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xen: tidy up whitespace in drivers/xen/Makefile
[linux-2.6.git] / net / ipv4 / route.c
blob99e6e4bb1c72d044b97ba93ad6c0bd944d170edd
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, 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 *oldflp4,
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 (oldflp4 && (oldflp4->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 *oldflp4,
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, oldflp4, 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 rt->rt_type = type;
1834 }
1835
1836 static struct rtable *rt_dst_alloc(bool nopolicy, bool noxfrm)
1837 {
1838 struct rtable *rt = dst_alloc(&ipv4_dst_ops, 1);
1839 if (rt) {
1840 rt->dst.obsolete = -1;
1841
1842 rt->dst.flags = DST_HOST |
1843 (nopolicy ? DST_NOPOLICY : 0) |
1844 (noxfrm ? DST_NOXFRM : 0);
1845 }
1846 return rt;
1847 }
1848
1849 /* called in rcu_read_lock() section */
1850 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1851 u8 tos, struct net_device *dev, int our)
1852 {
1853 unsigned int hash;
1854 struct rtable *rth;
1855 __be32 spec_dst;
1856 struct in_device *in_dev = __in_dev_get_rcu(dev);
1857 u32 itag = 0;
1858 int err;
1859
1860 /* Primary sanity checks. */
1861
1862 if (in_dev == NULL)
1863 return -EINVAL;
1864
1865 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1866 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1867 goto e_inval;
1868
1869 if (ipv4_is_zeronet(saddr)) {
1870 if (!ipv4_is_local_multicast(daddr))
1871 goto e_inval;
1872 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1873 } else {
1874 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1875 &itag, 0);
1876 if (err < 0)
1877 goto e_err;
1878 }
1879 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1880 if (!rth)
1881 goto e_nobufs;
1882
1883 rth->dst.output = ip_rt_bug;
1884
1885 rth->rt_key_dst = daddr;
1886 rth->rt_dst = daddr;
1887 rth->rt_tos = tos;
1888 rth->rt_mark = skb->mark;
1889 rth->rt_key_src = saddr;
1890 rth->rt_src = saddr;
1891 #ifdef CONFIG_IP_ROUTE_CLASSID
1892 rth->dst.tclassid = itag;
1893 #endif
1894 rth->rt_route_iif = dev->ifindex;
1895 rth->rt_iif = dev->ifindex;
1896 rth->dst.dev = init_net.loopback_dev;
1897 dev_hold(rth->dst.dev);
1898 rth->rt_oif = 0;
1899 rth->rt_gateway = daddr;
1900 rth->rt_spec_dst= spec_dst;
1901 rth->rt_genid = rt_genid(dev_net(dev));
1902 rth->rt_flags = RTCF_MULTICAST;
1903 rth->rt_type = RTN_MULTICAST;
1904 if (our) {
1905 rth->dst.input= ip_local_deliver;
1906 rth->rt_flags |= RTCF_LOCAL;
1907 }
1908
1909 #ifdef CONFIG_IP_MROUTE
1910 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1911 rth->dst.input = ip_mr_input;
1912 #endif
1913 RT_CACHE_STAT_INC(in_slow_mc);
1914
1915 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1916 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1917 err = 0;
1918 if (IS_ERR(rth))
1919 err = PTR_ERR(rth);
1920
1921 e_nobufs:
1922 return -ENOBUFS;
1923 e_inval:
1924 return -EINVAL;
1925 e_err:
1926 return err;
1927 }
1928
1929
1930 static void ip_handle_martian_source(struct net_device *dev,
1931 struct in_device *in_dev,
1932 struct sk_buff *skb,
1933 __be32 daddr,
1934 __be32 saddr)
1935 {
1936 RT_CACHE_STAT_INC(in_martian_src);
1937 #ifdef CONFIG_IP_ROUTE_VERBOSE
1938 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1939 /*
1940 * RFC1812 recommendation, if source is martian,
1941 * the only hint is MAC header.
1942 */
1943 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1944 &daddr, &saddr, dev->name);
1945 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1946 int i;
1947 const unsigned char *p = skb_mac_header(skb);
1948 printk(KERN_WARNING "ll header: ");
1949 for (i = 0; i < dev->hard_header_len; i++, p++) {
1950 printk("%02x", *p);
1951 if (i < (dev->hard_header_len - 1))
1952 printk(":");
1953 }
1954 printk("\n");
1955 }
1956 }
1957 #endif
1958 }
1959
1960 /* called in rcu_read_lock() section */
1961 static int __mkroute_input(struct sk_buff *skb,
1962 const struct fib_result *res,
1963 struct in_device *in_dev,
1964 __be32 daddr, __be32 saddr, u32 tos,
1965 struct rtable **result)
1966 {
1967 struct rtable *rth;
1968 int err;
1969 struct in_device *out_dev;
1970 unsigned int flags = 0;
1971 __be32 spec_dst;
1972 u32 itag;
1973
1974 /* get a working reference to the output device */
1975 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1976 if (out_dev == NULL) {
1977 if (net_ratelimit())
1978 printk(KERN_CRIT "Bug in ip_route_input" \
1979 "_slow(). Please, report\n");
1980 return -EINVAL;
1981 }
1982
1983
1984 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1985 in_dev->dev, &spec_dst, &itag, skb->mark);
1986 if (err < 0) {
1987 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1988 saddr);
1989
1990 goto cleanup;
1991 }
1992
1993 if (err)
1994 flags |= RTCF_DIRECTSRC;
1995
1996 if (out_dev == in_dev && err &&
1997 (IN_DEV_SHARED_MEDIA(out_dev) ||
1998 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1999 flags |= RTCF_DOREDIRECT;
2000
2001 if (skb->protocol != htons(ETH_P_IP)) {
2002 /* Not IP (i.e. ARP). Do not create route, if it is
2003 * invalid for proxy arp. DNAT routes are always valid.
2004 *
2005 * Proxy arp feature have been extended to allow, ARP
2006 * replies back to the same interface, to support
2007 * Private VLAN switch technologies. See arp.c.
2008 */
2009 if (out_dev == in_dev &&
2010 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2011 err = -EINVAL;
2012 goto cleanup;
2013 }
2014 }
2015
2016 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
2017 IN_DEV_CONF_GET(out_dev, NOXFRM));
2018 if (!rth) {
2019 err = -ENOBUFS;
2020 goto cleanup;
2021 }
2022
2023 rth->rt_key_dst = daddr;
2024 rth->rt_dst = daddr;
2025 rth->rt_tos = tos;
2026 rth->rt_mark = skb->mark;
2027 rth->rt_key_src = saddr;
2028 rth->rt_src = saddr;
2029 rth->rt_gateway = daddr;
2030 rth->rt_route_iif = in_dev->dev->ifindex;
2031 rth->rt_iif = in_dev->dev->ifindex;
2032 rth->dst.dev = (out_dev)->dev;
2033 dev_hold(rth->dst.dev);
2034 rth->rt_oif = 0;
2035 rth->rt_spec_dst= spec_dst;
2036
2037 rth->dst.input = ip_forward;
2038 rth->dst.output = ip_output;
2039 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2040
2041 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2042
2043 rth->rt_flags = flags;
2044
2045 *result = rth;
2046 err = 0;
2047 cleanup:
2048 return err;
2049 }
2050
2051 static int ip_mkroute_input(struct sk_buff *skb,
2052 struct fib_result *res,
2053 const struct flowi4 *fl4,
2054 struct in_device *in_dev,
2055 __be32 daddr, __be32 saddr, u32 tos)
2056 {
2057 struct rtable* rth = NULL;
2058 int err;
2059 unsigned hash;
2060
2061 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2062 if (res->fi && res->fi->fib_nhs > 1)
2063 fib_select_multipath(res);
2064 #endif
2065
2066 /* create a routing cache entry */
2067 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2068 if (err)
2069 return err;
2070
2071 /* put it into the cache */
2072 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2073 rt_genid(dev_net(rth->dst.dev)));
2074 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2075 if (IS_ERR(rth))
2076 return PTR_ERR(rth);
2077 return 0;
2078 }
2079
2080 /*
2081 * NOTE. We drop all the packets that has local source
2082 * addresses, because every properly looped back packet
2083 * must have correct destination already attached by output routine.
2084 *
2085 * Such approach solves two big problems:
2086 * 1. Not simplex devices are handled properly.
2087 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2088 * called with rcu_read_lock()
2089 */
2090
2091 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2092 u8 tos, struct net_device *dev)
2093 {
2094 struct fib_result res;
2095 struct in_device *in_dev = __in_dev_get_rcu(dev);
2096 struct flowi4 fl4;
2097 unsigned flags = 0;
2098 u32 itag = 0;
2099 struct rtable * rth;
2100 unsigned hash;
2101 __be32 spec_dst;
2102 int err = -EINVAL;
2103 struct net * net = dev_net(dev);
2104
2105 /* IP on this device is disabled. */
2106
2107 if (!in_dev)
2108 goto out;
2109
2110 /* Check for the most weird martians, which can be not detected
2111 by fib_lookup.
2112 */
2113
2114 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2115 ipv4_is_loopback(saddr))
2116 goto martian_source;
2117
2118 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2119 goto brd_input;
2120
2121 /* Accept zero addresses only to limited broadcast;
2122 * I even do not know to fix it or not. Waiting for complains :-)
2123 */
2124 if (ipv4_is_zeronet(saddr))
2125 goto martian_source;
2126
2127 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2128 goto martian_destination;
2129
2130 /*
2131 * Now we are ready to route packet.
2132 */
2133 fl4.flowi4_oif = 0;
2134 fl4.flowi4_iif = dev->ifindex;
2135 fl4.flowi4_mark = skb->mark;
2136 fl4.flowi4_tos = tos;
2137 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2138 fl4.daddr = daddr;
2139 fl4.saddr = saddr;
2140 err = fib_lookup(net, &fl4, &res);
2141 if (err != 0) {
2142 if (!IN_DEV_FORWARD(in_dev))
2143 goto e_hostunreach;
2144 goto no_route;
2145 }
2146
2147 RT_CACHE_STAT_INC(in_slow_tot);
2148
2149 if (res.type == RTN_BROADCAST)
2150 goto brd_input;
2151
2152 if (res.type == RTN_LOCAL) {
2153 err = fib_validate_source(saddr, daddr, tos,
2154 net->loopback_dev->ifindex,
2155 dev, &spec_dst, &itag, skb->mark);
2156 if (err < 0)
2157 goto martian_source_keep_err;
2158 if (err)
2159 flags |= RTCF_DIRECTSRC;
2160 spec_dst = daddr;
2161 goto local_input;
2162 }
2163
2164 if (!IN_DEV_FORWARD(in_dev))
2165 goto e_hostunreach;
2166 if (res.type != RTN_UNICAST)
2167 goto martian_destination;
2168
2169 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2170 out: return err;
2171
2172 brd_input:
2173 if (skb->protocol != htons(ETH_P_IP))
2174 goto e_inval;
2175
2176 if (ipv4_is_zeronet(saddr))
2177 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2178 else {
2179 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2180 &itag, skb->mark);
2181 if (err < 0)
2182 goto martian_source_keep_err;
2183 if (err)
2184 flags |= RTCF_DIRECTSRC;
2185 }
2186 flags |= RTCF_BROADCAST;
2187 res.type = RTN_BROADCAST;
2188 RT_CACHE_STAT_INC(in_brd);
2189
2190 local_input:
2191 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2192 if (!rth)
2193 goto e_nobufs;
2194
2195 rth->dst.output= ip_rt_bug;
2196 rth->rt_genid = rt_genid(net);
2197
2198 rth->rt_key_dst = daddr;
2199 rth->rt_dst = daddr;
2200 rth->rt_tos = tos;
2201 rth->rt_mark = skb->mark;
2202 rth->rt_key_src = saddr;
2203 rth->rt_src = saddr;
2204 #ifdef CONFIG_IP_ROUTE_CLASSID
2205 rth->dst.tclassid = itag;
2206 #endif
2207 rth->rt_route_iif = dev->ifindex;
2208 rth->rt_iif = dev->ifindex;
2209 rth->dst.dev = net->loopback_dev;
2210 dev_hold(rth->dst.dev);
2211 rth->rt_gateway = daddr;
2212 rth->rt_spec_dst= spec_dst;
2213 rth->dst.input= ip_local_deliver;
2214 rth->rt_flags = flags|RTCF_LOCAL;
2215 if (res.type == RTN_UNREACHABLE) {
2216 rth->dst.input= ip_error;
2217 rth->dst.error= -err;
2218 rth->rt_flags &= ~RTCF_LOCAL;
2219 }
2220 rth->rt_type = res.type;
2221 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2222 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2223 err = 0;
2224 if (IS_ERR(rth))
2225 err = PTR_ERR(rth);
2226 goto out;
2227
2228 no_route:
2229 RT_CACHE_STAT_INC(in_no_route);
2230 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2231 res.type = RTN_UNREACHABLE;
2232 if (err == -ESRCH)
2233 err = -ENETUNREACH;
2234 goto local_input;
2235
2236 /*
2237 * Do not cache martian addresses: they should be logged (RFC1812)
2238 */
2239 martian_destination:
2240 RT_CACHE_STAT_INC(in_martian_dst);
2241 #ifdef CONFIG_IP_ROUTE_VERBOSE
2242 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2243 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2244 &daddr, &saddr, dev->name);
2245 #endif
2246
2247 e_hostunreach:
2248 err = -EHOSTUNREACH;
2249 goto out;
2250
2251 e_inval:
2252 err = -EINVAL;
2253 goto out;
2254
2255 e_nobufs:
2256 err = -ENOBUFS;
2257 goto out;
2258
2259 martian_source:
2260 err = -EINVAL;
2261 martian_source_keep_err:
2262 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2263 goto out;
2264 }
2265
2266 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2267 u8 tos, struct net_device *dev, bool noref)
2268 {
2269 struct rtable * rth;
2270 unsigned hash;
2271 int iif = dev->ifindex;
2272 struct net *net;
2273 int res;
2274
2275 net = dev_net(dev);
2276
2277 rcu_read_lock();
2278
2279 if (!rt_caching(net))
2280 goto skip_cache;
2281
2282 tos &= IPTOS_RT_MASK;
2283 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2284
2285 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2286 rth = rcu_dereference(rth->dst.rt_next)) {
2287 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2288 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2289 (rth->rt_iif ^ iif) |
2290 rth->rt_oif |
2291 (rth->rt_tos ^ tos)) == 0 &&
2292 rth->rt_mark == skb->mark &&
2293 net_eq(dev_net(rth->dst.dev), net) &&
2294 !rt_is_expired(rth)) {
2295 if (noref) {
2296 dst_use_noref(&rth->dst, jiffies);
2297 skb_dst_set_noref(skb, &rth->dst);
2298 } else {
2299 dst_use(&rth->dst, jiffies);
2300 skb_dst_set(skb, &rth->dst);
2301 }
2302 RT_CACHE_STAT_INC(in_hit);
2303 rcu_read_unlock();
2304 return 0;
2305 }
2306 RT_CACHE_STAT_INC(in_hlist_search);
2307 }
2308
2309 skip_cache:
2310 /* Multicast recognition logic is moved from route cache to here.
2311 The problem was that too many Ethernet cards have broken/missing
2312 hardware multicast filters :-( As result the host on multicasting
2313 network acquires a lot of useless route cache entries, sort of
2314 SDR messages from all the world. Now we try to get rid of them.
2315 Really, provided software IP multicast filter is organized
2316 reasonably (at least, hashed), it does not result in a slowdown
2317 comparing with route cache reject entries.
2318 Note, that multicast routers are not affected, because
2319 route cache entry is created eventually.
2320 */
2321 if (ipv4_is_multicast(daddr)) {
2322 struct in_device *in_dev = __in_dev_get_rcu(dev);
2323
2324 if (in_dev) {
2325 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2326 ip_hdr(skb)->protocol);
2327 if (our
2328 #ifdef CONFIG_IP_MROUTE
2329 ||
2330 (!ipv4_is_local_multicast(daddr) &&
2331 IN_DEV_MFORWARD(in_dev))
2332 #endif
2333 ) {
2334 int res = ip_route_input_mc(skb, daddr, saddr,
2335 tos, dev, our);
2336 rcu_read_unlock();
2337 return res;
2338 }
2339 }
2340 rcu_read_unlock();
2341 return -EINVAL;
2342 }
2343 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2344 rcu_read_unlock();
2345 return res;
2346 }
2347 EXPORT_SYMBOL(ip_route_input_common);
2348
2349 /* called with rcu_read_lock() */
2350 static struct rtable *__mkroute_output(const struct fib_result *res,
2351 const struct flowi4 *fl4,
2352 const struct flowi4 *oldflp4,
2353 struct net_device *dev_out,
2354 unsigned int flags)
2355 {
2356 struct fib_info *fi = res->fi;
2357 u32 tos = RT_FL_TOS(oldflp4);
2358 struct in_device *in_dev;
2359 u16 type = res->type;
2360 struct rtable *rth;
2361
2362 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2363 return ERR_PTR(-EINVAL);
2364
2365 if (ipv4_is_lbcast(fl4->daddr))
2366 type = RTN_BROADCAST;
2367 else if (ipv4_is_multicast(fl4->daddr))
2368 type = RTN_MULTICAST;
2369 else if (ipv4_is_zeronet(fl4->daddr))
2370 return ERR_PTR(-EINVAL);
2371
2372 if (dev_out->flags & IFF_LOOPBACK)
2373 flags |= RTCF_LOCAL;
2374
2375 in_dev = __in_dev_get_rcu(dev_out);
2376 if (!in_dev)
2377 return ERR_PTR(-EINVAL);
2378
2379 if (type == RTN_BROADCAST) {
2380 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2381 fi = NULL;
2382 } else if (type == RTN_MULTICAST) {
2383 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2384 if (!ip_check_mc_rcu(in_dev, oldflp4->daddr, oldflp4->saddr,
2385 oldflp4->flowi4_proto))
2386 flags &= ~RTCF_LOCAL;
2387 /* If multicast route do not exist use
2388 * default one, but do not gateway in this case.
2389 * Yes, it is hack.
2390 */
2391 if (fi && res->prefixlen < 4)
2392 fi = NULL;
2393 }
2394
2395 rth = rt_dst_alloc(IN_DEV_CONF_GET(in_dev, NOPOLICY),
2396 IN_DEV_CONF_GET(in_dev, NOXFRM));
2397 if (!rth)
2398 return ERR_PTR(-ENOBUFS);
2399
2400 rth->rt_key_dst = oldflp4->daddr;
2401 rth->rt_tos = tos;
2402 rth->rt_key_src = oldflp4->saddr;
2403 rth->rt_oif = oldflp4->flowi4_oif;
2404 rth->rt_mark = oldflp4->flowi4_mark;
2405 rth->rt_dst = fl4->daddr;
2406 rth->rt_src = fl4->saddr;
2407 rth->rt_route_iif = 0;
2408 rth->rt_iif = oldflp4->flowi4_oif ? : dev_out->ifindex;
2409 /* get references to the devices that are to be hold by the routing
2410 cache entry */
2411 rth->dst.dev = dev_out;
2412 dev_hold(dev_out);
2413 rth->rt_gateway = fl4->daddr;
2414 rth->rt_spec_dst= fl4->saddr;
2415
2416 rth->dst.output=ip_output;
2417 rth->rt_genid = rt_genid(dev_net(dev_out));
2418
2419 RT_CACHE_STAT_INC(out_slow_tot);
2420
2421 if (flags & RTCF_LOCAL) {
2422 rth->dst.input = ip_local_deliver;
2423 rth->rt_spec_dst = fl4->daddr;
2424 }
2425 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2426 rth->rt_spec_dst = fl4->saddr;
2427 if (flags & RTCF_LOCAL &&
2428 !(dev_out->flags & IFF_LOOPBACK)) {
2429 rth->dst.output = ip_mc_output;
2430 RT_CACHE_STAT_INC(out_slow_mc);
2431 }
2432 #ifdef CONFIG_IP_MROUTE
2433 if (type == RTN_MULTICAST) {
2434 if (IN_DEV_MFORWARD(in_dev) &&
2435 !ipv4_is_local_multicast(oldflp4->daddr)) {
2436 rth->dst.input = ip_mr_input;
2437 rth->dst.output = ip_mc_output;
2438 }
2439 }
2440 #endif
2441 }
2442
2443 rt_set_nexthop(rth, oldflp4, res, fi, type, 0);
2444
2445 rth->rt_flags = flags;
2446 return rth;
2447 }
2448
2449 /*
2450 * Major route resolver routine.
2451 * called with rcu_read_lock();
2452 */
2453
2454 static struct rtable *ip_route_output_slow(struct net *net,
2455 const struct flowi4 *oldflp4)
2456 {
2457 u32 tos = RT_FL_TOS(oldflp4);
2458 struct flowi4 fl4;
2459 struct fib_result res;
2460 unsigned int flags = 0;
2461 struct net_device *dev_out = NULL;
2462 struct rtable *rth;
2463
2464 res.fi = NULL;
2465 #ifdef CONFIG_IP_MULTIPLE_TABLES
2466 res.r = NULL;
2467 #endif
2468
2469 fl4.flowi4_oif = oldflp4->flowi4_oif;
2470 fl4.flowi4_iif = net->loopback_dev->ifindex;
2471 fl4.flowi4_mark = oldflp4->flowi4_mark;
2472 fl4.daddr = oldflp4->daddr;
2473 fl4.saddr = oldflp4->saddr;
2474 fl4.flowi4_tos = tos & IPTOS_RT_MASK;
2475 fl4.flowi4_scope = ((tos & RTO_ONLINK) ?
2476 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2477
2478 rcu_read_lock();
2479 if (oldflp4->saddr) {
2480 rth = ERR_PTR(-EINVAL);
2481 if (ipv4_is_multicast(oldflp4->saddr) ||
2482 ipv4_is_lbcast(oldflp4->saddr) ||
2483 ipv4_is_zeronet(oldflp4->saddr))
2484 goto out;
2485
2486 /* I removed check for oif == dev_out->oif here.
2487 It was wrong for two reasons:
2488 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2489 is assigned to multiple interfaces.
2490 2. Moreover, we are allowed to send packets with saddr
2491 of another iface. --ANK
2492 */
2493
2494 if (oldflp4->flowi4_oif == 0 &&
2495 (ipv4_is_multicast(oldflp4->daddr) ||
2496 ipv4_is_lbcast(oldflp4->daddr))) {
2497 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2498 dev_out = __ip_dev_find(net, oldflp4->saddr, false);
2499 if (dev_out == NULL)
2500 goto out;
2501
2502 /* Special hack: user can direct multicasts
2503 and limited broadcast via necessary interface
2504 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2505 This hack is not just for fun, it allows
2506 vic,vat and friends to work.
2507 They bind socket to loopback, set ttl to zero
2508 and expect that it will work.
2509 From the viewpoint of routing cache they are broken,
2510 because we are not allowed to build multicast path
2511 with loopback source addr (look, routing cache
2512 cannot know, that ttl is zero, so that packet
2513 will not leave this host and route is valid).
2514 Luckily, this hack is good workaround.
2515 */
2516
2517 fl4.flowi4_oif = dev_out->ifindex;
2518 goto make_route;
2519 }
2520
2521 if (!(oldflp4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2522 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2523 if (!__ip_dev_find(net, oldflp4->saddr, false))
2524 goto out;
2525 }
2526 }
2527
2528
2529 if (oldflp4->flowi4_oif) {
2530 dev_out = dev_get_by_index_rcu(net, oldflp4->flowi4_oif);
2531 rth = ERR_PTR(-ENODEV);
2532 if (dev_out == NULL)
2533 goto out;
2534
2535 /* RACE: Check return value of inet_select_addr instead. */
2536 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2537 rth = ERR_PTR(-ENETUNREACH);
2538 goto out;
2539 }
2540 if (ipv4_is_local_multicast(oldflp4->daddr) ||
2541 ipv4_is_lbcast(oldflp4->daddr)) {
2542 if (!fl4.saddr)
2543 fl4.saddr = inet_select_addr(dev_out, 0,
2544 RT_SCOPE_LINK);
2545 goto make_route;
2546 }
2547 if (!fl4.saddr) {
2548 if (ipv4_is_multicast(oldflp4->daddr))
2549 fl4.saddr = inet_select_addr(dev_out, 0,
2550 fl4.flowi4_scope);
2551 else if (!oldflp4->daddr)
2552 fl4.saddr = inet_select_addr(dev_out, 0,
2553 RT_SCOPE_HOST);
2554 }
2555 }
2556
2557 if (!fl4.daddr) {
2558 fl4.daddr = fl4.saddr;
2559 if (!fl4.daddr)
2560 fl4.daddr = fl4.saddr = htonl(INADDR_LOOPBACK);
2561 dev_out = net->loopback_dev;
2562 fl4.flowi4_oif = net->loopback_dev->ifindex;
2563 res.type = RTN_LOCAL;
2564 flags |= RTCF_LOCAL;
2565 goto make_route;
2566 }
2567
2568 if (fib_lookup(net, &fl4, &res)) {
2569 res.fi = NULL;
2570 if (oldflp4->flowi4_oif) {
2571 /* Apparently, routing tables are wrong. Assume,
2572 that the destination is on link.
2573
2574 WHY? DW.
2575 Because we are allowed to send to iface
2576 even if it has NO routes and NO assigned
2577 addresses. When oif is specified, routing
2578 tables are looked up with only one purpose:
2579 to catch if destination is gatewayed, rather than
2580 direct. Moreover, if MSG_DONTROUTE is set,
2581 we send packet, ignoring both routing tables
2582 and ifaddr state. --ANK
2583
2584
2585 We could make it even if oif is unknown,
2586 likely IPv6, but we do not.
2587 */
2588
2589 if (fl4.saddr == 0)
2590 fl4.saddr = inet_select_addr(dev_out, 0,
2591 RT_SCOPE_LINK);
2592 res.type = RTN_UNICAST;
2593 goto make_route;
2594 }
2595 rth = ERR_PTR(-ENETUNREACH);
2596 goto out;
2597 }
2598
2599 if (res.type == RTN_LOCAL) {
2600 if (!fl4.saddr) {
2601 if (res.fi->fib_prefsrc)
2602 fl4.saddr = res.fi->fib_prefsrc;
2603 else
2604 fl4.saddr = fl4.daddr;
2605 }
2606 dev_out = net->loopback_dev;
2607 fl4.flowi4_oif = dev_out->ifindex;
2608 res.fi = NULL;
2609 flags |= RTCF_LOCAL;
2610 goto make_route;
2611 }
2612
2613 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2614 if (res.fi->fib_nhs > 1 && fl4.flowi4_oif == 0)
2615 fib_select_multipath(&res);
2616 else
2617 #endif
2618 if (!res.prefixlen && res.type == RTN_UNICAST && !fl4.flowi4_oif)
2619 fib_select_default(&res);
2620
2621 if (!fl4.saddr)
2622 fl4.saddr = FIB_RES_PREFSRC(net, res);
2623
2624 dev_out = FIB_RES_DEV(res);
2625 fl4.flowi4_oif = dev_out->ifindex;
2626
2627
2628 make_route:
2629 rth = __mkroute_output(&res, &fl4, oldflp4, dev_out, flags);
2630 if (!IS_ERR(rth)) {
2631 unsigned int hash;
2632
2633 hash = rt_hash(oldflp4->daddr, oldflp4->saddr, oldflp4->flowi4_oif,
2634 rt_genid(dev_net(dev_out)));
2635 rth = rt_intern_hash(hash, rth, NULL, oldflp4->flowi4_oif);
2636 }
2637
2638 out:
2639 rcu_read_unlock();
2640 return rth;
2641 }
2642
2643 struct rtable *__ip_route_output_key(struct net *net, const struct flowi4 *flp4)
2644 {
2645 struct rtable *rth;
2646 unsigned int hash;
2647
2648 if (!rt_caching(net))
2649 goto slow_output;
2650
2651 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2652
2653 rcu_read_lock_bh();
2654 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2655 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2656 if (rth->rt_key_dst == flp4->daddr &&
2657 rth->rt_key_src == flp4->saddr &&
2658 rt_is_output_route(rth) &&
2659 rth->rt_oif == flp4->flowi4_oif &&
2660 rth->rt_mark == flp4->flowi4_mark &&
2661 !((rth->rt_tos ^ flp4->flowi4_tos) &
2662 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2663 net_eq(dev_net(rth->dst.dev), net) &&
2664 !rt_is_expired(rth)) {
2665 dst_use(&rth->dst, jiffies);
2666 RT_CACHE_STAT_INC(out_hit);
2667 rcu_read_unlock_bh();
2668 return rth;
2669 }
2670 RT_CACHE_STAT_INC(out_hlist_search);
2671 }
2672 rcu_read_unlock_bh();
2673
2674 slow_output:
2675 return ip_route_output_slow(net, flp4);
2676 }
2677 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2678
2679 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2680 {
2681 return NULL;
2682 }
2683
2684 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2685 {
2686 return 0;
2687 }
2688
2689 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2690 {
2691 }
2692
2693 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2694 unsigned long old)
2695 {
2696 return NULL;
2697 }
2698
2699 static struct dst_ops ipv4_dst_blackhole_ops = {
2700 .family = AF_INET,
2701 .protocol = cpu_to_be16(ETH_P_IP),
2702 .destroy = ipv4_dst_destroy,
2703 .check = ipv4_blackhole_dst_check,
2704 .default_mtu = ipv4_blackhole_default_mtu,
2705 .default_advmss = ipv4_default_advmss,
2706 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2707 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2708 };
2709
2710 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2711 {
2712 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, 1);
2713 struct rtable *ort = (struct rtable *) dst_orig;
2714
2715 if (rt) {
2716 struct dst_entry *new = &rt->dst;
2717
2718 new->__use = 1;
2719 new->input = dst_discard;
2720 new->output = dst_discard;
2721 dst_copy_metrics(new, &ort->dst);
2722
2723 new->dev = ort->dst.dev;
2724 if (new->dev)
2725 dev_hold(new->dev);
2726
2727 rt->rt_key_dst = ort->rt_key_dst;
2728 rt->rt_key_src = ort->rt_key_src;
2729 rt->rt_tos = ort->rt_tos;
2730 rt->rt_route_iif = ort->rt_route_iif;
2731 rt->rt_iif = ort->rt_iif;
2732 rt->rt_oif = ort->rt_oif;
2733 rt->rt_mark = ort->rt_mark;
2734
2735 rt->rt_genid = rt_genid(net);
2736 rt->rt_flags = ort->rt_flags;
2737 rt->rt_type = ort->rt_type;
2738 rt->rt_dst = ort->rt_dst;
2739 rt->rt_src = ort->rt_src;
2740 rt->rt_gateway = ort->rt_gateway;
2741 rt->rt_spec_dst = ort->rt_spec_dst;
2742 rt->peer = ort->peer;
2743 if (rt->peer)
2744 atomic_inc(&rt->peer->refcnt);
2745 rt->fi = ort->fi;
2746 if (rt->fi)
2747 atomic_inc(&rt->fi->fib_clntref);
2748
2749 dst_free(new);
2750 }
2751
2752 dst_release(dst_orig);
2753
2754 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2755 }
2756
2757 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2758 struct sock *sk)
2759 {
2760 struct rtable *rt = __ip_route_output_key(net, flp4);
2761
2762 if (IS_ERR(rt))
2763 return rt;
2764
2765 if (flp4->flowi4_proto) {
2766 if (!flp4->saddr)
2767 flp4->saddr = rt->rt_src;
2768 if (!flp4->daddr)
2769 flp4->daddr = rt->rt_dst;
2770 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2771 flowi4_to_flowi(flp4),
2772 sk, 0);
2773 }
2774
2775 return rt;
2776 }
2777 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2778
2779 static int rt_fill_info(struct net *net,
2780 struct sk_buff *skb, u32 pid, u32 seq, int event,
2781 int nowait, unsigned int flags)
2782 {
2783 struct rtable *rt = skb_rtable(skb);
2784 struct rtmsg *r;
2785 struct nlmsghdr *nlh;
2786 long expires;
2787 u32 id = 0, ts = 0, tsage = 0, error;
2788
2789 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2790 if (nlh == NULL)
2791 return -EMSGSIZE;
2792
2793 r = nlmsg_data(nlh);
2794 r->rtm_family = AF_INET;
2795 r->rtm_dst_len = 32;
2796 r->rtm_src_len = 0;
2797 r->rtm_tos = rt->rt_tos;
2798 r->rtm_table = RT_TABLE_MAIN;
2799 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2800 r->rtm_type = rt->rt_type;
2801 r->rtm_scope = RT_SCOPE_UNIVERSE;
2802 r->rtm_protocol = RTPROT_UNSPEC;
2803 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2804 if (rt->rt_flags & RTCF_NOTIFY)
2805 r->rtm_flags |= RTM_F_NOTIFY;
2806
2807 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2808
2809 if (rt->rt_key_src) {
2810 r->rtm_src_len = 32;
2811 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2812 }
2813 if (rt->dst.dev)
2814 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2815 #ifdef CONFIG_IP_ROUTE_CLASSID
2816 if (rt->dst.tclassid)
2817 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2818 #endif
2819 if (rt_is_input_route(rt))
2820 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2821 else if (rt->rt_src != rt->rt_key_src)
2822 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2823
2824 if (rt->rt_dst != rt->rt_gateway)
2825 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2826
2827 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2828 goto nla_put_failure;
2829
2830 if (rt->rt_mark)
2831 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2832
2833 error = rt->dst.error;
2834 expires = (rt->peer && rt->peer->pmtu_expires) ?
2835 rt->peer->pmtu_expires - jiffies : 0;
2836 if (rt->peer) {
2837 inet_peer_refcheck(rt->peer);
2838 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2839 if (rt->peer->tcp_ts_stamp) {
2840 ts = rt->peer->tcp_ts;
2841 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2842 }
2843 }
2844
2845 if (rt_is_input_route(rt)) {
2846 #ifdef CONFIG_IP_MROUTE
2847 __be32 dst = rt->rt_dst;
2848
2849 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2850 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2851 int err = ipmr_get_route(net, skb, r, nowait);
2852 if (err <= 0) {
2853 if (!nowait) {
2854 if (err == 0)
2855 return 0;
2856 goto nla_put_failure;
2857 } else {
2858 if (err == -EMSGSIZE)
2859 goto nla_put_failure;
2860 error = err;
2861 }
2862 }
2863 } else
2864 #endif
2865 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2866 }
2867
2868 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2869 expires, error) < 0)
2870 goto nla_put_failure;
2871
2872 return nlmsg_end(skb, nlh);
2873
2874 nla_put_failure:
2875 nlmsg_cancel(skb, nlh);
2876 return -EMSGSIZE;
2877 }
2878
2879 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2880 {
2881 struct net *net = sock_net(in_skb->sk);
2882 struct rtmsg *rtm;
2883 struct nlattr *tb[RTA_MAX+1];
2884 struct rtable *rt = NULL;
2885 __be32 dst = 0;
2886 __be32 src = 0;
2887 u32 iif;
2888 int err;
2889 int mark;
2890 struct sk_buff *skb;
2891
2892 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2893 if (err < 0)
2894 goto errout;
2895
2896 rtm = nlmsg_data(nlh);
2897
2898 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2899 if (skb == NULL) {
2900 err = -ENOBUFS;
2901 goto errout;
2902 }
2903
2904 /* Reserve room for dummy headers, this skb can pass
2905 through good chunk of routing engine.
2906 */
2907 skb_reset_mac_header(skb);
2908 skb_reset_network_header(skb);
2909
2910 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2911 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2912 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2913
2914 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2915 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2916 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2917 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2918
2919 if (iif) {
2920 struct net_device *dev;
2921
2922 dev = __dev_get_by_index(net, iif);
2923 if (dev == NULL) {
2924 err = -ENODEV;
2925 goto errout_free;
2926 }
2927
2928 skb->protocol = htons(ETH_P_IP);
2929 skb->dev = dev;
2930 skb->mark = mark;
2931 local_bh_disable();
2932 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2933 local_bh_enable();
2934
2935 rt = skb_rtable(skb);
2936 if (err == 0 && rt->dst.error)
2937 err = -rt->dst.error;
2938 } else {
2939 struct flowi4 fl4 = {
2940 .daddr = dst,
2941 .saddr = src,
2942 .flowi4_tos = rtm->rtm_tos,
2943 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2944 .flowi4_mark = mark,
2945 };
2946 rt = ip_route_output_key(net, &fl4);
2947
2948 err = 0;
2949 if (IS_ERR(rt))
2950 err = PTR_ERR(rt);
2951 }
2952
2953 if (err)
2954 goto errout_free;
2955
2956 skb_dst_set(skb, &rt->dst);
2957 if (rtm->rtm_flags & RTM_F_NOTIFY)
2958 rt->rt_flags |= RTCF_NOTIFY;
2959
2960 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2961 RTM_NEWROUTE, 0, 0);
2962 if (err <= 0)
2963 goto errout_free;
2964
2965 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2966 errout:
2967 return err;
2968
2969 errout_free:
2970 kfree_skb(skb);
2971 goto errout;
2972 }
2973
2974 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2975 {
2976 struct rtable *rt;
2977 int h, s_h;
2978 int idx, s_idx;
2979 struct net *net;
2980
2981 net = sock_net(skb->sk);
2982
2983 s_h = cb->args[0];
2984 if (s_h < 0)
2985 s_h = 0;
2986 s_idx = idx = cb->args[1];
2987 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2988 if (!rt_hash_table[h].chain)
2989 continue;
2990 rcu_read_lock_bh();
2991 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2992 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2993 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2994 continue;
2995 if (rt_is_expired(rt))
2996 continue;
2997 skb_dst_set_noref(skb, &rt->dst);
2998 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
2999 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3000 1, NLM_F_MULTI) <= 0) {
3001 skb_dst_drop(skb);
3002 rcu_read_unlock_bh();
3003 goto done;
3004 }
3005 skb_dst_drop(skb);
3006 }
3007 rcu_read_unlock_bh();
3008 }
3009
3010 done:
3011 cb->args[0] = h;
3012 cb->args[1] = idx;
3013 return skb->len;
3014 }
3015
3016 void ip_rt_multicast_event(struct in_device *in_dev)
3017 {
3018 rt_cache_flush(dev_net(in_dev->dev), 0);
3019 }
3020
3021 #ifdef CONFIG_SYSCTL
3022 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3023 void __user *buffer,
3024 size_t *lenp, loff_t *ppos)
3025 {
3026 if (write) {
3027 int flush_delay;
3028 ctl_table ctl;
3029 struct net *net;
3030
3031 memcpy(&ctl, __ctl, sizeof(ctl));
3032 ctl.data = &flush_delay;
3033 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3034
3035 net = (struct net *)__ctl->extra1;
3036 rt_cache_flush(net, flush_delay);
3037 return 0;
3038 }
3039
3040 return -EINVAL;
3041 }
3042
3043 static ctl_table ipv4_route_table[] = {
3044 {
3045 .procname = "gc_thresh",
3046 .data = &ipv4_dst_ops.gc_thresh,
3047 .maxlen = sizeof(int),
3048 .mode = 0644,
3049 .proc_handler = proc_dointvec,
3050 },
3051 {
3052 .procname = "max_size",
3053 .data = &ip_rt_max_size,
3054 .maxlen = sizeof(int),
3055 .mode = 0644,
3056 .proc_handler = proc_dointvec,
3057 },
3058 {
3059 /* Deprecated. Use gc_min_interval_ms */
3060
3061 .procname = "gc_min_interval",
3062 .data = &ip_rt_gc_min_interval,
3063 .maxlen = sizeof(int),
3064 .mode = 0644,
3065 .proc_handler = proc_dointvec_jiffies,
3066 },
3067 {
3068 .procname = "gc_min_interval_ms",
3069 .data = &ip_rt_gc_min_interval,
3070 .maxlen = sizeof(int),
3071 .mode = 0644,
3072 .proc_handler = proc_dointvec_ms_jiffies,
3073 },
3074 {
3075 .procname = "gc_timeout",
3076 .data = &ip_rt_gc_timeout,
3077 .maxlen = sizeof(int),
3078 .mode = 0644,
3079 .proc_handler = proc_dointvec_jiffies,
3080 },
3081 {
3082 .procname = "gc_interval",
3083 .data = &ip_rt_gc_interval,
3084 .maxlen = sizeof(int),
3085 .mode = 0644,
3086 .proc_handler = proc_dointvec_jiffies,
3087 },
3088 {
3089 .procname = "redirect_load",
3090 .data = &ip_rt_redirect_load,
3091 .maxlen = sizeof(int),
3092 .mode = 0644,
3093 .proc_handler = proc_dointvec,
3094 },
3095 {
3096 .procname = "redirect_number",
3097 .data = &ip_rt_redirect_number,
3098 .maxlen = sizeof(int),
3099 .mode = 0644,
3100 .proc_handler = proc_dointvec,
3101 },
3102 {
3103 .procname = "redirect_silence",
3104 .data = &ip_rt_redirect_silence,
3105 .maxlen = sizeof(int),
3106 .mode = 0644,
3107 .proc_handler = proc_dointvec,
3108 },
3109 {
3110 .procname = "error_cost",
3111 .data = &ip_rt_error_cost,
3112 .maxlen = sizeof(int),
3113 .mode = 0644,
3114 .proc_handler = proc_dointvec,
3115 },
3116 {
3117 .procname = "error_burst",
3118 .data = &ip_rt_error_burst,
3119 .maxlen = sizeof(int),
3120 .mode = 0644,
3121 .proc_handler = proc_dointvec,
3122 },
3123 {
3124 .procname = "gc_elasticity",
3125 .data = &ip_rt_gc_elasticity,
3126 .maxlen = sizeof(int),
3127 .mode = 0644,
3128 .proc_handler = proc_dointvec,
3129 },
3130 {
3131 .procname = "mtu_expires",
3132 .data = &ip_rt_mtu_expires,
3133 .maxlen = sizeof(int),
3134 .mode = 0644,
3135 .proc_handler = proc_dointvec_jiffies,
3136 },
3137 {
3138 .procname = "min_pmtu",
3139 .data = &ip_rt_min_pmtu,
3140 .maxlen = sizeof(int),
3141 .mode = 0644,
3142 .proc_handler = proc_dointvec,
3143 },
3144 {
3145 .procname = "min_adv_mss",
3146 .data = &ip_rt_min_advmss,
3147 .maxlen = sizeof(int),
3148 .mode = 0644,
3149 .proc_handler = proc_dointvec,
3150 },
3151 { }
3152 };
3153
3154 static struct ctl_table empty[1];
3155
3156 static struct ctl_table ipv4_skeleton[] =
3157 {
3158 { .procname = "route",
3159 .mode = 0555, .child = ipv4_route_table},
3160 { .procname = "neigh",
3161 .mode = 0555, .child = empty},
3162 { }
3163 };
3164
3165 static __net_initdata struct ctl_path ipv4_path[] = {
3166 { .procname = "net", },
3167 { .procname = "ipv4", },
3168 { },
3169 };
3170
3171 static struct ctl_table ipv4_route_flush_table[] = {
3172 {
3173 .procname = "flush",
3174 .maxlen = sizeof(int),
3175 .mode = 0200,
3176 .proc_handler = ipv4_sysctl_rtcache_flush,
3177 },
3178 { },
3179 };
3180
3181 static __net_initdata struct ctl_path ipv4_route_path[] = {
3182 { .procname = "net", },
3183 { .procname = "ipv4", },
3184 { .procname = "route", },
3185 { },
3186 };
3187
3188 static __net_init int sysctl_route_net_init(struct net *net)
3189 {
3190 struct ctl_table *tbl;
3191
3192 tbl = ipv4_route_flush_table;
3193 if (!net_eq(net, &init_net)) {
3194 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3195 if (tbl == NULL)
3196 goto err_dup;
3197 }
3198 tbl[0].extra1 = net;
3199
3200 net->ipv4.route_hdr =
3201 register_net_sysctl_table(net, ipv4_route_path, tbl);
3202 if (net->ipv4.route_hdr == NULL)
3203 goto err_reg;
3204 return 0;
3205
3206 err_reg:
3207 if (tbl != ipv4_route_flush_table)
3208 kfree(tbl);
3209 err_dup:
3210 return -ENOMEM;
3211 }
3212
3213 static __net_exit void sysctl_route_net_exit(struct net *net)
3214 {
3215 struct ctl_table *tbl;
3216
3217 tbl = net->ipv4.route_hdr->ctl_table_arg;
3218 unregister_net_sysctl_table(net->ipv4.route_hdr);
3219 BUG_ON(tbl == ipv4_route_flush_table);
3220 kfree(tbl);
3221 }
3222
3223 static __net_initdata struct pernet_operations sysctl_route_ops = {
3224 .init = sysctl_route_net_init,
3225 .exit = sysctl_route_net_exit,
3226 };
3227 #endif
3228
3229 static __net_init int rt_genid_init(struct net *net)
3230 {
3231 get_random_bytes(&net->ipv4.rt_genid,
3232 sizeof(net->ipv4.rt_genid));
3233 get_random_bytes(&net->ipv4.dev_addr_genid,
3234 sizeof(net->ipv4.dev_addr_genid));
3235 return 0;
3236 }
3237
3238 static __net_initdata struct pernet_operations rt_genid_ops = {
3239 .init = rt_genid_init,
3240 };
3241
3242
3243 #ifdef CONFIG_IP_ROUTE_CLASSID
3244 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3245 #endif /* CONFIG_IP_ROUTE_CLASSID */
3246
3247 static __initdata unsigned long rhash_entries;
3248 static int __init set_rhash_entries(char *str)
3249 {
3250 if (!str)
3251 return 0;
3252 rhash_entries = simple_strtoul(str, &str, 0);
3253 return 1;
3254 }
3255 __setup("rhash_entries=", set_rhash_entries);
3256
3257 int __init ip_rt_init(void)
3258 {
3259 int rc = 0;
3260
3261 #ifdef CONFIG_IP_ROUTE_CLASSID
3262 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3263 if (!ip_rt_acct)
3264 panic("IP: failed to allocate ip_rt_acct\n");
3265 #endif
3266
3267 ipv4_dst_ops.kmem_cachep =
3268 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3269 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3270
3271 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3272
3273 if (dst_entries_init(&ipv4_dst_ops) < 0)
3274 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3275
3276 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3277 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3278
3279 rt_hash_table = (struct rt_hash_bucket *)
3280 alloc_large_system_hash("IP route cache",
3281 sizeof(struct rt_hash_bucket),
3282 rhash_entries,
3283 (totalram_pages >= 128 * 1024) ?
3284 15 : 17,
3285 0,
3286 &rt_hash_log,
3287 &rt_hash_mask,
3288 rhash_entries ? 0 : 512 * 1024);
3289 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3290 rt_hash_lock_init();
3291
3292 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3293 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3294
3295 devinet_init();
3296 ip_fib_init();
3297
3298 if (ip_rt_proc_init())
3299 printk(KERN_ERR "Unable to create route proc files\n");
3300 #ifdef CONFIG_XFRM
3301 xfrm_init();
3302 xfrm4_init(ip_rt_max_size);
3303 #endif
3304 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3305
3306 #ifdef CONFIG_SYSCTL
3307 register_pernet_subsys(&sysctl_route_ops);
3308 #endif
3309 register_pernet_subsys(&rt_genid_ops);
3310 return rc;
3311 }
3312
3313 #ifdef CONFIG_SYSCTL
3314 /*
3315 * We really need to sanitize the damn ipv4 init order, then all
3316 * this nonsense will go away.
3317 */
3318 void __init ip_static_sysctl_init(void)
3319 {
3320 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3321 }
3322 #endif
Linus' kernel tree