLICY;
2042 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2043 rth->u.dst.flags |= DST_NOXFRM;
2044 rth->fl.fl4_dst = daddr;
2045 rth->rt_dst = daddr;
2046 rth->fl.fl4_tos = tos;
2047 rth->fl.mark = skb->mark;
2048 rth->fl.fl4_src = saddr;
2049 rth->rt_src = saddr;
2050 rth->rt_gateway = daddr;
2051 rth->rt_iif =
2052 rth->fl.iif = in_dev->dev->ifindex;
2053 rth->u.dst.dev = (out_dev)->dev;
2054 dev_hold(rth->u.dst.dev);
2055 rth->idev = in_dev_get(rth->u.dst.dev);
2056 rth->fl.oif = 0;
2057 rth->rt_spec_dst= spec_dst;
2058
2059 rth->u.dst.input = ip_forward;
2060 rth->u.dst.output = ip_output;
2061 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
2062
2063 rt_set_nexthop(rth, res, itag);
2064
2065 rth->rt_flags = flags;
2066
2067 *result = rth;
2068 err = 0;
2069 cleanup:
2070 /* release the working reference to the output device */
2071 in_dev_put(out_dev);
2072 return err;
2073 }
2074
2075 static int ip_mkroute_input(struct sk_buff *skb,
2076 struct fib_result *res,
2077 const struct flowi *fl,
2078 struct in_device *in_dev,
2079 __be32 daddr, __be32 saddr, u32 tos)
2080 {
2081 struct rtable* rth = NULL;
2082 int err;
2083 unsigned hash;
2084
2085 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2086 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2087 fib_select_multipath(fl, res);
2088 #endif
2089
2090 /* create a routing cache entry */
2091 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2092 if (err)
2093 return err;
2094
2095 /* put it into the cache */
2096 hash = rt_hash(daddr, saddr, fl->iif,
2097 rt_genid(dev_net(rth->u.dst.dev)));
2098 return rt_intern_hash(hash, rth, NULL, skb);
2099 }
2100
2101 /*
2102 * NOTE. We drop all the packets that has local source
2103 * addresses, because every properly looped back packet
2104 * must have correct destination already attached by output routine.
2105 *
2106 * Such approach solves two big problems:
2107 * 1. Not simplex devices are handled properly.
2108 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2109 */
2110
2111 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2112 u8 tos, struct net_device *dev)
2113 {
2114 struct fib_result res;
2115 struct in_device *in_dev = in_dev_get(dev);
2116 struct flowi fl = { .nl_u = { .ip4_u =
2117 { .daddr = daddr,
2118 .saddr = saddr,
2119 .tos = tos,
2120 .scope = RT_SCOPE_UNIVERSE,
2121 } },
2122 .mark = skb->mark,
2123 .iif = dev->ifindex };
2124 unsigned flags = 0;
2125 u32 itag = 0;
2126 struct rtable * rth;
2127 unsigned hash;
2128 __be32 spec_dst;
2129 int err = -EINVAL;
2130 int free_res = 0;
2131 struct net * net = dev_net(dev);
2132
2133 /* IP on this device is disabled. */
2134
2135 if (!in_dev)
2136 goto out;
2137
2138 /* Check for the most weird martians, which can be not detected
2139 by fib_lookup.
2140 */
2141
2142 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2143 ipv4_is_loopback(saddr))
2144 goto martian_source;
2145
2146 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
2147 goto brd_input;
2148
2149 /* Accept zero addresses only to limited broadcast;
2150 * I even do not know to fix it or not. Waiting for complains :-)
2151 */
2152 if (ipv4_is_zeronet(saddr))
2153 goto martian_source;
2154
2155 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
2156 ipv4_is_loopback(daddr))
2157 goto martian_destination;
2158
2159 /*
2160 * Now we are ready to route packet.
2161 */
2162 if ((err = fib_lookup(net, &fl, &res)) != 0) {
2163 if (!IN_DEV_FORWARD(in_dev))
2164 goto e_hostunreach;
2165 goto no_route;
2166 }
2167 free_res = 1;
2168
2169 RT_CACHE_STAT_INC(in_slow_tot);
2170
2171 if (res.type == RTN_BROADCAST)
2172 goto brd_input;
2173
2174 if (res.type == RTN_LOCAL) {
2175 int result;
2176 result = fib_validate_source(saddr, daddr, tos,
2177 net->loopback_dev->ifindex,
2178 dev, &spec_dst, &itag, skb->mark);
2179 if (result < 0)
2180 goto martian_source;
2181 if (result)
2182 flags |= RTCF_DIRECTSRC;
2183 spec_dst = daddr;
2184 goto local_input;
2185 }
2186
2187 if (!IN_DEV_FORWARD(in_dev))
2188 goto e_hostunreach;
2189 if (res.type != RTN_UNICAST)
2190 goto martian_destination;
2191
2192 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2193 done:
2194 in_dev_put(in_dev);
2195 if (free_res)
2196 fib_res_put(&res);
2197 out: return err;
2198
2199 brd_input:
2200 if (skb->protocol != htons(ETH_P_IP))
2201 goto e_inval;
2202
2203 if (ipv4_is_zeronet(saddr))
2204 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2205 else {
2206 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2207 &itag, skb->mark);
2208 if (err < 0)
2209 goto martian_source;
2210 if (err)
2211 flags |= RTCF_DIRECTSRC;
2212 }
2213 flags |= RTCF_BROADCAST;
2214 res.type = RTN_BROADCAST;
2215 RT_CACHE_STAT_INC(in_brd);
2216
2217 local_input:
2218 rth = dst_alloc(&ipv4_dst_ops);
2219 if (!rth)
2220 goto e_nobufs;
2221
2222 rth->u.dst.output= ip_rt_bug;
2223 rth->rt_genid = rt_genid(net);
2224
2225 atomic_set(&rth->u.dst.__refcnt, 1);
2226 rth->u.dst.flags= DST_HOST;
2227 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2228 rth->u.dst.flags |= DST_NOPOLICY;
2229 rth->fl.fl4_dst = daddr;
2230 rth->rt_dst = daddr;
2231 rth->fl.fl4_tos = tos;
2232 rth->fl.mark = skb->mark;
2233 rth->fl.fl4_src = saddr;
2234 rth->rt_src = saddr;
2235 #ifdef CONFIG_NET_CLS_ROUTE
2236 rth->u.dst.tclassid = itag;
2237 #endif
2238 rth->rt_iif =
2239 rth->fl.iif = dev->ifindex;
2240 rth->u.dst.dev = net->loopback_dev;
2241 dev_hold(rth->u.dst.dev);
2242 rth->idev = in_dev_get(rth->u.dst.dev);
2243 rth->rt_gateway = daddr;
2244 rth->rt_spec_dst= spec_dst;
2245 rth->u.dst.input= ip_local_deliver;
2246 rth->rt_flags = flags|RTCF_LOCAL;
2247 if (res.type == RTN_UNREACHABLE) {
2248 rth->u.dst.input= ip_error;
2249 rth->u.dst.error= -err;
2250 rth->rt_flags &= ~RTCF_LOCAL;
2251 }
2252 rth->rt_type = res.type;
2253 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2254 err = rt_intern_hash(hash, rth, NULL, skb);
2255 goto done;
2256
2257 no_route:
2258 RT_CACHE_STAT_INC(in_no_route);
2259 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2260 res.type = RTN_UNREACHABLE;
2261 if (err == -ESRCH)
2262 err = -ENETUNREACH;
2263 goto local_input;
2264
2265 /*
2266 * Do not cache martian addresses: they should be logged (RFC1812)
2267 */
2268 martian_destination:
2269 RT_CACHE_STAT_INC(in_martian_dst);
2270 #ifdef CONFIG_IP_ROUTE_VERBOSE
2271 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2272 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2273 &daddr, &saddr, dev->name);
2274 #endif
2275
2276 e_hostunreach:
2277 err = -EHOSTUNREACH;
2278 goto done;
2279
2280 e_inval:
2281 err = -EINVAL;
2282 goto done;
2283
2284 e_nobufs:
2285 err = -ENOBUFS;
2286 goto done;
2287
2288 martian_source:
2289 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2290 goto e_inval;
2291 }
2292
2293 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2294 u8 tos, struct net_device *dev)
2295 {
2296 struct rtable * rth;
2297 unsigned hash;
2298 int iif = dev->ifindex;
2299 struct net *net;
2300
2301 net = dev_net(dev);
2302
2303 if (!rt_caching(net))
2304 goto skip_cache;
2305
2306 tos &= IPTOS_RT_MASK;
2307 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2308
2309 rcu_read_lock();
2310 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2311 rth = rcu_dereference(rth->u.dst.rt_next)) {
2312 if (((rth->fl.fl4_dst ^ daddr) |
2313 (rth->fl.fl4_src ^ saddr) |
2314 (rth->fl.iif ^ iif) |
2315 rth->fl.oif |
2316 (rth->fl.fl4_tos ^ tos)) == 0 &&
2317 rth->fl.mark == skb->mark &&
2318 net_eq(dev_net(rth->u.dst.dev), net) &&
2319 !rt_is_expired(rth)) {
2320 dst_use(&rth->u.dst, jiffies);
2321 RT_CACHE_STAT_INC(in_hit);
2322 rcu_read_unlock();
2323 skb_dst_set(skb, &rth->u.dst);
2324 return 0;
2325 }
2326 RT_CACHE_STAT_INC(in_hlist_search);
2327 }
2328 rcu_read_unlock();
2329
2330 skip_cache:
2331 /* Multicast recognition logic is moved from route cache to here.
2332 The problem was that too many Ethernet cards have broken/missing
2333 hardware multicast filters :-( As result the host on multicasting
2334 network acquires a lot of useless route cache entries, sort of
2335 SDR messages from all the world. Now we try to get rid of them.
2336 Really, provided software IP multicast filter is organized
2337 reasonably (at least, hashed), it does not result in a slowdown
2338 comparing with route cache reject entries.
2339 Note, that multicast routers are not affected, because
2340 route cache entry is created eventually.
2341 */
2342 if (ipv4_is_multicast(daddr)) {
2343 struct in_device *in_dev;
2344
2345 rcu_read_lock();
2346 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2347 int our = ip_check_mc(in_dev, daddr, saddr,
2348 ip_hdr(skb)->protocol);
2349 if (our
2350 #ifdef CONFIG_IP_MROUTE
2351 ||
2352 (!ipv4_is_local_multicast(daddr) &&
2353 IN_DEV_MFORWARD(in_dev))
2354 #endif
2355 ) {
2356 rcu_read_unlock();
2357 return ip_route_input_mc(skb, daddr, saddr,
2358 tos, dev, our);
2359 }
2360 }
2361 rcu_read_unlock();
2362 return -EINVAL;
2363 }
2364 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2365 }
2366
2367 static int __mkroute_output(struct rtable **result,
2368 struct fib_result *res,
2369 const struct flowi *fl,
2370 const struct flowi *oldflp,
2371 struct net_device *dev_out,
2372 unsigned flags)
2373 {
2374 struct rtable *rth;
2375 struct in_device *in_dev;
2376 u32 tos = RT_FL_TOS(oldflp);
2377 int err = 0;
2378
2379 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2380 return -EINVAL;
2381
2382 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2383 res->type = RTN_BROADCAST;
2384 else if (ipv4_is_multicast(fl->fl4_dst))
2385 res->type = RTN_MULTICAST;
2386 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2387 return -EINVAL;
2388
2389 if (dev_out->flags & IFF_LOOPBACK)
2390 flags |= RTCF_LOCAL;
2391
2392 /* get work reference to inet device */
2393 in_dev = in_dev_get(dev_out);
2394 if (!in_dev)
2395 return -EINVAL;
2396
2397 if (res->type == RTN_BROADCAST) {
2398 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2399 if (res->fi) {
2400 fib_info_put(res->fi);
2401 res->fi = NULL;
2402 }
2403 } else if (res->type == RTN_MULTICAST) {
2404 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2405 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2406 oldflp->proto))
2407 flags &= ~RTCF_LOCAL;
2408 /* If multicast route do not exist use
2409 default one, but do not gateway in this case.
2410 Yes, it is hack.
2411 */
2412 if (res->fi && res->prefixlen < 4) {
2413 fib_info_put(res->fi);
2414 res->fi = NULL;
2415 }
2416 }
2417
2418
2419 rth = dst_alloc(&ipv4_dst_ops);
2420 if (!rth) {
2421 err = -ENOBUFS;
2422 goto cleanup;
2423 }
2424
2425 atomic_set(&rth->u.dst.__refcnt, 1);
2426 rth->u.dst.flags= DST_HOST;
2427 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2428 rth->u.dst.flags |= DST_NOXFRM;
2429 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2430 rth->u.dst.flags |= DST_NOPOLICY;
2431
2432 rth->fl.fl4_dst = oldflp->fl4_dst;
2433 rth->fl.fl4_tos = tos;
2434 rth->fl.fl4_src = oldflp->fl4_src;
2435 rth->fl.oif = oldflp->oif;
2436 rth->fl.mark = oldflp->mark;
2437 rth->rt_dst = fl->fl4_dst;
2438 rth->rt_src = fl->fl4_src;
2439 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2440 /* get references to the devices that are to be hold by the routing
2441 cache entry */
2442 rth->u.dst.dev = dev_out;
2443 dev_hold(dev_out);
2444 rth->idev = in_dev_get(dev_out);
2445 rth->rt_gateway = fl->fl4_dst;
2446 rth->rt_spec_dst= fl->fl4_src;
2447
2448 rth->u.dst.output=ip_output;
2449 rth->rt_genid = rt_genid(dev_net(dev_out));
2450
2451 RT_CACHE_STAT_INC(out_slow_tot);
2452
2453 if (flags & RTCF_LOCAL) {
2454 rth->u.dst.input = ip_local_deliver;
2455 rth->rt_spec_dst = fl->fl4_dst;
2456 }
2457 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2458 rth->rt_spec_dst = fl->fl4_src;
2459 if (flags & RTCF_LOCAL &&
2460 !(dev_out->flags & IFF_LOOPBACK)) {
2461 rth->u.dst.output = ip_mc_output;
2462 RT_CACHE_STAT_INC(out_slow_mc);
2463 }
2464 #ifdef CONFIG_IP_MROUTE
2465 if (res->type == RTN_MULTICAST) {
2466 if (IN_DEV_MFORWARD(in_dev) &&
2467 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2468 rth->u.dst.input = ip_mr_input;
2469 rth->u.dst.output = ip_mc_output;
2470 }
2471 }
2472 #endif
2473 }
2474
2475 rt_set_nexthop(rth, res, 0);
2476
2477 rth->rt_flags = flags;
2478
2479 *result = rth;
2480 cleanup:
2481 /* release work reference to inet device */
2482 in_dev_put(in_dev);
2483
2484 return err;
2485 }
2486
2487 static int ip_mkroute_output(struct rtable **rp,
2488 struct fib_result *res,
2489 const struct flowi *fl,
2490 const struct flowi *oldflp,
2491 struct net_device *dev_out,
2492 unsigned flags)
2493 {
2494 struct rtable *rth = NULL;
2495 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2496 unsigned hash;
2497 if (err == 0) {
2498 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2499 rt_genid(dev_net(dev_out)));
2500 err = rt_intern_hash(hash, rth, rp, NULL);
2501 }
2502
2503 return err;
2504 }
2505
2506 /*
2507 * Major route resolver routine.
2508 */
2509
2510 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2511 const struct flowi *oldflp)
2512 {
2513 u32 tos = RT_FL_TOS(oldflp);
2514 struct flowi fl = { .nl_u = { .ip4_u =
2515 { .daddr = oldflp->fl4_dst,
2516 .saddr = oldflp->fl4_src,
2517 .tos = tos & IPTOS_RT_MASK,
2518 .scope = ((tos & RTO_ONLINK) ?
2519 RT_SCOPE_LINK :
2520 RT_SCOPE_UNIVERSE),
2521 } },
2522 .mark = oldflp->mark,
2523 .iif = net->loopback_dev->ifindex,
2524 .oif = oldflp->oif };
2525 struct fib_result res;
2526 unsigned flags = 0;
2527 struct net_device *dev_out = NULL;
2528 int free_res = 0;
2529 int err;
2530
2531
2532 res.fi = NULL;
2533 #ifdef CONFIG_IP_MULTIPLE_TABLES
2534 res.r = NULL;
2535 #endif
2536
2537 if (oldflp->fl4_src) {
2538 err = -EINVAL;
2539 if (ipv4_is_multicast(oldflp->fl4_src) ||
2540 ipv4_is_lbcast(oldflp->fl4_src) ||
2541 ipv4_is_zeronet(oldflp->fl4_src))
2542 goto out;
2543
2544 /* I removed check for oif == dev_out->oif here.
2545 It was wrong for two reasons:
2546 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2547 is assigned to multiple interfaces.
2548 2. Moreover, we are allowed to send packets with saddr
2549 of another iface. --ANK
2550 */
2551
2552 if (oldflp->oif == 0 &&
2553 (ipv4_is_multicast(oldflp->fl4_dst) ||
2554 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2555 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2556 dev_out = ip_dev_find(net, oldflp->fl4_src);
2557 if (dev_out == NULL)
2558 goto out;
2559
2560 /* Special hack: user can direct multicasts
2561 and limited broadcast via necessary interface
2562 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2563 This hack is not just for fun, it allows
2564 vic,vat and friends to work.
2565 They bind socket to loopback, set ttl to zero
2566 and expect that it will work.
2567 From the viewpoint of routing cache they are broken,
2568 because we are not allowed to build multicast path
2569 with loopback source addr (look, routing cache
2570 cannot know, that ttl is zero, so that packet
2571 will not leave this host and route is valid).
2572 Luckily, this hack is good workaround.
2573 */
2574
2575 fl.oif = dev_out->ifindex;
2576 goto make_route;
2577 }
2578
2579 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2580 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2581 dev_out = ip_dev_find(net, oldflp->fl4_src);
2582 if (dev_out == NULL)
2583 goto out;
2584 dev_put(dev_out);
2585 dev_out = NULL;
2586 }
2587 }
2588
2589
2590 if (oldflp->oif) {
2591 dev_out = dev_get_by_index(net, oldflp->oif);
2592 err = -ENODEV;
2593 if (dev_out == NULL)
2594 goto out;
2595
2596 /* RACE: Check return value of inet_select_addr instead. */
2597 if (__in_dev_get_rtnl(dev_out) == NULL) {
2598 dev_put(dev_out);
2599 goto out; /* Wrong error code */
2600 }
2601
2602 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2603 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2604 if (!fl.fl4_src)
2605 fl.fl4_src = inet_select_addr(dev_out, 0,
2606 RT_SCOPE_LINK);
2607 goto make_route;
2608 }
2609 if (!fl.fl4_src) {
2610 if (ipv4_is_multicast(oldflp->fl4_dst))
2611 fl.fl4_src = inet_select_addr(dev_out, 0,
2612 fl.fl4_scope);
2613 else if (!oldflp->fl4_dst)
2614 fl.fl4_src = inet_select_addr(dev_out, 0,
2615 RT_SCOPE_HOST);
2616 }
2617 }
2618
2619 if (!fl.fl4_dst) {
2620 fl.fl4_dst = fl.fl4_src;
2621 if (!fl.fl4_dst)
2622 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2623 if (dev_out)
2624 dev_put(dev_out);
2625 dev_out = net->loopback_dev;
2626 dev_hold(dev_out);
2627 fl.oif = net->loopback_dev->ifindex;
2628 res.type = RTN_LOCAL;
2629 flags |= RTCF_LOCAL;
2630 goto make_route;
2631 }
2632
2633 if (fib_lookup(net, &fl, &res)) {
2634 res.fi = NULL;
2635 if (oldflp->oif) {
2636 /* Apparently, routing tables are wrong. Assume,
2637 that the destination is on link.
2638
2639 WHY? DW.
2640 Because we are allowed to send to iface
2641 even if it has NO routes and NO assigned
2642 addresses. When oif is specified, routing
2643 tables are looked up with only one purpose:
2644 to catch if destination is gatewayed, rather than
2645 direct. Moreover, if MSG_DONTROUTE is set,
2646 we send packet, ignoring both routing tables
2647 and ifaddr state. --ANK
2648
2649
2650 We could make it even if oif is unknown,
2651 likely IPv6, but we do not.
2652 */
2653
2654 if (fl.fl4_src == 0)
2655 fl.fl4_src = inet_select_addr(dev_out, 0,
2656 RT_SCOPE_LINK);
2657 res.type = RTN_UNICAST;
2658 goto make_route;
2659 }
2660 if (dev_out)
2661 dev_put(dev_out);
2662 err = -ENETUNREACH;
2663 goto out;
2664 }
2665 free_res = 1;
2666
2667 if (res.type == RTN_LOCAL) {
2668 if (!fl.fl4_src)
2669 fl.fl4_src = fl.fl4_dst;
2670 if (dev_out)
2671 dev_put(dev_out);
2672 dev_out = net->loopback_dev;
2673 dev_hold(dev_out);
2674 fl.oif = dev_out->ifindex;
2675 if (res.fi)
2676 fib_info_put(res.fi);
2677 res.fi = NULL;
2678 flags |= RTCF_LOCAL;
2679 goto make_route;
2680 }
2681
2682 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2683 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2684 fib_select_multipath(&fl, &res);
2685 else
2686 #endif
2687 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2688 fib_select_default(net, &fl, &res);
2689
2690 if (!fl.fl4_src)
2691 fl.fl4_src = FIB_RES_PREFSRC(res);
2692
2693 if (dev_out)
2694 dev_put(dev_out);
2695 dev_out = FIB_RES_DEV(res);
2696 dev_hold(dev_out);
2697 fl.oif = dev_out->ifindex;
2698
2699
2700 make_route:
2701 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2702
2703
2704 if (free_res)
2705 fib_res_put(&res);
2706 if (dev_out)
2707 dev_put(dev_out);
2708 out: return err;
2709 }
2710
2711 int __ip_route_output_key(struct net *net, struct rtable **rp,
2712 const struct flowi *flp)
2713 {
2714 unsigned hash;
2715 struct rtable *rth;
2716
2717 if (!rt_caching(net))
2718 goto slow_output;
2719
2720 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2721
2722 rcu_read_lock_bh();
2723 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2724 rth = rcu_dereference_bh(rth->u.dst.rt_next)) {
2725 if (rth->fl.fl4_dst == flp->fl4_dst &&
2726 rth->fl.fl4_src == flp->fl4_src &&
2727 rth->fl.iif == 0 &&
2728 rth->fl.oif == flp->oif &&
2729 rth->fl.mark == flp->mark &&
2730 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2731 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2732 net_eq(dev_net(rth->u.dst.dev), net) &&
2733 !rt_is_expired(rth)) {
2734 dst_use(&rth->u.dst, jiffies);
2735 RT_CACHE_STAT_INC(out_hit);
2736 rcu_read_unlock_bh();
2737 *rp = rth;
2738 return 0;
2739 }
2740 RT_CACHE_STAT_INC(out_hlist_search);
2741 }
2742 rcu_read_unlock_bh();
2743
2744 slow_output:
2745 return ip_route_output_slow(net, rp, flp);
2746 }
2747
2748 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2749
2750 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2751 {
2752 }
2753
2754 static struct dst_ops ipv4_dst_blackhole_ops = {
2755 .family = AF_INET,
2756 .protocol = cpu_to_be16(ETH_P_IP),
2757 .destroy = ipv4_dst_destroy,
2758 .check = ipv4_dst_check,
2759 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2760 .entries = ATOMIC_INIT(0),
2761 };
2762
2763
2764 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2765 {
2766 struct rtable *ort = *rp;
2767 struct rtable *rt = (struct rtable *)
2768 dst_alloc(&ipv4_dst_blackhole_ops);
2769
2770 if (rt) {
2771 struct dst_entry *new = &rt->u.dst;
2772
2773 atomic_set(&new->__refcnt, 1);
2774 new->__use = 1;
2775 new->input = dst_discard;
2776 new->output = dst_discard;
2777 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2778
2779 new->dev = ort->u.dst.dev;
2780 if (new->dev)
2781 dev_hold(new->dev);
2782
2783 rt->fl = ort->fl;
2784
2785 rt->idev = ort->idev;
2786 if (rt->idev)
2787 in_dev_hold(rt->idev);
2788 rt->rt_genid = rt_genid(net);
2789 rt->rt_flags = ort->rt_flags;
2790 rt->rt_type = ort->rt_type;
2791 rt->rt_dst = ort->rt_dst;
2792 rt->rt_src = ort->rt_src;
2793 rt->rt_iif = ort->rt_iif;
2794 rt->rt_gateway = ort->rt_gateway;
2795 rt->rt_spec_dst = ort->rt_spec_dst;
2796 rt->peer = ort->peer;
2797 if (rt->peer)
2798 atomic_inc(&rt->peer->refcnt);
2799
2800 dst_free(new);
2801 }
2802
2803 dst_release(&(*rp)->u.dst);
2804 *rp = rt;
2805 return (rt ? 0 : -ENOMEM);
2806 }
2807
2808 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2809 struct sock *sk, int flags)
2810 {
2811 int err;
2812
2813 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2814 return err;
2815
2816 if (flp->proto) {
2817 if (!flp->fl4_src)
2818 flp->fl4_src = (*rp)->rt_src;
2819 if (!flp->fl4_dst)
2820 flp->fl4_dst = (*rp)->rt_dst;
2821 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2822 flags ? XFRM_LOOKUP_WAIT : 0);
2823 if (err == -EREMOTE)
2824 err = ipv4_dst_blackhole(net, rp, flp);
2825
2826 return err;
2827 }
2828
2829 return 0;
2830 }
2831
2832 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2833
2834 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2835 {
2836 return ip_route_output_flow(net, rp, flp, NULL, 0);
2837 }
2838
2839 static int rt_fill_info(struct net *net,
2840 struct sk_buff *skb, u32 pid, u32 seq, int event,
2841 int nowait, unsigned int flags)
2842 {
2843 struct rtable *rt = skb_rtable(skb);
2844 struct rtmsg *r;
2845 struct nlmsghdr *nlh;
2846 long expires;
2847 u32 id = 0, ts = 0, tsage = 0, error;
2848
2849 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2850 if (nlh == NULL)
2851 return -EMSGSIZE;
2852
2853 r = nlmsg_data(nlh);
2854 r->rtm_family = AF_INET;
2855 r->rtm_dst_len = 32;
2856 r->rtm_src_len = 0;
2857 r->rtm_tos = rt->fl.fl4_tos;
2858 r->rtm_table = RT_TABLE_MAIN;
2859 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2860 r->rtm_type = rt->rt_type;
2861 r->rtm_scope = RT_SCOPE_UNIVERSE;
2862 r->rtm_protocol = RTPROT_UNSPEC;
2863 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2864 if (rt->rt_flags & RTCF_NOTIFY)
2865 r->rtm_flags |= RTM_F_NOTIFY;
2866
2867 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2868
2869 if (rt->fl.fl4_src) {
2870 r->rtm_src_len = 32;
2871 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2872 }
2873 if (rt->u.dst.dev)
2874 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2875 #ifdef CONFIG_NET_CLS_ROUTE
2876 if (rt->u.dst.tclassid)
2877 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2878 #endif
2879 if (rt->fl.iif)
2880 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2881 else if (rt->rt_src != rt->fl.fl4_src)
2882 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2883
2884 if (rt->rt_dst != rt->rt_gateway)
2885 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2886
2887 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2888 goto nla_put_failure;
2889
2890 error = rt->u.dst.error;
2891 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2892 if (rt->peer) {
2893 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2894 if (rt->peer->tcp_ts_stamp) {
2895 ts = rt->peer->tcp_ts;
2896 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2897 }
2898 }
2899
2900 if (rt->fl.iif) {
2901 #ifdef CONFIG_IP_MROUTE
2902 __be32 dst = rt->rt_dst;
2903
2904 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2905 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2906 int err = ipmr_get_route(net, skb, r, nowait);
2907 if (err <= 0) {
2908 if (!nowait) {
2909 if (err == 0)
2910 return 0;
2911 goto nla_put_failure;
2912 } else {
2913 if (err == -EMSGSIZE)
2914 goto nla_put_failure;
2915 error = err;
2916 }
2917 }
2918 } else
2919 #endif
2920 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2921 }
2922
2923 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2924 expires, error) < 0)
2925 goto nla_put_failure;
2926
2927 return nlmsg_end(skb, nlh);
2928
2929 nla_put_failure:
2930 nlmsg_cancel(skb, nlh);
2931 return -EMSGSIZE;
2932 }
2933
2934 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2935 {
2936 struct net *net = sock_net(in_skb->sk);
2937 struct rtmsg *rtm;
2938 struct nlattr *tb[RTA_MAX+1];
2939 struct rtable *rt = NULL;
2940 __be32 dst = 0;
2941 __be32 src = 0;
2942 u32 iif;
2943 int err;
2944 struct sk_buff *skb;
2945
2946 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2947 if (err < 0)
2948 goto errout;
2949
2950 rtm = nlmsg_data(nlh);
2951
2952 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2953 if (skb == NULL) {
2954 err = -ENOBUFS;
2955 goto errout;
2956 }
2957
2958 /* Reserve room for dummy headers, this skb can pass
2959 through good chunk of routing engine.
2960 */
2961 skb_reset_mac_header(skb);
2962 skb_reset_network_header(skb);
2963
2964 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2965 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2966 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2967
2968 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2969 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2970 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2971
2972 if (iif) {
2973 struct net_device *dev;
2974
2975 dev = __dev_get_by_index(net, iif);
2976 if (dev == NULL) {
2977 err = -ENODEV;
2978 goto errout_free;
2979 }
2980
2981 skb->protocol = htons(ETH_P_IP);
2982 skb->dev = dev;
2983 local_bh_disable();
2984 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2985 local_bh_enable();
2986
2987 rt = skb_rtable(skb);
2988 if (err == 0 && rt->u.dst.error)
2989 err = -rt->u.dst.error;
2990 } else {
2991 struct flowi fl = {
2992 .nl_u = {
2993 .ip4_u = {
2994 .daddr = dst,
2995 .saddr = src,
2996 .tos = rtm->rtm_tos,
2997 },
2998 },
2999 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3000 };
3001 err = ip_route_output_key(net, &rt, &fl);
3002 }
3003
3004 if (err)
3005 goto errout_free;
3006
3007 skb_dst_set(skb, &rt->u.dst);
3008 if (rtm->rtm_flags & RTM_F_NOTIFY)
3009 rt->rt_flags |= RTCF_NOTIFY;
3010
3011 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3012 RTM_NEWROUTE, 0, 0);
3013 if (err <= 0)
3014 goto errout_free;
3015
3016 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3017 errout:
3018 return err;
3019
3020 errout_free:
3021 kfree_skb(skb);
3022 goto errout;
3023 }
3024
3025 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3026 {
3027 struct rtable *rt;
3028 int h, s_h;
3029 int idx, s_idx;
3030 struct net *net;
3031
3032 net = sock_net(skb->sk);
3033
3034 s_h = cb->args[0];
3035 if (s_h < 0)
3036 s_h = 0;
3037 s_idx = idx = cb->args[1];
3038 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3039 if (!rt_hash_table[h].chain)
3040 continue;
3041 rcu_read_lock_bh();
3042 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3043 rt = rcu_dereference_bh(rt->u.dst.rt_next), idx++) {
3044 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
3045 continue;
3046 if (rt_is_expired(rt))
3047 continue;
3048 skb_dst_set(skb, dst_clone(&rt->u.dst));
3049 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3050 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3051 1, NLM_F_MULTI) <= 0) {
3052 skb_dst_drop(skb);
3053 rcu_read_unlock_bh();
3054 goto done;
3055 }
3056 skb_dst_drop(skb);
3057 }
3058 rcu_read_unlock_bh();
3059 }
3060
3061 done:
3062 cb->args[0] = h;
3063 cb->args[1] = idx;
3064 return skb->len;
3065 }
3066
3067 void ip_rt_multicast_event(struct in_device *in_dev)
3068 {
3069 rt_cache_flush(dev_net(in_dev->dev), 0);
3070 }
3071
3072 #ifdef CONFIG_SYSCTL
3073 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3074 void __user *buffer,
3075 size_t *lenp, loff_t *ppos)
3076 {
3077 if (write) {
3078 int flush_delay;
3079 ctl_table ctl;
3080 struct net *net;
3081
3082 memcpy(&ctl, __ctl, sizeof(ctl));
3083 ctl.data = &flush_delay;
3084 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3085
3086 net = (struct net *)__ctl->extra1;
3087 rt_cache_flush(net, flush_delay);
3088 return 0;
3089 }
3090
3091 return -EINVAL;
3092 }
3093
3094 static void rt_secret_reschedule(int old)
3095 {
3096 struct net *net;
3097 int new = ip_rt_secret_interval;
3098 int diff = new - old;
3099
3100 if (!diff)
3101 return;
3102
3103 rtnl_lock();
3104 for_each_net(net) {
3105 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
3106
3107 if (!new)
3108 continue;
3109
3110 if (deleted) {
3111 long time = net->ipv4.rt_secret_timer.expires - jiffies;
3112
3113 if (time <= 0 || (time += diff) <= 0)
3114 time = 0;
3115
3116 net->ipv4.rt_secret_timer.expires = time;
3117 } else
3118 net->ipv4.rt_secret_timer.expires = new;
3119
3120 net->ipv4.rt_secret_timer.expires += jiffies;
3121 add_timer(&net->ipv4.rt_secret_timer);
3122 }
3123 rtnl_unlock();
3124 }
3125
3126 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
3127 void __user *buffer, size_t *lenp,
3128 loff_t *ppos)
3129 {
3130 int old = ip_rt_secret_interval;
3131 int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
3132
3133 rt_secret_reschedule(old);
3134
3135 return ret;
3136 }
3137
3138 static ctl_table ipv4_route_table[] = {
3139 {
3140 .procname = "gc_thresh",
3141 .data = &ipv4_dst_ops.gc_thresh,
3142 .maxlen = sizeof(int),
3143 .mode = 0644,
3144 .proc_handler = proc_dointvec,
3145 },
3146 {
3147 .procname = "max_size",
3148 .data = &ip_rt_max_size,
3149 .maxlen = sizeof(int),
3150 .mode = 0644,
3151 .proc_handler = proc_dointvec,
3152 },
3153 {
3154 /* Deprecated. Use gc_min_interval_ms */
3155
3156 .procname = "gc_min_interval",
3157 .data = &ip_rt_gc_min_interval,
3158 .maxlen = sizeof(int),
3159 .mode = 0644,
3160 .proc_handler = proc_dointvec_jiffies,
3161 },
3162 {
3163 .procname = "gc_min_interval_ms",
3164 .data = &ip_rt_gc_min_interval,
3165 .maxlen = sizeof(int),
3166 .mode = 0644,
3167 .proc_handler = proc_dointvec_ms_jiffies,
3168 },
3169 {
3170 .procname = "gc_timeout",
3171 .data = &ip_rt_gc_timeout,
3172 .maxlen = sizeof(int),
3173 .mode = 0644,
3174 .proc_handler = proc_dointvec_jiffies,
3175 },
3176 {
3177 .procname = "gc_interval",
3178 .data = &ip_rt_gc_interval,
3179 .maxlen = sizeof(int),
3180 .mode = 0644,
3181 .proc_handler = proc_dointvec_jiffies,
3182 },
3183 {
3184 .procname = "redirect_load",
3185 .data = &ip_rt_redirect_load,
3186 .maxlen = sizeof(int),
3187 .mode = 0644,
3188 .proc_handler = proc_dointvec,
3189 },
3190 {
3191 .procname = "redirect_number",
3192 .data = &ip_rt_redirect_number,
3193 .maxlen = sizeof(int),
3194 .mode = 0644,
3195 .proc_handler = proc_dointvec,
3196 },
3197 {
3198 .procname = "redirect_silence",
3199 .data = &ip_rt_redirect_silence,
3200 .maxlen = sizeof(int),
3201 .mode = 0644,
3202 .proc_handler = proc_dointvec,
3203 },
3204 {
3205 .procname = "error_cost",
3206 .data = &ip_rt_error_cost,
3207 .maxlen = sizeof(int),
3208 .mode = 0644,
3209 .proc_handler = proc_dointvec,
3210 },
3211 {
3212 .procname = "error_burst",
3213 .data = &ip_rt_error_burst,
3214 .maxlen = sizeof(int),
3215 .mode = 0644,
3216 .proc_handler = proc_dointvec,
3217 },
3218 {
3219 .procname = "gc_elasticity",
3220 .data = &ip_rt_gc_elasticity,
3221 .maxlen = sizeof(int),
3222 .mode = 0644,
3223 .proc_handler = proc_dointvec,
3224 },
3225 {
3226 .procname = "mtu_expires",
3227 .data = &ip_rt_mtu_expires,
3228 .maxlen = sizeof(int),
3229 .mode = 0644,
3230 .proc_handler = proc_dointvec_jiffies,
3231 },
3232 {
3233 .procname = "min_pmtu",
3234 .data = &ip_rt_min_pmtu,
3235 .maxlen = sizeof(int),
3236 .mode = 0644,
3237 .proc_handler = proc_dointvec,
3238 },
3239 {
3240 .procname = "min_adv_mss",
3241 .data = &ip_rt_min_advmss,
3242 .maxlen = sizeof(int),
3243 .mode = 0644,
3244 .proc_handler = proc_dointvec,
3245 },
3246 {
3247 .procname = "secret_interval",
3248 .data = &ip_rt_secret_interval,
3249 .maxlen = sizeof(int),
3250 .mode = 0644,
3251 .proc_handler = ipv4_sysctl_rt_secret_interval,
3252 },
3253 { }
3254 };
3255
3256 static struct ctl_table empty[1];
3257
3258 static struct ctl_table ipv4_skeleton[] =
3259 {
3260 { .procname = "route",
3261 .mode = 0555, .child = ipv4_route_table},
3262 { .procname = "neigh",
3263 .mode = 0555, .child = empty},
3264 { }
3265 };
3266
3267 static __net_initdata struct ctl_path ipv4_path[] = {
3268 { .procname = "net", },
3269 { .procname = "ipv4", },
3270 { },
3271 };
3272
3273 static struct ctl_table ipv4_route_flush_table[] = {
3274 {
3275 .procname = "flush",
3276 .maxlen = sizeof(int),
3277 .mode = 0200,
3278 .proc_handler = ipv4_sysctl_rtcache_flush,
3279 },
3280 { },
3281 };
3282
3283 static __net_initdata struct ctl_path ipv4_route_path[] = {
3284 { .procname = "net", },
3285 { .procname = "ipv4", },
3286 { .procname = "route", },
3287 { },
3288 };
3289
3290 static __net_init int sysctl_route_net_init(struct net *net)
3291 {
3292 struct ctl_table *tbl;
3293
3294 tbl = ipv4_route_flush_table;
3295 if (!net_eq(net, &init_net)) {
3296 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3297 if (tbl == NULL)
3298 goto err_dup;
3299 }
3300 tbl[0].extra1 = net;
3301
3302 net->ipv4.route_hdr =
3303 register_net_sysctl_table(net, ipv4_route_path, tbl);
3304 if (net->ipv4.route_hdr == NULL)
3305 goto err_reg;
3306 return 0;
3307
3308 err_reg:
3309 if (tbl != ipv4_route_flush_table)
3310 kfree(tbl);
3311 err_dup:
3312 return -ENOMEM;
3313 }
3314
3315 static __net_exit void sysctl_route_net_exit(struct net *net)
3316 {
3317 struct ctl_table *tbl;
3318
3319 tbl = net->ipv4.route_hdr->ctl_table_arg;
3320 unregister_net_sysctl_table(net->ipv4.route_hdr);
3321 BUG_ON(tbl == ipv4_route_flush_table);
3322 kfree(tbl);
3323 }
3324
3325 static __net_initdata struct pernet_operations sysctl_route_ops = {
3326 .init = sysctl_route_net_init,
3327 .exit = sysctl_route_net_exit,
3328 };
3329 #endif
3330
3331
3332 static __net_init int rt_secret_timer_init(struct net *net)
3333 {
3334 atomic_set(&net->ipv4.rt_genid,
3335 (int) ((num_physpages ^ (num_physpages>>8)) ^
3336 (jiffies ^ (jiffies >> 7))));
3337
3338 net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
3339 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3340 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3341
3342 if (ip_rt_secret_interval) {
3343 net->ipv4.rt_secret_timer.expires =
3344 jiffies + net_random() % ip_rt_secret_interval +
3345 ip_rt_secret_interval;
3346 add_timer(&net->ipv4.rt_secret_timer);
3347 }
3348 return 0;
3349 }
3350
3351 static __net_exit void rt_secret_timer_exit(struct net *net)
3352 {
3353 del_timer_sync(&net->ipv4.rt_secret_timer);
3354 }
3355
3356 static __net_initdata struct pernet_operations rt_secret_timer_ops = {
3357 .init = rt_secret_timer_init,
3358 .exit = rt_secret_timer_exit,
3359 };
3360
3361
3362 #ifdef CONFIG_NET_CLS_ROUTE
3363 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3364 #endif /* CONFIG_NET_CLS_ROUTE */
3365
3366 static __initdata unsigned long rhash_entries;
3367 static int __init set_rhash_entries(char *str)
3368 {
3369 if (!str)
3370 return 0;
3371 rhash_entries = simple_strtoul(str, &str, 0);
3372 return 1;
3373 }
3374 __setup("rhash_entries=", set_rhash_entries);
3375
3376 int __init ip_rt_init(void)
3377 {
3378 int rc = 0;
3379
3380 #ifdef CONFIG_NET_CLS_ROUTE
3381 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3382 if (!ip_rt_acct)
3383 panic("IP: failed to allocate ip_rt_acct\n");
3384 #endif
3385
3386 ipv4_dst_ops.kmem_cachep =
3387 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3388 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3389
3390 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3391
3392 rt_hash_table = (struct rt_hash_bucket *)
3393 alloc_large_system_hash("IP route cache",
3394 sizeof(struct rt_hash_bucket),
3395 rhash_entries,
3396 (totalram_pages >= 128 * 1024) ?
3397 15 : 17,
3398 0,
3399 &rt_hash_log,
3400 &rt_hash_mask,
3401 rhash_entries ? 0 : 512 * 1024);
3402 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3403 rt_hash_lock_init();
3404
3405 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3406 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3407
3408 devinet_init();
3409 ip_fib_init();
3410
3411 /* All the timers, started at system startup tend
3412 to synchronize. Perturb it a bit.
3413 */
3414 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3415 expires_ljiffies = jiffies;
3416 schedule_delayed_work(&expires_work,
3417 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3418
3419 if (register_pernet_subsys(&rt_secret_timer_ops))
3420 printk(KERN_ERR "Unable to setup rt_secret_timer\n");
3421
3422 if (ip_rt_proc_init())
3423 printk(KERN_ERR "Unable to create route proc files\n");
3424 #ifdef CONFIG_XFRM
3425 xfrm_init();
3426 xfrm4_init(ip_rt_max_size);
3427 #endif
3428 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3429
3430 #ifdef CONFIG_SYSCTL
3431 register_pernet_subsys(&sysctl_route_ops);
3432 #endif
3433 return rc;
3434 }
3435
3436 #ifdef CONFIG_SYSCTL
3437 /*
3438 * We really need to sanitize the damn ipv4 init order, then all
3439 * this nonsense will go away.
3440 */
3441 void __init ip_static_sysctl_init(void)
3442 {
3443 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3444 }
3445 #endif
3446
3447 EXPORT_SYMBOL(__ip_select_ident);
3448 EXPORT_SYMBOL(ip_route_input);
3449 EXPORT_SYMBOL(ip_route_output_key);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree