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[NETNS]: Add namespace parameter to ip_route_output_key.
[linux-2.6/kvm.git] / net / ipv4 / route.c
blob39a40342142f37dfd2416b12ba65e0fefbcbf156
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 * Version: $Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
14 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 *
16 * Fixes:
17 * Alan Cox : Verify area fixes.
18 * Alan Cox : cli() protects routing changes
19 * Rui Oliveira : ICMP routing table updates
20 * (rco@di.uminho.pt) Routing table insertion and update
21 * Linus Torvalds : Rewrote bits to be sensible
22 * Alan Cox : Added BSD route gw semantics
23 * Alan Cox : Super /proc >4K
24 * Alan Cox : MTU in route table
25 * Alan Cox : MSS actually. Also added the window
26 * clamper.
27 * Sam Lantinga : Fixed route matching in rt_del()
28 * Alan Cox : Routing cache support.
29 * Alan Cox : Removed compatibility cruft.
30 * Alan Cox : RTF_REJECT support.
31 * Alan Cox : TCP irtt support.
32 * Jonathan Naylor : Added Metric support.
33 * Miquel van Smoorenburg : BSD API fixes.
34 * Miquel van Smoorenburg : Metrics.
35 * Alan Cox : Use __u32 properly
36 * Alan Cox : Aligned routing errors more closely with BSD
37 * our system is still very different.
38 * Alan Cox : Faster /proc handling
39 * Alexey Kuznetsov : Massive rework to support tree based routing,
40 * routing caches and better behaviour.
41 *
42 * Olaf Erb : irtt wasn't being copied right.
43 * Bjorn Ekwall : Kerneld route support.
44 * Alan Cox : Multicast fixed (I hope)
45 * Pavel Krauz : Limited broadcast fixed
46 * Mike McLagan : Routing by source
47 * Alexey Kuznetsov : End of old history. Split to fib.c and
48 * route.c and rewritten from scratch.
49 * Andi Kleen : Load-limit warning messages.
50 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
51 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
52 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
53 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
54 * Marc Boucher : routing by fwmark
55 * Robert Olsson : Added rt_cache statistics
56 * Arnaldo C. Melo : Convert proc stuff to seq_file
57 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
58 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
59 * Ilia Sotnikov : Removed TOS from hash calculations
60 *
61 * This program is free software; you can redistribute it and/or
62 * modify it under the terms of the GNU General Public License
63 * as published by the Free Software Foundation; either version
64 * 2 of the License, or (at your option) any later version.
65 */
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <asm/system.h>
70 #include <linux/bitops.h>
71 #include <linux/types.h>
72 #include <linux/kernel.h>
73 #include <linux/mm.h>
74 #include <linux/bootmem.h>
75 #include <linux/string.h>
76 #include <linux/socket.h>
77 #include <linux/sockios.h>
78 #include <linux/errno.h>
79 #include <linux/in.h>
80 #include <linux/inet.h>
81 #include <linux/netdevice.h>
82 #include <linux/proc_fs.h>
83 #include <linux/init.h>
84 #include <linux/workqueue.h>
85 #include <linux/skbuff.h>
86 #include <linux/inetdevice.h>
87 #include <linux/igmp.h>
88 #include <linux/pkt_sched.h>
89 #include <linux/mroute.h>
90 #include <linux/netfilter_ipv4.h>
91 #include <linux/random.h>
92 #include <linux/jhash.h>
93 #include <linux/rcupdate.h>
94 #include <linux/times.h>
95 #include <net/dst.h>
96 #include <net/net_namespace.h>
97 #include <net/protocol.h>
98 #include <net/ip.h>
99 #include <net/route.h>
100 #include <net/inetpeer.h>
101 #include <net/sock.h>
102 #include <net/ip_fib.h>
103 #include <net/arp.h>
104 #include <net/tcp.h>
105 #include <net/icmp.h>
106 #include <net/xfrm.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #endif
112
113 #define RT_FL_TOS(oldflp) \
114 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
115
116 #define IP_MAX_MTU 0xFFF0
117
118 #define RT_GC_TIMEOUT (300*HZ)
119
120 static int ip_rt_min_delay = 2 * HZ;
121 static int ip_rt_max_delay = 10 * HZ;
122 static int ip_rt_max_size;
123 static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
124 static int ip_rt_gc_interval = 60 * HZ;
125 static int ip_rt_gc_min_interval = HZ / 2;
126 static int ip_rt_redirect_number = 9;
127 static int ip_rt_redirect_load = HZ / 50;
128 static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
129 static int ip_rt_error_cost = HZ;
130 static int ip_rt_error_burst = 5 * HZ;
131 static int ip_rt_gc_elasticity = 8;
132 static int ip_rt_mtu_expires = 10 * 60 * HZ;
133 static int ip_rt_min_pmtu = 512 + 20 + 20;
134 static int ip_rt_min_advmss = 256;
135 static int ip_rt_secret_interval = 10 * 60 * HZ;
136 static int ip_rt_flush_expected;
137 static unsigned long rt_deadline;
138
139 #define RTprint(a...) printk(KERN_DEBUG a)
140
141 static struct timer_list rt_flush_timer;
142 static void rt_worker_func(struct work_struct *work);
143 static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
144 static struct timer_list rt_secret_timer;
145
146 /*
147 * Interface to generic destination cache.
148 */
149
150 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
151 static void ipv4_dst_destroy(struct dst_entry *dst);
152 static void ipv4_dst_ifdown(struct dst_entry *dst,
153 struct net_device *dev, int how);
154 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
155 static void ipv4_link_failure(struct sk_buff *skb);
156 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
157 static int rt_garbage_collect(struct dst_ops *ops);
158
159
160 static struct dst_ops ipv4_dst_ops = {
161 .family = AF_INET,
162 .protocol = __constant_htons(ETH_P_IP),
163 .gc = rt_garbage_collect,
164 .check = ipv4_dst_check,
165 .destroy = ipv4_dst_destroy,
166 .ifdown = ipv4_dst_ifdown,
167 .negative_advice = ipv4_negative_advice,
168 .link_failure = ipv4_link_failure,
169 .update_pmtu = ip_rt_update_pmtu,
170 .local_out = ip_local_out,
171 .entry_size = sizeof(struct rtable),
172 };
173
174 #define ECN_OR_COST(class) TC_PRIO_##class
175
176 const __u8 ip_tos2prio[16] = {
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(FILLER),
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK)
193 };
194
195
196 /*
197 * Route cache.
198 */
199
200 /* The locking scheme is rather straight forward:
201 *
202 * 1) Read-Copy Update protects the buckets of the central route hash.
203 * 2) Only writers remove entries, and they hold the lock
204 * as they look at rtable reference counts.
205 * 3) Only readers acquire references to rtable entries,
206 * they do so with atomic increments and with the
207 * lock held.
208 */
209
210 struct rt_hash_bucket {
211 struct rtable *chain;
212 };
213 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
214 defined(CONFIG_PROVE_LOCKING)
215 /*
216 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
217 * The size of this table is a power of two and depends on the number of CPUS.
218 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
219 */
220 #ifdef CONFIG_LOCKDEP
221 # define RT_HASH_LOCK_SZ 256
222 #else
223 # if NR_CPUS >= 32
224 # define RT_HASH_LOCK_SZ 4096
225 # elif NR_CPUS >= 16
226 # define RT_HASH_LOCK_SZ 2048
227 # elif NR_CPUS >= 8
228 # define RT_HASH_LOCK_SZ 1024
229 # elif NR_CPUS >= 4
230 # define RT_HASH_LOCK_SZ 512
231 # else
232 # define RT_HASH_LOCK_SZ 256
233 # endif
234 #endif
235
236 static spinlock_t *rt_hash_locks;
237 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
238
239 static __init void rt_hash_lock_init(void)
240 {
241 int i;
242
243 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
244 GFP_KERNEL);
245 if (!rt_hash_locks)
246 panic("IP: failed to allocate rt_hash_locks\n");
247
248 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
249 spin_lock_init(&rt_hash_locks[i]);
250 }
251 #else
252 # define rt_hash_lock_addr(slot) NULL
253
254 static inline void rt_hash_lock_init(void)
255 {
256 }
257 #endif
258
259 static struct rt_hash_bucket *rt_hash_table;
260 static unsigned rt_hash_mask;
261 static unsigned int rt_hash_log;
262 static unsigned int rt_hash_rnd;
263
264 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
265 #define RT_CACHE_STAT_INC(field) \
266 (__raw_get_cpu_var(rt_cache_stat).field++)
267
268 static int rt_intern_hash(unsigned hash, struct rtable *rth,
269 struct rtable **res);
270
271 static unsigned int rt_hash_code(u32 daddr, u32 saddr)
272 {
273 return (jhash_2words(daddr, saddr, rt_hash_rnd)
274 & rt_hash_mask);
275 }
276
277 #define rt_hash(daddr, saddr, idx) \
278 rt_hash_code((__force u32)(__be32)(daddr),\
279 (__force u32)(__be32)(saddr) ^ ((idx) << 5))
280
281 #ifdef CONFIG_PROC_FS
282 struct rt_cache_iter_state {
283 int bucket;
284 };
285
286 static struct rtable *rt_cache_get_first(struct seq_file *seq)
287 {
288 struct rtable *r = NULL;
289 struct rt_cache_iter_state *st = seq->private;
290
291 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
292 rcu_read_lock_bh();
293 r = rt_hash_table[st->bucket].chain;
294 if (r)
295 break;
296 rcu_read_unlock_bh();
297 }
298 return rcu_dereference(r);
299 }
300
301 static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
302 {
303 struct rt_cache_iter_state *st = seq->private;
304
305 r = r->u.dst.rt_next;
306 while (!r) {
307 rcu_read_unlock_bh();
308 if (--st->bucket < 0)
309 break;
310 rcu_read_lock_bh();
311 r = rt_hash_table[st->bucket].chain;
312 }
313 return rcu_dereference(r);
314 }
315
316 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
317 {
318 struct rtable *r = rt_cache_get_first(seq);
319
320 if (r)
321 while (pos && (r = rt_cache_get_next(seq, r)))
322 --pos;
323 return pos ? NULL : r;
324 }
325
326 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
327 {
328 return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
329 }
330
331 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
332 {
333 struct rtable *r = NULL;
334
335 if (v == SEQ_START_TOKEN)
336 r = rt_cache_get_first(seq);
337 else
338 r = rt_cache_get_next(seq, v);
339 ++*pos;
340 return r;
341 }
342
343 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
344 {
345 if (v && v != SEQ_START_TOKEN)
346 rcu_read_unlock_bh();
347 }
348
349 static int rt_cache_seq_show(struct seq_file *seq, void *v)
350 {
351 if (v == SEQ_START_TOKEN)
352 seq_printf(seq, "%-127s\n",
353 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
354 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
355 "HHUptod\tSpecDst");
356 else {
357 struct rtable *r = v;
358 char temp[256];
359
360 sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
361 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
362 r->u.dst.dev ? r->u.dst.dev->name : "*",
363 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
364 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
365 r->u.dst.__use, 0, (unsigned long)r->rt_src,
366 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
367 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
368 dst_metric(&r->u.dst, RTAX_WINDOW),
369 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
370 dst_metric(&r->u.dst, RTAX_RTTVAR)),
371 r->fl.fl4_tos,
372 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
373 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
374 dev_queue_xmit) : 0,
375 r->rt_spec_dst);
376 seq_printf(seq, "%-127s\n", temp);
377 }
378 return 0;
379 }
380
381 static const struct seq_operations rt_cache_seq_ops = {
382 .start = rt_cache_seq_start,
383 .next = rt_cache_seq_next,
384 .stop = rt_cache_seq_stop,
385 .show = rt_cache_seq_show,
386 };
387
388 static int rt_cache_seq_open(struct inode *inode, struct file *file)
389 {
390 return seq_open_private(file, &rt_cache_seq_ops,
391 sizeof(struct rt_cache_iter_state));
392 }
393
394 static const struct file_operations rt_cache_seq_fops = {
395 .owner = THIS_MODULE,
396 .open = rt_cache_seq_open,
397 .read = seq_read,
398 .llseek = seq_lseek,
399 .release = seq_release_private,
400 };
401
402
403 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
404 {
405 int cpu;
406
407 if (*pos == 0)
408 return SEQ_START_TOKEN;
409
410 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
411 if (!cpu_possible(cpu))
412 continue;
413 *pos = cpu+1;
414 return &per_cpu(rt_cache_stat, cpu);
415 }
416 return NULL;
417 }
418
419 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
420 {
421 int cpu;
422
423 for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
424 if (!cpu_possible(cpu))
425 continue;
426 *pos = cpu+1;
427 return &per_cpu(rt_cache_stat, cpu);
428 }
429 return NULL;
430
431 }
432
433 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
434 {
435
436 }
437
438 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
439 {
440 struct rt_cache_stat *st = v;
441
442 if (v == SEQ_START_TOKEN) {
443 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");
444 return 0;
445 }
446
447 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
448 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
449 atomic_read(&ipv4_dst_ops.entries),
450 st->in_hit,
451 st->in_slow_tot,
452 st->in_slow_mc,
453 st->in_no_route,
454 st->in_brd,
455 st->in_martian_dst,
456 st->in_martian_src,
457
458 st->out_hit,
459 st->out_slow_tot,
460 st->out_slow_mc,
461
462 st->gc_total,
463 st->gc_ignored,
464 st->gc_goal_miss,
465 st->gc_dst_overflow,
466 st->in_hlist_search,
467 st->out_hlist_search
468 );
469 return 0;
470 }
471
472 static const struct seq_operations rt_cpu_seq_ops = {
473 .start = rt_cpu_seq_start,
474 .next = rt_cpu_seq_next,
475 .stop = rt_cpu_seq_stop,
476 .show = rt_cpu_seq_show,
477 };
478
479
480 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
481 {
482 return seq_open(file, &rt_cpu_seq_ops);
483 }
484
485 static const struct file_operations rt_cpu_seq_fops = {
486 .owner = THIS_MODULE,
487 .open = rt_cpu_seq_open,
488 .read = seq_read,
489 .llseek = seq_lseek,
490 .release = seq_release,
491 };
492
493 #ifdef CONFIG_NET_CLS_ROUTE
494 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
495 int length, int *eof, void *data)
496 {
497 unsigned int i;
498
499 if ((offset & 3) || (length & 3))
500 return -EIO;
501
502 if (offset >= sizeof(struct ip_rt_acct) * 256) {
503 *eof = 1;
504 return 0;
505 }
506
507 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
508 length = sizeof(struct ip_rt_acct) * 256 - offset;
509 *eof = 1;
510 }
511
512 offset /= sizeof(u32);
513
514 if (length > 0) {
515 u32 *dst = (u32 *) buffer;
516
517 *start = buffer;
518 memset(dst, 0, length);
519
520 for_each_possible_cpu(i) {
521 unsigned int j;
522 u32 *src;
523
524 src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
525 for (j = 0; j < length/4; j++)
526 dst[j] += src[j];
527 }
528 }
529 return length;
530 }
531 #endif
532
533 static __init int ip_rt_proc_init(struct net *net)
534 {
535 struct proc_dir_entry *pde;
536
537 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
538 &rt_cache_seq_fops);
539 if (!pde)
540 goto err1;
541
542 pde = create_proc_entry("rt_cache", S_IRUGO, net->proc_net_stat);
543 if (!pde)
544 goto err2;
545
546 pde->proc_fops = &rt_cpu_seq_fops;
547
548 #ifdef CONFIG_NET_CLS_ROUTE
549 pde = create_proc_read_entry("rt_acct", 0, net->proc_net,
550 ip_rt_acct_read, NULL);
551 if (!pde)
552 goto err3;
553 #endif
554 return 0;
555
556 #ifdef CONFIG_NET_CLS_ROUTE
557 err3:
558 remove_proc_entry("rt_cache", net->proc_net_stat);
559 #endif
560 err2:
561 remove_proc_entry("rt_cache", net->proc_net);
562 err1:
563 return -ENOMEM;
564 }
565 #else
566 static inline int ip_rt_proc_init(struct net *net)
567 {
568 return 0;
569 }
570 #endif /* CONFIG_PROC_FS */
571
572 static __inline__ void rt_free(struct rtable *rt)
573 {
574 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
575 }
576
577 static __inline__ void rt_drop(struct rtable *rt)
578 {
579 ip_rt_put(rt);
580 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
581 }
582
583 static __inline__ int rt_fast_clean(struct rtable *rth)
584 {
585 /* Kill broadcast/multicast entries very aggresively, if they
586 collide in hash table with more useful entries */
587 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
588 rth->fl.iif && rth->u.dst.rt_next;
589 }
590
591 static __inline__ int rt_valuable(struct rtable *rth)
592 {
593 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
594 rth->u.dst.expires;
595 }
596
597 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
598 {
599 unsigned long age;
600 int ret = 0;
601
602 if (atomic_read(&rth->u.dst.__refcnt))
603 goto out;
604
605 ret = 1;
606 if (rth->u.dst.expires &&
607 time_after_eq(jiffies, rth->u.dst.expires))
608 goto out;
609
610 age = jiffies - rth->u.dst.lastuse;
611 ret = 0;
612 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
613 (age <= tmo2 && rt_valuable(rth)))
614 goto out;
615 ret = 1;
616 out: return ret;
617 }
618
619 /* Bits of score are:
620 * 31: very valuable
621 * 30: not quite useless
622 * 29..0: usage counter
623 */
624 static inline u32 rt_score(struct rtable *rt)
625 {
626 u32 score = jiffies - rt->u.dst.lastuse;
627
628 score = ~score & ~(3<<30);
629
630 if (rt_valuable(rt))
631 score |= (1<<31);
632
633 if (!rt->fl.iif ||
634 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
635 score |= (1<<30);
636
637 return score;
638 }
639
640 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
641 {
642 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
643 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
644 (fl1->mark ^ fl2->mark) |
645 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
646 *(u16 *)&fl2->nl_u.ip4_u.tos) |
647 (fl1->oif ^ fl2->oif) |
648 (fl1->iif ^ fl2->iif)) == 0;
649 }
650
651 /*
652 * Perform a full scan of hash table and free all entries.
653 * Can be called by a softirq or a process.
654 * In the later case, we want to be reschedule if necessary
655 */
656 static void rt_do_flush(int process_context)
657 {
658 unsigned int i;
659 struct rtable *rth, *next;
660
661 for (i = 0; i <= rt_hash_mask; i++) {
662 if (process_context && need_resched())
663 cond_resched();
664 rth = rt_hash_table[i].chain;
665 if (!rth)
666 continue;
667
668 spin_lock_bh(rt_hash_lock_addr(i));
669 rth = rt_hash_table[i].chain;
670 rt_hash_table[i].chain = NULL;
671 spin_unlock_bh(rt_hash_lock_addr(i));
672
673 for (; rth; rth = next) {
674 next = rth->u.dst.rt_next;
675 rt_free(rth);
676 }
677 }
678 }
679
680 static void rt_check_expire(void)
681 {
682 static unsigned int rover;
683 unsigned int i = rover, goal;
684 struct rtable *rth, **rthp;
685 u64 mult;
686
687 mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
688 if (ip_rt_gc_timeout > 1)
689 do_div(mult, ip_rt_gc_timeout);
690 goal = (unsigned int)mult;
691 if (goal > rt_hash_mask)
692 goal = rt_hash_mask + 1;
693 for (; goal > 0; goal--) {
694 unsigned long tmo = ip_rt_gc_timeout;
695
696 i = (i + 1) & rt_hash_mask;
697 rthp = &rt_hash_table[i].chain;
698
699 if (need_resched())
700 cond_resched();
701
702 if (*rthp == NULL)
703 continue;
704 spin_lock_bh(rt_hash_lock_addr(i));
705 while ((rth = *rthp) != NULL) {
706 if (rth->u.dst.expires) {
707 /* Entry is expired even if it is in use */
708 if (time_before_eq(jiffies, rth->u.dst.expires)) {
709 tmo >>= 1;
710 rthp = &rth->u.dst.rt_next;
711 continue;
712 }
713 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
714 tmo >>= 1;
715 rthp = &rth->u.dst.rt_next;
716 continue;
717 }
718
719 /* Cleanup aged off entries. */
720 *rthp = rth->u.dst.rt_next;
721 rt_free(rth);
722 }
723 spin_unlock_bh(rt_hash_lock_addr(i));
724 }
725 rover = i;
726 }
727
728 /*
729 * rt_worker_func() is run in process context.
730 * If a whole flush was scheduled, it is done.
731 * Else, we call rt_check_expire() to scan part of the hash table
732 */
733 static void rt_worker_func(struct work_struct *work)
734 {
735 if (ip_rt_flush_expected) {
736 ip_rt_flush_expected = 0;
737 rt_do_flush(1);
738 } else
739 rt_check_expire();
740 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
741 }
742
743 /* This can run from both BH and non-BH contexts, the latter
744 * in the case of a forced flush event.
745 */
746 static void rt_run_flush(unsigned long process_context)
747 {
748 rt_deadline = 0;
749
750 get_random_bytes(&rt_hash_rnd, 4);
751
752 rt_do_flush(process_context);
753 }
754
755 static DEFINE_SPINLOCK(rt_flush_lock);
756
757 void rt_cache_flush(int delay)
758 {
759 unsigned long now = jiffies;
760 int user_mode = !in_softirq();
761
762 if (delay < 0)
763 delay = ip_rt_min_delay;
764
765 spin_lock_bh(&rt_flush_lock);
766
767 if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
768 long tmo = (long)(rt_deadline - now);
769
770 /* If flush timer is already running
771 and flush request is not immediate (delay > 0):
772
773 if deadline is not achieved, prolongate timer to "delay",
774 otherwise fire it at deadline time.
775 */
776
777 if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
778 tmo = 0;
779
780 if (delay > tmo)
781 delay = tmo;
782 }
783
784 if (delay <= 0) {
785 spin_unlock_bh(&rt_flush_lock);
786 rt_run_flush(user_mode);
787 return;
788 }
789
790 if (rt_deadline == 0)
791 rt_deadline = now + ip_rt_max_delay;
792
793 mod_timer(&rt_flush_timer, now+delay);
794 spin_unlock_bh(&rt_flush_lock);
795 }
796
797 /*
798 * We change rt_hash_rnd and ask next rt_worker_func() invocation
799 * to perform a flush in process context
800 */
801 static void rt_secret_rebuild(unsigned long dummy)
802 {
803 get_random_bytes(&rt_hash_rnd, 4);
804 ip_rt_flush_expected = 1;
805 cancel_delayed_work(&expires_work);
806 schedule_delayed_work(&expires_work, HZ/10);
807 mod_timer(&rt_secret_timer, jiffies + ip_rt_secret_interval);
808 }
809
810 /*
811 Short description of GC goals.
812
813 We want to build algorithm, which will keep routing cache
814 at some equilibrium point, when number of aged off entries
815 is kept approximately equal to newly generated ones.
816
817 Current expiration strength is variable "expire".
818 We try to adjust it dynamically, so that if networking
819 is idle expires is large enough to keep enough of warm entries,
820 and when load increases it reduces to limit cache size.
821 */
822
823 static int rt_garbage_collect(struct dst_ops *ops)
824 {
825 static unsigned long expire = RT_GC_TIMEOUT;
826 static unsigned long last_gc;
827 static int rover;
828 static int equilibrium;
829 struct rtable *rth, **rthp;
830 unsigned long now = jiffies;
831 int goal;
832
833 /*
834 * Garbage collection is pretty expensive,
835 * do not make it too frequently.
836 */
837
838 RT_CACHE_STAT_INC(gc_total);
839
840 if (now - last_gc < ip_rt_gc_min_interval &&
841 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
842 RT_CACHE_STAT_INC(gc_ignored);
843 goto out;
844 }
845
846 /* Calculate number of entries, which we want to expire now. */
847 goal = atomic_read(&ipv4_dst_ops.entries) -
848 (ip_rt_gc_elasticity << rt_hash_log);
849 if (goal <= 0) {
850 if (equilibrium < ipv4_dst_ops.gc_thresh)
851 equilibrium = ipv4_dst_ops.gc_thresh;
852 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
853 if (goal > 0) {
854 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
855 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
856 }
857 } else {
858 /* We are in dangerous area. Try to reduce cache really
859 * aggressively.
860 */
861 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
862 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
863 }
864
865 if (now - last_gc >= ip_rt_gc_min_interval)
866 last_gc = now;
867
868 if (goal <= 0) {
869 equilibrium += goal;
870 goto work_done;
871 }
872
873 do {
874 int i, k;
875
876 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
877 unsigned long tmo = expire;
878
879 k = (k + 1) & rt_hash_mask;
880 rthp = &rt_hash_table[k].chain;
881 spin_lock_bh(rt_hash_lock_addr(k));
882 while ((rth = *rthp) != NULL) {
883 if (!rt_may_expire(rth, tmo, expire)) {
884 tmo >>= 1;
885 rthp = &rth->u.dst.rt_next;
886 continue;
887 }
888 *rthp = rth->u.dst.rt_next;
889 rt_free(rth);
890 goal--;
891 }
892 spin_unlock_bh(rt_hash_lock_addr(k));
893 if (goal <= 0)
894 break;
895 }
896 rover = k;
897
898 if (goal <= 0)
899 goto work_done;
900
901 /* Goal is not achieved. We stop process if:
902
903 - if expire reduced to zero. Otherwise, expire is halfed.
904 - if table is not full.
905 - if we are called from interrupt.
906 - jiffies check is just fallback/debug loop breaker.
907 We will not spin here for long time in any case.
908 */
909
910 RT_CACHE_STAT_INC(gc_goal_miss);
911
912 if (expire == 0)
913 break;
914
915 expire >>= 1;
916 #if RT_CACHE_DEBUG >= 2
917 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
918 atomic_read(&ipv4_dst_ops.entries), goal, i);
919 #endif
920
921 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
922 goto out;
923 } while (!in_softirq() && time_before_eq(jiffies, now));
924
925 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
926 goto out;
927 if (net_ratelimit())
928 printk(KERN_WARNING "dst cache overflow\n");
929 RT_CACHE_STAT_INC(gc_dst_overflow);
930 return 1;
931
932 work_done:
933 expire += ip_rt_gc_min_interval;
934 if (expire > ip_rt_gc_timeout ||
935 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
936 expire = ip_rt_gc_timeout;
937 #if RT_CACHE_DEBUG >= 2
938 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
939 atomic_read(&ipv4_dst_ops.entries), goal, rover);
940 #endif
941 out: return 0;
942 }
943
944 static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
945 {
946 struct rtable *rth, **rthp;
947 unsigned long now;
948 struct rtable *cand, **candp;
949 u32 min_score;
950 int chain_length;
951 int attempts = !in_softirq();
952
953 restart:
954 chain_length = 0;
955 min_score = ~(u32)0;
956 cand = NULL;
957 candp = NULL;
958 now = jiffies;
959
960 rthp = &rt_hash_table[hash].chain;
961
962 spin_lock_bh(rt_hash_lock_addr(hash));
963 while ((rth = *rthp) != NULL) {
964 if (compare_keys(&rth->fl, &rt->fl)) {
965 /* Put it first */
966 *rthp = rth->u.dst.rt_next;
967 /*
968 * Since lookup is lockfree, the deletion
969 * must be visible to another weakly ordered CPU before
970 * the insertion at the start of the hash chain.
971 */
972 rcu_assign_pointer(rth->u.dst.rt_next,
973 rt_hash_table[hash].chain);
974 /*
975 * Since lookup is lockfree, the update writes
976 * must be ordered for consistency on SMP.
977 */
978 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
979
980 dst_use(&rth->u.dst, now);
981 spin_unlock_bh(rt_hash_lock_addr(hash));
982
983 rt_drop(rt);
984 *rp = rth;
985 return 0;
986 }
987
988 if (!atomic_read(&rth->u.dst.__refcnt)) {
989 u32 score = rt_score(rth);
990
991 if (score <= min_score) {
992 cand = rth;
993 candp = rthp;
994 min_score = score;
995 }
996 }
997
998 chain_length++;
999
1000 rthp = &rth->u.dst.rt_next;
1001 }
1002
1003 if (cand) {
1004 /* ip_rt_gc_elasticity used to be average length of chain
1005 * length, when exceeded gc becomes really aggressive.
1006 *
1007 * The second limit is less certain. At the moment it allows
1008 * only 2 entries per bucket. We will see.
1009 */
1010 if (chain_length > ip_rt_gc_elasticity) {
1011 *candp = cand->u.dst.rt_next;
1012 rt_free(cand);
1013 }
1014 }
1015
1016 /* Try to bind route to arp only if it is output
1017 route or unicast forwarding path.
1018 */
1019 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1020 int err = arp_bind_neighbour(&rt->u.dst);
1021 if (err) {
1022 spin_unlock_bh(rt_hash_lock_addr(hash));
1023
1024 if (err != -ENOBUFS) {
1025 rt_drop(rt);
1026 return err;
1027 }
1028
1029 /* Neighbour tables are full and nothing
1030 can be released. Try to shrink route cache,
1031 it is most likely it holds some neighbour records.
1032 */
1033 if (attempts-- > 0) {
1034 int saved_elasticity = ip_rt_gc_elasticity;
1035 int saved_int = ip_rt_gc_min_interval;
1036 ip_rt_gc_elasticity = 1;
1037 ip_rt_gc_min_interval = 0;
1038 rt_garbage_collect(&ipv4_dst_ops);
1039 ip_rt_gc_min_interval = saved_int;
1040 ip_rt_gc_elasticity = saved_elasticity;
1041 goto restart;
1042 }
1043
1044 if (net_ratelimit())
1045 printk(KERN_WARNING "Neighbour table overflow.\n");
1046 rt_drop(rt);
1047 return -ENOBUFS;
1048 }
1049 }
1050
1051 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1052 #if RT_CACHE_DEBUG >= 2
1053 if (rt->u.dst.rt_next) {
1054 struct rtable *trt;
1055 printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
1056 NIPQUAD(rt->rt_dst));
1057 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1058 printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
1059 printk("\n");
1060 }
1061 #endif
1062 rt_hash_table[hash].chain = rt;
1063 spin_unlock_bh(rt_hash_lock_addr(hash));
1064 *rp = rt;
1065 return 0;
1066 }
1067
1068 void rt_bind_peer(struct rtable *rt, int create)
1069 {
1070 static DEFINE_SPINLOCK(rt_peer_lock);
1071 struct inet_peer *peer;
1072
1073 peer = inet_getpeer(rt->rt_dst, create);
1074
1075 spin_lock_bh(&rt_peer_lock);
1076 if (rt->peer == NULL) {
1077 rt->peer = peer;
1078 peer = NULL;
1079 }
1080 spin_unlock_bh(&rt_peer_lock);
1081 if (peer)
1082 inet_putpeer(peer);
1083 }
1084
1085 /*
1086 * Peer allocation may fail only in serious out-of-memory conditions. However
1087 * we still can generate some output.
1088 * Random ID selection looks a bit dangerous because we have no chances to
1089 * select ID being unique in a reasonable period of time.
1090 * But broken packet identifier may be better than no packet at all.
1091 */
1092 static void ip_select_fb_ident(struct iphdr *iph)
1093 {
1094 static DEFINE_SPINLOCK(ip_fb_id_lock);
1095 static u32 ip_fallback_id;
1096 u32 salt;
1097
1098 spin_lock_bh(&ip_fb_id_lock);
1099 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1100 iph->id = htons(salt & 0xFFFF);
1101 ip_fallback_id = salt;
1102 spin_unlock_bh(&ip_fb_id_lock);
1103 }
1104
1105 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1106 {
1107 struct rtable *rt = (struct rtable *) dst;
1108
1109 if (rt) {
1110 if (rt->peer == NULL)
1111 rt_bind_peer(rt, 1);
1112
1113 /* If peer is attached to destination, it is never detached,
1114 so that we need not to grab a lock to dereference it.
1115 */
1116 if (rt->peer) {
1117 iph->id = htons(inet_getid(rt->peer, more));
1118 return;
1119 }
1120 } else
1121 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1122 __builtin_return_address(0));
1123
1124 ip_select_fb_ident(iph);
1125 }
1126
1127 static void rt_del(unsigned hash, struct rtable *rt)
1128 {
1129 struct rtable **rthp;
1130
1131 spin_lock_bh(rt_hash_lock_addr(hash));
1132 ip_rt_put(rt);
1133 for (rthp = &rt_hash_table[hash].chain; *rthp;
1134 rthp = &(*rthp)->u.dst.rt_next)
1135 if (*rthp == rt) {
1136 *rthp = rt->u.dst.rt_next;
1137 rt_free(rt);
1138 break;
1139 }
1140 spin_unlock_bh(rt_hash_lock_addr(hash));
1141 }
1142
1143 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1144 __be32 saddr, struct net_device *dev)
1145 {
1146 int i, k;
1147 struct in_device *in_dev = in_dev_get(dev);
1148 struct rtable *rth, **rthp;
1149 __be32 skeys[2] = { saddr, 0 };
1150 int ikeys[2] = { dev->ifindex, 0 };
1151 struct netevent_redirect netevent;
1152
1153 if (!in_dev)
1154 return;
1155
1156 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1157 || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
1158 || ipv4_is_zeronet(new_gw))
1159 goto reject_redirect;
1160
1161 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1162 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1163 goto reject_redirect;
1164 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1165 goto reject_redirect;
1166 } else {
1167 if (inet_addr_type(&init_net, new_gw) != RTN_UNICAST)
1168 goto reject_redirect;
1169 }
1170
1171 for (i = 0; i < 2; i++) {
1172 for (k = 0; k < 2; k++) {
1173 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
1174
1175 rthp=&rt_hash_table[hash].chain;
1176
1177 rcu_read_lock();
1178 while ((rth = rcu_dereference(*rthp)) != NULL) {
1179 struct rtable *rt;
1180
1181 if (rth->fl.fl4_dst != daddr ||
1182 rth->fl.fl4_src != skeys[i] ||
1183 rth->fl.oif != ikeys[k] ||
1184 rth->fl.iif != 0) {
1185 rthp = &rth->u.dst.rt_next;
1186 continue;
1187 }
1188
1189 if (rth->rt_dst != daddr ||
1190 rth->rt_src != saddr ||
1191 rth->u.dst.error ||
1192 rth->rt_gateway != old_gw ||
1193 rth->u.dst.dev != dev)
1194 break;
1195
1196 dst_hold(&rth->u.dst);
1197 rcu_read_unlock();
1198
1199 rt = dst_alloc(&ipv4_dst_ops);
1200 if (rt == NULL) {
1201 ip_rt_put(rth);
1202 in_dev_put(in_dev);
1203 return;
1204 }
1205
1206 /* Copy all the information. */
1207 *rt = *rth;
1208 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1209 rt->u.dst.__use = 1;
1210 atomic_set(&rt->u.dst.__refcnt, 1);
1211 rt->u.dst.child = NULL;
1212 if (rt->u.dst.dev)
1213 dev_hold(rt->u.dst.dev);
1214 if (rt->idev)
1215 in_dev_hold(rt->idev);
1216 rt->u.dst.obsolete = 0;
1217 rt->u.dst.lastuse = jiffies;
1218 rt->u.dst.path = &rt->u.dst;
1219 rt->u.dst.neighbour = NULL;
1220 rt->u.dst.hh = NULL;
1221 rt->u.dst.xfrm = NULL;
1222
1223 rt->rt_flags |= RTCF_REDIRECTED;
1224
1225 /* Gateway is different ... */
1226 rt->rt_gateway = new_gw;
1227
1228 /* Redirect received -> path was valid */
1229 dst_confirm(&rth->u.dst);
1230
1231 if (rt->peer)
1232 atomic_inc(&rt->peer->refcnt);
1233
1234 if (arp_bind_neighbour(&rt->u.dst) ||
1235 !(rt->u.dst.neighbour->nud_state &
1236 NUD_VALID)) {
1237 if (rt->u.dst.neighbour)
1238 neigh_event_send(rt->u.dst.neighbour, NULL);
1239 ip_rt_put(rth);
1240 rt_drop(rt);
1241 goto do_next;
1242 }
1243
1244 netevent.old = &rth->u.dst;
1245 netevent.new = &rt->u.dst;
1246 call_netevent_notifiers(NETEVENT_REDIRECT,
1247 &netevent);
1248
1249 rt_del(hash, rth);
1250 if (!rt_intern_hash(hash, rt, &rt))
1251 ip_rt_put(rt);
1252 goto do_next;
1253 }
1254 rcu_read_unlock();
1255 do_next:
1256 ;
1257 }
1258 }
1259 in_dev_put(in_dev);
1260 return;
1261
1262 reject_redirect:
1263 #ifdef CONFIG_IP_ROUTE_VERBOSE
1264 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1265 printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
1266 "%u.%u.%u.%u ignored.\n"
1267 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n",
1268 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1269 NIPQUAD(saddr), NIPQUAD(daddr));
1270 #endif
1271 in_dev_put(in_dev);
1272 }
1273
1274 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1275 {
1276 struct rtable *rt = (struct rtable*)dst;
1277 struct dst_entry *ret = dst;
1278
1279 if (rt) {
1280 if (dst->obsolete) {
1281 ip_rt_put(rt);
1282 ret = NULL;
1283 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1284 rt->u.dst.expires) {
1285 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1286 rt->fl.oif);
1287 #if RT_CACHE_DEBUG >= 1
1288 printk(KERN_DEBUG "ipv4_negative_advice: redirect to "
1289 "%u.%u.%u.%u/%02x dropped\n",
1290 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1291 #endif
1292 rt_del(hash, rt);
1293 ret = NULL;
1294 }
1295 }
1296 return ret;
1297 }
1298
1299 /*
1300 * Algorithm:
1301 * 1. The first ip_rt_redirect_number redirects are sent
1302 * with exponential backoff, then we stop sending them at all,
1303 * assuming that the host ignores our redirects.
1304 * 2. If we did not see packets requiring redirects
1305 * during ip_rt_redirect_silence, we assume that the host
1306 * forgot redirected route and start to send redirects again.
1307 *
1308 * This algorithm is much cheaper and more intelligent than dumb load limiting
1309 * in icmp.c.
1310 *
1311 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1312 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1313 */
1314
1315 void ip_rt_send_redirect(struct sk_buff *skb)
1316 {
1317 struct rtable *rt = (struct rtable*)skb->dst;
1318 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1319
1320 if (!in_dev)
1321 return;
1322
1323 if (!IN_DEV_TX_REDIRECTS(in_dev))
1324 goto out;
1325
1326 /* No redirected packets during ip_rt_redirect_silence;
1327 * reset the algorithm.
1328 */
1329 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1330 rt->u.dst.rate_tokens = 0;
1331
1332 /* Too many ignored redirects; do not send anything
1333 * set u.dst.rate_last to the last seen redirected packet.
1334 */
1335 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1336 rt->u.dst.rate_last = jiffies;
1337 goto out;
1338 }
1339
1340 /* Check for load limit; set rate_last to the latest sent
1341 * redirect.
1342 */
1343 if (rt->u.dst.rate_tokens == 0 ||
1344 time_after(jiffies,
1345 (rt->u.dst.rate_last +
1346 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1347 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1348 rt->u.dst.rate_last = jiffies;
1349 ++rt->u.dst.rate_tokens;
1350 #ifdef CONFIG_IP_ROUTE_VERBOSE
1351 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1352 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1353 net_ratelimit())
1354 printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
1355 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1356 NIPQUAD(rt->rt_src), rt->rt_iif,
1357 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1358 #endif
1359 }
1360 out:
1361 in_dev_put(in_dev);
1362 }
1363
1364 static int ip_error(struct sk_buff *skb)
1365 {
1366 struct rtable *rt = (struct rtable*)skb->dst;
1367 unsigned long now;
1368 int code;
1369
1370 switch (rt->u.dst.error) {
1371 case EINVAL:
1372 default:
1373 goto out;
1374 case EHOSTUNREACH:
1375 code = ICMP_HOST_UNREACH;
1376 break;
1377 case ENETUNREACH:
1378 code = ICMP_NET_UNREACH;
1379 IP_INC_STATS_BH(IPSTATS_MIB_INNOROUTES);
1380 break;
1381 case EACCES:
1382 code = ICMP_PKT_FILTERED;
1383 break;
1384 }
1385
1386 now = jiffies;
1387 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1388 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1389 rt->u.dst.rate_tokens = ip_rt_error_burst;
1390 rt->u.dst.rate_last = now;
1391 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1392 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1393 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1394 }
1395
1396 out: kfree_skb(skb);
1397 return 0;
1398 }
1399
1400 /*
1401 * The last two values are not from the RFC but
1402 * are needed for AMPRnet AX.25 paths.
1403 */
1404
1405 static const unsigned short mtu_plateau[] =
1406 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1407
1408 static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
1409 {
1410 int i;
1411
1412 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1413 if (old_mtu > mtu_plateau[i])
1414 return mtu_plateau[i];
1415 return 68;
1416 }
1417
1418 unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
1419 {
1420 int i;
1421 unsigned short old_mtu = ntohs(iph->tot_len);
1422 struct rtable *rth;
1423 __be32 skeys[2] = { iph->saddr, 0, };
1424 __be32 daddr = iph->daddr;
1425 unsigned short est_mtu = 0;
1426
1427 if (ipv4_config.no_pmtu_disc)
1428 return 0;
1429
1430 for (i = 0; i < 2; i++) {
1431 unsigned hash = rt_hash(daddr, skeys[i], 0);
1432
1433 rcu_read_lock();
1434 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1435 rth = rcu_dereference(rth->u.dst.rt_next)) {
1436 if (rth->fl.fl4_dst == daddr &&
1437 rth->fl.fl4_src == skeys[i] &&
1438 rth->rt_dst == daddr &&
1439 rth->rt_src == iph->saddr &&
1440 rth->fl.iif == 0 &&
1441 !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
1442 unsigned short mtu = new_mtu;
1443
1444 if (new_mtu < 68 || new_mtu >= old_mtu) {
1445
1446 /* BSD 4.2 compatibility hack :-( */
1447 if (mtu == 0 &&
1448 old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
1449 old_mtu >= 68 + (iph->ihl << 2))
1450 old_mtu -= iph->ihl << 2;
1451
1452 mtu = guess_mtu(old_mtu);
1453 }
1454 if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1455 if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
1456 dst_confirm(&rth->u.dst);
1457 if (mtu < ip_rt_min_pmtu) {
1458 mtu = ip_rt_min_pmtu;
1459 rth->u.dst.metrics[RTAX_LOCK-1] |=
1460 (1 << RTAX_MTU);
1461 }
1462 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1463 dst_set_expires(&rth->u.dst,
1464 ip_rt_mtu_expires);
1465 }
1466 est_mtu = mtu;
1467 }
1468 }
1469 }
1470 rcu_read_unlock();
1471 }
1472 return est_mtu ? : new_mtu;
1473 }
1474
1475 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1476 {
1477 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
1478 !(dst_metric_locked(dst, RTAX_MTU))) {
1479 if (mtu < ip_rt_min_pmtu) {
1480 mtu = ip_rt_min_pmtu;
1481 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1482 }
1483 dst->metrics[RTAX_MTU-1] = mtu;
1484 dst_set_expires(dst, ip_rt_mtu_expires);
1485 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1486 }
1487 }
1488
1489 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1490 {
1491 return NULL;
1492 }
1493
1494 static void ipv4_dst_destroy(struct dst_entry *dst)
1495 {
1496 struct rtable *rt = (struct rtable *) dst;
1497 struct inet_peer *peer = rt->peer;
1498 struct in_device *idev = rt->idev;
1499
1500 if (peer) {
1501 rt->peer = NULL;
1502 inet_putpeer(peer);
1503 }
1504
1505 if (idev) {
1506 rt->idev = NULL;
1507 in_dev_put(idev);
1508 }
1509 }
1510
1511 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1512 int how)
1513 {
1514 struct rtable *rt = (struct rtable *) dst;
1515 struct in_device *idev = rt->idev;
1516 if (dev != dev->nd_net->loopback_dev && idev && idev->dev == dev) {
1517 struct in_device *loopback_idev =
1518 in_dev_get(dev->nd_net->loopback_dev);
1519 if (loopback_idev) {
1520 rt->idev = loopback_idev;
1521 in_dev_put(idev);
1522 }
1523 }
1524 }
1525
1526 static void ipv4_link_failure(struct sk_buff *skb)
1527 {
1528 struct rtable *rt;
1529
1530 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1531
1532 rt = (struct rtable *) skb->dst;
1533 if (rt)
1534 dst_set_expires(&rt->u.dst, 0);
1535 }
1536
1537 static int ip_rt_bug(struct sk_buff *skb)
1538 {
1539 printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1540 NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(ip_hdr(skb)->daddr),
1541 skb->dev ? skb->dev->name : "?");
1542 kfree_skb(skb);
1543 return 0;
1544 }
1545
1546 /*
1547 We do not cache source address of outgoing interface,
1548 because it is used only by IP RR, TS and SRR options,
1549 so that it out of fast path.
1550
1551 BTW remember: "addr" is allowed to be not aligned
1552 in IP options!
1553 */
1554
1555 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1556 {
1557 __be32 src;
1558 struct fib_result res;
1559
1560 if (rt->fl.iif == 0)
1561 src = rt->rt_src;
1562 else if (fib_lookup(rt->u.dst.dev->nd_net, &rt->fl, &res) == 0) {
1563 src = FIB_RES_PREFSRC(res);
1564 fib_res_put(&res);
1565 } else
1566 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1567 RT_SCOPE_UNIVERSE);
1568 memcpy(addr, &src, 4);
1569 }
1570
1571 #ifdef CONFIG_NET_CLS_ROUTE
1572 static void set_class_tag(struct rtable *rt, u32 tag)
1573 {
1574 if (!(rt->u.dst.tclassid & 0xFFFF))
1575 rt->u.dst.tclassid |= tag & 0xFFFF;
1576 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1577 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1578 }
1579 #endif
1580
1581 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1582 {
1583 struct fib_info *fi = res->fi;
1584
1585 if (fi) {
1586 if (FIB_RES_GW(*res) &&
1587 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1588 rt->rt_gateway = FIB_RES_GW(*res);
1589 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1590 sizeof(rt->u.dst.metrics));
1591 if (fi->fib_mtu == 0) {
1592 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1593 if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
1594 rt->rt_gateway != rt->rt_dst &&
1595 rt->u.dst.dev->mtu > 576)
1596 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1597 }
1598 #ifdef CONFIG_NET_CLS_ROUTE
1599 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1600 #endif
1601 } else
1602 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1603
1604 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1605 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1606 if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
1607 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1608 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
1609 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1610 ip_rt_min_advmss);
1611 if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
1612 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1613
1614 #ifdef CONFIG_NET_CLS_ROUTE
1615 #ifdef CONFIG_IP_MULTIPLE_TABLES
1616 set_class_tag(rt, fib_rules_tclass(res));
1617 #endif
1618 set_class_tag(rt, itag);
1619 #endif
1620 rt->rt_type = res->type;
1621 }
1622
1623 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1624 u8 tos, struct net_device *dev, int our)
1625 {
1626 unsigned hash;
1627 struct rtable *rth;
1628 __be32 spec_dst;
1629 struct in_device *in_dev = in_dev_get(dev);
1630 u32 itag = 0;
1631
1632 /* Primary sanity checks. */
1633
1634 if (in_dev == NULL)
1635 return -EINVAL;
1636
1637 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1638 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1639 goto e_inval;
1640
1641 if (ipv4_is_zeronet(saddr)) {
1642 if (!ipv4_is_local_multicast(daddr))
1643 goto e_inval;
1644 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1645 } else if (fib_validate_source(saddr, 0, tos, 0,
1646 dev, &spec_dst, &itag) < 0)
1647 goto e_inval;
1648
1649 rth = dst_alloc(&ipv4_dst_ops);
1650 if (!rth)
1651 goto e_nobufs;
1652
1653 rth->u.dst.output= ip_rt_bug;
1654
1655 atomic_set(&rth->u.dst.__refcnt, 1);
1656 rth->u.dst.flags= DST_HOST;
1657 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1658 rth->u.dst.flags |= DST_NOPOLICY;
1659 rth->fl.fl4_dst = daddr;
1660 rth->rt_dst = daddr;
1661 rth->fl.fl4_tos = tos;
1662 rth->fl.mark = skb->mark;
1663 rth->fl.fl4_src = saddr;
1664 rth->rt_src = saddr;
1665 #ifdef CONFIG_NET_CLS_ROUTE
1666 rth->u.dst.tclassid = itag;
1667 #endif
1668 rth->rt_iif =
1669 rth->fl.iif = dev->ifindex;
1670 rth->u.dst.dev = init_net.loopback_dev;
1671 dev_hold(rth->u.dst.dev);
1672 rth->idev = in_dev_get(rth->u.dst.dev);
1673 rth->fl.oif = 0;
1674 rth->rt_gateway = daddr;
1675 rth->rt_spec_dst= spec_dst;
1676 rth->rt_type = RTN_MULTICAST;
1677 rth->rt_flags = RTCF_MULTICAST;
1678 if (our) {
1679 rth->u.dst.input= ip_local_deliver;
1680 rth->rt_flags |= RTCF_LOCAL;
1681 }
1682
1683 #ifdef CONFIG_IP_MROUTE
1684 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1685 rth->u.dst.input = ip_mr_input;
1686 #endif
1687 RT_CACHE_STAT_INC(in_slow_mc);
1688
1689 in_dev_put(in_dev);
1690 hash = rt_hash(daddr, saddr, dev->ifindex);
1691 return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
1692
1693 e_nobufs:
1694 in_dev_put(in_dev);
1695 return -ENOBUFS;
1696
1697 e_inval:
1698 in_dev_put(in_dev);
1699 return -EINVAL;
1700 }
1701
1702
1703 static void ip_handle_martian_source(struct net_device *dev,
1704 struct in_device *in_dev,
1705 struct sk_buff *skb,
1706 __be32 daddr,
1707 __be32 saddr)
1708 {
1709 RT_CACHE_STAT_INC(in_martian_src);
1710 #ifdef CONFIG_IP_ROUTE_VERBOSE
1711 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1712 /*
1713 * RFC1812 recommendation, if source is martian,
1714 * the only hint is MAC header.
1715 */
1716 printk(KERN_WARNING "martian source %u.%u.%u.%u from "
1717 "%u.%u.%u.%u, on dev %s\n",
1718 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1719 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1720 int i;
1721 const unsigned char *p = skb_mac_header(skb);
1722 printk(KERN_WARNING "ll header: ");
1723 for (i = 0; i < dev->hard_header_len; i++, p++) {
1724 printk("%02x", *p);
1725 if (i < (dev->hard_header_len - 1))
1726 printk(":");
1727 }
1728 printk("\n");
1729 }
1730 }
1731 #endif
1732 }
1733
1734 static inline int __mkroute_input(struct sk_buff *skb,
1735 struct fib_result* res,
1736 struct in_device *in_dev,
1737 __be32 daddr, __be32 saddr, u32 tos,
1738 struct rtable **result)
1739 {
1740
1741 struct rtable *rth;
1742 int err;
1743 struct in_device *out_dev;
1744 unsigned flags = 0;
1745 __be32 spec_dst;
1746 u32 itag;
1747
1748 /* get a working reference to the output device */
1749 out_dev = in_dev_get(FIB_RES_DEV(*res));
1750 if (out_dev == NULL) {
1751 if (net_ratelimit())
1752 printk(KERN_CRIT "Bug in ip_route_input" \
1753 "_slow(). Please, report\n");
1754 return -EINVAL;
1755 }
1756
1757
1758 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1759 in_dev->dev, &spec_dst, &itag);
1760 if (err < 0) {
1761 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1762 saddr);
1763
1764 err = -EINVAL;
1765 goto cleanup;
1766 }
1767
1768 if (err)
1769 flags |= RTCF_DIRECTSRC;
1770
1771 if (out_dev == in_dev && err && !(flags & RTCF_MASQ) &&
1772 (IN_DEV_SHARED_MEDIA(out_dev) ||
1773 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1774 flags |= RTCF_DOREDIRECT;
1775
1776 if (skb->protocol != htons(ETH_P_IP)) {
1777 /* Not IP (i.e. ARP). Do not create route, if it is
1778 * invalid for proxy arp. DNAT routes are always valid.
1779 */
1780 if (out_dev == in_dev) {
1781 err = -EINVAL;
1782 goto cleanup;
1783 }
1784 }
1785
1786
1787 rth = dst_alloc(&ipv4_dst_ops);
1788 if (!rth) {
1789 err = -ENOBUFS;
1790 goto cleanup;
1791 }
1792
1793 atomic_set(&rth->u.dst.__refcnt, 1);
1794 rth->u.dst.flags= DST_HOST;
1795 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1796 rth->u.dst.flags |= DST_NOPOLICY;
1797 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
1798 rth->u.dst.flags |= DST_NOXFRM;
1799 rth->fl.fl4_dst = daddr;
1800 rth->rt_dst = daddr;
1801 rth->fl.fl4_tos = tos;
1802 rth->fl.mark = skb->mark;
1803 rth->fl.fl4_src = saddr;
1804 rth->rt_src = saddr;
1805 rth->rt_gateway = daddr;
1806 rth->rt_iif =
1807 rth->fl.iif = in_dev->dev->ifindex;
1808 rth->u.dst.dev = (out_dev)->dev;
1809 dev_hold(rth->u.dst.dev);
1810 rth->idev = in_dev_get(rth->u.dst.dev);
1811 rth->fl.oif = 0;
1812 rth->rt_spec_dst= spec_dst;
1813
1814 rth->u.dst.input = ip_forward;
1815 rth->u.dst.output = ip_output;
1816
1817 rt_set_nexthop(rth, res, itag);
1818
1819 rth->rt_flags = flags;
1820
1821 *result = rth;
1822 err = 0;
1823 cleanup:
1824 /* release the working reference to the output device */
1825 in_dev_put(out_dev);
1826 return err;
1827 }
1828
1829 static inline int ip_mkroute_input(struct sk_buff *skb,
1830 struct fib_result* res,
1831 const struct flowi *fl,
1832 struct in_device *in_dev,
1833 __be32 daddr, __be32 saddr, u32 tos)
1834 {
1835 struct rtable* rth = NULL;
1836 int err;
1837 unsigned hash;
1838
1839 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1840 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
1841 fib_select_multipath(fl, res);
1842 #endif
1843
1844 /* create a routing cache entry */
1845 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1846 if (err)
1847 return err;
1848
1849 /* put it into the cache */
1850 hash = rt_hash(daddr, saddr, fl->iif);
1851 return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1852 }
1853
1854 /*
1855 * NOTE. We drop all the packets that has local source
1856 * addresses, because every properly looped back packet
1857 * must have correct destination already attached by output routine.
1858 *
1859 * Such approach solves two big problems:
1860 * 1. Not simplex devices are handled properly.
1861 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1862 */
1863
1864 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1865 u8 tos, struct net_device *dev)
1866 {
1867 struct fib_result res;
1868 struct in_device *in_dev = in_dev_get(dev);
1869 struct flowi fl = { .nl_u = { .ip4_u =
1870 { .daddr = daddr,
1871 .saddr = saddr,
1872 .tos = tos,
1873 .scope = RT_SCOPE_UNIVERSE,
1874 } },
1875 .mark = skb->mark,
1876 .iif = dev->ifindex };
1877 unsigned flags = 0;
1878 u32 itag = 0;
1879 struct rtable * rth;
1880 unsigned hash;
1881 __be32 spec_dst;
1882 int err = -EINVAL;
1883 int free_res = 0;
1884 struct net * net = dev->nd_net;
1885
1886 /* IP on this device is disabled. */
1887
1888 if (!in_dev)
1889 goto out;
1890
1891 /* Check for the most weird martians, which can be not detected
1892 by fib_lookup.
1893 */
1894
1895 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1896 ipv4_is_loopback(saddr))
1897 goto martian_source;
1898
1899 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
1900 goto brd_input;
1901
1902 /* Accept zero addresses only to limited broadcast;
1903 * I even do not know to fix it or not. Waiting for complains :-)
1904 */
1905 if (ipv4_is_zeronet(saddr))
1906 goto martian_source;
1907
1908 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
1909 ipv4_is_loopback(daddr))
1910 goto martian_destination;
1911
1912 /*
1913 * Now we are ready to route packet.
1914 */
1915 if ((err = fib_lookup(net, &fl, &res)) != 0) {
1916 if (!IN_DEV_FORWARD(in_dev))
1917 goto e_hostunreach;
1918 goto no_route;
1919 }
1920 free_res = 1;
1921
1922 RT_CACHE_STAT_INC(in_slow_tot);
1923
1924 if (res.type == RTN_BROADCAST)
1925 goto brd_input;
1926
1927 if (res.type == RTN_LOCAL) {
1928 int result;
1929 result = fib_validate_source(saddr, daddr, tos,
1930 net->loopback_dev->ifindex,
1931 dev, &spec_dst, &itag);
1932 if (result < 0)
1933 goto martian_source;
1934 if (result)
1935 flags |= RTCF_DIRECTSRC;
1936 spec_dst = daddr;
1937 goto local_input;
1938 }
1939
1940 if (!IN_DEV_FORWARD(in_dev))
1941 goto e_hostunreach;
1942 if (res.type != RTN_UNICAST)
1943 goto martian_destination;
1944
1945 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
1946 done:
1947 in_dev_put(in_dev);
1948 if (free_res)
1949 fib_res_put(&res);
1950 out: return err;
1951
1952 brd_input:
1953 if (skb->protocol != htons(ETH_P_IP))
1954 goto e_inval;
1955
1956 if (ipv4_is_zeronet(saddr))
1957 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1958 else {
1959 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1960 &itag);
1961 if (err < 0)
1962 goto martian_source;
1963 if (err)
1964 flags |= RTCF_DIRECTSRC;
1965 }
1966 flags |= RTCF_BROADCAST;
1967 res.type = RTN_BROADCAST;
1968 RT_CACHE_STAT_INC(in_brd);
1969
1970 local_input:
1971 rth = dst_alloc(&ipv4_dst_ops);
1972 if (!rth)
1973 goto e_nobufs;
1974
1975 rth->u.dst.output= ip_rt_bug;
1976
1977 atomic_set(&rth->u.dst.__refcnt, 1);
1978 rth->u.dst.flags= DST_HOST;
1979 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1980 rth->u.dst.flags |= DST_NOPOLICY;
1981 rth->fl.fl4_dst = daddr;
1982 rth->rt_dst = daddr;
1983 rth->fl.fl4_tos = tos;
1984 rth->fl.mark = skb->mark;
1985 rth->fl.fl4_src = saddr;
1986 rth->rt_src = saddr;
1987 #ifdef CONFIG_NET_CLS_ROUTE
1988 rth->u.dst.tclassid = itag;
1989 #endif
1990 rth->rt_iif =
1991 rth->fl.iif = dev->ifindex;
1992 rth->u.dst.dev = net->loopback_dev;
1993 dev_hold(rth->u.dst.dev);
1994 rth->idev = in_dev_get(rth->u.dst.dev);
1995 rth->rt_gateway = daddr;
1996 rth->rt_spec_dst= spec_dst;
1997 rth->u.dst.input= ip_local_deliver;
1998 rth->rt_flags = flags|RTCF_LOCAL;
1999 if (res.type == RTN_UNREACHABLE) {
2000 rth->u.dst.input= ip_error;
2001 rth->u.dst.error= -err;
2002 rth->rt_flags &= ~RTCF_LOCAL;
2003 }
2004 rth->rt_type = res.type;
2005 hash = rt_hash(daddr, saddr, fl.iif);
2006 err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
2007 goto done;
2008
2009 no_route:
2010 RT_CACHE_STAT_INC(in_no_route);
2011 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2012 res.type = RTN_UNREACHABLE;
2013 if (err == -ESRCH)
2014 err = -ENETUNREACH;
2015 goto local_input;
2016
2017 /*
2018 * Do not cache martian addresses: they should be logged (RFC1812)
2019 */
2020 martian_destination:
2021 RT_CACHE_STAT_INC(in_martian_dst);
2022 #ifdef CONFIG_IP_ROUTE_VERBOSE
2023 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2024 printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
2025 "%u.%u.%u.%u, dev %s\n",
2026 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
2027 #endif
2028
2029 e_hostunreach:
2030 err = -EHOSTUNREACH;
2031 goto done;
2032
2033 e_inval:
2034 err = -EINVAL;
2035 goto done;
2036
2037 e_nobufs:
2038 err = -ENOBUFS;
2039 goto done;
2040
2041 martian_source:
2042 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2043 goto e_inval;
2044 }
2045
2046 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2047 u8 tos, struct net_device *dev)
2048 {
2049 struct rtable * rth;
2050 unsigned hash;
2051 int iif = dev->ifindex;
2052
2053 tos &= IPTOS_RT_MASK;
2054 hash = rt_hash(daddr, saddr, iif);
2055
2056 rcu_read_lock();
2057 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2058 rth = rcu_dereference(rth->u.dst.rt_next)) {
2059 if (rth->fl.fl4_dst == daddr &&
2060 rth->fl.fl4_src == saddr &&
2061 rth->fl.iif == iif &&
2062 rth->fl.oif == 0 &&
2063 rth->fl.mark == skb->mark &&
2064 rth->fl.fl4_tos == tos) {
2065 dst_use(&rth->u.dst, jiffies);
2066 RT_CACHE_STAT_INC(in_hit);
2067 rcu_read_unlock();
2068 skb->dst = (struct dst_entry*)rth;
2069 return 0;
2070 }
2071 RT_CACHE_STAT_INC(in_hlist_search);
2072 }
2073 rcu_read_unlock();
2074
2075 /* Multicast recognition logic is moved from route cache to here.
2076 The problem was that too many Ethernet cards have broken/missing
2077 hardware multicast filters :-( As result the host on multicasting
2078 network acquires a lot of useless route cache entries, sort of
2079 SDR messages from all the world. Now we try to get rid of them.
2080 Really, provided software IP multicast filter is organized
2081 reasonably (at least, hashed), it does not result in a slowdown
2082 comparing with route cache reject entries.
2083 Note, that multicast routers are not affected, because
2084 route cache entry is created eventually.
2085 */
2086 if (ipv4_is_multicast(daddr)) {
2087 struct in_device *in_dev;
2088
2089 rcu_read_lock();
2090 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2091 int our = ip_check_mc(in_dev, daddr, saddr,
2092 ip_hdr(skb)->protocol);
2093 if (our
2094 #ifdef CONFIG_IP_MROUTE
2095 || (!ipv4_is_local_multicast(daddr) &&
2096 IN_DEV_MFORWARD(in_dev))
2097 #endif
2098 ) {
2099 rcu_read_unlock();
2100 return ip_route_input_mc(skb, daddr, saddr,
2101 tos, dev, our);
2102 }
2103 }
2104 rcu_read_unlock();
2105 return -EINVAL;
2106 }
2107 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2108 }
2109
2110 static inline int __mkroute_output(struct rtable **result,
2111 struct fib_result* res,
2112 const struct flowi *fl,
2113 const struct flowi *oldflp,
2114 struct net_device *dev_out,
2115 unsigned flags)
2116 {
2117 struct rtable *rth;
2118 struct in_device *in_dev;
2119 u32 tos = RT_FL_TOS(oldflp);
2120 int err = 0;
2121
2122 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2123 return -EINVAL;
2124
2125 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2126 res->type = RTN_BROADCAST;
2127 else if (ipv4_is_multicast(fl->fl4_dst))
2128 res->type = RTN_MULTICAST;
2129 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2130 return -EINVAL;
2131
2132 if (dev_out->flags & IFF_LOOPBACK)
2133 flags |= RTCF_LOCAL;
2134
2135 /* get work reference to inet device */
2136 in_dev = in_dev_get(dev_out);
2137 if (!in_dev)
2138 return -EINVAL;
2139
2140 if (res->type == RTN_BROADCAST) {
2141 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2142 if (res->fi) {
2143 fib_info_put(res->fi);
2144 res->fi = NULL;
2145 }
2146 } else if (res->type == RTN_MULTICAST) {
2147 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2148 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2149 oldflp->proto))
2150 flags &= ~RTCF_LOCAL;
2151 /* If multicast route do not exist use
2152 default one, but do not gateway in this case.
2153 Yes, it is hack.
2154 */
2155 if (res->fi && res->prefixlen < 4) {
2156 fib_info_put(res->fi);
2157 res->fi = NULL;
2158 }
2159 }
2160
2161
2162 rth = dst_alloc(&ipv4_dst_ops);
2163 if (!rth) {
2164 err = -ENOBUFS;
2165 goto cleanup;
2166 }
2167
2168 atomic_set(&rth->u.dst.__refcnt, 1);
2169 rth->u.dst.flags= DST_HOST;
2170 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2171 rth->u.dst.flags |= DST_NOXFRM;
2172 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2173 rth->u.dst.flags |= DST_NOPOLICY;
2174
2175 rth->fl.fl4_dst = oldflp->fl4_dst;
2176 rth->fl.fl4_tos = tos;
2177 rth->fl.fl4_src = oldflp->fl4_src;
2178 rth->fl.oif = oldflp->oif;
2179 rth->fl.mark = oldflp->mark;
2180 rth->rt_dst = fl->fl4_dst;
2181 rth->rt_src = fl->fl4_src;
2182 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2183 /* get references to the devices that are to be hold by the routing
2184 cache entry */
2185 rth->u.dst.dev = dev_out;
2186 dev_hold(dev_out);
2187 rth->idev = in_dev_get(dev_out);
2188 rth->rt_gateway = fl->fl4_dst;
2189 rth->rt_spec_dst= fl->fl4_src;
2190
2191 rth->u.dst.output=ip_output;
2192
2193 RT_CACHE_STAT_INC(out_slow_tot);
2194
2195 if (flags & RTCF_LOCAL) {
2196 rth->u.dst.input = ip_local_deliver;
2197 rth->rt_spec_dst = fl->fl4_dst;
2198 }
2199 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2200 rth->rt_spec_dst = fl->fl4_src;
2201 if (flags & RTCF_LOCAL &&
2202 !(dev_out->flags & IFF_LOOPBACK)) {
2203 rth->u.dst.output = ip_mc_output;
2204 RT_CACHE_STAT_INC(out_slow_mc);
2205 }
2206 #ifdef CONFIG_IP_MROUTE
2207 if (res->type == RTN_MULTICAST) {
2208 if (IN_DEV_MFORWARD(in_dev) &&
2209 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2210 rth->u.dst.input = ip_mr_input;
2211 rth->u.dst.output = ip_mc_output;
2212 }
2213 }
2214 #endif
2215 }
2216
2217 rt_set_nexthop(rth, res, 0);
2218
2219 rth->rt_flags = flags;
2220
2221 *result = rth;
2222 cleanup:
2223 /* release work reference to inet device */
2224 in_dev_put(in_dev);
2225
2226 return err;
2227 }
2228
2229 static inline int ip_mkroute_output(struct rtable **rp,
2230 struct fib_result* res,
2231 const struct flowi *fl,
2232 const struct flowi *oldflp,
2233 struct net_device *dev_out,
2234 unsigned flags)
2235 {
2236 struct rtable *rth = NULL;
2237 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2238 unsigned hash;
2239 if (err == 0) {
2240 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
2241 err = rt_intern_hash(hash, rth, rp);
2242 }
2243
2244 return err;
2245 }
2246
2247 /*
2248 * Major route resolver routine.
2249 */
2250
2251 static int ip_route_output_slow(struct net *net, struct rtable **rp,
2252 const struct flowi *oldflp)
2253 {
2254 u32 tos = RT_FL_TOS(oldflp);
2255 struct flowi fl = { .nl_u = { .ip4_u =
2256 { .daddr = oldflp->fl4_dst,
2257 .saddr = oldflp->fl4_src,
2258 .tos = tos & IPTOS_RT_MASK,
2259 .scope = ((tos & RTO_ONLINK) ?
2260 RT_SCOPE_LINK :
2261 RT_SCOPE_UNIVERSE),
2262 } },
2263 .mark = oldflp->mark,
2264 .iif = net->loopback_dev->ifindex,
2265 .oif = oldflp->oif };
2266 struct fib_result res;
2267 unsigned flags = 0;
2268 struct net_device *dev_out = NULL;
2269 int free_res = 0;
2270 int err;
2271
2272
2273 res.fi = NULL;
2274 #ifdef CONFIG_IP_MULTIPLE_TABLES
2275 res.r = NULL;
2276 #endif
2277
2278 if (oldflp->fl4_src) {
2279 err = -EINVAL;
2280 if (ipv4_is_multicast(oldflp->fl4_src) ||
2281 ipv4_is_lbcast(oldflp->fl4_src) ||
2282 ipv4_is_zeronet(oldflp->fl4_src))
2283 goto out;
2284
2285 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2286 dev_out = ip_dev_find(net, oldflp->fl4_src);
2287 if (dev_out == NULL)
2288 goto out;
2289
2290 /* I removed check for oif == dev_out->oif here.
2291 It was wrong for two reasons:
2292 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2293 is assigned to multiple interfaces.
2294 2. Moreover, we are allowed to send packets with saddr
2295 of another iface. --ANK
2296 */
2297
2298 if (oldflp->oif == 0
2299 && (ipv4_is_multicast(oldflp->fl4_dst) ||
2300 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2301 /* Special hack: user can direct multicasts
2302 and limited broadcast via necessary interface
2303 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2304 This hack is not just for fun, it allows
2305 vic,vat and friends to work.
2306 They bind socket to loopback, set ttl to zero
2307 and expect that it will work.
2308 From the viewpoint of routing cache they are broken,
2309 because we are not allowed to build multicast path
2310 with loopback source addr (look, routing cache
2311 cannot know, that ttl is zero, so that packet
2312 will not leave this host and route is valid).
2313 Luckily, this hack is good workaround.
2314 */
2315
2316 fl.oif = dev_out->ifindex;
2317 goto make_route;
2318 }
2319 if (dev_out)
2320 dev_put(dev_out);
2321 dev_out = NULL;
2322 }
2323
2324
2325 if (oldflp->oif) {
2326 dev_out = dev_get_by_index(net, oldflp->oif);
2327 err = -ENODEV;
2328 if (dev_out == NULL)
2329 goto out;
2330
2331 /* RACE: Check return value of inet_select_addr instead. */
2332 if (__in_dev_get_rtnl(dev_out) == NULL) {
2333 dev_put(dev_out);
2334 goto out; /* Wrong error code */
2335 }
2336
2337 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2338 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2339 if (!fl.fl4_src)
2340 fl.fl4_src = inet_select_addr(dev_out, 0,
2341 RT_SCOPE_LINK);
2342 goto make_route;
2343 }
2344 if (!fl.fl4_src) {
2345 if (ipv4_is_multicast(oldflp->fl4_dst))
2346 fl.fl4_src = inet_select_addr(dev_out, 0,
2347 fl.fl4_scope);
2348 else if (!oldflp->fl4_dst)
2349 fl.fl4_src = inet_select_addr(dev_out, 0,
2350 RT_SCOPE_HOST);
2351 }
2352 }
2353
2354 if (!fl.fl4_dst) {
2355 fl.fl4_dst = fl.fl4_src;
2356 if (!fl.fl4_dst)
2357 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2358 if (dev_out)
2359 dev_put(dev_out);
2360 dev_out = net->loopback_dev;
2361 dev_hold(dev_out);
2362 fl.oif = net->loopback_dev->ifindex;
2363 res.type = RTN_LOCAL;
2364 flags |= RTCF_LOCAL;
2365 goto make_route;
2366 }
2367
2368 if (fib_lookup(net, &fl, &res)) {
2369 res.fi = NULL;
2370 if (oldflp->oif) {
2371 /* Apparently, routing tables are wrong. Assume,
2372 that the destination is on link.
2373
2374 WHY? DW.
2375 Because we are allowed to send to iface
2376 even if it has NO routes and NO assigned
2377 addresses. When oif is specified, routing
2378 tables are looked up with only one purpose:
2379 to catch if destination is gatewayed, rather than
2380 direct. Moreover, if MSG_DONTROUTE is set,
2381 we send packet, ignoring both routing tables
2382 and ifaddr state. --ANK
2383
2384
2385 We could make it even if oif is unknown,
2386 likely IPv6, but we do not.
2387 */
2388
2389 if (fl.fl4_src == 0)
2390 fl.fl4_src = inet_select_addr(dev_out, 0,
2391 RT_SCOPE_LINK);
2392 res.type = RTN_UNICAST;
2393 goto make_route;
2394 }
2395 if (dev_out)
2396 dev_put(dev_out);
2397 err = -ENETUNREACH;
2398 goto out;
2399 }
2400 free_res = 1;
2401
2402 if (res.type == RTN_LOCAL) {
2403 if (!fl.fl4_src)
2404 fl.fl4_src = fl.fl4_dst;
2405 if (dev_out)
2406 dev_put(dev_out);
2407 dev_out = net->loopback_dev;
2408 dev_hold(dev_out);
2409 fl.oif = dev_out->ifindex;
2410 if (res.fi)
2411 fib_info_put(res.fi);
2412 res.fi = NULL;
2413 flags |= RTCF_LOCAL;
2414 goto make_route;
2415 }
2416
2417 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2418 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2419 fib_select_multipath(&fl, &res);
2420 else
2421 #endif
2422 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2423 fib_select_default(net, &fl, &res);
2424
2425 if (!fl.fl4_src)
2426 fl.fl4_src = FIB_RES_PREFSRC(res);
2427
2428 if (dev_out)
2429 dev_put(dev_out);
2430 dev_out = FIB_RES_DEV(res);
2431 dev_hold(dev_out);
2432 fl.oif = dev_out->ifindex;
2433
2434
2435 make_route:
2436 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2437
2438
2439 if (free_res)
2440 fib_res_put(&res);
2441 if (dev_out)
2442 dev_put(dev_out);
2443 out: return err;
2444 }
2445
2446 int __ip_route_output_key(struct net *net, struct rtable **rp,
2447 const struct flowi *flp)
2448 {
2449 unsigned hash;
2450 struct rtable *rth;
2451
2452 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
2453
2454 rcu_read_lock_bh();
2455 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2456 rth = rcu_dereference(rth->u.dst.rt_next)) {
2457 if (rth->fl.fl4_dst == flp->fl4_dst &&
2458 rth->fl.fl4_src == flp->fl4_src &&
2459 rth->fl.iif == 0 &&
2460 rth->fl.oif == flp->oif &&
2461 rth->fl.mark == flp->mark &&
2462 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2463 (IPTOS_RT_MASK | RTO_ONLINK))) {
2464 dst_use(&rth->u.dst, jiffies);
2465 RT_CACHE_STAT_INC(out_hit);
2466 rcu_read_unlock_bh();
2467 *rp = rth;
2468 return 0;
2469 }
2470 RT_CACHE_STAT_INC(out_hlist_search);
2471 }
2472 rcu_read_unlock_bh();
2473
2474 return ip_route_output_slow(net, rp, flp);
2475 }
2476
2477 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2478
2479 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2480 {
2481 }
2482
2483 static struct dst_ops ipv4_dst_blackhole_ops = {
2484 .family = AF_INET,
2485 .protocol = __constant_htons(ETH_P_IP),
2486 .destroy = ipv4_dst_destroy,
2487 .check = ipv4_dst_check,
2488 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2489 .entry_size = sizeof(struct rtable),
2490 };
2491
2492
2493 static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp, struct sock *sk)
2494 {
2495 struct rtable *ort = *rp;
2496 struct rtable *rt = (struct rtable *)
2497 dst_alloc(&ipv4_dst_blackhole_ops);
2498
2499 if (rt) {
2500 struct dst_entry *new = &rt->u.dst;
2501
2502 atomic_set(&new->__refcnt, 1);
2503 new->__use = 1;
2504 new->input = dst_discard;
2505 new->output = dst_discard;
2506 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2507
2508 new->dev = ort->u.dst.dev;
2509 if (new->dev)
2510 dev_hold(new->dev);
2511
2512 rt->fl = ort->fl;
2513
2514 rt->idev = ort->idev;
2515 if (rt->idev)
2516 in_dev_hold(rt->idev);
2517 rt->rt_flags = ort->rt_flags;
2518 rt->rt_type = ort->rt_type;
2519 rt->rt_dst = ort->rt_dst;
2520 rt->rt_src = ort->rt_src;
2521 rt->rt_iif = ort->rt_iif;
2522 rt->rt_gateway = ort->rt_gateway;
2523 rt->rt_spec_dst = ort->rt_spec_dst;
2524 rt->peer = ort->peer;
2525 if (rt->peer)
2526 atomic_inc(&rt->peer->refcnt);
2527
2528 dst_free(new);
2529 }
2530
2531 dst_release(&(*rp)->u.dst);
2532 *rp = rt;
2533 return (rt ? 0 : -ENOMEM);
2534 }
2535
2536 int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2537 struct sock *sk, int flags)
2538 {
2539 int err;
2540
2541 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2542 return err;
2543
2544 if (flp->proto) {
2545 if (!flp->fl4_src)
2546 flp->fl4_src = (*rp)->rt_src;
2547 if (!flp->fl4_dst)
2548 flp->fl4_dst = (*rp)->rt_dst;
2549 err = __xfrm_lookup((struct dst_entry **)rp, flp, sk,
2550 flags ? XFRM_LOOKUP_WAIT : 0);
2551 if (err == -EREMOTE)
2552 err = ipv4_dst_blackhole(rp, flp, sk);
2553
2554 return err;
2555 }
2556
2557 return 0;
2558 }
2559
2560 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2561
2562 int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2563 {
2564 return ip_route_output_flow(net, rp, flp, NULL, 0);
2565 }
2566
2567 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2568 int nowait, unsigned int flags)
2569 {
2570 struct rtable *rt = (struct rtable*)skb->dst;
2571 struct rtmsg *r;
2572 struct nlmsghdr *nlh;
2573 long expires;
2574 u32 id = 0, ts = 0, tsage = 0, error;
2575
2576 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2577 if (nlh == NULL)
2578 return -EMSGSIZE;
2579
2580 r = nlmsg_data(nlh);
2581 r->rtm_family = AF_INET;
2582 r->rtm_dst_len = 32;
2583 r->rtm_src_len = 0;
2584 r->rtm_tos = rt->fl.fl4_tos;
2585 r->rtm_table = RT_TABLE_MAIN;
2586 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2587 r->rtm_type = rt->rt_type;
2588 r->rtm_scope = RT_SCOPE_UNIVERSE;
2589 r->rtm_protocol = RTPROT_UNSPEC;
2590 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2591 if (rt->rt_flags & RTCF_NOTIFY)
2592 r->rtm_flags |= RTM_F_NOTIFY;
2593
2594 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2595
2596 if (rt->fl.fl4_src) {
2597 r->rtm_src_len = 32;
2598 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2599 }
2600 if (rt->u.dst.dev)
2601 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2602 #ifdef CONFIG_NET_CLS_ROUTE
2603 if (rt->u.dst.tclassid)
2604 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2605 #endif
2606 if (rt->fl.iif)
2607 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2608 else if (rt->rt_src != rt->fl.fl4_src)
2609 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2610
2611 if (rt->rt_dst != rt->rt_gateway)
2612 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2613
2614 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2615 goto nla_put_failure;
2616
2617 error = rt->u.dst.error;
2618 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2619 if (rt->peer) {
2620 id = rt->peer->ip_id_count;
2621 if (rt->peer->tcp_ts_stamp) {
2622 ts = rt->peer->tcp_ts;
2623 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2624 }
2625 }
2626
2627 if (rt->fl.iif) {
2628 #ifdef CONFIG_IP_MROUTE
2629 __be32 dst = rt->rt_dst;
2630
2631 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2632 IPV4_DEVCONF_ALL(&init_net, MC_FORWARDING)) {
2633 int err = ipmr_get_route(skb, r, nowait);
2634 if (err <= 0) {
2635 if (!nowait) {
2636 if (err == 0)
2637 return 0;
2638 goto nla_put_failure;
2639 } else {
2640 if (err == -EMSGSIZE)
2641 goto nla_put_failure;
2642 error = err;
2643 }
2644 }
2645 } else
2646 #endif
2647 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2648 }
2649
2650 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2651 expires, error) < 0)
2652 goto nla_put_failure;
2653
2654 return nlmsg_end(skb, nlh);
2655
2656 nla_put_failure:
2657 nlmsg_cancel(skb, nlh);
2658 return -EMSGSIZE;
2659 }
2660
2661 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2662 {
2663 struct net *net = in_skb->sk->sk_net;
2664 struct rtmsg *rtm;
2665 struct nlattr *tb[RTA_MAX+1];
2666 struct rtable *rt = NULL;
2667 __be32 dst = 0;
2668 __be32 src = 0;
2669 u32 iif;
2670 int err;
2671 struct sk_buff *skb;
2672
2673 if (net != &init_net)
2674 return -EINVAL;
2675
2676 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2677 if (err < 0)
2678 goto errout;
2679
2680 rtm = nlmsg_data(nlh);
2681
2682 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2683 if (skb == NULL) {
2684 err = -ENOBUFS;
2685 goto errout;
2686 }
2687
2688 /* Reserve room for dummy headers, this skb can pass
2689 through good chunk of routing engine.
2690 */
2691 skb_reset_mac_header(skb);
2692 skb_reset_network_header(skb);
2693
2694 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2695 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2696 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2697
2698 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2699 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2700 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2701
2702 if (iif) {
2703 struct net_device *dev;
2704
2705 dev = __dev_get_by_index(&init_net, iif);
2706 if (dev == NULL) {
2707 err = -ENODEV;
2708 goto errout_free;
2709 }
2710
2711 skb->protocol = htons(ETH_P_IP);
2712 skb->dev = dev;
2713 local_bh_disable();
2714 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2715 local_bh_enable();
2716
2717 rt = (struct rtable*) skb->dst;
2718 if (err == 0 && rt->u.dst.error)
2719 err = -rt->u.dst.error;
2720 } else {
2721 struct flowi fl = {
2722 .nl_u = {
2723 .ip4_u = {
2724 .daddr = dst,
2725 .saddr = src,
2726 .tos = rtm->rtm_tos,
2727 },
2728 },
2729 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2730 };
2731 err = ip_route_output_key(&init_net, &rt, &fl);
2732 }
2733
2734 if (err)
2735 goto errout_free;
2736
2737 skb->dst = &rt->u.dst;
2738 if (rtm->rtm_flags & RTM_F_NOTIFY)
2739 rt->rt_flags |= RTCF_NOTIFY;
2740
2741 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2742 RTM_NEWROUTE, 0, 0);
2743 if (err <= 0)
2744 goto errout_free;
2745
2746 err = rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
2747 errout:
2748 return err;
2749
2750 errout_free:
2751 kfree_skb(skb);
2752 goto errout;
2753 }
2754
2755 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2756 {
2757 struct rtable *rt;
2758 int h, s_h;
2759 int idx, s_idx;
2760
2761 s_h = cb->args[0];
2762 if (s_h < 0)
2763 s_h = 0;
2764 s_idx = idx = cb->args[1];
2765 for (h = s_h; h <= rt_hash_mask; h++) {
2766 rcu_read_lock_bh();
2767 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2768 rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
2769 if (idx < s_idx)
2770 continue;
2771 skb->dst = dst_clone(&rt->u.dst);
2772 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2773 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2774 1, NLM_F_MULTI) <= 0) {
2775 dst_release(xchg(&skb->dst, NULL));
2776 rcu_read_unlock_bh();
2777 goto done;
2778 }
2779 dst_release(xchg(&skb->dst, NULL));
2780 }
2781 rcu_read_unlock_bh();
2782 s_idx = 0;
2783 }
2784
2785 done:
2786 cb->args[0] = h;
2787 cb->args[1] = idx;
2788 return skb->len;
2789 }
2790
2791 void ip_rt_multicast_event(struct in_device *in_dev)
2792 {
2793 rt_cache_flush(0);
2794 }
2795
2796 #ifdef CONFIG_SYSCTL
2797 static int flush_delay;
2798
2799 static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
2800 struct file *filp, void __user *buffer,
2801 size_t *lenp, loff_t *ppos)
2802 {
2803 if (write) {
2804 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2805 rt_cache_flush(flush_delay);
2806 return 0;
2807 }
2808
2809 return -EINVAL;
2810 }
2811
2812 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2813 int __user *name,
2814 int nlen,
2815 void __user *oldval,
2816 size_t __user *oldlenp,
2817 void __user *newval,
2818 size_t newlen)
2819 {
2820 int delay;
2821 if (newlen != sizeof(int))
2822 return -EINVAL;
2823 if (get_user(delay, (int __user *)newval))
2824 return -EFAULT;
2825 rt_cache_flush(delay);
2826 return 0;
2827 }
2828
2829 ctl_table ipv4_route_table[] = {
2830 {
2831 .ctl_name = NET_IPV4_ROUTE_FLUSH,
2832 .procname = "flush",
2833 .data = &flush_delay,
2834 .maxlen = sizeof(int),
2835 .mode = 0200,
2836 .proc_handler = &ipv4_sysctl_rtcache_flush,
2837 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
2838 },
2839 {
2840 .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
2841 .procname = "min_delay",
2842 .data = &ip_rt_min_delay,
2843 .maxlen = sizeof(int),
2844 .mode = 0644,
2845 .proc_handler = &proc_dointvec_jiffies,
2846 .strategy = &sysctl_jiffies,
2847 },
2848 {
2849 .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
2850 .procname = "max_delay",
2851 .data = &ip_rt_max_delay,
2852 .maxlen = sizeof(int),
2853 .mode = 0644,
2854 .proc_handler = &proc_dointvec_jiffies,
2855 .strategy = &sysctl_jiffies,
2856 },
2857 {
2858 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2859 .procname = "gc_thresh",
2860 .data = &ipv4_dst_ops.gc_thresh,
2861 .maxlen = sizeof(int),
2862 .mode = 0644,
2863 .proc_handler = &proc_dointvec,
2864 },
2865 {
2866 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
2867 .procname = "max_size",
2868 .data = &ip_rt_max_size,
2869 .maxlen = sizeof(int),
2870 .mode = 0644,
2871 .proc_handler = &proc_dointvec,
2872 },
2873 {
2874 /* Deprecated. Use gc_min_interval_ms */
2875
2876 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
2877 .procname = "gc_min_interval",
2878 .data = &ip_rt_gc_min_interval,
2879 .maxlen = sizeof(int),
2880 .mode = 0644,
2881 .proc_handler = &proc_dointvec_jiffies,
2882 .strategy = &sysctl_jiffies,
2883 },
2884 {
2885 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
2886 .procname = "gc_min_interval_ms",
2887 .data = &ip_rt_gc_min_interval,
2888 .maxlen = sizeof(int),
2889 .mode = 0644,
2890 .proc_handler = &proc_dointvec_ms_jiffies,
2891 .strategy = &sysctl_ms_jiffies,
2892 },
2893 {
2894 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
2895 .procname = "gc_timeout",
2896 .data = &ip_rt_gc_timeout,
2897 .maxlen = sizeof(int),
2898 .mode = 0644,
2899 .proc_handler = &proc_dointvec_jiffies,
2900 .strategy = &sysctl_jiffies,
2901 },
2902 {
2903 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
2904 .procname = "gc_interval",
2905 .data = &ip_rt_gc_interval,
2906 .maxlen = sizeof(int),
2907 .mode = 0644,
2908 .proc_handler = &proc_dointvec_jiffies,
2909 .strategy = &sysctl_jiffies,
2910 },
2911 {
2912 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
2913 .procname = "redirect_load",
2914 .data = &ip_rt_redirect_load,
2915 .maxlen = sizeof(int),
2916 .mode = 0644,
2917 .proc_handler = &proc_dointvec,
2918 },
2919 {
2920 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
2921 .procname = "redirect_number",
2922 .data = &ip_rt_redirect_number,
2923 .maxlen = sizeof(int),
2924 .mode = 0644,
2925 .proc_handler = &proc_dointvec,
2926 },
2927 {
2928 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
2929 .procname = "redirect_silence",
2930 .data = &ip_rt_redirect_silence,
2931 .maxlen = sizeof(int),
2932 .mode = 0644,
2933 .proc_handler = &proc_dointvec,
2934 },
2935 {
2936 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
2937 .procname = "error_cost",
2938 .data = &ip_rt_error_cost,
2939 .maxlen = sizeof(int),
2940 .mode = 0644,
2941 .proc_handler = &proc_dointvec,
2942 },
2943 {
2944 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
2945 .procname = "error_burst",
2946 .data = &ip_rt_error_burst,
2947 .maxlen = sizeof(int),
2948 .mode = 0644,
2949 .proc_handler = &proc_dointvec,
2950 },
2951 {
2952 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
2953 .procname = "gc_elasticity",
2954 .data = &ip_rt_gc_elasticity,
2955 .maxlen = sizeof(int),
2956 .mode = 0644,
2957 .proc_handler = &proc_dointvec,
2958 },
2959 {
2960 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
2961 .procname = "mtu_expires",
2962 .data = &ip_rt_mtu_expires,
2963 .maxlen = sizeof(int),
2964 .mode = 0644,
2965 .proc_handler = &proc_dointvec_jiffies,
2966 .strategy = &sysctl_jiffies,
2967 },
2968 {
2969 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
2970 .procname = "min_pmtu",
2971 .data = &ip_rt_min_pmtu,
2972 .maxlen = sizeof(int),
2973 .mode = 0644,
2974 .proc_handler = &proc_dointvec,
2975 },
2976 {
2977 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
2978 .procname = "min_adv_mss",
2979 .data = &ip_rt_min_advmss,
2980 .maxlen = sizeof(int),
2981 .mode = 0644,
2982 .proc_handler = &proc_dointvec,
2983 },
2984 {
2985 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
2986 .procname = "secret_interval",
2987 .data = &ip_rt_secret_interval,
2988 .maxlen = sizeof(int),
2989 .mode = 0644,
2990 .proc_handler = &proc_dointvec_jiffies,
2991 .strategy = &sysctl_jiffies,
2992 },
2993 { .ctl_name = 0 }
2994 };
2995 #endif
2996
2997 #ifdef CONFIG_NET_CLS_ROUTE
2998 struct ip_rt_acct *ip_rt_acct __read_mostly;
2999 #endif /* CONFIG_NET_CLS_ROUTE */
3000
3001 static __initdata unsigned long rhash_entries;
3002 static int __init set_rhash_entries(char *str)
3003 {
3004 if (!str)
3005 return 0;
3006 rhash_entries = simple_strtoul(str, &str, 0);
3007 return 1;
3008 }
3009 __setup("rhash_entries=", set_rhash_entries);
3010
3011 int __init ip_rt_init(void)
3012 {
3013 int rc = 0;
3014
3015 rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
3016 (jiffies ^ (jiffies >> 7)));
3017
3018 #ifdef CONFIG_NET_CLS_ROUTE
3019 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
3020 if (!ip_rt_acct)
3021 panic("IP: failed to allocate ip_rt_acct\n");
3022 #endif
3023
3024 ipv4_dst_ops.kmem_cachep =
3025 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3026 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3027
3028 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3029
3030 rt_hash_table = (struct rt_hash_bucket *)
3031 alloc_large_system_hash("IP route cache",
3032 sizeof(struct rt_hash_bucket),
3033 rhash_entries,
3034 (num_physpages >= 128 * 1024) ?
3035 15 : 17,
3036 0,
3037 &rt_hash_log,
3038 &rt_hash_mask,
3039 0);
3040 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3041 rt_hash_lock_init();
3042
3043 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3044 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3045
3046 devinet_init();
3047 ip_fib_init();
3048
3049 setup_timer(&rt_flush_timer, rt_run_flush, 0);
3050 setup_timer(&rt_secret_timer, rt_secret_rebuild, 0);
3051
3052 /* All the timers, started at system startup tend
3053 to synchronize. Perturb it a bit.
3054 */
3055 schedule_delayed_work(&expires_work,
3056 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3057
3058 rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
3059 ip_rt_secret_interval;
3060 add_timer(&rt_secret_timer);
3061
3062 if (ip_rt_proc_init(&init_net))
3063 printk(KERN_ERR "Unable to create route proc files\n");
3064 #ifdef CONFIG_XFRM
3065 xfrm_init();
3066 xfrm4_init();
3067 #endif
3068 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3069
3070 return rc;
3071 }
3072
3073 EXPORT_SYMBOL(__ip_select_ident);
3074 EXPORT_SYMBOL(ip_route_input);
3075 EXPORT_SYMBOL(ip_route_output_key);
kernel-based virtual machine