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1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
94 #include <net/dst.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
108 #ifdef CONFIG_SYSCTL
109 #include <linux/sysctl.h>
110 #endif
111
112 #define RT_FL_TOS(oldflp4) \
113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 /*
135 * Interface to generic destination cache.
136 */
137
138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
145 static int rt_garbage_collect(struct dst_ops *ops);
146
147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
148 int how)
149 {
150 }
151
152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
153 {
154 struct rtable *rt = (struct rtable *) dst;
155 struct inet_peer *peer;
156 u32 *p = NULL;
157
158 if (!rt->peer)
159 rt_bind_peer(rt, rt->rt_dst, 1);
160
161 peer = rt->peer;
162 if (peer) {
163 u32 *old_p = __DST_METRICS_PTR(old);
164 unsigned long prev, new;
165
166 p = peer->metrics;
167 if (inet_metrics_new(peer))
168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
169
170 new = (unsigned long) p;
171 prev = cmpxchg(&dst->_metrics, old, new);
172
173 if (prev != old) {
174 p = __DST_METRICS_PTR(prev);
175 if (prev & DST_METRICS_READ_ONLY)
176 p = NULL;
177 } else {
178 if (rt->fi) {
179 fib_info_put(rt->fi);
180 rt->fi = NULL;
181 }
182 }
183 }
184 return p;
185 }
186
187 static struct dst_ops ipv4_dst_ops = {
188 .family = AF_INET,
189 .protocol = cpu_to_be16(ETH_P_IP),
190 .gc = rt_garbage_collect,
191 .check = ipv4_dst_check,
192 .default_advmss = ipv4_default_advmss,
193 .default_mtu = ipv4_default_mtu,
194 .cow_metrics = ipv4_cow_metrics,
195 .destroy = ipv4_dst_destroy,
196 .ifdown = ipv4_dst_ifdown,
197 .negative_advice = ipv4_negative_advice,
198 .link_failure = ipv4_link_failure,
199 .update_pmtu = ip_rt_update_pmtu,
200 .local_out = __ip_local_out,
201 };
202
203 #define ECN_OR_COST(class) TC_PRIO_##class
204
205 const __u8 ip_tos2prio[16] = {
206 TC_PRIO_BESTEFFORT,
207 ECN_OR_COST(BESTEFFORT),
208 TC_PRIO_BESTEFFORT,
209 ECN_OR_COST(BESTEFFORT),
210 TC_PRIO_BULK,
211 ECN_OR_COST(BULK),
212 TC_PRIO_BULK,
213 ECN_OR_COST(BULK),
214 TC_PRIO_INTERACTIVE,
215 ECN_OR_COST(INTERACTIVE),
216 TC_PRIO_INTERACTIVE,
217 ECN_OR_COST(INTERACTIVE),
218 TC_PRIO_INTERACTIVE_BULK,
219 ECN_OR_COST(INTERACTIVE_BULK),
220 TC_PRIO_INTERACTIVE_BULK,
221 ECN_OR_COST(INTERACTIVE_BULK)
222 };
223
224
225 /*
226 * Route cache.
227 */
228
229 /* The locking scheme is rather straight forward:
230 *
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
236 * lock held.
237 */
238
239 struct rt_hash_bucket {
240 struct rtable __rcu *chain;
241 };
242
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
245 /*
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
249 */
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
252 #else
253 # if NR_CPUS >= 32
254 # define RT_HASH_LOCK_SZ 4096
255 # elif NR_CPUS >= 16
256 # define RT_HASH_LOCK_SZ 2048
257 # elif NR_CPUS >= 8
258 # define RT_HASH_LOCK_SZ 1024
259 # elif NR_CPUS >= 4
260 # define RT_HASH_LOCK_SZ 512
261 # else
262 # define RT_HASH_LOCK_SZ 256
263 # endif
264 #endif
265
266 static spinlock_t *rt_hash_locks;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
268
269 static __init void rt_hash_lock_init(void)
270 {
271 int i;
272
273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
274 GFP_KERNEL);
275 if (!rt_hash_locks)
276 panic("IP: failed to allocate rt_hash_locks\n");
277
278 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
279 spin_lock_init(&rt_hash_locks[i]);
280 }
281 #else
282 # define rt_hash_lock_addr(slot) NULL
283
284 static inline void rt_hash_lock_init(void)
285 {
286 }
287 #endif
288
289 static struct rt_hash_bucket *rt_hash_table __read_mostly;
290 static unsigned rt_hash_mask __read_mostly;
291 static unsigned int rt_hash_log __read_mostly;
292
293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
295
296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
297 int genid)
298 {
299 return jhash_3words((__force u32)daddr, (__force u32)saddr,
300 idx, genid)
301 & rt_hash_mask;
302 }
303
304 static inline int rt_genid(struct net *net)
305 {
306 return atomic_read(&net->ipv4.rt_genid);
307 }
308
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state {
311 struct seq_net_private p;
312 int bucket;
313 int genid;
314 };
315
316 static struct rtable *rt_cache_get_first(struct seq_file *seq)
317 {
318 struct rt_cache_iter_state *st = seq->private;
319 struct rtable *r = NULL;
320
321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
323 continue;
324 rcu_read_lock_bh();
325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
326 while (r) {
327 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
328 r->rt_genid == st->genid)
329 return r;
330 r = rcu_dereference_bh(r->dst.rt_next);
331 }
332 rcu_read_unlock_bh();
333 }
334 return r;
335 }
336
337 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
338 struct rtable *r)
339 {
340 struct rt_cache_iter_state *st = seq->private;
341
342 r = rcu_dereference_bh(r->dst.rt_next);
343 while (!r) {
344 rcu_read_unlock_bh();
345 do {
346 if (--st->bucket < 0)
347 return NULL;
348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
349 rcu_read_lock_bh();
350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
351 }
352 return r;
353 }
354
355 static struct rtable *rt_cache_get_next(struct seq_file *seq,
356 struct rtable *r)
357 {
358 struct rt_cache_iter_state *st = seq->private;
359 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
360 if (dev_net(r->dst.dev) != seq_file_net(seq))
361 continue;
362 if (r->rt_genid == st->genid)
363 break;
364 }
365 return r;
366 }
367
368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
369 {
370 struct rtable *r = rt_cache_get_first(seq);
371
372 if (r)
373 while (pos && (r = rt_cache_get_next(seq, r)))
374 --pos;
375 return pos ? NULL : r;
376 }
377
378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
379 {
380 struct rt_cache_iter_state *st = seq->private;
381 if (*pos)
382 return rt_cache_get_idx(seq, *pos - 1);
383 st->genid = rt_genid(seq_file_net(seq));
384 return SEQ_START_TOKEN;
385 }
386
387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
388 {
389 struct rtable *r;
390
391 if (v == SEQ_START_TOKEN)
392 r = rt_cache_get_first(seq);
393 else
394 r = rt_cache_get_next(seq, v);
395 ++*pos;
396 return r;
397 }
398
399 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
400 {
401 if (v && v != SEQ_START_TOKEN)
402 rcu_read_unlock_bh();
403 }
404
405 static int rt_cache_seq_show(struct seq_file *seq, void *v)
406 {
407 if (v == SEQ_START_TOKEN)
408 seq_printf(seq, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
411 "HHUptod\tSpecDst");
412 else {
413 struct rtable *r = v;
414 int len;
415
416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r->dst.dev ? r->dst.dev->name : "*",
419 (__force u32)r->rt_dst,
420 (__force u32)r->rt_gateway,
421 r->rt_flags, atomic_read(&r->dst.__refcnt),
422 r->dst.__use, 0, (__force u32)r->rt_src,
423 dst_metric_advmss(&r->dst) + 40,
424 dst_metric(&r->dst, RTAX_WINDOW),
425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
426 dst_metric(&r->dst, RTAX_RTTVAR)),
427 r->rt_key_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
828 */
829 static void rt_cache_invalidate(struct net *net)
830 {
831 unsigned char shuffle;
832
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
835 }
836
837 /*
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
840 */
841 void rt_cache_flush(struct net *net, int delay)
842 {
843 rt_cache_invalidate(net);
844 if (delay >= 0)
845 rt_do_flush(net, !in_softirq());
846 }
847
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
850 {
851 rt_do_flush(net, !in_softirq());
852 }
853
854 static void rt_emergency_hash_rebuild(struct net *net)
855 {
856 if (net_ratelimit())
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
859 }
860
861 /*
862 Short description of GC goals.
863
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
867
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
872 */
873
874 static int rt_garbage_collect(struct dst_ops *ops)
875 {
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
878 static int rover;
879 static int equilibrium;
880 struct rtable *rth;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
883 int goal;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
885
886 /*
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
889 */
890
891 RT_CACHE_STAT_INC(gc_total);
892
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
896 goto out;
897 }
898
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
902 if (goal <= 0) {
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
906 if (goal > 0) {
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
909 }
910 } else {
911 /* We are in dangerous area. Try to reduce cache really
912 * aggressively.
913 */
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
916 }
917
918 if (now - last_gc >= ip_rt_gc_min_interval)
919 last_gc = now;
920
921 if (goal <= 0) {
922 equilibrium += goal;
923 goto work_done;
924 }
925
926 do {
927 int i, k;
928
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
931
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
939 tmo >>= 1;
940 rthp = &rth->dst.rt_next;
941 continue;
942 }
943 *rthp = rth->dst.rt_next;
944 rt_free(rth);
945 goal--;
946 }
947 spin_unlock_bh(rt_hash_lock_addr(k));
948 if (goal <= 0)
949 break;
950 }
951 rover = k;
952
953 if (goal <= 0)
954 goto work_done;
955
956 /* Goal is not achieved. We stop process if:
957
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
963 */
964
965 RT_CACHE_STAT_INC(gc_goal_miss);
966
967 if (expire == 0)
968 break;
969
970 expire >>= 1;
971
972 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
973 goto out;
974 } while (!in_softirq() && time_before_eq(jiffies, now));
975
976 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
977 goto out;
978 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
979 goto out;
980 if (net_ratelimit())
981 printk(KERN_WARNING "dst cache overflow\n");
982 RT_CACHE_STAT_INC(gc_dst_overflow);
983 return 1;
984
985 work_done:
986 expire += ip_rt_gc_min_interval;
987 if (expire > ip_rt_gc_timeout ||
988 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
989 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
990 expire = ip_rt_gc_timeout;
991 out: return 0;
992 }
993
994 /*
995 * Returns number of entries in a hash chain that have different hash_inputs
996 */
997 static int slow_chain_length(const struct rtable *head)
998 {
999 int length = 0;
1000 const struct rtable *rth = head;
1001
1002 while (rth) {
1003 length += has_noalias(head, rth);
1004 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1005 }
1006 return length >> FRACT_BITS;
1007 }
1008
1009 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1010 struct sk_buff *skb, int ifindex)
1011 {
1012 struct rtable *rth, *cand;
1013 struct rtable __rcu **rthp, **candp;
1014 unsigned long now;
1015 u32 min_score;
1016 int chain_length;
1017 int attempts = !in_softirq();
1018
1019 restart:
1020 chain_length = 0;
1021 min_score = ~(u32)0;
1022 cand = NULL;
1023 candp = NULL;
1024 now = jiffies;
1025
1026 if (!rt_caching(dev_net(rt->dst.dev))) {
1027 /*
1028 * If we're not caching, just tell the caller we
1029 * were successful and don't touch the route. The
1030 * caller hold the sole reference to the cache entry, and
1031 * it will be released when the caller is done with it.
1032 * If we drop it here, the callers have no way to resolve routes
1033 * when we're not caching. Instead, just point *rp at rt, so
1034 * the caller gets a single use out of the route
1035 * Note that we do rt_free on this new route entry, so that
1036 * once its refcount hits zero, we are still able to reap it
1037 * (Thanks Alexey)
1038 * Note: To avoid expensive rcu stuff for this uncached dst,
1039 * we set DST_NOCACHE so that dst_release() can free dst without
1040 * waiting a grace period.
1041 */
1042
1043 rt->dst.flags |= DST_NOCACHE;
1044 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1045 int err = arp_bind_neighbour(&rt->dst);
1046 if (err) {
1047 if (net_ratelimit())
1048 printk(KERN_WARNING
1049 "Neighbour table failure & not caching routes.\n");
1050 ip_rt_put(rt);
1051 return ERR_PTR(err);
1052 }
1053 }
1054
1055 goto skip_hashing;
1056 }
1057
1058 rthp = &rt_hash_table[hash].chain;
1059
1060 spin_lock_bh(rt_hash_lock_addr(hash));
1061 while ((rth = rcu_dereference_protected(*rthp,
1062 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1063 if (rt_is_expired(rth)) {
1064 *rthp = rth->dst.rt_next;
1065 rt_free(rth);
1066 continue;
1067 }
1068 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1069 /* Put it first */
1070 *rthp = rth->dst.rt_next;
1071 /*
1072 * Since lookup is lockfree, the deletion
1073 * must be visible to another weakly ordered CPU before
1074 * the insertion at the start of the hash chain.
1075 */
1076 rcu_assign_pointer(rth->dst.rt_next,
1077 rt_hash_table[hash].chain);
1078 /*
1079 * Since lookup is lockfree, the update writes
1080 * must be ordered for consistency on SMP.
1081 */
1082 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1083
1084 dst_use(&rth->dst, now);
1085 spin_unlock_bh(rt_hash_lock_addr(hash));
1086
1087 rt_drop(rt);
1088 if (skb)
1089 skb_dst_set(skb, &rth->dst);
1090 return rth;
1091 }
1092
1093 if (!atomic_read(&rth->dst.__refcnt)) {
1094 u32 score = rt_score(rth);
1095
1096 if (score <= min_score) {
1097 cand = rth;
1098 candp = rthp;
1099 min_score = score;
1100 }
1101 }
1102
1103 chain_length++;
1104
1105 rthp = &rth->dst.rt_next;
1106 }
1107
1108 if (cand) {
1109 /* ip_rt_gc_elasticity used to be average length of chain
1110 * length, when exceeded gc becomes really aggressive.
1111 *
1112 * The second limit is less certain. At the moment it allows
1113 * only 2 entries per bucket. We will see.
1114 */
1115 if (chain_length > ip_rt_gc_elasticity) {
1116 *candp = cand->dst.rt_next;
1117 rt_free(cand);
1118 }
1119 } else {
1120 if (chain_length > rt_chain_length_max &&
1121 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1122 struct net *net = dev_net(rt->dst.dev);
1123 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1124 if (!rt_caching(net)) {
1125 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1126 rt->dst.dev->name, num);
1127 }
1128 rt_emergency_hash_rebuild(net);
1129 spin_unlock_bh(rt_hash_lock_addr(hash));
1130
1131 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1132 ifindex, rt_genid(net));
1133 goto restart;
1134 }
1135 }
1136
1137 /* Try to bind route to arp only if it is output
1138 route or unicast forwarding path.
1139 */
1140 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1141 int err = arp_bind_neighbour(&rt->dst);
1142 if (err) {
1143 spin_unlock_bh(rt_hash_lock_addr(hash));
1144
1145 if (err != -ENOBUFS) {
1146 rt_drop(rt);
1147 return ERR_PTR(err);
1148 }
1149
1150 /* Neighbour tables are full and nothing
1151 can be released. Try to shrink route cache,
1152 it is most likely it holds some neighbour records.
1153 */
1154 if (attempts-- > 0) {
1155 int saved_elasticity = ip_rt_gc_elasticity;
1156 int saved_int = ip_rt_gc_min_interval;
1157 ip_rt_gc_elasticity = 1;
1158 ip_rt_gc_min_interval = 0;
1159 rt_garbage_collect(&ipv4_dst_ops);
1160 ip_rt_gc_min_interval = saved_int;
1161 ip_rt_gc_elasticity = saved_elasticity;
1162 goto restart;
1163 }
1164
1165 if (net_ratelimit())
1166 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1167 rt_drop(rt);
1168 return ERR_PTR(-ENOBUFS);
1169 }
1170 }
1171
1172 rt->dst.rt_next = rt_hash_table[hash].chain;
1173
1174 /*
1175 * Since lookup is lockfree, we must make sure
1176 * previous writes to rt are committed to memory
1177 * before making rt visible to other CPUS.
1178 */
1179 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1180
1181 spin_unlock_bh(rt_hash_lock_addr(hash));
1182
1183 skip_hashing:
1184 if (skb)
1185 skb_dst_set(skb, &rt->dst);
1186 return rt;
1187 }
1188
1189 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1190
1191 static u32 rt_peer_genid(void)
1192 {
1193 return atomic_read(&__rt_peer_genid);
1194 }
1195
1196 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1197 {
1198 struct inet_peer *peer;
1199
1200 peer = inet_getpeer_v4(daddr, create);
1201
1202 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1203 inet_putpeer(peer);
1204 else
1205 rt->rt_peer_genid = rt_peer_genid();
1206 }
1207
1208 /*
1209 * Peer allocation may fail only in serious out-of-memory conditions. However
1210 * we still can generate some output.
1211 * Random ID selection looks a bit dangerous because we have no chances to
1212 * select ID being unique in a reasonable period of time.
1213 * But broken packet identifier may be better than no packet at all.
1214 */
1215 static void ip_select_fb_ident(struct iphdr *iph)
1216 {
1217 static DEFINE_SPINLOCK(ip_fb_id_lock);
1218 static u32 ip_fallback_id;
1219 u32 salt;
1220
1221 spin_lock_bh(&ip_fb_id_lock);
1222 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1223 iph->id = htons(salt & 0xFFFF);
1224 ip_fallback_id = salt;
1225 spin_unlock_bh(&ip_fb_id_lock);
1226 }
1227
1228 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1229 {
1230 struct rtable *rt = (struct rtable *) dst;
1231
1232 if (rt) {
1233 if (rt->peer == NULL)
1234 rt_bind_peer(rt, rt->rt_dst, 1);
1235
1236 /* If peer is attached to destination, it is never detached,
1237 so that we need not to grab a lock to dereference it.
1238 */
1239 if (rt->peer) {
1240 iph->id = htons(inet_getid(rt->peer, more));
1241 return;
1242 }
1243 } else
1244 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1245 __builtin_return_address(0));
1246
1247 ip_select_fb_ident(iph);
1248 }
1249 EXPORT_SYMBOL(__ip_select_ident);
1250
1251 static void rt_del(unsigned hash, struct rtable *rt)
1252 {
1253 struct rtable __rcu **rthp;
1254 struct rtable *aux;
1255
1256 rthp = &rt_hash_table[hash].chain;
1257 spin_lock_bh(rt_hash_lock_addr(hash));
1258 ip_rt_put(rt);
1259 while ((aux = rcu_dereference_protected(*rthp,
1260 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1261 if (aux == rt || rt_is_expired(aux)) {
1262 *rthp = aux->dst.rt_next;
1263 rt_free(aux);
1264 continue;
1265 }
1266 rthp = &aux->dst.rt_next;
1267 }
1268 spin_unlock_bh(rt_hash_lock_addr(hash));
1269 }
1270
1271 /* called in rcu_read_lock() section */
1272 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1273 __be32 saddr, struct net_device *dev)
1274 {
1275 struct in_device *in_dev = __in_dev_get_rcu(dev);
1276 struct inet_peer *peer;
1277 struct net *net;
1278
1279 if (!in_dev)
1280 return;
1281
1282 net = dev_net(dev);
1283 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1284 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1285 ipv4_is_zeronet(new_gw))
1286 goto reject_redirect;
1287
1288 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1289 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1290 goto reject_redirect;
1291 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1292 goto reject_redirect;
1293 } else {
1294 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1295 goto reject_redirect;
1296 }
1297
1298 peer = inet_getpeer_v4(daddr, 1);
1299 if (peer) {
1300 peer->redirect_learned.a4 = new_gw;
1301
1302 inet_putpeer(peer);
1303
1304 atomic_inc(&__rt_peer_genid);
1305 }
1306 return;
1307
1308 reject_redirect:
1309 #ifdef CONFIG_IP_ROUTE_VERBOSE
1310 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1311 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1312 " Advised path = %pI4 -> %pI4\n",
1313 &old_gw, dev->name, &new_gw,
1314 &saddr, &daddr);
1315 #endif
1316 ;
1317 }
1318
1319 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1320 {
1321 struct rtable *rt = (struct rtable *)dst;
1322 struct dst_entry *ret = dst;
1323
1324 if (rt) {
1325 if (dst->obsolete > 0) {
1326 ip_rt_put(rt);
1327 ret = NULL;
1328 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1329 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1330 rt->rt_oif,
1331 rt_genid(dev_net(dst->dev)));
1332 rt_del(hash, rt);
1333 ret = NULL;
1334 } else if (rt->peer &&
1335 rt->peer->pmtu_expires &&
1336 time_after_eq(jiffies, rt->peer->pmtu_expires)) {
1337 unsigned long orig = rt->peer->pmtu_expires;
1338
1339 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1340 dst_metric_set(dst, RTAX_MTU,
1341 rt->peer->pmtu_orig);
1342 }
1343 }
1344 return ret;
1345 }
1346
1347 /*
1348 * Algorithm:
1349 * 1. The first ip_rt_redirect_number redirects are sent
1350 * with exponential backoff, then we stop sending them at all,
1351 * assuming that the host ignores our redirects.
1352 * 2. If we did not see packets requiring redirects
1353 * during ip_rt_redirect_silence, we assume that the host
1354 * forgot redirected route and start to send redirects again.
1355 *
1356 * This algorithm is much cheaper and more intelligent than dumb load limiting
1357 * in icmp.c.
1358 *
1359 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1360 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1361 */
1362
1363 void ip_rt_send_redirect(struct sk_buff *skb)
1364 {
1365 struct rtable *rt = skb_rtable(skb);
1366 struct in_device *in_dev;
1367 struct inet_peer *peer;
1368 int log_martians;
1369
1370 rcu_read_lock();
1371 in_dev = __in_dev_get_rcu(rt->dst.dev);
1372 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1373 rcu_read_unlock();
1374 return;
1375 }
1376 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1377 rcu_read_unlock();
1378
1379 if (!rt->peer)
1380 rt_bind_peer(rt, rt->rt_dst, 1);
1381 peer = rt->peer;
1382 if (!peer) {
1383 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1384 return;
1385 }
1386
1387 /* No redirected packets during ip_rt_redirect_silence;
1388 * reset the algorithm.
1389 */
1390 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1391 peer->rate_tokens = 0;
1392
1393 /* Too many ignored redirects; do not send anything
1394 * set dst.rate_last to the last seen redirected packet.
1395 */
1396 if (peer->rate_tokens >= ip_rt_redirect_number) {
1397 peer->rate_last = jiffies;
1398 return;
1399 }
1400
1401 /* Check for load limit; set rate_last to the latest sent
1402 * redirect.
1403 */
1404 if (peer->rate_tokens == 0 ||
1405 time_after(jiffies,
1406 (peer->rate_last +
1407 (ip_rt_redirect_load << peer->rate_tokens)))) {
1408 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1409 peer->rate_last = jiffies;
1410 ++peer->rate_tokens;
1411 #ifdef CONFIG_IP_ROUTE_VERBOSE
1412 if (log_martians &&
1413 peer->rate_tokens == ip_rt_redirect_number &&
1414 net_ratelimit())
1415 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1416 &ip_hdr(skb)->saddr, rt->rt_iif,
1417 &rt->rt_dst, &rt->rt_gateway);
1418 #endif
1419 }
1420 }
1421
1422 static int ip_error(struct sk_buff *skb)
1423 {
1424 struct rtable *rt = skb_rtable(skb);
1425 struct inet_peer *peer;
1426 unsigned long now;
1427 bool send;
1428 int code;
1429
1430 switch (rt->dst.error) {
1431 case EINVAL:
1432 default:
1433 goto out;
1434 case EHOSTUNREACH:
1435 code = ICMP_HOST_UNREACH;
1436 break;
1437 case ENETUNREACH:
1438 code = ICMP_NET_UNREACH;
1439 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1440 IPSTATS_MIB_INNOROUTES);
1441 break;
1442 case EACCES:
1443 code = ICMP_PKT_FILTERED;
1444 break;
1445 }
1446
1447 if (!rt->peer)
1448 rt_bind_peer(rt, rt->rt_dst, 1);
1449 peer = rt->peer;
1450
1451 send = true;
1452 if (peer) {
1453 now = jiffies;
1454 peer->rate_tokens += now - peer->rate_last;
1455 if (peer->rate_tokens > ip_rt_error_burst)
1456 peer->rate_tokens = ip_rt_error_burst;
1457 peer->rate_last = now;
1458 if (peer->rate_tokens >= ip_rt_error_cost)
1459 peer->rate_tokens -= ip_rt_error_cost;
1460 else
1461 send = false;
1462 }
1463 if (send)
1464 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1465
1466 out: kfree_skb(skb);
1467 return 0;
1468 }
1469
1470 /*
1471 * The last two values are not from the RFC but
1472 * are needed for AMPRnet AX.25 paths.
1473 */
1474
1475 static const unsigned short mtu_plateau[] =
1476 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1477
1478 static inline unsigned short guess_mtu(unsigned short old_mtu)
1479 {
1480 int i;
1481
1482 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1483 if (old_mtu > mtu_plateau[i])
1484 return mtu_plateau[i];
1485 return 68;
1486 }
1487
1488 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1489 unsigned short new_mtu,
1490 struct net_device *dev)
1491 {
1492 unsigned short old_mtu = ntohs(iph->tot_len);
1493 unsigned short est_mtu = 0;
1494 struct inet_peer *peer;
1495
1496 peer = inet_getpeer_v4(iph->daddr, 1);
1497 if (peer) {
1498 unsigned short mtu = new_mtu;
1499
1500 if (new_mtu < 68 || new_mtu >= old_mtu) {
1501 /* BSD 4.2 derived systems incorrectly adjust
1502 * tot_len by the IP header length, and report
1503 * a zero MTU in the ICMP message.
1504 */
1505 if (mtu == 0 &&
1506 old_mtu >= 68 + (iph->ihl << 2))
1507 old_mtu -= iph->ihl << 2;
1508 mtu = guess_mtu(old_mtu);
1509 }
1510
1511 if (mtu < ip_rt_min_pmtu)
1512 mtu = ip_rt_min_pmtu;
1513 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1514 unsigned long pmtu_expires;
1515
1516 pmtu_expires = jiffies + ip_rt_mtu_expires;
1517 if (!pmtu_expires)
1518 pmtu_expires = 1UL;
1519
1520 est_mtu = mtu;
1521 peer->pmtu_learned = mtu;
1522 peer->pmtu_expires = pmtu_expires;
1523 }
1524
1525 inet_putpeer(peer);
1526
1527 atomic_inc(&__rt_peer_genid);
1528 }
1529 return est_mtu ? : new_mtu;
1530 }
1531
1532 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1533 {
1534 unsigned long expires = peer->pmtu_expires;
1535
1536 if (time_before(jiffies, expires)) {
1537 u32 orig_dst_mtu = dst_mtu(dst);
1538 if (peer->pmtu_learned < orig_dst_mtu) {
1539 if (!peer->pmtu_orig)
1540 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1541 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1542 }
1543 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1544 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1545 }
1546
1547 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1548 {
1549 struct rtable *rt = (struct rtable *) dst;
1550 struct inet_peer *peer;
1551
1552 dst_confirm(dst);
1553
1554 if (!rt->peer)
1555 rt_bind_peer(rt, rt->rt_dst, 1);
1556 peer = rt->peer;
1557 if (peer) {
1558 if (mtu < ip_rt_min_pmtu)
1559 mtu = ip_rt_min_pmtu;
1560 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1561 unsigned long pmtu_expires;
1562
1563 pmtu_expires = jiffies + ip_rt_mtu_expires;
1564 if (!pmtu_expires)
1565 pmtu_expires = 1UL;
1566
1567 peer->pmtu_learned = mtu;
1568 peer->pmtu_expires = pmtu_expires;
1569
1570 atomic_inc(&__rt_peer_genid);
1571 rt->rt_peer_genid = rt_peer_genid();
1572 }
1573 check_peer_pmtu(dst, peer);
1574 }
1575 }
1576
1577 static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1578 {
1579 struct rtable *rt = (struct rtable *) dst;
1580 __be32 orig_gw = rt->rt_gateway;
1581
1582 dst_confirm(&rt->dst);
1583
1584 neigh_release(rt->dst.neighbour);
1585 rt->dst.neighbour = NULL;
1586
1587 rt->rt_gateway = peer->redirect_learned.a4;
1588 if (arp_bind_neighbour(&rt->dst) ||
1589 !(rt->dst.neighbour->nud_state & NUD_VALID)) {
1590 if (rt->dst.neighbour)
1591 neigh_event_send(rt->dst.neighbour, NULL);
1592 rt->rt_gateway = orig_gw;
1593 return -EAGAIN;
1594 } else {
1595 rt->rt_flags |= RTCF_REDIRECTED;
1596 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE,
1597 rt->dst.neighbour);
1598 }
1599 return 0;
1600 }
1601
1602 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1603 {
1604 struct rtable *rt = (struct rtable *) dst;
1605
1606 if (rt_is_expired(rt))
1607 return NULL;
1608 if (rt->rt_peer_genid != rt_peer_genid()) {
1609 struct inet_peer *peer;
1610
1611 if (!rt->peer)
1612 rt_bind_peer(rt, rt->rt_dst, 0);
1613
1614 peer = rt->peer;
1615 if (peer && peer->pmtu_expires)
1616 check_peer_pmtu(dst, peer);
1617
1618 if (peer && peer->redirect_learned.a4 &&
1619 peer->redirect_learned.a4 != rt->rt_gateway) {
1620 if (check_peer_redir(dst, peer))
1621 return NULL;
1622 }
1623
1624 rt->rt_peer_genid = rt_peer_genid();
1625 }
1626 return dst;
1627 }
1628
1629 static void ipv4_dst_destroy(struct dst_entry *dst)
1630 {
1631 struct rtable *rt = (struct rtable *) dst;
1632 struct inet_peer *peer = rt->peer;
1633
1634 if (rt->fi) {
1635 fib_info_put(rt->fi);
1636 rt->fi = NULL;
1637 }
1638 if (peer) {
1639 rt->peer = NULL;
1640 inet_putpeer(peer);
1641 }
1642 }
1643
1644
1645 static void ipv4_link_failure(struct sk_buff *skb)
1646 {
1647 struct rtable *rt;
1648
1649 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1650
1651 rt = skb_rtable(skb);
1652 if (rt &&
1653 rt->peer &&
1654 rt->peer->pmtu_expires) {
1655 unsigned long orig = rt->peer->pmtu_expires;
1656
1657 if (cmpxchg(&rt->peer->pmtu_expires, orig, 0) == orig)
1658 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1659 }
1660 }
1661
1662 static int ip_rt_bug(struct sk_buff *skb)
1663 {
1664 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1665 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1666 skb->dev ? skb->dev->name : "?");
1667 kfree_skb(skb);
1668 WARN_ON(1);
1669 return 0;
1670 }
1671
1672 /*
1673 We do not cache source address of outgoing interface,
1674 because it is used only by IP RR, TS and SRR options,
1675 so that it out of fast path.
1676
1677 BTW remember: "addr" is allowed to be not aligned
1678 in IP options!
1679 */
1680
1681 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1682 {
1683 __be32 src;
1684
1685 if (rt_is_output_route(rt))
1686 src = ip_hdr(skb)->saddr;
1687 else {
1688 struct fib_result res;
1689 struct flowi4 fl4;
1690 struct iphdr *iph;
1691
1692 iph = ip_hdr(skb);
1693
1694 memset(&fl4, 0, sizeof(fl4));
1695 fl4.daddr = iph->daddr;
1696 fl4.saddr = iph->saddr;
1697 fl4.flowi4_tos = iph->tos;
1698 fl4.flowi4_oif = rt->dst.dev->ifindex;
1699 fl4.flowi4_iif = skb->dev->ifindex;
1700 fl4.flowi4_mark = skb->mark;
1701
1702 rcu_read_lock();
1703 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1704 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1705 else
1706 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1707 RT_SCOPE_UNIVERSE);
1708 rcu_read_unlock();
1709 }
1710 memcpy(addr, &src, 4);
1711 }
1712
1713 #ifdef CONFIG_IP_ROUTE_CLASSID
1714 static void set_class_tag(struct rtable *rt, u32 tag)
1715 {
1716 if (!(rt->dst.tclassid & 0xFFFF))
1717 rt->dst.tclassid |= tag & 0xFFFF;
1718 if (!(rt->dst.tclassid & 0xFFFF0000))
1719 rt->dst.tclassid |= tag & 0xFFFF0000;
1720 }
1721 #endif
1722
1723 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1724 {
1725 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1726
1727 if (advmss == 0) {
1728 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1729 ip_rt_min_advmss);
1730 if (advmss > 65535 - 40)
1731 advmss = 65535 - 40;
1732 }
1733 return advmss;
1734 }
1735
1736 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1737 {
1738 unsigned int mtu = dst->dev->mtu;
1739
1740 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1741 const struct rtable *rt = (const struct rtable *) dst;
1742
1743 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1744 mtu = 576;
1745 }
1746
1747 if (mtu > IP_MAX_MTU)
1748 mtu = IP_MAX_MTU;
1749
1750 return mtu;
1751 }
1752
1753 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1754 struct fib_info *fi)
1755 {
1756 struct inet_peer *peer;
1757 int create = 0;
1758
1759 /* If a peer entry exists for this destination, we must hook
1760 * it up in order to get at cached metrics.
1761 */
1762 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1763 create = 1;
1764
1765 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1766 if (peer) {
1767 rt->rt_peer_genid = rt_peer_genid();
1768 if (inet_metrics_new(peer))
1769 memcpy(peer->metrics, fi->fib_metrics,
1770 sizeof(u32) * RTAX_MAX);
1771 dst_init_metrics(&rt->dst, peer->metrics, false);
1772
1773 if (peer->pmtu_expires)
1774 check_peer_pmtu(&rt->dst, peer);
1775 if (peer->redirect_learned.a4 &&
1776 peer->redirect_learned.a4 != rt->rt_gateway) {
1777 rt->rt_gateway = peer->redirect_learned.a4;
1778 rt->rt_flags |= RTCF_REDIRECTED;
1779 }
1780 } else {
1781 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1782 rt->fi = fi;
1783 atomic_inc(&fi->fib_clntref);
1784 }
1785 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1786 }
1787 }
1788
1789 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1790 const struct fib_result *res,
1791 struct fib_info *fi, u16 type, u32 itag)
1792 {
1793 struct dst_entry *dst = &rt->dst;
1794
1795 if (fi) {
1796 if (FIB_RES_GW(*res) &&
1797 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1798 rt->rt_gateway = FIB_RES_GW(*res);
1799 rt_init_metrics(rt, fl4, fi);
1800 #ifdef CONFIG_IP_ROUTE_CLASSID
1801 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1802 #endif
1803 }
1804
1805 if (dst_mtu(dst) > IP_MAX_MTU)
1806 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1807 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1808 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1809
1810 #ifdef CONFIG_IP_ROUTE_CLASSID
1811 #ifdef CONFIG_IP_MULTIPLE_TABLES
1812 set_class_tag(rt, fib_rules_tclass(res));
1813 #endif
1814 set_class_tag(rt, itag);
1815 #endif
1816 }
1817
1818 static struct rtable *rt_dst_alloc(struct net_device *dev,
1819 bool nopolicy, bool noxfrm)
1820 {
1821 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1822 DST_HOST |
1823 (nopolicy ? DST_NOPOLICY : 0) |
1824 (noxfrm ? DST_NOXFRM : 0));
1825 }
1826
1827 /* called in rcu_read_lock() section */
1828 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1829 u8 tos, struct net_device *dev, int our)
1830 {
1831 unsigned int hash;
1832 struct rtable *rth;
1833 __be32 spec_dst;
1834 struct in_device *in_dev = __in_dev_get_rcu(dev);
1835 u32 itag = 0;
1836 int err;
1837
1838 /* Primary sanity checks. */
1839
1840 if (in_dev == NULL)
1841 return -EINVAL;
1842
1843 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1844 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1845 goto e_inval;
1846
1847 if (ipv4_is_zeronet(saddr)) {
1848 if (!ipv4_is_local_multicast(daddr))
1849 goto e_inval;
1850 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1851 } else {
1852 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1853 &itag);
1854 if (err < 0)
1855 goto e_err;
1856 }
1857 rth = rt_dst_alloc(init_net.loopback_dev,
1858 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1859 if (!rth)
1860 goto e_nobufs;
1861
1862 #ifdef CONFIG_IP_ROUTE_CLASSID
1863 rth->dst.tclassid = itag;
1864 #endif
1865 rth->dst.output = ip_rt_bug;
1866
1867 rth->rt_key_dst = daddr;
1868 rth->rt_key_src = saddr;
1869 rth->rt_genid = rt_genid(dev_net(dev));
1870 rth->rt_flags = RTCF_MULTICAST;
1871 rth->rt_type = RTN_MULTICAST;
1872 rth->rt_key_tos = tos;
1873 rth->rt_dst = daddr;
1874 rth->rt_src = saddr;
1875 rth->rt_route_iif = dev->ifindex;
1876 rth->rt_iif = dev->ifindex;
1877 rth->rt_oif = 0;
1878 rth->rt_mark = skb->mark;
1879 rth->rt_gateway = daddr;
1880 rth->rt_spec_dst= spec_dst;
1881 rth->rt_peer_genid = 0;
1882 rth->peer = NULL;
1883 rth->fi = NULL;
1884 if (our) {
1885 rth->dst.input= ip_local_deliver;
1886 rth->rt_flags |= RTCF_LOCAL;
1887 }
1888
1889 #ifdef CONFIG_IP_MROUTE
1890 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1891 rth->dst.input = ip_mr_input;
1892 #endif
1893 RT_CACHE_STAT_INC(in_slow_mc);
1894
1895 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1896 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1897 err = 0;
1898 if (IS_ERR(rth))
1899 err = PTR_ERR(rth);
1900
1901 e_nobufs:
1902 return -ENOBUFS;
1903 e_inval:
1904 return -EINVAL;
1905 e_err:
1906 return err;
1907 }
1908
1909
1910 static void ip_handle_martian_source(struct net_device *dev,
1911 struct in_device *in_dev,
1912 struct sk_buff *skb,
1913 __be32 daddr,
1914 __be32 saddr)
1915 {
1916 RT_CACHE_STAT_INC(in_martian_src);
1917 #ifdef CONFIG_IP_ROUTE_VERBOSE
1918 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1919 /*
1920 * RFC1812 recommendation, if source is martian,
1921 * the only hint is MAC header.
1922 */
1923 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1924 &daddr, &saddr, dev->name);
1925 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1926 int i;
1927 const unsigned char *p = skb_mac_header(skb);
1928 printk(KERN_WARNING "ll header: ");
1929 for (i = 0; i < dev->hard_header_len; i++, p++) {
1930 printk("%02x", *p);
1931 if (i < (dev->hard_header_len - 1))
1932 printk(":");
1933 }
1934 printk("\n");
1935 }
1936 }
1937 #endif
1938 }
1939
1940 /* called in rcu_read_lock() section */
1941 static int __mkroute_input(struct sk_buff *skb,
1942 const struct fib_result *res,
1943 struct in_device *in_dev,
1944 __be32 daddr, __be32 saddr, u32 tos,
1945 struct rtable **result)
1946 {
1947 struct rtable *rth;
1948 int err;
1949 struct in_device *out_dev;
1950 unsigned int flags = 0;
1951 __be32 spec_dst;
1952 u32 itag;
1953
1954 /* get a working reference to the output device */
1955 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1956 if (out_dev == NULL) {
1957 if (net_ratelimit())
1958 printk(KERN_CRIT "Bug in ip_route_input" \
1959 "_slow(). Please, report\n");
1960 return -EINVAL;
1961 }
1962
1963
1964 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1965 in_dev->dev, &spec_dst, &itag);
1966 if (err < 0) {
1967 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1968 saddr);
1969
1970 goto cleanup;
1971 }
1972
1973 if (err)
1974 flags |= RTCF_DIRECTSRC;
1975
1976 if (out_dev == in_dev && err &&
1977 (IN_DEV_SHARED_MEDIA(out_dev) ||
1978 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1979 flags |= RTCF_DOREDIRECT;
1980
1981 if (skb->protocol != htons(ETH_P_IP)) {
1982 /* Not IP (i.e. ARP). Do not create route, if it is
1983 * invalid for proxy arp. DNAT routes are always valid.
1984 *
1985 * Proxy arp feature have been extended to allow, ARP
1986 * replies back to the same interface, to support
1987 * Private VLAN switch technologies. See arp.c.
1988 */
1989 if (out_dev == in_dev &&
1990 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1991 err = -EINVAL;
1992 goto cleanup;
1993 }
1994 }
1995
1996 rth = rt_dst_alloc(out_dev->dev,
1997 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1998 IN_DEV_CONF_GET(out_dev, NOXFRM));
1999 if (!rth) {
2000 err = -ENOBUFS;
2001 goto cleanup;
2002 }
2003
2004 rth->rt_key_dst = daddr;
2005 rth->rt_key_src = saddr;
2006 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2007 rth->rt_flags = flags;
2008 rth->rt_type = res->type;
2009 rth->rt_key_tos = tos;
2010 rth->rt_dst = daddr;
2011 rth->rt_src = saddr;
2012 rth->rt_route_iif = in_dev->dev->ifindex;
2013 rth->rt_iif = in_dev->dev->ifindex;
2014 rth->rt_oif = 0;
2015 rth->rt_mark = skb->mark;
2016 rth->rt_gateway = daddr;
2017 rth->rt_spec_dst= spec_dst;
2018 rth->rt_peer_genid = 0;
2019 rth->peer = NULL;
2020 rth->fi = NULL;
2021
2022 rth->dst.input = ip_forward;
2023 rth->dst.output = ip_output;
2024
2025 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2026
2027 *result = rth;
2028 err = 0;
2029 cleanup:
2030 return err;
2031 }
2032
2033 static int ip_mkroute_input(struct sk_buff *skb,
2034 struct fib_result *res,
2035 const struct flowi4 *fl4,
2036 struct in_device *in_dev,
2037 __be32 daddr, __be32 saddr, u32 tos)
2038 {
2039 struct rtable* rth = NULL;
2040 int err;
2041 unsigned hash;
2042
2043 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2044 if (res->fi && res->fi->fib_nhs > 1)
2045 fib_select_multipath(res);
2046 #endif
2047
2048 /* create a routing cache entry */
2049 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2050 if (err)
2051 return err;
2052
2053 /* put it into the cache */
2054 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2055 rt_genid(dev_net(rth->dst.dev)));
2056 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2057 if (IS_ERR(rth))
2058 return PTR_ERR(rth);
2059 return 0;
2060 }
2061
2062 /*
2063 * NOTE. We drop all the packets that has local source
2064 * addresses, because every properly looped back packet
2065 * must have correct destination already attached by output routine.
2066 *
2067 * Such approach solves two big problems:
2068 * 1. Not simplex devices are handled properly.
2069 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2070 * called with rcu_read_lock()
2071 */
2072
2073 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2074 u8 tos, struct net_device *dev)
2075 {
2076 struct fib_result res;
2077 struct in_device *in_dev = __in_dev_get_rcu(dev);
2078 struct flowi4 fl4;
2079 unsigned flags = 0;
2080 u32 itag = 0;
2081 struct rtable * rth;
2082 unsigned hash;
2083 __be32 spec_dst;
2084 int err = -EINVAL;
2085 struct net * net = dev_net(dev);
2086
2087 /* IP on this device is disabled. */
2088
2089 if (!in_dev)
2090 goto out;
2091
2092 /* Check for the most weird martians, which can be not detected
2093 by fib_lookup.
2094 */
2095
2096 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2097 ipv4_is_loopback(saddr))
2098 goto martian_source;
2099
2100 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2101 goto brd_input;
2102
2103 /* Accept zero addresses only to limited broadcast;
2104 * I even do not know to fix it or not. Waiting for complains :-)
2105 */
2106 if (ipv4_is_zeronet(saddr))
2107 goto martian_source;
2108
2109 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2110 goto martian_destination;
2111
2112 /*
2113 * Now we are ready to route packet.
2114 */
2115 fl4.flowi4_oif = 0;
2116 fl4.flowi4_iif = dev->ifindex;
2117 fl4.flowi4_mark = skb->mark;
2118 fl4.flowi4_tos = tos;
2119 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2120 fl4.daddr = daddr;
2121 fl4.saddr = saddr;
2122 err = fib_lookup(net, &fl4, &res);
2123 if (err != 0) {
2124 if (!IN_DEV_FORWARD(in_dev))
2125 goto e_hostunreach;
2126 goto no_route;
2127 }
2128
2129 RT_CACHE_STAT_INC(in_slow_tot);
2130
2131 if (res.type == RTN_BROADCAST)
2132 goto brd_input;
2133
2134 if (res.type == RTN_LOCAL) {
2135 err = fib_validate_source(skb, saddr, daddr, tos,
2136 net->loopback_dev->ifindex,
2137 dev, &spec_dst, &itag);
2138 if (err < 0)
2139 goto martian_source_keep_err;
2140 if (err)
2141 flags |= RTCF_DIRECTSRC;
2142 spec_dst = daddr;
2143 goto local_input;
2144 }
2145
2146 if (!IN_DEV_FORWARD(in_dev))
2147 goto e_hostunreach;
2148 if (res.type != RTN_UNICAST)
2149 goto martian_destination;
2150
2151 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2152 out: return err;
2153
2154 brd_input:
2155 if (skb->protocol != htons(ETH_P_IP))
2156 goto e_inval;
2157
2158 if (ipv4_is_zeronet(saddr))
2159 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2160 else {
2161 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2162 &itag);
2163 if (err < 0)
2164 goto martian_source_keep_err;
2165 if (err)
2166 flags |= RTCF_DIRECTSRC;
2167 }
2168 flags |= RTCF_BROADCAST;
2169 res.type = RTN_BROADCAST;
2170 RT_CACHE_STAT_INC(in_brd);
2171
2172 local_input:
2173 rth = rt_dst_alloc(net->loopback_dev,
2174 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2175 if (!rth)
2176 goto e_nobufs;
2177
2178 rth->dst.input= ip_local_deliver;
2179 rth->dst.output= ip_rt_bug;
2180 #ifdef CONFIG_IP_ROUTE_CLASSID
2181 rth->dst.tclassid = itag;
2182 #endif
2183
2184 rth->rt_key_dst = daddr;
2185 rth->rt_key_src = saddr;
2186 rth->rt_genid = rt_genid(net);
2187 rth->rt_flags = flags|RTCF_LOCAL;
2188 rth->rt_type = res.type;
2189 rth->rt_key_tos = tos;
2190 rth->rt_dst = daddr;
2191 rth->rt_src = saddr;
2192 #ifdef CONFIG_IP_ROUTE_CLASSID
2193 rth->dst.tclassid = itag;
2194 #endif
2195 rth->rt_route_iif = dev->ifindex;
2196 rth->rt_iif = dev->ifindex;
2197 rth->rt_oif = 0;
2198 rth->rt_mark = skb->mark;
2199 rth->rt_gateway = daddr;
2200 rth->rt_spec_dst= spec_dst;
2201 rth->rt_peer_genid = 0;
2202 rth->peer = NULL;
2203 rth->fi = NULL;
2204 if (res.type == RTN_UNREACHABLE) {
2205 rth->dst.input= ip_error;
2206 rth->dst.error= -err;
2207 rth->rt_flags &= ~RTCF_LOCAL;
2208 }
2209 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2210 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2211 err = 0;
2212 if (IS_ERR(rth))
2213 err = PTR_ERR(rth);
2214 goto out;
2215
2216 no_route:
2217 RT_CACHE_STAT_INC(in_no_route);
2218 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2219 res.type = RTN_UNREACHABLE;
2220 if (err == -ESRCH)
2221 err = -ENETUNREACH;
2222 goto local_input;
2223
2224 /*
2225 * Do not cache martian addresses: they should be logged (RFC1812)
2226 */
2227 martian_destination:
2228 RT_CACHE_STAT_INC(in_martian_dst);
2229 #ifdef CONFIG_IP_ROUTE_VERBOSE
2230 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2231 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2232 &daddr, &saddr, dev->name);
2233 #endif
2234
2235 e_hostunreach:
2236 err = -EHOSTUNREACH;
2237 goto out;
2238
2239 e_inval:
2240 err = -EINVAL;
2241 goto out;
2242
2243 e_nobufs:
2244 err = -ENOBUFS;
2245 goto out;
2246
2247 martian_source:
2248 err = -EINVAL;
2249 martian_source_keep_err:
2250 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2251 goto out;
2252 }
2253
2254 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2255 u8 tos, struct net_device *dev, bool noref)
2256 {
2257 struct rtable * rth;
2258 unsigned hash;
2259 int iif = dev->ifindex;
2260 struct net *net;
2261 int res;
2262
2263 net = dev_net(dev);
2264
2265 rcu_read_lock();
2266
2267 if (!rt_caching(net))
2268 goto skip_cache;
2269
2270 tos &= IPTOS_RT_MASK;
2271 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2272
2273 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2274 rth = rcu_dereference(rth->dst.rt_next)) {
2275 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2276 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2277 (rth->rt_iif ^ iif) |
2278 rth->rt_oif |
2279 (rth->rt_key_tos ^ tos)) == 0 &&
2280 rth->rt_mark == skb->mark &&
2281 net_eq(dev_net(rth->dst.dev), net) &&
2282 !rt_is_expired(rth)) {
2283 if (noref) {
2284 dst_use_noref(&rth->dst, jiffies);
2285 skb_dst_set_noref(skb, &rth->dst);
2286 } else {
2287 dst_use(&rth->dst, jiffies);
2288 skb_dst_set(skb, &rth->dst);
2289 }
2290 RT_CACHE_STAT_INC(in_hit);
2291 rcu_read_unlock();
2292 return 0;
2293 }
2294 RT_CACHE_STAT_INC(in_hlist_search);
2295 }
2296
2297 skip_cache:
2298 /* Multicast recognition logic is moved from route cache to here.
2299 The problem was that too many Ethernet cards have broken/missing
2300 hardware multicast filters :-( As result the host on multicasting
2301 network acquires a lot of useless route cache entries, sort of
2302 SDR messages from all the world. Now we try to get rid of them.
2303 Really, provided software IP multicast filter is organized
2304 reasonably (at least, hashed), it does not result in a slowdown
2305 comparing with route cache reject entries.
2306 Note, that multicast routers are not affected, because
2307 route cache entry is created eventually.
2308 */
2309 if (ipv4_is_multicast(daddr)) {
2310 struct in_device *in_dev = __in_dev_get_rcu(dev);
2311
2312 if (in_dev) {
2313 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2314 ip_hdr(skb)->protocol);
2315 if (our
2316 #ifdef CONFIG_IP_MROUTE
2317 ||
2318 (!ipv4_is_local_multicast(daddr) &&
2319 IN_DEV_MFORWARD(in_dev))
2320 #endif
2321 ) {
2322 int res = ip_route_input_mc(skb, daddr, saddr,
2323 tos, dev, our);
2324 rcu_read_unlock();
2325 return res;
2326 }
2327 }
2328 rcu_read_unlock();
2329 return -EINVAL;
2330 }
2331 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2332 rcu_read_unlock();
2333 return res;
2334 }
2335 EXPORT_SYMBOL(ip_route_input_common);
2336
2337 /* called with rcu_read_lock() */
2338 static struct rtable *__mkroute_output(const struct fib_result *res,
2339 const struct flowi4 *fl4,
2340 __be32 orig_daddr, __be32 orig_saddr,
2341 int orig_oif, struct net_device *dev_out,
2342 unsigned int flags)
2343 {
2344 struct fib_info *fi = res->fi;
2345 u32 tos = RT_FL_TOS(fl4);
2346 struct in_device *in_dev;
2347 u16 type = res->type;
2348 struct rtable *rth;
2349
2350 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2351 return ERR_PTR(-EINVAL);
2352
2353 if (ipv4_is_lbcast(fl4->daddr))
2354 type = RTN_BROADCAST;
2355 else if (ipv4_is_multicast(fl4->daddr))
2356 type = RTN_MULTICAST;
2357 else if (ipv4_is_zeronet(fl4->daddr))
2358 return ERR_PTR(-EINVAL);
2359
2360 if (dev_out->flags & IFF_LOOPBACK)
2361 flags |= RTCF_LOCAL;
2362
2363 in_dev = __in_dev_get_rcu(dev_out);
2364 if (!in_dev)
2365 return ERR_PTR(-EINVAL);
2366
2367 if (type == RTN_BROADCAST) {
2368 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2369 fi = NULL;
2370 } else if (type == RTN_MULTICAST) {
2371 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2372 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2373 fl4->flowi4_proto))
2374 flags &= ~RTCF_LOCAL;
2375 /* If multicast route do not exist use
2376 * default one, but do not gateway in this case.
2377 * Yes, it is hack.
2378 */
2379 if (fi && res->prefixlen < 4)
2380 fi = NULL;
2381 }
2382
2383 rth = rt_dst_alloc(dev_out,
2384 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2385 IN_DEV_CONF_GET(in_dev, NOXFRM));
2386 if (!rth)
2387 return ERR_PTR(-ENOBUFS);
2388
2389 rth->dst.output = ip_output;
2390
2391 rth->rt_key_dst = orig_daddr;
2392 rth->rt_key_src = orig_saddr;
2393 rth->rt_genid = rt_genid(dev_net(dev_out));
2394 rth->rt_flags = flags;
2395 rth->rt_type = type;
2396 rth->rt_key_tos = tos;
2397 rth->rt_dst = fl4->daddr;
2398 rth->rt_src = fl4->saddr;
2399 rth->rt_route_iif = 0;
2400 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2401 rth->rt_oif = orig_oif;
2402 rth->rt_mark = fl4->flowi4_mark;
2403 rth->rt_gateway = fl4->daddr;
2404 rth->rt_spec_dst= fl4->saddr;
2405 rth->rt_peer_genid = 0;
2406 rth->peer = NULL;
2407 rth->fi = NULL;
2408
2409 RT_CACHE_STAT_INC(out_slow_tot);
2410
2411 if (flags & RTCF_LOCAL) {
2412 rth->dst.input = ip_local_deliver;
2413 rth->rt_spec_dst = fl4->daddr;
2414 }
2415 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2416 rth->rt_spec_dst = fl4->saddr;
2417 if (flags & RTCF_LOCAL &&
2418 !(dev_out->flags & IFF_LOOPBACK)) {
2419 rth->dst.output = ip_mc_output;
2420 RT_CACHE_STAT_INC(out_slow_mc);
2421 }
2422 #ifdef CONFIG_IP_MROUTE
2423 if (type == RTN_MULTICAST) {
2424 if (IN_DEV_MFORWARD(in_dev) &&
2425 !ipv4_is_local_multicast(fl4->daddr)) {
2426 rth->dst.input = ip_mr_input;
2427 rth->dst.output = ip_mc_output;
2428 }
2429 }
2430 #endif
2431 }
2432
2433 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2434
2435 return rth;
2436 }
2437
2438 /*
2439 * Major route resolver routine.
2440 * called with rcu_read_lock();
2441 */
2442
2443 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2444 {
2445 struct net_device *dev_out = NULL;
2446 u32 tos = RT_FL_TOS(fl4);
2447 unsigned int flags = 0;
2448 struct fib_result res;
2449 struct rtable *rth;
2450 __be32 orig_daddr;
2451 __be32 orig_saddr;
2452 int orig_oif;
2453
2454 res.fi = NULL;
2455 #ifdef CONFIG_IP_MULTIPLE_TABLES
2456 res.r = NULL;
2457 #endif
2458
2459 orig_daddr = fl4->daddr;
2460 orig_saddr = fl4->saddr;
2461 orig_oif = fl4->flowi4_oif;
2462
2463 fl4->flowi4_iif = net->loopback_dev->ifindex;
2464 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2465 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2466 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2467
2468 rcu_read_lock();
2469 if (fl4->saddr) {
2470 rth = ERR_PTR(-EINVAL);
2471 if (ipv4_is_multicast(fl4->saddr) ||
2472 ipv4_is_lbcast(fl4->saddr) ||
2473 ipv4_is_zeronet(fl4->saddr))
2474 goto out;
2475
2476 /* I removed check for oif == dev_out->oif here.
2477 It was wrong for two reasons:
2478 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2479 is assigned to multiple interfaces.
2480 2. Moreover, we are allowed to send packets with saddr
2481 of another iface. --ANK
2482 */
2483
2484 if (fl4->flowi4_oif == 0 &&
2485 (ipv4_is_multicast(fl4->daddr) ||
2486 ipv4_is_lbcast(fl4->daddr))) {
2487 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2488 dev_out = __ip_dev_find(net, fl4->saddr, false);
2489 if (dev_out == NULL)
2490 goto out;
2491
2492 /* Special hack: user can direct multicasts
2493 and limited broadcast via necessary interface
2494 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2495 This hack is not just for fun, it allows
2496 vic,vat and friends to work.
2497 They bind socket to loopback, set ttl to zero
2498 and expect that it will work.
2499 From the viewpoint of routing cache they are broken,
2500 because we are not allowed to build multicast path
2501 with loopback source addr (look, routing cache
2502 cannot know, that ttl is zero, so that packet
2503 will not leave this host and route is valid).
2504 Luckily, this hack is good workaround.
2505 */
2506
2507 fl4->flowi4_oif = dev_out->ifindex;
2508 goto make_route;
2509 }
2510
2511 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2512 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2513 if (!__ip_dev_find(net, fl4->saddr, false))
2514 goto out;
2515 }
2516 }
2517
2518
2519 if (fl4->flowi4_oif) {
2520 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2521 rth = ERR_PTR(-ENODEV);
2522 if (dev_out == NULL)
2523 goto out;
2524
2525 /* RACE: Check return value of inet_select_addr instead. */
2526 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2527 rth = ERR_PTR(-ENETUNREACH);
2528 goto out;
2529 }
2530 if (ipv4_is_local_multicast(fl4->daddr) ||
2531 ipv4_is_lbcast(fl4->daddr)) {
2532 if (!fl4->saddr)
2533 fl4->saddr = inet_select_addr(dev_out, 0,
2534 RT_SCOPE_LINK);
2535 goto make_route;
2536 }
2537 if (fl4->saddr) {
2538 if (ipv4_is_multicast(fl4->daddr))
2539 fl4->saddr = inet_select_addr(dev_out, 0,
2540 fl4->flowi4_scope);
2541 else if (!fl4->daddr)
2542 fl4->saddr = inet_select_addr(dev_out, 0,
2543 RT_SCOPE_HOST);
2544 }
2545 }
2546
2547 if (!fl4->daddr) {
2548 fl4->daddr = fl4->saddr;
2549 if (!fl4->daddr)
2550 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2551 dev_out = net->loopback_dev;
2552 fl4->flowi4_oif = net->loopback_dev->ifindex;
2553 res.type = RTN_LOCAL;
2554 flags |= RTCF_LOCAL;
2555 goto make_route;
2556 }
2557
2558 if (fib_lookup(net, fl4, &res)) {
2559 res.fi = NULL;
2560 if (fl4->flowi4_oif) {
2561 /* Apparently, routing tables are wrong. Assume,
2562 that the destination is on link.
2563
2564 WHY? DW.
2565 Because we are allowed to send to iface
2566 even if it has NO routes and NO assigned
2567 addresses. When oif is specified, routing
2568 tables are looked up with only one purpose:
2569 to catch if destination is gatewayed, rather than
2570 direct. Moreover, if MSG_DONTROUTE is set,
2571 we send packet, ignoring both routing tables
2572 and ifaddr state. --ANK
2573
2574
2575 We could make it even if oif is unknown,
2576 likely IPv6, but we do not.
2577 */
2578
2579 if (fl4->saddr == 0)
2580 fl4->saddr = inet_select_addr(dev_out, 0,
2581 RT_SCOPE_LINK);
2582 res.type = RTN_UNICAST;
2583 goto make_route;
2584 }
2585 rth = ERR_PTR(-ENETUNREACH);
2586 goto out;
2587 }
2588
2589 if (res.type == RTN_LOCAL) {
2590 if (!fl4->saddr) {
2591 if (res.fi->fib_prefsrc)
2592 fl4->saddr = res.fi->fib_prefsrc;
2593 else
2594 fl4->saddr = fl4->daddr;
2595 }
2596 dev_out = net->loopback_dev;
2597 fl4->flowi4_oif = dev_out->ifindex;
2598 res.fi = NULL;
2599 flags |= RTCF_LOCAL;
2600 goto make_route;
2601 }
2602
2603 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2604 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2605 fib_select_multipath(&res);
2606 else
2607 #endif
2608 if (!res.prefixlen &&
2609 res.table->tb_num_default > 1 &&
2610 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2611 fib_select_default(&res);
2612
2613 if (!fl4->saddr)
2614 fl4->saddr = FIB_RES_PREFSRC(net, res);
2615
2616 dev_out = FIB_RES_DEV(res);
2617 fl4->flowi4_oif = dev_out->ifindex;
2618
2619
2620 make_route:
2621 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2622 dev_out, flags);
2623 if (!IS_ERR(rth)) {
2624 unsigned int hash;
2625
2626 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2627 rt_genid(dev_net(dev_out)));
2628 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2629 }
2630
2631 out:
2632 rcu_read_unlock();
2633 return rth;
2634 }
2635
2636 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2637 {
2638 struct rtable *rth;
2639 unsigned int hash;
2640
2641 if (!rt_caching(net))
2642 goto slow_output;
2643
2644 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2645
2646 rcu_read_lock_bh();
2647 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2648 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2649 if (rth->rt_key_dst == flp4->daddr &&
2650 rth->rt_key_src == flp4->saddr &&
2651 rt_is_output_route(rth) &&
2652 rth->rt_oif == flp4->flowi4_oif &&
2653 rth->rt_mark == flp4->flowi4_mark &&
2654 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2655 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2656 net_eq(dev_net(rth->dst.dev), net) &&
2657 !rt_is_expired(rth)) {
2658 dst_use(&rth->dst, jiffies);
2659 RT_CACHE_STAT_INC(out_hit);
2660 rcu_read_unlock_bh();
2661 if (!flp4->saddr)
2662 flp4->saddr = rth->rt_src;
2663 if (!flp4->daddr)
2664 flp4->daddr = rth->rt_dst;
2665 return rth;
2666 }
2667 RT_CACHE_STAT_INC(out_hlist_search);
2668 }
2669 rcu_read_unlock_bh();
2670
2671 slow_output:
2672 return ip_route_output_slow(net, flp4);
2673 }
2674 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2675
2676 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2677 {
2678 return NULL;
2679 }
2680
2681 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2682 {
2683 return 0;
2684 }
2685
2686 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2687 {
2688 }
2689
2690 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2691 unsigned long old)
2692 {
2693 return NULL;
2694 }
2695
2696 static struct dst_ops ipv4_dst_blackhole_ops = {
2697 .family = AF_INET,
2698 .protocol = cpu_to_be16(ETH_P_IP),
2699 .destroy = ipv4_dst_destroy,
2700 .check = ipv4_blackhole_dst_check,
2701 .default_mtu = ipv4_blackhole_default_mtu,
2702 .default_advmss = ipv4_default_advmss,
2703 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2704 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2705 };
2706
2707 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2708 {
2709 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2710 struct rtable *ort = (struct rtable *) dst_orig;
2711
2712 if (rt) {
2713 struct dst_entry *new = &rt->dst;
2714
2715 new->__use = 1;
2716 new->input = dst_discard;
2717 new->output = dst_discard;
2718 dst_copy_metrics(new, &ort->dst);
2719
2720 new->dev = ort->dst.dev;
2721 if (new->dev)
2722 dev_hold(new->dev);
2723
2724 rt->rt_key_dst = ort->rt_key_dst;
2725 rt->rt_key_src = ort->rt_key_src;
2726 rt->rt_key_tos = ort->rt_key_tos;
2727 rt->rt_route_iif = ort->rt_route_iif;
2728 rt->rt_iif = ort->rt_iif;
2729 rt->rt_oif = ort->rt_oif;
2730 rt->rt_mark = ort->rt_mark;
2731
2732 rt->rt_genid = rt_genid(net);
2733 rt->rt_flags = ort->rt_flags;
2734 rt->rt_type = ort->rt_type;
2735 rt->rt_dst = ort->rt_dst;
2736 rt->rt_src = ort->rt_src;
2737 rt->rt_gateway = ort->rt_gateway;
2738 rt->rt_spec_dst = ort->rt_spec_dst;
2739 rt->peer = ort->peer;
2740 if (rt->peer)
2741 atomic_inc(&rt->peer->refcnt);
2742 rt->fi = ort->fi;
2743 if (rt->fi)
2744 atomic_inc(&rt->fi->fib_clntref);
2745
2746 dst_free(new);
2747 }
2748
2749 dst_release(dst_orig);
2750
2751 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2752 }
2753
2754 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2755 struct sock *sk)
2756 {
2757 struct rtable *rt = __ip_route_output_key(net, flp4);
2758
2759 if (IS_ERR(rt))
2760 return rt;
2761
2762 if (flp4->flowi4_proto)
2763 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2764 flowi4_to_flowi(flp4),
2765 sk, 0);
2766
2767 return rt;
2768 }
2769 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2770
2771 static int rt_fill_info(struct net *net,
2772 struct sk_buff *skb, u32 pid, u32 seq, int event,
2773 int nowait, unsigned int flags)
2774 {
2775 struct rtable *rt = skb_rtable(skb);
2776 struct rtmsg *r;
2777 struct nlmsghdr *nlh;
2778 long expires;
2779 u32 id = 0, ts = 0, tsage = 0, error;
2780
2781 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2782 if (nlh == NULL)
2783 return -EMSGSIZE;
2784
2785 r = nlmsg_data(nlh);
2786 r->rtm_family = AF_INET;
2787 r->rtm_dst_len = 32;
2788 r->rtm_src_len = 0;
2789 r->rtm_tos = rt->rt_key_tos;
2790 r->rtm_table = RT_TABLE_MAIN;
2791 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2792 r->rtm_type = rt->rt_type;
2793 r->rtm_scope = RT_SCOPE_UNIVERSE;
2794 r->rtm_protocol = RTPROT_UNSPEC;
2795 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2796 if (rt->rt_flags & RTCF_NOTIFY)
2797 r->rtm_flags |= RTM_F_NOTIFY;
2798
2799 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2800
2801 if (rt->rt_key_src) {
2802 r->rtm_src_len = 32;
2803 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2804 }
2805 if (rt->dst.dev)
2806 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2807 #ifdef CONFIG_IP_ROUTE_CLASSID
2808 if (rt->dst.tclassid)
2809 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2810 #endif
2811 if (rt_is_input_route(rt))
2812 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2813 else if (rt->rt_src != rt->rt_key_src)
2814 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2815
2816 if (rt->rt_dst != rt->rt_gateway)
2817 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2818
2819 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2820 goto nla_put_failure;
2821
2822 if (rt->rt_mark)
2823 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2824
2825 error = rt->dst.error;
2826 expires = (rt->peer && rt->peer->pmtu_expires) ?
2827 rt->peer->pmtu_expires - jiffies : 0;
2828 if (rt->peer) {
2829 inet_peer_refcheck(rt->peer);
2830 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2831 if (rt->peer->tcp_ts_stamp) {
2832 ts = rt->peer->tcp_ts;
2833 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2834 }
2835 }
2836
2837 if (rt_is_input_route(rt)) {
2838 #ifdef CONFIG_IP_MROUTE
2839 __be32 dst = rt->rt_dst;
2840
2841 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2842 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2843 int err = ipmr_get_route(net, skb,
2844 rt->rt_src, rt->rt_dst,
2845 r, nowait);
2846 if (err <= 0) {
2847 if (!nowait) {
2848 if (err == 0)
2849 return 0;
2850 goto nla_put_failure;
2851 } else {
2852 if (err == -EMSGSIZE)
2853 goto nla_put_failure;
2854 error = err;
2855 }
2856 }
2857 } else
2858 #endif
2859 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2860 }
2861
2862 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2863 expires, error) < 0)
2864 goto nla_put_failure;
2865
2866 return nlmsg_end(skb, nlh);
2867
2868 nla_put_failure:
2869 nlmsg_cancel(skb, nlh);
2870 return -EMSGSIZE;
2871 }
2872
2873 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2874 {
2875 struct net *net = sock_net(in_skb->sk);
2876 struct rtmsg *rtm;
2877 struct nlattr *tb[RTA_MAX+1];
2878 struct rtable *rt = NULL;
2879 __be32 dst = 0;
2880 __be32 src = 0;
2881 u32 iif;
2882 int err;
2883 int mark;
2884 struct sk_buff *skb;
2885
2886 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2887 if (err < 0)
2888 goto errout;
2889
2890 rtm = nlmsg_data(nlh);
2891
2892 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2893 if (skb == NULL) {
2894 err = -ENOBUFS;
2895 goto errout;
2896 }
2897
2898 /* Reserve room for dummy headers, this skb can pass
2899 through good chunk of routing engine.
2900 */
2901 skb_reset_mac_header(skb);
2902 skb_reset_network_header(skb);
2903
2904 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2905 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2906 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2907
2908 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2909 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2910 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2911 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2912
2913 if (iif) {
2914 struct net_device *dev;
2915
2916 dev = __dev_get_by_index(net, iif);
2917 if (dev == NULL) {
2918 err = -ENODEV;
2919 goto errout_free;
2920 }
2921
2922 skb->protocol = htons(ETH_P_IP);
2923 skb->dev = dev;
2924 skb->mark = mark;
2925 local_bh_disable();
2926 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2927 local_bh_enable();
2928
2929 rt = skb_rtable(skb);
2930 if (err == 0 && rt->dst.error)
2931 err = -rt->dst.error;
2932 } else {
2933 struct flowi4 fl4 = {
2934 .daddr = dst,
2935 .saddr = src,
2936 .flowi4_tos = rtm->rtm_tos,
2937 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2938 .flowi4_mark = mark,
2939 };
2940 rt = ip_route_output_key(net, &fl4);
2941
2942 err = 0;
2943 if (IS_ERR(rt))
2944 err = PTR_ERR(rt);
2945 }
2946
2947 if (err)
2948 goto errout_free;
2949
2950 skb_dst_set(skb, &rt->dst);
2951 if (rtm->rtm_flags & RTM_F_NOTIFY)
2952 rt->rt_flags |= RTCF_NOTIFY;
2953
2954 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2955 RTM_NEWROUTE, 0, 0);
2956 if (err <= 0)
2957 goto errout_free;
2958
2959 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2960 errout:
2961 return err;
2962
2963 errout_free:
2964 kfree_skb(skb);
2965 goto errout;
2966 }
2967
2968 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2969 {
2970 struct rtable *rt;
2971 int h, s_h;
2972 int idx, s_idx;
2973 struct net *net;
2974
2975 net = sock_net(skb->sk);
2976
2977 s_h = cb->args[0];
2978 if (s_h < 0)
2979 s_h = 0;
2980 s_idx = idx = cb->args[1];
2981 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2982 if (!rt_hash_table[h].chain)
2983 continue;
2984 rcu_read_lock_bh();
2985 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2986 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2987 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2988 continue;
2989 if (rt_is_expired(rt))
2990 continue;
2991 skb_dst_set_noref(skb, &rt->dst);
2992 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
2993 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2994 1, NLM_F_MULTI) <= 0) {
2995 skb_dst_drop(skb);
2996 rcu_read_unlock_bh();
2997 goto done;
2998 }
2999 skb_dst_drop(skb);
3000 }
3001 rcu_read_unlock_bh();
3002 }
3003
3004 done:
3005 cb->args[0] = h;
3006 cb->args[1] = idx;
3007 return skb->len;
3008 }
3009
3010 void ip_rt_multicast_event(struct in_device *in_dev)
3011 {
3012 rt_cache_flush(dev_net(in_dev->dev), 0);
3013 }
3014
3015 #ifdef CONFIG_SYSCTL
3016 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3017 void __user *buffer,
3018 size_t *lenp, loff_t *ppos)
3019 {
3020 if (write) {
3021 int flush_delay;
3022 ctl_table ctl;
3023 struct net *net;
3024
3025 memcpy(&ctl, __ctl, sizeof(ctl));
3026 ctl.data = &flush_delay;
3027 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3028
3029 net = (struct net *)__ctl->extra1;
3030 rt_cache_flush(net, flush_delay);
3031 return 0;
3032 }
3033
3034 return -EINVAL;
3035 }
3036
3037 static ctl_table ipv4_route_table[] = {
3038 {
3039 .procname = "gc_thresh",
3040 .data = &ipv4_dst_ops.gc_thresh,
3041 .maxlen = sizeof(int),
3042 .mode = 0644,
3043 .proc_handler = proc_dointvec,
3044 },
3045 {
3046 .procname = "max_size",
3047 .data = &ip_rt_max_size,
3048 .maxlen = sizeof(int),
3049 .mode = 0644,
3050 .proc_handler = proc_dointvec,
3051 },
3052 {
3053 /* Deprecated. Use gc_min_interval_ms */
3054
3055 .procname = "gc_min_interval",
3056 .data = &ip_rt_gc_min_interval,
3057 .maxlen = sizeof(int),
3058 .mode = 0644,
3059 .proc_handler = proc_dointvec_jiffies,
3060 },
3061 {
3062 .procname = "gc_min_interval_ms",
3063 .data = &ip_rt_gc_min_interval,
3064 .maxlen = sizeof(int),
3065 .mode = 0644,
3066 .proc_handler = proc_dointvec_ms_jiffies,
3067 },
3068 {
3069 .procname = "gc_timeout",
3070 .data = &ip_rt_gc_timeout,
3071 .maxlen = sizeof(int),
3072 .mode = 0644,
3073 .proc_handler = proc_dointvec_jiffies,
3074 },
3075 {
3076 .procname = "gc_interval",
3077 .data = &ip_rt_gc_interval,
3078 .maxlen = sizeof(int),
3079 .mode = 0644,
3080 .proc_handler = proc_dointvec_jiffies,
3081 },
3082 {
3083 .procname = "redirect_load",
3084 .data = &ip_rt_redirect_load,
3085 .maxlen = sizeof(int),
3086 .mode = 0644,
3087 .proc_handler = proc_dointvec,
3088 },
3089 {
3090 .procname = "redirect_number",
3091 .data = &ip_rt_redirect_number,
3092 .maxlen = sizeof(int),
3093 .mode = 0644,
3094 .proc_handler = proc_dointvec,
3095 },
3096 {
3097 .procname = "redirect_silence",
3098 .data = &ip_rt_redirect_silence,
3099 .maxlen = sizeof(int),
3100 .mode = 0644,
3101 .proc_handler = proc_dointvec,
3102 },
3103 {
3104 .procname = "error_cost",
3105 .data = &ip_rt_error_cost,
3106 .maxlen = sizeof(int),
3107 .mode = 0644,
3108 .proc_handler = proc_dointvec,
3109 },
3110 {
3111 .procname = "error_burst",
3112 .data = &ip_rt_error_burst,
3113 .maxlen = sizeof(int),
3114 .mode = 0644,
3115 .proc_handler = proc_dointvec,
3116 },
3117 {
3118 .procname = "gc_elasticity",
3119 .data = &ip_rt_gc_elasticity,
3120 .maxlen = sizeof(int),
3121 .mode = 0644,
3122 .proc_handler = proc_dointvec,
3123 },
3124 {
3125 .procname = "mtu_expires",
3126 .data = &ip_rt_mtu_expires,
3127 .maxlen = sizeof(int),
3128 .mode = 0644,
3129 .proc_handler = proc_dointvec_jiffies,
3130 },
3131 {
3132 .procname = "min_pmtu",
3133 .data = &ip_rt_min_pmtu,
3134 .maxlen = sizeof(int),
3135 .mode = 0644,
3136 .proc_handler = proc_dointvec,
3137 },
3138 {
3139 .procname = "min_adv_mss",
3140 .data = &ip_rt_min_advmss,
3141 .maxlen = sizeof(int),
3142 .mode = 0644,
3143 .proc_handler = proc_dointvec,
3144 },
3145 { }
3146 };
3147
3148 static struct ctl_table empty[1];
3149
3150 static struct ctl_table ipv4_skeleton[] =
3151 {
3152 { .procname = "route",
3153 .mode = 0555, .child = ipv4_route_table},
3154 { .procname = "neigh",
3155 .mode = 0555, .child = empty},
3156 { }
3157 };
3158
3159 static __net_initdata struct ctl_path ipv4_path[] = {
3160 { .procname = "net", },
3161 { .procname = "ipv4", },
3162 { },
3163 };
3164
3165 static struct ctl_table ipv4_route_flush_table[] = {
3166 {
3167 .procname = "flush",
3168 .maxlen = sizeof(int),
3169 .mode = 0200,
3170 .proc_handler = ipv4_sysctl_rtcache_flush,
3171 },
3172 { },
3173 };
3174
3175 static __net_initdata struct ctl_path ipv4_route_path[] = {
3176 { .procname = "net", },
3177 { .procname = "ipv4", },
3178 { .procname = "route", },
3179 { },
3180 };
3181
3182 static __net_init int sysctl_route_net_init(struct net *net)
3183 {
3184 struct ctl_table *tbl;
3185
3186 tbl = ipv4_route_flush_table;
3187 if (!net_eq(net, &init_net)) {
3188 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3189 if (tbl == NULL)
3190 goto err_dup;
3191 }
3192 tbl[0].extra1 = net;
3193
3194 net->ipv4.route_hdr =
3195 register_net_sysctl_table(net, ipv4_route_path, tbl);
3196 if (net->ipv4.route_hdr == NULL)
3197 goto err_reg;
3198 return 0;
3199
3200 err_reg:
3201 if (tbl != ipv4_route_flush_table)
3202 kfree(tbl);
3203 err_dup:
3204 return -ENOMEM;
3205 }
3206
3207 static __net_exit void sysctl_route_net_exit(struct net *net)
3208 {
3209 struct ctl_table *tbl;
3210
3211 tbl = net->ipv4.route_hdr->ctl_table_arg;
3212 unregister_net_sysctl_table(net->ipv4.route_hdr);
3213 BUG_ON(tbl == ipv4_route_flush_table);
3214 kfree(tbl);
3215 }
3216
3217 static __net_initdata struct pernet_operations sysctl_route_ops = {
3218 .init = sysctl_route_net_init,
3219 .exit = sysctl_route_net_exit,
3220 };
3221 #endif
3222
3223 static __net_init int rt_genid_init(struct net *net)
3224 {
3225 get_random_bytes(&net->ipv4.rt_genid,
3226 sizeof(net->ipv4.rt_genid));
3227 get_random_bytes(&net->ipv4.dev_addr_genid,
3228 sizeof(net->ipv4.dev_addr_genid));
3229 return 0;
3230 }
3231
3232 static __net_initdata struct pernet_operations rt_genid_ops = {
3233 .init = rt_genid_init,
3234 };
3235
3236
3237 #ifdef CONFIG_IP_ROUTE_CLASSID
3238 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3239 #endif /* CONFIG_IP_ROUTE_CLASSID */
3240
3241 static __initdata unsigned long rhash_entries;
3242 static int __init set_rhash_entries(char *str)
3243 {
3244 if (!str)
3245 return 0;
3246 rhash_entries = simple_strtoul(str, &str, 0);
3247 return 1;
3248 }
3249 __setup("rhash_entries=", set_rhash_entries);
3250
3251 int __init ip_rt_init(void)
3252 {
3253 int rc = 0;
3254
3255 #ifdef CONFIG_IP_ROUTE_CLASSID
3256 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3257 if (!ip_rt_acct)
3258 panic("IP: failed to allocate ip_rt_acct\n");
3259 #endif
3260
3261 ipv4_dst_ops.kmem_cachep =
3262 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3263 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3264
3265 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3266
3267 if (dst_entries_init(&ipv4_dst_ops) < 0)
3268 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3269
3270 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3271 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3272
3273 rt_hash_table = (struct rt_hash_bucket *)
3274 alloc_large_system_hash("IP route cache",
3275 sizeof(struct rt_hash_bucket),
3276 rhash_entries,
3277 (totalram_pages >= 128 * 1024) ?
3278 15 : 17,
3279 0,
3280 &rt_hash_log,
3281 &rt_hash_mask,
3282 rhash_entries ? 0 : 512 * 1024);
3283 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3284 rt_hash_lock_init();
3285
3286 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3287 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3288
3289 devinet_init();
3290 ip_fib_init();
3291
3292 if (ip_rt_proc_init())
3293 printk(KERN_ERR "Unable to create route proc files\n");
3294 #ifdef CONFIG_XFRM
3295 xfrm_init();
3296 xfrm4_init(ip_rt_max_size);
3297 #endif
3298 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3299
3300 #ifdef CONFIG_SYSCTL
3301 register_pernet_subsys(&sysctl_route_ops);
3302 #endif
3303 register_pernet_subsys(&rt_genid_ops);
3304 return rc;
3305 }
3306
3307 #ifdef CONFIG_SYSCTL
3308 /*
3309 * We really need to sanitize the damn ipv4 init order, then all
3310 * this nonsense will go away.
3311 */
3312 void __init ip_static_sysctl_init(void)
3313 {
3314 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3315 }
3316 #endif
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