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ipv4: Remove now superfluous code in ip_route_connect().
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blob93f71be1d5d1ec33c21bfc7018477ee16068d264
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, 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_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_tos ^ rt2->rt_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * 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 #if RT_CACHE_DEBUG >= 2
972 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
973 dst_entries_get_fast(&ipv4_dst_ops), goal, i);
974 #endif
975
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
977 goto out;
978 } while (!in_softirq() && time_before_eq(jiffies, now));
979
980 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
981 goto out;
982 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
983 goto out;
984 if (net_ratelimit())
985 printk(KERN_WARNING "dst cache overflow\n");
986 RT_CACHE_STAT_INC(gc_dst_overflow);
987 return 1;
988
989 work_done:
990 expire += ip_rt_gc_min_interval;
991 if (expire > ip_rt_gc_timeout ||
992 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
993 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
994 expire = ip_rt_gc_timeout;
995 #if RT_CACHE_DEBUG >= 2
996 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
997 dst_entries_get_fast(&ipv4_dst_ops), goal, rover);
998 #endif
999 out: return 0;
1000 }
1001
1002 /*
1003 * Returns number of entries in a hash chain that have different hash_inputs
1004 */
1005 static int slow_chain_length(const struct rtable *head)
1006 {
1007 int length = 0;
1008 const struct rtable *rth = head;
1009
1010 while (rth) {
1011 length += has_noalias(head, rth);
1012 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1013 }
1014 return length >> FRACT_BITS;
1015 }
1016
1017 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1018 struct sk_buff *skb, int ifindex)
1019 {
1020 struct rtable *rth, *cand;
1021 struct rtable __rcu **rthp, **candp;
1022 unsigned long now;
1023 u32 min_score;
1024 int chain_length;
1025 int attempts = !in_softirq();
1026
1027 restart:
1028 chain_length = 0;
1029 min_score = ~(u32)0;
1030 cand = NULL;
1031 candp = NULL;
1032 now = jiffies;
1033
1034 if (!rt_caching(dev_net(rt->dst.dev))) {
1035 /*
1036 * If we're not caching, just tell the caller we
1037 * were successful and don't touch the route. The
1038 * caller hold the sole reference to the cache entry, and
1039 * it will be released when the caller is done with it.
1040 * If we drop it here, the callers have no way to resolve routes
1041 * when we're not caching. Instead, just point *rp at rt, so
1042 * the caller gets a single use out of the route
1043 * Note that we do rt_free on this new route entry, so that
1044 * once its refcount hits zero, we are still able to reap it
1045 * (Thanks Alexey)
1046 * Note: To avoid expensive rcu stuff for this uncached dst,
1047 * we set DST_NOCACHE so that dst_release() can free dst without
1048 * waiting a grace period.
1049 */
1050
1051 rt->dst.flags |= DST_NOCACHE;
1052 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1053 int err = arp_bind_neighbour(&rt->dst);
1054 if (err) {
1055 if (net_ratelimit())
1056 printk(KERN_WARNING
1057 "Neighbour table failure & not caching routes.\n");
1058 ip_rt_put(rt);
1059 return ERR_PTR(err);
1060 }
1061 }
1062
1063 goto skip_hashing;
1064 }
1065
1066 rthp = &rt_hash_table[hash].chain;
1067
1068 spin_lock_bh(rt_hash_lock_addr(hash));
1069 while ((rth = rcu_dereference_protected(*rthp,
1070 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1071 if (rt_is_expired(rth)) {
1072 *rthp = rth->dst.rt_next;
1073 rt_free(rth);
1074 continue;
1075 }
1076 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1077 /* Put it first */
1078 *rthp = rth->dst.rt_next;
1079 /*
1080 * Since lookup is lockfree, the deletion
1081 * must be visible to another weakly ordered CPU before
1082 * the insertion at the start of the hash chain.
1083 */
1084 rcu_assign_pointer(rth->dst.rt_next,
1085 rt_hash_table[hash].chain);
1086 /*
1087 * Since lookup is lockfree, the update writes
1088 * must be ordered for consistency on SMP.
1089 */
1090 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1091
1092 dst_use(&rth->dst, now);
1093 spin_unlock_bh(rt_hash_lock_addr(hash));
1094
1095 rt_drop(rt);
1096 if (skb)
1097 skb_dst_set(skb, &rth->dst);
1098 return rth;
1099 }
1100
1101 if (!atomic_read(&rth->dst.__refcnt)) {
1102 u32 score = rt_score(rth);
1103
1104 if (score <= min_score) {
1105 cand = rth;
1106 candp = rthp;
1107 min_score = score;
1108 }
1109 }
1110
1111 chain_length++;
1112
1113 rthp = &rth->dst.rt_next;
1114 }
1115
1116 if (cand) {
1117 /* ip_rt_gc_elasticity used to be average length of chain
1118 * length, when exceeded gc becomes really aggressive.
1119 *
1120 * The second limit is less certain. At the moment it allows
1121 * only 2 entries per bucket. We will see.
1122 */
1123 if (chain_length > ip_rt_gc_elasticity) {
1124 *candp = cand->dst.rt_next;
1125 rt_free(cand);
1126 }
1127 } else {
1128 if (chain_length > rt_chain_length_max &&
1129 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1130 struct net *net = dev_net(rt->dst.dev);
1131 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1132 if (!rt_caching(net)) {
1133 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1134 rt->dst.dev->name, num);
1135 }
1136 rt_emergency_hash_rebuild(net);
1137 spin_unlock_bh(rt_hash_lock_addr(hash));
1138
1139 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1140 ifindex, rt_genid(net));
1141 goto restart;
1142 }
1143 }
1144
1145 /* Try to bind route to arp only if it is output
1146 route or unicast forwarding path.
1147 */
1148 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1149 int err = arp_bind_neighbour(&rt->dst);
1150 if (err) {
1151 spin_unlock_bh(rt_hash_lock_addr(hash));
1152
1153 if (err != -ENOBUFS) {
1154 rt_drop(rt);
1155 return ERR_PTR(err);
1156 }
1157
1158 /* Neighbour tables are full and nothing
1159 can be released. Try to shrink route cache,
1160 it is most likely it holds some neighbour records.
1161 */
1162 if (attempts-- > 0) {
1163 int saved_elasticity = ip_rt_gc_elasticity;
1164 int saved_int = ip_rt_gc_min_interval;
1165 ip_rt_gc_elasticity = 1;
1166 ip_rt_gc_min_interval = 0;
1167 rt_garbage_collect(&ipv4_dst_ops);
1168 ip_rt_gc_min_interval = saved_int;
1169 ip_rt_gc_elasticity = saved_elasticity;
1170 goto restart;
1171 }
1172
1173 if (net_ratelimit())
1174 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1175 rt_drop(rt);
1176 return ERR_PTR(-ENOBUFS);
1177 }
1178 }
1179
1180 rt->dst.rt_next = rt_hash_table[hash].chain;
1181
1182 #if RT_CACHE_DEBUG >= 2
1183 if (rt->dst.rt_next) {
1184 struct rtable *trt;
1185 printk(KERN_DEBUG "rt_cache @%02x: %pI4",
1186 hash, &rt->rt_dst);
1187 for (trt = rt->dst.rt_next; trt; trt = trt->dst.rt_next)
1188 printk(" . %pI4", &trt->rt_dst);
1189 printk("\n");
1190 }
1191 #endif
1192 /*
1193 * Since lookup is lockfree, we must make sure
1194 * previous writes to rt are committed to memory
1195 * before making rt visible to other CPUS.
1196 */
1197 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1198
1199 spin_unlock_bh(rt_hash_lock_addr(hash));
1200
1201 skip_hashing:
1202 if (skb)
1203 skb_dst_set(skb, &rt->dst);
1204 return rt;
1205 }
1206
1207 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1208
1209 static u32 rt_peer_genid(void)
1210 {
1211 return atomic_read(&__rt_peer_genid);
1212 }
1213
1214 void rt_bind_peer(struct rtable *rt, int create)
1215 {
1216 struct inet_peer *peer;
1217
1218 peer = inet_getpeer_v4(rt->rt_dst, create);
1219
1220 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1221 inet_putpeer(peer);
1222 else
1223 rt->rt_peer_genid = rt_peer_genid();
1224 }
1225
1226 /*
1227 * Peer allocation may fail only in serious out-of-memory conditions. However
1228 * we still can generate some output.
1229 * Random ID selection looks a bit dangerous because we have no chances to
1230 * select ID being unique in a reasonable period of time.
1231 * But broken packet identifier may be better than no packet at all.
1232 */
1233 static void ip_select_fb_ident(struct iphdr *iph)
1234 {
1235 static DEFINE_SPINLOCK(ip_fb_id_lock);
1236 static u32 ip_fallback_id;
1237 u32 salt;
1238
1239 spin_lock_bh(&ip_fb_id_lock);
1240 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1241 iph->id = htons(salt & 0xFFFF);
1242 ip_fallback_id = salt;
1243 spin_unlock_bh(&ip_fb_id_lock);
1244 }
1245
1246 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1247 {
1248 struct rtable *rt = (struct rtable *) dst;
1249
1250 if (rt) {
1251 if (rt->peer == NULL)
1252 rt_bind_peer(rt, 1);
1253
1254 /* If peer is attached to destination, it is never detached,
1255 so that we need not to grab a lock to dereference it.
1256 */
1257 if (rt->peer) {
1258 iph->id = htons(inet_getid(rt->peer, more));
1259 return;
1260 }
1261 } else
1262 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1263 __builtin_return_address(0));
1264
1265 ip_select_fb_ident(iph);
1266 }
1267 EXPORT_SYMBOL(__ip_select_ident);
1268
1269 static void rt_del(unsigned hash, struct rtable *rt)
1270 {
1271 struct rtable __rcu **rthp;
1272 struct rtable *aux;
1273
1274 rthp = &rt_hash_table[hash].chain;
1275 spin_lock_bh(rt_hash_lock_addr(hash));
1276 ip_rt_put(rt);
1277 while ((aux = rcu_dereference_protected(*rthp,
1278 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1279 if (aux == rt || rt_is_expired(aux)) {
1280 *rthp = aux->dst.rt_next;
1281 rt_free(aux);
1282 continue;
1283 }
1284 rthp = &aux->dst.rt_next;
1285 }
1286 spin_unlock_bh(rt_hash_lock_addr(hash));
1287 }
1288
1289 /* called in rcu_read_lock() section */
1290 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1291 __be32 saddr, struct net_device *dev)
1292 {
1293 struct in_device *in_dev = __in_dev_get_rcu(dev);
1294 struct inet_peer *peer;
1295 struct net *net;
1296
1297 if (!in_dev)
1298 return;
1299
1300 net = dev_net(dev);
1301 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1302 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1303 ipv4_is_zeronet(new_gw))
1304 goto reject_redirect;
1305
1306 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1307 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1308 goto reject_redirect;
1309 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1310 goto reject_redirect;
1311 } else {
1312 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1313 goto reject_redirect;
1314 }
1315
1316 peer = inet_getpeer_v4(daddr, 1);
1317 if (peer) {
1318 peer->redirect_learned.a4 = new_gw;
1319
1320 inet_putpeer(peer);
1321
1322 atomic_inc(&__rt_peer_genid);
1323 }
1324 return;
1325
1326 reject_redirect:
1327 #ifdef CONFIG_IP_ROUTE_VERBOSE
1328 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1329 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1330 " Advised path = %pI4 -> %pI4\n",
1331 &old_gw, dev->name, &new_gw,
1332 &saddr, &daddr);
1333 #endif
1334 ;
1335 }
1336
1337 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1338 {
1339 struct rtable *rt = (struct rtable *)dst;
1340 struct dst_entry *ret = dst;
1341
1342 if (rt) {
1343 if (dst->obsolete > 0) {
1344 ip_rt_put(rt);
1345 ret = NULL;
1346 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1347 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1348 rt->rt_oif,
1349 rt_genid(dev_net(dst->dev)));
1350 #if RT_CACHE_DEBUG >= 1
1351 printk(KERN_DEBUG "ipv4_negative_advice: redirect to %pI4/%02x dropped\n",
1352 &rt->rt_dst, rt->rt_tos);
1353 #endif
1354 rt_del(hash, rt);
1355 ret = NULL;
1356 } else if (rt->peer &&
1357 rt->peer->pmtu_expires &&
1358 time_after_eq(jiffies, rt->peer->pmtu_expires)) {
1359 unsigned long orig = rt->peer->pmtu_expires;
1360
1361 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1362 dst_metric_set(dst, RTAX_MTU,
1363 rt->peer->pmtu_orig);
1364 }
1365 }
1366 return ret;
1367 }
1368
1369 /*
1370 * Algorithm:
1371 * 1. The first ip_rt_redirect_number redirects are sent
1372 * with exponential backoff, then we stop sending them at all,
1373 * assuming that the host ignores our redirects.
1374 * 2. If we did not see packets requiring redirects
1375 * during ip_rt_redirect_silence, we assume that the host
1376 * forgot redirected route and start to send redirects again.
1377 *
1378 * This algorithm is much cheaper and more intelligent than dumb load limiting
1379 * in icmp.c.
1380 *
1381 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1382 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1383 */
1384
1385 void ip_rt_send_redirect(struct sk_buff *skb)
1386 {
1387 struct rtable *rt = skb_rtable(skb);
1388 struct in_device *in_dev;
1389 struct inet_peer *peer;
1390 int log_martians;
1391
1392 rcu_read_lock();
1393 in_dev = __in_dev_get_rcu(rt->dst.dev);
1394 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1395 rcu_read_unlock();
1396 return;
1397 }
1398 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1399 rcu_read_unlock();
1400
1401 if (!rt->peer)
1402 rt_bind_peer(rt, 1);
1403 peer = rt->peer;
1404 if (!peer) {
1405 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1406 return;
1407 }
1408
1409 /* No redirected packets during ip_rt_redirect_silence;
1410 * reset the algorithm.
1411 */
1412 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1413 peer->rate_tokens = 0;
1414
1415 /* Too many ignored redirects; do not send anything
1416 * set dst.rate_last to the last seen redirected packet.
1417 */
1418 if (peer->rate_tokens >= ip_rt_redirect_number) {
1419 peer->rate_last = jiffies;
1420 return;
1421 }
1422
1423 /* Check for load limit; set rate_last to the latest sent
1424 * redirect.
1425 */
1426 if (peer->rate_tokens == 0 ||
1427 time_after(jiffies,
1428 (peer->rate_last +
1429 (ip_rt_redirect_load << peer->rate_tokens)))) {
1430 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1431 peer->rate_last = jiffies;
1432 ++peer->rate_tokens;
1433 #ifdef CONFIG_IP_ROUTE_VERBOSE
1434 if (log_martians &&
1435 peer->rate_tokens == ip_rt_redirect_number &&
1436 net_ratelimit())
1437 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1438 &rt->rt_src, rt->rt_iif,
1439 &rt->rt_dst, &rt->rt_gateway);
1440 #endif
1441 }
1442 }
1443
1444 static int ip_error(struct sk_buff *skb)
1445 {
1446 struct rtable *rt = skb_rtable(skb);
1447 struct inet_peer *peer;
1448 unsigned long now;
1449 bool send;
1450 int code;
1451
1452 switch (rt->dst.error) {
1453 case EINVAL:
1454 default:
1455 goto out;
1456 case EHOSTUNREACH:
1457 code = ICMP_HOST_UNREACH;
1458 break;
1459 case ENETUNREACH:
1460 code = ICMP_NET_UNREACH;
1461 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1462 IPSTATS_MIB_INNOROUTES);
1463 break;
1464 case EACCES:
1465 code = ICMP_PKT_FILTERED;
1466 break;
1467 }
1468
1469 if (!rt->peer)
1470 rt_bind_peer(rt, 1);
1471 peer = rt->peer;
1472
1473 send = true;
1474 if (peer) {
1475 now = jiffies;
1476 peer->rate_tokens += now - peer->rate_last;
1477 if (peer->rate_tokens > ip_rt_error_burst)
1478 peer->rate_tokens = ip_rt_error_burst;
1479 peer->rate_last = now;
1480 if (peer->rate_tokens >= ip_rt_error_cost)
1481 peer->rate_tokens -= ip_rt_error_cost;
1482 else
1483 send = false;
1484 }
1485 if (send)
1486 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1487
1488 out: kfree_skb(skb);
1489 return 0;
1490 }
1491
1492 /*
1493 * The last two values are not from the RFC but
1494 * are needed for AMPRnet AX.25 paths.
1495 */
1496
1497 static const unsigned short mtu_plateau[] =
1498 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1499
1500 static inline unsigned short guess_mtu(unsigned short old_mtu)
1501 {
1502 int i;
1503
1504 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1505 if (old_mtu > mtu_plateau[i])
1506 return mtu_plateau[i];
1507 return 68;
1508 }
1509
1510 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1511 unsigned short new_mtu,
1512 struct net_device *dev)
1513 {
1514 unsigned short old_mtu = ntohs(iph->tot_len);
1515 unsigned short est_mtu = 0;
1516 struct inet_peer *peer;
1517
1518 peer = inet_getpeer_v4(iph->daddr, 1);
1519 if (peer) {
1520 unsigned short mtu = new_mtu;
1521
1522 if (new_mtu < 68 || new_mtu >= old_mtu) {
1523 /* BSD 4.2 derived systems incorrectly adjust
1524 * tot_len by the IP header length, and report
1525 * a zero MTU in the ICMP message.
1526 */
1527 if (mtu == 0 &&
1528 old_mtu >= 68 + (iph->ihl << 2))
1529 old_mtu -= iph->ihl << 2;
1530 mtu = guess_mtu(old_mtu);
1531 }
1532
1533 if (mtu < ip_rt_min_pmtu)
1534 mtu = ip_rt_min_pmtu;
1535 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1536 unsigned long pmtu_expires;
1537
1538 pmtu_expires = jiffies + ip_rt_mtu_expires;
1539 if (!pmtu_expires)
1540 pmtu_expires = 1UL;
1541
1542 est_mtu = mtu;
1543 peer->pmtu_learned = mtu;
1544 peer->pmtu_expires = pmtu_expires;
1545 }
1546
1547 inet_putpeer(peer);
1548
1549 atomic_inc(&__rt_peer_genid);
1550 }
1551 return est_mtu ? : new_mtu;
1552 }
1553
1554 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1555 {
1556 unsigned long expires = peer->pmtu_expires;
1557
1558 if (time_before(jiffies, expires)) {
1559 u32 orig_dst_mtu = dst_mtu(dst);
1560 if (peer->pmtu_learned < orig_dst_mtu) {
1561 if (!peer->pmtu_orig)
1562 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1563 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1564 }
1565 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1566 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1567 }
1568
1569 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1570 {
1571 struct rtable *rt = (struct rtable *) dst;
1572 struct inet_peer *peer;
1573
1574 dst_confirm(dst);
1575
1576 if (!rt->peer)
1577 rt_bind_peer(rt, 1);
1578 peer = rt->peer;
1579 if (peer) {
1580 if (mtu < ip_rt_min_pmtu)
1581 mtu = ip_rt_min_pmtu;
1582 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1583 unsigned long pmtu_expires;
1584
1585 pmtu_expires = jiffies + ip_rt_mtu_expires;
1586 if (!pmtu_expires)
1587 pmtu_expires = 1UL;
1588
1589 peer->pmtu_learned = mtu;
1590 peer->pmtu_expires = pmtu_expires;
1591
1592 atomic_inc(&__rt_peer_genid);
1593 rt->rt_peer_genid = rt_peer_genid();
1594 }
1595 check_peer_pmtu(dst, peer);
1596 }
1597 }
1598
1599 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1600 {
1601 struct rtable *rt = (struct rtable *) dst;
1602 __be32 orig_gw = rt->rt_gateway;
1603
1604 dst_confirm(&rt->dst);
1605
1606 neigh_release(rt->dst.neighbour);
1607 rt->dst.neighbour = NULL;
1608
1609 rt->rt_gateway = peer->redirect_learned.a4;
1610 if (arp_bind_neighbour(&rt->dst) ||
1611 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1612 if (rt->dst.neighbour)
1613 neigh_event_send(rt->dst.neighbour, NULL);
1614 rt->rt_gateway = orig_gw;
1615 return -EAGAIN;
1616 } else {
1617 rt->rt_flags |= RTCF_REDIRECTED;
1618 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1619 rt->dst.neighbour);
1620 }
1621 return 0;
1622 }
1623
1624 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1625 {
1626 struct rtable *rt = (struct rtable *) dst;
1627
1628 if (rt_is_expired(rt))
1629 return NULL;
1630 if (rt->rt_peer_genid != rt_peer_genid()) {
1631 struct inet_peer *peer;
1632
1633 if (!rt->peer)
1634 rt_bind_peer(rt, 0);
1635
1636 peer = rt->peer;
1637 if (peer && peer->pmtu_expires)
1638 check_peer_pmtu(dst, peer);
1639
1640 if (peer && peer->redirect_learned.a4 &&
1641 peer->redirect_learned.a4 != rt->rt_gateway) {
1642 if (check_peer_redir(dst, peer))
1643 return NULL;
1644 }
1645
1646 rt->rt_peer_genid = rt_peer_genid();
1647 }
1648 return dst;
1649 }
1650
1651 static void ipv4_dst_destroy(struct dst_entry *dst)
1652 {
1653 struct rtable *rt = (struct rtable *) dst;
1654 struct inet_peer *peer = rt->peer;
1655
1656 if (rt->fi) {
1657 fib_info_put(rt->fi);
1658 rt->fi = NULL;
1659 }
1660 if (peer) {
1661 rt->peer = NULL;
1662 inet_putpeer(peer);
1663 }
1664 }
1665
1666
1667 static void ipv4_link_failure(struct sk_buff *skb)
1668 {
1669 struct rtable *rt;
1670
1671 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1672
1673 rt = skb_rtable(skb);
1674 if (rt &&
1675 rt->peer &&
1676 rt->peer->pmtu_expires) {
1677 unsigned long orig = rt->peer->pmtu_expires;
1678
1679 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1680 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1681 }
1682 }
1683
1684 static int ip_rt_bug(struct sk_buff *skb)
1685 {
1686 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1687 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1688 skb->dev ? skb->dev->name : "?");
1689 kfree_skb(skb);
1690 return 0;
1691 }
1692
1693 /*
1694 We do not cache source address of outgoing interface,
1695 because it is used only by IP RR, TS and SRR options,
1696 so that it out of fast path.
1697
1698 BTW remember: "addr" is allowed to be not aligned
1699 in IP options!
1700 */
1701
1702 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1703 {
1704 __be32 src;
1705 struct fib_result res;
1706
1707 if (rt_is_output_route(rt))
1708 src = rt->rt_src;
1709 else {
1710 struct flowi4 fl4 = {
1711 .daddr = rt->rt_key_dst,
1712 .saddr = rt->rt_key_src,
1713 .flowi4_tos = rt->rt_tos,
1714 .flowi4_oif = rt->rt_oif,
1715 .flowi4_iif = rt->rt_iif,
1716 .flowi4_mark = rt->rt_mark,
1717 };
1718
1719 rcu_read_lock();
1720 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1721 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1722 else
1723 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1724 RT_SCOPE_UNIVERSE);
1725 rcu_read_unlock();
1726 }
1727 memcpy(addr, &src, 4);
1728 }
1729
1730 #ifdef CONFIG_IP_ROUTE_CLASSID
1731 static void set_class_tag(struct rtable *rt, u32 tag)
1732 {
1733 if (!(rt->dst.tclassid & 0xFFFF))
1734 rt->dst.tclassid |= tag & 0xFFFF;
1735 if (!(rt->dst.tclassid & 0xFFFF0000))
1736 rt->dst.tclassid |= tag & 0xFFFF0000;
1737 }
1738 #endif
1739
1740 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1741 {
1742 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1743
1744 if (advmss == 0) {
1745 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1746 ip_rt_min_advmss);
1747 if (advmss > 65535 - 40)
1748 advmss = 65535 - 40;
1749 }
1750 return advmss;
1751 }
1752
1753 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1754 {
1755 unsigned int mtu = dst->dev->mtu;
1756
1757 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1758 const struct rtable *rt = (const struct rtable *) dst;
1759
1760 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1761 mtu = 576;
1762 }
1763
1764 if (mtu > IP_MAX_MTU)
1765 mtu = IP_MAX_MTU;
1766
1767 return mtu;
1768 }
1769
1770 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1771 struct fib_info *fi)
1772 {
1773 struct inet_peer *peer;
1774 int create = 0;
1775
1776 /* If a peer entry exists for this destination, we must hook
1777 * it up in order to get at cached metrics.
1778 */
1779 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1780 create = 1;
1781
1782 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1783 if (peer) {
1784 rt->rt_peer_genid = rt_peer_genid();
1785 if (inet_metrics_new(peer))
1786 memcpy(peer->metrics, fi->fib_metrics,
1787 sizeof(u32) * RTAX_MAX);
1788 dst_init_metrics(&rt->dst, peer->metrics, false);
1789
1790 if (peer->pmtu_expires)
1791 check_peer_pmtu(&rt->dst, peer);
1792 if (peer->redirect_learned.a4 &&
1793 peer->redirect_learned.a4 != rt->rt_gateway) {
1794 rt->rt_gateway = peer->redirect_learned.a4;
1795 rt->rt_flags |= RTCF_REDIRECTED;
1796 }
1797 } else {
1798 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1799 rt->fi = fi;
1800 atomic_inc(&fi->fib_clntref);
1801 }
1802 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1803 }
1804 }
1805
1806 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1807 const struct fib_result *res,
1808 struct fib_info *fi, u16 type, u32 itag)
1809 {
1810 struct dst_entry *dst = &rt->dst;
1811
1812 if (fi) {
1813 if (FIB_RES_GW(*res) &&
1814 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1815 rt->rt_gateway = FIB_RES_GW(*res);
1816 rt_init_metrics(rt, fl4, fi);
1817 #ifdef CONFIG_IP_ROUTE_CLASSID
1818 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1819 #endif
1820 }
1821
1822 if (dst_mtu(dst) > IP_MAX_MTU)
1823 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1824 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1825 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1826
1827 #ifdef CONFIG_IP_ROUTE_CLASSID
1828 #ifdef CONFIG_IP_MULTIPLE_TABLES
1829 set_class_tag(rt, fib_rules_tclass(res));
1830 #endif
1831 set_class_tag(rt, itag);
1832 #endif
1833 }
1834
1835 static struct rtable *rt_dst_alloc(struct net_device *dev,
1836 bool nopolicy, bool noxfrm)
1837 {
1838 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1839 DST_HOST |
1840 (nopolicy ? DST_NOPOLICY : 0) |
1841 (noxfrm ? DST_NOXFRM : 0));
1842 }
1843
1844 /* called in rcu_read_lock() section */
1845 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1846 u8 tos, struct net_device *dev, int our)
1847 {
1848 unsigned int hash;
1849 struct rtable *rth;
1850 __be32 spec_dst;
1851 struct in_device *in_dev = __in_dev_get_rcu(dev);
1852 u32 itag = 0;
1853 int err;
1854
1855 /* Primary sanity checks. */
1856
1857 if (in_dev == NULL)
1858 return -EINVAL;
1859
1860 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1861 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1862 goto e_inval;
1863
1864 if (ipv4_is_zeronet(saddr)) {
1865 if (!ipv4_is_local_multicast(daddr))
1866 goto e_inval;
1867 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1868 } else {
1869 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1870 &itag);
1871 if (err < 0)
1872 goto e_err;
1873 }
1874 rth = rt_dst_alloc(init_net.loopback_dev,
1875 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1876 if (!rth)
1877 goto e_nobufs;
1878
1879 #ifdef CONFIG_IP_ROUTE_CLASSID
1880 rth->dst.tclassid = itag;
1881 #endif
1882 rth->dst.output = ip_rt_bug;
1883
1884 rth->rt_key_dst = daddr;
1885 rth->rt_key_src = saddr;
1886 rth->rt_genid = rt_genid(dev_net(dev));
1887 rth->rt_flags = RTCF_MULTICAST;
1888 rth->rt_type = RTN_MULTICAST;
1889 rth->rt_tos = tos;
1890 rth->rt_dst = daddr;
1891 rth->rt_src = saddr;
1892 rth->rt_route_iif = dev->ifindex;
1893 rth->rt_iif = dev->ifindex;
1894 rth->rt_oif = 0;
1895 rth->rt_mark = skb->mark;
1896 rth->rt_gateway = daddr;
1897 rth->rt_spec_dst= spec_dst;
1898 rth->rt_peer_genid = 0;
1899 rth->peer = NULL;
1900 rth->fi = NULL;
1901 if (our) {
1902 rth->dst.input= ip_local_deliver;
1903 rth->rt_flags |= RTCF_LOCAL;
1904 }
1905
1906 #ifdef CONFIG_IP_MROUTE
1907 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1908 rth->dst.input = ip_mr_input;
1909 #endif
1910 RT_CACHE_STAT_INC(in_slow_mc);
1911
1912 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1913 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1914 err = 0;
1915 if (IS_ERR(rth))
1916 err = PTR_ERR(rth);
1917
1918 e_nobufs:
1919 return -ENOBUFS;
1920 e_inval:
1921 return -EINVAL;
1922 e_err:
1923 return err;
1924 }
1925
1926
1927 static void ip_handle_martian_source(struct net_device *dev,
1928 struct in_device *in_dev,
1929 struct sk_buff *skb,
1930 __be32 daddr,
1931 __be32 saddr)
1932 {
1933 RT_CACHE_STAT_INC(in_martian_src);
1934 #ifdef CONFIG_IP_ROUTE_VERBOSE
1935 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1936 /*
1937 * RFC1812 recommendation, if source is martian,
1938 * the only hint is MAC header.
1939 */
1940 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1941 &daddr, &saddr, dev->name);
1942 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1943 int i;
1944 const unsigned char *p = skb_mac_header(skb);
1945 printk(KERN_WARNING "ll header: ");
1946 for (i = 0; i < dev->hard_header_len; i++, p++) {
1947 printk("%02x", *p);
1948 if (i < (dev->hard_header_len - 1))
1949 printk(":");
1950 }
1951 printk("\n");
1952 }
1953 }
1954 #endif
1955 }
1956
1957 /* called in rcu_read_lock() section */
1958 static int __mkroute_input(struct sk_buff *skb,
1959 const struct fib_result *res,
1960 struct in_device *in_dev,
1961 __be32 daddr, __be32 saddr, u32 tos,
1962 struct rtable **result)
1963 {
1964 struct rtable *rth;
1965 int err;
1966 struct in_device *out_dev;
1967 unsigned int flags = 0;
1968 __be32 spec_dst;
1969 u32 itag;
1970
1971 /* get a working reference to the output device */
1972 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1973 if (out_dev == NULL) {
1974 if (net_ratelimit())
1975 printk(KERN_CRIT "Bug in ip_route_input" \
1976 "_slow(). Please, report\n");
1977 return -EINVAL;
1978 }
1979
1980
1981 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1982 in_dev->dev, &spec_dst, &itag);
1983 if (err < 0) {
1984 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1985 saddr);
1986
1987 goto cleanup;
1988 }
1989
1990 if (err)
1991 flags |= RTCF_DIRECTSRC;
1992
1993 if (out_dev == in_dev && err &&
1994 (IN_DEV_SHARED_MEDIA(out_dev) ||
1995 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1996 flags |= RTCF_DOREDIRECT;
1997
1998 if (skb->protocol != htons(ETH_P_IP)) {
1999 /* Not IP (i.e. ARP). Do not create route, if it is
2000 * invalid for proxy arp. DNAT routes are always valid.
2001 *
2002 * Proxy arp feature have been extended to allow, ARP
2003 * replies back to the same interface, to support
2004 * Private VLAN switch technologies. See arp.c.
2005 */
2006 if (out_dev == in_dev &&
2007 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2008 err = -EINVAL;
2009 goto cleanup;
2010 }
2011 }
2012
2013 rth = rt_dst_alloc(out_dev->dev,
2014 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2015 IN_DEV_CONF_GET(out_dev, NOXFRM));
2016 if (!rth) {
2017 err = -ENOBUFS;
2018 goto cleanup;
2019 }
2020
2021 rth->rt_key_dst = daddr;
2022 rth->rt_key_src = saddr;
2023 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2024 rth->rt_flags = flags;
2025 rth->rt_type = res->type;
2026 rth->rt_tos = tos;
2027 rth->rt_dst = daddr;
2028 rth->rt_src = saddr;
2029 rth->rt_route_iif = in_dev->dev->ifindex;
2030 rth->rt_iif = in_dev->dev->ifindex;
2031 rth->rt_oif = 0;
2032 rth->rt_mark = skb->mark;
2033 rth->rt_gateway = daddr;
2034 rth->rt_spec_dst= spec_dst;
2035 rth->rt_peer_genid = 0;
2036 rth->peer = NULL;
2037 rth->fi = NULL;
2038
2039 rth->dst.input = ip_forward;
2040 rth->dst.output = ip_output;
2041
2042 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2043
2044 *result = rth;
2045 err = 0;
2046 cleanup:
2047 return err;
2048 }
2049
2050 static int ip_mkroute_input(struct sk_buff *skb,
2051 struct fib_result *res,
2052 const struct flowi4 *fl4,
2053 struct in_device *in_dev,
2054 __be32 daddr, __be32 saddr, u32 tos)
2055 {
2056 struct rtable* rth = NULL;
2057 int err;
2058 unsigned hash;
2059
2060 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2061 if (res->fi && res->fi->fib_nhs > 1)
2062 fib_select_multipath(res);
2063 #endif
2064
2065 /* create a routing cache entry */
2066 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2067 if (err)
2068 return err;
2069
2070 /* put it into the cache */
2071 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2072 rt_genid(dev_net(rth->dst.dev)));
2073 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2074 if (IS_ERR(rth))
2075 return PTR_ERR(rth);
2076 return 0;
2077 }
2078
2079 /*
2080 * NOTE. We drop all the packets that has local source
2081 * addresses, because every properly looped back packet
2082 * must have correct destination already attached by output routine.
2083 *
2084 * Such approach solves two big problems:
2085 * 1. Not simplex devices are handled properly.
2086 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2087 * called with rcu_read_lock()
2088 */
2089
2090 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2091 u8 tos, struct net_device *dev)
2092 {
2093 struct fib_result res;
2094 struct in_device *in_dev = __in_dev_get_rcu(dev);
2095 struct flowi4 fl4;
2096 unsigned flags = 0;
2097 u32 itag = 0;
2098 struct rtable * rth;
2099 unsigned hash;
2100 __be32 spec_dst;
2101 int err = -EINVAL;
2102 struct net * net = dev_net(dev);
2103
2104 /* IP on this device is disabled. */
2105
2106 if (!in_dev)
2107 goto out;
2108
2109 /* Check for the most weird martians, which can be not detected
2110 by fib_lookup.
2111 */
2112
2113 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2114 ipv4_is_loopback(saddr))
2115 goto martian_source;
2116
2117 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2118 goto brd_input;
2119
2120 /* Accept zero addresses only to limited broadcast;
2121 * I even do not know to fix it or not. Waiting for complains :-)
2122 */
2123 if (ipv4_is_zeronet(saddr))
2124 goto martian_source;
2125
2126 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2127 goto martian_destination;
2128
2129 /*
2130 * Now we are ready to route packet.
2131 */
2132 fl4.flowi4_oif = 0;
2133 fl4.flowi4_iif = dev->ifindex;
2134 fl4.flowi4_mark = skb->mark;
2135 fl4.flowi4_tos = tos;
2136 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2137 fl4.daddr = daddr;
2138 fl4.saddr = saddr;
2139 err = fib_lookup(net, &fl4, &res);
2140 if (err != 0) {
2141 if (!IN_DEV_FORWARD(in_dev))
2142 goto e_hostunreach;
2143 goto no_route;
2144 }
2145
2146 RT_CACHE_STAT_INC(in_slow_tot);
2147
2148 if (res.type == RTN_BROADCAST)
2149 goto brd_input;
2150
2151 if (res.type == RTN_LOCAL) {
2152 err = fib_validate_source(skb, saddr, daddr, tos,
2153 net->loopback_dev->ifindex,
2154 dev, &spec_dst, &itag);
2155 if (err < 0)
2156 goto martian_source_keep_err;
2157 if (err)
2158 flags |= RTCF_DIRECTSRC;
2159 spec_dst = daddr;
2160 goto local_input;
2161 }
2162
2163 if (!IN_DEV_FORWARD(in_dev))
2164 goto e_hostunreach;
2165 if (res.type != RTN_UNICAST)
2166 goto martian_destination;
2167
2168 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2169 out: return err;
2170
2171 brd_input:
2172 if (skb->protocol != htons(ETH_P_IP))
2173 goto e_inval;
2174
2175 if (ipv4_is_zeronet(saddr))
2176 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2177 else {
2178 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2179 &itag);
2180 if (err < 0)
2181 goto martian_source_keep_err;
2182 if (err)
2183 flags |= RTCF_DIRECTSRC;
2184 }
2185 flags |= RTCF_BROADCAST;
2186 res.type = RTN_BROADCAST;
2187 RT_CACHE_STAT_INC(in_brd);
2188
2189 local_input:
2190 rth = rt_dst_alloc(net->loopback_dev,
2191 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2192 if (!rth)
2193 goto e_nobufs;
2194
2195 rth->dst.input= ip_local_deliver;
2196 rth->dst.output= ip_rt_bug;
2197 #ifdef CONFIG_IP_ROUTE_CLASSID
2198 rth->dst.tclassid = itag;
2199 #endif
2200
2201 rth->rt_key_dst = daddr;
2202 rth->rt_key_src = saddr;
2203 rth->rt_genid = rt_genid(net);
2204 rth->rt_flags = flags|RTCF_LOCAL;
2205 rth->rt_type = res.type;
2206 rth->rt_tos = tos;
2207 rth->rt_dst = daddr;
2208 rth->rt_src = saddr;
2209 #ifdef CONFIG_IP_ROUTE_CLASSID
2210 rth->dst.tclassid = itag;
2211 #endif
2212 rth->rt_route_iif = dev->ifindex;
2213 rth->rt_iif = dev->ifindex;
2214 rth->rt_oif = 0;
2215 rth->rt_mark = skb->mark;
2216 rth->rt_gateway = daddr;
2217 rth->rt_spec_dst= spec_dst;
2218 rth->rt_peer_genid = 0;
2219 rth->peer = NULL;
2220 rth->fi = NULL;
2221 if (res.type == RTN_UNREACHABLE) {
2222 rth->dst.input= ip_error;
2223 rth->dst.error= -err;
2224 rth->rt_flags &= ~RTCF_LOCAL;
2225 }
2226 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2227 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2228 err = 0;
2229 if (IS_ERR(rth))
2230 err = PTR_ERR(rth);
2231 goto out;
2232
2233 no_route:
2234 RT_CACHE_STAT_INC(in_no_route);
2235 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2236 res.type = RTN_UNREACHABLE;
2237 if (err == -ESRCH)
2238 err = -ENETUNREACH;
2239 goto local_input;
2240
2241 /*
2242 * Do not cache martian addresses: they should be logged (RFC1812)
2243 */
2244 martian_destination:
2245 RT_CACHE_STAT_INC(in_martian_dst);
2246 #ifdef CONFIG_IP_ROUTE_VERBOSE
2247 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2248 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2249 &daddr, &saddr, dev->name);
2250 #endif
2251
2252 e_hostunreach:
2253 err = -EHOSTUNREACH;
2254 goto out;
2255
2256 e_inval:
2257 err = -EINVAL;
2258 goto out;
2259
2260 e_nobufs:
2261 err = -ENOBUFS;
2262 goto out;
2263
2264 martian_source:
2265 err = -EINVAL;
2266 martian_source_keep_err:
2267 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2268 goto out;
2269 }
2270
2271 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2272 u8 tos, struct net_device *dev, bool noref)
2273 {
2274 struct rtable * rth;
2275 unsigned hash;
2276 int iif = dev->ifindex;
2277 struct net *net;
2278 int res;
2279
2280 net = dev_net(dev);
2281
2282 rcu_read_lock();
2283
2284 if (!rt_caching(net))
2285 goto skip_cache;
2286
2287 tos &= IPTOS_RT_MASK;
2288 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2289
2290 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2291 rth = rcu_dereference(rth->dst.rt_next)) {
2292 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2293 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2294 (rth->rt_iif ^ iif) |
2295 rth->rt_oif |
2296 (rth->rt_tos ^ tos)) == 0 &&
2297 rth->rt_mark == skb->mark &&
2298 net_eq(dev_net(rth->dst.dev), net) &&
2299 !rt_is_expired(rth)) {
2300 if (noref) {
2301 dst_use_noref(&rth->dst, jiffies);
2302 skb_dst_set_noref(skb, &rth->dst);
2303 } else {
2304 dst_use(&rth->dst, jiffies);
2305 skb_dst_set(skb, &rth->dst);
2306 }
2307 RT_CACHE_STAT_INC(in_hit);
2308 rcu_read_unlock();
2309 return 0;
2310 }
2311 RT_CACHE_STAT_INC(in_hlist_search);
2312 }
2313
2314 skip_cache:
2315 /* Multicast recognition logic is moved from route cache to here.
2316 The problem was that too many Ethernet cards have broken/missing
2317 hardware multicast filters :-( As result the host on multicasting
2318 network acquires a lot of useless route cache entries, sort of
2319 SDR messages from all the world. Now we try to get rid of them.
2320 Really, provided software IP multicast filter is organized
2321 reasonably (at least, hashed), it does not result in a slowdown
2322 comparing with route cache reject entries.
2323 Note, that multicast routers are not affected, because
2324 route cache entry is created eventually.
2325 */
2326 if (ipv4_is_multicast(daddr)) {
2327 struct in_device *in_dev = __in_dev_get_rcu(dev);
2328
2329 if (in_dev) {
2330 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2331 ip_hdr(skb)->protocol);
2332 if (our
2333 #ifdef CONFIG_IP_MROUTE
2334 ||
2335 (!ipv4_is_local_multicast(daddr) &&
2336 IN_DEV_MFORWARD(in_dev))
2337 #endif
2338 ) {
2339 int res = ip_route_input_mc(skb, daddr, saddr,
2340 tos, dev, our);
2341 rcu_read_unlock();
2342 return res;
2343 }
2344 }
2345 rcu_read_unlock();
2346 return -EINVAL;
2347 }
2348 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2349 rcu_read_unlock();
2350 return res;
2351 }
2352 EXPORT_SYMBOL(ip_route_input_common);
2353
2354 /* called with rcu_read_lock() */
2355 static struct rtable *__mkroute_output(const struct fib_result *res,
2356 const struct flowi4 *fl4,
2357 __be32 orig_daddr, __be32 orig_saddr,
2358 int orig_oif, struct net_device *dev_out,
2359 unsigned int flags)
2360 {
2361 struct fib_info *fi = res->fi;
2362 u32 tos = RT_FL_TOS(fl4);
2363 struct in_device *in_dev;
2364 u16 type = res->type;
2365 struct rtable *rth;
2366
2367 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2368 return ERR_PTR(-EINVAL);
2369
2370 if (ipv4_is_lbcast(fl4->daddr))
2371 type = RTN_BROADCAST;
2372 else if (ipv4_is_multicast(fl4->daddr))
2373 type = RTN_MULTICAST;
2374 else if (ipv4_is_zeronet(fl4->daddr))
2375 return ERR_PTR(-EINVAL);
2376
2377 if (dev_out->flags & IFF_LOOPBACK)
2378 flags |= RTCF_LOCAL;
2379
2380 in_dev = __in_dev_get_rcu(dev_out);
2381 if (!in_dev)
2382 return ERR_PTR(-EINVAL);
2383
2384 if (type == RTN_BROADCAST) {
2385 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2386 fi = NULL;
2387 } else if (type == RTN_MULTICAST) {
2388 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2389 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2390 fl4->flowi4_proto))
2391 flags &= ~RTCF_LOCAL;
2392 /* If multicast route do not exist use
2393 * default one, but do not gateway in this case.
2394 * Yes, it is hack.
2395 */
2396 if (fi && res->prefixlen < 4)
2397 fi = NULL;
2398 }
2399
2400 rth = rt_dst_alloc(dev_out,
2401 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2402 IN_DEV_CONF_GET(in_dev, NOXFRM));
2403 if (!rth)
2404 return ERR_PTR(-ENOBUFS);
2405
2406 rth->dst.output = ip_output;
2407
2408 rth->rt_key_dst = orig_daddr;
2409 rth->rt_key_src = orig_saddr;
2410 rth->rt_genid = rt_genid(dev_net(dev_out));
2411 rth->rt_flags = flags;
2412 rth->rt_type = type;
2413 rth->rt_tos = tos;
2414 rth->rt_dst = fl4->daddr;
2415 rth->rt_src = fl4->saddr;
2416 rth->rt_route_iif = 0;
2417 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2418 rth->rt_oif = orig_oif;
2419 rth->rt_mark = fl4->flowi4_mark;
2420 rth->rt_gateway = fl4->daddr;
2421 rth->rt_spec_dst= fl4->saddr;
2422 rth->rt_peer_genid = 0;
2423 rth->peer = NULL;
2424 rth->fi = NULL;
2425
2426 RT_CACHE_STAT_INC(out_slow_tot);
2427
2428 if (flags & RTCF_LOCAL) {
2429 rth->dst.input = ip_local_deliver;
2430 rth->rt_spec_dst = fl4->daddr;
2431 }
2432 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2433 rth->rt_spec_dst = fl4->saddr;
2434 if (flags & RTCF_LOCAL &&
2435 !(dev_out->flags & IFF_LOOPBACK)) {
2436 rth->dst.output = ip_mc_output;
2437 RT_CACHE_STAT_INC(out_slow_mc);
2438 }
2439 #ifdef CONFIG_IP_MROUTE
2440 if (type == RTN_MULTICAST) {
2441 if (IN_DEV_MFORWARD(in_dev) &&
2442 !ipv4_is_local_multicast(fl4->daddr)) {
2443 rth->dst.input = ip_mr_input;
2444 rth->dst.output = ip_mc_output;
2445 }
2446 }
2447 #endif
2448 }
2449
2450 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2451
2452 return rth;
2453 }
2454
2455 /*
2456 * Major route resolver routine.
2457 * called with rcu_read_lock();
2458 */
2459
2460 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2461 {
2462 struct net_device *dev_out = NULL;
2463 u32 tos = RT_FL_TOS(fl4);
2464 unsigned int flags = 0;
2465 struct fib_result res;
2466 struct rtable *rth;
2467 __be32 orig_daddr;
2468 __be32 orig_saddr;
2469 int orig_oif;
2470
2471 res.fi = NULL;
2472 #ifdef CONFIG_IP_MULTIPLE_TABLES
2473 res.r = NULL;
2474 #endif
2475
2476 orig_daddr = fl4->daddr;
2477 orig_saddr = fl4->saddr;
2478 orig_oif = fl4->flowi4_oif;
2479
2480 fl4->flowi4_iif = net->loopback_dev->ifindex;
2481 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2482 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2483 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2484
2485 rcu_read_lock();
2486 if (fl4->saddr) {
2487 rth = ERR_PTR(-EINVAL);
2488 if (ipv4_is_multicast(fl4->saddr) ||
2489 ipv4_is_lbcast(fl4->saddr) ||
2490 ipv4_is_zeronet(fl4->saddr))
2491 goto out;
2492
2493 /* I removed check for oif == dev_out->oif here.
2494 It was wrong for two reasons:
2495 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2496 is assigned to multiple interfaces.
2497 2. Moreover, we are allowed to send packets with saddr
2498 of another iface. --ANK
2499 */
2500
2501 if (fl4->flowi4_oif == 0 &&
2502 (ipv4_is_multicast(fl4->daddr) ||
2503 ipv4_is_lbcast(fl4->daddr))) {
2504 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2505 dev_out = __ip_dev_find(net, fl4->saddr, false);
2506 if (dev_out == NULL)
2507 goto out;
2508
2509 /* Special hack: user can direct multicasts
2510 and limited broadcast via necessary interface
2511 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2512 This hack is not just for fun, it allows
2513 vic,vat and friends to work.
2514 They bind socket to loopback, set ttl to zero
2515 and expect that it will work.
2516 From the viewpoint of routing cache they are broken,
2517 because we are not allowed to build multicast path
2518 with loopback source addr (look, routing cache
2519 cannot know, that ttl is zero, so that packet
2520 will not leave this host and route is valid).
2521 Luckily, this hack is good workaround.
2522 */
2523
2524 fl4->flowi4_oif = dev_out->ifindex;
2525 goto make_route;
2526 }
2527
2528 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2529 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2530 if (!__ip_dev_find(net, fl4->saddr, false))
2531 goto out;
2532 }
2533 }
2534
2535
2536 if (fl4->flowi4_oif) {
2537 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2538 rth = ERR_PTR(-ENODEV);
2539 if (dev_out == NULL)
2540 goto out;
2541
2542 /* RACE: Check return value of inet_select_addr instead. */
2543 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2544 rth = ERR_PTR(-ENETUNREACH);
2545 goto out;
2546 }
2547 if (ipv4_is_local_multicast(fl4->daddr) ||
2548 ipv4_is_lbcast(fl4->daddr)) {
2549 if (!fl4->saddr)
2550 fl4->saddr = inet_select_addr(dev_out, 0,
2551 RT_SCOPE_LINK);
2552 goto make_route;
2553 }
2554 if (fl4->saddr) {
2555 if (ipv4_is_multicast(fl4->daddr))
2556 fl4->saddr = inet_select_addr(dev_out, 0,
2557 fl4->flowi4_scope);
2558 else if (!fl4->daddr)
2559 fl4->saddr = inet_select_addr(dev_out, 0,
2560 RT_SCOPE_HOST);
2561 }
2562 }
2563
2564 if (!fl4->daddr) {
2565 fl4->daddr = fl4->saddr;
2566 if (!fl4->daddr)
2567 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2568 dev_out = net->loopback_dev;
2569 fl4->flowi4_oif = net->loopback_dev->ifindex;
2570 res.type = RTN_LOCAL;
2571 flags |= RTCF_LOCAL;
2572 goto make_route;
2573 }
2574
2575 if (fib_lookup(net, fl4, &res)) {
2576 res.fi = NULL;
2577 if (fl4->flowi4_oif) {
2578 /* Apparently, routing tables are wrong. Assume,
2579 that the destination is on link.
2580
2581 WHY? DW.
2582 Because we are allowed to send to iface
2583 even if it has NO routes and NO assigned
2584 addresses. When oif is specified, routing
2585 tables are looked up with only one purpose:
2586 to catch if destination is gatewayed, rather than
2587 direct. Moreover, if MSG_DONTROUTE is set,
2588 we send packet, ignoring both routing tables
2589 and ifaddr state. --ANK
2590
2591
2592 We could make it even if oif is unknown,
2593 likely IPv6, but we do not.
2594 */
2595
2596 if (fl4->saddr == 0)
2597 fl4->saddr = inet_select_addr(dev_out, 0,
2598 RT_SCOPE_LINK);
2599 res.type = RTN_UNICAST;
2600 goto make_route;
2601 }
2602 rth = ERR_PTR(-ENETUNREACH);
2603 goto out;
2604 }
2605
2606 if (res.type == RTN_LOCAL) {
2607 if (!fl4->saddr) {
2608 if (res.fi->fib_prefsrc)
2609 fl4->saddr = res.fi->fib_prefsrc;
2610 else
2611 fl4->saddr = fl4->daddr;
2612 }
2613 dev_out = net->loopback_dev;
2614 fl4->flowi4_oif = dev_out->ifindex;
2615 res.fi = NULL;
2616 flags |= RTCF_LOCAL;
2617 goto make_route;
2618 }
2619
2620 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2621 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2622 fib_select_multipath(&res);
2623 else
2624 #endif
2625 if (!res.prefixlen &&
2626 res.table->tb_num_default > 1 &&
2627 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2628 fib_select_default(&res);
2629
2630 if (!fl4->saddr)
2631 fl4->saddr = FIB_RES_PREFSRC(net, res);
2632
2633 dev_out = FIB_RES_DEV(res);
2634 fl4->flowi4_oif = dev_out->ifindex;
2635
2636
2637 make_route:
2638 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2639 dev_out, flags);
2640 if (!IS_ERR(rth)) {
2641 unsigned int hash;
2642
2643 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2644 rt_genid(dev_net(dev_out)));
2645 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2646 }
2647
2648 out:
2649 rcu_read_unlock();
2650 return rth;
2651 }
2652
2653 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2654 {
2655 struct rtable *rth;
2656 unsigned int hash;
2657
2658 if (!rt_caching(net))
2659 goto slow_output;
2660
2661 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2662
2663 rcu_read_lock_bh();
2664 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2665 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2666 if (rth->rt_key_dst == flp4->daddr &&
2667 rth->rt_key_src == flp4->saddr &&
2668 rt_is_output_route(rth) &&
2669 rth->rt_oif == flp4->flowi4_oif &&
2670 rth->rt_mark == flp4->flowi4_mark &&
2671 !((rth->rt_tos ^ flp4->flowi4_tos) &
2672 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2673 net_eq(dev_net(rth->dst.dev), net) &&
2674 !rt_is_expired(rth)) {
2675 dst_use(&rth->dst, jiffies);
2676 RT_CACHE_STAT_INC(out_hit);
2677 rcu_read_unlock_bh();
2678 return rth;
2679 }
2680 RT_CACHE_STAT_INC(out_hlist_search);
2681 }
2682 rcu_read_unlock_bh();
2683
2684 slow_output:
2685 return ip_route_output_slow(net, flp4);
2686 }
2687 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2688
2689 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2690 {
2691 return NULL;
2692 }
2693
2694 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2695 {
2696 return 0;
2697 }
2698
2699 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2700 {
2701 }
2702
2703 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2704 unsigned long old)
2705 {
2706 return NULL;
2707 }
2708
2709 static struct dst_ops ipv4_dst_blackhole_ops = {
2710 .family = AF_INET,
2711 .protocol = cpu_to_be16(ETH_P_IP),
2712 .destroy = ipv4_dst_destroy,
2713 .check = ipv4_blackhole_dst_check,
2714 .default_mtu = ipv4_blackhole_default_mtu,
2715 .default_advmss = ipv4_default_advmss,
2716 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2717 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2718 };
2719
2720 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2721 {
2722 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2723 struct rtable *ort = (struct rtable *) dst_orig;
2724
2725 if (rt) {
2726 struct dst_entry *new = &rt->dst;
2727
2728 new->__use = 1;
2729 new->input = dst_discard;
2730 new->output = dst_discard;
2731 dst_copy_metrics(new, &ort->dst);
2732
2733 new->dev = ort->dst.dev;
2734 if (new->dev)
2735 dev_hold(new->dev);
2736
2737 rt->rt_key_dst = ort->rt_key_dst;
2738 rt->rt_key_src = ort->rt_key_src;
2739 rt->rt_tos = ort->rt_tos;
2740 rt->rt_route_iif = ort->rt_route_iif;
2741 rt->rt_iif = ort->rt_iif;
2742 rt->rt_oif = ort->rt_oif;
2743 rt->rt_mark = ort->rt_mark;
2744
2745 rt->rt_genid = rt_genid(net);
2746 rt->rt_flags = ort->rt_flags;
2747 rt->rt_type = ort->rt_type;
2748 rt->rt_dst = ort->rt_dst;
2749 rt->rt_src = ort->rt_src;
2750 rt->rt_gateway = ort->rt_gateway;
2751 rt->rt_spec_dst = ort->rt_spec_dst;
2752 rt->peer = ort->peer;
2753 if (rt->peer)
2754 atomic_inc(&rt->peer->refcnt);
2755 rt->fi = ort->fi;
2756 if (rt->fi)
2757 atomic_inc(&rt->fi->fib_clntref);
2758
2759 dst_free(new);
2760 }
2761
2762 dst_release(dst_orig);
2763
2764 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2765 }
2766
2767 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2768 struct sock *sk)
2769 {
2770 struct rtable *rt = __ip_route_output_key(net, flp4);
2771
2772 if (IS_ERR(rt))
2773 return rt;
2774
2775 if (flp4->flowi4_proto) {
2776 if (!flp4->saddr)
2777 flp4->saddr = rt->rt_src;
2778 if (!flp4->daddr)
2779 flp4->daddr = rt->rt_dst;
2780 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2781 flowi4_to_flowi(flp4),
2782 sk, 0);
2783 }
2784
2785 return rt;
2786 }
2787 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2788
2789 static int rt_fill_info(struct net *net,
2790 struct sk_buff *skb, u32 pid, u32 seq, int event,
2791 int nowait, unsigned int flags)
2792 {
2793 struct rtable *rt = skb_rtable(skb);
2794 struct rtmsg *r;
2795 struct nlmsghdr *nlh;
2796 long expires;
2797 u32 id = 0, ts = 0, tsage = 0, error;
2798
2799 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2800 if (nlh == NULL)
2801 return -EMSGSIZE;
2802
2803 r = nlmsg_data(nlh);
2804 r->rtm_family = AF_INET;
2805 r->rtm_dst_len = 32;
2806 r->rtm_src_len = 0;
2807 r->rtm_tos = rt->rt_tos;
2808 r->rtm_table = RT_TABLE_MAIN;
2809 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2810 r->rtm_type = rt->rt_type;
2811 r->rtm_scope = RT_SCOPE_UNIVERSE;
2812 r->rtm_protocol = RTPROT_UNSPEC;
2813 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2814 if (rt->rt_flags & RTCF_NOTIFY)
2815 r->rtm_flags |= RTM_F_NOTIFY;
2816
2817 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2818
2819 if (rt->rt_key_src) {
2820 r->rtm_src_len = 32;
2821 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2822 }
2823 if (rt->dst.dev)
2824 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2825 #ifdef CONFIG_IP_ROUTE_CLASSID
2826 if (rt->dst.tclassid)
2827 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2828 #endif
2829 if (rt_is_input_route(rt))
2830 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2831 else if (rt->rt_src != rt->rt_key_src)
2832 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2833
2834 if (rt->rt_dst != rt->rt_gateway)
2835 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2836
2837 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2838 goto nla_put_failure;
2839
2840 if (rt->rt_mark)
2841 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2842
2843 error = rt->dst.error;
2844 expires = (rt->peer && rt->peer->pmtu_expires) ?
2845 rt->peer->pmtu_expires - jiffies : 0;
2846 if (rt->peer) {
2847 inet_peer_refcheck(rt->peer);
2848 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2849 if (rt->peer->tcp_ts_stamp) {
2850 ts = rt->peer->tcp_ts;
2851 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2852 }
2853 }
2854
2855 if (rt_is_input_route(rt)) {
2856 #ifdef CONFIG_IP_MROUTE
2857 __be32 dst = rt->rt_dst;
2858
2859 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2860 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2861 int err = ipmr_get_route(net, skb, r, nowait);
2862 if (err <= 0) {
2863 if (!nowait) {
2864 if (err == 0)
2865 return 0;
2866 goto nla_put_failure;
2867 } else {
2868 if (err == -EMSGSIZE)
2869 goto nla_put_failure;
2870 error = err;
2871 }
2872 }
2873 } else
2874 #endif
2875 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2876 }
2877
2878 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2879 expires, error) < 0)
2880 goto nla_put_failure;
2881
2882 return nlmsg_end(skb, nlh);
2883
2884 nla_put_failure:
2885 nlmsg_cancel(skb, nlh);
2886 return -EMSGSIZE;
2887 }
2888
2889 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2890 {
2891 struct net *net = sock_net(in_skb->sk);
2892 struct rtmsg *rtm;
2893 struct nlattr *tb[RTA_MAX+1];
2894 struct rtable *rt = NULL;
2895 __be32 dst = 0;
2896 __be32 src = 0;
2897 u32 iif;
2898 int err;
2899 int mark;
2900 struct sk_buff *skb;
2901
2902 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2903 if (err < 0)
2904 goto errout;
2905
2906 rtm = nlmsg_data(nlh);
2907
2908 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2909 if (skb == NULL) {
2910 err = -ENOBUFS;
2911 goto errout;
2912 }
2913
2914 /* Reserve room for dummy headers, this skb can pass
2915 through good chunk of routing engine.
2916 */
2917 skb_reset_mac_header(skb);
2918 skb_reset_network_header(skb);
2919
2920 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2921 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2922 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2923
2924 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2925 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2926 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2927 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2928
2929 if (iif) {
2930 struct net_device *dev;
2931
2932 dev = __dev_get_by_index(net, iif);
2933 if (dev == NULL) {
2934 err = -ENODEV;
2935 goto errout_free;
2936 }
2937
2938 skb->protocol = htons(ETH_P_IP);
2939 skb->dev = dev;
2940 skb->mark = mark;
2941 local_bh_disable();
2942 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2943 local_bh_enable();
2944
2945 rt = skb_rtable(skb);
2946 if (err == 0 && rt->dst.error)
2947 err = -rt->dst.error;
2948 } else {
2949 struct flowi4 fl4 = {
2950 .daddr = dst,
2951 .saddr = src,
2952 .flowi4_tos = rtm->rtm_tos,
2953 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2954 .flowi4_mark = mark,
2955 };
2956 rt = ip_route_output_key(net, &fl4);
2957
2958 err = 0;
2959 if (IS_ERR(rt))
2960 err = PTR_ERR(rt);
2961 }
2962
2963 if (err)
2964 goto errout_free;
2965
2966 skb_dst_set(skb, &rt->dst);
2967 if (rtm->rtm_flags & RTM_F_NOTIFY)
2968 rt->rt_flags |= RTCF_NOTIFY;
2969
2970 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2971 RTM_NEWROUTE, 0, 0);
2972 if (err <= 0)
2973 goto errout_free;
2974
2975 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2976 errout:
2977 return err;
2978
2979 errout_free:
2980 kfree_skb(skb);
2981 goto errout;
2982 }
2983
2984 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2985 {
2986 struct rtable *rt;
2987 int h, s_h;
2988 int idx, s_idx;
2989 struct net *net;
2990
2991 net = sock_net(skb->sk);
2992
2993 s_h = cb->args[0];
2994 if (s_h < 0)
2995 s_h = 0;
2996 s_idx = idx = cb->args[1];
2997 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2998 if (!rt_hash_table[h].chain)
2999 continue;
3000 rcu_read_lock_bh();
3001 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3002 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3003 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3004 continue;
3005 if (rt_is_expired(rt))
3006 continue;
3007 skb_dst_set_noref(skb, &rt->dst);
3008 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3009 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3010 1, NLM_F_MULTI) <= 0) {
3011 skb_dst_drop(skb);
3012 rcu_read_unlock_bh();
3013 goto done;
3014 }
3015 skb_dst_drop(skb);
3016 }
3017 rcu_read_unlock_bh();
3018 }
3019
3020 done:
3021 cb->args[0] = h;
3022 cb->args[1] = idx;
3023 return skb->len;
3024 }
3025
3026 void ip_rt_multicast_event(struct in_device *in_dev)
3027 {
3028 rt_cache_flush(dev_net(in_dev->dev), 0);
3029 }
3030
3031 #ifdef CONFIG_SYSCTL
3032 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3033 void __user *buffer,
3034 size_t *lenp, loff_t *ppos)
3035 {
3036 if (write) {
3037 int flush_delay;
3038 ctl_table ctl;
3039 struct net *net;
3040
3041 memcpy(&ctl, __ctl, sizeof(ctl));
3042 ctl.data = &flush_delay;
3043 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3044
3045 net = (struct net *)__ctl->extra1;
3046 rt_cache_flush(net, flush_delay);
3047 return 0;
3048 }
3049
3050 return -EINVAL;
3051 }
3052
3053 static ctl_table ipv4_route_table[] = {
3054 {
3055 .procname = "gc_thresh",
3056 .data = &ipv4_dst_ops.gc_thresh,
3057 .maxlen = sizeof(int),
3058 .mode = 0644,
3059 .proc_handler = proc_dointvec,
3060 },
3061 {
3062 .procname = "max_size",
3063 .data = &ip_rt_max_size,
3064 .maxlen = sizeof(int),
3065 .mode = 0644,
3066 .proc_handler = proc_dointvec,
3067 },
3068 {
3069 /* Deprecated. Use gc_min_interval_ms */
3070
3071 .procname = "gc_min_interval",
3072 .data = &ip_rt_gc_min_interval,
3073 .maxlen = sizeof(int),
3074 .mode = 0644,
3075 .proc_handler = proc_dointvec_jiffies,
3076 },
3077 {
3078 .procname = "gc_min_interval_ms",
3079 .data = &ip_rt_gc_min_interval,
3080 .maxlen = sizeof(int),
3081 .mode = 0644,
3082 .proc_handler = proc_dointvec_ms_jiffies,
3083 },
3084 {
3085 .procname = "gc_timeout",
3086 .data = &ip_rt_gc_timeout,
3087 .maxlen = sizeof(int),
3088 .mode = 0644,
3089 .proc_handler = proc_dointvec_jiffies,
3090 },
3091 {
3092 .procname = "gc_interval",
3093 .data = &ip_rt_gc_interval,
3094 .maxlen = sizeof(int),
3095 .mode = 0644,
3096 .proc_handler = proc_dointvec_jiffies,
3097 },
3098 {
3099 .procname = "redirect_load",
3100 .data = &ip_rt_redirect_load,
3101 .maxlen = sizeof(int),
3102 .mode = 0644,
3103 .proc_handler = proc_dointvec,
3104 },
3105 {
3106 .procname = "redirect_number",
3107 .data = &ip_rt_redirect_number,
3108 .maxlen = sizeof(int),
3109 .mode = 0644,
3110 .proc_handler = proc_dointvec,
3111 },
3112 {
3113 .procname = "redirect_silence",
3114 .data = &ip_rt_redirect_silence,
3115 .maxlen = sizeof(int),
3116 .mode = 0644,
3117 .proc_handler = proc_dointvec,
3118 },
3119 {
3120 .procname = "error_cost",
3121 .data = &ip_rt_error_cost,
3122 .maxlen = sizeof(int),
3123 .mode = 0644,
3124 .proc_handler = proc_dointvec,
3125 },
3126 {
3127 .procname = "error_burst",
3128 .data = &ip_rt_error_burst,
3129 .maxlen = sizeof(int),
3130 .mode = 0644,
3131 .proc_handler = proc_dointvec,
3132 },
3133 {
3134 .procname = "gc_elasticity",
3135 .data = &ip_rt_gc_elasticity,
3136 .maxlen = sizeof(int),
3137 .mode = 0644,
3138 .proc_handler = proc_dointvec,
3139 },
3140 {
3141 .procname = "mtu_expires",
3142 .data = &ip_rt_mtu_expires,
3143 .maxlen = sizeof(int),
3144 .mode = 0644,
3145 .proc_handler = proc_dointvec_jiffies,
3146 },
3147 {
3148 .procname = "min_pmtu",
3149 .data = &ip_rt_min_pmtu,
3150 .maxlen = sizeof(int),
3151 .mode = 0644,
3152 .proc_handler = proc_dointvec,
3153 },
3154 {
3155 .procname = "min_adv_mss",
3156 .data = &ip_rt_min_advmss,
3157 .maxlen = sizeof(int),
3158 .mode = 0644,
3159 .proc_handler = proc_dointvec,
3160 },
3161 { }
3162 };
3163
3164 static struct ctl_table empty[1];
3165
3166 static struct ctl_table ipv4_skeleton[] =
3167 {
3168 { .procname = "route",
3169 .mode = 0555, .child = ipv4_route_table},
3170 { .procname = "neigh",
3171 .mode = 0555, .child = empty},
3172 { }
3173 };
3174
3175 static __net_initdata struct ctl_path ipv4_path[] = {
3176 { .procname = "net", },
3177 { .procname = "ipv4", },
3178 { },
3179 };
3180
3181 static struct ctl_table ipv4_route_flush_table[] = {
3182 {
3183 .procname = "flush",
3184 .maxlen = sizeof(int),
3185 .mode = 0200,
3186 .proc_handler = ipv4_sysctl_rtcache_flush,
3187 },
3188 { },
3189 };
3190
3191 static __net_initdata struct ctl_path ipv4_route_path[] = {
3192 { .procname = "net", },
3193 { .procname = "ipv4", },
3194 { .procname = "route", },
3195 { },
3196 };
3197
3198 static __net_init int sysctl_route_net_init(struct net *net)
3199 {
3200 struct ctl_table *tbl;
3201
3202 tbl = ipv4_route_flush_table;
3203 if (!net_eq(net, &init_net)) {
3204 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3205 if (tbl == NULL)
3206 goto err_dup;
3207 }
3208 tbl[0].extra1 = net;
3209
3210 net->ipv4.route_hdr =
3211 register_net_sysctl_table(net, ipv4_route_path, tbl);
3212 if (net->ipv4.route_hdr == NULL)
3213 goto err_reg;
3214 return 0;
3215
3216 err_reg:
3217 if (tbl != ipv4_route_flush_table)
3218 kfree(tbl);
3219 err_dup:
3220 return -ENOMEM;
3221 }
3222
3223 static __net_exit void sysctl_route_net_exit(struct net *net)
3224 {
3225 struct ctl_table *tbl;
3226
3227 tbl = net->ipv4.route_hdr->ctl_table_arg;
3228 unregister_net_sysctl_table(net->ipv4.route_hdr);
3229 BUG_ON(tbl == ipv4_route_flush_table);
3230 kfree(tbl);
3231 }
3232
3233 static __net_initdata struct pernet_operations sysctl_route_ops = {
3234 .init = sysctl_route_net_init,
3235 .exit = sysctl_route_net_exit,
3236 };
3237 #endif
3238
3239 static __net_init int rt_genid_init(struct net *net)
3240 {
3241 get_random_bytes(&net->ipv4.rt_genid,
3242 sizeof(net->ipv4.rt_genid));
3243 get_random_bytes(&net->ipv4.dev_addr_genid,
3244 sizeof(net->ipv4.dev_addr_genid));
3245 return 0;
3246 }
3247
3248 static __net_initdata struct pernet_operations rt_genid_ops = {
3249 .init = rt_genid_init,
3250 };
3251
3252
3253 #ifdef CONFIG_IP_ROUTE_CLASSID
3254 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3255 #endif /* CONFIG_IP_ROUTE_CLASSID */
3256
3257 static __initdata unsigned long rhash_entries;
3258 static int __init set_rhash_entries(char *str)
3259 {
3260 if (!str)
3261 return 0;
3262 rhash_entries = simple_strtoul(str, &str, 0);
3263 return 1;
3264 }
3265 __setup("rhash_entries=", set_rhash_entries);
3266
3267 int __init ip_rt_init(void)
3268 {
3269 int rc = 0;
3270
3271 #ifdef CONFIG_IP_ROUTE_CLASSID
3272 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3273 if (!ip_rt_acct)
3274 panic("IP: failed to allocate ip_rt_acct\n");
3275 #endif
3276
3277 ipv4_dst_ops.kmem_cachep =
3278 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3279 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3280
3281 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3282
3283 if (dst_entries_init(&ipv4_dst_ops) < 0)
3284 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3285
3286 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3287 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3288
3289 rt_hash_table = (struct rt_hash_bucket *)
3290 alloc_large_system_hash("IP route cache",
3291 sizeof(struct rt_hash_bucket),
3292 rhash_entries,
3293 (totalram_pages >= 128 * 1024) ?
3294 15 : 17,
3295 0,
3296 &rt_hash_log,
3297 &rt_hash_mask,
3298 rhash_entries ? 0 : 512 * 1024);
3299 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3300 rt_hash_lock_init();
3301
3302 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3303 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3304
3305 devinet_init();
3306 ip_fib_init();
3307
3308 if (ip_rt_proc_init())
3309 printk(KERN_ERR "Unable to create route proc files\n");
3310 #ifdef CONFIG_XFRM
3311 xfrm_init();
3312 xfrm4_init(ip_rt_max_size);
3313 #endif
3314 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3315
3316 #ifdef CONFIG_SYSCTL
3317 register_pernet_subsys(&sysctl_route_ops);
3318 #endif
3319 register_pernet_subsys(&rt_genid_ops);
3320 return rc;
3321 }
3322
3323 #ifdef CONFIG_SYSCTL
3324 /*
3325 * We really need to sanitize the damn ipv4 init order, then all
3326 * this nonsense will go away.
3327 */
3328 void __init ip_static_sysctl_init(void)
3329 {
3330 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3331 }
3332 #endif
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree