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ipv4: using prefetch requires including prefetch.h
[deliverable/linux.git] / net / ipv4 / route.c
CommitLineData
1da177e4
LT		 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 *
02c30a84 8 * Authors: Ross Biro
1da177e4
LT		 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
e905a9ed 21 * Alan Cox : Super /proc >4K
1da177e4
LT		 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.
e905a9ed 39 *
1da177e4
LT		 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
bb1d23b0 55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
cef2685e
IS		 56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
1da177e4
LT		 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
1da177e4
LT		 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>
1da177e4 71#include <linux/mm.h>
424c4b70 72#include <linux/bootmem.h>
1da177e4
LT		 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>
39c90ece 82#include <linux/workqueue.h>
1da177e4 83#include <linux/skbuff.h>
1da177e4
LT		 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>
5a0e3ad6 93#include <linux/slab.h>
b9eda06f 94#include <linux/prefetch.h>
352e512c 95#include <net/dst.h>
457c4cbc 96#include <net/net_namespace.h>
1da177e4
LT		 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>
8d71740c 107#include <net/netevent.h>
63f3444f 108#include <net/rtnetlink.h>
1da177e4
LT		 109#ifdef CONFIG_SYSCTL
110#include <linux/sysctl.h>
111#endif
3769cffb 112#include <net/atmclip.h>
6e5714ea 113#include <net/secure_seq.h>
1da177e4 114
68a5e3dd 115#define RT_FL_TOS(oldflp4) \
f61759e6 116 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
1da177e4
LT		 117
118#define IP_MAX_MTU 0xFFF0
119
120#define RT_GC_TIMEOUT (300*HZ)
121
1da177e4 122static int ip_rt_max_size;
817bc4db 123static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
9f28a2fc 124static int ip_rt_gc_interval __read_mostly = 60 * HZ;
817bc4db
SH		 125static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
126static int ip_rt_redirect_number __read_mostly = 9;
127static int ip_rt_redirect_load __read_mostly = HZ / 50;
128static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
129static int ip_rt_error_cost __read_mostly = HZ;
130static int ip_rt_error_burst __read_mostly = 5 * HZ;
131static int ip_rt_gc_elasticity __read_mostly = 8;
132static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
133static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
134static int ip_rt_min_advmss __read_mostly = 256;
1080d709 135static int rt_chain_length_max __read_mostly = 20;
de68dca1 136static int redirect_genid;
1da177e4 137
9f28a2fc
ED		 138static struct delayed_work expires_work;
139static unsigned long expires_ljiffies;
140
1da177e4
LT		 141/*
142 * Interface to generic destination cache.
143 */
144
145static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
0dbaee3b 146static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
ebb762f2 147static unsigned int ipv4_mtu(const struct dst_entry *dst);
1da177e4 148static void ipv4_dst_destroy(struct dst_entry *dst);
1da177e4
LT		 149static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
150static void ipv4_link_failure(struct sk_buff *skb);
151static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
569d3645 152static int rt_garbage_collect(struct dst_ops *ops);
1da177e4 153
72cdd1d9
ED		 154static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
155 int how)
156{
157}
1da177e4 158
62fa8a84
DM		 159static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
160{
06582540
DM		 161 struct rtable *rt = (struct rtable *) dst;
162 struct inet_peer *peer;
163 u32 *p = NULL;
164
165 if (!rt->peer)
a48eff12 166 rt_bind_peer(rt, rt->rt_dst, 1);
62fa8a84 167
06582540
DM		 168 peer = rt->peer;
169 if (peer) {
62fa8a84
DM		 170 u32 *old_p = __DST_METRICS_PTR(old);
171 unsigned long prev, new;
172
06582540
DM		 173 p = peer->metrics;
174 if (inet_metrics_new(peer))
175 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
62fa8a84
DM		 176
177 new = (unsigned long) p;
178 prev = cmpxchg(&dst->_metrics, old, new);
179
180 if (prev != old) {
62fa8a84
DM		 181 p = __DST_METRICS_PTR(prev);
182 if (prev & DST_METRICS_READ_ONLY)
183 p = NULL;
184 } else {
62fa8a84
DM		 185 if (rt->fi) {
186 fib_info_put(rt->fi);
187 rt->fi = NULL;
188 }
189 }
190 }
191 return p;
192}
193
d3aaeb38
DM		 194static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
195
1da177e4
LT		 196static struct dst_ops ipv4_dst_ops = {
197 .family = AF_INET,
09640e63 198 .protocol = cpu_to_be16(ETH_P_IP),
1da177e4
LT		 199 .gc = rt_garbage_collect,
200 .check = ipv4_dst_check,
0dbaee3b 201 .default_advmss = ipv4_default_advmss,
ebb762f2 202 .mtu = ipv4_mtu,
62fa8a84 203 .cow_metrics = ipv4_cow_metrics,
1da177e4
LT		 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,
1ac06e03 209 .local_out = __ip_local_out,
d3aaeb38 210 .neigh_lookup = ipv4_neigh_lookup,
1da177e4
LT		 211};
212
213#define ECN_OR_COST(class) TC_PRIO_##class
214
4839c52b 215const __u8 ip_tos2prio[16] = {
1da177e4 216 TC_PRIO_BESTEFFORT,
4a2b9c37 217 ECN_OR_COST(BESTEFFORT),
1da177e4
LT		 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
249struct rt_hash_bucket {
1c31720a 250 struct rtable __rcu *chain;
22c047cc 251};
1080d709 252
8a25d5de
IM		 253#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
254 defined(CONFIG_PROVE_LOCKING)
22c047cc
ED		 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.
62051200 258 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
22c047cc 259 */
62051200
IM		 260#ifdef CONFIG_LOCKDEP
261# define RT_HASH_LOCK_SZ 256
22c047cc 262#else
62051200
IM		 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
22c047cc
ED		 274#endif
275
276static spinlock_t *rt_hash_locks;
277# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
1ff1cc20
PE		 278
279static __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}
22c047cc
ED		 291#else
292# define rt_hash_lock_addr(slot) NULL
1ff1cc20
PE		 293
294static inline void rt_hash_lock_init(void)
295{
296}
22c047cc 297#endif
1da177e4 298
817bc4db
SH		 299static struct rt_hash_bucket *rt_hash_table __read_mostly;
300static unsigned rt_hash_mask __read_mostly;
301static unsigned int rt_hash_log __read_mostly;
1da177e4 302
2f970d83 303static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
27f39c73 304#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
1da177e4 305
b00180de 306static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
0eae88f3 307 int genid)
1da177e4 308{
0eae88f3 309 return jhash_3words((__force u32)daddr, (__force u32)saddr,
b00180de 310 idx, genid)
29e75252 311 & rt_hash_mask;
1da177e4
LT		 312}
313
e84f84f2
DL		 314static inline int rt_genid(struct net *net)
315{
316 return atomic_read(&net->ipv4.rt_genid);
317}
318
1da177e4
LT		 319#ifdef CONFIG_PROC_FS
320struct rt_cache_iter_state {
a75e936f 321 struct seq_net_private p;
1da177e4 322 int bucket;
29e75252 323 int genid;
1da177e4
LT		 324};
325
1218854a 326static struct rtable *rt_cache_get_first(struct seq_file *seq)
1da177e4 327{
1218854a 328 struct rt_cache_iter_state *st = seq->private;
1da177e4 329 struct rtable *r = NULL;
1da177e4
LT		 330
331 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
33d480ce 332 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
a6272665 333 continue;
1da177e4 334 rcu_read_lock_bh();
a898def2 335 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
29e75252 336 while (r) {
d8d1f30b 337 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
a75e936f 338 r->rt_genid == st->genid)
29e75252 339 return r;
d8d1f30b 340 r = rcu_dereference_bh(r->dst.rt_next);
29e75252 341 }
1da177e4
LT		 342 rcu_read_unlock_bh();
343 }
29e75252 344 return r;
1da177e4
LT		 345}
346
1218854a 347static struct rtable *__rt_cache_get_next(struct seq_file *seq,
642d6318 348 struct rtable *r)
1da177e4 349{
1218854a 350 struct rt_cache_iter_state *st = seq->private;
a6272665 351
1c31720a 352 r = rcu_dereference_bh(r->dst.rt_next);
1da177e4
LT		 353 while (!r) {
354 rcu_read_unlock_bh();
a6272665
ED		 355 do {
356 if (--st->bucket < 0)
357 return NULL;
33d480ce 358 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
1da177e4 359 rcu_read_lock_bh();
1c31720a 360 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
1da177e4 361 }
1c31720a 362 return r;
1da177e4
LT		 363}
364
1218854a 365static struct rtable *rt_cache_get_next(struct seq_file *seq,
642d6318
DL		 366 struct rtable *r)
367{
1218854a
YH		 368 struct rt_cache_iter_state *st = seq->private;
369 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
d8d1f30b 370 if (dev_net(r->dst.dev) != seq_file_net(seq))
a75e936f 371 continue;
642d6318
DL		 372 if (r->rt_genid == st->genid)
373 break;
374 }
375 return r;
376}
377
1218854a 378static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
1da177e4 379{
1218854a 380 struct rtable *r = rt_cache_get_first(seq);
1da177e4
LT		 381
382 if (r)
1218854a 383 while (pos && (r = rt_cache_get_next(seq, r)))
1da177e4
LT		 384 --pos;
385 return pos ? NULL : r;
386}
387
388static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
389{
29e75252 390 struct rt_cache_iter_state *st = seq->private;
29e75252 391 if (*pos)
1218854a 392 return rt_cache_get_idx(seq, *pos - 1);
e84f84f2 393 st->genid = rt_genid(seq_file_net(seq));
29e75252 394 return SEQ_START_TOKEN;
1da177e4
LT		 395}
396
397static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
398{
29e75252 399 struct rtable *r;
1da177e4
LT		 400
401 if (v == SEQ_START_TOKEN)
1218854a 402 r = rt_cache_get_first(seq);
1da177e4 403 else
1218854a 404 r = rt_cache_get_next(seq, v);
1da177e4
LT		 405 ++*pos;
406 return r;
407}
408
409static 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
415static 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;
69cce1d1 424 struct neighbour *n;
218fa90f 425 int len, HHUptod;
1da177e4 426
218fa90f 427 rcu_read_lock();
69cce1d1 428 n = dst_get_neighbour(&r->dst);
218fa90f
ED		 429 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
430 rcu_read_unlock();
431
0eae88f3
ED		 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",
d8d1f30b 434 r->dst.dev ? r->dst.dev->name : "*",
0eae88f3
ED		 435 (__force u32)r->rt_dst,
436 (__force u32)r->rt_gateway,
d8d1f30b
CG		 437 r->rt_flags, atomic_read(&r->dst.__refcnt),
438 r->dst.__use, 0, (__force u32)r->rt_src,
0dbaee3b 439 dst_metric_advmss(&r->dst) + 40,
d8d1f30b
CG		 440 dst_metric(&r->dst, RTAX_WINDOW),
441 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
442 dst_metric(&r->dst, RTAX_RTTVAR)),
475949d8 443 r->rt_key_tos,
f6b72b62 444 -1,
218fa90f 445 HHUptod,
5e659e4c
PE		 446 r->rt_spec_dst, &len);
447
448 seq_printf(seq, "%*s\n", 127 - len, "");
e905a9ed
YH		 449 }
450 return 0;
1da177e4
LT		 451}
452
f690808e 453static const struct seq_operations rt_cache_seq_ops = {
1da177e4
LT		 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
460static int rt_cache_seq_open(struct inode *inode, struct file *file)
461{
a75e936f 462 return seq_open_net(inode, file, &rt_cache_seq_ops,
cf7732e4 463 sizeof(struct rt_cache_iter_state));
1da177e4
LT		 464}
465
9a32144e 466static const struct file_operations rt_cache_seq_fops = {
1da177e4
LT		 467 .owner = THIS_MODULE,
468 .open = rt_cache_seq_open,
469 .read = seq_read,
470 .llseek = seq_lseek,
a75e936f 471 .release = seq_release_net,
1da177e4
LT		 472};
473
474
475static 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
0f23174a 482 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
1da177e4
LT		 483 if (!cpu_possible(cpu))
484 continue;
485 *pos = cpu+1;
2f970d83 486 return &per_cpu(rt_cache_stat, cpu);
1da177e4
LT		 487 }
488 return NULL;
489}
490
491static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
492{
493 int cpu;
494
0f23174a 495 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
1da177e4
LT		 496 if (!cpu_possible(cpu))
497 continue;
498 *pos = cpu+1;
2f970d83 499 return &per_cpu(rt_cache_stat, cpu);
1da177e4
LT		 500 }
501 return NULL;
e905a9ed 502
1da177e4
LT		 503}
504
505static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
506{
507
508}
509
510static 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) {
5bec0039 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");
1da177e4
LT		 516 return 0;
517 }
e905a9ed 518
1da177e4
LT		 519 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
520 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
fc66f95c 521 dst_entries_get_slow(&ipv4_dst_ops),
1da177e4
LT		 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,
e905a9ed 532 st->out_slow_mc,
1da177e4
LT		 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
f690808e 544static const struct seq_operations rt_cpu_seq_ops = {
1da177e4
LT		 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
552static int rt_cpu_seq_open(struct inode *inode, struct file *file)
553{
554 return seq_open(file, &rt_cpu_seq_ops);
555}
556
9a32144e 557static const struct file_operations rt_cpu_seq_fops = {
1da177e4
LT		 558 .owner = THIS_MODULE,
559 .open = rt_cpu_seq_open,
560 .read = seq_read,
561 .llseek = seq_lseek,
562 .release = seq_release,
563};
564
c7066f70 565#ifdef CONFIG_IP_ROUTE_CLASSID
a661c419 566static int rt_acct_proc_show(struct seq_file *m, void *v)
78c686e9 567{
a661c419
AD		 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 }
78c686e9
PE		 583 }
584
a661c419
AD		 585 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
586 kfree(dst);
587 return 0;
588}
78c686e9 589
a661c419
AD		 590static int rt_acct_proc_open(struct inode *inode, struct file *file)
591{
592 return single_open(file, rt_acct_proc_show, NULL);
78c686e9 593}
a661c419
AD		 594
595static 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};
78c686e9 602#endif
107f1634 603
73b38711 604static int __net_init ip_rt_do_proc_init(struct net *net)
107f1634
PE		 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
77020720
WC		 613 pde = proc_create("rt_cache", S_IRUGO,
614 net->proc_net_stat, &rt_cpu_seq_fops);
107f1634
PE		 615 if (!pde)
616 goto err2;
617
c7066f70 618#ifdef CONFIG_IP_ROUTE_CLASSID
a661c419 619 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
107f1634
PE		 620 if (!pde)
621 goto err3;
622#endif
623 return 0;
624
c7066f70 625#ifdef CONFIG_IP_ROUTE_CLASSID
107f1634
PE		 626err3:
627 remove_proc_entry("rt_cache", net->proc_net_stat);
628#endif
629err2:
630 remove_proc_entry("rt_cache", net->proc_net);
631err1:
632 return -ENOMEM;
633}
73b38711
DL		 634
635static 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);
c7066f70 639#ifdef CONFIG_IP_ROUTE_CLASSID
73b38711 640 remove_proc_entry("rt_acct", net->proc_net);
0a931acf 641#endif
73b38711
DL		 642}
643
644static 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
649static int __init ip_rt_proc_init(void)
650{
651 return register_pernet_subsys(&ip_rt_proc_ops);
652}
653
107f1634 654#else
73b38711 655static inline int ip_rt_proc_init(void)
107f1634
PE		 656{
657 return 0;
658}
1da177e4 659#endif /* CONFIG_PROC_FS */
e905a9ed 660
5969f71d 661static inline void rt_free(struct rtable *rt)
1da177e4 662{
d8d1f30b 663 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
1da177e4
LT		 664}
665
5969f71d 666static inline void rt_drop(struct rtable *rt)
1da177e4 667{
1da177e4 668 ip_rt_put(rt);
d8d1f30b 669 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
1da177e4
LT		 670}
671
5969f71d 672static inline int rt_fast_clean(struct rtable *rth)
1da177e4
LT		 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)) &&
c7537967 677 rt_is_input_route(rth) && rth->dst.rt_next;
1da177e4
LT		 678}
679
5969f71d 680static inline int rt_valuable(struct rtable *rth)
1da177e4
LT		 681{
682 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
2c8cec5c 683 (rth->peer && rth->peer->pmtu_expires);
1da177e4
LT		 684}
685
686static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
687{
688 unsigned long age;
689 int ret = 0;
690
d8d1f30b 691 if (atomic_read(&rth->dst.__refcnt))
1da177e4
LT		 692 goto out;
693
d8d1f30b 694 age = jiffies - rth->dst.lastuse;
1da177e4
LT		 695 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
696 (age <= tmo2 && rt_valuable(rth)))
697 goto out;
698 ret = 1;
699out: return ret;
700}
701
702/* Bits of score are:
703 * 31: very valuable
704 * 30: not quite useless
705 * 29..0: usage counter
706 */
707static inline u32 rt_score(struct rtable *rt)
708{
d8d1f30b 709 u32 score = jiffies - rt->dst.lastuse;
1da177e4
LT		 710
711 score = ~score & ~(3<<30);
712
713 if (rt_valuable(rt))
714 score |= (1<<31);
715
c7537967 716 if (rt_is_output_route(rt) ||
1da177e4
LT		 717 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
718 score |= (1<<30);
719
720 return score;
721}
722
1080d709
NH		 723static 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
5e2b61f7
DM		 729static inline bool compare_hash_inputs(const struct rtable *rt1,
730 const struct rtable *rt2)
1080d709 731{
5e2b61f7
DM		 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) |
97a80410 734 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
1080d709
NH		 735}
736
5e2b61f7 737static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
1da177e4 738{
5e2b61f7
DM		 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) |
475949d8 742 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
d547f727 743 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
97a80410 744 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
1da177e4
LT		 745}
746
b5921910
DL		 747static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
748{
d8d1f30b 749 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
b5921910
DL		 750}
751
e84f84f2
DL		 752static inline int rt_is_expired(struct rtable *rth)
753{
d8d1f30b 754 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
e84f84f2
DL		 755}
756
beb659bd
ED		 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 */
6561a3b1 762static void rt_do_flush(struct net *net, int process_context)
beb659bd
ED		 763{
764 unsigned int i;
765 struct rtable *rth, *next;
766
767 for (i = 0; i <= rt_hash_mask; i++) {
6561a3b1
DM		 768 struct rtable __rcu **pprev;
769 struct rtable *list;
770
beb659bd
ED		 771 if (process_context && need_resched())
772 cond_resched();
33d480ce 773 rth = rcu_access_pointer(rt_hash_table[i].chain);
beb659bd
ED		 774 if (!rth)
775 continue;
776
777 spin_lock_bh(rt_hash_lock_addr(i));
32cb5b4e 778
6561a3b1
DM		 779 list = NULL;
780 pprev = &rt_hash_table[i].chain;
781 rth = rcu_dereference_protected(*pprev,
1c31720a 782 lockdep_is_held(rt_hash_lock_addr(i)));
32cb5b4e 783
6561a3b1
DM		 784 while (rth) {
785 next = rcu_dereference_protected(rth->dst.rt_next,
1c31720a 786 lockdep_is_held(rt_hash_lock_addr(i)));
6561a3b1
DM		 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;
32cb5b4e 793 } else {
6561a3b1 794 pprev = &rth->dst.rt_next;
32cb5b4e 795 }
6561a3b1 796 rth = next;
32cb5b4e 797 }
6561a3b1 798
beb659bd
ED		 799 spin_unlock_bh(rt_hash_lock_addr(i));
800
6561a3b1
DM		 801 for (; list; list = next) {
802 next = rcu_dereference_protected(list->dst.rt_next, 1);
803 rt_free(list);
beb659bd
ED		 804 }
805 }
806}
807
1080d709
NH		 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
98376387
ED		 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 */
826static int has_noalias(const struct rtable *head, const struct rtable *rth)
827{
828 const struct rtable *aux = head;
829
830 while (aux != rth) {
5e2b61f7 831 if (compare_hash_inputs(aux, rth))
98376387 832 return 0;
1c31720a 833 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
98376387
ED		 834 }
835 return ONE;
836}
837
9f28a2fc
ED		 838static 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)) {
884nofree:
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 */
923static 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
29e75252 929/*
25985edc 930 * Perturbation of rt_genid by a small quantity [1..256]
29e75252
ED		 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.
1da177e4 934 */
86c657f6 935static void rt_cache_invalidate(struct net *net)
1da177e4 936{
29e75252 937 unsigned char shuffle;
1da177e4 938
29e75252 939 get_random_bytes(&shuffle, sizeof(shuffle));
e84f84f2 940 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
de68dca1 941 redirect_genid++;
1da177e4
LT		 942}
943
29e75252
ED		 944/*
945 * delay < 0 : invalidate cache (fast : entries will be deleted later)
946 * delay >= 0 : invalidate & flush cache (can be long)
947 */
76e6ebfb 948void rt_cache_flush(struct net *net, int delay)
1da177e4 949{
86c657f6 950 rt_cache_invalidate(net);
29e75252 951 if (delay >= 0)
6561a3b1 952 rt_do_flush(net, !in_softirq());
1da177e4
LT		 953}
954
a5ee1551 955/* Flush previous cache invalidated entries from the cache */
6561a3b1 956void rt_cache_flush_batch(struct net *net)
a5ee1551 957{
6561a3b1 958 rt_do_flush(net, !in_softirq());
a5ee1551
EB		 959}
960
1080d709
NH		 961static void rt_emergency_hash_rebuild(struct net *net)
962{
3ee94372 963 if (net_ratelimit())
1080d709 964 printk(KERN_WARNING "Route hash chain too long!\n");
3ee94372 965 rt_cache_invalidate(net);
1080d709
NH		 966}
967
1da177e4
LT		 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
569d3645 981static int rt_garbage_collect(struct dst_ops *ops)
1da177e4
LT		 982{
983 static unsigned long expire = RT_GC_TIMEOUT;
984 static unsigned long last_gc;
985 static int rover;
986 static int equilibrium;
1c31720a
ED		 987 struct rtable *rth;
988 struct rtable __rcu **rthp;
1da177e4
LT		 989 unsigned long now = jiffies;
990 int goal;
fc66f95c 991 int entries = dst_entries_get_fast(&ipv4_dst_ops);
1da177e4
LT		 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 &&
fc66f95c 1001 entries < ip_rt_max_size) {
1da177e4
LT		 1002 RT_CACHE_STAT_INC(gc_ignored);
1003 goto out;
1004 }
1005
fc66f95c 1006 entries = dst_entries_get_slow(&ipv4_dst_ops);
1da177e4 1007 /* Calculate number of entries, which we want to expire now. */
fc66f95c 1008 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1da177e4
LT		 1009 if (goal <= 0) {
1010 if (equilibrium < ipv4_dst_ops.gc_thresh)
1011 equilibrium = ipv4_dst_ops.gc_thresh;
fc66f95c 1012 goal = entries - equilibrium;
1da177e4 1013 if (goal > 0) {
b790cedd 1014 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
fc66f95c 1015 goal = entries - equilibrium;
1da177e4
LT		 1016 }
1017 } else {
1018 /* We are in dangerous area. Try to reduce cache really
1019 * aggressively.
1020 */
b790cedd 1021 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
fc66f95c 1022 equilibrium = entries - goal;
1da177e4
LT		 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;
22c047cc 1041 spin_lock_bh(rt_hash_lock_addr(k));
1c31720a
ED		 1042 while ((rth = rcu_dereference_protected(*rthp,
1043 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
e84f84f2 1044 if (!rt_is_expired(rth) &&
29e75252 1045 !rt_may_expire(rth, tmo, expire)) {
1da177e4 1046 tmo >>= 1;
d8d1f30b 1047 rthp = &rth->dst.rt_next;
1da177e4
LT		 1048 continue;
1049 }
d8d1f30b 1050 *rthp = rth->dst.rt_next;
1da177e4
LT		 1051 rt_free(rth);
1052 goal--;
1da177e4 1053 }
22c047cc 1054 spin_unlock_bh(rt_hash_lock_addr(k));
1da177e4
LT		 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;
1da177e4 1078
fc66f95c 1079 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1da177e4
LT		 1080 goto out;
1081 } while (!in_softirq() && time_before_eq(jiffies, now));
1082
fc66f95c
ED		 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)
1da177e4
LT		 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
1092work_done:
1093 expire += ip_rt_gc_min_interval;
1094 if (expire > ip_rt_gc_timeout ||
fc66f95c
ED		 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)
1da177e4 1097 expire = ip_rt_gc_timeout;
1da177e4
LT		 1098out: return 0;
1099}
1100
98376387
ED		 1101/*
1102 * Returns number of entries in a hash chain that have different hash_inputs
1103 */
1104static 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);
1c31720a 1111 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
98376387
ED		 1112 }
1113 return length >> FRACT_BITS;
1114}
1115
d3aaeb38 1116static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
3769cffb 1117{
3769cffb 1118 struct neigh_table *tbl = &arp_tbl;
d3aaeb38
DM		 1119 static const __be32 inaddr_any = 0;
1120 struct net_device *dev = dst->dev;
1121 const __be32 *pkey = daddr;
3769cffb
DM		 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
3769cffb 1128 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
d3aaeb38
DM		 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
1137static int rt_bind_neighbour(struct rtable *rt)
1138{
1139 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
3769cffb
DM		 1140 if (IS_ERR(n))
1141 return PTR_ERR(n);
69cce1d1 1142 dst_set_neighbour(&rt->dst, n);
3769cffb
DM		 1143
1144 return 0;
1145}
1146
b23dd4fe
DM		 1147static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1148 struct sk_buff *skb, int ifindex)
1da177e4 1149{
1c31720a
ED		 1150 struct rtable *rth, *cand;
1151 struct rtable __rcu **rthp, **candp;
1da177e4 1152 unsigned long now;
1da177e4
LT		 1153 u32 min_score;
1154 int chain_length;
1155 int attempts = !in_softirq();
1156
1157restart:
1158 chain_length = 0;
1159 min_score = ~(u32)0;
1160 cand = NULL;
1161 candp = NULL;
1162 now = jiffies;
1163
d8d1f30b 1164 if (!rt_caching(dev_net(rt->dst.dev))) {
73e42897
NH		 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
b6280b47
NH		 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)
27b75c95
ED		 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.
73e42897 1179 */
b6280b47 1180
c7d4426a 1181 rt->dst.flags |= DST_NOCACHE;
c7537967 1182 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
3769cffb 1183 int err = rt_bind_neighbour(rt);
b6280b47
NH		 1184 if (err) {
1185 if (net_ratelimit())
1186 printk(KERN_WARNING
1187 "Neighbour table failure & not caching routes.\n");
27b75c95 1188 ip_rt_put(rt);
b23dd4fe 1189 return ERR_PTR(err);
b6280b47
NH		 1190 }
1191 }
1192
b6280b47 1193 goto skip_hashing;
1080d709
NH		 1194 }
1195
1da177e4
LT		 1196 rthp = &rt_hash_table[hash].chain;
1197
22c047cc 1198 spin_lock_bh(rt_hash_lock_addr(hash));
1c31720a
ED		 1199 while ((rth = rcu_dereference_protected(*rthp,
1200 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
e84f84f2 1201 if (rt_is_expired(rth)) {
d8d1f30b 1202 *rthp = rth->dst.rt_next;
29e75252
ED		 1203 rt_free(rth);
1204 continue;
1205 }
5e2b61f7 1206 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1da177e4 1207 /* Put it first */
d8d1f30b 1208 *rthp = rth->dst.rt_next;
1da177e4
LT		 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 */
d8d1f30b 1214 rcu_assign_pointer(rth->dst.rt_next,
1da177e4
LT		 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
d8d1f30b 1222 dst_use(&rth->dst, now);
22c047cc 1223 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1224
1225 rt_drop(rt);
b23dd4fe 1226 if (skb)
d8d1f30b 1227 skb_dst_set(skb, &rth->dst);
b23dd4fe 1228 return rth;
1da177e4
LT		 1229 }
1230
d8d1f30b 1231 if (!atomic_read(&rth->dst.__refcnt)) {
1da177e4
LT		 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
d8d1f30b 1243 rthp = &rth->dst.rt_next;
1da177e4
LT		 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) {
d8d1f30b 1254 *candp = cand->dst.rt_next;
1da177e4
LT		 1255 rt_free(cand);
1256 }
1080d709 1257 } else {
98376387
ED		 1258 if (chain_length > rt_chain_length_max &&
1259 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
d8d1f30b 1260 struct net *net = dev_net(rt->dst.dev);
1080d709 1261 int num = ++net->ipv4.current_rt_cache_rebuild_count;
b35ecb5d 1262 if (!rt_caching(net)) {
1080d709 1263 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
d8d1f30b 1264 rt->dst.dev->name, num);
1080d709 1265 }
b35ecb5d 1266 rt_emergency_hash_rebuild(net);
6a2bad70
PE		 1267 spin_unlock_bh(rt_hash_lock_addr(hash));
1268
5e2b61f7 1269 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
6a2bad70
PE		 1270 ifindex, rt_genid(net));
1271 goto restart;
1080d709 1272 }
1da177e4
LT		 1273 }
1274
1275 /* Try to bind route to arp only if it is output
1276 route or unicast forwarding path.
1277 */
c7537967 1278 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
3769cffb 1279 int err = rt_bind_neighbour(rt);
1da177e4 1280 if (err) {
22c047cc 1281 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1282
1283 if (err != -ENOBUFS) {
1284 rt_drop(rt);
b23dd4fe 1285 return ERR_PTR(err);
1da177e4
LT		 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;
569d3645 1297 rt_garbage_collect(&ipv4_dst_ops);
1da177e4
LT		 1298 ip_rt_gc_min_interval = saved_int;
1299 ip_rt_gc_elasticity = saved_elasticity;
1300 goto restart;
1301 }
1302
1303 if (net_ratelimit())
7e1b33e5 1304 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1da177e4 1305 rt_drop(rt);
b23dd4fe 1306 return ERR_PTR(-ENOBUFS);
1da177e4
LT		 1307 }
1308 }
1309
d8d1f30b 1310 rt->dst.rt_next = rt_hash_table[hash].chain;
1080d709 1311
00269b54
ED		 1312 /*
1313 * Since lookup is lockfree, we must make sure
25985edc 1314 * previous writes to rt are committed to memory
00269b54
ED		 1315 * before making rt visible to other CPUS.
1316 */
1ddbcb00 1317 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1080d709 1318
22c047cc 1319 spin_unlock_bh(rt_hash_lock_addr(hash));
73e42897 1320
b6280b47 1321skip_hashing:
b23dd4fe 1322 if (skb)
d8d1f30b 1323 skb_dst_set(skb, &rt->dst);
b23dd4fe 1324 return rt;
1da177e4
LT		 1325}
1326
6431cbc2
DM		 1327static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1328
1329static u32 rt_peer_genid(void)
1330{
1331 return atomic_read(&__rt_peer_genid);
1332}
1333
a48eff12 1334void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1da177e4 1335{
1da177e4
LT		 1336 struct inet_peer *peer;
1337
a48eff12 1338 peer = inet_getpeer_v4(daddr, create);
1da177e4 1339
49e8ab03 1340 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1da177e4 1341 inet_putpeer(peer);
6431cbc2
DM		 1342 else
1343 rt->rt_peer_genid = rt_peer_genid();
1da177e4
LT		 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 */
1353static 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);
e448515c 1360 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1da177e4
LT		 1361 iph->id = htons(salt & 0xFFFF);
1362 ip_fallback_id = salt;
1363 spin_unlock_bh(&ip_fb_id_lock);
1364}
1365
1366void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1367{
1368 struct rtable *rt = (struct rtable *) dst;
1369
1370 if (rt) {
1371 if (rt->peer == NULL)
a48eff12 1372 rt_bind_peer(rt, rt->rt_dst, 1);
1da177e4
LT		 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
e905a9ed 1382 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
9c2b3328 1383 __builtin_return_address(0));
1da177e4
LT		 1384
1385 ip_select_fb_ident(iph);
1386}
4bc2f18b 1387EXPORT_SYMBOL(__ip_select_ident);
1da177e4
LT		 1388
1389static void rt_del(unsigned hash, struct rtable *rt)
1390{
1c31720a
ED		 1391 struct rtable __rcu **rthp;
1392 struct rtable *aux;
1da177e4 1393
29e75252 1394 rthp = &rt_hash_table[hash].chain;
22c047cc 1395 spin_lock_bh(rt_hash_lock_addr(hash));
1da177e4 1396 ip_rt_put(rt);
1c31720a
ED		 1397 while ((aux = rcu_dereference_protected(*rthp,
1398 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
e84f84f2 1399 if (aux == rt || rt_is_expired(aux)) {
d8d1f30b 1400 *rthp = aux->dst.rt_next;
29e75252
ED		 1401 rt_free(aux);
1402 continue;
1da177e4 1403 }
d8d1f30b 1404 rthp = &aux->dst.rt_next;
29e75252 1405 }
22c047cc 1406 spin_unlock_bh(rt_hash_lock_addr(hash));
1da177e4
LT		 1407}
1408
de398fb8 1409static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
9cc20b26
ED		 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);
de398fb8
DM		 1420 if (IS_ERR(n)) {
1421 rt->rt_gateway = orig_gw;
1422 return;
1423 }
9cc20b26
ED		 1424 old_n = xchg(&rt->dst._neighbour, n);
1425 if (old_n)
1426 neigh_release(old_n);
de398fb8
DM		 1427 if (!(n->nud_state & NUD_VALID)) {
1428 neigh_event_send(n, NULL);
9cc20b26
ED		 1429 } else {
1430 rt->rt_flags |= RTCF_REDIRECTED;
1431 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1432 }
9cc20b26
ED		 1433}
1434
ed7865a4 1435/* called in rcu_read_lock() section */
f7655229
AV		 1436void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1437 __be32 saddr, struct net_device *dev)
1da177e4 1438{
7cc9150e 1439 int s, i;
ed7865a4 1440 struct in_device *in_dev = __in_dev_get_rcu(dev);
7cc9150e
FL		 1441 __be32 skeys[2] = { saddr, 0 };
1442 int ikeys[2] = { dev->ifindex, 0 };
f39925db 1443 struct inet_peer *peer;
317805b8 1444 struct net *net;
1da177e4 1445
1da177e4
LT		 1446 if (!in_dev)
1447 return;
1448
c346dca1 1449 net = dev_net(dev);
9d4fb27d
JP		 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))
1da177e4
LT		 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 {
317805b8 1461 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1da177e4
LT		 1462 goto reject_redirect;
1463 }
1464
7cc9150e
FL		 1465 for (s = 0; s < 2; s++) {
1466 for (i = 0; i < 2; i++) {
9cc20b26
ED		 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;
e905a9ed 1488
9cc20b26
ED		 1489 if (!rt->peer)
1490 rt_bind_peer(rt, rt->rt_dst, 1);
1da177e4 1491
9cc20b26
ED		 1492 peer = rt->peer;
1493 if (peer) {
de68dca1
ED		 1494 if (peer->redirect_learned.a4 != new_gw ||
1495 peer->redirect_genid != redirect_genid) {
9cc20b26 1496 peer->redirect_learned.a4 = new_gw;
de68dca1 1497 peer->redirect_genid = redirect_genid;
9cc20b26
ED		 1498 atomic_inc(&__rt_peer_genid);
1499 }
1500 check_peer_redir(&rt->dst, peer);
1501 }
7cc9150e 1502 }
7cc9150e 1503 }
1da177e4 1504 }
1da177e4
LT		 1505 return;
1506
1507reject_redirect:
1508#ifdef CONFIG_IP_ROUTE_VERBOSE
1509 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
673d57e7
HH		 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);
1da177e4 1514#endif
ed7865a4 1515 ;
1da177e4
LT		 1516}
1517
fe6fe792
ED		 1518static 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
1527static 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
1da177e4
LT		 1535static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1536{
ee6b9673 1537 struct rtable *rt = (struct rtable *)dst;
1da177e4
LT		 1538 struct dst_entry *ret = dst;
1539
1540 if (rt) {
d11a4dc1 1541 if (dst->obsolete > 0) {
1da177e4
LT		 1542 ip_rt_put(rt);
1543 ret = NULL;
2c8cec5c 1544 } else if (rt->rt_flags & RTCF_REDIRECTED) {
5e2b61f7
DM		 1545 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1546 rt->rt_oif,
e84f84f2 1547 rt_genid(dev_net(dst->dev)));
1da177e4
LT		 1548 rt_del(hash, rt);
1549 ret = NULL;
fe6fe792
ED		 1550 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1551 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1da177e4
LT		 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
1573void ip_rt_send_redirect(struct sk_buff *skb)
1574{
511c3f92 1575 struct rtable *rt = skb_rtable(skb);
30038fc6 1576 struct in_device *in_dev;
92d86829 1577 struct inet_peer *peer;
30038fc6 1578 int log_martians;
1da177e4 1579
30038fc6 1580 rcu_read_lock();
d8d1f30b 1581 in_dev = __in_dev_get_rcu(rt->dst.dev);
30038fc6
ED		 1582 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1583 rcu_read_unlock();
1da177e4 1584 return;
30038fc6
ED		 1585 }
1586 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1587 rcu_read_unlock();
1da177e4 1588
92d86829 1589 if (!rt->peer)
a48eff12 1590 rt_bind_peer(rt, rt->rt_dst, 1);
92d86829
DM		 1591 peer = rt->peer;
1592 if (!peer) {
1593 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1594 return;
1595 }
1596
1da177e4
LT		 1597 /* No redirected packets during ip_rt_redirect_silence;
1598 * reset the algorithm.
1599 */
92d86829
DM		 1600 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1601 peer->rate_tokens = 0;
1da177e4
LT		 1602
1603 /* Too many ignored redirects; do not send anything
d8d1f30b 1604 * set dst.rate_last to the last seen redirected packet.
1da177e4 1605 */
92d86829
DM		 1606 if (peer->rate_tokens >= ip_rt_redirect_number) {
1607 peer->rate_last = jiffies;
30038fc6 1608 return;
1da177e4
LT		 1609 }
1610
1611 /* Check for load limit; set rate_last to the latest sent
1612 * redirect.
1613 */
92d86829 1614 if (peer->rate_tokens == 0 ||
14fb8a76 1615 time_after(jiffies,
92d86829
DM		 1616 (peer->rate_last +
1617 (ip_rt_redirect_load << peer->rate_tokens)))) {
1da177e4 1618 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
92d86829
DM		 1619 peer->rate_last = jiffies;
1620 ++peer->rate_tokens;
1da177e4 1621#ifdef CONFIG_IP_ROUTE_VERBOSE
30038fc6 1622 if (log_martians &&
92d86829 1623 peer->rate_tokens == ip_rt_redirect_number &&
1da177e4 1624 net_ratelimit())
673d57e7 1625 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
c5be24ff 1626 &ip_hdr(skb)->saddr, rt->rt_iif,
673d57e7 1627 &rt->rt_dst, &rt->rt_gateway);
1da177e4
LT		 1628#endif
1629 }
1da177e4
LT		 1630}
1631
1632static int ip_error(struct sk_buff *skb)
1633{
511c3f92 1634 struct rtable *rt = skb_rtable(skb);
92d86829 1635 struct inet_peer *peer;
1da177e4 1636 unsigned long now;
92d86829 1637 bool send;
1da177e4
LT		 1638 int code;
1639
d8d1f30b 1640 switch (rt->dst.error) {
4500ebf8
JP		 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;
1da177e4
LT		 1655 }
1656
92d86829 1657 if (!rt->peer)
a48eff12 1658 rt_bind_peer(rt, rt->rt_dst, 1);
92d86829
DM		 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;
1da177e4 1672 }
92d86829
DM		 1673 if (send)
1674 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1da177e4
LT		 1675
1676out: kfree_skb(skb);
1677 return 0;
e905a9ed 1678}
1da177e4
LT		 1679
1680/*
1681 * The last two values are not from the RFC but
1682 * are needed for AMPRnet AX.25 paths.
1683 */
1684
9b5b5cff 1685static const unsigned short mtu_plateau[] =
1da177e4
LT		 1686{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1687
5969f71d 1688static inline unsigned short guess_mtu(unsigned short old_mtu)
1da177e4
LT		 1689{
1690 int i;
e905a9ed 1691
1da177e4
LT		 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
b71d1d42 1698unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
0010e465
TT		 1699 unsigned short new_mtu,
1700 struct net_device *dev)
1da177e4 1701{
1da177e4 1702 unsigned short old_mtu = ntohs(iph->tot_len);
1da177e4 1703 unsigned short est_mtu = 0;
2c8cec5c 1704 struct inet_peer *peer;
1da177e4 1705
2c8cec5c
DM		 1706 peer = inet_getpeer_v4(iph->daddr, 1);
1707 if (peer) {
1708 unsigned short mtu = new_mtu;
1da177e4 1709
2c8cec5c
DM		 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 }
0010e465 1720
2c8cec5c
DM		 1721 if (mtu < ip_rt_min_pmtu)
1722 mtu = ip_rt_min_pmtu;
1723 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
46af3180
HS		 1724 unsigned long pmtu_expires;
1725
1726 pmtu_expires = jiffies + ip_rt_mtu_expires;
1727 if (!pmtu_expires)
1728 pmtu_expires = 1UL;
1729
2c8cec5c
DM		 1730 est_mtu = mtu;
1731 peer->pmtu_learned = mtu;
46af3180 1732 peer->pmtu_expires = pmtu_expires;
59445b6b 1733 atomic_inc(&__rt_peer_genid);
2c8cec5c 1734 }
1da177e4 1735
2c8cec5c 1736 inet_putpeer(peer);
1da177e4
LT		 1737 }
1738 return est_mtu ? : new_mtu;
1739}
1740
2c8cec5c
DM		 1741static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1742{
fe6fe792 1743 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
2c8cec5c 1744
fe6fe792
ED		 1745 if (!expires)
1746 return;
46af3180 1747 if (time_before(jiffies, expires)) {
2c8cec5c
DM		 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
1da177e4
LT		 1758static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1759{
2c8cec5c
DM		 1760 struct rtable *rt = (struct rtable *) dst;
1761 struct inet_peer *peer;
1762
1763 dst_confirm(dst);
1764
1765 if (!rt->peer)
a48eff12 1766 rt_bind_peer(rt, rt->rt_dst, 1);
2c8cec5c
DM		 1767 peer = rt->peer;
1768 if (peer) {
fe6fe792
ED		 1769 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1770
2c8cec5c 1771 if (mtu < ip_rt_min_pmtu)
1da177e4 1772 mtu = ip_rt_min_pmtu;
fe6fe792 1773 if (!pmtu_expires || mtu < peer->pmtu_learned) {
46af3180
HS		 1774
1775 pmtu_expires = jiffies + ip_rt_mtu_expires;
1776 if (!pmtu_expires)
1777 pmtu_expires = 1UL;
1778
2c8cec5c 1779 peer->pmtu_learned = mtu;
46af3180 1780 peer->pmtu_expires = pmtu_expires;
2c8cec5c
DM		 1781
1782 atomic_inc(&__rt_peer_genid);
1783 rt->rt_peer_genid = rt_peer_genid();
1da177e4 1784 }
46af3180 1785 check_peer_pmtu(dst, peer);
1da177e4
LT		 1786 }
1787}
1788
f39925db 1789
de398fb8 1790static void ipv4_validate_peer(struct rtable *rt)
1da177e4 1791{
6431cbc2 1792 if (rt->rt_peer_genid != rt_peer_genid()) {
2c8cec5c
DM		 1793 struct inet_peer *peer;
1794
6431cbc2 1795 if (!rt->peer)
a48eff12 1796 rt_bind_peer(rt, rt->rt_dst, 0);
6431cbc2 1797
2c8cec5c 1798 peer = rt->peer;
fe6fe792 1799 if (peer) {
efbc368d 1800 check_peer_pmtu(&rt->dst, peer);
2c8cec5c 1801
de68dca1
ED		 1802 if (peer->redirect_genid != redirect_genid)
1803 peer->redirect_learned.a4 = 0;
fe6fe792 1804 if (peer->redirect_learned.a4 &&
de398fb8
DM		 1805 peer->redirect_learned.a4 != rt->rt_gateway)
1806 check_peer_redir(&rt->dst, peer);
f39925db
DM		 1807 }
1808
6431cbc2
DM		 1809 rt->rt_peer_genid = rt_peer_genid();
1810 }
efbc368d
DM		 1811}
1812
1813static 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;
de398fb8 1819 ipv4_validate_peer(rt);
d11a4dc1 1820 return dst;
1da177e4
LT		 1821}
1822
1823static void ipv4_dst_destroy(struct dst_entry *dst)
1824{
1825 struct rtable *rt = (struct rtable *) dst;
1826 struct inet_peer *peer = rt->peer;
1da177e4 1827
62fa8a84
DM		 1828 if (rt->fi) {
1829 fib_info_put(rt->fi);
1830 rt->fi = NULL;
1831 }
1da177e4
LT		 1832 if (peer) {
1833 rt->peer = NULL;
1834 inet_putpeer(peer);
1835 }
1da177e4
LT		 1836}
1837
1da177e4
LT		 1838
1839static 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
511c3f92 1845 rt = skb_rtable(skb);
fe6fe792
ED		 1846 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1847 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1da177e4
LT		 1848}
1849
1850static int ip_rt_bug(struct sk_buff *skb)
1851{
673d57e7
HH		 1852 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1853 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1da177e4
LT		 1854 skb->dev ? skb->dev->name : "?");
1855 kfree_skb(skb);
c378a9c0 1856 WARN_ON(1);
1da177e4
LT		 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
8e36360a 1869void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1da177e4 1870{
a61ced5d 1871 __be32 src;
1da177e4 1872
c7537967 1873 if (rt_is_output_route(rt))
c5be24ff 1874 src = ip_hdr(skb)->saddr;
ebc0ffae 1875 else {
8e36360a
DM		 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;
b0fe4a31 1885 fl4.flowi4_tos = RT_TOS(iph->tos);
8e36360a
DM		 1886 fl4.flowi4_oif = rt->dst.dev->ifindex;
1887 fl4.flowi4_iif = skb->dev->ifindex;
1888 fl4.flowi4_mark = skb->mark;
5e2b61f7 1889
ebc0ffae 1890 rcu_read_lock();
68a5e3dd 1891 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
436c3b66 1892 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
ebc0ffae
ED		 1893 else
1894 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1da177e4 1895 RT_SCOPE_UNIVERSE);
ebc0ffae
ED		 1896 rcu_read_unlock();
1897 }
1da177e4
LT		 1898 memcpy(addr, &src, 4);
1899}
1900
c7066f70 1901#ifdef CONFIG_IP_ROUTE_CLASSID
1da177e4
LT		 1902static void set_class_tag(struct rtable *rt, u32 tag)
1903{
d8d1f30b
CG		 1904 if (!(rt->dst.tclassid & 0xFFFF))
1905 rt->dst.tclassid |= tag & 0xFFFF;
1906 if (!(rt->dst.tclassid & 0xFFFF0000))
1907 rt->dst.tclassid |= tag & 0xFFFF0000;
1da177e4
LT		 1908}
1909#endif
1910
0dbaee3b
DM		 1911static 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
ebb762f2 1924static unsigned int ipv4_mtu(const struct dst_entry *dst)
d33e4553 1925{
261663b0 1926 const struct rtable *rt = (const struct rtable *) dst;
618f9bc7
SK		 1927 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1928
261663b0 1929 if (mtu && rt_is_output_route(rt))
618f9bc7
SK		 1930 return mtu;
1931
1932 mtu = dst->dev->mtu;
d33e4553
DM		 1933
1934 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
d33e4553
DM		 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
813b3b5d 1946static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
5e2b61f7 1947 struct fib_info *fi)
a4daad6b 1948{
0131ba45
DM		 1949 struct inet_peer *peer;
1950 int create = 0;
a4daad6b 1951
0131ba45
DM		 1952 /* If a peer entry exists for this destination, we must hook
1953 * it up in order to get at cached metrics.
1954 */
813b3b5d 1955 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
0131ba45
DM		 1956 create = 1;
1957
3c0afdca 1958 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
0131ba45 1959 if (peer) {
3c0afdca 1960 rt->rt_peer_genid = rt_peer_genid();
a4daad6b
DM		 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);
2c8cec5c 1965
fe6fe792 1966 check_peer_pmtu(&rt->dst, peer);
de68dca1
ED		 1967 if (peer->redirect_genid != redirect_genid)
1968 peer->redirect_learned.a4 = 0;
f39925db
DM		 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 }
0131ba45
DM		 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);
a4daad6b
DM		 1980 }
1981}
1982
813b3b5d 1983static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
5e2b61f7 1984 const struct fib_result *res,
982721f3 1985 struct fib_info *fi, u16 type, u32 itag)
1da177e4 1986{
defb3519 1987 struct dst_entry *dst = &rt->dst;
1da177e4
LT		 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);
813b3b5d 1993 rt_init_metrics(rt, fl4, fi);
c7066f70 1994#ifdef CONFIG_IP_ROUTE_CLASSID
defb3519 1995 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1da177e4 1996#endif
d33e4553 1997 }
defb3519 1998
defb3519
DM		 1999 if (dst_mtu(dst) > IP_MAX_MTU)
2000 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
0dbaee3b 2001 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
defb3519 2002 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1da177e4 2003
c7066f70 2004#ifdef CONFIG_IP_ROUTE_CLASSID
1da177e4
LT		 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
1da177e4
LT		 2010}
2011
5c1e6aa3
DM		 2012static struct rtable *rt_dst_alloc(struct net_device *dev,
2013 bool nopolicy, bool noxfrm)
0c4dcd58 2014{
5c1e6aa3
DM		 2015 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
2016 DST_HOST |
2017 (nopolicy ? DST_NOPOLICY : 0) |
2018 (noxfrm ? DST_NOXFRM : 0));
0c4dcd58
DM		 2019}
2020
96d36220 2021/* called in rcu_read_lock() section */
9e12bb22 2022static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1da177e4
LT		 2023 u8 tos, struct net_device *dev, int our)
2024{
96d36220 2025 unsigned int hash;
1da177e4 2026 struct rtable *rth;
a61ced5d 2027 __be32 spec_dst;
96d36220 2028 struct in_device *in_dev = __in_dev_get_rcu(dev);
1da177e4 2029 u32 itag = 0;
b5f7e755 2030 int err;
1da177e4
LT		 2031
2032 /* Primary sanity checks. */
2033
2034 if (in_dev == NULL)
2035 return -EINVAL;
2036
1e637c74 2037 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
f97c1e0c 2038 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1da177e4
LT		 2039 goto e_inval;
2040
f97c1e0c
JP		 2041 if (ipv4_is_zeronet(saddr)) {
2042 if (!ipv4_is_local_multicast(daddr))
1da177e4
LT		 2043 goto e_inval;
2044 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
b5f7e755 2045 } else {
5c04c819
MS		 2046 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2047 &itag);
b5f7e755
ED		 2048 if (err < 0)
2049 goto e_err;
2050 }
5c1e6aa3
DM		 2051 rth = rt_dst_alloc(init_net.loopback_dev,
2052 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1da177e4
LT		 2053 if (!rth)
2054 goto e_nobufs;
2055
cf911662
DM		 2056#ifdef CONFIG_IP_ROUTE_CLASSID
2057 rth->dst.tclassid = itag;
2058#endif
d8d1f30b 2059 rth->dst.output = ip_rt_bug;
1da177e4 2060
5e2b61f7 2061 rth->rt_key_dst = daddr;
5e2b61f7 2062 rth->rt_key_src = saddr;
cf911662
DM		 2063 rth->rt_genid = rt_genid(dev_net(dev));
2064 rth->rt_flags = RTCF_MULTICAST;
2065 rth->rt_type = RTN_MULTICAST;
475949d8 2066 rth->rt_key_tos = tos;
cf911662 2067 rth->rt_dst = daddr;
1da177e4 2068 rth->rt_src = saddr;
1b86a58f 2069 rth->rt_route_iif = dev->ifindex;
5e2b61f7 2070 rth->rt_iif = dev->ifindex;
5e2b61f7 2071 rth->rt_oif = 0;
cf911662 2072 rth->rt_mark = skb->mark;
1da177e4
LT		 2073 rth->rt_gateway = daddr;
2074 rth->rt_spec_dst= spec_dst;
cf911662
DM		 2075 rth->rt_peer_genid = 0;
2076 rth->peer = NULL;
2077 rth->fi = NULL;
1da177e4 2078 if (our) {
d8d1f30b 2079 rth->dst.input= ip_local_deliver;
1da177e4
LT		 2080 rth->rt_flags |= RTCF_LOCAL;
2081 }
2082
2083#ifdef CONFIG_IP_MROUTE
f97c1e0c 2084 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
d8d1f30b 2085 rth->dst.input = ip_mr_input;
1da177e4
LT		 2086#endif
2087 RT_CACHE_STAT_INC(in_slow_mc);
2088
e84f84f2 2089 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
b23dd4fe 2090 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
9aa3c94c 2091 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
1da177e4
LT		 2092
2093e_nobufs:
1da177e4 2094 return -ENOBUFS;
1da177e4 2095e_inval:
96d36220 2096 return -EINVAL;
b5f7e755 2097e_err:
b5f7e755 2098 return err;
1da177e4
LT		 2099}
2100
2101
2102static void ip_handle_martian_source(struct net_device *dev,
2103 struct in_device *in_dev,
2104 struct sk_buff *skb,
9e12bb22
AV		 2105 __be32 daddr,
2106 __be32 saddr)
1da177e4
LT		 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 */
673d57e7
HH		 2115 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2116 &daddr, &saddr, dev->name);
98e399f8 2117 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1da177e4 2118 int i;
98e399f8 2119 const unsigned char *p = skb_mac_header(skb);
1da177e4
LT		 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
47360228 2132/* called in rcu_read_lock() section */
5969f71d 2133static int __mkroute_input(struct sk_buff *skb,
982721f3 2134 const struct fib_result *res,
5969f71d
SH		 2135 struct in_device *in_dev,
2136 __be32 daddr, __be32 saddr, u32 tos,
2137 struct rtable **result)
1da177e4 2138{
1da177e4
LT		 2139 struct rtable *rth;
2140 int err;
2141 struct in_device *out_dev;
47360228 2142 unsigned int flags = 0;
d9c9df8c
AV		 2143 __be32 spec_dst;
2144 u32 itag;
1da177e4
LT		 2145
2146 /* get a working reference to the output device */
47360228 2147 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1da177e4
LT		 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
5c04c819
MS		 2156 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2157 in_dev->dev, &spec_dst, &itag);
1da177e4 2158 if (err < 0) {
e905a9ed 2159 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1da177e4 2160 saddr);
e905a9ed 2161
1da177e4
LT		 2162 goto cleanup;
2163 }
2164
2165 if (err)
2166 flags |= RTCF_DIRECTSRC;
2167
51b77cae 2168 if (out_dev == in_dev && err &&
1da177e4
LT		 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.
65324144
JDB		 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.
1da177e4 2180 */
65324144
JDB		 2181 if (out_dev == in_dev &&
2182 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1da177e4
LT		 2183 err = -EINVAL;
2184 goto cleanup;
2185 }
2186 }
2187
5c1e6aa3
DM		 2188 rth = rt_dst_alloc(out_dev->dev,
2189 IN_DEV_CONF_GET(in_dev, NOPOLICY),
0c4dcd58 2190 IN_DEV_CONF_GET(out_dev, NOXFRM));
1da177e4
LT		 2191 if (!rth) {
2192 err = -ENOBUFS;
2193 goto cleanup;
2194 }
2195
5e2b61f7 2196 rth->rt_key_dst = daddr;
5e2b61f7 2197 rth->rt_key_src = saddr;
cf911662
DM		 2198 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2199 rth->rt_flags = flags;
2200 rth->rt_type = res->type;
475949d8 2201 rth->rt_key_tos = tos;
cf911662 2202 rth->rt_dst = daddr;
1da177e4 2203 rth->rt_src = saddr;
1b86a58f 2204 rth->rt_route_iif = in_dev->dev->ifindex;
5e2b61f7 2205 rth->rt_iif = in_dev->dev->ifindex;
5e2b61f7 2206 rth->rt_oif = 0;
cf911662
DM		 2207 rth->rt_mark = skb->mark;
2208 rth->rt_gateway = daddr;
1da177e4 2209 rth->rt_spec_dst= spec_dst;
cf911662
DM		 2210 rth->rt_peer_genid = 0;
2211 rth->peer = NULL;
2212 rth->fi = NULL;
1da177e4 2213
d8d1f30b
CG		 2214 rth->dst.input = ip_forward;
2215 rth->dst.output = ip_output;
1da177e4 2216
5e2b61f7 2217 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
1da177e4 2218
1da177e4
LT		 2219 *result = rth;
2220 err = 0;
2221 cleanup:
1da177e4 2222 return err;
e905a9ed 2223}
1da177e4 2224
5969f71d
SH		 2225static int ip_mkroute_input(struct sk_buff *skb,
2226 struct fib_result *res,
68a5e3dd 2227 const struct flowi4 *fl4,
5969f71d
SH		 2228 struct in_device *in_dev,
2229 __be32 daddr, __be32 saddr, u32 tos)
1da177e4 2230{
7abaa27c 2231 struct rtable* rth = NULL;
1da177e4
LT		 2232 int err;
2233 unsigned hash;
2234
2235#ifdef CONFIG_IP_ROUTE_MULTIPATH
ff3fccb3 2236 if (res->fi && res->fi->fib_nhs > 1)
1b7fe593 2237 fib_select_multipath(res);
1da177e4
LT		 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;
1da177e4
LT		 2244
2245 /* put it into the cache */
68a5e3dd 2246 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
d8d1f30b 2247 rt_genid(dev_net(rth->dst.dev)));
68a5e3dd 2248 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
b23dd4fe
DM		 2249 if (IS_ERR(rth))
2250 return PTR_ERR(rth);
2251 return 0;
1da177e4
LT		 2252}
2253
1da177e4
LT		 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.
ebc0ffae 2262 * called with rcu_read_lock()
1da177e4
LT		 2263 */
2264
9e12bb22 2265static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1da177e4
LT		 2266 u8 tos, struct net_device *dev)
2267{
2268 struct fib_result res;
96d36220 2269 struct in_device *in_dev = __in_dev_get_rcu(dev);
68a5e3dd 2270 struct flowi4 fl4;
1da177e4
LT		 2271 unsigned flags = 0;
2272 u32 itag = 0;
2273 struct rtable * rth;
2274 unsigned hash;
9e12bb22 2275 __be32 spec_dst;
1da177e4 2276 int err = -EINVAL;
c346dca1 2277 struct net * net = dev_net(dev);
1da177e4
LT		 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
1e637c74 2288 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
f97c1e0c 2289 ipv4_is_loopback(saddr))
1da177e4
LT		 2290 goto martian_source;
2291
27a954bd 2292 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1da177e4
LT		 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 */
f97c1e0c 2298 if (ipv4_is_zeronet(saddr))
1da177e4
LT		 2299 goto martian_source;
2300
27a954bd 2301 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
1da177e4
LT		 2302 goto martian_destination;
2303
2304 /*
2305 * Now we are ready to route packet.
2306 */
68a5e3dd
DM		 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);
ebc0ffae 2315 if (err != 0) {
1da177e4 2316 if (!IN_DEV_FORWARD(in_dev))
2c2910a4 2317 goto e_hostunreach;
1da177e4
LT		 2318 goto no_route;
2319 }
1da177e4
LT		 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) {
5c04c819 2327 err = fib_validate_source(skb, saddr, daddr, tos,
ebc0ffae 2328 net->loopback_dev->ifindex,
5c04c819 2329 dev, &spec_dst, &itag);
b5f7e755
ED		 2330 if (err < 0)
2331 goto martian_source_keep_err;
2332 if (err)
1da177e4
LT		 2333 flags |= RTCF_DIRECTSRC;
2334 spec_dst = daddr;
2335 goto local_input;
2336 }
2337
2338 if (!IN_DEV_FORWARD(in_dev))
2c2910a4 2339 goto e_hostunreach;
1da177e4
LT		 2340 if (res.type != RTN_UNICAST)
2341 goto martian_destination;
2342
68a5e3dd 2343 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1da177e4
LT		 2344out: return err;
2345
2346brd_input:
2347 if (skb->protocol != htons(ETH_P_IP))
2348 goto e_inval;
2349
f97c1e0c 2350 if (ipv4_is_zeronet(saddr))
1da177e4
LT		 2351 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2352 else {
5c04c819
MS		 2353 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2354 &itag);
1da177e4 2355 if (err < 0)
b5f7e755 2356 goto martian_source_keep_err;
1da177e4
LT		 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
2364local_input:
5c1e6aa3
DM		 2365 rth = rt_dst_alloc(net->loopback_dev,
2366 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1da177e4
LT		 2367 if (!rth)
2368 goto e_nobufs;
2369
cf911662 2370 rth->dst.input= ip_local_deliver;
d8d1f30b 2371 rth->dst.output= ip_rt_bug;
cf911662
DM		 2372#ifdef CONFIG_IP_ROUTE_CLASSID
2373 rth->dst.tclassid = itag;
2374#endif
1da177e4 2375
5e2b61f7 2376 rth->rt_key_dst = daddr;
5e2b61f7 2377 rth->rt_key_src = saddr;
cf911662
DM		 2378 rth->rt_genid = rt_genid(net);
2379 rth->rt_flags = flags|RTCF_LOCAL;
2380 rth->rt_type = res.type;
475949d8 2381 rth->rt_key_tos = tos;
cf911662 2382 rth->rt_dst = daddr;
1da177e4 2383 rth->rt_src = saddr;
c7066f70 2384#ifdef CONFIG_IP_ROUTE_CLASSID
d8d1f30b 2385 rth->dst.tclassid = itag;
1da177e4 2386#endif
1b86a58f 2387 rth->rt_route_iif = dev->ifindex;
5e2b61f7 2388 rth->rt_iif = dev->ifindex;
cf911662
DM		 2389 rth->rt_oif = 0;
2390 rth->rt_mark = skb->mark;
1da177e4
LT		 2391 rth->rt_gateway = daddr;
2392 rth->rt_spec_dst= spec_dst;
cf911662
DM		 2393 rth->rt_peer_genid = 0;
2394 rth->peer = NULL;
2395 rth->fi = NULL;
1da177e4 2396 if (res.type == RTN_UNREACHABLE) {
d8d1f30b
CG		 2397 rth->dst.input= ip_error;
2398 rth->dst.error= -err;
1da177e4
LT		 2399 rth->rt_flags &= ~RTCF_LOCAL;
2400 }
68a5e3dd
DM		 2401 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2402 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
b23dd4fe
DM		 2403 err = 0;
2404 if (IS_ERR(rth))
2405 err = PTR_ERR(rth);
ebc0ffae 2406 goto out;
1da177e4
LT		 2407
2408no_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;
7f53878d
MC		 2412 if (err == -ESRCH)
2413 err = -ENETUNREACH;
1da177e4
LT		 2414 goto local_input;
2415
2416 /*
2417 * Do not cache martian addresses: they should be logged (RFC1812)
2418 */
2419martian_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())
673d57e7
HH		 2423 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2424 &daddr, &saddr, dev->name);
1da177e4 2425#endif
2c2910a4
DE		 2426
2427e_hostunreach:
e905a9ed 2428 err = -EHOSTUNREACH;
ebc0ffae 2429 goto out;
2c2910a4 2430
1da177e4
LT		 2431e_inval:
2432 err = -EINVAL;
ebc0ffae 2433 goto out;
1da177e4
LT		 2434
2435e_nobufs:
2436 err = -ENOBUFS;
ebc0ffae 2437 goto out;
1da177e4
LT		 2438
2439martian_source:
b5f7e755
ED		 2440 err = -EINVAL;
2441martian_source_keep_err:
1da177e4 2442 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
ebc0ffae 2443 goto out;
1da177e4
LT		 2444}
2445
407eadd9
ED		 2446int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2447 u8 tos, struct net_device *dev, bool noref)
1da177e4
LT		 2448{
2449 struct rtable * rth;
2450 unsigned hash;
2451 int iif = dev->ifindex;
b5921910 2452 struct net *net;
96d36220 2453 int res;
1da177e4 2454
c346dca1 2455 net = dev_net(dev);
1080d709 2456
96d36220
ED		 2457 rcu_read_lock();
2458
1080d709
NH		 2459 if (!rt_caching(net))
2460 goto skip_cache;
2461
1da177e4 2462 tos &= IPTOS_RT_MASK;
e84f84f2 2463 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
1da177e4 2464
1da177e4 2465 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
d8d1f30b 2466 rth = rcu_dereference(rth->dst.rt_next)) {
5e2b61f7
DM		 2467 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2468 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
97a80410 2469 (rth->rt_route_iif ^ iif) |
475949d8 2470 (rth->rt_key_tos ^ tos)) == 0 &&
5e2b61f7 2471 rth->rt_mark == skb->mark &&
d8d1f30b 2472 net_eq(dev_net(rth->dst.dev), net) &&
e84f84f2 2473 !rt_is_expired(rth)) {
de398fb8 2474 ipv4_validate_peer(rth);
407eadd9 2475 if (noref) {
d8d1f30b
CG		 2476 dst_use_noref(&rth->dst, jiffies);
2477 skb_dst_set_noref(skb, &rth->dst);
407eadd9 2478 } else {
d8d1f30b
CG		 2479 dst_use(&rth->dst, jiffies);
2480 skb_dst_set(skb, &rth->dst);
407eadd9 2481 }
1da177e4
LT		 2482 RT_CACHE_STAT_INC(in_hit);
2483 rcu_read_unlock();
1da177e4
LT		 2484 return 0;
2485 }
2486 RT_CACHE_STAT_INC(in_hlist_search);
2487 }
1da177e4 2488
1080d709 2489skip_cache:
1da177e4
LT		 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 */
f97c1e0c 2501 if (ipv4_is_multicast(daddr)) {
96d36220 2502 struct in_device *in_dev = __in_dev_get_rcu(dev);
1da177e4 2503
96d36220 2504 if (in_dev) {
dbdd9a52
DM		 2505 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2506 ip_hdr(skb)->protocol);
1da177e4
LT		 2507 if (our
2508#ifdef CONFIG_IP_MROUTE
9d4fb27d
JP		 2509 ||
2510 (!ipv4_is_local_multicast(daddr) &&
2511 IN_DEV_MFORWARD(in_dev))
1da177e4 2512#endif
9d4fb27d 2513 ) {
96d36220
ED		 2514 int res = ip_route_input_mc(skb, daddr, saddr,
2515 tos, dev, our);
1da177e4 2516 rcu_read_unlock();
96d36220 2517 return res;
1da177e4
LT		 2518 }
2519 }
2520 rcu_read_unlock();
2521 return -EINVAL;
2522 }
96d36220
ED		 2523 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2524 rcu_read_unlock();
2525 return res;
1da177e4 2526}
407eadd9 2527EXPORT_SYMBOL(ip_route_input_common);
1da177e4 2528
ebc0ffae 2529/* called with rcu_read_lock() */
982721f3 2530static struct rtable *__mkroute_output(const struct fib_result *res,
68a5e3dd 2531 const struct flowi4 *fl4,
813b3b5d 2532 __be32 orig_daddr, __be32 orig_saddr,
f61759e6
JA		 2533 int orig_oif, __u8 orig_rtos,
2534 struct net_device *dev_out,
5ada5527 2535 unsigned int flags)
1da177e4 2536{
982721f3 2537 struct fib_info *fi = res->fi;
5ada5527 2538 struct in_device *in_dev;
982721f3 2539 u16 type = res->type;
5ada5527 2540 struct rtable *rth;
1da177e4 2541
68a5e3dd 2542 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
5ada5527 2543 return ERR_PTR(-EINVAL);
1da177e4 2544
68a5e3dd 2545 if (ipv4_is_lbcast(fl4->daddr))
982721f3 2546 type = RTN_BROADCAST;
68a5e3dd 2547 else if (ipv4_is_multicast(fl4->daddr))
982721f3 2548 type = RTN_MULTICAST;
68a5e3dd 2549 else if (ipv4_is_zeronet(fl4->daddr))
5ada5527 2550 return ERR_PTR(-EINVAL);
1da177e4
LT		 2551
2552 if (dev_out->flags & IFF_LOOPBACK)
2553 flags |= RTCF_LOCAL;
2554
dd28d1a0 2555 in_dev = __in_dev_get_rcu(dev_out);
ebc0ffae 2556 if (!in_dev)
5ada5527 2557 return ERR_PTR(-EINVAL);
ebc0ffae 2558
982721f3 2559 if (type == RTN_BROADCAST) {
1da177e4 2560 flags |= RTCF_BROADCAST | RTCF_LOCAL;
982721f3
DM		 2561 fi = NULL;
2562 } else if (type == RTN_MULTICAST) {
dd28d1a0 2563 flags |= RTCF_MULTICAST | RTCF_LOCAL;
813b3b5d
DM		 2564 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2565 fl4->flowi4_proto))
1da177e4
LT		 2566 flags &= ~RTCF_LOCAL;
2567 /* If multicast route do not exist use
dd28d1a0
ED		 2568 * default one, but do not gateway in this case.
2569 * Yes, it is hack.
1da177e4 2570 */
982721f3
DM		 2571 if (fi && res->prefixlen < 4)
2572 fi = NULL;
1da177e4
LT		 2573 }
2574
5c1e6aa3
DM		 2575 rth = rt_dst_alloc(dev_out,
2576 IN_DEV_CONF_GET(in_dev, NOPOLICY),
0c4dcd58 2577 IN_DEV_CONF_GET(in_dev, NOXFRM));
8391d07b 2578 if (!rth)
5ada5527 2579 return ERR_PTR(-ENOBUFS);
8391d07b 2580
cf911662
DM		 2581 rth->dst.output = ip_output;
2582
813b3b5d
DM		 2583 rth->rt_key_dst = orig_daddr;
2584 rth->rt_key_src = orig_saddr;
cf911662
DM		 2585 rth->rt_genid = rt_genid(dev_net(dev_out));
2586 rth->rt_flags = flags;
2587 rth->rt_type = type;
f61759e6 2588 rth->rt_key_tos = orig_rtos;
68a5e3dd
DM		 2589 rth->rt_dst = fl4->daddr;
2590 rth->rt_src = fl4->saddr;
1b86a58f 2591 rth->rt_route_iif = 0;
813b3b5d
DM		 2592 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2593 rth->rt_oif = orig_oif;
2594 rth->rt_mark = fl4->flowi4_mark;
68a5e3dd
DM		 2595 rth->rt_gateway = fl4->daddr;
2596 rth->rt_spec_dst= fl4->saddr;
cf911662
DM		 2597 rth->rt_peer_genid = 0;
2598 rth->peer = NULL;
2599 rth->fi = NULL;
1da177e4
LT		 2600
2601 RT_CACHE_STAT_INC(out_slow_tot);
2602
2603 if (flags & RTCF_LOCAL) {
d8d1f30b 2604 rth->dst.input = ip_local_deliver;
68a5e3dd 2605 rth->rt_spec_dst = fl4->daddr;
1da177e4
LT		 2606 }
2607 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
68a5e3dd 2608 rth->rt_spec_dst = fl4->saddr;
e905a9ed 2609 if (flags & RTCF_LOCAL &&
1da177e4 2610 !(dev_out->flags & IFF_LOOPBACK)) {
d8d1f30b 2611 rth->dst.output = ip_mc_output;
1da177e4
LT		 2612 RT_CACHE_STAT_INC(out_slow_mc);
2613 }
2614#ifdef CONFIG_IP_MROUTE
982721f3 2615 if (type == RTN_MULTICAST) {
1da177e4 2616 if (IN_DEV_MFORWARD(in_dev) &&
813b3b5d 2617 !ipv4_is_local_multicast(fl4->daddr)) {
d8d1f30b
CG		 2618 rth->dst.input = ip_mr_input;
2619 rth->dst.output = ip_mc_output;
1da177e4
LT		 2620 }
2621 }
2622#endif
2623 }
2624
813b3b5d 2625 rt_set_nexthop(rth, fl4, res, fi, type, 0);
1da177e4 2626
5ada5527 2627 return rth;
1da177e4
LT		 2628}
2629
1da177e4
LT		 2630/*
2631 * Major route resolver routine.
0197aa38 2632 * called with rcu_read_lock();
1da177e4
LT		 2633 */
2634
813b3b5d 2635static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
1da177e4 2636{
1da177e4 2637 struct net_device *dev_out = NULL;
f61759e6 2638 __u8 tos = RT_FL_TOS(fl4);
813b3b5d
DM		 2639 unsigned int flags = 0;
2640 struct fib_result res;
5ada5527 2641 struct rtable *rth;
813b3b5d
DM		 2642 __be32 orig_daddr;
2643 __be32 orig_saddr;
2644 int orig_oif;
1da177e4
LT		 2645
2646 res.fi = NULL;
2647#ifdef CONFIG_IP_MULTIPLE_TABLES
2648 res.r = NULL;
2649#endif
2650
813b3b5d
DM		 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);
44713b67 2659
010c2708 2660 rcu_read_lock();
813b3b5d 2661 if (fl4->saddr) {
b23dd4fe 2662 rth = ERR_PTR(-EINVAL);
813b3b5d
DM		 2663 if (ipv4_is_multicast(fl4->saddr) ||
2664 ipv4_is_lbcast(fl4->saddr) ||
2665 ipv4_is_zeronet(fl4->saddr))
1da177e4
LT		 2666 goto out;
2667
1da177e4
LT		 2668 /* I removed check for oif == dev_out->oif here.
2669 It was wrong for two reasons:
1ab35276
DL		 2670 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2671 is assigned to multiple interfaces.
1da177e4
LT		 2672 2. Moreover, we are allowed to send packets with saddr
2673 of another iface. --ANK
2674 */
2675
813b3b5d
DM		 2676 if (fl4->flowi4_oif == 0 &&
2677 (ipv4_is_multicast(fl4->daddr) ||
2678 ipv4_is_lbcast(fl4->daddr))) {
a210d01a 2679 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
813b3b5d 2680 dev_out = __ip_dev_find(net, fl4->saddr, false);
a210d01a
JA		 2681 if (dev_out == NULL)
2682 goto out;
2683
1da177e4
LT		 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
813b3b5d 2699 fl4->flowi4_oif = dev_out->ifindex;
1da177e4
LT		 2700 goto make_route;
2701 }
a210d01a 2702
813b3b5d 2703 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
a210d01a 2704 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
813b3b5d 2705 if (!__ip_dev_find(net, fl4->saddr, false))
a210d01a 2706 goto out;
a210d01a 2707 }
1da177e4
LT		 2708 }
2709
2710
813b3b5d
DM		 2711 if (fl4->flowi4_oif) {
2712 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
b23dd4fe 2713 rth = ERR_PTR(-ENODEV);
1da177e4
LT		 2714 if (dev_out == NULL)
2715 goto out;
e5ed6399
HX		 2716
2717 /* RACE: Check return value of inet_select_addr instead. */
fc75fc83 2718 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
b23dd4fe 2719 rth = ERR_PTR(-ENETUNREACH);
fc75fc83
ED		 2720 goto out;
2721 }
813b3b5d
DM		 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);
1da177e4
LT		 2727 goto make_route;
2728 }
813b3b5d
DM		 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);
1da177e4
LT		 2736 }
2737 }
2738
813b3b5d
DM		 2739 if (!fl4->daddr) {
2740 fl4->daddr = fl4->saddr;
2741 if (!fl4->daddr)
2742 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
b40afd0e 2743 dev_out = net->loopback_dev;
813b3b5d 2744 fl4->flowi4_oif = net->loopback_dev->ifindex;
1da177e4
LT		 2745 res.type = RTN_LOCAL;
2746 flags |= RTCF_LOCAL;
2747 goto make_route;
2748 }
2749
813b3b5d 2750 if (fib_lookup(net, fl4, &res)) {
1da177e4 2751 res.fi = NULL;
813b3b5d 2752 if (fl4->flowi4_oif) {
1da177e4
LT		 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
813b3b5d
DM		 2771 if (fl4->saddr == 0)
2772 fl4->saddr = inet_select_addr(dev_out, 0,
2773 RT_SCOPE_LINK);
1da177e4
LT		 2774 res.type = RTN_UNICAST;
2775 goto make_route;
2776 }
b23dd4fe 2777 rth = ERR_PTR(-ENETUNREACH);
1da177e4
LT		 2778 goto out;
2779 }
1da177e4
LT		 2780
2781 if (res.type == RTN_LOCAL) {
813b3b5d 2782 if (!fl4->saddr) {
9fc3bbb4 2783 if (res.fi->fib_prefsrc)
813b3b5d 2784 fl4->saddr = res.fi->fib_prefsrc;
9fc3bbb4 2785 else
813b3b5d 2786 fl4->saddr = fl4->daddr;
9fc3bbb4 2787 }
b40afd0e 2788 dev_out = net->loopback_dev;
813b3b5d 2789 fl4->flowi4_oif = dev_out->ifindex;
1da177e4
LT		 2790 res.fi = NULL;
2791 flags |= RTCF_LOCAL;
2792 goto make_route;
2793 }
2794
2795#ifdef CONFIG_IP_ROUTE_MULTIPATH
813b3b5d 2796 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
1b7fe593 2797 fib_select_multipath(&res);
1da177e4
LT		 2798 else
2799#endif
21d8c49e
DM		 2800 if (!res.prefixlen &&
2801 res.table->tb_num_default > 1 &&
813b3b5d 2802 res.type == RTN_UNICAST && !fl4->flowi4_oif)
0c838ff1 2803 fib_select_default(&res);
1da177e4 2804
813b3b5d
DM		 2805 if (!fl4->saddr)
2806 fl4->saddr = FIB_RES_PREFSRC(net, res);
1da177e4 2807
1da177e4 2808 dev_out = FIB_RES_DEV(res);
813b3b5d 2809 fl4->flowi4_oif = dev_out->ifindex;
1da177e4
LT		 2810
2811
2812make_route:
813b3b5d 2813 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
f61759e6 2814 tos, dev_out, flags);
b23dd4fe 2815 if (!IS_ERR(rth)) {
5ada5527
DM		 2816 unsigned int hash;
2817
813b3b5d 2818 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
5ada5527 2819 rt_genid(dev_net(dev_out)));
813b3b5d 2820 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
5ada5527 2821 }
1da177e4 2822
010c2708
DM		 2823out:
2824 rcu_read_unlock();
b23dd4fe 2825 return rth;
1da177e4
LT		 2826}
2827
813b3b5d 2828struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
1da177e4 2829{
1da177e4 2830 struct rtable *rth;
010c2708 2831 unsigned int hash;
1da177e4 2832
1080d709
NH		 2833 if (!rt_caching(net))
2834 goto slow_output;
2835
9d6ec938 2836 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
1da177e4
LT		 2837
2838 rcu_read_lock_bh();
a898def2 2839 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
d8d1f30b 2840 rth = rcu_dereference_bh(rth->dst.rt_next)) {
9d6ec938
DM		 2841 if (rth->rt_key_dst == flp4->daddr &&
2842 rth->rt_key_src == flp4->saddr &&
c7537967 2843 rt_is_output_route(rth) &&
9d6ec938
DM		 2844 rth->rt_oif == flp4->flowi4_oif &&
2845 rth->rt_mark == flp4->flowi4_mark &&
475949d8 2846 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
b5921910 2847 (IPTOS_RT_MASK | RTO_ONLINK)) &&
d8d1f30b 2848 net_eq(dev_net(rth->dst.dev), net) &&
e84f84f2 2849 !rt_is_expired(rth)) {
de398fb8 2850 ipv4_validate_peer(rth);
d8d1f30b 2851 dst_use(&rth->dst, jiffies);
1da177e4
LT		 2852 RT_CACHE_STAT_INC(out_hit);
2853 rcu_read_unlock_bh();
56157872
DM		 2854 if (!flp4->saddr)
2855 flp4->saddr = rth->rt_src;
2856 if (!flp4->daddr)
2857 flp4->daddr = rth->rt_dst;
b23dd4fe 2858 return rth;
1da177e4
LT		 2859 }
2860 RT_CACHE_STAT_INC(out_hlist_search);
2861 }
2862 rcu_read_unlock_bh();
2863
1080d709 2864slow_output:
9d6ec938 2865 return ip_route_output_slow(net, flp4);
1da177e4 2866}
d8c97a94
ACM		 2867EXPORT_SYMBOL_GPL(__ip_route_output_key);
2868
ae2688d5
JW		 2869static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2870{
2871 return NULL;
2872}
2873
ebb762f2 2874static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
ec831ea7 2875{
618f9bc7
SK		 2876 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2877
2878 return mtu ? : dst->dev->mtu;
ec831ea7
RD		 2879}
2880
14e50e57
DM		 2881static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2882{
2883}
2884
0972ddb2
HB		 2885static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2886 unsigned long old)
2887{
2888 return NULL;
2889}
2890
14e50e57
DM		 2891static struct dst_ops ipv4_dst_blackhole_ops = {
2892 .family = AF_INET,
09640e63 2893 .protocol = cpu_to_be16(ETH_P_IP),
14e50e57 2894 .destroy = ipv4_dst_destroy,
ae2688d5 2895 .check = ipv4_blackhole_dst_check,
ebb762f2 2896 .mtu = ipv4_blackhole_mtu,
214f45c9 2897 .default_advmss = ipv4_default_advmss,
14e50e57 2898 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
0972ddb2 2899 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
d3aaeb38 2900 .neigh_lookup = ipv4_neigh_lookup,
14e50e57
DM		 2901};
2902
2774c131 2903struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
14e50e57 2904{
5c1e6aa3 2905 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2774c131 2906 struct rtable *ort = (struct rtable *) dst_orig;
14e50e57
DM		 2907
2908 if (rt) {
d8d1f30b 2909 struct dst_entry *new = &rt->dst;
14e50e57 2910
14e50e57 2911 new->__use = 1;
352e512c
HX		 2912 new->input = dst_discard;
2913 new->output = dst_discard;
defb3519 2914 dst_copy_metrics(new, &ort->dst);
14e50e57 2915
d8d1f30b 2916 new->dev = ort->dst.dev;
14e50e57
DM		 2917 if (new->dev)
2918 dev_hold(new->dev);
2919
5e2b61f7
DM		 2920 rt->rt_key_dst = ort->rt_key_dst;
2921 rt->rt_key_src = ort->rt_key_src;
475949d8 2922 rt->rt_key_tos = ort->rt_key_tos;
1b86a58f 2923 rt->rt_route_iif = ort->rt_route_iif;
5e2b61f7
DM		 2924 rt->rt_iif = ort->rt_iif;
2925 rt->rt_oif = ort->rt_oif;
2926 rt->rt_mark = ort->rt_mark;
14e50e57 2927
e84f84f2 2928 rt->rt_genid = rt_genid(net);
14e50e57
DM		 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;
14e50e57
DM		 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);
62fa8a84
DM		 2938 rt->fi = ort->fi;
2939 if (rt->fi)
2940 atomic_inc(&rt->fi->fib_clntref);
14e50e57
DM		 2941
2942 dst_free(new);
2943 }
2944
2774c131
DM		 2945 dst_release(dst_orig);
2946
2947 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
14e50e57
DM		 2948}
2949
9d6ec938 2950struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
b23dd4fe 2951 struct sock *sk)
1da177e4 2952{
9d6ec938 2953 struct rtable *rt = __ip_route_output_key(net, flp4);
1da177e4 2954
b23dd4fe
DM		 2955 if (IS_ERR(rt))
2956 return rt;
1da177e4 2957
56157872 2958 if (flp4->flowi4_proto)
9d6ec938
DM		 2959 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2960 flowi4_to_flowi(flp4),
2961 sk, 0);
1da177e4 2962
b23dd4fe 2963 return rt;
1da177e4 2964}
d8c97a94
ACM		 2965EXPORT_SYMBOL_GPL(ip_route_output_flow);
2966
4feb88e5
BT		 2967static int rt_fill_info(struct net *net,
2968 struct sk_buff *skb, u32 pid, u32 seq, int event,
b6544c0b 2969 int nowait, unsigned int flags)
1da177e4 2970{
511c3f92 2971 struct rtable *rt = skb_rtable(skb);
1da177e4 2972 struct rtmsg *r;
be403ea1 2973 struct nlmsghdr *nlh;
2bc8ca40 2974 unsigned long expires = 0;
fe6fe792 2975 const struct inet_peer *peer = rt->peer;
e3703b3d 2976 u32 id = 0, ts = 0, tsage = 0, error;
be403ea1
TG		 2977
2978 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2979 if (nlh == NULL)
26932566 2980 return -EMSGSIZE;
be403ea1
TG		 2981
2982 r = nlmsg_data(nlh);
1da177e4
LT		 2983 r->rtm_family = AF_INET;
2984 r->rtm_dst_len = 32;
2985 r->rtm_src_len = 0;
475949d8 2986 r->rtm_tos = rt->rt_key_tos;
1da177e4 2987 r->rtm_table = RT_TABLE_MAIN;
be403ea1 2988 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
1da177e4
LT		 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;
be403ea1 2995
17fb2c64 2996 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
be403ea1 2997
5e2b61f7 2998 if (rt->rt_key_src) {
1da177e4 2999 r->rtm_src_len = 32;
5e2b61f7 3000 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
1da177e4 3001 }
d8d1f30b
CG		 3002 if (rt->dst.dev)
3003 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
c7066f70 3004#ifdef CONFIG_IP_ROUTE_CLASSID
d8d1f30b
CG		 3005 if (rt->dst.tclassid)
3006 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
1da177e4 3007#endif
c7537967 3008 if (rt_is_input_route(rt))
17fb2c64 3009 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
5e2b61f7 3010 else if (rt->rt_src != rt->rt_key_src)
17fb2c64 3011 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
be403ea1 3012
1da177e4 3013 if (rt->rt_dst != rt->rt_gateway)
17fb2c64 3014 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
be403ea1 3015
defb3519 3016 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
be403ea1
TG		 3017 goto nla_put_failure;
3018
5e2b61f7
DM		 3019 if (rt->rt_mark)
3020 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
963bfeee 3021
d8d1f30b 3022 error = rt->dst.error;
fe6fe792 3023 if (peer) {
317fe0e6 3024 inet_peer_refcheck(rt->peer);
fe6fe792
ED		 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;
1da177e4 3029 }
fe6fe792 3030 expires = ACCESS_ONCE(peer->pmtu_expires);
2bc8ca40
SK		 3031 if (expires) {
3032 if (time_before(jiffies, expires))
3033 expires -= jiffies;
3034 else
3035 expires = 0;
3036 }
1da177e4 3037 }
be403ea1 3038
c7537967 3039 if (rt_is_input_route(rt)) {
1da177e4 3040#ifdef CONFIG_IP_MROUTE
e448515c 3041 __be32 dst = rt->rt_dst;
1da177e4 3042
f97c1e0c 3043 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
4feb88e5 3044 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
9a1b9496
DM		 3045 int err = ipmr_get_route(net, skb,
3046 rt->rt_src, rt->rt_dst,
3047 r, nowait);
1da177e4
LT		 3048 if (err <= 0) {
3049 if (!nowait) {
3050 if (err == 0)
3051 return 0;
be403ea1 3052 goto nla_put_failure;
1da177e4
LT		 3053 } else {
3054 if (err == -EMSGSIZE)
be403ea1 3055 goto nla_put_failure;
e3703b3d 3056 error = err;
1da177e4
LT		 3057 }
3058 }
3059 } else
3060#endif
5e2b61f7 3061 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
1da177e4
LT		 3062 }
3063
d8d1f30b 3064 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
e3703b3d
TG		 3065 expires, error) < 0)
3066 goto nla_put_failure;
be403ea1
TG		 3067
3068 return nlmsg_end(skb, nlh);
1da177e4 3069
be403ea1 3070nla_put_failure:
26932566
PM		 3071 nlmsg_cancel(skb, nlh);
3072 return -EMSGSIZE;
1da177e4
LT		 3073}
3074
63f3444f 3075static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
1da177e4 3076{
3b1e0a65 3077 struct net *net = sock_net(in_skb->sk);
d889ce3b
TG		 3078 struct rtmsg *rtm;
3079 struct nlattr *tb[RTA_MAX+1];
1da177e4 3080 struct rtable *rt = NULL;
9e12bb22
AV		 3081 __be32 dst = 0;
3082 __be32 src = 0;
3083 u32 iif;
d889ce3b 3084 int err;
963bfeee 3085 int mark;
1da177e4
LT		 3086 struct sk_buff *skb;
3087
d889ce3b
TG		 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
1da177e4 3094 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
d889ce3b
TG		 3095 if (skb == NULL) {
3096 err = -ENOBUFS;
3097 goto errout;
3098 }
1da177e4
LT		 3099
3100 /* Reserve room for dummy headers, this skb can pass
3101 through good chunk of routing engine.
3102 */
459a98ed 3103 skb_reset_mac_header(skb);
c1d2bbe1 3104 skb_reset_network_header(skb);
d2c962b8
SH		 3105
3106 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
eddc9ec5 3107 ip_hdr(skb)->protocol = IPPROTO_ICMP;
1da177e4
LT		 3108 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3109
17fb2c64
AV		 3110 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3111 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
d889ce3b 3112 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
963bfeee 3113 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
1da177e4
LT		 3114
3115 if (iif) {
d889ce3b
TG		 3116 struct net_device *dev;
3117
1937504d 3118 dev = __dev_get_by_index(net, iif);
d889ce3b
TG		 3119 if (dev == NULL) {
3120 err = -ENODEV;
3121 goto errout_free;
3122 }
3123
1da177e4
LT		 3124 skb->protocol = htons(ETH_P_IP);
3125 skb->dev = dev;
963bfeee 3126 skb->mark = mark;
1da177e4
LT		 3127 local_bh_disable();
3128 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3129 local_bh_enable();
d889ce3b 3130
511c3f92 3131 rt = skb_rtable(skb);
d8d1f30b
CG		 3132 if (err == 0 && rt->dst.error)
3133 err = -rt->dst.error;
1da177e4 3134 } else {
68a5e3dd
DM		 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,
d889ce3b 3141 };
9d6ec938 3142 rt = ip_route_output_key(net, &fl4);
b23dd4fe
DM		 3143
3144 err = 0;
3145 if (IS_ERR(rt))
3146 err = PTR_ERR(rt);
1da177e4 3147 }
d889ce3b 3148
1da177e4 3149 if (err)
d889ce3b 3150 goto errout_free;
1da177e4 3151
d8d1f30b 3152 skb_dst_set(skb, &rt->dst);
1da177e4
LT		 3153 if (rtm->rtm_flags & RTM_F_NOTIFY)
3154 rt->rt_flags |= RTCF_NOTIFY;
3155
4feb88e5 3156 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1937504d 3157 RTM_NEWROUTE, 0, 0);
d889ce3b
TG		 3158 if (err <= 0)
3159 goto errout_free;
1da177e4 3160
1937504d 3161 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
d889ce3b 3162errout:
2942e900 3163 return err;
1da177e4 3164
d889ce3b 3165errout_free:
1da177e4 3166 kfree_skb(skb);
d889ce3b 3167 goto errout;
1da177e4
LT		 3168}
3169
3170int 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;
1937504d
DL		 3175 struct net *net;
3176
3b1e0a65 3177 net = sock_net(skb->sk);
1da177e4
LT		 3178
3179 s_h = cb->args[0];
d8c92830
ED		 3180 if (s_h < 0)
3181 s_h = 0;
1da177e4 3182 s_idx = idx = cb->args[1];
a6272665
ED		 3183 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3184 if (!rt_hash_table[h].chain)
3185 continue;
1da177e4 3186 rcu_read_lock_bh();
a898def2 3187 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
d8d1f30b
CG		 3188 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3189 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
1da177e4 3190 continue;
e84f84f2 3191 if (rt_is_expired(rt))
29e75252 3192 continue;
d8d1f30b 3193 skb_dst_set_noref(skb, &rt->dst);
4feb88e5 3194 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
e905a9ed 3195 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
b6544c0b 3196 1, NLM_F_MULTI) <= 0) {
adf30907 3197 skb_dst_drop(skb);
1da177e4
LT		 3198 rcu_read_unlock_bh();
3199 goto done;
3200 }
adf30907 3201 skb_dst_drop(skb);
1da177e4
LT		 3202 }
3203 rcu_read_unlock_bh();
3204 }
3205
3206done:
3207 cb->args[0] = h;
3208 cb->args[1] = idx;
3209 return skb->len;
3210}
3211
3212void ip_rt_multicast_event(struct in_device *in_dev)
3213{
76e6ebfb 3214 rt_cache_flush(dev_net(in_dev->dev), 0);
1da177e4
LT		 3215}
3216
3217#ifdef CONFIG_SYSCTL
81c684d1 3218static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
8d65af78 3219 void __user *buffer,
1da177e4
LT		 3220 size_t *lenp, loff_t *ppos)
3221{
3222 if (write) {
639e104f 3223 int flush_delay;
81c684d1 3224 ctl_table ctl;
39a23e75 3225 struct net *net;
639e104f 3226
81c684d1
DL		 3227 memcpy(&ctl, __ctl, sizeof(ctl));
3228 ctl.data = &flush_delay;
8d65af78 3229 proc_dointvec(&ctl, write, buffer, lenp, ppos);
639e104f 3230
81c684d1 3231 net = (struct net *)__ctl->extra1;
39a23e75 3232 rt_cache_flush(net, flush_delay);
1da177e4 3233 return 0;
e905a9ed 3234 }
1da177e4
LT		 3235
3236 return -EINVAL;
3237}
3238
eeb61f71 3239static ctl_table ipv4_route_table[] = {
1da177e4 3240 {
1da177e4
LT		 3241 .procname = "gc_thresh",
3242 .data = &ipv4_dst_ops.gc_thresh,
3243 .maxlen = sizeof(int),
3244 .mode = 0644,
6d9f239a 3245 .proc_handler = proc_dointvec,
1da177e4
LT		 3246 },
3247 {
1da177e4
LT		 3248 .procname = "max_size",
3249 .data = &ip_rt_max_size,
3250 .maxlen = sizeof(int),
3251 .mode = 0644,
6d9f239a 3252 .proc_handler = proc_dointvec,
1da177e4
LT		 3253 },
3254 {
3255 /* Deprecated. Use gc_min_interval_ms */
e905a9ed 3256
1da177e4
LT		 3257 .procname = "gc_min_interval",
3258 .data = &ip_rt_gc_min_interval,
3259 .maxlen = sizeof(int),
3260 .mode = 0644,
6d9f239a 3261 .proc_handler = proc_dointvec_jiffies,
1da177e4
LT		 3262 },
3263 {
1da177e4
LT		 3264 .procname = "gc_min_interval_ms",
3265 .data = &ip_rt_gc_min_interval,
3266 .maxlen = sizeof(int),
3267 .mode = 0644,
6d9f239a 3268 .proc_handler = proc_dointvec_ms_jiffies,
1da177e4
LT		 3269 },
3270 {
1da177e4
LT		 3271 .procname = "gc_timeout",
3272 .data = &ip_rt_gc_timeout,
3273 .maxlen = sizeof(int),
3274 .mode = 0644,
6d9f239a 3275 .proc_handler = proc_dointvec_jiffies,
1da177e4 3276 },
9f28a2fc
ED		 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 },
1da177e4 3284 {
1da177e4
LT		 3285 .procname = "redirect_load",
3286 .data = &ip_rt_redirect_load,
3287 .maxlen = sizeof(int),
3288 .mode = 0644,
6d9f239a 3289 .proc_handler = proc_dointvec,
1da177e4
LT		 3290 },
3291 {
1da177e4
LT		 3292 .procname = "redirect_number",
3293 .data = &ip_rt_redirect_number,
3294 .maxlen = sizeof(int),
3295 .mode = 0644,
6d9f239a 3296 .proc_handler = proc_dointvec,
1da177e4
LT		 3297 },
3298 {
1da177e4
LT		 3299 .procname = "redirect_silence",
3300 .data = &ip_rt_redirect_silence,
3301 .maxlen = sizeof(int),
3302 .mode = 0644,
6d9f239a 3303 .proc_handler = proc_dointvec,
1da177e4
LT		 3304 },
3305 {
1da177e4
LT		 3306 .procname = "error_cost",
3307 .data = &ip_rt_error_cost,
3308 .maxlen = sizeof(int),
3309 .mode = 0644,
6d9f239a 3310 .proc_handler = proc_dointvec,
1da177e4
LT		 3311 },
3312 {
1da177e4
LT		 3313 .procname = "error_burst",
3314 .data = &ip_rt_error_burst,
3315 .maxlen = sizeof(int),
3316 .mode = 0644,
6d9f239a 3317 .proc_handler = proc_dointvec,
1da177e4
LT		 3318 },
3319 {
1da177e4
LT		 3320 .procname = "gc_elasticity",
3321 .data = &ip_rt_gc_elasticity,
3322 .maxlen = sizeof(int),
3323 .mode = 0644,
6d9f239a 3324 .proc_handler = proc_dointvec,
1da177e4
LT		 3325 },
3326 {
1da177e4
LT		 3327 .procname = "mtu_expires",
3328 .data = &ip_rt_mtu_expires,
3329 .maxlen = sizeof(int),
3330 .mode = 0644,
6d9f239a 3331 .proc_handler = proc_dointvec_jiffies,
1da177e4
LT		 3332 },
3333 {
1da177e4
LT		 3334 .procname = "min_pmtu",
3335 .data = &ip_rt_min_pmtu,
3336 .maxlen = sizeof(int),
3337 .mode = 0644,
6d9f239a 3338 .proc_handler = proc_dointvec,
1da177e4
LT		 3339 },
3340 {
1da177e4
LT		 3341 .procname = "min_adv_mss",
3342 .data = &ip_rt_min_advmss,
3343 .maxlen = sizeof(int),
3344 .mode = 0644,
6d9f239a 3345 .proc_handler = proc_dointvec,
1da177e4 3346 },
f8572d8f 3347 { }
1da177e4 3348};
39a23e75 3349
2f4520d3
AV		 3350static struct ctl_table empty[1];
3351
3352static struct ctl_table ipv4_skeleton[] =
3353{
f8572d8f 3354 { .procname = "route",
d994af0d 3355 .mode = 0555, .child = ipv4_route_table},
f8572d8f 3356 { .procname = "neigh",
d994af0d 3357 .mode = 0555, .child = empty},
2f4520d3
AV		 3358 { }
3359};
3360
3361static __net_initdata struct ctl_path ipv4_path[] = {
f8572d8f
EB		 3362 { .procname = "net", },
3363 { .procname = "ipv4", },
39a23e75
DL		 3364 { },
3365};
3366
39a23e75
DL		 3367static struct ctl_table ipv4_route_flush_table[] = {
3368 {
39a23e75
DL		 3369 .procname = "flush",
3370 .maxlen = sizeof(int),
3371 .mode = 0200,
6d9f239a 3372 .proc_handler = ipv4_sysctl_rtcache_flush,
39a23e75 3373 },
f8572d8f 3374 { },
39a23e75
DL		 3375};
3376
2f4520d3 3377static __net_initdata struct ctl_path ipv4_route_path[] = {
f8572d8f
EB		 3378 { .procname = "net", },
3379 { .procname = "ipv4", },
3380 { .procname = "route", },
2f4520d3
AV		 3381 { },
3382};
3383
39a23e75
DL		 3384static __net_init int sysctl_route_net_init(struct net *net)
3385{
3386 struct ctl_table *tbl;
3387
3388 tbl = ipv4_route_flush_table;
09ad9bc7 3389 if (!net_eq(net, &init_net)) {
39a23e75
DL		 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
3402err_reg:
3403 if (tbl != ipv4_route_flush_table)
3404 kfree(tbl);
3405err_dup:
3406 return -ENOMEM;
3407}
3408
3409static __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
3419static __net_initdata struct pernet_operations sysctl_route_ops = {
3420 .init = sysctl_route_net_init,
3421 .exit = sysctl_route_net_exit,
3422};
1da177e4
LT		 3423#endif
3424
3ee94372 3425static __net_init int rt_genid_init(struct net *net)
9f5e97e5 3426{
3ee94372
NH		 3427 get_random_bytes(&net->ipv4.rt_genid,
3428 sizeof(net->ipv4.rt_genid));
436c3b66
DM		 3429 get_random_bytes(&net->ipv4.dev_addr_genid,
3430 sizeof(net->ipv4.dev_addr_genid));
9f5e97e5
DL		 3431 return 0;
3432}
3433
3ee94372
NH		 3434static __net_initdata struct pernet_operations rt_genid_ops = {
3435 .init = rt_genid_init,
9f5e97e5
DL		 3436};
3437
3438
c7066f70 3439#ifdef CONFIG_IP_ROUTE_CLASSID
7d720c3e 3440struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
c7066f70 3441#endif /* CONFIG_IP_ROUTE_CLASSID */
1da177e4
LT		 3442
3443static __initdata unsigned long rhash_entries;
3444static 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
3453int __init ip_rt_init(void)
3454{
424c4b70 3455 int rc = 0;
1da177e4 3456
c7066f70 3457#ifdef CONFIG_IP_ROUTE_CLASSID
0dcec8c2 3458 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
1da177e4
LT		 3459 if (!ip_rt_acct)
3460 panic("IP: failed to allocate ip_rt_acct\n");
1da177e4
LT		 3461#endif
3462
e5d679f3
AD		 3463 ipv4_dst_ops.kmem_cachep =
3464 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
20c2df83 3465 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1da177e4 3466
14e50e57
DM		 3467 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3468
fc66f95c
ED		 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
424c4b70
ED		 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,
4481374c 3479 (totalram_pages >= 128 * 1024) ?
18955cfc 3480 15 : 17,
8d1502de 3481 0,
424c4b70
ED		 3482 &rt_hash_log,
3483 &rt_hash_mask,
c9503e0f 3484 rhash_entries ? 0 : 512 * 1024);
22c047cc
ED		 3485 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3486 rt_hash_lock_init();
1da177e4
LT		 3487
3488 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3489 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3490
1da177e4
LT		 3491 devinet_init();
3492 ip_fib_init();
3493
9f28a2fc
ED		 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
73b38711 3499 if (ip_rt_proc_init())
107f1634 3500 printk(KERN_ERR "Unable to create route proc files\n");
1da177e4
LT		 3501#ifdef CONFIG_XFRM
3502 xfrm_init();
a33bc5c1 3503 xfrm4_init(ip_rt_max_size);
1da177e4 3504#endif
c7ac8679 3505 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
63f3444f 3506
39a23e75
DL		 3507#ifdef CONFIG_SYSCTL
3508 register_pernet_subsys(&sysctl_route_ops);
3509#endif
3ee94372 3510 register_pernet_subsys(&rt_genid_ops);
1da177e4
LT		 3511 return rc;
3512}
3513
a1bc6eb4 3514#ifdef CONFIG_SYSCTL
eeb61f71
AV		 3515/*
3516 * We really need to sanitize the damn ipv4 init order, then all
3517 * this nonsense will go away.
3518 */
3519void __init ip_static_sysctl_init(void)
3520{
2f4520d3 3521 register_sysctl_paths(ipv4_path, ipv4_skeleton);
eeb61f71 3522}
a1bc6eb4 3523#endif
Linux kernel - Deliverables
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