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[net-next-2.6.git] / net / ipv4 / route.c
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1da177e4
LT		 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 *
02c30a84 10 * Authors: Ross Biro
1da177e4
LT		 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
bb1d23b0 57 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
cef2685e
IS		 58 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
59 * Ilia Sotnikov : Removed TOS from hash calculations
1da177e4
LT		 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
1da177e4
LT		 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/sched.h>
74#include <linux/mm.h>
424c4b70 75#include <linux/bootmem.h>
1da177e4
LT		 76#include <linux/string.h>
77#include <linux/socket.h>
78#include <linux/sockios.h>
79#include <linux/errno.h>
80#include <linux/in.h>
81#include <linux/inet.h>
82#include <linux/netdevice.h>
83#include <linux/proc_fs.h>
84#include <linux/init.h>
85#include <linux/skbuff.h>
86#include <linux/rtnetlink.h>
87#include <linux/inetdevice.h>
88#include <linux/igmp.h>
89#include <linux/pkt_sched.h>
90#include <linux/mroute.h>
91#include <linux/netfilter_ipv4.h>
92#include <linux/random.h>
93#include <linux/jhash.h>
94#include <linux/rcupdate.h>
95#include <linux/times.h>
96#include <net/protocol.h>
97#include <net/ip.h>
98#include <net/route.h>
99#include <net/inetpeer.h>
100#include <net/sock.h>
101#include <net/ip_fib.h>
102#include <net/arp.h>
103#include <net/tcp.h>
104#include <net/icmp.h>
105#include <net/xfrm.h>
106#include <net/ip_mp_alg.h>
8d71740c 107#include <net/netevent.h>
1da177e4
LT		 108#ifdef CONFIG_SYSCTL
109#include <linux/sysctl.h>
110#endif
111
112#define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114
115#define IP_MAX_MTU 0xFFF0
116
117#define RT_GC_TIMEOUT (300*HZ)
118
119static int ip_rt_min_delay = 2 * HZ;
120static int ip_rt_max_delay = 10 * HZ;
121static int ip_rt_max_size;
122static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
123static int ip_rt_gc_interval = 60 * HZ;
124static int ip_rt_gc_min_interval = HZ / 2;
125static int ip_rt_redirect_number = 9;
126static int ip_rt_redirect_load = HZ / 50;
127static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
128static int ip_rt_error_cost = HZ;
129static int ip_rt_error_burst = 5 * HZ;
130static int ip_rt_gc_elasticity = 8;
131static int ip_rt_mtu_expires = 10 * 60 * HZ;
132static int ip_rt_min_pmtu = 512 + 20 + 20;
133static int ip_rt_min_advmss = 256;
134static int ip_rt_secret_interval = 10 * 60 * HZ;
135static unsigned long rt_deadline;
136
137#define RTprint(a...) printk(KERN_DEBUG a)
138
139static struct timer_list rt_flush_timer;
140static struct timer_list rt_periodic_timer;
141static struct timer_list rt_secret_timer;
142
143/*
144 * Interface to generic destination cache.
145 */
146
147static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
148static void ipv4_dst_destroy(struct dst_entry *dst);
149static void ipv4_dst_ifdown(struct dst_entry *dst,
150 struct net_device *dev, int how);
151static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
152static void ipv4_link_failure(struct sk_buff *skb);
153static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
154static int rt_garbage_collect(void);
155
156
157static struct dst_ops ipv4_dst_ops = {
158 .family = AF_INET,
159 .protocol = __constant_htons(ETH_P_IP),
160 .gc = rt_garbage_collect,
161 .check = ipv4_dst_check,
162 .destroy = ipv4_dst_destroy,
163 .ifdown = ipv4_dst_ifdown,
164 .negative_advice = ipv4_negative_advice,
165 .link_failure = ipv4_link_failure,
166 .update_pmtu = ip_rt_update_pmtu,
167 .entry_size = sizeof(struct rtable),
168};
169
170#define ECN_OR_COST(class) TC_PRIO_##class
171
172__u8 ip_tos2prio[16] = {
173 TC_PRIO_BESTEFFORT,
174 ECN_OR_COST(FILLER),
175 TC_PRIO_BESTEFFORT,
176 ECN_OR_COST(BESTEFFORT),
177 TC_PRIO_BULK,
178 ECN_OR_COST(BULK),
179 TC_PRIO_BULK,
180 ECN_OR_COST(BULK),
181 TC_PRIO_INTERACTIVE,
182 ECN_OR_COST(INTERACTIVE),
183 TC_PRIO_INTERACTIVE,
184 ECN_OR_COST(INTERACTIVE),
185 TC_PRIO_INTERACTIVE_BULK,
186 ECN_OR_COST(INTERACTIVE_BULK),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK)
189};
190
191
192/*
193 * Route cache.
194 */
195
196/* The locking scheme is rather straight forward:
197 *
198 * 1) Read-Copy Update protects the buckets of the central route hash.
199 * 2) Only writers remove entries, and they hold the lock
200 * as they look at rtable reference counts.
201 * 3) Only readers acquire references to rtable entries,
202 * they do so with atomic increments and with the
203 * lock held.
204 */
205
206struct rt_hash_bucket {
207 struct rtable *chain;
22c047cc 208};
8a25d5de
IM		 209#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
210 defined(CONFIG_PROVE_LOCKING)
22c047cc
ED		 211/*
212 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
213 * The size of this table is a power of two and depends on the number of CPUS.
62051200 214 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
22c047cc 215 */
62051200
IM		 216#ifdef CONFIG_LOCKDEP
217# define RT_HASH_LOCK_SZ 256
22c047cc 218#else
62051200
IM		 219# if NR_CPUS >= 32
220# define RT_HASH_LOCK_SZ 4096
221# elif NR_CPUS >= 16
222# define RT_HASH_LOCK_SZ 2048
223# elif NR_CPUS >= 8
224# define RT_HASH_LOCK_SZ 1024
225# elif NR_CPUS >= 4
226# define RT_HASH_LOCK_SZ 512
227# else
228# define RT_HASH_LOCK_SZ 256
229# endif
22c047cc
ED		 230#endif
231
232static spinlock_t *rt_hash_locks;
233# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
234# define rt_hash_lock_init() { \
235 int i; \
236 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, GFP_KERNEL); \
237 if (!rt_hash_locks) panic("IP: failed to allocate rt_hash_locks\n"); \
238 for (i = 0; i < RT_HASH_LOCK_SZ; i++) \
239 spin_lock_init(&rt_hash_locks[i]); \
240 }
241#else
242# define rt_hash_lock_addr(slot) NULL
243# define rt_hash_lock_init()
244#endif
1da177e4
LT		 245
246static struct rt_hash_bucket *rt_hash_table;
247static unsigned rt_hash_mask;
248static int rt_hash_log;
249static unsigned int rt_hash_rnd;
250
2f970d83 251static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
dbd2915c 252#define RT_CACHE_STAT_INC(field) \
bfe5d834 253 (__raw_get_cpu_var(rt_cache_stat).field++)
1da177e4
LT		 254
255static int rt_intern_hash(unsigned hash, struct rtable *rth,
256 struct rtable **res);
257
cef2685e 258static unsigned int rt_hash_code(u32 daddr, u32 saddr)
1da177e4 259{
cef2685e 260 return (jhash_2words(daddr, saddr, rt_hash_rnd)
1da177e4
LT		 261 & rt_hash_mask);
262}
263
8c7bc840
AV		 264#define rt_hash(daddr, saddr, idx) \
265 rt_hash_code((__force u32)(__be32)(daddr),\
266 (__force u32)(__be32)(saddr) ^ ((idx) << 5))
267
1da177e4
LT		 268#ifdef CONFIG_PROC_FS
269struct rt_cache_iter_state {
270 int bucket;
271};
272
273static struct rtable *rt_cache_get_first(struct seq_file *seq)
274{
275 struct rtable *r = NULL;
276 struct rt_cache_iter_state *st = seq->private;
277
278 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
279 rcu_read_lock_bh();
280 r = rt_hash_table[st->bucket].chain;
281 if (r)
282 break;
283 rcu_read_unlock_bh();
284 }
285 return r;
286}
287
288static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
289{
290 struct rt_cache_iter_state *st = rcu_dereference(seq->private);
291
292 r = r->u.rt_next;
293 while (!r) {
294 rcu_read_unlock_bh();
295 if (--st->bucket < 0)
296 break;
297 rcu_read_lock_bh();
298 r = rt_hash_table[st->bucket].chain;
299 }
300 return r;
301}
302
303static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
304{
305 struct rtable *r = rt_cache_get_first(seq);
306
307 if (r)
308 while (pos && (r = rt_cache_get_next(seq, r)))
309 --pos;
310 return pos ? NULL : r;
311}
312
313static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
314{
315 return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
316}
317
318static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
319{
320 struct rtable *r = NULL;
321
322 if (v == SEQ_START_TOKEN)
323 r = rt_cache_get_first(seq);
324 else
325 r = rt_cache_get_next(seq, v);
326 ++*pos;
327 return r;
328}
329
330static void rt_cache_seq_stop(struct seq_file *seq, void *v)
331{
332 if (v && v != SEQ_START_TOKEN)
333 rcu_read_unlock_bh();
334}
335
336static int rt_cache_seq_show(struct seq_file *seq, void *v)
337{
338 if (v == SEQ_START_TOKEN)
339 seq_printf(seq, "%-127s\n",
340 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
341 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
342 "HHUptod\tSpecDst");
343 else {
344 struct rtable *r = v;
345 char temp[256];
346
347 sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
348 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
349 r->u.dst.dev ? r->u.dst.dev->name : "*",
350 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
351 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
352 r->u.dst.__use, 0, (unsigned long)r->rt_src,
353 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
354 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
355 dst_metric(&r->u.dst, RTAX_WINDOW),
356 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
357 dst_metric(&r->u.dst, RTAX_RTTVAR)),
358 r->fl.fl4_tos,
359 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
360 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
361 dev_queue_xmit) : 0,
362 r->rt_spec_dst);
363 seq_printf(seq, "%-127s\n", temp);
364 }
365 return 0;
366}
367
368static struct seq_operations rt_cache_seq_ops = {
369 .start = rt_cache_seq_start,
370 .next = rt_cache_seq_next,
371 .stop = rt_cache_seq_stop,
372 .show = rt_cache_seq_show,
373};
374
375static int rt_cache_seq_open(struct inode *inode, struct file *file)
376{
377 struct seq_file *seq;
378 int rc = -ENOMEM;
379 struct rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
380
381 if (!s)
382 goto out;
383 rc = seq_open(file, &rt_cache_seq_ops);
384 if (rc)
385 goto out_kfree;
386 seq = file->private_data;
387 seq->private = s;
388 memset(s, 0, sizeof(*s));
389out:
390 return rc;
391out_kfree:
392 kfree(s);
393 goto out;
394}
395
396static struct file_operations rt_cache_seq_fops = {
397 .owner = THIS_MODULE,
398 .open = rt_cache_seq_open,
399 .read = seq_read,
400 .llseek = seq_lseek,
401 .release = seq_release_private,
402};
403
404
405static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
406{
407 int cpu;
408
409 if (*pos == 0)
410 return SEQ_START_TOKEN;
411
412 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
413 if (!cpu_possible(cpu))
414 continue;
415 *pos = cpu+1;
2f970d83 416 return &per_cpu(rt_cache_stat, cpu);
1da177e4
LT		 417 }
418 return NULL;
419}
420
421static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
422{
423 int cpu;
424
425 for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
426 if (!cpu_possible(cpu))
427 continue;
428 *pos = cpu+1;
2f970d83 429 return &per_cpu(rt_cache_stat, cpu);
1da177e4
LT		 430 }
431 return NULL;
432
433}
434
435static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
436{
437
438}
439
440static int rt_cpu_seq_show(struct seq_file *seq, void *v)
441{
442 struct rt_cache_stat *st = v;
443
444 if (v == SEQ_START_TOKEN) {
5bec0039 445 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");
1da177e4
LT		 446 return 0;
447 }
448
449 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
450 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
451 atomic_read(&ipv4_dst_ops.entries),
452 st->in_hit,
453 st->in_slow_tot,
454 st->in_slow_mc,
455 st->in_no_route,
456 st->in_brd,
457 st->in_martian_dst,
458 st->in_martian_src,
459
460 st->out_hit,
461 st->out_slow_tot,
462 st->out_slow_mc,
463
464 st->gc_total,
465 st->gc_ignored,
466 st->gc_goal_miss,
467 st->gc_dst_overflow,
468 st->in_hlist_search,
469 st->out_hlist_search
470 );
471 return 0;
472}
473
474static struct seq_operations rt_cpu_seq_ops = {
475 .start = rt_cpu_seq_start,
476 .next = rt_cpu_seq_next,
477 .stop = rt_cpu_seq_stop,
478 .show = rt_cpu_seq_show,
479};
480
481
482static int rt_cpu_seq_open(struct inode *inode, struct file *file)
483{
484 return seq_open(file, &rt_cpu_seq_ops);
485}
486
487static struct file_operations rt_cpu_seq_fops = {
488 .owner = THIS_MODULE,
489 .open = rt_cpu_seq_open,
490 .read = seq_read,
491 .llseek = seq_lseek,
492 .release = seq_release,
493};
494
495#endif /* CONFIG_PROC_FS */
496
497static __inline__ void rt_free(struct rtable *rt)
498{
499 multipath_remove(rt);
500 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
501}
502
503static __inline__ void rt_drop(struct rtable *rt)
504{
505 multipath_remove(rt);
506 ip_rt_put(rt);
507 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
508}
509
510static __inline__ int rt_fast_clean(struct rtable *rth)
511{
512 /* Kill broadcast/multicast entries very aggresively, if they
513 collide in hash table with more useful entries */
514 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
515 rth->fl.iif && rth->u.rt_next;
516}
517
518static __inline__ int rt_valuable(struct rtable *rth)
519{
520 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
521 rth->u.dst.expires;
522}
523
524static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
525{
526 unsigned long age;
527 int ret = 0;
528
529 if (atomic_read(&rth->u.dst.__refcnt))
530 goto out;
531
532 ret = 1;
533 if (rth->u.dst.expires &&
534 time_after_eq(jiffies, rth->u.dst.expires))
535 goto out;
536
537 age = jiffies - rth->u.dst.lastuse;
538 ret = 0;
539 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
540 (age <= tmo2 && rt_valuable(rth)))
541 goto out;
542 ret = 1;
543out: return ret;
544}
545
546/* Bits of score are:
547 * 31: very valuable
548 * 30: not quite useless
549 * 29..0: usage counter
550 */
551static inline u32 rt_score(struct rtable *rt)
552{
553 u32 score = jiffies - rt->u.dst.lastuse;
554
555 score = ~score & ~(3<<30);
556
557 if (rt_valuable(rt))
558 score |= (1<<31);
559
560 if (!rt->fl.iif ||
561 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
562 score |= (1<<30);
563
564 return score;
565}
566
567static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
568{
8238b218
DM		 569 return ((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
570 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) |
571#ifdef CONFIG_IP_ROUTE_FWMARK
572 (fl1->nl_u.ip4_u.fwmark ^ fl2->nl_u.ip4_u.fwmark) |
573#endif
574 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
575 *(u16 *)&fl2->nl_u.ip4_u.tos) |
576 (fl1->oif ^ fl2->oif) |
577 (fl1->iif ^ fl2->iif)) == 0;
1da177e4
LT		 578}
579
580#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
581static struct rtable **rt_remove_balanced_route(struct rtable **chain_head,
582 struct rtable *expentry,
583 int *removed_count)
584{
585 int passedexpired = 0;
586 struct rtable **nextstep = NULL;
587 struct rtable **rthp = chain_head;
588 struct rtable *rth;
589
590 if (removed_count)
591 *removed_count = 0;
592
593 while ((rth = *rthp) != NULL) {
594 if (rth == expentry)
595 passedexpired = 1;
596
597 if (((*rthp)->u.dst.flags & DST_BALANCED) != 0 &&
598 compare_keys(&(*rthp)->fl, &expentry->fl)) {
599 if (*rthp == expentry) {
600 *rthp = rth->u.rt_next;
601 continue;
602 } else {
603 *rthp = rth->u.rt_next;
604 rt_free(rth);
605 if (removed_count)
606 ++(*removed_count);
607 }
608 } else {
609 if (!((*rthp)->u.dst.flags & DST_BALANCED) &&
610 passedexpired && !nextstep)
611 nextstep = &rth->u.rt_next;
612
613 rthp = &rth->u.rt_next;
614 }
615 }
616
617 rt_free(expentry);
618 if (removed_count)
619 ++(*removed_count);
620
621 return nextstep;
622}
623#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
624
625
626/* This runs via a timer and thus is always in BH context. */
627static void rt_check_expire(unsigned long dummy)
628{
bb1d23b0
ED		 629 static unsigned int rover;
630 unsigned int i = rover, goal;
1da177e4
LT		 631 struct rtable *rth, **rthp;
632 unsigned long now = jiffies;
bb1d23b0
ED		 633 u64 mult;
634
635 mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
636 if (ip_rt_gc_timeout > 1)
637 do_div(mult, ip_rt_gc_timeout);
638 goal = (unsigned int)mult;
639 if (goal > rt_hash_mask) goal = rt_hash_mask + 1;
640 for (; goal > 0; goal--) {
1da177e4
LT		 641 unsigned long tmo = ip_rt_gc_timeout;
642
643 i = (i + 1) & rt_hash_mask;
644 rthp = &rt_hash_table[i].chain;
645
bb1d23b0
ED		 646 if (*rthp == 0)
647 continue;
22c047cc 648 spin_lock(rt_hash_lock_addr(i));
1da177e4
LT		 649 while ((rth = *rthp) != NULL) {
650 if (rth->u.dst.expires) {
651 /* Entry is expired even if it is in use */
652 if (time_before_eq(now, rth->u.dst.expires)) {
653 tmo >>= 1;
654 rthp = &rth->u.rt_next;
655 continue;
656 }
657 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
658 tmo >>= 1;
659 rthp = &rth->u.rt_next;
660 continue;
661 }
662
663 /* Cleanup aged off entries. */
664#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
665 /* remove all related balanced entries if necessary */
666 if (rth->u.dst.flags & DST_BALANCED) {
667 rthp = rt_remove_balanced_route(
668 &rt_hash_table[i].chain,
669 rth, NULL);
670 if (!rthp)
671 break;
672 } else {
673 *rthp = rth->u.rt_next;
674 rt_free(rth);
675 }
676#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
677 *rthp = rth->u.rt_next;
678 rt_free(rth);
679#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
680 }
22c047cc 681 spin_unlock(rt_hash_lock_addr(i));
1da177e4
LT		 682
683 /* Fallback loop breaker. */
684 if (time_after(jiffies, now))
685 break;
686 }
687 rover = i;
bb1d23b0 688 mod_timer(&rt_periodic_timer, jiffies + ip_rt_gc_interval);
1da177e4
LT		 689}
690
691/* This can run from both BH and non-BH contexts, the latter
692 * in the case of a forced flush event.
693 */
694static void rt_run_flush(unsigned long dummy)
695{
696 int i;
697 struct rtable *rth, *next;
698
699 rt_deadline = 0;
700
701 get_random_bytes(&rt_hash_rnd, 4);
702
703 for (i = rt_hash_mask; i >= 0; i--) {
22c047cc 704 spin_lock_bh(rt_hash_lock_addr(i));
1da177e4
LT		 705 rth = rt_hash_table[i].chain;
706 if (rth)
707 rt_hash_table[i].chain = NULL;
22c047cc 708 spin_unlock_bh(rt_hash_lock_addr(i));
1da177e4
LT		 709
710 for (; rth; rth = next) {
711 next = rth->u.rt_next;
712 rt_free(rth);
713 }
714 }
715}
716
717static DEFINE_SPINLOCK(rt_flush_lock);
718
719void rt_cache_flush(int delay)
720{
721 unsigned long now = jiffies;
722 int user_mode = !in_softirq();
723
724 if (delay < 0)
725 delay = ip_rt_min_delay;
726
727 /* flush existing multipath state*/
728 multipath_flush();
729
730 spin_lock_bh(&rt_flush_lock);
731
732 if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
733 long tmo = (long)(rt_deadline - now);
734
735 /* If flush timer is already running
736 and flush request is not immediate (delay > 0):
737
738 if deadline is not achieved, prolongate timer to "delay",
739 otherwise fire it at deadline time.
740 */
741
742 if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
743 tmo = 0;
744
745 if (delay > tmo)
746 delay = tmo;
747 }
748
749 if (delay <= 0) {
750 spin_unlock_bh(&rt_flush_lock);
751 rt_run_flush(0);
752 return;
753 }
754
755 if (rt_deadline == 0)
756 rt_deadline = now + ip_rt_max_delay;
757
758 mod_timer(&rt_flush_timer, now+delay);
759 spin_unlock_bh(&rt_flush_lock);
760}
761
762static void rt_secret_rebuild(unsigned long dummy)
763{
764 unsigned long now = jiffies;
765
766 rt_cache_flush(0);
767 mod_timer(&rt_secret_timer, now + ip_rt_secret_interval);
768}
769
770/*
771 Short description of GC goals.
772
773 We want to build algorithm, which will keep routing cache
774 at some equilibrium point, when number of aged off entries
775 is kept approximately equal to newly generated ones.
776
777 Current expiration strength is variable "expire".
778 We try to adjust it dynamically, so that if networking
779 is idle expires is large enough to keep enough of warm entries,
780 and when load increases it reduces to limit cache size.
781 */
782
783static int rt_garbage_collect(void)
784{
785 static unsigned long expire = RT_GC_TIMEOUT;
786 static unsigned long last_gc;
787 static int rover;
788 static int equilibrium;
789 struct rtable *rth, **rthp;
790 unsigned long now = jiffies;
791 int goal;
792
793 /*
794 * Garbage collection is pretty expensive,
795 * do not make it too frequently.
796 */
797
798 RT_CACHE_STAT_INC(gc_total);
799
800 if (now - last_gc < ip_rt_gc_min_interval &&
801 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
802 RT_CACHE_STAT_INC(gc_ignored);
803 goto out;
804 }
805
806 /* Calculate number of entries, which we want to expire now. */
807 goal = atomic_read(&ipv4_dst_ops.entries) -
808 (ip_rt_gc_elasticity << rt_hash_log);
809 if (goal <= 0) {
810 if (equilibrium < ipv4_dst_ops.gc_thresh)
811 equilibrium = ipv4_dst_ops.gc_thresh;
812 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
813 if (goal > 0) {
814 equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
815 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
816 }
817 } else {
818 /* We are in dangerous area. Try to reduce cache really
819 * aggressively.
820 */
821 goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
822 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
823 }
824
825 if (now - last_gc >= ip_rt_gc_min_interval)
826 last_gc = now;
827
828 if (goal <= 0) {
829 equilibrium += goal;
830 goto work_done;
831 }
832
833 do {
834 int i, k;
835
836 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
837 unsigned long tmo = expire;
838
839 k = (k + 1) & rt_hash_mask;
840 rthp = &rt_hash_table[k].chain;
22c047cc 841 spin_lock_bh(rt_hash_lock_addr(k));
1da177e4
LT		 842 while ((rth = *rthp) != NULL) {
843 if (!rt_may_expire(rth, tmo, expire)) {
844 tmo >>= 1;
845 rthp = &rth->u.rt_next;
846 continue;
847 }
848#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
849 /* remove all related balanced entries
850 * if necessary
851 */
852 if (rth->u.dst.flags & DST_BALANCED) {
853 int r;
854
855 rthp = rt_remove_balanced_route(
85259878 856 &rt_hash_table[k].chain,
1da177e4
LT		 857 rth,
858 &r);
859 goal -= r;
860 if (!rthp)
861 break;
862 } else {
863 *rthp = rth->u.rt_next;
864 rt_free(rth);
865 goal--;
866 }
867#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
868 *rthp = rth->u.rt_next;
869 rt_free(rth);
870 goal--;
871#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
872 }
22c047cc 873 spin_unlock_bh(rt_hash_lock_addr(k));
1da177e4
LT		 874 if (goal <= 0)
875 break;
876 }
877 rover = k;
878
879 if (goal <= 0)
880 goto work_done;
881
882 /* Goal is not achieved. We stop process if:
883
884 - if expire reduced to zero. Otherwise, expire is halfed.
885 - if table is not full.
886 - if we are called from interrupt.
887 - jiffies check is just fallback/debug loop breaker.
888 We will not spin here for long time in any case.
889 */
890
891 RT_CACHE_STAT_INC(gc_goal_miss);
892
893 if (expire == 0)
894 break;
895
896 expire >>= 1;
897#if RT_CACHE_DEBUG >= 2
898 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
899 atomic_read(&ipv4_dst_ops.entries), goal, i);
900#endif
901
902 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
903 goto out;
904 } while (!in_softirq() && time_before_eq(jiffies, now));
905
906 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
907 goto out;
908 if (net_ratelimit())
909 printk(KERN_WARNING "dst cache overflow\n");
910 RT_CACHE_STAT_INC(gc_dst_overflow);
911 return 1;
912
913work_done:
914 expire += ip_rt_gc_min_interval;
915 if (expire > ip_rt_gc_timeout ||
916 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
917 expire = ip_rt_gc_timeout;
918#if RT_CACHE_DEBUG >= 2
919 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
920 atomic_read(&ipv4_dst_ops.entries), goal, rover);
921#endif
922out: return 0;
923}
924
925static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
926{
927 struct rtable *rth, **rthp;
928 unsigned long now;
929 struct rtable *cand, **candp;
930 u32 min_score;
931 int chain_length;
932 int attempts = !in_softirq();
933
934restart:
935 chain_length = 0;
936 min_score = ~(u32)0;
937 cand = NULL;
938 candp = NULL;
939 now = jiffies;
940
941 rthp = &rt_hash_table[hash].chain;
942
22c047cc 943 spin_lock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 944 while ((rth = *rthp) != NULL) {
945#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
946 if (!(rth->u.dst.flags & DST_BALANCED) &&
947 compare_keys(&rth->fl, &rt->fl)) {
948#else
949 if (compare_keys(&rth->fl, &rt->fl)) {
950#endif
951 /* Put it first */
952 *rthp = rth->u.rt_next;
953 /*
954 * Since lookup is lockfree, the deletion
955 * must be visible to another weakly ordered CPU before
956 * the insertion at the start of the hash chain.
957 */
958 rcu_assign_pointer(rth->u.rt_next,
959 rt_hash_table[hash].chain);
960 /*
961 * Since lookup is lockfree, the update writes
962 * must be ordered for consistency on SMP.
963 */
964 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
965
966 rth->u.dst.__use++;
967 dst_hold(&rth->u.dst);
968 rth->u.dst.lastuse = now;
22c047cc 969 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 970
971 rt_drop(rt);
972 *rp = rth;
973 return 0;
974 }
975
976 if (!atomic_read(&rth->u.dst.__refcnt)) {
977 u32 score = rt_score(rth);
978
979 if (score <= min_score) {
980 cand = rth;
981 candp = rthp;
982 min_score = score;
983 }
984 }
985
986 chain_length++;
987
988 rthp = &rth->u.rt_next;
989 }
990
991 if (cand) {
992 /* ip_rt_gc_elasticity used to be average length of chain
993 * length, when exceeded gc becomes really aggressive.
994 *
995 * The second limit is less certain. At the moment it allows
996 * only 2 entries per bucket. We will see.
997 */
998 if (chain_length > ip_rt_gc_elasticity) {
999 *candp = cand->u.rt_next;
1000 rt_free(cand);
1001 }
1002 }
1003
1004 /* Try to bind route to arp only if it is output
1005 route or unicast forwarding path.
1006 */
1007 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1008 int err = arp_bind_neighbour(&rt->u.dst);
1009 if (err) {
22c047cc 1010 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1011
1012 if (err != -ENOBUFS) {
1013 rt_drop(rt);
1014 return err;
1015 }
1016
1017 /* Neighbour tables are full and nothing
1018 can be released. Try to shrink route cache,
1019 it is most likely it holds some neighbour records.
1020 */
1021 if (attempts-- > 0) {
1022 int saved_elasticity = ip_rt_gc_elasticity;
1023 int saved_int = ip_rt_gc_min_interval;
1024 ip_rt_gc_elasticity = 1;
1025 ip_rt_gc_min_interval = 0;
1026 rt_garbage_collect();
1027 ip_rt_gc_min_interval = saved_int;
1028 ip_rt_gc_elasticity = saved_elasticity;
1029 goto restart;
1030 }
1031
1032 if (net_ratelimit())
1033 printk(KERN_WARNING "Neighbour table overflow.\n");
1034 rt_drop(rt);
1035 return -ENOBUFS;
1036 }
1037 }
1038
1039 rt->u.rt_next = rt_hash_table[hash].chain;
1040#if RT_CACHE_DEBUG >= 2
1041 if (rt->u.rt_next) {
1042 struct rtable *trt;
1043 printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
1044 NIPQUAD(rt->rt_dst));
1045 for (trt = rt->u.rt_next; trt; trt = trt->u.rt_next)
1046 printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
1047 printk("\n");
1048 }
1049#endif
1050 rt_hash_table[hash].chain = rt;
22c047cc 1051 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1052 *rp = rt;
1053 return 0;
1054}
1055
1056void rt_bind_peer(struct rtable *rt, int create)
1057{
1058 static DEFINE_SPINLOCK(rt_peer_lock);
1059 struct inet_peer *peer;
1060
1061 peer = inet_getpeer(rt->rt_dst, create);
1062
1063 spin_lock_bh(&rt_peer_lock);
1064 if (rt->peer == NULL) {
1065 rt->peer = peer;
1066 peer = NULL;
1067 }
1068 spin_unlock_bh(&rt_peer_lock);
1069 if (peer)
1070 inet_putpeer(peer);
1071}
1072
1073/*
1074 * Peer allocation may fail only in serious out-of-memory conditions. However
1075 * we still can generate some output.
1076 * Random ID selection looks a bit dangerous because we have no chances to
1077 * select ID being unique in a reasonable period of time.
1078 * But broken packet identifier may be better than no packet at all.
1079 */
1080static void ip_select_fb_ident(struct iphdr *iph)
1081{
1082 static DEFINE_SPINLOCK(ip_fb_id_lock);
1083 static u32 ip_fallback_id;
1084 u32 salt;
1085
1086 spin_lock_bh(&ip_fb_id_lock);
e448515c 1087 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1da177e4
LT		 1088 iph->id = htons(salt & 0xFFFF);
1089 ip_fallback_id = salt;
1090 spin_unlock_bh(&ip_fb_id_lock);
1091}
1092
1093void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1094{
1095 struct rtable *rt = (struct rtable *) dst;
1096
1097 if (rt) {
1098 if (rt->peer == NULL)
1099 rt_bind_peer(rt, 1);
1100
1101 /* If peer is attached to destination, it is never detached,
1102 so that we need not to grab a lock to dereference it.
1103 */
1104 if (rt->peer) {
1105 iph->id = htons(inet_getid(rt->peer, more));
1106 return;
1107 }
1108 } else
9c2b3328
SH		 1109 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1110 __builtin_return_address(0));
1da177e4
LT		 1111
1112 ip_select_fb_ident(iph);
1113}
1114
1115static void rt_del(unsigned hash, struct rtable *rt)
1116{
1117 struct rtable **rthp;
1118
22c047cc 1119 spin_lock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1120 ip_rt_put(rt);
1121 for (rthp = &rt_hash_table[hash].chain; *rthp;
1122 rthp = &(*rthp)->u.rt_next)
1123 if (*rthp == rt) {
1124 *rthp = rt->u.rt_next;
1125 rt_free(rt);
1126 break;
1127 }
22c047cc 1128 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1129}
1130
f7655229
AV		 1131void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1132 __be32 saddr, struct net_device *dev)
1da177e4
LT		 1133{
1134 int i, k;
1135 struct in_device *in_dev = in_dev_get(dev);
1136 struct rtable *rth, **rthp;
f7655229 1137 __be32 skeys[2] = { saddr, 0 };
1da177e4 1138 int ikeys[2] = { dev->ifindex, 0 };
8d71740c 1139 struct netevent_redirect netevent;
1da177e4 1140
1da177e4
LT		 1141 if (!in_dev)
1142 return;
1143
1144 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1145 || MULTICAST(new_gw) || BADCLASS(new_gw) || ZERONET(new_gw))
1146 goto reject_redirect;
1147
1148 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1149 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1150 goto reject_redirect;
1151 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1152 goto reject_redirect;
1153 } else {
1154 if (inet_addr_type(new_gw) != RTN_UNICAST)
1155 goto reject_redirect;
1156 }
1157
1158 for (i = 0; i < 2; i++) {
1159 for (k = 0; k < 2; k++) {
8c7bc840 1160 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
1da177e4
LT		 1161
1162 rthp=&rt_hash_table[hash].chain;
1163
1164 rcu_read_lock();
1165 while ((rth = rcu_dereference(*rthp)) != NULL) {
1166 struct rtable *rt;
1167
1168 if (rth->fl.fl4_dst != daddr ||
1169 rth->fl.fl4_src != skeys[i] ||
1da177e4
LT		 1170 rth->fl.oif != ikeys[k] ||
1171 rth->fl.iif != 0) {
1172 rthp = &rth->u.rt_next;
1173 continue;
1174 }
1175
1176 if (rth->rt_dst != daddr ||
1177 rth->rt_src != saddr ||
1178 rth->u.dst.error ||
1179 rth->rt_gateway != old_gw ||
1180 rth->u.dst.dev != dev)
1181 break;
1182
1183 dst_hold(&rth->u.dst);
1184 rcu_read_unlock();
1185
1186 rt = dst_alloc(&ipv4_dst_ops);
1187 if (rt == NULL) {
1188 ip_rt_put(rth);
1189 in_dev_put(in_dev);
1190 return;
1191 }
1192
1193 /* Copy all the information. */
1194 *rt = *rth;
1195 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1196 rt->u.dst.__use = 1;
1197 atomic_set(&rt->u.dst.__refcnt, 1);
1198 rt->u.dst.child = NULL;
1199 if (rt->u.dst.dev)
1200 dev_hold(rt->u.dst.dev);
1201 if (rt->idev)
1202 in_dev_hold(rt->idev);
1203 rt->u.dst.obsolete = 0;
1204 rt->u.dst.lastuse = jiffies;
1205 rt->u.dst.path = &rt->u.dst;
1206 rt->u.dst.neighbour = NULL;
1207 rt->u.dst.hh = NULL;
1208 rt->u.dst.xfrm = NULL;
1209
1210 rt->rt_flags |= RTCF_REDIRECTED;
1211
1212 /* Gateway is different ... */
1213 rt->rt_gateway = new_gw;
1214
1215 /* Redirect received -> path was valid */
1216 dst_confirm(&rth->u.dst);
1217
1218 if (rt->peer)
1219 atomic_inc(&rt->peer->refcnt);
1220
1221 if (arp_bind_neighbour(&rt->u.dst) ||
1222 !(rt->u.dst.neighbour->nud_state &
1223 NUD_VALID)) {
1224 if (rt->u.dst.neighbour)
1225 neigh_event_send(rt->u.dst.neighbour, NULL);
1226 ip_rt_put(rth);
1227 rt_drop(rt);
1228 goto do_next;
1229 }
8d71740c
TT		 1230
1231 netevent.old = &rth->u.dst;
1232 netevent.new = &rt->u.dst;
1233 call_netevent_notifiers(NETEVENT_REDIRECT,
1234 &netevent);
1da177e4
LT		 1235
1236 rt_del(hash, rth);
1237 if (!rt_intern_hash(hash, rt, &rt))
1238 ip_rt_put(rt);
1239 goto do_next;
1240 }
1241 rcu_read_unlock();
1242 do_next:
1243 ;
1244 }
1245 }
1246 in_dev_put(in_dev);
1247 return;
1248
1249reject_redirect:
1250#ifdef CONFIG_IP_ROUTE_VERBOSE
1251 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1252 printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
1253 "%u.%u.%u.%u ignored.\n"
cef2685e 1254 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n",
1da177e4 1255 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
cef2685e 1256 NIPQUAD(saddr), NIPQUAD(daddr));
1da177e4
LT		 1257#endif
1258 in_dev_put(in_dev);
1259}
1260
1261static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1262{
1263 struct rtable *rt = (struct rtable*)dst;
1264 struct dst_entry *ret = dst;
1265
1266 if (rt) {
1267 if (dst->obsolete) {
1268 ip_rt_put(rt);
1269 ret = NULL;
1270 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1271 rt->u.dst.expires) {
8c7bc840
AV		 1272 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1273 rt->fl.oif);
1da177e4
LT		 1274#if RT_CACHE_DEBUG >= 1
1275 printk(KERN_DEBUG "ip_rt_advice: redirect to "
1276 "%u.%u.%u.%u/%02x dropped\n",
1277 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1278#endif
1279 rt_del(hash, rt);
1280 ret = NULL;
1281 }
1282 }
1283 return ret;
1284}
1285
1286/*
1287 * Algorithm:
1288 * 1. The first ip_rt_redirect_number redirects are sent
1289 * with exponential backoff, then we stop sending them at all,
1290 * assuming that the host ignores our redirects.
1291 * 2. If we did not see packets requiring redirects
1292 * during ip_rt_redirect_silence, we assume that the host
1293 * forgot redirected route and start to send redirects again.
1294 *
1295 * This algorithm is much cheaper and more intelligent than dumb load limiting
1296 * in icmp.c.
1297 *
1298 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1299 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1300 */
1301
1302void ip_rt_send_redirect(struct sk_buff *skb)
1303{
1304 struct rtable *rt = (struct rtable*)skb->dst;
1305 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1306
1307 if (!in_dev)
1308 return;
1309
1310 if (!IN_DEV_TX_REDIRECTS(in_dev))
1311 goto out;
1312
1313 /* No redirected packets during ip_rt_redirect_silence;
1314 * reset the algorithm.
1315 */
1316 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1317 rt->u.dst.rate_tokens = 0;
1318
1319 /* Too many ignored redirects; do not send anything
1320 * set u.dst.rate_last to the last seen redirected packet.
1321 */
1322 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1323 rt->u.dst.rate_last = jiffies;
1324 goto out;
1325 }
1326
1327 /* Check for load limit; set rate_last to the latest sent
1328 * redirect.
1329 */
1330 if (time_after(jiffies,
1331 (rt->u.dst.rate_last +
1332 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1333 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1334 rt->u.dst.rate_last = jiffies;
1335 ++rt->u.dst.rate_tokens;
1336#ifdef CONFIG_IP_ROUTE_VERBOSE
1337 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1338 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1339 net_ratelimit())
1340 printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
1341 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1342 NIPQUAD(rt->rt_src), rt->rt_iif,
1343 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1344#endif
1345 }
1346out:
1347 in_dev_put(in_dev);
1348}
1349
1350static int ip_error(struct sk_buff *skb)
1351{
1352 struct rtable *rt = (struct rtable*)skb->dst;
1353 unsigned long now;
1354 int code;
1355
1356 switch (rt->u.dst.error) {
1357 case EINVAL:
1358 default:
1359 goto out;
1360 case EHOSTUNREACH:
1361 code = ICMP_HOST_UNREACH;
1362 break;
1363 case ENETUNREACH:
1364 code = ICMP_NET_UNREACH;
1365 break;
1366 case EACCES:
1367 code = ICMP_PKT_FILTERED;
1368 break;
1369 }
1370
1371 now = jiffies;
1372 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1373 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1374 rt->u.dst.rate_tokens = ip_rt_error_burst;
1375 rt->u.dst.rate_last = now;
1376 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1377 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1378 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1379 }
1380
1381out: kfree_skb(skb);
1382 return 0;
1383}
1384
1385/*
1386 * The last two values are not from the RFC but
1387 * are needed for AMPRnet AX.25 paths.
1388 */
1389
9b5b5cff 1390static const unsigned short mtu_plateau[] =
1da177e4
LT		 1391{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1392
1393static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
1394{
1395 int i;
1396
1397 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1398 if (old_mtu > mtu_plateau[i])
1399 return mtu_plateau[i];
1400 return 68;
1401}
1402
1403unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
1404{
1405 int i;
1406 unsigned short old_mtu = ntohs(iph->tot_len);
1407 struct rtable *rth;
e448515c
AV		 1408 __be32 skeys[2] = { iph->saddr, 0, };
1409 __be32 daddr = iph->daddr;
1da177e4
LT		 1410 unsigned short est_mtu = 0;
1411
1412 if (ipv4_config.no_pmtu_disc)
1413 return 0;
1414
1415 for (i = 0; i < 2; i++) {
8c7bc840 1416 unsigned hash = rt_hash(daddr, skeys[i], 0);
1da177e4
LT		 1417
1418 rcu_read_lock();
1419 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1420 rth = rcu_dereference(rth->u.rt_next)) {
1421 if (rth->fl.fl4_dst == daddr &&
1422 rth->fl.fl4_src == skeys[i] &&
1423 rth->rt_dst == daddr &&
1424 rth->rt_src == iph->saddr &&
1da177e4
LT		 1425 rth->fl.iif == 0 &&
1426 !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
1427 unsigned short mtu = new_mtu;
1428
1429 if (new_mtu < 68 || new_mtu >= old_mtu) {
1430
1431 /* BSD 4.2 compatibility hack :-( */
1432 if (mtu == 0 &&
1433 old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
1434 old_mtu >= 68 + (iph->ihl << 2))
1435 old_mtu -= iph->ihl << 2;
1436
1437 mtu = guess_mtu(old_mtu);
1438 }
1439 if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1440 if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
1441 dst_confirm(&rth->u.dst);
1442 if (mtu < ip_rt_min_pmtu) {
1443 mtu = ip_rt_min_pmtu;
1444 rth->u.dst.metrics[RTAX_LOCK-1] |=
1445 (1 << RTAX_MTU);
1446 }
1447 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1448 dst_set_expires(&rth->u.dst,
1449 ip_rt_mtu_expires);
1450 }
1451 est_mtu = mtu;
1452 }
1453 }
1454 }
1455 rcu_read_unlock();
1456 }
1457 return est_mtu ? : new_mtu;
1458}
1459
1460static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1461{
1462 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
1463 !(dst_metric_locked(dst, RTAX_MTU))) {
1464 if (mtu < ip_rt_min_pmtu) {
1465 mtu = ip_rt_min_pmtu;
1466 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1467 }
1468 dst->metrics[RTAX_MTU-1] = mtu;
1469 dst_set_expires(dst, ip_rt_mtu_expires);
8d71740c 1470 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1da177e4
LT		 1471 }
1472}
1473
1474static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1475{
1476 return NULL;
1477}
1478
1479static void ipv4_dst_destroy(struct dst_entry *dst)
1480{
1481 struct rtable *rt = (struct rtable *) dst;
1482 struct inet_peer *peer = rt->peer;
1483 struct in_device *idev = rt->idev;
1484
1485 if (peer) {
1486 rt->peer = NULL;
1487 inet_putpeer(peer);
1488 }
1489
1490 if (idev) {
1491 rt->idev = NULL;
1492 in_dev_put(idev);
1493 }
1494}
1495
1496static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1497 int how)
1498{
1499 struct rtable *rt = (struct rtable *) dst;
1500 struct in_device *idev = rt->idev;
1501 if (dev != &loopback_dev && idev && idev->dev == dev) {
1502 struct in_device *loopback_idev = in_dev_get(&loopback_dev);
1503 if (loopback_idev) {
1504 rt->idev = loopback_idev;
1505 in_dev_put(idev);
1506 }
1507 }
1508}
1509
1510static void ipv4_link_failure(struct sk_buff *skb)
1511{
1512 struct rtable *rt;
1513
1514 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1515
1516 rt = (struct rtable *) skb->dst;
1517 if (rt)
1518 dst_set_expires(&rt->u.dst, 0);
1519}
1520
1521static int ip_rt_bug(struct sk_buff *skb)
1522{
1523 printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1524 NIPQUAD(skb->nh.iph->saddr), NIPQUAD(skb->nh.iph->daddr),
1525 skb->dev ? skb->dev->name : "?");
1526 kfree_skb(skb);
1527 return 0;
1528}
1529
1530/*
1531 We do not cache source address of outgoing interface,
1532 because it is used only by IP RR, TS and SRR options,
1533 so that it out of fast path.
1534
1535 BTW remember: "addr" is allowed to be not aligned
1536 in IP options!
1537 */
1538
1539void ip_rt_get_source(u8 *addr, struct rtable *rt)
1540{
a61ced5d 1541 __be32 src;
1da177e4
LT		 1542 struct fib_result res;
1543
1544 if (rt->fl.iif == 0)
1545 src = rt->rt_src;
1546 else if (fib_lookup(&rt->fl, &res) == 0) {
1547 src = FIB_RES_PREFSRC(res);
1548 fib_res_put(&res);
1549 } else
1550 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1551 RT_SCOPE_UNIVERSE);
1552 memcpy(addr, &src, 4);
1553}
1554
1555#ifdef CONFIG_NET_CLS_ROUTE
1556static void set_class_tag(struct rtable *rt, u32 tag)
1557{
1558 if (!(rt->u.dst.tclassid & 0xFFFF))
1559 rt->u.dst.tclassid |= tag & 0xFFFF;
1560 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1561 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1562}
1563#endif
1564
1565static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1566{
1567 struct fib_info *fi = res->fi;
1568
1569 if (fi) {
1570 if (FIB_RES_GW(*res) &&
1571 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1572 rt->rt_gateway = FIB_RES_GW(*res);
1573 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1574 sizeof(rt->u.dst.metrics));
1575 if (fi->fib_mtu == 0) {
1576 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1577 if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
1578 rt->rt_gateway != rt->rt_dst &&
1579 rt->u.dst.dev->mtu > 576)
1580 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1581 }
1582#ifdef CONFIG_NET_CLS_ROUTE
1583 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1584#endif
1585 } else
1586 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1587
1588 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1589 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1590 if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
1591 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1592 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
1593 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1594 ip_rt_min_advmss);
1595 if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
1596 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1597
1598#ifdef CONFIG_NET_CLS_ROUTE
1599#ifdef CONFIG_IP_MULTIPLE_TABLES
1600 set_class_tag(rt, fib_rules_tclass(res));
1601#endif
1602 set_class_tag(rt, itag);
1603#endif
1604 rt->rt_type = res->type;
1605}
1606
9e12bb22 1607static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1da177e4
LT		 1608 u8 tos, struct net_device *dev, int our)
1609{
1610 unsigned hash;
1611 struct rtable *rth;
a61ced5d 1612 __be32 spec_dst;
1da177e4
LT		 1613 struct in_device *in_dev = in_dev_get(dev);
1614 u32 itag = 0;
1615
1616 /* Primary sanity checks. */
1617
1618 if (in_dev == NULL)
1619 return -EINVAL;
1620
1621 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr) ||
1622 skb->protocol != htons(ETH_P_IP))
1623 goto e_inval;
1624
1625 if (ZERONET(saddr)) {
1626 if (!LOCAL_MCAST(daddr))
1627 goto e_inval;
1628 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1629 } else if (fib_validate_source(saddr, 0, tos, 0,
1630 dev, &spec_dst, &itag) < 0)
1631 goto e_inval;
1632
1633 rth = dst_alloc(&ipv4_dst_ops);
1634 if (!rth)
1635 goto e_nobufs;
1636
1637 rth->u.dst.output= ip_rt_bug;
1638
1639 atomic_set(&rth->u.dst.__refcnt, 1);
1640 rth->u.dst.flags= DST_HOST;
1641 if (in_dev->cnf.no_policy)
1642 rth->u.dst.flags |= DST_NOPOLICY;
1643 rth->fl.fl4_dst = daddr;
1644 rth->rt_dst = daddr;
1645 rth->fl.fl4_tos = tos;
1646#ifdef CONFIG_IP_ROUTE_FWMARK
82e91ffe 1647 rth->fl.fl4_fwmark= skb->mark;
1da177e4
LT		 1648#endif
1649 rth->fl.fl4_src = saddr;
1650 rth->rt_src = saddr;
1651#ifdef CONFIG_NET_CLS_ROUTE
1652 rth->u.dst.tclassid = itag;
1653#endif
1654 rth->rt_iif =
1655 rth->fl.iif = dev->ifindex;
1656 rth->u.dst.dev = &loopback_dev;
1657 dev_hold(rth->u.dst.dev);
1658 rth->idev = in_dev_get(rth->u.dst.dev);
1659 rth->fl.oif = 0;
1660 rth->rt_gateway = daddr;
1661 rth->rt_spec_dst= spec_dst;
1662 rth->rt_type = RTN_MULTICAST;
1663 rth->rt_flags = RTCF_MULTICAST;
1664 if (our) {
1665 rth->u.dst.input= ip_local_deliver;
1666 rth->rt_flags |= RTCF_LOCAL;
1667 }
1668
1669#ifdef CONFIG_IP_MROUTE
1670 if (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1671 rth->u.dst.input = ip_mr_input;
1672#endif
1673 RT_CACHE_STAT_INC(in_slow_mc);
1674
1675 in_dev_put(in_dev);
8c7bc840 1676 hash = rt_hash(daddr, saddr, dev->ifindex);
1da177e4
LT		 1677 return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
1678
1679e_nobufs:
1680 in_dev_put(in_dev);
1681 return -ENOBUFS;
1682
1683e_inval:
1684 in_dev_put(in_dev);
1685 return -EINVAL;
1686}
1687
1688
1689static void ip_handle_martian_source(struct net_device *dev,
1690 struct in_device *in_dev,
1691 struct sk_buff *skb,
9e12bb22
AV		 1692 __be32 daddr,
1693 __be32 saddr)
1da177e4
LT		 1694{
1695 RT_CACHE_STAT_INC(in_martian_src);
1696#ifdef CONFIG_IP_ROUTE_VERBOSE
1697 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1698 /*
1699 * RFC1812 recommendation, if source is martian,
1700 * the only hint is MAC header.
1701 */
1702 printk(KERN_WARNING "martian source %u.%u.%u.%u from "
1703 "%u.%u.%u.%u, on dev %s\n",
1704 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
0b7f22aa 1705 if (dev->hard_header_len && skb->mac.raw) {
1da177e4
LT		 1706 int i;
1707 unsigned char *p = skb->mac.raw;
1708 printk(KERN_WARNING "ll header: ");
1709 for (i = 0; i < dev->hard_header_len; i++, p++) {
1710 printk("%02x", *p);
1711 if (i < (dev->hard_header_len - 1))
1712 printk(":");
1713 }
1714 printk("\n");
1715 }
1716 }
1717#endif
1718}
1719
1720static inline int __mkroute_input(struct sk_buff *skb,
1721 struct fib_result* res,
1722 struct in_device *in_dev,
9e12bb22 1723 __be32 daddr, __be32 saddr, u32 tos,
1da177e4
LT		 1724 struct rtable **result)
1725{
1726
1727 struct rtable *rth;
1728 int err;
1729 struct in_device *out_dev;
1730 unsigned flags = 0;
d9c9df8c
AV		 1731 __be32 spec_dst;
1732 u32 itag;
1da177e4
LT		 1733
1734 /* get a working reference to the output device */
1735 out_dev = in_dev_get(FIB_RES_DEV(*res));
1736 if (out_dev == NULL) {
1737 if (net_ratelimit())
1738 printk(KERN_CRIT "Bug in ip_route_input" \
1739 "_slow(). Please, report\n");
1740 return -EINVAL;
1741 }
1742
1743
1744 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1745 in_dev->dev, &spec_dst, &itag);
1746 if (err < 0) {
1747 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1748 saddr);
1749
1750 err = -EINVAL;
1751 goto cleanup;
1752 }
1753
1754 if (err)
1755 flags |= RTCF_DIRECTSRC;
1756
1757 if (out_dev == in_dev && err && !(flags & (RTCF_NAT | RTCF_MASQ)) &&
1758 (IN_DEV_SHARED_MEDIA(out_dev) ||
1759 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1760 flags |= RTCF_DOREDIRECT;
1761
1762 if (skb->protocol != htons(ETH_P_IP)) {
1763 /* Not IP (i.e. ARP). Do not create route, if it is
1764 * invalid for proxy arp. DNAT routes are always valid.
1765 */
1766 if (out_dev == in_dev && !(flags & RTCF_DNAT)) {
1767 err = -EINVAL;
1768 goto cleanup;
1769 }
1770 }
1771
1772
1773 rth = dst_alloc(&ipv4_dst_ops);
1774 if (!rth) {
1775 err = -ENOBUFS;
1776 goto cleanup;
1777 }
1778
ce723d8e 1779 atomic_set(&rth->u.dst.__refcnt, 1);
1da177e4
LT		 1780 rth->u.dst.flags= DST_HOST;
1781#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1782 if (res->fi->fib_nhs > 1)
1783 rth->u.dst.flags |= DST_BALANCED;
1784#endif
1785 if (in_dev->cnf.no_policy)
1786 rth->u.dst.flags |= DST_NOPOLICY;
1787 if (in_dev->cnf.no_xfrm)
1788 rth->u.dst.flags |= DST_NOXFRM;
1789 rth->fl.fl4_dst = daddr;
1790 rth->rt_dst = daddr;
1791 rth->fl.fl4_tos = tos;
1792#ifdef CONFIG_IP_ROUTE_FWMARK
82e91ffe 1793 rth->fl.fl4_fwmark= skb->mark;
1da177e4
LT		 1794#endif
1795 rth->fl.fl4_src = saddr;
1796 rth->rt_src = saddr;
1797 rth->rt_gateway = daddr;
1798 rth->rt_iif =
1799 rth->fl.iif = in_dev->dev->ifindex;
1800 rth->u.dst.dev = (out_dev)->dev;
1801 dev_hold(rth->u.dst.dev);
1802 rth->idev = in_dev_get(rth->u.dst.dev);
1803 rth->fl.oif = 0;
1804 rth->rt_spec_dst= spec_dst;
1805
1806 rth->u.dst.input = ip_forward;
1807 rth->u.dst.output = ip_output;
1808
1809 rt_set_nexthop(rth, res, itag);
1810
1811 rth->rt_flags = flags;
1812
1813 *result = rth;
1814 err = 0;
1815 cleanup:
1816 /* release the working reference to the output device */
1817 in_dev_put(out_dev);
1818 return err;
1819}
1820
1821static inline int ip_mkroute_input_def(struct sk_buff *skb,
1822 struct fib_result* res,
1823 const struct flowi *fl,
1824 struct in_device *in_dev,
9e12bb22 1825 __be32 daddr, __be32 saddr, u32 tos)
1da177e4 1826{
7abaa27c 1827 struct rtable* rth = NULL;
1da177e4
LT		 1828 int err;
1829 unsigned hash;
1830
1831#ifdef CONFIG_IP_ROUTE_MULTIPATH
1832 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
1833 fib_select_multipath(fl, res);
1834#endif
1835
1836 /* create a routing cache entry */
1837 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1838 if (err)
1839 return err;
1da177e4
LT		 1840
1841 /* put it into the cache */
8c7bc840 1842 hash = rt_hash(daddr, saddr, fl->iif);
1da177e4
LT		 1843 return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1844}
1845
1846static inline int ip_mkroute_input(struct sk_buff *skb,
1847 struct fib_result* res,
1848 const struct flowi *fl,
1849 struct in_device *in_dev,
9e12bb22 1850 __be32 daddr, __be32 saddr, u32 tos)
1da177e4
LT		 1851{
1852#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
ce723d8e
JA		 1853 struct rtable* rth = NULL, *rtres;
1854 unsigned char hop, hopcount;
1da177e4
LT		 1855 int err = -EINVAL;
1856 unsigned int hash;
1857
1858 if (res->fi)
1859 hopcount = res->fi->fib_nhs;
1860 else
1861 hopcount = 1;
1862
1da177e4
LT		 1863 /* distinguish between multipath and singlepath */
1864 if (hopcount < 2)
1865 return ip_mkroute_input_def(skb, res, fl, in_dev, daddr,
1866 saddr, tos);
1867
1868 /* add all alternatives to the routing cache */
1869 for (hop = 0; hop < hopcount; hop++) {
1870 res->nh_sel = hop;
1871
ce723d8e
JA		 1872 /* put reference to previous result */
1873 if (hop)
1874 ip_rt_put(rtres);
1875
1da177e4
LT		 1876 /* create a routing cache entry */
1877 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos,
1878 &rth);
1879 if (err)
1880 return err;
1881
1882 /* put it into the cache */
8c7bc840 1883 hash = rt_hash(daddr, saddr, fl->iif);
ce723d8e 1884 err = rt_intern_hash(hash, rth, &rtres);
1da177e4
LT		 1885 if (err)
1886 return err;
1887
1888 /* forward hop information to multipath impl. */
1889 multipath_set_nhinfo(rth,
1890 FIB_RES_NETWORK(*res),
1891 FIB_RES_NETMASK(*res),
1892 res->prefixlen,
1893 &FIB_RES_NH(*res));
1da177e4 1894 }
ce723d8e 1895 skb->dst = &rtres->u.dst;
1da177e4
LT		 1896 return err;
1897#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1898 return ip_mkroute_input_def(skb, res, fl, in_dev, daddr, saddr, tos);
1899#endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1900}
1901
1902
1903/*
1904 * NOTE. We drop all the packets that has local source
1905 * addresses, because every properly looped back packet
1906 * must have correct destination already attached by output routine.
1907 *
1908 * Such approach solves two big problems:
1909 * 1. Not simplex devices are handled properly.
1910 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1911 */
1912
9e12bb22 1913static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1da177e4
LT		 1914 u8 tos, struct net_device *dev)
1915{
1916 struct fib_result res;
1917 struct in_device *in_dev = in_dev_get(dev);
1918 struct flowi fl = { .nl_u = { .ip4_u =
1919 { .daddr = daddr,
1920 .saddr = saddr,
1921 .tos = tos,
1922 .scope = RT_SCOPE_UNIVERSE,
1923#ifdef CONFIG_IP_ROUTE_FWMARK
82e91ffe 1924 .fwmark = skb->mark
1da177e4
LT		 1925#endif
1926 } },
1927 .iif = dev->ifindex };
1928 unsigned flags = 0;
1929 u32 itag = 0;
1930 struct rtable * rth;
1931 unsigned hash;
9e12bb22 1932 __be32 spec_dst;
1da177e4
LT		 1933 int err = -EINVAL;
1934 int free_res = 0;
1935
1936 /* IP on this device is disabled. */
1937
1938 if (!in_dev)
1939 goto out;
1940
1941 /* Check for the most weird martians, which can be not detected
1942 by fib_lookup.
1943 */
1944
1945 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr))
1946 goto martian_source;
1947
e448515c 1948 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
1da177e4
LT		 1949 goto brd_input;
1950
1951 /* Accept zero addresses only to limited broadcast;
1952 * I even do not know to fix it or not. Waiting for complains :-)
1953 */
1954 if (ZERONET(saddr))
1955 goto martian_source;
1956
1957 if (BADCLASS(daddr) || ZERONET(daddr) || LOOPBACK(daddr))
1958 goto martian_destination;
1959
1960 /*
1961 * Now we are ready to route packet.
1962 */
1963 if ((err = fib_lookup(&fl, &res)) != 0) {
1964 if (!IN_DEV_FORWARD(in_dev))
2c2910a4 1965 goto e_hostunreach;
1da177e4
LT		 1966 goto no_route;
1967 }
1968 free_res = 1;
1969
1970 RT_CACHE_STAT_INC(in_slow_tot);
1971
1972 if (res.type == RTN_BROADCAST)
1973 goto brd_input;
1974
1975 if (res.type == RTN_LOCAL) {
1976 int result;
1977 result = fib_validate_source(saddr, daddr, tos,
1978 loopback_dev.ifindex,
1979 dev, &spec_dst, &itag);
1980 if (result < 0)
1981 goto martian_source;
1982 if (result)
1983 flags |= RTCF_DIRECTSRC;
1984 spec_dst = daddr;
1985 goto local_input;
1986 }
1987
1988 if (!IN_DEV_FORWARD(in_dev))
2c2910a4 1989 goto e_hostunreach;
1da177e4
LT		 1990 if (res.type != RTN_UNICAST)
1991 goto martian_destination;
1992
1993 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
1994 if (err == -ENOBUFS)
1995 goto e_nobufs;
1996 if (err == -EINVAL)
1997 goto e_inval;
1998
1999done:
2000 in_dev_put(in_dev);
2001 if (free_res)
2002 fib_res_put(&res);
2003out: return err;
2004
2005brd_input:
2006 if (skb->protocol != htons(ETH_P_IP))
2007 goto e_inval;
2008
2009 if (ZERONET(saddr))
2010 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2011 else {
2012 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2013 &itag);
2014 if (err < 0)
2015 goto martian_source;
2016 if (err)
2017 flags |= RTCF_DIRECTSRC;
2018 }
2019 flags |= RTCF_BROADCAST;
2020 res.type = RTN_BROADCAST;
2021 RT_CACHE_STAT_INC(in_brd);
2022
2023local_input:
2024 rth = dst_alloc(&ipv4_dst_ops);
2025 if (!rth)
2026 goto e_nobufs;
2027
2028 rth->u.dst.output= ip_rt_bug;
2029
2030 atomic_set(&rth->u.dst.__refcnt, 1);
2031 rth->u.dst.flags= DST_HOST;
2032 if (in_dev->cnf.no_policy)
2033 rth->u.dst.flags |= DST_NOPOLICY;
2034 rth->fl.fl4_dst = daddr;
2035 rth->rt_dst = daddr;
2036 rth->fl.fl4_tos = tos;
2037#ifdef CONFIG_IP_ROUTE_FWMARK
82e91ffe 2038 rth->fl.fl4_fwmark= skb->mark;
1da177e4
LT		 2039#endif
2040 rth->fl.fl4_src = saddr;
2041 rth->rt_src = saddr;
2042#ifdef CONFIG_NET_CLS_ROUTE
2043 rth->u.dst.tclassid = itag;
2044#endif
2045 rth->rt_iif =
2046 rth->fl.iif = dev->ifindex;
2047 rth->u.dst.dev = &loopback_dev;
2048 dev_hold(rth->u.dst.dev);
2049 rth->idev = in_dev_get(rth->u.dst.dev);
2050 rth->rt_gateway = daddr;
2051 rth->rt_spec_dst= spec_dst;
2052 rth->u.dst.input= ip_local_deliver;
2053 rth->rt_flags = flags|RTCF_LOCAL;
2054 if (res.type == RTN_UNREACHABLE) {
2055 rth->u.dst.input= ip_error;
2056 rth->u.dst.error= -err;
2057 rth->rt_flags &= ~RTCF_LOCAL;
2058 }
2059 rth->rt_type = res.type;
8c7bc840 2060 hash = rt_hash(daddr, saddr, fl.iif);
1da177e4
LT		 2061 err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
2062 goto done;
2063
2064no_route:
2065 RT_CACHE_STAT_INC(in_no_route);
2066 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2067 res.type = RTN_UNREACHABLE;
2068 goto local_input;
2069
2070 /*
2071 * Do not cache martian addresses: they should be logged (RFC1812)
2072 */
2073martian_destination:
2074 RT_CACHE_STAT_INC(in_martian_dst);
2075#ifdef CONFIG_IP_ROUTE_VERBOSE
2076 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2077 printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
2078 "%u.%u.%u.%u, dev %s\n",
2079 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
2080#endif
2c2910a4
DE		 2081
2082e_hostunreach:
2083 err = -EHOSTUNREACH;
2084 goto done;
2085
1da177e4
LT		 2086e_inval:
2087 err = -EINVAL;
2088 goto done;
2089
2090e_nobufs:
2091 err = -ENOBUFS;
2092 goto done;
2093
2094martian_source:
2095 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2096 goto e_inval;
2097}
2098
9e12bb22 2099int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1da177e4
LT		 2100 u8 tos, struct net_device *dev)
2101{
2102 struct rtable * rth;
2103 unsigned hash;
2104 int iif = dev->ifindex;
2105
2106 tos &= IPTOS_RT_MASK;
8c7bc840 2107 hash = rt_hash(daddr, saddr, iif);
1da177e4
LT		 2108
2109 rcu_read_lock();
2110 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2111 rth = rcu_dereference(rth->u.rt_next)) {
2112 if (rth->fl.fl4_dst == daddr &&
2113 rth->fl.fl4_src == saddr &&
2114 rth->fl.iif == iif &&
2115 rth->fl.oif == 0 &&
2116#ifdef CONFIG_IP_ROUTE_FWMARK
82e91ffe 2117 rth->fl.fl4_fwmark == skb->mark &&
1da177e4
LT		 2118#endif
2119 rth->fl.fl4_tos == tos) {
2120 rth->u.dst.lastuse = jiffies;
2121 dst_hold(&rth->u.dst);
2122 rth->u.dst.__use++;
2123 RT_CACHE_STAT_INC(in_hit);
2124 rcu_read_unlock();
2125 skb->dst = (struct dst_entry*)rth;
2126 return 0;
2127 }
2128 RT_CACHE_STAT_INC(in_hlist_search);
2129 }
2130 rcu_read_unlock();
2131
2132 /* Multicast recognition logic is moved from route cache to here.
2133 The problem was that too many Ethernet cards have broken/missing
2134 hardware multicast filters :-( As result the host on multicasting
2135 network acquires a lot of useless route cache entries, sort of
2136 SDR messages from all the world. Now we try to get rid of them.
2137 Really, provided software IP multicast filter is organized
2138 reasonably (at least, hashed), it does not result in a slowdown
2139 comparing with route cache reject entries.
2140 Note, that multicast routers are not affected, because
2141 route cache entry is created eventually.
2142 */
2143 if (MULTICAST(daddr)) {
2144 struct in_device *in_dev;
2145
2146 rcu_read_lock();
e5ed6399 2147 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
1da177e4
LT		 2148 int our = ip_check_mc(in_dev, daddr, saddr,
2149 skb->nh.iph->protocol);
2150 if (our
2151#ifdef CONFIG_IP_MROUTE
2152 || (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
2153#endif
2154 ) {
2155 rcu_read_unlock();
2156 return ip_route_input_mc(skb, daddr, saddr,
2157 tos, dev, our);
2158 }
2159 }
2160 rcu_read_unlock();
2161 return -EINVAL;
2162 }
2163 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2164}
2165
2166static inline int __mkroute_output(struct rtable **result,
2167 struct fib_result* res,
2168 const struct flowi *fl,
2169 const struct flowi *oldflp,
2170 struct net_device *dev_out,
2171 unsigned flags)
2172{
2173 struct rtable *rth;
2174 struct in_device *in_dev;
2175 u32 tos = RT_FL_TOS(oldflp);
2176 int err = 0;
2177
2178 if (LOOPBACK(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2179 return -EINVAL;
2180
e448515c 2181 if (fl->fl4_dst == htonl(0xFFFFFFFF))
1da177e4
LT		 2182 res->type = RTN_BROADCAST;
2183 else if (MULTICAST(fl->fl4_dst))
2184 res->type = RTN_MULTICAST;
2185 else if (BADCLASS(fl->fl4_dst) || ZERONET(fl->fl4_dst))
2186 return -EINVAL;
2187
2188 if (dev_out->flags & IFF_LOOPBACK)
2189 flags |= RTCF_LOCAL;
2190
2191 /* get work reference to inet device */
2192 in_dev = in_dev_get(dev_out);
2193 if (!in_dev)
2194 return -EINVAL;
2195
2196 if (res->type == RTN_BROADCAST) {
2197 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2198 if (res->fi) {
2199 fib_info_put(res->fi);
2200 res->fi = NULL;
2201 }
2202 } else if (res->type == RTN_MULTICAST) {
2203 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2204 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2205 oldflp->proto))
2206 flags &= ~RTCF_LOCAL;
2207 /* If multicast route do not exist use
2208 default one, but do not gateway in this case.
2209 Yes, it is hack.
2210 */
2211 if (res->fi && res->prefixlen < 4) {
2212 fib_info_put(res->fi);
2213 res->fi = NULL;
2214 }
2215 }
2216
2217
2218 rth = dst_alloc(&ipv4_dst_ops);
2219 if (!rth) {
2220 err = -ENOBUFS;
2221 goto cleanup;
2222 }
2223
ce723d8e 2224 atomic_set(&rth->u.dst.__refcnt, 1);
1da177e4
LT		 2225 rth->u.dst.flags= DST_HOST;
2226#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2227 if (res->fi) {
2228 rth->rt_multipath_alg = res->fi->fib_mp_alg;
2229 if (res->fi->fib_nhs > 1)
2230 rth->u.dst.flags |= DST_BALANCED;
2231 }
2232#endif
2233 if (in_dev->cnf.no_xfrm)
2234 rth->u.dst.flags |= DST_NOXFRM;
2235 if (in_dev->cnf.no_policy)
2236 rth->u.dst.flags |= DST_NOPOLICY;
2237
2238 rth->fl.fl4_dst = oldflp->fl4_dst;
2239 rth->fl.fl4_tos = tos;
2240 rth->fl.fl4_src = oldflp->fl4_src;
2241 rth->fl.oif = oldflp->oif;
2242#ifdef CONFIG_IP_ROUTE_FWMARK
2243 rth->fl.fl4_fwmark= oldflp->fl4_fwmark;
2244#endif
2245 rth->rt_dst = fl->fl4_dst;
2246 rth->rt_src = fl->fl4_src;
2247 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2248 /* get references to the devices that are to be hold by the routing
2249 cache entry */
2250 rth->u.dst.dev = dev_out;
2251 dev_hold(dev_out);
2252 rth->idev = in_dev_get(dev_out);
2253 rth->rt_gateway = fl->fl4_dst;
2254 rth->rt_spec_dst= fl->fl4_src;
2255
2256 rth->u.dst.output=ip_output;
2257
2258 RT_CACHE_STAT_INC(out_slow_tot);
2259
2260 if (flags & RTCF_LOCAL) {
2261 rth->u.dst.input = ip_local_deliver;
2262 rth->rt_spec_dst = fl->fl4_dst;
2263 }
2264 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2265 rth->rt_spec_dst = fl->fl4_src;
2266 if (flags & RTCF_LOCAL &&
2267 !(dev_out->flags & IFF_LOOPBACK)) {
2268 rth->u.dst.output = ip_mc_output;
2269 RT_CACHE_STAT_INC(out_slow_mc);
2270 }
2271#ifdef CONFIG_IP_MROUTE
2272 if (res->type == RTN_MULTICAST) {
2273 if (IN_DEV_MFORWARD(in_dev) &&
2274 !LOCAL_MCAST(oldflp->fl4_dst)) {
2275 rth->u.dst.input = ip_mr_input;
2276 rth->u.dst.output = ip_mc_output;
2277 }
2278 }
2279#endif
2280 }
2281
2282 rt_set_nexthop(rth, res, 0);
2283
2284 rth->rt_flags = flags;
2285
2286 *result = rth;
2287 cleanup:
2288 /* release work reference to inet device */
2289 in_dev_put(in_dev);
2290
2291 return err;
2292}
2293
2294static inline int ip_mkroute_output_def(struct rtable **rp,
2295 struct fib_result* res,
2296 const struct flowi *fl,
2297 const struct flowi *oldflp,
2298 struct net_device *dev_out,
2299 unsigned flags)
2300{
7abaa27c 2301 struct rtable *rth = NULL;
1da177e4
LT		 2302 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2303 unsigned hash;
2304 if (err == 0) {
8c7bc840 2305 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
1da177e4
LT		 2306 err = rt_intern_hash(hash, rth, rp);
2307 }
2308
2309 return err;
2310}
2311
2312static inline int ip_mkroute_output(struct rtable** rp,
2313 struct fib_result* res,
2314 const struct flowi *fl,
2315 const struct flowi *oldflp,
2316 struct net_device *dev_out,
2317 unsigned flags)
2318{
2319#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1da177e4
LT		 2320 unsigned char hop;
2321 unsigned hash;
2322 int err = -EINVAL;
7abaa27c 2323 struct rtable *rth = NULL;
1da177e4
LT		 2324
2325 if (res->fi && res->fi->fib_nhs > 1) {
2326 unsigned char hopcount = res->fi->fib_nhs;
2327
2328 for (hop = 0; hop < hopcount; hop++) {
2329 struct net_device *dev2nexthop;
2330
2331 res->nh_sel = hop;
2332
2333 /* hold a work reference to the output device */
2334 dev2nexthop = FIB_RES_DEV(*res);
2335 dev_hold(dev2nexthop);
2336
ce723d8e
JA		 2337 /* put reference to previous result */
2338 if (hop)
2339 ip_rt_put(*rp);
2340
1da177e4
LT		 2341 err = __mkroute_output(&rth, res, fl, oldflp,
2342 dev2nexthop, flags);
2343
2344 if (err != 0)
2345 goto cleanup;
2346
8c7bc840
AV		 2347 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src,
2348 oldflp->oif);
1da177e4
LT		 2349 err = rt_intern_hash(hash, rth, rp);
2350
2351 /* forward hop information to multipath impl. */
2352 multipath_set_nhinfo(rth,
2353 FIB_RES_NETWORK(*res),
2354 FIB_RES_NETMASK(*res),
2355 res->prefixlen,
2356 &FIB_RES_NH(*res));
2357 cleanup:
2358 /* release work reference to output device */
2359 dev_put(dev2nexthop);
2360
2361 if (err != 0)
2362 return err;
2363 }
1da177e4
LT		 2364 return err;
2365 } else {
2366 return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out,
2367 flags);
2368 }
2369#else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
2370 return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out, flags);
2371#endif
2372}
2373
2374/*
2375 * Major route resolver routine.
2376 */
2377
2378static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
2379{
2380 u32 tos = RT_FL_TOS(oldflp);
2381 struct flowi fl = { .nl_u = { .ip4_u =
2382 { .daddr = oldflp->fl4_dst,
2383 .saddr = oldflp->fl4_src,
2384 .tos = tos & IPTOS_RT_MASK,
2385 .scope = ((tos & RTO_ONLINK) ?
2386 RT_SCOPE_LINK :
2387 RT_SCOPE_UNIVERSE),
2388#ifdef CONFIG_IP_ROUTE_FWMARK
2389 .fwmark = oldflp->fl4_fwmark
2390#endif
2391 } },
2392 .iif = loopback_dev.ifindex,
2393 .oif = oldflp->oif };
2394 struct fib_result res;
2395 unsigned flags = 0;
2396 struct net_device *dev_out = NULL;
2397 int free_res = 0;
2398 int err;
2399
2400
2401 res.fi = NULL;
2402#ifdef CONFIG_IP_MULTIPLE_TABLES
2403 res.r = NULL;
2404#endif
2405
2406 if (oldflp->fl4_src) {
2407 err = -EINVAL;
2408 if (MULTICAST(oldflp->fl4_src) ||
2409 BADCLASS(oldflp->fl4_src) ||
2410 ZERONET(oldflp->fl4_src))
2411 goto out;
2412
2413 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2414 dev_out = ip_dev_find(oldflp->fl4_src);
2415 if (dev_out == NULL)
2416 goto out;
2417
2418 /* I removed check for oif == dev_out->oif here.
2419 It was wrong for two reasons:
2420 1. ip_dev_find(saddr) can return wrong iface, if saddr is
2421 assigned to multiple interfaces.
2422 2. Moreover, we are allowed to send packets with saddr
2423 of another iface. --ANK
2424 */
2425
2426 if (oldflp->oif == 0
e448515c 2427 && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
1da177e4
LT		 2428 /* Special hack: user can direct multicasts
2429 and limited broadcast via necessary interface
2430 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2431 This hack is not just for fun, it allows
2432 vic,vat and friends to work.
2433 They bind socket to loopback, set ttl to zero
2434 and expect that it will work.
2435 From the viewpoint of routing cache they are broken,
2436 because we are not allowed to build multicast path
2437 with loopback source addr (look, routing cache
2438 cannot know, that ttl is zero, so that packet
2439 will not leave this host and route is valid).
2440 Luckily, this hack is good workaround.
2441 */
2442
2443 fl.oif = dev_out->ifindex;
2444 goto make_route;
2445 }
2446 if (dev_out)
2447 dev_put(dev_out);
2448 dev_out = NULL;
2449 }
2450
2451
2452 if (oldflp->oif) {
2453 dev_out = dev_get_by_index(oldflp->oif);
2454 err = -ENODEV;
2455 if (dev_out == NULL)
2456 goto out;
e5ed6399
HX		 2457
2458 /* RACE: Check return value of inet_select_addr instead. */
2459 if (__in_dev_get_rtnl(dev_out) == NULL) {
1da177e4
LT		 2460 dev_put(dev_out);
2461 goto out; /* Wrong error code */
2462 }
2463
e448515c 2464 if (LOCAL_MCAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
1da177e4
LT		 2465 if (!fl.fl4_src)
2466 fl.fl4_src = inet_select_addr(dev_out, 0,
2467 RT_SCOPE_LINK);
2468 goto make_route;
2469 }
2470 if (!fl.fl4_src) {
2471 if (MULTICAST(oldflp->fl4_dst))
2472 fl.fl4_src = inet_select_addr(dev_out, 0,
2473 fl.fl4_scope);
2474 else if (!oldflp->fl4_dst)
2475 fl.fl4_src = inet_select_addr(dev_out, 0,
2476 RT_SCOPE_HOST);
2477 }
2478 }
2479
2480 if (!fl.fl4_dst) {
2481 fl.fl4_dst = fl.fl4_src;
2482 if (!fl.fl4_dst)
2483 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2484 if (dev_out)
2485 dev_put(dev_out);
2486 dev_out = &loopback_dev;
2487 dev_hold(dev_out);
2488 fl.oif = loopback_dev.ifindex;
2489 res.type = RTN_LOCAL;
2490 flags |= RTCF_LOCAL;
2491 goto make_route;
2492 }
2493
2494 if (fib_lookup(&fl, &res)) {
2495 res.fi = NULL;
2496 if (oldflp->oif) {
2497 /* Apparently, routing tables are wrong. Assume,
2498 that the destination is on link.
2499
2500 WHY? DW.
2501 Because we are allowed to send to iface
2502 even if it has NO routes and NO assigned
2503 addresses. When oif is specified, routing
2504 tables are looked up with only one purpose:
2505 to catch if destination is gatewayed, rather than
2506 direct. Moreover, if MSG_DONTROUTE is set,
2507 we send packet, ignoring both routing tables
2508 and ifaddr state. --ANK
2509
2510
2511 We could make it even if oif is unknown,
2512 likely IPv6, but we do not.
2513 */
2514
2515 if (fl.fl4_src == 0)
2516 fl.fl4_src = inet_select_addr(dev_out, 0,
2517 RT_SCOPE_LINK);
2518 res.type = RTN_UNICAST;
2519 goto make_route;
2520 }
2521 if (dev_out)
2522 dev_put(dev_out);
2523 err = -ENETUNREACH;
2524 goto out;
2525 }
2526 free_res = 1;
2527
2528 if (res.type == RTN_LOCAL) {
2529 if (!fl.fl4_src)
2530 fl.fl4_src = fl.fl4_dst;
2531 if (dev_out)
2532 dev_put(dev_out);
2533 dev_out = &loopback_dev;
2534 dev_hold(dev_out);
2535 fl.oif = dev_out->ifindex;
2536 if (res.fi)
2537 fib_info_put(res.fi);
2538 res.fi = NULL;
2539 flags |= RTCF_LOCAL;
2540 goto make_route;
2541 }
2542
2543#ifdef CONFIG_IP_ROUTE_MULTIPATH
2544 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2545 fib_select_multipath(&fl, &res);
2546 else
2547#endif
2548 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2549 fib_select_default(&fl, &res);
2550
2551 if (!fl.fl4_src)
2552 fl.fl4_src = FIB_RES_PREFSRC(res);
2553
2554 if (dev_out)
2555 dev_put(dev_out);
2556 dev_out = FIB_RES_DEV(res);
2557 dev_hold(dev_out);
2558 fl.oif = dev_out->ifindex;
2559
2560
2561make_route:
2562 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2563
2564
2565 if (free_res)
2566 fib_res_put(&res);
2567 if (dev_out)
2568 dev_put(dev_out);
2569out: return err;
2570}
2571
2572int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
2573{
2574 unsigned hash;
2575 struct rtable *rth;
2576
8c7bc840 2577 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
1da177e4
LT		 2578
2579 rcu_read_lock_bh();
2580 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2581 rth = rcu_dereference(rth->u.rt_next)) {
2582 if (rth->fl.fl4_dst == flp->fl4_dst &&
2583 rth->fl.fl4_src == flp->fl4_src &&
2584 rth->fl.iif == 0 &&
2585 rth->fl.oif == flp->oif &&
2586#ifdef CONFIG_IP_ROUTE_FWMARK
2587 rth->fl.fl4_fwmark == flp->fl4_fwmark &&
2588#endif
2589 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2590 (IPTOS_RT_MASK | RTO_ONLINK))) {
2591
2592 /* check for multipath routes and choose one if
2593 * necessary
2594 */
2595 if (multipath_select_route(flp, rth, rp)) {
2596 dst_hold(&(*rp)->u.dst);
2597 RT_CACHE_STAT_INC(out_hit);
2598 rcu_read_unlock_bh();
2599 return 0;
2600 }
2601
2602 rth->u.dst.lastuse = jiffies;
2603 dst_hold(&rth->u.dst);
2604 rth->u.dst.__use++;
2605 RT_CACHE_STAT_INC(out_hit);
2606 rcu_read_unlock_bh();
2607 *rp = rth;
2608 return 0;
2609 }
2610 RT_CACHE_STAT_INC(out_hlist_search);
2611 }
2612 rcu_read_unlock_bh();
2613
2614 return ip_route_output_slow(rp, flp);
2615}
2616
d8c97a94
ACM		 2617EXPORT_SYMBOL_GPL(__ip_route_output_key);
2618
1da177e4
LT		 2619int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
2620{
2621 int err;
2622
2623 if ((err = __ip_route_output_key(rp, flp)) != 0)
2624 return err;
2625
2626 if (flp->proto) {
2627 if (!flp->fl4_src)
2628 flp->fl4_src = (*rp)->rt_src;
2629 if (!flp->fl4_dst)
2630 flp->fl4_dst = (*rp)->rt_dst;
2631 return xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
2632 }
2633
2634 return 0;
2635}
2636
d8c97a94
ACM		 2637EXPORT_SYMBOL_GPL(ip_route_output_flow);
2638
1da177e4
LT		 2639int ip_route_output_key(struct rtable **rp, struct flowi *flp)
2640{
2641 return ip_route_output_flow(rp, flp, NULL, 0);
2642}
2643
2644static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
b6544c0b 2645 int nowait, unsigned int flags)
1da177e4
LT		 2646{
2647 struct rtable *rt = (struct rtable*)skb->dst;
2648 struct rtmsg *r;
be403ea1 2649 struct nlmsghdr *nlh;
1da177e4 2650 struct rta_cacheinfo ci;
be403ea1
TG		 2651
2652 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2653 if (nlh == NULL)
2654 return -ENOBUFS;
2655
2656 r = nlmsg_data(nlh);
1da177e4
LT		 2657 r->rtm_family = AF_INET;
2658 r->rtm_dst_len = 32;
2659 r->rtm_src_len = 0;
2660 r->rtm_tos = rt->fl.fl4_tos;
2661 r->rtm_table = RT_TABLE_MAIN;
be403ea1 2662 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1da177e4
LT		 2663 r->rtm_type = rt->rt_type;
2664 r->rtm_scope = RT_SCOPE_UNIVERSE;
2665 r->rtm_protocol = RTPROT_UNSPEC;
2666 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2667 if (rt->rt_flags & RTCF_NOTIFY)
2668 r->rtm_flags |= RTM_F_NOTIFY;
be403ea1 2669
17fb2c64 2670 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
be403ea1 2671
1da177e4
LT		 2672 if (rt->fl.fl4_src) {
2673 r->rtm_src_len = 32;
17fb2c64 2674 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
1da177e4
LT		 2675 }
2676 if (rt->u.dst.dev)
be403ea1 2677 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
1da177e4
LT		 2678#ifdef CONFIG_NET_CLS_ROUTE
2679 if (rt->u.dst.tclassid)
be403ea1 2680 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
1da177e4
LT		 2681#endif
2682#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
be403ea1
TG		 2683 if (rt->rt_multipath_alg != IP_MP_ALG_NONE)
2684 NLA_PUT_U32(skb, RTA_MP_ALGO, rt->rt_multipath_alg);
1da177e4
LT		 2685#endif
2686 if (rt->fl.iif)
17fb2c64 2687 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
1da177e4 2688 else if (rt->rt_src != rt->fl.fl4_src)
17fb2c64 2689 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
be403ea1 2690
1da177e4 2691 if (rt->rt_dst != rt->rt_gateway)
17fb2c64 2692 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
be403ea1 2693
1da177e4 2694 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
be403ea1
TG		 2695 goto nla_put_failure;
2696
1da177e4
LT		 2697 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse);
2698 ci.rta_used = rt->u.dst.__use;
2699 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt);
2700 if (rt->u.dst.expires)
2701 ci.rta_expires = jiffies_to_clock_t(rt->u.dst.expires - jiffies);
2702 else
2703 ci.rta_expires = 0;
2704 ci.rta_error = rt->u.dst.error;
2705 ci.rta_id = ci.rta_ts = ci.rta_tsage = 0;
2706 if (rt->peer) {
2707 ci.rta_id = rt->peer->ip_id_count;
2708 if (rt->peer->tcp_ts_stamp) {
2709 ci.rta_ts = rt->peer->tcp_ts;
2710 ci.rta_tsage = xtime.tv_sec - rt->peer->tcp_ts_stamp;
2711 }
2712 }
be403ea1 2713
1da177e4
LT		 2714 if (rt->fl.iif) {
2715#ifdef CONFIG_IP_MROUTE
e448515c 2716 __be32 dst = rt->rt_dst;
1da177e4
LT		 2717
2718 if (MULTICAST(dst) && !LOCAL_MCAST(dst) &&
2719 ipv4_devconf.mc_forwarding) {
2720 int err = ipmr_get_route(skb, r, nowait);
2721 if (err <= 0) {
2722 if (!nowait) {
2723 if (err == 0)
2724 return 0;
be403ea1 2725 goto nla_put_failure;
1da177e4
LT		 2726 } else {
2727 if (err == -EMSGSIZE)
be403ea1
TG		 2728 goto nla_put_failure;
2729 ci.rta_error = err;
1da177e4
LT		 2730 }
2731 }
2732 } else
2733#endif
be403ea1 2734 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
1da177e4
LT		 2735 }
2736
be403ea1
TG		 2737 NLA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci);
2738
2739 return nlmsg_end(skb, nlh);
1da177e4 2740
be403ea1
TG		 2741nla_put_failure:
2742 return nlmsg_cancel(skb, nlh);
1da177e4
LT		 2743}
2744
2745int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2746{
d889ce3b
TG		 2747 struct rtmsg *rtm;
2748 struct nlattr *tb[RTA_MAX+1];
1da177e4 2749 struct rtable *rt = NULL;
9e12bb22
AV		 2750 __be32 dst = 0;
2751 __be32 src = 0;
2752 u32 iif;
d889ce3b 2753 int err;
1da177e4
LT		 2754 struct sk_buff *skb;
2755
d889ce3b
TG		 2756 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2757 if (err < 0)
2758 goto errout;
2759
2760 rtm = nlmsg_data(nlh);
2761
1da177e4 2762 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
d889ce3b
TG		 2763 if (skb == NULL) {
2764 err = -ENOBUFS;
2765 goto errout;
2766 }
1da177e4
LT		 2767
2768 /* Reserve room for dummy headers, this skb can pass
2769 through good chunk of routing engine.
2770 */
d2c962b8
SH		 2771 skb->mac.raw = skb->nh.raw = skb->data;
2772
2773 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2774 skb->nh.iph->protocol = IPPROTO_ICMP;
1da177e4
LT		 2775 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2776
17fb2c64
AV		 2777 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2778 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
d889ce3b 2779 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
1da177e4
LT		 2780
2781 if (iif) {
d889ce3b
TG		 2782 struct net_device *dev;
2783
2784 dev = __dev_get_by_index(iif);
2785 if (dev == NULL) {
2786 err = -ENODEV;
2787 goto errout_free;
2788 }
2789
1da177e4
LT		 2790 skb->protocol = htons(ETH_P_IP);
2791 skb->dev = dev;
2792 local_bh_disable();
2793 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2794 local_bh_enable();
d889ce3b
TG		 2795
2796 rt = (struct rtable*) skb->dst;
2797 if (err == 0 && rt->u.dst.error)
1da177e4
LT		 2798 err = -rt->u.dst.error;
2799 } else {
d889ce3b
TG		 2800 struct flowi fl = {
2801 .nl_u = {
2802 .ip4_u = {
2803 .daddr = dst,
2804 .saddr = src,
2805 .tos = rtm->rtm_tos,
2806 },
2807 },
2808 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2809 };
1da177e4
LT		 2810 err = ip_route_output_key(&rt, &fl);
2811 }
d889ce3b 2812
1da177e4 2813 if (err)
d889ce3b 2814 goto errout_free;
1da177e4
LT		 2815
2816 skb->dst = &rt->u.dst;
2817 if (rtm->rtm_flags & RTM_F_NOTIFY)
2818 rt->rt_flags |= RTCF_NOTIFY;
2819
1da177e4 2820 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
b6544c0b 2821 RTM_NEWROUTE, 0, 0);
d889ce3b
TG		 2822 if (err <= 0)
2823 goto errout_free;
1da177e4 2824
2942e900 2825 err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
d889ce3b 2826errout:
2942e900 2827 return err;
1da177e4 2828
d889ce3b 2829errout_free:
1da177e4 2830 kfree_skb(skb);
d889ce3b 2831 goto errout;
1da177e4
LT		 2832}
2833
2834int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2835{
2836 struct rtable *rt;
2837 int h, s_h;
2838 int idx, s_idx;
2839
2840 s_h = cb->args[0];
2841 s_idx = idx = cb->args[1];
2842 for (h = 0; h <= rt_hash_mask; h++) {
2843 if (h < s_h) continue;
2844 if (h > s_h)
2845 s_idx = 0;
2846 rcu_read_lock_bh();
2847 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2848 rt = rcu_dereference(rt->u.rt_next), idx++) {
2849 if (idx < s_idx)
2850 continue;
2851 skb->dst = dst_clone(&rt->u.dst);
2852 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
b6544c0b
JHS		 2853 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2854 1, NLM_F_MULTI) <= 0) {
1da177e4
LT		 2855 dst_release(xchg(&skb->dst, NULL));
2856 rcu_read_unlock_bh();
2857 goto done;
2858 }
2859 dst_release(xchg(&skb->dst, NULL));
2860 }
2861 rcu_read_unlock_bh();
2862 }
2863
2864done:
2865 cb->args[0] = h;
2866 cb->args[1] = idx;
2867 return skb->len;
2868}
2869
2870void ip_rt_multicast_event(struct in_device *in_dev)
2871{
2872 rt_cache_flush(0);
2873}
2874
2875#ifdef CONFIG_SYSCTL
2876static int flush_delay;
2877
2878static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
2879 struct file *filp, void __user *buffer,
2880 size_t *lenp, loff_t *ppos)
2881{
2882 if (write) {
2883 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2884 rt_cache_flush(flush_delay);
2885 return 0;
2886 }
2887
2888 return -EINVAL;
2889}
2890
2891static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2892 int __user *name,
2893 int nlen,
2894 void __user *oldval,
2895 size_t __user *oldlenp,
2896 void __user *newval,
2897 size_t newlen,
2898 void **context)
2899{
2900 int delay;
2901 if (newlen != sizeof(int))
2902 return -EINVAL;
2903 if (get_user(delay, (int __user *)newval))
2904 return -EFAULT;
2905 rt_cache_flush(delay);
2906 return 0;
2907}
2908
2909ctl_table ipv4_route_table[] = {
2910 {
2911 .ctl_name = NET_IPV4_ROUTE_FLUSH,
2912 .procname = "flush",
2913 .data = &flush_delay,
2914 .maxlen = sizeof(int),
7e3e0360 2915 .mode = 0200,
1da177e4
LT		 2916 .proc_handler = &ipv4_sysctl_rtcache_flush,
2917 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
2918 },
2919 {
2920 .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
2921 .procname = "min_delay",
2922 .data = &ip_rt_min_delay,
2923 .maxlen = sizeof(int),
2924 .mode = 0644,
2925 .proc_handler = &proc_dointvec_jiffies,
2926 .strategy = &sysctl_jiffies,
2927 },
2928 {
2929 .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
2930 .procname = "max_delay",
2931 .data = &ip_rt_max_delay,
2932 .maxlen = sizeof(int),
2933 .mode = 0644,
2934 .proc_handler = &proc_dointvec_jiffies,
2935 .strategy = &sysctl_jiffies,
2936 },
2937 {
2938 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2939 .procname = "gc_thresh",
2940 .data = &ipv4_dst_ops.gc_thresh,
2941 .maxlen = sizeof(int),
2942 .mode = 0644,
2943 .proc_handler = &proc_dointvec,
2944 },
2945 {
2946 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
2947 .procname = "max_size",
2948 .data = &ip_rt_max_size,
2949 .maxlen = sizeof(int),
2950 .mode = 0644,
2951 .proc_handler = &proc_dointvec,
2952 },
2953 {
2954 /* Deprecated. Use gc_min_interval_ms */
2955
2956 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
2957 .procname = "gc_min_interval",
2958 .data = &ip_rt_gc_min_interval,
2959 .maxlen = sizeof(int),
2960 .mode = 0644,
2961 .proc_handler = &proc_dointvec_jiffies,
2962 .strategy = &sysctl_jiffies,
2963 },
2964 {
2965 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
2966 .procname = "gc_min_interval_ms",
2967 .data = &ip_rt_gc_min_interval,
2968 .maxlen = sizeof(int),
2969 .mode = 0644,
2970 .proc_handler = &proc_dointvec_ms_jiffies,
2971 .strategy = &sysctl_ms_jiffies,
2972 },
2973 {
2974 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
2975 .procname = "gc_timeout",
2976 .data = &ip_rt_gc_timeout,
2977 .maxlen = sizeof(int),
2978 .mode = 0644,
2979 .proc_handler = &proc_dointvec_jiffies,
2980 .strategy = &sysctl_jiffies,
2981 },
2982 {
2983 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
2984 .procname = "gc_interval",
2985 .data = &ip_rt_gc_interval,
2986 .maxlen = sizeof(int),
2987 .mode = 0644,
2988 .proc_handler = &proc_dointvec_jiffies,
2989 .strategy = &sysctl_jiffies,
2990 },
2991 {
2992 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
2993 .procname = "redirect_load",
2994 .data = &ip_rt_redirect_load,
2995 .maxlen = sizeof(int),
2996 .mode = 0644,
2997 .proc_handler = &proc_dointvec,
2998 },
2999 {
3000 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
3001 .procname = "redirect_number",
3002 .data = &ip_rt_redirect_number,
3003 .maxlen = sizeof(int),
3004 .mode = 0644,
3005 .proc_handler = &proc_dointvec,
3006 },
3007 {
3008 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
3009 .procname = "redirect_silence",
3010 .data = &ip_rt_redirect_silence,
3011 .maxlen = sizeof(int),
3012 .mode = 0644,
3013 .proc_handler = &proc_dointvec,
3014 },
3015 {
3016 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
3017 .procname = "error_cost",
3018 .data = &ip_rt_error_cost,
3019 .maxlen = sizeof(int),
3020 .mode = 0644,
3021 .proc_handler = &proc_dointvec,
3022 },
3023 {
3024 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
3025 .procname = "error_burst",
3026 .data = &ip_rt_error_burst,
3027 .maxlen = sizeof(int),
3028 .mode = 0644,
3029 .proc_handler = &proc_dointvec,
3030 },
3031 {
3032 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
3033 .procname = "gc_elasticity",
3034 .data = &ip_rt_gc_elasticity,
3035 .maxlen = sizeof(int),
3036 .mode = 0644,
3037 .proc_handler = &proc_dointvec,
3038 },
3039 {
3040 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
3041 .procname = "mtu_expires",
3042 .data = &ip_rt_mtu_expires,
3043 .maxlen = sizeof(int),
3044 .mode = 0644,
3045 .proc_handler = &proc_dointvec_jiffies,
3046 .strategy = &sysctl_jiffies,
3047 },
3048 {
3049 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
3050 .procname = "min_pmtu",
3051 .data = &ip_rt_min_pmtu,
3052 .maxlen = sizeof(int),
3053 .mode = 0644,
3054 .proc_handler = &proc_dointvec,
3055 },
3056 {
3057 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
3058 .procname = "min_adv_mss",
3059 .data = &ip_rt_min_advmss,
3060 .maxlen = sizeof(int),
3061 .mode = 0644,
3062 .proc_handler = &proc_dointvec,
3063 },
3064 {
3065 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
3066 .procname = "secret_interval",
3067 .data = &ip_rt_secret_interval,
3068 .maxlen = sizeof(int),
3069 .mode = 0644,
3070 .proc_handler = &proc_dointvec_jiffies,
3071 .strategy = &sysctl_jiffies,
3072 },
3073 { .ctl_name = 0 }
3074};
3075#endif
3076
3077#ifdef CONFIG_NET_CLS_ROUTE
3078struct ip_rt_acct *ip_rt_acct;
3079
3080/* This code sucks. But you should have seen it before! --RR */
3081
3082/* IP route accounting ptr for this logical cpu number. */
3083#define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
3084
3085#ifdef CONFIG_PROC_FS
3086static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
3087 int length, int *eof, void *data)
3088{
3089 unsigned int i;
3090
3091 if ((offset & 3) || (length & 3))
3092 return -EIO;
3093
3094 if (offset >= sizeof(struct ip_rt_acct) * 256) {
3095 *eof = 1;
3096 return 0;
3097 }
3098
3099 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
3100 length = sizeof(struct ip_rt_acct) * 256 - offset;
3101 *eof = 1;
3102 }
3103
3104 offset /= sizeof(u32);
3105
3106 if (length > 0) {
3107 u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
3108 u32 *dst = (u32 *) buffer;
3109
3110 /* Copy first cpu. */
3111 *start = buffer;
3112 memcpy(dst, src, length);
3113
3114 /* Add the other cpus in, one int at a time */
6f912042 3115 for_each_possible_cpu(i) {
1da177e4
LT		 3116 unsigned int j;
3117
3118 src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
3119
3120 for (j = 0; j < length/4; j++)
3121 dst[j] += src[j];
3122 }
3123 }
3124 return length;
3125}
3126#endif /* CONFIG_PROC_FS */
3127#endif /* CONFIG_NET_CLS_ROUTE */
3128
3129static __initdata unsigned long rhash_entries;
3130static int __init set_rhash_entries(char *str)
3131{
3132 if (!str)
3133 return 0;
3134 rhash_entries = simple_strtoul(str, &str, 0);
3135 return 1;
3136}
3137__setup("rhash_entries=", set_rhash_entries);
3138
3139int __init ip_rt_init(void)
3140{
424c4b70 3141 int rc = 0;
1da177e4
LT		 3142
3143 rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
3144 (jiffies ^ (jiffies >> 7)));
3145
3146#ifdef CONFIG_NET_CLS_ROUTE
424c4b70
ED		 3147 {
3148 int order;
1da177e4
LT		 3149 for (order = 0;
3150 (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
3151 /* NOTHING */;
3152 ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
3153 if (!ip_rt_acct)
3154 panic("IP: failed to allocate ip_rt_acct\n");
3155 memset(ip_rt_acct, 0, PAGE_SIZE << order);
424c4b70 3156 }
1da177e4
LT		 3157#endif
3158
e5d679f3
AD		 3159 ipv4_dst_ops.kmem_cachep =
3160 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3161 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1da177e4 3162
424c4b70
ED		 3163 rt_hash_table = (struct rt_hash_bucket *)
3164 alloc_large_system_hash("IP route cache",
3165 sizeof(struct rt_hash_bucket),
3166 rhash_entries,
3167 (num_physpages >= 128 * 1024) ?
18955cfc 3168 15 : 17,
8d1502de 3169 0,
424c4b70
ED		 3170 &rt_hash_log,
3171 &rt_hash_mask,
3172 0);
22c047cc
ED		 3173 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3174 rt_hash_lock_init();
1da177e4
LT		 3175
3176 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3177 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3178
1da177e4
LT		 3179 devinet_init();
3180 ip_fib_init();
3181
3182 init_timer(&rt_flush_timer);
3183 rt_flush_timer.function = rt_run_flush;
3184 init_timer(&rt_periodic_timer);
3185 rt_periodic_timer.function = rt_check_expire;
3186 init_timer(&rt_secret_timer);
3187 rt_secret_timer.function = rt_secret_rebuild;
3188
3189 /* All the timers, started at system startup tend
3190 to synchronize. Perturb it a bit.
3191 */
3192 rt_periodic_timer.expires = jiffies + net_random() % ip_rt_gc_interval +
3193 ip_rt_gc_interval;
3194 add_timer(&rt_periodic_timer);
3195
3196 rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
3197 ip_rt_secret_interval;
3198 add_timer(&rt_secret_timer);
3199
3200#ifdef CONFIG_PROC_FS
3201 {
3202 struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
3203 if (!proc_net_fops_create("rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
3204 !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
3205 proc_net_stat))) {
1da177e4
LT		 3206 return -ENOMEM;
3207 }
3208 rtstat_pde->proc_fops = &rt_cpu_seq_fops;
3209 }
3210#ifdef CONFIG_NET_CLS_ROUTE
3211 create_proc_read_entry("rt_acct", 0, proc_net, ip_rt_acct_read, NULL);
3212#endif
3213#endif
3214#ifdef CONFIG_XFRM
3215 xfrm_init();
3216 xfrm4_init();
3217#endif
3218 return rc;
3219}
3220
3221EXPORT_SYMBOL(__ip_select_ident);
3222EXPORT_SYMBOL(ip_route_input);
3223EXPORT_SYMBOL(ip_route_output_key);
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