?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'perf/core'
[linux-2.6/x86.git] / net / ipv4 / route.c
blobaa13ef1051108dac93a9151d0819d9fd7447ec64
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(oldflp4) \
113 ((u32)(oldflp4->flowi4_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, rt->rt_dst, 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(BESTEFFORT),
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_key_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_key_tos ^ rt2->rt_key_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 * Perturbation 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
972 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
973 goto out;
974 } while (!in_softirq() && time_before_eq(jiffies, now));
975
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
977 goto out;
978 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
979 goto out;
980 if (net_ratelimit())
981 printk(KERN_WARNING "dst cache overflow\n");
982 RT_CACHE_STAT_INC(gc_dst_overflow);
983 return 1;
984
985 work_done:
986 expire += ip_rt_gc_min_interval;
987 if (expire > ip_rt_gc_timeout ||
988 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
989 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
990 expire = ip_rt_gc_timeout;
991 out: return 0;
992 }
993
994 /*
995 * Returns number of entries in a hash chain that have different hash_inputs
996 */
997 static int slow_chain_length(const struct rtable *head)
998 {
999 int length = 0;
1000 const struct rtable *rth = head;
1001
1002 while (rth) {
1003 length += has_noalias(head, rth);
1004 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1005 }
1006 return length >> FRACT_BITS;
1007 }
1008
1009 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1010 struct sk_buff *skb, int ifindex)
1011 {
1012 struct rtable *rth, *cand;
1013 struct rtable __rcu **rthp, **candp;
1014 unsigned long now;
1015 u32 min_score;
1016 int chain_length;
1017 int attempts = !in_softirq();
1018
1019 restart:
1020 chain_length = 0;
1021 min_score = ~(u32)0;
1022 cand = NULL;
1023 candp = NULL;
1024 now = jiffies;
1025
1026 if (!rt_caching(dev_net(rt->dst.dev))) {
1027 /*
1028 * If we're not caching, just tell the caller we
1029 * were successful and don't touch the route. The
1030 * caller hold the sole reference to the cache entry, and
1031 * it will be released when the caller is done with it.
1032 * If we drop it here, the callers have no way to resolve routes
1033 * when we're not caching. Instead, just point *rp at rt, so
1034 * the caller gets a single use out of the route
1035 * Note that we do rt_free on this new route entry, so that
1036 * once its refcount hits zero, we are still able to reap it
1037 * (Thanks Alexey)
1038 * Note: To avoid expensive rcu stuff for this uncached dst,
1039 * we set DST_NOCACHE so that dst_release() can free dst without
1040 * waiting a grace period.
1041 */
1042
1043 rt->dst.flags |= DST_NOCACHE;
1044 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1045 int err = arp_bind_neighbour(&rt->dst);
1046 if (err) {
1047 if (net_ratelimit())
1048 printk(KERN_WARNING
1049 "Neighbour table failure & not caching routes.\n");
1050 ip_rt_put(rt);
1051 return ERR_PTR(err);
1052 }
1053 }
1054
1055 goto skip_hashing;
1056 }
1057
1058 rthp = &rt_hash_table[hash].chain;
1059
1060 spin_lock_bh(rt_hash_lock_addr(hash));
1061 while ((rth = rcu_dereference_protected(*rthp,
1062 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1063 if (rt_is_expired(rth)) {
1064 *rthp = rth->dst.rt_next;
1065 rt_free(rth);
1066 continue;
1067 }
1068 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1069 /* Put it first */
1070 *rthp = rth->dst.rt_next;
1071 /*
1072 * Since lookup is lockfree, the deletion
1073 * must be visible to another weakly ordered CPU before
1074 * the insertion at the start of the hash chain.
1075 */
1076 rcu_assign_pointer(rth->dst.rt_next,
1077 rt_hash_table[hash].chain);
1078 /*
1079 * Since lookup is lockfree, the update writes
1080 * must be ordered for consistency on SMP.
1081 */
1082 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1083
1084 dst_use(&rth->dst, now);
1085 spin_unlock_bh(rt_hash_lock_addr(hash));
1086
1087 rt_drop(rt);
1088 if (skb)
1089 skb_dst_set(skb, &rth->dst);
1090 return rth;
1091 }
1092
1093 if (!atomic_read(&rth->dst.__refcnt)) {
1094 u32 score = rt_score(rth);
1095
1096 if (score <= min_score) {
1097 cand = rth;
1098 candp = rthp;
1099 min_score = score;
1100 }
1101 }
1102
1103 chain_length++;
1104
1105 rthp = &rth->dst.rt_next;
1106 }
1107
1108 if (cand) {
1109 /* ip_rt_gc_elasticity used to be average length of chain
1110 * length, when exceeded gc becomes really aggressive.
1111 *
1112 * The second limit is less certain. At the moment it allows
1113 * only 2 entries per bucket. We will see.
1114 */
1115 if (chain_length > ip_rt_gc_elasticity) {
1116 *candp = cand->dst.rt_next;
1117 rt_free(cand);
1118 }
1119 } else {
1120 if (chain_length > rt_chain_length_max &&
1121 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1122 struct net *net = dev_net(rt->dst.dev);
1123 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1124 if (!rt_caching(net)) {
1125 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1126 rt->dst.dev->name, num);
1127 }
1128 rt_emergency_hash_rebuild(net);
1129 spin_unlock_bh(rt_hash_lock_addr(hash));
1130
1131 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1132 ifindex, rt_genid(net));
1133 goto restart;
1134 }
1135 }
1136
1137 /* Try to bind route to arp only if it is output
1138 route or unicast forwarding path.
1139 */
1140 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1141 int err = arp_bind_neighbour(&rt->dst);
1142 if (err) {
1143 spin_unlock_bh(rt_hash_lock_addr(hash));
1144
1145 if (err != -ENOBUFS) {
1146 rt_drop(rt);
1147 return ERR_PTR(err);
1148 }
1149
1150 /* Neighbour tables are full and nothing
1151 can be released. Try to shrink route cache,
1152 it is most likely it holds some neighbour records.
1153 */
1154 if (attempts-- > 0) {
1155 int saved_elasticity = ip_rt_gc_elasticity;
1156 int saved_int = ip_rt_gc_min_interval;
1157 ip_rt_gc_elasticity = 1;
1158 ip_rt_gc_min_interval = 0;
1159 rt_garbage_collect(&ipv4_dst_ops);
1160 ip_rt_gc_min_interval = saved_int;
1161 ip_rt_gc_elasticity = saved_elasticity;
1162 goto restart;
1163 }
1164
1165 if (net_ratelimit())
1166 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1167 rt_drop(rt);
1168 return ERR_PTR(-ENOBUFS);
1169 }
1170 }
1171
1172 rt->dst.rt_next = rt_hash_table[hash].chain;
1173
1174 /*
1175 * Since lookup is lockfree, we must make sure
1176 * previous writes to rt are committed to memory
1177 * before making rt visible to other CPUS.
1178 */
1179 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1180
1181 spin_unlock_bh(rt_hash_lock_addr(hash));
1182
1183 skip_hashing:
1184 if (skb)
1185 skb_dst_set(skb, &rt->dst);
1186 return rt;
1187 }
1188
1189 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1190
1191 static u32 rt_peer_genid(void)
1192 {
1193 return atomic_read(&__rt_peer_genid);
1194 }
1195
1196 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1197 {
1198 struct inet_peer *peer;
1199
1200 peer = inet_getpeer_v4(daddr, create);
1201
1202 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1203 inet_putpeer(peer);
1204 else
1205 rt->rt_peer_genid = rt_peer_genid();
1206 }
1207
1208 /*
1209 * Peer allocation may fail only in serious out-of-memory conditions. However
1210 * we still can generate some output.
1211 * Random ID selection looks a bit dangerous because we have no chances to
1212 * select ID being unique in a reasonable period of time.
1213 * But broken packet identifier may be better than no packet at all.
1214 */
1215 static void ip_select_fb_ident(struct iphdr *iph)
1216 {
1217 static DEFINE_SPINLOCK(ip_fb_id_lock);
1218 static u32 ip_fallback_id;
1219 u32 salt;
1220
1221 spin_lock_bh(&ip_fb_id_lock);
1222 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1223 iph->id = htons(salt & 0xFFFF);
1224 ip_fallback_id = salt;
1225 spin_unlock_bh(&ip_fb_id_lock);
1226 }
1227
1228 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1229 {
1230 struct rtable *rt = (struct rtable *) dst;
1231
1232 if (rt) {
1233 if (rt->peer == NULL)
1234 rt_bind_peer(rt, rt->rt_dst, 1);
1235
1236 /* If peer is attached to destination, it is never detached,
1237 so that we need not to grab a lock to dereference it.
1238 */
1239 if (rt->peer) {
1240 iph->id = htons(inet_getid(rt->peer, more));
1241 return;
1242 }
1243 } else
1244 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1245 __builtin_return_address(0));
1246
1247 ip_select_fb_ident(iph);
1248 }
1249 EXPORT_SYMBOL(__ip_select_ident);
1250
1251 static void rt_del(unsigned hash, struct rtable *rt)
1252 {
1253 struct rtable __rcu **rthp;
1254 struct rtable *aux;
1255
1256 rthp = &rt_hash_table[hash].chain;
1257 spin_lock_bh(rt_hash_lock_addr(hash));
1258 ip_rt_put(rt);
1259 while ((aux = rcu_dereference_protected(*rthp,
1260 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1261 if (aux == rt || rt_is_expired(aux)) {
1262 *rthp = aux->dst.rt_next;
1263 rt_free(aux);
1264 continue;
1265 }
1266 rthp = &aux->dst.rt_next;
1267 }
1268 spin_unlock_bh(rt_hash_lock_addr(hash));
1269 }
1270
1271 /* called in rcu_read_lock() section */
1272 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1273 __be32 saddr, struct net_device *dev)
1274 {
1275 struct in_device *in_dev = __in_dev_get_rcu(dev);
1276 struct inet_peer *peer;
1277 struct net *net;
1278
1279 if (!in_dev)
1280 return;
1281
1282 net = dev_net(dev);
1283 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1284 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1285 ipv4_is_zeronet(new_gw))
1286 goto reject_redirect;
1287
1288 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1289 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1290 goto reject_redirect;
1291 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1292 goto reject_redirect;
1293 } else {
1294 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1295 goto reject_redirect;
1296 }
1297
1298 peer = inet_getpeer_v4(daddr, 1);
1299 if (peer) {
1300 peer->redirect_learned.a4 = new_gw;
1301
1302 inet_putpeer(peer);
1303
1304 atomic_inc(&__rt_peer_genid);
1305 }
1306 return;
1307
1308 reject_redirect:
1309 #ifdef CONFIG_IP_ROUTE_VERBOSE
1310 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1311 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1312 " Advised path = %pI4 -> %pI4\n",
1313 &old_gw, dev->name, &new_gw,
1314 &saddr, &daddr);
1315 #endif
1316 ;
1317 }
1318
1319 static bool peer_pmtu_expired(struct inet_peer *peer)
1320 {
1321 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1322
1323 return orig &&
1324 time_after_eq(jiffies, orig) &&
1325 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1326 }
1327
1328 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1329 {
1330 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1331
1332 return orig &&
1333 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1334 }
1335
1336 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1337 {
1338 struct rtable *rt = (struct rtable *)dst;
1339 struct dst_entry *ret = dst;
1340
1341 if (rt) {
1342 if (dst->obsolete > 0) {
1343 ip_rt_put(rt);
1344 ret = NULL;
1345 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1346 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1347 rt->rt_oif,
1348 rt_genid(dev_net(dst->dev)));
1349 rt_del(hash, rt);
1350 ret = NULL;
1351 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1352 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1353 }
1354 }
1355 return ret;
1356 }
1357
1358 /*
1359 * Algorithm:
1360 * 1. The first ip_rt_redirect_number redirects are sent
1361 * with exponential backoff, then we stop sending them at all,
1362 * assuming that the host ignores our redirects.
1363 * 2. If we did not see packets requiring redirects
1364 * during ip_rt_redirect_silence, we assume that the host
1365 * forgot redirected route and start to send redirects again.
1366 *
1367 * This algorithm is much cheaper and more intelligent than dumb load limiting
1368 * in icmp.c.
1369 *
1370 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1371 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1372 */
1373
1374 void ip_rt_send_redirect(struct sk_buff *skb)
1375 {
1376 struct rtable *rt = skb_rtable(skb);
1377 struct in_device *in_dev;
1378 struct inet_peer *peer;
1379 int log_martians;
1380
1381 rcu_read_lock();
1382 in_dev = __in_dev_get_rcu(rt->dst.dev);
1383 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1384 rcu_read_unlock();
1385 return;
1386 }
1387 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1388 rcu_read_unlock();
1389
1390 if (!rt->peer)
1391 rt_bind_peer(rt, rt->rt_dst, 1);
1392 peer = rt->peer;
1393 if (!peer) {
1394 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1395 return;
1396 }
1397
1398 /* No redirected packets during ip_rt_redirect_silence;
1399 * reset the algorithm.
1400 */
1401 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1402 peer->rate_tokens = 0;
1403
1404 /* Too many ignored redirects; do not send anything
1405 * set dst.rate_last to the last seen redirected packet.
1406 */
1407 if (peer->rate_tokens >= ip_rt_redirect_number) {
1408 peer->rate_last = jiffies;
1409 return;
1410 }
1411
1412 /* Check for load limit; set rate_last to the latest sent
1413 * redirect.
1414 */
1415 if (peer->rate_tokens == 0 ||
1416 time_after(jiffies,
1417 (peer->rate_last +
1418 (ip_rt_redirect_load << peer->rate_tokens)))) {
1419 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1420 peer->rate_last = jiffies;
1421 ++peer->rate_tokens;
1422 #ifdef CONFIG_IP_ROUTE_VERBOSE
1423 if (log_martians &&
1424 peer->rate_tokens == ip_rt_redirect_number &&
1425 net_ratelimit())
1426 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1427 &ip_hdr(skb)->saddr, rt->rt_iif,
1428 &rt->rt_dst, &rt->rt_gateway);
1429 #endif
1430 }
1431 }
1432
1433 static int ip_error(struct sk_buff *skb)
1434 {
1435 struct rtable *rt = skb_rtable(skb);
1436 struct inet_peer *peer;
1437 unsigned long now;
1438 bool send;
1439 int code;
1440
1441 switch (rt->dst.error) {
1442 case EINVAL:
1443 default:
1444 goto out;
1445 case EHOSTUNREACH:
1446 code = ICMP_HOST_UNREACH;
1447 break;
1448 case ENETUNREACH:
1449 code = ICMP_NET_UNREACH;
1450 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1451 IPSTATS_MIB_INNOROUTES);
1452 break;
1453 case EACCES:
1454 code = ICMP_PKT_FILTERED;
1455 break;
1456 }
1457
1458 if (!rt->peer)
1459 rt_bind_peer(rt, rt->rt_dst, 1);
1460 peer = rt->peer;
1461
1462 send = true;
1463 if (peer) {
1464 now = jiffies;
1465 peer->rate_tokens += now - peer->rate_last;
1466 if (peer->rate_tokens > ip_rt_error_burst)
1467 peer->rate_tokens = ip_rt_error_burst;
1468 peer->rate_last = now;
1469 if (peer->rate_tokens >= ip_rt_error_cost)
1470 peer->rate_tokens -= ip_rt_error_cost;
1471 else
1472 send = false;
1473 }
1474 if (send)
1475 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1476
1477 out: kfree_skb(skb);
1478 return 0;
1479 }
1480
1481 /*
1482 * The last two values are not from the RFC but
1483 * are needed for AMPRnet AX.25 paths.
1484 */
1485
1486 static const unsigned short mtu_plateau[] =
1487 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1488
1489 static inline unsigned short guess_mtu(unsigned short old_mtu)
1490 {
1491 int i;
1492
1493 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1494 if (old_mtu > mtu_plateau[i])
1495 return mtu_plateau[i];
1496 return 68;
1497 }
1498
1499 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1500 unsigned short new_mtu,
1501 struct net_device *dev)
1502 {
1503 unsigned short old_mtu = ntohs(iph->tot_len);
1504 unsigned short est_mtu = 0;
1505 struct inet_peer *peer;
1506
1507 peer = inet_getpeer_v4(iph->daddr, 1);
1508 if (peer) {
1509 unsigned short mtu = new_mtu;
1510
1511 if (new_mtu < 68 || new_mtu >= old_mtu) {
1512 /* BSD 4.2 derived systems incorrectly adjust
1513 * tot_len by the IP header length, and report
1514 * a zero MTU in the ICMP message.
1515 */
1516 if (mtu == 0 &&
1517 old_mtu >= 68 + (iph->ihl << 2))
1518 old_mtu -= iph->ihl << 2;
1519 mtu = guess_mtu(old_mtu);
1520 }
1521
1522 if (mtu < ip_rt_min_pmtu)
1523 mtu = ip_rt_min_pmtu;
1524 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1525 unsigned long pmtu_expires;
1526
1527 pmtu_expires = jiffies + ip_rt_mtu_expires;
1528 if (!pmtu_expires)
1529 pmtu_expires = 1UL;
1530
1531 est_mtu = mtu;
1532 peer->pmtu_learned = mtu;
1533 peer->pmtu_expires = pmtu_expires;
1534 }
1535
1536 inet_putpeer(peer);
1537
1538 atomic_inc(&__rt_peer_genid);
1539 }
1540 return est_mtu ? : new_mtu;
1541 }
1542
1543 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1544 {
1545 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1546
1547 if (!expires)
1548 return;
1549 if (time_before(jiffies, expires)) {
1550 u32 orig_dst_mtu = dst_mtu(dst);
1551 if (peer->pmtu_learned < orig_dst_mtu) {
1552 if (!peer->pmtu_orig)
1553 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1554 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1555 }
1556 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1557 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1558 }
1559
1560 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1561 {
1562 struct rtable *rt = (struct rtable *) dst;
1563 struct inet_peer *peer;
1564
1565 dst_confirm(dst);
1566
1567 if (!rt->peer)
1568 rt_bind_peer(rt, rt->rt_dst, 1);
1569 peer = rt->peer;
1570 if (peer) {
1571 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1572
1573 if (mtu < ip_rt_min_pmtu)
1574 mtu = ip_rt_min_pmtu;
1575 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1576
1577 pmtu_expires = jiffies + ip_rt_mtu_expires;
1578 if (!pmtu_expires)
1579 pmtu_expires = 1UL;
1580
1581 peer->pmtu_learned = mtu;
1582 peer->pmtu_expires = pmtu_expires;
1583
1584 atomic_inc(&__rt_peer_genid);
1585 rt->rt_peer_genid = rt_peer_genid();
1586 }
1587 check_peer_pmtu(dst, peer);
1588 }
1589 }
1590
1591 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1592 {
1593 struct rtable *rt = (struct rtable *) dst;
1594 __be32 orig_gw = rt->rt_gateway;
1595
1596 dst_confirm(&rt->dst);
1597
1598 neigh_release(rt->dst.neighbour);
1599 rt->dst.neighbour = NULL;
1600
1601 rt->rt_gateway = peer->redirect_learned.a4;
1602 if (arp_bind_neighbour(&rt->dst) ||
1603 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1604 if (rt->dst.neighbour)
1605 neigh_event_send(rt->dst.neighbour, NULL);
1606 rt->rt_gateway = orig_gw;
1607 return -EAGAIN;
1608 } else {
1609 rt->rt_flags |= RTCF_REDIRECTED;
1610 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1611 rt->dst.neighbour);
1612 }
1613 return 0;
1614 }
1615
1616 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1617 {
1618 struct rtable *rt = (struct rtable *) dst;
1619
1620 if (rt_is_expired(rt))
1621 return NULL;
1622 if (rt->rt_peer_genid != rt_peer_genid()) {
1623 struct inet_peer *peer;
1624
1625 if (!rt->peer)
1626 rt_bind_peer(rt, rt->rt_dst, 0);
1627
1628 peer = rt->peer;
1629 if (peer) {
1630 check_peer_pmtu(dst, peer);
1631
1632 if (peer->redirect_learned.a4 &&
1633 peer->redirect_learned.a4 != rt->rt_gateway) {
1634 if (check_peer_redir(dst, peer))
1635 return NULL;
1636 }
1637 }
1638
1639 rt->rt_peer_genid = rt_peer_genid();
1640 }
1641 return dst;
1642 }
1643
1644 static void ipv4_dst_destroy(struct dst_entry *dst)
1645 {
1646 struct rtable *rt = (struct rtable *) dst;
1647 struct inet_peer *peer = rt->peer;
1648
1649 if (rt->fi) {
1650 fib_info_put(rt->fi);
1651 rt->fi = NULL;
1652 }
1653 if (peer) {
1654 rt->peer = NULL;
1655 inet_putpeer(peer);
1656 }
1657 }
1658
1659
1660 static void ipv4_link_failure(struct sk_buff *skb)
1661 {
1662 struct rtable *rt;
1663
1664 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1665
1666 rt = skb_rtable(skb);
1667 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1668 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1669 }
1670
1671 static int ip_rt_bug(struct sk_buff *skb)
1672 {
1673 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1674 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1675 skb->dev ? skb->dev->name : "?");
1676 kfree_skb(skb);
1677 WARN_ON(1);
1678 return 0;
1679 }
1680
1681 /*
1682 We do not cache source address of outgoing interface,
1683 because it is used only by IP RR, TS and SRR options,
1684 so that it out of fast path.
1685
1686 BTW remember: "addr" is allowed to be not aligned
1687 in IP options!
1688 */
1689
1690 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1691 {
1692 __be32 src;
1693
1694 if (rt_is_output_route(rt))
1695 src = ip_hdr(skb)->saddr;
1696 else {
1697 struct fib_result res;
1698 struct flowi4 fl4;
1699 struct iphdr *iph;
1700
1701 iph = ip_hdr(skb);
1702
1703 memset(&fl4, 0, sizeof(fl4));
1704 fl4.daddr = iph->daddr;
1705 fl4.saddr = iph->saddr;
1706 fl4.flowi4_tos = iph->tos;
1707 fl4.flowi4_oif = rt->dst.dev->ifindex;
1708 fl4.flowi4_iif = skb->dev->ifindex;
1709 fl4.flowi4_mark = skb->mark;
1710
1711 rcu_read_lock();
1712 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1713 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1714 else
1715 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1716 RT_SCOPE_UNIVERSE);
1717 rcu_read_unlock();
1718 }
1719 memcpy(addr, &src, 4);
1720 }
1721
1722 #ifdef CONFIG_IP_ROUTE_CLASSID
1723 static void set_class_tag(struct rtable *rt, u32 tag)
1724 {
1725 if (!(rt->dst.tclassid & 0xFFFF))
1726 rt->dst.tclassid |= tag & 0xFFFF;
1727 if (!(rt->dst.tclassid & 0xFFFF0000))
1728 rt->dst.tclassid |= tag & 0xFFFF0000;
1729 }
1730 #endif
1731
1732 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1733 {
1734 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1735
1736 if (advmss == 0) {
1737 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1738 ip_rt_min_advmss);
1739 if (advmss > 65535 - 40)
1740 advmss = 65535 - 40;
1741 }
1742 return advmss;
1743 }
1744
1745 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1746 {
1747 unsigned int mtu = dst->dev->mtu;
1748
1749 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1750 const struct rtable *rt = (const struct rtable *) dst;
1751
1752 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1753 mtu = 576;
1754 }
1755
1756 if (mtu > IP_MAX_MTU)
1757 mtu = IP_MAX_MTU;
1758
1759 return mtu;
1760 }
1761
1762 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1763 struct fib_info *fi)
1764 {
1765 struct inet_peer *peer;
1766 int create = 0;
1767
1768 /* If a peer entry exists for this destination, we must hook
1769 * it up in order to get at cached metrics.
1770 */
1771 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1772 create = 1;
1773
1774 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1775 if (peer) {
1776 rt->rt_peer_genid = rt_peer_genid();
1777 if (inet_metrics_new(peer))
1778 memcpy(peer->metrics, fi->fib_metrics,
1779 sizeof(u32) * RTAX_MAX);
1780 dst_init_metrics(&rt->dst, peer->metrics, false);
1781
1782 check_peer_pmtu(&rt->dst, peer);
1783 if (peer->redirect_learned.a4 &&
1784 peer->redirect_learned.a4 != rt->rt_gateway) {
1785 rt->rt_gateway = peer->redirect_learned.a4;
1786 rt->rt_flags |= RTCF_REDIRECTED;
1787 }
1788 } else {
1789 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1790 rt->fi = fi;
1791 atomic_inc(&fi->fib_clntref);
1792 }
1793 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1794 }
1795 }
1796
1797 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1798 const struct fib_result *res,
1799 struct fib_info *fi, u16 type, u32 itag)
1800 {
1801 struct dst_entry *dst = &rt->dst;
1802
1803 if (fi) {
1804 if (FIB_RES_GW(*res) &&
1805 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1806 rt->rt_gateway = FIB_RES_GW(*res);
1807 rt_init_metrics(rt, fl4, fi);
1808 #ifdef CONFIG_IP_ROUTE_CLASSID
1809 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1810 #endif
1811 }
1812
1813 if (dst_mtu(dst) > IP_MAX_MTU)
1814 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1815 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1816 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1817
1818 #ifdef CONFIG_IP_ROUTE_CLASSID
1819 #ifdef CONFIG_IP_MULTIPLE_TABLES
1820 set_class_tag(rt, fib_rules_tclass(res));
1821 #endif
1822 set_class_tag(rt, itag);
1823 #endif
1824 }
1825
1826 static struct rtable *rt_dst_alloc(struct net_device *dev,
1827 bool nopolicy, bool noxfrm)
1828 {
1829 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1830 DST_HOST |
1831 (nopolicy ? DST_NOPOLICY : 0) |
1832 (noxfrm ? DST_NOXFRM : 0));
1833 }
1834
1835 /* called in rcu_read_lock() section */
1836 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1837 u8 tos, struct net_device *dev, int our)
1838 {
1839 unsigned int hash;
1840 struct rtable *rth;
1841 __be32 spec_dst;
1842 struct in_device *in_dev = __in_dev_get_rcu(dev);
1843 u32 itag = 0;
1844 int err;
1845
1846 /* Primary sanity checks. */
1847
1848 if (in_dev == NULL)
1849 return -EINVAL;
1850
1851 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1852 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1853 goto e_inval;
1854
1855 if (ipv4_is_zeronet(saddr)) {
1856 if (!ipv4_is_local_multicast(daddr))
1857 goto e_inval;
1858 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1859 } else {
1860 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1861 &itag);
1862 if (err < 0)
1863 goto e_err;
1864 }
1865 rth = rt_dst_alloc(init_net.loopback_dev,
1866 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1867 if (!rth)
1868 goto e_nobufs;
1869
1870 #ifdef CONFIG_IP_ROUTE_CLASSID
1871 rth->dst.tclassid = itag;
1872 #endif
1873 rth->dst.output = ip_rt_bug;
1874
1875 rth->rt_key_dst = daddr;
1876 rth->rt_key_src = saddr;
1877 rth->rt_genid = rt_genid(dev_net(dev));
1878 rth->rt_flags = RTCF_MULTICAST;
1879 rth->rt_type = RTN_MULTICAST;
1880 rth->rt_key_tos = tos;
1881 rth->rt_dst = daddr;
1882 rth->rt_src = saddr;
1883 rth->rt_route_iif = dev->ifindex;
1884 rth->rt_iif = dev->ifindex;
1885 rth->rt_oif = 0;
1886 rth->rt_mark = skb->mark;
1887 rth->rt_gateway = daddr;
1888 rth->rt_spec_dst= spec_dst;
1889 rth->rt_peer_genid = 0;
1890 rth->peer = NULL;
1891 rth->fi = NULL;
1892 if (our) {
1893 rth->dst.input= ip_local_deliver;
1894 rth->rt_flags |= RTCF_LOCAL;
1895 }
1896
1897 #ifdef CONFIG_IP_MROUTE
1898 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1899 rth->dst.input = ip_mr_input;
1900 #endif
1901 RT_CACHE_STAT_INC(in_slow_mc);
1902
1903 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1904 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1905 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
1906
1907 e_nobufs:
1908 return -ENOBUFS;
1909 e_inval:
1910 return -EINVAL;
1911 e_err:
1912 return err;
1913 }
1914
1915
1916 static void ip_handle_martian_source(struct net_device *dev,
1917 struct in_device *in_dev,
1918 struct sk_buff *skb,
1919 __be32 daddr,
1920 __be32 saddr)
1921 {
1922 RT_CACHE_STAT_INC(in_martian_src);
1923 #ifdef CONFIG_IP_ROUTE_VERBOSE
1924 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1925 /*
1926 * RFC1812 recommendation, if source is martian,
1927 * the only hint is MAC header.
1928 */
1929 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1930 &daddr, &saddr, dev->name);
1931 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1932 int i;
1933 const unsigned char *p = skb_mac_header(skb);
1934 printk(KERN_WARNING "ll header: ");
1935 for (i = 0; i < dev->hard_header_len; i++, p++) {
1936 printk("%02x", *p);
1937 if (i < (dev->hard_header_len - 1))
1938 printk(":");
1939 }
1940 printk("\n");
1941 }
1942 }
1943 #endif
1944 }
1945
1946 /* called in rcu_read_lock() section */
1947 static int __mkroute_input(struct sk_buff *skb,
1948 const struct fib_result *res,
1949 struct in_device *in_dev,
1950 __be32 daddr, __be32 saddr, u32 tos,
1951 struct rtable **result)
1952 {
1953 struct rtable *rth;
1954 int err;
1955 struct in_device *out_dev;
1956 unsigned int flags = 0;
1957 __be32 spec_dst;
1958 u32 itag;
1959
1960 /* get a working reference to the output device */
1961 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1962 if (out_dev == NULL) {
1963 if (net_ratelimit())
1964 printk(KERN_CRIT "Bug in ip_route_input" \
1965 "_slow(). Please, report\n");
1966 return -EINVAL;
1967 }
1968
1969
1970 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1971 in_dev->dev, &spec_dst, &itag);
1972 if (err < 0) {
1973 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1974 saddr);
1975
1976 goto cleanup;
1977 }
1978
1979 if (err)
1980 flags |= RTCF_DIRECTSRC;
1981
1982 if (out_dev == in_dev && err &&
1983 (IN_DEV_SHARED_MEDIA(out_dev) ||
1984 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1985 flags |= RTCF_DOREDIRECT;
1986
1987 if (skb->protocol != htons(ETH_P_IP)) {
1988 /* Not IP (i.e. ARP). Do not create route, if it is
1989 * invalid for proxy arp. DNAT routes are always valid.
1990 *
1991 * Proxy arp feature have been extended to allow, ARP
1992 * replies back to the same interface, to support
1993 * Private VLAN switch technologies. See arp.c.
1994 */
1995 if (out_dev == in_dev &&
1996 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1997 err = -EINVAL;
1998 goto cleanup;
1999 }
2000 }
2001
2002 rth = rt_dst_alloc(out_dev->dev,
2003 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2004 IN_DEV_CONF_GET(out_dev, NOXFRM));
2005 if (!rth) {
2006 err = -ENOBUFS;
2007 goto cleanup;
2008 }
2009
2010 rth->rt_key_dst = daddr;
2011 rth->rt_key_src = saddr;
2012 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2013 rth->rt_flags = flags;
2014 rth->rt_type = res->type;
2015 rth->rt_key_tos = tos;
2016 rth->rt_dst = daddr;
2017 rth->rt_src = saddr;
2018 rth->rt_route_iif = in_dev->dev->ifindex;
2019 rth->rt_iif = in_dev->dev->ifindex;
2020 rth->rt_oif = 0;
2021 rth->rt_mark = skb->mark;
2022 rth->rt_gateway = daddr;
2023 rth->rt_spec_dst= spec_dst;
2024 rth->rt_peer_genid = 0;
2025 rth->peer = NULL;
2026 rth->fi = NULL;
2027
2028 rth->dst.input = ip_forward;
2029 rth->dst.output = ip_output;
2030
2031 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
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 flowi4 *fl4,
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)
2051 fib_select_multipath(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, fl4->flowi4_iif,
2061 rt_genid(dev_net(rth->dst.dev)));
2062 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_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 flowi4 fl4;
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 fl4.flowi4_oif = 0;
2122 fl4.flowi4_iif = dev->ifindex;
2123 fl4.flowi4_mark = skb->mark;
2124 fl4.flowi4_tos = tos;
2125 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2126 fl4.daddr = daddr;
2127 fl4.saddr = saddr;
2128 err = fib_lookup(net, &fl4, &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(skb, saddr, daddr, tos,
2142 net->loopback_dev->ifindex,
2143 dev, &spec_dst, &itag);
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, &fl4, 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(skb, saddr, 0, tos, 0, dev, &spec_dst,
2168 &itag);
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(net->loopback_dev,
2180 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2181 if (!rth)
2182 goto e_nobufs;
2183
2184 rth->dst.input= ip_local_deliver;
2185 rth->dst.output= ip_rt_bug;
2186 #ifdef CONFIG_IP_ROUTE_CLASSID
2187 rth->dst.tclassid = itag;
2188 #endif
2189
2190 rth->rt_key_dst = daddr;
2191 rth->rt_key_src = saddr;
2192 rth->rt_genid = rt_genid(net);
2193 rth->rt_flags = flags|RTCF_LOCAL;
2194 rth->rt_type = res.type;
2195 rth->rt_key_tos = tos;
2196 rth->rt_dst = daddr;
2197 rth->rt_src = saddr;
2198 #ifdef CONFIG_IP_ROUTE_CLASSID
2199 rth->dst.tclassid = itag;
2200 #endif
2201 rth->rt_route_iif = dev->ifindex;
2202 rth->rt_iif = dev->ifindex;
2203 rth->rt_oif = 0;
2204 rth->rt_mark = skb->mark;
2205 rth->rt_gateway = daddr;
2206 rth->rt_spec_dst= spec_dst;
2207 rth->rt_peer_genid = 0;
2208 rth->peer = NULL;
2209 rth->fi = NULL;
2210 if (res.type == RTN_UNREACHABLE) {
2211 rth->dst.input= ip_error;
2212 rth->dst.error= -err;
2213 rth->rt_flags &= ~RTCF_LOCAL;
2214 }
2215 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2216 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2217 err = 0;
2218 if (IS_ERR(rth))
2219 err = PTR_ERR(rth);
2220 goto out;
2221
2222 no_route:
2223 RT_CACHE_STAT_INC(in_no_route);
2224 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2225 res.type = RTN_UNREACHABLE;
2226 if (err == -ESRCH)
2227 err = -ENETUNREACH;
2228 goto local_input;
2229
2230 /*
2231 * Do not cache martian addresses: they should be logged (RFC1812)
2232 */
2233 martian_destination:
2234 RT_CACHE_STAT_INC(in_martian_dst);
2235 #ifdef CONFIG_IP_ROUTE_VERBOSE
2236 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2237 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2238 &daddr, &saddr, dev->name);
2239 #endif
2240
2241 e_hostunreach:
2242 err = -EHOSTUNREACH;
2243 goto out;
2244
2245 e_inval:
2246 err = -EINVAL;
2247 goto out;
2248
2249 e_nobufs:
2250 err = -ENOBUFS;
2251 goto out;
2252
2253 martian_source:
2254 err = -EINVAL;
2255 martian_source_keep_err:
2256 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2257 goto out;
2258 }
2259
2260 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2261 u8 tos, struct net_device *dev, bool noref)
2262 {
2263 struct rtable * rth;
2264 unsigned hash;
2265 int iif = dev->ifindex;
2266 struct net *net;
2267 int res;
2268
2269 net = dev_net(dev);
2270
2271 rcu_read_lock();
2272
2273 if (!rt_caching(net))
2274 goto skip_cache;
2275
2276 tos &= IPTOS_RT_MASK;
2277 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2278
2279 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2280 rth = rcu_dereference(rth->dst.rt_next)) {
2281 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2282 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2283 (rth->rt_iif ^ iif) |
2284 rth->rt_oif |
2285 (rth->rt_key_tos ^ tos)) == 0 &&
2286 rth->rt_mark == skb->mark &&
2287 net_eq(dev_net(rth->dst.dev), net) &&
2288 !rt_is_expired(rth)) {
2289 if (noref) {
2290 dst_use_noref(&rth->dst, jiffies);
2291 skb_dst_set_noref(skb, &rth->dst);
2292 } else {
2293 dst_use(&rth->dst, jiffies);
2294 skb_dst_set(skb, &rth->dst);
2295 }
2296 RT_CACHE_STAT_INC(in_hit);
2297 rcu_read_unlock();
2298 return 0;
2299 }
2300 RT_CACHE_STAT_INC(in_hlist_search);
2301 }
2302
2303 skip_cache:
2304 /* Multicast recognition logic is moved from route cache to here.
2305 The problem was that too many Ethernet cards have broken/missing
2306 hardware multicast filters :-( As result the host on multicasting
2307 network acquires a lot of useless route cache entries, sort of
2308 SDR messages from all the world. Now we try to get rid of them.
2309 Really, provided software IP multicast filter is organized
2310 reasonably (at least, hashed), it does not result in a slowdown
2311 comparing with route cache reject entries.
2312 Note, that multicast routers are not affected, because
2313 route cache entry is created eventually.
2314 */
2315 if (ipv4_is_multicast(daddr)) {
2316 struct in_device *in_dev = __in_dev_get_rcu(dev);
2317
2318 if (in_dev) {
2319 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2320 ip_hdr(skb)->protocol);
2321 if (our
2322 #ifdef CONFIG_IP_MROUTE
2323 ||
2324 (!ipv4_is_local_multicast(daddr) &&
2325 IN_DEV_MFORWARD(in_dev))
2326 #endif
2327 ) {
2328 int res = ip_route_input_mc(skb, daddr, saddr,
2329 tos, dev, our);
2330 rcu_read_unlock();
2331 return res;
2332 }
2333 }
2334 rcu_read_unlock();
2335 return -EINVAL;
2336 }
2337 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2338 rcu_read_unlock();
2339 return res;
2340 }
2341 EXPORT_SYMBOL(ip_route_input_common);
2342
2343 /* called with rcu_read_lock() */
2344 static struct rtable *__mkroute_output(const struct fib_result *res,
2345 const struct flowi4 *fl4,
2346 __be32 orig_daddr, __be32 orig_saddr,
2347 int orig_oif, struct net_device *dev_out,
2348 unsigned int flags)
2349 {
2350 struct fib_info *fi = res->fi;
2351 u32 tos = RT_FL_TOS(fl4);
2352 struct in_device *in_dev;
2353 u16 type = res->type;
2354 struct rtable *rth;
2355
2356 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2357 return ERR_PTR(-EINVAL);
2358
2359 if (ipv4_is_lbcast(fl4->daddr))
2360 type = RTN_BROADCAST;
2361 else if (ipv4_is_multicast(fl4->daddr))
2362 type = RTN_MULTICAST;
2363 else if (ipv4_is_zeronet(fl4->daddr))
2364 return ERR_PTR(-EINVAL);
2365
2366 if (dev_out->flags & IFF_LOOPBACK)
2367 flags |= RTCF_LOCAL;
2368
2369 in_dev = __in_dev_get_rcu(dev_out);
2370 if (!in_dev)
2371 return ERR_PTR(-EINVAL);
2372
2373 if (type == RTN_BROADCAST) {
2374 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2375 fi = NULL;
2376 } else if (type == RTN_MULTICAST) {
2377 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2378 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2379 fl4->flowi4_proto))
2380 flags &= ~RTCF_LOCAL;
2381 /* If multicast route do not exist use
2382 * default one, but do not gateway in this case.
2383 * Yes, it is hack.
2384 */
2385 if (fi && res->prefixlen < 4)
2386 fi = NULL;
2387 }
2388
2389 rth = rt_dst_alloc(dev_out,
2390 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2391 IN_DEV_CONF_GET(in_dev, NOXFRM));
2392 if (!rth)
2393 return ERR_PTR(-ENOBUFS);
2394
2395 rth->dst.output = ip_output;
2396
2397 rth->rt_key_dst = orig_daddr;
2398 rth->rt_key_src = orig_saddr;
2399 rth->rt_genid = rt_genid(dev_net(dev_out));
2400 rth->rt_flags = flags;
2401 rth->rt_type = type;
2402 rth->rt_key_tos = tos;
2403 rth->rt_dst = fl4->daddr;
2404 rth->rt_src = fl4->saddr;
2405 rth->rt_route_iif = 0;
2406 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2407 rth->rt_oif = orig_oif;
2408 rth->rt_mark = fl4->flowi4_mark;
2409 rth->rt_gateway = fl4->daddr;
2410 rth->rt_spec_dst= fl4->saddr;
2411 rth->rt_peer_genid = 0;
2412 rth->peer = NULL;
2413 rth->fi = NULL;
2414
2415 RT_CACHE_STAT_INC(out_slow_tot);
2416
2417 if (flags & RTCF_LOCAL) {
2418 rth->dst.input = ip_local_deliver;
2419 rth->rt_spec_dst = fl4->daddr;
2420 }
2421 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2422 rth->rt_spec_dst = fl4->saddr;
2423 if (flags & RTCF_LOCAL &&
2424 !(dev_out->flags & IFF_LOOPBACK)) {
2425 rth->dst.output = ip_mc_output;
2426 RT_CACHE_STAT_INC(out_slow_mc);
2427 }
2428 #ifdef CONFIG_IP_MROUTE
2429 if (type == RTN_MULTICAST) {
2430 if (IN_DEV_MFORWARD(in_dev) &&
2431 !ipv4_is_local_multicast(fl4->daddr)) {
2432 rth->dst.input = ip_mr_input;
2433 rth->dst.output = ip_mc_output;
2434 }
2435 }
2436 #endif
2437 }
2438
2439 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2440
2441 return rth;
2442 }
2443
2444 /*
2445 * Major route resolver routine.
2446 * called with rcu_read_lock();
2447 */
2448
2449 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2450 {
2451 struct net_device *dev_out = NULL;
2452 u32 tos = RT_FL_TOS(fl4);
2453 unsigned int flags = 0;
2454 struct fib_result res;
2455 struct rtable *rth;
2456 __be32 orig_daddr;
2457 __be32 orig_saddr;
2458 int orig_oif;
2459
2460 res.fi = NULL;
2461 #ifdef CONFIG_IP_MULTIPLE_TABLES
2462 res.r = NULL;
2463 #endif
2464
2465 orig_daddr = fl4->daddr;
2466 orig_saddr = fl4->saddr;
2467 orig_oif = fl4->flowi4_oif;
2468
2469 fl4->flowi4_iif = net->loopback_dev->ifindex;
2470 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2471 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2472 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2473
2474 rcu_read_lock();
2475 if (fl4->saddr) {
2476 rth = ERR_PTR(-EINVAL);
2477 if (ipv4_is_multicast(fl4->saddr) ||
2478 ipv4_is_lbcast(fl4->saddr) ||
2479 ipv4_is_zeronet(fl4->saddr))
2480 goto out;
2481
2482 /* I removed check for oif == dev_out->oif here.
2483 It was wrong for two reasons:
2484 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2485 is assigned to multiple interfaces.
2486 2. Moreover, we are allowed to send packets with saddr
2487 of another iface. --ANK
2488 */
2489
2490 if (fl4->flowi4_oif == 0 &&
2491 (ipv4_is_multicast(fl4->daddr) ||
2492 ipv4_is_lbcast(fl4->daddr))) {
2493 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2494 dev_out = __ip_dev_find(net, fl4->saddr, false);
2495 if (dev_out == NULL)
2496 goto out;
2497
2498 /* Special hack: user can direct multicasts
2499 and limited broadcast via necessary interface
2500 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2501 This hack is not just for fun, it allows
2502 vic,vat and friends to work.
2503 They bind socket to loopback, set ttl to zero
2504 and expect that it will work.
2505 From the viewpoint of routing cache they are broken,
2506 because we are not allowed to build multicast path
2507 with loopback source addr (look, routing cache
2508 cannot know, that ttl is zero, so that packet
2509 will not leave this host and route is valid).
2510 Luckily, this hack is good workaround.
2511 */
2512
2513 fl4->flowi4_oif = dev_out->ifindex;
2514 goto make_route;
2515 }
2516
2517 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2518 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2519 if (!__ip_dev_find(net, fl4->saddr, false))
2520 goto out;
2521 }
2522 }
2523
2524
2525 if (fl4->flowi4_oif) {
2526 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2527 rth = ERR_PTR(-ENODEV);
2528 if (dev_out == NULL)
2529 goto out;
2530
2531 /* RACE: Check return value of inet_select_addr instead. */
2532 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2533 rth = ERR_PTR(-ENETUNREACH);
2534 goto out;
2535 }
2536 if (ipv4_is_local_multicast(fl4->daddr) ||
2537 ipv4_is_lbcast(fl4->daddr)) {
2538 if (!fl4->saddr)
2539 fl4->saddr = inet_select_addr(dev_out, 0,
2540 RT_SCOPE_LINK);
2541 goto make_route;
2542 }
2543 if (fl4->saddr) {
2544 if (ipv4_is_multicast(fl4->daddr))
2545 fl4->saddr = inet_select_addr(dev_out, 0,
2546 fl4->flowi4_scope);
2547 else if (!fl4->daddr)
2548 fl4->saddr = inet_select_addr(dev_out, 0,
2549 RT_SCOPE_HOST);
2550 }
2551 }
2552
2553 if (!fl4->daddr) {
2554 fl4->daddr = fl4->saddr;
2555 if (!fl4->daddr)
2556 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2557 dev_out = net->loopback_dev;
2558 fl4->flowi4_oif = net->loopback_dev->ifindex;
2559 res.type = RTN_LOCAL;
2560 flags |= RTCF_LOCAL;
2561 goto make_route;
2562 }
2563
2564 if (fib_lookup(net, fl4, &res)) {
2565 res.fi = NULL;
2566 if (fl4->flowi4_oif) {
2567 /* Apparently, routing tables are wrong. Assume,
2568 that the destination is on link.
2569
2570 WHY? DW.
2571 Because we are allowed to send to iface
2572 even if it has NO routes and NO assigned
2573 addresses. When oif is specified, routing
2574 tables are looked up with only one purpose:
2575 to catch if destination is gatewayed, rather than
2576 direct. Moreover, if MSG_DONTROUTE is set,
2577 we send packet, ignoring both routing tables
2578 and ifaddr state. --ANK
2579
2580
2581 We could make it even if oif is unknown,
2582 likely IPv6, but we do not.
2583 */
2584
2585 if (fl4->saddr == 0)
2586 fl4->saddr = inet_select_addr(dev_out, 0,
2587 RT_SCOPE_LINK);
2588 res.type = RTN_UNICAST;
2589 goto make_route;
2590 }
2591 rth = ERR_PTR(-ENETUNREACH);
2592 goto out;
2593 }
2594
2595 if (res.type == RTN_LOCAL) {
2596 if (!fl4->saddr) {
2597 if (res.fi->fib_prefsrc)
2598 fl4->saddr = res.fi->fib_prefsrc;
2599 else
2600 fl4->saddr = fl4->daddr;
2601 }
2602 dev_out = net->loopback_dev;
2603 fl4->flowi4_oif = dev_out->ifindex;
2604 res.fi = NULL;
2605 flags |= RTCF_LOCAL;
2606 goto make_route;
2607 }
2608
2609 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2610 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2611 fib_select_multipath(&res);
2612 else
2613 #endif
2614 if (!res.prefixlen &&
2615 res.table->tb_num_default > 1 &&
2616 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2617 fib_select_default(&res);
2618
2619 if (!fl4->saddr)
2620 fl4->saddr = FIB_RES_PREFSRC(net, res);
2621
2622 dev_out = FIB_RES_DEV(res);
2623 fl4->flowi4_oif = dev_out->ifindex;
2624
2625
2626 make_route:
2627 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2628 dev_out, flags);
2629 if (!IS_ERR(rth)) {
2630 unsigned int hash;
2631
2632 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2633 rt_genid(dev_net(dev_out)));
2634 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2635 }
2636
2637 out:
2638 rcu_read_unlock();
2639 return rth;
2640 }
2641
2642 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2643 {
2644 struct rtable *rth;
2645 unsigned int hash;
2646
2647 if (!rt_caching(net))
2648 goto slow_output;
2649
2650 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2651
2652 rcu_read_lock_bh();
2653 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2654 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2655 if (rth->rt_key_dst == flp4->daddr &&
2656 rth->rt_key_src == flp4->saddr &&
2657 rt_is_output_route(rth) &&
2658 rth->rt_oif == flp4->flowi4_oif &&
2659 rth->rt_mark == flp4->flowi4_mark &&
2660 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2661 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2662 net_eq(dev_net(rth->dst.dev), net) &&
2663 !rt_is_expired(rth)) {
2664 dst_use(&rth->dst, jiffies);
2665 RT_CACHE_STAT_INC(out_hit);
2666 rcu_read_unlock_bh();
2667 if (!flp4->saddr)
2668 flp4->saddr = rth->rt_src;
2669 if (!flp4->daddr)
2670 flp4->daddr = rth->rt_dst;
2671 return rth;
2672 }
2673 RT_CACHE_STAT_INC(out_hlist_search);
2674 }
2675 rcu_read_unlock_bh();
2676
2677 slow_output:
2678 return ip_route_output_slow(net, flp4);
2679 }
2680 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2681
2682 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2683 {
2684 return NULL;
2685 }
2686
2687 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2688 {
2689 return 0;
2690 }
2691
2692 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2693 {
2694 }
2695
2696 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2697 unsigned long old)
2698 {
2699 return NULL;
2700 }
2701
2702 static struct dst_ops ipv4_dst_blackhole_ops = {
2703 .family = AF_INET,
2704 .protocol = cpu_to_be16(ETH_P_IP),
2705 .destroy = ipv4_dst_destroy,
2706 .check = ipv4_blackhole_dst_check,
2707 .default_mtu = ipv4_blackhole_default_mtu,
2708 .default_advmss = ipv4_default_advmss,
2709 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2710 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2711 };
2712
2713 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2714 {
2715 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2716 struct rtable *ort = (struct rtable *) dst_orig;
2717
2718 if (rt) {
2719 struct dst_entry *new = &rt->dst;
2720
2721 new->__use = 1;
2722 new->input = dst_discard;
2723 new->output = dst_discard;
2724 dst_copy_metrics(new, &ort->dst);
2725
2726 new->dev = ort->dst.dev;
2727 if (new->dev)
2728 dev_hold(new->dev);
2729
2730 rt->rt_key_dst = ort->rt_key_dst;
2731 rt->rt_key_src = ort->rt_key_src;
2732 rt->rt_key_tos = ort->rt_key_tos;
2733 rt->rt_route_iif = ort->rt_route_iif;
2734 rt->rt_iif = ort->rt_iif;
2735 rt->rt_oif = ort->rt_oif;
2736 rt->rt_mark = ort->rt_mark;
2737
2738 rt->rt_genid = rt_genid(net);
2739 rt->rt_flags = ort->rt_flags;
2740 rt->rt_type = ort->rt_type;
2741 rt->rt_dst = ort->rt_dst;
2742 rt->rt_src = ort->rt_src;
2743 rt->rt_gateway = ort->rt_gateway;
2744 rt->rt_spec_dst = ort->rt_spec_dst;
2745 rt->peer = ort->peer;
2746 if (rt->peer)
2747 atomic_inc(&rt->peer->refcnt);
2748 rt->fi = ort->fi;
2749 if (rt->fi)
2750 atomic_inc(&rt->fi->fib_clntref);
2751
2752 dst_free(new);
2753 }
2754
2755 dst_release(dst_orig);
2756
2757 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2758 }
2759
2760 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2761 struct sock *sk)
2762 {
2763 struct rtable *rt = __ip_route_output_key(net, flp4);
2764
2765 if (IS_ERR(rt))
2766 return rt;
2767
2768 if (flp4->flowi4_proto)
2769 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2770 flowi4_to_flowi(flp4),
2771 sk, 0);
2772
2773 return rt;
2774 }
2775 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2776
2777 static int rt_fill_info(struct net *net,
2778 struct sk_buff *skb, u32 pid, u32 seq, int event,
2779 int nowait, unsigned int flags)
2780 {
2781 struct rtable *rt = skb_rtable(skb);
2782 struct rtmsg *r;
2783 struct nlmsghdr *nlh;
2784 long expires = 0;
2785 const struct inet_peer *peer = rt->peer;
2786 u32 id = 0, ts = 0, tsage = 0, error;
2787
2788 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2789 if (nlh == NULL)
2790 return -EMSGSIZE;
2791
2792 r = nlmsg_data(nlh);
2793 r->rtm_family = AF_INET;
2794 r->rtm_dst_len = 32;
2795 r->rtm_src_len = 0;
2796 r->rtm_tos = rt->rt_key_tos;
2797 r->rtm_table = RT_TABLE_MAIN;
2798 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2799 r->rtm_type = rt->rt_type;
2800 r->rtm_scope = RT_SCOPE_UNIVERSE;
2801 r->rtm_protocol = RTPROT_UNSPEC;
2802 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2803 if (rt->rt_flags & RTCF_NOTIFY)
2804 r->rtm_flags |= RTM_F_NOTIFY;
2805
2806 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2807
2808 if (rt->rt_key_src) {
2809 r->rtm_src_len = 32;
2810 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2811 }
2812 if (rt->dst.dev)
2813 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2814 #ifdef CONFIG_IP_ROUTE_CLASSID
2815 if (rt->dst.tclassid)
2816 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2817 #endif
2818 if (rt_is_input_route(rt))
2819 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2820 else if (rt->rt_src != rt->rt_key_src)
2821 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2822
2823 if (rt->rt_dst != rt->rt_gateway)
2824 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2825
2826 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2827 goto nla_put_failure;
2828
2829 if (rt->rt_mark)
2830 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2831
2832 error = rt->dst.error;
2833 if (peer) {
2834 inet_peer_refcheck(rt->peer);
2835 id = atomic_read(&peer->ip_id_count) & 0xffff;
2836 if (peer->tcp_ts_stamp) {
2837 ts = peer->tcp_ts;
2838 tsage = get_seconds() - peer->tcp_ts_stamp;
2839 }
2840 expires = ACCESS_ONCE(peer->pmtu_expires);
2841 if (expires)
2842 expires -= jiffies;
2843 }
2844
2845 if (rt_is_input_route(rt)) {
2846 #ifdef CONFIG_IP_MROUTE
2847 __be32 dst = rt->rt_dst;
2848
2849 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2850 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2851 int err = ipmr_get_route(net, skb,
2852 rt->rt_src, rt->rt_dst,
2853 r, nowait);
2854 if (err <= 0) {
2855 if (!nowait) {
2856 if (err == 0)
2857 return 0;
2858 goto nla_put_failure;
2859 } else {
2860 if (err == -EMSGSIZE)
2861 goto nla_put_failure;
2862 error = err;
2863 }
2864 }
2865 } else
2866 #endif
2867 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2868 }
2869
2870 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2871 expires, error) < 0)
2872 goto nla_put_failure;
2873
2874 return nlmsg_end(skb, nlh);
2875
2876 nla_put_failure:
2877 nlmsg_cancel(skb, nlh);
2878 return -EMSGSIZE;
2879 }
2880
2881 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2882 {
2883 struct net *net = sock_net(in_skb->sk);
2884 struct rtmsg *rtm;
2885 struct nlattr *tb[RTA_MAX+1];
2886 struct rtable *rt = NULL;
2887 __be32 dst = 0;
2888 __be32 src = 0;
2889 u32 iif;
2890 int err;
2891 int mark;
2892 struct sk_buff *skb;
2893
2894 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2895 if (err < 0)
2896 goto errout;
2897
2898 rtm = nlmsg_data(nlh);
2899
2900 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2901 if (skb == NULL) {
2902 err = -ENOBUFS;
2903 goto errout;
2904 }
2905
2906 /* Reserve room for dummy headers, this skb can pass
2907 through good chunk of routing engine.
2908 */
2909 skb_reset_mac_header(skb);
2910 skb_reset_network_header(skb);
2911
2912 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2913 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2914 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2915
2916 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2917 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2918 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2919 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2920
2921 if (iif) {
2922 struct net_device *dev;
2923
2924 dev = __dev_get_by_index(net, iif);
2925 if (dev == NULL) {
2926 err = -ENODEV;
2927 goto errout_free;
2928 }
2929
2930 skb->protocol = htons(ETH_P_IP);
2931 skb->dev = dev;
2932 skb->mark = mark;
2933 local_bh_disable();
2934 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2935 local_bh_enable();
2936
2937 rt = skb_rtable(skb);
2938 if (err == 0 && rt->dst.error)
2939 err = -rt->dst.error;
2940 } else {
2941 struct flowi4 fl4 = {
2942 .daddr = dst,
2943 .saddr = src,
2944 .flowi4_tos = rtm->rtm_tos,
2945 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2946 .flowi4_mark = mark,
2947 };
2948 rt = ip_route_output_key(net, &fl4);
2949
2950 err = 0;
2951 if (IS_ERR(rt))
2952 err = PTR_ERR(rt);
2953 }
2954
2955 if (err)
2956 goto errout_free;
2957
2958 skb_dst_set(skb, &rt->dst);
2959 if (rtm->rtm_flags & RTM_F_NOTIFY)
2960 rt->rt_flags |= RTCF_NOTIFY;
2961
2962 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2963 RTM_NEWROUTE, 0, 0);
2964 if (err <= 0)
2965 goto errout_free;
2966
2967 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2968 errout:
2969 return err;
2970
2971 errout_free:
2972 kfree_skb(skb);
2973 goto errout;
2974 }
2975
2976 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2977 {
2978 struct rtable *rt;
2979 int h, s_h;
2980 int idx, s_idx;
2981 struct net *net;
2982
2983 net = sock_net(skb->sk);
2984
2985 s_h = cb->args[0];
2986 if (s_h < 0)
2987 s_h = 0;
2988 s_idx = idx = cb->args[1];
2989 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2990 if (!rt_hash_table[h].chain)
2991 continue;
2992 rcu_read_lock_bh();
2993 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2994 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2995 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2996 continue;
2997 if (rt_is_expired(rt))
2998 continue;
2999 skb_dst_set_noref(skb, &rt->dst);
3000 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3001 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3002 1, NLM_F_MULTI) <= 0) {
3003 skb_dst_drop(skb);
3004 rcu_read_unlock_bh();
3005 goto done;
3006 }
3007 skb_dst_drop(skb);
3008 }
3009 rcu_read_unlock_bh();
3010 }
3011
3012 done:
3013 cb->args[0] = h;
3014 cb->args[1] = idx;
3015 return skb->len;
3016 }
3017
3018 void ip_rt_multicast_event(struct in_device *in_dev)
3019 {
3020 rt_cache_flush(dev_net(in_dev->dev), 0);
3021 }
3022
3023 #ifdef CONFIG_SYSCTL
3024 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3025 void __user *buffer,
3026 size_t *lenp, loff_t *ppos)
3027 {
3028 if (write) {
3029 int flush_delay;
3030 ctl_table ctl;
3031 struct net *net;
3032
3033 memcpy(&ctl, __ctl, sizeof(ctl));
3034 ctl.data = &flush_delay;
3035 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3036
3037 net = (struct net *)__ctl->extra1;
3038 rt_cache_flush(net, flush_delay);
3039 return 0;
3040 }
3041
3042 return -EINVAL;
3043 }
3044
3045 static ctl_table ipv4_route_table[] = {
3046 {
3047 .procname = "gc_thresh",
3048 .data = &ipv4_dst_ops.gc_thresh,
3049 .maxlen = sizeof(int),
3050 .mode = 0644,
3051 .proc_handler = proc_dointvec,
3052 },
3053 {
3054 .procname = "max_size",
3055 .data = &ip_rt_max_size,
3056 .maxlen = sizeof(int),
3057 .mode = 0644,
3058 .proc_handler = proc_dointvec,
3059 },
3060 {
3061 /* Deprecated. Use gc_min_interval_ms */
3062
3063 .procname = "gc_min_interval",
3064 .data = &ip_rt_gc_min_interval,
3065 .maxlen = sizeof(int),
3066 .mode = 0644,
3067 .proc_handler = proc_dointvec_jiffies,
3068 },
3069 {
3070 .procname = "gc_min_interval_ms",
3071 .data = &ip_rt_gc_min_interval,
3072 .maxlen = sizeof(int),
3073 .mode = 0644,
3074 .proc_handler = proc_dointvec_ms_jiffies,
3075 },
3076 {
3077 .procname = "gc_timeout",
3078 .data = &ip_rt_gc_timeout,
3079 .maxlen = sizeof(int),
3080 .mode = 0644,
3081 .proc_handler = proc_dointvec_jiffies,
3082 },
3083 {
3084 .procname = "gc_interval",
3085 .data = &ip_rt_gc_interval,
3086 .maxlen = sizeof(int),
3087 .mode = 0644,
3088 .proc_handler = proc_dointvec_jiffies,
3089 },
3090 {
3091 .procname = "redirect_load",
3092 .data = &ip_rt_redirect_load,
3093 .maxlen = sizeof(int),
3094 .mode = 0644,
3095 .proc_handler = proc_dointvec,
3096 },
3097 {
3098 .procname = "redirect_number",
3099 .data = &ip_rt_redirect_number,
3100 .maxlen = sizeof(int),
3101 .mode = 0644,
3102 .proc_handler = proc_dointvec,
3103 },
3104 {
3105 .procname = "redirect_silence",
3106 .data = &ip_rt_redirect_silence,
3107 .maxlen = sizeof(int),
3108 .mode = 0644,
3109 .proc_handler = proc_dointvec,
3110 },
3111 {
3112 .procname = "error_cost",
3113 .data = &ip_rt_error_cost,
3114 .maxlen = sizeof(int),
3115 .mode = 0644,
3116 .proc_handler = proc_dointvec,
3117 },
3118 {
3119 .procname = "error_burst",
3120 .data = &ip_rt_error_burst,
3121 .maxlen = sizeof(int),
3122 .mode = 0644,
3123 .proc_handler = proc_dointvec,
3124 },
3125 {
3126 .procname = "gc_elasticity",
3127 .data = &ip_rt_gc_elasticity,
3128 .maxlen = sizeof(int),
3129 .mode = 0644,
3130 .proc_handler = proc_dointvec,
3131 },
3132 {
3133 .procname = "mtu_expires",
3134 .data = &ip_rt_mtu_expires,
3135 .maxlen = sizeof(int),
3136 .mode = 0644,
3137 .proc_handler = proc_dointvec_jiffies,
3138 },
3139 {
3140 .procname = "min_pmtu",
3141 .data = &ip_rt_min_pmtu,
3142 .maxlen = sizeof(int),
3143 .mode = 0644,
3144 .proc_handler = proc_dointvec,
3145 },
3146 {
3147 .procname = "min_adv_mss",
3148 .data = &ip_rt_min_advmss,
3149 .maxlen = sizeof(int),
3150 .mode = 0644,
3151 .proc_handler = proc_dointvec,
3152 },
3153 { }
3154 };
3155
3156 static struct ctl_table empty[1];
3157
3158 static struct ctl_table ipv4_skeleton[] =
3159 {
3160 { .procname = "route",
3161 .mode = 0555, .child = ipv4_route_table},
3162 { .procname = "neigh",
3163 .mode = 0555, .child = empty},
3164 { }
3165 };
3166
3167 static __net_initdata struct ctl_path ipv4_path[] = {
3168 { .procname = "net", },
3169 { .procname = "ipv4", },
3170 { },
3171 };
3172
3173 static struct ctl_table ipv4_route_flush_table[] = {
3174 {
3175 .procname = "flush",
3176 .maxlen = sizeof(int),
3177 .mode = 0200,
3178 .proc_handler = ipv4_sysctl_rtcache_flush,
3179 },
3180 { },
3181 };
3182
3183 static __net_initdata struct ctl_path ipv4_route_path[] = {
3184 { .procname = "net", },
3185 { .procname = "ipv4", },
3186 { .procname = "route", },
3187 { },
3188 };
3189
3190 static __net_init int sysctl_route_net_init(struct net *net)
3191 {
3192 struct ctl_table *tbl;
3193
3194 tbl = ipv4_route_flush_table;
3195 if (!net_eq(net, &init_net)) {
3196 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3197 if (tbl == NULL)
3198 goto err_dup;
3199 }
3200 tbl[0].extra1 = net;
3201
3202 net->ipv4.route_hdr =
3203 register_net_sysctl_table(net, ipv4_route_path, tbl);
3204 if (net->ipv4.route_hdr == NULL)
3205 goto err_reg;
3206 return 0;
3207
3208 err_reg:
3209 if (tbl != ipv4_route_flush_table)
3210 kfree(tbl);
3211 err_dup:
3212 return -ENOMEM;
3213 }
3214
3215 static __net_exit void sysctl_route_net_exit(struct net *net)
3216 {
3217 struct ctl_table *tbl;
3218
3219 tbl = net->ipv4.route_hdr->ctl_table_arg;
3220 unregister_net_sysctl_table(net->ipv4.route_hdr);
3221 BUG_ON(tbl == ipv4_route_flush_table);
3222 kfree(tbl);
3223 }
3224
3225 static __net_initdata struct pernet_operations sysctl_route_ops = {
3226 .init = sysctl_route_net_init,
3227 .exit = sysctl_route_net_exit,
3228 };
3229 #endif
3230
3231 static __net_init int rt_genid_init(struct net *net)
3232 {
3233 get_random_bytes(&net->ipv4.rt_genid,
3234 sizeof(net->ipv4.rt_genid));
3235 get_random_bytes(&net->ipv4.dev_addr_genid,
3236 sizeof(net->ipv4.dev_addr_genid));
3237 return 0;
3238 }
3239
3240 static __net_initdata struct pernet_operations rt_genid_ops = {
3241 .init = rt_genid_init,
3242 };
3243
3244
3245 #ifdef CONFIG_IP_ROUTE_CLASSID
3246 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3247 #endif /* CONFIG_IP_ROUTE_CLASSID */
3248
3249 static __initdata unsigned long rhash_entries;
3250 static int __init set_rhash_entries(char *str)
3251 {
3252 if (!str)
3253 return 0;
3254 rhash_entries = simple_strtoul(str, &str, 0);
3255 return 1;
3256 }
3257 __setup("rhash_entries=", set_rhash_entries);
3258
3259 int __init ip_rt_init(void)
3260 {
3261 int rc = 0;
3262
3263 #ifdef CONFIG_IP_ROUTE_CLASSID
3264 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3265 if (!ip_rt_acct)
3266 panic("IP: failed to allocate ip_rt_acct\n");
3267 #endif
3268
3269 ipv4_dst_ops.kmem_cachep =
3270 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3271 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3272
3273 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3274
3275 if (dst_entries_init(&ipv4_dst_ops) < 0)
3276 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3277
3278 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3279 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3280
3281 rt_hash_table = (struct rt_hash_bucket *)
3282 alloc_large_system_hash("IP route cache",
3283 sizeof(struct rt_hash_bucket),
3284 rhash_entries,
3285 (totalram_pages >= 128 * 1024) ?
3286 15 : 17,
3287 0,
3288 &rt_hash_log,
3289 &rt_hash_mask,
3290 rhash_entries ? 0 : 512 * 1024);
3291 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3292 rt_hash_lock_init();
3293
3294 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3295 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3296
3297 devinet_init();
3298 ip_fib_init();
3299
3300 if (ip_rt_proc_init())
3301 printk(KERN_ERR "Unable to create route proc files\n");
3302 #ifdef CONFIG_XFRM
3303 xfrm_init();
3304 xfrm4_init(ip_rt_max_size);
3305 #endif
3306 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3307
3308 #ifdef CONFIG_SYSCTL
3309 register_pernet_subsys(&sysctl_route_ops);
3310 #endif
3311 register_pernet_subsys(&rt_genid_ops);
3312 return rc;
3313 }
3314
3315 #ifdef CONFIG_SYSCTL
3316 /*
3317 * We really need to sanitize the damn ipv4 init order, then all
3318 * this nonsense will go away.
3319 */
3320 void __init ip_static_sysctl_init(void)
3321 {
3322 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3323 }
3324 #endif
x86 "subsystem" repository