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ipv4: Trivial rt->rt_src conversions in net/ipv4/route.c
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blobcb93c32027d73dfb454b37742871af57031f2394
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_key_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
828 */
829 static void rt_cache_invalidate(struct net *net)
830 {
831 unsigned char shuffle;
832
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
835 }
836
837 /*
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
840 */
841 void rt_cache_flush(struct net *net, int delay)
842 {
843 rt_cache_invalidate(net);
844 if (delay >= 0)
845 rt_do_flush(net, !in_softirq());
846 }
847
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
850 {
851 rt_do_flush(net, !in_softirq());
852 }
853
854 static void rt_emergency_hash_rebuild(struct net *net)
855 {
856 if (net_ratelimit())
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
859 }
860
861 /*
862 Short description of GC goals.
863
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
867
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
872 */
873
874 static int rt_garbage_collect(struct dst_ops *ops)
875 {
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
878 static int rover;
879 static int equilibrium;
880 struct rtable *rth;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
883 int goal;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
885
886 /*
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
889 */
890
891 RT_CACHE_STAT_INC(gc_total);
892
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
896 goto out;
897 }
898
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
902 if (goal <= 0) {
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
906 if (goal > 0) {
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
909 }
910 } else {
911 /* We are in dangerous area. Try to reduce cache really
912 * aggressively.
913 */
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
916 }
917
918 if (now - last_gc >= ip_rt_gc_min_interval)
919 last_gc = now;
920
921 if (goal <= 0) {
922 equilibrium += goal;
923 goto work_done;
924 }
925
926 do {
927 int i, k;
928
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
931
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
939 tmo >>= 1;
940 rthp = &rth->dst.rt_next;
941 continue;
942 }
943 *rthp = rth->dst.rt_next;
944 rt_free(rth);
945 goal--;
946 }
947 spin_unlock_bh(rt_hash_lock_addr(k));
948 if (goal <= 0)
949 break;
950 }
951 rover = k;
952
953 if (goal <= 0)
954 goto work_done;
955
956 /* Goal is not achieved. We stop process if:
957
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
963 */
964
965 RT_CACHE_STAT_INC(gc_goal_miss);
966
967 if (expire == 0)
968 break;
969
970 expire >>= 1;
971 #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_key_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 &ip_hdr(skb)->saddr, rt->rt_iif,
1439 &rt->rt_dst, &rt->rt_gateway);
1440 #endif
1441 }
1442 }
1443
1444 static int ip_error(struct sk_buff *skb)
1445 {
1446 struct rtable *rt = skb_rtable(skb);
1447 struct inet_peer *peer;
1448 unsigned long now;
1449 bool send;
1450 int code;
1451
1452 switch (rt->dst.error) {
1453 case EINVAL:
1454 default:
1455 goto out;
1456 case EHOSTUNREACH:
1457 code = ICMP_HOST_UNREACH;
1458 break;
1459 case ENETUNREACH:
1460 code = ICMP_NET_UNREACH;
1461 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1462 IPSTATS_MIB_INNOROUTES);
1463 break;
1464 case EACCES:
1465 code = ICMP_PKT_FILTERED;
1466 break;
1467 }
1468
1469 if (!rt->peer)
1470 rt_bind_peer(rt, 1);
1471 peer = rt->peer;
1472
1473 send = true;
1474 if (peer) {
1475 now = jiffies;
1476 peer->rate_tokens += now - peer->rate_last;
1477 if (peer->rate_tokens > ip_rt_error_burst)
1478 peer->rate_tokens = ip_rt_error_burst;
1479 peer->rate_last = now;
1480 if (peer->rate_tokens >= ip_rt_error_cost)
1481 peer->rate_tokens -= ip_rt_error_cost;
1482 else
1483 send = false;
1484 }
1485 if (send)
1486 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1487
1488 out: kfree_skb(skb);
1489 return 0;
1490 }
1491
1492 /*
1493 * The last two values are not from the RFC but
1494 * are needed for AMPRnet AX.25 paths.
1495 */
1496
1497 static const unsigned short mtu_plateau[] =
1498 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1499
1500 static inline unsigned short guess_mtu(unsigned short old_mtu)
1501 {
1502 int i;
1503
1504 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1505 if (old_mtu > mtu_plateau[i])
1506 return mtu_plateau[i];
1507 return 68;
1508 }
1509
1510 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1511 unsigned short new_mtu,
1512 struct net_device *dev)
1513 {
1514 unsigned short old_mtu = ntohs(iph->tot_len);
1515 unsigned short est_mtu = 0;
1516 struct inet_peer *peer;
1517
1518 peer = inet_getpeer_v4(iph->daddr, 1);
1519 if (peer) {
1520 unsigned short mtu = new_mtu;
1521
1522 if (new_mtu < 68 || new_mtu >= old_mtu) {
1523 /* BSD 4.2 derived systems incorrectly adjust
1524 * tot_len by the IP header length, and report
1525 * a zero MTU in the ICMP message.
1526 */
1527 if (mtu == 0 &&
1528 old_mtu >= 68 + (iph->ihl << 2))
1529 old_mtu -= iph->ihl << 2;
1530 mtu = guess_mtu(old_mtu);
1531 }
1532
1533 if (mtu < ip_rt_min_pmtu)
1534 mtu = ip_rt_min_pmtu;
1535 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1536 unsigned long pmtu_expires;
1537
1538 pmtu_expires = jiffies + ip_rt_mtu_expires;
1539 if (!pmtu_expires)
1540 pmtu_expires = 1UL;
1541
1542 est_mtu = mtu;
1543 peer->pmtu_learned = mtu;
1544 peer->pmtu_expires = pmtu_expires;
1545 }
1546
1547 inet_putpeer(peer);
1548
1549 atomic_inc(&__rt_peer_genid);
1550 }
1551 return est_mtu ? : new_mtu;
1552 }
1553
1554 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1555 {
1556 unsigned long expires = peer->pmtu_expires;
1557
1558 if (time_before(jiffies, expires)) {
1559 u32 orig_dst_mtu = dst_mtu(dst);
1560 if (peer->pmtu_learned < orig_dst_mtu) {
1561 if (!peer->pmtu_orig)
1562 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1563 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1564 }
1565 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1566 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1567 }
1568
1569 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1570 {
1571 struct rtable *rt = (struct rtable *) dst;
1572 struct inet_peer *peer;
1573
1574 dst_confirm(dst);
1575
1576 if (!rt->peer)
1577 rt_bind_peer(rt, 1);
1578 peer = rt->peer;
1579 if (peer) {
1580 if (mtu < ip_rt_min_pmtu)
1581 mtu = ip_rt_min_pmtu;
1582 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1583 unsigned long pmtu_expires;
1584
1585 pmtu_expires = jiffies + ip_rt_mtu_expires;
1586 if (!pmtu_expires)
1587 pmtu_expires = 1UL;
1588
1589 peer->pmtu_learned = mtu;
1590 peer->pmtu_expires = pmtu_expires;
1591
1592 atomic_inc(&__rt_peer_genid);
1593 rt->rt_peer_genid = rt_peer_genid();
1594 }
1595 check_peer_pmtu(dst, peer);
1596 }
1597 }
1598
1599 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1600 {
1601 struct rtable *rt = (struct rtable *) dst;
1602 __be32 orig_gw = rt->rt_gateway;
1603
1604 dst_confirm(&rt->dst);
1605
1606 neigh_release(rt->dst.neighbour);
1607 rt->dst.neighbour = NULL;
1608
1609 rt->rt_gateway = peer->redirect_learned.a4;
1610 if (arp_bind_neighbour(&rt->dst) ||
1611 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1612 if (rt->dst.neighbour)
1613 neigh_event_send(rt->dst.neighbour, NULL);
1614 rt->rt_gateway = orig_gw;
1615 return -EAGAIN;
1616 } else {
1617 rt->rt_flags |= RTCF_REDIRECTED;
1618 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1619 rt->dst.neighbour);
1620 }
1621 return 0;
1622 }
1623
1624 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1625 {
1626 struct rtable *rt = (struct rtable *) dst;
1627
1628 if (rt_is_expired(rt))
1629 return NULL;
1630 if (rt->rt_peer_genid != rt_peer_genid()) {
1631 struct inet_peer *peer;
1632
1633 if (!rt->peer)
1634 rt_bind_peer(rt, 0);
1635
1636 peer = rt->peer;
1637 if (peer && peer->pmtu_expires)
1638 check_peer_pmtu(dst, peer);
1639
1640 if (peer && peer->redirect_learned.a4 &&
1641 peer->redirect_learned.a4 != rt->rt_gateway) {
1642 if (check_peer_redir(dst, peer))
1643 return NULL;
1644 }
1645
1646 rt->rt_peer_genid = rt_peer_genid();
1647 }
1648 return dst;
1649 }
1650
1651 static void ipv4_dst_destroy(struct dst_entry *dst)
1652 {
1653 struct rtable *rt = (struct rtable *) dst;
1654 struct inet_peer *peer = rt->peer;
1655
1656 if (rt->fi) {
1657 fib_info_put(rt->fi);
1658 rt->fi = NULL;
1659 }
1660 if (peer) {
1661 rt->peer = NULL;
1662 inet_putpeer(peer);
1663 }
1664 }
1665
1666
1667 static void ipv4_link_failure(struct sk_buff *skb)
1668 {
1669 struct rtable *rt;
1670
1671 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1672
1673 rt = skb_rtable(skb);
1674 if (rt &&
1675 rt->peer &&
1676 rt->peer->pmtu_expires) {
1677 unsigned long orig = rt->peer->pmtu_expires;
1678
1679 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1680 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1681 }
1682 }
1683
1684 static int ip_rt_bug(struct sk_buff *skb)
1685 {
1686 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1687 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1688 skb->dev ? skb->dev->name : "?");
1689 kfree_skb(skb);
1690 return 0;
1691 }
1692
1693 /*
1694 We do not cache source address of outgoing interface,
1695 because it is used only by IP RR, TS and SRR options,
1696 so that it out of fast path.
1697
1698 BTW remember: "addr" is allowed to be not aligned
1699 in IP options!
1700 */
1701
1702 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1703 {
1704 __be32 src;
1705
1706 if (rt_is_output_route(rt))
1707 src = ip_hdr(skb)->saddr;
1708 else {
1709 struct fib_result res;
1710 struct flowi4 fl4;
1711 struct iphdr *iph;
1712
1713 iph = ip_hdr(skb);
1714
1715 memset(&fl4, 0, sizeof(fl4));
1716 fl4.daddr = iph->daddr;
1717 fl4.saddr = iph->saddr;
1718 fl4.flowi4_tos = iph->tos;
1719 fl4.flowi4_oif = rt->dst.dev->ifindex;
1720 fl4.flowi4_iif = skb->dev->ifindex;
1721 fl4.flowi4_mark = skb->mark;
1722
1723 rcu_read_lock();
1724 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1725 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1726 else
1727 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1728 RT_SCOPE_UNIVERSE);
1729 rcu_read_unlock();
1730 }
1731 memcpy(addr, &src, 4);
1732 }
1733
1734 #ifdef CONFIG_IP_ROUTE_CLASSID
1735 static void set_class_tag(struct rtable *rt, u32 tag)
1736 {
1737 if (!(rt->dst.tclassid & 0xFFFF))
1738 rt->dst.tclassid |= tag & 0xFFFF;
1739 if (!(rt->dst.tclassid & 0xFFFF0000))
1740 rt->dst.tclassid |= tag & 0xFFFF0000;
1741 }
1742 #endif
1743
1744 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1745 {
1746 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1747
1748 if (advmss == 0) {
1749 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1750 ip_rt_min_advmss);
1751 if (advmss > 65535 - 40)
1752 advmss = 65535 - 40;
1753 }
1754 return advmss;
1755 }
1756
1757 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1758 {
1759 unsigned int mtu = dst->dev->mtu;
1760
1761 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1762 const struct rtable *rt = (const struct rtable *) dst;
1763
1764 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1765 mtu = 576;
1766 }
1767
1768 if (mtu > IP_MAX_MTU)
1769 mtu = IP_MAX_MTU;
1770
1771 return mtu;
1772 }
1773
1774 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1775 struct fib_info *fi)
1776 {
1777 struct inet_peer *peer;
1778 int create = 0;
1779
1780 /* If a peer entry exists for this destination, we must hook
1781 * it up in order to get at cached metrics.
1782 */
1783 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1784 create = 1;
1785
1786 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1787 if (peer) {
1788 rt->rt_peer_genid = rt_peer_genid();
1789 if (inet_metrics_new(peer))
1790 memcpy(peer->metrics, fi->fib_metrics,
1791 sizeof(u32) * RTAX_MAX);
1792 dst_init_metrics(&rt->dst, peer->metrics, false);
1793
1794 if (peer->pmtu_expires)
1795 check_peer_pmtu(&rt->dst, peer);
1796 if (peer->redirect_learned.a4 &&
1797 peer->redirect_learned.a4 != rt->rt_gateway) {
1798 rt->rt_gateway = peer->redirect_learned.a4;
1799 rt->rt_flags |= RTCF_REDIRECTED;
1800 }
1801 } else {
1802 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1803 rt->fi = fi;
1804 atomic_inc(&fi->fib_clntref);
1805 }
1806 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1807 }
1808 }
1809
1810 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1811 const struct fib_result *res,
1812 struct fib_info *fi, u16 type, u32 itag)
1813 {
1814 struct dst_entry *dst = &rt->dst;
1815
1816 if (fi) {
1817 if (FIB_RES_GW(*res) &&
1818 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1819 rt->rt_gateway = FIB_RES_GW(*res);
1820 rt_init_metrics(rt, fl4, fi);
1821 #ifdef CONFIG_IP_ROUTE_CLASSID
1822 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1823 #endif
1824 }
1825
1826 if (dst_mtu(dst) > IP_MAX_MTU)
1827 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1828 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1829 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1830
1831 #ifdef CONFIG_IP_ROUTE_CLASSID
1832 #ifdef CONFIG_IP_MULTIPLE_TABLES
1833 set_class_tag(rt, fib_rules_tclass(res));
1834 #endif
1835 set_class_tag(rt, itag);
1836 #endif
1837 }
1838
1839 static struct rtable *rt_dst_alloc(struct net_device *dev,
1840 bool nopolicy, bool noxfrm)
1841 {
1842 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1843 DST_HOST |
1844 (nopolicy ? DST_NOPOLICY : 0) |
1845 (noxfrm ? DST_NOXFRM : 0));
1846 }
1847
1848 /* called in rcu_read_lock() section */
1849 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1850 u8 tos, struct net_device *dev, int our)
1851 {
1852 unsigned int hash;
1853 struct rtable *rth;
1854 __be32 spec_dst;
1855 struct in_device *in_dev = __in_dev_get_rcu(dev);
1856 u32 itag = 0;
1857 int err;
1858
1859 /* Primary sanity checks. */
1860
1861 if (in_dev == NULL)
1862 return -EINVAL;
1863
1864 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1865 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1866 goto e_inval;
1867
1868 if (ipv4_is_zeronet(saddr)) {
1869 if (!ipv4_is_local_multicast(daddr))
1870 goto e_inval;
1871 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1872 } else {
1873 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1874 &itag);
1875 if (err < 0)
1876 goto e_err;
1877 }
1878 rth = rt_dst_alloc(init_net.loopback_dev,
1879 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1880 if (!rth)
1881 goto e_nobufs;
1882
1883 #ifdef CONFIG_IP_ROUTE_CLASSID
1884 rth->dst.tclassid = itag;
1885 #endif
1886 rth->dst.output = ip_rt_bug;
1887
1888 rth->rt_key_dst = daddr;
1889 rth->rt_key_src = saddr;
1890 rth->rt_genid = rt_genid(dev_net(dev));
1891 rth->rt_flags = RTCF_MULTICAST;
1892 rth->rt_type = RTN_MULTICAST;
1893 rth->rt_key_tos = tos;
1894 rth->rt_dst = daddr;
1895 rth->rt_src = saddr;
1896 rth->rt_route_iif = dev->ifindex;
1897 rth->rt_iif = dev->ifindex;
1898 rth->rt_oif = 0;
1899 rth->rt_mark = skb->mark;
1900 rth->rt_gateway = daddr;
1901 rth->rt_spec_dst= spec_dst;
1902 rth->rt_peer_genid = 0;
1903 rth->peer = NULL;
1904 rth->fi = NULL;
1905 if (our) {
1906 rth->dst.input= ip_local_deliver;
1907 rth->rt_flags |= RTCF_LOCAL;
1908 }
1909
1910 #ifdef CONFIG_IP_MROUTE
1911 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1912 rth->dst.input = ip_mr_input;
1913 #endif
1914 RT_CACHE_STAT_INC(in_slow_mc);
1915
1916 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1917 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1918 err = 0;
1919 if (IS_ERR(rth))
1920 err = PTR_ERR(rth);
1921
1922 e_nobufs:
1923 return -ENOBUFS;
1924 e_inval:
1925 return -EINVAL;
1926 e_err:
1927 return err;
1928 }
1929
1930
1931 static void ip_handle_martian_source(struct net_device *dev,
1932 struct in_device *in_dev,
1933 struct sk_buff *skb,
1934 __be32 daddr,
1935 __be32 saddr)
1936 {
1937 RT_CACHE_STAT_INC(in_martian_src);
1938 #ifdef CONFIG_IP_ROUTE_VERBOSE
1939 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1940 /*
1941 * RFC1812 recommendation, if source is martian,
1942 * the only hint is MAC header.
1943 */
1944 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1945 &daddr, &saddr, dev->name);
1946 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1947 int i;
1948 const unsigned char *p = skb_mac_header(skb);
1949 printk(KERN_WARNING "ll header: ");
1950 for (i = 0; i < dev->hard_header_len; i++, p++) {
1951 printk("%02x", *p);
1952 if (i < (dev->hard_header_len - 1))
1953 printk(":");
1954 }
1955 printk("\n");
1956 }
1957 }
1958 #endif
1959 }
1960
1961 /* called in rcu_read_lock() section */
1962 static int __mkroute_input(struct sk_buff *skb,
1963 const struct fib_result *res,
1964 struct in_device *in_dev,
1965 __be32 daddr, __be32 saddr, u32 tos,
1966 struct rtable **result)
1967 {
1968 struct rtable *rth;
1969 int err;
1970 struct in_device *out_dev;
1971 unsigned int flags = 0;
1972 __be32 spec_dst;
1973 u32 itag;
1974
1975 /* get a working reference to the output device */
1976 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1977 if (out_dev == NULL) {
1978 if (net_ratelimit())
1979 printk(KERN_CRIT "Bug in ip_route_input" \
1980 "_slow(). Please, report\n");
1981 return -EINVAL;
1982 }
1983
1984
1985 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1986 in_dev->dev, &spec_dst, &itag);
1987 if (err < 0) {
1988 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1989 saddr);
1990
1991 goto cleanup;
1992 }
1993
1994 if (err)
1995 flags |= RTCF_DIRECTSRC;
1996
1997 if (out_dev == in_dev && err &&
1998 (IN_DEV_SHARED_MEDIA(out_dev) ||
1999 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2000 flags |= RTCF_DOREDIRECT;
2001
2002 if (skb->protocol != htons(ETH_P_IP)) {
2003 /* Not IP (i.e. ARP). Do not create route, if it is
2004 * invalid for proxy arp. DNAT routes are always valid.
2005 *
2006 * Proxy arp feature have been extended to allow, ARP
2007 * replies back to the same interface, to support
2008 * Private VLAN switch technologies. See arp.c.
2009 */
2010 if (out_dev == in_dev &&
2011 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2012 err = -EINVAL;
2013 goto cleanup;
2014 }
2015 }
2016
2017 rth = rt_dst_alloc(out_dev->dev,
2018 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2019 IN_DEV_CONF_GET(out_dev, NOXFRM));
2020 if (!rth) {
2021 err = -ENOBUFS;
2022 goto cleanup;
2023 }
2024
2025 rth->rt_key_dst = daddr;
2026 rth->rt_key_src = saddr;
2027 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2028 rth->rt_flags = flags;
2029 rth->rt_type = res->type;
2030 rth->rt_key_tos = tos;
2031 rth->rt_dst = daddr;
2032 rth->rt_src = saddr;
2033 rth->rt_route_iif = in_dev->dev->ifindex;
2034 rth->rt_iif = in_dev->dev->ifindex;
2035 rth->rt_oif = 0;
2036 rth->rt_mark = skb->mark;
2037 rth->rt_gateway = daddr;
2038 rth->rt_spec_dst= spec_dst;
2039 rth->rt_peer_genid = 0;
2040 rth->peer = NULL;
2041 rth->fi = NULL;
2042
2043 rth->dst.input = ip_forward;
2044 rth->dst.output = ip_output;
2045
2046 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2047
2048 *result = rth;
2049 err = 0;
2050 cleanup:
2051 return err;
2052 }
2053
2054 static int ip_mkroute_input(struct sk_buff *skb,
2055 struct fib_result *res,
2056 const struct flowi4 *fl4,
2057 struct in_device *in_dev,
2058 __be32 daddr, __be32 saddr, u32 tos)
2059 {
2060 struct rtable* rth = NULL;
2061 int err;
2062 unsigned hash;
2063
2064 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2065 if (res->fi && res->fi->fib_nhs > 1)
2066 fib_select_multipath(res);
2067 #endif
2068
2069 /* create a routing cache entry */
2070 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2071 if (err)
2072 return err;
2073
2074 /* put it into the cache */
2075 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2076 rt_genid(dev_net(rth->dst.dev)));
2077 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2078 if (IS_ERR(rth))
2079 return PTR_ERR(rth);
2080 return 0;
2081 }
2082
2083 /*
2084 * NOTE. We drop all the packets that has local source
2085 * addresses, because every properly looped back packet
2086 * must have correct destination already attached by output routine.
2087 *
2088 * Such approach solves two big problems:
2089 * 1. Not simplex devices are handled properly.
2090 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2091 * called with rcu_read_lock()
2092 */
2093
2094 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2095 u8 tos, struct net_device *dev)
2096 {
2097 struct fib_result res;
2098 struct in_device *in_dev = __in_dev_get_rcu(dev);
2099 struct flowi4 fl4;
2100 unsigned flags = 0;
2101 u32 itag = 0;
2102 struct rtable * rth;
2103 unsigned hash;
2104 __be32 spec_dst;
2105 int err = -EINVAL;
2106 struct net * net = dev_net(dev);
2107
2108 /* IP on this device is disabled. */
2109
2110 if (!in_dev)
2111 goto out;
2112
2113 /* Check for the most weird martians, which can be not detected
2114 by fib_lookup.
2115 */
2116
2117 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2118 ipv4_is_loopback(saddr))
2119 goto martian_source;
2120
2121 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2122 goto brd_input;
2123
2124 /* Accept zero addresses only to limited broadcast;
2125 * I even do not know to fix it or not. Waiting for complains :-)
2126 */
2127 if (ipv4_is_zeronet(saddr))
2128 goto martian_source;
2129
2130 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2131 goto martian_destination;
2132
2133 /*
2134 * Now we are ready to route packet.
2135 */
2136 fl4.flowi4_oif = 0;
2137 fl4.flowi4_iif = dev->ifindex;
2138 fl4.flowi4_mark = skb->mark;
2139 fl4.flowi4_tos = tos;
2140 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2141 fl4.daddr = daddr;
2142 fl4.saddr = saddr;
2143 err = fib_lookup(net, &fl4, &res);
2144 if (err != 0) {
2145 if (!IN_DEV_FORWARD(in_dev))
2146 goto e_hostunreach;
2147 goto no_route;
2148 }
2149
2150 RT_CACHE_STAT_INC(in_slow_tot);
2151
2152 if (res.type == RTN_BROADCAST)
2153 goto brd_input;
2154
2155 if (res.type == RTN_LOCAL) {
2156 err = fib_validate_source(skb, saddr, daddr, tos,
2157 net->loopback_dev->ifindex,
2158 dev, &spec_dst, &itag);
2159 if (err < 0)
2160 goto martian_source_keep_err;
2161 if (err)
2162 flags |= RTCF_DIRECTSRC;
2163 spec_dst = daddr;
2164 goto local_input;
2165 }
2166
2167 if (!IN_DEV_FORWARD(in_dev))
2168 goto e_hostunreach;
2169 if (res.type != RTN_UNICAST)
2170 goto martian_destination;
2171
2172 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2173 out: return err;
2174
2175 brd_input:
2176 if (skb->protocol != htons(ETH_P_IP))
2177 goto e_inval;
2178
2179 if (ipv4_is_zeronet(saddr))
2180 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2181 else {
2182 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2183 &itag);
2184 if (err < 0)
2185 goto martian_source_keep_err;
2186 if (err)
2187 flags |= RTCF_DIRECTSRC;
2188 }
2189 flags |= RTCF_BROADCAST;
2190 res.type = RTN_BROADCAST;
2191 RT_CACHE_STAT_INC(in_brd);
2192
2193 local_input:
2194 rth = rt_dst_alloc(net->loopback_dev,
2195 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2196 if (!rth)
2197 goto e_nobufs;
2198
2199 rth->dst.input= ip_local_deliver;
2200 rth->dst.output= ip_rt_bug;
2201 #ifdef CONFIG_IP_ROUTE_CLASSID
2202 rth->dst.tclassid = itag;
2203 #endif
2204
2205 rth->rt_key_dst = daddr;
2206 rth->rt_key_src = saddr;
2207 rth->rt_genid = rt_genid(net);
2208 rth->rt_flags = flags|RTCF_LOCAL;
2209 rth->rt_type = res.type;
2210 rth->rt_key_tos = tos;
2211 rth->rt_dst = daddr;
2212 rth->rt_src = saddr;
2213 #ifdef CONFIG_IP_ROUTE_CLASSID
2214 rth->dst.tclassid = itag;
2215 #endif
2216 rth->rt_route_iif = dev->ifindex;
2217 rth->rt_iif = dev->ifindex;
2218 rth->rt_oif = 0;
2219 rth->rt_mark = skb->mark;
2220 rth->rt_gateway = daddr;
2221 rth->rt_spec_dst= spec_dst;
2222 rth->rt_peer_genid = 0;
2223 rth->peer = NULL;
2224 rth->fi = NULL;
2225 if (res.type == RTN_UNREACHABLE) {
2226 rth->dst.input= ip_error;
2227 rth->dst.error= -err;
2228 rth->rt_flags &= ~RTCF_LOCAL;
2229 }
2230 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2231 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2232 err = 0;
2233 if (IS_ERR(rth))
2234 err = PTR_ERR(rth);
2235 goto out;
2236
2237 no_route:
2238 RT_CACHE_STAT_INC(in_no_route);
2239 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2240 res.type = RTN_UNREACHABLE;
2241 if (err == -ESRCH)
2242 err = -ENETUNREACH;
2243 goto local_input;
2244
2245 /*
2246 * Do not cache martian addresses: they should be logged (RFC1812)
2247 */
2248 martian_destination:
2249 RT_CACHE_STAT_INC(in_martian_dst);
2250 #ifdef CONFIG_IP_ROUTE_VERBOSE
2251 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2252 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2253 &daddr, &saddr, dev->name);
2254 #endif
2255
2256 e_hostunreach:
2257 err = -EHOSTUNREACH;
2258 goto out;
2259
2260 e_inval:
2261 err = -EINVAL;
2262 goto out;
2263
2264 e_nobufs:
2265 err = -ENOBUFS;
2266 goto out;
2267
2268 martian_source:
2269 err = -EINVAL;
2270 martian_source_keep_err:
2271 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2272 goto out;
2273 }
2274
2275 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2276 u8 tos, struct net_device *dev, bool noref)
2277 {
2278 struct rtable * rth;
2279 unsigned hash;
2280 int iif = dev->ifindex;
2281 struct net *net;
2282 int res;
2283
2284 net = dev_net(dev);
2285
2286 rcu_read_lock();
2287
2288 if (!rt_caching(net))
2289 goto skip_cache;
2290
2291 tos &= IPTOS_RT_MASK;
2292 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2293
2294 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2295 rth = rcu_dereference(rth->dst.rt_next)) {
2296 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2297 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2298 (rth->rt_iif ^ iif) |
2299 rth->rt_oif |
2300 (rth->rt_key_tos ^ tos)) == 0 &&
2301 rth->rt_mark == skb->mark &&
2302 net_eq(dev_net(rth->dst.dev), net) &&
2303 !rt_is_expired(rth)) {
2304 if (noref) {
2305 dst_use_noref(&rth->dst, jiffies);
2306 skb_dst_set_noref(skb, &rth->dst);
2307 } else {
2308 dst_use(&rth->dst, jiffies);
2309 skb_dst_set(skb, &rth->dst);
2310 }
2311 RT_CACHE_STAT_INC(in_hit);
2312 rcu_read_unlock();
2313 return 0;
2314 }
2315 RT_CACHE_STAT_INC(in_hlist_search);
2316 }
2317
2318 skip_cache:
2319 /* Multicast recognition logic is moved from route cache to here.
2320 The problem was that too many Ethernet cards have broken/missing
2321 hardware multicast filters :-( As result the host on multicasting
2322 network acquires a lot of useless route cache entries, sort of
2323 SDR messages from all the world. Now we try to get rid of them.
2324 Really, provided software IP multicast filter is organized
2325 reasonably (at least, hashed), it does not result in a slowdown
2326 comparing with route cache reject entries.
2327 Note, that multicast routers are not affected, because
2328 route cache entry is created eventually.
2329 */
2330 if (ipv4_is_multicast(daddr)) {
2331 struct in_device *in_dev = __in_dev_get_rcu(dev);
2332
2333 if (in_dev) {
2334 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2335 ip_hdr(skb)->protocol);
2336 if (our
2337 #ifdef CONFIG_IP_MROUTE
2338 ||
2339 (!ipv4_is_local_multicast(daddr) &&
2340 IN_DEV_MFORWARD(in_dev))
2341 #endif
2342 ) {
2343 int res = ip_route_input_mc(skb, daddr, saddr,
2344 tos, dev, our);
2345 rcu_read_unlock();
2346 return res;
2347 }
2348 }
2349 rcu_read_unlock();
2350 return -EINVAL;
2351 }
2352 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2353 rcu_read_unlock();
2354 return res;
2355 }
2356 EXPORT_SYMBOL(ip_route_input_common);
2357
2358 /* called with rcu_read_lock() */
2359 static struct rtable *__mkroute_output(const struct fib_result *res,
2360 const struct flowi4 *fl4,
2361 __be32 orig_daddr, __be32 orig_saddr,
2362 int orig_oif, struct net_device *dev_out,
2363 unsigned int flags)
2364 {
2365 struct fib_info *fi = res->fi;
2366 u32 tos = RT_FL_TOS(fl4);
2367 struct in_device *in_dev;
2368 u16 type = res->type;
2369 struct rtable *rth;
2370
2371 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2372 return ERR_PTR(-EINVAL);
2373
2374 if (ipv4_is_lbcast(fl4->daddr))
2375 type = RTN_BROADCAST;
2376 else if (ipv4_is_multicast(fl4->daddr))
2377 type = RTN_MULTICAST;
2378 else if (ipv4_is_zeronet(fl4->daddr))
2379 return ERR_PTR(-EINVAL);
2380
2381 if (dev_out->flags & IFF_LOOPBACK)
2382 flags |= RTCF_LOCAL;
2383
2384 in_dev = __in_dev_get_rcu(dev_out);
2385 if (!in_dev)
2386 return ERR_PTR(-EINVAL);
2387
2388 if (type == RTN_BROADCAST) {
2389 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2390 fi = NULL;
2391 } else if (type == RTN_MULTICAST) {
2392 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2393 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2394 fl4->flowi4_proto))
2395 flags &= ~RTCF_LOCAL;
2396 /* If multicast route do not exist use
2397 * default one, but do not gateway in this case.
2398 * Yes, it is hack.
2399 */
2400 if (fi && res->prefixlen < 4)
2401 fi = NULL;
2402 }
2403
2404 rth = rt_dst_alloc(dev_out,
2405 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2406 IN_DEV_CONF_GET(in_dev, NOXFRM));
2407 if (!rth)
2408 return ERR_PTR(-ENOBUFS);
2409
2410 rth->dst.output = ip_output;
2411
2412 rth->rt_key_dst = orig_daddr;
2413 rth->rt_key_src = orig_saddr;
2414 rth->rt_genid = rt_genid(dev_net(dev_out));
2415 rth->rt_flags = flags;
2416 rth->rt_type = type;
2417 rth->rt_key_tos = tos;
2418 rth->rt_dst = fl4->daddr;
2419 rth->rt_src = fl4->saddr;
2420 rth->rt_route_iif = 0;
2421 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2422 rth->rt_oif = orig_oif;
2423 rth->rt_mark = fl4->flowi4_mark;
2424 rth->rt_gateway = fl4->daddr;
2425 rth->rt_spec_dst= fl4->saddr;
2426 rth->rt_peer_genid = 0;
2427 rth->peer = NULL;
2428 rth->fi = NULL;
2429
2430 RT_CACHE_STAT_INC(out_slow_tot);
2431
2432 if (flags & RTCF_LOCAL) {
2433 rth->dst.input = ip_local_deliver;
2434 rth->rt_spec_dst = fl4->daddr;
2435 }
2436 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2437 rth->rt_spec_dst = fl4->saddr;
2438 if (flags & RTCF_LOCAL &&
2439 !(dev_out->flags & IFF_LOOPBACK)) {
2440 rth->dst.output = ip_mc_output;
2441 RT_CACHE_STAT_INC(out_slow_mc);
2442 }
2443 #ifdef CONFIG_IP_MROUTE
2444 if (type == RTN_MULTICAST) {
2445 if (IN_DEV_MFORWARD(in_dev) &&
2446 !ipv4_is_local_multicast(fl4->daddr)) {
2447 rth->dst.input = ip_mr_input;
2448 rth->dst.output = ip_mc_output;
2449 }
2450 }
2451 #endif
2452 }
2453
2454 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2455
2456 return rth;
2457 }
2458
2459 /*
2460 * Major route resolver routine.
2461 * called with rcu_read_lock();
2462 */
2463
2464 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2465 {
2466 struct net_device *dev_out = NULL;
2467 u32 tos = RT_FL_TOS(fl4);
2468 unsigned int flags = 0;
2469 struct fib_result res;
2470 struct rtable *rth;
2471 __be32 orig_daddr;
2472 __be32 orig_saddr;
2473 int orig_oif;
2474
2475 res.fi = NULL;
2476 #ifdef CONFIG_IP_MULTIPLE_TABLES
2477 res.r = NULL;
2478 #endif
2479
2480 orig_daddr = fl4->daddr;
2481 orig_saddr = fl4->saddr;
2482 orig_oif = fl4->flowi4_oif;
2483
2484 fl4->flowi4_iif = net->loopback_dev->ifindex;
2485 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2486 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2487 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2488
2489 rcu_read_lock();
2490 if (fl4->saddr) {
2491 rth = ERR_PTR(-EINVAL);
2492 if (ipv4_is_multicast(fl4->saddr) ||
2493 ipv4_is_lbcast(fl4->saddr) ||
2494 ipv4_is_zeronet(fl4->saddr))
2495 goto out;
2496
2497 /* I removed check for oif == dev_out->oif here.
2498 It was wrong for two reasons:
2499 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2500 is assigned to multiple interfaces.
2501 2. Moreover, we are allowed to send packets with saddr
2502 of another iface. --ANK
2503 */
2504
2505 if (fl4->flowi4_oif == 0 &&
2506 (ipv4_is_multicast(fl4->daddr) ||
2507 ipv4_is_lbcast(fl4->daddr))) {
2508 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2509 dev_out = __ip_dev_find(net, fl4->saddr, false);
2510 if (dev_out == NULL)
2511 goto out;
2512
2513 /* Special hack: user can direct multicasts
2514 and limited broadcast via necessary interface
2515 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2516 This hack is not just for fun, it allows
2517 vic,vat and friends to work.
2518 They bind socket to loopback, set ttl to zero
2519 and expect that it will work.
2520 From the viewpoint of routing cache they are broken,
2521 because we are not allowed to build multicast path
2522 with loopback source addr (look, routing cache
2523 cannot know, that ttl is zero, so that packet
2524 will not leave this host and route is valid).
2525 Luckily, this hack is good workaround.
2526 */
2527
2528 fl4->flowi4_oif = dev_out->ifindex;
2529 goto make_route;
2530 }
2531
2532 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2533 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2534 if (!__ip_dev_find(net, fl4->saddr, false))
2535 goto out;
2536 }
2537 }
2538
2539
2540 if (fl4->flowi4_oif) {
2541 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2542 rth = ERR_PTR(-ENODEV);
2543 if (dev_out == NULL)
2544 goto out;
2545
2546 /* RACE: Check return value of inet_select_addr instead. */
2547 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2548 rth = ERR_PTR(-ENETUNREACH);
2549 goto out;
2550 }
2551 if (ipv4_is_local_multicast(fl4->daddr) ||
2552 ipv4_is_lbcast(fl4->daddr)) {
2553 if (!fl4->saddr)
2554 fl4->saddr = inet_select_addr(dev_out, 0,
2555 RT_SCOPE_LINK);
2556 goto make_route;
2557 }
2558 if (fl4->saddr) {
2559 if (ipv4_is_multicast(fl4->daddr))
2560 fl4->saddr = inet_select_addr(dev_out, 0,
2561 fl4->flowi4_scope);
2562 else if (!fl4->daddr)
2563 fl4->saddr = inet_select_addr(dev_out, 0,
2564 RT_SCOPE_HOST);
2565 }
2566 }
2567
2568 if (!fl4->daddr) {
2569 fl4->daddr = fl4->saddr;
2570 if (!fl4->daddr)
2571 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2572 dev_out = net->loopback_dev;
2573 fl4->flowi4_oif = net->loopback_dev->ifindex;
2574 res.type = RTN_LOCAL;
2575 flags |= RTCF_LOCAL;
2576 goto make_route;
2577 }
2578
2579 if (fib_lookup(net, fl4, &res)) {
2580 res.fi = NULL;
2581 if (fl4->flowi4_oif) {
2582 /* Apparently, routing tables are wrong. Assume,
2583 that the destination is on link.
2584
2585 WHY? DW.
2586 Because we are allowed to send to iface
2587 even if it has NO routes and NO assigned
2588 addresses. When oif is specified, routing
2589 tables are looked up with only one purpose:
2590 to catch if destination is gatewayed, rather than
2591 direct. Moreover, if MSG_DONTROUTE is set,
2592 we send packet, ignoring both routing tables
2593 and ifaddr state. --ANK
2594
2595
2596 We could make it even if oif is unknown,
2597 likely IPv6, but we do not.
2598 */
2599
2600 if (fl4->saddr == 0)
2601 fl4->saddr = inet_select_addr(dev_out, 0,
2602 RT_SCOPE_LINK);
2603 res.type = RTN_UNICAST;
2604 goto make_route;
2605 }
2606 rth = ERR_PTR(-ENETUNREACH);
2607 goto out;
2608 }
2609
2610 if (res.type == RTN_LOCAL) {
2611 if (!fl4->saddr) {
2612 if (res.fi->fib_prefsrc)
2613 fl4->saddr = res.fi->fib_prefsrc;
2614 else
2615 fl4->saddr = fl4->daddr;
2616 }
2617 dev_out = net->loopback_dev;
2618 fl4->flowi4_oif = dev_out->ifindex;
2619 res.fi = NULL;
2620 flags |= RTCF_LOCAL;
2621 goto make_route;
2622 }
2623
2624 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2625 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2626 fib_select_multipath(&res);
2627 else
2628 #endif
2629 if (!res.prefixlen &&
2630 res.table->tb_num_default > 1 &&
2631 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2632 fib_select_default(&res);
2633
2634 if (!fl4->saddr)
2635 fl4->saddr = FIB_RES_PREFSRC(net, res);
2636
2637 dev_out = FIB_RES_DEV(res);
2638 fl4->flowi4_oif = dev_out->ifindex;
2639
2640
2641 make_route:
2642 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2643 dev_out, flags);
2644 if (!IS_ERR(rth)) {
2645 unsigned int hash;
2646
2647 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2648 rt_genid(dev_net(dev_out)));
2649 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2650 }
2651
2652 out:
2653 rcu_read_unlock();
2654 return rth;
2655 }
2656
2657 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2658 {
2659 struct rtable *rth;
2660 unsigned int hash;
2661
2662 if (!rt_caching(net))
2663 goto slow_output;
2664
2665 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2666
2667 rcu_read_lock_bh();
2668 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2669 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2670 if (rth->rt_key_dst == flp4->daddr &&
2671 rth->rt_key_src == flp4->saddr &&
2672 rt_is_output_route(rth) &&
2673 rth->rt_oif == flp4->flowi4_oif &&
2674 rth->rt_mark == flp4->flowi4_mark &&
2675 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2676 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2677 net_eq(dev_net(rth->dst.dev), net) &&
2678 !rt_is_expired(rth)) {
2679 dst_use(&rth->dst, jiffies);
2680 RT_CACHE_STAT_INC(out_hit);
2681 rcu_read_unlock_bh();
2682 if (!flp4->saddr)
2683 flp4->saddr = rth->rt_src;
2684 if (!flp4->daddr)
2685 flp4->daddr = rth->rt_dst;
2686 return rth;
2687 }
2688 RT_CACHE_STAT_INC(out_hlist_search);
2689 }
2690 rcu_read_unlock_bh();
2691
2692 slow_output:
2693 return ip_route_output_slow(net, flp4);
2694 }
2695 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2696
2697 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2698 {
2699 return NULL;
2700 }
2701
2702 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2703 {
2704 return 0;
2705 }
2706
2707 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2708 {
2709 }
2710
2711 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2712 unsigned long old)
2713 {
2714 return NULL;
2715 }
2716
2717 static struct dst_ops ipv4_dst_blackhole_ops = {
2718 .family = AF_INET,
2719 .protocol = cpu_to_be16(ETH_P_IP),
2720 .destroy = ipv4_dst_destroy,
2721 .check = ipv4_blackhole_dst_check,
2722 .default_mtu = ipv4_blackhole_default_mtu,
2723 .default_advmss = ipv4_default_advmss,
2724 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2725 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2726 };
2727
2728 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2729 {
2730 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2731 struct rtable *ort = (struct rtable *) dst_orig;
2732
2733 if (rt) {
2734 struct dst_entry *new = &rt->dst;
2735
2736 new->__use = 1;
2737 new->input = dst_discard;
2738 new->output = dst_discard;
2739 dst_copy_metrics(new, &ort->dst);
2740
2741 new->dev = ort->dst.dev;
2742 if (new->dev)
2743 dev_hold(new->dev);
2744
2745 rt->rt_key_dst = ort->rt_key_dst;
2746 rt->rt_key_src = ort->rt_key_src;
2747 rt->rt_key_tos = ort->rt_key_tos;
2748 rt->rt_route_iif = ort->rt_route_iif;
2749 rt->rt_iif = ort->rt_iif;
2750 rt->rt_oif = ort->rt_oif;
2751 rt->rt_mark = ort->rt_mark;
2752
2753 rt->rt_genid = rt_genid(net);
2754 rt->rt_flags = ort->rt_flags;
2755 rt->rt_type = ort->rt_type;
2756 rt->rt_dst = ort->rt_dst;
2757 rt->rt_src = ort->rt_src;
2758 rt->rt_gateway = ort->rt_gateway;
2759 rt->rt_spec_dst = ort->rt_spec_dst;
2760 rt->peer = ort->peer;
2761 if (rt->peer)
2762 atomic_inc(&rt->peer->refcnt);
2763 rt->fi = ort->fi;
2764 if (rt->fi)
2765 atomic_inc(&rt->fi->fib_clntref);
2766
2767 dst_free(new);
2768 }
2769
2770 dst_release(dst_orig);
2771
2772 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2773 }
2774
2775 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2776 struct sock *sk)
2777 {
2778 struct rtable *rt = __ip_route_output_key(net, flp4);
2779
2780 if (IS_ERR(rt))
2781 return rt;
2782
2783 if (flp4->flowi4_proto)
2784 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2785 flowi4_to_flowi(flp4),
2786 sk, 0);
2787
2788 return rt;
2789 }
2790 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2791
2792 static int rt_fill_info(struct net *net,
2793 struct sk_buff *skb, u32 pid, u32 seq, int event,
2794 int nowait, unsigned int flags)
2795 {
2796 struct rtable *rt = skb_rtable(skb);
2797 struct rtmsg *r;
2798 struct nlmsghdr *nlh;
2799 long expires;
2800 u32 id = 0, ts = 0, tsage = 0, error;
2801
2802 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2803 if (nlh == NULL)
2804 return -EMSGSIZE;
2805
2806 r = nlmsg_data(nlh);
2807 r->rtm_family = AF_INET;
2808 r->rtm_dst_len = 32;
2809 r->rtm_src_len = 0;
2810 r->rtm_tos = rt->rt_key_tos;
2811 r->rtm_table = RT_TABLE_MAIN;
2812 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2813 r->rtm_type = rt->rt_type;
2814 r->rtm_scope = RT_SCOPE_UNIVERSE;
2815 r->rtm_protocol = RTPROT_UNSPEC;
2816 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2817 if (rt->rt_flags & RTCF_NOTIFY)
2818 r->rtm_flags |= RTM_F_NOTIFY;
2819
2820 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2821
2822 if (rt->rt_key_src) {
2823 r->rtm_src_len = 32;
2824 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2825 }
2826 if (rt->dst.dev)
2827 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2828 #ifdef CONFIG_IP_ROUTE_CLASSID
2829 if (rt->dst.tclassid)
2830 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2831 #endif
2832 if (rt_is_input_route(rt))
2833 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2834 else if (rt->rt_src != rt->rt_key_src)
2835 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2836
2837 if (rt->rt_dst != rt->rt_gateway)
2838 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2839
2840 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2841 goto nla_put_failure;
2842
2843 if (rt->rt_mark)
2844 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2845
2846 error = rt->dst.error;
2847 expires = (rt->peer && rt->peer->pmtu_expires) ?
2848 rt->peer->pmtu_expires - jiffies : 0;
2849 if (rt->peer) {
2850 inet_peer_refcheck(rt->peer);
2851 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2852 if (rt->peer->tcp_ts_stamp) {
2853 ts = rt->peer->tcp_ts;
2854 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2855 }
2856 }
2857
2858 if (rt_is_input_route(rt)) {
2859 #ifdef CONFIG_IP_MROUTE
2860 __be32 dst = rt->rt_dst;
2861
2862 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2863 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2864 int err = ipmr_get_route(net, skb,
2865 rt->rt_src, rt->rt_dst,
2866 r, nowait);
2867 if (err <= 0) {
2868 if (!nowait) {
2869 if (err == 0)
2870 return 0;
2871 goto nla_put_failure;
2872 } else {
2873 if (err == -EMSGSIZE)
2874 goto nla_put_failure;
2875 error = err;
2876 }
2877 }
2878 } else
2879 #endif
2880 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2881 }
2882
2883 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2884 expires, error) < 0)
2885 goto nla_put_failure;
2886
2887 return nlmsg_end(skb, nlh);
2888
2889 nla_put_failure:
2890 nlmsg_cancel(skb, nlh);
2891 return -EMSGSIZE;
2892 }
2893
2894 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2895 {
2896 struct net *net = sock_net(in_skb->sk);
2897 struct rtmsg *rtm;
2898 struct nlattr *tb[RTA_MAX+1];
2899 struct rtable *rt = NULL;
2900 __be32 dst = 0;
2901 __be32 src = 0;
2902 u32 iif;
2903 int err;
2904 int mark;
2905 struct sk_buff *skb;
2906
2907 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2908 if (err < 0)
2909 goto errout;
2910
2911 rtm = nlmsg_data(nlh);
2912
2913 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2914 if (skb == NULL) {
2915 err = -ENOBUFS;
2916 goto errout;
2917 }
2918
2919 /* Reserve room for dummy headers, this skb can pass
2920 through good chunk of routing engine.
2921 */
2922 skb_reset_mac_header(skb);
2923 skb_reset_network_header(skb);
2924
2925 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2926 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2927 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2928
2929 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2930 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2931 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2932 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2933
2934 if (iif) {
2935 struct net_device *dev;
2936
2937 dev = __dev_get_by_index(net, iif);
2938 if (dev == NULL) {
2939 err = -ENODEV;
2940 goto errout_free;
2941 }
2942
2943 skb->protocol = htons(ETH_P_IP);
2944 skb->dev = dev;
2945 skb->mark = mark;
2946 local_bh_disable();
2947 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2948 local_bh_enable();
2949
2950 rt = skb_rtable(skb);
2951 if (err == 0 && rt->dst.error)
2952 err = -rt->dst.error;
2953 } else {
2954 struct flowi4 fl4 = {
2955 .daddr = dst,
2956 .saddr = src,
2957 .flowi4_tos = rtm->rtm_tos,
2958 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2959 .flowi4_mark = mark,
2960 };
2961 rt = ip_route_output_key(net, &fl4);
2962
2963 err = 0;
2964 if (IS_ERR(rt))
2965 err = PTR_ERR(rt);
2966 }
2967
2968 if (err)
2969 goto errout_free;
2970
2971 skb_dst_set(skb, &rt->dst);
2972 if (rtm->rtm_flags & RTM_F_NOTIFY)
2973 rt->rt_flags |= RTCF_NOTIFY;
2974
2975 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2976 RTM_NEWROUTE, 0, 0);
2977 if (err <= 0)
2978 goto errout_free;
2979
2980 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2981 errout:
2982 return err;
2983
2984 errout_free:
2985 kfree_skb(skb);
2986 goto errout;
2987 }
2988
2989 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2990 {
2991 struct rtable *rt;
2992 int h, s_h;
2993 int idx, s_idx;
2994 struct net *net;
2995
2996 net = sock_net(skb->sk);
2997
2998 s_h = cb->args[0];
2999 if (s_h < 0)
3000 s_h = 0;
3001 s_idx = idx = cb->args[1];
3002 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3003 if (!rt_hash_table[h].chain)
3004 continue;
3005 rcu_read_lock_bh();
3006 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3007 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3008 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3009 continue;
3010 if (rt_is_expired(rt))
3011 continue;
3012 skb_dst_set_noref(skb, &rt->dst);
3013 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3014 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3015 1, NLM_F_MULTI) <= 0) {
3016 skb_dst_drop(skb);
3017 rcu_read_unlock_bh();
3018 goto done;
3019 }
3020 skb_dst_drop(skb);
3021 }
3022 rcu_read_unlock_bh();
3023 }
3024
3025 done:
3026 cb->args[0] = h;
3027 cb->args[1] = idx;
3028 return skb->len;
3029 }
3030
3031 void ip_rt_multicast_event(struct in_device *in_dev)
3032 {
3033 rt_cache_flush(dev_net(in_dev->dev), 0);
3034 }
3035
3036 #ifdef CONFIG_SYSCTL
3037 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3038 void __user *buffer,
3039 size_t *lenp, loff_t *ppos)
3040 {
3041 if (write) {
3042 int flush_delay;
3043 ctl_table ctl;
3044 struct net *net;
3045
3046 memcpy(&ctl, __ctl, sizeof(ctl));
3047 ctl.data = &flush_delay;
3048 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3049
3050 net = (struct net *)__ctl->extra1;
3051 rt_cache_flush(net, flush_delay);
3052 return 0;
3053 }
3054
3055 return -EINVAL;
3056 }
3057
3058 static ctl_table ipv4_route_table[] = {
3059 {
3060 .procname = "gc_thresh",
3061 .data = &ipv4_dst_ops.gc_thresh,
3062 .maxlen = sizeof(int),
3063 .mode = 0644,
3064 .proc_handler = proc_dointvec,
3065 },
3066 {
3067 .procname = "max_size",
3068 .data = &ip_rt_max_size,
3069 .maxlen = sizeof(int),
3070 .mode = 0644,
3071 .proc_handler = proc_dointvec,
3072 },
3073 {
3074 /* Deprecated. Use gc_min_interval_ms */
3075
3076 .procname = "gc_min_interval",
3077 .data = &ip_rt_gc_min_interval,
3078 .maxlen = sizeof(int),
3079 .mode = 0644,
3080 .proc_handler = proc_dointvec_jiffies,
3081 },
3082 {
3083 .procname = "gc_min_interval_ms",
3084 .data = &ip_rt_gc_min_interval,
3085 .maxlen = sizeof(int),
3086 .mode = 0644,
3087 .proc_handler = proc_dointvec_ms_jiffies,
3088 },
3089 {
3090 .procname = "gc_timeout",
3091 .data = &ip_rt_gc_timeout,
3092 .maxlen = sizeof(int),
3093 .mode = 0644,
3094 .proc_handler = proc_dointvec_jiffies,
3095 },
3096 {
3097 .procname = "gc_interval",
3098 .data = &ip_rt_gc_interval,
3099 .maxlen = sizeof(int),
3100 .mode = 0644,
3101 .proc_handler = proc_dointvec_jiffies,
3102 },
3103 {
3104 .procname = "redirect_load",
3105 .data = &ip_rt_redirect_load,
3106 .maxlen = sizeof(int),
3107 .mode = 0644,
3108 .proc_handler = proc_dointvec,
3109 },
3110 {
3111 .procname = "redirect_number",
3112 .data = &ip_rt_redirect_number,
3113 .maxlen = sizeof(int),
3114 .mode = 0644,
3115 .proc_handler = proc_dointvec,
3116 },
3117 {
3118 .procname = "redirect_silence",
3119 .data = &ip_rt_redirect_silence,
3120 .maxlen = sizeof(int),
3121 .mode = 0644,
3122 .proc_handler = proc_dointvec,
3123 },
3124 {
3125 .procname = "error_cost",
3126 .data = &ip_rt_error_cost,
3127 .maxlen = sizeof(int),
3128 .mode = 0644,
3129 .proc_handler = proc_dointvec,
3130 },
3131 {
3132 .procname = "error_burst",
3133 .data = &ip_rt_error_burst,
3134 .maxlen = sizeof(int),
3135 .mode = 0644,
3136 .proc_handler = proc_dointvec,
3137 },
3138 {
3139 .procname = "gc_elasticity",
3140 .data = &ip_rt_gc_elasticity,
3141 .maxlen = sizeof(int),
3142 .mode = 0644,
3143 .proc_handler = proc_dointvec,
3144 },
3145 {
3146 .procname = "mtu_expires",
3147 .data = &ip_rt_mtu_expires,
3148 .maxlen = sizeof(int),
3149 .mode = 0644,
3150 .proc_handler = proc_dointvec_jiffies,
3151 },
3152 {
3153 .procname = "min_pmtu",
3154 .data = &ip_rt_min_pmtu,
3155 .maxlen = sizeof(int),
3156 .mode = 0644,
3157 .proc_handler = proc_dointvec,
3158 },
3159 {
3160 .procname = "min_adv_mss",
3161 .data = &ip_rt_min_advmss,
3162 .maxlen = sizeof(int),
3163 .mode = 0644,
3164 .proc_handler = proc_dointvec,
3165 },
3166 { }
3167 };
3168
3169 static struct ctl_table empty[1];
3170
3171 static struct ctl_table ipv4_skeleton[] =
3172 {
3173 { .procname = "route",
3174 .mode = 0555, .child = ipv4_route_table},
3175 { .procname = "neigh",
3176 .mode = 0555, .child = empty},
3177 { }
3178 };
3179
3180 static __net_initdata struct ctl_path ipv4_path[] = {
3181 { .procname = "net", },
3182 { .procname = "ipv4", },
3183 { },
3184 };
3185
3186 static struct ctl_table ipv4_route_flush_table[] = {
3187 {
3188 .procname = "flush",
3189 .maxlen = sizeof(int),
3190 .mode = 0200,
3191 .proc_handler = ipv4_sysctl_rtcache_flush,
3192 },
3193 { },
3194 };
3195
3196 static __net_initdata struct ctl_path ipv4_route_path[] = {
3197 { .procname = "net", },
3198 { .procname = "ipv4", },
3199 { .procname = "route", },
3200 { },
3201 };
3202
3203 static __net_init int sysctl_route_net_init(struct net *net)
3204 {
3205 struct ctl_table *tbl;
3206
3207 tbl = ipv4_route_flush_table;
3208 if (!net_eq(net, &init_net)) {
3209 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3210 if (tbl == NULL)
3211 goto err_dup;
3212 }
3213 tbl[0].extra1 = net;
3214
3215 net->ipv4.route_hdr =
3216 register_net_sysctl_table(net, ipv4_route_path, tbl);
3217 if (net->ipv4.route_hdr == NULL)
3218 goto err_reg;
3219 return 0;
3220
3221 err_reg:
3222 if (tbl != ipv4_route_flush_table)
3223 kfree(tbl);
3224 err_dup:
3225 return -ENOMEM;
3226 }
3227
3228 static __net_exit void sysctl_route_net_exit(struct net *net)
3229 {
3230 struct ctl_table *tbl;
3231
3232 tbl = net->ipv4.route_hdr->ctl_table_arg;
3233 unregister_net_sysctl_table(net->ipv4.route_hdr);
3234 BUG_ON(tbl == ipv4_route_flush_table);
3235 kfree(tbl);
3236 }
3237
3238 static __net_initdata struct pernet_operations sysctl_route_ops = {
3239 .init = sysctl_route_net_init,
3240 .exit = sysctl_route_net_exit,
3241 };
3242 #endif
3243
3244 static __net_init int rt_genid_init(struct net *net)
3245 {
3246 get_random_bytes(&net->ipv4.rt_genid,
3247 sizeof(net->ipv4.rt_genid));
3248 get_random_bytes(&net->ipv4.dev_addr_genid,
3249 sizeof(net->ipv4.dev_addr_genid));
3250 return 0;
3251 }
3252
3253 static __net_initdata struct pernet_operations rt_genid_ops = {
3254 .init = rt_genid_init,
3255 };
3256
3257
3258 #ifdef CONFIG_IP_ROUTE_CLASSID
3259 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3260 #endif /* CONFIG_IP_ROUTE_CLASSID */
3261
3262 static __initdata unsigned long rhash_entries;
3263 static int __init set_rhash_entries(char *str)
3264 {
3265 if (!str)
3266 return 0;
3267 rhash_entries = simple_strtoul(str, &str, 0);
3268 return 1;
3269 }
3270 __setup("rhash_entries=", set_rhash_entries);
3271
3272 int __init ip_rt_init(void)
3273 {
3274 int rc = 0;
3275
3276 #ifdef CONFIG_IP_ROUTE_CLASSID
3277 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3278 if (!ip_rt_acct)
3279 panic("IP: failed to allocate ip_rt_acct\n");
3280 #endif
3281
3282 ipv4_dst_ops.kmem_cachep =
3283 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3284 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3285
3286 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3287
3288 if (dst_entries_init(&ipv4_dst_ops) < 0)
3289 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3290
3291 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3292 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3293
3294 rt_hash_table = (struct rt_hash_bucket *)
3295 alloc_large_system_hash("IP route cache",
3296 sizeof(struct rt_hash_bucket),
3297 rhash_entries,
3298 (totalram_pages >= 128 * 1024) ?
3299 15 : 17,
3300 0,
3301 &rt_hash_log,
3302 &rt_hash_mask,
3303 rhash_entries ? 0 : 512 * 1024);
3304 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3305 rt_hash_lock_init();
3306
3307 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3308 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3309
3310 devinet_init();
3311 ip_fib_init();
3312
3313 if (ip_rt_proc_init())
3314 printk(KERN_ERR "Unable to create route proc files\n");
3315 #ifdef CONFIG_XFRM
3316 xfrm_init();
3317 xfrm4_init(ip_rt_max_size);
3318 #endif
3319 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3320
3321 #ifdef CONFIG_SYSCTL
3322 register_pernet_subsys(&sysctl_route_ops);
3323 #endif
3324 register_pernet_subsys(&rt_genid_ops);
3325 return rc;
3326 }
3327
3328 #ifdef CONFIG_SYSCTL
3329 /*
3330 * We really need to sanitize the damn ipv4 init order, then all
3331 * this nonsense will go away.
3332 */
3333 void __init ip_static_sysctl_init(void)
3334 {
3335 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3336 }
3337 #endif
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree