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ipv4: Kill RT_CACHE_DEBUG
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
94 #include <net/dst.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
108 #ifdef CONFIG_SYSCTL
109 #include <linux/sysctl.h>
110 #endif
111
112 #define RT_FL_TOS(oldflp4) \
113 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132 static int rt_chain_length_max __read_mostly = 20;
133
134 /*
135 * Interface to generic destination cache.
136 */
137
138 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140 static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
141 static void ipv4_dst_destroy(struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
145 static int rt_garbage_collect(struct dst_ops *ops);
146
147 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
148 int how)
149 {
150 }
151
152 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
153 {
154 struct rtable *rt = (struct rtable *) dst;
155 struct inet_peer *peer;
156 u32 *p = NULL;
157
158 if (!rt->peer)
159 rt_bind_peer(rt, 1);
160
161 peer = rt->peer;
162 if (peer) {
163 u32 *old_p = __DST_METRICS_PTR(old);
164 unsigned long prev, new;
165
166 p = peer->metrics;
167 if (inet_metrics_new(peer))
168 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
169
170 new = (unsigned long) p;
171 prev = cmpxchg(&dst->_metrics, old, new);
172
173 if (prev != old) {
174 p = __DST_METRICS_PTR(prev);
175 if (prev & DST_METRICS_READ_ONLY)
176 p = NULL;
177 } else {
178 if (rt->fi) {
179 fib_info_put(rt->fi);
180 rt->fi = NULL;
181 }
182 }
183 }
184 return p;
185 }
186
187 static struct dst_ops ipv4_dst_ops = {
188 .family = AF_INET,
189 .protocol = cpu_to_be16(ETH_P_IP),
190 .gc = rt_garbage_collect,
191 .check = ipv4_dst_check,
192 .default_advmss = ipv4_default_advmss,
193 .default_mtu = ipv4_default_mtu,
194 .cow_metrics = ipv4_cow_metrics,
195 .destroy = ipv4_dst_destroy,
196 .ifdown = ipv4_dst_ifdown,
197 .negative_advice = ipv4_negative_advice,
198 .link_failure = ipv4_link_failure,
199 .update_pmtu = ip_rt_update_pmtu,
200 .local_out = __ip_local_out,
201 };
202
203 #define ECN_OR_COST(class) TC_PRIO_##class
204
205 const __u8 ip_tos2prio[16] = {
206 TC_PRIO_BESTEFFORT,
207 ECN_OR_COST(BESTEFFORT),
208 TC_PRIO_BESTEFFORT,
209 ECN_OR_COST(BESTEFFORT),
210 TC_PRIO_BULK,
211 ECN_OR_COST(BULK),
212 TC_PRIO_BULK,
213 ECN_OR_COST(BULK),
214 TC_PRIO_INTERACTIVE,
215 ECN_OR_COST(INTERACTIVE),
216 TC_PRIO_INTERACTIVE,
217 ECN_OR_COST(INTERACTIVE),
218 TC_PRIO_INTERACTIVE_BULK,
219 ECN_OR_COST(INTERACTIVE_BULK),
220 TC_PRIO_INTERACTIVE_BULK,
221 ECN_OR_COST(INTERACTIVE_BULK)
222 };
223
224
225 /*
226 * Route cache.
227 */
228
229 /* The locking scheme is rather straight forward:
230 *
231 * 1) Read-Copy Update protects the buckets of the central route hash.
232 * 2) Only writers remove entries, and they hold the lock
233 * as they look at rtable reference counts.
234 * 3) Only readers acquire references to rtable entries,
235 * they do so with atomic increments and with the
236 * lock held.
237 */
238
239 struct rt_hash_bucket {
240 struct rtable __rcu *chain;
241 };
242
243 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
244 defined(CONFIG_PROVE_LOCKING)
245 /*
246 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
247 * The size of this table is a power of two and depends on the number of CPUS.
248 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
249 */
250 #ifdef CONFIG_LOCKDEP
251 # define RT_HASH_LOCK_SZ 256
252 #else
253 # if NR_CPUS >= 32
254 # define RT_HASH_LOCK_SZ 4096
255 # elif NR_CPUS >= 16
256 # define RT_HASH_LOCK_SZ 2048
257 # elif NR_CPUS >= 8
258 # define RT_HASH_LOCK_SZ 1024
259 # elif NR_CPUS >= 4
260 # define RT_HASH_LOCK_SZ 512
261 # else
262 # define RT_HASH_LOCK_SZ 256
263 # endif
264 #endif
265
266 static spinlock_t *rt_hash_locks;
267 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
268
269 static __init void rt_hash_lock_init(void)
270 {
271 int i;
272
273 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
274 GFP_KERNEL);
275 if (!rt_hash_locks)
276 panic("IP: failed to allocate rt_hash_locks\n");
277
278 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
279 spin_lock_init(&rt_hash_locks[i]);
280 }
281 #else
282 # define rt_hash_lock_addr(slot) NULL
283
284 static inline void rt_hash_lock_init(void)
285 {
286 }
287 #endif
288
289 static struct rt_hash_bucket *rt_hash_table __read_mostly;
290 static unsigned rt_hash_mask __read_mostly;
291 static unsigned int rt_hash_log __read_mostly;
292
293 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
294 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
295
296 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
297 int genid)
298 {
299 return jhash_3words((__force u32)daddr, (__force u32)saddr,
300 idx, genid)
301 & rt_hash_mask;
302 }
303
304 static inline int rt_genid(struct net *net)
305 {
306 return atomic_read(&net->ipv4.rt_genid);
307 }
308
309 #ifdef CONFIG_PROC_FS
310 struct rt_cache_iter_state {
311 struct seq_net_private p;
312 int bucket;
313 int genid;
314 };
315
316 static struct rtable *rt_cache_get_first(struct seq_file *seq)
317 {
318 struct rt_cache_iter_state *st = seq->private;
319 struct rtable *r = NULL;
320
321 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
322 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
323 continue;
324 rcu_read_lock_bh();
325 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
326 while (r) {
327 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
328 r->rt_genid == st->genid)
329 return r;
330 r = rcu_dereference_bh(r->dst.rt_next);
331 }
332 rcu_read_unlock_bh();
333 }
334 return r;
335 }
336
337 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
338 struct rtable *r)
339 {
340 struct rt_cache_iter_state *st = seq->private;
341
342 r = rcu_dereference_bh(r->dst.rt_next);
343 while (!r) {
344 rcu_read_unlock_bh();
345 do {
346 if (--st->bucket < 0)
347 return NULL;
348 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
349 rcu_read_lock_bh();
350 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
351 }
352 return r;
353 }
354
355 static struct rtable *rt_cache_get_next(struct seq_file *seq,
356 struct rtable *r)
357 {
358 struct rt_cache_iter_state *st = seq->private;
359 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
360 if (dev_net(r->dst.dev) != seq_file_net(seq))
361 continue;
362 if (r->rt_genid == st->genid)
363 break;
364 }
365 return r;
366 }
367
368 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
369 {
370 struct rtable *r = rt_cache_get_first(seq);
371
372 if (r)
373 while (pos && (r = rt_cache_get_next(seq, r)))
374 --pos;
375 return pos ? NULL : r;
376 }
377
378 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
379 {
380 struct rt_cache_iter_state *st = seq->private;
381 if (*pos)
382 return rt_cache_get_idx(seq, *pos - 1);
383 st->genid = rt_genid(seq_file_net(seq));
384 return SEQ_START_TOKEN;
385 }
386
387 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
388 {
389 struct rtable *r;
390
391 if (v == SEQ_START_TOKEN)
392 r = rt_cache_get_first(seq);
393 else
394 r = rt_cache_get_next(seq, v);
395 ++*pos;
396 return r;
397 }
398
399 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
400 {
401 if (v && v != SEQ_START_TOKEN)
402 rcu_read_unlock_bh();
403 }
404
405 static int rt_cache_seq_show(struct seq_file *seq, void *v)
406 {
407 if (v == SEQ_START_TOKEN)
408 seq_printf(seq, "%-127s\n",
409 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
410 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
411 "HHUptod\tSpecDst");
412 else {
413 struct rtable *r = v;
414 int len;
415
416 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
417 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
418 r->dst.dev ? r->dst.dev->name : "*",
419 (__force u32)r->rt_dst,
420 (__force u32)r->rt_gateway,
421 r->rt_flags, atomic_read(&r->dst.__refcnt),
422 r->dst.__use, 0, (__force u32)r->rt_src,
423 dst_metric_advmss(&r->dst) + 40,
424 dst_metric(&r->dst, RTAX_WINDOW),
425 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
426 dst_metric(&r->dst, RTAX_RTTVAR)),
427 r->rt_key_tos,
428 r->dst.hh ? atomic_read(&r->dst.hh->hh_refcnt) : -1,
429 r->dst.hh ? (r->dst.hh->hh_output ==
430 dev_queue_xmit) : 0,
431 r->rt_spec_dst, &len);
432
433 seq_printf(seq, "%*s\n", 127 - len, "");
434 }
435 return 0;
436 }
437
438 static const struct seq_operations rt_cache_seq_ops = {
439 .start = rt_cache_seq_start,
440 .next = rt_cache_seq_next,
441 .stop = rt_cache_seq_stop,
442 .show = rt_cache_seq_show,
443 };
444
445 static int rt_cache_seq_open(struct inode *inode, struct file *file)
446 {
447 return seq_open_net(inode, file, &rt_cache_seq_ops,
448 sizeof(struct rt_cache_iter_state));
449 }
450
451 static const struct file_operations rt_cache_seq_fops = {
452 .owner = THIS_MODULE,
453 .open = rt_cache_seq_open,
454 .read = seq_read,
455 .llseek = seq_lseek,
456 .release = seq_release_net,
457 };
458
459
460 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
461 {
462 int cpu;
463
464 if (*pos == 0)
465 return SEQ_START_TOKEN;
466
467 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
468 if (!cpu_possible(cpu))
469 continue;
470 *pos = cpu+1;
471 return &per_cpu(rt_cache_stat, cpu);
472 }
473 return NULL;
474 }
475
476 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
477 {
478 int cpu;
479
480 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487
488 }
489
490 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
491 {
492
493 }
494
495 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
496 {
497 struct rt_cache_stat *st = v;
498
499 if (v == SEQ_START_TOKEN) {
500 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
501 return 0;
502 }
503
504 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
505 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
506 dst_entries_get_slow(&ipv4_dst_ops),
507 st->in_hit,
508 st->in_slow_tot,
509 st->in_slow_mc,
510 st->in_no_route,
511 st->in_brd,
512 st->in_martian_dst,
513 st->in_martian_src,
514
515 st->out_hit,
516 st->out_slow_tot,
517 st->out_slow_mc,
518
519 st->gc_total,
520 st->gc_ignored,
521 st->gc_goal_miss,
522 st->gc_dst_overflow,
523 st->in_hlist_search,
524 st->out_hlist_search
525 );
526 return 0;
527 }
528
529 static const struct seq_operations rt_cpu_seq_ops = {
530 .start = rt_cpu_seq_start,
531 .next = rt_cpu_seq_next,
532 .stop = rt_cpu_seq_stop,
533 .show = rt_cpu_seq_show,
534 };
535
536
537 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
538 {
539 return seq_open(file, &rt_cpu_seq_ops);
540 }
541
542 static const struct file_operations rt_cpu_seq_fops = {
543 .owner = THIS_MODULE,
544 .open = rt_cpu_seq_open,
545 .read = seq_read,
546 .llseek = seq_lseek,
547 .release = seq_release,
548 };
549
550 #ifdef CONFIG_IP_ROUTE_CLASSID
551 static int rt_acct_proc_show(struct seq_file *m, void *v)
552 {
553 struct ip_rt_acct *dst, *src;
554 unsigned int i, j;
555
556 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
557 if (!dst)
558 return -ENOMEM;
559
560 for_each_possible_cpu(i) {
561 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
562 for (j = 0; j < 256; j++) {
563 dst[j].o_bytes += src[j].o_bytes;
564 dst[j].o_packets += src[j].o_packets;
565 dst[j].i_bytes += src[j].i_bytes;
566 dst[j].i_packets += src[j].i_packets;
567 }
568 }
569
570 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
571 kfree(dst);
572 return 0;
573 }
574
575 static int rt_acct_proc_open(struct inode *inode, struct file *file)
576 {
577 return single_open(file, rt_acct_proc_show, NULL);
578 }
579
580 static const struct file_operations rt_acct_proc_fops = {
581 .owner = THIS_MODULE,
582 .open = rt_acct_proc_open,
583 .read = seq_read,
584 .llseek = seq_lseek,
585 .release = single_release,
586 };
587 #endif
588
589 static int __net_init ip_rt_do_proc_init(struct net *net)
590 {
591 struct proc_dir_entry *pde;
592
593 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
594 &rt_cache_seq_fops);
595 if (!pde)
596 goto err1;
597
598 pde = proc_create("rt_cache", S_IRUGO,
599 net->proc_net_stat, &rt_cpu_seq_fops);
600 if (!pde)
601 goto err2;
602
603 #ifdef CONFIG_IP_ROUTE_CLASSID
604 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
605 if (!pde)
606 goto err3;
607 #endif
608 return 0;
609
610 #ifdef CONFIG_IP_ROUTE_CLASSID
611 err3:
612 remove_proc_entry("rt_cache", net->proc_net_stat);
613 #endif
614 err2:
615 remove_proc_entry("rt_cache", net->proc_net);
616 err1:
617 return -ENOMEM;
618 }
619
620 static void __net_exit ip_rt_do_proc_exit(struct net *net)
621 {
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623 remove_proc_entry("rt_cache", net->proc_net);
624 #ifdef CONFIG_IP_ROUTE_CLASSID
625 remove_proc_entry("rt_acct", net->proc_net);
626 #endif
627 }
628
629 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
630 .init = ip_rt_do_proc_init,
631 .exit = ip_rt_do_proc_exit,
632 };
633
634 static int __init ip_rt_proc_init(void)
635 {
636 return register_pernet_subsys(&ip_rt_proc_ops);
637 }
638
639 #else
640 static inline int ip_rt_proc_init(void)
641 {
642 return 0;
643 }
644 #endif /* CONFIG_PROC_FS */
645
646 static inline void rt_free(struct rtable *rt)
647 {
648 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
649 }
650
651 static inline void rt_drop(struct rtable *rt)
652 {
653 ip_rt_put(rt);
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655 }
656
657 static inline int rt_fast_clean(struct rtable *rth)
658 {
659 /* Kill broadcast/multicast entries very aggresively, if they
660 collide in hash table with more useful entries */
661 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
662 rt_is_input_route(rth) && rth->dst.rt_next;
663 }
664
665 static inline int rt_valuable(struct rtable *rth)
666 {
667 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
668 (rth->peer && rth->peer->pmtu_expires);
669 }
670
671 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
672 {
673 unsigned long age;
674 int ret = 0;
675
676 if (atomic_read(&rth->dst.__refcnt))
677 goto out;
678
679 age = jiffies - rth->dst.lastuse;
680 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
681 (age <= tmo2 && rt_valuable(rth)))
682 goto out;
683 ret = 1;
684 out: return ret;
685 }
686
687 /* Bits of score are:
688 * 31: very valuable
689 * 30: not quite useless
690 * 29..0: usage counter
691 */
692 static inline u32 rt_score(struct rtable *rt)
693 {
694 u32 score = jiffies - rt->dst.lastuse;
695
696 score = ~score & ~(3<<30);
697
698 if (rt_valuable(rt))
699 score |= (1<<31);
700
701 if (rt_is_output_route(rt) ||
702 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
703 score |= (1<<30);
704
705 return score;
706 }
707
708 static inline bool rt_caching(const struct net *net)
709 {
710 return net->ipv4.current_rt_cache_rebuild_count <=
711 net->ipv4.sysctl_rt_cache_rebuild_count;
712 }
713
714 static inline bool compare_hash_inputs(const struct rtable *rt1,
715 const struct rtable *rt2)
716 {
717 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
718 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
719 (rt1->rt_iif ^ rt2->rt_iif)) == 0);
720 }
721
722 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
723 {
724 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
725 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
726 (rt1->rt_mark ^ rt2->rt_mark) |
727 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
728 (rt1->rt_oif ^ rt2->rt_oif) |
729 (rt1->rt_iif ^ rt2->rt_iif)) == 0;
730 }
731
732 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
733 {
734 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
735 }
736
737 static inline int rt_is_expired(struct rtable *rth)
738 {
739 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
740 }
741
742 /*
743 * Perform a full scan of hash table and free all entries.
744 * Can be called by a softirq or a process.
745 * In the later case, we want to be reschedule if necessary
746 */
747 static void rt_do_flush(struct net *net, int process_context)
748 {
749 unsigned int i;
750 struct rtable *rth, *next;
751
752 for (i = 0; i <= rt_hash_mask; i++) {
753 struct rtable __rcu **pprev;
754 struct rtable *list;
755
756 if (process_context && need_resched())
757 cond_resched();
758 rth = rcu_dereference_raw(rt_hash_table[i].chain);
759 if (!rth)
760 continue;
761
762 spin_lock_bh(rt_hash_lock_addr(i));
763
764 list = NULL;
765 pprev = &rt_hash_table[i].chain;
766 rth = rcu_dereference_protected(*pprev,
767 lockdep_is_held(rt_hash_lock_addr(i)));
768
769 while (rth) {
770 next = rcu_dereference_protected(rth->dst.rt_next,
771 lockdep_is_held(rt_hash_lock_addr(i)));
772
773 if (!net ||
774 net_eq(dev_net(rth->dst.dev), net)) {
775 rcu_assign_pointer(*pprev, next);
776 rcu_assign_pointer(rth->dst.rt_next, list);
777 list = rth;
778 } else {
779 pprev = &rth->dst.rt_next;
780 }
781 rth = next;
782 }
783
784 spin_unlock_bh(rt_hash_lock_addr(i));
785
786 for (; list; list = next) {
787 next = rcu_dereference_protected(list->dst.rt_next, 1);
788 rt_free(list);
789 }
790 }
791 }
792
793 /*
794 * While freeing expired entries, we compute average chain length
795 * and standard deviation, using fixed-point arithmetic.
796 * This to have an estimation of rt_chain_length_max
797 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
798 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
799 */
800
801 #define FRACT_BITS 3
802 #define ONE (1UL << FRACT_BITS)
803
804 /*
805 * Given a hash chain and an item in this hash chain,
806 * find if a previous entry has the same hash_inputs
807 * (but differs on tos, mark or oif)
808 * Returns 0 if an alias is found.
809 * Returns ONE if rth has no alias before itself.
810 */
811 static int has_noalias(const struct rtable *head, const struct rtable *rth)
812 {
813 const struct rtable *aux = head;
814
815 while (aux != rth) {
816 if (compare_hash_inputs(aux, rth))
817 return 0;
818 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
819 }
820 return ONE;
821 }
822
823 /*
824 * Perturbation of rt_genid by a small quantity [1..256]
825 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
826 * many times (2^24) without giving recent rt_genid.
827 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
828 */
829 static void rt_cache_invalidate(struct net *net)
830 {
831 unsigned char shuffle;
832
833 get_random_bytes(&shuffle, sizeof(shuffle));
834 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
835 }
836
837 /*
838 * delay < 0 : invalidate cache (fast : entries will be deleted later)
839 * delay >= 0 : invalidate & flush cache (can be long)
840 */
841 void rt_cache_flush(struct net *net, int delay)
842 {
843 rt_cache_invalidate(net);
844 if (delay >= 0)
845 rt_do_flush(net, !in_softirq());
846 }
847
848 /* Flush previous cache invalidated entries from the cache */
849 void rt_cache_flush_batch(struct net *net)
850 {
851 rt_do_flush(net, !in_softirq());
852 }
853
854 static void rt_emergency_hash_rebuild(struct net *net)
855 {
856 if (net_ratelimit())
857 printk(KERN_WARNING "Route hash chain too long!\n");
858 rt_cache_invalidate(net);
859 }
860
861 /*
862 Short description of GC goals.
863
864 We want to build algorithm, which will keep routing cache
865 at some equilibrium point, when number of aged off entries
866 is kept approximately equal to newly generated ones.
867
868 Current expiration strength is variable "expire".
869 We try to adjust it dynamically, so that if networking
870 is idle expires is large enough to keep enough of warm entries,
871 and when load increases it reduces to limit cache size.
872 */
873
874 static int rt_garbage_collect(struct dst_ops *ops)
875 {
876 static unsigned long expire = RT_GC_TIMEOUT;
877 static unsigned long last_gc;
878 static int rover;
879 static int equilibrium;
880 struct rtable *rth;
881 struct rtable __rcu **rthp;
882 unsigned long now = jiffies;
883 int goal;
884 int entries = dst_entries_get_fast(&ipv4_dst_ops);
885
886 /*
887 * Garbage collection is pretty expensive,
888 * do not make it too frequently.
889 */
890
891 RT_CACHE_STAT_INC(gc_total);
892
893 if (now - last_gc < ip_rt_gc_min_interval &&
894 entries < ip_rt_max_size) {
895 RT_CACHE_STAT_INC(gc_ignored);
896 goto out;
897 }
898
899 entries = dst_entries_get_slow(&ipv4_dst_ops);
900 /* Calculate number of entries, which we want to expire now. */
901 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
902 if (goal <= 0) {
903 if (equilibrium < ipv4_dst_ops.gc_thresh)
904 equilibrium = ipv4_dst_ops.gc_thresh;
905 goal = entries - equilibrium;
906 if (goal > 0) {
907 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
908 goal = entries - equilibrium;
909 }
910 } else {
911 /* We are in dangerous area. Try to reduce cache really
912 * aggressively.
913 */
914 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
915 equilibrium = entries - goal;
916 }
917
918 if (now - last_gc >= ip_rt_gc_min_interval)
919 last_gc = now;
920
921 if (goal <= 0) {
922 equilibrium += goal;
923 goto work_done;
924 }
925
926 do {
927 int i, k;
928
929 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
930 unsigned long tmo = expire;
931
932 k = (k + 1) & rt_hash_mask;
933 rthp = &rt_hash_table[k].chain;
934 spin_lock_bh(rt_hash_lock_addr(k));
935 while ((rth = rcu_dereference_protected(*rthp,
936 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
937 if (!rt_is_expired(rth) &&
938 !rt_may_expire(rth, tmo, expire)) {
939 tmo >>= 1;
940 rthp = &rth->dst.rt_next;
941 continue;
942 }
943 *rthp = rth->dst.rt_next;
944 rt_free(rth);
945 goal--;
946 }
947 spin_unlock_bh(rt_hash_lock_addr(k));
948 if (goal <= 0)
949 break;
950 }
951 rover = k;
952
953 if (goal <= 0)
954 goto work_done;
955
956 /* Goal is not achieved. We stop process if:
957
958 - if expire reduced to zero. Otherwise, expire is halfed.
959 - if table is not full.
960 - if we are called from interrupt.
961 - jiffies check is just fallback/debug loop breaker.
962 We will not spin here for long time in any case.
963 */
964
965 RT_CACHE_STAT_INC(gc_goal_miss);
966
967 if (expire == 0)
968 break;
969
970 expire >>= 1;
971
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, int create)
1197 {
1198 struct inet_peer *peer;
1199
1200 peer = inet_getpeer_v4(rt->rt_dst, 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, 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, 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, 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, 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, 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 return 0;
1669 }
1670
1671 /*
1672 We do not cache source address of outgoing interface,
1673 because it is used only by IP RR, TS and SRR options,
1674 so that it out of fast path.
1675
1676 BTW remember: "addr" is allowed to be not aligned
1677 in IP options!
1678 */
1679
1680 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1681 {
1682 __be32 src;
1683
1684 if (rt_is_output_route(rt))
1685 src = ip_hdr(skb)->saddr;
1686 else {
1687 struct fib_result res;
1688 struct flowi4 fl4;
1689 struct iphdr *iph;
1690
1691 iph = ip_hdr(skb);
1692
1693 memset(&fl4, 0, sizeof(fl4));
1694 fl4.daddr = iph->daddr;
1695 fl4.saddr = iph->saddr;
1696 fl4.flowi4_tos = iph->tos;
1697 fl4.flowi4_oif = rt->dst.dev->ifindex;
1698 fl4.flowi4_iif = skb->dev->ifindex;
1699 fl4.flowi4_mark = skb->mark;
1700
1701 rcu_read_lock();
1702 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1703 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1704 else
1705 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1706 RT_SCOPE_UNIVERSE);
1707 rcu_read_unlock();
1708 }
1709 memcpy(addr, &src, 4);
1710 }
1711
1712 #ifdef CONFIG_IP_ROUTE_CLASSID
1713 static void set_class_tag(struct rtable *rt, u32 tag)
1714 {
1715 if (!(rt->dst.tclassid & 0xFFFF))
1716 rt->dst.tclassid |= tag & 0xFFFF;
1717 if (!(rt->dst.tclassid & 0xFFFF0000))
1718 rt->dst.tclassid |= tag & 0xFFFF0000;
1719 }
1720 #endif
1721
1722 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1723 {
1724 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1725
1726 if (advmss == 0) {
1727 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1728 ip_rt_min_advmss);
1729 if (advmss > 65535 - 40)
1730 advmss = 65535 - 40;
1731 }
1732 return advmss;
1733 }
1734
1735 static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1736 {
1737 unsigned int mtu = dst->dev->mtu;
1738
1739 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1740 const struct rtable *rt = (const struct rtable *) dst;
1741
1742 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1743 mtu = 576;
1744 }
1745
1746 if (mtu > IP_MAX_MTU)
1747 mtu = IP_MAX_MTU;
1748
1749 return mtu;
1750 }
1751
1752 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1753 struct fib_info *fi)
1754 {
1755 struct inet_peer *peer;
1756 int create = 0;
1757
1758 /* If a peer entry exists for this destination, we must hook
1759 * it up in order to get at cached metrics.
1760 */
1761 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1762 create = 1;
1763
1764 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1765 if (peer) {
1766 rt->rt_peer_genid = rt_peer_genid();
1767 if (inet_metrics_new(peer))
1768 memcpy(peer->metrics, fi->fib_metrics,
1769 sizeof(u32) * RTAX_MAX);
1770 dst_init_metrics(&rt->dst, peer->metrics, false);
1771
1772 if (peer->pmtu_expires)
1773 check_peer_pmtu(&rt->dst, peer);
1774 if (peer->redirect_learned.a4 &&
1775 peer->redirect_learned.a4 != rt->rt_gateway) {
1776 rt->rt_gateway = peer->redirect_learned.a4;
1777 rt->rt_flags |= RTCF_REDIRECTED;
1778 }
1779 } else {
1780 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1781 rt->fi = fi;
1782 atomic_inc(&fi->fib_clntref);
1783 }
1784 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1785 }
1786 }
1787
1788 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1789 const struct fib_result *res,
1790 struct fib_info *fi, u16 type, u32 itag)
1791 {
1792 struct dst_entry *dst = &rt->dst;
1793
1794 if (fi) {
1795 if (FIB_RES_GW(*res) &&
1796 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1797 rt->rt_gateway = FIB_RES_GW(*res);
1798 rt_init_metrics(rt, fl4, fi);
1799 #ifdef CONFIG_IP_ROUTE_CLASSID
1800 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1801 #endif
1802 }
1803
1804 if (dst_mtu(dst) > IP_MAX_MTU)
1805 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1806 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1807 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1808
1809 #ifdef CONFIG_IP_ROUTE_CLASSID
1810 #ifdef CONFIG_IP_MULTIPLE_TABLES
1811 set_class_tag(rt, fib_rules_tclass(res));
1812 #endif
1813 set_class_tag(rt, itag);
1814 #endif
1815 }
1816
1817 static struct rtable *rt_dst_alloc(struct net_device *dev,
1818 bool nopolicy, bool noxfrm)
1819 {
1820 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1821 DST_HOST |
1822 (nopolicy ? DST_NOPOLICY : 0) |
1823 (noxfrm ? DST_NOXFRM : 0));
1824 }
1825
1826 /* called in rcu_read_lock() section */
1827 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1828 u8 tos, struct net_device *dev, int our)
1829 {
1830 unsigned int hash;
1831 struct rtable *rth;
1832 __be32 spec_dst;
1833 struct in_device *in_dev = __in_dev_get_rcu(dev);
1834 u32 itag = 0;
1835 int err;
1836
1837 /* Primary sanity checks. */
1838
1839 if (in_dev == NULL)
1840 return -EINVAL;
1841
1842 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1843 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1844 goto e_inval;
1845
1846 if (ipv4_is_zeronet(saddr)) {
1847 if (!ipv4_is_local_multicast(daddr))
1848 goto e_inval;
1849 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1850 } else {
1851 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1852 &itag);
1853 if (err < 0)
1854 goto e_err;
1855 }
1856 rth = rt_dst_alloc(init_net.loopback_dev,
1857 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1858 if (!rth)
1859 goto e_nobufs;
1860
1861 #ifdef CONFIG_IP_ROUTE_CLASSID
1862 rth->dst.tclassid = itag;
1863 #endif
1864 rth->dst.output = ip_rt_bug;
1865
1866 rth->rt_key_dst = daddr;
1867 rth->rt_key_src = saddr;
1868 rth->rt_genid = rt_genid(dev_net(dev));
1869 rth->rt_flags = RTCF_MULTICAST;
1870 rth->rt_type = RTN_MULTICAST;
1871 rth->rt_key_tos = tos;
1872 rth->rt_dst = daddr;
1873 rth->rt_src = saddr;
1874 rth->rt_route_iif = dev->ifindex;
1875 rth->rt_iif = dev->ifindex;
1876 rth->rt_oif = 0;
1877 rth->rt_mark = skb->mark;
1878 rth->rt_gateway = daddr;
1879 rth->rt_spec_dst= spec_dst;
1880 rth->rt_peer_genid = 0;
1881 rth->peer = NULL;
1882 rth->fi = NULL;
1883 if (our) {
1884 rth->dst.input= ip_local_deliver;
1885 rth->rt_flags |= RTCF_LOCAL;
1886 }
1887
1888 #ifdef CONFIG_IP_MROUTE
1889 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1890 rth->dst.input = ip_mr_input;
1891 #endif
1892 RT_CACHE_STAT_INC(in_slow_mc);
1893
1894 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1895 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1896 err = 0;
1897 if (IS_ERR(rth))
1898 err = PTR_ERR(rth);
1899
1900 e_nobufs:
1901 return -ENOBUFS;
1902 e_inval:
1903 return -EINVAL;
1904 e_err:
1905 return err;
1906 }
1907
1908
1909 static void ip_handle_martian_source(struct net_device *dev,
1910 struct in_device *in_dev,
1911 struct sk_buff *skb,
1912 __be32 daddr,
1913 __be32 saddr)
1914 {
1915 RT_CACHE_STAT_INC(in_martian_src);
1916 #ifdef CONFIG_IP_ROUTE_VERBOSE
1917 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1918 /*
1919 * RFC1812 recommendation, if source is martian,
1920 * the only hint is MAC header.
1921 */
1922 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1923 &daddr, &saddr, dev->name);
1924 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1925 int i;
1926 const unsigned char *p = skb_mac_header(skb);
1927 printk(KERN_WARNING "ll header: ");
1928 for (i = 0; i < dev->hard_header_len; i++, p++) {
1929 printk("%02x", *p);
1930 if (i < (dev->hard_header_len - 1))
1931 printk(":");
1932 }
1933 printk("\n");
1934 }
1935 }
1936 #endif
1937 }
1938
1939 /* called in rcu_read_lock() section */
1940 static int __mkroute_input(struct sk_buff *skb,
1941 const struct fib_result *res,
1942 struct in_device *in_dev,
1943 __be32 daddr, __be32 saddr, u32 tos,
1944 struct rtable **result)
1945 {
1946 struct rtable *rth;
1947 int err;
1948 struct in_device *out_dev;
1949 unsigned int flags = 0;
1950 __be32 spec_dst;
1951 u32 itag;
1952
1953 /* get a working reference to the output device */
1954 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1955 if (out_dev == NULL) {
1956 if (net_ratelimit())
1957 printk(KERN_CRIT "Bug in ip_route_input" \
1958 "_slow(). Please, report\n");
1959 return -EINVAL;
1960 }
1961
1962
1963 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1964 in_dev->dev, &spec_dst, &itag);
1965 if (err < 0) {
1966 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1967 saddr);
1968
1969 goto cleanup;
1970 }
1971
1972 if (err)
1973 flags |= RTCF_DIRECTSRC;
1974
1975 if (out_dev == in_dev && err &&
1976 (IN_DEV_SHARED_MEDIA(out_dev) ||
1977 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1978 flags |= RTCF_DOREDIRECT;
1979
1980 if (skb->protocol != htons(ETH_P_IP)) {
1981 /* Not IP (i.e. ARP). Do not create route, if it is
1982 * invalid for proxy arp. DNAT routes are always valid.
1983 *
1984 * Proxy arp feature have been extended to allow, ARP
1985 * replies back to the same interface, to support
1986 * Private VLAN switch technologies. See arp.c.
1987 */
1988 if (out_dev == in_dev &&
1989 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1990 err = -EINVAL;
1991 goto cleanup;
1992 }
1993 }
1994
1995 rth = rt_dst_alloc(out_dev->dev,
1996 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1997 IN_DEV_CONF_GET(out_dev, NOXFRM));
1998 if (!rth) {
1999 err = -ENOBUFS;
2000 goto cleanup;
2001 }
2002
2003 rth->rt_key_dst = daddr;
2004 rth->rt_key_src = saddr;
2005 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2006 rth->rt_flags = flags;
2007 rth->rt_type = res->type;
2008 rth->rt_key_tos = tos;
2009 rth->rt_dst = daddr;
2010 rth->rt_src = saddr;
2011 rth->rt_route_iif = in_dev->dev->ifindex;
2012 rth->rt_iif = in_dev->dev->ifindex;
2013 rth->rt_oif = 0;
2014 rth->rt_mark = skb->mark;
2015 rth->rt_gateway = daddr;
2016 rth->rt_spec_dst= spec_dst;
2017 rth->rt_peer_genid = 0;
2018 rth->peer = NULL;
2019 rth->fi = NULL;
2020
2021 rth->dst.input = ip_forward;
2022 rth->dst.output = ip_output;
2023
2024 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2025
2026 *result = rth;
2027 err = 0;
2028 cleanup:
2029 return err;
2030 }
2031
2032 static int ip_mkroute_input(struct sk_buff *skb,
2033 struct fib_result *res,
2034 const struct flowi4 *fl4,
2035 struct in_device *in_dev,
2036 __be32 daddr, __be32 saddr, u32 tos)
2037 {
2038 struct rtable* rth = NULL;
2039 int err;
2040 unsigned hash;
2041
2042 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2043 if (res->fi && res->fi->fib_nhs > 1)
2044 fib_select_multipath(res);
2045 #endif
2046
2047 /* create a routing cache entry */
2048 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2049 if (err)
2050 return err;
2051
2052 /* put it into the cache */
2053 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2054 rt_genid(dev_net(rth->dst.dev)));
2055 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2056 if (IS_ERR(rth))
2057 return PTR_ERR(rth);
2058 return 0;
2059 }
2060
2061 /*
2062 * NOTE. We drop all the packets that has local source
2063 * addresses, because every properly looped back packet
2064 * must have correct destination already attached by output routine.
2065 *
2066 * Such approach solves two big problems:
2067 * 1. Not simplex devices are handled properly.
2068 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2069 * called with rcu_read_lock()
2070 */
2071
2072 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2073 u8 tos, struct net_device *dev)
2074 {
2075 struct fib_result res;
2076 struct in_device *in_dev = __in_dev_get_rcu(dev);
2077 struct flowi4 fl4;
2078 unsigned flags = 0;
2079 u32 itag = 0;
2080 struct rtable * rth;
2081 unsigned hash;
2082 __be32 spec_dst;
2083 int err = -EINVAL;
2084 struct net * net = dev_net(dev);
2085
2086 /* IP on this device is disabled. */
2087
2088 if (!in_dev)
2089 goto out;
2090
2091 /* Check for the most weird martians, which can be not detected
2092 by fib_lookup.
2093 */
2094
2095 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2096 ipv4_is_loopback(saddr))
2097 goto martian_source;
2098
2099 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2100 goto brd_input;
2101
2102 /* Accept zero addresses only to limited broadcast;
2103 * I even do not know to fix it or not. Waiting for complains :-)
2104 */
2105 if (ipv4_is_zeronet(saddr))
2106 goto martian_source;
2107
2108 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2109 goto martian_destination;
2110
2111 /*
2112 * Now we are ready to route packet.
2113 */
2114 fl4.flowi4_oif = 0;
2115 fl4.flowi4_iif = dev->ifindex;
2116 fl4.flowi4_mark = skb->mark;
2117 fl4.flowi4_tos = tos;
2118 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2119 fl4.daddr = daddr;
2120 fl4.saddr = saddr;
2121 err = fib_lookup(net, &fl4, &res);
2122 if (err != 0) {
2123 if (!IN_DEV_FORWARD(in_dev))
2124 goto e_hostunreach;
2125 goto no_route;
2126 }
2127
2128 RT_CACHE_STAT_INC(in_slow_tot);
2129
2130 if (res.type == RTN_BROADCAST)
2131 goto brd_input;
2132
2133 if (res.type == RTN_LOCAL) {
2134 err = fib_validate_source(skb, saddr, daddr, tos,
2135 net->loopback_dev->ifindex,
2136 dev, &spec_dst, &itag);
2137 if (err < 0)
2138 goto martian_source_keep_err;
2139 if (err)
2140 flags |= RTCF_DIRECTSRC;
2141 spec_dst = daddr;
2142 goto local_input;
2143 }
2144
2145 if (!IN_DEV_FORWARD(in_dev))
2146 goto e_hostunreach;
2147 if (res.type != RTN_UNICAST)
2148 goto martian_destination;
2149
2150 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2151 out: return err;
2152
2153 brd_input:
2154 if (skb->protocol != htons(ETH_P_IP))
2155 goto e_inval;
2156
2157 if (ipv4_is_zeronet(saddr))
2158 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2159 else {
2160 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2161 &itag);
2162 if (err < 0)
2163 goto martian_source_keep_err;
2164 if (err)
2165 flags |= RTCF_DIRECTSRC;
2166 }
2167 flags |= RTCF_BROADCAST;
2168 res.type = RTN_BROADCAST;
2169 RT_CACHE_STAT_INC(in_brd);
2170
2171 local_input:
2172 rth = rt_dst_alloc(net->loopback_dev,
2173 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2174 if (!rth)
2175 goto e_nobufs;
2176
2177 rth->dst.input= ip_local_deliver;
2178 rth->dst.output= ip_rt_bug;
2179 #ifdef CONFIG_IP_ROUTE_CLASSID
2180 rth->dst.tclassid = itag;
2181 #endif
2182
2183 rth->rt_key_dst = daddr;
2184 rth->rt_key_src = saddr;
2185 rth->rt_genid = rt_genid(net);
2186 rth->rt_flags = flags|RTCF_LOCAL;
2187 rth->rt_type = res.type;
2188 rth->rt_key_tos = tos;
2189 rth->rt_dst = daddr;
2190 rth->rt_src = saddr;
2191 #ifdef CONFIG_IP_ROUTE_CLASSID
2192 rth->dst.tclassid = itag;
2193 #endif
2194 rth->rt_route_iif = dev->ifindex;
2195 rth->rt_iif = dev->ifindex;
2196 rth->rt_oif = 0;
2197 rth->rt_mark = skb->mark;
2198 rth->rt_gateway = daddr;
2199 rth->rt_spec_dst= spec_dst;
2200 rth->rt_peer_genid = 0;
2201 rth->peer = NULL;
2202 rth->fi = NULL;
2203 if (res.type == RTN_UNREACHABLE) {
2204 rth->dst.input= ip_error;
2205 rth->dst.error= -err;
2206 rth->rt_flags &= ~RTCF_LOCAL;
2207 }
2208 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2209 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2210 err = 0;
2211 if (IS_ERR(rth))
2212 err = PTR_ERR(rth);
2213 goto out;
2214
2215 no_route:
2216 RT_CACHE_STAT_INC(in_no_route);
2217 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2218 res.type = RTN_UNREACHABLE;
2219 if (err == -ESRCH)
2220 err = -ENETUNREACH;
2221 goto local_input;
2222
2223 /*
2224 * Do not cache martian addresses: they should be logged (RFC1812)
2225 */
2226 martian_destination:
2227 RT_CACHE_STAT_INC(in_martian_dst);
2228 #ifdef CONFIG_IP_ROUTE_VERBOSE
2229 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2230 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2231 &daddr, &saddr, dev->name);
2232 #endif
2233
2234 e_hostunreach:
2235 err = -EHOSTUNREACH;
2236 goto out;
2237
2238 e_inval:
2239 err = -EINVAL;
2240 goto out;
2241
2242 e_nobufs:
2243 err = -ENOBUFS;
2244 goto out;
2245
2246 martian_source:
2247 err = -EINVAL;
2248 martian_source_keep_err:
2249 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2250 goto out;
2251 }
2252
2253 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2254 u8 tos, struct net_device *dev, bool noref)
2255 {
2256 struct rtable * rth;
2257 unsigned hash;
2258 int iif = dev->ifindex;
2259 struct net *net;
2260 int res;
2261
2262 net = dev_net(dev);
2263
2264 rcu_read_lock();
2265
2266 if (!rt_caching(net))
2267 goto skip_cache;
2268
2269 tos &= IPTOS_RT_MASK;
2270 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2271
2272 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2273 rth = rcu_dereference(rth->dst.rt_next)) {
2274 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2275 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2276 (rth->rt_iif ^ iif) |
2277 rth->rt_oif |
2278 (rth->rt_key_tos ^ tos)) == 0 &&
2279 rth->rt_mark == skb->mark &&
2280 net_eq(dev_net(rth->dst.dev), net) &&
2281 !rt_is_expired(rth)) {
2282 if (noref) {
2283 dst_use_noref(&rth->dst, jiffies);
2284 skb_dst_set_noref(skb, &rth->dst);
2285 } else {
2286 dst_use(&rth->dst, jiffies);
2287 skb_dst_set(skb, &rth->dst);
2288 }
2289 RT_CACHE_STAT_INC(in_hit);
2290 rcu_read_unlock();
2291 return 0;
2292 }
2293 RT_CACHE_STAT_INC(in_hlist_search);
2294 }
2295
2296 skip_cache:
2297 /* Multicast recognition logic is moved from route cache to here.
2298 The problem was that too many Ethernet cards have broken/missing
2299 hardware multicast filters :-( As result the host on multicasting
2300 network acquires a lot of useless route cache entries, sort of
2301 SDR messages from all the world. Now we try to get rid of them.
2302 Really, provided software IP multicast filter is organized
2303 reasonably (at least, hashed), it does not result in a slowdown
2304 comparing with route cache reject entries.
2305 Note, that multicast routers are not affected, because
2306 route cache entry is created eventually.
2307 */
2308 if (ipv4_is_multicast(daddr)) {
2309 struct in_device *in_dev = __in_dev_get_rcu(dev);
2310
2311 if (in_dev) {
2312 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2313 ip_hdr(skb)->protocol);
2314 if (our
2315 #ifdef CONFIG_IP_MROUTE
2316 ||
2317 (!ipv4_is_local_multicast(daddr) &&
2318 IN_DEV_MFORWARD(in_dev))
2319 #endif
2320 ) {
2321 int res = ip_route_input_mc(skb, daddr, saddr,
2322 tos, dev, our);
2323 rcu_read_unlock();
2324 return res;
2325 }
2326 }
2327 rcu_read_unlock();
2328 return -EINVAL;
2329 }
2330 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2331 rcu_read_unlock();
2332 return res;
2333 }
2334 EXPORT_SYMBOL(ip_route_input_common);
2335
2336 /* called with rcu_read_lock() */
2337 static struct rtable *__mkroute_output(const struct fib_result *res,
2338 const struct flowi4 *fl4,
2339 __be32 orig_daddr, __be32 orig_saddr,
2340 int orig_oif, struct net_device *dev_out,
2341 unsigned int flags)
2342 {
2343 struct fib_info *fi = res->fi;
2344 u32 tos = RT_FL_TOS(fl4);
2345 struct in_device *in_dev;
2346 u16 type = res->type;
2347 struct rtable *rth;
2348
2349 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2350 return ERR_PTR(-EINVAL);
2351
2352 if (ipv4_is_lbcast(fl4->daddr))
2353 type = RTN_BROADCAST;
2354 else if (ipv4_is_multicast(fl4->daddr))
2355 type = RTN_MULTICAST;
2356 else if (ipv4_is_zeronet(fl4->daddr))
2357 return ERR_PTR(-EINVAL);
2358
2359 if (dev_out->flags & IFF_LOOPBACK)
2360 flags |= RTCF_LOCAL;
2361
2362 in_dev = __in_dev_get_rcu(dev_out);
2363 if (!in_dev)
2364 return ERR_PTR(-EINVAL);
2365
2366 if (type == RTN_BROADCAST) {
2367 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2368 fi = NULL;
2369 } else if (type == RTN_MULTICAST) {
2370 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2371 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2372 fl4->flowi4_proto))
2373 flags &= ~RTCF_LOCAL;
2374 /* If multicast route do not exist use
2375 * default one, but do not gateway in this case.
2376 * Yes, it is hack.
2377 */
2378 if (fi && res->prefixlen < 4)
2379 fi = NULL;
2380 }
2381
2382 rth = rt_dst_alloc(dev_out,
2383 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2384 IN_DEV_CONF_GET(in_dev, NOXFRM));
2385 if (!rth)
2386 return ERR_PTR(-ENOBUFS);
2387
2388 rth->dst.output = ip_output;
2389
2390 rth->rt_key_dst = orig_daddr;
2391 rth->rt_key_src = orig_saddr;
2392 rth->rt_genid = rt_genid(dev_net(dev_out));
2393 rth->rt_flags = flags;
2394 rth->rt_type = type;
2395 rth->rt_key_tos = tos;
2396 rth->rt_dst = fl4->daddr;
2397 rth->rt_src = fl4->saddr;
2398 rth->rt_route_iif = 0;
2399 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2400 rth->rt_oif = orig_oif;
2401 rth->rt_mark = fl4->flowi4_mark;
2402 rth->rt_gateway = fl4->daddr;
2403 rth->rt_spec_dst= fl4->saddr;
2404 rth->rt_peer_genid = 0;
2405 rth->peer = NULL;
2406 rth->fi = NULL;
2407
2408 RT_CACHE_STAT_INC(out_slow_tot);
2409
2410 if (flags & RTCF_LOCAL) {
2411 rth->dst.input = ip_local_deliver;
2412 rth->rt_spec_dst = fl4->daddr;
2413 }
2414 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2415 rth->rt_spec_dst = fl4->saddr;
2416 if (flags & RTCF_LOCAL &&
2417 !(dev_out->flags & IFF_LOOPBACK)) {
2418 rth->dst.output = ip_mc_output;
2419 RT_CACHE_STAT_INC(out_slow_mc);
2420 }
2421 #ifdef CONFIG_IP_MROUTE
2422 if (type == RTN_MULTICAST) {
2423 if (IN_DEV_MFORWARD(in_dev) &&
2424 !ipv4_is_local_multicast(fl4->daddr)) {
2425 rth->dst.input = ip_mr_input;
2426 rth->dst.output = ip_mc_output;
2427 }
2428 }
2429 #endif
2430 }
2431
2432 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2433
2434 return rth;
2435 }
2436
2437 /*
2438 * Major route resolver routine.
2439 * called with rcu_read_lock();
2440 */
2441
2442 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2443 {
2444 struct net_device *dev_out = NULL;
2445 u32 tos = RT_FL_TOS(fl4);
2446 unsigned int flags = 0;
2447 struct fib_result res;
2448 struct rtable *rth;
2449 __be32 orig_daddr;
2450 __be32 orig_saddr;
2451 int orig_oif;
2452
2453 res.fi = NULL;
2454 #ifdef CONFIG_IP_MULTIPLE_TABLES
2455 res.r = NULL;
2456 #endif
2457
2458 orig_daddr = fl4->daddr;
2459 orig_saddr = fl4->saddr;
2460 orig_oif = fl4->flowi4_oif;
2461
2462 fl4->flowi4_iif = net->loopback_dev->ifindex;
2463 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2464 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2465 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2466
2467 rcu_read_lock();
2468 if (fl4->saddr) {
2469 rth = ERR_PTR(-EINVAL);
2470 if (ipv4_is_multicast(fl4->saddr) ||
2471 ipv4_is_lbcast(fl4->saddr) ||
2472 ipv4_is_zeronet(fl4->saddr))
2473 goto out;
2474
2475 /* I removed check for oif == dev_out->oif here.
2476 It was wrong for two reasons:
2477 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2478 is assigned to multiple interfaces.
2479 2. Moreover, we are allowed to send packets with saddr
2480 of another iface. --ANK
2481 */
2482
2483 if (fl4->flowi4_oif == 0 &&
2484 (ipv4_is_multicast(fl4->daddr) ||
2485 ipv4_is_lbcast(fl4->daddr))) {
2486 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2487 dev_out = __ip_dev_find(net, fl4->saddr, false);
2488 if (dev_out == NULL)
2489 goto out;
2490
2491 /* Special hack: user can direct multicasts
2492 and limited broadcast via necessary interface
2493 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2494 This hack is not just for fun, it allows
2495 vic,vat and friends to work.
2496 They bind socket to loopback, set ttl to zero
2497 and expect that it will work.
2498 From the viewpoint of routing cache they are broken,
2499 because we are not allowed to build multicast path
2500 with loopback source addr (look, routing cache
2501 cannot know, that ttl is zero, so that packet
2502 will not leave this host and route is valid).
2503 Luckily, this hack is good workaround.
2504 */
2505
2506 fl4->flowi4_oif = dev_out->ifindex;
2507 goto make_route;
2508 }
2509
2510 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2511 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2512 if (!__ip_dev_find(net, fl4->saddr, false))
2513 goto out;
2514 }
2515 }
2516
2517
2518 if (fl4->flowi4_oif) {
2519 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2520 rth = ERR_PTR(-ENODEV);
2521 if (dev_out == NULL)
2522 goto out;
2523
2524 /* RACE: Check return value of inet_select_addr instead. */
2525 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2526 rth = ERR_PTR(-ENETUNREACH);
2527 goto out;
2528 }
2529 if (ipv4_is_local_multicast(fl4->daddr) ||
2530 ipv4_is_lbcast(fl4->daddr)) {
2531 if (!fl4->saddr)
2532 fl4->saddr = inet_select_addr(dev_out, 0,
2533 RT_SCOPE_LINK);
2534 goto make_route;
2535 }
2536 if (fl4->saddr) {
2537 if (ipv4_is_multicast(fl4->daddr))
2538 fl4->saddr = inet_select_addr(dev_out, 0,
2539 fl4->flowi4_scope);
2540 else if (!fl4->daddr)
2541 fl4->saddr = inet_select_addr(dev_out, 0,
2542 RT_SCOPE_HOST);
2543 }
2544 }
2545
2546 if (!fl4->daddr) {
2547 fl4->daddr = fl4->saddr;
2548 if (!fl4->daddr)
2549 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2550 dev_out = net->loopback_dev;
2551 fl4->flowi4_oif = net->loopback_dev->ifindex;
2552 res.type = RTN_LOCAL;
2553 flags |= RTCF_LOCAL;
2554 goto make_route;
2555 }
2556
2557 if (fib_lookup(net, fl4, &res)) {
2558 res.fi = NULL;
2559 if (fl4->flowi4_oif) {
2560 /* Apparently, routing tables are wrong. Assume,
2561 that the destination is on link.
2562
2563 WHY? DW.
2564 Because we are allowed to send to iface
2565 even if it has NO routes and NO assigned
2566 addresses. When oif is specified, routing
2567 tables are looked up with only one purpose:
2568 to catch if destination is gatewayed, rather than
2569 direct. Moreover, if MSG_DONTROUTE is set,
2570 we send packet, ignoring both routing tables
2571 and ifaddr state. --ANK
2572
2573
2574 We could make it even if oif is unknown,
2575 likely IPv6, but we do not.
2576 */
2577
2578 if (fl4->saddr == 0)
2579 fl4->saddr = inet_select_addr(dev_out, 0,
2580 RT_SCOPE_LINK);
2581 res.type = RTN_UNICAST;
2582 goto make_route;
2583 }
2584 rth = ERR_PTR(-ENETUNREACH);
2585 goto out;
2586 }
2587
2588 if (res.type == RTN_LOCAL) {
2589 if (!fl4->saddr) {
2590 if (res.fi->fib_prefsrc)
2591 fl4->saddr = res.fi->fib_prefsrc;
2592 else
2593 fl4->saddr = fl4->daddr;
2594 }
2595 dev_out = net->loopback_dev;
2596 fl4->flowi4_oif = dev_out->ifindex;
2597 res.fi = NULL;
2598 flags |= RTCF_LOCAL;
2599 goto make_route;
2600 }
2601
2602 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2603 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2604 fib_select_multipath(&res);
2605 else
2606 #endif
2607 if (!res.prefixlen &&
2608 res.table->tb_num_default > 1 &&
2609 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2610 fib_select_default(&res);
2611
2612 if (!fl4->saddr)
2613 fl4->saddr = FIB_RES_PREFSRC(net, res);
2614
2615 dev_out = FIB_RES_DEV(res);
2616 fl4->flowi4_oif = dev_out->ifindex;
2617
2618
2619 make_route:
2620 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2621 dev_out, flags);
2622 if (!IS_ERR(rth)) {
2623 unsigned int hash;
2624
2625 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2626 rt_genid(dev_net(dev_out)));
2627 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2628 }
2629
2630 out:
2631 rcu_read_unlock();
2632 return rth;
2633 }
2634
2635 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2636 {
2637 struct rtable *rth;
2638 unsigned int hash;
2639
2640 if (!rt_caching(net))
2641 goto slow_output;
2642
2643 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2644
2645 rcu_read_lock_bh();
2646 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2647 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2648 if (rth->rt_key_dst == flp4->daddr &&
2649 rth->rt_key_src == flp4->saddr &&
2650 rt_is_output_route(rth) &&
2651 rth->rt_oif == flp4->flowi4_oif &&
2652 rth->rt_mark == flp4->flowi4_mark &&
2653 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2654 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2655 net_eq(dev_net(rth->dst.dev), net) &&
2656 !rt_is_expired(rth)) {
2657 dst_use(&rth->dst, jiffies);
2658 RT_CACHE_STAT_INC(out_hit);
2659 rcu_read_unlock_bh();
2660 if (!flp4->saddr)
2661 flp4->saddr = rth->rt_src;
2662 if (!flp4->daddr)
2663 flp4->daddr = rth->rt_dst;
2664 return rth;
2665 }
2666 RT_CACHE_STAT_INC(out_hlist_search);
2667 }
2668 rcu_read_unlock_bh();
2669
2670 slow_output:
2671 return ip_route_output_slow(net, flp4);
2672 }
2673 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2674
2675 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2676 {
2677 return NULL;
2678 }
2679
2680 static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2681 {
2682 return 0;
2683 }
2684
2685 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2686 {
2687 }
2688
2689 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2690 unsigned long old)
2691 {
2692 return NULL;
2693 }
2694
2695 static struct dst_ops ipv4_dst_blackhole_ops = {
2696 .family = AF_INET,
2697 .protocol = cpu_to_be16(ETH_P_IP),
2698 .destroy = ipv4_dst_destroy,
2699 .check = ipv4_blackhole_dst_check,
2700 .default_mtu = ipv4_blackhole_default_mtu,
2701 .default_advmss = ipv4_default_advmss,
2702 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2703 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2704 };
2705
2706 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2707 {
2708 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2709 struct rtable *ort = (struct rtable *) dst_orig;
2710
2711 if (rt) {
2712 struct dst_entry *new = &rt->dst;
2713
2714 new->__use = 1;
2715 new->input = dst_discard;
2716 new->output = dst_discard;
2717 dst_copy_metrics(new, &ort->dst);
2718
2719 new->dev = ort->dst.dev;
2720 if (new->dev)
2721 dev_hold(new->dev);
2722
2723 rt->rt_key_dst = ort->rt_key_dst;
2724 rt->rt_key_src = ort->rt_key_src;
2725 rt->rt_key_tos = ort->rt_key_tos;
2726 rt->rt_route_iif = ort->rt_route_iif;
2727 rt->rt_iif = ort->rt_iif;
2728 rt->rt_oif = ort->rt_oif;
2729 rt->rt_mark = ort->rt_mark;
2730
2731 rt->rt_genid = rt_genid(net);
2732 rt->rt_flags = ort->rt_flags;
2733 rt->rt_type = ort->rt_type;
2734 rt->rt_dst = ort->rt_dst;
2735 rt->rt_src = ort->rt_src;
2736 rt->rt_gateway = ort->rt_gateway;
2737 rt->rt_spec_dst = ort->rt_spec_dst;
2738 rt->peer = ort->peer;
2739 if (rt->peer)
2740 atomic_inc(&rt->peer->refcnt);
2741 rt->fi = ort->fi;
2742 if (rt->fi)
2743 atomic_inc(&rt->fi->fib_clntref);
2744
2745 dst_free(new);
2746 }
2747
2748 dst_release(dst_orig);
2749
2750 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2751 }
2752
2753 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2754 struct sock *sk)
2755 {
2756 struct rtable *rt = __ip_route_output_key(net, flp4);
2757
2758 if (IS_ERR(rt))
2759 return rt;
2760
2761 if (flp4->flowi4_proto)
2762 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2763 flowi4_to_flowi(flp4),
2764 sk, 0);
2765
2766 return rt;
2767 }
2768 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2769
2770 static int rt_fill_info(struct net *net,
2771 struct sk_buff *skb, u32 pid, u32 seq, int event,
2772 int nowait, unsigned int flags)
2773 {
2774 struct rtable *rt = skb_rtable(skb);
2775 struct rtmsg *r;
2776 struct nlmsghdr *nlh;
2777 long expires;
2778 u32 id = 0, ts = 0, tsage = 0, error;
2779
2780 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2781 if (nlh == NULL)
2782 return -EMSGSIZE;
2783
2784 r = nlmsg_data(nlh);
2785 r->rtm_family = AF_INET;
2786 r->rtm_dst_len = 32;
2787 r->rtm_src_len = 0;
2788 r->rtm_tos = rt->rt_key_tos;
2789 r->rtm_table = RT_TABLE_MAIN;
2790 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2791 r->rtm_type = rt->rt_type;
2792 r->rtm_scope = RT_SCOPE_UNIVERSE;
2793 r->rtm_protocol = RTPROT_UNSPEC;
2794 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2795 if (rt->rt_flags & RTCF_NOTIFY)
2796 r->rtm_flags |= RTM_F_NOTIFY;
2797
2798 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2799
2800 if (rt->rt_key_src) {
2801 r->rtm_src_len = 32;
2802 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2803 }
2804 if (rt->dst.dev)
2805 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2806 #ifdef CONFIG_IP_ROUTE_CLASSID
2807 if (rt->dst.tclassid)
2808 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2809 #endif
2810 if (rt_is_input_route(rt))
2811 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2812 else if (rt->rt_src != rt->rt_key_src)
2813 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2814
2815 if (rt->rt_dst != rt->rt_gateway)
2816 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2817
2818 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2819 goto nla_put_failure;
2820
2821 if (rt->rt_mark)
2822 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2823
2824 error = rt->dst.error;
2825 expires = (rt->peer && rt->peer->pmtu_expires) ?
2826 rt->peer->pmtu_expires - jiffies : 0;
2827 if (rt->peer) {
2828 inet_peer_refcheck(rt->peer);
2829 id = atomic_read(&rt->peer->ip_id_count) & 0xffff;
2830 if (rt->peer->tcp_ts_stamp) {
2831 ts = rt->peer->tcp_ts;
2832 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2833 }
2834 }
2835
2836 if (rt_is_input_route(rt)) {
2837 #ifdef CONFIG_IP_MROUTE
2838 __be32 dst = rt->rt_dst;
2839
2840 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2841 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2842 int err = ipmr_get_route(net, skb,
2843 rt->rt_src, rt->rt_dst,
2844 r, nowait);
2845 if (err <= 0) {
2846 if (!nowait) {
2847 if (err == 0)
2848 return 0;
2849 goto nla_put_failure;
2850 } else {
2851 if (err == -EMSGSIZE)
2852 goto nla_put_failure;
2853 error = err;
2854 }
2855 }
2856 } else
2857 #endif
2858 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2859 }
2860
2861 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2862 expires, error) < 0)
2863 goto nla_put_failure;
2864
2865 return nlmsg_end(skb, nlh);
2866
2867 nla_put_failure:
2868 nlmsg_cancel(skb, nlh);
2869 return -EMSGSIZE;
2870 }
2871
2872 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2873 {
2874 struct net *net = sock_net(in_skb->sk);
2875 struct rtmsg *rtm;
2876 struct nlattr *tb[RTA_MAX+1];
2877 struct rtable *rt = NULL;
2878 __be32 dst = 0;
2879 __be32 src = 0;
2880 u32 iif;
2881 int err;
2882 int mark;
2883 struct sk_buff *skb;
2884
2885 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2886 if (err < 0)
2887 goto errout;
2888
2889 rtm = nlmsg_data(nlh);
2890
2891 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2892 if (skb == NULL) {
2893 err = -ENOBUFS;
2894 goto errout;
2895 }
2896
2897 /* Reserve room for dummy headers, this skb can pass
2898 through good chunk of routing engine.
2899 */
2900 skb_reset_mac_header(skb);
2901 skb_reset_network_header(skb);
2902
2903 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2904 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2905 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2906
2907 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2908 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2909 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2910 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2911
2912 if (iif) {
2913 struct net_device *dev;
2914
2915 dev = __dev_get_by_index(net, iif);
2916 if (dev == NULL) {
2917 err = -ENODEV;
2918 goto errout_free;
2919 }
2920
2921 skb->protocol = htons(ETH_P_IP);
2922 skb->dev = dev;
2923 skb->mark = mark;
2924 local_bh_disable();
2925 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2926 local_bh_enable();
2927
2928 rt = skb_rtable(skb);
2929 if (err == 0 && rt->dst.error)
2930 err = -rt->dst.error;
2931 } else {
2932 struct flowi4 fl4 = {
2933 .daddr = dst,
2934 .saddr = src,
2935 .flowi4_tos = rtm->rtm_tos,
2936 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2937 .flowi4_mark = mark,
2938 };
2939 rt = ip_route_output_key(net, &fl4);
2940
2941 err = 0;
2942 if (IS_ERR(rt))
2943 err = PTR_ERR(rt);
2944 }
2945
2946 if (err)
2947 goto errout_free;
2948
2949 skb_dst_set(skb, &rt->dst);
2950 if (rtm->rtm_flags & RTM_F_NOTIFY)
2951 rt->rt_flags |= RTCF_NOTIFY;
2952
2953 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2954 RTM_NEWROUTE, 0, 0);
2955 if (err <= 0)
2956 goto errout_free;
2957
2958 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2959 errout:
2960 return err;
2961
2962 errout_free:
2963 kfree_skb(skb);
2964 goto errout;
2965 }
2966
2967 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2968 {
2969 struct rtable *rt;
2970 int h, s_h;
2971 int idx, s_idx;
2972 struct net *net;
2973
2974 net = sock_net(skb->sk);
2975
2976 s_h = cb->args[0];
2977 if (s_h < 0)
2978 s_h = 0;
2979 s_idx = idx = cb->args[1];
2980 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
2981 if (!rt_hash_table[h].chain)
2982 continue;
2983 rcu_read_lock_bh();
2984 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
2985 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
2986 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
2987 continue;
2988 if (rt_is_expired(rt))
2989 continue;
2990 skb_dst_set_noref(skb, &rt->dst);
2991 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
2992 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2993 1, NLM_F_MULTI) <= 0) {
2994 skb_dst_drop(skb);
2995 rcu_read_unlock_bh();
2996 goto done;
2997 }
2998 skb_dst_drop(skb);
2999 }
3000 rcu_read_unlock_bh();
3001 }
3002
3003 done:
3004 cb->args[0] = h;
3005 cb->args[1] = idx;
3006 return skb->len;
3007 }
3008
3009 void ip_rt_multicast_event(struct in_device *in_dev)
3010 {
3011 rt_cache_flush(dev_net(in_dev->dev), 0);
3012 }
3013
3014 #ifdef CONFIG_SYSCTL
3015 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3016 void __user *buffer,
3017 size_t *lenp, loff_t *ppos)
3018 {
3019 if (write) {
3020 int flush_delay;
3021 ctl_table ctl;
3022 struct net *net;
3023
3024 memcpy(&ctl, __ctl, sizeof(ctl));
3025 ctl.data = &flush_delay;
3026 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3027
3028 net = (struct net *)__ctl->extra1;
3029 rt_cache_flush(net, flush_delay);
3030 return 0;
3031 }
3032
3033 return -EINVAL;
3034 }
3035
3036 static ctl_table ipv4_route_table[] = {
3037 {
3038 .procname = "gc_thresh",
3039 .data = &ipv4_dst_ops.gc_thresh,
3040 .maxlen = sizeof(int),
3041 .mode = 0644,
3042 .proc_handler = proc_dointvec,
3043 },
3044 {
3045 .procname = "max_size",
3046 .data = &ip_rt_max_size,
3047 .maxlen = sizeof(int),
3048 .mode = 0644,
3049 .proc_handler = proc_dointvec,
3050 },
3051 {
3052 /* Deprecated. Use gc_min_interval_ms */
3053
3054 .procname = "gc_min_interval",
3055 .data = &ip_rt_gc_min_interval,
3056 .maxlen = sizeof(int),
3057 .mode = 0644,
3058 .proc_handler = proc_dointvec_jiffies,
3059 },
3060 {
3061 .procname = "gc_min_interval_ms",
3062 .data = &ip_rt_gc_min_interval,
3063 .maxlen = sizeof(int),
3064 .mode = 0644,
3065 .proc_handler = proc_dointvec_ms_jiffies,
3066 },
3067 {
3068 .procname = "gc_timeout",
3069 .data = &ip_rt_gc_timeout,
3070 .maxlen = sizeof(int),
3071 .mode = 0644,
3072 .proc_handler = proc_dointvec_jiffies,
3073 },
3074 {
3075 .procname = "gc_interval",
3076 .data = &ip_rt_gc_interval,
3077 .maxlen = sizeof(int),
3078 .mode = 0644,
3079 .proc_handler = proc_dointvec_jiffies,
3080 },
3081 {
3082 .procname = "redirect_load",
3083 .data = &ip_rt_redirect_load,
3084 .maxlen = sizeof(int),
3085 .mode = 0644,
3086 .proc_handler = proc_dointvec,
3087 },
3088 {
3089 .procname = "redirect_number",
3090 .data = &ip_rt_redirect_number,
3091 .maxlen = sizeof(int),
3092 .mode = 0644,
3093 .proc_handler = proc_dointvec,
3094 },
3095 {
3096 .procname = "redirect_silence",
3097 .data = &ip_rt_redirect_silence,
3098 .maxlen = sizeof(int),
3099 .mode = 0644,
3100 .proc_handler = proc_dointvec,
3101 },
3102 {
3103 .procname = "error_cost",
3104 .data = &ip_rt_error_cost,
3105 .maxlen = sizeof(int),
3106 .mode = 0644,
3107 .proc_handler = proc_dointvec,
3108 },
3109 {
3110 .procname = "error_burst",
3111 .data = &ip_rt_error_burst,
3112 .maxlen = sizeof(int),
3113 .mode = 0644,
3114 .proc_handler = proc_dointvec,
3115 },
3116 {
3117 .procname = "gc_elasticity",
3118 .data = &ip_rt_gc_elasticity,
3119 .maxlen = sizeof(int),
3120 .mode = 0644,
3121 .proc_handler = proc_dointvec,
3122 },
3123 {
3124 .procname = "mtu_expires",
3125 .data = &ip_rt_mtu_expires,
3126 .maxlen = sizeof(int),
3127 .mode = 0644,
3128 .proc_handler = proc_dointvec_jiffies,
3129 },
3130 {
3131 .procname = "min_pmtu",
3132 .data = &ip_rt_min_pmtu,
3133 .maxlen = sizeof(int),
3134 .mode = 0644,
3135 .proc_handler = proc_dointvec,
3136 },
3137 {
3138 .procname = "min_adv_mss",
3139 .data = &ip_rt_min_advmss,
3140 .maxlen = sizeof(int),
3141 .mode = 0644,
3142 .proc_handler = proc_dointvec,
3143 },
3144 { }
3145 };
3146
3147 static struct ctl_table empty[1];
3148
3149 static struct ctl_table ipv4_skeleton[] =
3150 {
3151 { .procname = "route",
3152 .mode = 0555, .child = ipv4_route_table},
3153 { .procname = "neigh",
3154 .mode = 0555, .child = empty},
3155 { }
3156 };
3157
3158 static __net_initdata struct ctl_path ipv4_path[] = {
3159 { .procname = "net", },
3160 { .procname = "ipv4", },
3161 { },
3162 };
3163
3164 static struct ctl_table ipv4_route_flush_table[] = {
3165 {
3166 .procname = "flush",
3167 .maxlen = sizeof(int),
3168 .mode = 0200,
3169 .proc_handler = ipv4_sysctl_rtcache_flush,
3170 },
3171 { },
3172 };
3173
3174 static __net_initdata struct ctl_path ipv4_route_path[] = {
3175 { .procname = "net", },
3176 { .procname = "ipv4", },
3177 { .procname = "route", },
3178 { },
3179 };
3180
3181 static __net_init int sysctl_route_net_init(struct net *net)
3182 {
3183 struct ctl_table *tbl;
3184
3185 tbl = ipv4_route_flush_table;
3186 if (!net_eq(net, &init_net)) {
3187 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3188 if (tbl == NULL)
3189 goto err_dup;
3190 }
3191 tbl[0].extra1 = net;
3192
3193 net->ipv4.route_hdr =
3194 register_net_sysctl_table(net, ipv4_route_path, tbl);
3195 if (net->ipv4.route_hdr == NULL)
3196 goto err_reg;
3197 return 0;
3198
3199 err_reg:
3200 if (tbl != ipv4_route_flush_table)
3201 kfree(tbl);
3202 err_dup:
3203 return -ENOMEM;
3204 }
3205
3206 static __net_exit void sysctl_route_net_exit(struct net *net)
3207 {
3208 struct ctl_table *tbl;
3209
3210 tbl = net->ipv4.route_hdr->ctl_table_arg;
3211 unregister_net_sysctl_table(net->ipv4.route_hdr);
3212 BUG_ON(tbl == ipv4_route_flush_table);
3213 kfree(tbl);
3214 }
3215
3216 static __net_initdata struct pernet_operations sysctl_route_ops = {
3217 .init = sysctl_route_net_init,
3218 .exit = sysctl_route_net_exit,
3219 };
3220 #endif
3221
3222 static __net_init int rt_genid_init(struct net *net)
3223 {
3224 get_random_bytes(&net->ipv4.rt_genid,
3225 sizeof(net->ipv4.rt_genid));
3226 get_random_bytes(&net->ipv4.dev_addr_genid,
3227 sizeof(net->ipv4.dev_addr_genid));
3228 return 0;
3229 }
3230
3231 static __net_initdata struct pernet_operations rt_genid_ops = {
3232 .init = rt_genid_init,
3233 };
3234
3235
3236 #ifdef CONFIG_IP_ROUTE_CLASSID
3237 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3238 #endif /* CONFIG_IP_ROUTE_CLASSID */
3239
3240 static __initdata unsigned long rhash_entries;
3241 static int __init set_rhash_entries(char *str)
3242 {
3243 if (!str)
3244 return 0;
3245 rhash_entries = simple_strtoul(str, &str, 0);
3246 return 1;
3247 }
3248 __setup("rhash_entries=", set_rhash_entries);
3249
3250 int __init ip_rt_init(void)
3251 {
3252 int rc = 0;
3253
3254 #ifdef CONFIG_IP_ROUTE_CLASSID
3255 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3256 if (!ip_rt_acct)
3257 panic("IP: failed to allocate ip_rt_acct\n");
3258 #endif
3259
3260 ipv4_dst_ops.kmem_cachep =
3261 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3262 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3263
3264 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3265
3266 if (dst_entries_init(&ipv4_dst_ops) < 0)
3267 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3268
3269 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3270 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3271
3272 rt_hash_table = (struct rt_hash_bucket *)
3273 alloc_large_system_hash("IP route cache",
3274 sizeof(struct rt_hash_bucket),
3275 rhash_entries,
3276 (totalram_pages >= 128 * 1024) ?
3277 15 : 17,
3278 0,
3279 &rt_hash_log,
3280 &rt_hash_mask,
3281 rhash_entries ? 0 : 512 * 1024);
3282 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3283 rt_hash_lock_init();
3284
3285 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3286 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3287
3288 devinet_init();
3289 ip_fib_init();
3290
3291 if (ip_rt_proc_init())
3292 printk(KERN_ERR "Unable to create route proc files\n");
3293 #ifdef CONFIG_XFRM
3294 xfrm_init();
3295 xfrm4_init(ip_rt_max_size);
3296 #endif
3297 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3298
3299 #ifdef CONFIG_SYSCTL
3300 register_pernet_subsys(&sysctl_route_ops);
3301 #endif
3302 register_pernet_subsys(&rt_genid_ops);
3303 return rc;
3304 }
3305
3306 #ifdef CONFIG_SYSCTL
3307 /*
3308 * We really need to sanitize the damn ipv4 init order, then all
3309 * this nonsense will go away.
3310 */
3311 void __init ip_static_sysctl_init(void)
3312 {
3313 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3314 }
3315 #endif