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igmp: Avoid zero delay when receiving odd mixture of IGMP queries
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / ipv4 / route.c
blob94cdbc55ca7ead13879d563608f8a191ca3b424c
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 <linux/prefetch.h>
95 #include <net/dst.h>
96 #include <net/net_namespace.h>
97 #include <net/protocol.h>
98 #include <net/ip.h>
99 #include <net/route.h>
100 #include <net/inetpeer.h>
101 #include <net/sock.h>
102 #include <net/ip_fib.h>
103 #include <net/arp.h>
104 #include <net/tcp.h>
105 #include <net/icmp.h>
106 #include <net/xfrm.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #endif
112 #include <net/atmclip.h>
113 #include <net/secure_seq.h>
114
115 #define RT_FL_TOS(oldflp4) \
116 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
117
118 #define IP_MAX_MTU 0xFFF0
119
120 #define RT_GC_TIMEOUT (300*HZ)
121
122 static int ip_rt_max_size;
123 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
124 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
125 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
126 static int ip_rt_redirect_number __read_mostly = 9;
127 static int ip_rt_redirect_load __read_mostly = HZ / 50;
128 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
129 static int ip_rt_error_cost __read_mostly = HZ;
130 static int ip_rt_error_burst __read_mostly = 5 * HZ;
131 static int ip_rt_gc_elasticity __read_mostly = 8;
132 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
133 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
134 static int ip_rt_min_advmss __read_mostly = 256;
135 static int rt_chain_length_max __read_mostly = 20;
136 static int redirect_genid;
137
138 static struct delayed_work expires_work;
139 static unsigned long expires_ljiffies;
140
141 /*
142 * Interface to generic destination cache.
143 */
144
145 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
146 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
147 static unsigned int ipv4_mtu(const struct dst_entry *dst);
148 static void ipv4_dst_destroy(struct dst_entry *dst);
149 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
150 static void ipv4_link_failure(struct sk_buff *skb);
151 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
152 static int rt_garbage_collect(struct dst_ops *ops);
153
154 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
155 int how)
156 {
157 }
158
159 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
160 {
161 struct rtable *rt = (struct rtable *) dst;
162 struct inet_peer *peer;
163 u32 *p = NULL;
164
165 if (!rt->peer)
166 rt_bind_peer(rt, rt->rt_dst, 1);
167
168 peer = rt->peer;
169 if (peer) {
170 u32 *old_p = __DST_METRICS_PTR(old);
171 unsigned long prev, new;
172
173 p = peer->metrics;
174 if (inet_metrics_new(peer))
175 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
176
177 new = (unsigned long) p;
178 prev = cmpxchg(&dst->_metrics, old, new);
179
180 if (prev != old) {
181 p = __DST_METRICS_PTR(prev);
182 if (prev & DST_METRICS_READ_ONLY)
183 p = NULL;
184 } else {
185 if (rt->fi) {
186 fib_info_put(rt->fi);
187 rt->fi = NULL;
188 }
189 }
190 }
191 return p;
192 }
193
194 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
195
196 static struct dst_ops ipv4_dst_ops = {
197 .family = AF_INET,
198 .protocol = cpu_to_be16(ETH_P_IP),
199 .gc = rt_garbage_collect,
200 .check = ipv4_dst_check,
201 .default_advmss = ipv4_default_advmss,
202 .mtu = ipv4_mtu,
203 .cow_metrics = ipv4_cow_metrics,
204 .destroy = ipv4_dst_destroy,
205 .ifdown = ipv4_dst_ifdown,
206 .negative_advice = ipv4_negative_advice,
207 .link_failure = ipv4_link_failure,
208 .update_pmtu = ip_rt_update_pmtu,
209 .local_out = __ip_local_out,
210 .neigh_lookup = ipv4_neigh_lookup,
211 };
212
213 #define ECN_OR_COST(class) TC_PRIO_##class
214
215 const __u8 ip_tos2prio[16] = {
216 TC_PRIO_BESTEFFORT,
217 ECN_OR_COST(BESTEFFORT),
218 TC_PRIO_BESTEFFORT,
219 ECN_OR_COST(BESTEFFORT),
220 TC_PRIO_BULK,
221 ECN_OR_COST(BULK),
222 TC_PRIO_BULK,
223 ECN_OR_COST(BULK),
224 TC_PRIO_INTERACTIVE,
225 ECN_OR_COST(INTERACTIVE),
226 TC_PRIO_INTERACTIVE,
227 ECN_OR_COST(INTERACTIVE),
228 TC_PRIO_INTERACTIVE_BULK,
229 ECN_OR_COST(INTERACTIVE_BULK),
230 TC_PRIO_INTERACTIVE_BULK,
231 ECN_OR_COST(INTERACTIVE_BULK)
232 };
233
234
235 /*
236 * Route cache.
237 */
238
239 /* The locking scheme is rather straight forward:
240 *
241 * 1) Read-Copy Update protects the buckets of the central route hash.
242 * 2) Only writers remove entries, and they hold the lock
243 * as they look at rtable reference counts.
244 * 3) Only readers acquire references to rtable entries,
245 * they do so with atomic increments and with the
246 * lock held.
247 */
248
249 struct rt_hash_bucket {
250 struct rtable __rcu *chain;
251 };
252
253 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
254 defined(CONFIG_PROVE_LOCKING)
255 /*
256 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
257 * The size of this table is a power of two and depends on the number of CPUS.
258 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
259 */
260 #ifdef CONFIG_LOCKDEP
261 # define RT_HASH_LOCK_SZ 256
262 #else
263 # if NR_CPUS >= 32
264 # define RT_HASH_LOCK_SZ 4096
265 # elif NR_CPUS >= 16
266 # define RT_HASH_LOCK_SZ 2048
267 # elif NR_CPUS >= 8
268 # define RT_HASH_LOCK_SZ 1024
269 # elif NR_CPUS >= 4
270 # define RT_HASH_LOCK_SZ 512
271 # else
272 # define RT_HASH_LOCK_SZ 256
273 # endif
274 #endif
275
276 static spinlock_t *rt_hash_locks;
277 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
278
279 static __init void rt_hash_lock_init(void)
280 {
281 int i;
282
283 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
284 GFP_KERNEL);
285 if (!rt_hash_locks)
286 panic("IP: failed to allocate rt_hash_locks\n");
287
288 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
289 spin_lock_init(&rt_hash_locks[i]);
290 }
291 #else
292 # define rt_hash_lock_addr(slot) NULL
293
294 static inline void rt_hash_lock_init(void)
295 {
296 }
297 #endif
298
299 static struct rt_hash_bucket *rt_hash_table __read_mostly;
300 static unsigned rt_hash_mask __read_mostly;
301 static unsigned int rt_hash_log __read_mostly;
302
303 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
304 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
305
306 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
307 int genid)
308 {
309 return jhash_3words((__force u32)daddr, (__force u32)saddr,
310 idx, genid)
311 & rt_hash_mask;
312 }
313
314 static inline int rt_genid(struct net *net)
315 {
316 return atomic_read(&net->ipv4.rt_genid);
317 }
318
319 #ifdef CONFIG_PROC_FS
320 struct rt_cache_iter_state {
321 struct seq_net_private p;
322 int bucket;
323 int genid;
324 };
325
326 static struct rtable *rt_cache_get_first(struct seq_file *seq)
327 {
328 struct rt_cache_iter_state *st = seq->private;
329 struct rtable *r = NULL;
330
331 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
332 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
333 continue;
334 rcu_read_lock_bh();
335 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
336 while (r) {
337 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
338 r->rt_genid == st->genid)
339 return r;
340 r = rcu_dereference_bh(r->dst.rt_next);
341 }
342 rcu_read_unlock_bh();
343 }
344 return r;
345 }
346
347 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
348 struct rtable *r)
349 {
350 struct rt_cache_iter_state *st = seq->private;
351
352 r = rcu_dereference_bh(r->dst.rt_next);
353 while (!r) {
354 rcu_read_unlock_bh();
355 do {
356 if (--st->bucket < 0)
357 return NULL;
358 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
359 rcu_read_lock_bh();
360 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
361 }
362 return r;
363 }
364
365 static struct rtable *rt_cache_get_next(struct seq_file *seq,
366 struct rtable *r)
367 {
368 struct rt_cache_iter_state *st = seq->private;
369 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
370 if (dev_net(r->dst.dev) != seq_file_net(seq))
371 continue;
372 if (r->rt_genid == st->genid)
373 break;
374 }
375 return r;
376 }
377
378 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
379 {
380 struct rtable *r = rt_cache_get_first(seq);
381
382 if (r)
383 while (pos && (r = rt_cache_get_next(seq, r)))
384 --pos;
385 return pos ? NULL : r;
386 }
387
388 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
389 {
390 struct rt_cache_iter_state *st = seq->private;
391 if (*pos)
392 return rt_cache_get_idx(seq, *pos - 1);
393 st->genid = rt_genid(seq_file_net(seq));
394 return SEQ_START_TOKEN;
395 }
396
397 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
398 {
399 struct rtable *r;
400
401 if (v == SEQ_START_TOKEN)
402 r = rt_cache_get_first(seq);
403 else
404 r = rt_cache_get_next(seq, v);
405 ++*pos;
406 return r;
407 }
408
409 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
410 {
411 if (v && v != SEQ_START_TOKEN)
412 rcu_read_unlock_bh();
413 }
414
415 static int rt_cache_seq_show(struct seq_file *seq, void *v)
416 {
417 if (v == SEQ_START_TOKEN)
418 seq_printf(seq, "%-127s\n",
419 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
420 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
421 "HHUptod\tSpecDst");
422 else {
423 struct rtable *r = v;
424 struct neighbour *n;
425 int len, HHUptod;
426
427 rcu_read_lock();
428 n = dst_get_neighbour(&r->dst);
429 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
430 rcu_read_unlock();
431
432 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
433 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
434 r->dst.dev ? r->dst.dev->name : "*",
435 (__force u32)r->rt_dst,
436 (__force u32)r->rt_gateway,
437 r->rt_flags, atomic_read(&r->dst.__refcnt),
438 r->dst.__use, 0, (__force u32)r->rt_src,
439 dst_metric_advmss(&r->dst) + 40,
440 dst_metric(&r->dst, RTAX_WINDOW),
441 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
442 dst_metric(&r->dst, RTAX_RTTVAR)),
443 r->rt_key_tos,
444 -1,
445 HHUptod,
446 r->rt_spec_dst, &len);
447
448 seq_printf(seq, "%*s\n", 127 - len, "");
449 }
450 return 0;
451 }
452
453 static const struct seq_operations rt_cache_seq_ops = {
454 .start = rt_cache_seq_start,
455 .next = rt_cache_seq_next,
456 .stop = rt_cache_seq_stop,
457 .show = rt_cache_seq_show,
458 };
459
460 static int rt_cache_seq_open(struct inode *inode, struct file *file)
461 {
462 return seq_open_net(inode, file, &rt_cache_seq_ops,
463 sizeof(struct rt_cache_iter_state));
464 }
465
466 static const struct file_operations rt_cache_seq_fops = {
467 .owner = THIS_MODULE,
468 .open = rt_cache_seq_open,
469 .read = seq_read,
470 .llseek = seq_lseek,
471 .release = seq_release_net,
472 };
473
474
475 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
476 {
477 int cpu;
478
479 if (*pos == 0)
480 return SEQ_START_TOKEN;
481
482 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
483 if (!cpu_possible(cpu))
484 continue;
485 *pos = cpu+1;
486 return &per_cpu(rt_cache_stat, cpu);
487 }
488 return NULL;
489 }
490
491 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492 {
493 int cpu;
494
495 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
496 if (!cpu_possible(cpu))
497 continue;
498 *pos = cpu+1;
499 return &per_cpu(rt_cache_stat, cpu);
500 }
501 return NULL;
502
503 }
504
505 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
506 {
507
508 }
509
510 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
511 {
512 struct rt_cache_stat *st = v;
513
514 if (v == SEQ_START_TOKEN) {
515 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");
516 return 0;
517 }
518
519 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
520 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
521 dst_entries_get_slow(&ipv4_dst_ops),
522 st->in_hit,
523 st->in_slow_tot,
524 st->in_slow_mc,
525 st->in_no_route,
526 st->in_brd,
527 st->in_martian_dst,
528 st->in_martian_src,
529
530 st->out_hit,
531 st->out_slow_tot,
532 st->out_slow_mc,
533
534 st->gc_total,
535 st->gc_ignored,
536 st->gc_goal_miss,
537 st->gc_dst_overflow,
538 st->in_hlist_search,
539 st->out_hlist_search
540 );
541 return 0;
542 }
543
544 static const struct seq_operations rt_cpu_seq_ops = {
545 .start = rt_cpu_seq_start,
546 .next = rt_cpu_seq_next,
547 .stop = rt_cpu_seq_stop,
548 .show = rt_cpu_seq_show,
549 };
550
551
552 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
553 {
554 return seq_open(file, &rt_cpu_seq_ops);
555 }
556
557 static const struct file_operations rt_cpu_seq_fops = {
558 .owner = THIS_MODULE,
559 .open = rt_cpu_seq_open,
560 .read = seq_read,
561 .llseek = seq_lseek,
562 .release = seq_release,
563 };
564
565 #ifdef CONFIG_IP_ROUTE_CLASSID
566 static int rt_acct_proc_show(struct seq_file *m, void *v)
567 {
568 struct ip_rt_acct *dst, *src;
569 unsigned int i, j;
570
571 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
572 if (!dst)
573 return -ENOMEM;
574
575 for_each_possible_cpu(i) {
576 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
577 for (j = 0; j < 256; j++) {
578 dst[j].o_bytes += src[j].o_bytes;
579 dst[j].o_packets += src[j].o_packets;
580 dst[j].i_bytes += src[j].i_bytes;
581 dst[j].i_packets += src[j].i_packets;
582 }
583 }
584
585 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
586 kfree(dst);
587 return 0;
588 }
589
590 static int rt_acct_proc_open(struct inode *inode, struct file *file)
591 {
592 return single_open(file, rt_acct_proc_show, NULL);
593 }
594
595 static const struct file_operations rt_acct_proc_fops = {
596 .owner = THIS_MODULE,
597 .open = rt_acct_proc_open,
598 .read = seq_read,
599 .llseek = seq_lseek,
600 .release = single_release,
601 };
602 #endif
603
604 static int __net_init ip_rt_do_proc_init(struct net *net)
605 {
606 struct proc_dir_entry *pde;
607
608 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
609 &rt_cache_seq_fops);
610 if (!pde)
611 goto err1;
612
613 pde = proc_create("rt_cache", S_IRUGO,
614 net->proc_net_stat, &rt_cpu_seq_fops);
615 if (!pde)
616 goto err2;
617
618 #ifdef CONFIG_IP_ROUTE_CLASSID
619 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
620 if (!pde)
621 goto err3;
622 #endif
623 return 0;
624
625 #ifdef CONFIG_IP_ROUTE_CLASSID
626 err3:
627 remove_proc_entry("rt_cache", net->proc_net_stat);
628 #endif
629 err2:
630 remove_proc_entry("rt_cache", net->proc_net);
631 err1:
632 return -ENOMEM;
633 }
634
635 static void __net_exit ip_rt_do_proc_exit(struct net *net)
636 {
637 remove_proc_entry("rt_cache", net->proc_net_stat);
638 remove_proc_entry("rt_cache", net->proc_net);
639 #ifdef CONFIG_IP_ROUTE_CLASSID
640 remove_proc_entry("rt_acct", net->proc_net);
641 #endif
642 }
643
644 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
645 .init = ip_rt_do_proc_init,
646 .exit = ip_rt_do_proc_exit,
647 };
648
649 static int __init ip_rt_proc_init(void)
650 {
651 return register_pernet_subsys(&ip_rt_proc_ops);
652 }
653
654 #else
655 static inline int ip_rt_proc_init(void)
656 {
657 return 0;
658 }
659 #endif /* CONFIG_PROC_FS */
660
661 static inline void rt_free(struct rtable *rt)
662 {
663 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
664 }
665
666 static inline void rt_drop(struct rtable *rt)
667 {
668 ip_rt_put(rt);
669 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
670 }
671
672 static inline int rt_fast_clean(struct rtable *rth)
673 {
674 /* Kill broadcast/multicast entries very aggresively, if they
675 collide in hash table with more useful entries */
676 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
677 rt_is_input_route(rth) && rth->dst.rt_next;
678 }
679
680 static inline int rt_valuable(struct rtable *rth)
681 {
682 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
683 (rth->peer && rth->peer->pmtu_expires);
684 }
685
686 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
687 {
688 unsigned long age;
689 int ret = 0;
690
691 if (atomic_read(&rth->dst.__refcnt))
692 goto out;
693
694 age = jiffies - rth->dst.lastuse;
695 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
696 (age <= tmo2 && rt_valuable(rth)))
697 goto out;
698 ret = 1;
699 out: return ret;
700 }
701
702 /* Bits of score are:
703 * 31: very valuable
704 * 30: not quite useless
705 * 29..0: usage counter
706 */
707 static inline u32 rt_score(struct rtable *rt)
708 {
709 u32 score = jiffies - rt->dst.lastuse;
710
711 score = ~score & ~(3<<30);
712
713 if (rt_valuable(rt))
714 score |= (1<<31);
715
716 if (rt_is_output_route(rt) ||
717 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
718 score |= (1<<30);
719
720 return score;
721 }
722
723 static inline bool rt_caching(const struct net *net)
724 {
725 return net->ipv4.current_rt_cache_rebuild_count <=
726 net->ipv4.sysctl_rt_cache_rebuild_count;
727 }
728
729 static inline bool compare_hash_inputs(const struct rtable *rt1,
730 const struct rtable *rt2)
731 {
732 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
733 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
734 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
735 }
736
737 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
738 {
739 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
740 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
741 (rt1->rt_mark ^ rt2->rt_mark) |
742 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
743 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
744 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
745 }
746
747 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
748 {
749 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
750 }
751
752 static inline int rt_is_expired(struct rtable *rth)
753 {
754 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
755 }
756
757 /*
758 * Perform a full scan of hash table and free all entries.
759 * Can be called by a softirq or a process.
760 * In the later case, we want to be reschedule if necessary
761 */
762 static void rt_do_flush(struct net *net, int process_context)
763 {
764 unsigned int i;
765 struct rtable *rth, *next;
766
767 for (i = 0; i <= rt_hash_mask; i++) {
768 struct rtable __rcu **pprev;
769 struct rtable *list;
770
771 if (process_context && need_resched())
772 cond_resched();
773 rth = rcu_access_pointer(rt_hash_table[i].chain);
774 if (!rth)
775 continue;
776
777 spin_lock_bh(rt_hash_lock_addr(i));
778
779 list = NULL;
780 pprev = &rt_hash_table[i].chain;
781 rth = rcu_dereference_protected(*pprev,
782 lockdep_is_held(rt_hash_lock_addr(i)));
783
784 while (rth) {
785 next = rcu_dereference_protected(rth->dst.rt_next,
786 lockdep_is_held(rt_hash_lock_addr(i)));
787
788 if (!net ||
789 net_eq(dev_net(rth->dst.dev), net)) {
790 rcu_assign_pointer(*pprev, next);
791 rcu_assign_pointer(rth->dst.rt_next, list);
792 list = rth;
793 } else {
794 pprev = &rth->dst.rt_next;
795 }
796 rth = next;
797 }
798
799 spin_unlock_bh(rt_hash_lock_addr(i));
800
801 for (; list; list = next) {
802 next = rcu_dereference_protected(list->dst.rt_next, 1);
803 rt_free(list);
804 }
805 }
806 }
807
808 /*
809 * While freeing expired entries, we compute average chain length
810 * and standard deviation, using fixed-point arithmetic.
811 * This to have an estimation of rt_chain_length_max
812 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
813 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
814 */
815
816 #define FRACT_BITS 3
817 #define ONE (1UL << FRACT_BITS)
818
819 /*
820 * Given a hash chain and an item in this hash chain,
821 * find if a previous entry has the same hash_inputs
822 * (but differs on tos, mark or oif)
823 * Returns 0 if an alias is found.
824 * Returns ONE if rth has no alias before itself.
825 */
826 static int has_noalias(const struct rtable *head, const struct rtable *rth)
827 {
828 const struct rtable *aux = head;
829
830 while (aux != rth) {
831 if (compare_hash_inputs(aux, rth))
832 return 0;
833 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
834 }
835 return ONE;
836 }
837
838 static void rt_check_expire(void)
839 {
840 static unsigned int rover;
841 unsigned int i = rover, goal;
842 struct rtable *rth;
843 struct rtable __rcu **rthp;
844 unsigned long samples = 0;
845 unsigned long sum = 0, sum2 = 0;
846 unsigned long delta;
847 u64 mult;
848
849 delta = jiffies - expires_ljiffies;
850 expires_ljiffies = jiffies;
851 mult = ((u64)delta) << rt_hash_log;
852 if (ip_rt_gc_timeout > 1)
853 do_div(mult, ip_rt_gc_timeout);
854 goal = (unsigned int)mult;
855 if (goal > rt_hash_mask)
856 goal = rt_hash_mask + 1;
857 for (; goal > 0; goal--) {
858 unsigned long tmo = ip_rt_gc_timeout;
859 unsigned long length;
860
861 i = (i + 1) & rt_hash_mask;
862 rthp = &rt_hash_table[i].chain;
863
864 if (need_resched())
865 cond_resched();
866
867 samples++;
868
869 if (rcu_dereference_raw(*rthp) == NULL)
870 continue;
871 length = 0;
872 spin_lock_bh(rt_hash_lock_addr(i));
873 while ((rth = rcu_dereference_protected(*rthp,
874 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
875 prefetch(rth->dst.rt_next);
876 if (rt_is_expired(rth)) {
877 *rthp = rth->dst.rt_next;
878 rt_free(rth);
879 continue;
880 }
881 if (rth->dst.expires) {
882 /* Entry is expired even if it is in use */
883 if (time_before_eq(jiffies, rth->dst.expires)) {
884 nofree:
885 tmo >>= 1;
886 rthp = &rth->dst.rt_next;
887 /*
888 * We only count entries on
889 * a chain with equal hash inputs once
890 * so that entries for different QOS
891 * levels, and other non-hash input
892 * attributes don't unfairly skew
893 * the length computation
894 */
895 length += has_noalias(rt_hash_table[i].chain, rth);
896 continue;
897 }
898 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
899 goto nofree;
900
901 /* Cleanup aged off entries. */
902 *rthp = rth->dst.rt_next;
903 rt_free(rth);
904 }
905 spin_unlock_bh(rt_hash_lock_addr(i));
906 sum += length;
907 sum2 += length*length;
908 }
909 if (samples) {
910 unsigned long avg = sum / samples;
911 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
912 rt_chain_length_max = max_t(unsigned long,
913 ip_rt_gc_elasticity,
914 (avg + 4*sd) >> FRACT_BITS);
915 }
916 rover = i;
917 }
918
919 /*
920 * rt_worker_func() is run in process context.
921 * we call rt_check_expire() to scan part of the hash table
922 */
923 static void rt_worker_func(struct work_struct *work)
924 {
925 rt_check_expire();
926 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
927 }
928
929 /*
930 * Perturbation of rt_genid by a small quantity [1..256]
931 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
932 * many times (2^24) without giving recent rt_genid.
933 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
934 */
935 static void rt_cache_invalidate(struct net *net)
936 {
937 unsigned char shuffle;
938
939 get_random_bytes(&shuffle, sizeof(shuffle));
940 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
941 redirect_genid++;
942 }
943
944 /*
945 * delay < 0 : invalidate cache (fast : entries will be deleted later)
946 * delay >= 0 : invalidate & flush cache (can be long)
947 */
948 void rt_cache_flush(struct net *net, int delay)
949 {
950 rt_cache_invalidate(net);
951 if (delay >= 0)
952 rt_do_flush(net, !in_softirq());
953 }
954
955 /* Flush previous cache invalidated entries from the cache */
956 void rt_cache_flush_batch(struct net *net)
957 {
958 rt_do_flush(net, !in_softirq());
959 }
960
961 static void rt_emergency_hash_rebuild(struct net *net)
962 {
963 if (net_ratelimit())
964 printk(KERN_WARNING "Route hash chain too long!\n");
965 rt_cache_invalidate(net);
966 }
967
968 /*
969 Short description of GC goals.
970
971 We want to build algorithm, which will keep routing cache
972 at some equilibrium point, when number of aged off entries
973 is kept approximately equal to newly generated ones.
974
975 Current expiration strength is variable "expire".
976 We try to adjust it dynamically, so that if networking
977 is idle expires is large enough to keep enough of warm entries,
978 and when load increases it reduces to limit cache size.
979 */
980
981 static int rt_garbage_collect(struct dst_ops *ops)
982 {
983 static unsigned long expire = RT_GC_TIMEOUT;
984 static unsigned long last_gc;
985 static int rover;
986 static int equilibrium;
987 struct rtable *rth;
988 struct rtable __rcu **rthp;
989 unsigned long now = jiffies;
990 int goal;
991 int entries = dst_entries_get_fast(&ipv4_dst_ops);
992
993 /*
994 * Garbage collection is pretty expensive,
995 * do not make it too frequently.
996 */
997
998 RT_CACHE_STAT_INC(gc_total);
999
1000 if (now - last_gc < ip_rt_gc_min_interval &&
1001 entries < ip_rt_max_size) {
1002 RT_CACHE_STAT_INC(gc_ignored);
1003 goto out;
1004 }
1005
1006 entries = dst_entries_get_slow(&ipv4_dst_ops);
1007 /* Calculate number of entries, which we want to expire now. */
1008 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1009 if (goal <= 0) {
1010 if (equilibrium < ipv4_dst_ops.gc_thresh)
1011 equilibrium = ipv4_dst_ops.gc_thresh;
1012 goal = entries - equilibrium;
1013 if (goal > 0) {
1014 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1015 goal = entries - equilibrium;
1016 }
1017 } else {
1018 /* We are in dangerous area. Try to reduce cache really
1019 * aggressively.
1020 */
1021 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1022 equilibrium = entries - goal;
1023 }
1024
1025 if (now - last_gc >= ip_rt_gc_min_interval)
1026 last_gc = now;
1027
1028 if (goal <= 0) {
1029 equilibrium += goal;
1030 goto work_done;
1031 }
1032
1033 do {
1034 int i, k;
1035
1036 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1037 unsigned long tmo = expire;
1038
1039 k = (k + 1) & rt_hash_mask;
1040 rthp = &rt_hash_table[k].chain;
1041 spin_lock_bh(rt_hash_lock_addr(k));
1042 while ((rth = rcu_dereference_protected(*rthp,
1043 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1044 if (!rt_is_expired(rth) &&
1045 !rt_may_expire(rth, tmo, expire)) {
1046 tmo >>= 1;
1047 rthp = &rth->dst.rt_next;
1048 continue;
1049 }
1050 *rthp = rth->dst.rt_next;
1051 rt_free(rth);
1052 goal--;
1053 }
1054 spin_unlock_bh(rt_hash_lock_addr(k));
1055 if (goal <= 0)
1056 break;
1057 }
1058 rover = k;
1059
1060 if (goal <= 0)
1061 goto work_done;
1062
1063 /* Goal is not achieved. We stop process if:
1064
1065 - if expire reduced to zero. Otherwise, expire is halfed.
1066 - if table is not full.
1067 - if we are called from interrupt.
1068 - jiffies check is just fallback/debug loop breaker.
1069 We will not spin here for long time in any case.
1070 */
1071
1072 RT_CACHE_STAT_INC(gc_goal_miss);
1073
1074 if (expire == 0)
1075 break;
1076
1077 expire >>= 1;
1078
1079 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1080 goto out;
1081 } while (!in_softirq() && time_before_eq(jiffies, now));
1082
1083 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1084 goto out;
1085 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1086 goto out;
1087 if (net_ratelimit())
1088 printk(KERN_WARNING "dst cache overflow\n");
1089 RT_CACHE_STAT_INC(gc_dst_overflow);
1090 return 1;
1091
1092 work_done:
1093 expire += ip_rt_gc_min_interval;
1094 if (expire > ip_rt_gc_timeout ||
1095 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1096 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1097 expire = ip_rt_gc_timeout;
1098 out: return 0;
1099 }
1100
1101 /*
1102 * Returns number of entries in a hash chain that have different hash_inputs
1103 */
1104 static int slow_chain_length(const struct rtable *head)
1105 {
1106 int length = 0;
1107 const struct rtable *rth = head;
1108
1109 while (rth) {
1110 length += has_noalias(head, rth);
1111 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1112 }
1113 return length >> FRACT_BITS;
1114 }
1115
1116 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1117 {
1118 struct neigh_table *tbl = &arp_tbl;
1119 static const __be32 inaddr_any = 0;
1120 struct net_device *dev = dst->dev;
1121 const __be32 *pkey = daddr;
1122 struct neighbour *n;
1123
1124 #if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1125 if (dev->type == ARPHRD_ATM)
1126 tbl = clip_tbl_hook;
1127 #endif
1128 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1129 pkey = &inaddr_any;
1130
1131 n = __ipv4_neigh_lookup(tbl, dev, *(__force u32 *)pkey);
1132 if (n)
1133 return n;
1134 return neigh_create(tbl, pkey, dev);
1135 }
1136
1137 static int rt_bind_neighbour(struct rtable *rt)
1138 {
1139 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1140 if (IS_ERR(n))
1141 return PTR_ERR(n);
1142 dst_set_neighbour(&rt->dst, n);
1143
1144 return 0;
1145 }
1146
1147 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1148 struct sk_buff *skb, int ifindex)
1149 {
1150 struct rtable *rth, *cand;
1151 struct rtable __rcu **rthp, **candp;
1152 unsigned long now;
1153 u32 min_score;
1154 int chain_length;
1155 int attempts = !in_softirq();
1156
1157 restart:
1158 chain_length = 0;
1159 min_score = ~(u32)0;
1160 cand = NULL;
1161 candp = NULL;
1162 now = jiffies;
1163
1164 if (!rt_caching(dev_net(rt->dst.dev))) {
1165 /*
1166 * If we're not caching, just tell the caller we
1167 * were successful and don't touch the route. The
1168 * caller hold the sole reference to the cache entry, and
1169 * it will be released when the caller is done with it.
1170 * If we drop it here, the callers have no way to resolve routes
1171 * when we're not caching. Instead, just point *rp at rt, so
1172 * the caller gets a single use out of the route
1173 * Note that we do rt_free on this new route entry, so that
1174 * once its refcount hits zero, we are still able to reap it
1175 * (Thanks Alexey)
1176 * Note: To avoid expensive rcu stuff for this uncached dst,
1177 * we set DST_NOCACHE so that dst_release() can free dst without
1178 * waiting a grace period.
1179 */
1180
1181 rt->dst.flags |= DST_NOCACHE;
1182 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1183 int err = rt_bind_neighbour(rt);
1184 if (err) {
1185 if (net_ratelimit())
1186 printk(KERN_WARNING
1187 "Neighbour table failure & not caching routes.\n");
1188 ip_rt_put(rt);
1189 return ERR_PTR(err);
1190 }
1191 }
1192
1193 goto skip_hashing;
1194 }
1195
1196 rthp = &rt_hash_table[hash].chain;
1197
1198 spin_lock_bh(rt_hash_lock_addr(hash));
1199 while ((rth = rcu_dereference_protected(*rthp,
1200 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1201 if (rt_is_expired(rth)) {
1202 *rthp = rth->dst.rt_next;
1203 rt_free(rth);
1204 continue;
1205 }
1206 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1207 /* Put it first */
1208 *rthp = rth->dst.rt_next;
1209 /*
1210 * Since lookup is lockfree, the deletion
1211 * must be visible to another weakly ordered CPU before
1212 * the insertion at the start of the hash chain.
1213 */
1214 rcu_assign_pointer(rth->dst.rt_next,
1215 rt_hash_table[hash].chain);
1216 /*
1217 * Since lookup is lockfree, the update writes
1218 * must be ordered for consistency on SMP.
1219 */
1220 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1221
1222 dst_use(&rth->dst, now);
1223 spin_unlock_bh(rt_hash_lock_addr(hash));
1224
1225 rt_drop(rt);
1226 if (skb)
1227 skb_dst_set(skb, &rth->dst);
1228 return rth;
1229 }
1230
1231 if (!atomic_read(&rth->dst.__refcnt)) {
1232 u32 score = rt_score(rth);
1233
1234 if (score <= min_score) {
1235 cand = rth;
1236 candp = rthp;
1237 min_score = score;
1238 }
1239 }
1240
1241 chain_length++;
1242
1243 rthp = &rth->dst.rt_next;
1244 }
1245
1246 if (cand) {
1247 /* ip_rt_gc_elasticity used to be average length of chain
1248 * length, when exceeded gc becomes really aggressive.
1249 *
1250 * The second limit is less certain. At the moment it allows
1251 * only 2 entries per bucket. We will see.
1252 */
1253 if (chain_length > ip_rt_gc_elasticity) {
1254 *candp = cand->dst.rt_next;
1255 rt_free(cand);
1256 }
1257 } else {
1258 if (chain_length > rt_chain_length_max &&
1259 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1260 struct net *net = dev_net(rt->dst.dev);
1261 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1262 if (!rt_caching(net)) {
1263 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1264 rt->dst.dev->name, num);
1265 }
1266 rt_emergency_hash_rebuild(net);
1267 spin_unlock_bh(rt_hash_lock_addr(hash));
1268
1269 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1270 ifindex, rt_genid(net));
1271 goto restart;
1272 }
1273 }
1274
1275 /* Try to bind route to arp only if it is output
1276 route or unicast forwarding path.
1277 */
1278 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1279 int err = rt_bind_neighbour(rt);
1280 if (err) {
1281 spin_unlock_bh(rt_hash_lock_addr(hash));
1282
1283 if (err != -ENOBUFS) {
1284 rt_drop(rt);
1285 return ERR_PTR(err);
1286 }
1287
1288 /* Neighbour tables are full and nothing
1289 can be released. Try to shrink route cache,
1290 it is most likely it holds some neighbour records.
1291 */
1292 if (attempts-- > 0) {
1293 int saved_elasticity = ip_rt_gc_elasticity;
1294 int saved_int = ip_rt_gc_min_interval;
1295 ip_rt_gc_elasticity = 1;
1296 ip_rt_gc_min_interval = 0;
1297 rt_garbage_collect(&ipv4_dst_ops);
1298 ip_rt_gc_min_interval = saved_int;
1299 ip_rt_gc_elasticity = saved_elasticity;
1300 goto restart;
1301 }
1302
1303 if (net_ratelimit())
1304 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1305 rt_drop(rt);
1306 return ERR_PTR(-ENOBUFS);
1307 }
1308 }
1309
1310 rt->dst.rt_next = rt_hash_table[hash].chain;
1311
1312 /*
1313 * Since lookup is lockfree, we must make sure
1314 * previous writes to rt are committed to memory
1315 * before making rt visible to other CPUS.
1316 */
1317 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1318
1319 spin_unlock_bh(rt_hash_lock_addr(hash));
1320
1321 skip_hashing:
1322 if (skb)
1323 skb_dst_set(skb, &rt->dst);
1324 return rt;
1325 }
1326
1327 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1328
1329 static u32 rt_peer_genid(void)
1330 {
1331 return atomic_read(&__rt_peer_genid);
1332 }
1333
1334 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1335 {
1336 struct inet_peer *peer;
1337
1338 peer = inet_getpeer_v4(daddr, create);
1339
1340 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1341 inet_putpeer(peer);
1342 else
1343 rt->rt_peer_genid = rt_peer_genid();
1344 }
1345
1346 /*
1347 * Peer allocation may fail only in serious out-of-memory conditions. However
1348 * we still can generate some output.
1349 * Random ID selection looks a bit dangerous because we have no chances to
1350 * select ID being unique in a reasonable period of time.
1351 * But broken packet identifier may be better than no packet at all.
1352 */
1353 static void ip_select_fb_ident(struct iphdr *iph)
1354 {
1355 static DEFINE_SPINLOCK(ip_fb_id_lock);
1356 static u32 ip_fallback_id;
1357 u32 salt;
1358
1359 spin_lock_bh(&ip_fb_id_lock);
1360 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1361 iph->id = htons(salt & 0xFFFF);
1362 ip_fallback_id = salt;
1363 spin_unlock_bh(&ip_fb_id_lock);
1364 }
1365
1366 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1367 {
1368 struct rtable *rt = (struct rtable *) dst;
1369
1370 if (rt && !(rt->dst.flags & DST_NOPEER)) {
1371 if (rt->peer == NULL)
1372 rt_bind_peer(rt, rt->rt_dst, 1);
1373
1374 /* If peer is attached to destination, it is never detached,
1375 so that we need not to grab a lock to dereference it.
1376 */
1377 if (rt->peer) {
1378 iph->id = htons(inet_getid(rt->peer, more));
1379 return;
1380 }
1381 } else if (!rt)
1382 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1383 __builtin_return_address(0));
1384
1385 ip_select_fb_ident(iph);
1386 }
1387 EXPORT_SYMBOL(__ip_select_ident);
1388
1389 static void rt_del(unsigned hash, struct rtable *rt)
1390 {
1391 struct rtable __rcu **rthp;
1392 struct rtable *aux;
1393
1394 rthp = &rt_hash_table[hash].chain;
1395 spin_lock_bh(rt_hash_lock_addr(hash));
1396 ip_rt_put(rt);
1397 while ((aux = rcu_dereference_protected(*rthp,
1398 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1399 if (aux == rt || rt_is_expired(aux)) {
1400 *rthp = aux->dst.rt_next;
1401 rt_free(aux);
1402 continue;
1403 }
1404 rthp = &aux->dst.rt_next;
1405 }
1406 spin_unlock_bh(rt_hash_lock_addr(hash));
1407 }
1408
1409 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1410 {
1411 struct rtable *rt = (struct rtable *) dst;
1412 __be32 orig_gw = rt->rt_gateway;
1413 struct neighbour *n, *old_n;
1414
1415 dst_confirm(&rt->dst);
1416
1417 rt->rt_gateway = peer->redirect_learned.a4;
1418
1419 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1420 if (IS_ERR(n)) {
1421 rt->rt_gateway = orig_gw;
1422 return;
1423 }
1424 old_n = xchg(&rt->dst._neighbour, n);
1425 if (old_n)
1426 neigh_release(old_n);
1427 if (!(n->nud_state & NUD_VALID)) {
1428 neigh_event_send(n, NULL);
1429 } else {
1430 rt->rt_flags |= RTCF_REDIRECTED;
1431 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1432 }
1433 }
1434
1435 /* called in rcu_read_lock() section */
1436 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1437 __be32 saddr, struct net_device *dev)
1438 {
1439 int s, i;
1440 struct in_device *in_dev = __in_dev_get_rcu(dev);
1441 __be32 skeys[2] = { saddr, 0 };
1442 int ikeys[2] = { dev->ifindex, 0 };
1443 struct inet_peer *peer;
1444 struct net *net;
1445
1446 if (!in_dev)
1447 return;
1448
1449 net = dev_net(dev);
1450 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1451 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1452 ipv4_is_zeronet(new_gw))
1453 goto reject_redirect;
1454
1455 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1456 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1457 goto reject_redirect;
1458 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1459 goto reject_redirect;
1460 } else {
1461 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1462 goto reject_redirect;
1463 }
1464
1465 for (s = 0; s < 2; s++) {
1466 for (i = 0; i < 2; i++) {
1467 unsigned int hash;
1468 struct rtable __rcu **rthp;
1469 struct rtable *rt;
1470
1471 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1472
1473 rthp = &rt_hash_table[hash].chain;
1474
1475 while ((rt = rcu_dereference(*rthp)) != NULL) {
1476 rthp = &rt->dst.rt_next;
1477
1478 if (rt->rt_key_dst != daddr ||
1479 rt->rt_key_src != skeys[s] ||
1480 rt->rt_oif != ikeys[i] ||
1481 rt_is_input_route(rt) ||
1482 rt_is_expired(rt) ||
1483 !net_eq(dev_net(rt->dst.dev), net) ||
1484 rt->dst.error ||
1485 rt->dst.dev != dev ||
1486 rt->rt_gateway != old_gw)
1487 continue;
1488
1489 if (!rt->peer)
1490 rt_bind_peer(rt, rt->rt_dst, 1);
1491
1492 peer = rt->peer;
1493 if (peer) {
1494 if (peer->redirect_learned.a4 != new_gw ||
1495 peer->redirect_genid != redirect_genid) {
1496 peer->redirect_learned.a4 = new_gw;
1497 peer->redirect_genid = redirect_genid;
1498 atomic_inc(&__rt_peer_genid);
1499 }
1500 check_peer_redir(&rt->dst, peer);
1501 }
1502 }
1503 }
1504 }
1505 return;
1506
1507 reject_redirect:
1508 #ifdef CONFIG_IP_ROUTE_VERBOSE
1509 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1510 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1511 " Advised path = %pI4 -> %pI4\n",
1512 &old_gw, dev->name, &new_gw,
1513 &saddr, &daddr);
1514 #endif
1515 ;
1516 }
1517
1518 static bool peer_pmtu_expired(struct inet_peer *peer)
1519 {
1520 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1521
1522 return orig &&
1523 time_after_eq(jiffies, orig) &&
1524 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1525 }
1526
1527 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1528 {
1529 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1530
1531 return orig &&
1532 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1533 }
1534
1535 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1536 {
1537 struct rtable *rt = (struct rtable *)dst;
1538 struct dst_entry *ret = dst;
1539
1540 if (rt) {
1541 if (dst->obsolete > 0) {
1542 ip_rt_put(rt);
1543 ret = NULL;
1544 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1545 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1546 rt->rt_oif,
1547 rt_genid(dev_net(dst->dev)));
1548 rt_del(hash, rt);
1549 ret = NULL;
1550 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1551 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1552 }
1553 }
1554 return ret;
1555 }
1556
1557 /*
1558 * Algorithm:
1559 * 1. The first ip_rt_redirect_number redirects are sent
1560 * with exponential backoff, then we stop sending them at all,
1561 * assuming that the host ignores our redirects.
1562 * 2. If we did not see packets requiring redirects
1563 * during ip_rt_redirect_silence, we assume that the host
1564 * forgot redirected route and start to send redirects again.
1565 *
1566 * This algorithm is much cheaper and more intelligent than dumb load limiting
1567 * in icmp.c.
1568 *
1569 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1570 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1571 */
1572
1573 void ip_rt_send_redirect(struct sk_buff *skb)
1574 {
1575 struct rtable *rt = skb_rtable(skb);
1576 struct in_device *in_dev;
1577 struct inet_peer *peer;
1578 int log_martians;
1579
1580 rcu_read_lock();
1581 in_dev = __in_dev_get_rcu(rt->dst.dev);
1582 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1583 rcu_read_unlock();
1584 return;
1585 }
1586 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1587 rcu_read_unlock();
1588
1589 if (!rt->peer)
1590 rt_bind_peer(rt, rt->rt_dst, 1);
1591 peer = rt->peer;
1592 if (!peer) {
1593 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1594 return;
1595 }
1596
1597 /* No redirected packets during ip_rt_redirect_silence;
1598 * reset the algorithm.
1599 */
1600 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1601 peer->rate_tokens = 0;
1602
1603 /* Too many ignored redirects; do not send anything
1604 * set dst.rate_last to the last seen redirected packet.
1605 */
1606 if (peer->rate_tokens >= ip_rt_redirect_number) {
1607 peer->rate_last = jiffies;
1608 return;
1609 }
1610
1611 /* Check for load limit; set rate_last to the latest sent
1612 * redirect.
1613 */
1614 if (peer->rate_tokens == 0 ||
1615 time_after(jiffies,
1616 (peer->rate_last +
1617 (ip_rt_redirect_load << peer->rate_tokens)))) {
1618 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1619 peer->rate_last = jiffies;
1620 ++peer->rate_tokens;
1621 #ifdef CONFIG_IP_ROUTE_VERBOSE
1622 if (log_martians &&
1623 peer->rate_tokens == ip_rt_redirect_number &&
1624 net_ratelimit())
1625 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1626 &ip_hdr(skb)->saddr, rt->rt_iif,
1627 &rt->rt_dst, &rt->rt_gateway);
1628 #endif
1629 }
1630 }
1631
1632 static int ip_error(struct sk_buff *skb)
1633 {
1634 struct rtable *rt = skb_rtable(skb);
1635 struct inet_peer *peer;
1636 unsigned long now;
1637 bool send;
1638 int code;
1639
1640 switch (rt->dst.error) {
1641 case EINVAL:
1642 default:
1643 goto out;
1644 case EHOSTUNREACH:
1645 code = ICMP_HOST_UNREACH;
1646 break;
1647 case ENETUNREACH:
1648 code = ICMP_NET_UNREACH;
1649 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1650 IPSTATS_MIB_INNOROUTES);
1651 break;
1652 case EACCES:
1653 code = ICMP_PKT_FILTERED;
1654 break;
1655 }
1656
1657 if (!rt->peer)
1658 rt_bind_peer(rt, rt->rt_dst, 1);
1659 peer = rt->peer;
1660
1661 send = true;
1662 if (peer) {
1663 now = jiffies;
1664 peer->rate_tokens += now - peer->rate_last;
1665 if (peer->rate_tokens > ip_rt_error_burst)
1666 peer->rate_tokens = ip_rt_error_burst;
1667 peer->rate_last = now;
1668 if (peer->rate_tokens >= ip_rt_error_cost)
1669 peer->rate_tokens -= ip_rt_error_cost;
1670 else
1671 send = false;
1672 }
1673 if (send)
1674 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1675
1676 out: kfree_skb(skb);
1677 return 0;
1678 }
1679
1680 /*
1681 * The last two values are not from the RFC but
1682 * are needed for AMPRnet AX.25 paths.
1683 */
1684
1685 static const unsigned short mtu_plateau[] =
1686 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1687
1688 static inline unsigned short guess_mtu(unsigned short old_mtu)
1689 {
1690 int i;
1691
1692 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1693 if (old_mtu > mtu_plateau[i])
1694 return mtu_plateau[i];
1695 return 68;
1696 }
1697
1698 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1699 unsigned short new_mtu,
1700 struct net_device *dev)
1701 {
1702 unsigned short old_mtu = ntohs(iph->tot_len);
1703 unsigned short est_mtu = 0;
1704 struct inet_peer *peer;
1705
1706 peer = inet_getpeer_v4(iph->daddr, 1);
1707 if (peer) {
1708 unsigned short mtu = new_mtu;
1709
1710 if (new_mtu < 68 || new_mtu >= old_mtu) {
1711 /* BSD 4.2 derived systems incorrectly adjust
1712 * tot_len by the IP header length, and report
1713 * a zero MTU in the ICMP message.
1714 */
1715 if (mtu == 0 &&
1716 old_mtu >= 68 + (iph->ihl << 2))
1717 old_mtu -= iph->ihl << 2;
1718 mtu = guess_mtu(old_mtu);
1719 }
1720
1721 if (mtu < ip_rt_min_pmtu)
1722 mtu = ip_rt_min_pmtu;
1723 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1724 unsigned long pmtu_expires;
1725
1726 pmtu_expires = jiffies + ip_rt_mtu_expires;
1727 if (!pmtu_expires)
1728 pmtu_expires = 1UL;
1729
1730 est_mtu = mtu;
1731 peer->pmtu_learned = mtu;
1732 peer->pmtu_expires = pmtu_expires;
1733 atomic_inc(&__rt_peer_genid);
1734 }
1735
1736 inet_putpeer(peer);
1737 }
1738 return est_mtu ? : new_mtu;
1739 }
1740
1741 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1742 {
1743 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1744
1745 if (!expires)
1746 return;
1747 if (time_before(jiffies, expires)) {
1748 u32 orig_dst_mtu = dst_mtu(dst);
1749 if (peer->pmtu_learned < orig_dst_mtu) {
1750 if (!peer->pmtu_orig)
1751 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1752 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1753 }
1754 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1755 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1756 }
1757
1758 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1759 {
1760 struct rtable *rt = (struct rtable *) dst;
1761 struct inet_peer *peer;
1762
1763 dst_confirm(dst);
1764
1765 if (!rt->peer)
1766 rt_bind_peer(rt, rt->rt_dst, 1);
1767 peer = rt->peer;
1768 if (peer) {
1769 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1770
1771 if (mtu < ip_rt_min_pmtu)
1772 mtu = ip_rt_min_pmtu;
1773 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1774
1775 pmtu_expires = jiffies + ip_rt_mtu_expires;
1776 if (!pmtu_expires)
1777 pmtu_expires = 1UL;
1778
1779 peer->pmtu_learned = mtu;
1780 peer->pmtu_expires = pmtu_expires;
1781
1782 atomic_inc(&__rt_peer_genid);
1783 rt->rt_peer_genid = rt_peer_genid();
1784 }
1785 check_peer_pmtu(dst, peer);
1786 }
1787 }
1788
1789
1790 static void ipv4_validate_peer(struct rtable *rt)
1791 {
1792 if (rt->rt_peer_genid != rt_peer_genid()) {
1793 struct inet_peer *peer;
1794
1795 if (!rt->peer)
1796 rt_bind_peer(rt, rt->rt_dst, 0);
1797
1798 peer = rt->peer;
1799 if (peer) {
1800 check_peer_pmtu(&rt->dst, peer);
1801
1802 if (peer->redirect_genid != redirect_genid)
1803 peer->redirect_learned.a4 = 0;
1804 if (peer->redirect_learned.a4 &&
1805 peer->redirect_learned.a4 != rt->rt_gateway)
1806 check_peer_redir(&rt->dst, peer);
1807 }
1808
1809 rt->rt_peer_genid = rt_peer_genid();
1810 }
1811 }
1812
1813 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1814 {
1815 struct rtable *rt = (struct rtable *) dst;
1816
1817 if (rt_is_expired(rt))
1818 return NULL;
1819 ipv4_validate_peer(rt);
1820 return dst;
1821 }
1822
1823 static void ipv4_dst_destroy(struct dst_entry *dst)
1824 {
1825 struct rtable *rt = (struct rtable *) dst;
1826 struct inet_peer *peer = rt->peer;
1827
1828 if (rt->fi) {
1829 fib_info_put(rt->fi);
1830 rt->fi = NULL;
1831 }
1832 if (peer) {
1833 rt->peer = NULL;
1834 inet_putpeer(peer);
1835 }
1836 }
1837
1838
1839 static void ipv4_link_failure(struct sk_buff *skb)
1840 {
1841 struct rtable *rt;
1842
1843 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1844
1845 rt = skb_rtable(skb);
1846 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1847 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1848 }
1849
1850 static int ip_rt_bug(struct sk_buff *skb)
1851 {
1852 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1853 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1854 skb->dev ? skb->dev->name : "?");
1855 kfree_skb(skb);
1856 WARN_ON(1);
1857 return 0;
1858 }
1859
1860 /*
1861 We do not cache source address of outgoing interface,
1862 because it is used only by IP RR, TS and SRR options,
1863 so that it out of fast path.
1864
1865 BTW remember: "addr" is allowed to be not aligned
1866 in IP options!
1867 */
1868
1869 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1870 {
1871 __be32 src;
1872
1873 if (rt_is_output_route(rt))
1874 src = ip_hdr(skb)->saddr;
1875 else {
1876 struct fib_result res;
1877 struct flowi4 fl4;
1878 struct iphdr *iph;
1879
1880 iph = ip_hdr(skb);
1881
1882 memset(&fl4, 0, sizeof(fl4));
1883 fl4.daddr = iph->daddr;
1884 fl4.saddr = iph->saddr;
1885 fl4.flowi4_tos = RT_TOS(iph->tos);
1886 fl4.flowi4_oif = rt->dst.dev->ifindex;
1887 fl4.flowi4_iif = skb->dev->ifindex;
1888 fl4.flowi4_mark = skb->mark;
1889
1890 rcu_read_lock();
1891 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1892 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1893 else
1894 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1895 RT_SCOPE_UNIVERSE);
1896 rcu_read_unlock();
1897 }
1898 memcpy(addr, &src, 4);
1899 }
1900
1901 #ifdef CONFIG_IP_ROUTE_CLASSID
1902 static void set_class_tag(struct rtable *rt, u32 tag)
1903 {
1904 if (!(rt->dst.tclassid & 0xFFFF))
1905 rt->dst.tclassid |= tag & 0xFFFF;
1906 if (!(rt->dst.tclassid & 0xFFFF0000))
1907 rt->dst.tclassid |= tag & 0xFFFF0000;
1908 }
1909 #endif
1910
1911 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1912 {
1913 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1914
1915 if (advmss == 0) {
1916 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1917 ip_rt_min_advmss);
1918 if (advmss > 65535 - 40)
1919 advmss = 65535 - 40;
1920 }
1921 return advmss;
1922 }
1923
1924 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1925 {
1926 const struct rtable *rt = (const struct rtable *) dst;
1927 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1928
1929 if (mtu && rt_is_output_route(rt))
1930 return mtu;
1931
1932 mtu = dst->dev->mtu;
1933
1934 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1935
1936 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1937 mtu = 576;
1938 }
1939
1940 if (mtu > IP_MAX_MTU)
1941 mtu = IP_MAX_MTU;
1942
1943 return mtu;
1944 }
1945
1946 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1947 struct fib_info *fi)
1948 {
1949 struct inet_peer *peer;
1950 int create = 0;
1951
1952 /* If a peer entry exists for this destination, we must hook
1953 * it up in order to get at cached metrics.
1954 */
1955 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1956 create = 1;
1957
1958 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1959 if (peer) {
1960 rt->rt_peer_genid = rt_peer_genid();
1961 if (inet_metrics_new(peer))
1962 memcpy(peer->metrics, fi->fib_metrics,
1963 sizeof(u32) * RTAX_MAX);
1964 dst_init_metrics(&rt->dst, peer->metrics, false);
1965
1966 check_peer_pmtu(&rt->dst, peer);
1967 if (peer->redirect_genid != redirect_genid)
1968 peer->redirect_learned.a4 = 0;
1969 if (peer->redirect_learned.a4 &&
1970 peer->redirect_learned.a4 != rt->rt_gateway) {
1971 rt->rt_gateway = peer->redirect_learned.a4;
1972 rt->rt_flags |= RTCF_REDIRECTED;
1973 }
1974 } else {
1975 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1976 rt->fi = fi;
1977 atomic_inc(&fi->fib_clntref);
1978 }
1979 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1980 }
1981 }
1982
1983 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1984 const struct fib_result *res,
1985 struct fib_info *fi, u16 type, u32 itag)
1986 {
1987 struct dst_entry *dst = &rt->dst;
1988
1989 if (fi) {
1990 if (FIB_RES_GW(*res) &&
1991 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1992 rt->rt_gateway = FIB_RES_GW(*res);
1993 rt_init_metrics(rt, fl4, fi);
1994 #ifdef CONFIG_IP_ROUTE_CLASSID
1995 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1996 #endif
1997 }
1998
1999 if (dst_mtu(dst) > IP_MAX_MTU)
2000 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
2001 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
2002 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
2003
2004 #ifdef CONFIG_IP_ROUTE_CLASSID
2005 #ifdef CONFIG_IP_MULTIPLE_TABLES
2006 set_class_tag(rt, fib_rules_tclass(res));
2007 #endif
2008 set_class_tag(rt, itag);
2009 #endif
2010 }
2011
2012 static struct rtable *rt_dst_alloc(struct net_device *dev,
2013 bool nopolicy, bool noxfrm)
2014 {
2015 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
2016 DST_HOST |
2017 (nopolicy ? DST_NOPOLICY : 0) |
2018 (noxfrm ? DST_NOXFRM : 0));
2019 }
2020
2021 /* called in rcu_read_lock() section */
2022 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2023 u8 tos, struct net_device *dev, int our)
2024 {
2025 unsigned int hash;
2026 struct rtable *rth;
2027 __be32 spec_dst;
2028 struct in_device *in_dev = __in_dev_get_rcu(dev);
2029 u32 itag = 0;
2030 int err;
2031
2032 /* Primary sanity checks. */
2033
2034 if (in_dev == NULL)
2035 return -EINVAL;
2036
2037 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2038 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
2039 goto e_inval;
2040
2041 if (ipv4_is_zeronet(saddr)) {
2042 if (!ipv4_is_local_multicast(daddr))
2043 goto e_inval;
2044 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2045 } else {
2046 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2047 &itag);
2048 if (err < 0)
2049 goto e_err;
2050 }
2051 rth = rt_dst_alloc(init_net.loopback_dev,
2052 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2053 if (!rth)
2054 goto e_nobufs;
2055
2056 #ifdef CONFIG_IP_ROUTE_CLASSID
2057 rth->dst.tclassid = itag;
2058 #endif
2059 rth->dst.output = ip_rt_bug;
2060
2061 rth->rt_key_dst = daddr;
2062 rth->rt_key_src = saddr;
2063 rth->rt_genid = rt_genid(dev_net(dev));
2064 rth->rt_flags = RTCF_MULTICAST;
2065 rth->rt_type = RTN_MULTICAST;
2066 rth->rt_key_tos = tos;
2067 rth->rt_dst = daddr;
2068 rth->rt_src = saddr;
2069 rth->rt_route_iif = dev->ifindex;
2070 rth->rt_iif = dev->ifindex;
2071 rth->rt_oif = 0;
2072 rth->rt_mark = skb->mark;
2073 rth->rt_gateway = daddr;
2074 rth->rt_spec_dst= spec_dst;
2075 rth->rt_peer_genid = 0;
2076 rth->peer = NULL;
2077 rth->fi = NULL;
2078 if (our) {
2079 rth->dst.input= ip_local_deliver;
2080 rth->rt_flags |= RTCF_LOCAL;
2081 }
2082
2083 #ifdef CONFIG_IP_MROUTE
2084 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
2085 rth->dst.input = ip_mr_input;
2086 #endif
2087 RT_CACHE_STAT_INC(in_slow_mc);
2088
2089 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
2090 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
2091 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2092
2093 e_nobufs:
2094 return -ENOBUFS;
2095 e_inval:
2096 return -EINVAL;
2097 e_err:
2098 return err;
2099 }
2100
2101
2102 static void ip_handle_martian_source(struct net_device *dev,
2103 struct in_device *in_dev,
2104 struct sk_buff *skb,
2105 __be32 daddr,
2106 __be32 saddr)
2107 {
2108 RT_CACHE_STAT_INC(in_martian_src);
2109 #ifdef CONFIG_IP_ROUTE_VERBOSE
2110 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2111 /*
2112 * RFC1812 recommendation, if source is martian,
2113 * the only hint is MAC header.
2114 */
2115 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2116 &daddr, &saddr, dev->name);
2117 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2118 int i;
2119 const unsigned char *p = skb_mac_header(skb);
2120 printk(KERN_WARNING "ll header: ");
2121 for (i = 0; i < dev->hard_header_len; i++, p++) {
2122 printk("%02x", *p);
2123 if (i < (dev->hard_header_len - 1))
2124 printk(":");
2125 }
2126 printk("\n");
2127 }
2128 }
2129 #endif
2130 }
2131
2132 /* called in rcu_read_lock() section */
2133 static int __mkroute_input(struct sk_buff *skb,
2134 const struct fib_result *res,
2135 struct in_device *in_dev,
2136 __be32 daddr, __be32 saddr, u32 tos,
2137 struct rtable **result)
2138 {
2139 struct rtable *rth;
2140 int err;
2141 struct in_device *out_dev;
2142 unsigned int flags = 0;
2143 __be32 spec_dst;
2144 u32 itag;
2145
2146 /* get a working reference to the output device */
2147 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2148 if (out_dev == NULL) {
2149 if (net_ratelimit())
2150 printk(KERN_CRIT "Bug in ip_route_input" \
2151 "_slow(). Please, report\n");
2152 return -EINVAL;
2153 }
2154
2155
2156 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2157 in_dev->dev, &spec_dst, &itag);
2158 if (err < 0) {
2159 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2160 saddr);
2161
2162 goto cleanup;
2163 }
2164
2165 if (err)
2166 flags |= RTCF_DIRECTSRC;
2167
2168 if (out_dev == in_dev && err &&
2169 (IN_DEV_SHARED_MEDIA(out_dev) ||
2170 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2171 flags |= RTCF_DOREDIRECT;
2172
2173 if (skb->protocol != htons(ETH_P_IP)) {
2174 /* Not IP (i.e. ARP). Do not create route, if it is
2175 * invalid for proxy arp. DNAT routes are always valid.
2176 *
2177 * Proxy arp feature have been extended to allow, ARP
2178 * replies back to the same interface, to support
2179 * Private VLAN switch technologies. See arp.c.
2180 */
2181 if (out_dev == in_dev &&
2182 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2183 err = -EINVAL;
2184 goto cleanup;
2185 }
2186 }
2187
2188 rth = rt_dst_alloc(out_dev->dev,
2189 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2190 IN_DEV_CONF_GET(out_dev, NOXFRM));
2191 if (!rth) {
2192 err = -ENOBUFS;
2193 goto cleanup;
2194 }
2195
2196 rth->rt_key_dst = daddr;
2197 rth->rt_key_src = saddr;
2198 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2199 rth->rt_flags = flags;
2200 rth->rt_type = res->type;
2201 rth->rt_key_tos = tos;
2202 rth->rt_dst = daddr;
2203 rth->rt_src = saddr;
2204 rth->rt_route_iif = in_dev->dev->ifindex;
2205 rth->rt_iif = in_dev->dev->ifindex;
2206 rth->rt_oif = 0;
2207 rth->rt_mark = skb->mark;
2208 rth->rt_gateway = daddr;
2209 rth->rt_spec_dst= spec_dst;
2210 rth->rt_peer_genid = 0;
2211 rth->peer = NULL;
2212 rth->fi = NULL;
2213
2214 rth->dst.input = ip_forward;
2215 rth->dst.output = ip_output;
2216
2217 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2218
2219 *result = rth;
2220 err = 0;
2221 cleanup:
2222 return err;
2223 }
2224
2225 static int ip_mkroute_input(struct sk_buff *skb,
2226 struct fib_result *res,
2227 const struct flowi4 *fl4,
2228 struct in_device *in_dev,
2229 __be32 daddr, __be32 saddr, u32 tos)
2230 {
2231 struct rtable* rth = NULL;
2232 int err;
2233 unsigned hash;
2234
2235 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2236 if (res->fi && res->fi->fib_nhs > 1)
2237 fib_select_multipath(res);
2238 #endif
2239
2240 /* create a routing cache entry */
2241 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2242 if (err)
2243 return err;
2244
2245 /* put it into the cache */
2246 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2247 rt_genid(dev_net(rth->dst.dev)));
2248 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2249 if (IS_ERR(rth))
2250 return PTR_ERR(rth);
2251 return 0;
2252 }
2253
2254 /*
2255 * NOTE. We drop all the packets that has local source
2256 * addresses, because every properly looped back packet
2257 * must have correct destination already attached by output routine.
2258 *
2259 * Such approach solves two big problems:
2260 * 1. Not simplex devices are handled properly.
2261 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2262 * called with rcu_read_lock()
2263 */
2264
2265 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2266 u8 tos, struct net_device *dev)
2267 {
2268 struct fib_result res;
2269 struct in_device *in_dev = __in_dev_get_rcu(dev);
2270 struct flowi4 fl4;
2271 unsigned flags = 0;
2272 u32 itag = 0;
2273 struct rtable * rth;
2274 unsigned hash;
2275 __be32 spec_dst;
2276 int err = -EINVAL;
2277 struct net * net = dev_net(dev);
2278
2279 /* IP on this device is disabled. */
2280
2281 if (!in_dev)
2282 goto out;
2283
2284 /* Check for the most weird martians, which can be not detected
2285 by fib_lookup.
2286 */
2287
2288 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2289 ipv4_is_loopback(saddr))
2290 goto martian_source;
2291
2292 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2293 goto brd_input;
2294
2295 /* Accept zero addresses only to limited broadcast;
2296 * I even do not know to fix it or not. Waiting for complains :-)
2297 */
2298 if (ipv4_is_zeronet(saddr))
2299 goto martian_source;
2300
2301 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2302 goto martian_destination;
2303
2304 /*
2305 * Now we are ready to route packet.
2306 */
2307 fl4.flowi4_oif = 0;
2308 fl4.flowi4_iif = dev->ifindex;
2309 fl4.flowi4_mark = skb->mark;
2310 fl4.flowi4_tos = tos;
2311 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2312 fl4.daddr = daddr;
2313 fl4.saddr = saddr;
2314 err = fib_lookup(net, &fl4, &res);
2315 if (err != 0) {
2316 if (!IN_DEV_FORWARD(in_dev))
2317 goto e_hostunreach;
2318 goto no_route;
2319 }
2320
2321 RT_CACHE_STAT_INC(in_slow_tot);
2322
2323 if (res.type == RTN_BROADCAST)
2324 goto brd_input;
2325
2326 if (res.type == RTN_LOCAL) {
2327 err = fib_validate_source(skb, saddr, daddr, tos,
2328 net->loopback_dev->ifindex,
2329 dev, &spec_dst, &itag);
2330 if (err < 0)
2331 goto martian_source_keep_err;
2332 if (err)
2333 flags |= RTCF_DIRECTSRC;
2334 spec_dst = daddr;
2335 goto local_input;
2336 }
2337
2338 if (!IN_DEV_FORWARD(in_dev))
2339 goto e_hostunreach;
2340 if (res.type != RTN_UNICAST)
2341 goto martian_destination;
2342
2343 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2344 out: return err;
2345
2346 brd_input:
2347 if (skb->protocol != htons(ETH_P_IP))
2348 goto e_inval;
2349
2350 if (ipv4_is_zeronet(saddr))
2351 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2352 else {
2353 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2354 &itag);
2355 if (err < 0)
2356 goto martian_source_keep_err;
2357 if (err)
2358 flags |= RTCF_DIRECTSRC;
2359 }
2360 flags |= RTCF_BROADCAST;
2361 res.type = RTN_BROADCAST;
2362 RT_CACHE_STAT_INC(in_brd);
2363
2364 local_input:
2365 rth = rt_dst_alloc(net->loopback_dev,
2366 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2367 if (!rth)
2368 goto e_nobufs;
2369
2370 rth->dst.input= ip_local_deliver;
2371 rth->dst.output= ip_rt_bug;
2372 #ifdef CONFIG_IP_ROUTE_CLASSID
2373 rth->dst.tclassid = itag;
2374 #endif
2375
2376 rth->rt_key_dst = daddr;
2377 rth->rt_key_src = saddr;
2378 rth->rt_genid = rt_genid(net);
2379 rth->rt_flags = flags|RTCF_LOCAL;
2380 rth->rt_type = res.type;
2381 rth->rt_key_tos = tos;
2382 rth->rt_dst = daddr;
2383 rth->rt_src = saddr;
2384 #ifdef CONFIG_IP_ROUTE_CLASSID
2385 rth->dst.tclassid = itag;
2386 #endif
2387 rth->rt_route_iif = dev->ifindex;
2388 rth->rt_iif = dev->ifindex;
2389 rth->rt_oif = 0;
2390 rth->rt_mark = skb->mark;
2391 rth->rt_gateway = daddr;
2392 rth->rt_spec_dst= spec_dst;
2393 rth->rt_peer_genid = 0;
2394 rth->peer = NULL;
2395 rth->fi = NULL;
2396 if (res.type == RTN_UNREACHABLE) {
2397 rth->dst.input= ip_error;
2398 rth->dst.error= -err;
2399 rth->rt_flags &= ~RTCF_LOCAL;
2400 }
2401 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2402 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2403 err = 0;
2404 if (IS_ERR(rth))
2405 err = PTR_ERR(rth);
2406 goto out;
2407
2408 no_route:
2409 RT_CACHE_STAT_INC(in_no_route);
2410 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2411 res.type = RTN_UNREACHABLE;
2412 if (err == -ESRCH)
2413 err = -ENETUNREACH;
2414 goto local_input;
2415
2416 /*
2417 * Do not cache martian addresses: they should be logged (RFC1812)
2418 */
2419 martian_destination:
2420 RT_CACHE_STAT_INC(in_martian_dst);
2421 #ifdef CONFIG_IP_ROUTE_VERBOSE
2422 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2423 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2424 &daddr, &saddr, dev->name);
2425 #endif
2426
2427 e_hostunreach:
2428 err = -EHOSTUNREACH;
2429 goto out;
2430
2431 e_inval:
2432 err = -EINVAL;
2433 goto out;
2434
2435 e_nobufs:
2436 err = -ENOBUFS;
2437 goto out;
2438
2439 martian_source:
2440 err = -EINVAL;
2441 martian_source_keep_err:
2442 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2443 goto out;
2444 }
2445
2446 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2447 u8 tos, struct net_device *dev, bool noref)
2448 {
2449 struct rtable * rth;
2450 unsigned hash;
2451 int iif = dev->ifindex;
2452 struct net *net;
2453 int res;
2454
2455 net = dev_net(dev);
2456
2457 rcu_read_lock();
2458
2459 if (!rt_caching(net))
2460 goto skip_cache;
2461
2462 tos &= IPTOS_RT_MASK;
2463 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2464
2465 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2466 rth = rcu_dereference(rth->dst.rt_next)) {
2467 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2468 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2469 (rth->rt_route_iif ^ iif) |
2470 (rth->rt_key_tos ^ tos)) == 0 &&
2471 rth->rt_mark == skb->mark &&
2472 net_eq(dev_net(rth->dst.dev), net) &&
2473 !rt_is_expired(rth)) {
2474 ipv4_validate_peer(rth);
2475 if (noref) {
2476 dst_use_noref(&rth->dst, jiffies);
2477 skb_dst_set_noref(skb, &rth->dst);
2478 } else {
2479 dst_use(&rth->dst, jiffies);
2480 skb_dst_set(skb, &rth->dst);
2481 }
2482 RT_CACHE_STAT_INC(in_hit);
2483 rcu_read_unlock();
2484 return 0;
2485 }
2486 RT_CACHE_STAT_INC(in_hlist_search);
2487 }
2488
2489 skip_cache:
2490 /* Multicast recognition logic is moved from route cache to here.
2491 The problem was that too many Ethernet cards have broken/missing
2492 hardware multicast filters :-( As result the host on multicasting
2493 network acquires a lot of useless route cache entries, sort of
2494 SDR messages from all the world. Now we try to get rid of them.
2495 Really, provided software IP multicast filter is organized
2496 reasonably (at least, hashed), it does not result in a slowdown
2497 comparing with route cache reject entries.
2498 Note, that multicast routers are not affected, because
2499 route cache entry is created eventually.
2500 */
2501 if (ipv4_is_multicast(daddr)) {
2502 struct in_device *in_dev = __in_dev_get_rcu(dev);
2503
2504 if (in_dev) {
2505 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2506 ip_hdr(skb)->protocol);
2507 if (our
2508 #ifdef CONFIG_IP_MROUTE
2509 ||
2510 (!ipv4_is_local_multicast(daddr) &&
2511 IN_DEV_MFORWARD(in_dev))
2512 #endif
2513 ) {
2514 int res = ip_route_input_mc(skb, daddr, saddr,
2515 tos, dev, our);
2516 rcu_read_unlock();
2517 return res;
2518 }
2519 }
2520 rcu_read_unlock();
2521 return -EINVAL;
2522 }
2523 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2524 rcu_read_unlock();
2525 return res;
2526 }
2527 EXPORT_SYMBOL(ip_route_input_common);
2528
2529 /* called with rcu_read_lock() */
2530 static struct rtable *__mkroute_output(const struct fib_result *res,
2531 const struct flowi4 *fl4,
2532 __be32 orig_daddr, __be32 orig_saddr,
2533 int orig_oif, __u8 orig_rtos,
2534 struct net_device *dev_out,
2535 unsigned int flags)
2536 {
2537 struct fib_info *fi = res->fi;
2538 struct in_device *in_dev;
2539 u16 type = res->type;
2540 struct rtable *rth;
2541
2542 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2543 return ERR_PTR(-EINVAL);
2544
2545 if (ipv4_is_lbcast(fl4->daddr))
2546 type = RTN_BROADCAST;
2547 else if (ipv4_is_multicast(fl4->daddr))
2548 type = RTN_MULTICAST;
2549 else if (ipv4_is_zeronet(fl4->daddr))
2550 return ERR_PTR(-EINVAL);
2551
2552 if (dev_out->flags & IFF_LOOPBACK)
2553 flags |= RTCF_LOCAL;
2554
2555 in_dev = __in_dev_get_rcu(dev_out);
2556 if (!in_dev)
2557 return ERR_PTR(-EINVAL);
2558
2559 if (type == RTN_BROADCAST) {
2560 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2561 fi = NULL;
2562 } else if (type == RTN_MULTICAST) {
2563 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2564 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2565 fl4->flowi4_proto))
2566 flags &= ~RTCF_LOCAL;
2567 /* If multicast route do not exist use
2568 * default one, but do not gateway in this case.
2569 * Yes, it is hack.
2570 */
2571 if (fi && res->prefixlen < 4)
2572 fi = NULL;
2573 }
2574
2575 rth = rt_dst_alloc(dev_out,
2576 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2577 IN_DEV_CONF_GET(in_dev, NOXFRM));
2578 if (!rth)
2579 return ERR_PTR(-ENOBUFS);
2580
2581 rth->dst.output = ip_output;
2582
2583 rth->rt_key_dst = orig_daddr;
2584 rth->rt_key_src = orig_saddr;
2585 rth->rt_genid = rt_genid(dev_net(dev_out));
2586 rth->rt_flags = flags;
2587 rth->rt_type = type;
2588 rth->rt_key_tos = orig_rtos;
2589 rth->rt_dst = fl4->daddr;
2590 rth->rt_src = fl4->saddr;
2591 rth->rt_route_iif = 0;
2592 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2593 rth->rt_oif = orig_oif;
2594 rth->rt_mark = fl4->flowi4_mark;
2595 rth->rt_gateway = fl4->daddr;
2596 rth->rt_spec_dst= fl4->saddr;
2597 rth->rt_peer_genid = 0;
2598 rth->peer = NULL;
2599 rth->fi = NULL;
2600
2601 RT_CACHE_STAT_INC(out_slow_tot);
2602
2603 if (flags & RTCF_LOCAL) {
2604 rth->dst.input = ip_local_deliver;
2605 rth->rt_spec_dst = fl4->daddr;
2606 }
2607 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2608 rth->rt_spec_dst = fl4->saddr;
2609 if (flags & RTCF_LOCAL &&
2610 !(dev_out->flags & IFF_LOOPBACK)) {
2611 rth->dst.output = ip_mc_output;
2612 RT_CACHE_STAT_INC(out_slow_mc);
2613 }
2614 #ifdef CONFIG_IP_MROUTE
2615 if (type == RTN_MULTICAST) {
2616 if (IN_DEV_MFORWARD(in_dev) &&
2617 !ipv4_is_local_multicast(fl4->daddr)) {
2618 rth->dst.input = ip_mr_input;
2619 rth->dst.output = ip_mc_output;
2620 }
2621 }
2622 #endif
2623 }
2624
2625 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2626
2627 return rth;
2628 }
2629
2630 /*
2631 * Major route resolver routine.
2632 * called with rcu_read_lock();
2633 */
2634
2635 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2636 {
2637 struct net_device *dev_out = NULL;
2638 __u8 tos = RT_FL_TOS(fl4);
2639 unsigned int flags = 0;
2640 struct fib_result res;
2641 struct rtable *rth;
2642 __be32 orig_daddr;
2643 __be32 orig_saddr;
2644 int orig_oif;
2645
2646 res.fi = NULL;
2647 #ifdef CONFIG_IP_MULTIPLE_TABLES
2648 res.r = NULL;
2649 #endif
2650
2651 orig_daddr = fl4->daddr;
2652 orig_saddr = fl4->saddr;
2653 orig_oif = fl4->flowi4_oif;
2654
2655 fl4->flowi4_iif = net->loopback_dev->ifindex;
2656 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2657 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2658 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2659
2660 rcu_read_lock();
2661 if (fl4->saddr) {
2662 rth = ERR_PTR(-EINVAL);
2663 if (ipv4_is_multicast(fl4->saddr) ||
2664 ipv4_is_lbcast(fl4->saddr) ||
2665 ipv4_is_zeronet(fl4->saddr))
2666 goto out;
2667
2668 /* I removed check for oif == dev_out->oif here.
2669 It was wrong for two reasons:
2670 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2671 is assigned to multiple interfaces.
2672 2. Moreover, we are allowed to send packets with saddr
2673 of another iface. --ANK
2674 */
2675
2676 if (fl4->flowi4_oif == 0 &&
2677 (ipv4_is_multicast(fl4->daddr) ||
2678 ipv4_is_lbcast(fl4->daddr))) {
2679 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2680 dev_out = __ip_dev_find(net, fl4->saddr, false);
2681 if (dev_out == NULL)
2682 goto out;
2683
2684 /* Special hack: user can direct multicasts
2685 and limited broadcast via necessary interface
2686 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2687 This hack is not just for fun, it allows
2688 vic,vat and friends to work.
2689 They bind socket to loopback, set ttl to zero
2690 and expect that it will work.
2691 From the viewpoint of routing cache they are broken,
2692 because we are not allowed to build multicast path
2693 with loopback source addr (look, routing cache
2694 cannot know, that ttl is zero, so that packet
2695 will not leave this host and route is valid).
2696 Luckily, this hack is good workaround.
2697 */
2698
2699 fl4->flowi4_oif = dev_out->ifindex;
2700 goto make_route;
2701 }
2702
2703 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2704 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2705 if (!__ip_dev_find(net, fl4->saddr, false))
2706 goto out;
2707 }
2708 }
2709
2710
2711 if (fl4->flowi4_oif) {
2712 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2713 rth = ERR_PTR(-ENODEV);
2714 if (dev_out == NULL)
2715 goto out;
2716
2717 /* RACE: Check return value of inet_select_addr instead. */
2718 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2719 rth = ERR_PTR(-ENETUNREACH);
2720 goto out;
2721 }
2722 if (ipv4_is_local_multicast(fl4->daddr) ||
2723 ipv4_is_lbcast(fl4->daddr)) {
2724 if (!fl4->saddr)
2725 fl4->saddr = inet_select_addr(dev_out, 0,
2726 RT_SCOPE_LINK);
2727 goto make_route;
2728 }
2729 if (fl4->saddr) {
2730 if (ipv4_is_multicast(fl4->daddr))
2731 fl4->saddr = inet_select_addr(dev_out, 0,
2732 fl4->flowi4_scope);
2733 else if (!fl4->daddr)
2734 fl4->saddr = inet_select_addr(dev_out, 0,
2735 RT_SCOPE_HOST);
2736 }
2737 }
2738
2739 if (!fl4->daddr) {
2740 fl4->daddr = fl4->saddr;
2741 if (!fl4->daddr)
2742 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2743 dev_out = net->loopback_dev;
2744 fl4->flowi4_oif = net->loopback_dev->ifindex;
2745 res.type = RTN_LOCAL;
2746 flags |= RTCF_LOCAL;
2747 goto make_route;
2748 }
2749
2750 if (fib_lookup(net, fl4, &res)) {
2751 res.fi = NULL;
2752 if (fl4->flowi4_oif) {
2753 /* Apparently, routing tables are wrong. Assume,
2754 that the destination is on link.
2755
2756 WHY? DW.
2757 Because we are allowed to send to iface
2758 even if it has NO routes and NO assigned
2759 addresses. When oif is specified, routing
2760 tables are looked up with only one purpose:
2761 to catch if destination is gatewayed, rather than
2762 direct. Moreover, if MSG_DONTROUTE is set,
2763 we send packet, ignoring both routing tables
2764 and ifaddr state. --ANK
2765
2766
2767 We could make it even if oif is unknown,
2768 likely IPv6, but we do not.
2769 */
2770
2771 if (fl4->saddr == 0)
2772 fl4->saddr = inet_select_addr(dev_out, 0,
2773 RT_SCOPE_LINK);
2774 res.type = RTN_UNICAST;
2775 goto make_route;
2776 }
2777 rth = ERR_PTR(-ENETUNREACH);
2778 goto out;
2779 }
2780
2781 if (res.type == RTN_LOCAL) {
2782 if (!fl4->saddr) {
2783 if (res.fi->fib_prefsrc)
2784 fl4->saddr = res.fi->fib_prefsrc;
2785 else
2786 fl4->saddr = fl4->daddr;
2787 }
2788 dev_out = net->loopback_dev;
2789 fl4->flowi4_oif = dev_out->ifindex;
2790 res.fi = NULL;
2791 flags |= RTCF_LOCAL;
2792 goto make_route;
2793 }
2794
2795 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2796 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2797 fib_select_multipath(&res);
2798 else
2799 #endif
2800 if (!res.prefixlen &&
2801 res.table->tb_num_default > 1 &&
2802 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2803 fib_select_default(&res);
2804
2805 if (!fl4->saddr)
2806 fl4->saddr = FIB_RES_PREFSRC(net, res);
2807
2808 dev_out = FIB_RES_DEV(res);
2809 fl4->flowi4_oif = dev_out->ifindex;
2810
2811
2812 make_route:
2813 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2814 tos, dev_out, flags);
2815 if (!IS_ERR(rth)) {
2816 unsigned int hash;
2817
2818 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2819 rt_genid(dev_net(dev_out)));
2820 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2821 }
2822
2823 out:
2824 rcu_read_unlock();
2825 return rth;
2826 }
2827
2828 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2829 {
2830 struct rtable *rth;
2831 unsigned int hash;
2832
2833 if (!rt_caching(net))
2834 goto slow_output;
2835
2836 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2837
2838 rcu_read_lock_bh();
2839 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2840 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2841 if (rth->rt_key_dst == flp4->daddr &&
2842 rth->rt_key_src == flp4->saddr &&
2843 rt_is_output_route(rth) &&
2844 rth->rt_oif == flp4->flowi4_oif &&
2845 rth->rt_mark == flp4->flowi4_mark &&
2846 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2847 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2848 net_eq(dev_net(rth->dst.dev), net) &&
2849 !rt_is_expired(rth)) {
2850 ipv4_validate_peer(rth);
2851 dst_use(&rth->dst, jiffies);
2852 RT_CACHE_STAT_INC(out_hit);
2853 rcu_read_unlock_bh();
2854 if (!flp4->saddr)
2855 flp4->saddr = rth->rt_src;
2856 if (!flp4->daddr)
2857 flp4->daddr = rth->rt_dst;
2858 return rth;
2859 }
2860 RT_CACHE_STAT_INC(out_hlist_search);
2861 }
2862 rcu_read_unlock_bh();
2863
2864 slow_output:
2865 return ip_route_output_slow(net, flp4);
2866 }
2867 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2868
2869 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2870 {
2871 return NULL;
2872 }
2873
2874 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2875 {
2876 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2877
2878 return mtu ? : dst->dev->mtu;
2879 }
2880
2881 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2882 {
2883 }
2884
2885 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2886 unsigned long old)
2887 {
2888 return NULL;
2889 }
2890
2891 static struct dst_ops ipv4_dst_blackhole_ops = {
2892 .family = AF_INET,
2893 .protocol = cpu_to_be16(ETH_P_IP),
2894 .destroy = ipv4_dst_destroy,
2895 .check = ipv4_blackhole_dst_check,
2896 .mtu = ipv4_blackhole_mtu,
2897 .default_advmss = ipv4_default_advmss,
2898 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2899 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2900 .neigh_lookup = ipv4_neigh_lookup,
2901 };
2902
2903 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2904 {
2905 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2906 struct rtable *ort = (struct rtable *) dst_orig;
2907
2908 if (rt) {
2909 struct dst_entry *new = &rt->dst;
2910
2911 new->__use = 1;
2912 new->input = dst_discard;
2913 new->output = dst_discard;
2914 dst_copy_metrics(new, &ort->dst);
2915
2916 new->dev = ort->dst.dev;
2917 if (new->dev)
2918 dev_hold(new->dev);
2919
2920 rt->rt_key_dst = ort->rt_key_dst;
2921 rt->rt_key_src = ort->rt_key_src;
2922 rt->rt_key_tos = ort->rt_key_tos;
2923 rt->rt_route_iif = ort->rt_route_iif;
2924 rt->rt_iif = ort->rt_iif;
2925 rt->rt_oif = ort->rt_oif;
2926 rt->rt_mark = ort->rt_mark;
2927
2928 rt->rt_genid = rt_genid(net);
2929 rt->rt_flags = ort->rt_flags;
2930 rt->rt_type = ort->rt_type;
2931 rt->rt_dst = ort->rt_dst;
2932 rt->rt_src = ort->rt_src;
2933 rt->rt_gateway = ort->rt_gateway;
2934 rt->rt_spec_dst = ort->rt_spec_dst;
2935 rt->peer = ort->peer;
2936 if (rt->peer)
2937 atomic_inc(&rt->peer->refcnt);
2938 rt->fi = ort->fi;
2939 if (rt->fi)
2940 atomic_inc(&rt->fi->fib_clntref);
2941
2942 dst_free(new);
2943 }
2944
2945 dst_release(dst_orig);
2946
2947 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2948 }
2949
2950 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2951 struct sock *sk)
2952 {
2953 struct rtable *rt = __ip_route_output_key(net, flp4);
2954
2955 if (IS_ERR(rt))
2956 return rt;
2957
2958 if (flp4->flowi4_proto)
2959 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2960 flowi4_to_flowi(flp4),
2961 sk, 0);
2962
2963 return rt;
2964 }
2965 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2966
2967 static int rt_fill_info(struct net *net,
2968 struct sk_buff *skb, u32 pid, u32 seq, int event,
2969 int nowait, unsigned int flags)
2970 {
2971 struct rtable *rt = skb_rtable(skb);
2972 struct rtmsg *r;
2973 struct nlmsghdr *nlh;
2974 unsigned long expires = 0;
2975 const struct inet_peer *peer = rt->peer;
2976 u32 id = 0, ts = 0, tsage = 0, error;
2977
2978 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2979 if (nlh == NULL)
2980 return -EMSGSIZE;
2981
2982 r = nlmsg_data(nlh);
2983 r->rtm_family = AF_INET;
2984 r->rtm_dst_len = 32;
2985 r->rtm_src_len = 0;
2986 r->rtm_tos = rt->rt_key_tos;
2987 r->rtm_table = RT_TABLE_MAIN;
2988 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2989 r->rtm_type = rt->rt_type;
2990 r->rtm_scope = RT_SCOPE_UNIVERSE;
2991 r->rtm_protocol = RTPROT_UNSPEC;
2992 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2993 if (rt->rt_flags & RTCF_NOTIFY)
2994 r->rtm_flags |= RTM_F_NOTIFY;
2995
2996 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2997
2998 if (rt->rt_key_src) {
2999 r->rtm_src_len = 32;
3000 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
3001 }
3002 if (rt->dst.dev)
3003 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
3004 #ifdef CONFIG_IP_ROUTE_CLASSID
3005 if (rt->dst.tclassid)
3006 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
3007 #endif
3008 if (rt_is_input_route(rt))
3009 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
3010 else if (rt->rt_src != rt->rt_key_src)
3011 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
3012
3013 if (rt->rt_dst != rt->rt_gateway)
3014 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
3015
3016 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
3017 goto nla_put_failure;
3018
3019 if (rt->rt_mark)
3020 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
3021
3022 error = rt->dst.error;
3023 if (peer) {
3024 inet_peer_refcheck(rt->peer);
3025 id = atomic_read(&peer->ip_id_count) & 0xffff;
3026 if (peer->tcp_ts_stamp) {
3027 ts = peer->tcp_ts;
3028 tsage = get_seconds() - peer->tcp_ts_stamp;
3029 }
3030 expires = ACCESS_ONCE(peer->pmtu_expires);
3031 if (expires) {
3032 if (time_before(jiffies, expires))
3033 expires -= jiffies;
3034 else
3035 expires = 0;
3036 }
3037 }
3038
3039 if (rt_is_input_route(rt)) {
3040 #ifdef CONFIG_IP_MROUTE
3041 __be32 dst = rt->rt_dst;
3042
3043 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
3044 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
3045 int err = ipmr_get_route(net, skb,
3046 rt->rt_src, rt->rt_dst,
3047 r, nowait);
3048 if (err <= 0) {
3049 if (!nowait) {
3050 if (err == 0)
3051 return 0;
3052 goto nla_put_failure;
3053 } else {
3054 if (err == -EMSGSIZE)
3055 goto nla_put_failure;
3056 error = err;
3057 }
3058 }
3059 } else
3060 #endif
3061 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
3062 }
3063
3064 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
3065 expires, error) < 0)
3066 goto nla_put_failure;
3067
3068 return nlmsg_end(skb, nlh);
3069
3070 nla_put_failure:
3071 nlmsg_cancel(skb, nlh);
3072 return -EMSGSIZE;
3073 }
3074
3075 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
3076 {
3077 struct net *net = sock_net(in_skb->sk);
3078 struct rtmsg *rtm;
3079 struct nlattr *tb[RTA_MAX+1];
3080 struct rtable *rt = NULL;
3081 __be32 dst = 0;
3082 __be32 src = 0;
3083 u32 iif;
3084 int err;
3085 int mark;
3086 struct sk_buff *skb;
3087
3088 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
3089 if (err < 0)
3090 goto errout;
3091
3092 rtm = nlmsg_data(nlh);
3093
3094 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3095 if (skb == NULL) {
3096 err = -ENOBUFS;
3097 goto errout;
3098 }
3099
3100 /* Reserve room for dummy headers, this skb can pass
3101 through good chunk of routing engine.
3102 */
3103 skb_reset_mac_header(skb);
3104 skb_reset_network_header(skb);
3105
3106 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3107 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3108 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3109
3110 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3111 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3112 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3113 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3114
3115 if (iif) {
3116 struct net_device *dev;
3117
3118 dev = __dev_get_by_index(net, iif);
3119 if (dev == NULL) {
3120 err = -ENODEV;
3121 goto errout_free;
3122 }
3123
3124 skb->protocol = htons(ETH_P_IP);
3125 skb->dev = dev;
3126 skb->mark = mark;
3127 local_bh_disable();
3128 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3129 local_bh_enable();
3130
3131 rt = skb_rtable(skb);
3132 if (err == 0 && rt->dst.error)
3133 err = -rt->dst.error;
3134 } else {
3135 struct flowi4 fl4 = {
3136 .daddr = dst,
3137 .saddr = src,
3138 .flowi4_tos = rtm->rtm_tos,
3139 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3140 .flowi4_mark = mark,
3141 };
3142 rt = ip_route_output_key(net, &fl4);
3143
3144 err = 0;
3145 if (IS_ERR(rt))
3146 err = PTR_ERR(rt);
3147 }
3148
3149 if (err)
3150 goto errout_free;
3151
3152 skb_dst_set(skb, &rt->dst);
3153 if (rtm->rtm_flags & RTM_F_NOTIFY)
3154 rt->rt_flags |= RTCF_NOTIFY;
3155
3156 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3157 RTM_NEWROUTE, 0, 0);
3158 if (err <= 0)
3159 goto errout_free;
3160
3161 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3162 errout:
3163 return err;
3164
3165 errout_free:
3166 kfree_skb(skb);
3167 goto errout;
3168 }
3169
3170 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3171 {
3172 struct rtable *rt;
3173 int h, s_h;
3174 int idx, s_idx;
3175 struct net *net;
3176
3177 net = sock_net(skb->sk);
3178
3179 s_h = cb->args[0];
3180 if (s_h < 0)
3181 s_h = 0;
3182 s_idx = idx = cb->args[1];
3183 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3184 if (!rt_hash_table[h].chain)
3185 continue;
3186 rcu_read_lock_bh();
3187 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3188 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3189 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3190 continue;
3191 if (rt_is_expired(rt))
3192 continue;
3193 skb_dst_set_noref(skb, &rt->dst);
3194 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3195 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3196 1, NLM_F_MULTI) <= 0) {
3197 skb_dst_drop(skb);
3198 rcu_read_unlock_bh();
3199 goto done;
3200 }
3201 skb_dst_drop(skb);
3202 }
3203 rcu_read_unlock_bh();
3204 }
3205
3206 done:
3207 cb->args[0] = h;
3208 cb->args[1] = idx;
3209 return skb->len;
3210 }
3211
3212 void ip_rt_multicast_event(struct in_device *in_dev)
3213 {
3214 rt_cache_flush(dev_net(in_dev->dev), 0);
3215 }
3216
3217 #ifdef CONFIG_SYSCTL
3218 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3219 void __user *buffer,
3220 size_t *lenp, loff_t *ppos)
3221 {
3222 if (write) {
3223 int flush_delay;
3224 ctl_table ctl;
3225 struct net *net;
3226
3227 memcpy(&ctl, __ctl, sizeof(ctl));
3228 ctl.data = &flush_delay;
3229 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3230
3231 net = (struct net *)__ctl->extra1;
3232 rt_cache_flush(net, flush_delay);
3233 return 0;
3234 }
3235
3236 return -EINVAL;
3237 }
3238
3239 static ctl_table ipv4_route_table[] = {
3240 {
3241 .procname = "gc_thresh",
3242 .data = &ipv4_dst_ops.gc_thresh,
3243 .maxlen = sizeof(int),
3244 .mode = 0644,
3245 .proc_handler = proc_dointvec,
3246 },
3247 {
3248 .procname = "max_size",
3249 .data = &ip_rt_max_size,
3250 .maxlen = sizeof(int),
3251 .mode = 0644,
3252 .proc_handler = proc_dointvec,
3253 },
3254 {
3255 /* Deprecated. Use gc_min_interval_ms */
3256
3257 .procname = "gc_min_interval",
3258 .data = &ip_rt_gc_min_interval,
3259 .maxlen = sizeof(int),
3260 .mode = 0644,
3261 .proc_handler = proc_dointvec_jiffies,
3262 },
3263 {
3264 .procname = "gc_min_interval_ms",
3265 .data = &ip_rt_gc_min_interval,
3266 .maxlen = sizeof(int),
3267 .mode = 0644,
3268 .proc_handler = proc_dointvec_ms_jiffies,
3269 },
3270 {
3271 .procname = "gc_timeout",
3272 .data = &ip_rt_gc_timeout,
3273 .maxlen = sizeof(int),
3274 .mode = 0644,
3275 .proc_handler = proc_dointvec_jiffies,
3276 },
3277 {
3278 .procname = "gc_interval",
3279 .data = &ip_rt_gc_interval,
3280 .maxlen = sizeof(int),
3281 .mode = 0644,
3282 .proc_handler = proc_dointvec_jiffies,
3283 },
3284 {
3285 .procname = "redirect_load",
3286 .data = &ip_rt_redirect_load,
3287 .maxlen = sizeof(int),
3288 .mode = 0644,
3289 .proc_handler = proc_dointvec,
3290 },
3291 {
3292 .procname = "redirect_number",
3293 .data = &ip_rt_redirect_number,
3294 .maxlen = sizeof(int),
3295 .mode = 0644,
3296 .proc_handler = proc_dointvec,
3297 },
3298 {
3299 .procname = "redirect_silence",
3300 .data = &ip_rt_redirect_silence,
3301 .maxlen = sizeof(int),
3302 .mode = 0644,
3303 .proc_handler = proc_dointvec,
3304 },
3305 {
3306 .procname = "error_cost",
3307 .data = &ip_rt_error_cost,
3308 .maxlen = sizeof(int),
3309 .mode = 0644,
3310 .proc_handler = proc_dointvec,
3311 },
3312 {
3313 .procname = "error_burst",
3314 .data = &ip_rt_error_burst,
3315 .maxlen = sizeof(int),
3316 .mode = 0644,
3317 .proc_handler = proc_dointvec,
3318 },
3319 {
3320 .procname = "gc_elasticity",
3321 .data = &ip_rt_gc_elasticity,
3322 .maxlen = sizeof(int),
3323 .mode = 0644,
3324 .proc_handler = proc_dointvec,
3325 },
3326 {
3327 .procname = "mtu_expires",
3328 .data = &ip_rt_mtu_expires,
3329 .maxlen = sizeof(int),
3330 .mode = 0644,
3331 .proc_handler = proc_dointvec_jiffies,
3332 },
3333 {
3334 .procname = "min_pmtu",
3335 .data = &ip_rt_min_pmtu,
3336 .maxlen = sizeof(int),
3337 .mode = 0644,
3338 .proc_handler = proc_dointvec,
3339 },
3340 {
3341 .procname = "min_adv_mss",
3342 .data = &ip_rt_min_advmss,
3343 .maxlen = sizeof(int),
3344 .mode = 0644,
3345 .proc_handler = proc_dointvec,
3346 },
3347 { }
3348 };
3349
3350 static struct ctl_table empty[1];
3351
3352 static struct ctl_table ipv4_skeleton[] =
3353 {
3354 { .procname = "route",
3355 .mode = 0555, .child = ipv4_route_table},
3356 { .procname = "neigh",
3357 .mode = 0555, .child = empty},
3358 { }
3359 };
3360
3361 static __net_initdata struct ctl_path ipv4_path[] = {
3362 { .procname = "net", },
3363 { .procname = "ipv4", },
3364 { },
3365 };
3366
3367 static struct ctl_table ipv4_route_flush_table[] = {
3368 {
3369 .procname = "flush",
3370 .maxlen = sizeof(int),
3371 .mode = 0200,
3372 .proc_handler = ipv4_sysctl_rtcache_flush,
3373 },
3374 { },
3375 };
3376
3377 static __net_initdata struct ctl_path ipv4_route_path[] = {
3378 { .procname = "net", },
3379 { .procname = "ipv4", },
3380 { .procname = "route", },
3381 { },
3382 };
3383
3384 static __net_init int sysctl_route_net_init(struct net *net)
3385 {
3386 struct ctl_table *tbl;
3387
3388 tbl = ipv4_route_flush_table;
3389 if (!net_eq(net, &init_net)) {
3390 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3391 if (tbl == NULL)
3392 goto err_dup;
3393 }
3394 tbl[0].extra1 = net;
3395
3396 net->ipv4.route_hdr =
3397 register_net_sysctl_table(net, ipv4_route_path, tbl);
3398 if (net->ipv4.route_hdr == NULL)
3399 goto err_reg;
3400 return 0;
3401
3402 err_reg:
3403 if (tbl != ipv4_route_flush_table)
3404 kfree(tbl);
3405 err_dup:
3406 return -ENOMEM;
3407 }
3408
3409 static __net_exit void sysctl_route_net_exit(struct net *net)
3410 {
3411 struct ctl_table *tbl;
3412
3413 tbl = net->ipv4.route_hdr->ctl_table_arg;
3414 unregister_net_sysctl_table(net->ipv4.route_hdr);
3415 BUG_ON(tbl == ipv4_route_flush_table);
3416 kfree(tbl);
3417 }
3418
3419 static __net_initdata struct pernet_operations sysctl_route_ops = {
3420 .init = sysctl_route_net_init,
3421 .exit = sysctl_route_net_exit,
3422 };
3423 #endif
3424
3425 static __net_init int rt_genid_init(struct net *net)
3426 {
3427 get_random_bytes(&net->ipv4.rt_genid,
3428 sizeof(net->ipv4.rt_genid));
3429 get_random_bytes(&net->ipv4.dev_addr_genid,
3430 sizeof(net->ipv4.dev_addr_genid));
3431 return 0;
3432 }
3433
3434 static __net_initdata struct pernet_operations rt_genid_ops = {
3435 .init = rt_genid_init,
3436 };
3437
3438
3439 #ifdef CONFIG_IP_ROUTE_CLASSID
3440 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3441 #endif /* CONFIG_IP_ROUTE_CLASSID */
3442
3443 static __initdata unsigned long rhash_entries;
3444 static int __init set_rhash_entries(char *str)
3445 {
3446 if (!str)
3447 return 0;
3448 rhash_entries = simple_strtoul(str, &str, 0);
3449 return 1;
3450 }
3451 __setup("rhash_entries=", set_rhash_entries);
3452
3453 int __init ip_rt_init(void)
3454 {
3455 int rc = 0;
3456
3457 #ifdef CONFIG_IP_ROUTE_CLASSID
3458 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3459 if (!ip_rt_acct)
3460 panic("IP: failed to allocate ip_rt_acct\n");
3461 #endif
3462
3463 ipv4_dst_ops.kmem_cachep =
3464 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3465 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3466
3467 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3468
3469 if (dst_entries_init(&ipv4_dst_ops) < 0)
3470 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3471
3472 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3473 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3474
3475 rt_hash_table = (struct rt_hash_bucket *)
3476 alloc_large_system_hash("IP route cache",
3477 sizeof(struct rt_hash_bucket),
3478 rhash_entries,
3479 (totalram_pages >= 128 * 1024) ?
3480 15 : 17,
3481 0,
3482 &rt_hash_log,
3483 &rt_hash_mask,
3484 rhash_entries ? 0 : 512 * 1024);
3485 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3486 rt_hash_lock_init();
3487
3488 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3489 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3490
3491 devinet_init();
3492 ip_fib_init();
3493
3494 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3495 expires_ljiffies = jiffies;
3496 schedule_delayed_work(&expires_work,
3497 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3498
3499 if (ip_rt_proc_init())
3500 printk(KERN_ERR "Unable to create route proc files\n");
3501 #ifdef CONFIG_XFRM
3502 xfrm_init();
3503 xfrm4_init(ip_rt_max_size);
3504 #endif
3505 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3506
3507 #ifdef CONFIG_SYSCTL
3508 register_pernet_subsys(&sysctl_route_ops);
3509 #endif
3510 register_pernet_subsys(&rt_genid_ops);
3511 return rc;
3512 }
3513
3514 #ifdef CONFIG_SYSCTL
3515 /*
3516 * We really need to sanitize the damn ipv4 init order, then all
3517 * this nonsense will go away.
3518 */
3519 void __init ip_static_sysctl_init(void)
3520 {
3521 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3522 }
3523 #endif
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree