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ipv4: Remove redundant RCU locking in ip_check_mc().
[mirror_ubuntu-artful-kernel.git] / net / ipv4 / route.c
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
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 /*
135 * Interface to generic destination cache.
136 */
137
138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
145 static int rt_garbage_collect(struct dst_ops *ops);
146
147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
148 int how)
149 {
150 }
151
152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
153 {
154 struct rtable *rt = (struct rtable *) dst;
155 struct inet_peer *peer;
156 u32 *p = NULL;
157
158 if (!rt->peer)
159 rt_bind_peer(rt, 1);
160
161 peer = rt->peer;
162 if (peer) {
163 u32 *old_p = __DST_METRICS_PTR(old);
164 unsigned long prev, new;
165
166 p = peer->metrics;
167 if (inet_metrics_new(peer))
168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
169
170 new = (unsigned long) p;
171 prev = cmpxchg(&dst->_metrics, old, new);
172
173 if (prev != old) {
174 p = __DST_METRICS_PTR(prev);
175 if (prev & DST_METRICS_READ_ONLY)
176 p = NULL;
177 } else {
178 if (rt->fi) {
179 fib_info_put(rt->fi);
180 rt->fi = NULL;
181 }
182 }
183 }
184 return p;
185 }
186
187 static struct dst_ops ipv4_dst_ops = {
188 .family = AF_INET,
189 .protocol = cpu_to_be16(ETH_P_IP),
190 .gc = rt_garbage_collect,
191 .check = ipv4_dst_check,
192 .default_advmss = ipv4_default_advmss,
193 .default_mtu = ipv4_default_mtu,
194 .cow_metrics = ipv4_cow_metrics,
195 .destroy = ipv4_dst_destroy,
196 .ifdown = ipv4_dst_ifdown,
197 .negative_advice = ipv4_negative_advice,
198 .link_failure = ipv4_link_failure,
199 .update_pmtu = ip_rt_update_pmtu,
200 .local_out = __ip_local_out,
201 };
202
203 #define ECN_OR_COST(class) TC_PRIO_##class
204
205 const __u8 ip_tos2prio[16] = {
206 TC_PRIO_BESTEFFORT,
207 ECN_OR_COST(FILLER),
208 TC_PRIO_BESTEFFORT,
209 ECN_OR_COST(BESTEFFORT),
210 TC_PRIO_BULK,
211 ECN_OR_COST(BULK),
212 TC_PRIO_BULK,
213 ECN_OR_COST(BULK),
214 TC_PRIO_INTERACTIVE,
215 ECN_OR_COST(INTERACTIVE),
216 TC_PRIO_INTERACTIVE,
217 ECN_OR_COST(INTERACTIVE),
218 TC_PRIO_INTERACTIVE_BULK,
219 ECN_OR_COST(INTERACTIVE_BULK),
220 TC_PRIO_INTERACTIVE_BULK,
221 ECN_OR_COST(INTERACTIVE_BULK)
222 };
223
224
225 /*
226 * Route cache.
227 */
228
229 /* The locking scheme is rather straight forward:
230 *
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
236 * lock held.
237 */
238
239 struct rt_hash_bucket {
240 struct rtable __rcu *chain;
241 };
242
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
245 /*
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
249 */
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
252 #else
253 # if NR_CPUS >= 32
254 # define RT_HASH_LOCK_SZ 4096
255 # elif NR_CPUS >= 16
256 # define RT_HASH_LOCK_SZ 2048
257 # elif NR_CPUS >= 8
258 # define RT_HASH_LOCK_SZ 1024
259 # elif NR_CPUS >= 4
260 # define RT_HASH_LOCK_SZ 512
261 # else
262 # define RT_HASH_LOCK_SZ 256
263 # endif
264 #endif
265
266 static spinlock_t *rt_hash_locks;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
268
269 static __init void rt_hash_lock_init(void)
270 {
271 int i;
272
273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
274 GFP_KERNEL);
275 if (!rt_hash_locks)
276 panic("IP: failed to allocate rt_hash_locks\n");
277
278 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
279 spin_lock_init(&rt_hash_locks[i]);
280 }
281 #else
282 # define rt_hash_lock_addr(slot) NULL
283
284 static inline void rt_hash_lock_init(void)
285 {
286 }
287 #endif
288
289 static struct rt_hash_bucket *rt_hash_table __read_mostly;
290 static unsigned rt_hash_mask __read_mostly;
291 static unsigned int rt_hash_log __read_mostly;
292
293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
295
296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
297 int genid)
298 {
299 return jhash_3words((__force u32)daddr, (__force u32)saddr,
300 idx, genid)
301 & rt_hash_mask;
302 }
303
304 static inline int rt_genid(struct net *net)
305 {
306 return atomic_read(&net->ipv4.rt_genid);
307 }
308
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state {
311 struct seq_net_private p;
312 int bucket;
313 int genid;
314 };
315
316 static struct rtable *rt_cache_get_first(struct seq_file *seq)
317 {
318 struct rt_cache_iter_state *st = seq->private;
319 struct rtable *r = NULL;
320
321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
323 continue;
324 rcu_read_lock_bh();
325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
326 while (r) {
327 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
328 r->rt_genid == st->genid)
329 return r;
330 r = rcu_dereference_bh(r->dst.rt_next);
331 }
332 rcu_read_unlock_bh();
333 }
334 return r;
335 }
336
337 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
338 struct rtable *r)
339 {
340 struct rt_cache_iter_state *st = seq->private;
341
342 r = rcu_dereference_bh(r->dst.rt_next);
343 while (!r) {
344 rcu_read_unlock_bh();
345 do {
346 if (--st->bucket < 0)
347 return NULL;
348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
349 rcu_read_lock_bh();
350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
351 }
352 return r;
353 }
354
355 static struct rtable *rt_cache_get_next(struct seq_file *seq,
356 struct rtable *r)
357 {
358 struct rt_cache_iter_state *st = seq->private;
359 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
360 if (dev_net(r->dst.dev) != seq_file_net(seq))
361 continue;
362 if (r->rt_genid == st->genid)
363 break;
364 }
365 return r;
366 }
367
368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
369 {
370 struct rtable *r = rt_cache_get_first(seq);
371
372 if (r)
373 while (pos && (r = rt_cache_get_next(seq, r)))
374 --pos;
375 return pos ? NULL : r;
376 }
377
378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
379 {
380 struct rt_cache_iter_state *st = seq->private;
381 if (*pos)
382 return rt_cache_get_idx(seq, *pos - 1);
383 st->genid = rt_genid(seq_file_net(seq));
384 return SEQ_START_TOKEN;
385 }
386
387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
388 {
389 struct rtable *r;
390
391 if (v == SEQ_START_TOKEN)
392 r = rt_cache_get_first(seq);
393 else
394 r = rt_cache_get_next(seq, v);
395 ++*pos;
396 return r;
397 }
398
399 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
400 {
401 if (v && v != SEQ_START_TOKEN)
402 rcu_read_unlock_bh();
403 }
404
405 static int rt_cache_seq_show(struct seq_file *seq, void *v)
406 {
407 if (v == SEQ_START_TOKEN)
408 seq_printf(seq, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
411 "HHUptod\tSpecDst");
412 else {
413 struct rtable *r = v;
414 int len;
415
416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r->dst.dev ? r->dst.dev->name : "*",
419 (__force u32)r->rt_dst,
420 (__force u32)r->rt_gateway,
421 r->rt_flags, atomic_read(&r->dst.__refcnt),
422 r->dst.__use, 0, (__force u32)r->rt_src,
423 dst_metric_advmss(&r->dst) + 40,
424 dst_metric(&r->dst, RTAX_WINDOW),
425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
426 dst_metric(&r->dst, RTAX_RTTVAR)),
427 r->rt_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 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");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_tos ^ rt2->rt_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * Pertubation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
828 */
829 static void rt_cache_invalidate(struct net *net)
830 {
831 unsigned char shuffle;
832
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
835 }
836
837 /*
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
840 */
841 void rt_cache_flush(struct net *net, int delay)
842 {
843 rt_cache_invalidate(net);
844 if (delay >= 0)
845 rt_do_flush(net, !in_softirq());
846 }
847
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
850 {
851 rt_do_flush(net, !in_softirq());
852 }
853
854 static void rt_emergency_hash_rebuild(struct net *net)
855 {
856 if (net_ratelimit())
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
859 }
860
861 /*
862 Short description of GC goals.
863
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
867
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
872 */
873
874 static int rt_garbage_collect(struct dst_ops *ops)
875 {
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
878 static int rover;
879 static int equilibrium;
880 struct rtable *rth;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
883 int goal;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
885
886 /*
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
889 */
890
891 RT_CACHE_STAT_INC(gc_total);
892
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
896 goto out;
897 }
898
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
902 if (goal <= 0) {
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
906 if (goal > 0) {
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
909 }
910 } else {
911 /* We are in dangerous area. Try to reduce cache really
912 * aggressively.
913 */
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
916 }
917
918 if (now - last_gc >= ip_rt_gc_min_interval)
919 last_gc = now;
920
921 if (goal <= 0) {
922 equilibrium += goal;
923 goto work_done;
924 }
925
926 do {
927 int i, k;
928
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
931
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
939 tmo >>= 1;
940 rthp = &rth->dst.rt_next;
941 continue;
942 }
943 *rthp = rth->dst.rt_next;
944 rt_free(rth);
945 goal--;
946 }
947 spin_unlock_bh(rt_hash_lock_addr(k));
948 if (goal <= 0)
949 break;
950 }
951 rover = k;
952
953 if (goal <= 0)
954 goto work_done;
955
956 /* Goal is not achieved. We stop process if:
957
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
963 */
964
965 RT_CACHE_STAT_INC(gc_goal_miss);
966
967 if (expire == 0)
968 break;
969
970 expire >>= 1;
971 #if RT_CACHE_DEBUG >= 2
972 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
973 dst_entries_get_fast(&ipv4_dst_ops), goal, i);
974 #endif
975
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
977 goto out;
978 } while (!in_softirq() && time_before_eq(jiffies, now));
979
980 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
981 goto out;
982 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
983 goto out;
984 if (net_ratelimit())
985 printk(KERN_WARNING "dst cache overflow\n");
986 RT_CACHE_STAT_INC(gc_dst_overflow);
987 return 1;
988
989 work_done:
990 expire += ip_rt_gc_min_interval;
991 if (expire > ip_rt_gc_timeout ||
992 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
993 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
994 expire = ip_rt_gc_timeout;
995 #if RT_CACHE_DEBUG >= 2
996 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
997 dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
998 #endif
999 out: return 0;
1000 }
1001
1002 /*
1003 * Returns number of entries in a hash chain that have different hash_inputs
1004 */
1005 static int slow_chain_length(const struct rtable *head)
1006 {
1007 int length = 0;
1008 const struct rtable *rth = head;
1009
1010 while (rth) {
1011 length += has_noalias(head, rth);
1012 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1013 }
1014 return length >> FRACT_BITS;
1015 }
1016
1017 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1018 struct sk_buff *skb, int ifindex)
1019 {
1020 struct rtable *rth, *cand;
1021 struct rtable __rcu **rthp, **candp;
1022 unsigned long now;
1023 u32 min_score;
1024 int chain_length;
1025 int attempts = !in_softirq();
1026
1027 restart:
1028 chain_length = 0;
1029 min_score = ~(u32)0;
1030 cand = NULL;
1031 candp = NULL;
1032 now = jiffies;
1033
1034 if (!rt_caching(dev_net(rt->dst.dev))) {
1035 /*
1036 * If we're not caching, just tell the caller we
1037 * were successful and don't touch the route. The
1038 * caller hold the sole reference to the cache entry, and
1039 * it will be released when the caller is done with it.
1040 * If we drop it here, the callers have no way to resolve routes
1041 * when we're not caching. Instead, just point *rp at rt, so
1042 * the caller gets a single use out of the route
1043 * Note that we do rt_free on this new route entry, so that
1044 * once its refcount hits zero, we are still able to reap it
1045 * (Thanks Alexey)
1046 * Note: To avoid expensive rcu stuff for this uncached dst,
1047 * we set DST_NOCACHE so that dst_release() can free dst without
1048 * waiting a grace period.
1049 */
1050
1051 rt->dst.flags |= DST_NOCACHE;
1052 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1053 int err = arp_bind_neighbour(&rt->dst);
1054 if (err) {
1055 if (net_ratelimit())
1056 printk(KERN_WARNING
1057 "Neighbour table failure & not caching routes.\n");
1058 ip_rt_put(rt);
1059 return ERR_PTR(err);
1060 }
1061 }
1062
1063 goto skip_hashing;
1064 }
1065
1066 rthp = &rt_hash_table[hash].chain;
1067
1068 spin_lock_bh(rt_hash_lock_addr(hash));
1069 while ((rth = rcu_dereference_protected(*rthp,
1070 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1071 if (rt_is_expired(rth)) {
1072 *rthp = rth->dst.rt_next;
1073 rt_free(rth);
1074 continue;
1075 }
1076 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1077 /* Put it first */
1078 *rthp = rth->dst.rt_next;
1079 /*
1080 * Since lookup is lockfree, the deletion
1081 * must be visible to another weakly ordered CPU before
1082 * the insertion at the start of the hash chain.
1083 */
1084 rcu_assign_pointer(rth->dst.rt_next,
1085 rt_hash_table[hash].chain);
1086 /*
1087 * Since lookup is lockfree, the update writes
1088 * must be ordered for consistency on SMP.
1089 */
1090 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1091
1092 dst_use(&rth->dst, now);
1093 spin_unlock_bh(rt_hash_lock_addr(hash));
1094
1095 rt_drop(rt);
1096 if (skb)
1097 skb_dst_set(skb, &rth->dst);
1098 return rth;
1099 }
1100
1101 if (!atomic_read(&rth->dst.__refcnt)) {
1102 u32 score = rt_score(rth);
1103
1104 if (score <= min_score) {
1105 cand = rth;
1106 candp = rthp;
1107 min_score = score;
1108 }
1109 }
1110
1111 chain_length++;
1112
1113 rthp = &rth->dst.rt_next;
1114 }
1115
1116 if (cand) {
1117 /* ip_rt_gc_elasticity used to be average length of chain
1118 * length, when exceeded gc becomes really aggressive.
1119 *
1120 * The second limit is less certain. At the moment it allows
1121 * only 2 entries per bucket. We will see.
1122 */
1123 if (chain_length > ip_rt_gc_elasticity) {
1124 *candp = cand->dst.rt_next;
1125 rt_free(cand);
1126 }
1127 } else {
1128 if (chain_length > rt_chain_length_max &&
1129 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1130 struct net *net = dev_net(rt->dst.dev);
1131 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1132 if (!rt_caching(net)) {
1133 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1134 rt->dst.dev->name, num);
1135 }
1136 rt_emergency_hash_rebuild(net);
1137 spin_unlock_bh(rt_hash_lock_addr(hash));
1138
1139 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1140 ifindex, rt_genid(net));
1141 goto restart;
1142 }
1143 }
1144
1145 /* Try to bind route to arp only if it is output
1146 route or unicast forwarding path.
1147 */
1148 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1149 int err = arp_bind_neighbour(&rt->dst);
1150 if (err) {
1151 spin_unlock_bh(rt_hash_lock_addr(hash));
1152
1153 if (err != -ENOBUFS) {
1154 rt_drop(rt);
1155 return ERR_PTR(err);
1156 }
1157
1158 /* Neighbour tables are full and nothing
1159 can be released. Try to shrink route cache,
1160 it is most likely it holds some neighbour records.
1161 */
1162 if (attempts-- > 0) {
1163 int saved_elasticity = ip_rt_gc_elasticity;
1164 int saved_int = ip_rt_gc_min_interval;
1165 ip_rt_gc_elasticity = 1;
1166 ip_rt_gc_min_interval = 0;
1167 rt_garbage_collect(&ipv4_dst_ops);
1168 ip_rt_gc_min_interval = saved_int;
1169 ip_rt_gc_elasticity = saved_elasticity;
1170 goto restart;
1171 }
1172
1173 if (net_ratelimit())
1174 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1175 rt_drop(rt);
1176 return ERR_PTR(-ENOBUFS);
1177 }
1178 }
1179
1180 rt->dst.rt_next = rt_hash_table[hash].chain;
1181
1182 #if RT_CACHE_DEBUG >= 2
1183 if (rt->dst.rt_next) {
1184 struct rtable *trt;
1185 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1186 hash, &rt->rt_dst);
1187 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1188 printk(" . %pI4", &trt->rt_dst);
1189 printk("\n");
1190 }
1191 #endif
1192 /*
1193 * Since lookup is lockfree, we must make sure
1194 * previous writes to rt are comitted to memory
1195 * before making rt visible to other CPUS.
1196 */
1197 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1198
1199 spin_unlock_bh(rt_hash_lock_addr(hash));
1200
1201 skip_hashing:
1202 if (skb)
1203 skb_dst_set(skb, &rt->dst);
1204 return rt;
1205 }
1206
1207 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1208
1209 static u32 rt_peer_genid(void)
1210 {
1211 return atomic_read(&__rt_peer_genid);
1212 }
1213
1214 void rt_bind_peer(struct rtable *rt, int create)
1215 {
1216 struct inet_peer *peer;
1217
1218 peer = inet_getpeer_v4(rt->rt_dst, create);
1219
1220 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1221 inet_putpeer(peer);
1222 else
1223 rt->rt_peer_genid = rt_peer_genid();
1224 }
1225
1226 /*
1227 * Peer allocation may fail only in serious out-of-memory conditions. However
1228 * we still can generate some output.
1229 * Random ID selection looks a bit dangerous because we have no chances to
1230 * select ID being unique in a reasonable period of time.
1231 * But broken packet identifier may be better than no packet at all.
1232 */
1233 static void ip_select_fb_ident(struct iphdr *iph)
1234 {
1235 static DEFINE_SPINLOCK(ip_fb_id_lock);
1236 static u32 ip_fallback_id;
1237 u32 salt;
1238
1239 spin_lock_bh(&ip_fb_id_lock);
1240 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1241 iph->id = htons(salt & 0xFFFF);
1242 ip_fallback_id = salt;
1243 spin_unlock_bh(&ip_fb_id_lock);
1244 }
1245
1246 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1247 {
1248 struct rtable *rt = (struct rtable *) dst;
1249
1250 if (rt) {
1251 if (rt->peer == NULL)
1252 rt_bind_peer(rt, 1);
1253
1254 /* If peer is attached to destination, it is never detached,
1255 so that we need not to grab a lock to dereference it.
1256 */
1257 if (rt->peer) {
1258 iph->id = htons(inet_getid(rt->peer, more));
1259 return;
1260 }
1261 } else
1262 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1263 __builtin_return_address(0));
1264
1265 ip_select_fb_ident(iph);
1266 }
1267 EXPORT_SYMBOL(__ip_select_ident);
1268
1269 static void rt_del(unsigned hash, struct rtable *rt)
1270 {
1271 struct rtable __rcu **rthp;
1272 struct rtable *aux;
1273
1274 rthp = &rt_hash_table[hash].chain;
1275 spin_lock_bh(rt_hash_lock_addr(hash));
1276 ip_rt_put(rt);
1277 while ((aux = rcu_dereference_protected(*rthp,
1278 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1279 if (aux == rt || rt_is_expired(aux)) {
1280 *rthp = aux->dst.rt_next;
1281 rt_free(aux);
1282 continue;
1283 }
1284 rthp = &aux->dst.rt_next;
1285 }
1286 spin_unlock_bh(rt_hash_lock_addr(hash));
1287 }
1288
1289 /* called in rcu_read_lock() section */
1290 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1291 __be32 saddr, struct net_device *dev)
1292 {
1293 struct in_device *in_dev = __in_dev_get_rcu(dev);
1294 struct inet_peer *peer;
1295 struct net *net;
1296
1297 if (!in_dev)
1298 return;
1299
1300 net = dev_net(dev);
1301 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1302 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1303 ipv4_is_zeronet(new_gw))
1304 goto reject_redirect;
1305
1306 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1307 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1308 goto reject_redirect;
1309 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1310 goto reject_redirect;
1311 } else {
1312 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1313 goto reject_redirect;
1314 }
1315
1316 peer = inet_getpeer_v4(daddr, 1);
1317 if (peer) {
1318 peer->redirect_learned.a4 = new_gw;
1319
1320 inet_putpeer(peer);
1321
1322 atomic_inc(&__rt_peer_genid);
1323 }
1324 return;
1325
1326 reject_redirect:
1327 #ifdef CONFIG_IP_ROUTE_VERBOSE
1328 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1329 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1330 " Advised path = %pI4 -> %pI4\n",
1331 &old_gw, dev->name, &new_gw,
1332 &saddr, &daddr);
1333 #endif
1334 ;
1335 }
1336
1337 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1338 {
1339 struct rtable *rt = (struct rtable *)dst;
1340 struct dst_entry *ret = dst;
1341
1342 if (rt) {
1343 if (dst->obsolete > 0) {
1344 ip_rt_put(rt);
1345 ret = NULL;
1346 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1347 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1348 rt->rt_oif,
1349 rt_genid(dev_net(dst->dev)));
1350 #if RT_CACHE_DEBUG >= 1
1351 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1352 &rt->rt_dst, rt->rt_tos);
1353 #endif
1354 rt_del(hash, rt);
1355 ret = NULL;
1356 } else if (rt->peer &&
1357 rt->peer->pmtu_expires &&
1358 time_after_eq(jiffies, rt->peer->pmtu_expires)) {
1359 unsigned long orig = rt->peer->pmtu_expires;
1360
1361 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1362 dst_metric_set(dst, RTAX_MTU,
1363 rt->peer->pmtu_orig);
1364 }
1365 }
1366 return ret;
1367 }
1368
1369 /*
1370 * Algorithm:
1371 * 1. The first ip_rt_redirect_number redirects are sent
1372 * with exponential backoff, then we stop sending them at all,
1373 * assuming that the host ignores our redirects.
1374 * 2. If we did not see packets requiring redirects
1375 * during ip_rt_redirect_silence, we assume that the host
1376 * forgot redirected route and start to send redirects again.
1377 *
1378 * This algorithm is much cheaper and more intelligent than dumb load limiting
1379 * in icmp.c.
1380 *
1381 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1382 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1383 */
1384
1385 void ip_rt_send_redirect(struct sk_buff *skb)
1386 {
1387 struct rtable *rt = skb_rtable(skb);
1388 struct in_device *in_dev;
1389 struct inet_peer *peer;
1390 int log_martians;
1391
1392 rcu_read_lock();
1393 in_dev = __in_dev_get_rcu(rt->dst.dev);
1394 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1395 rcu_read_unlock();
1396 return;
1397 }
1398 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1399 rcu_read_unlock();
1400
1401 if (!rt->peer)
1402 rt_bind_peer(rt, 1);
1403 peer = rt->peer;
1404 if (!peer) {
1405 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1406 return;
1407 }
1408
1409 /* No redirected packets during ip_rt_redirect_silence;
1410 * reset the algorithm.
1411 */
1412 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1413 peer->rate_tokens = 0;
1414
1415 /* Too many ignored redirects; do not send anything
1416 * set dst.rate_last to the last seen redirected packet.
1417 */
1418 if (peer->rate_tokens >= ip_rt_redirect_number) {
1419 peer->rate_last = jiffies;
1420 return;
1421 }
1422
1423 /* Check for load limit; set rate_last to the latest sent
1424 * redirect.
1425 */
1426 if (peer->rate_tokens == 0 ||
1427 time_after(jiffies,
1428 (peer->rate_last +
1429 (ip_rt_redirect_load << peer->rate_tokens)))) {
1430 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1431 peer->rate_last = jiffies;
1432 ++peer->rate_tokens;
1433 #ifdef CONFIG_IP_ROUTE_VERBOSE
1434 if (log_martians &&
1435 peer->rate_tokens == ip_rt_redirect_number &&
1436 net_ratelimit())
1437 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1438 &rt->rt_src, rt->rt_iif,
1439 &rt->rt_dst, &rt->rt_gateway);
1440 #endif
1441 }
1442 }
1443
1444 static int ip_error(struct sk_buff *skb)
1445 {
1446 struct rtable *rt = skb_rtable(skb);
1447 struct inet_peer *peer;
1448 unsigned long now;
1449 bool send;
1450 int code;
1451
1452 switch (rt->dst.error) {
1453 case EINVAL:
1454 default:
1455 goto out;
1456 case EHOSTUNREACH:
1457 code = ICMP_HOST_UNREACH;
1458 break;
1459 case ENETUNREACH:
1460 code = ICMP_NET_UNREACH;
1461 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1462 IPSTATS_MIB_INNOROUTES);
1463 break;
1464 case EACCES:
1465 code = ICMP_PKT_FILTERED;
1466 break;
1467 }
1468
1469 if (!rt->peer)
1470 rt_bind_peer(rt, 1);
1471 peer = rt->peer;
1472
1473 send = true;
1474 if (peer) {
1475 now = jiffies;
1476 peer->rate_tokens += now - peer->rate_last;
1477 if (peer->rate_tokens > ip_rt_error_burst)
1478 peer->rate_tokens = ip_rt_error_burst;
1479 peer->rate_last = now;
1480 if (peer->rate_tokens >= ip_rt_error_cost)
1481 peer->rate_tokens -= ip_rt_error_cost;
1482 else
1483 send = false;
1484 }
1485 if (send)
1486 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1487
1488 out: kfree_skb(skb);
1489 return 0;
1490 }
1491
1492 /*
1493 * The last two values are not from the RFC but
1494 * are needed for AMPRnet AX.25 paths.
1495 */
1496
1497 static const unsigned short mtu_plateau[] =
1498 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1499
1500 static inline unsigned short guess_mtu(unsigned short old_mtu)
1501 {
1502 int i;
1503
1504 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1505 if (old_mtu > mtu_plateau[i])
1506 return mtu_plateau[i];
1507 return 68;
1508 }
1509
1510 unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
1511 unsigned short new_mtu,
1512 struct net_device *dev)
1513 {
1514 unsigned short old_mtu = ntohs(iph->tot_len);
1515 unsigned short est_mtu = 0;
1516 struct inet_peer *peer;
1517
1518 peer = inet_getpeer_v4(iph->daddr, 1);
1519 if (peer) {
1520 unsigned short mtu = new_mtu;
1521
1522 if (new_mtu < 68 || new_mtu >= old_mtu) {
1523 /* BSD 4.2 derived systems incorrectly adjust
1524 * tot_len by the IP header length, and report
1525 * a zero MTU in the ICMP message.
1526 */
1527 if (mtu == 0 &&
1528 old_mtu >= 68 + (iph->ihl << 2))
1529 old_mtu -= iph->ihl << 2;
1530 mtu = guess_mtu(old_mtu);
1531 }
1532
1533 if (mtu < ip_rt_min_pmtu)
1534 mtu = ip_rt_min_pmtu;
1535 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1536 est_mtu = mtu;
1537 peer->pmtu_learned = mtu;
1538 peer->pmtu_expires = jiffies + ip_rt_mtu_expires;
1539 }
1540
1541 inet_putpeer(peer);
1542
1543 atomic_inc(&__rt_peer_genid);
1544 }
1545 return est_mtu ? : new_mtu;
1546 }
1547
1548 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1549 {
1550 unsigned long expires = peer->pmtu_expires;
1551
1552 if (time_before(expires, jiffies)) {
1553 u32 orig_dst_mtu = dst_mtu(dst);
1554 if (peer->pmtu_learned < orig_dst_mtu) {
1555 if (!peer->pmtu_orig)
1556 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1557 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1558 }
1559 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1560 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1561 }
1562
1563 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1564 {
1565 struct rtable *rt = (struct rtable *) dst;
1566 struct inet_peer *peer;
1567
1568 dst_confirm(dst);
1569
1570 if (!rt->peer)
1571 rt_bind_peer(rt, 1);
1572 peer = rt->peer;
1573 if (peer) {
1574 if (mtu < ip_rt_min_pmtu)
1575 mtu = ip_rt_min_pmtu;
1576 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1577 peer->pmtu_learned = mtu;
1578 peer->pmtu_expires = jiffies + ip_rt_mtu_expires;
1579
1580 atomic_inc(&__rt_peer_genid);
1581 rt->rt_peer_genid = rt_peer_genid();
1582
1583 check_peer_pmtu(dst, peer);
1584 }
1585 inet_putpeer(peer);
1586 }
1587 }
1588
1589 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1590 {
1591 struct rtable *rt = (struct rtable *) dst;
1592 __be32 orig_gw = rt->rt_gateway;
1593
1594 dst_confirm(&rt->dst);
1595
1596 neigh_release(rt->dst.neighbour);
1597 rt->dst.neighbour = NULL;
1598
1599 rt->rt_gateway = peer->redirect_learned.a4;
1600 if (arp_bind_neighbour(&rt->dst) ||
1601 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1602 if (rt->dst.neighbour)
1603 neigh_event_send(rt->dst.neighbour, NULL);
1604 rt->rt_gateway = orig_gw;
1605 return -EAGAIN;
1606 } else {
1607 rt->rt_flags |= RTCF_REDIRECTED;
1608 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1609 rt->dst.neighbour);
1610 }
1611 return 0;
1612 }
1613
1614 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1615 {
1616 struct rtable *rt = (struct rtable *) dst;
1617
1618 if (rt_is_expired(rt))
1619 return NULL;
1620 if (rt->rt_peer_genid != rt_peer_genid()) {
1621 struct inet_peer *peer;
1622
1623 if (!rt->peer)
1624 rt_bind_peer(rt, 0);
1625
1626 peer = rt->peer;
1627 if (peer && peer->pmtu_expires)
1628 check_peer_pmtu(dst, peer);
1629
1630 if (peer && peer->redirect_learned.a4 &&
1631 peer->redirect_learned.a4 != rt->rt_gateway) {
1632 if (check_peer_redir(dst, peer))
1633 return NULL;
1634 }
1635
1636 rt->rt_peer_genid = rt_peer_genid();
1637 }
1638 return dst;
1639 }
1640
1641 static void ipv4_dst_destroy(struct dst_entry *dst)
1642 {
1643 struct rtable *rt = (struct rtable *) dst;
1644 struct inet_peer *peer = rt->peer;
1645
1646 if (rt->fi) {
1647 fib_info_put(rt->fi);
1648 rt->fi = NULL;
1649 }
1650 if (peer) {
1651 rt->peer = NULL;
1652 inet_putpeer(peer);
1653 }
1654 }
1655
1656
1657 static void ipv4_link_failure(struct sk_buff *skb)
1658 {
1659 struct rtable *rt;
1660
1661 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1662
1663 rt = skb_rtable(skb);
1664 if (rt &&
1665 rt->peer &&
1666 rt->peer->pmtu_expires) {
1667 unsigned long orig = rt->peer->pmtu_expires;
1668
1669 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1670 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1671 }
1672 }
1673
1674 static int ip_rt_bug(struct sk_buff *skb)
1675 {
1676 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1677 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1678 skb->dev ? skb->dev->name : "?");
1679 kfree_skb(skb);
1680 return 0;
1681 }
1682
1683 /*
1684 We do not cache source address of outgoing interface,
1685 because it is used only by IP RR, TS and SRR options,
1686 so that it out of fast path.
1687
1688 BTW remember: "addr" is allowed to be not aligned
1689 in IP options!
1690 */
1691
1692 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1693 {
1694 __be32 src;
1695 struct fib_result res;
1696
1697 if (rt_is_output_route(rt))
1698 src = rt->rt_src;
1699 else {
1700 struct flowi fl = {
1701 .fl4_dst = rt->rt_key_dst,
1702 .fl4_src = rt->rt_key_src,
1703 .fl4_tos = rt->rt_tos,
1704 .oif = rt->rt_oif,
1705 .iif = rt->rt_iif,
1706 .mark = rt->rt_mark,
1707 };
1708
1709 rcu_read_lock();
1710 if (fib_lookup(dev_net(rt->dst.dev), &fl, &res) == 0)
1711 src = FIB_RES_PREFSRC(res);
1712 else
1713 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1714 RT_SCOPE_UNIVERSE);
1715 rcu_read_unlock();
1716 }
1717 memcpy(addr, &src, 4);
1718 }
1719
1720 #ifdef CONFIG_IP_ROUTE_CLASSID
1721 static void set_class_tag(struct rtable *rt, u32 tag)
1722 {
1723 if (!(rt->dst.tclassid & 0xFFFF))
1724 rt->dst.tclassid |= tag & 0xFFFF;
1725 if (!(rt->dst.tclassid & 0xFFFF0000))
1726 rt->dst.tclassid |= tag & 0xFFFF0000;
1727 }
1728 #endif
1729
1730 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1731 {
1732 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1733
1734 if (advmss == 0) {
1735 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1736 ip_rt_min_advmss);
1737 if (advmss > 65535 - 40)
1738 advmss = 65535 - 40;
1739 }
1740 return advmss;
1741 }
1742
1743 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1744 {
1745 unsigned int mtu = dst->dev->mtu;
1746
1747 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1748 const struct rtable *rt = (const struct rtable *) dst;
1749
1750 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1751 mtu = 576;
1752 }
1753
1754 if (mtu > IP_MAX_MTU)
1755 mtu = IP_MAX_MTU;
1756
1757 return mtu;
1758 }
1759
1760 static void rt_init_metrics(struct rtable *rt, const struct flowi *oldflp,
1761 struct fib_info *fi)
1762 {
1763 struct inet_peer *peer;
1764 int create = 0;
1765
1766 /* If a peer entry exists for this destination, we must hook
1767 * it up in order to get at cached metrics.
1768 */
1769 if (oldflp && (oldflp->flags & FLOWI_FLAG_PRECOW_METRICS))
1770 create = 1;
1771
1772 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1773 if (peer) {
1774 rt->rt_peer_genid = rt_peer_genid();
1775 if (inet_metrics_new(peer))
1776 memcpy(peer->metrics, fi->fib_metrics,
1777 sizeof(u32) * RTAX_MAX);
1778 dst_init_metrics(&rt->dst, peer->metrics, false);
1779
1780 if (peer->pmtu_expires)
1781 check_peer_pmtu(&rt->dst, peer);
1782 if (peer->redirect_learned.a4 &&
1783 peer->redirect_learned.a4 != rt->rt_gateway) {
1784 rt->rt_gateway = peer->redirect_learned.a4;
1785 rt->rt_flags |= RTCF_REDIRECTED;
1786 }
1787 } else {
1788 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1789 rt->fi = fi;
1790 atomic_inc(&fi->fib_clntref);
1791 }
1792 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1793 }
1794 }
1795
1796 static void rt_set_nexthop(struct rtable *rt, const struct flowi *oldflp,
1797 const struct fib_result *res,
1798 struct fib_info *fi, u16 type, u32 itag)
1799 {
1800 struct dst_entry *dst = &rt->dst;
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 rt_init_metrics(rt, oldflp, fi);
1807 #ifdef CONFIG_IP_ROUTE_CLASSID
1808 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1809 #endif
1810 }
1811
1812 if (dst_mtu(dst) > IP_MAX_MTU)
1813 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1814 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1815 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1816
1817 #ifdef CONFIG_IP_ROUTE_CLASSID
1818 #ifdef CONFIG_IP_MULTIPLE_TABLES
1819 set_class_tag(rt, fib_rules_tclass(res));
1820 #endif
1821 set_class_tag(rt, itag);
1822 #endif
1823 rt->rt_type = type;
1824 }
1825
1826 static struct rtable *rt_dst_alloc(bool nopolicy, bool noxfrm)
1827 {
1828 struct rtable *rt = dst_alloc(&ipv4_dst_ops, 1);
1829 if (rt) {
1830 rt->dst.obsolete = -1;
1831
1832 rt->dst.flags = DST_HOST |
1833 (nopolicy ? DST_NOPOLICY : 0) |
1834 (noxfrm ? DST_NOXFRM : 0);
1835 }
1836 return rt;
1837 }
1838
1839 /* called in rcu_read_lock() section */
1840 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1841 u8 tos, struct net_device *dev, int our)
1842 {
1843 unsigned int hash;
1844 struct rtable *rth;
1845 __be32 spec_dst;
1846 struct in_device *in_dev = __in_dev_get_rcu(dev);
1847 u32 itag = 0;
1848 int err;
1849
1850 /* Primary sanity checks. */
1851
1852 if (in_dev == NULL)
1853 return -EINVAL;
1854
1855 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1856 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1857 goto e_inval;
1858
1859 if (ipv4_is_zeronet(saddr)) {
1860 if (!ipv4_is_local_multicast(daddr))
1861 goto e_inval;
1862 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1863 } else {
1864 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1865 &itag, 0);
1866 if (err < 0)
1867 goto e_err;
1868 }
1869 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1870 if (!rth)
1871 goto e_nobufs;
1872
1873 rth->dst.output = ip_rt_bug;
1874
1875 rth->rt_key_dst = daddr;
1876 rth->rt_dst = daddr;
1877 rth->rt_tos = tos;
1878 rth->rt_mark = skb->mark;
1879 rth->rt_key_src = saddr;
1880 rth->rt_src = saddr;
1881 #ifdef CONFIG_IP_ROUTE_CLASSID
1882 rth->dst.tclassid = itag;
1883 #endif
1884 rth->rt_iif = dev->ifindex;
1885 rth->dst.dev = init_net.loopback_dev;
1886 dev_hold(rth->dst.dev);
1887 rth->rt_oif = 0;
1888 rth->rt_gateway = daddr;
1889 rth->rt_spec_dst= spec_dst;
1890 rth->rt_genid = rt_genid(dev_net(dev));
1891 rth->rt_flags = RTCF_MULTICAST;
1892 rth->rt_type = RTN_MULTICAST;
1893 if (our) {
1894 rth->dst.input= ip_local_deliver;
1895 rth->rt_flags |= RTCF_LOCAL;
1896 }
1897
1898 #ifdef CONFIG_IP_MROUTE
1899 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1900 rth->dst.input = ip_mr_input;
1901 #endif
1902 RT_CACHE_STAT_INC(in_slow_mc);
1903
1904 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1905 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1906 err = 0;
1907 if (IS_ERR(rth))
1908 err = PTR_ERR(rth);
1909
1910 e_nobufs:
1911 return -ENOBUFS;
1912 e_inval:
1913 return -EINVAL;
1914 e_err:
1915 return err;
1916 }
1917
1918
1919 static void ip_handle_martian_source(struct net_device *dev,
1920 struct in_device *in_dev,
1921 struct sk_buff *skb,
1922 __be32 daddr,
1923 __be32 saddr)
1924 {
1925 RT_CACHE_STAT_INC(in_martian_src);
1926 #ifdef CONFIG_IP_ROUTE_VERBOSE
1927 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1928 /*
1929 * RFC1812 recommendation, if source is martian,
1930 * the only hint is MAC header.
1931 */
1932 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1933 &daddr, &saddr, dev->name);
1934 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1935 int i;
1936 const unsigned char *p = skb_mac_header(skb);
1937 printk(KERN_WARNING "ll header: ");
1938 for (i = 0; i < dev->hard_header_len; i++, p++) {
1939 printk("%02x", *p);
1940 if (i < (dev->hard_header_len - 1))
1941 printk(":");
1942 }
1943 printk("\n");
1944 }
1945 }
1946 #endif
1947 }
1948
1949 /* called in rcu_read_lock() section */
1950 static int __mkroute_input(struct sk_buff *skb,
1951 const struct fib_result *res,
1952 struct in_device *in_dev,
1953 __be32 daddr, __be32 saddr, u32 tos,
1954 struct rtable **result)
1955 {
1956 struct rtable *rth;
1957 int err;
1958 struct in_device *out_dev;
1959 unsigned int flags = 0;
1960 __be32 spec_dst;
1961 u32 itag;
1962
1963 /* get a working reference to the output device */
1964 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1965 if (out_dev == NULL) {
1966 if (net_ratelimit())
1967 printk(KERN_CRIT "Bug in ip_route_input" \
1968 "_slow(). Please, report\n");
1969 return -EINVAL;
1970 }
1971
1972
1973 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1974 in_dev->dev, &spec_dst, &itag, skb->mark);
1975 if (err < 0) {
1976 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1977 saddr);
1978
1979 goto cleanup;
1980 }
1981
1982 if (err)
1983 flags |= RTCF_DIRECTSRC;
1984
1985 if (out_dev == in_dev && err &&
1986 (IN_DEV_SHARED_MEDIA(out_dev) ||
1987 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1988 flags |= RTCF_DOREDIRECT;
1989
1990 if (skb->protocol != htons(ETH_P_IP)) {
1991 /* Not IP (i.e. ARP). Do not create route, if it is
1992 * invalid for proxy arp. DNAT routes are always valid.
1993 *
1994 * Proxy arp feature have been extended to allow, ARP
1995 * replies back to the same interface, to support
1996 * Private VLAN switch technologies. See arp.c.
1997 */
1998 if (out_dev == in_dev &&
1999 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2000 err = -EINVAL;
2001 goto cleanup;
2002 }
2003 }
2004
2005 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
2006 IN_DEV_CONF_GET(out_dev, NOXFRM));
2007 if (!rth) {
2008 err = -ENOBUFS;
2009 goto cleanup;
2010 }
2011
2012 rth->rt_key_dst = daddr;
2013 rth->rt_dst = daddr;
2014 rth->rt_tos = tos;
2015 rth->rt_mark = skb->mark;
2016 rth->rt_key_src = saddr;
2017 rth->rt_src = saddr;
2018 rth->rt_gateway = daddr;
2019 rth->rt_iif = in_dev->dev->ifindex;
2020 rth->dst.dev = (out_dev)->dev;
2021 dev_hold(rth->dst.dev);
2022 rth->rt_oif = 0;
2023 rth->rt_spec_dst= spec_dst;
2024
2025 rth->dst.input = ip_forward;
2026 rth->dst.output = ip_output;
2027 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2028
2029 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2030
2031 rth->rt_flags = flags;
2032
2033 *result = rth;
2034 err = 0;
2035 cleanup:
2036 return err;
2037 }
2038
2039 static int ip_mkroute_input(struct sk_buff *skb,
2040 struct fib_result *res,
2041 const struct flowi *fl,
2042 struct in_device *in_dev,
2043 __be32 daddr, __be32 saddr, u32 tos)
2044 {
2045 struct rtable* rth = NULL;
2046 int err;
2047 unsigned hash;
2048
2049 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2050 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
2051 fib_select_multipath(fl, res);
2052 #endif
2053
2054 /* create a routing cache entry */
2055 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2056 if (err)
2057 return err;
2058
2059 /* put it into the cache */
2060 hash = rt_hash(daddr, saddr, fl->iif,
2061 rt_genid(dev_net(rth->dst.dev)));
2062 rth = rt_intern_hash(hash, rth, skb, fl->iif);
2063 if (IS_ERR(rth))
2064 return PTR_ERR(rth);
2065 return 0;
2066 }
2067
2068 /*
2069 * NOTE. We drop all the packets that has local source
2070 * addresses, because every properly looped back packet
2071 * must have correct destination already attached by output routine.
2072 *
2073 * Such approach solves two big problems:
2074 * 1. Not simplex devices are handled properly.
2075 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2076 * called with rcu_read_lock()
2077 */
2078
2079 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2080 u8 tos, struct net_device *dev)
2081 {
2082 struct fib_result res;
2083 struct in_device *in_dev = __in_dev_get_rcu(dev);
2084 struct flowi fl;
2085 unsigned flags = 0;
2086 u32 itag = 0;
2087 struct rtable * rth;
2088 unsigned hash;
2089 __be32 spec_dst;
2090 int err = -EINVAL;
2091 struct net * net = dev_net(dev);
2092
2093 /* IP on this device is disabled. */
2094
2095 if (!in_dev)
2096 goto out;
2097
2098 /* Check for the most weird martians, which can be not detected
2099 by fib_lookup.
2100 */
2101
2102 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2103 ipv4_is_loopback(saddr))
2104 goto martian_source;
2105
2106 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2107 goto brd_input;
2108
2109 /* Accept zero addresses only to limited broadcast;
2110 * I even do not know to fix it or not. Waiting for complains :-)
2111 */
2112 if (ipv4_is_zeronet(saddr))
2113 goto martian_source;
2114
2115 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2116 goto martian_destination;
2117
2118 /*
2119 * Now we are ready to route packet.
2120 */
2121 fl.oif = 0;
2122 fl.iif = dev->ifindex;
2123 fl.mark = skb->mark;
2124 fl.fl4_dst = daddr;
2125 fl.fl4_src = saddr;
2126 fl.fl4_tos = tos;
2127 fl.fl4_scope = RT_SCOPE_UNIVERSE;
2128 err = fib_lookup(net, &fl, &res);
2129 if (err != 0) {
2130 if (!IN_DEV_FORWARD(in_dev))
2131 goto e_hostunreach;
2132 goto no_route;
2133 }
2134
2135 RT_CACHE_STAT_INC(in_slow_tot);
2136
2137 if (res.type == RTN_BROADCAST)
2138 goto brd_input;
2139
2140 if (res.type == RTN_LOCAL) {
2141 err = fib_validate_source(saddr, daddr, tos,
2142 net->loopback_dev->ifindex,
2143 dev, &spec_dst, &itag, skb->mark);
2144 if (err < 0)
2145 goto martian_source_keep_err;
2146 if (err)
2147 flags |= RTCF_DIRECTSRC;
2148 spec_dst = daddr;
2149 goto local_input;
2150 }
2151
2152 if (!IN_DEV_FORWARD(in_dev))
2153 goto e_hostunreach;
2154 if (res.type != RTN_UNICAST)
2155 goto martian_destination;
2156
2157 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
2158 out: return err;
2159
2160 brd_input:
2161 if (skb->protocol != htons(ETH_P_IP))
2162 goto e_inval;
2163
2164 if (ipv4_is_zeronet(saddr))
2165 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2166 else {
2167 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2168 &itag, skb->mark);
2169 if (err < 0)
2170 goto martian_source_keep_err;
2171 if (err)
2172 flags |= RTCF_DIRECTSRC;
2173 }
2174 flags |= RTCF_BROADCAST;
2175 res.type = RTN_BROADCAST;
2176 RT_CACHE_STAT_INC(in_brd);
2177
2178 local_input:
2179 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2180 if (!rth)
2181 goto e_nobufs;
2182
2183 rth->dst.output= ip_rt_bug;
2184 rth->rt_genid = rt_genid(net);
2185
2186 rth->rt_key_dst = daddr;
2187 rth->rt_dst = daddr;
2188 rth->rt_tos = tos;
2189 rth->rt_mark = skb->mark;
2190 rth->rt_key_src = saddr;
2191 rth->rt_src = saddr;
2192 #ifdef CONFIG_IP_ROUTE_CLASSID
2193 rth->dst.tclassid = itag;
2194 #endif
2195 rth->rt_iif = dev->ifindex;
2196 rth->dst.dev = net->loopback_dev;
2197 dev_hold(rth->dst.dev);
2198 rth->rt_gateway = daddr;
2199 rth->rt_spec_dst= spec_dst;
2200 rth->dst.input= ip_local_deliver;
2201 rth->rt_flags = flags|RTCF_LOCAL;
2202 if (res.type == RTN_UNREACHABLE) {
2203 rth->dst.input= ip_error;
2204 rth->dst.error= -err;
2205 rth->rt_flags &= ~RTCF_LOCAL;
2206 }
2207 rth->rt_type = res.type;
2208 hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
2209 rth = rt_intern_hash(hash, rth, skb, fl.iif);
2210 err = 0;
2211 if (IS_ERR(rth))
2212 err = PTR_ERR(rth);
2213 goto out;
2214
2215 no_route:
2216 RT_CACHE_STAT_INC(in_no_route);
2217 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2218 res.type = RTN_UNREACHABLE;
2219 if (err == -ESRCH)
2220 err = -ENETUNREACH;
2221 goto local_input;
2222
2223 /*
2224 * Do not cache martian addresses: they should be logged (RFC1812)
2225 */
2226 martian_destination:
2227 RT_CACHE_STAT_INC(in_martian_dst);
2228 #ifdef CONFIG_IP_ROUTE_VERBOSE
2229 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2230 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2231 &daddr, &saddr, dev->name);
2232 #endif
2233
2234 e_hostunreach:
2235 err = -EHOSTUNREACH;
2236 goto out;
2237
2238 e_inval:
2239 err = -EINVAL;
2240 goto out;
2241
2242 e_nobufs:
2243 err = -ENOBUFS;
2244 goto out;
2245
2246 martian_source:
2247 err = -EINVAL;
2248 martian_source_keep_err:
2249 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2250 goto out;
2251 }
2252
2253 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2254 u8 tos, struct net_device *dev, bool noref)
2255 {
2256 struct rtable * rth;
2257 unsigned hash;
2258 int iif = dev->ifindex;
2259 struct net *net;
2260 int res;
2261
2262 net = dev_net(dev);
2263
2264 rcu_read_lock();
2265
2266 if (!rt_caching(net))
2267 goto skip_cache;
2268
2269 tos &= IPTOS_RT_MASK;
2270 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2271
2272 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2273 rth = rcu_dereference(rth->dst.rt_next)) {
2274 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2275 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2276 (rth->rt_iif ^ iif) |
2277 rth->rt_oif |
2278 (rth->rt_tos ^ tos)) == 0 &&
2279 rth->rt_mark == skb->mark &&
2280 net_eq(dev_net(rth->dst.dev), net) &&
2281 !rt_is_expired(rth)) {
2282 if (noref) {
2283 dst_use_noref(&rth->dst, jiffies);
2284 skb_dst_set_noref(skb, &rth->dst);
2285 } else {
2286 dst_use(&rth->dst, jiffies);
2287 skb_dst_set(skb, &rth->dst);
2288 }
2289 RT_CACHE_STAT_INC(in_hit);
2290 rcu_read_unlock();
2291 return 0;
2292 }
2293 RT_CACHE_STAT_INC(in_hlist_search);
2294 }
2295
2296 skip_cache:
2297 /* Multicast recognition logic is moved from route cache to here.
2298 The problem was that too many Ethernet cards have broken/missing
2299 hardware multicast filters :-( As result the host on multicasting
2300 network acquires a lot of useless route cache entries, sort of
2301 SDR messages from all the world. Now we try to get rid of them.
2302 Really, provided software IP multicast filter is organized
2303 reasonably (at least, hashed), it does not result in a slowdown
2304 comparing with route cache reject entries.
2305 Note, that multicast routers are not affected, because
2306 route cache entry is created eventually.
2307 */
2308 if (ipv4_is_multicast(daddr)) {
2309 struct in_device *in_dev = __in_dev_get_rcu(dev);
2310
2311 if (in_dev) {
2312 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2313 ip_hdr(skb)->protocol);
2314 if (our
2315 #ifdef CONFIG_IP_MROUTE
2316 ||
2317 (!ipv4_is_local_multicast(daddr) &&
2318 IN_DEV_MFORWARD(in_dev))
2319 #endif
2320 ) {
2321 int res = ip_route_input_mc(skb, daddr, saddr,
2322 tos, dev, our);
2323 rcu_read_unlock();
2324 return res;
2325 }
2326 }
2327 rcu_read_unlock();
2328 return -EINVAL;
2329 }
2330 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2331 rcu_read_unlock();
2332 return res;
2333 }
2334 EXPORT_SYMBOL(ip_route_input_common);
2335
2336 /* called with rcu_read_lock() */
2337 static struct rtable *__mkroute_output(const struct fib_result *res,
2338 const struct flowi *fl,
2339 const struct flowi *oldflp,
2340 struct net_device *dev_out,
2341 unsigned int flags)
2342 {
2343 struct fib_info *fi = res->fi;
2344 u32 tos = RT_FL_TOS(oldflp);
2345 struct in_device *in_dev;
2346 u16 type = res->type;
2347 struct rtable *rth;
2348
2349 if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags & IFF_LOOPBACK))
2350 return ERR_PTR(-EINVAL);
2351
2352 if (ipv4_is_lbcast(fl->fl4_dst))
2353 type = RTN_BROADCAST;
2354 else if (ipv4_is_multicast(fl->fl4_dst))
2355 type = RTN_MULTICAST;
2356 else if (ipv4_is_zeronet(fl->fl4_dst))
2357 return ERR_PTR(-EINVAL);
2358
2359 if (dev_out->flags & IFF_LOOPBACK)
2360 flags |= RTCF_LOCAL;
2361
2362 in_dev = __in_dev_get_rcu(dev_out);
2363 if (!in_dev)
2364 return ERR_PTR(-EINVAL);
2365
2366 if (type == RTN_BROADCAST) {
2367 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2368 fi = NULL;
2369 } else if (type == RTN_MULTICAST) {
2370 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2371 if (!ip_check_mc_rcu(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2372 oldflp->proto))
2373 flags &= ~RTCF_LOCAL;
2374 /* If multicast route do not exist use
2375 * default one, but do not gateway in this case.
2376 * Yes, it is hack.
2377 */
2378 if (fi && res->prefixlen < 4)
2379 fi = NULL;
2380 }
2381
2382 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
2383 IN_DEV_CONF_GET(in_dev, NOXFRM));
2384 if (!rth)
2385 return ERR_PTR(-ENOBUFS);
2386
2387 rth->rt_key_dst = oldflp->fl4_dst;
2388 rth->rt_tos = tos;
2389 rth->rt_key_src = oldflp->fl4_src;
2390 rth->rt_oif = oldflp->oif;
2391 rth->rt_mark = oldflp->mark;
2392 rth->rt_dst = fl->fl4_dst;
2393 rth->rt_src = fl->fl4_src;
2394 rth->rt_iif = 0;
2395 /* get references to the devices that are to be hold by the routing
2396 cache entry */
2397 rth->dst.dev = dev_out;
2398 dev_hold(dev_out);
2399 rth->rt_gateway = fl->fl4_dst;
2400 rth->rt_spec_dst= fl->fl4_src;
2401
2402 rth->dst.output=ip_output;
2403 rth->rt_genid = rt_genid(dev_net(dev_out));
2404
2405 RT_CACHE_STAT_INC(out_slow_tot);
2406
2407 if (flags & RTCF_LOCAL) {
2408 rth->dst.input = ip_local_deliver;
2409 rth->rt_spec_dst = fl->fl4_dst;
2410 }
2411 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2412 rth->rt_spec_dst = fl->fl4_src;
2413 if (flags & RTCF_LOCAL &&
2414 !(dev_out->flags & IFF_LOOPBACK)) {
2415 rth->dst.output = ip_mc_output;
2416 RT_CACHE_STAT_INC(out_slow_mc);
2417 }
2418 #ifdef CONFIG_IP_MROUTE
2419 if (type == RTN_MULTICAST) {
2420 if (IN_DEV_MFORWARD(in_dev) &&
2421 !ipv4_is_local_multicast(oldflp->fl4_dst)) {
2422 rth->dst.input = ip_mr_input;
2423 rth->dst.output = ip_mc_output;
2424 }
2425 }
2426 #endif
2427 }
2428
2429 rt_set_nexthop(rth, oldflp, res, fi, type, 0);
2430
2431 rth->rt_flags = flags;
2432 return rth;
2433 }
2434
2435 /*
2436 * Major route resolver routine.
2437 * called with rcu_read_lock();
2438 */
2439
2440 static struct rtable *ip_route_output_slow(struct net *net,
2441 const struct flowi *oldflp)
2442 {
2443 u32 tos = RT_FL_TOS(oldflp);
2444 struct flowi fl;
2445 struct fib_result res;
2446 unsigned int flags = 0;
2447 struct net_device *dev_out = NULL;
2448 struct rtable *rth;
2449
2450 res.fi = NULL;
2451 #ifdef CONFIG_IP_MULTIPLE_TABLES
2452 res.r = NULL;
2453 #endif
2454
2455 fl.oif = oldflp->oif;
2456 fl.iif = net->loopback_dev->ifindex;
2457 fl.mark = oldflp->mark;
2458 fl.fl4_dst = oldflp->fl4_dst;
2459 fl.fl4_src = oldflp->fl4_src;
2460 fl.fl4_tos = tos & IPTOS_RT_MASK;
2461 fl.fl4_scope = ((tos & RTO_ONLINK) ?
2462 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2463
2464 rcu_read_lock();
2465 if (oldflp->fl4_src) {
2466 rth = ERR_PTR(-EINVAL);
2467 if (ipv4_is_multicast(oldflp->fl4_src) ||
2468 ipv4_is_lbcast(oldflp->fl4_src) ||
2469 ipv4_is_zeronet(oldflp->fl4_src))
2470 goto out;
2471
2472 /* I removed check for oif == dev_out->oif here.
2473 It was wrong for two reasons:
2474 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2475 is assigned to multiple interfaces.
2476 2. Moreover, we are allowed to send packets with saddr
2477 of another iface. --ANK
2478 */
2479
2480 if (oldflp->oif == 0 &&
2481 (ipv4_is_multicast(oldflp->fl4_dst) ||
2482 ipv4_is_lbcast(oldflp->fl4_dst))) {
2483 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2484 dev_out = __ip_dev_find(net, oldflp->fl4_src, false);
2485 if (dev_out == NULL)
2486 goto out;
2487
2488 /* Special hack: user can direct multicasts
2489 and limited broadcast via necessary interface
2490 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2491 This hack is not just for fun, it allows
2492 vic,vat and friends to work.
2493 They bind socket to loopback, set ttl to zero
2494 and expect that it will work.
2495 From the viewpoint of routing cache they are broken,
2496 because we are not allowed to build multicast path
2497 with loopback source addr (look, routing cache
2498 cannot know, that ttl is zero, so that packet
2499 will not leave this host and route is valid).
2500 Luckily, this hack is good workaround.
2501 */
2502
2503 fl.oif = dev_out->ifindex;
2504 goto make_route;
2505 }
2506
2507 if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
2508 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2509 if (!__ip_dev_find(net, oldflp->fl4_src, false))
2510 goto out;
2511 }
2512 }
2513
2514
2515 if (oldflp->oif) {
2516 dev_out = dev_get_by_index_rcu(net, oldflp->oif);
2517 rth = ERR_PTR(-ENODEV);
2518 if (dev_out == NULL)
2519 goto out;
2520
2521 /* RACE: Check return value of inet_select_addr instead. */
2522 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2523 rth = ERR_PTR(-ENETUNREACH);
2524 goto out;
2525 }
2526 if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
2527 ipv4_is_lbcast(oldflp->fl4_dst)) {
2528 if (!fl.fl4_src)
2529 fl.fl4_src = inet_select_addr(dev_out, 0,
2530 RT_SCOPE_LINK);
2531 goto make_route;
2532 }
2533 if (!fl.fl4_src) {
2534 if (ipv4_is_multicast(oldflp->fl4_dst))
2535 fl.fl4_src = inet_select_addr(dev_out, 0,
2536 fl.fl4_scope);
2537 else if (!oldflp->fl4_dst)
2538 fl.fl4_src = inet_select_addr(dev_out, 0,
2539 RT_SCOPE_HOST);
2540 }
2541 }
2542
2543 if (!fl.fl4_dst) {
2544 fl.fl4_dst = fl.fl4_src;
2545 if (!fl.fl4_dst)
2546 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2547 dev_out = net->loopback_dev;
2548 fl.oif = net->loopback_dev->ifindex;
2549 res.type = RTN_LOCAL;
2550 flags |= RTCF_LOCAL;
2551 goto make_route;
2552 }
2553
2554 if (fib_lookup(net, &fl, &res)) {
2555 res.fi = NULL;
2556 if (oldflp->oif) {
2557 /* Apparently, routing tables are wrong. Assume,
2558 that the destination is on link.
2559
2560 WHY? DW.
2561 Because we are allowed to send to iface
2562 even if it has NO routes and NO assigned
2563 addresses. When oif is specified, routing
2564 tables are looked up with only one purpose:
2565 to catch if destination is gatewayed, rather than
2566 direct. Moreover, if MSG_DONTROUTE is set,
2567 we send packet, ignoring both routing tables
2568 and ifaddr state. --ANK
2569
2570
2571 We could make it even if oif is unknown,
2572 likely IPv6, but we do not.
2573 */
2574
2575 if (fl.fl4_src == 0)
2576 fl.fl4_src = inet_select_addr(dev_out, 0,
2577 RT_SCOPE_LINK);
2578 res.type = RTN_UNICAST;
2579 goto make_route;
2580 }
2581 rth = ERR_PTR(-ENETUNREACH);
2582 goto out;
2583 }
2584
2585 if (res.type == RTN_LOCAL) {
2586 if (!fl.fl4_src) {
2587 if (res.fi->fib_prefsrc)
2588 fl.fl4_src = res.fi->fib_prefsrc;
2589 else
2590 fl.fl4_src = fl.fl4_dst;
2591 }
2592 dev_out = net->loopback_dev;
2593 fl.oif = dev_out->ifindex;
2594 res.fi = NULL;
2595 flags |= RTCF_LOCAL;
2596 goto make_route;
2597 }
2598
2599 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2600 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2601 fib_select_multipath(&fl, &res);
2602 else
2603 #endif
2604 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2605 fib_select_default(&res);
2606
2607 if (!fl.fl4_src)
2608 fl.fl4_src = FIB_RES_PREFSRC(res);
2609
2610 dev_out = FIB_RES_DEV(res);
2611 fl.oif = dev_out->ifindex;
2612
2613
2614 make_route:
2615 rth = __mkroute_output(&res, &fl, oldflp, dev_out, flags);
2616 if (!IS_ERR(rth)) {
2617 unsigned int hash;
2618
2619 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
2620 rt_genid(dev_net(dev_out)));
2621 rth = rt_intern_hash(hash, rth, NULL, oldflp->oif);
2622 }
2623
2624 out:
2625 rcu_read_unlock();
2626 return rth;
2627 }
2628
2629 struct rtable *__ip_route_output_key(struct net *net, const struct flowi *flp)
2630 {
2631 struct rtable *rth;
2632 unsigned int hash;
2633
2634 if (!rt_caching(net))
2635 goto slow_output;
2636
2637 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
2638
2639 rcu_read_lock_bh();
2640 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2641 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2642 if (rth->rt_key_dst == flp->fl4_dst &&
2643 rth->rt_key_src == flp->fl4_src &&
2644 rt_is_output_route(rth) &&
2645 rth->rt_oif == flp->oif &&
2646 rth->rt_mark == flp->mark &&
2647 !((rth->rt_tos ^ flp->fl4_tos) &
2648 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2649 net_eq(dev_net(rth->dst.dev), net) &&
2650 !rt_is_expired(rth)) {
2651 dst_use(&rth->dst, jiffies);
2652 RT_CACHE_STAT_INC(out_hit);
2653 rcu_read_unlock_bh();
2654 return rth;
2655 }
2656 RT_CACHE_STAT_INC(out_hlist_search);
2657 }
2658 rcu_read_unlock_bh();
2659
2660 slow_output:
2661 return ip_route_output_slow(net, flp);
2662 }
2663 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2664
2665 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2666 {
2667 return NULL;
2668 }
2669
2670 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2671 {
2672 return 0;
2673 }
2674
2675 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2676 {
2677 }
2678
2679 static struct dst_ops ipv4_dst_blackhole_ops = {
2680 .family = AF_INET,
2681 .protocol = cpu_to_be16(ETH_P_IP),
2682 .destroy = ipv4_dst_destroy,
2683 .check = ipv4_blackhole_dst_check,
2684 .default_mtu = ipv4_blackhole_default_mtu,
2685 .default_advmss = ipv4_default_advmss,
2686 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2687 };
2688
2689 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2690 {
2691 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, 1);
2692 struct rtable *ort = (struct rtable *) dst_orig;
2693
2694 if (rt) {
2695 struct dst_entry *new = &rt->dst;
2696
2697 new->__use = 1;
2698 new->input = dst_discard;
2699 new->output = dst_discard;
2700 dst_copy_metrics(new, &ort->dst);
2701
2702 new->dev = ort->dst.dev;
2703 if (new->dev)
2704 dev_hold(new->dev);
2705
2706 rt->rt_key_dst = ort->rt_key_dst;
2707 rt->rt_key_src = ort->rt_key_src;
2708 rt->rt_tos = ort->rt_tos;
2709 rt->rt_iif = ort->rt_iif;
2710 rt->rt_oif = ort->rt_oif;
2711 rt->rt_mark = ort->rt_mark;
2712
2713 rt->rt_genid = rt_genid(net);
2714 rt->rt_flags = ort->rt_flags;
2715 rt->rt_type = ort->rt_type;
2716 rt->rt_dst = ort->rt_dst;
2717 rt->rt_src = ort->rt_src;
2718 rt->rt_iif = ort->rt_iif;
2719 rt->rt_gateway = ort->rt_gateway;
2720 rt->rt_spec_dst = ort->rt_spec_dst;
2721 rt->peer = ort->peer;
2722 if (rt->peer)
2723 atomic_inc(&rt->peer->refcnt);
2724 rt->fi = ort->fi;
2725 if (rt->fi)
2726 atomic_inc(&rt->fi->fib_clntref);
2727
2728 dst_free(new);
2729 }
2730
2731 dst_release(dst_orig);
2732
2733 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2734 }
2735
2736 struct rtable *ip_route_output_flow(struct net *net, struct flowi *flp,
2737 struct sock *sk)
2738 {
2739 struct rtable *rt = __ip_route_output_key(net, flp);
2740
2741 if (IS_ERR(rt))
2742 return rt;
2743
2744 if (flp->proto) {
2745 if (!flp->fl4_src)
2746 flp->fl4_src = rt->rt_src;
2747 if (!flp->fl4_dst)
2748 flp->fl4_dst = rt->rt_dst;
2749 rt = (struct rtable *) xfrm_lookup(net, &rt->dst, flp, sk, 0);
2750 }
2751
2752 return rt;
2753 }
2754 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2755
2756 static int rt_fill_info(struct net *net,
2757 struct sk_buff *skb, u32 pid, u32 seq, int event,
2758 int nowait, unsigned int flags)
2759 {
2760 struct rtable *rt = skb_rtable(skb);
2761 struct rtmsg *r;
2762 struct nlmsghdr *nlh;
2763 long expires;
2764 u32 id = 0, ts = 0, tsage = 0, error;
2765
2766 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2767 if (nlh == NULL)
2768 return -EMSGSIZE;
2769
2770 r = nlmsg_data(nlh);
2771 r->rtm_family = AF_INET;
2772 r->rtm_dst_len = 32;
2773 r->rtm_src_len = 0;
2774 r->rtm_tos = rt->rt_tos;
2775 r->rtm_table = RT_TABLE_MAIN;
2776 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2777 r->rtm_type = rt->rt_type;
2778 r->rtm_scope = RT_SCOPE_UNIVERSE;
2779 r->rtm_protocol = RTPROT_UNSPEC;
2780 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2781 if (rt->rt_flags & RTCF_NOTIFY)
2782 r->rtm_flags |= RTM_F_NOTIFY;
2783
2784 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2785
2786 if (rt->rt_key_src) {
2787 r->rtm_src_len = 32;
2788 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2789 }
2790 if (rt->dst.dev)
2791 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2792 #ifdef CONFIG_IP_ROUTE_CLASSID
2793 if (rt->dst.tclassid)
2794 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2795 #endif
2796 if (rt_is_input_route(rt))
2797 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2798 else if (rt->rt_src != rt->rt_key_src)
2799 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2800
2801 if (rt->rt_dst != rt->rt_gateway)
2802 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2803
2804 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2805 goto nla_put_failure;
2806
2807 if (rt->rt_mark)
2808 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2809
2810 error = rt->dst.error;
2811 expires = (rt->peer && rt->peer->pmtu_expires) ?
2812 rt->peer->pmtu_expires - jiffies : 0;
2813 if (rt->peer) {
2814 inet_peer_refcheck(rt->peer);
2815 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2816 if (rt->peer->tcp_ts_stamp) {
2817 ts = rt->peer->tcp_ts;
2818 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2819 }
2820 }
2821
2822 if (rt_is_input_route(rt)) {
2823 #ifdef CONFIG_IP_MROUTE
2824 __be32 dst = rt->rt_dst;
2825
2826 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2827 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2828 int err = ipmr_get_route(net, skb, r, nowait);
2829 if (err <= 0) {
2830 if (!nowait) {
2831 if (err == 0)
2832 return 0;
2833 goto nla_put_failure;
2834 } else {
2835 if (err == -EMSGSIZE)
2836 goto nla_put_failure;
2837 error = err;
2838 }
2839 }
2840 } else
2841 #endif
2842 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2843 }
2844
2845 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2846 expires, error) < 0)
2847 goto nla_put_failure;
2848
2849 return nlmsg_end(skb, nlh);
2850
2851 nla_put_failure:
2852 nlmsg_cancel(skb, nlh);
2853 return -EMSGSIZE;
2854 }
2855
2856 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2857 {
2858 struct net *net = sock_net(in_skb->sk);
2859 struct rtmsg *rtm;
2860 struct nlattr *tb[RTA_MAX+1];
2861 struct rtable *rt = NULL;
2862 __be32 dst = 0;
2863 __be32 src = 0;
2864 u32 iif;
2865 int err;
2866 int mark;
2867 struct sk_buff *skb;
2868
2869 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2870 if (err < 0)
2871 goto errout;
2872
2873 rtm = nlmsg_data(nlh);
2874
2875 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2876 if (skb == NULL) {
2877 err = -ENOBUFS;
2878 goto errout;
2879 }
2880
2881 /* Reserve room for dummy headers, this skb can pass
2882 through good chunk of routing engine.
2883 */
2884 skb_reset_mac_header(skb);
2885 skb_reset_network_header(skb);
2886
2887 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2888 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2889 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2890
2891 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2892 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2893 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2894 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2895
2896 if (iif) {
2897 struct net_device *dev;
2898
2899 dev = __dev_get_by_index(net, iif);
2900 if (dev == NULL) {
2901 err = -ENODEV;
2902 goto errout_free;
2903 }
2904
2905 skb->protocol = htons(ETH_P_IP);
2906 skb->dev = dev;
2907 skb->mark = mark;
2908 local_bh_disable();
2909 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2910 local_bh_enable();
2911
2912 rt = skb_rtable(skb);
2913 if (err == 0 && rt->dst.error)
2914 err = -rt->dst.error;
2915 } else {
2916 struct flowi fl = {
2917 .fl4_dst = dst,
2918 .fl4_src = src,
2919 .fl4_tos = rtm->rtm_tos,
2920 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2921 .mark = mark,
2922 };
2923 rt = ip_route_output_key(net, &fl);
2924
2925 err = 0;
2926 if (IS_ERR(rt))
2927 err = PTR_ERR(rt);
2928 }
2929
2930 if (err)
2931 goto errout_free;
2932
2933 skb_dst_set(skb, &rt->dst);
2934 if (rtm->rtm_flags & RTM_F_NOTIFY)
2935 rt->rt_flags |= RTCF_NOTIFY;
2936
2937 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2938 RTM_NEWROUTE, 0, 0);
2939 if (err <= 0)
2940 goto errout_free;
2941
2942 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2943 errout:
2944 return err;
2945
2946 errout_free:
2947 kfree_skb(skb);
2948 goto errout;
2949 }
2950
2951 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2952 {
2953 struct rtable *rt;
2954 int h, s_h;
2955 int idx, s_idx;
2956 struct net *net;
2957
2958 net = sock_net(skb->sk);
2959
2960 s_h = cb->args[0];
2961 if (s_h < 0)
2962 s_h = 0;
2963 s_idx = idx = cb->args[1];
2964 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2965 if (!rt_hash_table[h].chain)
2966 continue;
2967 rcu_read_lock_bh();
2968 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2969 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2970 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2971 continue;
2972 if (rt_is_expired(rt))
2973 continue;
2974 skb_dst_set_noref(skb, &rt->dst);
2975 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
2976 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2977 1, NLM_F_MULTI) <= 0) {
2978 skb_dst_drop(skb);
2979 rcu_read_unlock_bh();
2980 goto done;
2981 }
2982 skb_dst_drop(skb);
2983 }
2984 rcu_read_unlock_bh();
2985 }
2986
2987 done:
2988 cb->args[0] = h;
2989 cb->args[1] = idx;
2990 return skb->len;
2991 }
2992
2993 void ip_rt_multicast_event(struct in_device *in_dev)
2994 {
2995 rt_cache_flush(dev_net(in_dev->dev), 0);
2996 }
2997
2998 #ifdef CONFIG_SYSCTL
2999 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3000 void __user *buffer,
3001 size_t *lenp, loff_t *ppos)
3002 {
3003 if (write) {
3004 int flush_delay;
3005 ctl_table ctl;
3006 struct net *net;
3007
3008 memcpy(&ctl, __ctl, sizeof(ctl));
3009 ctl.data = &flush_delay;
3010 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3011
3012 net = (struct net *)__ctl->extra1;
3013 rt_cache_flush(net, flush_delay);
3014 return 0;
3015 }
3016
3017 return -EINVAL;
3018 }
3019
3020 static ctl_table ipv4_route_table[] = {
3021 {
3022 .procname = "gc_thresh",
3023 .data = &ipv4_dst_ops.gc_thresh,
3024 .maxlen = sizeof(int),
3025 .mode = 0644,
3026 .proc_handler = proc_dointvec,
3027 },
3028 {
3029 .procname = "max_size",
3030 .data = &ip_rt_max_size,
3031 .maxlen = sizeof(int),
3032 .mode = 0644,
3033 .proc_handler = proc_dointvec,
3034 },
3035 {
3036 /* Deprecated. Use gc_min_interval_ms */
3037
3038 .procname = "gc_min_interval",
3039 .data = &ip_rt_gc_min_interval,
3040 .maxlen = sizeof(int),
3041 .mode = 0644,
3042 .proc_handler = proc_dointvec_jiffies,
3043 },
3044 {
3045 .procname = "gc_min_interval_ms",
3046 .data = &ip_rt_gc_min_interval,
3047 .maxlen = sizeof(int),
3048 .mode = 0644,
3049 .proc_handler = proc_dointvec_ms_jiffies,
3050 },
3051 {
3052 .procname = "gc_timeout",
3053 .data = &ip_rt_gc_timeout,
3054 .maxlen = sizeof(int),
3055 .mode = 0644,
3056 .proc_handler = proc_dointvec_jiffies,
3057 },
3058 {
3059 .procname = "gc_interval",
3060 .data = &ip_rt_gc_interval,
3061 .maxlen = sizeof(int),
3062 .mode = 0644,
3063 .proc_handler = proc_dointvec_jiffies,
3064 },
3065 {
3066 .procname = "redirect_load",
3067 .data = &ip_rt_redirect_load,
3068 .maxlen = sizeof(int),
3069 .mode = 0644,
3070 .proc_handler = proc_dointvec,
3071 },
3072 {
3073 .procname = "redirect_number",
3074 .data = &ip_rt_redirect_number,
3075 .maxlen = sizeof(int),
3076 .mode = 0644,
3077 .proc_handler = proc_dointvec,
3078 },
3079 {
3080 .procname = "redirect_silence",
3081 .data = &ip_rt_redirect_silence,
3082 .maxlen = sizeof(int),
3083 .mode = 0644,
3084 .proc_handler = proc_dointvec,
3085 },
3086 {
3087 .procname = "error_cost",
3088 .data = &ip_rt_error_cost,
3089 .maxlen = sizeof(int),
3090 .mode = 0644,
3091 .proc_handler = proc_dointvec,
3092 },
3093 {
3094 .procname = "error_burst",
3095 .data = &ip_rt_error_burst,
3096 .maxlen = sizeof(int),
3097 .mode = 0644,
3098 .proc_handler = proc_dointvec,
3099 },
3100 {
3101 .procname = "gc_elasticity",
3102 .data = &ip_rt_gc_elasticity,
3103 .maxlen = sizeof(int),
3104 .mode = 0644,
3105 .proc_handler = proc_dointvec,
3106 },
3107 {
3108 .procname = "mtu_expires",
3109 .data = &ip_rt_mtu_expires,
3110 .maxlen = sizeof(int),
3111 .mode = 0644,
3112 .proc_handler = proc_dointvec_jiffies,
3113 },
3114 {
3115 .procname = "min_pmtu",
3116 .data = &ip_rt_min_pmtu,
3117 .maxlen = sizeof(int),
3118 .mode = 0644,
3119 .proc_handler = proc_dointvec,
3120 },
3121 {
3122 .procname = "min_adv_mss",
3123 .data = &ip_rt_min_advmss,
3124 .maxlen = sizeof(int),
3125 .mode = 0644,
3126 .proc_handler = proc_dointvec,
3127 },
3128 { }
3129 };
3130
3131 static struct ctl_table empty[1];
3132
3133 static struct ctl_table ipv4_skeleton[] =
3134 {
3135 { .procname = "route",
3136 .mode = 0555, .child = ipv4_route_table},
3137 { .procname = "neigh",
3138 .mode = 0555, .child = empty},
3139 { }
3140 };
3141
3142 static __net_initdata struct ctl_path ipv4_path[] = {
3143 { .procname = "net", },
3144 { .procname = "ipv4", },
3145 { },
3146 };
3147
3148 static struct ctl_table ipv4_route_flush_table[] = {
3149 {
3150 .procname = "flush",
3151 .maxlen = sizeof(int),
3152 .mode = 0200,
3153 .proc_handler = ipv4_sysctl_rtcache_flush,
3154 },
3155 { },
3156 };
3157
3158 static __net_initdata struct ctl_path ipv4_route_path[] = {
3159 { .procname = "net", },
3160 { .procname = "ipv4", },
3161 { .procname = "route", },
3162 { },
3163 };
3164
3165 static __net_init int sysctl_route_net_init(struct net *net)
3166 {
3167 struct ctl_table *tbl;
3168
3169 tbl = ipv4_route_flush_table;
3170 if (!net_eq(net, &init_net)) {
3171 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3172 if (tbl == NULL)
3173 goto err_dup;
3174 }
3175 tbl[0].extra1 = net;
3176
3177 net->ipv4.route_hdr =
3178 register_net_sysctl_table(net, ipv4_route_path, tbl);
3179 if (net->ipv4.route_hdr == NULL)
3180 goto err_reg;
3181 return 0;
3182
3183 err_reg:
3184 if (tbl != ipv4_route_flush_table)
3185 kfree(tbl);
3186 err_dup:
3187 return -ENOMEM;
3188 }
3189
3190 static __net_exit void sysctl_route_net_exit(struct net *net)
3191 {
3192 struct ctl_table *tbl;
3193
3194 tbl = net->ipv4.route_hdr->ctl_table_arg;
3195 unregister_net_sysctl_table(net->ipv4.route_hdr);
3196 BUG_ON(tbl == ipv4_route_flush_table);
3197 kfree(tbl);
3198 }
3199
3200 static __net_initdata struct pernet_operations sysctl_route_ops = {
3201 .init = sysctl_route_net_init,
3202 .exit = sysctl_route_net_exit,
3203 };
3204 #endif
3205
3206 static __net_init int rt_genid_init(struct net *net)
3207 {
3208 get_random_bytes(&net->ipv4.rt_genid,
3209 sizeof(net->ipv4.rt_genid));
3210 return 0;
3211 }
3212
3213 static __net_initdata struct pernet_operations rt_genid_ops = {
3214 .init = rt_genid_init,
3215 };
3216
3217
3218 #ifdef CONFIG_IP_ROUTE_CLASSID
3219 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3220 #endif /* CONFIG_IP_ROUTE_CLASSID */
3221
3222 static __initdata unsigned long rhash_entries;
3223 static int __init set_rhash_entries(char *str)
3224 {
3225 if (!str)
3226 return 0;
3227 rhash_entries = simple_strtoul(str, &str, 0);
3228 return 1;
3229 }
3230 __setup("rhash_entries=", set_rhash_entries);
3231
3232 int __init ip_rt_init(void)
3233 {
3234 int rc = 0;
3235
3236 #ifdef CONFIG_IP_ROUTE_CLASSID
3237 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3238 if (!ip_rt_acct)
3239 panic("IP: failed to allocate ip_rt_acct\n");
3240 #endif
3241
3242 ipv4_dst_ops.kmem_cachep =
3243 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3244 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3245
3246 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3247
3248 if (dst_entries_init(&ipv4_dst_ops) < 0)
3249 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3250
3251 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3252 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3253
3254 rt_hash_table = (struct rt_hash_bucket *)
3255 alloc_large_system_hash("IP route cache",
3256 sizeof(struct rt_hash_bucket),
3257 rhash_entries,
3258 (totalram_pages >= 128 * 1024) ?
3259 15 : 17,
3260 0,
3261 &rt_hash_log,
3262 &rt_hash_mask,
3263 rhash_entries ? 0 : 512 * 1024);
3264 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3265 rt_hash_lock_init();
3266
3267 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3268 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3269
3270 devinet_init();
3271 ip_fib_init();
3272
3273 if (ip_rt_proc_init())
3274 printk(KERN_ERR "Unable to create route proc files\n");
3275 #ifdef CONFIG_XFRM
3276 xfrm_init();
3277 xfrm4_init(ip_rt_max_size);
3278 #endif
3279 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3280
3281 #ifdef CONFIG_SYSCTL
3282 register_pernet_subsys(&sysctl_route_ops);
3283 #endif
3284 register_pernet_subsys(&rt_genid_ops);
3285 return rc;
3286 }
3287
3288 #ifdef CONFIG_SYSCTL
3289 /*
3290 * We really need to sanitize the damn ipv4 init order, then all
3291 * this nonsense will go away.
3292 */
3293 void __init ip_static_sysctl_init(void)
3294 {
3295 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3296 }
3297 #endif
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