1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #endif
110
111 #define RT_FL_TOS(oldflp) \
112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
113
114 #define IP_MAX_MTU 0xFFF0
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_max_size;
119 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
120 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
121 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
122 static int ip_rt_redirect_number __read_mostly = 9;
123 static int ip_rt_redirect_load __read_mostly = HZ / 50;
124 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
125 static int ip_rt_error_cost __read_mostly = HZ;
126 static int ip_rt_error_burst __read_mostly = 5 * HZ;
127 static int ip_rt_gc_elasticity __read_mostly = 8;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131 static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 static struct delayed_work expires_work;
135 static unsigned long expires_ljiffies;
136
137 /*
138 * Interface to generic destination cache.
139 */
140
141 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142 static void ipv4_dst_destroy(struct dst_entry *dst);
143 static void ipv4_dst_ifdown(struct dst_entry *dst,
144 struct net_device *dev, int how);
145 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
146 static void ipv4_link_failure(struct sk_buff *skb);
147 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
148 static int rt_garbage_collect(struct dst_ops *ops);
149 static void rt_emergency_hash_rebuild(struct net *net);
150
151
152 static struct dst_ops ipv4_dst_ops = {
153 .family = AF_INET,
154 .protocol = cpu_to_be16(ETH_P_IP),
155 .gc = rt_garbage_collect,
156 .check = ipv4_dst_check,
157 .destroy = ipv4_dst_destroy,
158 .ifdown = ipv4_dst_ifdown,
159 .negative_advice = ipv4_negative_advice,
160 .link_failure = ipv4_link_failure,
161 .update_pmtu = ip_rt_update_pmtu,
162 .local_out = __ip_local_out,
163 .entries = ATOMIC_INIT(0),
164 };
165
166 #define ECN_OR_COST(class) TC_PRIO_##class
167
168 const __u8 ip_tos2prio[16] = {
169 TC_PRIO_BESTEFFORT,
170 ECN_OR_COST(FILLER),
171 TC_PRIO_BESTEFFORT,
172 ECN_OR_COST(BESTEFFORT),
173 TC_PRIO_BULK,
174 ECN_OR_COST(BULK),
175 TC_PRIO_BULK,
176 ECN_OR_COST(BULK),
177 TC_PRIO_INTERACTIVE,
178 ECN_OR_COST(INTERACTIVE),
179 TC_PRIO_INTERACTIVE,
180 ECN_OR_COST(INTERACTIVE),
181 TC_PRIO_INTERACTIVE_BULK,
182 ECN_OR_COST(INTERACTIVE_BULK),
183 TC_PRIO_INTERACTIVE_BULK,
184 ECN_OR_COST(INTERACTIVE_BULK)
185 };
186
187
188 /*
189 * Route cache.
190 */
191
192 /* The locking scheme is rather straight forward:
193 *
194 * 1) Read-Copy Update protects the buckets of the central route hash.
195 * 2) Only writers remove entries, and they hold the lock
196 * as they look at rtable reference counts.
197 * 3) Only readers acquire references to rtable entries,
198 * they do so with atomic increments and with the
199 * lock held.
200 */
201
202 struct rt_hash_bucket {
203 struct rtable *chain;
204 };
205
206 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
207 defined(CONFIG_PROVE_LOCKING)
208 /*
209 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
210 * The size of this table is a power of two and depends on the number of CPUS.
211 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
212 */
213 #ifdef CONFIG_LOCKDEP
214 # define RT_HASH_LOCK_SZ 256
215 #else
216 # if NR_CPUS >= 32
217 # define RT_HASH_LOCK_SZ 4096
218 # elif NR_CPUS >= 16
219 # define RT_HASH_LOCK_SZ 2048
220 # elif NR_CPUS >= 8
221 # define RT_HASH_LOCK_SZ 1024
222 # elif NR_CPUS >= 4
223 # define RT_HASH_LOCK_SZ 512
224 # else
225 # define RT_HASH_LOCK_SZ 256
226 # endif
227 #endif
228
229 static spinlock_t *rt_hash_locks;
230 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
231
232 static __init void rt_hash_lock_init(void)
233 {
234 int i;
235
236 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
237 GFP_KERNEL);
238 if (!rt_hash_locks)
239 panic("IP: failed to allocate rt_hash_locks\n");
240
241 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
242 spin_lock_init(&rt_hash_locks[i]);
243 }
244 #else
245 # define rt_hash_lock_addr(slot) NULL
246
247 static inline void rt_hash_lock_init(void)
248 {
249 }
250 #endif
251
252 static struct rt_hash_bucket *rt_hash_table __read_mostly;
253 static unsigned rt_hash_mask __read_mostly;
254 static unsigned int rt_hash_log __read_mostly;
255
256 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
257 #define RT_CACHE_STAT_INC(field) \
258 (__raw_get_cpu_var(rt_cache_stat).field++)
259
260 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
261 int genid)
262 {
263 return jhash_3words((__force u32)(__be32)(daddr),
264 (__force u32)(__be32)(saddr),
265 idx, genid)
266 & rt_hash_mask;
267 }
268
269 static inline int rt_genid(struct net *net)
270 {
271 return atomic_read(&net->ipv4.rt_genid);
272 }
273
274 #ifdef CONFIG_PROC_FS
275 struct rt_cache_iter_state {
276 struct seq_net_private p;
277 int bucket;
278 int genid;
279 };
280
281 static struct rtable *rt_cache_get_first(struct seq_file *seq)
282 {
283 struct rt_cache_iter_state *st = seq->private;
284 struct rtable *r = NULL;
285
286 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
287 if (!rt_hash_table[st->bucket].chain)
288 continue;
289 rcu_read_lock_bh();
290 r = rcu_dereference(rt_hash_table[st->bucket].chain);
291 while (r) {
292 if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
293 r->rt_genid == st->genid)
294 return r;
295 r = rcu_dereference(r->u.dst.rt_next);
296 }
297 rcu_read_unlock_bh();
298 }
299 return r;
300 }
301
302 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
303 struct rtable *r)
304 {
305 struct rt_cache_iter_state *st = seq->private;
306
307 r = r->u.dst.rt_next;
308 while (!r) {
309 rcu_read_unlock_bh();
310 do {
311 if (--st->bucket < 0)
312 return NULL;
313 } while (!rt_hash_table[st->bucket].chain);
314 rcu_read_lock_bh();
315 r = rt_hash_table[st->bucket].chain;
316 }
317 return rcu_dereference(r);
318 }
319
320 static struct rtable *rt_cache_get_next(struct seq_file *seq,
321 struct rtable *r)
322 {
323 struct rt_cache_iter_state *st = seq->private;
324 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
325 if (dev_net(r->u.dst.dev) != seq_file_net(seq))
326 continue;
327 if (r->rt_genid == st->genid)
328 break;
329 }
330 return r;
331 }
332
333 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
334 {
335 struct rtable *r = rt_cache_get_first(seq);
336
337 if (r)
338 while (pos && (r = rt_cache_get_next(seq, r)))
339 --pos;
340 return pos ? NULL : r;
341 }
342
343 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
344 {
345 struct rt_cache_iter_state *st = seq->private;
346 if (*pos)
347 return rt_cache_get_idx(seq, *pos - 1);
348 st->genid = rt_genid(seq_file_net(seq));
349 return SEQ_START_TOKEN;
350 }
351
352 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
353 {
354 struct rtable *r;
355
356 if (v == SEQ_START_TOKEN)
357 r = rt_cache_get_first(seq);
358 else
359 r = rt_cache_get_next(seq, v);
360 ++*pos;
361 return r;
362 }
363
364 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
365 {
366 if (v && v != SEQ_START_TOKEN)
367 rcu_read_unlock_bh();
368 }
369
370 static int rt_cache_seq_show(struct seq_file *seq, void *v)
371 {
372 if (v == SEQ_START_TOKEN)
373 seq_printf(seq, "%-127s\n",
374 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
375 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
376 "HHUptod\tSpecDst");
377 else {
378 struct rtable *r = v;
379 int len;
380
381 seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
382 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
383 r->u.dst.dev ? r->u.dst.dev->name : "*",
384 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
385 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
386 r->u.dst.__use, 0, (unsigned long)r->rt_src,
387 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
388 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
389 dst_metric(&r->u.dst, RTAX_WINDOW),
390 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
391 dst_metric(&r->u.dst, RTAX_RTTVAR)),
392 r->fl.fl4_tos,
393 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
394 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
395 dev_queue_xmit) : 0,
396 r->rt_spec_dst, &len);
397
398 seq_printf(seq, "%*s\n", 127 - len, "");
399 }
400 return 0;
401 }
402
403 static const struct seq_operations rt_cache_seq_ops = {
404 .start = rt_cache_seq_start,
405 .next = rt_cache_seq_next,
406 .stop = rt_cache_seq_stop,
407 .show = rt_cache_seq_show,
408 };
409
410 static int rt_cache_seq_open(struct inode *inode, struct file *file)
411 {
412 return seq_open_net(inode, file, &rt_cache_seq_ops,
413 sizeof(struct rt_cache_iter_state));
414 }
415
416 static const struct file_operations rt_cache_seq_fops = {
417 .owner = THIS_MODULE,
418 .open = rt_cache_seq_open,
419 .read = seq_read,
420 .llseek = seq_lseek,
421 .release = seq_release_net,
422 };
423
424
425 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
426 {
427 int cpu;
428
429 if (*pos == 0)
430 return SEQ_START_TOKEN;
431
432 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
433 if (!cpu_possible(cpu))
434 continue;
435 *pos = cpu+1;
436 return &per_cpu(rt_cache_stat, cpu);
437 }
438 return NULL;
439 }
440
441 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
442 {
443 int cpu;
444
445 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
446 if (!cpu_possible(cpu))
447 continue;
448 *pos = cpu+1;
449 return &per_cpu(rt_cache_stat, cpu);
450 }
451 return NULL;
452
453 }
454
455 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
456 {
457
458 }
459
460 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
461 {
462 struct rt_cache_stat *st = v;
463
464 if (v == SEQ_START_TOKEN) {
465 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");
466 return 0;
467 }
468
469 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
470 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
471 atomic_read(&ipv4_dst_ops.entries),
472 st->in_hit,
473 st->in_slow_tot,
474 st->in_slow_mc,
475 st->in_no_route,
476 st->in_brd,
477 st->in_martian_dst,
478 st->in_martian_src,
479
480 st->out_hit,
481 st->out_slow_tot,
482 st->out_slow_mc,
483
484 st->gc_total,
485 st->gc_ignored,
486 st->gc_goal_miss,
487 st->gc_dst_overflow,
488 st->in_hlist_search,
489 st->out_hlist_search
490 );
491 return 0;
492 }
493
494 static const struct seq_operations rt_cpu_seq_ops = {
495 .start = rt_cpu_seq_start,
496 .next = rt_cpu_seq_next,
497 .stop = rt_cpu_seq_stop,
498 .show = rt_cpu_seq_show,
499 };
500
501
502 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
503 {
504 return seq_open(file, &rt_cpu_seq_ops);
505 }
506
507 static const struct file_operations rt_cpu_seq_fops = {
508 .owner = THIS_MODULE,
509 .open = rt_cpu_seq_open,
510 .read = seq_read,
511 .llseek = seq_lseek,
512 .release = seq_release,
513 };
514
515 #ifdef CONFIG_NET_CLS_ROUTE
516 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
517 int length, int *eof, void *data)
518 {
519 unsigned int i;
520
521 if ((offset & 3) || (length & 3))
522 return -EIO;
523
524 if (offset >= sizeof(struct ip_rt_acct) * 256) {
525 *eof = 1;
526 return 0;
527 }
528
529 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
530 length = sizeof(struct ip_rt_acct) * 256 - offset;
531 *eof = 1;
532 }
533
534 offset /= sizeof(u32);
535
536 if (length > 0) {
537 u32 *dst = (u32 *) buffer;
538
539 *start = buffer;
540 memset(dst, 0, length);
541
542 for_each_possible_cpu(i) {
543 unsigned int j;
544 u32 *src;
545
546 src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
547 for (j = 0; j < length/4; j++)
548 dst[j] += src[j];
549 }
550 }
551 return length;
552 }
553 #endif
554
555 static int __net_init ip_rt_do_proc_init(struct net *net)
556 {
557 struct proc_dir_entry *pde;
558
559 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
560 &rt_cache_seq_fops);
561 if (!pde)
562 goto err1;
563
564 pde = proc_create("rt_cache", S_IRUGO,
565 net->proc_net_stat, &rt_cpu_seq_fops);
566 if (!pde)
567 goto err2;
568
569 #ifdef CONFIG_NET_CLS_ROUTE
570 pde = create_proc_read_entry("rt_acct", 0, net->proc_net,
571 ip_rt_acct_read, NULL);
572 if (!pde)
573 goto err3;
574 #endif
575 return 0;
576
577 #ifdef CONFIG_NET_CLS_ROUTE
578 err3:
579 remove_proc_entry("rt_cache", net->proc_net_stat);
580 #endif
581 err2:
582 remove_proc_entry("rt_cache", net->proc_net);
583 err1:
584 return -ENOMEM;
585 }
586
587 static void __net_exit ip_rt_do_proc_exit(struct net *net)
588 {
589 remove_proc_entry("rt_cache", net->proc_net_stat);
590 remove_proc_entry("rt_cache", net->proc_net);
591 remove_proc_entry("rt_acct", net->proc_net);
592 }
593
594 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
595 .init = ip_rt_do_proc_init,
596 .exit = ip_rt_do_proc_exit,
597 };
598
599 static int __init ip_rt_proc_init(void)
600 {
601 return register_pernet_subsys(&ip_rt_proc_ops);
602 }
603
604 #else
605 static inline int ip_rt_proc_init(void)
606 {
607 return 0;
608 }
609 #endif /* CONFIG_PROC_FS */
610
611 static inline void rt_free(struct rtable *rt)
612 {
613 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
614 }
615
616 static inline void rt_drop(struct rtable *rt)
617 {
618 ip_rt_put(rt);
619 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
620 }
621
622 static inline int rt_fast_clean(struct rtable *rth)
623 {
624 /* Kill broadcast/multicast entries very aggresively, if they
625 collide in hash table with more useful entries */
626 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
627 rth->fl.iif && rth->u.dst.rt_next;
628 }
629
630 static inline int rt_valuable(struct rtable *rth)
631 {
632 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
633 rth->u.dst.expires;
634 }
635
636 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
637 {
638 unsigned long age;
639 int ret = 0;
640
641 if (atomic_read(&rth->u.dst.__refcnt))
642 goto out;
643
644 ret = 1;
645 if (rth->u.dst.expires &&
646 time_after_eq(jiffies, rth->u.dst.expires))
647 goto out;
648
649 age = jiffies - rth->u.dst.lastuse;
650 ret = 0;
651 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
652 (age <= tmo2 && rt_valuable(rth)))
653 goto out;
654 ret = 1;
655 out: return ret;
656 }
657
658 /* Bits of score are:
659 * 31: very valuable
660 * 30: not quite useless
661 * 29..0: usage counter
662 */
663 static inline u32 rt_score(struct rtable *rt)
664 {
665 u32 score = jiffies - rt->u.dst.lastuse;
666
667 score = ~score & ~(3<<30);
668
669 if (rt_valuable(rt))
670 score |= (1<<31);
671
672 if (!rt->fl.iif ||
673 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
674 score |= (1<<30);
675
676 return score;
677 }
678
679 static inline bool rt_caching(const struct net *net)
680 {
681 return net->ipv4.current_rt_cache_rebuild_count <=
682 net->ipv4.sysctl_rt_cache_rebuild_count;
683 }
684
685 static inline bool compare_hash_inputs(const struct flowi *fl1,
686 const struct flowi *fl2)
687 {
688 return (__force u32)(((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
689 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) |
690 (fl1->iif ^ fl2->iif)) == 0);
691 }
692
693 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
694 {
695 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
696 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
697 (fl1->mark ^ fl2->mark) |
698 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
699 *(u16 *)&fl2->nl_u.ip4_u.tos) |
700 (fl1->oif ^ fl2->oif) |
701 (fl1->iif ^ fl2->iif)) == 0;
702 }
703
704 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
705 {
706 return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.dst.dev);
707 }
708
709 static inline int rt_is_expired(struct rtable *rth)
710 {
711 return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev));
712 }
713
714 /*
715 * Perform a full scan of hash table and free all entries.
716 * Can be called by a softirq or a process.
717 * In the later case, we want to be reschedule if necessary
718 */
719 static void rt_do_flush(int process_context)
720 {
721 unsigned int i;
722 struct rtable *rth, *next;
723 struct rtable * tail;
724
725 for (i = 0; i <= rt_hash_mask; i++) {
726 if (process_context && need_resched())
727 cond_resched();
728 rth = rt_hash_table[i].chain;
729 if (!rth)
730 continue;
731
732 spin_lock_bh(rt_hash_lock_addr(i));
733 #ifdef CONFIG_NET_NS
734 {
735 struct rtable ** prev, * p;
736
737 rth = rt_hash_table[i].chain;
738
739 /* defer releasing the head of the list after spin_unlock */
740 for (tail = rth; tail; tail = tail->u.dst.rt_next)
741 if (!rt_is_expired(tail))
742 break;
743 if (rth != tail)
744 rt_hash_table[i].chain = tail;
745
746 /* call rt_free on entries after the tail requiring flush */
747 prev = &rt_hash_table[i].chain;
748 for (p = *prev; p; p = next) {
749 next = p->u.dst.rt_next;
750 if (!rt_is_expired(p)) {
751 prev = &p->u.dst.rt_next;
752 } else {
753 *prev = next;
754 rt_free(p);
755 }
756 }
757 }
758 #else
759 rth = rt_hash_table[i].chain;
760 rt_hash_table[i].chain = NULL;
761 tail = NULL;
762 #endif
763 spin_unlock_bh(rt_hash_lock_addr(i));
764
765 for (; rth != tail; rth = next) {
766 next = rth->u.dst.rt_next;
767 rt_free(rth);
768 }
769 }
770 }
771
772 /*
773 * While freeing expired entries, we compute average chain length
774 * and standard deviation, using fixed-point arithmetic.
775 * This to have an estimation of rt_chain_length_max
776 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
777 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
778 */
779
780 #define FRACT_BITS 3
781 #define ONE (1UL << FRACT_BITS)
782
783 static void rt_check_expire(void)
784 {
785 static unsigned int rover;
786 unsigned int i = rover, goal;
787 struct rtable *rth, *aux, **rthp;
788 unsigned long samples = 0;
789 unsigned long sum = 0, sum2 = 0;
790 unsigned long delta;
791 u64 mult;
792
793 delta = jiffies - expires_ljiffies;
794 expires_ljiffies = jiffies;
795 mult = ((u64)delta) << rt_hash_log;
796 if (ip_rt_gc_timeout > 1)
797 do_div(mult, ip_rt_gc_timeout);
798 goal = (unsigned int)mult;
799 if (goal > rt_hash_mask)
800 goal = rt_hash_mask + 1;
801 for (; goal > 0; goal--) {
802 unsigned long tmo = ip_rt_gc_timeout;
803 unsigned long length;
804
805 i = (i + 1) & rt_hash_mask;
806 rthp = &rt_hash_table[i].chain;
807
808 if (need_resched())
809 cond_resched();
810
811 samples++;
812
813 if (*rthp == NULL)
814 continue;
815 length = 0;
816 spin_lock_bh(rt_hash_lock_addr(i));
817 while ((rth = *rthp) != NULL) {
818 prefetch(rth->u.dst.rt_next);
819 if (rt_is_expired(rth)) {
820 *rthp = rth->u.dst.rt_next;
821 rt_free(rth);
822 continue;
823 }
824 if (rth->u.dst.expires) {
825 /* Entry is expired even if it is in use */
826 if (time_before_eq(jiffies, rth->u.dst.expires)) {
827 nofree:
828 tmo >>= 1;
829 rthp = &rth->u.dst.rt_next;
830 /*
831 * We only count entries on
832 * a chain with equal hash inputs once
833 * so that entries for different QOS
834 * levels, and other non-hash input
835 * attributes don't unfairly skew
836 * the length computation
837 */
838 for (aux = rt_hash_table[i].chain;;) {
839 if (aux == rth) {
840 length += ONE;
841 break;
842 }
843 if (compare_hash_inputs(&aux->fl, &rth->fl))
844 break;
845 aux = aux->u.dst.rt_next;
846 }
847 continue;
848 }
849 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
850 goto nofree;
851
852 /* Cleanup aged off entries. */
853 *rthp = rth->u.dst.rt_next;
854 rt_free(rth);
855 }
856 spin_unlock_bh(rt_hash_lock_addr(i));
857 sum += length;
858 sum2 += length*length;
859 }
860 if (samples) {
861 unsigned long avg = sum / samples;
862 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
863 rt_chain_length_max = max_t(unsigned long,
864 ip_rt_gc_elasticity,
865 (avg + 4*sd) >> FRACT_BITS);
866 }
867 rover = i;
868 }
869
870 /*
871 * rt_worker_func() is run in process context.
872 * we call rt_check_expire() to scan part of the hash table
873 */
874 static void rt_worker_func(struct work_struct *work)
875 {
876 rt_check_expire();
877 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
878 }
879
880 /*
881 * Pertubation of rt_genid by a small quantity [1..256]
882 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
883 * many times (2^24) without giving recent rt_genid.
884 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
885 */
886 static void rt_cache_invalidate(struct net *net)
887 {
888 unsigned char shuffle;
889
890 get_random_bytes(&shuffle, sizeof(shuffle));
891 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
892 }
893
894 /*
895 * delay < 0 : invalidate cache (fast : entries will be deleted later)
896 * delay >= 0 : invalidate & flush cache (can be long)
897 */
898 void rt_cache_flush(struct net *net, int delay)
899 {
900 rt_cache_invalidate(net);
901 if (delay >= 0)
902 rt_do_flush(!in_softirq());
903 }
904
905 /*
906 * We change rt_genid and let gc do the cleanup
907 */
908 static void rt_secret_rebuild(unsigned long __net)
909 {
910 struct net *net = (struct net *)__net;
911 rt_cache_invalidate(net);
912 mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
913 }
914
915 static void rt_secret_rebuild_oneshot(struct net *net)
916 {
917 del_timer_sync(&net->ipv4.rt_secret_timer);
918 rt_cache_invalidate(net);
919 if (ip_rt_secret_interval) {
920 net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
921 add_timer(&net->ipv4.rt_secret_timer);
922 }
923 }
924
925 static void rt_emergency_hash_rebuild(struct net *net)
926 {
927 if (net_ratelimit()) {
928 printk(KERN_WARNING "Route hash chain too long!\n");
929 printk(KERN_WARNING "Adjust your secret_interval!\n");
930 }
931
932 rt_secret_rebuild_oneshot(net);
933 }
934
935 /*
936 Short description of GC goals.
937
938 We want to build algorithm, which will keep routing cache
939 at some equilibrium point, when number of aged off entries
940 is kept approximately equal to newly generated ones.
941
942 Current expiration strength is variable "expire".
943 We try to adjust it dynamically, so that if networking
944 is idle expires is large enough to keep enough of warm entries,
945 and when load increases it reduces to limit cache size.
946 */
947
948 static int rt_garbage_collect(struct dst_ops *ops)
949 {
950 static unsigned long expire = RT_GC_TIMEOUT;
951 static unsigned long last_gc;
952 static int rover;
953 static int equilibrium;
954 struct rtable *rth, **rthp;
955 unsigned long now = jiffies;
956 int goal;
957
958 /*
959 * Garbage collection is pretty expensive,
960 * do not make it too frequently.
961 */
962
963 RT_CACHE_STAT_INC(gc_total);
964
965 if (now - last_gc < ip_rt_gc_min_interval &&
966 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
967 RT_CACHE_STAT_INC(gc_ignored);
968 goto out;
969 }
970
971 /* Calculate number of entries, which we want to expire now. */
972 goal = atomic_read(&ipv4_dst_ops.entries) -
973 (ip_rt_gc_elasticity << rt_hash_log);
974 if (goal <= 0) {
975 if (equilibrium < ipv4_dst_ops.gc_thresh)
976 equilibrium = ipv4_dst_ops.gc_thresh;
977 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
978 if (goal > 0) {
979 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
980 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
981 }
982 } else {
983 /* We are in dangerous area. Try to reduce cache really
984 * aggressively.
985 */
986 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
987 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
988 }
989
990 if (now - last_gc >= ip_rt_gc_min_interval)
991 last_gc = now;
992
993 if (goal <= 0) {
994 equilibrium += goal;
995 goto work_done;
996 }
997
998 do {
999 int i, k;
1000
1001 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1002 unsigned long tmo = expire;
1003
1004 k = (k + 1) & rt_hash_mask;
1005 rthp = &rt_hash_table[k].chain;
1006 spin_lock_bh(rt_hash_lock_addr(k));
1007 while ((rth = *rthp) != NULL) {
1008 if (!rt_is_expired(rth) &&
1009 !rt_may_expire(rth, tmo, expire)) {
1010 tmo >>= 1;
1011 rthp = &rth->u.dst.rt_next;
1012 continue;
1013 }
1014 *rthp = rth->u.dst.rt_next;
1015 rt_free(rth);
1016 goal--;
1017 }
1018 spin_unlock_bh(rt_hash_lock_addr(k));
1019 if (goal <= 0)
1020 break;
1021 }
1022 rover = k;
1023
1024 if (goal <= 0)
1025 goto work_done;
1026
1027 /* Goal is not achieved. We stop process if:
1028
1029 - if expire reduced to zero. Otherwise, expire is halfed.
1030 - if table is not full.
1031 - if we are called from interrupt.
1032 - jiffies check is just fallback/debug loop breaker.
1033 We will not spin here for long time in any case.
1034 */
1035
1036 RT_CACHE_STAT_INC(gc_goal_miss);
1037
1038 if (expire == 0)
1039 break;
1040
1041 expire >>= 1;
1042 #if RT_CACHE_DEBUG >= 2
1043 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1044 atomic_read(&ipv4_dst_ops.entries), goal, i);
1045 #endif
1046
1047 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1048 goto out;
1049 } while (!in_softirq() && time_before_eq(jiffies, now));
1050
1051 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1052 goto out;
1053 if (net_ratelimit())
1054 printk(KERN_WARNING "dst cache overflow\n");
1055 RT_CACHE_STAT_INC(gc_dst_overflow);
1056 return 1;
1057
1058 work_done:
1059 expire += ip_rt_gc_min_interval;
1060 if (expire > ip_rt_gc_timeout ||
1061 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
1062 expire = ip_rt_gc_timeout;
1063 #if RT_CACHE_DEBUG >= 2
1064 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1065 atomic_read(&ipv4_dst_ops.entries), goal, rover);
1066 #endif
1067 out: return 0;
1068 }
1069
1070 static int rt_intern_hash(unsigned hash, struct rtable *rt,
1071 struct rtable **rp, struct sk_buff *skb)
1072 {
1073 struct rtable *rth, **rthp;
1074 unsigned long now;
1075 struct rtable *cand, **candp;
1076 u32 min_score;
1077 int chain_length;
1078 int attempts = !in_softirq();
1079
1080 restart:
1081 chain_length = 0;
1082 min_score = ~(u32)0;
1083 cand = NULL;
1084 candp = NULL;
1085 now = jiffies;
1086
1087 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1088 /*
1089 * If we're not caching, just tell the caller we
1090 * were successful and don't touch the route. The
1091 * caller hold the sole reference to the cache entry, and
1092 * it will be released when the caller is done with it.
1093 * If we drop it here, the callers have no way to resolve routes
1094 * when we're not caching. Instead, just point *rp at rt, so
1095 * the caller gets a single use out of the route
1096 * Note that we do rt_free on this new route entry, so that
1097 * once its refcount hits zero, we are still able to reap it
1098 * (Thanks Alexey)
1099 * Note also the rt_free uses call_rcu. We don't actually
1100 * need rcu protection here, this is just our path to get
1101 * on the route gc list.
1102 */
1103
1104 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1105 int err = arp_bind_neighbour(&rt->u.dst);
1106 if (err) {
1107 if (net_ratelimit())
1108 printk(KERN_WARNING
1109 "Neighbour table failure & not caching routes.\n");
1110 rt_drop(rt);
1111 return err;
1112 }
1113 }
1114
1115 rt_free(rt);
1116 goto skip_hashing;
1117 }
1118
1119 rthp = &rt_hash_table[hash].chain;
1120
1121 spin_lock_bh(rt_hash_lock_addr(hash));
1122 while ((rth = *rthp) != NULL) {
1123 if (rt_is_expired(rth)) {
1124 *rthp = rth->u.dst.rt_next;
1125 rt_free(rth);
1126 continue;
1127 }
1128 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1129 /* Put it first */
1130 *rthp = rth->u.dst.rt_next;
1131 /*
1132 * Since lookup is lockfree, the deletion
1133 * must be visible to another weakly ordered CPU before
1134 * the insertion at the start of the hash chain.
1135 */
1136 rcu_assign_pointer(rth->u.dst.rt_next,
1137 rt_hash_table[hash].chain);
1138 /*
1139 * Since lookup is lockfree, the update writes
1140 * must be ordered for consistency on SMP.
1141 */
1142 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1143
1144 dst_use(&rth->u.dst, now);
1145 spin_unlock_bh(rt_hash_lock_addr(hash));
1146
1147 rt_drop(rt);
1148 if (rp)
1149 *rp = rth;
1150 else
1151 skb_dst_set(skb, &rth->u.dst);
1152 return 0;
1153 }
1154
1155 if (!atomic_read(&rth->u.dst.__refcnt)) {
1156 u32 score = rt_score(rth);
1157
1158 if (score <= min_score) {
1159 cand = rth;
1160 candp = rthp;
1161 min_score = score;
1162 }
1163 }
1164
1165 chain_length++;
1166
1167 rthp = &rth->u.dst.rt_next;
1168 }
1169
1170 if (cand) {
1171 /* ip_rt_gc_elasticity used to be average length of chain
1172 * length, when exceeded gc becomes really aggressive.
1173 *
1174 * The second limit is less certain. At the moment it allows
1175 * only 2 entries per bucket. We will see.
1176 */
1177 if (chain_length > ip_rt_gc_elasticity) {
1178 *candp = cand->u.dst.rt_next;
1179 rt_free(cand);
1180 }
1181 } else {
1182 if (chain_length > rt_chain_length_max) {
1183 struct net *net = dev_net(rt->u.dst.dev);
1184 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1185 if (!rt_caching(dev_net(rt->u.dst.dev))) {
1186 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1187 rt->u.dst.dev->name, num);
1188 }
1189 rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
1190 }
1191 }
1192
1193 /* Try to bind route to arp only if it is output
1194 route or unicast forwarding path.
1195 */
1196 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1197 int err = arp_bind_neighbour(&rt->u.dst);
1198 if (err) {
1199 spin_unlock_bh(rt_hash_lock_addr(hash));
1200
1201 if (err != -ENOBUFS) {
1202 rt_drop(rt);
1203 return err;
1204 }
1205
1206 /* Neighbour tables are full and nothing
1207 can be released. Try to shrink route cache,
1208 it is most likely it holds some neighbour records.
1209 */
1210 if (attempts-- > 0) {
1211 int saved_elasticity = ip_rt_gc_elasticity;
1212 int saved_int = ip_rt_gc_min_interval;
1213 ip_rt_gc_elasticity = 1;
1214 ip_rt_gc_min_interval = 0;
1215 rt_garbage_collect(&ipv4_dst_ops);
1216 ip_rt_gc_min_interval = saved_int;
1217 ip_rt_gc_elasticity = saved_elasticity;
1218 goto restart;
1219 }
1220
1221 if (net_ratelimit())
1222 printk(KERN_WARNING "Neighbour table overflow.\n");
1223 rt_drop(rt);
1224 return -ENOBUFS;
1225 }
1226 }
1227
1228 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1229
1230 #if RT_CACHE_DEBUG >= 2
1231 if (rt->u.dst.rt_next) {
1232 struct rtable *trt;
1233 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1234 hash, &rt->rt_dst);
1235 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1236 printk(" . %pI4", &trt->rt_dst);
1237 printk("\n");
1238 }
1239 #endif
1240 /*
1241 * Since lookup is lockfree, we must make sure
1242 * previous writes to rt are comitted to memory
1243 * before making rt visible to other CPUS.
1244 */
1245 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1246
1247 spin_unlock_bh(rt_hash_lock_addr(hash));
1248
1249 skip_hashing:
1250 if (rp)
1251 *rp = rt;
1252 else
1253 skb_dst_set(skb, &rt->u.dst);
1254 return 0;
1255 }
1256
1257 void rt_bind_peer(struct rtable *rt, int create)
1258 {
1259 static DEFINE_SPINLOCK(rt_peer_lock);
1260 struct inet_peer *peer;
1261
1262 peer = inet_getpeer(rt->rt_dst, create);
1263
1264 spin_lock_bh(&rt_peer_lock);
1265 if (rt->peer == NULL) {
1266 rt->peer = peer;
1267 peer = NULL;
1268 }
1269 spin_unlock_bh(&rt_peer_lock);
1270 if (peer)
1271 inet_putpeer(peer);
1272 }
1273
1274 /*
1275 * Peer allocation may fail only in serious out-of-memory conditions. However
1276 * we still can generate some output.
1277 * Random ID selection looks a bit dangerous because we have no chances to
1278 * select ID being unique in a reasonable period of time.
1279 * But broken packet identifier may be better than no packet at all.
1280 */
1281 static void ip_select_fb_ident(struct iphdr *iph)
1282 {
1283 static DEFINE_SPINLOCK(ip_fb_id_lock);
1284 static u32 ip_fallback_id;
1285 u32 salt;
1286
1287 spin_lock_bh(&ip_fb_id_lock);
1288 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1289 iph->id = htons(salt & 0xFFFF);
1290 ip_fallback_id = salt;
1291 spin_unlock_bh(&ip_fb_id_lock);
1292 }
1293
1294 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1295 {
1296 struct rtable *rt = (struct rtable *) dst;
1297
1298 if (rt) {
1299 if (rt->peer == NULL)
1300 rt_bind_peer(rt, 1);
1301
1302 /* If peer is attached to destination, it is never detached,
1303 so that we need not to grab a lock to dereference it.
1304 */
1305 if (rt->peer) {
1306 iph->id = htons(inet_getid(rt->peer, more));
1307 return;
1308 }
1309 } else
1310 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1311 __builtin_return_address(0));
1312
1313 ip_select_fb_ident(iph);
1314 }
1315
1316 static void rt_del(unsigned hash, struct rtable *rt)
1317 {
1318 struct rtable **rthp, *aux;
1319
1320 rthp = &rt_hash_table[hash].chain;
1321 spin_lock_bh(rt_hash_lock_addr(hash));
1322 ip_rt_put(rt);
1323 while ((aux = *rthp) != NULL) {
1324 if (aux == rt || rt_is_expired(aux)) {
1325 *rthp = aux->u.dst.rt_next;
1326 rt_free(aux);
1327 continue;
1328 }
1329 rthp = &aux->u.dst.rt_next;
1330 }
1331 spin_unlock_bh(rt_hash_lock_addr(hash));
1332 }
1333
1334 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1335 __be32 saddr, struct net_device *dev)
1336 {
1337 int i, k;
1338 struct in_device *in_dev = in_dev_get(dev);
1339 struct rtable *rth, **rthp;
1340 __be32 skeys[2] = { saddr, 0 };
1341 int ikeys[2] = { dev->ifindex, 0 };
1342 struct netevent_redirect netevent;
1343 struct net *net;
1344
1345 if (!in_dev)
1346 return;
1347
1348 net = dev_net(dev);
1349 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1350 || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
1351 || ipv4_is_zeronet(new_gw))
1352 goto reject_redirect;
1353
1354 if (!rt_caching(net))
1355 goto reject_redirect;
1356
1357 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1358 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1359 goto reject_redirect;
1360 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1361 goto reject_redirect;
1362 } else {
1363 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1364 goto reject_redirect;
1365 }
1366
1367 for (i = 0; i < 2; i++) {
1368 for (k = 0; k < 2; k++) {
1369 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1370 rt_genid(net));
1371
1372 rthp=&rt_hash_table[hash].chain;
1373
1374 rcu_read_lock();
1375 while ((rth = rcu_dereference(*rthp)) != NULL) {
1376 struct rtable *rt;
1377
1378 if (rth->fl.fl4_dst != daddr ||
1379 rth->fl.fl4_src != skeys[i] ||
1380 rth->fl.oif != ikeys[k] ||
1381 rth->fl.iif != 0 ||
1382 rt_is_expired(rth) ||
1383 !net_eq(dev_net(rth->u.dst.dev), net)) {
1384 rthp = &rth->u.dst.rt_next;
1385 continue;
1386 }
1387
1388 if (rth->rt_dst != daddr ||
1389 rth->rt_src != saddr ||
1390 rth->u.dst.error ||
1391 rth->rt_gateway != old_gw ||
1392 rth->u.dst.dev != dev)
1393 break;
1394
1395 dst_hold(&rth->u.dst);
1396 rcu_read_unlock();
1397
1398 rt = dst_alloc(&ipv4_dst_ops);
1399 if (rt == NULL) {
1400 ip_rt_put(rth);
1401 in_dev_put(in_dev);
1402 return;
1403 }
1404
1405 /* Copy all the information. */
1406 *rt = *rth;
1407 rt->u.dst.__use = 1;
1408 atomic_set(&rt->u.dst.__refcnt, 1);
1409 rt->u.dst.child = NULL;
1410 if (rt->u.dst.dev)
1411 dev_hold(rt->u.dst.dev);
1412 if (rt->idev)
1413 in_dev_hold(rt->idev);
1414 rt->u.dst.obsolete = 0;
1415 rt->u.dst.lastuse = jiffies;
1416 rt->u.dst.path = &rt->u.dst;
1417 rt->u.dst.neighbour = NULL;
1418 rt->u.dst.hh = NULL;
1419 #ifdef CONFIG_XFRM
1420 rt->u.dst.xfrm = NULL;
1421 #endif
1422 rt->rt_genid = rt_genid(net);
1423 rt->rt_flags |= RTCF_REDIRECTED;
1424
1425 /* Gateway is different ... */
1426 rt->rt_gateway = new_gw;
1427
1428 /* Redirect received -> path was valid */
1429 dst_confirm(&rth->u.dst);
1430
1431 if (rt->peer)
1432 atomic_inc(&rt->peer->refcnt);
1433
1434 if (arp_bind_neighbour(&rt->u.dst) ||
1435 !(rt->u.dst.neighbour->nud_state &
1436 NUD_VALID)) {
1437 if (rt->u.dst.neighbour)
1438 neigh_event_send(rt->u.dst.neighbour, NULL);
1439 ip_rt_put(rth);
1440 rt_drop(rt);
1441 goto do_next;
1442 }
1443
1444 netevent.old = &rth->u.dst;
1445 netevent.new = &rt->u.dst;
1446 call_netevent_notifiers(NETEVENT_REDIRECT,
1447 &netevent);
1448
1449 rt_del(hash, rth);
1450 if (!rt_intern_hash(hash, rt, &rt, NULL))
1451 ip_rt_put(rt);
1452 goto do_next;
1453 }
1454 rcu_read_unlock();
1455 do_next:
1456 ;
1457 }
1458 }
1459 in_dev_put(in_dev);
1460 return;
1461
1462 reject_redirect:
1463 #ifdef CONFIG_IP_ROUTE_VERBOSE
1464 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1465 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1466 " Advised path = %pI4 -> %pI4\n",
1467 &old_gw, dev->name, &new_gw,
1468 &saddr, &daddr);
1469 #endif
1470 in_dev_put(in_dev);
1471 }
1472
1473 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1474 {
1475 struct rtable *rt = (struct rtable *)dst;
1476 struct dst_entry *ret = dst;
1477
1478 if (rt) {
1479 if (dst->obsolete) {
1480 ip_rt_put(rt);
1481 ret = NULL;
1482 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1483 rt->u.dst.expires) {
1484 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1485 rt->fl.oif,
1486 rt_genid(dev_net(dst->dev)));
1487 #if RT_CACHE_DEBUG >= 1
1488 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1489 &rt->rt_dst, rt->fl.fl4_tos);
1490 #endif
1491 rt_del(hash, rt);
1492 ret = NULL;
1493 }
1494 }
1495 return ret;
1496 }
1497
1498 /*
1499 * Algorithm:
1500 * 1. The first ip_rt_redirect_number redirects are sent
1501 * with exponential backoff, then we stop sending them at all,
1502 * assuming that the host ignores our redirects.
1503 * 2. If we did not see packets requiring redirects
1504 * during ip_rt_redirect_silence, we assume that the host
1505 * forgot redirected route and start to send redirects again.
1506 *
1507 * This algorithm is much cheaper and more intelligent than dumb load limiting
1508 * in icmp.c.
1509 *
1510 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1511 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1512 */
1513
1514 void ip_rt_send_redirect(struct sk_buff *skb)
1515 {
1516 struct rtable *rt = skb_rtable(skb);
1517 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1518
1519 if (!in_dev)
1520 return;
1521
1522 if (!IN_DEV_TX_REDIRECTS(in_dev))
1523 goto out;
1524
1525 /* No redirected packets during ip_rt_redirect_silence;
1526 * reset the algorithm.
1527 */
1528 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1529 rt->u.dst.rate_tokens = 0;
1530
1531 /* Too many ignored redirects; do not send anything
1532 * set u.dst.rate_last to the last seen redirected packet.
1533 */
1534 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1535 rt->u.dst.rate_last = jiffies;
1536 goto out;
1537 }
1538
1539 /* Check for load limit; set rate_last to the latest sent
1540 * redirect.
1541 */
1542 if (rt->u.dst.rate_tokens == 0 ||
1543 time_after(jiffies,
1544 (rt->u.dst.rate_last +
1545 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1546 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1547 rt->u.dst.rate_last = jiffies;
1548 ++rt->u.dst.rate_tokens;
1549 #ifdef CONFIG_IP_ROUTE_VERBOSE
1550 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1551 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1552 net_ratelimit())
1553 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1554 &rt->rt_src, rt->rt_iif,
1555 &rt->rt_dst, &rt->rt_gateway);
1556 #endif
1557 }
1558 out:
1559 in_dev_put(in_dev);
1560 }
1561
1562 static int ip_error(struct sk_buff *skb)
1563 {
1564 struct rtable *rt = skb_rtable(skb);
1565 unsigned long now;
1566 int code;
1567
1568 switch (rt->u.dst.error) {
1569 case EINVAL:
1570 default:
1571 goto out;
1572 case EHOSTUNREACH:
1573 code = ICMP_HOST_UNREACH;
1574 break;
1575 case ENETUNREACH:
1576 code = ICMP_NET_UNREACH;
1577 IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
1578 IPSTATS_MIB_INNOROUTES);
1579 break;
1580 case EACCES:
1581 code = ICMP_PKT_FILTERED;
1582 break;
1583 }
1584
1585 now = jiffies;
1586 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1587 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1588 rt->u.dst.rate_tokens = ip_rt_error_burst;
1589 rt->u.dst.rate_last = now;
1590 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1591 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1592 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1593 }
1594
1595 out: kfree_skb(skb);
1596 return 0;
1597 }
1598
1599 /*
1600 * The last two values are not from the RFC but
1601 * are needed for AMPRnet AX.25 paths.
1602 */
1603
1604 static const unsigned short mtu_plateau[] =
1605 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1606
1607 static inline unsigned short guess_mtu(unsigned short old_mtu)
1608 {
1609 int i;
1610
1611 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1612 if (old_mtu > mtu_plateau[i])
1613 return mtu_plateau[i];
1614 return 68;
1615 }
1616
1617 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1618 unsigned short new_mtu,
1619 struct net_device *dev)
1620 {
1621 int i, k;
1622 unsigned short old_mtu = ntohs(iph->tot_len);
1623 struct rtable *rth;
1624 int ikeys[2] = { dev->ifindex, 0 };
1625 __be32 skeys[2] = { iph->saddr, 0, };
1626 __be32 daddr = iph->daddr;
1627 unsigned short est_mtu = 0;
1628
1629 if (ipv4_config.no_pmtu_disc)
1630 return 0;
1631
1632 for (k = 0; k < 2; k++) {
1633 for (i = 0; i < 2; i++) {
1634 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1635 rt_genid(net));
1636
1637 rcu_read_lock();
1638 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1639 rth = rcu_dereference(rth->u.dst.rt_next)) {
1640 unsigned short mtu = new_mtu;
1641
1642 if (rth->fl.fl4_dst != daddr ||
1643 rth->fl.fl4_src != skeys[i] ||
1644 rth->rt_dst != daddr ||
1645 rth->rt_src != iph->saddr ||
1646 rth->fl.oif != ikeys[k] ||
1647 rth->fl.iif != 0 ||
1648 dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
1649 !net_eq(dev_net(rth->u.dst.dev), net) ||
1650 rt_is_expired(rth))
1651 continue;
1652
1653 if (new_mtu < 68 || new_mtu >= old_mtu) {
1654
1655 /* BSD 4.2 compatibility hack :-( */
1656 if (mtu == 0 &&
1657 old_mtu >= dst_mtu(&rth->u.dst) &&
1658 old_mtu >= 68 + (iph->ihl << 2))
1659 old_mtu -= iph->ihl << 2;
1660
1661 mtu = guess_mtu(old_mtu);
1662 }
1663 if (mtu <= dst_mtu(&rth->u.dst)) {
1664 if (mtu < dst_mtu(&rth->u.dst)) {
1665 dst_confirm(&rth->u.dst);
1666 if (mtu < ip_rt_min_pmtu) {
1667 mtu = ip_rt_min_pmtu;
1668 rth->u.dst.metrics[RTAX_LOCK-1] |=
1669 (1 << RTAX_MTU);
1670 }
1671 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1672 dst_set_expires(&rth->u.dst,
1673 ip_rt_mtu_expires);
1674 }
1675 est_mtu = mtu;
1676 }
1677 }
1678 rcu_read_unlock();
1679 }
1680 }
1681 return est_mtu ? : new_mtu;
1682 }
1683
1684 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1685 {
1686 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1687 !(dst_metric_locked(dst, RTAX_MTU))) {
1688 if (mtu < ip_rt_min_pmtu) {
1689 mtu = ip_rt_min_pmtu;
1690 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1691 }
1692 dst->metrics[RTAX_MTU-1] = mtu;
1693 dst_set_expires(dst, ip_rt_mtu_expires);
1694 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1695 }
1696 }
1697
1698 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1699 {
1700 return NULL;
1701 }
1702
1703 static void ipv4_dst_destroy(struct dst_entry *dst)
1704 {
1705 struct rtable *rt = (struct rtable *) dst;
1706 struct inet_peer *peer = rt->peer;
1707 struct in_device *idev = rt->idev;
1708
1709 if (peer) {
1710 rt->peer = NULL;
1711 inet_putpeer(peer);
1712 }
1713
1714 if (idev) {
1715 rt->idev = NULL;
1716 in_dev_put(idev);
1717 }
1718 }
1719
1720 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1721 int how)
1722 {
1723 struct rtable *rt = (struct rtable *) dst;
1724 struct in_device *idev = rt->idev;
1725 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1726 struct in_device *loopback_idev =
1727 in_dev_get(dev_net(dev)->loopback_dev);
1728 if (loopback_idev) {
1729 rt->idev = loopback_idev;
1730 in_dev_put(idev);
1731 }
1732 }
1733 }
1734
1735 static void ipv4_link_failure(struct sk_buff *skb)
1736 {
1737 struct rtable *rt;
1738
1739 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1740
1741 rt = skb_rtable(skb);
1742 if (rt)
1743 dst_set_expires(&rt->u.dst, 0);
1744 }
1745
1746 static int ip_rt_bug(struct sk_buff *skb)
1747 {
1748 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1749 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1750 skb->dev ? skb->dev->name : "?");
1751 kfree_skb(skb);
1752 return 0;
1753 }
1754
1755 /*
1756 We do not cache source address of outgoing interface,
1757 because it is used only by IP RR, TS and SRR options,
1758 so that it out of fast path.
1759
1760 BTW remember: "addr" is allowed to be not aligned
1761 in IP options!
1762 */
1763
1764 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1765 {
1766 __be32 src;
1767 struct fib_result res;
1768
1769 if (rt->fl.iif == 0)
1770 src = rt->rt_src;
1771 else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
1772 src = FIB_RES_PREFSRC(res);
1773 fib_res_put(&res);
1774 } else
1775 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1776 RT_SCOPE_UNIVERSE);
1777 memcpy(addr, &src, 4);
1778 }
1779
1780 #ifdef CONFIG_NET_CLS_ROUTE
1781 static void set_class_tag(struct rtable *rt, u32 tag)
1782 {
1783 if (!(rt->u.dst.tclassid & 0xFFFF))
1784 rt->u.dst.tclassid |= tag & 0xFFFF;
1785 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1786 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1787 }
1788 #endif
1789
1790 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1791 {
1792 struct fib_info *fi = res->fi;
1793
1794 if (fi) {
1795 if (FIB_RES_GW(*res) &&
1796 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1797 rt->rt_gateway = FIB_RES_GW(*res);
1798 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1799 sizeof(rt->u.dst.metrics));
1800 if (fi->fib_mtu == 0) {
1801 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1802 if (dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
1803 rt->rt_gateway != rt->rt_dst &&
1804 rt->u.dst.dev->mtu > 576)
1805 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1806 }
1807 #ifdef CONFIG_NET_CLS_ROUTE
1808 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1809 #endif
1810 } else
1811 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1812
1813 if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
1814 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1815 if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
1816 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1817 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
1818 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1819 ip_rt_min_advmss);
1820 if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40)
1821 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1822
1823 #ifdef CONFIG_NET_CLS_ROUTE
1824 #ifdef CONFIG_IP_MULTIPLE_TABLES
1825 set_class_tag(rt, fib_rules_tclass(res));
1826 #endif
1827 set_class_tag(rt, itag);
1828 #endif
1829 rt->rt_type = res->type;
1830 }
1831
1832 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1833 u8 tos, struct net_device *dev, int our)
1834 {
1835 unsigned hash;
1836 struct rtable *rth;
1837 __be32 spec_dst;
1838 struct in_device *in_dev = in_dev_get(dev);
1839 u32 itag = 0;
1840
1841 /* Primary sanity checks. */
1842
1843 if (in_dev == NULL)
1844 return -EINVAL;
1845
1846 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1847 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1848 goto e_inval;
1849
1850 if (ipv4_is_zeronet(saddr)) {
1851 if (!ipv4_is_local_multicast(daddr))
1852 goto e_inval;
1853 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1854 } else if (fib_validate_source(saddr, 0, tos, 0,
1855 dev, &spec_dst, &itag) < 0)
1856 goto e_inval;
1857
1858 rth = dst_alloc(&ipv4_dst_ops);
1859 if (!rth)
1860 goto e_nobufs;
1861
1862 rth->u.dst.output= ip_rt_bug;
1863
1864 atomic_set(&rth->u.dst.__refcnt, 1);
1865 rth->u.dst.flags= DST_HOST;
1866 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1867 rth->u.dst.flags |= DST_NOPOLICY;
1868 rth->fl.fl4_dst = daddr;
1869 rth->rt_dst = daddr;
1870 rth->fl.fl4_tos = tos;
1871 rth->fl.mark = skb->mark;
1872 rth->fl.fl4_src = saddr;
1873 rth->rt_src = saddr;
1874 #ifdef CONFIG_NET_CLS_ROUTE
1875 rth->u.dst.tclassid = itag;
1876 #endif
1877 rth->rt_iif =
1878 rth->fl.iif = dev->ifindex;
1879 rth->u.dst.dev = init_net.loopback_dev;
1880 dev_hold(rth->u.dst.dev);
1881 rth->idev = in_dev_get(rth->u.dst.dev);
1882 rth->fl.oif = 0;
1883 rth->rt_gateway = daddr;
1884 rth->rt_spec_dst= spec_dst;
1885 rth->rt_genid = rt_genid(dev_net(dev));
1886 rth->rt_flags = RTCF_MULTICAST;
1887 rth->rt_type = RTN_MULTICAST;
1888 if (our) {
1889 rth->u.dst.input= ip_local_deliver;
1890 rth->rt_flags |= RTCF_LOCAL;
1891 }
1892
1893 #ifdef CONFIG_IP_MROUTE
1894 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1895 rth->u.dst.input = ip_mr_input;
1896 #endif
1897 RT_CACHE_STAT_INC(in_slow_mc);
1898
1899 in_dev_put(in_dev);
1900 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1901 return rt_intern_hash(hash, rth, NULL, skb);
1902
1903 e_nobufs:
1904 in_dev_put(in_dev);
1905 return -ENOBUFS;
1906
1907 e_inval:
1908 in_dev_put(in_dev);
1909 return -EINVAL;
1910 }
1911
1912
1913 static void ip_handle_martian_source(struct net_device *dev,
1914 struct in_device *in_dev,
1915 struct sk_buff *skb,
1916 __be32 daddr,
1917 __be32 saddr)
1918 {
1919 RT_CACHE_STAT_INC(in_martian_src);
1920 #ifdef CONFIG_IP_ROUTE_VERBOSE
1921 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1922 /*
1923 * RFC1812 recommendation, if source is martian,
1924 * the only hint is MAC header.
1925 */
1926 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1927 &daddr, &saddr, dev->name);
1928 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1929 int i;
1930 const unsigned char *p = skb_mac_header(skb);
1931 printk(KERN_WARNING "ll header: ");
1932 for (i = 0; i < dev->hard_header_len; i++, p++) {
1933 printk("%02x", *p);
1934 if (i < (dev->hard_header_len - 1))
1935 printk(":");
1936 }
1937 printk("\n");
1938 }
1939 }
1940 #endif
1941 }
1942
1943 static int __mkroute_input(struct sk_buff *skb,
1944 struct fib_result *res,
1945 struct in_device *in_dev,
1946 __be32 daddr, __be32 saddr, u32 tos,
1947 struct rtable **result)
1948 {
1949
1950 struct rtable *rth;
1951 int err;
1952 struct in_device *out_dev;
1953 unsigned flags = 0;
1954 __be32 spec_dst;
1955 u32 itag;
1956
1957 /* get a working reference to the output device */
1958 out_dev = in_dev_get(FIB_RES_DEV(*res));
1959 if (out_dev == NULL) {
1960 if (net_ratelimit())
1961 printk(KERN_CRIT "Bug in ip_route_input" \
1962 "_slow(). Please, report\n");
1963 return -EINVAL;
1964 }
1965
1966
1967 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1968 in_dev->dev, &spec_dst, &itag);
1969 if (err < 0) {
1970 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1971 saddr);
1972
1973 err = -EINVAL;
1974 goto cleanup;
1975 }
1976
1977 if (err)
1978 flags |= RTCF_DIRECTSRC;
1979
1980 if (out_dev == in_dev && err &&
1981 (IN_DEV_SHARED_MEDIA(out_dev) ||
1982 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1983 flags |= RTCF_DOREDIRECT;
1984
1985 if (skb->protocol != htons(ETH_P_IP)) {
1986 /* Not IP (i.e. ARP). Do not create route, if it is
1987 * invalid for proxy arp. DNAT routes are always valid.
1988 */
1989 if (out_dev == in_dev) {
1990 err = -EINVAL;
1991 goto cleanup;
1992 }
1993 }
1994
1995
1996 rth = dst_alloc(&ipv4_dst_ops);
1997 if (!rth) {
1998 err = -ENOBUFS;
1999 goto cleanup;
2000 }
2001
2002 atomic_set(&rth->u.dst.__refcnt, 1);
2003 rth->u.dst.flags= DST_HOST;
2004 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2005 rth->u.dst.flags |= DST_NOPOLICY;
2006 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2007 rth->u.dst.flags |= DST_NOXFRM;
2008 rth->fl.fl4_dst = daddr;
2009 rth->rt_dst = daddr;
2010 rth->fl.fl4_tos = tos;
2011 rth->fl.mark = skb->mark;
2012 rth->fl.fl4_src = saddr;
2013 rth->rt_src = saddr;
2014 rth->rt_gateway = daddr;
2015 rth->rt_iif =
2016 rth->fl.iif = in_dev->dev->ifindex;
2017 rth->u.dst.dev = (out_dev)->dev;
2018 dev_hold(rth->u.dst.dev);
2019 rth->idev = in_dev_get(rth->u.dst.dev);
2020 rth->fl.oif = 0;
2021 rth->rt_spec_dst= spec_dst;
2022
2023 rth->u.dst.input = ip_forward;
2024 rth->u.dst.output = ip_output;
2025 rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
2026
2027 rt_set_nexthop(rth, res, itag);
2028
2029 rth->rt_flags = flags;
2030
2031 *result = rth;
2032 err = 0;
2033 cleanup:
2034 /* release the working reference to the output device */
2035 in_dev_put(out_dev);
2036 return err;
2037 }
2038
2039 static int ip_mkroute_input(struct sk_buff *skb,
2040 struct fib_result *res,
2041 const struct flowi *fl,
2042 struct in_device *in_dev,
2043 __be32 daddr, __be32 saddr, u32 tos)
2044 {
2045 struct rtable* rth = NULL;
2046 int err;
2047 unsigned hash;
2048
2049 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2050 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2051 fib_select_multipath(fl, res);
2052 #endif
2053
2054 /* create a routing cache entry */
2055 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2056 if (err)
2057 return err;
2058
2059 /* put it into the cache */
2060 hash = rt_hash(daddr, saddr, fl->iif,
2061 rt_genid(dev_net(rth->u.dst.dev)));
2062 return rt_intern_hash(hash, rth, NULL, skb);
2063 }
2064
2065 /*
2066 * NOTE. We drop all the packets that has local source
2067 * addresses, because every properly looped back packet
2068 * must have correct destination already attached by output routine.
2069 *
2070 * Such approach solves two big problems:
2071 * 1. Not simplex devices are handled properly.
2072 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2073 */
2074
2075 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2076 u8 tos, struct net_device *dev)
2077 {
2078 struct fib_result res;
2079 struct in_device *in_dev = in_dev_get(dev);
2080 struct flowi fl = { .nl_u = { .ip4_u =
2081 { .daddr = daddr,
2082 .saddr = saddr,
2083 .tos = tos,
2084 .scope = RT_SCOPE_UNIVERSE,
2085 } },
2086 .mark = skb->mark,
2087 .iif = dev->ifindex };
2088 unsigned flags = 0;
2089 u32 itag = 0;
2090 struct rtable * rth;
2091 unsigned hash;
2092 __be32 spec_dst;
2093 int err = -EINVAL;
2094 int free_res = 0;
2095 struct net * net = dev_net(dev);
2096
2097 /* IP on this device is disabled. */
2098
2099 if (!in_dev)
2100 goto out;
2101
2102 /* Check for the most weird martians, which can be not detected
2103 by fib_lookup.
2104 */
2105
2106 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2107 ipv4_is_loopback(saddr))
2108 goto martian_source;
2109
2110 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
2111 goto brd_input;
2112
2113 /* Accept zero addresses only to limited broadcast;
2114 * I even do not know to fix it or not. Waiting for complains :-)
2115 */
2116 if (ipv4_is_zeronet(saddr))
2117 goto martian_source;
2118
2119 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
2120 ipv4_is_loopback(daddr))
2121 goto martian_destination;
2122
2123 /*
2124 * Now we are ready to route packet.
2125 */
2126 if ((err = fib_lookup(net, &fl, &res)) != 0) {
2127 if (!IN_DEV_FORWARD(in_dev))
2128 goto e_hostunreach;
2129 goto no_route;
2130 }
2131 free_res = 1;
2132
2133 RT_CACHE_STAT_INC(in_slow_tot);
2134
2135 if (res.type == RTN_BROADCAST)
2136 goto brd_input;
2137
2138 if (res.type == RTN_LOCAL) {
2139 int result;
2140 result = fib_validate_source(saddr, daddr, tos,
2141 net->loopback_dev->ifindex,
2142 dev, &spec_dst, &itag);
2143 if (result < 0)
2144 goto martian_source;
2145 if (result)
2146 flags |= RTCF_DIRECTSRC;
2147 spec_dst = daddr;
2148 goto local_input;
2149 }
2150
2151 if (!IN_DEV_FORWARD(in_dev))
2152 goto e_hostunreach;
2153 if (res.type != RTN_UNICAST)
2154 goto martian_destination;
2155
2156 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2157 done:
2158 in_dev_put(in_dev);
2159 if (free_res)
2160 fib_res_put(&res);
2161 out: return err;
2162
2163 brd_input:
2164 if (skb->protocol != htons(ETH_P_IP))
2165 goto e_inval;
2166
2167 if (ipv4_is_zeronet(saddr))
2168 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2169 else {
2170 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2171 &itag);
2172 if (err < 0)
2173 goto martian_source;
2174 if (err)
2175 flags |= RTCF_DIRECTSRC;
2176 }
2177 flags |= RTCF_BROADCAST;
2178 res.type = RTN_BROADCAST;
2179 RT_CACHE_STAT_INC(in_brd);
2180
2181 local_input:
2182 rth = dst_alloc(&ipv4_dst_ops);
2183 if (!rth)
2184 goto e_nobufs;
2185
2186 rth->u.dst.output= ip_rt_bug;
2187 rth->rt_genid = rt_genid(net);
2188
2189 atomic_set(&rth->u.dst.__refcnt, 1);
2190 rth->u.dst.flags= DST_HOST;
2191 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2192 rth->u.dst.flags |= DST_NOPOLICY;
2193 rth->fl.fl4_dst = daddr;
2194 rth->rt_dst = daddr;
2195 rth->fl.fl4_tos = tos;
2196 rth->fl.mark = skb->mark;
2197 rth->fl.fl4_src = saddr;
2198 rth->rt_src = saddr;
2199 #ifdef CONFIG_NET_CLS_ROUTE
2200 rth->u.dst.tclassid = itag;
2201 #endif
2202 rth->rt_iif =
2203 rth->fl.iif = dev->ifindex;
2204 rth->u.dst.dev = net->loopback_dev;
2205 dev_hold(rth->u.dst.dev);
2206 rth->idev = in_dev_get(rth->u.dst.dev);
2207 rth->rt_gateway = daddr;
2208 rth->rt_spec_dst= spec_dst;
2209 rth->u.dst.input= ip_local_deliver;
2210 rth->rt_flags = flags|RTCF_LOCAL;
2211 if (res.type == RTN_UNREACHABLE) {
2212 rth->u.dst.input= ip_error;
2213 rth->u.dst.error= -err;
2214 rth->rt_flags &= ~RTCF_LOCAL;
2215 }
2216 rth->rt_type = res.type;
2217 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2218 err = rt_intern_hash(hash, rth, NULL, skb);
2219 goto done;
2220
2221 no_route:
2222 RT_CACHE_STAT_INC(in_no_route);
2223 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2224 res.type = RTN_UNREACHABLE;
2225 if (err == -ESRCH)
2226 err = -ENETUNREACH;
2227 goto local_input;
2228
2229 /*
2230 * Do not cache martian addresses: they should be logged (RFC1812)
2231 */
2232 martian_destination:
2233 RT_CACHE_STAT_INC(in_martian_dst);
2234 #ifdef CONFIG_IP_ROUTE_VERBOSE
2235 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2236 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2237 &daddr, &saddr, dev->name);
2238 #endif
2239
2240 e_hostunreach:
2241 err = -EHOSTUNREACH;
2242 goto done;
2243
2244 e_inval:
2245 err = -EINVAL;
2246 goto done;
2247
2248 e_nobufs:
2249 err = -ENOBUFS;
2250 goto done;
2251
2252 martian_source:
2253 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2254 goto e_inval;
2255 }
2256
2257 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2258 u8 tos, struct net_device *dev)
2259 {
2260 struct rtable * rth;
2261 unsigned hash;
2262 int iif = dev->ifindex;
2263 struct net *net;
2264
2265 net = dev_net(dev);
2266
2267 if (!rt_caching(net))
2268 goto skip_cache;
2269
2270 tos &= IPTOS_RT_MASK;
2271 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2272
2273 rcu_read_lock();
2274 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2275 rth = rcu_dereference(rth->u.dst.rt_next)) {
2276 if (((rth->fl.fl4_dst ^ daddr) |
2277 (rth->fl.fl4_src ^ saddr) |
2278 (rth->fl.iif ^ iif) |
2279 rth->fl.oif |
2280 (rth->fl.fl4_tos ^ tos)) == 0 &&
2281 rth->fl.mark == skb->mark &&
2282 net_eq(dev_net(rth->u.dst.dev), net) &&
2283 !rt_is_expired(rth)) {
2284 dst_use(&rth->u.dst, jiffies);
2285 RT_CACHE_STAT_INC(in_hit);
2286 rcu_read_unlock();
2287 skb_dst_set(skb, &rth->u.dst);
2288 return 0;
2289 }
2290 RT_CACHE_STAT_INC(in_hlist_search);
2291 }
2292 rcu_read_unlock();
2293
2294 skip_cache:
2295 /* Multicast recognition logic is moved from route cache to here.
2296 The problem was that too many Ethernet cards have broken/missing
2297 hardware multicast filters :-( As result the host on multicasting
2298 network acquires a lot of useless route cache entries, sort of
2299 SDR messages from all the world. Now we try to get rid of them.
2300 Really, provided software IP multicast filter is organized
2301 reasonably (at least, hashed), it does not result in a slowdown
2302 comparing with route cache reject entries.
2303 Note, that multicast routers are not affected, because
2304 route cache entry is created eventually.
2305 */
2306 if (ipv4_is_multicast(daddr)) {
2307 struct in_device *in_dev;
2308
2309 rcu_read_lock();
2310 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2311 int our = ip_check_mc(in_dev, daddr, saddr,
2312 ip_hdr(skb)->protocol);
2313 if (our
2314 #ifdef CONFIG_IP_MROUTE
2315 || (!ipv4_is_local_multicast(daddr) &&
2316 IN_DEV_MFORWARD(in_dev))
2317 #endif
2318 ) {
2319 rcu_read_unlock();
2320 return ip_route_input_mc(skb, daddr, saddr,
2321 tos, dev, our);
2322 }
2323 }
2324 rcu_read_unlock();
2325 return -EINVAL;
2326 }
2327 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2328 }
2329
2330 static int __mkroute_output(struct rtable **result,
2331 struct fib_result *res,
2332 const struct flowi *fl,
2333 const struct flowi *oldflp,
2334 struct net_device *dev_out,
2335 unsigned flags)
2336 {
2337 struct rtable *rth;
2338 struct in_device *in_dev;
2339 u32 tos = RT_FL_TOS(oldflp);
2340 int err = 0;
2341
2342 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2343 return -EINVAL;
2344
2345 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2346 res->type = RTN_BROADCAST;
2347 else if (ipv4_is_multicast(fl->fl4_dst))
2348 res->type = RTN_MULTICAST;
2349 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2350 return -EINVAL;
2351
2352 if (dev_out->flags & IFF_LOOPBACK)
2353 flags |= RTCF_LOCAL;
2354
2355 /* get work reference to inet device */
2356 in_dev = in_dev_get(dev_out);
2357 if (!in_dev)
2358 return -EINVAL;
2359
2360 if (res->type == RTN_BROADCAST) {
2361 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2362 if (res->fi) {
2363 fib_info_put(res->fi);
2364 res->fi = NULL;
2365 }
2366 } else if (res->type == RTN_MULTICAST) {
2367 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2368 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2369 oldflp->proto))
2370 flags &= ~RTCF_LOCAL;
2371 /* If multicast route do not exist use
2372 default one, but do not gateway in this case.
2373 Yes, it is hack.
2374 */
2375 if (res->fi && res->prefixlen < 4) {
2376 fib_info_put(res->fi);
2377 res->fi = NULL;
2378 }
2379 }
2380
2381
2382 rth = dst_alloc(&ipv4_dst_ops);
2383 if (!rth) {
2384 err = -ENOBUFS;
2385 goto cleanup;
2386 }
2387
2388 atomic_set(&rth->u.dst.__refcnt, 1);
2389 rth->u.dst.flags= DST_HOST;
2390 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2391 rth->u.dst.flags |= DST_NOXFRM;
2392 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2393 rth->u.dst.flags |= DST_NOPOLICY;
2394
2395 rth->fl.fl4_dst = oldflp->fl4_dst;
2396 rth->fl.fl4_tos = tos;
2397 rth->fl.fl4_src = oldflp->fl4_src;
2398 rth->fl.oif = oldflp->oif;
2399 rth->fl.mark = oldflp->mark;
2400 rth->rt_dst = fl->fl4_dst;
2401 rth->rt_src = fl->fl4_src;
2402 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2403 /* get references to the devices that are to be hold by the routing
2404 cache entry */
2405 rth->u.dst.dev = dev_out;
2406 dev_hold(dev_out);
2407 rth->idev = in_dev_get(dev_out);
2408 rth->rt_gateway = fl->fl4_dst;
2409 rth->rt_spec_dst= fl->fl4_src;
2410
2411 rth->u.dst.output=ip_output;
2412 rth->rt_genid = rt_genid(dev_net(dev_out));
2413
2414 RT_CACHE_STAT_INC(out_slow_tot);
2415
2416 if (flags & RTCF_LOCAL) {
2417 rth->u.dst.input = ip_local_deliver;
2418 rth->rt_spec_dst = fl->fl4_dst;
2419 }
2420 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2421 rth->rt_spec_dst = fl->fl4_src;
2422 if (flags & RTCF_LOCAL &&
2423 !(dev_out->flags & IFF_LOOPBACK)) {
2424 rth->u.dst.output = ip_mc_output;
2425 RT_CACHE_STAT_INC(out_slow_mc);
2426 }
2427 #ifdef CONFIG_IP_MROUTE
2428 if (res->type == RTN_MULTICAST) {
2429 if (IN_DEV_MFORWARD(in_dev) &&
2430 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2431 rth->u.dst.input = ip_mr_input;
2432 rth->u.dst.output = ip_mc_output;
2433 }
2434 }
2435 #endif
2436 }
2437
2438 rt_set_nexthop(rth, res, 0);
2439
2440 rth->rt_flags = flags;
2441
2442 *result = rth;
2443 cleanup:
2444 /* release work reference to inet device */
2445 in_dev_put(in_dev);
2446
2447 return err;
2448 }
2449
2450 static int ip_mkroute_output(struct rtable **rp,
2451 struct fib_result *res,
2452 const struct flowi *fl,
2453 const struct flowi *oldflp,
2454 struct net_device *dev_out,
2455 unsigned flags)
2456 {
2457 struct rtable *rth = NULL;
2458 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2459 unsigned hash;
2460 if (err == 0) {
2461 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2462 rt_genid(dev_net(dev_out)));
2463 err = rt_intern_hash(hash, rth, rp, NULL);
2464 }
2465
2466 return err;
2467 }
2468
2469 /*
2470 * Major route resolver routine.
2471 */
2472
2473 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2474 const struct flowi *oldflp)
2475 {
2476 u32 tos = RT_FL_TOS(oldflp);
2477 struct flowi fl = { .nl_u = { .ip4_u =
2478 { .daddr = oldflp->fl4_dst,
2479 .saddr = oldflp->fl4_src,
2480 .tos = tos & IPTOS_RT_MASK,
2481 .scope = ((tos & RTO_ONLINK) ?
2482 RT_SCOPE_LINK :
2483 RT_SCOPE_UNIVERSE),
2484 } },
2485 .mark = oldflp->mark,
2486 .iif = net->loopback_dev->ifindex,
2487 .oif = oldflp->oif };
2488 struct fib_result res;
2489 unsigned flags = 0;
2490 struct net_device *dev_out = NULL;
2491 int free_res = 0;
2492 int err;
2493
2494
2495 res.fi = NULL;
2496 #ifdef CONFIG_IP_MULTIPLE_TABLES
2497 res.r = NULL;
2498 #endif
2499
2500 if (oldflp->fl4_src) {
2501 err = -EINVAL;
2502 if (ipv4_is_multicast(oldflp->fl4_src) ||
2503 ipv4_is_lbcast(oldflp->fl4_src) ||
2504 ipv4_is_zeronet(oldflp->fl4_src))
2505 goto out;
2506
2507 /* I removed check for oif == dev_out->oif here.
2508 It was wrong for two reasons:
2509 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2510 is assigned to multiple interfaces.
2511 2. Moreover, we are allowed to send packets with saddr
2512 of another iface. --ANK
2513 */
2514
2515 if (oldflp->oif == 0
2516 && (ipv4_is_multicast(oldflp->fl4_dst) ||
2517 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2518 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2519 dev_out = ip_dev_find(net, oldflp->fl4_src);
2520 if (dev_out == NULL)
2521 goto out;
2522
2523 /* Special hack: user can direct multicasts
2524 and limited broadcast via necessary interface
2525 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2526 This hack is not just for fun, it allows
2527 vic,vat and friends to work.
2528 They bind socket to loopback, set ttl to zero
2529 and expect that it will work.
2530 From the viewpoint of routing cache they are broken,
2531 because we are not allowed to build multicast path
2532 with loopback source addr (look, routing cache
2533 cannot know, that ttl is zero, so that packet
2534 will not leave this host and route is valid).
2535 Luckily, this hack is good workaround.
2536 */
2537
2538 fl.oif = dev_out->ifindex;
2539 goto make_route;
2540 }
2541
2542 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2543 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2544 dev_out = ip_dev_find(net, oldflp->fl4_src);
2545 if (dev_out == NULL)
2546 goto out;
2547 dev_put(dev_out);
2548 dev_out = NULL;
2549 }
2550 }
2551
2552
2553 if (oldflp->oif) {
2554 dev_out = dev_get_by_index(net, oldflp->oif);
2555 err = -ENODEV;
2556 if (dev_out == NULL)
2557 goto out;
2558
2559 /* RACE: Check return value of inet_select_addr instead. */
2560 if (__in_dev_get_rtnl(dev_out) == NULL) {
2561 dev_put(dev_out);
2562 goto out; /* Wrong error code */
2563 }
2564
2565 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2566 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2567 if (!fl.fl4_src)
2568 fl.fl4_src = inet_select_addr(dev_out, 0,
2569 RT_SCOPE_LINK);
2570 goto make_route;
2571 }
2572 if (!fl.fl4_src) {
2573 if (ipv4_is_multicast(oldflp->fl4_dst))
2574 fl.fl4_src = inet_select_addr(dev_out, 0,
2575 fl.fl4_scope);
2576 else if (!oldflp->fl4_dst)
2577 fl.fl4_src = inet_select_addr(dev_out, 0,
2578 RT_SCOPE_HOST);
2579 }
2580 }
2581
2582 if (!fl.fl4_dst) {
2583 fl.fl4_dst = fl.fl4_src;
2584 if (!fl.fl4_dst)
2585 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2586 if (dev_out)
2587 dev_put(dev_out);
2588 dev_out = net->loopback_dev;
2589 dev_hold(dev_out);
2590 fl.oif = net->loopback_dev->ifindex;
2591 res.type = RTN_LOCAL;
2592 flags |= RTCF_LOCAL;
2593 goto make_route;
2594 }
2595
2596 if (fib_lookup(net, &fl, &res)) {
2597 res.fi = NULL;
2598 if (oldflp->oif) {
2599 /* Apparently, routing tables are wrong. Assume,
2600 that the destination is on link.
2601
2602 WHY? DW.
2603 Because we are allowed to send to iface
2604 even if it has NO routes and NO assigned
2605 addresses. When oif is specified, routing
2606 tables are looked up with only one purpose:
2607 to catch if destination is gatewayed, rather than
2608 direct. Moreover, if MSG_DONTROUTE is set,
2609 we send packet, ignoring both routing tables
2610 and ifaddr state. --ANK
2611
2612
2613 We could make it even if oif is unknown,
2614 likely IPv6, but we do not.
2615 */
2616
2617 if (fl.fl4_src == 0)
2618 fl.fl4_src = inet_select_addr(dev_out, 0,
2619 RT_SCOPE_LINK);
2620 res.type = RTN_UNICAST;
2621 goto make_route;
2622 }
2623 if (dev_out)
2624 dev_put(dev_out);
2625 err = -ENETUNREACH;
2626 goto out;
2627 }
2628 free_res = 1;
2629
2630 if (res.type == RTN_LOCAL) {
2631 if (!fl.fl4_src)
2632 fl.fl4_src = fl.fl4_dst;
2633 if (dev_out)
2634 dev_put(dev_out);
2635 dev_out = net->loopback_dev;
2636 dev_hold(dev_out);
2637 fl.oif = dev_out->ifindex;
2638 if (res.fi)
2639 fib_info_put(res.fi);
2640 res.fi = NULL;
2641 flags |= RTCF_LOCAL;
2642 goto make_route;
2643 }
2644
2645 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2646 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2647 fib_select_multipath(&fl, &res);
2648 else
2649 #endif
2650 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2651 fib_select_default(net, &fl, &res);
2652
2653 if (!fl.fl4_src)
2654 fl.fl4_src = FIB_RES_PREFSRC(res);
2655
2656 if (dev_out)
2657 dev_put(dev_out);
2658 dev_out = FIB_RES_DEV(res);
2659 dev_hold(dev_out);
2660 fl.oif = dev_out->ifindex;
2661
2662
2663 make_route:
2664 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2665
2666
2667 if (free_res)
2668 fib_res_put(&res);
2669 if (dev_out)
2670 dev_put(dev_out);
2671 out: return err;
2672 }
2673
2674 int __ip_route_output_key(struct net *net, struct rtable **rp,
2675 const struct flowi *flp)
2676 {
2677 unsigned hash;
2678 struct rtable *rth;
2679
2680 if (!rt_caching(net))
2681 goto slow_output;
2682
2683 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2684
2685 rcu_read_lock_bh();
2686 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2687 rth = rcu_dereference(rth->u.dst.rt_next)) {
2688 if (rth->fl.fl4_dst == flp->fl4_dst &&
2689 rth->fl.fl4_src == flp->fl4_src &&
2690 rth->fl.iif == 0 &&
2691 rth->fl.oif == flp->oif &&
2692 rth->fl.mark == flp->mark &&
2693 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2694 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2695 net_eq(dev_net(rth->u.dst.dev), net) &&
2696 !rt_is_expired(rth)) {
2697 dst_use(&rth->u.dst, jiffies);
2698 RT_CACHE_STAT_INC(out_hit);
2699 rcu_read_unlock_bh();
2700 *rp = rth;
2701 return 0;
2702 }
2703 RT_CACHE_STAT_INC(out_hlist_search);
2704 }
2705 rcu_read_unlock_bh();
2706
2707 slow_output:
2708 return ip_route_output_slow(net, rp, flp);
2709 }
2710
2711 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2712
2713 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2714 {
2715 }
2716
2717 static struct dst_ops ipv4_dst_blackhole_ops = {
2718 .family = AF_INET,
2719 .protocol = cpu_to_be16(ETH_P_IP),
2720 .destroy = ipv4_dst_destroy,
2721 .check = ipv4_dst_check,
2722 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2723 .entries = ATOMIC_INIT(0),
2724 };
2725
2726
2727 static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2728 {
2729 struct rtable *ort = *rp;
2730 struct rtable *rt = (struct rtable *)
2731 dst_alloc(&ipv4_dst_blackhole_ops);
2732
2733 if (rt) {
2734 struct dst_entry *new = &rt->u.dst;
2735
2736 atomic_set(&new->__refcnt, 1);
2737 new->__use = 1;
2738 new->input = dst_discard;
2739 new->output = dst_discard;
2740 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2741
2742 new->dev = ort->u.dst.dev;
2743 if (new->dev)
2744 dev_hold(new->dev);
2745
2746 rt->fl = ort->fl;
2747
2748 rt->idev = ort->idev;
2749 if (rt->idev)
2750 in_dev_hold(rt->idev);
2751 rt->rt_genid = rt_genid(net);
2752 rt->rt_flags = ort->rt_flags;
2753 rt->rt_type = ort->rt_type;
2754 rt->rt_dst = ort->rt_dst;
2755 rt->rt_src = ort->rt_src;
2756 rt->rt_iif = ort->rt_iif;
2757 rt->rt_gateway = ort->rt_gateway;
2758 rt->rt_spec_dst = ort->rt_spec_dst;
2759 rt->peer = ort->peer;
2760 if (rt->peer)
2761 atomic_inc(&rt->peer->refcnt);
2762
2763 dst_free(new);
2764 }
2765
2766 dst_release(&(*rp)->u.dst);
2767 *rp = rt;
2768 return (rt ? 0 : -ENOMEM);
2769 }
2770
2771 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2772 struct sock *sk, int flags)
2773 {
2774 int err;
2775
2776 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2777 return err;
2778
2779 if (flp->proto) {
2780 if (!flp->fl4_src)
2781 flp->fl4_src = (*rp)->rt_src;
2782 if (!flp->fl4_dst)
2783 flp->fl4_dst = (*rp)->rt_dst;
2784 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2785 flags ? XFRM_LOOKUP_WAIT : 0);
2786 if (err == -EREMOTE)
2787 err = ipv4_dst_blackhole(net, rp, flp);
2788
2789 return err;
2790 }
2791
2792 return 0;
2793 }
2794
2795 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2796
2797 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2798 {
2799 return ip_route_output_flow(net, rp, flp, NULL, 0);
2800 }
2801
2802 static int rt_fill_info(struct net *net,
2803 struct sk_buff *skb, u32 pid, u32 seq, int event,
2804 int nowait, unsigned int flags)
2805 {
2806 struct rtable *rt = skb_rtable(skb);
2807 struct rtmsg *r;
2808 struct nlmsghdr *nlh;
2809 long expires;
2810 u32 id = 0, ts = 0, tsage = 0, error;
2811
2812 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2813 if (nlh == NULL)
2814 return -EMSGSIZE;
2815
2816 r = nlmsg_data(nlh);
2817 r->rtm_family = AF_INET;
2818 r->rtm_dst_len = 32;
2819 r->rtm_src_len = 0;
2820 r->rtm_tos = rt->fl.fl4_tos;
2821 r->rtm_table = RT_TABLE_MAIN;
2822 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2823 r->rtm_type = rt->rt_type;
2824 r->rtm_scope = RT_SCOPE_UNIVERSE;
2825 r->rtm_protocol = RTPROT_UNSPEC;
2826 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2827 if (rt->rt_flags & RTCF_NOTIFY)
2828 r->rtm_flags |= RTM_F_NOTIFY;
2829
2830 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2831
2832 if (rt->fl.fl4_src) {
2833 r->rtm_src_len = 32;
2834 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2835 }
2836 if (rt->u.dst.dev)
2837 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2838 #ifdef CONFIG_NET_CLS_ROUTE
2839 if (rt->u.dst.tclassid)
2840 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2841 #endif
2842 if (rt->fl.iif)
2843 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2844 else if (rt->rt_src != rt->fl.fl4_src)
2845 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2846
2847 if (rt->rt_dst != rt->rt_gateway)
2848 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2849
2850 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2851 goto nla_put_failure;
2852
2853 error = rt->u.dst.error;
2854 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2855 if (rt->peer) {
2856 id = rt->peer->ip_id_count;
2857 if (rt->peer->tcp_ts_stamp) {
2858 ts = rt->peer->tcp_ts;
2859 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2860 }
2861 }
2862
2863 if (rt->fl.iif) {
2864 #ifdef CONFIG_IP_MROUTE
2865 __be32 dst = rt->rt_dst;
2866
2867 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2868 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2869 int err = ipmr_get_route(net, skb, r, nowait);
2870 if (err <= 0) {
2871 if (!nowait) {
2872 if (err == 0)
2873 return 0;
2874 goto nla_put_failure;
2875 } else {
2876 if (err == -EMSGSIZE)
2877 goto nla_put_failure;
2878 error = err;
2879 }
2880 }
2881 } else
2882 #endif
2883 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2884 }
2885
2886 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2887 expires, error) < 0)
2888 goto nla_put_failure;
2889
2890 return nlmsg_end(skb, nlh);
2891
2892 nla_put_failure:
2893 nlmsg_cancel(skb, nlh);
2894 return -EMSGSIZE;
2895 }
2896
2897 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2898 {
2899 struct net *net = sock_net(in_skb->sk);
2900 struct rtmsg *rtm;
2901 struct nlattr *tb[RTA_MAX+1];
2902 struct rtable *rt = NULL;
2903 __be32 dst = 0;
2904 __be32 src = 0;
2905 u32 iif;
2906 int err;
2907 struct sk_buff *skb;
2908
2909 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2910 if (err < 0)
2911 goto errout;
2912
2913 rtm = nlmsg_data(nlh);
2914
2915 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2916 if (skb == NULL) {
2917 err = -ENOBUFS;
2918 goto errout;
2919 }
2920
2921 /* Reserve room for dummy headers, this skb can pass
2922 through good chunk of routing engine.
2923 */
2924 skb_reset_mac_header(skb);
2925 skb_reset_network_header(skb);
2926
2927 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2928 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2929 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2930
2931 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2932 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2933 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2934
2935 if (iif) {
2936 struct net_device *dev;
2937
2938 dev = __dev_get_by_index(net, iif);
2939 if (dev == NULL) {
2940 err = -ENODEV;
2941 goto errout_free;
2942 }
2943
2944 skb->protocol = htons(ETH_P_IP);
2945 skb->dev = dev;
2946 local_bh_disable();
2947 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2948 local_bh_enable();
2949
2950 rt = skb_rtable(skb);
2951 if (err == 0 && rt->u.dst.error)
2952 err = -rt->u.dst.error;
2953 } else {
2954 struct flowi fl = {
2955 .nl_u = {
2956 .ip4_u = {
2957 .daddr = dst,
2958 .saddr = src,
2959 .tos = rtm->rtm_tos,
2960 },
2961 },
2962 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2963 };
2964 err = ip_route_output_key(net, &rt, &fl);
2965 }
2966
2967 if (err)
2968 goto errout_free;
2969
2970 skb_dst_set(skb, &rt->u.dst);
2971 if (rtm->rtm_flags & RTM_F_NOTIFY)
2972 rt->rt_flags |= RTCF_NOTIFY;
2973
2974 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2975 RTM_NEWROUTE, 0, 0);
2976 if (err <= 0)
2977 goto errout_free;
2978
2979 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2980 errout:
2981 return err;
2982
2983 errout_free:
2984 kfree_skb(skb);
2985 goto errout;
2986 }
2987
2988 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2989 {
2990 struct rtable *rt;
2991 int h, s_h;
2992 int idx, s_idx;
2993 struct net *net;
2994
2995 net = sock_net(skb->sk);
2996
2997 s_h = cb->args[0];
2998 if (s_h < 0)
2999 s_h = 0;
3000 s_idx = idx = cb->args[1];
3001 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3002 if (!rt_hash_table[h].chain)
3003 continue;
3004 rcu_read_lock_bh();
3005 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
3006 rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
3007 if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
3008 continue;
3009 if (rt_is_expired(rt))
3010 continue;
3011 skb_dst_set(skb, dst_clone(&rt->u.dst));
3012 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3013 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3014 1, NLM_F_MULTI) <= 0) {
3015 skb_dst_drop(skb);
3016 rcu_read_unlock_bh();
3017 goto done;
3018 }
3019 skb_dst_drop(skb);
3020 }
3021 rcu_read_unlock_bh();
3022 }
3023
3024 done:
3025 cb->args[0] = h;
3026 cb->args[1] = idx;
3027 return skb->len;
3028 }
3029
3030 void ip_rt_multicast_event(struct in_device *in_dev)
3031 {
3032 rt_cache_flush(dev_net(in_dev->dev), 0);
3033 }
3034
3035 #ifdef CONFIG_SYSCTL
3036 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3037 struct file *filp, void __user *buffer,
3038 size_t *lenp, loff_t *ppos)
3039 {
3040 if (write) {
3041 int flush_delay;
3042 ctl_table ctl;
3043 struct net *net;
3044
3045 memcpy(&ctl, __ctl, sizeof(ctl));
3046 ctl.data = &flush_delay;
3047 proc_dointvec(&ctl, write, filp, buffer, lenp, ppos);
3048
3049 net = (struct net *)__ctl->extra1;
3050 rt_cache_flush(net, flush_delay);
3051 return 0;
3052 }
3053
3054 return -EINVAL;
3055 }
3056
3057 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
3058 void __user *oldval,
3059 size_t __user *oldlenp,
3060 void __user *newval,
3061 size_t newlen)
3062 {
3063 int delay;
3064 struct net *net;
3065 if (newlen != sizeof(int))
3066 return -EINVAL;
3067 if (get_user(delay, (int __user *)newval))
3068 return -EFAULT;
3069 net = (struct net *)table->extra1;
3070 rt_cache_flush(net, delay);
3071 return 0;
3072 }
3073
3074 static void rt_secret_reschedule(int old)
3075 {
3076 struct net *net;
3077 int new = ip_rt_secret_interval;
3078 int diff = new - old;
3079
3080 if (!diff)
3081 return;
3082
3083 rtnl_lock();
3084 for_each_net(net) {
3085 int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
3086
3087 if (!new)
3088 continue;
3089
3090 if (deleted) {
3091 long time = net->ipv4.rt_secret_timer.expires - jiffies;
3092
3093 if (time <= 0 || (time += diff) <= 0)
3094 time = 0;
3095
3096 net->ipv4.rt_secret_timer.expires = time;
3097 } else
3098 net->ipv4.rt_secret_timer.expires = new;
3099
3100 net->ipv4.rt_secret_timer.expires += jiffies;
3101 add_timer(&net->ipv4.rt_secret_timer);
3102 }
3103 rtnl_unlock();
3104 }
3105
3106 static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
3107 struct file *filp,
3108 void __user *buffer, size_t *lenp,
3109 loff_t *ppos)
3110 {
3111 int old = ip_rt_secret_interval;
3112 int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
3113
3114 rt_secret_reschedule(old);
3115
3116 return ret;
3117 }
3118
3119 static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
3120 void __user *oldval,
3121 size_t __user *oldlenp,
3122 void __user *newval,
3123 size_t newlen)
3124 {
3125 int old = ip_rt_secret_interval;
3126 int ret = sysctl_jiffies(table, oldval, oldlenp, newval, newlen);
3127
3128 rt_secret_reschedule(old);
3129
3130 return ret;
3131 }
3132
3133 static ctl_table ipv4_route_table[] = {
3134 {
3135 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
3136 .procname = "gc_thresh",
3137 .data = &ipv4_dst_ops.gc_thresh,
3138 .maxlen = sizeof(int),
3139 .mode = 0644,
3140 .proc_handler = proc_dointvec,
3141 },
3142 {
3143 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
3144 .procname = "max_size",
3145 .data = &ip_rt_max_size,
3146 .maxlen = sizeof(int),
3147 .mode = 0644,
3148 .proc_handler = proc_dointvec,
3149 },
3150 {
3151 /* Deprecated. Use gc_min_interval_ms */
3152
3153 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
3154 .procname = "gc_min_interval",
3155 .data = &ip_rt_gc_min_interval,
3156 .maxlen = sizeof(int),
3157 .mode = 0644,
3158 .proc_handler = proc_dointvec_jiffies,
3159 .strategy = sysctl_jiffies,
3160 },
3161 {
3162 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
3163 .procname = "gc_min_interval_ms",
3164 .data = &ip_rt_gc_min_interval,
3165 .maxlen = sizeof(int),
3166 .mode = 0644,
3167 .proc_handler = proc_dointvec_ms_jiffies,
3168 .strategy = sysctl_ms_jiffies,
3169 },
3170 {
3171 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
3172 .procname = "gc_timeout",
3173 .data = &ip_rt_gc_timeout,
3174 .maxlen = sizeof(int),
3175 .mode = 0644,
3176 .proc_handler = proc_dointvec_jiffies,
3177 .strategy = sysctl_jiffies,
3178 },
3179 {
3180 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
3181 .procname = "gc_interval",
3182 .data = &ip_rt_gc_interval,
3183 .maxlen = sizeof(int),
3184 .mode = 0644,
3185 .proc_handler = proc_dointvec_jiffies,
3186 .strategy = sysctl_jiffies,
3187 },
3188 {
3189 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
3190 .procname = "redirect_load",
3191 .data = &ip_rt_redirect_load,
3192 .maxlen = sizeof(int),
3193 .mode = 0644,
3194 .proc_handler = proc_dointvec,
3195 },
3196 {
3197 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
3198 .procname = "redirect_number",
3199 .data = &ip_rt_redirect_number,
3200 .maxlen = sizeof(int),
3201 .mode = 0644,
3202 .proc_handler = proc_dointvec,
3203 },
3204 {
3205 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
3206 .procname = "redirect_silence",
3207 .data = &ip_rt_redirect_silence,
3208 .maxlen = sizeof(int),
3209 .mode = 0644,
3210 .proc_handler = proc_dointvec,
3211 },
3212 {
3213 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
3214 .procname = "error_cost",
3215 .data = &ip_rt_error_cost,
3216 .maxlen = sizeof(int),
3217 .mode = 0644,
3218 .proc_handler = proc_dointvec,
3219 },
3220 {
3221 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
3222 .procname = "error_burst",
3223 .data = &ip_rt_error_burst,
3224 .maxlen = sizeof(int),
3225 .mode = 0644,
3226 .proc_handler = proc_dointvec,
3227 },
3228 {
3229 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
3230 .procname = "gc_elasticity",
3231 .data = &ip_rt_gc_elasticity,
3232 .maxlen = sizeof(int),
3233 .mode = 0644,
3234 .proc_handler = proc_dointvec,
3235 },
3236 {
3237 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
3238 .procname = "mtu_expires",
3239 .data = &ip_rt_mtu_expires,
3240 .maxlen = sizeof(int),
3241 .mode = 0644,
3242 .proc_handler = proc_dointvec_jiffies,
3243 .strategy = sysctl_jiffies,
3244 },
3245 {
3246 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
3247 .procname = "min_pmtu",
3248 .data = &ip_rt_min_pmtu,
3249 .maxlen = sizeof(int),
3250 .mode = 0644,
3251 .proc_handler = proc_dointvec,
3252 },
3253 {
3254 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
3255 .procname = "min_adv_mss",
3256 .data = &ip_rt_min_advmss,
3257 .maxlen = sizeof(int),
3258 .mode = 0644,
3259 .proc_handler = proc_dointvec,
3260 },
3261 {
3262 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
3263 .procname = "secret_interval",
3264 .data = &ip_rt_secret_interval,
3265 .maxlen = sizeof(int),
3266 .mode = 0644,
3267 .proc_handler = ipv4_sysctl_rt_secret_interval,
3268 .strategy = ipv4_sysctl_rt_secret_interval_strategy,
3269 },
3270 { .ctl_name = 0 }
3271 };
3272
3273 static struct ctl_table empty[1];
3274
3275 static struct ctl_table ipv4_skeleton[] =
3276 {
3277 { .procname = "route", .ctl_name = NET_IPV4_ROUTE,
3278 .mode = 0555, .child = ipv4_route_table},
3279 { .procname = "neigh", .ctl_name = NET_IPV4_NEIGH,
3280 .mode = 0555, .child = empty},
3281 { }
3282 };
3283
3284 static __net_initdata struct ctl_path ipv4_path[] = {
3285 { .procname = "net", .ctl_name = CTL_NET, },
3286 { .procname = "ipv4", .ctl_name = NET_IPV4, },
3287 { },
3288 };
3289
3290 static struct ctl_table ipv4_route_flush_table[] = {
3291 {
3292 .ctl_name = NET_IPV4_ROUTE_FLUSH,
3293 .procname = "flush",
3294 .maxlen = sizeof(int),
3295 .mode = 0200,
3296 .proc_handler = ipv4_sysctl_rtcache_flush,
3297 .strategy = ipv4_sysctl_rtcache_flush_strategy,
3298 },
3299 { .ctl_name = 0 },
3300 };
3301
3302 static __net_initdata struct ctl_path ipv4_route_path[] = {
3303 { .procname = "net", .ctl_name = CTL_NET, },
3304 { .procname = "ipv4", .ctl_name = NET_IPV4, },
3305 { .procname = "route", .ctl_name = NET_IPV4_ROUTE, },
3306 { },
3307 };
3308
3309 static __net_init int sysctl_route_net_init(struct net *net)
3310 {
3311 struct ctl_table *tbl;
3312
3313 tbl = ipv4_route_flush_table;
3314 if (net != &init_net) {
3315 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3316 if (tbl == NULL)
3317 goto err_dup;
3318 }
3319 tbl[0].extra1 = net;
3320
3321 net->ipv4.route_hdr =
3322 register_net_sysctl_table(net, ipv4_route_path, tbl);
3323 if (net->ipv4.route_hdr == NULL)
3324 goto err_reg;
3325 return 0;
3326
3327 err_reg:
3328 if (tbl != ipv4_route_flush_table)
3329 kfree(tbl);
3330 err_dup:
3331 return -ENOMEM;
3332 }
3333
3334 static __net_exit void sysctl_route_net_exit(struct net *net)
3335 {
3336 struct ctl_table *tbl;
3337
3338 tbl = net->ipv4.route_hdr->ctl_table_arg;
3339 unregister_net_sysctl_table(net->ipv4.route_hdr);
3340 BUG_ON(tbl == ipv4_route_flush_table);
3341 kfree(tbl);
3342 }
3343
3344 static __net_initdata struct pernet_operations sysctl_route_ops = {
3345 .init = sysctl_route_net_init,
3346 .exit = sysctl_route_net_exit,
3347 };
3348 #endif
3349
3350
3351 static __net_init int rt_secret_timer_init(struct net *net)
3352 {
3353 atomic_set(&net->ipv4.rt_genid,
3354 (int) ((num_physpages ^ (num_physpages>>8)) ^
3355 (jiffies ^ (jiffies >> 7))));
3356
3357 net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
3358 net->ipv4.rt_secret_timer.data = (unsigned long)net;
3359 init_timer_deferrable(&net->ipv4.rt_secret_timer);
3360
3361 if (ip_rt_secret_interval) {
3362 net->ipv4.rt_secret_timer.expires =
3363 jiffies + net_random() % ip_rt_secret_interval +
3364 ip_rt_secret_interval;
3365 add_timer(&net->ipv4.rt_secret_timer);
3366 }
3367 return 0;
3368 }
3369
3370 static __net_exit void rt_secret_timer_exit(struct net *net)
3371 {
3372 del_timer_sync(&net->ipv4.rt_secret_timer);
3373 }
3374
3375 static __net_initdata struct pernet_operations rt_secret_timer_ops = {
3376 .init = rt_secret_timer_init,
3377 .exit = rt_secret_timer_exit,
3378 };
3379
3380
3381 #ifdef CONFIG_NET_CLS_ROUTE
3382 struct ip_rt_acct *ip_rt_acct __read_mostly;
3383 #endif /* CONFIG_NET_CLS_ROUTE */
3384
3385 static __initdata unsigned long rhash_entries;
3386 static int __init set_rhash_entries(char *str)
3387 {
3388 if (!str)
3389 return 0;
3390 rhash_entries = simple_strtoul(str, &str, 0);
3391 return 1;
3392 }
3393 __setup("rhash_entries=", set_rhash_entries);
3394
3395 int __init ip_rt_init(void)
3396 {
3397 int rc = 0;
3398
3399 #ifdef CONFIG_NET_CLS_ROUTE
3400 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3401 if (!ip_rt_acct)
3402 panic("IP: failed to allocate ip_rt_acct\n");
3403 #endif
3404
3405 ipv4_dst_ops.kmem_cachep =
3406 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3407 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3408
3409 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3410
3411 rt_hash_table = (struct rt_hash_bucket *)
3412 alloc_large_system_hash("IP route cache",
3413 sizeof(struct rt_hash_bucket),
3414 rhash_entries,
3415 (totalram_pages >= 128 * 1024) ?
3416 15 : 17,
3417 0,
3418 &rt_hash_log,
3419 &rt_hash_mask,
3420 rhash_entries ? 0 : 512 * 1024);
3421 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3422 rt_hash_lock_init();
3423
3424 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3425 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3426
3427 devinet_init();
3428 ip_fib_init();
3429
3430 /* All the timers, started at system startup tend
3431 to synchronize. Perturb it a bit.
3432 */
3433 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3434 expires_ljiffies = jiffies;
3435 schedule_delayed_work(&expires_work,
3436 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3437
3438 if (register_pernet_subsys(&rt_secret_timer_ops))
3439 printk(KERN_ERR "Unable to setup rt_secret_timer\n");
3440
3441 if (ip_rt_proc_init())
3442 printk(KERN_ERR "Unable to create route proc files\n");
3443 #ifdef CONFIG_XFRM
3444 xfrm_init();
3445 xfrm4_init();
3446 #endif
3447 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3448
3449 #ifdef CONFIG_SYSCTL
3450 register_pernet_subsys(&sysctl_route_ops);
3451 #endif
3452 return rc;
3453 }
3454
3455 #ifdef CONFIG_SYSCTL
3456 /*
3457 * We really need to sanitize the damn ipv4 init order, then all
3458 * this nonsense will go away.
3459 */
3460 void __init ip_static_sysctl_init(void)
3461 {
3462 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3463 }
3464 #endif
3465
3466 EXPORT_SYMBOL(__ip_select_ident);
3467 EXPORT_SYMBOL(ip_route_input);
3468 EXPORT_SYMBOL(ip_route_output_key);
3469
|
This page was automatically generated by the
LXR engine.
|