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, <bir7@leland.Stanford.Edu>
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 *
58 * This program is free software; you can redistribute it and/or
59 * modify it under the terms of the GNU General Public License
60 * as published by the Free Software Foundation; either version
61 * 2 of the License, or (at your option) any later version.
62 */
63
64 #include <linux/config.h>
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/sched.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/rtnetlink.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/protocol.h>
94 #include <net/ip.h>
95 #include <net/route.h>
96 #include <net/inetpeer.h>
97 #include <net/sock.h>
98 #include <net/ip_fib.h>
99 #include <net/arp.h>
100 #include <net/tcp.h>
101 #include <net/icmp.h>
102 #include <net/xfrm.h>
103 #ifdef CONFIG_SYSCTL
104 #include <linux/sysctl.h>
105 #endif
106
107 #define IP_MAX_MTU 0xFFF0
108
109 #define RT_GC_TIMEOUT (300*HZ)
110
111 static int ip_rt_min_delay = 2 * HZ;
112 static int ip_rt_max_delay = 10 * HZ;
113 static int ip_rt_max_size;
114 static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
115 static int ip_rt_gc_interval = 60 * HZ;
116 static int ip_rt_gc_min_interval = HZ / 2;
117 static int ip_rt_redirect_number = 9;
118 static int ip_rt_redirect_load = HZ / 50;
119 static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
120 static int ip_rt_error_cost = HZ;
121 static int ip_rt_error_burst = 5 * HZ;
122 static int ip_rt_gc_elasticity = 8;
123 static int ip_rt_mtu_expires = 10 * 60 * HZ;
124 static int ip_rt_min_pmtu = 512 + 20 + 20;
125 static int ip_rt_min_advmss = 256;
126 static int ip_rt_secret_interval = 10 * 60 * HZ;
127 static unsigned long rt_deadline;
128
129 #define RTprint(a...) printk(KERN_DEBUG a)
130
131 static struct timer_list rt_flush_timer;
132 static struct timer_list rt_periodic_timer;
133 static struct timer_list rt_secret_timer;
134
135 /*
136 * Interface to generic destination cache.
137 */
138
139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
140 static void ipv4_dst_destroy(struct dst_entry *dst);
141 static void ipv4_dst_ifdown(struct dst_entry *dst,
142 struct net_device *dev, int how);
143 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
144 static void ipv4_link_failure(struct sk_buff *skb);
145 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
146 static int rt_garbage_collect(void);
147
148
149 static struct dst_ops ipv4_dst_ops = {
150 .family = AF_INET,
151 .protocol = __constant_htons(ETH_P_IP),
152 .gc = rt_garbage_collect,
153 .check = ipv4_dst_check,
154 .destroy = ipv4_dst_destroy,
155 .ifdown = ipv4_dst_ifdown,
156 .negative_advice = ipv4_negative_advice,
157 .link_failure = ipv4_link_failure,
158 .update_pmtu = ip_rt_update_pmtu,
159 .entry_size = sizeof(struct rtable),
160 };
161
162 #define ECN_OR_COST(class) TC_PRIO_##class
163
164 __u8 ip_tos2prio[16] = {
165 TC_PRIO_BESTEFFORT,
166 ECN_OR_COST(FILLER),
167 TC_PRIO_BESTEFFORT,
168 ECN_OR_COST(BESTEFFORT),
169 TC_PRIO_BULK,
170 ECN_OR_COST(BULK),
171 TC_PRIO_BULK,
172 ECN_OR_COST(BULK),
173 TC_PRIO_INTERACTIVE,
174 ECN_OR_COST(INTERACTIVE),
175 TC_PRIO_INTERACTIVE,
176 ECN_OR_COST(INTERACTIVE),
177 TC_PRIO_INTERACTIVE_BULK,
178 ECN_OR_COST(INTERACTIVE_BULK),
179 TC_PRIO_INTERACTIVE_BULK,
180 ECN_OR_COST(INTERACTIVE_BULK)
181 };
182
183
184 /*
185 * Route cache.
186 */
187
188 /* The locking scheme is rather straight forward:
189 *
190 * 1) Read-Copy Update protects the buckets of the central route hash.
191 * 2) Only writers remove entries, and they hold the lock
192 * as they look at rtable reference counts.
193 * 3) Only readers acquire references to rtable entries,
194 * they do so with atomic increments and with the
195 * lock held.
196 */
197
198 struct rt_hash_bucket {
199 struct rtable *chain;
200 spinlock_t lock;
201 } __attribute__((__aligned__(8)));
202
203 static struct rt_hash_bucket *rt_hash_table;
204 static unsigned rt_hash_mask;
205 static int rt_hash_log;
206 static unsigned int rt_hash_rnd;
207
208 struct rt_cache_stat *rt_cache_stat;
209
210 static int rt_intern_hash(unsigned hash, struct rtable *rth,
211 struct rtable **res);
212
213 static unsigned int rt_hash_code(u32 daddr, u32 saddr, u8 tos)
214 {
215 return (jhash_3words(daddr, saddr, (u32) tos, rt_hash_rnd)
216 & rt_hash_mask);
217 }
218
219 #ifdef CONFIG_PROC_FS
220 struct rt_cache_iter_state {
221 int bucket;
222 };
223
224 static struct rtable *rt_cache_get_first(struct seq_file *seq)
225 {
226 struct rtable *r = NULL;
227 struct rt_cache_iter_state *st = seq->private;
228
229 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
230 rcu_read_lock_bh();
231 r = rt_hash_table[st->bucket].chain;
232 if (r)
233 break;
234 rcu_read_unlock_bh();
235 }
236 return r;
237 }
238
239 static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
240 {
241 struct rt_cache_iter_state *st = rcu_dereference(seq->private);
242
243 r = r->u.rt_next;
244 while (!r) {
245 rcu_read_unlock_bh();
246 if (--st->bucket < 0)
247 break;
248 rcu_read_lock_bh();
249 r = rt_hash_table[st->bucket].chain;
250 }
251 return r;
252 }
253
254 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
255 {
256 struct rtable *r = rt_cache_get_first(seq);
257
258 if (r)
259 while (pos && (r = rt_cache_get_next(seq, r)))
260 --pos;
261 return pos ? NULL : r;
262 }
263
264 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
265 {
266 return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
267 }
268
269 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
270 {
271 struct rtable *r = NULL;
272
273 if (v == SEQ_START_TOKEN)
274 r = rt_cache_get_first(seq);
275 else
276 r = rt_cache_get_next(seq, v);
277 ++*pos;
278 return r;
279 }
280
281 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
282 {
283 if (v && v != SEQ_START_TOKEN)
284 rcu_read_unlock_bh();
285 }
286
287 static int rt_cache_seq_show(struct seq_file *seq, void *v)
288 {
289 if (v == SEQ_START_TOKEN)
290 seq_printf(seq, "%-127s\n",
291 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
292 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
293 "HHUptod\tSpecDst");
294 else {
295 struct rtable *r = v;
296 char temp[256];
297
298 sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
299 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
300 r->u.dst.dev ? r->u.dst.dev->name : "*",
301 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
302 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
303 r->u.dst.__use, 0, (unsigned long)r->rt_src,
304 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
305 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
306 dst_metric(&r->u.dst, RTAX_WINDOW),
307 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
308 dst_metric(&r->u.dst, RTAX_RTTVAR)),
309 r->fl.fl4_tos,
310 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
311 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
312 dev_queue_xmit) : 0,
313 r->rt_spec_dst);
314 seq_printf(seq, "%-127s\n", temp);
315 }
316 return 0;
317 }
318
319 static struct seq_operations rt_cache_seq_ops = {
320 .start = rt_cache_seq_start,
321 .next = rt_cache_seq_next,
322 .stop = rt_cache_seq_stop,
323 .show = rt_cache_seq_show,
324 };
325
326 static int rt_cache_seq_open(struct inode *inode, struct file *file)
327 {
328 struct seq_file *seq;
329 int rc = -ENOMEM;
330 struct rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
331
332 if (!s)
333 goto out;
334 rc = seq_open(file, &rt_cache_seq_ops);
335 if (rc)
336 goto out_kfree;
337 seq = file->private_data;
338 seq->private = s;
339 memset(s, 0, sizeof(*s));
340 out:
341 return rc;
342 out_kfree:
343 kfree(s);
344 goto out;
345 }
346
347 static struct file_operations rt_cache_seq_fops = {
348 .owner = THIS_MODULE,
349 .open = rt_cache_seq_open,
350 .read = seq_read,
351 .llseek = seq_lseek,
352 .release = seq_release_private,
353 };
354
355
356 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
357 {
358 int cpu;
359
360 if (*pos == 0)
361 return SEQ_START_TOKEN;
362
363 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
364 if (!cpu_possible(cpu))
365 continue;
366 *pos = cpu+1;
367 return per_cpu_ptr(rt_cache_stat, cpu);
368 }
369 return NULL;
370 }
371
372 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
373 {
374 int cpu;
375
376 for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
377 if (!cpu_possible(cpu))
378 continue;
379 *pos = cpu+1;
380 return per_cpu_ptr(rt_cache_stat, cpu);
381 }
382 return NULL;
383
384 }
385
386 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
387 {
388
389 }
390
391 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
392 {
393 struct rt_cache_stat *st = v;
394
395 if (v == SEQ_START_TOKEN) {
396 seq_printf(seq, "entries in_hit in_slow_tot 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");
397 return 0;
398 }
399
400 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
401 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
402 atomic_read(&ipv4_dst_ops.entries),
403 st->in_hit,
404 st->in_slow_tot,
405 st->in_slow_mc,
406 st->in_no_route,
407 st->in_brd,
408 st->in_martian_dst,
409 st->in_martian_src,
410
411 st->out_hit,
412 st->out_slow_tot,
413 st->out_slow_mc,
414
415 st->gc_total,
416 st->gc_ignored,
417 st->gc_goal_miss,
418 st->gc_dst_overflow,
419 st->in_hlist_search,
420 st->out_hlist_search
421 );
422 return 0;
423 }
424
425 static struct seq_operations rt_cpu_seq_ops = {
426 .start = rt_cpu_seq_start,
427 .next = rt_cpu_seq_next,
428 .stop = rt_cpu_seq_stop,
429 .show = rt_cpu_seq_show,
430 };
431
432
433 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
434 {
435 return seq_open(file, &rt_cpu_seq_ops);
436 }
437
438 static struct file_operations rt_cpu_seq_fops = {
439 .owner = THIS_MODULE,
440 .open = rt_cpu_seq_open,
441 .read = seq_read,
442 .llseek = seq_lseek,
443 .release = seq_release,
444 };
445
446 #endif /* CONFIG_PROC_FS */
447
448 static __inline__ void rt_free(struct rtable *rt)
449 {
450 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
451 }
452
453 static __inline__ void rt_drop(struct rtable *rt)
454 {
455 ip_rt_put(rt);
456 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
457 }
458
459 static __inline__ int rt_fast_clean(struct rtable *rth)
460 {
461 /* Kill broadcast/multicast entries very aggresively, if they
462 collide in hash table with more useful entries */
463 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
464 rth->fl.iif && rth->u.rt_next;
465 }
466
467 static __inline__ int rt_valuable(struct rtable *rth)
468 {
469 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
470 rth->u.dst.expires;
471 }
472
473 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
474 {
475 unsigned long age;
476 int ret = 0;
477
478 if (atomic_read(&rth->u.dst.__refcnt))
479 goto out;
480
481 ret = 1;
482 if (rth->u.dst.expires &&
483 time_after_eq(jiffies, rth->u.dst.expires))
484 goto out;
485
486 age = jiffies - rth->u.dst.lastuse;
487 ret = 0;
488 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
489 (age <= tmo2 && rt_valuable(rth)))
490 goto out;
491 ret = 1;
492 out: return ret;
493 }
494
495 /* Bits of score are:
496 * 31: very valuable
497 * 30: not quite useless
498 * 29..0: usage counter
499 */
500 static inline u32 rt_score(struct rtable *rt)
501 {
502 u32 score = jiffies - rt->u.dst.lastuse;
503
504 score = ~score & ~(3<<30);
505
506 if (rt_valuable(rt))
507 score |= (1<<31);
508
509 if (!rt->fl.iif ||
510 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
511 score |= (1<<30);
512
513 return score;
514 }
515
516 /* This runs via a timer and thus is always in BH context. */
517 static void rt_check_expire(unsigned long dummy)
518 {
519 static int rover;
520 int i = rover, t;
521 struct rtable *rth, **rthp;
522 unsigned long now = jiffies;
523
524 for (t = ip_rt_gc_interval << rt_hash_log; t >= 0;
525 t -= ip_rt_gc_timeout) {
526 unsigned long tmo = ip_rt_gc_timeout;
527
528 i = (i + 1) & rt_hash_mask;
529 rthp = &rt_hash_table[i].chain;
530
531 spin_lock(&rt_hash_table[i].lock);
532 while ((rth = *rthp) != NULL) {
533 if (rth->u.dst.expires) {
534 /* Entry is expired even if it is in use */
535 if (time_before_eq(now, rth->u.dst.expires)) {
536 tmo >>= 1;
537 rthp = &rth->u.rt_next;
538 continue;
539 }
540 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
541 tmo >>= 1;
542 rthp = &rth->u.rt_next;
543 continue;
544 }
545
546 /* Cleanup aged off entries. */
547 *rthp = rth->u.rt_next;
548 rt_free(rth);
549 }
550 spin_unlock(&rt_hash_table[i].lock);
551
552 /* Fallback loop breaker. */
553 if (time_after(jiffies, now))
554 break;
555 }
556 rover = i;
557 mod_timer(&rt_periodic_timer, now + ip_rt_gc_interval);
558 }
559
560 /* This can run from both BH and non-BH contexts, the latter
561 * in the case of a forced flush event.
562 */
563 static void rt_run_flush(unsigned long dummy)
564 {
565 int i;
566 struct rtable *rth, *next;
567
568 rt_deadline = 0;
569
570 get_random_bytes(&rt_hash_rnd, 4);
571
572 for (i = rt_hash_mask; i >= 0; i--) {
573 spin_lock_bh(&rt_hash_table[i].lock);
574 rth = rt_hash_table[i].chain;
575 if (rth)
576 rt_hash_table[i].chain = NULL;
577 spin_unlock_bh(&rt_hash_table[i].lock);
578
579 for (; rth; rth = next) {
580 next = rth->u.rt_next;
581 rt_free(rth);
582 }
583 }
584 }
585
586 static DEFINE_SPINLOCK(rt_flush_lock);
587
588 void rt_cache_flush(int delay)
589 {
590 unsigned long now = jiffies;
591 int user_mode = !in_softirq();
592
593 if (delay < 0)
594 delay = ip_rt_min_delay;
595
596 spin_lock_bh(&rt_flush_lock);
597
598 if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
599 long tmo = (long)(rt_deadline - now);
600
601 /* If flush timer is already running
602 and flush request is not immediate (delay > 0):
603
604 if deadline is not achieved, prolongate timer to "delay",
605 otherwise fire it at deadline time.
606 */
607
608 if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
609 tmo = 0;
610
611 if (delay > tmo)
612 delay = tmo;
613 }
614
615 if (delay <= 0) {
616 spin_unlock_bh(&rt_flush_lock);
617 rt_run_flush(0);
618 return;
619 }
620
621 if (rt_deadline == 0)
622 rt_deadline = now + ip_rt_max_delay;
623
624 mod_timer(&rt_flush_timer, now+delay);
625 spin_unlock_bh(&rt_flush_lock);
626 }
627
628 static void rt_secret_rebuild(unsigned long dummy)
629 {
630 unsigned long now = jiffies;
631
632 rt_cache_flush(0);
633 mod_timer(&rt_secret_timer, now + ip_rt_secret_interval);
634 }
635
636 /*
637 Short description of GC goals.
638
639 We want to build algorithm, which will keep routing cache
640 at some equilibrium point, when number of aged off entries
641 is kept approximately equal to newly generated ones.
642
643 Current expiration strength is variable "expire".
644 We try to adjust it dynamically, so that if networking
645 is idle expires is large enough to keep enough of warm entries,
646 and when load increases it reduces to limit cache size.
647 */
648
649 static int rt_garbage_collect(void)
650 {
651 static unsigned long expire = RT_GC_TIMEOUT;
652 static unsigned long last_gc;
653 static int rover;
654 static int equilibrium;
655 struct rtable *rth, **rthp;
656 unsigned long now = jiffies;
657 int goal;
658
659 /*
660 * Garbage collection is pretty expensive,
661 * do not make it too frequently.
662 */
663
664 RT_CACHE_STAT_INC(gc_total);
665
666 if (now - last_gc < ip_rt_gc_min_interval &&
667 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
668 RT_CACHE_STAT_INC(gc_ignored);
669 goto out;
670 }
671
672 /* Calculate number of entries, which we want to expire now. */
673 goal = atomic_read(&ipv4_dst_ops.entries) -
674 (ip_rt_gc_elasticity << rt_hash_log);
675 if (goal <= 0) {
676 if (equilibrium < ipv4_dst_ops.gc_thresh)
677 equilibrium = ipv4_dst_ops.gc_thresh;
678 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
679 if (goal > 0) {
680 equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
681 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
682 }
683 } else {
684 /* We are in dangerous area. Try to reduce cache really
685 * aggressively.
686 */
687 goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
688 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
689 }
690
691 if (now - last_gc >= ip_rt_gc_min_interval)
692 last_gc = now;
693
694 if (goal <= 0) {
695 equilibrium += goal;
696 goto work_done;
697 }
698
699 do {
700 int i, k;
701
702 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
703 unsigned long tmo = expire;
704
705 k = (k + 1) & rt_hash_mask;
706 rthp = &rt_hash_table[k].chain;
707 spin_lock_bh(&rt_hash_table[k].lock);
708 while ((rth = *rthp) != NULL) {
709 if (!rt_may_expire(rth, tmo, expire)) {
710 tmo >>= 1;
711 rthp = &rth->u.rt_next;
712 continue;
713 }
714 *rthp = rth->u.rt_next;
715 rt_free(rth);
716 goal--;
717 }
718 spin_unlock_bh(&rt_hash_table[k].lock);
719 if (goal <= 0)
720 break;
721 }
722 rover = k;
723
724 if (goal <= 0)
725 goto work_done;
726
727 /* Goal is not achieved. We stop process if:
728
729 - if expire reduced to zero. Otherwise, expire is halfed.
730 - if table is not full.
731 - if we are called from interrupt.
732 - jiffies check is just fallback/debug loop breaker.
733 We will not spin here for long time in any case.
734 */
735
736 RT_CACHE_STAT_INC(gc_goal_miss);
737
738 if (expire == 0)
739 break;
740
741 expire >>= 1;
742 #if RT_CACHE_DEBUG >= 2
743 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
744 atomic_read(&ipv4_dst_ops.entries), goal, i);
745 #endif
746
747 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
748 goto out;
749 } while (!in_softirq() && time_before_eq(jiffies, now));
750
751 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
752 goto out;
753 if (net_ratelimit())
754 printk(KERN_WARNING "dst cache overflow\n");
755 RT_CACHE_STAT_INC(gc_dst_overflow);
756 return 1;
757
758 work_done:
759 expire += ip_rt_gc_min_interval;
760 if (expire > ip_rt_gc_timeout ||
761 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
762 expire = ip_rt_gc_timeout;
763 #if RT_CACHE_DEBUG >= 2
764 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
765 atomic_read(&ipv4_dst_ops.entries), goal, rover);
766 #endif
767 out: return 0;
768 }
769
770 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
771 {
772 return memcmp(&fl1->nl_u.ip4_u, &fl2->nl_u.ip4_u, sizeof(fl1->nl_u.ip4_u)) == 0 &&
773 fl1->oif == fl2->oif &&
774 fl1->iif == fl2->iif;
775 }
776
777 static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
778 {
779 struct rtable *rth, **rthp;
780 unsigned long now;
781 struct rtable *cand, **candp;
782 u32 min_score;
783 int chain_length;
784 int attempts = !in_softirq();
785
786 restart:
787 chain_length = 0;
788 min_score = ~(u32)0;
789 cand = NULL;
790 candp = NULL;
791 now = jiffies;
792
793 rthp = &rt_hash_table[hash].chain;
794
795 spin_lock_bh(&rt_hash_table[hash].lock);
796 while ((rth = *rthp) != NULL) {
797 if (compare_keys(&rth->fl, &rt->fl)) {
798 /* Put it first */
799 *rthp = rth->u.rt_next;
800 /*
801 * Since lookup is lockfree, the deletion
802 * must be visible to another weakly ordered CPU before
803 * the insertion at the start of the hash chain.
804 */
805 rcu_assign_pointer(rth->u.rt_next,
806 rt_hash_table[hash].chain);
807 /*
808 * Since lookup is lockfree, the update writes
809 * must be ordered for consistency on SMP.
810 */
811 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
812
813 rth->u.dst.__use++;
814 dst_hold(&rth->u.dst);
815 rth->u.dst.lastuse = now;
816 spin_unlock_bh(&rt_hash_table[hash].lock);
817
818 rt_drop(rt);
819 *rp = rth;
820 return 0;
821 }
822
823 if (!atomic_read(&rth->u.dst.__refcnt)) {
824 u32 score = rt_score(rth);
825
826 if (score <= min_score) {
827 cand = rth;
828 candp = rthp;
829 min_score = score;
830 }
831 }
832
833 chain_length++;
834
835 rthp = &rth->u.rt_next;
836 }
837
838 if (cand) {
839 /* ip_rt_gc_elasticity used to be average length of chain
840 * length, when exceeded gc becomes really aggressive.
841 *
842 * The second limit is less certain. At the moment it allows
843 * only 2 entries per bucket. We will see.
844 */
845 if (chain_length > ip_rt_gc_elasticity) {
846 *candp = cand->u.rt_next;
847 rt_free(cand);
848 }
849 }
850
851 /* Try to bind route to arp only if it is output
852 route or unicast forwarding path.
853 */
854 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
855 int err = arp_bind_neighbour(&rt->u.dst);
856 if (err) {
857 spin_unlock_bh(&rt_hash_table[hash].lock);
858
859 if (err != -ENOBUFS) {
860 rt_drop(rt);
861 return err;
862 }
863
864 /* Neighbour tables are full and nothing
865 can be released. Try to shrink route cache,
866 it is most likely it holds some neighbour records.
867 */
868 if (attempts-- > 0) {
869 int saved_elasticity = ip_rt_gc_elasticity;
870 int saved_int = ip_rt_gc_min_interval;
871 ip_rt_gc_elasticity = 1;
872 ip_rt_gc_min_interval = 0;
873 rt_garbage_collect();
874 ip_rt_gc_min_interval = saved_int;
875 ip_rt_gc_elasticity = saved_elasticity;
876 goto restart;
877 }
878
879 if (net_ratelimit())
880 printk(KERN_WARNING "Neighbour table overflow.\n");
881 rt_drop(rt);
882 return -ENOBUFS;
883 }
884 }
885
886 rt->u.rt_next = rt_hash_table[hash].chain;
887 #if RT_CACHE_DEBUG >= 2
888 if (rt->u.rt_next) {
889 struct rtable *trt;
890 printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
891 NIPQUAD(rt->rt_dst));
892 for (trt = rt->u.rt_next; trt; trt = trt->u.rt_next)
893 printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
894 printk("\n");
895 }
896 #endif
897 rt_hash_table[hash].chain = rt;
898 spin_unlock_bh(&rt_hash_table[hash].lock);
899 *rp = rt;
900 return 0;
901 }
902
903 void rt_bind_peer(struct rtable *rt, int create)
904 {
905 static DEFINE_SPINLOCK(rt_peer_lock);
906 struct inet_peer *peer;
907
908 peer = inet_getpeer(rt->rt_dst, create);
909
910 spin_lock_bh(&rt_peer_lock);
911 if (rt->peer == NULL) {
912 rt->peer = peer;
913 peer = NULL;
914 }
915 spin_unlock_bh(&rt_peer_lock);
916 if (peer)
917 inet_putpeer(peer);
918 }
919
920 /*
921 * Peer allocation may fail only in serious out-of-memory conditions. However
922 * we still can generate some output.
923 * Random ID selection looks a bit dangerous because we have no chances to
924 * select ID being unique in a reasonable period of time.
925 * But broken packet identifier may be better than no packet at all.
926 */
927 static void ip_select_fb_ident(struct iphdr *iph)
928 {
929 static DEFINE_SPINLOCK(ip_fb_id_lock);
930 static u32 ip_fallback_id;
931 u32 salt;
932
933 spin_lock_bh(&ip_fb_id_lock);
934 salt = secure_ip_id(ip_fallback_id ^ iph->daddr);
935 iph->id = htons(salt & 0xFFFF);
936 ip_fallback_id = salt;
937 spin_unlock_bh(&ip_fb_id_lock);
938 }
939
940 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
941 {
942 struct rtable *rt = (struct rtable *) dst;
943
944 if (rt) {
945 if (rt->peer == NULL)
946 rt_bind_peer(rt, 1);
947
948 /* If peer is attached to destination, it is never detached,
949 so that we need not to grab a lock to dereference it.
950 */
951 if (rt->peer) {
952 iph->id = htons(inet_getid(rt->peer, more));
953 return;
954 }
955 } else
956 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n", NET_CALLER(iph));
957
958 ip_select_fb_ident(iph);
959 }
960
961 static void rt_del(unsigned hash, struct rtable *rt)
962 {
963 struct rtable **rthp;
964
965 spin_lock_bh(&rt_hash_table[hash].lock);
966 ip_rt_put(rt);
967 for (rthp = &rt_hash_table[hash].chain; *rthp;
968 rthp = &(*rthp)->u.rt_next)
969 if (*rthp == rt) {
970 *rthp = rt->u.rt_next;
971 rt_free(rt);
972 break;
973 }
974 spin_unlock_bh(&rt_hash_table[hash].lock);
975 }
976
977 void ip_rt_redirect(u32 old_gw, u32 daddr, u32 new_gw,
978 u32 saddr, u8 tos, struct net_device *dev)
979 {
980 int i, k;
981 struct in_device *in_dev = in_dev_get(dev);
982 struct rtable *rth, **rthp;
983 u32 skeys[2] = { saddr, 0 };
984 int ikeys[2] = { dev->ifindex, 0 };
985
986 tos &= IPTOS_RT_MASK;
987
988 if (!in_dev)
989 return;
990
991 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
992 || MULTICAST(new_gw) || BADCLASS(new_gw) || ZERONET(new_gw))
993 goto reject_redirect;
994
995 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
996 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
997 goto reject_redirect;
998 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
999 goto reject_redirect;
1000 } else {
1001 if (inet_addr_type(new_gw) != RTN_UNICAST)
1002 goto reject_redirect;
1003 }
1004
1005 for (i = 0; i < 2; i++) {
1006 for (k = 0; k < 2; k++) {
1007 unsigned hash = rt_hash_code(daddr,
1008 skeys[i] ^ (ikeys[k] << 5),
1009 tos);
1010
1011 rthp=&rt_hash_table[hash].chain;
1012
1013 rcu_read_lock();
1014 while ((rth = rcu_dereference(*rthp)) != NULL) {
1015 struct rtable *rt;
1016
1017 if (rth->fl.fl4_dst != daddr ||
1018 rth->fl.fl4_src != skeys[i] ||
1019 rth->fl.fl4_tos != tos ||
1020 rth->fl.oif != ikeys[k] ||
1021 rth->fl.iif != 0) {
1022 rthp = &rth->u.rt_next;
1023 continue;
1024 }
1025
1026 if (rth->rt_dst != daddr ||
1027 rth->rt_src != saddr ||
1028 rth->u.dst.error ||
1029 rth->rt_gateway != old_gw ||
1030 rth->u.dst.dev != dev)
1031 break;
1032
1033 dst_hold(&rth->u.dst);
1034 rcu_read_unlock();
1035
1036 rt = dst_alloc(&ipv4_dst_ops);
1037 if (rt == NULL) {
1038 ip_rt_put(rth);
1039 in_dev_put(in_dev);
1040 return;
1041 }
1042
1043 /* Copy all the information. */
1044 *rt = *rth;
1045 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1046 rt->u.dst.__use = 1;
1047 atomic_set(&rt->u.dst.__refcnt, 1);
1048 rt->u.dst.child = NULL;
1049 if (rt->u.dst.dev)
1050 dev_hold(rt->u.dst.dev);
1051 if (rt->idev)
1052 in_dev_hold(rt->idev);
1053 rt->u.dst.obsolete = 0;
1054 rt->u.dst.lastuse = jiffies;
1055 rt->u.dst.path = &rt->u.dst;
1056 rt->u.dst.neighbour = NULL;
1057 rt->u.dst.hh = NULL;
1058 rt->u.dst.xfrm = NULL;
1059
1060 rt->rt_flags |= RTCF_REDIRECTED;
1061
1062 /* Gateway is different ... */
1063 rt->rt_gateway = new_gw;
1064
1065 /* Redirect received -> path was valid */
1066 dst_confirm(&rth->u.dst);
1067
1068 if (rt->peer)
1069 atomic_inc(&rt->peer->refcnt);
1070
1071 if (arp_bind_neighbour(&rt->u.dst) ||
1072 !(rt->u.dst.neighbour->nud_state &
1073 NUD_VALID)) {
1074 if (rt->u.dst.neighbour)
1075 neigh_event_send(rt->u.dst.neighbour, NULL);
1076 ip_rt_put(rth);
1077 rt_drop(rt);
1078 goto do_next;
1079 }
1080
1081 rt_del(hash, rth);
1082 if (!rt_intern_hash(hash, rt, &rt))
1083 ip_rt_put(rt);
1084 goto do_next;
1085 }
1086 rcu_read_unlock();
1087 do_next:
1088 ;
1089 }
1090 }
1091 in_dev_put(in_dev);
1092 return;
1093
1094 reject_redirect:
1095 #ifdef CONFIG_IP_ROUTE_VERBOSE
1096 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1097 printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
1098 "%u.%u.%u.%u ignored.\n"
1099 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u, "
1100 "tos %02x\n",
1101 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1102 NIPQUAD(saddr), NIPQUAD(daddr), tos);
1103 #endif
1104 in_dev_put(in_dev);
1105 }
1106
1107 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1108 {
1109 struct rtable *rt = (struct rtable*)dst;
1110 struct dst_entry *ret = dst;
1111
1112 if (rt) {
1113 if (dst->obsolete) {
1114 ip_rt_put(rt);
1115 ret = NULL;
1116 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1117 rt->u.dst.expires) {
1118 unsigned hash = rt_hash_code(rt->fl.fl4_dst,
1119 rt->fl.fl4_src ^
1120 (rt->fl.oif << 5),
1121 rt->fl.fl4_tos);
1122 #if RT_CACHE_DEBUG >= 1
1123 printk(KERN_DEBUG "ip_rt_advice: redirect to "
1124 "%u.%u.%u.%u/%02x dropped\n",
1125 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1126 #endif
1127 rt_del(hash, rt);
1128 ret = NULL;
1129 }
1130 }
1131 return ret;
1132 }
1133
1134 /*
1135 * Algorithm:
1136 * 1. The first ip_rt_redirect_number redirects are sent
1137 * with exponential backoff, then we stop sending them at all,
1138 * assuming that the host ignores our redirects.
1139 * 2. If we did not see packets requiring redirects
1140 * during ip_rt_redirect_silence, we assume that the host
1141 * forgot redirected route and start to send redirects again.
1142 *
1143 * This algorithm is much cheaper and more intelligent than dumb load limiting
1144 * in icmp.c.
1145 *
1146 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1147 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1148 */
1149
1150 void ip_rt_send_redirect(struct sk_buff *skb)
1151 {
1152 struct rtable *rt = (struct rtable*)skb->dst;
1153 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1154
1155 if (!in_dev)
1156 return;
1157
1158 if (!IN_DEV_TX_REDIRECTS(in_dev))
1159 goto out;
1160
1161 /* No redirected packets during ip_rt_redirect_silence;
1162 * reset the algorithm.
1163 */
1164 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1165 rt->u.dst.rate_tokens = 0;
1166
1167 /* Too many ignored redirects; do not send anything
1168 * set u.dst.rate_last to the last seen redirected packet.
1169 */
1170 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1171 rt->u.dst.rate_last = jiffies;
1172 goto out;
1173 }
1174
1175 /* Check for load limit; set rate_last to the latest sent
1176 * redirect.
1177 */
1178 if (time_after(jiffies,
1179 (rt->u.dst.rate_last +
1180 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1181 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1182 rt->u.dst.rate_last = jiffies;
1183 ++rt->u.dst.rate_tokens;
1184 #ifdef CONFIG_IP_ROUTE_VERBOSE
1185 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1186 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1187 net_ratelimit())
1188 printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
1189 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1190 NIPQUAD(rt->rt_src), rt->rt_iif,
1191 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1192 #endif
1193 }
1194 out:
1195 in_dev_put(in_dev);
1196 }
1197
1198 static int ip_error(struct sk_buff *skb)
1199 {
1200 struct rtable *rt = (struct rtable*)skb->dst;
1201 unsigned long now;
1202 int code;
1203
1204 switch (rt->u.dst.error) {
1205 case EINVAL:
1206 default:
1207 goto out;
1208 case EHOSTUNREACH:
1209 code = ICMP_HOST_UNREACH;
1210 break;
1211 case ENETUNREACH:
1212 code = ICMP_NET_UNREACH;
1213 break;
1214 case EACCES:
1215 code = ICMP_PKT_FILTERED;
1216 break;
1217 }
1218
1219 now = jiffies;
1220 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1221 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1222 rt->u.dst.rate_tokens = ip_rt_error_burst;
1223 rt->u.dst.rate_last = now;
1224 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1225 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1226 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1227 }
1228
1229 out: kfree_skb(skb);
1230 return 0;
1231 }
1232
1233 /*
1234 * The last two values are not from the RFC but
1235 * are needed for AMPRnet AX.25 paths.
1236 */
1237
1238 static unsigned short mtu_plateau[] =
1239 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1240
1241 static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
1242 {
1243 int i;
1244
1245 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1246 if (old_mtu > mtu_plateau[i])
1247 return mtu_plateau[i];
1248 return 68;
1249 }
1250
1251 unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
1252 {
1253 int i;
1254 unsigned short old_mtu = ntohs(iph->tot_len);
1255 struct rtable *rth;
1256 u32 skeys[2] = { iph->saddr, 0, };
1257 u32 daddr = iph->daddr;
1258 u8 tos = iph->tos & IPTOS_RT_MASK;
1259 unsigned short est_mtu = 0;
1260
1261 if (ipv4_config.no_pmtu_disc)
1262 return 0;
1263
1264 for (i = 0; i < 2; i++) {
1265 unsigned hash = rt_hash_code(daddr, skeys[i], tos);
1266
1267 rcu_read_lock();
1268 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1269 rth = rcu_dereference(rth->u.rt_next)) {
1270 if (rth->fl.fl4_dst == daddr &&
1271 rth->fl.fl4_src == skeys[i] &&
1272 rth->rt_dst == daddr &&
1273 rth->rt_src == iph->saddr &&
1274 rth->fl.fl4_tos == tos &&
1275 rth->fl.iif == 0 &&
1276 !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
1277 unsigned short mtu = new_mtu;
1278
1279 if (new_mtu < 68 || new_mtu >= old_mtu) {
1280
1281 /* BSD 4.2 compatibility hack :-( */
1282 if (mtu == 0 &&
1283 old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
1284 old_mtu >= 68 + (iph->ihl << 2))
1285 old_mtu -= iph->ihl << 2;
1286
1287 mtu = guess_mtu(old_mtu);
1288 }
1289 if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1290 if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
1291 dst_confirm(&rth->u.dst);
1292 if (mtu < ip_rt_min_pmtu) {
1293 mtu = ip_rt_min_pmtu;
1294 rth->u.dst.metrics[RTAX_LOCK-1] |=
1295 (1 << RTAX_MTU);
1296 }
1297 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1298 dst_set_expires(&rth->u.dst,
1299 ip_rt_mtu_expires);
1300 }
1301 est_mtu = mtu;
1302 }
1303 }
1304 }
1305 rcu_read_unlock();
1306 }
1307 return est_mtu ? : new_mtu;
1308 }
1309
1310 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1311 {
1312 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
1313 !(dst_metric_locked(dst, RTAX_MTU))) {
1314 if (mtu < ip_rt_min_pmtu) {
1315 mtu = ip_rt_min_pmtu;
1316 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1317 }
1318 dst->metrics[RTAX_MTU-1] = mtu;
1319 dst_set_expires(dst, ip_rt_mtu_expires);
1320 }
1321 }
1322
1323 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1324 {
1325 dst_release(dst);
1326 return NULL;
1327 }
1328
1329 static void ipv4_dst_destroy(struct dst_entry *dst)
1330 {
1331 struct rtable *rt = (struct rtable *) dst;
1332 struct inet_peer *peer = rt->peer;
1333 struct in_device *idev = rt->idev;
1334
1335 if (peer) {
1336 rt->peer = NULL;
1337 inet_putpeer(peer);
1338 }
1339
1340 if (idev) {
1341 rt->idev = NULL;
1342 in_dev_put(idev);
1343 }
1344 }
1345
1346 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1347 int how)
1348 {
1349 struct rtable *rt = (struct rtable *) dst;
1350 struct in_device *idev = rt->idev;
1351 if (dev != &loopback_dev && idev && idev->dev == dev) {
1352 struct in_device *loopback_idev = in_dev_get(&loopback_dev);
1353 if (loopback_idev) {
1354 rt->idev = loopback_idev;
1355 in_dev_put(idev);
1356 }
1357 }
1358 }
1359
1360 static void ipv4_link_failure(struct sk_buff *skb)
1361 {
1362 struct rtable *rt;
1363
1364 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1365
1366 rt = (struct rtable *) skb->dst;
1367 if (rt)
1368 dst_set_expires(&rt->u.dst, 0);
1369 }
1370
1371 static int ip_rt_bug(struct sk_buff *skb)
1372 {
1373 printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1374 NIPQUAD(skb->nh.iph->saddr), NIPQUAD(skb->nh.iph->daddr),
1375 skb->dev ? skb->dev->name : "?");
1376 kfree_skb(skb);
1377 return 0;
1378 }
1379
1380 /*
1381 We do not cache source address of outgoing interface,
1382 because it is used only by IP RR, TS and SRR options,
1383 so that it out of fast path.
1384
1385 BTW remember: "addr" is allowed to be not aligned
1386 in IP options!
1387 */
1388
1389 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1390 {
1391 u32 src;
1392 struct fib_result res;
1393
1394 if (rt->fl.iif == 0)
1395 src = rt->rt_src;
1396 else if (fib_lookup(&rt->fl, &res) == 0) {
1397 src = FIB_RES_PREFSRC(res);
1398 fib_res_put(&res);
1399 } else
1400 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1401 RT_SCOPE_UNIVERSE);
1402 memcpy(addr, &src, 4);
1403 }
1404
1405 #ifdef CONFIG_NET_CLS_ROUTE
1406 static void set_class_tag(struct rtable *rt, u32 tag)
1407 {
1408 if (!(rt->u.dst.tclassid & 0xFFFF))
1409 rt->u.dst.tclassid |= tag & 0xFFFF;
1410 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1411 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1412 }
1413 #endif
1414
1415 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1416 {
1417 struct fib_info *fi = res->fi;
1418
1419 if (fi) {
1420 if (FIB_RES_GW(*res) &&
1421 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1422 rt->rt_gateway = FIB_RES_GW(*res);
1423 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1424 sizeof(rt->u.dst.metrics));
1425 if (fi->fib_mtu == 0) {
1426 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1427 if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
1428 rt->rt_gateway != rt->rt_dst &&
1429 rt->u.dst.dev->mtu > 576)
1430 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1431 }
1432 #ifdef CONFIG_NET_CLS_ROUTE
1433 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1434 #endif
1435 } else
1436 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1437
1438 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1439 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1440 if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
1441 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1442 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
1443 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1444 ip_rt_min_advmss);
1445 if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
1446 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1447
1448 #ifdef CONFIG_NET_CLS_ROUTE
1449 #ifdef CONFIG_IP_MULTIPLE_TABLES
1450 set_class_tag(rt, fib_rules_tclass(res));
1451 #endif
1452 set_class_tag(rt, itag);
1453 #endif
1454 rt->rt_type = res->type;
1455 }
1456
1457 static int ip_route_input_mc(struct sk_buff *skb, u32 daddr, u32 saddr,
1458 u8 tos, struct net_device *dev, int our)
1459 {
1460 unsigned hash;
1461 struct rtable *rth;
1462 u32 spec_dst;
1463 struct in_device *in_dev = in_dev_get(dev);
1464 u32 itag = 0;
1465
1466 /* Primary sanity checks. */
1467
1468 if (in_dev == NULL)
1469 return -EINVAL;
1470
1471 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr) ||
1472 skb->protocol != htons(ETH_P_IP))
1473 goto e_inval;
1474
1475 if (ZERONET(saddr)) {
1476 if (!LOCAL_MCAST(daddr))
1477 goto e_inval;
1478 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1479 } else if (fib_validate_source(saddr, 0, tos, 0,
1480 dev, &spec_dst, &itag) < 0)
1481 goto e_inval;
1482
1483 rth = dst_alloc(&ipv4_dst_ops);
1484 if (!rth)
1485 goto e_nobufs;
1486
1487 rth->u.dst.output= ip_rt_bug;
1488
1489 atomic_set(&rth->u.dst.__refcnt, 1);
1490 rth->u.dst.flags= DST_HOST;
1491 if (in_dev->cnf.no_policy)
1492 rth->u.dst.flags |= DST_NOPOLICY;
1493 rth->fl.fl4_dst = daddr;
1494 rth->rt_dst = daddr;
1495 rth->fl.fl4_tos = tos;
1496 #ifdef CONFIG_IP_ROUTE_FWMARK
1497 rth->fl.fl4_fwmark= skb->nfmark;
1498 #endif
1499 rth->fl.fl4_src = saddr;
1500 rth->rt_src = saddr;
1501 #ifdef CONFIG_NET_CLS_ROUTE
1502 rth->u.dst.tclassid = itag;
1503 #endif
1504 rth->rt_iif =
1505 rth->fl.iif = dev->ifindex;
1506 rth->u.dst.dev = &loopback_dev;
1507 dev_hold(rth->u.dst.dev);
1508 rth->idev = in_dev_get(rth->u.dst.dev);
1509 rth->fl.oif = 0;
1510 rth->rt_gateway = daddr;
1511 rth->rt_spec_dst= spec_dst;
1512 rth->rt_type = RTN_MULTICAST;
1513 rth->rt_flags = RTCF_MULTICAST;
1514 if (our) {
1515 rth->u.dst.input= ip_local_deliver;
1516 rth->rt_flags |= RTCF_LOCAL;
1517 }
1518
1519 #ifdef CONFIG_IP_MROUTE
1520 if (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1521 rth->u.dst.input = ip_mr_input;
1522 #endif
1523 RT_CACHE_STAT_INC(in_slow_mc);
1524
1525 in_dev_put(in_dev);
1526 hash = rt_hash_code(daddr, saddr ^ (dev->ifindex << 5), tos);
1527 return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
1528
1529 e_nobufs:
1530 in_dev_put(in_dev);
1531 return -ENOBUFS;
1532
1533 e_inval:
1534 in_dev_put(in_dev);
1535 return -EINVAL;
1536 }
1537
1538 /*
1539 * NOTE. We drop all the packets that has local source
1540 * addresses, because every properly looped back packet
1541 * must have correct destination already attached by output routine.
1542 *
1543 * Such approach solves two big problems:
1544 * 1. Not simplex devices are handled properly.
1545 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1546 */
1547
1548 static int ip_route_input_slow(struct sk_buff *skb, u32 daddr, u32 saddr,
1549 u8 tos, struct net_device *dev)
1550 {
1551 struct fib_result res;
1552 struct in_device *in_dev = in_dev_get(dev);
1553 struct in_device *out_dev = NULL;
1554 struct flowi fl = { .nl_u = { .ip4_u =
1555 { .daddr = daddr,
1556 .saddr = saddr,
1557 .tos = tos,
1558 .scope = RT_SCOPE_UNIVERSE,
1559 #ifdef CONFIG_IP_ROUTE_FWMARK
1560 .fwmark = skb->nfmark
1561 #endif
1562 } },
1563 .iif = dev->ifindex };
1564 unsigned flags = 0;
1565 u32 itag = 0;
1566 struct rtable * rth;
1567 unsigned hash;
1568 u32 spec_dst;
1569 int err = -EINVAL;
1570 int free_res = 0;
1571
1572 /* IP on this device is disabled. */
1573
1574 if (!in_dev)
1575 goto out;
1576
1577 hash = rt_hash_code(daddr, saddr ^ (fl.iif << 5), tos);
1578
1579 /* Check for the most weird martians, which can be not detected
1580 by fib_lookup.
1581 */
1582
1583 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr))
1584 goto martian_source;
1585
1586 if (daddr == 0xFFFFFFFF || (saddr == 0 && daddr == 0))
1587 goto brd_input;
1588
1589 /* Accept zero addresses only to limited broadcast;
1590 * I even do not know to fix it or not. Waiting for complains :-)
1591 */
1592 if (ZERONET(saddr))
1593 goto martian_source;
1594
1595 if (BADCLASS(daddr) || ZERONET(daddr) || LOOPBACK(daddr))
1596 goto martian_destination;
1597
1598 /*
1599 * Now we are ready to route packet.
1600 */
1601 if ((err = fib_lookup(&fl, &res)) != 0) {
1602 if (!IN_DEV_FORWARD(in_dev))
1603 goto e_inval;
1604 goto no_route;
1605 }
1606 free_res = 1;
1607
1608 RT_CACHE_STAT_INC(in_slow_tot);
1609
1610 if (res.type == RTN_BROADCAST)
1611 goto brd_input;
1612
1613 if (res.type == RTN_LOCAL) {
1614 int result;
1615 result = fib_validate_source(saddr, daddr, tos,
1616 loopback_dev.ifindex,
1617 dev, &spec_dst, &itag);
1618 if (result < 0)
1619 goto martian_source;
1620 if (result)
1621 flags |= RTCF_DIRECTSRC;
1622 spec_dst = daddr;
1623 goto local_input;
1624 }
1625
1626 if (!IN_DEV_FORWARD(in_dev))
1627 goto e_inval;
1628 if (res.type != RTN_UNICAST)
1629 goto martian_destination;
1630
1631 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1632 if (res.fi->fib_nhs > 1 && fl.oif == 0)
1633 fib_select_multipath(&fl, &res);
1634 #endif
1635 out_dev = in_dev_get(FIB_RES_DEV(res));
1636 if (out_dev == NULL) {
1637 if (net_ratelimit())
1638 printk(KERN_CRIT "Bug in ip_route_input_slow(). "
1639 "Please, report\n");
1640 goto e_inval;
1641 }
1642
1643 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(res), dev,
1644 &spec_dst, &itag);
1645 if (err < 0)
1646 goto martian_source;
1647
1648 if (err)
1649 flags |= RTCF_DIRECTSRC;
1650
1651 if (out_dev == in_dev && err && !(flags & (RTCF_NAT | RTCF_MASQ)) &&
1652 (IN_DEV_SHARED_MEDIA(out_dev) ||
1653 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(res))))
1654 flags |= RTCF_DOREDIRECT;
1655
1656 if (skb->protocol != htons(ETH_P_IP)) {
1657 /* Not IP (i.e. ARP). Do not create route, if it is
1658 * invalid for proxy arp. DNAT routes are always valid.
1659 */
1660 if (out_dev == in_dev && !(flags & RTCF_DNAT))
1661 goto e_inval;
1662 }
1663
1664 rth = dst_alloc(&ipv4_dst_ops);
1665 if (!rth)
1666 goto e_nobufs;
1667
1668 atomic_set(&rth->u.dst.__refcnt, 1);
1669 rth->u.dst.flags= DST_HOST;
1670 if (in_dev->cnf.no_policy)
1671 rth->u.dst.flags |= DST_NOPOLICY;
1672 if (in_dev->cnf.no_xfrm)
1673 rth->u.dst.flags |= DST_NOXFRM;
1674 rth->fl.fl4_dst = daddr;
1675 rth->rt_dst = daddr;
1676 rth->fl.fl4_tos = tos;
1677 #ifdef CONFIG_IP_ROUTE_FWMARK
1678 rth->fl.fl4_fwmark= skb->nfmark;
1679 #endif
1680 rth->fl.fl4_src = saddr;
1681 rth->rt_src = saddr;
1682 rth->rt_gateway = daddr;
1683 rth->rt_iif =
1684 rth->fl.iif = dev->ifindex;
1685 rth->u.dst.dev = out_dev->dev;
1686 dev_hold(rth->u.dst.dev);
1687 rth->idev = in_dev_get(rth->u.dst.dev);
1688 rth->fl.oif = 0;
1689 rth->rt_spec_dst= spec_dst;
1690
1691 rth->u.dst.input = ip_forward;
1692 rth->u.dst.output = ip_output;
1693
1694 rt_set_nexthop(rth, &res, itag);
1695
1696 rth->rt_flags = flags;
1697
1698 intern:
1699 err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1700 done:
1701 in_dev_put(in_dev);
1702 if (out_dev)
1703 in_dev_put(out_dev);
1704 if (free_res)
1705 fib_res_put(&res);
1706 out: return err;
1707
1708 brd_input:
1709 if (skb->protocol != htons(ETH_P_IP))
1710 goto e_inval;
1711
1712 if (ZERONET(saddr))
1713 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1714 else {
1715 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1716 &itag);
1717 if (err < 0)
1718 goto martian_source;
1719 if (err)
1720 flags |= RTCF_DIRECTSRC;
1721 }
1722 flags |= RTCF_BROADCAST;
1723 res.type = RTN_BROADCAST;
1724 RT_CACHE_STAT_INC(in_brd);
1725
1726 local_input:
1727 rth = dst_alloc(&ipv4_dst_ops);
1728 if (!rth)
1729 goto e_nobufs;
1730
1731 rth->u.dst.output= ip_rt_bug;
1732
1733 atomic_set(&rth->u.dst.__refcnt, 1);
1734 rth->u.dst.flags= DST_HOST;
1735 if (in_dev->cnf.no_policy)
1736 rth->u.dst.flags |= DST_NOPOLICY;
1737 rth->fl.fl4_dst = daddr;
1738 rth->rt_dst = daddr;
1739 rth->fl.fl4_tos = tos;
1740 #ifdef CONFIG_IP_ROUTE_FWMARK
1741 rth->fl.fl4_fwmark= skb->nfmark;
1742 #endif
1743 rth->fl.fl4_src = saddr;
1744 rth->rt_src = saddr;
1745 #ifdef CONFIG_NET_CLS_ROUTE
1746 rth->u.dst.tclassid = itag;
1747 #endif
1748 rth->rt_iif =
1749 rth->fl.iif = dev->ifindex;
1750 rth->u.dst.dev = &loopback_dev;
1751 dev_hold(rth->u.dst.dev);
1752 rth->idev = in_dev_get(rth->u.dst.dev);
1753 rth->rt_gateway = daddr;
1754 rth->rt_spec_dst= spec_dst;
1755 rth->u.dst.input= ip_local_deliver;
1756 rth->rt_flags = flags|RTCF_LOCAL;
1757 if (res.type == RTN_UNREACHABLE) {
1758 rth->u.dst.input= ip_error;
1759 rth->u.dst.error= -err;
1760 rth->rt_flags &= ~RTCF_LOCAL;
1761 }
1762 rth->rt_type = res.type;
1763 goto intern;
1764
1765 no_route:
1766 RT_CACHE_STAT_INC(in_no_route);
1767 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
1768 res.type = RTN_UNREACHABLE;
1769 goto local_input;
1770
1771 /*
1772 * Do not cache martian addresses: they should be logged (RFC1812)
1773 */
1774 martian_destination:
1775 RT_CACHE_STAT_INC(in_martian_dst);
1776 #ifdef CONFIG_IP_ROUTE_VERBOSE
1777 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1778 printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
1779 "%u.%u.%u.%u, dev %s\n",
1780 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1781 #endif
1782 e_inval:
1783 err = -EINVAL;
1784 goto done;
1785
1786 e_nobufs:
1787 err = -ENOBUFS;
1788 goto done;
1789
1790 martian_source:
1791
1792 RT_CACHE_STAT_INC(in_martian_src);
1793 #ifdef CONFIG_IP_ROUTE_VERBOSE
1794 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1795 /*
1796 * RFC1812 recommendation, if source is martian,
1797 * the only hint is MAC header.
1798 */
1799 printk(KERN_WARNING "martian source %u.%u.%u.%u from "
1800 "%u.%u.%u.%u, on dev %s\n",
1801 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1802 if (dev->hard_header_len) {
1803 int i;
1804 unsigned char *p = skb->mac.raw;
1805 printk(KERN_WARNING "ll header: ");
1806 for (i = 0; i < dev->hard_header_len; i++, p++) {
1807 printk("%02x", *p);
1808 if (i < (dev->hard_header_len - 1))
1809 printk(":");
1810 }
1811 printk("\n");
1812 }
1813 }
1814 #endif
1815 goto e_inval;
1816 }
1817
1818 int ip_route_input(struct sk_buff *skb, u32 daddr, u32 saddr,
1819 u8 tos, struct net_device *dev)
1820 {
1821 struct rtable * rth;
1822 unsigned hash;
1823 int iif = dev->ifindex;
1824
1825 tos &= IPTOS_RT_MASK;
1826 hash = rt_hash_code(daddr, saddr ^ (iif << 5), tos);
1827
1828 rcu_read_lock();
1829 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1830 rth = rcu_dereference(rth->u.rt_next)) {
1831 if (rth->fl.fl4_dst == daddr &&
1832 rth->fl.fl4_src == saddr &&
1833 rth->fl.iif == iif &&
1834 rth->fl.oif == 0 &&
1835 #ifdef CONFIG_IP_ROUTE_FWMARK
1836 rth->fl.fl4_fwmark == skb->nfmark &&
1837 #endif
1838 rth->fl.fl4_tos == tos) {
1839 rth->u.dst.lastuse = jiffies;
1840 dst_hold(&rth->u.dst);
1841 rth->u.dst.__use++;
1842 RT_CACHE_STAT_INC(in_hit);
1843 rcu_read_unlock();
1844 skb->dst = (struct dst_entry*)rth;
1845 return 0;
1846 }
1847 RT_CACHE_STAT_INC(in_hlist_search);
1848 }
1849 rcu_read_unlock();
1850
1851 /* Multicast recognition logic is moved from route cache to here.
1852 The problem was that too many Ethernet cards have broken/missing
1853 hardware multicast filters :-( As result the host on multicasting
1854 network acquires a lot of useless route cache entries, sort of
1855 SDR messages from all the world. Now we try to get rid of them.
1856 Really, provided software IP multicast filter is organized
1857 reasonably (at least, hashed), it does not result in a slowdown
1858 comparing with route cache reject entries.
1859 Note, that multicast routers are not affected, because
1860 route cache entry is created eventually.
1861 */
1862 if (MULTICAST(daddr)) {
1863 struct in_device *in_dev;
1864
1865 rcu_read_lock();
1866 if ((in_dev = __in_dev_get(dev)) != NULL) {
1867 int our = ip_check_mc(in_dev, daddr, saddr,
1868 skb->nh.iph->protocol);
1869 if (our
1870 #ifdef CONFIG_IP_MROUTE
1871 || (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1872 #endif
1873 ) {
1874 rcu_read_unlock();
1875 return ip_route_input_mc(skb, daddr, saddr,
1876 tos, dev, our);
1877 }
1878 }
1879 rcu_read_unlock();
1880 return -EINVAL;
1881 }
1882 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
1883 }
1884
1885 /*
1886 * Major route resolver routine.
1887 */
1888
1889 static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
1890 {
1891 u32 tos = oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK);
1892 struct flowi fl = { .nl_u = { .ip4_u =
1893 { .daddr = oldflp->fl4_dst,
1894 .saddr = oldflp->fl4_src,
1895 .tos = tos & IPTOS_RT_MASK,
1896 .scope = ((tos & RTO_ONLINK) ?
1897 RT_SCOPE_LINK :
1898 RT_SCOPE_UNIVERSE),
1899 #ifdef CONFIG_IP_ROUTE_FWMARK
1900 .fwmark = oldflp->fl4_fwmark
1901 #endif
1902 } },
1903 .iif = loopback_dev.ifindex,
1904 .oif = oldflp->oif };
1905 struct fib_result res;
1906 unsigned flags = 0;
1907 struct rtable *rth;
1908 struct net_device *dev_out = NULL;
1909 struct in_device *in_dev = NULL;
1910 unsigned hash;
1911 int free_res = 0;
1912 int err;
1913
1914 res.fi = NULL;
1915 #ifdef CONFIG_IP_MULTIPLE_TABLES
1916 res.r = NULL;
1917 #endif
1918
1919 if (oldflp->fl4_src) {
1920 err = -EINVAL;
1921 if (MULTICAST(oldflp->fl4_src) ||
1922 BADCLASS(oldflp->fl4_src) ||
1923 ZERONET(oldflp->fl4_src))
1924 goto out;
1925
1926 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1927 dev_out = ip_dev_find(oldflp->fl4_src);
1928 if (dev_out == NULL)
1929 goto out;
1930
1931 /* I removed check for oif == dev_out->oif here.
1932 It was wrong for two reasons:
1933 1. ip_dev_find(saddr) can return wrong iface, if saddr is
1934 assigned to multiple interfaces.
1935 2. Moreover, we are allowed to send packets with saddr
1936 of another iface. --ANK
1937 */
1938
1939 if (oldflp->oif == 0
1940 && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == 0xFFFFFFFF)) {
1941 /* Special hack: user can direct multicasts
1942 and limited broadcast via necessary interface
1943 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1944 This hack is not just for fun, it allows
1945 vic,vat and friends to work.
1946 They bind socket to loopback, set ttl to zero
1947 and expect that it will work.
1948 From the viewpoint of routing cache they are broken,
1949 because we are not allowed to build multicast path
1950 with loopback source addr (look, routing cache
1951 cannot know, that ttl is zero, so that packet
1952 will not leave this host and route is valid).
1953 Luckily, this hack is good workaround.
1954 */
1955
1956 fl.oif = dev_out->ifindex;
1957 goto make_route;
1958 }
1959 if (dev_out)
1960 dev_put(dev_out);
1961 dev_out = NULL;
1962 }
1963 if (oldflp->oif) {
1964 dev_out = dev_get_by_index(oldflp->oif);
1965 err = -ENODEV;
1966 if (dev_out == NULL)
1967 goto out;
1968 if (__in_dev_get(dev_out) == NULL) {
1969 dev_put(dev_out);
1970 goto out; /* Wrong error code */
1971 }
1972
1973 if (LOCAL_MCAST(oldflp->fl4_dst) || oldflp->fl4_dst == 0xFFFFFFFF) {
1974 if (!fl.fl4_src)
1975 fl.fl4_src = inet_select_addr(dev_out, 0,
1976 RT_SCOPE_LINK);
1977 goto make_route;
1978 }
1979 if (!fl.fl4_src) {
1980 if (MULTICAST(oldflp->fl4_dst))
1981 fl.fl4_src = inet_select_addr(dev_out, 0,
1982 fl.fl4_scope);
1983 else if (!oldflp->fl4_dst)
1984 fl.fl4_src = inet_select_addr(dev_out, 0,
1985 RT_SCOPE_HOST);
1986 }
1987 }
1988
1989 if (!fl.fl4_dst) {
1990 fl.fl4_dst = fl.fl4_src;
1991 if (!fl.fl4_dst)
1992 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
1993 if (dev_out)
1994 dev_put(dev_out);
1995 dev_out = &loopback_dev;
1996 dev_hold(dev_out);
1997 fl.oif = loopback_dev.ifindex;
1998 res.type = RTN_LOCAL;
1999 flags |= RTCF_LOCAL;
2000 goto make_route;
2001 }
2002
2003 if (fib_lookup(&fl, &res)) {
2004 res.fi = NULL;
2005 if (oldflp->oif) {
2006 /* Apparently, routing tables are wrong. Assume,
2007 that the destination is on link.
2008
2009 WHY? DW.
2010 Because we are allowed to send to iface
2011 even if it has NO routes and NO assigned
2012 addresses. When oif is specified, routing
2013 tables are looked up with only one purpose:
2014 to catch if destination is gatewayed, rather than
2015 direct. Moreover, if MSG_DONTROUTE is set,
2016 we send packet, ignoring both routing tables
2017 and ifaddr state. --ANK
2018
2019
2020 We could make it even if oif is unknown,
2021 likely IPv6, but we do not.
2022 */
2023
2024 if (fl.fl4_src == 0)
2025 fl.fl4_src = inet_select_addr(dev_out, 0,
2026 RT_SCOPE_LINK);
2027 res.type = RTN_UNICAST;
2028 goto make_route;
2029 }
2030 if (dev_out)
2031 dev_put(dev_out);
2032 err = -ENETUNREACH;
2033 goto out;
2034 }
2035 free_res = 1;
2036
2037 if (res.type == RTN_LOCAL) {
2038 if (!fl.fl4_src)
2039 fl.fl4_src = fl.fl4_dst;
2040 if (dev_out)
2041 dev_put(dev_out);
2042 dev_out = &loopback_dev;
2043 dev_hold(dev_out);
2044 fl.oif = dev_out->ifindex;
2045 if (res.fi)
2046 fib_info_put(res.fi);
2047 res.fi = NULL;
2048 flags |= RTCF_LOCAL;
2049 goto make_route;
2050 }
2051
2052 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2053 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2054 fib_select_multipath(&fl, &res);
2055 else
2056 #endif
2057 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2058 fib_select_default(&fl, &res);
2059
2060 if (!fl.fl4_src)
2061 fl.fl4_src = FIB_RES_PREFSRC(res);
2062
2063 if (dev_out)
2064 dev_put(dev_out);
2065 dev_out = FIB_RES_DEV(res);
2066 dev_hold(dev_out);
2067 fl.oif = dev_out->ifindex;
2068
2069 make_route:
2070 if (LOOPBACK(fl.fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2071 goto e_inval;
2072
2073 if (fl.fl4_dst == 0xFFFFFFFF)
2074 res.type = RTN_BROADCAST;
2075 else if (MULTICAST(fl.fl4_dst))
2076 res.type = RTN_MULTICAST;
2077 else if (BADCLASS(fl.fl4_dst) || ZERONET(fl.fl4_dst))
2078 goto e_inval;
2079
2080 if (dev_out->flags & IFF_LOOPBACK)
2081 flags |= RTCF_LOCAL;
2082
2083 in_dev = in_dev_get(dev_out);
2084 if (!in_dev)
2085 goto e_inval;
2086
2087 if (res.type == RTN_BROADCAST) {
2088 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2089 if (res.fi) {
2090 fib_info_put(res.fi);
2091 res.fi = NULL;
2092 }
2093 } else if (res.type == RTN_MULTICAST) {
2094 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2095 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src, oldflp->proto))
2096 flags &= ~RTCF_LOCAL;
2097 /* If multicast route do not exist use
2098 default one, but do not gateway in this case.
2099 Yes, it is hack.
2100 */
2101 if (res.fi && res.prefixlen < 4) {
2102 fib_info_put(res.fi);
2103 res.fi = NULL;
2104 }
2105 }
2106
2107 rth = dst_alloc(&ipv4_dst_ops);
2108 if (!rth)
2109 goto e_nobufs;
2110
2111 atomic_set(&rth->u.dst.__refcnt, 1);
2112 rth->u.dst.flags= DST_HOST;
2113 if (in_dev->cnf.no_xfrm)
2114 rth->u.dst.flags |= DST_NOXFRM;
2115 if (in_dev->cnf.no_policy)
2116 rth->u.dst.flags |= DST_NOPOLICY;
2117 rth->fl.fl4_dst = oldflp->fl4_dst;
2118 rth->fl.fl4_tos = tos;
2119 rth->fl.fl4_src = oldflp->fl4_src;
2120 rth->fl.oif = oldflp->oif;
2121 #ifdef CONFIG_IP_ROUTE_FWMARK
2122 rth->fl.fl4_fwmark= oldflp->fl4_fwmark;
2123 #endif
2124 rth->rt_dst = fl.fl4_dst;
2125 rth->rt_src = fl.fl4_src;
2126 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2127 rth->u.dst.dev = dev_out;
2128 dev_hold(dev_out);
2129 rth->idev = in_dev_get(dev_out);
2130 rth->rt_gateway = fl.fl4_dst;
2131 rth->rt_spec_dst= fl.fl4_src;
2132
2133 rth->u.dst.output=ip_output;
2134
2135 RT_CACHE_STAT_INC(out_slow_tot);
2136
2137 if (flags & RTCF_LOCAL) {
2138 rth->u.dst.input = ip_local_deliver;
2139 rth->rt_spec_dst = fl.fl4_dst;
2140 }
2141 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2142 rth->rt_spec_dst = fl.fl4_src;
2143 if (flags & RTCF_LOCAL && !(dev_out->flags & IFF_LOOPBACK)) {
2144 rth->u.dst.output = ip_mc_output;
2145 RT_CACHE_STAT_INC(out_slow_mc);
2146 }
2147 #ifdef CONFIG_IP_MROUTE
2148 if (res.type == RTN_MULTICAST) {
2149 if (IN_DEV_MFORWARD(in_dev) &&
2150 !LOCAL_MCAST(oldflp->fl4_dst)) {
2151 rth->u.dst.input = ip_mr_input;
2152 rth->u.dst.output = ip_mc_output;
2153 }
2154 }
2155 #endif
2156 }
2157
2158 rt_set_nexthop(rth, &res, 0);
2159
2160
2161 rth->rt_flags = flags;
2162
2163 hash = rt_hash_code(oldflp->fl4_dst, oldflp->fl4_src ^ (oldflp->oif << 5), tos);
2164 err = rt_intern_hash(hash, rth, rp);
2165 done:
2166 if (free_res)
2167 fib_res_put(&res);
2168 if (dev_out)
2169 dev_put(dev_out);
2170 if (in_dev)
2171 in_dev_put(in_dev);
2172 out: return err;
2173
2174 e_inval:
2175 err = -EINVAL;
2176 goto done;
2177 e_nobufs:
2178 err = -ENOBUFS;
2179 goto done;
2180 }
2181
2182 int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
2183 {
2184 unsigned hash;
2185 struct rtable *rth;
2186
2187 hash = rt_hash_code(flp->fl4_dst, flp->fl4_src ^ (flp->oif << 5), flp->fl4_tos);
2188
2189 rcu_read_lock_bh();
2190 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2191 rth = rcu_dereference(rth->u.rt_next)) {
2192 if (rth->fl.fl4_dst == flp->fl4_dst &&
2193 rth->fl.fl4_src == flp->fl4_src &&
2194 rth->fl.iif == 0 &&
2195 rth->fl.oif == flp->oif &&
2196 #ifdef CONFIG_IP_ROUTE_FWMARK
2197 rth->fl.fl4_fwmark == flp->fl4_fwmark &&
2198 #endif
2199 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2200 (IPTOS_RT_MASK | RTO_ONLINK))) {
2201 rth->u.dst.lastuse = jiffies;
2202 dst_hold(&rth->u.dst);
2203 rth->u.dst.__use++;
2204 RT_CACHE_STAT_INC(out_hit);
2205 rcu_read_unlock_bh();
2206 *rp = rth;
2207 return 0;
2208 }
2209 RT_CACHE_STAT_INC(out_hlist_search);
2210 }
2211 rcu_read_unlock_bh();
2212
2213 return ip_route_output_slow(rp, flp);
2214 }
2215
2216 int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
2217 {
2218 int err;
2219
2220 if ((err = __ip_route_output_key(rp, flp)) != 0)
2221 return err;
2222
2223 if (flp->proto) {
2224 if (!flp->fl4_src)
2225 flp->fl4_src = (*rp)->rt_src;
2226 if (!flp->fl4_dst)
2227 flp->fl4_dst = (*rp)->rt_dst;
2228 return xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
2229 }
2230
2231 return 0;
2232 }
2233
2234 int ip_route_output_key(struct rtable **rp, struct flowi *flp)
2235 {
2236 return ip_route_output_flow(rp, flp, NULL, 0);
2237 }
2238
2239 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2240 int nowait)
2241 {
2242 struct rtable *rt = (struct rtable*)skb->dst;
2243 struct rtmsg *r;
2244 struct nlmsghdr *nlh;
2245 unsigned char *b = skb->tail;
2246 struct rta_cacheinfo ci;
2247 #ifdef CONFIG_IP_MROUTE
2248 struct rtattr *eptr;
2249 #endif
2250 nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*r));
2251 r = NLMSG_DATA(nlh);
2252 nlh->nlmsg_flags = (nowait && pid) ? NLM_F_MULTI : 0;
2253 r->rtm_family = AF_INET;
2254 r->rtm_dst_len = 32;
2255 r->rtm_src_len = 0;
2256 r->rtm_tos = rt->fl.fl4_tos;
2257 r->rtm_table = RT_TABLE_MAIN;
2258 r->rtm_type = rt->rt_type;
2259 r->rtm_scope = RT_SCOPE_UNIVERSE;
2260 r->rtm_protocol = RTPROT_UNSPEC;
2261 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2262 if (rt->rt_flags & RTCF_NOTIFY)
2263 r->rtm_flags |= RTM_F_NOTIFY;
2264 RTA_PUT(skb, RTA_DST, 4, &rt->rt_dst);
2265 if (rt->fl.fl4_src) {
2266 r->rtm_src_len = 32;
2267 RTA_PUT(skb, RTA_SRC, 4, &rt->fl.fl4_src);
2268 }
2269 if (rt->u.dst.dev)
2270 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->u.dst.dev->ifindex);
2271 #ifdef CONFIG_NET_CLS_ROUTE
2272 if (rt->u.dst.tclassid)
2273 RTA_PUT(skb, RTA_FLOW, 4, &rt->u.dst.tclassid);
2274 #endif
2275 if (rt->fl.iif)
2276 RTA_PUT(skb, RTA_PREFSRC, 4, &rt->rt_spec_dst);
2277 else if (rt->rt_src != rt->fl.fl4_src)
2278 RTA_PUT(skb, RTA_PREFSRC, 4, &rt->rt_src);
2279 if (rt->rt_dst != rt->rt_gateway)
2280 RTA_PUT(skb, RTA_GATEWAY, 4, &rt->rt_gateway);
2281 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2282 goto rtattr_failure;
2283 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
2284 ci.rta_used = rt->u.dst.__use;
2285 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
2286 if (rt->u.dst.expires)
2287 ci.rta_expires = jiffies_to_clock_t(rt->u.dst.expires - jiffies);
2288 else
2289 ci.rta_expires = 0;
2290 ci.rta_error = rt->u.dst.error;
2291 ci.rta_id = ci.rta_ts = ci.rta_tsage = 0;
2292 if (rt->peer) {
2293 ci.rta_id = rt->peer->ip_id_count;
2294 if (rt->peer->tcp_ts_stamp) {
2295 ci.rta_ts = rt->peer->tcp_ts;
2296 ci.rta_tsage = xtime.tv_sec - rt->peer->tcp_ts_stamp;
2297 }
2298 }
2299 #ifdef CONFIG_IP_MROUTE
2300 eptr = (struct rtattr*)skb->tail;
2301 #endif
2302 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
2303 if (rt->fl.iif) {
2304 #ifdef CONFIG_IP_MROUTE
2305 u32 dst = rt->rt_dst;
2306
2307 if (MULTICAST(dst) && !LOCAL_MCAST(dst) &&
2308 ipv4_devconf.mc_forwarding) {
2309 int err = ipmr_get_route(skb, r, nowait);
2310 if (err <= 0) {
2311 if (!nowait) {
2312 if (err == 0)
2313 return 0;
2314 goto nlmsg_failure;
2315 } else {
2316 if (err == -EMSGSIZE)
2317 goto nlmsg_failure;
2318 ((struct rta_cacheinfo*)RTA_DATA(eptr))->rta_error = err;
2319 }
2320 }
2321 } else
2322 #endif
2323 RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
2324 }
2325
2326 nlh->nlmsg_len = skb->tail - b;
2327 return skb->len;
2328
2329 nlmsg_failure:
2330 rtattr_failure:
2331 skb_trim(skb, b - skb->data);
2332 return -1;
2333 }
2334
2335 int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2336 {
2337 struct rtattr **rta = arg;
2338 struct rtmsg *rtm = NLMSG_DATA(nlh);
2339 struct rtable *rt = NULL;
2340 u32 dst = 0;
2341 u32 src = 0;
2342 int iif = 0;
2343 int err = -ENOBUFS;
2344 struct sk_buff *skb;
2345
2346 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2347 if (!skb)
2348 goto out;
2349
2350 /* Reserve room for dummy headers, this skb can pass
2351 through good chunk of routing engine.
2352 */
2353 skb->mac.raw = skb->data;
2354 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2355
2356 if (rta[RTA_SRC - 1])
2357 memcpy(&src, RTA_DATA(rta[RTA_SRC - 1]), 4);
2358 if (rta[RTA_DST - 1])
2359 memcpy(&dst, RTA_DATA(rta[RTA_DST - 1]), 4);
2360 if (rta[RTA_IIF - 1])
2361 memcpy(&iif, RTA_DATA(rta[RTA_IIF - 1]), sizeof(int));
2362
2363 if (iif) {
2364 struct net_device *dev = __dev_get_by_index(iif);
2365 err = -ENODEV;
2366 if (!dev)
2367 goto out_free;
2368 skb->protocol = htons(ETH_P_IP);
2369 skb->dev = dev;
2370 local_bh_disable();
2371 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2372 local_bh_enable();
2373 rt = (struct rtable*)skb->dst;
2374 if (!err && rt->u.dst.error)
2375 err = -rt->u.dst.error;
2376 } else {
2377 struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dst,
2378 .saddr = src,
2379 .tos = rtm->rtm_tos } } };
2380 int oif = 0;
2381 if (rta[RTA_OIF - 1])
2382 memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
2383 fl.oif = oif;
2384 err = ip_route_output_key(&rt, &fl);
2385 }
2386 if (err)
2387 goto out_free;
2388
2389 skb->dst = &rt->u.dst;
2390 if (rtm->rtm_flags & RTM_F_NOTIFY)
2391 rt->rt_flags |= RTCF_NOTIFY;
2392
2393 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
2394
2395 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2396 RTM_NEWROUTE, 0);
2397 if (!err)
2398 goto out_free;
2399 if (err < 0) {
2400 err = -EMSGSIZE;
2401 goto out_free;
2402 }
2403
2404 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
2405 if (err > 0)
2406 err = 0;
2407 out: return err;
2408
2409 out_free:
2410 kfree_skb(skb);
2411 goto out;
2412 }
2413
2414 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2415 {
2416 struct rtable *rt;
2417 int h, s_h;
2418 int idx, s_idx;
2419
2420 s_h = cb->args[0];
2421 s_idx = idx = cb->args[1];
2422 for (h = 0; h <= rt_hash_mask; h++) {
2423 if (h < s_h) continue;
2424 if (h > s_h)
2425 s_idx = 0;
2426 rcu_read_lock_bh();
2427 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2428 rt = rcu_dereference(rt->u.rt_next), idx++) {
2429 if (idx < s_idx)
2430 continue;
2431 skb->dst = dst_clone(&rt->u.dst);
2432 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2433 cb->nlh->nlmsg_seq,
2434 RTM_NEWROUTE, 1) <= 0) {
2435 dst_release(xchg(&skb->dst, NULL));
2436 rcu_read_unlock_bh();
2437 goto done;
2438 }
2439 dst_release(xchg(&skb->dst, NULL));
2440 }
2441 rcu_read_unlock_bh();
2442 }
2443
2444 done:
2445 cb->args[0] = h;
2446 cb->args[1] = idx;
2447 return skb->len;
2448 }
2449
2450 void ip_rt_multicast_event(struct in_device *in_dev)
2451 {
2452 rt_cache_flush(0);
2453 }
2454
2455 #ifdef CONFIG_SYSCTL
2456 static int flush_delay;
2457
2458 static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
2459 struct file *filp, void __user *buffer,
2460 size_t *lenp, loff_t *ppos)
2461 {
2462 if (write) {
2463 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2464 rt_cache_flush(flush_delay);
2465 return 0;
2466 }
2467
2468 return -EINVAL;
2469 }
2470
2471 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2472 int __user *name,
2473 int nlen,
2474 void __user *oldval,
2475 size_t __user *oldlenp,
2476 void __user *newval,
2477 size_t newlen,
2478 void **context)
2479 {
2480 int delay;
2481 if (newlen != sizeof(int))
2482 return -EINVAL;
2483 if (get_user(delay, (int __user *)newval))
2484 return -EFAULT;
2485 rt_cache_flush(delay);
2486 return 0;
2487 }
2488
2489 ctl_table ipv4_route_table[] = {
2490 {
2491 .ctl_name = NET_IPV4_ROUTE_FLUSH,
2492 .procname = "flush",
2493 .data = &flush_delay,
2494 .maxlen = sizeof(int),
2495 .mode = 0644,
2496 .proc_handler = &ipv4_sysctl_rtcache_flush,
2497 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
2498 },
2499 {
2500 .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
2501 .procname = "min_delay",
2502 .data = &ip_rt_min_delay,
2503 .maxlen = sizeof(int),
2504 .mode = 0644,
2505 .proc_handler = &proc_dointvec_jiffies,
2506 .strategy = &sysctl_jiffies,
2507 },
2508 {
2509 .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
2510 .procname = "max_delay",
2511 .data = &ip_rt_max_delay,
2512 .maxlen = sizeof(int),
2513 .mode = 0644,
2514 .proc_handler = &proc_dointvec_jiffies,
2515 .strategy = &sysctl_jiffies,
2516 },
2517 {
2518 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2519 .procname = "gc_thresh",
2520 .data = &ipv4_dst_ops.gc_thresh,
2521 .maxlen = sizeof(int),
2522 .mode = 0644,
2523 .proc_handler = &proc_dointvec,
2524 },
2525 {
2526 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
2527 .procname = "max_size",
2528 .data = &ip_rt_max_size,
2529 .maxlen = sizeof(int),
2530 .mode = 0644,
2531 .proc_handler = &proc_dointvec,
2532 },
2533 {
2534 /* Deprecated. Use gc_min_interval_ms */
2535
2536 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
2537 .procname = "gc_min_interval",
2538 .data = &ip_rt_gc_min_interval,
2539 .maxlen = sizeof(int),
2540 .mode = 0644,
2541 .proc_handler = &proc_dointvec_jiffies,
2542 .strategy = &sysctl_jiffies,
2543 },
2544 {
2545 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
2546 .procname = "gc_min_interval_ms",
2547 .data = &ip_rt_gc_min_interval,
2548 .maxlen = sizeof(int),
2549 .mode = 0644,
2550 .proc_handler = &proc_dointvec_ms_jiffies,
2551 .strategy = &sysctl_ms_jiffies,
2552 },
2553 {
2554 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
2555 .procname = "gc_timeout",
2556 .data = &ip_rt_gc_timeout,
2557 .maxlen = sizeof(int),
2558 .mode = 0644,
2559 .proc_handler = &proc_dointvec_jiffies,
2560 .strategy = &sysctl_jiffies,
2561 },
2562 {
2563 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
2564 .procname = "gc_interval",
2565 .data = &ip_rt_gc_interval,
2566 .maxlen = sizeof(int),
2567 .mode = 0644,
2568 .proc_handler = &proc_dointvec_jiffies,
2569 .strategy = &sysctl_jiffies,
2570 },
2571 {
2572 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
2573 .procname = "redirect_load",
2574 .data = &ip_rt_redirect_load,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = &proc_dointvec,
2578 },
2579 {
2580 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
2581 .procname = "redirect_number",
2582 .data = &ip_rt_redirect_number,
2583 .maxlen = sizeof(int),
2584 .mode = 0644,
2585 .proc_handler = &proc_dointvec,
2586 },
2587 {
2588 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
2589 .procname = "redirect_silence",
2590 .data = &ip_rt_redirect_silence,
2591 .maxlen = sizeof(int),
2592 .mode = 0644,
2593 .proc_handler = &proc_dointvec,
2594 },
2595 {
2596 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
2597 .procname = "error_cost",
2598 .data = &ip_rt_error_cost,
2599 .maxlen = sizeof(int),
2600 .mode = 0644,
2601 .proc_handler = &proc_dointvec,
2602 },
2603 {
2604 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
2605 .procname = "error_burst",
2606 .data = &ip_rt_error_burst,
2607 .maxlen = sizeof(int),
2608 .mode = 0644,
2609 .proc_handler = &proc_dointvec,
2610 },
2611 {
2612 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
2613 .procname = "gc_elasticity",
2614 .data = &ip_rt_gc_elasticity,
2615 .maxlen = sizeof(int),
2616 .mode = 0644,
2617 .proc_handler = &proc_dointvec,
2618 },
2619 {
2620 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
2621 .procname = "mtu_expires",
2622 .data = &ip_rt_mtu_expires,
2623 .maxlen = sizeof(int),
2624 .mode = 0644,
2625 .proc_handler = &proc_dointvec_jiffies,
2626 .strategy = &sysctl_jiffies,
2627 },
2628 {
2629 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
2630 .procname = "min_pmtu",
2631 .data = &ip_rt_min_pmtu,
2632 .maxlen = sizeof(int),
2633 .mode = 0644,
2634 .proc_handler = &proc_dointvec,
2635 },
2636 {
2637 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
2638 .procname = "min_adv_mss",
2639 .data = &ip_rt_min_advmss,
2640 .maxlen = sizeof(int),
2641 .mode = 0644,
2642 .proc_handler = &proc_dointvec,
2643 },
2644 {
2645 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
2646 .procname = "secret_interval",
2647 .data = &ip_rt_secret_interval,
2648 .maxlen = sizeof(int),
2649 .mode = 0644,
2650 .proc_handler = &proc_dointvec_jiffies,
2651 .strategy = &sysctl_jiffies,
2652 },
2653 { .ctl_name = 0 }
2654 };
2655 #endif
2656
2657 #ifdef CONFIG_NET_CLS_ROUTE
2658 struct ip_rt_acct *ip_rt_acct;
2659
2660 /* This code sucks. But you should have seen it before! --RR */
2661
2662 /* IP route accounting ptr for this logical cpu number. */
2663 #define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
2664
2665 #ifdef CONFIG_PROC_FS
2666 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
2667 int length, int *eof, void *data)
2668 {
2669 unsigned int i;
2670
2671 if ((offset & 3) || (length & 3))
2672 return -EIO;
2673
2674 if (offset >= sizeof(struct ip_rt_acct) * 256) {
2675 *eof = 1;
2676 return 0;
2677 }
2678
2679 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
2680 length = sizeof(struct ip_rt_acct) * 256 - offset;
2681 *eof = 1;
2682 }
2683
2684 offset /= sizeof(u32);
2685
2686 if (length > 0) {
2687 u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
2688 u32 *dst = (u32 *) buffer;
2689
2690 /* Copy first cpu. */
2691 *start = buffer;
2692 memcpy(dst, src, length);
2693
2694 /* Add the other cpus in, one int at a time */
2695 for_each_cpu(i) {
2696 unsigned int j;
2697
2698 src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
2699
2700 for (j = 0; j < length/4; j++)
2701 dst[j] += src[j];
2702 }
2703 }
2704 return length;
2705 }
2706 #endif /* CONFIG_PROC_FS */
2707 #endif /* CONFIG_NET_CLS_ROUTE */
2708
2709 static __initdata unsigned long rhash_entries;
2710 static int __init set_rhash_entries(char *str)
2711 {
2712 if (!str)
2713 return 0;
2714 rhash_entries = simple_strtoul(str, &str, 0);
2715 return 1;
2716 }
2717 __setup("rhash_entries=", set_rhash_entries);
2718
2719 int __init ip_rt_init(void)
2720 {
2721 int i, order, goal, rc = 0;
2722
2723 rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
2724 (jiffies ^ (jiffies >> 7)));
2725
2726 #ifdef CONFIG_NET_CLS_ROUTE
2727 for (order = 0;
2728 (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
2729 /* NOTHING */;
2730 ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
2731 if (!ip_rt_acct)
2732 panic("IP: failed to allocate ip_rt_acct\n");
2733 memset(ip_rt_acct, 0, PAGE_SIZE << order);
2734 #endif
2735
2736 ipv4_dst_ops.kmem_cachep = kmem_cache_create("ip_dst_cache",
2737 sizeof(struct rtable),
2738 0, SLAB_HWCACHE_ALIGN,
2739 NULL, NULL);
2740
2741 if (!ipv4_dst_ops.kmem_cachep)
2742 panic("IP: failed to allocate ip_dst_cache\n");
2743
2744 goal = num_physpages >> (26 - PAGE_SHIFT);
2745 if (rhash_entries)
2746 goal = (rhash_entries * sizeof(struct rt_hash_bucket)) >> PAGE_SHIFT;
2747 for (order = 0; (1UL << order) < goal; order++)
2748 /* NOTHING */;
2749
2750 do {
2751 rt_hash_mask = (1UL << order) * PAGE_SIZE /
2752 sizeof(struct rt_hash_bucket);
2753 while (rt_hash_mask & (rt_hash_mask - 1))
2754 rt_hash_mask--;
2755 rt_hash_table = (struct rt_hash_bucket *)
2756 __get_free_pages(GFP_ATOMIC, order);
2757 } while (rt_hash_table == NULL && --order > 0);
2758
2759 if (!rt_hash_table)
2760 panic("Failed to allocate IP route cache hash table\n");
2761
2762 printk(KERN_INFO "IP: routing cache hash table of %u buckets, %ldKbytes\n",
2763 rt_hash_mask,
2764 (long) (rt_hash_mask * sizeof(struct rt_hash_bucket)) / 1024);
2765
2766 for (rt_hash_log = 0; (1 << rt_hash_log) != rt_hash_mask; rt_hash_log++)
2767 /* NOTHING */;
2768
2769 rt_hash_mask--;
2770 for (i = 0; i <= rt_hash_mask; i++) {
2771 spin_lock_init(&rt_hash_table[i].lock);
2772 rt_hash_table[i].chain = NULL;
2773 }
2774
2775 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
2776 ip_rt_max_size = (rt_hash_mask + 1) * 16;
2777
2778 rt_cache_stat = alloc_percpu(struct rt_cache_stat);
2779 if (!rt_cache_stat)
2780 return -ENOMEM;
2781
2782 devinet_init();
2783 ip_fib_init();
2784
2785 init_timer(&rt_flush_timer);
2786 rt_flush_timer.function = rt_run_flush;
2787 init_timer(&rt_periodic_timer);
2788 rt_periodic_timer.function = rt_check_expire;
2789 init_timer(&rt_secret_timer);
2790 rt_secret_timer.function = rt_secret_rebuild;
2791
2792 /* All the timers, started at system startup tend
2793 to synchronize. Perturb it a bit.
2794 */
2795 rt_periodic_timer.expires = jiffies + net_random() % ip_rt_gc_interval +
2796 ip_rt_gc_interval;
2797 add_timer(&rt_periodic_timer);
2798
2799 rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
2800 ip_rt_secret_interval;
2801 add_timer(&rt_secret_timer);
2802
2803 #ifdef CONFIG_PROC_FS
2804 {
2805 struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
2806 if (!proc_net_fops_create("rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
2807 !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
2808 proc_net_stat))) {
2809 free_percpu(rt_cache_stat);
2810 return -ENOMEM;
2811 }
2812 rtstat_pde->proc_fops = &rt_cpu_seq_fops;
2813 }
2814 #ifdef CONFIG_NET_CLS_ROUTE
2815 create_proc_read_entry("rt_acct", 0, proc_net, ip_rt_acct_read, NULL);
2816 #endif
2817 #endif
2818 #ifdef CONFIG_XFRM
2819 xfrm_init();
2820 xfrm4_init();
2821 #endif
2822 return rc;
2823 }
2824
2825 EXPORT_SYMBOL(__ip_select_ident);
2826 EXPORT_SYMBOL(ip_route_input);
2827 EXPORT_SYMBOL(ip_route_output_key);
2828
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