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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / net / ipv4 / route.c
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1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65#include <linux/module.h>
66#include <asm/uaccess.h>
67#include <asm/system.h>
68#include <linux/bitops.h>
69#include <linux/types.h>
70#include <linux/kernel.h>
71#include <linux/mm.h>
72#include <linux/bootmem.h>
73#include <linux/string.h>
74#include <linux/socket.h>
75#include <linux/sockios.h>
76#include <linux/errno.h>
77#include <linux/in.h>
78#include <linux/inet.h>
79#include <linux/netdevice.h>
80#include <linux/proc_fs.h>
81#include <linux/init.h>
82#include <linux/workqueue.h>
83#include <linux/skbuff.h>
84#include <linux/inetdevice.h>
85#include <linux/igmp.h>
86#include <linux/pkt_sched.h>
87#include <linux/mroute.h>
88#include <linux/netfilter_ipv4.h>
89#include <linux/random.h>
90#include <linux/jhash.h>
91#include <linux/rcupdate.h>
92#include <linux/times.h>
93#include <linux/slab.h>
94#include <net/dst.h>
95#include <net/net_namespace.h>
96#include <net/protocol.h>
97#include <net/ip.h>
98#include <net/route.h>
99#include <net/inetpeer.h>
100#include <net/sock.h>
101#include <net/ip_fib.h>
102#include <net/arp.h>
103#include <net/tcp.h>
104#include <net/icmp.h>
105#include <net/xfrm.h>
106#include <net/netevent.h>
107#include <net/rtnetlink.h>
108#ifdef CONFIG_SYSCTL
109#include <linux/sysctl.h>
110#endif
111#include <net/atmclip.h>
112#include <net/secure_seq.h>
113
114#define RT_FL_TOS(oldflp4) \
115 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
116
117#define IP_MAX_MTU 0xFFF0
118
119#define RT_GC_TIMEOUT (300*HZ)
120
121static int ip_rt_max_size;
122static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
123static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
124static int ip_rt_redirect_number __read_mostly = 9;
125static int ip_rt_redirect_load __read_mostly = HZ / 50;
126static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
127static int ip_rt_error_cost __read_mostly = HZ;
128static int ip_rt_error_burst __read_mostly = 5 * HZ;
129static int ip_rt_gc_elasticity __read_mostly = 8;
130static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
131static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
132static int ip_rt_min_advmss __read_mostly = 256;
133static int rt_chain_length_max __read_mostly = 20;
134static int redirect_genid;
135
136/*
137 * Interface to generic destination cache.
138 */
139
140static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
141static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
142static unsigned int ipv4_mtu(const struct dst_entry *dst);
143static void ipv4_dst_destroy(struct dst_entry *dst);
144static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145static void ipv4_link_failure(struct sk_buff *skb);
146static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
147static int rt_garbage_collect(struct dst_ops *ops);
148
149static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
150 int how)
151{
152}
153
154static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
155{
156 struct rtable *rt = (struct rtable *) dst;
157 struct inet_peer *peer;
158 u32 *p = NULL;
159
160 if (!rt->peer)
161 rt_bind_peer(rt, rt->rt_dst, 1);
162
163 peer = rt->peer;
164 if (peer) {
165 u32 *old_p = __DST_METRICS_PTR(old);
166 unsigned long prev, new;
167
168 p = peer->metrics;
169 if (inet_metrics_new(peer))
170 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
171
172 new = (unsigned long) p;
173 prev = cmpxchg(&dst->_metrics, old, new);
174
175 if (prev != old) {
176 p = __DST_METRICS_PTR(prev);
177 if (prev & DST_METRICS_READ_ONLY)
178 p = NULL;
179 } else {
180 if (rt->fi) {
181 fib_info_put(rt->fi);
182 rt->fi = NULL;
183 }
184 }
185 }
186 return p;
187}
188
189static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
190
191static struct dst_ops ipv4_dst_ops = {
192 .family = AF_INET,
193 .protocol = cpu_to_be16(ETH_P_IP),
194 .gc = rt_garbage_collect,
195 .check = ipv4_dst_check,
196 .default_advmss = ipv4_default_advmss,
197 .mtu = ipv4_mtu,
198 .cow_metrics = ipv4_cow_metrics,
199 .destroy = ipv4_dst_destroy,
200 .ifdown = ipv4_dst_ifdown,
201 .negative_advice = ipv4_negative_advice,
202 .link_failure = ipv4_link_failure,
203 .update_pmtu = ip_rt_update_pmtu,
204 .local_out = __ip_local_out,
205 .neigh_lookup = ipv4_neigh_lookup,
206};
207
208#define ECN_OR_COST(class) TC_PRIO_##class
209
210const __u8 ip_tos2prio[16] = {
211 TC_PRIO_BESTEFFORT,
212 ECN_OR_COST(BESTEFFORT),
213 TC_PRIO_BESTEFFORT,
214 ECN_OR_COST(BESTEFFORT),
215 TC_PRIO_BULK,
216 ECN_OR_COST(BULK),
217 TC_PRIO_BULK,
218 ECN_OR_COST(BULK),
219 TC_PRIO_INTERACTIVE,
220 ECN_OR_COST(INTERACTIVE),
221 TC_PRIO_INTERACTIVE,
222 ECN_OR_COST(INTERACTIVE),
223 TC_PRIO_INTERACTIVE_BULK,
224 ECN_OR_COST(INTERACTIVE_BULK),
225 TC_PRIO_INTERACTIVE_BULK,
226 ECN_OR_COST(INTERACTIVE_BULK)
227};
228
229
230/*
231 * Route cache.
232 */
233
234/* The locking scheme is rather straight forward:
235 *
236 * 1) Read-Copy Update protects the buckets of the central route hash.
237 * 2) Only writers remove entries, and they hold the lock
238 * as they look at rtable reference counts.
239 * 3) Only readers acquire references to rtable entries,
240 * they do so with atomic increments and with the
241 * lock held.
242 */
243
244struct rt_hash_bucket {
245 struct rtable __rcu *chain;
246};
247
248#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
249 defined(CONFIG_PROVE_LOCKING)
250/*
251 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
252 * The size of this table is a power of two and depends on the number of CPUS.
253 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
254 */
255#ifdef CONFIG_LOCKDEP
256# define RT_HASH_LOCK_SZ 256
257#else
258# if NR_CPUS >= 32
259# define RT_HASH_LOCK_SZ 4096
260# elif NR_CPUS >= 16
261# define RT_HASH_LOCK_SZ 2048
262# elif NR_CPUS >= 8
263# define RT_HASH_LOCK_SZ 1024
264# elif NR_CPUS >= 4
265# define RT_HASH_LOCK_SZ 512
266# else
267# define RT_HASH_LOCK_SZ 256
268# endif
269#endif
270
271static spinlock_t *rt_hash_locks;
272# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
273
274static __init void rt_hash_lock_init(void)
275{
276 int i;
277
278 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
279 GFP_KERNEL);
280 if (!rt_hash_locks)
281 panic("IP: failed to allocate rt_hash_locks\n");
282
283 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
284 spin_lock_init(&rt_hash_locks[i]);
285}
286#else
287# define rt_hash_lock_addr(slot) NULL
288
289static inline void rt_hash_lock_init(void)
290{
291}
292#endif
293
294static struct rt_hash_bucket *rt_hash_table __read_mostly;
295static unsigned rt_hash_mask __read_mostly;
296static unsigned int rt_hash_log __read_mostly;
297
298static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
299#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
300
301static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
302 int genid)
303{
304 return jhash_3words((__force u32)daddr, (__force u32)saddr,
305 idx, genid)
306 & rt_hash_mask;
307}
308
309static inline int rt_genid(struct net *net)
310{
311 return atomic_read(&net->ipv4.rt_genid);
312}
313
314#ifdef CONFIG_PROC_FS
315struct rt_cache_iter_state {
316 struct seq_net_private p;
317 int bucket;
318 int genid;
319};
320
321static struct rtable *rt_cache_get_first(struct seq_file *seq)
322{
323 struct rt_cache_iter_state *st = seq->private;
324 struct rtable *r = NULL;
325
326 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
327 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
328 continue;
329 rcu_read_lock_bh();
330 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
331 while (r) {
332 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
333 r->rt_genid == st->genid)
334 return r;
335 r = rcu_dereference_bh(r->dst.rt_next);
336 }
337 rcu_read_unlock_bh();
338 }
339 return r;
340}
341
342static struct rtable *__rt_cache_get_next(struct seq_file *seq,
343 struct rtable *r)
344{
345 struct rt_cache_iter_state *st = seq->private;
346
347 r = rcu_dereference_bh(r->dst.rt_next);
348 while (!r) {
349 rcu_read_unlock_bh();
350 do {
351 if (--st->bucket < 0)
352 return NULL;
353 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
354 rcu_read_lock_bh();
355 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
356 }
357 return r;
358}
359
360static struct rtable *rt_cache_get_next(struct seq_file *seq,
361 struct rtable *r)
362{
363 struct rt_cache_iter_state *st = seq->private;
364 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
365 if (dev_net(r->dst.dev) != seq_file_net(seq))
366 continue;
367 if (r->rt_genid == st->genid)
368 break;
369 }
370 return r;
371}
372
373static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
374{
375 struct rtable *r = rt_cache_get_first(seq);
376
377 if (r)
378 while (pos && (r = rt_cache_get_next(seq, r)))
379 --pos;
380 return pos ? NULL : r;
381}
382
383static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
384{
385 struct rt_cache_iter_state *st = seq->private;
386 if (*pos)
387 return rt_cache_get_idx(seq, *pos - 1);
388 st->genid = rt_genid(seq_file_net(seq));
389 return SEQ_START_TOKEN;
390}
391
392static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
393{
394 struct rtable *r;
395
396 if (v == SEQ_START_TOKEN)
397 r = rt_cache_get_first(seq);
398 else
399 r = rt_cache_get_next(seq, v);
400 ++*pos;
401 return r;
402}
403
404static void rt_cache_seq_stop(struct seq_file *seq, void *v)
405{
406 if (v && v != SEQ_START_TOKEN)
407 rcu_read_unlock_bh();
408}
409
410static int rt_cache_seq_show(struct seq_file *seq, void *v)
411{
412 if (v == SEQ_START_TOKEN)
413 seq_printf(seq, "%-127s\n",
414 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
415 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
416 "HHUptod\tSpecDst");
417 else {
418 struct rtable *r = v;
419 struct neighbour *n;
420 int len, HHUptod;
421
422 rcu_read_lock();
423 n = dst_get_neighbour(&r->dst);
424 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
425 rcu_read_unlock();
426
427 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
428 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
429 r->dst.dev ? r->dst.dev->name : "*",
430 (__force u32)r->rt_dst,
431 (__force u32)r->rt_gateway,
432 r->rt_flags, atomic_read(&r->dst.__refcnt),
433 r->dst.__use, 0, (__force u32)r->rt_src,
434 dst_metric_advmss(&r->dst) + 40,
435 dst_metric(&r->dst, RTAX_WINDOW),
436 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
437 dst_metric(&r->dst, RTAX_RTTVAR)),
438 r->rt_key_tos,
439 -1,
440 HHUptod,
441 r->rt_spec_dst, &len);
442
443 seq_printf(seq, "%*s\n", 127 - len, "");
444 }
445 return 0;
446}
447
448static const struct seq_operations rt_cache_seq_ops = {
449 .start = rt_cache_seq_start,
450 .next = rt_cache_seq_next,
451 .stop = rt_cache_seq_stop,
452 .show = rt_cache_seq_show,
453};
454
455static int rt_cache_seq_open(struct inode *inode, struct file *file)
456{
457 return seq_open_net(inode, file, &rt_cache_seq_ops,
458 sizeof(struct rt_cache_iter_state));
459}
460
461static const struct file_operations rt_cache_seq_fops = {
462 .owner = THIS_MODULE,
463 .open = rt_cache_seq_open,
464 .read = seq_read,
465 .llseek = seq_lseek,
466 .release = seq_release_net,
467};
468
469
470static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
471{
472 int cpu;
473
474 if (*pos == 0)
475 return SEQ_START_TOKEN;
476
477 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
478 if (!cpu_possible(cpu))
479 continue;
480 *pos = cpu+1;
481 return &per_cpu(rt_cache_stat, cpu);
482 }
483 return NULL;
484}
485
486static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
487{
488 int cpu;
489
490 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
491 if (!cpu_possible(cpu))
492 continue;
493 *pos = cpu+1;
494 return &per_cpu(rt_cache_stat, cpu);
495 }
496 return NULL;
497
498}
499
500static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
501{
502
503}
504
505static int rt_cpu_seq_show(struct seq_file *seq, void *v)
506{
507 struct rt_cache_stat *st = v;
508
509 if (v == SEQ_START_TOKEN) {
510 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");
511 return 0;
512 }
513
514 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
515 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
516 dst_entries_get_slow(&ipv4_dst_ops),
517 st->in_hit,
518 st->in_slow_tot,
519 st->in_slow_mc,
520 st->in_no_route,
521 st->in_brd,
522 st->in_martian_dst,
523 st->in_martian_src,
524
525 st->out_hit,
526 st->out_slow_tot,
527 st->out_slow_mc,
528
529 st->gc_total,
530 st->gc_ignored,
531 st->gc_goal_miss,
532 st->gc_dst_overflow,
533 st->in_hlist_search,
534 st->out_hlist_search
535 );
536 return 0;
537}
538
539static const struct seq_operations rt_cpu_seq_ops = {
540 .start = rt_cpu_seq_start,
541 .next = rt_cpu_seq_next,
542 .stop = rt_cpu_seq_stop,
543 .show = rt_cpu_seq_show,
544};
545
546
547static int rt_cpu_seq_open(struct inode *inode, struct file *file)
548{
549 return seq_open(file, &rt_cpu_seq_ops);
550}
551
552static const struct file_operations rt_cpu_seq_fops = {
553 .owner = THIS_MODULE,
554 .open = rt_cpu_seq_open,
555 .read = seq_read,
556 .llseek = seq_lseek,
557 .release = seq_release,
558};
559
560#ifdef CONFIG_IP_ROUTE_CLASSID
561static int rt_acct_proc_show(struct seq_file *m, void *v)
562{
563 struct ip_rt_acct *dst, *src;
564 unsigned int i, j;
565
566 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
567 if (!dst)
568 return -ENOMEM;
569
570 for_each_possible_cpu(i) {
571 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
572 for (j = 0; j < 256; j++) {
573 dst[j].o_bytes += src[j].o_bytes;
574 dst[j].o_packets += src[j].o_packets;
575 dst[j].i_bytes += src[j].i_bytes;
576 dst[j].i_packets += src[j].i_packets;
577 }
578 }
579
580 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
581 kfree(dst);
582 return 0;
583}
584
585static int rt_acct_proc_open(struct inode *inode, struct file *file)
586{
587 return single_open(file, rt_acct_proc_show, NULL);
588}
589
590static const struct file_operations rt_acct_proc_fops = {
591 .owner = THIS_MODULE,
592 .open = rt_acct_proc_open,
593 .read = seq_read,
594 .llseek = seq_lseek,
595 .release = single_release,
596};
597#endif
598
599static int __net_init ip_rt_do_proc_init(struct net *net)
600{
601 struct proc_dir_entry *pde;
602
603 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
604 &rt_cache_seq_fops);
605 if (!pde)
606 goto err1;
607
608 pde = proc_create("rt_cache", S_IRUGO,
609 net->proc_net_stat, &rt_cpu_seq_fops);
610 if (!pde)
611 goto err2;
612
613#ifdef CONFIG_IP_ROUTE_CLASSID
614 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
615 if (!pde)
616 goto err3;
617#endif
618 return 0;
619
620#ifdef CONFIG_IP_ROUTE_CLASSID
621err3:
622 remove_proc_entry("rt_cache", net->proc_net_stat);
623#endif
624err2:
625 remove_proc_entry("rt_cache", net->proc_net);
626err1:
627 return -ENOMEM;
628}
629
630static void __net_exit ip_rt_do_proc_exit(struct net *net)
631{
632 remove_proc_entry("rt_cache", net->proc_net_stat);
633 remove_proc_entry("rt_cache", net->proc_net);
634#ifdef CONFIG_IP_ROUTE_CLASSID
635 remove_proc_entry("rt_acct", net->proc_net);
636#endif
637}
638
639static struct pernet_operations ip_rt_proc_ops __net_initdata = {
640 .init = ip_rt_do_proc_init,
641 .exit = ip_rt_do_proc_exit,
642};
643
644static int __init ip_rt_proc_init(void)
645{
646 return register_pernet_subsys(&ip_rt_proc_ops);
647}
648
649#else
650static inline int ip_rt_proc_init(void)
651{
652 return 0;
653}
654#endif /* CONFIG_PROC_FS */
655
656static inline void rt_free(struct rtable *rt)
657{
658 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
659}
660
661static inline void rt_drop(struct rtable *rt)
662{
663 ip_rt_put(rt);
664 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
665}
666
667static inline int rt_fast_clean(struct rtable *rth)
668{
669 /* Kill broadcast/multicast entries very aggresively, if they
670 collide in hash table with more useful entries */
671 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
672 rt_is_input_route(rth) && rth->dst.rt_next;
673}
674
675static inline int rt_valuable(struct rtable *rth)
676{
677 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
678 (rth->peer && rth->peer->pmtu_expires);
679}
680
681static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
682{
683 unsigned long age;
684 int ret = 0;
685
686 if (atomic_read(&rth->dst.__refcnt))
687 goto out;
688
689 age = jiffies - rth->dst.lastuse;
690 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
691 (age <= tmo2 && rt_valuable(rth)))
692 goto out;
693 ret = 1;
694out: return ret;
695}
696
697/* Bits of score are:
698 * 31: very valuable
699 * 30: not quite useless
700 * 29..0: usage counter
701 */
702static inline u32 rt_score(struct rtable *rt)
703{
704 u32 score = jiffies - rt->dst.lastuse;
705
706 score = ~score & ~(3<<30);
707
708 if (rt_valuable(rt))
709 score |= (1<<31);
710
711 if (rt_is_output_route(rt) ||
712 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
713 score |= (1<<30);
714
715 return score;
716}
717
718static inline bool rt_caching(const struct net *net)
719{
720 return net->ipv4.current_rt_cache_rebuild_count <=
721 net->ipv4.sysctl_rt_cache_rebuild_count;
722}
723
724static inline bool compare_hash_inputs(const struct rtable *rt1,
725 const struct rtable *rt2)
726{
727 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
728 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
729 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
730}
731
732static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
733{
734 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
735 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
736 (rt1->rt_mark ^ rt2->rt_mark) |
737 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
738 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
739 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
740}
741
742static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
743{
744 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
745}
746
747static inline int rt_is_expired(struct rtable *rth)
748{
749 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
750}
751
752/*
753 * Perform a full scan of hash table and free all entries.
754 * Can be called by a softirq or a process.
755 * In the later case, we want to be reschedule if necessary
756 */
757static void rt_do_flush(struct net *net, int process_context)
758{
759 unsigned int i;
760 struct rtable *rth, *next;
761
762 for (i = 0; i <= rt_hash_mask; i++) {
763 struct rtable __rcu **pprev;
764 struct rtable *list;
765
766 if (process_context && need_resched())
767 cond_resched();
768 rth = rcu_access_pointer(rt_hash_table[i].chain);
769 if (!rth)
770 continue;
771
772 spin_lock_bh(rt_hash_lock_addr(i));
773
774 list = NULL;
775 pprev = &rt_hash_table[i].chain;
776 rth = rcu_dereference_protected(*pprev,
777 lockdep_is_held(rt_hash_lock_addr(i)));
778
779 while (rth) {
780 next = rcu_dereference_protected(rth->dst.rt_next,
781 lockdep_is_held(rt_hash_lock_addr(i)));
782
783 if (!net ||
784 net_eq(dev_net(rth->dst.dev), net)) {
785 rcu_assign_pointer(*pprev, next);
786 rcu_assign_pointer(rth->dst.rt_next, list);
787 list = rth;
788 } else {
789 pprev = &rth->dst.rt_next;
790 }
791 rth = next;
792 }
793
794 spin_unlock_bh(rt_hash_lock_addr(i));
795
796 for (; list; list = next) {
797 next = rcu_dereference_protected(list->dst.rt_next, 1);
798 rt_free(list);
799 }
800 }
801}
802
803/*
804 * While freeing expired entries, we compute average chain length
805 * and standard deviation, using fixed-point arithmetic.
806 * This to have an estimation of rt_chain_length_max
807 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
808 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
809 */
810
811#define FRACT_BITS 3
812#define ONE (1UL << FRACT_BITS)
813
814/*
815 * Given a hash chain and an item in this hash chain,
816 * find if a previous entry has the same hash_inputs
817 * (but differs on tos, mark or oif)
818 * Returns 0 if an alias is found.
819 * Returns ONE if rth has no alias before itself.
820 */
821static int has_noalias(const struct rtable *head, const struct rtable *rth)
822{
823 const struct rtable *aux = head;
824
825 while (aux != rth) {
826 if (compare_hash_inputs(aux, rth))
827 return 0;
828 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
829 }
830 return ONE;
831}
832
833/*
834 * Perturbation of rt_genid by a small quantity [1..256]
835 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
836 * many times (2^24) without giving recent rt_genid.
837 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
838 */
839static void rt_cache_invalidate(struct net *net)
840{
841 unsigned char shuffle;
842
843 get_random_bytes(&shuffle, sizeof(shuffle));
844 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
845 redirect_genid++;
846}
847
848/*
849 * delay < 0 : invalidate cache (fast : entries will be deleted later)
850 * delay >= 0 : invalidate & flush cache (can be long)
851 */
852void rt_cache_flush(struct net *net, int delay)
853{
854 rt_cache_invalidate(net);
855 if (delay >= 0)
856 rt_do_flush(net, !in_softirq());
857}
858
859/* Flush previous cache invalidated entries from the cache */
860void rt_cache_flush_batch(struct net *net)
861{
862 rt_do_flush(net, !in_softirq());
863}
864
865static void rt_emergency_hash_rebuild(struct net *net)
866{
867 if (net_ratelimit())
868 printk(KERN_WARNING "Route hash chain too long!\n");
869 rt_cache_invalidate(net);
870}
871
872/*
873 Short description of GC goals.
874
875 We want to build algorithm, which will keep routing cache
876 at some equilibrium point, when number of aged off entries
877 is kept approximately equal to newly generated ones.
878
879 Current expiration strength is variable "expire".
880 We try to adjust it dynamically, so that if networking
881 is idle expires is large enough to keep enough of warm entries,
882 and when load increases it reduces to limit cache size.
883 */
884
885static int rt_garbage_collect(struct dst_ops *ops)
886{
887 static unsigned long expire = RT_GC_TIMEOUT;
888 static unsigned long last_gc;
889 static int rover;
890 static int equilibrium;
891 struct rtable *rth;
892 struct rtable __rcu **rthp;
893 unsigned long now = jiffies;
894 int goal;
895 int entries = dst_entries_get_fast(&ipv4_dst_ops);
896
897 /*
898 * Garbage collection is pretty expensive,
899 * do not make it too frequently.
900 */
901
902 RT_CACHE_STAT_INC(gc_total);
903
904 if (now - last_gc < ip_rt_gc_min_interval &&
905 entries < ip_rt_max_size) {
906 RT_CACHE_STAT_INC(gc_ignored);
907 goto out;
908 }
909
910 entries = dst_entries_get_slow(&ipv4_dst_ops);
911 /* Calculate number of entries, which we want to expire now. */
912 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
913 if (goal <= 0) {
914 if (equilibrium < ipv4_dst_ops.gc_thresh)
915 equilibrium = ipv4_dst_ops.gc_thresh;
916 goal = entries - equilibrium;
917 if (goal > 0) {
918 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
919 goal = entries - equilibrium;
920 }
921 } else {
922 /* We are in dangerous area. Try to reduce cache really
923 * aggressively.
924 */
925 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
926 equilibrium = entries - goal;
927 }
928
929 if (now - last_gc >= ip_rt_gc_min_interval)
930 last_gc = now;
931
932 if (goal <= 0) {
933 equilibrium += goal;
934 goto work_done;
935 }
936
937 do {
938 int i, k;
939
940 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
941 unsigned long tmo = expire;
942
943 k = (k + 1) & rt_hash_mask;
944 rthp = &rt_hash_table[k].chain;
945 spin_lock_bh(rt_hash_lock_addr(k));
946 while ((rth = rcu_dereference_protected(*rthp,
947 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
948 if (!rt_is_expired(rth) &&
949 !rt_may_expire(rth, tmo, expire)) {
950 tmo >>= 1;
951 rthp = &rth->dst.rt_next;
952 continue;
953 }
954 *rthp = rth->dst.rt_next;
955 rt_free(rth);
956 goal--;
957 }
958 spin_unlock_bh(rt_hash_lock_addr(k));
959 if (goal <= 0)
960 break;
961 }
962 rover = k;
963
964 if (goal <= 0)
965 goto work_done;
966
967 /* Goal is not achieved. We stop process if:
968
969 - if expire reduced to zero. Otherwise, expire is halfed.
970 - if table is not full.
971 - if we are called from interrupt.
972 - jiffies check is just fallback/debug loop breaker.
973 We will not spin here for long time in any case.
974 */
975
976 RT_CACHE_STAT_INC(gc_goal_miss);
977
978 if (expire == 0)
979 break;
980
981 expire >>= 1;
982
983 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
984 goto out;
985 } while (!in_softirq() && time_before_eq(jiffies, now));
986
987 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
988 goto out;
989 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
990 goto out;
991 if (net_ratelimit())
992 printk(KERN_WARNING "dst cache overflow\n");
993 RT_CACHE_STAT_INC(gc_dst_overflow);
994 return 1;
995
996work_done:
997 expire += ip_rt_gc_min_interval;
998 if (expire > ip_rt_gc_timeout ||
999 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1000 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1001 expire = ip_rt_gc_timeout;
1002out: return 0;
1003}
1004
1005/*
1006 * Returns number of entries in a hash chain that have different hash_inputs
1007 */
1008static int slow_chain_length(const struct rtable *head)
1009{
1010 int length = 0;
1011 const struct rtable *rth = head;
1012
1013 while (rth) {
1014 length += has_noalias(head, rth);
1015 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1016 }
1017 return length >> FRACT_BITS;
1018}
1019
1020static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1021{
1022 struct neigh_table *tbl = &arp_tbl;
1023 static const __be32 inaddr_any = 0;
1024 struct net_device *dev = dst->dev;
1025 const __be32 *pkey = daddr;
1026 struct neighbour *n;
1027
1028#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1029 if (dev->type == ARPHRD_ATM)
1030 tbl = clip_tbl_hook;
1031#endif
1032 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1033 pkey = &inaddr_any;
1034
1035 n = __ipv4_neigh_lookup(tbl, dev, *(__force u32 *)pkey);
1036 if (n)
1037 return n;
1038 return neigh_create(tbl, pkey, dev);
1039}
1040
1041static int rt_bind_neighbour(struct rtable *rt)
1042{
1043 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1044 if (IS_ERR(n))
1045 return PTR_ERR(n);
1046 dst_set_neighbour(&rt->dst, n);
1047
1048 return 0;
1049}
1050
1051static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1052 struct sk_buff *skb, int ifindex)
1053{
1054 struct rtable *rth, *cand;
1055 struct rtable __rcu **rthp, **candp;
1056 unsigned long now;
1057 u32 min_score;
1058 int chain_length;
1059 int attempts = !in_softirq();
1060
1061restart:
1062 chain_length = 0;
1063 min_score = ~(u32)0;
1064 cand = NULL;
1065 candp = NULL;
1066 now = jiffies;
1067
1068 if (!rt_caching(dev_net(rt->dst.dev))) {
1069 /*
1070 * If we're not caching, just tell the caller we
1071 * were successful and don't touch the route. The
1072 * caller hold the sole reference to the cache entry, and
1073 * it will be released when the caller is done with it.
1074 * If we drop it here, the callers have no way to resolve routes
1075 * when we're not caching. Instead, just point *rp at rt, so
1076 * the caller gets a single use out of the route
1077 * Note that we do rt_free on this new route entry, so that
1078 * once its refcount hits zero, we are still able to reap it
1079 * (Thanks Alexey)
1080 * Note: To avoid expensive rcu stuff for this uncached dst,
1081 * we set DST_NOCACHE so that dst_release() can free dst without
1082 * waiting a grace period.
1083 */
1084
1085 rt->dst.flags |= DST_NOCACHE;
1086 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1087 int err = rt_bind_neighbour(rt);
1088 if (err) {
1089 if (net_ratelimit())
1090 printk(KERN_WARNING
1091 "Neighbour table failure & not caching routes.\n");
1092 ip_rt_put(rt);
1093 return ERR_PTR(err);
1094 }
1095 }
1096
1097 goto skip_hashing;
1098 }
1099
1100 rthp = &rt_hash_table[hash].chain;
1101
1102 spin_lock_bh(rt_hash_lock_addr(hash));
1103 while ((rth = rcu_dereference_protected(*rthp,
1104 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1105 if (rt_is_expired(rth)) {
1106 *rthp = rth->dst.rt_next;
1107 rt_free(rth);
1108 continue;
1109 }
1110 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1111 /* Put it first */
1112 *rthp = rth->dst.rt_next;
1113 /*
1114 * Since lookup is lockfree, the deletion
1115 * must be visible to another weakly ordered CPU before
1116 * the insertion at the start of the hash chain.
1117 */
1118 rcu_assign_pointer(rth->dst.rt_next,
1119 rt_hash_table[hash].chain);
1120 /*
1121 * Since lookup is lockfree, the update writes
1122 * must be ordered for consistency on SMP.
1123 */
1124 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1125
1126 dst_use(&rth->dst, now);
1127 spin_unlock_bh(rt_hash_lock_addr(hash));
1128
1129 rt_drop(rt);
1130 if (skb)
1131 skb_dst_set(skb, &rth->dst);
1132 return rth;
1133 }
1134
1135 if (!atomic_read(&rth->dst.__refcnt)) {
1136 u32 score = rt_score(rth);
1137
1138 if (score <= min_score) {
1139 cand = rth;
1140 candp = rthp;
1141 min_score = score;
1142 }
1143 }
1144
1145 chain_length++;
1146
1147 rthp = &rth->dst.rt_next;
1148 }
1149
1150 if (cand) {
1151 /* ip_rt_gc_elasticity used to be average length of chain
1152 * length, when exceeded gc becomes really aggressive.
1153 *
1154 * The second limit is less certain. At the moment it allows
1155 * only 2 entries per bucket. We will see.
1156 */
1157 if (chain_length > ip_rt_gc_elasticity) {
1158 *candp = cand->dst.rt_next;
1159 rt_free(cand);
1160 }
1161 } else {
1162 if (chain_length > rt_chain_length_max &&
1163 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1164 struct net *net = dev_net(rt->dst.dev);
1165 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1166 if (!rt_caching(net)) {
1167 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1168 rt->dst.dev->name, num);
1169 }
1170 rt_emergency_hash_rebuild(net);
1171 spin_unlock_bh(rt_hash_lock_addr(hash));
1172
1173 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1174 ifindex, rt_genid(net));
1175 goto restart;
1176 }
1177 }
1178
1179 /* Try to bind route to arp only if it is output
1180 route or unicast forwarding path.
1181 */
1182 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1183 int err = rt_bind_neighbour(rt);
1184 if (err) {
1185 spin_unlock_bh(rt_hash_lock_addr(hash));
1186
1187 if (err != -ENOBUFS) {
1188 rt_drop(rt);
1189 return ERR_PTR(err);
1190 }
1191
1192 /* Neighbour tables are full and nothing
1193 can be released. Try to shrink route cache,
1194 it is most likely it holds some neighbour records.
1195 */
1196 if (attempts-- > 0) {
1197 int saved_elasticity = ip_rt_gc_elasticity;
1198 int saved_int = ip_rt_gc_min_interval;
1199 ip_rt_gc_elasticity = 1;
1200 ip_rt_gc_min_interval = 0;
1201 rt_garbage_collect(&ipv4_dst_ops);
1202 ip_rt_gc_min_interval = saved_int;
1203 ip_rt_gc_elasticity = saved_elasticity;
1204 goto restart;
1205 }
1206
1207 if (net_ratelimit())
1208 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1209 rt_drop(rt);
1210 return ERR_PTR(-ENOBUFS);
1211 }
1212 }
1213
1214 rt->dst.rt_next = rt_hash_table[hash].chain;
1215
1216 /*
1217 * Since lookup is lockfree, we must make sure
1218 * previous writes to rt are committed to memory
1219 * before making rt visible to other CPUS.
1220 */
1221 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1222
1223 spin_unlock_bh(rt_hash_lock_addr(hash));
1224
1225skip_hashing:
1226 if (skb)
1227 skb_dst_set(skb, &rt->dst);
1228 return rt;
1229}
1230
1231static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1232
1233static u32 rt_peer_genid(void)
1234{
1235 return atomic_read(&__rt_peer_genid);
1236}
1237
1238void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1239{
1240 struct inet_peer *peer;
1241
1242 peer = inet_getpeer_v4(daddr, create);
1243
1244 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1245 inet_putpeer(peer);
1246 else
1247 rt->rt_peer_genid = rt_peer_genid();
1248}
1249
1250/*
1251 * Peer allocation may fail only in serious out-of-memory conditions. However
1252 * we still can generate some output.
1253 * Random ID selection looks a bit dangerous because we have no chances to
1254 * select ID being unique in a reasonable period of time.
1255 * But broken packet identifier may be better than no packet at all.
1256 */
1257static void ip_select_fb_ident(struct iphdr *iph)
1258{
1259 static DEFINE_SPINLOCK(ip_fb_id_lock);
1260 static u32 ip_fallback_id;
1261 u32 salt;
1262
1263 spin_lock_bh(&ip_fb_id_lock);
1264 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1265 iph->id = htons(salt & 0xFFFF);
1266 ip_fallback_id = salt;
1267 spin_unlock_bh(&ip_fb_id_lock);
1268}
1269
1270void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1271{
1272 struct rtable *rt = (struct rtable *) dst;
1273
1274 if (rt) {
1275 if (rt->peer == NULL)
1276 rt_bind_peer(rt, rt->rt_dst, 1);
1277
1278 /* If peer is attached to destination, it is never detached,
1279 so that we need not to grab a lock to dereference it.
1280 */
1281 if (rt->peer) {
1282 iph->id = htons(inet_getid(rt->peer, more));
1283 return;
1284 }
1285 } else
1286 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1287 __builtin_return_address(0));
1288
1289 ip_select_fb_ident(iph);
1290}
1291EXPORT_SYMBOL(__ip_select_ident);
1292
1293static void rt_del(unsigned hash, struct rtable *rt)
1294{
1295 struct rtable __rcu **rthp;
1296 struct rtable *aux;
1297
1298 rthp = &rt_hash_table[hash].chain;
1299 spin_lock_bh(rt_hash_lock_addr(hash));
1300 ip_rt_put(rt);
1301 while ((aux = rcu_dereference_protected(*rthp,
1302 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1303 if (aux == rt || rt_is_expired(aux)) {
1304 *rthp = aux->dst.rt_next;
1305 rt_free(aux);
1306 continue;
1307 }
1308 rthp = &aux->dst.rt_next;
1309 }
1310 spin_unlock_bh(rt_hash_lock_addr(hash));
1311}
1312
1313static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1314{
1315 struct rtable *rt = (struct rtable *) dst;
1316 __be32 orig_gw = rt->rt_gateway;
1317 struct neighbour *n, *old_n;
1318
1319 dst_confirm(&rt->dst);
1320
1321 rt->rt_gateway = peer->redirect_learned.a4;
1322
1323 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1324 if (IS_ERR(n)) {
1325 rt->rt_gateway = orig_gw;
1326 return;
1327 }
1328 old_n = xchg(&rt->dst._neighbour, n);
1329 if (old_n)
1330 neigh_release(old_n);
1331 if (!(n->nud_state & NUD_VALID)) {
1332 neigh_event_send(n, NULL);
1333 } else {
1334 rt->rt_flags |= RTCF_REDIRECTED;
1335 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1336 }
1337}
1338
1339/* called in rcu_read_lock() section */
1340void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1341 __be32 saddr, struct net_device *dev)
1342{
1343 int s, i;
1344 struct in_device *in_dev = __in_dev_get_rcu(dev);
1345 __be32 skeys[2] = { saddr, 0 };
1346 int ikeys[2] = { dev->ifindex, 0 };
1347 struct inet_peer *peer;
1348 struct net *net;
1349
1350 if (!in_dev)
1351 return;
1352
1353 net = dev_net(dev);
1354 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1355 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1356 ipv4_is_zeronet(new_gw))
1357 goto reject_redirect;
1358
1359 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1360 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1361 goto reject_redirect;
1362 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1363 goto reject_redirect;
1364 } else {
1365 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1366 goto reject_redirect;
1367 }
1368
1369 for (s = 0; s < 2; s++) {
1370 for (i = 0; i < 2; i++) {
1371 unsigned int hash;
1372 struct rtable __rcu **rthp;
1373 struct rtable *rt;
1374
1375 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1376
1377 rthp = &rt_hash_table[hash].chain;
1378
1379 while ((rt = rcu_dereference(*rthp)) != NULL) {
1380 rthp = &rt->dst.rt_next;
1381
1382 if (rt->rt_key_dst != daddr ||
1383 rt->rt_key_src != skeys[s] ||
1384 rt->rt_oif != ikeys[i] ||
1385 rt_is_input_route(rt) ||
1386 rt_is_expired(rt) ||
1387 !net_eq(dev_net(rt->dst.dev), net) ||
1388 rt->dst.error ||
1389 rt->dst.dev != dev ||
1390 rt->rt_gateway != old_gw)
1391 continue;
1392
1393 if (!rt->peer)
1394 rt_bind_peer(rt, rt->rt_dst, 1);
1395
1396 peer = rt->peer;
1397 if (peer) {
1398 if (peer->redirect_learned.a4 != new_gw ||
1399 peer->redirect_genid != redirect_genid) {
1400 peer->redirect_learned.a4 = new_gw;
1401 peer->redirect_genid = redirect_genid;
1402 atomic_inc(&__rt_peer_genid);
1403 }
1404 check_peer_redir(&rt->dst, peer);
1405 }
1406 }
1407 }
1408 }
1409 return;
1410
1411reject_redirect:
1412#ifdef CONFIG_IP_ROUTE_VERBOSE
1413 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1414 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1415 " Advised path = %pI4 -> %pI4\n",
1416 &old_gw, dev->name, &new_gw,
1417 &saddr, &daddr);
1418#endif
1419 ;
1420}
1421
1422static bool peer_pmtu_expired(struct inet_peer *peer)
1423{
1424 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1425
1426 return orig &&
1427 time_after_eq(jiffies, orig) &&
1428 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1429}
1430
1431static bool peer_pmtu_cleaned(struct inet_peer *peer)
1432{
1433 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1434
1435 return orig &&
1436 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1437}
1438
1439static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1440{
1441 struct rtable *rt = (struct rtable *)dst;
1442 struct dst_entry *ret = dst;
1443
1444 if (rt) {
1445 if (dst->obsolete > 0) {
1446 ip_rt_put(rt);
1447 ret = NULL;
1448 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1449 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1450 rt->rt_oif,
1451 rt_genid(dev_net(dst->dev)));
1452 rt_del(hash, rt);
1453 ret = NULL;
1454 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1455 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1456 }
1457 }
1458 return ret;
1459}
1460
1461/*
1462 * Algorithm:
1463 * 1. The first ip_rt_redirect_number redirects are sent
1464 * with exponential backoff, then we stop sending them at all,
1465 * assuming that the host ignores our redirects.
1466 * 2. If we did not see packets requiring redirects
1467 * during ip_rt_redirect_silence, we assume that the host
1468 * forgot redirected route and start to send redirects again.
1469 *
1470 * This algorithm is much cheaper and more intelligent than dumb load limiting
1471 * in icmp.c.
1472 *
1473 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1474 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1475 */
1476
1477void ip_rt_send_redirect(struct sk_buff *skb)
1478{
1479 struct rtable *rt = skb_rtable(skb);
1480 struct in_device *in_dev;
1481 struct inet_peer *peer;
1482 int log_martians;
1483
1484 rcu_read_lock();
1485 in_dev = __in_dev_get_rcu(rt->dst.dev);
1486 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1487 rcu_read_unlock();
1488 return;
1489 }
1490 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1491 rcu_read_unlock();
1492
1493 if (!rt->peer)
1494 rt_bind_peer(rt, rt->rt_dst, 1);
1495 peer = rt->peer;
1496 if (!peer) {
1497 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1498 return;
1499 }
1500
1501 /* No redirected packets during ip_rt_redirect_silence;
1502 * reset the algorithm.
1503 */
1504 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1505 peer->rate_tokens = 0;
1506
1507 /* Too many ignored redirects; do not send anything
1508 * set dst.rate_last to the last seen redirected packet.
1509 */
1510 if (peer->rate_tokens >= ip_rt_redirect_number) {
1511 peer->rate_last = jiffies;
1512 return;
1513 }
1514
1515 /* Check for load limit; set rate_last to the latest sent
1516 * redirect.
1517 */
1518 if (peer->rate_tokens == 0 ||
1519 time_after(jiffies,
1520 (peer->rate_last +
1521 (ip_rt_redirect_load << peer->rate_tokens)))) {
1522 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1523 peer->rate_last = jiffies;
1524 ++peer->rate_tokens;
1525#ifdef CONFIG_IP_ROUTE_VERBOSE
1526 if (log_martians &&
1527 peer->rate_tokens == ip_rt_redirect_number &&
1528 net_ratelimit())
1529 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1530 &ip_hdr(skb)->saddr, rt->rt_iif,
1531 &rt->rt_dst, &rt->rt_gateway);
1532#endif
1533 }
1534}
1535
1536static int ip_error(struct sk_buff *skb)
1537{
1538 struct rtable *rt = skb_rtable(skb);
1539 struct inet_peer *peer;
1540 unsigned long now;
1541 bool send;
1542 int code;
1543
1544 switch (rt->dst.error) {
1545 case EINVAL:
1546 default:
1547 goto out;
1548 case EHOSTUNREACH:
1549 code = ICMP_HOST_UNREACH;
1550 break;
1551 case ENETUNREACH:
1552 code = ICMP_NET_UNREACH;
1553 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1554 IPSTATS_MIB_INNOROUTES);
1555 break;
1556 case EACCES:
1557 code = ICMP_PKT_FILTERED;
1558 break;
1559 }
1560
1561 if (!rt->peer)
1562 rt_bind_peer(rt, rt->rt_dst, 1);
1563 peer = rt->peer;
1564
1565 send = true;
1566 if (peer) {
1567 now = jiffies;
1568 peer->rate_tokens += now - peer->rate_last;
1569 if (peer->rate_tokens > ip_rt_error_burst)
1570 peer->rate_tokens = ip_rt_error_burst;
1571 peer->rate_last = now;
1572 if (peer->rate_tokens >= ip_rt_error_cost)
1573 peer->rate_tokens -= ip_rt_error_cost;
1574 else
1575 send = false;
1576 }
1577 if (send)
1578 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1579
1580out: kfree_skb(skb);
1581 return 0;
1582}
1583
1584/*
1585 * The last two values are not from the RFC but
1586 * are needed for AMPRnet AX.25 paths.
1587 */
1588
1589static const unsigned short mtu_plateau[] =
1590{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1591
1592static inline unsigned short guess_mtu(unsigned short old_mtu)
1593{
1594 int i;
1595
1596 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1597 if (old_mtu > mtu_plateau[i])
1598 return mtu_plateau[i];
1599 return 68;
1600}
1601
1602unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1603 unsigned short new_mtu,
1604 struct net_device *dev)
1605{
1606 unsigned short old_mtu = ntohs(iph->tot_len);
1607 unsigned short est_mtu = 0;
1608 struct inet_peer *peer;
1609
1610 peer = inet_getpeer_v4(iph->daddr, 1);
1611 if (peer) {
1612 unsigned short mtu = new_mtu;
1613
1614 if (new_mtu < 68 || new_mtu >= old_mtu) {
1615 /* BSD 4.2 derived systems incorrectly adjust
1616 * tot_len by the IP header length, and report
1617 * a zero MTU in the ICMP message.
1618 */
1619 if (mtu == 0 &&
1620 old_mtu >= 68 + (iph->ihl << 2))
1621 old_mtu -= iph->ihl << 2;
1622 mtu = guess_mtu(old_mtu);
1623 }
1624
1625 if (mtu < ip_rt_min_pmtu)
1626 mtu = ip_rt_min_pmtu;
1627 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1628 unsigned long pmtu_expires;
1629
1630 pmtu_expires = jiffies + ip_rt_mtu_expires;
1631 if (!pmtu_expires)
1632 pmtu_expires = 1UL;
1633
1634 est_mtu = mtu;
1635 peer->pmtu_learned = mtu;
1636 peer->pmtu_expires = pmtu_expires;
1637 atomic_inc(&__rt_peer_genid);
1638 }
1639
1640 inet_putpeer(peer);
1641 }
1642 return est_mtu ? : new_mtu;
1643}
1644
1645static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1646{
1647 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1648
1649 if (!expires)
1650 return;
1651 if (time_before(jiffies, expires)) {
1652 u32 orig_dst_mtu = dst_mtu(dst);
1653 if (peer->pmtu_learned < orig_dst_mtu) {
1654 if (!peer->pmtu_orig)
1655 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1656 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1657 }
1658 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1659 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1660}
1661
1662static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1663{
1664 struct rtable *rt = (struct rtable *) dst;
1665 struct inet_peer *peer;
1666
1667 dst_confirm(dst);
1668
1669 if (!rt->peer)
1670 rt_bind_peer(rt, rt->rt_dst, 1);
1671 peer = rt->peer;
1672 if (peer) {
1673 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1674
1675 if (mtu < ip_rt_min_pmtu)
1676 mtu = ip_rt_min_pmtu;
1677 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1678
1679 pmtu_expires = jiffies + ip_rt_mtu_expires;
1680 if (!pmtu_expires)
1681 pmtu_expires = 1UL;
1682
1683 peer->pmtu_learned = mtu;
1684 peer->pmtu_expires = pmtu_expires;
1685
1686 atomic_inc(&__rt_peer_genid);
1687 rt->rt_peer_genid = rt_peer_genid();
1688 }
1689 check_peer_pmtu(dst, peer);
1690 }
1691}
1692
1693
1694static void ipv4_validate_peer(struct rtable *rt)
1695{
1696 if (rt->rt_peer_genid != rt_peer_genid()) {
1697 struct inet_peer *peer;
1698
1699 if (!rt->peer)
1700 rt_bind_peer(rt, rt->rt_dst, 0);
1701
1702 peer = rt->peer;
1703 if (peer) {
1704 check_peer_pmtu(&rt->dst, peer);
1705
1706 if (peer->redirect_genid != redirect_genid)
1707 peer->redirect_learned.a4 = 0;
1708 if (peer->redirect_learned.a4 &&
1709 peer->redirect_learned.a4 != rt->rt_gateway)
1710 check_peer_redir(&rt->dst, peer);
1711 }
1712
1713 rt->rt_peer_genid = rt_peer_genid();
1714 }
1715}
1716
1717static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1718{
1719 struct rtable *rt = (struct rtable *) dst;
1720
1721 if (rt_is_expired(rt))
1722 return NULL;
1723 ipv4_validate_peer(rt);
1724 return dst;
1725}
1726
1727static void ipv4_dst_destroy(struct dst_entry *dst)
1728{
1729 struct rtable *rt = (struct rtable *) dst;
1730 struct inet_peer *peer = rt->peer;
1731
1732 if (rt->fi) {
1733 fib_info_put(rt->fi);
1734 rt->fi = NULL;
1735 }
1736 if (peer) {
1737 rt->peer = NULL;
1738 inet_putpeer(peer);
1739 }
1740}
1741
1742
1743static void ipv4_link_failure(struct sk_buff *skb)
1744{
1745 struct rtable *rt;
1746
1747 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1748
1749 rt = skb_rtable(skb);
1750 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1751 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1752}
1753
1754static int ip_rt_bug(struct sk_buff *skb)
1755{
1756 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1757 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1758 skb->dev ? skb->dev->name : "?");
1759 kfree_skb(skb);
1760 WARN_ON(1);
1761 return 0;
1762}
1763
1764/*
1765 We do not cache source address of outgoing interface,
1766 because it is used only by IP RR, TS and SRR options,
1767 so that it out of fast path.
1768
1769 BTW remember: "addr" is allowed to be not aligned
1770 in IP options!
1771 */
1772
1773void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1774{
1775 __be32 src;
1776
1777 if (rt_is_output_route(rt))
1778 src = ip_hdr(skb)->saddr;
1779 else {
1780 struct fib_result res;
1781 struct flowi4 fl4;
1782 struct iphdr *iph;
1783
1784 iph = ip_hdr(skb);
1785
1786 memset(&fl4, 0, sizeof(fl4));
1787 fl4.daddr = iph->daddr;
1788 fl4.saddr = iph->saddr;
1789 fl4.flowi4_tos = RT_TOS(iph->tos);
1790 fl4.flowi4_oif = rt->dst.dev->ifindex;
1791 fl4.flowi4_iif = skb->dev->ifindex;
1792 fl4.flowi4_mark = skb->mark;
1793
1794 rcu_read_lock();
1795 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1796 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1797 else
1798 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1799 RT_SCOPE_UNIVERSE);
1800 rcu_read_unlock();
1801 }
1802 memcpy(addr, &src, 4);
1803}
1804
1805#ifdef CONFIG_IP_ROUTE_CLASSID
1806static void set_class_tag(struct rtable *rt, u32 tag)
1807{
1808 if (!(rt->dst.tclassid & 0xFFFF))
1809 rt->dst.tclassid |= tag & 0xFFFF;
1810 if (!(rt->dst.tclassid & 0xFFFF0000))
1811 rt->dst.tclassid |= tag & 0xFFFF0000;
1812}
1813#endif
1814
1815static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1816{
1817 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1818
1819 if (advmss == 0) {
1820 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1821 ip_rt_min_advmss);
1822 if (advmss > 65535 - 40)
1823 advmss = 65535 - 40;
1824 }
1825 return advmss;
1826}
1827
1828static unsigned int ipv4_mtu(const struct dst_entry *dst)
1829{
1830 const struct rtable *rt = (const struct rtable *) dst;
1831 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1832
1833 if (mtu && rt_is_output_route(rt))
1834 return mtu;
1835
1836 mtu = dst->dev->mtu;
1837
1838 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1839
1840 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1841 mtu = 576;
1842 }
1843
1844 if (mtu > IP_MAX_MTU)
1845 mtu = IP_MAX_MTU;
1846
1847 return mtu;
1848}
1849
1850static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1851 struct fib_info *fi)
1852{
1853 struct inet_peer *peer;
1854 int create = 0;
1855
1856 /* If a peer entry exists for this destination, we must hook
1857 * it up in order to get at cached metrics.
1858 */
1859 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1860 create = 1;
1861
1862 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1863 if (peer) {
1864 rt->rt_peer_genid = rt_peer_genid();
1865 if (inet_metrics_new(peer))
1866 memcpy(peer->metrics, fi->fib_metrics,
1867 sizeof(u32) * RTAX_MAX);
1868 dst_init_metrics(&rt->dst, peer->metrics, false);
1869
1870 check_peer_pmtu(&rt->dst, peer);
1871 if (peer->redirect_genid != redirect_genid)
1872 peer->redirect_learned.a4 = 0;
1873 if (peer->redirect_learned.a4 &&
1874 peer->redirect_learned.a4 != rt->rt_gateway) {
1875 rt->rt_gateway = peer->redirect_learned.a4;
1876 rt->rt_flags |= RTCF_REDIRECTED;
1877 }
1878 } else {
1879 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1880 rt->fi = fi;
1881 atomic_inc(&fi->fib_clntref);
1882 }
1883 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1884 }
1885}
1886
1887static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1888 const struct fib_result *res,
1889 struct fib_info *fi, u16 type, u32 itag)
1890{
1891 struct dst_entry *dst = &rt->dst;
1892
1893 if (fi) {
1894 if (FIB_RES_GW(*res) &&
1895 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1896 rt->rt_gateway = FIB_RES_GW(*res);
1897 rt_init_metrics(rt, fl4, fi);
1898#ifdef CONFIG_IP_ROUTE_CLASSID
1899 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1900#endif
1901 }
1902
1903 if (dst_mtu(dst) > IP_MAX_MTU)
1904 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1905 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1906 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1907
1908#ifdef CONFIG_IP_ROUTE_CLASSID
1909#ifdef CONFIG_IP_MULTIPLE_TABLES
1910 set_class_tag(rt, fib_rules_tclass(res));
1911#endif
1912 set_class_tag(rt, itag);
1913#endif
1914}
1915
1916static struct rtable *rt_dst_alloc(struct net_device *dev,
1917 bool nopolicy, bool noxfrm)
1918{
1919 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1920 DST_HOST |
1921 (nopolicy ? DST_NOPOLICY : 0) |
1922 (noxfrm ? DST_NOXFRM : 0));
1923}
1924
1925/* called in rcu_read_lock() section */
1926static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1927 u8 tos, struct net_device *dev, int our)
1928{
1929 unsigned int hash;
1930 struct rtable *rth;
1931 __be32 spec_dst;
1932 struct in_device *in_dev = __in_dev_get_rcu(dev);
1933 u32 itag = 0;
1934 int err;
1935
1936 /* Primary sanity checks. */
1937
1938 if (in_dev == NULL)
1939 return -EINVAL;
1940
1941 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1942 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1943 goto e_inval;
1944
1945 if (ipv4_is_zeronet(saddr)) {
1946 if (!ipv4_is_local_multicast(daddr))
1947 goto e_inval;
1948 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1949 } else {
1950 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1951 &itag);
1952 if (err < 0)
1953 goto e_err;
1954 }
1955 rth = rt_dst_alloc(init_net.loopback_dev,
1956 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1957 if (!rth)
1958 goto e_nobufs;
1959
1960#ifdef CONFIG_IP_ROUTE_CLASSID
1961 rth->dst.tclassid = itag;
1962#endif
1963 rth->dst.output = ip_rt_bug;
1964
1965 rth->rt_key_dst = daddr;
1966 rth->rt_key_src = saddr;
1967 rth->rt_genid = rt_genid(dev_net(dev));
1968 rth->rt_flags = RTCF_MULTICAST;
1969 rth->rt_type = RTN_MULTICAST;
1970 rth->rt_key_tos = tos;
1971 rth->rt_dst = daddr;
1972 rth->rt_src = saddr;
1973 rth->rt_route_iif = dev->ifindex;
1974 rth->rt_iif = dev->ifindex;
1975 rth->rt_oif = 0;
1976 rth->rt_mark = skb->mark;
1977 rth->rt_gateway = daddr;
1978 rth->rt_spec_dst= spec_dst;
1979 rth->rt_peer_genid = 0;
1980 rth->peer = NULL;
1981 rth->fi = NULL;
1982 if (our) {
1983 rth->dst.input= ip_local_deliver;
1984 rth->rt_flags |= RTCF_LOCAL;
1985 }
1986
1987#ifdef CONFIG_IP_MROUTE
1988 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1989 rth->dst.input = ip_mr_input;
1990#endif
1991 RT_CACHE_STAT_INC(in_slow_mc);
1992
1993 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1994 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1995 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
1996
1997e_nobufs:
1998 return -ENOBUFS;
1999e_inval:
2000 return -EINVAL;
2001e_err:
2002 return err;
2003}
2004
2005
2006static void ip_handle_martian_source(struct net_device *dev,
2007 struct in_device *in_dev,
2008 struct sk_buff *skb,
2009 __be32 daddr,
2010 __be32 saddr)
2011{
2012 RT_CACHE_STAT_INC(in_martian_src);
2013#ifdef CONFIG_IP_ROUTE_VERBOSE
2014 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2015 /*
2016 * RFC1812 recommendation, if source is martian,
2017 * the only hint is MAC header.
2018 */
2019 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2020 &daddr, &saddr, dev->name);
2021 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2022 int i;
2023 const unsigned char *p = skb_mac_header(skb);
2024 printk(KERN_WARNING "ll header: ");
2025 for (i = 0; i < dev->hard_header_len; i++, p++) {
2026 printk("%02x", *p);
2027 if (i < (dev->hard_header_len - 1))
2028 printk(":");
2029 }
2030 printk("\n");
2031 }
2032 }
2033#endif
2034}
2035
2036/* called in rcu_read_lock() section */
2037static int __mkroute_input(struct sk_buff *skb,
2038 const struct fib_result *res,
2039 struct in_device *in_dev,
2040 __be32 daddr, __be32 saddr, u32 tos,
2041 struct rtable **result)
2042{
2043 struct rtable *rth;
2044 int err;
2045 struct in_device *out_dev;
2046 unsigned int flags = 0;
2047 __be32 spec_dst;
2048 u32 itag;
2049
2050 /* get a working reference to the output device */
2051 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2052 if (out_dev == NULL) {
2053 if (net_ratelimit())
2054 printk(KERN_CRIT "Bug in ip_route_input" \
2055 "_slow(). Please, report\n");
2056 return -EINVAL;
2057 }
2058
2059
2060 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2061 in_dev->dev, &spec_dst, &itag);
2062 if (err < 0) {
2063 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2064 saddr);
2065
2066 goto cleanup;
2067 }
2068
2069 if (err)
2070 flags |= RTCF_DIRECTSRC;
2071
2072 if (out_dev == in_dev && err &&
2073 (IN_DEV_SHARED_MEDIA(out_dev) ||
2074 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2075 flags |= RTCF_DOREDIRECT;
2076
2077 if (skb->protocol != htons(ETH_P_IP)) {
2078 /* Not IP (i.e. ARP). Do not create route, if it is
2079 * invalid for proxy arp. DNAT routes are always valid.
2080 *
2081 * Proxy arp feature have been extended to allow, ARP
2082 * replies back to the same interface, to support
2083 * Private VLAN switch technologies. See arp.c.
2084 */
2085 if (out_dev == in_dev &&
2086 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2087 err = -EINVAL;
2088 goto cleanup;
2089 }
2090 }
2091
2092 rth = rt_dst_alloc(out_dev->dev,
2093 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2094 IN_DEV_CONF_GET(out_dev, NOXFRM));
2095 if (!rth) {
2096 err = -ENOBUFS;
2097 goto cleanup;
2098 }
2099
2100 rth->rt_key_dst = daddr;
2101 rth->rt_key_src = saddr;
2102 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2103 rth->rt_flags = flags;
2104 rth->rt_type = res->type;
2105 rth->rt_key_tos = tos;
2106 rth->rt_dst = daddr;
2107 rth->rt_src = saddr;
2108 rth->rt_route_iif = in_dev->dev->ifindex;
2109 rth->rt_iif = in_dev->dev->ifindex;
2110 rth->rt_oif = 0;
2111 rth->rt_mark = skb->mark;
2112 rth->rt_gateway = daddr;
2113 rth->rt_spec_dst= spec_dst;
2114 rth->rt_peer_genid = 0;
2115 rth->peer = NULL;
2116 rth->fi = NULL;
2117
2118 rth->dst.input = ip_forward;
2119 rth->dst.output = ip_output;
2120
2121 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2122
2123 *result = rth;
2124 err = 0;
2125 cleanup:
2126 return err;
2127}
2128
2129static int ip_mkroute_input(struct sk_buff *skb,
2130 struct fib_result *res,
2131 const struct flowi4 *fl4,
2132 struct in_device *in_dev,
2133 __be32 daddr, __be32 saddr, u32 tos)
2134{
2135 struct rtable* rth = NULL;
2136 int err;
2137 unsigned hash;
2138
2139#ifdef CONFIG_IP_ROUTE_MULTIPATH
2140 if (res->fi && res->fi->fib_nhs > 1)
2141 fib_select_multipath(res);
2142#endif
2143
2144 /* create a routing cache entry */
2145 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2146 if (err)
2147 return err;
2148
2149 /* put it into the cache */
2150 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2151 rt_genid(dev_net(rth->dst.dev)));
2152 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2153 if (IS_ERR(rth))
2154 return PTR_ERR(rth);
2155 return 0;
2156}
2157
2158/*
2159 * NOTE. We drop all the packets that has local source
2160 * addresses, because every properly looped back packet
2161 * must have correct destination already attached by output routine.
2162 *
2163 * Such approach solves two big problems:
2164 * 1. Not simplex devices are handled properly.
2165 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2166 * called with rcu_read_lock()
2167 */
2168
2169static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2170 u8 tos, struct net_device *dev)
2171{
2172 struct fib_result res;
2173 struct in_device *in_dev = __in_dev_get_rcu(dev);
2174 struct flowi4 fl4;
2175 unsigned flags = 0;
2176 u32 itag = 0;
2177 struct rtable * rth;
2178 unsigned hash;
2179 __be32 spec_dst;
2180 int err = -EINVAL;
2181 struct net * net = dev_net(dev);
2182
2183 /* IP on this device is disabled. */
2184
2185 if (!in_dev)
2186 goto out;
2187
2188 /* Check for the most weird martians, which can be not detected
2189 by fib_lookup.
2190 */
2191
2192 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2193 ipv4_is_loopback(saddr))
2194 goto martian_source;
2195
2196 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2197 goto brd_input;
2198
2199 /* Accept zero addresses only to limited broadcast;
2200 * I even do not know to fix it or not. Waiting for complains :-)
2201 */
2202 if (ipv4_is_zeronet(saddr))
2203 goto martian_source;
2204
2205 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2206 goto martian_destination;
2207
2208 /*
2209 * Now we are ready to route packet.
2210 */
2211 fl4.flowi4_oif = 0;
2212 fl4.flowi4_iif = dev->ifindex;
2213 fl4.flowi4_mark = skb->mark;
2214 fl4.flowi4_tos = tos;
2215 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2216 fl4.daddr = daddr;
2217 fl4.saddr = saddr;
2218 err = fib_lookup(net, &fl4, &res);
2219 if (err != 0) {
2220 if (!IN_DEV_FORWARD(in_dev))
2221 goto e_hostunreach;
2222 goto no_route;
2223 }
2224
2225 RT_CACHE_STAT_INC(in_slow_tot);
2226
2227 if (res.type == RTN_BROADCAST)
2228 goto brd_input;
2229
2230 if (res.type == RTN_LOCAL) {
2231 err = fib_validate_source(skb, saddr, daddr, tos,
2232 net->loopback_dev->ifindex,
2233 dev, &spec_dst, &itag);
2234 if (err < 0)
2235 goto martian_source_keep_err;
2236 if (err)
2237 flags |= RTCF_DIRECTSRC;
2238 spec_dst = daddr;
2239 goto local_input;
2240 }
2241
2242 if (!IN_DEV_FORWARD(in_dev))
2243 goto e_hostunreach;
2244 if (res.type != RTN_UNICAST)
2245 goto martian_destination;
2246
2247 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2248out: return err;
2249
2250brd_input:
2251 if (skb->protocol != htons(ETH_P_IP))
2252 goto e_inval;
2253
2254 if (ipv4_is_zeronet(saddr))
2255 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2256 else {
2257 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2258 &itag);
2259 if (err < 0)
2260 goto martian_source_keep_err;
2261 if (err)
2262 flags |= RTCF_DIRECTSRC;
2263 }
2264 flags |= RTCF_BROADCAST;
2265 res.type = RTN_BROADCAST;
2266 RT_CACHE_STAT_INC(in_brd);
2267
2268local_input:
2269 rth = rt_dst_alloc(net->loopback_dev,
2270 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2271 if (!rth)
2272 goto e_nobufs;
2273
2274 rth->dst.input= ip_local_deliver;
2275 rth->dst.output= ip_rt_bug;
2276#ifdef CONFIG_IP_ROUTE_CLASSID
2277 rth->dst.tclassid = itag;
2278#endif
2279
2280 rth->rt_key_dst = daddr;
2281 rth->rt_key_src = saddr;
2282 rth->rt_genid = rt_genid(net);
2283 rth->rt_flags = flags|RTCF_LOCAL;
2284 rth->rt_type = res.type;
2285 rth->rt_key_tos = tos;
2286 rth->rt_dst = daddr;
2287 rth->rt_src = saddr;
2288#ifdef CONFIG_IP_ROUTE_CLASSID
2289 rth->dst.tclassid = itag;
2290#endif
2291 rth->rt_route_iif = dev->ifindex;
2292 rth->rt_iif = dev->ifindex;
2293 rth->rt_oif = 0;
2294 rth->rt_mark = skb->mark;
2295 rth->rt_gateway = daddr;
2296 rth->rt_spec_dst= spec_dst;
2297 rth->rt_peer_genid = 0;
2298 rth->peer = NULL;
2299 rth->fi = NULL;
2300 if (res.type == RTN_UNREACHABLE) {
2301 rth->dst.input= ip_error;
2302 rth->dst.error= -err;
2303 rth->rt_flags &= ~RTCF_LOCAL;
2304 }
2305 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2306 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2307 err = 0;
2308 if (IS_ERR(rth))
2309 err = PTR_ERR(rth);
2310 goto out;
2311
2312no_route:
2313 RT_CACHE_STAT_INC(in_no_route);
2314 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2315 res.type = RTN_UNREACHABLE;
2316 if (err == -ESRCH)
2317 err = -ENETUNREACH;
2318 goto local_input;
2319
2320 /*
2321 * Do not cache martian addresses: they should be logged (RFC1812)
2322 */
2323martian_destination:
2324 RT_CACHE_STAT_INC(in_martian_dst);
2325#ifdef CONFIG_IP_ROUTE_VERBOSE
2326 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2327 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2328 &daddr, &saddr, dev->name);
2329#endif
2330
2331e_hostunreach:
2332 err = -EHOSTUNREACH;
2333 goto out;
2334
2335e_inval:
2336 err = -EINVAL;
2337 goto out;
2338
2339e_nobufs:
2340 err = -ENOBUFS;
2341 goto out;
2342
2343martian_source:
2344 err = -EINVAL;
2345martian_source_keep_err:
2346 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2347 goto out;
2348}
2349
2350int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2351 u8 tos, struct net_device *dev, bool noref)
2352{
2353 struct rtable * rth;
2354 unsigned hash;
2355 int iif = dev->ifindex;
2356 struct net *net;
2357 int res;
2358
2359 net = dev_net(dev);
2360
2361 rcu_read_lock();
2362
2363 if (!rt_caching(net))
2364 goto skip_cache;
2365
2366 tos &= IPTOS_RT_MASK;
2367 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2368
2369 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2370 rth = rcu_dereference(rth->dst.rt_next)) {
2371 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2372 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2373 (rth->rt_route_iif ^ iif) |
2374 (rth->rt_key_tos ^ tos)) == 0 &&
2375 rth->rt_mark == skb->mark &&
2376 net_eq(dev_net(rth->dst.dev), net) &&
2377 !rt_is_expired(rth)) {
2378 ipv4_validate_peer(rth);
2379 if (noref) {
2380 dst_use_noref(&rth->dst, jiffies);
2381 skb_dst_set_noref(skb, &rth->dst);
2382 } else {
2383 dst_use(&rth->dst, jiffies);
2384 skb_dst_set(skb, &rth->dst);
2385 }
2386 RT_CACHE_STAT_INC(in_hit);
2387 rcu_read_unlock();
2388 return 0;
2389 }
2390 RT_CACHE_STAT_INC(in_hlist_search);
2391 }
2392
2393skip_cache:
2394 /* Multicast recognition logic is moved from route cache to here.
2395 The problem was that too many Ethernet cards have broken/missing
2396 hardware multicast filters :-( As result the host on multicasting
2397 network acquires a lot of useless route cache entries, sort of
2398 SDR messages from all the world. Now we try to get rid of them.
2399 Really, provided software IP multicast filter is organized
2400 reasonably (at least, hashed), it does not result in a slowdown
2401 comparing with route cache reject entries.
2402 Note, that multicast routers are not affected, because
2403 route cache entry is created eventually.
2404 */
2405 if (ipv4_is_multicast(daddr)) {
2406 struct in_device *in_dev = __in_dev_get_rcu(dev);
2407
2408 if (in_dev) {
2409 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2410 ip_hdr(skb)->protocol);
2411 if (our
2412#ifdef CONFIG_IP_MROUTE
2413 ||
2414 (!ipv4_is_local_multicast(daddr) &&
2415 IN_DEV_MFORWARD(in_dev))
2416#endif
2417 ) {
2418 int res = ip_route_input_mc(skb, daddr, saddr,
2419 tos, dev, our);
2420 rcu_read_unlock();
2421 return res;
2422 }
2423 }
2424 rcu_read_unlock();
2425 return -EINVAL;
2426 }
2427 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2428 rcu_read_unlock();
2429 return res;
2430}
2431EXPORT_SYMBOL(ip_route_input_common);
2432
2433/* called with rcu_read_lock() */
2434static struct rtable *__mkroute_output(const struct fib_result *res,
2435 const struct flowi4 *fl4,
2436 __be32 orig_daddr, __be32 orig_saddr,
2437 int orig_oif, __u8 orig_rtos,
2438 struct net_device *dev_out,
2439 unsigned int flags)
2440{
2441 struct fib_info *fi = res->fi;
2442 struct in_device *in_dev;
2443 u16 type = res->type;
2444 struct rtable *rth;
2445
2446 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2447 return ERR_PTR(-EINVAL);
2448
2449 if (ipv4_is_lbcast(fl4->daddr))
2450 type = RTN_BROADCAST;
2451 else if (ipv4_is_multicast(fl4->daddr))
2452 type = RTN_MULTICAST;
2453 else if (ipv4_is_zeronet(fl4->daddr))
2454 return ERR_PTR(-EINVAL);
2455
2456 if (dev_out->flags & IFF_LOOPBACK)
2457 flags |= RTCF_LOCAL;
2458
2459 in_dev = __in_dev_get_rcu(dev_out);
2460 if (!in_dev)
2461 return ERR_PTR(-EINVAL);
2462
2463 if (type == RTN_BROADCAST) {
2464 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2465 fi = NULL;
2466 } else if (type == RTN_MULTICAST) {
2467 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2468 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2469 fl4->flowi4_proto))
2470 flags &= ~RTCF_LOCAL;
2471 /* If multicast route do not exist use
2472 * default one, but do not gateway in this case.
2473 * Yes, it is hack.
2474 */
2475 if (fi && res->prefixlen < 4)
2476 fi = NULL;
2477 }
2478
2479 rth = rt_dst_alloc(dev_out,
2480 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2481 IN_DEV_CONF_GET(in_dev, NOXFRM));
2482 if (!rth)
2483 return ERR_PTR(-ENOBUFS);
2484
2485 rth->dst.output = ip_output;
2486
2487 rth->rt_key_dst = orig_daddr;
2488 rth->rt_key_src = orig_saddr;
2489 rth->rt_genid = rt_genid(dev_net(dev_out));
2490 rth->rt_flags = flags;
2491 rth->rt_type = type;
2492 rth->rt_key_tos = orig_rtos;
2493 rth->rt_dst = fl4->daddr;
2494 rth->rt_src = fl4->saddr;
2495 rth->rt_route_iif = 0;
2496 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2497 rth->rt_oif = orig_oif;
2498 rth->rt_mark = fl4->flowi4_mark;
2499 rth->rt_gateway = fl4->daddr;
2500 rth->rt_spec_dst= fl4->saddr;
2501 rth->rt_peer_genid = 0;
2502 rth->peer = NULL;
2503 rth->fi = NULL;
2504
2505 RT_CACHE_STAT_INC(out_slow_tot);
2506
2507 if (flags & RTCF_LOCAL) {
2508 rth->dst.input = ip_local_deliver;
2509 rth->rt_spec_dst = fl4->daddr;
2510 }
2511 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2512 rth->rt_spec_dst = fl4->saddr;
2513 if (flags & RTCF_LOCAL &&
2514 !(dev_out->flags & IFF_LOOPBACK)) {
2515 rth->dst.output = ip_mc_output;
2516 RT_CACHE_STAT_INC(out_slow_mc);
2517 }
2518#ifdef CONFIG_IP_MROUTE
2519 if (type == RTN_MULTICAST) {
2520 if (IN_DEV_MFORWARD(in_dev) &&
2521 !ipv4_is_local_multicast(fl4->daddr)) {
2522 rth->dst.input = ip_mr_input;
2523 rth->dst.output = ip_mc_output;
2524 }
2525 }
2526#endif
2527 }
2528
2529 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2530
2531 return rth;
2532}
2533
2534/*
2535 * Major route resolver routine.
2536 * called with rcu_read_lock();
2537 */
2538
2539static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2540{
2541 struct net_device *dev_out = NULL;
2542 __u8 tos = RT_FL_TOS(fl4);
2543 unsigned int flags = 0;
2544 struct fib_result res;
2545 struct rtable *rth;
2546 __be32 orig_daddr;
2547 __be32 orig_saddr;
2548 int orig_oif;
2549
2550 res.fi = NULL;
2551#ifdef CONFIG_IP_MULTIPLE_TABLES
2552 res.r = NULL;
2553#endif
2554
2555 orig_daddr = fl4->daddr;
2556 orig_saddr = fl4->saddr;
2557 orig_oif = fl4->flowi4_oif;
2558
2559 fl4->flowi4_iif = net->loopback_dev->ifindex;
2560 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2561 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2562 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2563
2564 rcu_read_lock();
2565 if (fl4->saddr) {
2566 rth = ERR_PTR(-EINVAL);
2567 if (ipv4_is_multicast(fl4->saddr) ||
2568 ipv4_is_lbcast(fl4->saddr) ||
2569 ipv4_is_zeronet(fl4->saddr))
2570 goto out;
2571
2572 /* I removed check for oif == dev_out->oif here.
2573 It was wrong for two reasons:
2574 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2575 is assigned to multiple interfaces.
2576 2. Moreover, we are allowed to send packets with saddr
2577 of another iface. --ANK
2578 */
2579
2580 if (fl4->flowi4_oif == 0 &&
2581 (ipv4_is_multicast(fl4->daddr) ||
2582 ipv4_is_lbcast(fl4->daddr))) {
2583 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2584 dev_out = __ip_dev_find(net, fl4->saddr, false);
2585 if (dev_out == NULL)
2586 goto out;
2587
2588 /* Special hack: user can direct multicasts
2589 and limited broadcast via necessary interface
2590 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2591 This hack is not just for fun, it allows
2592 vic,vat and friends to work.
2593 They bind socket to loopback, set ttl to zero
2594 and expect that it will work.
2595 From the viewpoint of routing cache they are broken,
2596 because we are not allowed to build multicast path
2597 with loopback source addr (look, routing cache
2598 cannot know, that ttl is zero, so that packet
2599 will not leave this host and route is valid).
2600 Luckily, this hack is good workaround.
2601 */
2602
2603 fl4->flowi4_oif = dev_out->ifindex;
2604 goto make_route;
2605 }
2606
2607 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2608 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2609 if (!__ip_dev_find(net, fl4->saddr, false))
2610 goto out;
2611 }
2612 }
2613
2614
2615 if (fl4->flowi4_oif) {
2616 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2617 rth = ERR_PTR(-ENODEV);
2618 if (dev_out == NULL)
2619 goto out;
2620
2621 /* RACE: Check return value of inet_select_addr instead. */
2622 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2623 rth = ERR_PTR(-ENETUNREACH);
2624 goto out;
2625 }
2626 if (ipv4_is_local_multicast(fl4->daddr) ||
2627 ipv4_is_lbcast(fl4->daddr)) {
2628 if (!fl4->saddr)
2629 fl4->saddr = inet_select_addr(dev_out, 0,
2630 RT_SCOPE_LINK);
2631 goto make_route;
2632 }
2633 if (fl4->saddr) {
2634 if (ipv4_is_multicast(fl4->daddr))
2635 fl4->saddr = inet_select_addr(dev_out, 0,
2636 fl4->flowi4_scope);
2637 else if (!fl4->daddr)
2638 fl4->saddr = inet_select_addr(dev_out, 0,
2639 RT_SCOPE_HOST);
2640 }
2641 }
2642
2643 if (!fl4->daddr) {
2644 fl4->daddr = fl4->saddr;
2645 if (!fl4->daddr)
2646 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2647 dev_out = net->loopback_dev;
2648 fl4->flowi4_oif = net->loopback_dev->ifindex;
2649 res.type = RTN_LOCAL;
2650 flags |= RTCF_LOCAL;
2651 goto make_route;
2652 }
2653
2654 if (fib_lookup(net, fl4, &res)) {
2655 res.fi = NULL;
2656 if (fl4->flowi4_oif) {
2657 /* Apparently, routing tables are wrong. Assume,
2658 that the destination is on link.
2659
2660 WHY? DW.
2661 Because we are allowed to send to iface
2662 even if it has NO routes and NO assigned
2663 addresses. When oif is specified, routing
2664 tables are looked up with only one purpose:
2665 to catch if destination is gatewayed, rather than
2666 direct. Moreover, if MSG_DONTROUTE is set,
2667 we send packet, ignoring both routing tables
2668 and ifaddr state. --ANK
2669
2670
2671 We could make it even if oif is unknown,
2672 likely IPv6, but we do not.
2673 */
2674
2675 if (fl4->saddr == 0)
2676 fl4->saddr = inet_select_addr(dev_out, 0,
2677 RT_SCOPE_LINK);
2678 res.type = RTN_UNICAST;
2679 goto make_route;
2680 }
2681 rth = ERR_PTR(-ENETUNREACH);
2682 goto out;
2683 }
2684
2685 if (res.type == RTN_LOCAL) {
2686 if (!fl4->saddr) {
2687 if (res.fi->fib_prefsrc)
2688 fl4->saddr = res.fi->fib_prefsrc;
2689 else
2690 fl4->saddr = fl4->daddr;
2691 }
2692 dev_out = net->loopback_dev;
2693 fl4->flowi4_oif = dev_out->ifindex;
2694 res.fi = NULL;
2695 flags |= RTCF_LOCAL;
2696 goto make_route;
2697 }
2698
2699#ifdef CONFIG_IP_ROUTE_MULTIPATH
2700 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2701 fib_select_multipath(&res);
2702 else
2703#endif
2704 if (!res.prefixlen &&
2705 res.table->tb_num_default > 1 &&
2706 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2707 fib_select_default(&res);
2708
2709 if (!fl4->saddr)
2710 fl4->saddr = FIB_RES_PREFSRC(net, res);
2711
2712 dev_out = FIB_RES_DEV(res);
2713 fl4->flowi4_oif = dev_out->ifindex;
2714
2715
2716make_route:
2717 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2718 tos, dev_out, flags);
2719 if (!IS_ERR(rth)) {
2720 unsigned int hash;
2721
2722 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2723 rt_genid(dev_net(dev_out)));
2724 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2725 }
2726
2727out:
2728 rcu_read_unlock();
2729 return rth;
2730}
2731
2732struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2733{
2734 struct rtable *rth;
2735 unsigned int hash;
2736
2737 if (!rt_caching(net))
2738 goto slow_output;
2739
2740 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2741
2742 rcu_read_lock_bh();
2743 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2744 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2745 if (rth->rt_key_dst == flp4->daddr &&
2746 rth->rt_key_src == flp4->saddr &&
2747 rt_is_output_route(rth) &&
2748 rth->rt_oif == flp4->flowi4_oif &&
2749 rth->rt_mark == flp4->flowi4_mark &&
2750 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2751 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2752 net_eq(dev_net(rth->dst.dev), net) &&
2753 !rt_is_expired(rth)) {
2754 ipv4_validate_peer(rth);
2755 dst_use(&rth->dst, jiffies);
2756 RT_CACHE_STAT_INC(out_hit);
2757 rcu_read_unlock_bh();
2758 if (!flp4->saddr)
2759 flp4->saddr = rth->rt_src;
2760 if (!flp4->daddr)
2761 flp4->daddr = rth->rt_dst;
2762 return rth;
2763 }
2764 RT_CACHE_STAT_INC(out_hlist_search);
2765 }
2766 rcu_read_unlock_bh();
2767
2768slow_output:
2769 return ip_route_output_slow(net, flp4);
2770}
2771EXPORT_SYMBOL_GPL(__ip_route_output_key);
2772
2773static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2774{
2775 return NULL;
2776}
2777
2778static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2779{
2780 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2781
2782 return mtu ? : dst->dev->mtu;
2783}
2784
2785static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2786{
2787}
2788
2789static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2790 unsigned long old)
2791{
2792 return NULL;
2793}
2794
2795static struct dst_ops ipv4_dst_blackhole_ops = {
2796 .family = AF_INET,
2797 .protocol = cpu_to_be16(ETH_P_IP),
2798 .destroy = ipv4_dst_destroy,
2799 .check = ipv4_blackhole_dst_check,
2800 .mtu = ipv4_blackhole_mtu,
2801 .default_advmss = ipv4_default_advmss,
2802 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2803 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2804 .neigh_lookup = ipv4_neigh_lookup,
2805};
2806
2807struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2808{
2809 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2810 struct rtable *ort = (struct rtable *) dst_orig;
2811
2812 if (rt) {
2813 struct dst_entry *new = &rt->dst;
2814
2815 new->__use = 1;
2816 new->input = dst_discard;
2817 new->output = dst_discard;
2818 dst_copy_metrics(new, &ort->dst);
2819
2820 new->dev = ort->dst.dev;
2821 if (new->dev)
2822 dev_hold(new->dev);
2823
2824 rt->rt_key_dst = ort->rt_key_dst;
2825 rt->rt_key_src = ort->rt_key_src;
2826 rt->rt_key_tos = ort->rt_key_tos;
2827 rt->rt_route_iif = ort->rt_route_iif;
2828 rt->rt_iif = ort->rt_iif;
2829 rt->rt_oif = ort->rt_oif;
2830 rt->rt_mark = ort->rt_mark;
2831
2832 rt->rt_genid = rt_genid(net);
2833 rt->rt_flags = ort->rt_flags;
2834 rt->rt_type = ort->rt_type;
2835 rt->rt_dst = ort->rt_dst;
2836 rt->rt_src = ort->rt_src;
2837 rt->rt_gateway = ort->rt_gateway;
2838 rt->rt_spec_dst = ort->rt_spec_dst;
2839 rt->peer = ort->peer;
2840 if (rt->peer)
2841 atomic_inc(&rt->peer->refcnt);
2842 rt->fi = ort->fi;
2843 if (rt->fi)
2844 atomic_inc(&rt->fi->fib_clntref);
2845
2846 dst_free(new);
2847 }
2848
2849 dst_release(dst_orig);
2850
2851 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2852}
2853
2854struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2855 struct sock *sk)
2856{
2857 struct rtable *rt = __ip_route_output_key(net, flp4);
2858
2859 if (IS_ERR(rt))
2860 return rt;
2861
2862 if (flp4->flowi4_proto)
2863 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2864 flowi4_to_flowi(flp4),
2865 sk, 0);
2866
2867 return rt;
2868}
2869EXPORT_SYMBOL_GPL(ip_route_output_flow);
2870
2871static int rt_fill_info(struct net *net,
2872 struct sk_buff *skb, u32 pid, u32 seq, int event,
2873 int nowait, unsigned int flags)
2874{
2875 struct rtable *rt = skb_rtable(skb);
2876 struct rtmsg *r;
2877 struct nlmsghdr *nlh;
2878 unsigned long expires = 0;
2879 const struct inet_peer *peer = rt->peer;
2880 u32 id = 0, ts = 0, tsage = 0, error;
2881
2882 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2883 if (nlh == NULL)
2884 return -EMSGSIZE;
2885
2886 r = nlmsg_data(nlh);
2887 r->rtm_family = AF_INET;
2888 r->rtm_dst_len = 32;
2889 r->rtm_src_len = 0;
2890 r->rtm_tos = rt->rt_key_tos;
2891 r->rtm_table = RT_TABLE_MAIN;
2892 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2893 r->rtm_type = rt->rt_type;
2894 r->rtm_scope = RT_SCOPE_UNIVERSE;
2895 r->rtm_protocol = RTPROT_UNSPEC;
2896 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2897 if (rt->rt_flags & RTCF_NOTIFY)
2898 r->rtm_flags |= RTM_F_NOTIFY;
2899
2900 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2901
2902 if (rt->rt_key_src) {
2903 r->rtm_src_len = 32;
2904 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2905 }
2906 if (rt->dst.dev)
2907 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2908#ifdef CONFIG_IP_ROUTE_CLASSID
2909 if (rt->dst.tclassid)
2910 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2911#endif
2912 if (rt_is_input_route(rt))
2913 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2914 else if (rt->rt_src != rt->rt_key_src)
2915 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2916
2917 if (rt->rt_dst != rt->rt_gateway)
2918 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2919
2920 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2921 goto nla_put_failure;
2922
2923 if (rt->rt_mark)
2924 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2925
2926 error = rt->dst.error;
2927 if (peer) {
2928 inet_peer_refcheck(rt->peer);
2929 id = atomic_read(&peer->ip_id_count) & 0xffff;
2930 if (peer->tcp_ts_stamp) {
2931 ts = peer->tcp_ts;
2932 tsage = get_seconds() - peer->tcp_ts_stamp;
2933 }
2934 expires = ACCESS_ONCE(peer->pmtu_expires);
2935 if (expires) {
2936 if (time_before(jiffies, expires))
2937 expires -= jiffies;
2938 else
2939 expires = 0;
2940 }
2941 }
2942
2943 if (rt_is_input_route(rt)) {
2944#ifdef CONFIG_IP_MROUTE
2945 __be32 dst = rt->rt_dst;
2946
2947 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2948 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2949 int err = ipmr_get_route(net, skb,
2950 rt->rt_src, rt->rt_dst,
2951 r, nowait);
2952 if (err <= 0) {
2953 if (!nowait) {
2954 if (err == 0)
2955 return 0;
2956 goto nla_put_failure;
2957 } else {
2958 if (err == -EMSGSIZE)
2959 goto nla_put_failure;
2960 error = err;
2961 }
2962 }
2963 } else
2964#endif
2965 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2966 }
2967
2968 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2969 expires, error) < 0)
2970 goto nla_put_failure;
2971
2972 return nlmsg_end(skb, nlh);
2973
2974nla_put_failure:
2975 nlmsg_cancel(skb, nlh);
2976 return -EMSGSIZE;
2977}
2978
2979static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2980{
2981 struct net *net = sock_net(in_skb->sk);
2982 struct rtmsg *rtm;
2983 struct nlattr *tb[RTA_MAX+1];
2984 struct rtable *rt = NULL;
2985 __be32 dst = 0;
2986 __be32 src = 0;
2987 u32 iif;
2988 int err;
2989 int mark;
2990 struct sk_buff *skb;
2991
2992 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2993 if (err < 0)
2994 goto errout;
2995
2996 rtm = nlmsg_data(nlh);
2997
2998 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2999 if (skb == NULL) {
3000 err = -ENOBUFS;
3001 goto errout;
3002 }
3003
3004 /* Reserve room for dummy headers, this skb can pass
3005 through good chunk of routing engine.
3006 */
3007 skb_reset_mac_header(skb);
3008 skb_reset_network_header(skb);
3009
3010 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3011 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3012 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3013
3014 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3015 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3016 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3017 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3018
3019 if (iif) {
3020 struct net_device *dev;
3021
3022 dev = __dev_get_by_index(net, iif);
3023 if (dev == NULL) {
3024 err = -ENODEV;
3025 goto errout_free;
3026 }
3027
3028 skb->protocol = htons(ETH_P_IP);
3029 skb->dev = dev;
3030 skb->mark = mark;
3031 local_bh_disable();
3032 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3033 local_bh_enable();
3034
3035 rt = skb_rtable(skb);
3036 if (err == 0 && rt->dst.error)
3037 err = -rt->dst.error;
3038 } else {
3039 struct flowi4 fl4 = {
3040 .daddr = dst,
3041 .saddr = src,
3042 .flowi4_tos = rtm->rtm_tos,
3043 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3044 .flowi4_mark = mark,
3045 };
3046 rt = ip_route_output_key(net, &fl4);
3047
3048 err = 0;
3049 if (IS_ERR(rt))
3050 err = PTR_ERR(rt);
3051 }
3052
3053 if (err)
3054 goto errout_free;
3055
3056 skb_dst_set(skb, &rt->dst);
3057 if (rtm->rtm_flags & RTM_F_NOTIFY)
3058 rt->rt_flags |= RTCF_NOTIFY;
3059
3060 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3061 RTM_NEWROUTE, 0, 0);
3062 if (err <= 0)
3063 goto errout_free;
3064
3065 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3066errout:
3067 return err;
3068
3069errout_free:
3070 kfree_skb(skb);
3071 goto errout;
3072}
3073
3074int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3075{
3076 struct rtable *rt;
3077 int h, s_h;
3078 int idx, s_idx;
3079 struct net *net;
3080
3081 net = sock_net(skb->sk);
3082
3083 s_h = cb->args[0];
3084 if (s_h < 0)
3085 s_h = 0;
3086 s_idx = idx = cb->args[1];
3087 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3088 if (!rt_hash_table[h].chain)
3089 continue;
3090 rcu_read_lock_bh();
3091 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3092 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3093 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3094 continue;
3095 if (rt_is_expired(rt))
3096 continue;
3097 skb_dst_set_noref(skb, &rt->dst);
3098 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3099 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3100 1, NLM_F_MULTI) <= 0) {
3101 skb_dst_drop(skb);
3102 rcu_read_unlock_bh();
3103 goto done;
3104 }
3105 skb_dst_drop(skb);
3106 }
3107 rcu_read_unlock_bh();
3108 }
3109
3110done:
3111 cb->args[0] = h;
3112 cb->args[1] = idx;
3113 return skb->len;
3114}
3115
3116void ip_rt_multicast_event(struct in_device *in_dev)
3117{
3118 rt_cache_flush(dev_net(in_dev->dev), 0);
3119}
3120
3121#ifdef CONFIG_SYSCTL
3122static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3123 void __user *buffer,
3124 size_t *lenp, loff_t *ppos)
3125{
3126 if (write) {
3127 int flush_delay;
3128 ctl_table ctl;
3129 struct net *net;
3130
3131 memcpy(&ctl, __ctl, sizeof(ctl));
3132 ctl.data = &flush_delay;
3133 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3134
3135 net = (struct net *)__ctl->extra1;
3136 rt_cache_flush(net, flush_delay);
3137 return 0;
3138 }
3139
3140 return -EINVAL;
3141}
3142
3143static ctl_table ipv4_route_table[] = {
3144 {
3145 .procname = "gc_thresh",
3146 .data = &ipv4_dst_ops.gc_thresh,
3147 .maxlen = sizeof(int),
3148 .mode = 0644,
3149 .proc_handler = proc_dointvec,
3150 },
3151 {
3152 .procname = "max_size",
3153 .data = &ip_rt_max_size,
3154 .maxlen = sizeof(int),
3155 .mode = 0644,
3156 .proc_handler = proc_dointvec,
3157 },
3158 {
3159 /* Deprecated. Use gc_min_interval_ms */
3160
3161 .procname = "gc_min_interval",
3162 .data = &ip_rt_gc_min_interval,
3163 .maxlen = sizeof(int),
3164 .mode = 0644,
3165 .proc_handler = proc_dointvec_jiffies,
3166 },
3167 {
3168 .procname = "gc_min_interval_ms",
3169 .data = &ip_rt_gc_min_interval,
3170 .maxlen = sizeof(int),
3171 .mode = 0644,
3172 .proc_handler = proc_dointvec_ms_jiffies,
3173 },
3174 {
3175 .procname = "gc_timeout",
3176 .data = &ip_rt_gc_timeout,
3177 .maxlen = sizeof(int),
3178 .mode = 0644,
3179 .proc_handler = proc_dointvec_jiffies,
3180 },
3181 {
3182 .procname = "redirect_load",
3183 .data = &ip_rt_redirect_load,
3184 .maxlen = sizeof(int),
3185 .mode = 0644,
3186 .proc_handler = proc_dointvec,
3187 },
3188 {
3189 .procname = "redirect_number",
3190 .data = &ip_rt_redirect_number,
3191 .maxlen = sizeof(int),
3192 .mode = 0644,
3193 .proc_handler = proc_dointvec,
3194 },
3195 {
3196 .procname = "redirect_silence",
3197 .data = &ip_rt_redirect_silence,
3198 .maxlen = sizeof(int),
3199 .mode = 0644,
3200 .proc_handler = proc_dointvec,
3201 },
3202 {
3203 .procname = "error_cost",
3204 .data = &ip_rt_error_cost,
3205 .maxlen = sizeof(int),
3206 .mode = 0644,
3207 .proc_handler = proc_dointvec,
3208 },
3209 {
3210 .procname = "error_burst",
3211 .data = &ip_rt_error_burst,
3212 .maxlen = sizeof(int),
3213 .mode = 0644,
3214 .proc_handler = proc_dointvec,
3215 },
3216 {
3217 .procname = "gc_elasticity",
3218 .data = &ip_rt_gc_elasticity,
3219 .maxlen = sizeof(int),
3220 .mode = 0644,
3221 .proc_handler = proc_dointvec,
3222 },
3223 {
3224 .procname = "mtu_expires",
3225 .data = &ip_rt_mtu_expires,
3226 .maxlen = sizeof(int),
3227 .mode = 0644,
3228 .proc_handler = proc_dointvec_jiffies,
3229 },
3230 {
3231 .procname = "min_pmtu",
3232 .data = &ip_rt_min_pmtu,
3233 .maxlen = sizeof(int),
3234 .mode = 0644,
3235 .proc_handler = proc_dointvec,
3236 },
3237 {
3238 .procname = "min_adv_mss",
3239 .data = &ip_rt_min_advmss,
3240 .maxlen = sizeof(int),
3241 .mode = 0644,
3242 .proc_handler = proc_dointvec,
3243 },
3244 { }
3245};
3246
3247static struct ctl_table empty[1];
3248
3249static struct ctl_table ipv4_skeleton[] =
3250{
3251 { .procname = "route",
3252 .mode = 0555, .child = ipv4_route_table},
3253 { .procname = "neigh",
3254 .mode = 0555, .child = empty},
3255 { }
3256};
3257
3258static __net_initdata struct ctl_path ipv4_path[] = {
3259 { .procname = "net", },
3260 { .procname = "ipv4", },
3261 { },
3262};
3263
3264static struct ctl_table ipv4_route_flush_table[] = {
3265 {
3266 .procname = "flush",
3267 .maxlen = sizeof(int),
3268 .mode = 0200,
3269 .proc_handler = ipv4_sysctl_rtcache_flush,
3270 },
3271 { },
3272};
3273
3274static __net_initdata struct ctl_path ipv4_route_path[] = {
3275 { .procname = "net", },
3276 { .procname = "ipv4", },
3277 { .procname = "route", },
3278 { },
3279};
3280
3281static __net_init int sysctl_route_net_init(struct net *net)
3282{
3283 struct ctl_table *tbl;
3284
3285 tbl = ipv4_route_flush_table;
3286 if (!net_eq(net, &init_net)) {
3287 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3288 if (tbl == NULL)
3289 goto err_dup;
3290 }
3291 tbl[0].extra1 = net;
3292
3293 net->ipv4.route_hdr =
3294 register_net_sysctl_table(net, ipv4_route_path, tbl);
3295 if (net->ipv4.route_hdr == NULL)
3296 goto err_reg;
3297 return 0;
3298
3299err_reg:
3300 if (tbl != ipv4_route_flush_table)
3301 kfree(tbl);
3302err_dup:
3303 return -ENOMEM;
3304}
3305
3306static __net_exit void sysctl_route_net_exit(struct net *net)
3307{
3308 struct ctl_table *tbl;
3309
3310 tbl = net->ipv4.route_hdr->ctl_table_arg;
3311 unregister_net_sysctl_table(net->ipv4.route_hdr);
3312 BUG_ON(tbl == ipv4_route_flush_table);
3313 kfree(tbl);
3314}
3315
3316static __net_initdata struct pernet_operations sysctl_route_ops = {
3317 .init = sysctl_route_net_init,
3318 .exit = sysctl_route_net_exit,
3319};
3320#endif
3321
3322static __net_init int rt_genid_init(struct net *net)
3323{
3324 get_random_bytes(&net->ipv4.rt_genid,
3325 sizeof(net->ipv4.rt_genid));
3326 get_random_bytes(&net->ipv4.dev_addr_genid,
3327 sizeof(net->ipv4.dev_addr_genid));
3328 return 0;
3329}
3330
3331static __net_initdata struct pernet_operations rt_genid_ops = {
3332 .init = rt_genid_init,
3333};
3334
3335
3336#ifdef CONFIG_IP_ROUTE_CLASSID
3337struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3338#endif /* CONFIG_IP_ROUTE_CLASSID */
3339
3340static __initdata unsigned long rhash_entries;
3341static int __init set_rhash_entries(char *str)
3342{
3343 if (!str)
3344 return 0;
3345 rhash_entries = simple_strtoul(str, &str, 0);
3346 return 1;
3347}
3348__setup("rhash_entries=", set_rhash_entries);
3349
3350int __init ip_rt_init(void)
3351{
3352 int rc = 0;
3353
3354#ifdef CONFIG_IP_ROUTE_CLASSID
3355 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3356 if (!ip_rt_acct)
3357 panic("IP: failed to allocate ip_rt_acct\n");
3358#endif
3359
3360 ipv4_dst_ops.kmem_cachep =
3361 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3362 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3363
3364 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3365
3366 if (dst_entries_init(&ipv4_dst_ops) < 0)
3367 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3368
3369 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3370 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3371
3372 rt_hash_table = (struct rt_hash_bucket *)
3373 alloc_large_system_hash("IP route cache",
3374 sizeof(struct rt_hash_bucket),
3375 rhash_entries,
3376 (totalram_pages >= 128 * 1024) ?
3377 15 : 17,
3378 0,
3379 &rt_hash_log,
3380 &rt_hash_mask,
3381 rhash_entries ? 0 : 512 * 1024);
3382 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3383 rt_hash_lock_init();
3384
3385 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3386 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3387
3388 devinet_init();
3389 ip_fib_init();
3390
3391 if (ip_rt_proc_init())
3392 printk(KERN_ERR "Unable to create route proc files\n");
3393#ifdef CONFIG_XFRM
3394 xfrm_init();
3395 xfrm4_init(ip_rt_max_size);
3396#endif
3397 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3398
3399#ifdef CONFIG_SYSCTL
3400 register_pernet_subsys(&sysctl_route_ops);
3401#endif
3402 register_pernet_subsys(&rt_genid_ops);
3403 return rc;
3404}
3405
3406#ifdef CONFIG_SYSCTL
3407/*
3408 * We really need to sanitize the damn ipv4 init order, then all
3409 * this nonsense will go away.
3410 */
3411void __init ip_static_sysctl_init(void)
3412{
3413 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3414}
3415#endif