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1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65#include <linux/module.h>
66#include <asm/uaccess.h>
67#include <asm/system.h>
68#include <linux/bitops.h>
69#include <linux/types.h>
70#include <linux/kernel.h>
71#include <linux/mm.h>
72#include <linux/bootmem.h>
73#include <linux/string.h>
74#include <linux/socket.h>
75#include <linux/sockios.h>
76#include <linux/errno.h>
77#include <linux/in.h>
78#include <linux/inet.h>
79#include <linux/netdevice.h>
80#include <linux/proc_fs.h>
81#include <linux/init.h>
82#include <linux/workqueue.h>
83#include <linux/skbuff.h>
84#include <linux/inetdevice.h>
85#include <linux/igmp.h>
86#include <linux/pkt_sched.h>
87#include <linux/mroute.h>
88#include <linux/netfilter_ipv4.h>
89#include <linux/random.h>
90#include <linux/jhash.h>
91#include <linux/rcupdate.h>
92#include <linux/times.h>
93#include <linux/slab.h>
94#include <net/dst.h>
95#include <net/net_namespace.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/netevent.h>
107#include <net/rtnetlink.h>
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_max_size;
120static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123static int ip_rt_redirect_number __read_mostly = 9;
124static int ip_rt_redirect_load __read_mostly = HZ / 50;
125static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126static int ip_rt_error_cost __read_mostly = HZ;
127static int ip_rt_error_burst __read_mostly = 5 * HZ;
128static int ip_rt_gc_elasticity __read_mostly = 8;
129static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131static int ip_rt_min_advmss __read_mostly = 256;
132static int rt_chain_length_max __read_mostly = 20;
133
134static struct delayed_work expires_work;
135static unsigned long expires_ljiffies;
136
137/*
138 * Interface to generic destination cache.
139 */
140
141static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142static void ipv4_dst_destroy(struct dst_entry *dst);
143static void ipv4_dst_ifdown(struct dst_entry *dst,
144 struct net_device *dev, int how);
145static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
146static void ipv4_link_failure(struct sk_buff *skb);
147static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
148static int rt_garbage_collect(struct dst_ops *ops);
149
150
151static struct dst_ops ipv4_dst_ops = {
152 .family = AF_INET,
153 .protocol = cpu_to_be16(ETH_P_IP),
154 .gc = rt_garbage_collect,
155 .check = ipv4_dst_check,
156 .destroy = ipv4_dst_destroy,
157 .ifdown = ipv4_dst_ifdown,
158 .negative_advice = ipv4_negative_advice,
159 .link_failure = ipv4_link_failure,
160 .update_pmtu = ip_rt_update_pmtu,
161 .local_out = __ip_local_out,
162 .entries = ATOMIC_INIT(0),
163};
164
165#define ECN_OR_COST(class) TC_PRIO_##class
166
167const __u8 ip_tos2prio[16] = {
168 TC_PRIO_BESTEFFORT,
169 ECN_OR_COST(FILLER),
170 TC_PRIO_BESTEFFORT,
171 ECN_OR_COST(BESTEFFORT),
172 TC_PRIO_BULK,
173 ECN_OR_COST(BULK),
174 TC_PRIO_BULK,
175 ECN_OR_COST(BULK),
176 TC_PRIO_INTERACTIVE,
177 ECN_OR_COST(INTERACTIVE),
178 TC_PRIO_INTERACTIVE,
179 ECN_OR_COST(INTERACTIVE),
180 TC_PRIO_INTERACTIVE_BULK,
181 ECN_OR_COST(INTERACTIVE_BULK),
182 TC_PRIO_INTERACTIVE_BULK,
183 ECN_OR_COST(INTERACTIVE_BULK)
184};
185
186
187/*
188 * Route cache.
189 */
190
191/* The locking scheme is rather straight forward:
192 *
193 * 1) Read-Copy Update protects the buckets of the central route hash.
194 * 2) Only writers remove entries, and they hold the lock
195 * as they look at rtable reference counts.
196 * 3) Only readers acquire references to rtable entries,
197 * they do so with atomic increments and with the
198 * lock held.
199 */
200
201struct rt_hash_bucket {
202 struct rtable *chain;
203};
204
205#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
206 defined(CONFIG_PROVE_LOCKING)
207/*
208 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
209 * The size of this table is a power of two and depends on the number of CPUS.
210 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
211 */
212#ifdef CONFIG_LOCKDEP
213# define RT_HASH_LOCK_SZ 256
214#else
215# if NR_CPUS >= 32
216# define RT_HASH_LOCK_SZ 4096
217# elif NR_CPUS >= 16
218# define RT_HASH_LOCK_SZ 2048
219# elif NR_CPUS >= 8
220# define RT_HASH_LOCK_SZ 1024
221# elif NR_CPUS >= 4
222# define RT_HASH_LOCK_SZ 512
223# else
224# define RT_HASH_LOCK_SZ 256
225# endif
226#endif
227
228static spinlock_t *rt_hash_locks;
229# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
230
231static __init void rt_hash_lock_init(void)
232{
233 int i;
234
235 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
236 GFP_KERNEL);
237 if (!rt_hash_locks)
238 panic("IP: failed to allocate rt_hash_locks\n");
239
240 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
241 spin_lock_init(&rt_hash_locks[i]);
242}
243#else
244# define rt_hash_lock_addr(slot) NULL
245
246static inline void rt_hash_lock_init(void)
247{
248}
249#endif
250
251static struct rt_hash_bucket *rt_hash_table __read_mostly;
252static unsigned rt_hash_mask __read_mostly;
253static unsigned int rt_hash_log __read_mostly;
254
255static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
256#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
257
258static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
259 int genid)
260{
261 return jhash_3words((__force u32)daddr, (__force u32)saddr,
262 idx, genid)
263 & rt_hash_mask;
264}
265
266static inline int rt_genid(struct net *net)
267{
268 return atomic_read(&net->ipv4.rt_genid);
269}
270
271#ifdef CONFIG_PROC_FS
272struct rt_cache_iter_state {
273 struct seq_net_private p;
274 int bucket;
275 int genid;
276};
277
278static struct rtable *rt_cache_get_first(struct seq_file *seq)
279{
280 struct rt_cache_iter_state *st = seq->private;
281 struct rtable *r = NULL;
282
283 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
284 if (!rt_hash_table[st->bucket].chain)
285 continue;
286 rcu_read_lock_bh();
287 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
288 while (r) {
289 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
290 r->rt_genid == st->genid)
291 return r;
292 r = rcu_dereference_bh(r->dst.rt_next);
293 }
294 rcu_read_unlock_bh();
295 }
296 return r;
297}
298
299static struct rtable *__rt_cache_get_next(struct seq_file *seq,
300 struct rtable *r)
301{
302 struct rt_cache_iter_state *st = seq->private;
303
304 r = r->dst.rt_next;
305 while (!r) {
306 rcu_read_unlock_bh();
307 do {
308 if (--st->bucket < 0)
309 return NULL;
310 } while (!rt_hash_table[st->bucket].chain);
311 rcu_read_lock_bh();
312 r = rt_hash_table[st->bucket].chain;
313 }
314 return rcu_dereference_bh(r);
315}
316
317static struct rtable *rt_cache_get_next(struct seq_file *seq,
318 struct rtable *r)
319{
320 struct rt_cache_iter_state *st = seq->private;
321 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
322 if (dev_net(r->dst.dev) != seq_file_net(seq))
323 continue;
324 if (r->rt_genid == st->genid)
325 break;
326 }
327 return r;
328}
329
330static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
331{
332 struct rtable *r = rt_cache_get_first(seq);
333
334 if (r)
335 while (pos && (r = rt_cache_get_next(seq, r)))
336 --pos;
337 return pos ? NULL : r;
338}
339
340static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
341{
342 struct rt_cache_iter_state *st = seq->private;
343 if (*pos)
344 return rt_cache_get_idx(seq, *pos - 1);
345 st->genid = rt_genid(seq_file_net(seq));
346 return SEQ_START_TOKEN;
347}
348
349static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
350{
351 struct rtable *r;
352
353 if (v == SEQ_START_TOKEN)
354 r = rt_cache_get_first(seq);
355 else
356 r = rt_cache_get_next(seq, v);
357 ++*pos;
358 return r;
359}
360
361static void rt_cache_seq_stop(struct seq_file *seq, void *v)
362{
363 if (v && v != SEQ_START_TOKEN)
364 rcu_read_unlock_bh();
365}
366
367static int rt_cache_seq_show(struct seq_file *seq, void *v)
368{
369 if (v == SEQ_START_TOKEN)
370 seq_printf(seq, "%-127s\n",
371 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
372 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
373 "HHUptod\tSpecDst");
374 else {
375 struct rtable *r = v;
376 int len;
377
378 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
379 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
380 r->dst.dev ? r->dst.dev->name : "*",
381 (__force u32)r->rt_dst,
382 (__force u32)r->rt_gateway,
383 r->rt_flags, atomic_read(&r->dst.__refcnt),
384 r->dst.__use, 0, (__force u32)r->rt_src,
385 (dst_metric(&r->dst, RTAX_ADVMSS) ?
386 (int)dst_metric(&r->dst, RTAX_ADVMSS) + 40 : 0),
387 dst_metric(&r->dst, RTAX_WINDOW),
388 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
389 dst_metric(&r->dst, RTAX_RTTVAR)),
390 r->fl.fl4_tos,
391 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
392 r->dst.hh ? (r->dst.hh->hh_output ==
393 dev_queue_xmit) : 0,
394 r->rt_spec_dst, &len);
395
396 seq_printf(seq, "%*s\n", 127 - len, "");
397 }
398 return 0;
399}
400
401static const struct seq_operations rt_cache_seq_ops = {
402 .start = rt_cache_seq_start,
403 .next = rt_cache_seq_next,
404 .stop = rt_cache_seq_stop,
405 .show = rt_cache_seq_show,
406};
407
408static int rt_cache_seq_open(struct inode *inode, struct file *file)
409{
410 return seq_open_net(inode, file, &rt_cache_seq_ops,
411 sizeof(struct rt_cache_iter_state));
412}
413
414static const struct file_operations rt_cache_seq_fops = {
415 .owner = THIS_MODULE,
416 .open = rt_cache_seq_open,
417 .read = seq_read,
418 .llseek = seq_lseek,
419 .release = seq_release_net,
420};
421
422
423static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
424{
425 int cpu;
426
427 if (*pos == 0)
428 return SEQ_START_TOKEN;
429
430 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
431 if (!cpu_possible(cpu))
432 continue;
433 *pos = cpu+1;
434 return &per_cpu(rt_cache_stat, cpu);
435 }
436 return NULL;
437}
438
439static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
440{
441 int cpu;
442
443 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
444 if (!cpu_possible(cpu))
445 continue;
446 *pos = cpu+1;
447 return &per_cpu(rt_cache_stat, cpu);
448 }
449 return NULL;
450
451}
452
453static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
454{
455
456}
457
458static int rt_cpu_seq_show(struct seq_file *seq, void *v)
459{
460 struct rt_cache_stat *st = v;
461
462 if (v == SEQ_START_TOKEN) {
463 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
464 return 0;
465 }
466
467 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
468 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
469 atomic_read(&ipv4_dst_ops.entries),
470 st->in_hit,
471 st->in_slow_tot,
472 st->in_slow_mc,
473 st->in_no_route,
474 st->in_brd,
475 st->in_martian_dst,
476 st->in_martian_src,
477
478 st->out_hit,
479 st->out_slow_tot,
480 st->out_slow_mc,
481
482 st->gc_total,
483 st->gc_ignored,
484 st->gc_goal_miss,
485 st->gc_dst_overflow,
486 st->in_hlist_search,
487 st->out_hlist_search
488 );
489 return 0;
490}
491
492static const struct seq_operations rt_cpu_seq_ops = {
493 .start = rt_cpu_seq_start,
494 .next = rt_cpu_seq_next,
495 .stop = rt_cpu_seq_stop,
496 .show = rt_cpu_seq_show,
497};
498
499
500static int rt_cpu_seq_open(struct inode *inode, struct file *file)
501{
502 return seq_open(file, &rt_cpu_seq_ops);
503}
504
505static const struct file_operations rt_cpu_seq_fops = {
506 .owner = THIS_MODULE,
507 .open = rt_cpu_seq_open,
508 .read = seq_read,
509 .llseek = seq_lseek,
510 .release = seq_release,
511};
512
513#ifdef CONFIG_NET_CLS_ROUTE
514static int rt_acct_proc_show(struct seq_file *m, void *v)
515{
516 struct ip_rt_acct *dst, *src;
517 unsigned int i, j;
518
519 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
520 if (!dst)
521 return -ENOMEM;
522
523 for_each_possible_cpu(i) {
524 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
525 for (j = 0; j < 256; j++) {
526 dst[j].o_bytes += src[j].o_bytes;
527 dst[j].o_packets += src[j].o_packets;
528 dst[j].i_bytes += src[j].i_bytes;
529 dst[j].i_packets += src[j].i_packets;
530 }
531 }
532
533 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
534 kfree(dst);
535 return 0;
536}
537
538static int rt_acct_proc_open(struct inode *inode, struct file *file)
539{
540 return single_open(file, rt_acct_proc_show, NULL);
541}
542
543static const struct file_operations rt_acct_proc_fops = {
544 .owner = THIS_MODULE,
545 .open = rt_acct_proc_open,
546 .read = seq_read,
547 .llseek = seq_lseek,
548 .release = single_release,
549};
550#endif
551
552static int __net_init ip_rt_do_proc_init(struct net *net)
553{
554 struct proc_dir_entry *pde;
555
556 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
557 &rt_cache_seq_fops);
558 if (!pde)
559 goto err1;
560
561 pde = proc_create("rt_cache", S_IRUGO,
562 net->proc_net_stat, &rt_cpu_seq_fops);
563 if (!pde)
564 goto err2;
565
566#ifdef CONFIG_NET_CLS_ROUTE
567 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
568 if (!pde)
569 goto err3;
570#endif
571 return 0;
572
573#ifdef CONFIG_NET_CLS_ROUTE
574err3:
575 remove_proc_entry("rt_cache", net->proc_net_stat);
576#endif
577err2:
578 remove_proc_entry("rt_cache", net->proc_net);
579err1:
580 return -ENOMEM;
581}
582
583static void __net_exit ip_rt_do_proc_exit(struct net *net)
584{
585 remove_proc_entry("rt_cache", net->proc_net_stat);
586 remove_proc_entry("rt_cache", net->proc_net);
587#ifdef CONFIG_NET_CLS_ROUTE
588 remove_proc_entry("rt_acct", net->proc_net);
589#endif
590}
591
592static struct pernet_operations ip_rt_proc_ops __net_initdata = {
593 .init = ip_rt_do_proc_init,
594 .exit = ip_rt_do_proc_exit,
595};
596
597static int __init ip_rt_proc_init(void)
598{
599 return register_pernet_subsys(&ip_rt_proc_ops);
600}
601
602#else
603static inline int ip_rt_proc_init(void)
604{
605 return 0;
606}
607#endif /* CONFIG_PROC_FS */
608
609static inline void rt_free(struct rtable *rt)
610{
611 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
612}
613
614static inline void rt_drop(struct rtable *rt)
615{
616 ip_rt_put(rt);
617 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
618}
619
620static inline int rt_fast_clean(struct rtable *rth)
621{
622 /* Kill broadcast/multicast entries very aggresively, if they
623 collide in hash table with more useful entries */
624 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
625 rth->fl.iif && rth->dst.rt_next;
626}
627
628static inline int rt_valuable(struct rtable *rth)
629{
630 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
631 rth->dst.expires;
632}
633
634static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
635{
636 unsigned long age;
637 int ret = 0;
638
639 if (atomic_read(&rth->dst.__refcnt))
640 goto out;
641
642 ret = 1;
643 if (rth->dst.expires &&
644 time_after_eq(jiffies, rth->dst.expires))
645 goto out;
646
647 age = jiffies - rth->dst.lastuse;
648 ret = 0;
649 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
650 (age <= tmo2 && rt_valuable(rth)))
651 goto out;
652 ret = 1;
653out: return ret;
654}
655
656/* Bits of score are:
657 * 31: very valuable
658 * 30: not quite useless
659 * 29..0: usage counter
660 */
661static inline u32 rt_score(struct rtable *rt)
662{
663 u32 score = jiffies - rt->dst.lastuse;
664
665 score = ~score & ~(3<<30);
666
667 if (rt_valuable(rt))
668 score |= (1<<31);
669
670 if (!rt->fl.iif ||
671 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
672 score |= (1<<30);
673
674 return score;
675}
676
677static inline bool rt_caching(const struct net *net)
678{
679 return net->ipv4.current_rt_cache_rebuild_count <=
680 net->ipv4.sysctl_rt_cache_rebuild_count;
681}
682
683static inline bool compare_hash_inputs(const struct flowi *fl1,
684 const struct flowi *fl2)
685{
686 return ((((__force u32)fl1->nl_u.ip4_u.daddr ^ (__force u32)fl2->nl_u.ip4_u.daddr) |
687 ((__force u32)fl1->nl_u.ip4_u.saddr ^ (__force u32)fl2->nl_u.ip4_u.saddr) |
688 (fl1->iif ^ fl2->iif)) == 0);
689}
690
691static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
692{
693 return (((__force u32)fl1->nl_u.ip4_u.daddr ^ (__force u32)fl2->nl_u.ip4_u.daddr) |
694 ((__force u32)fl1->nl_u.ip4_u.saddr ^ (__force u32)fl2->nl_u.ip4_u.saddr) |
695 (fl1->mark ^ fl2->mark) |
696 (*(u16 *)&fl1->nl_u.ip4_u.tos ^ *(u16 *)&fl2->nl_u.ip4_u.tos) |
697 (fl1->oif ^ fl2->oif) |
698 (fl1->iif ^ fl2->iif)) == 0;
699}
700
701static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
702{
703 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
704}
705
706static inline int rt_is_expired(struct rtable *rth)
707{
708 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
709}
710
711/*
712 * Perform a full scan of hash table and free all entries.
713 * Can be called by a softirq or a process.
714 * In the later case, we want to be reschedule if necessary
715 */
716static void rt_do_flush(int process_context)
717{
718 unsigned int i;
719 struct rtable *rth, *next;
720 struct rtable * tail;
721
722 for (i = 0; i <= rt_hash_mask; i++) {
723 if (process_context && need_resched())
724 cond_resched();
725 rth = rt_hash_table[i].chain;
726 if (!rth)
727 continue;
728
729 spin_lock_bh(rt_hash_lock_addr(i));
730#ifdef CONFIG_NET_NS
731 {
732 struct rtable ** prev, * p;
733
734 rth = rt_hash_table[i].chain;
735
736 /* defer releasing the head of the list after spin_unlock */
737 for (tail = rth; tail; tail = tail->dst.rt_next)
738 if (!rt_is_expired(tail))
739 break;
740 if (rth != tail)
741 rt_hash_table[i].chain = tail;
742
743 /* call rt_free on entries after the tail requiring flush */
744 prev = &rt_hash_table[i].chain;
745 for (p = *prev; p; p = next) {
746 next = p->dst.rt_next;
747 if (!rt_is_expired(p)) {
748 prev = &p->dst.rt_next;
749 } else {
750 *prev = next;
751 rt_free(p);
752 }
753 }
754 }
755#else
756 rth = rt_hash_table[i].chain;
757 rt_hash_table[i].chain = NULL;
758 tail = NULL;
759#endif
760 spin_unlock_bh(rt_hash_lock_addr(i));
761
762 for (; rth != tail; rth = next) {
763 next = rth->dst.rt_next;
764 rt_free(rth);
765 }
766 }
767}
768
769/*
770 * While freeing expired entries, we compute average chain length
771 * and standard deviation, using fixed-point arithmetic.
772 * This to have an estimation of rt_chain_length_max
773 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
774 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
775 */
776
777#define FRACT_BITS 3
778#define ONE (1UL << FRACT_BITS)
779
780/*
781 * Given a hash chain and an item in this hash chain,
782 * find if a previous entry has the same hash_inputs
783 * (but differs on tos, mark or oif)
784 * Returns 0 if an alias is found.
785 * Returns ONE if rth has no alias before itself.
786 */
787static int has_noalias(const struct rtable *head, const struct rtable *rth)
788{
789 const struct rtable *aux = head;
790
791 while (aux != rth) {
792 if (compare_hash_inputs(&aux->fl, &rth->fl))
793 return 0;
794 aux = aux->dst.rt_next;
795 }
796 return ONE;
797}
798
799static void rt_check_expire(void)
800{
801 static unsigned int rover;
802 unsigned int i = rover, goal;
803 struct rtable *rth, **rthp;
804 unsigned long samples = 0;
805 unsigned long sum = 0, sum2 = 0;
806 unsigned long delta;
807 u64 mult;
808
809 delta = jiffies - expires_ljiffies;
810 expires_ljiffies = jiffies;
811 mult = ((u64)delta) << rt_hash_log;
812 if (ip_rt_gc_timeout > 1)
813 do_div(mult, ip_rt_gc_timeout);
814 goal = (unsigned int)mult;
815 if (goal > rt_hash_mask)
816 goal = rt_hash_mask + 1;
817 for (; goal > 0; goal--) {
818 unsigned long tmo = ip_rt_gc_timeout;
819 unsigned long length;
820
821 i = (i + 1) & rt_hash_mask;
822 rthp = &rt_hash_table[i].chain;
823
824 if (need_resched())
825 cond_resched();
826
827 samples++;
828
829 if (*rthp == NULL)
830 continue;
831 length = 0;
832 spin_lock_bh(rt_hash_lock_addr(i));
833 while ((rth = *rthp) != NULL) {
834 prefetch(rth->dst.rt_next);
835 if (rt_is_expired(rth)) {
836 *rthp = rth->dst.rt_next;
837 rt_free(rth);
838 continue;
839 }
840 if (rth->dst.expires) {
841 /* Entry is expired even if it is in use */
842 if (time_before_eq(jiffies, rth->dst.expires)) {
843nofree:
844 tmo >>= 1;
845 rthp = &rth->dst.rt_next;
846 /*
847 * We only count entries on
848 * a chain with equal hash inputs once
849 * so that entries for different QOS
850 * levels, and other non-hash input
851 * attributes don't unfairly skew
852 * the length computation
853 */
854 length += has_noalias(rt_hash_table[i].chain, rth);
855 continue;
856 }
857 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
858 goto nofree;
859
860 /* Cleanup aged off entries. */
861 *rthp = rth->dst.rt_next;
862 rt_free(rth);
863 }
864 spin_unlock_bh(rt_hash_lock_addr(i));
865 sum += length;
866 sum2 += length*length;
867 }
868 if (samples) {
869 unsigned long avg = sum / samples;
870 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
871 rt_chain_length_max = max_t(unsigned long,
872 ip_rt_gc_elasticity,
873 (avg + 4*sd) >> FRACT_BITS);
874 }
875 rover = i;
876}
877
878/*
879 * rt_worker_func() is run in process context.
880 * we call rt_check_expire() to scan part of the hash table
881 */
882static void rt_worker_func(struct work_struct *work)
883{
884 rt_check_expire();
885 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
886}
887
888/*
889 * Pertubation of rt_genid by a small quantity [1..256]
890 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
891 * many times (2^24) without giving recent rt_genid.
892 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
893 */
894static void rt_cache_invalidate(struct net *net)
895{
896 unsigned char shuffle;
897
898 get_random_bytes(&shuffle, sizeof(shuffle));
899 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
900}
901
902/*
903 * delay < 0 : invalidate cache (fast : entries will be deleted later)
904 * delay >= 0 : invalidate & flush cache (can be long)
905 */
906void rt_cache_flush(struct net *net, int delay)
907{
908 rt_cache_invalidate(net);
909 if (delay >= 0)
910 rt_do_flush(!in_softirq());
911}
912
913/* Flush previous cache invalidated entries from the cache */
914void rt_cache_flush_batch(void)
915{
916 rt_do_flush(!in_softirq());
917}
918
919static void rt_emergency_hash_rebuild(struct net *net)
920{
921 if (net_ratelimit())
922 printk(KERN_WARNING "Route hash chain too long!\n");
923 rt_cache_invalidate(net);
924}
925
926/*
927 Short description of GC goals.
928
929 We want to build algorithm, which will keep routing cache
930 at some equilibrium point, when number of aged off entries
931 is kept approximately equal to newly generated ones.
932
933 Current expiration strength is variable "expire".
934 We try to adjust it dynamically, so that if networking
935 is idle expires is large enough to keep enough of warm entries,
936 and when load increases it reduces to limit cache size.
937 */
938
939static int rt_garbage_collect(struct dst_ops *ops)
940{
941 static unsigned long expire = RT_GC_TIMEOUT;
942 static unsigned long last_gc;
943 static int rover;
944 static int equilibrium;
945 struct rtable *rth, **rthp;
946 unsigned long now = jiffies;
947 int goal;
948
949 /*
950 * Garbage collection is pretty expensive,
951 * do not make it too frequently.
952 */
953
954 RT_CACHE_STAT_INC(gc_total);
955
956 if (now - last_gc < ip_rt_gc_min_interval &&
957 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
958 RT_CACHE_STAT_INC(gc_ignored);
959 goto out;
960 }
961
962 /* Calculate number of entries, which we want to expire now. */
963 goal = atomic_read(&ipv4_dst_ops.entries) -
964 (ip_rt_gc_elasticity << rt_hash_log);
965 if (goal <= 0) {
966 if (equilibrium < ipv4_dst_ops.gc_thresh)
967 equilibrium = ipv4_dst_ops.gc_thresh;
968 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
969 if (goal > 0) {
970 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
971 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
972 }
973 } else {
974 /* We are in dangerous area. Try to reduce cache really
975 * aggressively.
976 */
977 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
978 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
979 }
980
981 if (now - last_gc >= ip_rt_gc_min_interval)
982 last_gc = now;
983
984 if (goal <= 0) {
985 equilibrium += goal;
986 goto work_done;
987 }
988
989 do {
990 int i, k;
991
992 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
993 unsigned long tmo = expire;
994
995 k = (k + 1) & rt_hash_mask;
996 rthp = &rt_hash_table[k].chain;
997 spin_lock_bh(rt_hash_lock_addr(k));
998 while ((rth = *rthp) != NULL) {
999 if (!rt_is_expired(rth) &&
1000 !rt_may_expire(rth, tmo, expire)) {
1001 tmo >>= 1;
1002 rthp = &rth->dst.rt_next;
1003 continue;
1004 }
1005 *rthp = rth->dst.rt_next;
1006 rt_free(rth);
1007 goal--;
1008 }
1009 spin_unlock_bh(rt_hash_lock_addr(k));
1010 if (goal <= 0)
1011 break;
1012 }
1013 rover = k;
1014
1015 if (goal <= 0)
1016 goto work_done;
1017
1018 /* Goal is not achieved. We stop process if:
1019
1020 - if expire reduced to zero. Otherwise, expire is halfed.
1021 - if table is not full.
1022 - if we are called from interrupt.
1023 - jiffies check is just fallback/debug loop breaker.
1024 We will not spin here for long time in any case.
1025 */
1026
1027 RT_CACHE_STAT_INC(gc_goal_miss);
1028
1029 if (expire == 0)
1030 break;
1031
1032 expire >>= 1;
1033#if RT_CACHE_DEBUG >= 2
1034 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
1035 atomic_read(&ipv4_dst_ops.entries), goal, i);
1036#endif
1037
1038 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1039 goto out;
1040 } while (!in_softirq() && time_before_eq(jiffies, now));
1041
1042 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
1043 goto out;
1044 if (net_ratelimit())
1045 printk(KERN_WARNING "dst cache overflow\n");
1046 RT_CACHE_STAT_INC(gc_dst_overflow);
1047 return 1;
1048
1049work_done:
1050 expire += ip_rt_gc_min_interval;
1051 if (expire > ip_rt_gc_timeout ||
1052 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
1053 expire = ip_rt_gc_timeout;
1054#if RT_CACHE_DEBUG >= 2
1055 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
1056 atomic_read(&ipv4_dst_ops.entries), goal, rover);
1057#endif
1058out: return 0;
1059}
1060
1061/*
1062 * Returns number of entries in a hash chain that have different hash_inputs
1063 */
1064static int slow_chain_length(const struct rtable *head)
1065{
1066 int length = 0;
1067 const struct rtable *rth = head;
1068
1069 while (rth) {
1070 length += has_noalias(head, rth);
1071 rth = rth->dst.rt_next;
1072 }
1073 return length >> FRACT_BITS;
1074}
1075
1076static int rt_intern_hash(unsigned hash, struct rtable *rt,
1077 struct rtable **rp, struct sk_buff *skb, int ifindex)
1078{
1079 struct rtable *rth, **rthp;
1080 unsigned long now;
1081 struct rtable *cand, **candp;
1082 u32 min_score;
1083 int chain_length;
1084 int attempts = !in_softirq();
1085
1086restart:
1087 chain_length = 0;
1088 min_score = ~(u32)0;
1089 cand = NULL;
1090 candp = NULL;
1091 now = jiffies;
1092
1093 if (!rt_caching(dev_net(rt->dst.dev))) {
1094 /*
1095 * If we're not caching, just tell the caller we
1096 * were successful and don't touch the route. The
1097 * caller hold the sole reference to the cache entry, and
1098 * it will be released when the caller is done with it.
1099 * If we drop it here, the callers have no way to resolve routes
1100 * when we're not caching. Instead, just point *rp at rt, so
1101 * the caller gets a single use out of the route
1102 * Note that we do rt_free on this new route entry, so that
1103 * once its refcount hits zero, we are still able to reap it
1104 * (Thanks Alexey)
1105 * Note also the rt_free uses call_rcu. We don't actually
1106 * need rcu protection here, this is just our path to get
1107 * on the route gc list.
1108 */
1109
1110 rt->dst.flags |= DST_NOCACHE;
1111 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1112 int err = arp_bind_neighbour(&rt->dst);
1113 if (err) {
1114 if (net_ratelimit())
1115 printk(KERN_WARNING
1116 "Neighbour table failure & not caching routes.\n");
1117 rt_drop(rt);
1118 return err;
1119 }
1120 }
1121
1122 rt_free(rt);
1123 goto skip_hashing;
1124 }
1125
1126 rthp = &rt_hash_table[hash].chain;
1127
1128 spin_lock_bh(rt_hash_lock_addr(hash));
1129 while ((rth = *rthp) != NULL) {
1130 if (rt_is_expired(rth)) {
1131 *rthp = rth->dst.rt_next;
1132 rt_free(rth);
1133 continue;
1134 }
1135 if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
1136 /* Put it first */
1137 *rthp = rth->dst.rt_next;
1138 /*
1139 * Since lookup is lockfree, the deletion
1140 * must be visible to another weakly ordered CPU before
1141 * the insertion at the start of the hash chain.
1142 */
1143 rcu_assign_pointer(rth->dst.rt_next,
1144 rt_hash_table[hash].chain);
1145 /*
1146 * Since lookup is lockfree, the update writes
1147 * must be ordered for consistency on SMP.
1148 */
1149 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1150
1151 dst_use(&rth->dst, now);
1152 spin_unlock_bh(rt_hash_lock_addr(hash));
1153
1154 rt_drop(rt);
1155 if (rp)
1156 *rp = rth;
1157 else
1158 skb_dst_set(skb, &rth->dst);
1159 return 0;
1160 }
1161
1162 if (!atomic_read(&rth->dst.__refcnt)) {
1163 u32 score = rt_score(rth);
1164
1165 if (score <= min_score) {
1166 cand = rth;
1167 candp = rthp;
1168 min_score = score;
1169 }
1170 }
1171
1172 chain_length++;
1173
1174 rthp = &rth->dst.rt_next;
1175 }
1176
1177 if (cand) {
1178 /* ip_rt_gc_elasticity used to be average length of chain
1179 * length, when exceeded gc becomes really aggressive.
1180 *
1181 * The second limit is less certain. At the moment it allows
1182 * only 2 entries per bucket. We will see.
1183 */
1184 if (chain_length > ip_rt_gc_elasticity) {
1185 *candp = cand->dst.rt_next;
1186 rt_free(cand);
1187 }
1188 } else {
1189 if (chain_length > rt_chain_length_max &&
1190 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1191 struct net *net = dev_net(rt->dst.dev);
1192 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1193 if (!rt_caching(net)) {
1194 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1195 rt->dst.dev->name, num);
1196 }
1197 rt_emergency_hash_rebuild(net);
1198 spin_unlock_bh(rt_hash_lock_addr(hash));
1199
1200 hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1201 ifindex, rt_genid(net));
1202 goto restart;
1203 }
1204 }
1205
1206 /* Try to bind route to arp only if it is output
1207 route or unicast forwarding path.
1208 */
1209 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1210 int err = arp_bind_neighbour(&rt->dst);
1211 if (err) {
1212 spin_unlock_bh(rt_hash_lock_addr(hash));
1213
1214 if (err != -ENOBUFS) {
1215 rt_drop(rt);
1216 return err;
1217 }
1218
1219 /* Neighbour tables are full and nothing
1220 can be released. Try to shrink route cache,
1221 it is most likely it holds some neighbour records.
1222 */
1223 if (attempts-- > 0) {
1224 int saved_elasticity = ip_rt_gc_elasticity;
1225 int saved_int = ip_rt_gc_min_interval;
1226 ip_rt_gc_elasticity = 1;
1227 ip_rt_gc_min_interval = 0;
1228 rt_garbage_collect(&ipv4_dst_ops);
1229 ip_rt_gc_min_interval = saved_int;
1230 ip_rt_gc_elasticity = saved_elasticity;
1231 goto restart;
1232 }
1233
1234 if (net_ratelimit())
1235 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1236 rt_drop(rt);
1237 return -ENOBUFS;
1238 }
1239 }
1240
1241 rt->dst.rt_next = rt_hash_table[hash].chain;
1242
1243#if RT_CACHE_DEBUG >= 2
1244 if (rt->dst.rt_next) {
1245 struct rtable *trt;
1246 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1247 hash, &rt->rt_dst);
1248 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1249 printk(" . %pI4", &trt->rt_dst);
1250 printk("\n");
1251 }
1252#endif
1253 /*
1254 * Since lookup is lockfree, we must make sure
1255 * previous writes to rt are comitted to memory
1256 * before making rt visible to other CPUS.
1257 */
1258 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1259
1260 spin_unlock_bh(rt_hash_lock_addr(hash));
1261
1262skip_hashing:
1263 if (rp)
1264 *rp = rt;
1265 else
1266 skb_dst_set(skb, &rt->dst);
1267 return 0;
1268}
1269
1270void rt_bind_peer(struct rtable *rt, int create)
1271{
1272 struct inet_peer *peer;
1273
1274 peer = inet_getpeer(rt->rt_dst, create);
1275
1276 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1277 inet_putpeer(peer);
1278}
1279
1280/*
1281 * Peer allocation may fail only in serious out-of-memory conditions. However
1282 * we still can generate some output.
1283 * Random ID selection looks a bit dangerous because we have no chances to
1284 * select ID being unique in a reasonable period of time.
1285 * But broken packet identifier may be better than no packet at all.
1286 */
1287static void ip_select_fb_ident(struct iphdr *iph)
1288{
1289 static DEFINE_SPINLOCK(ip_fb_id_lock);
1290 static u32 ip_fallback_id;
1291 u32 salt;
1292
1293 spin_lock_bh(&ip_fb_id_lock);
1294 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1295 iph->id = htons(salt & 0xFFFF);
1296 ip_fallback_id = salt;
1297 spin_unlock_bh(&ip_fb_id_lock);
1298}
1299
1300void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1301{
1302 struct rtable *rt = (struct rtable *) dst;
1303
1304 if (rt) {
1305 if (rt->peer == NULL)
1306 rt_bind_peer(rt, 1);
1307
1308 /* If peer is attached to destination, it is never detached,
1309 so that we need not to grab a lock to dereference it.
1310 */
1311 if (rt->peer) {
1312 iph->id = htons(inet_getid(rt->peer, more));
1313 return;
1314 }
1315 } else
1316 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1317 __builtin_return_address(0));
1318
1319 ip_select_fb_ident(iph);
1320}
1321EXPORT_SYMBOL(__ip_select_ident);
1322
1323static void rt_del(unsigned hash, struct rtable *rt)
1324{
1325 struct rtable **rthp, *aux;
1326
1327 rthp = &rt_hash_table[hash].chain;
1328 spin_lock_bh(rt_hash_lock_addr(hash));
1329 ip_rt_put(rt);
1330 while ((aux = *rthp) != NULL) {
1331 if (aux == rt || rt_is_expired(aux)) {
1332 *rthp = aux->dst.rt_next;
1333 rt_free(aux);
1334 continue;
1335 }
1336 rthp = &aux->dst.rt_next;
1337 }
1338 spin_unlock_bh(rt_hash_lock_addr(hash));
1339}
1340
1341/* called in rcu_read_lock() section */
1342void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1343 __be32 saddr, struct net_device *dev)
1344{
1345 int i, k;
1346 struct in_device *in_dev = __in_dev_get_rcu(dev);
1347 struct rtable *rth, **rthp;
1348 __be32 skeys[2] = { saddr, 0 };
1349 int ikeys[2] = { dev->ifindex, 0 };
1350 struct netevent_redirect netevent;
1351 struct net *net;
1352
1353 if (!in_dev)
1354 return;
1355
1356 net = dev_net(dev);
1357 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1358 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1359 ipv4_is_zeronet(new_gw))
1360 goto reject_redirect;
1361
1362 if (!rt_caching(net))
1363 goto reject_redirect;
1364
1365 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1366 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1367 goto reject_redirect;
1368 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1369 goto reject_redirect;
1370 } else {
1371 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1372 goto reject_redirect;
1373 }
1374
1375 for (i = 0; i < 2; i++) {
1376 for (k = 0; k < 2; k++) {
1377 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1378 rt_genid(net));
1379
1380 rthp=&rt_hash_table[hash].chain;
1381
1382 while ((rth = rcu_dereference(*rthp)) != NULL) {
1383 struct rtable *rt;
1384
1385 if (rth->fl.fl4_dst != daddr ||
1386 rth->fl.fl4_src != skeys[i] ||
1387 rth->fl.oif != ikeys[k] ||
1388 rth->fl.iif != 0 ||
1389 rt_is_expired(rth) ||
1390 !net_eq(dev_net(rth->dst.dev), net)) {
1391 rthp = &rth->dst.rt_next;
1392 continue;
1393 }
1394
1395 if (rth->rt_dst != daddr ||
1396 rth->rt_src != saddr ||
1397 rth->dst.error ||
1398 rth->rt_gateway != old_gw ||
1399 rth->dst.dev != dev)
1400 break;
1401
1402 dst_hold(&rth->dst);
1403
1404 rt = dst_alloc(&ipv4_dst_ops);
1405 if (rt == NULL) {
1406 ip_rt_put(rth);
1407 return;
1408 }
1409
1410 /* Copy all the information. */
1411 *rt = *rth;
1412 rt->dst.__use = 1;
1413 atomic_set(&rt->dst.__refcnt, 1);
1414 rt->dst.child = NULL;
1415 if (rt->dst.dev)
1416 dev_hold(rt->dst.dev);
1417 if (rt->idev)
1418 in_dev_hold(rt->idev);
1419 rt->dst.obsolete = -1;
1420 rt->dst.lastuse = jiffies;
1421 rt->dst.path = &rt->dst;
1422 rt->dst.neighbour = NULL;
1423 rt->dst.hh = NULL;
1424#ifdef CONFIG_XFRM
1425 rt->dst.xfrm = NULL;
1426#endif
1427 rt->rt_genid = rt_genid(net);
1428 rt->rt_flags |= RTCF_REDIRECTED;
1429
1430 /* Gateway is different ... */
1431 rt->rt_gateway = new_gw;
1432
1433 /* Redirect received -> path was valid */
1434 dst_confirm(&rth->dst);
1435
1436 if (rt->peer)
1437 atomic_inc(&rt->peer->refcnt);
1438
1439 if (arp_bind_neighbour(&rt->dst) ||
1440 !(rt->dst.neighbour->nud_state &
1441 NUD_VALID)) {
1442 if (rt->dst.neighbour)
1443 neigh_event_send(rt->dst.neighbour, NULL);
1444 ip_rt_put(rth);
1445 rt_drop(rt);
1446 goto do_next;
1447 }
1448
1449 netevent.old = &rth->dst;
1450 netevent.new = &rt->dst;
1451 call_netevent_notifiers(NETEVENT_REDIRECT,
1452 &netevent);
1453
1454 rt_del(hash, rth);
1455 if (!rt_intern_hash(hash, rt, &rt, NULL, rt->fl.oif))
1456 ip_rt_put(rt);
1457 goto do_next;
1458 }
1459 do_next:
1460 ;
1461 }
1462 }
1463 return;
1464
1465reject_redirect:
1466#ifdef CONFIG_IP_ROUTE_VERBOSE
1467 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1468 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1469 " Advised path = %pI4 -> %pI4\n",
1470 &old_gw, dev->name, &new_gw,
1471 &saddr, &daddr);
1472#endif
1473 ;
1474}
1475
1476static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1477{
1478 struct rtable *rt = (struct rtable *)dst;
1479 struct dst_entry *ret = dst;
1480
1481 if (rt) {
1482 if (dst->obsolete > 0) {
1483 ip_rt_put(rt);
1484 ret = NULL;
1485 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1486 (rt->dst.expires &&
1487 time_after_eq(jiffies, rt->dst.expires))) {
1488 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1489 rt->fl.oif,
1490 rt_genid(dev_net(dst->dev)));
1491#if RT_CACHE_DEBUG >= 1
1492 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1493 &rt->rt_dst, rt->fl.fl4_tos);
1494#endif
1495 rt_del(hash, rt);
1496 ret = NULL;
1497 }
1498 }
1499 return ret;
1500}
1501
1502/*
1503 * Algorithm:
1504 * 1. The first ip_rt_redirect_number redirects are sent
1505 * with exponential backoff, then we stop sending them at all,
1506 * assuming that the host ignores our redirects.
1507 * 2. If we did not see packets requiring redirects
1508 * during ip_rt_redirect_silence, we assume that the host
1509 * forgot redirected route and start to send redirects again.
1510 *
1511 * This algorithm is much cheaper and more intelligent than dumb load limiting
1512 * in icmp.c.
1513 *
1514 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1515 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1516 */
1517
1518void ip_rt_send_redirect(struct sk_buff *skb)
1519{
1520 struct rtable *rt = skb_rtable(skb);
1521 struct in_device *in_dev;
1522 int log_martians;
1523
1524 rcu_read_lock();
1525 in_dev = __in_dev_get_rcu(rt->dst.dev);
1526 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1527 rcu_read_unlock();
1528 return;
1529 }
1530 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1531 rcu_read_unlock();
1532
1533 /* No redirected packets during ip_rt_redirect_silence;
1534 * reset the algorithm.
1535 */
1536 if (time_after(jiffies, rt->dst.rate_last + ip_rt_redirect_silence))
1537 rt->dst.rate_tokens = 0;
1538
1539 /* Too many ignored redirects; do not send anything
1540 * set dst.rate_last to the last seen redirected packet.
1541 */
1542 if (rt->dst.rate_tokens >= ip_rt_redirect_number) {
1543 rt->dst.rate_last = jiffies;
1544 return;
1545 }
1546
1547 /* Check for load limit; set rate_last to the latest sent
1548 * redirect.
1549 */
1550 if (rt->dst.rate_tokens == 0 ||
1551 time_after(jiffies,
1552 (rt->dst.rate_last +
1553 (ip_rt_redirect_load << rt->dst.rate_tokens)))) {
1554 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1555 rt->dst.rate_last = jiffies;
1556 ++rt->dst.rate_tokens;
1557#ifdef CONFIG_IP_ROUTE_VERBOSE
1558 if (log_martians &&
1559 rt->dst.rate_tokens == ip_rt_redirect_number &&
1560 net_ratelimit())
1561 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1562 &rt->rt_src, rt->rt_iif,
1563 &rt->rt_dst, &rt->rt_gateway);
1564#endif
1565 }
1566}
1567
1568static int ip_error(struct sk_buff *skb)
1569{
1570 struct rtable *rt = skb_rtable(skb);
1571 unsigned long now;
1572 int code;
1573
1574 switch (rt->dst.error) {
1575 case EINVAL:
1576 default:
1577 goto out;
1578 case EHOSTUNREACH:
1579 code = ICMP_HOST_UNREACH;
1580 break;
1581 case ENETUNREACH:
1582 code = ICMP_NET_UNREACH;
1583 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1584 IPSTATS_MIB_INNOROUTES);
1585 break;
1586 case EACCES:
1587 code = ICMP_PKT_FILTERED;
1588 break;
1589 }
1590
1591 now = jiffies;
1592 rt->dst.rate_tokens += now - rt->dst.rate_last;
1593 if (rt->dst.rate_tokens > ip_rt_error_burst)
1594 rt->dst.rate_tokens = ip_rt_error_burst;
1595 rt->dst.rate_last = now;
1596 if (rt->dst.rate_tokens >= ip_rt_error_cost) {
1597 rt->dst.rate_tokens -= ip_rt_error_cost;
1598 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1599 }
1600
1601out: kfree_skb(skb);
1602 return 0;
1603}
1604
1605/*
1606 * The last two values are not from the RFC but
1607 * are needed for AMPRnet AX.25 paths.
1608 */
1609
1610static const unsigned short mtu_plateau[] =
1611{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1612
1613static inline unsigned short guess_mtu(unsigned short old_mtu)
1614{
1615 int i;
1616
1617 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1618 if (old_mtu > mtu_plateau[i])
1619 return mtu_plateau[i];
1620 return 68;
1621}
1622
1623unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1624 unsigned short new_mtu,
1625 struct net_device *dev)
1626{
1627 int i, k;
1628 unsigned short old_mtu = ntohs(iph->tot_len);
1629 struct rtable *rth;
1630 int ikeys[2] = { dev->ifindex, 0 };
1631 __be32 skeys[2] = { iph->saddr, 0, };
1632 __be32 daddr = iph->daddr;
1633 unsigned short est_mtu = 0;
1634
1635 for (k = 0; k < 2; k++) {
1636 for (i = 0; i < 2; i++) {
1637 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
1638 rt_genid(net));
1639
1640 rcu_read_lock();
1641 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1642 rth = rcu_dereference(rth->dst.rt_next)) {
1643 unsigned short mtu = new_mtu;
1644
1645 if (rth->fl.fl4_dst != daddr ||
1646 rth->fl.fl4_src != skeys[i] ||
1647 rth->rt_dst != daddr ||
1648 rth->rt_src != iph->saddr ||
1649 rth->fl.oif != ikeys[k] ||
1650 rth->fl.iif != 0 ||
1651 dst_metric_locked(&rth->dst, RTAX_MTU) ||
1652 !net_eq(dev_net(rth->dst.dev), net) ||
1653 rt_is_expired(rth))
1654 continue;
1655
1656 if (new_mtu < 68 || new_mtu >= old_mtu) {
1657
1658 /* BSD 4.2 compatibility hack :-( */
1659 if (mtu == 0 &&
1660 old_mtu >= dst_mtu(&rth->dst) &&
1661 old_mtu >= 68 + (iph->ihl << 2))
1662 old_mtu -= iph->ihl << 2;
1663
1664 mtu = guess_mtu(old_mtu);
1665 }
1666 if (mtu <= dst_mtu(&rth->dst)) {
1667 if (mtu < dst_mtu(&rth->dst)) {
1668 dst_confirm(&rth->dst);
1669 if (mtu < ip_rt_min_pmtu) {
1670 mtu = ip_rt_min_pmtu;
1671 rth->dst.metrics[RTAX_LOCK-1] |=
1672 (1 << RTAX_MTU);
1673 }
1674 rth->dst.metrics[RTAX_MTU-1] = mtu;
1675 dst_set_expires(&rth->dst,
1676 ip_rt_mtu_expires);
1677 }
1678 est_mtu = mtu;
1679 }
1680 }
1681 rcu_read_unlock();
1682 }
1683 }
1684 return est_mtu ? : new_mtu;
1685}
1686
1687static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1688{
1689 if (dst_mtu(dst) > mtu && mtu >= 68 &&
1690 !(dst_metric_locked(dst, RTAX_MTU))) {
1691 if (mtu < ip_rt_min_pmtu) {
1692 mtu = ip_rt_min_pmtu;
1693 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1694 }
1695 dst->metrics[RTAX_MTU-1] = mtu;
1696 dst_set_expires(dst, ip_rt_mtu_expires);
1697 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1698 }
1699}
1700
1701static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1702{
1703 if (rt_is_expired((struct rtable *)dst))
1704 return NULL;
1705 return dst;
1706}
1707
1708static void ipv4_dst_destroy(struct dst_entry *dst)
1709{
1710 struct rtable *rt = (struct rtable *) dst;
1711 struct inet_peer *peer = rt->peer;
1712 struct in_device *idev = rt->idev;
1713
1714 if (peer) {
1715 rt->peer = NULL;
1716 inet_putpeer(peer);
1717 }
1718
1719 if (idev) {
1720 rt->idev = NULL;
1721 in_dev_put(idev);
1722 }
1723}
1724
1725static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1726 int how)
1727{
1728 struct rtable *rt = (struct rtable *) dst;
1729 struct in_device *idev = rt->idev;
1730 if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
1731 struct in_device *loopback_idev =
1732 in_dev_get(dev_net(dev)->loopback_dev);
1733 if (loopback_idev) {
1734 rt->idev = loopback_idev;
1735 in_dev_put(idev);
1736 }
1737 }
1738}
1739
1740static void ipv4_link_failure(struct sk_buff *skb)
1741{
1742 struct rtable *rt;
1743
1744 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1745
1746 rt = skb_rtable(skb);
1747 if (rt)
1748 dst_set_expires(&rt->dst, 0);
1749}
1750
1751static int ip_rt_bug(struct sk_buff *skb)
1752{
1753 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1754 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1755 skb->dev ? skb->dev->name : "?");
1756 kfree_skb(skb);
1757 return 0;
1758}
1759
1760/*
1761 We do not cache source address of outgoing interface,
1762 because it is used only by IP RR, TS and SRR options,
1763 so that it out of fast path.
1764
1765 BTW remember: "addr" is allowed to be not aligned
1766 in IP options!
1767 */
1768
1769void ip_rt_get_source(u8 *addr, struct rtable *rt)
1770{
1771 __be32 src;
1772 struct fib_result res;
1773
1774 if (rt->fl.iif == 0)
1775 src = rt->rt_src;
1776 else {
1777 rcu_read_lock();
1778 if (fib_lookup(dev_net(rt->dst.dev), &rt->fl, &res) == 0)
1779 src = FIB_RES_PREFSRC(res);
1780 else
1781 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1782 RT_SCOPE_UNIVERSE);
1783 rcu_read_unlock();
1784 }
1785 memcpy(addr, &src, 4);
1786}
1787
1788#ifdef CONFIG_NET_CLS_ROUTE
1789static void set_class_tag(struct rtable *rt, u32 tag)
1790{
1791 if (!(rt->dst.tclassid & 0xFFFF))
1792 rt->dst.tclassid |= tag & 0xFFFF;
1793 if (!(rt->dst.tclassid & 0xFFFF0000))
1794 rt->dst.tclassid |= tag & 0xFFFF0000;
1795}
1796#endif
1797
1798static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1799{
1800 struct fib_info *fi = res->fi;
1801
1802 if (fi) {
1803 if (FIB_RES_GW(*res) &&
1804 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1805 rt->rt_gateway = FIB_RES_GW(*res);
1806 memcpy(rt->dst.metrics, fi->fib_metrics,
1807 sizeof(rt->dst.metrics));
1808 if (fi->fib_mtu == 0) {
1809 rt->dst.metrics[RTAX_MTU-1] = rt->dst.dev->mtu;
1810 if (dst_metric_locked(&rt->dst, RTAX_MTU) &&
1811 rt->rt_gateway != rt->rt_dst &&
1812 rt->dst.dev->mtu > 576)
1813 rt->dst.metrics[RTAX_MTU-1] = 576;
1814 }
1815#ifdef CONFIG_NET_CLS_ROUTE
1816 rt->dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1817#endif
1818 } else
1819 rt->dst.metrics[RTAX_MTU-1]= rt->dst.dev->mtu;
1820
1821 if (dst_metric(&rt->dst, RTAX_HOPLIMIT) == 0)
1822 rt->dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1823 if (dst_mtu(&rt->dst) > IP_MAX_MTU)
1824 rt->dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1825 if (dst_metric(&rt->dst, RTAX_ADVMSS) == 0)
1826 rt->dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->dst.dev->mtu - 40,
1827 ip_rt_min_advmss);
1828 if (dst_metric(&rt->dst, RTAX_ADVMSS) > 65535 - 40)
1829 rt->dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1830
1831#ifdef CONFIG_NET_CLS_ROUTE
1832#ifdef CONFIG_IP_MULTIPLE_TABLES
1833 set_class_tag(rt, fib_rules_tclass(res));
1834#endif
1835 set_class_tag(rt, itag);
1836#endif
1837 rt->rt_type = res->type;
1838}
1839
1840/* called in rcu_read_lock() section */
1841static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1842 u8 tos, struct net_device *dev, int our)
1843{
1844 unsigned int hash;
1845 struct rtable *rth;
1846 __be32 spec_dst;
1847 struct in_device *in_dev = __in_dev_get_rcu(dev);
1848 u32 itag = 0;
1849 int err;
1850
1851 /* Primary sanity checks. */
1852
1853 if (in_dev == NULL)
1854 return -EINVAL;
1855
1856 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1857 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1858 goto e_inval;
1859
1860 if (ipv4_is_zeronet(saddr)) {
1861 if (!ipv4_is_local_multicast(daddr))
1862 goto e_inval;
1863 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1864 } else {
1865 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1866 &itag, 0);
1867 if (err < 0)
1868 goto e_err;
1869 }
1870 rth = dst_alloc(&ipv4_dst_ops);
1871 if (!rth)
1872 goto e_nobufs;
1873
1874 rth->dst.output = ip_rt_bug;
1875 rth->dst.obsolete = -1;
1876
1877 atomic_set(&rth->dst.__refcnt, 1);
1878 rth->dst.flags= DST_HOST;
1879 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1880 rth->dst.flags |= DST_NOPOLICY;
1881 rth->fl.fl4_dst = daddr;
1882 rth->rt_dst = daddr;
1883 rth->fl.fl4_tos = tos;
1884 rth->fl.mark = skb->mark;
1885 rth->fl.fl4_src = saddr;
1886 rth->rt_src = saddr;
1887#ifdef CONFIG_NET_CLS_ROUTE
1888 rth->dst.tclassid = itag;
1889#endif
1890 rth->rt_iif =
1891 rth->fl.iif = dev->ifindex;
1892 rth->dst.dev = init_net.loopback_dev;
1893 dev_hold(rth->dst.dev);
1894 rth->idev = in_dev_get(rth->dst.dev);
1895 rth->fl.oif = 0;
1896 rth->rt_gateway = daddr;
1897 rth->rt_spec_dst= spec_dst;
1898 rth->rt_genid = rt_genid(dev_net(dev));
1899 rth->rt_flags = RTCF_MULTICAST;
1900 rth->rt_type = RTN_MULTICAST;
1901 if (our) {
1902 rth->dst.input= ip_local_deliver;
1903 rth->rt_flags |= RTCF_LOCAL;
1904 }
1905
1906#ifdef CONFIG_IP_MROUTE
1907 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1908 rth->dst.input = ip_mr_input;
1909#endif
1910 RT_CACHE_STAT_INC(in_slow_mc);
1911
1912 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1913 return rt_intern_hash(hash, rth, NULL, skb, dev->ifindex);
1914
1915e_nobufs:
1916 return -ENOBUFS;
1917e_inval:
1918 return -EINVAL;
1919e_err:
1920 return err;
1921}
1922
1923
1924static void ip_handle_martian_source(struct net_device *dev,
1925 struct in_device *in_dev,
1926 struct sk_buff *skb,
1927 __be32 daddr,
1928 __be32 saddr)
1929{
1930 RT_CACHE_STAT_INC(in_martian_src);
1931#ifdef CONFIG_IP_ROUTE_VERBOSE
1932 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1933 /*
1934 * RFC1812 recommendation, if source is martian,
1935 * the only hint is MAC header.
1936 */
1937 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1938 &daddr, &saddr, dev->name);
1939 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1940 int i;
1941 const unsigned char *p = skb_mac_header(skb);
1942 printk(KERN_WARNING "ll header: ");
1943 for (i = 0; i < dev->hard_header_len; i++, p++) {
1944 printk("%02x", *p);
1945 if (i < (dev->hard_header_len - 1))
1946 printk(":");
1947 }
1948 printk("\n");
1949 }
1950 }
1951#endif
1952}
1953
1954/* called in rcu_read_lock() section */
1955static int __mkroute_input(struct sk_buff *skb,
1956 struct fib_result *res,
1957 struct in_device *in_dev,
1958 __be32 daddr, __be32 saddr, u32 tos,
1959 struct rtable **result)
1960{
1961 struct rtable *rth;
1962 int err;
1963 struct in_device *out_dev;
1964 unsigned int flags = 0;
1965 __be32 spec_dst;
1966 u32 itag;
1967
1968 /* get a working reference to the output device */
1969 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1970 if (out_dev == NULL) {
1971 if (net_ratelimit())
1972 printk(KERN_CRIT "Bug in ip_route_input" \
1973 "_slow(). Please, report\n");
1974 return -EINVAL;
1975 }
1976
1977
1978 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1979 in_dev->dev, &spec_dst, &itag, skb->mark);
1980 if (err < 0) {
1981 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1982 saddr);
1983
1984 goto cleanup;
1985 }
1986
1987 if (err)
1988 flags |= RTCF_DIRECTSRC;
1989
1990 if (out_dev == in_dev && err &&
1991 (IN_DEV_SHARED_MEDIA(out_dev) ||
1992 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1993 flags |= RTCF_DOREDIRECT;
1994
1995 if (skb->protocol != htons(ETH_P_IP)) {
1996 /* Not IP (i.e. ARP). Do not create route, if it is
1997 * invalid for proxy arp. DNAT routes are always valid.
1998 *
1999 * Proxy arp feature have been extended to allow, ARP
2000 * replies back to the same interface, to support
2001 * Private VLAN switch technologies. See arp.c.
2002 */
2003 if (out_dev == in_dev &&
2004 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2005 err = -EINVAL;
2006 goto cleanup;
2007 }
2008 }
2009
2010
2011 rth = dst_alloc(&ipv4_dst_ops);
2012 if (!rth) {
2013 err = -ENOBUFS;
2014 goto cleanup;
2015 }
2016
2017 atomic_set(&rth->dst.__refcnt, 1);
2018 rth->dst.flags= DST_HOST;
2019 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2020 rth->dst.flags |= DST_NOPOLICY;
2021 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
2022 rth->dst.flags |= DST_NOXFRM;
2023 rth->fl.fl4_dst = daddr;
2024 rth->rt_dst = daddr;
2025 rth->fl.fl4_tos = tos;
2026 rth->fl.mark = skb->mark;
2027 rth->fl.fl4_src = saddr;
2028 rth->rt_src = saddr;
2029 rth->rt_gateway = daddr;
2030 rth->rt_iif =
2031 rth->fl.iif = in_dev->dev->ifindex;
2032 rth->dst.dev = (out_dev)->dev;
2033 dev_hold(rth->dst.dev);
2034 rth->idev = in_dev_get(rth->dst.dev);
2035 rth->fl.oif = 0;
2036 rth->rt_spec_dst= spec_dst;
2037
2038 rth->dst.obsolete = -1;
2039 rth->dst.input = ip_forward;
2040 rth->dst.output = ip_output;
2041 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2042
2043 rt_set_nexthop(rth, res, itag);
2044
2045 rth->rt_flags = flags;
2046
2047 *result = rth;
2048 err = 0;
2049 cleanup:
2050 return err;
2051}
2052
2053static int ip_mkroute_input(struct sk_buff *skb,
2054 struct fib_result *res,
2055 const struct flowi *fl,
2056 struct in_device *in_dev,
2057 __be32 daddr, __be32 saddr, u32 tos)
2058{
2059 struct rtable* rth = NULL;
2060 int err;
2061 unsigned hash;
2062
2063#ifdef CONFIG_IP_ROUTE_MULTIPATH
2064 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2065 fib_select_multipath(fl, res);
2066#endif
2067
2068 /* create a routing cache entry */
2069 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2070 if (err)
2071 return err;
2072
2073 /* put it into the cache */
2074 hash = rt_hash(daddr, saddr, fl->iif,
2075 rt_genid(dev_net(rth->dst.dev)));
2076 return rt_intern_hash(hash, rth, NULL, skb, fl->iif);
2077}
2078
2079/*
2080 * NOTE. We drop all the packets that has local source
2081 * addresses, because every properly looped back packet
2082 * must have correct destination already attached by output routine.
2083 *
2084 * Such approach solves two big problems:
2085 * 1. Not simplex devices are handled properly.
2086 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2087 * called with rcu_read_lock()
2088 */
2089
2090static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2091 u8 tos, struct net_device *dev)
2092{
2093 struct fib_result res;
2094 struct in_device *in_dev = __in_dev_get_rcu(dev);
2095 struct flowi fl = { .nl_u = { .ip4_u =
2096 { .daddr = daddr,
2097 .saddr = saddr,
2098 .tos = tos,
2099 .scope = RT_SCOPE_UNIVERSE,
2100 } },
2101 .mark = skb->mark,
2102 .iif = dev->ifindex };
2103 unsigned flags = 0;
2104 u32 itag = 0;
2105 struct rtable * rth;
2106 unsigned hash;
2107 __be32 spec_dst;
2108 int err = -EINVAL;
2109 struct net * net = dev_net(dev);
2110
2111 /* IP on this device is disabled. */
2112
2113 if (!in_dev)
2114 goto out;
2115
2116 /* Check for the most weird martians, which can be not detected
2117 by fib_lookup.
2118 */
2119
2120 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2121 ipv4_is_loopback(saddr))
2122 goto martian_source;
2123
2124 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
2125 goto brd_input;
2126
2127 /* Accept zero addresses only to limited broadcast;
2128 * I even do not know to fix it or not. Waiting for complains :-)
2129 */
2130 if (ipv4_is_zeronet(saddr))
2131 goto martian_source;
2132
2133 if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
2134 ipv4_is_loopback(daddr))
2135 goto martian_destination;
2136
2137 /*
2138 * Now we are ready to route packet.
2139 */
2140 err = fib_lookup(net, &fl, &res);
2141 if (err != 0) {
2142 if (!IN_DEV_FORWARD(in_dev))
2143 goto e_hostunreach;
2144 goto no_route;
2145 }
2146
2147 RT_CACHE_STAT_INC(in_slow_tot);
2148
2149 if (res.type == RTN_BROADCAST)
2150 goto brd_input;
2151
2152 if (res.type == RTN_LOCAL) {
2153 err = fib_validate_source(saddr, daddr, tos,
2154 net->loopback_dev->ifindex,
2155 dev, &spec_dst, &itag, skb->mark);
2156 if (err < 0)
2157 goto martian_source_keep_err;
2158 if (err)
2159 flags |= RTCF_DIRECTSRC;
2160 spec_dst = daddr;
2161 goto local_input;
2162 }
2163
2164 if (!IN_DEV_FORWARD(in_dev))
2165 goto e_hostunreach;
2166 if (res.type != RTN_UNICAST)
2167 goto martian_destination;
2168
2169 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2170out: return err;
2171
2172brd_input:
2173 if (skb->protocol != htons(ETH_P_IP))
2174 goto e_inval;
2175
2176 if (ipv4_is_zeronet(saddr))
2177 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2178 else {
2179 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2180 &itag, skb->mark);
2181 if (err < 0)
2182 goto martian_source_keep_err;
2183 if (err)
2184 flags |= RTCF_DIRECTSRC;
2185 }
2186 flags |= RTCF_BROADCAST;
2187 res.type = RTN_BROADCAST;
2188 RT_CACHE_STAT_INC(in_brd);
2189
2190local_input:
2191 rth = dst_alloc(&ipv4_dst_ops);
2192 if (!rth)
2193 goto e_nobufs;
2194
2195 rth->dst.output= ip_rt_bug;
2196 rth->dst.obsolete = -1;
2197 rth->rt_genid = rt_genid(net);
2198
2199 atomic_set(&rth->dst.__refcnt, 1);
2200 rth->dst.flags= DST_HOST;
2201 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2202 rth->dst.flags |= DST_NOPOLICY;
2203 rth->fl.fl4_dst = daddr;
2204 rth->rt_dst = daddr;
2205 rth->fl.fl4_tos = tos;
2206 rth->fl.mark = skb->mark;
2207 rth->fl.fl4_src = saddr;
2208 rth->rt_src = saddr;
2209#ifdef CONFIG_NET_CLS_ROUTE
2210 rth->dst.tclassid = itag;
2211#endif
2212 rth->rt_iif =
2213 rth->fl.iif = dev->ifindex;
2214 rth->dst.dev = net->loopback_dev;
2215 dev_hold(rth->dst.dev);
2216 rth->idev = in_dev_get(rth->dst.dev);
2217 rth->rt_gateway = daddr;
2218 rth->rt_spec_dst= spec_dst;
2219 rth->dst.input= ip_local_deliver;
2220 rth->rt_flags = flags|RTCF_LOCAL;
2221 if (res.type == RTN_UNREACHABLE) {
2222 rth->dst.input= ip_error;
2223 rth->dst.error= -err;
2224 rth->rt_flags &= ~RTCF_LOCAL;
2225 }
2226 rth->rt_type = res.type;
2227 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2228 err = rt_intern_hash(hash, rth, NULL, skb, fl.iif);
2229 goto out;
2230
2231no_route:
2232 RT_CACHE_STAT_INC(in_no_route);
2233 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2234 res.type = RTN_UNREACHABLE;
2235 if (err == -ESRCH)
2236 err = -ENETUNREACH;
2237 goto local_input;
2238
2239 /*
2240 * Do not cache martian addresses: they should be logged (RFC1812)
2241 */
2242martian_destination:
2243 RT_CACHE_STAT_INC(in_martian_dst);
2244#ifdef CONFIG_IP_ROUTE_VERBOSE
2245 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2246 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2247 &daddr, &saddr, dev->name);
2248#endif
2249
2250e_hostunreach:
2251 err = -EHOSTUNREACH;
2252 goto out;
2253
2254e_inval:
2255 err = -EINVAL;
2256 goto out;
2257
2258e_nobufs:
2259 err = -ENOBUFS;
2260 goto out;
2261
2262martian_source:
2263 err = -EINVAL;
2264martian_source_keep_err:
2265 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2266 goto out;
2267}
2268
2269int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2270 u8 tos, struct net_device *dev, bool noref)
2271{
2272 struct rtable * rth;
2273 unsigned hash;
2274 int iif = dev->ifindex;
2275 struct net *net;
2276 int res;
2277
2278 net = dev_net(dev);
2279
2280 rcu_read_lock();
2281
2282 if (!rt_caching(net))
2283 goto skip_cache;
2284
2285 tos &= IPTOS_RT_MASK;
2286 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2287
2288 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2289 rth = rcu_dereference(rth->dst.rt_next)) {
2290 if ((((__force u32)rth->fl.fl4_dst ^ (__force u32)daddr) |
2291 ((__force u32)rth->fl.fl4_src ^ (__force u32)saddr) |
2292 (rth->fl.iif ^ iif) |
2293 rth->fl.oif |
2294 (rth->fl.fl4_tos ^ tos)) == 0 &&
2295 rth->fl.mark == skb->mark &&
2296 net_eq(dev_net(rth->dst.dev), net) &&
2297 !rt_is_expired(rth)) {
2298 if (noref) {
2299 dst_use_noref(&rth->dst, jiffies);
2300 skb_dst_set_noref(skb, &rth->dst);
2301 } else {
2302 dst_use(&rth->dst, jiffies);
2303 skb_dst_set(skb, &rth->dst);
2304 }
2305 RT_CACHE_STAT_INC(in_hit);
2306 rcu_read_unlock();
2307 return 0;
2308 }
2309 RT_CACHE_STAT_INC(in_hlist_search);
2310 }
2311
2312skip_cache:
2313 /* Multicast recognition logic is moved from route cache to here.
2314 The problem was that too many Ethernet cards have broken/missing
2315 hardware multicast filters :-( As result the host on multicasting
2316 network acquires a lot of useless route cache entries, sort of
2317 SDR messages from all the world. Now we try to get rid of them.
2318 Really, provided software IP multicast filter is organized
2319 reasonably (at least, hashed), it does not result in a slowdown
2320 comparing with route cache reject entries.
2321 Note, that multicast routers are not affected, because
2322 route cache entry is created eventually.
2323 */
2324 if (ipv4_is_multicast(daddr)) {
2325 struct in_device *in_dev = __in_dev_get_rcu(dev);
2326
2327 if (in_dev) {
2328 int our = ip_check_mc(in_dev, daddr, saddr,
2329 ip_hdr(skb)->protocol);
2330 if (our
2331#ifdef CONFIG_IP_MROUTE
2332 ||
2333 (!ipv4_is_local_multicast(daddr) &&
2334 IN_DEV_MFORWARD(in_dev))
2335#endif
2336 ) {
2337 int res = ip_route_input_mc(skb, daddr, saddr,
2338 tos, dev, our);
2339 rcu_read_unlock();
2340 return res;
2341 }
2342 }
2343 rcu_read_unlock();
2344 return -EINVAL;
2345 }
2346 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2347 rcu_read_unlock();
2348 return res;
2349}
2350EXPORT_SYMBOL(ip_route_input_common);
2351
2352/* called with rcu_read_lock() */
2353static int __mkroute_output(struct rtable **result,
2354 struct fib_result *res,
2355 const struct flowi *fl,
2356 const struct flowi *oldflp,
2357 struct net_device *dev_out,
2358 unsigned flags)
2359{
2360 struct rtable *rth;
2361 struct in_device *in_dev;
2362 u32 tos = RT_FL_TOS(oldflp);
2363
2364 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
2365 return -EINVAL;
2366
2367 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2368 res->type = RTN_BROADCAST;
2369 else if (ipv4_is_multicast(fl->fl4_dst))
2370 res->type = RTN_MULTICAST;
2371 else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
2372 return -EINVAL;
2373
2374 if (dev_out->flags & IFF_LOOPBACK)
2375 flags |= RTCF_LOCAL;
2376
2377 in_dev = __in_dev_get_rcu(dev_out);
2378 if (!in_dev)
2379 return -EINVAL;
2380
2381 if (res->type == RTN_BROADCAST) {
2382 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2383 res->fi = NULL;
2384 } else if (res->type == RTN_MULTICAST) {
2385 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2386 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2387 oldflp->proto))
2388 flags &= ~RTCF_LOCAL;
2389 /* If multicast route do not exist use
2390 * default one, but do not gateway in this case.
2391 * Yes, it is hack.
2392 */
2393 if (res->fi && res->prefixlen < 4)
2394 res->fi = NULL;
2395 }
2396
2397
2398 rth = dst_alloc(&ipv4_dst_ops);
2399 if (!rth) {
2400 rcu_read_unlock();
2401 return -ENOBUFS;
2402 }
2403 in_dev_hold(in_dev);
2404 rcu_read_unlock();
2405 rth->idev = in_dev;
2406
2407 atomic_set(&rth->dst.__refcnt, 1);
2408 rth->dst.flags= DST_HOST;
2409 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2410 rth->dst.flags |= DST_NOXFRM;
2411 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2412 rth->dst.flags |= DST_NOPOLICY;
2413
2414 rth->fl.fl4_dst = oldflp->fl4_dst;
2415 rth->fl.fl4_tos = tos;
2416 rth->fl.fl4_src = oldflp->fl4_src;
2417 rth->fl.oif = oldflp->oif;
2418 rth->fl.mark = oldflp->mark;
2419 rth->rt_dst = fl->fl4_dst;
2420 rth->rt_src = fl->fl4_src;
2421 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2422 /* get references to the devices that are to be hold by the routing
2423 cache entry */
2424 rth->dst.dev = dev_out;
2425 dev_hold(dev_out);
2426 rth->rt_gateway = fl->fl4_dst;
2427 rth->rt_spec_dst= fl->fl4_src;
2428
2429 rth->dst.output=ip_output;
2430 rth->dst.obsolete = -1;
2431 rth->rt_genid = rt_genid(dev_net(dev_out));
2432
2433 RT_CACHE_STAT_INC(out_slow_tot);
2434
2435 if (flags & RTCF_LOCAL) {
2436 rth->dst.input = ip_local_deliver;
2437 rth->rt_spec_dst = fl->fl4_dst;
2438 }
2439 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2440 rth->rt_spec_dst = fl->fl4_src;
2441 if (flags & RTCF_LOCAL &&
2442 !(dev_out->flags & IFF_LOOPBACK)) {
2443 rth->dst.output = ip_mc_output;
2444 RT_CACHE_STAT_INC(out_slow_mc);
2445 }
2446#ifdef CONFIG_IP_MROUTE
2447 if (res->type == RTN_MULTICAST) {
2448 if (IN_DEV_MFORWARD(in_dev) &&
2449 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2450 rth->dst.input = ip_mr_input;
2451 rth->dst.output = ip_mc_output;
2452 }
2453 }
2454#endif
2455 }
2456
2457 rt_set_nexthop(rth, res, 0);
2458
2459 rth->rt_flags = flags;
2460 *result = rth;
2461 return 0;
2462}
2463
2464/* called with rcu_read_lock() */
2465static int ip_mkroute_output(struct rtable **rp,
2466 struct fib_result *res,
2467 const struct flowi *fl,
2468 const struct flowi *oldflp,
2469 struct net_device *dev_out,
2470 unsigned flags)
2471{
2472 struct rtable *rth = NULL;
2473 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2474 unsigned hash;
2475 if (err == 0) {
2476 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2477 rt_genid(dev_net(dev_out)));
2478 err = rt_intern_hash(hash, rth, rp, NULL, oldflp->oif);
2479 }
2480
2481 return err;
2482}
2483
2484/*
2485 * Major route resolver routine.
2486 * called with rcu_read_lock();
2487 */
2488
2489static int ip_route_output_slow(struct net *net, struct rtable **rp,
2490 const struct flowi *oldflp)
2491{
2492 u32 tos = RT_FL_TOS(oldflp);
2493 struct flowi fl = { .nl_u = { .ip4_u =
2494 { .daddr = oldflp->fl4_dst,
2495 .saddr = oldflp->fl4_src,
2496 .tos = tos & IPTOS_RT_MASK,
2497 .scope = ((tos & RTO_ONLINK) ?
2498 RT_SCOPE_LINK :
2499 RT_SCOPE_UNIVERSE),
2500 } },
2501 .mark = oldflp->mark,
2502 .iif = net->loopback_dev->ifindex,
2503 .oif = oldflp->oif };
2504 struct fib_result res;
2505 unsigned int flags = 0;
2506 struct net_device *dev_out = NULL;
2507 int err;
2508
2509
2510 res.fi = NULL;
2511#ifdef CONFIG_IP_MULTIPLE_TABLES
2512 res.r = NULL;
2513#endif
2514
2515 if (oldflp->fl4_src) {
2516 err = -EINVAL;
2517 if (ipv4_is_multicast(oldflp->fl4_src) ||
2518 ipv4_is_lbcast(oldflp->fl4_src) ||
2519 ipv4_is_zeronet(oldflp->fl4_src))
2520 goto out;
2521
2522 /* I removed check for oif == dev_out->oif here.
2523 It was wrong for two reasons:
2524 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2525 is assigned to multiple interfaces.
2526 2. Moreover, we are allowed to send packets with saddr
2527 of another iface. --ANK
2528 */
2529
2530 if (oldflp->oif == 0 &&
2531 (ipv4_is_multicast(oldflp->fl4_dst) ||
2532 oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2533 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2534 dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
2535 if (dev_out == NULL)
2536 goto out;
2537
2538 /* Special hack: user can direct multicasts
2539 and limited broadcast via necessary interface
2540 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2541 This hack is not just for fun, it allows
2542 vic,vat and friends to work.
2543 They bind socket to loopback, set ttl to zero
2544 and expect that it will work.
2545 From the viewpoint of routing cache they are broken,
2546 because we are not allowed to build multicast path
2547 with loopback source addr (look, routing cache
2548 cannot know, that ttl is zero, so that packet
2549 will not leave this host and route is valid).
2550 Luckily, this hack is good workaround.
2551 */
2552
2553 fl.oif = dev_out->ifindex;
2554 goto make_route;
2555 }
2556
2557 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2558 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2559 if (!__ip_dev_find(net, oldflp->fl4_src, false))
2560 goto out;
2561 }
2562 }
2563
2564
2565 if (oldflp->oif) {
2566 dev_out = dev_get_by_index_rcu(net, oldflp->oif);
2567 err = -ENODEV;
2568 if (dev_out == NULL)
2569 goto out;
2570
2571 /* RACE: Check return value of inet_select_addr instead. */
2572 if (rcu_dereference(dev_out->ip_ptr) == NULL)
2573 goto out; /* Wrong error code */
2574
2575 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2576 oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2577 if (!fl.fl4_src)
2578 fl.fl4_src = inet_select_addr(dev_out, 0,
2579 RT_SCOPE_LINK);
2580 goto make_route;
2581 }
2582 if (!fl.fl4_src) {
2583 if (ipv4_is_multicast(oldflp->fl4_dst))
2584 fl.fl4_src = inet_select_addr(dev_out, 0,
2585 fl.fl4_scope);
2586 else if (!oldflp->fl4_dst)
2587 fl.fl4_src = inet_select_addr(dev_out, 0,
2588 RT_SCOPE_HOST);
2589 }
2590 }
2591
2592 if (!fl.fl4_dst) {
2593 fl.fl4_dst = fl.fl4_src;
2594 if (!fl.fl4_dst)
2595 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2596 dev_out = net->loopback_dev;
2597 fl.oif = net->loopback_dev->ifindex;
2598 res.type = RTN_LOCAL;
2599 flags |= RTCF_LOCAL;
2600 goto make_route;
2601 }
2602
2603 if (fib_lookup(net, &fl, &res)) {
2604 res.fi = NULL;
2605 if (oldflp->oif) {
2606 /* Apparently, routing tables are wrong. Assume,
2607 that the destination is on link.
2608
2609 WHY? DW.
2610 Because we are allowed to send to iface
2611 even if it has NO routes and NO assigned
2612 addresses. When oif is specified, routing
2613 tables are looked up with only one purpose:
2614 to catch if destination is gatewayed, rather than
2615 direct. Moreover, if MSG_DONTROUTE is set,
2616 we send packet, ignoring both routing tables
2617 and ifaddr state. --ANK
2618
2619
2620 We could make it even if oif is unknown,
2621 likely IPv6, but we do not.
2622 */
2623
2624 if (fl.fl4_src == 0)
2625 fl.fl4_src = inet_select_addr(dev_out, 0,
2626 RT_SCOPE_LINK);
2627 res.type = RTN_UNICAST;
2628 goto make_route;
2629 }
2630 err = -ENETUNREACH;
2631 goto out;
2632 }
2633
2634 if (res.type == RTN_LOCAL) {
2635 if (!fl.fl4_src)
2636 fl.fl4_src = fl.fl4_dst;
2637 dev_out = net->loopback_dev;
2638 fl.oif = dev_out->ifindex;
2639 res.fi = NULL;
2640 flags |= RTCF_LOCAL;
2641 goto make_route;
2642 }
2643
2644#ifdef CONFIG_IP_ROUTE_MULTIPATH
2645 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2646 fib_select_multipath(&fl, &res);
2647 else
2648#endif
2649 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2650 fib_select_default(net, &fl, &res);
2651
2652 if (!fl.fl4_src)
2653 fl.fl4_src = FIB_RES_PREFSRC(res);
2654
2655 dev_out = FIB_RES_DEV(res);
2656 fl.oif = dev_out->ifindex;
2657
2658
2659make_route:
2660 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2661
2662out: return err;
2663}
2664
2665int __ip_route_output_key(struct net *net, struct rtable **rp,
2666 const struct flowi *flp)
2667{
2668 unsigned int hash;
2669 int res;
2670 struct rtable *rth;
2671
2672 if (!rt_caching(net))
2673 goto slow_output;
2674
2675 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2676
2677 rcu_read_lock_bh();
2678 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2679 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2680 if (rth->fl.fl4_dst == flp->fl4_dst &&
2681 rth->fl.fl4_src == flp->fl4_src &&
2682 rth->fl.iif == 0 &&
2683 rth->fl.oif == flp->oif &&
2684 rth->fl.mark == flp->mark &&
2685 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2686 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2687 net_eq(dev_net(rth->dst.dev), net) &&
2688 !rt_is_expired(rth)) {
2689 dst_use(&rth->dst, jiffies);
2690 RT_CACHE_STAT_INC(out_hit);
2691 rcu_read_unlock_bh();
2692 *rp = rth;
2693 return 0;
2694 }
2695 RT_CACHE_STAT_INC(out_hlist_search);
2696 }
2697 rcu_read_unlock_bh();
2698
2699slow_output:
2700 rcu_read_lock();
2701 res = ip_route_output_slow(net, rp, flp);
2702 rcu_read_unlock();
2703 return res;
2704}
2705EXPORT_SYMBOL_GPL(__ip_route_output_key);
2706
2707static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2708{
2709 return NULL;
2710}
2711
2712static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2713{
2714}
2715
2716static struct dst_ops ipv4_dst_blackhole_ops = {
2717 .family = AF_INET,
2718 .protocol = cpu_to_be16(ETH_P_IP),
2719 .destroy = ipv4_dst_destroy,
2720 .check = ipv4_blackhole_dst_check,
2721 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2722 .entries = ATOMIC_INIT(0),
2723};
2724
2725
2726static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
2727{
2728 struct rtable *ort = *rp;
2729 struct rtable *rt = (struct rtable *)
2730 dst_alloc(&ipv4_dst_blackhole_ops);
2731
2732 if (rt) {
2733 struct dst_entry *new = &rt->dst;
2734
2735 atomic_set(&new->__refcnt, 1);
2736 new->__use = 1;
2737 new->input = dst_discard;
2738 new->output = dst_discard;
2739 memcpy(new->metrics, ort->dst.metrics, RTAX_MAX*sizeof(u32));
2740
2741 new->dev = ort->dst.dev;
2742 if (new->dev)
2743 dev_hold(new->dev);
2744
2745 rt->fl = ort->fl;
2746
2747 rt->idev = ort->idev;
2748 if (rt->idev)
2749 in_dev_hold(rt->idev);
2750 rt->rt_genid = rt_genid(net);
2751 rt->rt_flags = ort->rt_flags;
2752 rt->rt_type = ort->rt_type;
2753 rt->rt_dst = ort->rt_dst;
2754 rt->rt_src = ort->rt_src;
2755 rt->rt_iif = ort->rt_iif;
2756 rt->rt_gateway = ort->rt_gateway;
2757 rt->rt_spec_dst = ort->rt_spec_dst;
2758 rt->peer = ort->peer;
2759 if (rt->peer)
2760 atomic_inc(&rt->peer->refcnt);
2761
2762 dst_free(new);
2763 }
2764
2765 dst_release(&(*rp)->dst);
2766 *rp = rt;
2767 return rt ? 0 : -ENOMEM;
2768}
2769
2770int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
2771 struct sock *sk, int flags)
2772{
2773 int err;
2774
2775 if ((err = __ip_route_output_key(net, rp, flp)) != 0)
2776 return err;
2777
2778 if (flp->proto) {
2779 if (!flp->fl4_src)
2780 flp->fl4_src = (*rp)->rt_src;
2781 if (!flp->fl4_dst)
2782 flp->fl4_dst = (*rp)->rt_dst;
2783 err = __xfrm_lookup(net, (struct dst_entry **)rp, flp, sk,
2784 flags ? XFRM_LOOKUP_WAIT : 0);
2785 if (err == -EREMOTE)
2786 err = ipv4_dst_blackhole(net, rp, flp);
2787
2788 return err;
2789 }
2790
2791 return 0;
2792}
2793EXPORT_SYMBOL_GPL(ip_route_output_flow);
2794
2795int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
2796{
2797 return ip_route_output_flow(net, rp, flp, NULL, 0);
2798}
2799EXPORT_SYMBOL(ip_route_output_key);
2800
2801static int rt_fill_info(struct net *net,
2802 struct sk_buff *skb, u32 pid, u32 seq, int event,
2803 int nowait, unsigned int flags)
2804{
2805 struct rtable *rt = skb_rtable(skb);
2806 struct rtmsg *r;
2807 struct nlmsghdr *nlh;
2808 long expires;
2809 u32 id = 0, ts = 0, tsage = 0, error;
2810
2811 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2812 if (nlh == NULL)
2813 return -EMSGSIZE;
2814
2815 r = nlmsg_data(nlh);
2816 r->rtm_family = AF_INET;
2817 r->rtm_dst_len = 32;
2818 r->rtm_src_len = 0;
2819 r->rtm_tos = rt->fl.fl4_tos;
2820 r->rtm_table = RT_TABLE_MAIN;
2821 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2822 r->rtm_type = rt->rt_type;
2823 r->rtm_scope = RT_SCOPE_UNIVERSE;
2824 r->rtm_protocol = RTPROT_UNSPEC;
2825 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2826 if (rt->rt_flags & RTCF_NOTIFY)
2827 r->rtm_flags |= RTM_F_NOTIFY;
2828
2829 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2830
2831 if (rt->fl.fl4_src) {
2832 r->rtm_src_len = 32;
2833 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2834 }
2835 if (rt->dst.dev)
2836 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2837#ifdef CONFIG_NET_CLS_ROUTE
2838 if (rt->dst.tclassid)
2839 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2840#endif
2841 if (rt->fl.iif)
2842 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2843 else if (rt->rt_src != rt->fl.fl4_src)
2844 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2845
2846 if (rt->rt_dst != rt->rt_gateway)
2847 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2848
2849 if (rtnetlink_put_metrics(skb, rt->dst.metrics) < 0)
2850 goto nla_put_failure;
2851
2852 if (rt->fl.mark)
2853 NLA_PUT_BE32(skb, RTA_MARK, rt->fl.mark);
2854
2855 error = rt->dst.error;
2856 expires = rt->dst.expires ? rt->dst.expires - jiffies : 0;
2857 if (rt->peer) {
2858 inet_peer_refcheck(rt->peer);
2859 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2860 if (rt->peer->tcp_ts_stamp) {
2861 ts = rt->peer->tcp_ts;
2862 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2863 }
2864 }
2865
2866 if (rt->fl.iif) {
2867#ifdef CONFIG_IP_MROUTE
2868 __be32 dst = rt->rt_dst;
2869
2870 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2871 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2872 int err = ipmr_get_route(net, skb, r, nowait);
2873 if (err <= 0) {
2874 if (!nowait) {
2875 if (err == 0)
2876 return 0;
2877 goto nla_put_failure;
2878 } else {
2879 if (err == -EMSGSIZE)
2880 goto nla_put_failure;
2881 error = err;
2882 }
2883 }
2884 } else
2885#endif
2886 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2887 }
2888
2889 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2890 expires, error) < 0)
2891 goto nla_put_failure;
2892
2893 return nlmsg_end(skb, nlh);
2894
2895nla_put_failure:
2896 nlmsg_cancel(skb, nlh);
2897 return -EMSGSIZE;
2898}
2899
2900static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2901{
2902 struct net *net = sock_net(in_skb->sk);
2903 struct rtmsg *rtm;
2904 struct nlattr *tb[RTA_MAX+1];
2905 struct rtable *rt = NULL;
2906 __be32 dst = 0;
2907 __be32 src = 0;
2908 u32 iif;
2909 int err;
2910 int mark;
2911 struct sk_buff *skb;
2912
2913 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2914 if (err < 0)
2915 goto errout;
2916
2917 rtm = nlmsg_data(nlh);
2918
2919 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2920 if (skb == NULL) {
2921 err = -ENOBUFS;
2922 goto errout;
2923 }
2924
2925 /* Reserve room for dummy headers, this skb can pass
2926 through good chunk of routing engine.
2927 */
2928 skb_reset_mac_header(skb);
2929 skb_reset_network_header(skb);
2930
2931 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2932 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2933 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2934
2935 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2936 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2937 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2938 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2939
2940 if (iif) {
2941 struct net_device *dev;
2942
2943 dev = __dev_get_by_index(net, iif);
2944 if (dev == NULL) {
2945 err = -ENODEV;
2946 goto errout_free;
2947 }
2948
2949 skb->protocol = htons(ETH_P_IP);
2950 skb->dev = dev;
2951 skb->mark = mark;
2952 local_bh_disable();
2953 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2954 local_bh_enable();
2955
2956 rt = skb_rtable(skb);
2957 if (err == 0 && rt->dst.error)
2958 err = -rt->dst.error;
2959 } else {
2960 struct flowi fl = {
2961 .nl_u = {
2962 .ip4_u = {
2963 .daddr = dst,
2964 .saddr = src,
2965 .tos = rtm->rtm_tos,
2966 },
2967 },
2968 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2969 .mark = mark,
2970 };
2971 err = ip_route_output_key(net, &rt, &fl);
2972 }
2973
2974 if (err)
2975 goto errout_free;
2976
2977 skb_dst_set(skb, &rt->dst);
2978 if (rtm->rtm_flags & RTM_F_NOTIFY)
2979 rt->rt_flags |= RTCF_NOTIFY;
2980
2981 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2982 RTM_NEWROUTE, 0, 0);
2983 if (err <= 0)
2984 goto errout_free;
2985
2986 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2987errout:
2988 return err;
2989
2990errout_free:
2991 kfree_skb(skb);
2992 goto errout;
2993}
2994
2995int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2996{
2997 struct rtable *rt;
2998 int h, s_h;
2999 int idx, s_idx;
3000 struct net *net;
3001
3002 net = sock_net(skb->sk);
3003
3004 s_h = cb->args[0];
3005 if (s_h < 0)
3006 s_h = 0;
3007 s_idx = idx = cb->args[1];
3008 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3009 if (!rt_hash_table[h].chain)
3010 continue;
3011 rcu_read_lock_bh();
3012 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3013 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3014 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3015 continue;
3016 if (rt_is_expired(rt))
3017 continue;
3018 skb_dst_set_noref(skb, &rt->dst);
3019 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3020 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3021 1, NLM_F_MULTI) <= 0) {
3022 skb_dst_drop(skb);
3023 rcu_read_unlock_bh();
3024 goto done;
3025 }
3026 skb_dst_drop(skb);
3027 }
3028 rcu_read_unlock_bh();
3029 }
3030
3031done:
3032 cb->args[0] = h;
3033 cb->args[1] = idx;
3034 return skb->len;
3035}
3036
3037void ip_rt_multicast_event(struct in_device *in_dev)
3038{
3039 rt_cache_flush(dev_net(in_dev->dev), 0);
3040}
3041
3042#ifdef CONFIG_SYSCTL
3043static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3044 void __user *buffer,
3045 size_t *lenp, loff_t *ppos)
3046{
3047 if (write) {
3048 int flush_delay;
3049 ctl_table ctl;
3050 struct net *net;
3051
3052 memcpy(&ctl, __ctl, sizeof(ctl));
3053 ctl.data = &flush_delay;
3054 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3055
3056 net = (struct net *)__ctl->extra1;
3057 rt_cache_flush(net, flush_delay);
3058 return 0;
3059 }
3060
3061 return -EINVAL;
3062}
3063
3064static ctl_table ipv4_route_table[] = {
3065 {
3066 .procname = "gc_thresh",
3067 .data = &ipv4_dst_ops.gc_thresh,
3068 .maxlen = sizeof(int),
3069 .mode = 0644,
3070 .proc_handler = proc_dointvec,
3071 },
3072 {
3073 .procname = "max_size",
3074 .data = &ip_rt_max_size,
3075 .maxlen = sizeof(int),
3076 .mode = 0644,
3077 .proc_handler = proc_dointvec,
3078 },
3079 {
3080 /* Deprecated. Use gc_min_interval_ms */
3081
3082 .procname = "gc_min_interval",
3083 .data = &ip_rt_gc_min_interval,
3084 .maxlen = sizeof(int),
3085 .mode = 0644,
3086 .proc_handler = proc_dointvec_jiffies,
3087 },
3088 {
3089 .procname = "gc_min_interval_ms",
3090 .data = &ip_rt_gc_min_interval,
3091 .maxlen = sizeof(int),
3092 .mode = 0644,
3093 .proc_handler = proc_dointvec_ms_jiffies,
3094 },
3095 {
3096 .procname = "gc_timeout",
3097 .data = &ip_rt_gc_timeout,
3098 .maxlen = sizeof(int),
3099 .mode = 0644,
3100 .proc_handler = proc_dointvec_jiffies,
3101 },
3102 {
3103 .procname = "gc_interval",
3104 .data = &ip_rt_gc_interval,
3105 .maxlen = sizeof(int),
3106 .mode = 0644,
3107 .proc_handler = proc_dointvec_jiffies,
3108 },
3109 {
3110 .procname = "redirect_load",
3111 .data = &ip_rt_redirect_load,
3112 .maxlen = sizeof(int),
3113 .mode = 0644,
3114 .proc_handler = proc_dointvec,
3115 },
3116 {
3117 .procname = "redirect_number",
3118 .data = &ip_rt_redirect_number,
3119 .maxlen = sizeof(int),
3120 .mode = 0644,
3121 .proc_handler = proc_dointvec,
3122 },
3123 {
3124 .procname = "redirect_silence",
3125 .data = &ip_rt_redirect_silence,
3126 .maxlen = sizeof(int),
3127 .mode = 0644,
3128 .proc_handler = proc_dointvec,
3129 },
3130 {
3131 .procname = "error_cost",
3132 .data = &ip_rt_error_cost,
3133 .maxlen = sizeof(int),
3134 .mode = 0644,
3135 .proc_handler = proc_dointvec,
3136 },
3137 {
3138 .procname = "error_burst",
3139 .data = &ip_rt_error_burst,
3140 .maxlen = sizeof(int),
3141 .mode = 0644,
3142 .proc_handler = proc_dointvec,
3143 },
3144 {
3145 .procname = "gc_elasticity",
3146 .data = &ip_rt_gc_elasticity,
3147 .maxlen = sizeof(int),
3148 .mode = 0644,
3149 .proc_handler = proc_dointvec,
3150 },
3151 {
3152 .procname = "mtu_expires",
3153 .data = &ip_rt_mtu_expires,
3154 .maxlen = sizeof(int),
3155 .mode = 0644,
3156 .proc_handler = proc_dointvec_jiffies,
3157 },
3158 {
3159 .procname = "min_pmtu",
3160 .data = &ip_rt_min_pmtu,
3161 .maxlen = sizeof(int),
3162 .mode = 0644,
3163 .proc_handler = proc_dointvec,
3164 },
3165 {
3166 .procname = "min_adv_mss",
3167 .data = &ip_rt_min_advmss,
3168 .maxlen = sizeof(int),
3169 .mode = 0644,
3170 .proc_handler = proc_dointvec,
3171 },
3172 { }
3173};
3174
3175static struct ctl_table empty[1];
3176
3177static struct ctl_table ipv4_skeleton[] =
3178{
3179 { .procname = "route",
3180 .mode = 0555, .child = ipv4_route_table},
3181 { .procname = "neigh",
3182 .mode = 0555, .child = empty},
3183 { }
3184};
3185
3186static __net_initdata struct ctl_path ipv4_path[] = {
3187 { .procname = "net", },
3188 { .procname = "ipv4", },
3189 { },
3190};
3191
3192static struct ctl_table ipv4_route_flush_table[] = {
3193 {
3194 .procname = "flush",
3195 .maxlen = sizeof(int),
3196 .mode = 0200,
3197 .proc_handler = ipv4_sysctl_rtcache_flush,
3198 },
3199 { },
3200};
3201
3202static __net_initdata struct ctl_path ipv4_route_path[] = {
3203 { .procname = "net", },
3204 { .procname = "ipv4", },
3205 { .procname = "route", },
3206 { },
3207};
3208
3209static __net_init int sysctl_route_net_init(struct net *net)
3210{
3211 struct ctl_table *tbl;
3212
3213 tbl = ipv4_route_flush_table;
3214 if (!net_eq(net, &init_net)) {
3215 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3216 if (tbl == NULL)
3217 goto err_dup;
3218 }
3219 tbl[0].extra1 = net;
3220
3221 net->ipv4.route_hdr =
3222 register_net_sysctl_table(net, ipv4_route_path, tbl);
3223 if (net->ipv4.route_hdr == NULL)
3224 goto err_reg;
3225 return 0;
3226
3227err_reg:
3228 if (tbl != ipv4_route_flush_table)
3229 kfree(tbl);
3230err_dup:
3231 return -ENOMEM;
3232}
3233
3234static __net_exit void sysctl_route_net_exit(struct net *net)
3235{
3236 struct ctl_table *tbl;
3237
3238 tbl = net->ipv4.route_hdr->ctl_table_arg;
3239 unregister_net_sysctl_table(net->ipv4.route_hdr);
3240 BUG_ON(tbl == ipv4_route_flush_table);
3241 kfree(tbl);
3242}
3243
3244static __net_initdata struct pernet_operations sysctl_route_ops = {
3245 .init = sysctl_route_net_init,
3246 .exit = sysctl_route_net_exit,
3247};
3248#endif
3249
3250static __net_init int rt_genid_init(struct net *net)
3251{
3252 get_random_bytes(&net->ipv4.rt_genid,
3253 sizeof(net->ipv4.rt_genid));
3254 return 0;
3255}
3256
3257static __net_initdata struct pernet_operations rt_genid_ops = {
3258 .init = rt_genid_init,
3259};
3260
3261
3262#ifdef CONFIG_NET_CLS_ROUTE
3263struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3264#endif /* CONFIG_NET_CLS_ROUTE */
3265
3266static __initdata unsigned long rhash_entries;
3267static int __init set_rhash_entries(char *str)
3268{
3269 if (!str)
3270 return 0;
3271 rhash_entries = simple_strtoul(str, &str, 0);
3272 return 1;
3273}
3274__setup("rhash_entries=", set_rhash_entries);
3275
3276int __init ip_rt_init(void)
3277{
3278 int rc = 0;
3279
3280#ifdef CONFIG_NET_CLS_ROUTE
3281 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3282 if (!ip_rt_acct)
3283 panic("IP: failed to allocate ip_rt_acct\n");
3284#endif
3285
3286 ipv4_dst_ops.kmem_cachep =
3287 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3288 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3289
3290 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3291
3292 rt_hash_table = (struct rt_hash_bucket *)
3293 alloc_large_system_hash("IP route cache",
3294 sizeof(struct rt_hash_bucket),
3295 rhash_entries,
3296 (totalram_pages >= 128 * 1024) ?
3297 15 : 17,
3298 0,
3299 &rt_hash_log,
3300 &rt_hash_mask,
3301 rhash_entries ? 0 : 512 * 1024);
3302 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3303 rt_hash_lock_init();
3304
3305 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3306 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3307
3308 devinet_init();
3309 ip_fib_init();
3310
3311 /* All the timers, started at system startup tend
3312 to synchronize. Perturb it a bit.
3313 */
3314 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3315 expires_ljiffies = jiffies;
3316 schedule_delayed_work(&expires_work,
3317 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3318
3319 if (ip_rt_proc_init())
3320 printk(KERN_ERR "Unable to create route proc files\n");
3321#ifdef CONFIG_XFRM
3322 xfrm_init();
3323 xfrm4_init(ip_rt_max_size);
3324#endif
3325 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3326
3327#ifdef CONFIG_SYSCTL
3328 register_pernet_subsys(&sysctl_route_ops);
3329#endif
3330 register_pernet_subsys(&rt_genid_ops);
3331 return rc;
3332}
3333
3334#ifdef CONFIG_SYSCTL
3335/*
3336 * We really need to sanitize the damn ipv4 init order, then all
3337 * this nonsense will go away.
3338 */
3339void __init ip_static_sysctl_init(void)
3340{
3341 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3342}
3343#endif
Clone of davem's net-next-2.6 tree