?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blob2ea6dcc3e2ccd62b6faedb97b31e2206f121764a
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
133 static void rt_worker_func(struct work_struct *work);
134 static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
135
136 /*
137 * Interface to generic destination cache.
138 */
139
140 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static void ipv4_dst_ifdown(struct dst_entry *dst,
143 struct net_device *dev, int how);
144 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145 static void ipv4_link_failure(struct sk_buff *skb);
146 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
147 static int rt_garbage_collect(struct dst_ops *ops);
148
149
150 static struct dst_ops ipv4_dst_ops = {
151 .family = AF_INET,
152 .protocol = __constant_htons(ETH_P_IP),
153 .gc = rt_garbage_collect,
154 .check = ipv4_dst_check,
155 .destroy = ipv4_dst_destroy,
156 .ifdown = ipv4_dst_ifdown,
157 .negative_advice = ipv4_negative_advice,
158 .link_failure = ipv4_link_failure,
159 .update_pmtu = ip_rt_update_pmtu,
160 .local_out = __ip_local_out,
161 .entry_size = sizeof(struct rtable),
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 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
205 defined(CONFIG_PROVE_LOCKING)
206 /*
207 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
208 * The size of this table is a power of two and depends on the number of CPUS.
209 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
210 */
211 #ifdef CONFIG_LOCKDEP
212 # define RT_HASH_LOCK_SZ 256
213 #else
214 # if NR_CPUS >= 32
215 # define RT_HASH_LOCK_SZ 4096
216 # elif NR_CPUS >= 16
217 # define RT_HASH_LOCK_SZ 2048
218 # elif NR_CPUS >= 8
219 # define RT_HASH_LOCK_SZ 1024
220 # elif NR_CPUS >= 4
221 # define RT_HASH_LOCK_SZ 512
222 # else
223 # define RT_HASH_LOCK_SZ 256
224 # endif
225 #endif
226
227 static spinlock_t *rt_hash_locks;
228 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
229
230 static __init void rt_hash_lock_init(void)
231 {
232 int i;
233
234 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
235 GFP_KERNEL);
236 if (!rt_hash_locks)
237 panic("IP: failed to allocate rt_hash_locks\n");
238
239 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
240 spin_lock_init(&rt_hash_locks[i]);
241 }
242 #else
243 # define rt_hash_lock_addr(slot) NULL
244
245 static inline void rt_hash_lock_init(void)
246 {
247 }
248 #endif
249
250 static struct rt_hash_bucket *rt_hash_table __read_mostly;
251 static unsigned rt_hash_mask __read_mostly;
252 static unsigned int rt_hash_log __read_mostly;
253
254 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
255 #define RT_CACHE_STAT_INC(field) \
256 (__raw_get_cpu_var(rt_cache_stat).field++)
257
258 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
259 int genid)
260 {
261 return jhash_3words((__force u32)(__be32)(daddr),
262 (__force u32)(__be32)(saddr),
263 idx, genid)
264 & rt_hash_mask;
265 }
266
267 static inline int rt_genid(struct net *net)
268 {
269 return atomic_read(&net->ipv4.rt_genid);
270 }
271
272 #ifdef CONFIG_PROC_FS
273 struct rt_cache_iter_state {
274 struct seq_net_private p;
275 int bucket;
276 int genid;
277 };
278
279 static struct rtable *rt_cache_get_first(struct seq_file *seq)
280 {
281 struct rt_cache_iter_state *st = seq->private;
282 struct rtable *r = NULL;
283
284 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
285 if (!rt_hash_table[st->bucket].chain)
286 continue;
287 rcu_read_lock_bh();
288 r = rcu_dereference(rt_hash_table[st->bucket].chain);
289 while (r) {
290 if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
291 r->rt_genid == st->genid)
292 return r;
293 r = rcu_dereference(r->u.dst.rt_next);
294 }
295 rcu_read_unlock_bh();
296 }
297 return r;
298 }
299
300 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
301 struct rtable *r)
302 {
303 struct rt_cache_iter_state *st = seq->private;
304
305 r = r->u.dst.rt_next;
306 while (!r) {
307 rcu_read_unlock_bh();
308 do {
309 if (--st->bucket < 0)
310 return NULL;
311 } while (!rt_hash_table[st->bucket].chain);
312 rcu_read_lock_bh();
313 r = rt_hash_table[st->bucket].chain;
314 }
315 return rcu_dereference(r);
316 }
317
318 static struct rtable *rt_cache_get_next(struct seq_file *seq,
319 struct rtable *r)
320 {
321 struct rt_cache_iter_state *st = seq->private;
322 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
323 if (dev_net(r->u.dst.dev) != seq_file_net(seq))
324 continue;
325 if (r->rt_genid == st->genid)
326 break;
327 }
328 return r;
329 }
330
331 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
332 {
333 struct rtable *r = rt_cache_get_first(seq);
334
335 if (r)
336 while (pos && (r = rt_cache_get_next(seq, r)))
337 --pos;
338 return pos ? NULL : r;
339 }
340
341 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
342 {
343 struct rt_cache_iter_state *st = seq->private;
344 if (*pos)
345 return rt_cache_get_idx(seq, *pos - 1);
346 st->genid = rt_genid(seq_file_net(seq));
347 return SEQ_START_TOKEN;
348 }
349
350 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
351 {
352 struct rtable *r;
353
354 if (v == SEQ_START_TOKEN)
355 r = rt_cache_get_first(seq);
356 else
357 r = rt_cache_get_next(seq, v);
358 ++*pos;
359 return r;
360 }
361
362 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
363 {
364 if (v && v != SEQ_START_TOKEN)
365 rcu_read_unlock_bh();
366 }
367
368 static int rt_cache_seq_show(struct seq_file *seq, void *v)
369 {
370 if (v == SEQ_START_TOKEN)
371 seq_printf(seq, "%-127s\n",
372 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
373 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
374 "HHUptod\tSpecDst");
375 else {
376 struct rtable *r = v;
377 int len;
378
379 seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
380 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
381 r->u.dst.dev ? r->u.dst.dev->name : "*",
382 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
383 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
384 r->u.dst.__use, 0, (unsigned long)r->rt_src,
385 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
386 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
387 dst_metric(&r->u.dst, RTAX_WINDOW),
388 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
389 dst_metric(&r->u.dst, RTAX_RTTVAR)),
390 r->fl.fl4_tos,
391 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
392 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
393 dev_queue_xmit) : 0,
394 r->rt_spec_dst, &len);
395
396 seq_printf(seq, "%*s\n", 127 - len, "");
397 }
398 return 0;
399 }
400
401 static const struct seq_operations rt_cache_seq_ops = {
402 .start = rt_cache_seq_start,
403 .next = rt_cache_seq_next,
404 .stop = rt_cache_seq_stop,
405 .show = rt_cache_seq_show,
406 };
407
408 static int rt_cache_seq_open(struct inode *inode, struct file *file)
409 {
410 return seq_open_net(inode, file, &rt_cache_seq_ops,
411 sizeof(struct rt_cache_iter_state));
412 }
413
414 static const struct file_operations rt_cache_seq_fops = {
415 .owner = THIS_MODULE,
416 .open = rt_cache_seq_open,
417 .read = seq_read,
418 .llseek = seq_lseek,
419 .release = seq_release_net,
420 };
421
422
423 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
424 {
425 int cpu;
426
427 if (*pos == 0)
428 return SEQ_START_TOKEN;
429
430 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
431 if (!cpu_possible(cpu))
432 continue;
433 *pos = cpu+1;
434 return &per_cpu(rt_cache_stat, cpu);
435 }
436 return NULL;
437 }
438
439 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
440 {
441 int cpu;
442
443 for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
444 if (!cpu_possible(cpu))
445 continue;
446 *pos = cpu+1;
447 return &per_cpu(rt_cache_stat, cpu);
448 }
449 return NULL;
450
451 }
452
453 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
454 {
455
456 }
457
458 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
459 {
460 struct rt_cache_stat *st = v;
461
462 if (v == SEQ_START_TOKEN) {
463 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");
464 return 0;
465 }
466
467 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
468 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
469 atomic_read(&ipv4_dst_ops.entries),
470 st->in_hit,
471 st->in_slow_tot,
472 st->in_slow_mc,
473 st->in_no_route,
474 st->in_brd,
475 st->in_martian_dst,
476 st->in_martian_src,
477
478 st->out_hit,
479 st->out_slow_tot,
480 st->out_slow_mc,
481
482 st->gc_total,
483 st->gc_ignored,
484 st->gc_goal_miss,
485 st->gc_dst_overflow,
486 st->in_hlist_search,
487 st->out_hlist_search
488 );
489 return 0;
490 }
491
492 static const struct seq_operations rt_cpu_seq_ops = {
493 .start = rt_cpu_seq_start,
494 .next = rt_cpu_seq_next,
495 .stop = rt_cpu_seq_stop,
496 .show = rt_cpu_seq_show,
497 };
498
499
500 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
501 {
502 return seq_open(file, &rt_cpu_seq_ops);
503 }
504
505 static const struct file_operations rt_cpu_seq_fops = {
506 .owner = THIS_MODULE,
507 .open = rt_cpu_seq_open,
508 .read = seq_read,
509 .llseek = seq_lseek,
510 .release = seq_release,
511 };
512
513 #ifdef CONFIG_NET_CLS_ROUTE
514 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
515 int length, int *eof, void *data)
516 {
517 unsigned int i;
518
519 if ((offset & 3) || (length & 3))
520 return -EIO;
521
522 if (offset >= sizeof(struct ip_rt_acct) * 256) {
523 *eof = 1;
524 return 0;
525 }
526
527 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
528 length = sizeof(struct ip_rt_acct) * 256 - offset;
529 *eof = 1;
530 }
531
532 offset /= sizeof(u32);
533
534 if (length > 0) {
535 u32 *dst = (u32 *) buffer;
536
537 *start = buffer;
538 memset(dst, 0, length);
539
540 for_each_possible_cpu(i) {
541 unsigned int j;
542 u32 *src;
543
544 src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
545 for (j = 0; j < length/4; j++)
546 dst[j] += src[j];
547 }
548 }
549 return length;
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 = create_proc_read_entry("rt_acct", 0, net->proc_net,
569 ip_rt_acct_read, NULL);
570 if (!pde)
571 goto err3;
572 #endif
573 return 0;
574
575 #ifdef CONFIG_NET_CLS_ROUTE
576 err3:
577 remove_proc_entry("rt_cache", net->proc_net_stat);
578 #endif
579 err2:
580 remove_proc_entry("rt_cache", net->proc_net);
581 err1:
582 return -ENOMEM;
583 }
584
585 static void __net_exit ip_rt_do_proc_exit(struct net *net)
586 {
587 remove_proc_entry("rt_cache", net->proc_net_stat);
588 remove_proc_entry("rt_cache", net->proc_net);
589 remove_proc_entry("rt_acct", net->proc_net);
590 }
591
592 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
593 .init = ip_rt_do_proc_init,
594 .exit = ip_rt_do_proc_exit,
595 };
596
597 static int __init ip_rt_proc_init(void)
598 {
599 return register_pernet_subsys(&ip_rt_proc_ops);
600 }
601
602 #else
603 static inline int ip_rt_proc_init(void)
604 {
605 return 0;
606 }
607 #endif /* CONFIG_PROC_FS */
608
609 static inline void rt_free(struct rtable *rt)
610 {
611 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
612 }
613
614 static inline void rt_drop(struct rtable *rt)
615 {
616 ip_rt_put(rt);
617 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
618 }
619
620 static inline int rt_fast_clean(struct rtable *rth)
621 {
622 /* Kill broadcast/multicast entries very aggresively, if they
623 collide in hash table with more useful entries */
624 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
625 rth->fl.iif && rth->u.dst.rt_next;
626 }
627
628 static inline int rt_valuable(struct rtable *rth)
629 {
630 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
631 rth->u.dst.expires;
632 }
633
634 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
635 {
636 unsigned long age;
637 int ret = 0;
638
639 if (atomic_read(&rth->u.dst.__refcnt))
640 goto out;
641
642 ret = 1;
643 if (rth->u.dst.expires &&
644 time_after_eq(jiffies, rth->u.dst.expires))
645 goto out;
646
647 age = jiffies - rth->u.dst.lastuse;
648 ret = 0;
649 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
650 (age <= tmo2 && rt_valuable(rth)))
651 goto out;
652 ret = 1;
653 out: return ret;
654 }
655
656 /* Bits of score are:
657 * 31: very valuable
658 * 30: not quite useless
659 * 29..0: usage counter
660 */
661 static inline u32 rt_score(struct rtable *rt)
662 {
663 u32 score = jiffies - rt->u.dst.lastuse;
664
665 score = ~score & ~(3<<30);
666
667 if (rt_valuable(rt))
668 score |= (1<<31);
669
670 if (!rt->fl.iif ||
671 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
672 score |= (1<<30);
673
674 return score;
675 }
676
677 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
678 {
679 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
680 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
681 (fl1->mark ^ fl2->mark) |
682 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
683 *(u16 *)&fl2->nl_u.ip4_u.tos) |
684 (fl1->oif ^ fl2->oif) |
685 (fl1->iif ^ fl2->iif)) == 0;
686 }
687
688 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
689 {
690 return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.dst.dev);
691 }
692
693 static inline int rt_is_expired(struct rtable *rth)
694 {
695 return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev));
696 }
697
698 /*
699 * Perform a full scan of hash table and free all entries.
700 * Can be called by a softirq or a process.
701 * In the later case, we want to be reschedule if necessary
702 */
703 static void rt_do_flush(int process_context)
704 {
705 unsigned int i;
706 struct rtable *rth, *next;
707 struct rtable * tail;
708
709 for (i = 0; i <= rt_hash_mask; i++) {
710 if (process_context && need_resched())
711 cond_resched();
712 rth = rt_hash_table[i].chain;
713 if (!rth)
714 continue;
715
716 spin_lock_bh(rt_hash_lock_addr(i));
717 #ifdef CONFIG_NET_NS
718 {
719 struct rtable ** prev, * p;
720
721 rth = rt_hash_table[i].chain;
722
723 /* defer releasing the head of the list after spin_unlock */
724 for (tail = rth; tail; tail = tail->u.dst.rt_next)
725 if (!rt_is_expired(tail))
726 break;
727 if (rth != tail)
728 rt_hash_table[i].chain = tail;
729
730 /* call rt_free on entries after the tail requiring flush */
731 prev = &rt_hash_table[i].chain;
732 for (p = *prev; p; p = next) {
733 next = p->u.dst.rt_next;
734 if (!rt_is_expired(p)) {
735 prev = &p->u.dst.rt_next;
736 } else {
737 *prev = next;
738 rt_free(p);
739 }
740 }
741 }
742 #else
743 rth = rt_hash_table[i].chain;
744 rt_hash_table[i].chain = NULL;
745 tail = NULL;
746 #endif
747 spin_unlock_bh(rt_hash_lock_addr(i));
748
749 for (; rth != tail; rth = next) {
750 next = rth->u.dst.rt_next;
751 rt_free(rth);
752 }
753 }
754 }
755
756 static void rt_check_expire(void)
757 {
758 static unsigned int rover;
759 unsigned int i = rover, goal;
760 struct rtable *rth, **rthp;
761 u64 mult;
762
763 mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
764 if (ip_rt_gc_timeout > 1)
765 do_div(mult, ip_rt_gc_timeout);
766 goal = (unsigned int)mult;
767 if (goal > rt_hash_mask)
768 goal = rt_hash_mask + 1;
769 for (; goal > 0; goal--) {
770 unsigned long tmo = ip_rt_gc_timeout;
771
772 i = (i + 1) & rt_hash_mask;
773 rthp = &rt_hash_table[i].chain;
774
775 if (need_resched())
776 cond_resched();
777
778 if (*rthp == NULL)
779 continue;
780 spin_lock_bh(rt_hash_lock_addr(i));
781 while ((rth = *rthp) != NULL) {
782 if (rt_is_expired(rth)) {
783 *rthp = rth->u.dst.rt_next;
784 rt_free(rth);
785 continue;
786 }
787 if (rth->u.dst.expires) {
788 /* Entry is expired even if it is in use */
789 if (time_before_eq(jiffies, rth->u.dst.expires)) {
790 tmo >>= 1;
791 rthp = &rth->u.dst.rt_next;
792 continue;
793 }
794 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
795 tmo >>= 1;
796 rthp = &rth->u.dst.rt_next;
797 continue;
798 }
799
800 /* Cleanup aged off entries. */
801 *rthp = rth->u.dst.rt_next;
802 rt_free(rth);
803 }
804 spin_unlock_bh(rt_hash_lock_addr(i));
805 }
806 rover = i;
807 }
808
809 /*
810 * rt_worker_func() is run in process context.
811 * we call rt_check_expire() to scan part of the hash table
812 */
813 static void rt_worker_func(struct work_struct *work)
814 {
815 rt_check_expire();
816 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
817 }
818
819 /*
820 * Pertubation of rt_genid by a small quantity [1..256]
821 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
822 * many times (2^24) without giving recent rt_genid.
823 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
824 */
825 static void rt_cache_invalidate(struct net *net)
826 {
827 unsigned char shuffle;
828
829 get_random_bytes(&shuffle, sizeof(shuffle));
830 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
831 }
832
833 /*
834 * delay < 0 : invalidate cache (fast : entries will be deleted later)
835 * delay >= 0 : invalidate & flush cache (can be long)
836 */
837 void rt_cache_flush(struct net *net, int delay)
838 {
839 rt_cache_invalidate(net);
840 if (delay >= 0)
841 rt_do_flush(!in_softirq());
842 }
843
844 /*
845 * We change rt_genid and let gc do the cleanup
846 */
847 static void rt_secret_rebuild(unsigned long __net)
848 {
849 struct net *net = (struct net *)__net;
850 rt_cache_invalidate(net);
851 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
852 }
853
854 /*
855 Short description of GC goals.
856
857 We want to build algorithm, which will keep routing cache
858 at some equilibrium point, when number of aged off entries
859 is kept approximately equal to newly generated ones.
860
861 Current expiration strength is variable "expire".
862 We try to adjust it dynamically, so that if networking
863 is idle expires is large enough to keep enough of warm entries,
864 and when load increases it reduces to limit cache size.
865 */
866
867 static int rt_garbage_collect(struct dst_ops *ops)
868 {
869 static unsigned long expire = RT_GC_TIMEOUT;
870 static unsigned long last_gc;
871 static int rover;
872 static int equilibrium;
873 struct rtable *rth, **rthp;
874 unsigned long now = jiffies;
875 int goal;
876
877 /*
878 * Garbage collection is pretty expensive,
879 * do not make it too frequently.
880 */
881
882 RT_CACHE_STAT_INC(gc_total);
883
884 if (now - last_gc < ip_rt_gc_min_interval &&
885 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
886 RT_CACHE_STAT_INC(gc_ignored);
887 goto out;
888 }
889
890 /* Calculate number of entries, which we want to expire now. */
891 goal = atomic_read(&ipv4_dst_ops.entries) -
892 (ip_rt_gc_elasticity << rt_hash_log);
893 if (goal <= 0) {
894 if (equilibrium < ipv4_dst_ops.gc_thresh)
895 equilibrium = ipv4_dst_ops.gc_thresh;
896 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
897 if (goal > 0) {
898 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
899 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
900 }
901 } else {
902 /* We are in dangerous area. Try to reduce cache really
903 * aggressively.
904 */
905 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
906 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
907 }
908
909 if (now - last_gc >= ip_rt_gc_min_interval)
910 last_gc = now;
911
912 if (goal <= 0) {
913 equilibrium += goal;
914 goto work_done;
915 }
916
917 do {
918 int i, k;
919
920 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
921 unsigned long tmo = expire;
922
923 k = (k + 1) & rt_hash_mask;
924 rthp = &rt_hash_table[k].chain;
925 spin_lock_bh(rt_hash_lock_addr(k));
926 while ((rth = *rthp) != NULL) {
927 if (!rt_is_expired(rth) &&
928 !rt_may_expire(rth, tmo, expire)) {
929 tmo >>= 1;
930 rthp = &rth->u.dst.rt_next;
931 continue;
932 }
933 *rthp = rth->u.dst.rt_next;
934 rt_free(rth);
935 goal--;
936 }
937 spin_unlock_bh(rt_hash_lock_addr(k));
938 if (goal <= 0)
939 break;
940 }
941 rover = k;
942
943 if (goal <= 0)
944 goto work_done;
945
946 /* Goal is not achieved. We stop process if:
947
948 - if expire reduced to zero. Otherwise, expire is halfed.
949 - if table is not full.
950 - if we are called from interrupt.
951 - jiffies check is just fallback/debug loop breaker.
952 We will not spin here for long time in any case.
953 */
954
955 RT_CACHE_STAT_INC(gc_goal_miss);
956
957 if (expire == 0)
958 break;
959
960 expire >>= 1;
961 #if RT_CACHE_DEBUG >= 2
962 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
963 atomic_read(&ipv4_dst_ops.entries), goal, i);
964 #endif
965
966 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
967 goto out;
968 } while (!in_softirq() && time_before_eq(jiffies, now));
969
970 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
971 goto out;
972 if (net_ratelimit())
973 printk(KERN_WARNING "dst cache overflow\n");
974 RT_CACHE_STAT_INC(gc_dst_overflow);
975 return 1;
976
977 work_done:
978 expire += ip_rt_gc_min_interval;
979 if (expire > ip_rt_gc_timeout ||
980 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
981 expire = ip_rt_gc_timeout;
982 #if RT_CACHE_DEBUG >= 2
983 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
984 atomic_read(&ipv4_dst_ops.entries), goal, rover);
985 #endif
986 out: return 0;
987 }
988
989 static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
990 {
991 struct rtable *rth, **rthp;
992 unsigned long now;
993 struct rtable *cand, **candp;
994 u32 min_score;
995 int chain_length;
996 int attempts = !in_softirq();
997
998 restart:
999 chain_length = 0;
1000 min_score = ~(u32)0;
1001 cand = NULL;
1002 candp = NULL;
1003 now = jiffies;
1004
1005 rthp = &rt_hash_table[hash].chain;
1006
1007 spin_lock_bh(rt_hash_lock_addr(hash));
1008 while ((rth = *rthp) != NULL) {
1009 if (rt_is_expired(rth)) {
1010 *rthp = rth->u.dst.rt_next;
1011 rt_free(rth);
1012 continue;
1013 }
1014 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1015 /* Put it first */
1016 *rthp = rth->u.dst.rt_next;
1017 /*
1018 * Since lookup is lockfree, the deletion
1019 * must be visible to another weakly ordered CPU before
1020 * the insertion at the start of the hash chain.
1021 */
1022 rcu_assign_pointer(rth->u.dst.rt_next,
1023 rt_hash_table[hash].chain);
1024 /*
1025 * Since lookup is lockfree, the update writes
1026 * must be ordered for consistency on SMP.
1027 */
1028 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1029
1030 dst_use(&rth->u.dst, now);
1031 spin_unlock_bh(rt_hash_lock_addr(hash));
1032
1033 rt_drop(rt);
1034 *rp = rth;
1035 return 0;
1036 }
1037
1038 if (!atomic_read(&rth->u.dst.__refcnt)) {
1039 u32 score = rt_score(rth);
1040
1041 if (score <= min_score) {
1042 cand = rth;
1043 candp = rthp;
1044 min_score = score;
1045 }
1046 }
1047
1048 chain_length++;
1049
1050 rthp = &rth->u.dst.rt_next;
1051 }
1052
1053 if (cand) {
1054 /* ip_rt_gc_elasticity used to be average length of chain
1055 * length, when exceeded gc becomes really aggressive.
1056 *
1057 * The second limit is less certain. At the moment it allows
1058 * only 2 entries per bucket. We will see.
1059 */
1060 if (chain_length > ip_rt_gc_elasticity) {
1061 *candp = cand->u.dst.rt_next;
1062 rt_free(cand);
1063 }
1064 }
1065
1066 /* Try to bind route to arp only if it is output
1067 route or unicast forwarding path.
1068 */
1069 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1070 int err = arp_bind_neighbour(&rt->u.dst);
1071 if (err) {
1072 spin_unlock_bh(rt_hash_lock_addr(hash));
1073
1074 if (err != -ENOBUFS) {
1075 rt_drop(rt);
1076 return err;
1077 }
1078
1079 /* Neighbour tables are full and nothing
1080 can be released. Try to shrink route cache,
1081 it is most likely it holds some neighbour records.
1082 */
1083 if (attempts-- > 0) {
1084 int saved_elasticity = ip_rt_gc_elasticity;
1085 int saved_int = ip_rt_gc_min_interval;
1086 ip_rt_gc_elasticity = 1;
1087 ip_rt_gc_min_interval = 0;
1088 rt_garbage_collect(&ipv4_dst_ops);
1089 ip_rt_gc_min_interval = saved_int;
1090 ip_rt_gc_elasticity = saved_elasticity;
1091 goto restart;
1092 }
1093
1094 if (net_ratelimit())
1095 printk(KERN_WARNING "Neighbour table overflow.\n");
1096 rt_drop(rt);
1097 return -ENOBUFS;
1098 }
1099 }
1100
1101 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1102 #if RT_CACHE_DEBUG >= 2
1103 if (rt->u.dst.rt_next) {
1104 struct rtable *trt;
1105 printk(KERN_DEBUG "rt_cache @%02x: " NIPQUAD_FMT, hash,
1106 NIPQUAD(rt->rt_dst));
1107 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1108 printk(" . " NIPQUAD_FMT, NIPQUAD(trt->rt_dst));
1109 printk("\n");
1110 }
1111 #endif
1112 /*
1113 * Since lookup is lockfree, we must make sure
1114 * previous writes to rt are comitted to memory
1115 * before making rt visible to other CPUS.
1116 */
1117 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1118 spin_unlock_bh(rt_hash_lock_addr(hash));
1119 *rp = rt;
1120 return 0;
1121 }
1122
1123 void rt_bind_peer(struct rtable *rt, int create)
1124 {
1125 static DEFINE_SPINLOCK(rt_peer_lock);
1126 struct inet_peer *peer;
1127
1128 peer = inet_getpeer(rt->rt_dst, create);
1129
1130 spin_lock_bh(&rt_peer_lock);
1131 if (rt->peer == NULL) {
1132 rt->peer = peer;
1133 peer = NULL;
1134 }
1135 spin_unlock_bh(&rt_peer_lock);
1136 if (peer)
1137 inet_putpeer(peer);
1138 }
1139
1140 /*
1141 * Peer allocation may fail only in serious out-of-memory conditions. However
1142 * we still can generate some output.
1143 * Random ID selection looks a bit dangerous because we have no chances to
1144 * select ID being unique in a reasonable period of time.
1145 * But broken packet identifier may be better than no packet at all.
1146 */
1147 static void ip_select_fb_ident(struct iphdr *iph)
1148 {
1149 static DEFINE_SPINLOCK(ip_fb_id_lock);
1150 static u32 ip_fallback_id;
1151 u32 salt;
1152
1153 spin_lock_bh(&ip_fb_id_lock);
1154 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1155 iph->id = htons(salt & 0xFFFF);
1156 ip_fallback_id = salt;
1157 spin_unlock_bh(&ip_fb_id_lock);
1158 }
1159
1160 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1161 {
1162 struct rtable *rt = (struct rtable *) dst;
1163
1164 if (rt) {
1165 if (rt->peer == NULL)
1166 rt_bind_peer(rt, 1);
1167
1168 /* If peer is attached to destination, it is never detached,
1169 so that we need not to grab a lock to dereference it.
1170 */
1171 if (rt->peer) {
1172 iph->id = htons(inet_getid(rt->peer, more));
1173 return;
1174 }
1175 } else
1176 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1177 __builtin_return_address(0));
1178
1179 ip_select_fb_ident(iph);
1180 }
1181
1182 static void rt_del(unsigned hash, struct rtable *rt)
1183 {
1184 struct rtable **rthp, *aux;
1185
1186 rthp = &rt_hash_table[hash].chain;
1187 spin_lock_bh(rt_hash_lock_addr(hash));
1188 ip_rt_put(rt);
1189 while ((aux = *rthp) != NULL) {
1190 if (aux == rt || rt_is_expired(aux)) {
1191 *rthp = aux->u.dst.rt_next;
1192 rt_free(aux);
1193 continue;
1194 }
1195 rthp = &aux->u.dst.rt_next;
1196 }
1197 spin_unlock_bh(rt_hash_lock_addr(hash));
1198 }
1199
1200 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1201 __be32 saddr, struct net_device *dev)
1202 {
1203 int i, k;
1204 struct in_device *in_dev = in_dev_get(dev);
1205 struct rtable *rth, **rthp;
1206 __be32 skeys[2] = { saddr, 0 };
1207 int ikeys[2] = { dev->ifindex, 0 };
1208 struct netevent_redirect netevent;
1209 struct net *net;
1210
1211 if (!in_dev)
1212 return;
1213
1214 net = dev_net(dev);
1215 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1216 || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
1217 || ipv4_is_zeronet(new_gw))
1218 goto reject_redirect;
1219
1220 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1221 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1222 goto reject_redirect;
1223 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1224 goto reject_redirect;
1225 } else {
1226 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1227 goto reject_redirect;
1228 }
1229
1230 for (i = 0; i < 2; i++) {
1231 for (k = 0; k < 2; k++) {
1232 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1233 rt_genid(net));
1234
1235 rthp=&rt_hash_table[hash].chain;
1236
1237 rcu_read_lock();
1238 while ((rth = rcu_dereference(*rthp)) != NULL) {
1239 struct rtable *rt;
1240
1241 if (rth->fl.fl4_dst != daddr ||
1242 rth->fl.fl4_src != skeys[i] ||
1243 rth->fl.oif != ikeys[k] ||
1244 rth->fl.iif != 0 ||
1245 rt_is_expired(rth) ||
1246 !net_eq(dev_net(rth->u.dst.dev), net)) {
1247 rthp = &rth->u.dst.rt_next;
1248 continue;
1249 }
1250
1251 if (rth->rt_dst != daddr ||
1252 rth->rt_src != saddr ||
1253 rth->u.dst.error ||
1254 rth->rt_gateway != old_gw ||
1255 rth->u.dst.dev != dev)
1256 break;
1257
1258 dst_hold(&rth->u.dst);
1259 rcu_read_unlock();
1260
1261 rt = dst_alloc(&ipv4_dst_ops);
1262 if (rt == NULL) {
1263 ip_rt_put(rth);
1264 in_dev_put(in_dev);
1265 return;
1266 }
1267
1268 /* Copy all the information. */
1269 *rt = *rth;
1270 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1271 rt->u.dst.__use = 1;
1272 atomic_set(&rt->u.dst.__refcnt, 1);
1273 rt->u.dst.child = NULL;
1274 if (rt->u.dst.dev)
1275 dev_hold(rt->u.dst.dev);
1276 if (rt->idev)
1277 in_dev_hold(rt->idev);
1278 rt->u.dst.obsolete = 0;
1279 rt->u.dst.lastuse = jiffies;
1280 rt->u.dst.path = &rt->u.dst;
1281 rt->u.dst.neighbour = NULL;
1282 rt->u.dst.hh = NULL;
1283 rt->u.dst.xfrm = NULL;
1284 rt->rt_genid = rt_genid(net);
1285 rt->rt_flags |= RTCF_REDIRECTED;
1286
1287 /* Gateway is different ... */
1288 rt->rt_gateway = new_gw;
1289
1290 /* Redirect received -> path was valid */
1291 dst_confirm(&rth->u.dst);
1292
1293 if (rt->peer)
1294 atomic_inc(&rt->peer->refcnt);
1295
1296 if (arp_bind_neighbour(&rt->u.dst) ||
1297 !(rt->u.dst.neighbour->nud_state &
1298 NUD_VALID)) {
1299 if (rt->u.dst.neighbour)
1300 neigh_event_send(rt->u.dst.neighbour, NULL);
1301 ip_rt_put(rth);
1302 rt_drop(rt);
1303 goto do_next;
1304 }
1305
1306 netevent.old = &rth->u.dst;
1307 netevent.new = &rt->u.dst;
1308 call_netevent_notifiers(NETEVENT_REDIRECT,
1309 &netevent);
1310
1311 rt_del(hash, rth);
1312 if (!rt_intern_hash(hash, rt, &rt))
1313 ip_rt_put(rt);
1314 goto do_next;
1315 }
1316 rcu_read_unlock();
1317 do_next:
1318 ;
1319 }
1320 }
1321 in_dev_put(in_dev);
1322 return;
1323
1324 reject_redirect:
1325 #ifdef CONFIG_IP_ROUTE_VERBOSE
1326 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1327 printk(KERN_INFO "Redirect from " NIPQUAD_FMT " on %s about "
1328 NIPQUAD_FMT " ignored.\n"
1329 " Advised path = " NIPQUAD_FMT " -> " NIPQUAD_FMT "\n",
1330 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1331 NIPQUAD(saddr), NIPQUAD(daddr));
1332 #endif
1333 in_dev_put(in_dev);
1334 }
1335
1336 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1337 {
1338 struct rtable *rt = (struct rtable *)dst;
1339 struct dst_entry *ret = dst;
1340
1341 if (rt) {
1342 if (dst->obsolete) {
1343 ip_rt_put(rt);
1344 ret = NULL;
1345 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1346 rt->u.dst.expires) {
1347 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1348 rt->fl.oif,
1349 rt_genid(dev_net(dst->dev)));
1350 #if RT_CACHE_DEBUG >= 1
1351 printk(KERN_DEBUG "ipv4_negative_advice: redirect to "
1352 NIPQUAD_FMT "/%02x dropped\n",
1353 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1354 #endif
1355 rt_del(hash, rt);
1356 ret = NULL;
1357 }
1358 }
1359 return ret;
1360 }
1361
1362 /*
1363 * Algorithm:
1364 * 1. The first ip_rt_redirect_number redirects are sent
1365 * with exponential backoff, then we stop sending them at all,
1366 * assuming that the host ignores our redirects.
1367 * 2. If we did not see packets requiring redirects
1368 * during ip_rt_redirect_silence, we assume that the host
1369 * forgot redirected route and start to send redirects again.
1370 *
1371 * This algorithm is much cheaper and more intelligent than dumb load limiting
1372 * in icmp.c.
1373 *
1374 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1375 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1376 */
1377
1378 void ip_rt_send_redirect(struct sk_buff *skb)
1379 {
1380 struct rtable *rt = skb->rtable;
1381 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1382
1383 if (!in_dev)
1384 return;
1385
1386 if (!IN_DEV_TX_REDIRECTS(in_dev))
1387 goto out;
1388
1389 /* No redirected packets during ip_rt_redirect_silence;
1390 * reset the algorithm.
1391 */
1392 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1393 rt->u.dst.rate_tokens = 0;
1394
1395 /* Too many ignored redirects; do not send anything
1396 * set u.dst.rate_last to the last seen redirected packet.
1397 */
1398 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1399 rt->u.dst.rate_last = jiffies;
1400 goto out;
1401 }
1402
1403 /* Check for load limit; set rate_last to the latest sent
1404 * redirect.
1405 */
1406 if (rt->u.dst.rate_tokens == 0 ||
1407 time_after(jiffies,
1408 (rt->u.dst.rate_last +
1409 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1410 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1411 rt->u.dst.rate_last = jiffies;
1412 ++rt->u.dst.rate_tokens;
1413 #ifdef CONFIG_IP_ROUTE_VERBOSE
1414 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1415 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1416 net_ratelimit())
1417 printk(KERN_WARNING "host " NIPQUAD_FMT "/if%d ignores "
1418 "redirects for " NIPQUAD_FMT " to " NIPQUAD_FMT ".\n",
1419 NIPQUAD(rt->rt_src), rt->rt_iif,
1420 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1421 #endif
1422 }
1423 out:
1424 in_dev_put(in_dev);
1425 }
1426
1427 static int ip_error(struct sk_buff *skb)
1428 {
1429 struct rtable *rt = skb->rtable;
1430 unsigned long now;
1431 int code;
1432
1433 switch (rt->u.dst.error) {
1434 case EINVAL:
1435 default:
1436 goto out;
1437 case EHOSTUNREACH:
1438 code = ICMP_HOST_UNREACH;
1439 break;
1440 case ENETUNREACH:
1441 code = ICMP_NET_UNREACH;
1442 IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
1443 IPSTATS_MIB_INNOROUTES);
1444 break;
1445 case EACCES:
1446 code = ICMP_PKT_FILTERED;
1447 break;
1448 }
1449
1450 now = jiffies;
1451 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1452 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1453 rt->u.dst.rate_tokens = ip_rt_error_burst;
1454 rt->u.dst.rate_last = now;
1455 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1456 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1457 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1458 }
1459
1460 out: kfree_skb(skb);
1461 return 0;
1462 }
1463
1464 /*
1465 * The last two values are not from the RFC but
1466 * are needed for AMPRnet AX.25 paths.
1467 */
1468
1469 static const unsigned short mtu_plateau[] =
1470 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1471
1472 static inline unsigned short guess_mtu(unsigned short old_mtu)
1473 {
1474 int i;
1475
1476 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1477 if (old_mtu > mtu_plateau[i])
1478 return mtu_plateau[i];
1479 return 68;
1480 }
1481
1482 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1483 unsigned short new_mtu,
1484 struct net_device *dev)
1485 {
1486 int i, k;
1487 unsigned short old_mtu = ntohs(iph->tot_len);
1488 struct rtable *rth;
1489 int ikeys[2] = { dev->ifindex, 0 };
1490 __be32 skeys[2] = { iph->saddr, 0, };
1491 __be32 daddr = iph->daddr;
1492 unsigned short est_mtu = 0;
1493
1494 if (ipv4_config.no_pmtu_disc)
1495 return 0;
1496
1497 for (k = 0; k < 2; k++) {
1498 for (i = 0; i < 2; i++) {
1499 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1500 rt_genid(net));
1501
1502 rcu_read_lock();
1503 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1504 rth = rcu_dereference(rth->u.dst.rt_next)) {
1505 unsigned short mtu = new_mtu;
1506
1507 if (rth->fl.fl4_dst != daddr ||
1508 rth->fl.fl4_src != skeys[i] ||
1509 rth->rt_dst != daddr ||
1510 rth->rt_src != iph->saddr ||
1511 rth->fl.oif != ikeys[k] ||
1512 rth->fl.iif != 0 ||
1513 dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
1514 !net_eq(dev_net(rth->u.dst.dev), net) ||
1515 rt_is_expired(rth))
1516 continue;
1517
1518 if (new_mtu < 68 || new_mtu >= old_mtu) {
1519
1520 /* BSD 4.2 compatibility hack :-( */
1521 if (mtu == 0 &&
1522 old_mtu >= dst_mtu(&rth->u.dst) &&
1523 old_mtu >= 68 + (iph->ihl << 2))
1524 old_mtu -= iph->ihl << 2;
1525
1526 mtu = guess_mtu(old_mtu);
1527 }
1528 if (mtu <= dst_mtu(&rth->u.dst)) {
1529 if (mtu < dst_mtu(&rth->u.dst)) {
1530 dst_confirm(&rth->u.dst);
1531 if (mtu < ip_rt_min_pmtu) {
1532 mtu = ip_rt_min_pmtu;
1533 rth->u.dst.metrics[RTAX_LOCK-1] |=
1534 (1 << RTAX_MTU);
1535 }
1536 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1537 dst_set_expires(&rth->u.dst,
1538 ip_rt_mtu_expires);
1539 }
1540 est_mtu = mtu;
1541 }
1542 }
1543 rcu_read_unlock();
1544 }
1545 }
1546 return est_mtu ? : new_mtu;
1547 }
1548
1549 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1550 {
1551 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1552 !(dst_metric_locked(dst, RTAX_MTU))) {
1553 if (mtu < ip_rt_min_pmtu) {
1554 mtu = ip_rt_min_pmtu;
1555 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1556 }
1557 dst->metrics[RTAX_MTU-1] = mtu;
1558 dst_set_expires(dst, ip_rt_mtu_expires);
1559 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1560 }
1561 }
1562
1563 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1564 {
1565 return NULL;
1566 }
1567
1568 static void ipv4_dst_destroy(struct dst_entry *dst)
1569 {
1570 struct rtable *rt = (struct rtable *) dst;
1571 struct inet_peer *peer = rt->peer;
1572 struct in_device *idev = rt->idev;
1573
1574 if (peer) {
1575 rt->peer = NULL;
1576 inet_putpeer(peer);
1577 }
1578
1579 if (idev) {
1580 rt->idev = NULL;
1581 in_dev_put(idev);
1582 }
1583 }
1584
1585 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1586 int how)
1587 {
1588 struct rtable *rt = (struct rtable *) dst;
1589 struct in_device *idev = rt->idev;
1590 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1591 struct in_device *loopback_idev =
1592 in_dev_get(dev_net(dev)->loopback_dev);
1593 if (loopback_idev) {
1594 rt->idev = loopback_idev;
1595 in_dev_put(idev);
1596 }
1597 }
1598 }
1599
1600 static void ipv4_link_failure(struct sk_buff *skb)
1601 {
1602 struct rtable *rt;
1603
1604 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1605
1606 rt = skb->rtable;
1607 if (rt)
1608 dst_set_expires(&rt->u.dst, 0);
1609 }
1610
1611 static int ip_rt_bug(struct sk_buff *skb)
1612 {
1613 printk(KERN_DEBUG "ip_rt_bug: " NIPQUAD_FMT " -> " NIPQUAD_FMT ", %s\n",
1614 NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(ip_hdr(skb)->daddr),
1615 skb->dev ? skb->dev->name : "?");
1616 kfree_skb(skb);
1617 return 0;
1618 }
1619
1620 /*
1621 We do not cache source address of outgoing interface,
1622 because it is used only by IP RR, TS and SRR options,
1623 so that it out of fast path.
1624
1625 BTW remember: "addr" is allowed to be not aligned
1626 in IP options!
1627 */
1628
1629 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1630 {
1631 __be32 src;
1632 struct fib_result res;
1633
1634 if (rt->fl.iif == 0)
1635 src = rt->rt_src;
1636 else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
1637 src = FIB_RES_PREFSRC(res);
1638 fib_res_put(&res);
1639 } else
1640 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1641 RT_SCOPE_UNIVERSE);
1642 memcpy(addr, &src, 4);
1643 }
1644
1645 #ifdef CONFIG_NET_CLS_ROUTE
1646 static void set_class_tag(struct rtable *rt, u32 tag)
1647 {
1648 if (!(rt->u.dst.tclassid & 0xFFFF))
1649 rt->u.dst.tclassid |= tag & 0xFFFF;
1650 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1651 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1652 }
1653 #endif
1654
1655 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1656 {
1657 struct fib_info *fi = res->fi;
1658
1659 if (fi) {
1660 if (FIB_RES_GW(*res) &&
1661 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1662 rt->rt_gateway = FIB_RES_GW(*res);
1663 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1664 sizeof(rt->u.dst.metrics));
1665 if (fi->fib_mtu == 0) {
1666 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1667 if (dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1668 rt->rt_gateway != rt->rt_dst &&
1669 rt->u.dst.dev->mtu > 576)
1670 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1671 }
1672 #ifdef CONFIG_NET_CLS_ROUTE
1673 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1674 #endif
1675 } else
1676 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1677
1678 if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
1679 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1680 if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
1681 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1682 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
1683 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1684 ip_rt_min_advmss);
1685 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40)
1686 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1687
1688 #ifdef CONFIG_NET_CLS_ROUTE
1689 #ifdef CONFIG_IP_MULTIPLE_TABLES
1690 set_class_tag(rt, fib_rules_tclass(res));
1691 #endif
1692 set_class_tag(rt, itag);
1693 #endif
1694 rt->rt_type = res->type;
1695 }
1696
1697 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1698 u8 tos, struct net_device *dev, int our)
1699 {
1700 unsigned hash;
1701 struct rtable *rth;
1702 __be32 spec_dst;
1703 struct in_device *in_dev = in_dev_get(dev);
1704 u32 itag = 0;
1705
1706 /* Primary sanity checks. */
1707
1708 if (in_dev == NULL)
1709 return -EINVAL;
1710
1711 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1712 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1713 goto e_inval;
1714
1715 if (ipv4_is_zeronet(saddr)) {
1716 if (!ipv4_is_local_multicast(daddr))
1717 goto e_inval;
1718 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1719 } else if (fib_validate_source(saddr, 0, tos, 0,
1720 dev, &spec_dst, &itag) < 0)
1721 goto e_inval;
1722
1723 rth = dst_alloc(&ipv4_dst_ops);
1724 if (!rth)
1725 goto e_nobufs;
1726
1727 rth->u.dst.output= ip_rt_bug;
1728
1729 atomic_set(&rth->u.dst.__refcnt, 1);
1730 rth->u.dst.flags= DST_HOST;
1731 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1732 rth->u.dst.flags |= DST_NOPOLICY;
1733 rth->fl.fl4_dst = daddr;
1734 rth->rt_dst = daddr;
1735 rth->fl.fl4_tos = tos;
1736 rth->fl.mark = skb->mark;
1737 rth->fl.fl4_src = saddr;
1738 rth->rt_src = saddr;
1739 #ifdef CONFIG_NET_CLS_ROUTE
1740 rth->u.dst.tclassid = itag;
1741 #endif
1742 rth->rt_iif =
1743 rth->fl.iif = dev->ifindex;
1744 rth->u.dst.dev = init_net.loopback_dev;
1745 dev_hold(rth->u.dst.dev);
1746 rth->idev = in_dev_get(rth->u.dst.dev);
1747 rth->fl.oif = 0;
1748 rth->rt_gateway = daddr;
1749 rth->rt_spec_dst= spec_dst;
1750 rth->rt_genid = rt_genid(dev_net(dev));
1751 rth->rt_flags = RTCF_MULTICAST;
1752 rth->rt_type = RTN_MULTICAST;
1753 if (our) {
1754 rth->u.dst.input= ip_local_deliver;
1755 rth->rt_flags |= RTCF_LOCAL;
1756 }
1757
1758 #ifdef CONFIG_IP_MROUTE
1759 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1760 rth->u.dst.input = ip_mr_input;
1761 #endif
1762 RT_CACHE_STAT_INC(in_slow_mc);
1763
1764 in_dev_put(in_dev);
1765 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1766 return rt_intern_hash(hash, rth, &skb->rtable);
1767
1768 e_nobufs:
1769 in_dev_put(in_dev);
1770 return -ENOBUFS;
1771
1772 e_inval:
1773 in_dev_put(in_dev);
1774 return -EINVAL;
1775 }
1776
1777
1778 static void ip_handle_martian_source(struct net_device *dev,
1779 struct in_device *in_dev,
1780 struct sk_buff *skb,
1781 __be32 daddr,
1782 __be32 saddr)
1783 {
1784 RT_CACHE_STAT_INC(in_martian_src);
1785 #ifdef CONFIG_IP_ROUTE_VERBOSE
1786 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1787 /*
1788 * RFC1812 recommendation, if source is martian,
1789 * the only hint is MAC header.
1790 */
1791 printk(KERN_WARNING "martian source " NIPQUAD_FMT " from "
1792 NIPQUAD_FMT", on dev %s\n",
1793 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1794 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1795 int i;
1796 const unsigned char *p = skb_mac_header(skb);
1797 printk(KERN_WARNING "ll header: ");
1798 for (i = 0; i < dev->hard_header_len; i++, p++) {
1799 printk("%02x", *p);
1800 if (i < (dev->hard_header_len - 1))
1801 printk(":");
1802 }
1803 printk("\n");
1804 }
1805 }
1806 #endif
1807 }
1808
1809 static int __mkroute_input(struct sk_buff *skb,
1810 struct fib_result *res,
1811 struct in_device *in_dev,
1812 __be32 daddr, __be32 saddr, u32 tos,
1813 struct rtable **result)
1814 {
1815
1816 struct rtable *rth;
1817 int err;
1818 struct in_device *out_dev;
1819 unsigned flags = 0;
1820 __be32 spec_dst;
1821 u32 itag;
1822
1823 /* get a working reference to the output device */
1824 out_dev = in_dev_get(FIB_RES_DEV(*res));
1825 if (out_dev == NULL) {
1826 if (net_ratelimit())
1827 printk(KERN_CRIT "Bug in ip_route_input" \
1828 "_slow(). Please, report\n");
1829 return -EINVAL;
1830 }
1831
1832
1833 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1834 in_dev->dev, &spec_dst, &itag);
1835 if (err < 0) {
1836 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1837 saddr);
1838
1839 err = -EINVAL;
1840 goto cleanup;
1841 }
1842
1843 if (err)
1844 flags |= RTCF_DIRECTSRC;
1845
1846 if (out_dev == in_dev && err &&
1847 (IN_DEV_SHARED_MEDIA(out_dev) ||
1848 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1849 flags |= RTCF_DOREDIRECT;
1850
1851 if (skb->protocol != htons(ETH_P_IP)) {
1852 /* Not IP (i.e. ARP). Do not create route, if it is
1853 * invalid for proxy arp. DNAT routes are always valid.
1854 */
1855 if (out_dev == in_dev) {
1856 err = -EINVAL;
1857 goto cleanup;
1858 }
1859 }
1860
1861
1862 rth = dst_alloc(&ipv4_dst_ops);
1863 if (!rth) {
1864 err = -ENOBUFS;
1865 goto cleanup;
1866 }
1867
1868 atomic_set(&rth->u.dst.__refcnt, 1);
1869 rth->u.dst.flags= DST_HOST;
1870 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1871 rth->u.dst.flags |= DST_NOPOLICY;
1872 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
1873 rth->u.dst.flags |= DST_NOXFRM;
1874 rth->fl.fl4_dst = daddr;
1875 rth->rt_dst = daddr;
1876 rth->fl.fl4_tos = tos;
1877 rth->fl.mark = skb->mark;
1878 rth->fl.fl4_src = saddr;
1879 rth->rt_src = saddr;
1880 rth->rt_gateway = daddr;
1881 rth->rt_iif =
1882 rth->fl.iif = in_dev->dev->ifindex;
1883 rth->u.dst.dev = (out_dev)->dev;
1884 dev_hold(rth->u.dst.dev);
1885 rth->idev = in_dev_get(rth->u.dst.dev);
1886 rth->fl.oif = 0;
1887 rth->rt_spec_dst= spec_dst;
1888
1889 rth->u.dst.input = ip_forward;
1890 rth->u.dst.output = ip_output;
1891 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
1892
1893 rt_set_nexthop(rth, res, itag);
1894
1895 rth->rt_flags = flags;
1896
1897 *result = rth;
1898 err = 0;
1899 cleanup:
1900 /* release the working reference to the output device */
1901 in_dev_put(out_dev);
1902 return err;
1903 }
1904
1905 static int ip_mkroute_input(struct sk_buff *skb,
1906 struct fib_result *res,
1907 const struct flowi *fl,
1908 struct in_device *in_dev,
1909 __be32 daddr, __be32 saddr, u32 tos)
1910 {
1911 struct rtable* rth = NULL;
1912 int err;
1913 unsigned hash;
1914
1915 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1916 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
1917 fib_select_multipath(fl, res);
1918 #endif
1919
1920 /* create a routing cache entry */
1921 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1922 if (err)
1923 return err;
1924
1925 /* put it into the cache */
1926 hash = rt_hash(daddr, saddr, fl->iif,
1927 rt_genid(dev_net(rth->u.dst.dev)));
1928 return rt_intern_hash(hash, rth, &skb->rtable);
1929 }
1930
1931 /*
1932 * NOTE. We drop all the packets that has local source
1933 * addresses, because every properly looped back packet
1934 * must have correct destination already attached by output routine.
1935 *
1936 * Such approach solves two big problems:
1937 * 1. Not simplex devices are handled properly.
1938 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1939 */
1940
1941 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1942 u8 tos, struct net_device *dev)
1943 {
1944 struct fib_result res;
1945 struct in_device *in_dev = in_dev_get(dev);
1946 struct flowi fl = { .nl_u = { .ip4_u =
1947 { .daddr = daddr,
1948 .saddr = saddr,
1949 .tos = tos,
1950 .scope = RT_SCOPE_UNIVERSE,
1951 } },
1952 .mark = skb->mark,
1953 .iif = dev->ifindex };
1954 unsigned flags = 0;
1955 u32 itag = 0;
1956 struct rtable * rth;
1957 unsigned hash;
1958 __be32 spec_dst;
1959 int err = -EINVAL;
1960 int free_res = 0;
1961 struct net * net = dev_net(dev);
1962
1963 /* IP on this device is disabled. */
1964
1965 if (!in_dev)
1966 goto out;
1967
1968 /* Check for the most weird martians, which can be not detected
1969 by fib_lookup.
1970 */
1971
1972 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1973 ipv4_is_loopback(saddr))
1974 goto martian_source;
1975
1976 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
1977 goto brd_input;
1978
1979 /* Accept zero addresses only to limited broadcast;
1980 * I even do not know to fix it or not. Waiting for complains :-)
1981 */
1982 if (ipv4_is_zeronet(saddr))
1983 goto martian_source;
1984
1985 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
1986 ipv4_is_loopback(daddr))
1987 goto martian_destination;
1988
1989 /*
1990 * Now we are ready to route packet.
1991 */
1992 if ((err = fib_lookup(net, &fl, &res)) != 0) {
1993 if (!IN_DEV_FORWARD(in_dev))
1994 goto e_hostunreach;
1995 goto no_route;
1996 }
1997 free_res = 1;
1998
1999 RT_CACHE_STAT_INC(in_slow_tot);
2000
2001 if (res.type == RTN_BROADCAST)
2002 goto brd_input;
2003
2004 if (res.type == RTN_LOCAL) {
2005 int result;
2006 result = fib_validate_source(saddr, daddr, tos,
2007 net->loopback_dev->ifindex,
2008 dev, &spec_dst, &itag);
2009 if (result < 0)
2010 goto martian_source;
2011 if (result)
2012 flags |= RTCF_DIRECTSRC;
2013 spec_dst = daddr;
2014 goto local_input;
2015 }
2016
2017 if (!IN_DEV_FORWARD(in_dev))
2018 goto e_hostunreach;
2019 if (res.type != RTN_UNICAST)
2020 goto martian_destination;
2021
2022 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2023 done:
2024 in_dev_put(in_dev);
2025 if (free_res)
2026 fib_res_put(&res);
2027 out: return err;
2028
2029 brd_input:
2030 if (skb->protocol != htons(ETH_P_IP))
2031 goto e_inval;
2032
2033 if (ipv4_is_zeronet(saddr))
2034 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2035 else {
2036 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2037 &itag);
2038 if (err < 0)
2039 goto martian_source;
2040 if (err)
2041 flags |= RTCF_DIRECTSRC;
2042 }
2043 flags |= RTCF_BROADCAST;
2044 res.type = RTN_BROADCAST;
2045 RT_CACHE_STAT_INC(in_brd);
2046
2047 local_input:
2048 rth = dst_alloc(&ipv4_dst_ops);
2049 if (!rth)
2050 goto e_nobufs;
2051
2052 rth->u.dst.output= ip_rt_bug;
2053 rth->rt_genid = rt_genid(net);
2054
2055 atomic_set(&rth->u.dst.__refcnt, 1);
2056 rth->u.dst.flags= DST_HOST;
2057 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2058 rth->u.dst.flags |= DST_NOPOLICY;
2059 rth->fl.fl4_dst = daddr;
2060 rth->rt_dst = daddr;
2061 rth->fl.fl4_tos = tos;
2062 rth->fl.mark = skb->mark;
2063 rth->fl.fl4_src = saddr;
2064 rth->rt_src = saddr;
2065 #ifdef CONFIG_NET_CLS_ROUTE
2066 rth->u.dst.tclassid = itag;
2067 #endif
2068 rth->rt_iif =
2069 rth->fl.iif = dev->ifindex;
2070 rth->u.dst.dev = net->loopback_dev;
2071 dev_hold(rth->u.dst.dev);
2072 rth->idev = in_dev_get(rth->u.dst.dev);
2073 rth->rt_gateway = daddr;
2074 rth->rt_spec_dst= spec_dst;
2075 rth->u.dst.input= ip_local_deliver;
2076 rth->rt_flags = flags|RTCF_LOCAL;
2077 if (res.type == RTN_UNREACHABLE) {
2078 rth->u.dst.input= ip_error;
2079 rth->u.dst.error= -err;
2080 rth->rt_flags &= ~RTCF_LOCAL;
2081 }
2082 rth->rt_type = res.type;
2083 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2084 err = rt_intern_hash(hash, rth, &skb->rtable);
2085 goto done;
2086
2087 no_route:
2088 RT_CACHE_STAT_INC(in_no_route);
2089 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2090 res.type = RTN_UNREACHABLE;
2091 if (err == -ESRCH)
2092 err = -ENETUNREACH;
2093 goto local_input;
2094
2095 /*
2096 * Do not cache martian addresses: they should be logged (RFC1812)
2097 */
2098 martian_destination:
2099 RT_CACHE_STAT_INC(in_martian_dst);
2100 #ifdef CONFIG_IP_ROUTE_VERBOSE
2101 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2102 printk(KERN_WARNING "martian destination " NIPQUAD_FMT " from "
2103 NIPQUAD_FMT ", dev %s\n",
2104 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
2105 #endif
2106
2107 e_hostunreach:
2108 err = -EHOSTUNREACH;
2109 goto done;
2110
2111 e_inval:
2112 err = -EINVAL;
2113 goto done;
2114
2115 e_nobufs:
2116 err = -ENOBUFS;
2117 goto done;
2118
2119 martian_source:
2120 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2121 goto e_inval;
2122 }
2123
2124 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2125 u8 tos, struct net_device *dev)
2126 {
2127 struct rtable * rth;
2128 unsigned hash;
2129 int iif = dev->ifindex;
2130 struct net *net;
2131
2132 net = dev_net(dev);
2133 tos &= IPTOS_RT_MASK;
2134 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2135
2136 rcu_read_lock();
2137 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2138 rth = rcu_dereference(rth->u.dst.rt_next)) {
2139 if (((rth->fl.fl4_dst ^ daddr) |
2140 (rth->fl.fl4_src ^ saddr) |
2141 (rth->fl.iif ^ iif) |
2142 rth->fl.oif |
2143 (rth->fl.fl4_tos ^ tos)) == 0 &&
2144 rth->fl.mark == skb->mark &&
2145 net_eq(dev_net(rth->u.dst.dev), net) &&
2146 !rt_is_expired(rth)) {
2147 dst_use(&rth->u.dst, jiffies);
2148 RT_CACHE_STAT_INC(in_hit);
2149 rcu_read_unlock();
2150 skb->rtable = rth;
2151 return 0;
2152 }
2153 RT_CACHE_STAT_INC(in_hlist_search);
2154 }
2155 rcu_read_unlock();
2156
2157 /* Multicast recognition logic is moved from route cache to here.
2158 The problem was that too many Ethernet cards have broken/missing
2159 hardware multicast filters :-( As result the host on multicasting
2160 network acquires a lot of useless route cache entries, sort of
2161 SDR messages from all the world. Now we try to get rid of them.
2162 Really, provided software IP multicast filter is organized
2163 reasonably (at least, hashed), it does not result in a slowdown
2164 comparing with route cache reject entries.
2165 Note, that multicast routers are not affected, because
2166 route cache entry is created eventually.
2167 */
2168 if (ipv4_is_multicast(daddr)) {
2169 struct in_device *in_dev;
2170
2171 rcu_read_lock();
2172 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2173 int our = ip_check_mc(in_dev, daddr, saddr,
2174 ip_hdr(skb)->protocol);
2175 if (our
2176 #ifdef CONFIG_IP_MROUTE
2177 || (!ipv4_is_local_multicast(daddr) &&
2178 IN_DEV_MFORWARD(in_dev))
2179 #endif
2180 ) {
2181 rcu_read_unlock();
2182 return ip_route_input_mc(skb, daddr, saddr,
2183 tos, dev, our);
2184 }
2185 }
2186 rcu_read_unlock();
2187 return -EINVAL;
2188 }
2189 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2190 }
2191
2192 static int __mkroute_output(struct rtable **result,
2193 struct fib_result *res,
2194 const struct flowi *fl,
2195 const struct flowi *oldflp,
2196 struct net_device *dev_out,
2197 unsigned flags)
2198 {
2199 struct rtable *rth;
2200 struct in_device *in_dev;
2201 u32 tos = RT_FL_TOS(oldflp);
2202 int err = 0;
2203
2204 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2205 return -EINVAL;
2206
2207 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2208 res->type = RTN_BROADCAST;
2209 else if (ipv4_is_multicast(fl->fl4_dst))
2210 res->type = RTN_MULTICAST;
2211 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2212 return -EINVAL;
2213
2214 if (dev_out->flags & IFF_LOOPBACK)
2215 flags |= RTCF_LOCAL;
2216
2217 /* get work reference to inet device */
2218 in_dev = in_dev_get(dev_out);
2219 if (!in_dev)
2220 return -EINVAL;
2221
2222 if (res->type == RTN_BROADCAST) {
2223 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2224 if (res->fi) {
2225 fib_info_put(res->fi);
2226 res->fi = NULL;
2227 }
2228 } else if (res->type == RTN_MULTICAST) {
2229 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2230 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2231 oldflp->proto))
2232 flags &= ~RTCF_LOCAL;
2233 /* If multicast route do not exist use
2234 default one, but do not gateway in this case.
2235 Yes, it is hack.
2236 */
2237 if (res->fi && res->prefixlen < 4) {
2238 fib_info_put(res->fi);
2239 res->fi = NULL;
2240 }
2241 }
2242
2243
2244 rth = dst_alloc(&ipv4_dst_ops);
2245 if (!rth) {
2246 err = -ENOBUFS;
2247 goto cleanup;
2248 }
2249
2250 atomic_set(&rth->u.dst.__refcnt, 1);
2251 rth->u.dst.flags= DST_HOST;
2252 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2253 rth->u.dst.flags |= DST_NOXFRM;
2254 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2255 rth->u.dst.flags |= DST_NOPOLICY;
2256
2257 rth->fl.fl4_dst = oldflp->fl4_dst;
2258 rth->fl.fl4_tos = tos;
2259 rth->fl.fl4_src = oldflp->fl4_src;
2260 rth->fl.oif = oldflp->oif;
2261 rth->fl.mark = oldflp->mark;
2262 rth->rt_dst = fl->fl4_dst;
2263 rth->rt_src = fl->fl4_src;
2264 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2265 /* get references to the devices that are to be hold by the routing
2266 cache entry */
2267 rth->u.dst.dev = dev_out;
2268 dev_hold(dev_out);
2269 rth->idev = in_dev_get(dev_out);
2270 rth->rt_gateway = fl->fl4_dst;
2271 rth->rt_spec_dst= fl->fl4_src;
2272
2273 rth->u.dst.output=ip_output;
2274 rth->rt_genid = rt_genid(dev_net(dev_out));
2275
2276 RT_CACHE_STAT_INC(out_slow_tot);
2277
2278 if (flags & RTCF_LOCAL) {
2279 rth->u.dst.input = ip_local_deliver;
2280 rth->rt_spec_dst = fl->fl4_dst;
2281 }
2282 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2283 rth->rt_spec_dst = fl->fl4_src;
2284 if (flags & RTCF_LOCAL &&
2285 !(dev_out->flags & IFF_LOOPBACK)) {
2286 rth->u.dst.output = ip_mc_output;
2287 RT_CACHE_STAT_INC(out_slow_mc);
2288 }
2289 #ifdef CONFIG_IP_MROUTE
2290 if (res->type == RTN_MULTICAST) {
2291 if (IN_DEV_MFORWARD(in_dev) &&
2292 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2293 rth->u.dst.input = ip_mr_input;
2294 rth->u.dst.output = ip_mc_output;
2295 }
2296 }
2297 #endif
2298 }
2299
2300 rt_set_nexthop(rth, res, 0);
2301
2302 rth->rt_flags = flags;
2303
2304 *result = rth;
2305 cleanup:
2306 /* release work reference to inet device */
2307 in_dev_put(in_dev);
2308
2309 return err;
2310 }
2311
2312 static int ip_mkroute_output(struct rtable **rp,
2313 struct fib_result *res,
2314 const struct flowi *fl,
2315 const struct flowi *oldflp,
2316 struct net_device *dev_out,
2317 unsigned flags)
2318 {
2319 struct rtable *rth = NULL;
2320 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2321 unsigned hash;
2322 if (err == 0) {
2323 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2324 rt_genid(dev_net(dev_out)));
2325 err = rt_intern_hash(hash, rth, rp);
2326 }
2327
2328 return err;
2329 }
2330
2331 /*
2332 * Major route resolver routine.
2333 */
2334
2335 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2336 const struct flowi *oldflp)
2337 {
2338 u32 tos = RT_FL_TOS(oldflp);
2339 struct flowi fl = { .nl_u = { .ip4_u =
2340 { .daddr = oldflp->fl4_dst,
2341 .saddr = oldflp->fl4_src,
2342 .tos = tos & IPTOS_RT_MASK,
2343 .scope = ((tos & RTO_ONLINK) ?
2344 RT_SCOPE_LINK :
2345 RT_SCOPE_UNIVERSE),
2346 } },
2347 .mark = oldflp->mark,
2348 .iif = net->loopback_dev->ifindex,
2349 .oif = oldflp->oif };
2350 struct fib_result res;
2351 unsigned flags = 0;
2352 struct net_device *dev_out = NULL;
2353 int free_res = 0;
2354 int err;
2355
2356
2357 res.fi = NULL;
2358 #ifdef CONFIG_IP_MULTIPLE_TABLES
2359 res.r = NULL;
2360 #endif
2361
2362 if (oldflp->fl4_src) {
2363 err = -EINVAL;
2364 if (ipv4_is_multicast(oldflp->fl4_src) ||
2365 ipv4_is_lbcast(oldflp->fl4_src) ||
2366 ipv4_is_zeronet(oldflp->fl4_src))
2367 goto out;
2368
2369 /* I removed check for oif == dev_out->oif here.
2370 It was wrong for two reasons:
2371 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2372 is assigned to multiple interfaces.
2373 2. Moreover, we are allowed to send packets with saddr
2374 of another iface. --ANK
2375 */
2376
2377 if (oldflp->oif == 0
2378 && (ipv4_is_multicast(oldflp->fl4_dst) ||
2379 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2380 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2381 dev_out = ip_dev_find(net, oldflp->fl4_src);
2382 if (dev_out == NULL)
2383 goto out;
2384
2385 /* Special hack: user can direct multicasts
2386 and limited broadcast via necessary interface
2387 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2388 This hack is not just for fun, it allows
2389 vic,vat and friends to work.
2390 They bind socket to loopback, set ttl to zero
2391 and expect that it will work.
2392 From the viewpoint of routing cache they are broken,
2393 because we are not allowed to build multicast path
2394 with loopback source addr (look, routing cache
2395 cannot know, that ttl is zero, so that packet
2396 will not leave this host and route is valid).
2397 Luckily, this hack is good workaround.
2398 */
2399
2400 fl.oif = dev_out->ifindex;
2401 goto make_route;
2402 }
2403
2404 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2405 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2406 dev_out = ip_dev_find(net, oldflp->fl4_src);
2407 if (dev_out == NULL)
2408 goto out;
2409 dev_put(dev_out);
2410 dev_out = NULL;
2411 }
2412 }
2413
2414
2415 if (oldflp->oif) {
2416 dev_out = dev_get_by_index(net, oldflp->oif);
2417 err = -ENODEV;
2418 if (dev_out == NULL)
2419 goto out;
2420
2421 /* RACE: Check return value of inet_select_addr instead. */
2422 if (__in_dev_get_rtnl(dev_out) == NULL) {
2423 dev_put(dev_out);
2424 goto out; /* Wrong error code */
2425 }
2426
2427 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2428 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2429 if (!fl.fl4_src)
2430 fl.fl4_src = inet_select_addr(dev_out, 0,
2431 RT_SCOPE_LINK);
2432 goto make_route;
2433 }
2434 if (!fl.fl4_src) {
2435 if (ipv4_is_multicast(oldflp->fl4_dst))
2436 fl.fl4_src = inet_select_addr(dev_out, 0,
2437 fl.fl4_scope);
2438 else if (!oldflp->fl4_dst)
2439 fl.fl4_src = inet_select_addr(dev_out, 0,
2440 RT_SCOPE_HOST);
2441 }
2442 }
2443
2444 if (!fl.fl4_dst) {
2445 fl.fl4_dst = fl.fl4_src;
2446 if (!fl.fl4_dst)
2447 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2448 if (dev_out)
2449 dev_put(dev_out);
2450 dev_out = net->loopback_dev;
2451 dev_hold(dev_out);
2452 fl.oif = net->loopback_dev->ifindex;
2453 res.type = RTN_LOCAL;
2454 flags |= RTCF_LOCAL;
2455 goto make_route;
2456 }
2457
2458 if (fib_lookup(net, &fl, &res)) {
2459 res.fi = NULL;
2460 if (oldflp->oif) {
2461 /* Apparently, routing tables are wrong. Assume,
2462 that the destination is on link.
2463
2464 WHY? DW.
2465 Because we are allowed to send to iface
2466 even if it has NO routes and NO assigned
2467 addresses. When oif is specified, routing
2468 tables are looked up with only one purpose:
2469 to catch if destination is gatewayed, rather than
2470 direct. Moreover, if MSG_DONTROUTE is set,
2471 we send packet, ignoring both routing tables
2472 and ifaddr state. --ANK
2473
2474
2475 We could make it even if oif is unknown,
2476 likely IPv6, but we do not.
2477 */
2478
2479 if (fl.fl4_src == 0)
2480 fl.fl4_src = inet_select_addr(dev_out, 0,
2481 RT_SCOPE_LINK);
2482 res.type = RTN_UNICAST;
2483 goto make_route;
2484 }
2485 if (dev_out)
2486 dev_put(dev_out);
2487 err = -ENETUNREACH;
2488 goto out;
2489 }
2490 free_res = 1;
2491
2492 if (res.type == RTN_LOCAL) {
2493 if (!fl.fl4_src)
2494 fl.fl4_src = fl.fl4_dst;
2495 if (dev_out)
2496 dev_put(dev_out);
2497 dev_out = net->loopback_dev;
2498 dev_hold(dev_out);
2499 fl.oif = dev_out->ifindex;
2500 if (res.fi)
2501 fib_info_put(res.fi);
2502 res.fi = NULL;
2503 flags |= RTCF_LOCAL;
2504 goto make_route;
2505 }
2506
2507 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2508 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2509 fib_select_multipath(&fl, &res);
2510 else
2511 #endif
2512 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2513 fib_select_default(net, &fl, &res);
2514
2515 if (!fl.fl4_src)
2516 fl.fl4_src = FIB_RES_PREFSRC(res);
2517
2518 if (dev_out)
2519 dev_put(dev_out);
2520 dev_out = FIB_RES_DEV(res);
2521 dev_hold(dev_out);
2522 fl.oif = dev_out->ifindex;
2523
2524
2525 make_route:
2526 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2527
2528
2529 if (free_res)
2530 fib_res_put(&res);
2531 if (dev_out)
2532 dev_put(dev_out);
2533 out: return err;
2534 }
2535
2536 int __ip_route_output_key(struct net *net, struct rtable **rp,
2537 const struct flowi *flp)
2538 {
2539 unsigned hash;
2540 struct rtable *rth;
2541
2542 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2543
2544 rcu_read_lock_bh();
2545 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2546 rth = rcu_dereference(rth->u.dst.rt_next)) {
2547 if (rth->fl.fl4_dst == flp->fl4_dst &&
2548 rth->fl.fl4_src == flp->fl4_src &&
2549 rth->fl.iif == 0 &&
2550 rth->fl.oif == flp->oif &&
2551 rth->fl.mark == flp->mark &&
2552 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2553 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2554 net_eq(dev_net(rth->u.dst.dev), net) &&
2555 !rt_is_expired(rth)) {
2556 dst_use(&rth->u.dst, jiffies);
2557 RT_CACHE_STAT_INC(out_hit);
2558 rcu_read_unlock_bh();
2559 *rp = rth;
2560 return 0;
2561 }
2562 RT_CACHE_STAT_INC(out_hlist_search);
2563 }
2564 rcu_read_unlock_bh();
2565
2566 return ip_route_output_slow(net, rp, flp);
2567 }
2568
2569 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2570
2571 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2572 {
2573 }
2574
2575 static struct dst_ops ipv4_dst_blackhole_ops = {
2576 .family = AF_INET,
2577 .protocol = __constant_htons(ETH_P_IP),
2578 .destroy = ipv4_dst_destroy,
2579 .check = ipv4_dst_check,
2580 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2581 .entry_size = sizeof(struct rtable),
2582 .entries = ATOMIC_INIT(0),
2583 };
2584
2585
2586 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2587 {
2588 struct rtable *ort = *rp;
2589 struct rtable *rt = (struct rtable *)
2590 dst_alloc(&ipv4_dst_blackhole_ops);
2591
2592 if (rt) {
2593 struct dst_entry *new = &rt->u.dst;
2594
2595 atomic_set(&new->__refcnt, 1);
2596 new->__use = 1;
2597 new->input = dst_discard;
2598 new->output = dst_discard;
2599 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2600
2601 new->dev = ort->u.dst.dev;
2602 if (new->dev)
2603 dev_hold(new->dev);
2604
2605 rt->fl = ort->fl;
2606
2607 rt->idev = ort->idev;
2608 if (rt->idev)
2609 in_dev_hold(rt->idev);
2610 rt->rt_genid = rt_genid(net);
2611 rt->rt_flags = ort->rt_flags;
2612 rt->rt_type = ort->rt_type;
2613 rt->rt_dst = ort->rt_dst;
2614 rt->rt_src = ort->rt_src;
2615 rt->rt_iif = ort->rt_iif;
2616 rt->rt_gateway = ort->rt_gateway;
2617 rt->rt_spec_dst = ort->rt_spec_dst;
2618 rt->peer = ort->peer;
2619 if (rt->peer)
2620 atomic_inc(&rt->peer->refcnt);
2621
2622 dst_free(new);
2623 }
2624
2625 dst_release(&(*rp)->u.dst);
2626 *rp = rt;
2627 return (rt ? 0 : -ENOMEM);
2628 }
2629
2630 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2631 struct sock *sk, int flags)
2632 {
2633 int err;
2634
2635 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2636 return err;
2637
2638 if (flp->proto) {
2639 if (!flp->fl4_src)
2640 flp->fl4_src = (*rp)->rt_src;
2641 if (!flp->fl4_dst)
2642 flp->fl4_dst = (*rp)->rt_dst;
2643 err = __xfrm_lookup((struct dst_entry **)rp, flp, sk,
2644 flags ? XFRM_LOOKUP_WAIT : 0);
2645 if (err == -EREMOTE)
2646 err = ipv4_dst_blackhole(net, rp, flp);
2647
2648 return err;
2649 }
2650
2651 return 0;
2652 }
2653
2654 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2655
2656 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2657 {
2658 return ip_route_output_flow(net, rp, flp, NULL, 0);
2659 }
2660
2661 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2662 int nowait, unsigned int flags)
2663 {
2664 struct rtable *rt = skb->rtable;
2665 struct rtmsg *r;
2666 struct nlmsghdr *nlh;
2667 long expires;
2668 u32 id = 0, ts = 0, tsage = 0, error;
2669
2670 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2671 if (nlh == NULL)
2672 return -EMSGSIZE;
2673
2674 r = nlmsg_data(nlh);
2675 r->rtm_family = AF_INET;
2676 r->rtm_dst_len = 32;
2677 r->rtm_src_len = 0;
2678 r->rtm_tos = rt->fl.fl4_tos;
2679 r->rtm_table = RT_TABLE_MAIN;
2680 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2681 r->rtm_type = rt->rt_type;
2682 r->rtm_scope = RT_SCOPE_UNIVERSE;
2683 r->rtm_protocol = RTPROT_UNSPEC;
2684 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2685 if (rt->rt_flags & RTCF_NOTIFY)
2686 r->rtm_flags |= RTM_F_NOTIFY;
2687
2688 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2689
2690 if (rt->fl.fl4_src) {
2691 r->rtm_src_len = 32;
2692 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2693 }
2694 if (rt->u.dst.dev)
2695 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2696 #ifdef CONFIG_NET_CLS_ROUTE
2697 if (rt->u.dst.tclassid)
2698 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2699 #endif
2700 if (rt->fl.iif)
2701 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2702 else if (rt->rt_src != rt->fl.fl4_src)
2703 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2704
2705 if (rt->rt_dst != rt->rt_gateway)
2706 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2707
2708 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2709 goto nla_put_failure;
2710
2711 error = rt->u.dst.error;
2712 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2713 if (rt->peer) {
2714 id = rt->peer->ip_id_count;
2715 if (rt->peer->tcp_ts_stamp) {
2716 ts = rt->peer->tcp_ts;
2717 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2718 }
2719 }
2720
2721 if (rt->fl.iif) {
2722 #ifdef CONFIG_IP_MROUTE
2723 __be32 dst = rt->rt_dst;
2724
2725 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2726 IPV4_DEVCONF_ALL(&init_net, MC_FORWARDING)) {
2727 int err = ipmr_get_route(skb, r, nowait);
2728 if (err <= 0) {
2729 if (!nowait) {
2730 if (err == 0)
2731 return 0;
2732 goto nla_put_failure;
2733 } else {
2734 if (err == -EMSGSIZE)
2735 goto nla_put_failure;
2736 error = err;
2737 }
2738 }
2739 } else
2740 #endif
2741 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2742 }
2743
2744 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2745 expires, error) < 0)
2746 goto nla_put_failure;
2747
2748 return nlmsg_end(skb, nlh);
2749
2750 nla_put_failure:
2751 nlmsg_cancel(skb, nlh);
2752 return -EMSGSIZE;
2753 }
2754
2755 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2756 {
2757 struct net *net = sock_net(in_skb->sk);
2758 struct rtmsg *rtm;
2759 struct nlattr *tb[RTA_MAX+1];
2760 struct rtable *rt = NULL;
2761 __be32 dst = 0;
2762 __be32 src = 0;
2763 u32 iif;
2764 int err;
2765 struct sk_buff *skb;
2766
2767 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2768 if (err < 0)
2769 goto errout;
2770
2771 rtm = nlmsg_data(nlh);
2772
2773 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2774 if (skb == NULL) {
2775 err = -ENOBUFS;
2776 goto errout;
2777 }
2778
2779 /* Reserve room for dummy headers, this skb can pass
2780 through good chunk of routing engine.
2781 */
2782 skb_reset_mac_header(skb);
2783 skb_reset_network_header(skb);
2784
2785 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2786 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2787 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2788
2789 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2790 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2791 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2792
2793 if (iif) {
2794 struct net_device *dev;
2795
2796 dev = __dev_get_by_index(net, iif);
2797 if (dev == NULL) {
2798 err = -ENODEV;
2799 goto errout_free;
2800 }
2801
2802 skb->protocol = htons(ETH_P_IP);
2803 skb->dev = dev;
2804 local_bh_disable();
2805 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2806 local_bh_enable();
2807
2808 rt = skb->rtable;
2809 if (err == 0 && rt->u.dst.error)
2810 err = -rt->u.dst.error;
2811 } else {
2812 struct flowi fl = {
2813 .nl_u = {
2814 .ip4_u = {
2815 .daddr = dst,
2816 .saddr = src,
2817 .tos = rtm->rtm_tos,
2818 },
2819 },
2820 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2821 };
2822 err = ip_route_output_key(net, &rt, &fl);
2823 }
2824
2825 if (err)
2826 goto errout_free;
2827
2828 skb->rtable = rt;
2829 if (rtm->rtm_flags & RTM_F_NOTIFY)
2830 rt->rt_flags |= RTCF_NOTIFY;
2831
2832 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2833 RTM_NEWROUTE, 0, 0);
2834 if (err <= 0)
2835 goto errout_free;
2836
2837 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2838 errout:
2839 return err;
2840
2841 errout_free:
2842 kfree_skb(skb);
2843 goto errout;
2844 }
2845
2846 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2847 {
2848 struct rtable *rt;
2849 int h, s_h;
2850 int idx, s_idx;
2851 struct net *net;
2852
2853 net = sock_net(skb->sk);
2854
2855 s_h = cb->args[0];
2856 if (s_h < 0)
2857 s_h = 0;
2858 s_idx = idx = cb->args[1];
2859 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2860 if (!rt_hash_table[h].chain)
2861 continue;
2862 rcu_read_lock_bh();
2863 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2864 rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
2865 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
2866 continue;
2867 if (rt_is_expired(rt))
2868 continue;
2869 skb->dst = dst_clone(&rt->u.dst);
2870 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2871 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2872 1, NLM_F_MULTI) <= 0) {
2873 dst_release(xchg(&skb->dst, NULL));
2874 rcu_read_unlock_bh();
2875 goto done;
2876 }
2877 dst_release(xchg(&skb->dst, NULL));
2878 }
2879 rcu_read_unlock_bh();
2880 }
2881
2882 done:
2883 cb->args[0] = h;
2884 cb->args[1] = idx;
2885 return skb->len;
2886 }
2887
2888 void ip_rt_multicast_event(struct in_device *in_dev)
2889 {
2890 rt_cache_flush(dev_net(in_dev->dev), 0);
2891 }
2892
2893 #ifdef CONFIG_SYSCTL
2894 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2895 struct file *filp, void __user *buffer,
2896 size_t *lenp, loff_t *ppos)
2897 {
2898 if (write) {
2899 int flush_delay;
2900 ctl_table ctl;
2901 struct net *net;
2902
2903 memcpy(&ctl, __ctl, sizeof(ctl));
2904 ctl.data = &flush_delay;
2905 proc_dointvec(&ctl, write, filp, buffer, lenp, ppos);
2906
2907 net = (struct net *)__ctl->extra1;
2908 rt_cache_flush(net, flush_delay);
2909 return 0;
2910 }
2911
2912 return -EINVAL;
2913 }
2914
2915 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2916 void __user *oldval,
2917 size_t __user *oldlenp,
2918 void __user *newval,
2919 size_t newlen)
2920 {
2921 int delay;
2922 struct net *net;
2923 if (newlen != sizeof(int))
2924 return -EINVAL;
2925 if (get_user(delay, (int __user *)newval))
2926 return -EFAULT;
2927 net = (struct net *)table->extra1;
2928 rt_cache_flush(net, delay);
2929 return 0;
2930 }
2931
2932 static void rt_secret_reschedule(int old)
2933 {
2934 struct net *net;
2935 int new = ip_rt_secret_interval;
2936 int diff = new - old;
2937
2938 if (!diff)
2939 return;
2940
2941 rtnl_lock();
2942 for_each_net(net) {
2943 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
2944
2945 if (!new)
2946 continue;
2947
2948 if (deleted) {
2949 long time = net->ipv4.rt_secret_timer.expires - jiffies;
2950
2951 if (time <= 0 || (time += diff) <= 0)
2952 time = 0;
2953
2954 net->ipv4.rt_secret_timer.expires = time;
2955 } else
2956 net->ipv4.rt_secret_timer.expires = new;
2957
2958 net->ipv4.rt_secret_timer.expires += jiffies;
2959 add_timer(&net->ipv4.rt_secret_timer);
2960 }
2961 rtnl_unlock();
2962 }
2963
2964 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
2965 struct file *filp,
2966 void __user *buffer, size_t *lenp,
2967 loff_t *ppos)
2968 {
2969 int old = ip_rt_secret_interval;
2970 int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
2971
2972 rt_secret_reschedule(old);
2973
2974 return ret;
2975 }
2976
2977 static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
2978 void __user *oldval,
2979 size_t __user *oldlenp,
2980 void __user *newval,
2981 size_t newlen)
2982 {
2983 int old = ip_rt_secret_interval;
2984 int ret = sysctl_jiffies(table, oldval, oldlenp, newval, newlen);
2985
2986 rt_secret_reschedule(old);
2987
2988 return ret;
2989 }
2990
2991 static ctl_table ipv4_route_table[] = {
2992 {
2993 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2994 .procname = "gc_thresh",
2995 .data = &ipv4_dst_ops.gc_thresh,
2996 .maxlen = sizeof(int),
2997 .mode = 0644,
2998 .proc_handler = &proc_dointvec,
2999 },
3000 {
3001 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
3002 .procname = "max_size",
3003 .data = &ip_rt_max_size,
3004 .maxlen = sizeof(int),
3005 .mode = 0644,
3006 .proc_handler = &proc_dointvec,
3007 },
3008 {
3009 /* Deprecated. Use gc_min_interval_ms */
3010
3011 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
3012 .procname = "gc_min_interval",
3013 .data = &ip_rt_gc_min_interval,
3014 .maxlen = sizeof(int),
3015 .mode = 0644,
3016 .proc_handler = &proc_dointvec_jiffies,
3017 .strategy = &sysctl_jiffies,
3018 },
3019 {
3020 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
3021 .procname = "gc_min_interval_ms",
3022 .data = &ip_rt_gc_min_interval,
3023 .maxlen = sizeof(int),
3024 .mode = 0644,
3025 .proc_handler = &proc_dointvec_ms_jiffies,
3026 .strategy = &sysctl_ms_jiffies,
3027 },
3028 {
3029 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
3030 .procname = "gc_timeout",
3031 .data = &ip_rt_gc_timeout,
3032 .maxlen = sizeof(int),
3033 .mode = 0644,
3034 .proc_handler = &proc_dointvec_jiffies,
3035 .strategy = &sysctl_jiffies,
3036 },
3037 {
3038 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
3039 .procname = "gc_interval",
3040 .data = &ip_rt_gc_interval,
3041 .maxlen = sizeof(int),
3042 .mode = 0644,
3043 .proc_handler = &proc_dointvec_jiffies,
3044 .strategy = &sysctl_jiffies,
3045 },
3046 {
3047 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
3048 .procname = "redirect_load",
3049 .data = &ip_rt_redirect_load,
3050 .maxlen = sizeof(int),
3051 .mode = 0644,
3052 .proc_handler = &proc_dointvec,
3053 },
3054 {
3055 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
3056 .procname = "redirect_number",
3057 .data = &ip_rt_redirect_number,
3058 .maxlen = sizeof(int),
3059 .mode = 0644,
3060 .proc_handler = &proc_dointvec,
3061 },
3062 {
3063 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
3064 .procname = "redirect_silence",
3065 .data = &ip_rt_redirect_silence,
3066 .maxlen = sizeof(int),
3067 .mode = 0644,
3068 .proc_handler = &proc_dointvec,
3069 },
3070 {
3071 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
3072 .procname = "error_cost",
3073 .data = &ip_rt_error_cost,
3074 .maxlen = sizeof(int),
3075 .mode = 0644,
3076 .proc_handler = &proc_dointvec,
3077 },
3078 {
3079 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
3080 .procname = "error_burst",
3081 .data = &ip_rt_error_burst,
3082 .maxlen = sizeof(int),
3083 .mode = 0644,
3084 .proc_handler = &proc_dointvec,
3085 },
3086 {
3087 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
3088 .procname = "gc_elasticity",
3089 .data = &ip_rt_gc_elasticity,
3090 .maxlen = sizeof(int),
3091 .mode = 0644,
3092 .proc_handler = &proc_dointvec,
3093 },
3094 {
3095 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
3096 .procname = "mtu_expires",
3097 .data = &ip_rt_mtu_expires,
3098 .maxlen = sizeof(int),
3099 .mode = 0644,
3100 .proc_handler = &proc_dointvec_jiffies,
3101 .strategy = &sysctl_jiffies,
3102 },
3103 {
3104 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
3105 .procname = "min_pmtu",
3106 .data = &ip_rt_min_pmtu,
3107 .maxlen = sizeof(int),
3108 .mode = 0644,
3109 .proc_handler = &proc_dointvec,
3110 },
3111 {
3112 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
3113 .procname = "min_adv_mss",
3114 .data = &ip_rt_min_advmss,
3115 .maxlen = sizeof(int),
3116 .mode = 0644,
3117 .proc_handler = &proc_dointvec,
3118 },
3119 {
3120 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
3121 .procname = "secret_interval",
3122 .data = &ip_rt_secret_interval,
3123 .maxlen = sizeof(int),
3124 .mode = 0644,
3125 .proc_handler = &ipv4_sysctl_rt_secret_interval,
3126 .strategy = &ipv4_sysctl_rt_secret_interval_strategy,
3127 },
3128 { .ctl_name = 0 }
3129 };
3130
3131 static struct ctl_table empty[1];
3132
3133 static struct ctl_table ipv4_skeleton[] =
3134 {
3135 { .procname = "route", .ctl_name = NET_IPV4_ROUTE,
3136 .mode = 0555, .child = ipv4_route_table},
3137 { .procname = "neigh", .ctl_name = NET_IPV4_NEIGH,
3138 .mode = 0555, .child = empty},
3139 { }
3140 };
3141
3142 static __net_initdata struct ctl_path ipv4_path[] = {
3143 { .procname = "net", .ctl_name = CTL_NET, },
3144 { .procname = "ipv4", .ctl_name = NET_IPV4, },
3145 { },
3146 };
3147
3148 static struct ctl_table ipv4_route_flush_table[] = {
3149 {
3150 .ctl_name = NET_IPV4_ROUTE_FLUSH,
3151 .procname = "flush",
3152 .maxlen = sizeof(int),
3153 .mode = 0200,
3154 .proc_handler = &ipv4_sysctl_rtcache_flush,
3155 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
3156 },
3157 { .ctl_name = 0 },
3158 };
3159
3160 static __net_initdata struct ctl_path ipv4_route_path[] = {
3161 { .procname = "net", .ctl_name = CTL_NET, },
3162 { .procname = "ipv4", .ctl_name = NET_IPV4, },
3163 { .procname = "route", .ctl_name = NET_IPV4_ROUTE, },
3164 { },
3165 };
3166
3167 static __net_init int sysctl_route_net_init(struct net *net)
3168 {
3169 struct ctl_table *tbl;
3170
3171 tbl = ipv4_route_flush_table;
3172 if (net != &init_net) {
3173 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3174 if (tbl == NULL)
3175 goto err_dup;
3176 }
3177 tbl[0].extra1 = net;
3178
3179 net->ipv4.route_hdr =
3180 register_net_sysctl_table(net, ipv4_route_path, tbl);
3181 if (net->ipv4.route_hdr == NULL)
3182 goto err_reg;
3183 return 0;
3184
3185 err_reg:
3186 if (tbl != ipv4_route_flush_table)
3187 kfree(tbl);
3188 err_dup:
3189 return -ENOMEM;
3190 }
3191
3192 static __net_exit void sysctl_route_net_exit(struct net *net)
3193 {
3194 struct ctl_table *tbl;
3195
3196 tbl = net->ipv4.route_hdr->ctl_table_arg;
3197 unregister_net_sysctl_table(net->ipv4.route_hdr);
3198 BUG_ON(tbl == ipv4_route_flush_table);
3199 kfree(tbl);
3200 }
3201
3202 static __net_initdata struct pernet_operations sysctl_route_ops = {
3203 .init = sysctl_route_net_init,
3204 .exit = sysctl_route_net_exit,
3205 };
3206 #endif
3207
3208
3209 static __net_init int rt_secret_timer_init(struct net *net)
3210 {
3211 atomic_set(&net->ipv4.rt_genid,
3212 (int) ((num_physpages ^ (num_physpages>>8)) ^
3213 (jiffies ^ (jiffies >> 7))));
3214
3215 net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
3216 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3217 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3218
3219 if (ip_rt_secret_interval) {
3220 net->ipv4.rt_secret_timer.expires =
3221 jiffies + net_random() % ip_rt_secret_interval +
3222 ip_rt_secret_interval;
3223 add_timer(&net->ipv4.rt_secret_timer);
3224 }
3225 return 0;
3226 }
3227
3228 static __net_exit void rt_secret_timer_exit(struct net *net)
3229 {
3230 del_timer_sync(&net->ipv4.rt_secret_timer);
3231 }
3232
3233 static __net_initdata struct pernet_operations rt_secret_timer_ops = {
3234 .init = rt_secret_timer_init,
3235 .exit = rt_secret_timer_exit,
3236 };
3237
3238
3239 #ifdef CONFIG_NET_CLS_ROUTE
3240 struct ip_rt_acct *ip_rt_acct __read_mostly;
3241 #endif /* CONFIG_NET_CLS_ROUTE */
3242
3243 static __initdata unsigned long rhash_entries;
3244 static int __init set_rhash_entries(char *str)
3245 {
3246 if (!str)
3247 return 0;
3248 rhash_entries = simple_strtoul(str, &str, 0);
3249 return 1;
3250 }
3251 __setup("rhash_entries=", set_rhash_entries);
3252
3253 int __init ip_rt_init(void)
3254 {
3255 int rc = 0;
3256
3257 #ifdef CONFIG_NET_CLS_ROUTE
3258 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
3259 if (!ip_rt_acct)
3260 panic("IP: failed to allocate ip_rt_acct\n");
3261 #endif
3262
3263 ipv4_dst_ops.kmem_cachep =
3264 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3265 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3266
3267 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3268
3269 rt_hash_table = (struct rt_hash_bucket *)
3270 alloc_large_system_hash("IP route cache",
3271 sizeof(struct rt_hash_bucket),
3272 rhash_entries,
3273 (num_physpages >= 128 * 1024) ?
3274 15 : 17,
3275 0,
3276 &rt_hash_log,
3277 &rt_hash_mask,
3278 0);
3279 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3280 rt_hash_lock_init();
3281
3282 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3283 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3284
3285 devinet_init();
3286 ip_fib_init();
3287
3288 /* All the timers, started at system startup tend
3289 to synchronize. Perturb it a bit.
3290 */
3291 schedule_delayed_work(&expires_work,
3292 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3293
3294 if (register_pernet_subsys(&rt_secret_timer_ops))
3295 printk(KERN_ERR "Unable to setup rt_secret_timer\n");
3296
3297 if (ip_rt_proc_init())
3298 printk(KERN_ERR "Unable to create route proc files\n");
3299 #ifdef CONFIG_XFRM
3300 xfrm_init();
3301 xfrm4_init();
3302 #endif
3303 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3304
3305 #ifdef CONFIG_SYSCTL
3306 register_pernet_subsys(&sysctl_route_ops);
3307 #endif
3308 return rc;
3309 }
3310
3311 #ifdef CONFIG_SYSCTL
3312 /*
3313 * We really need to sanitize the damn ipv4 init order, then all
3314 * this nonsense will go away.
3315 */
3316 void __init ip_static_sysctl_init(void)
3317 {
3318 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3319 }
3320 #endif
3321
3322 EXPORT_SYMBOL(__ip_select_ident);
3323 EXPORT_SYMBOL(ip_route_input);
3324 EXPORT_SYMBOL(ip_route_output_key);
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree