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[MIPS] RTLX: Protect rtlx_{read,write} with mutex.
[linux-2.6/linux-mips.git] / net / ipv4 / route.c
blob37e0d4d5cf94e85bc28248ab054266afbe1ecc98
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Version: $Id: route.c,v 1.103 2002/01/12 07:44:09 davem Exp $
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Alan Cox, <gw4pts@gw4pts.ampr.org>
13 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
14 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
15 *
16 * Fixes:
17 * Alan Cox : Verify area fixes.
18 * Alan Cox : cli() protects routing changes
19 * Rui Oliveira : ICMP routing table updates
20 * (rco@di.uminho.pt) Routing table insertion and update
21 * Linus Torvalds : Rewrote bits to be sensible
22 * Alan Cox : Added BSD route gw semantics
23 * Alan Cox : Super /proc >4K
24 * Alan Cox : MTU in route table
25 * Alan Cox : MSS actually. Also added the window
26 * clamper.
27 * Sam Lantinga : Fixed route matching in rt_del()
28 * Alan Cox : Routing cache support.
29 * Alan Cox : Removed compatibility cruft.
30 * Alan Cox : RTF_REJECT support.
31 * Alan Cox : TCP irtt support.
32 * Jonathan Naylor : Added Metric support.
33 * Miquel van Smoorenburg : BSD API fixes.
34 * Miquel van Smoorenburg : Metrics.
35 * Alan Cox : Use __u32 properly
36 * Alan Cox : Aligned routing errors more closely with BSD
37 * our system is still very different.
38 * Alan Cox : Faster /proc handling
39 * Alexey Kuznetsov : Massive rework to support tree based routing,
40 * routing caches and better behaviour.
41 *
42 * Olaf Erb : irtt wasn't being copied right.
43 * Bjorn Ekwall : Kerneld route support.
44 * Alan Cox : Multicast fixed (I hope)
45 * Pavel Krauz : Limited broadcast fixed
46 * Mike McLagan : Routing by source
47 * Alexey Kuznetsov : End of old history. Split to fib.c and
48 * route.c and rewritten from scratch.
49 * Andi Kleen : Load-limit warning messages.
50 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
51 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
52 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
53 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
54 * Marc Boucher : routing by fwmark
55 * Robert Olsson : Added rt_cache statistics
56 * Arnaldo C. Melo : Convert proc stuff to seq_file
57 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
58 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
59 * Ilia Sotnikov : Removed TOS from hash calculations
60 *
61 * This program is free software; you can redistribute it and/or
62 * modify it under the terms of the GNU General Public License
63 * as published by the Free Software Foundation; either version
64 * 2 of the License, or (at your option) any later version.
65 */
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <asm/system.h>
70 #include <linux/bitops.h>
71 #include <linux/types.h>
72 #include <linux/kernel.h>
73 #include <linux/mm.h>
74 #include <linux/bootmem.h>
75 #include <linux/string.h>
76 #include <linux/socket.h>
77 #include <linux/sockios.h>
78 #include <linux/errno.h>
79 #include <linux/in.h>
80 #include <linux/inet.h>
81 #include <linux/netdevice.h>
82 #include <linux/proc_fs.h>
83 #include <linux/init.h>
84 #include <linux/skbuff.h>
85 #include <linux/rtnetlink.h>
86 #include <linux/inetdevice.h>
87 #include <linux/igmp.h>
88 #include <linux/pkt_sched.h>
89 #include <linux/mroute.h>
90 #include <linux/netfilter_ipv4.h>
91 #include <linux/random.h>
92 #include <linux/jhash.h>
93 #include <linux/rcupdate.h>
94 #include <linux/times.h>
95 #include <net/protocol.h>
96 #include <net/ip.h>
97 #include <net/route.h>
98 #include <net/inetpeer.h>
99 #include <net/sock.h>
100 #include <net/ip_fib.h>
101 #include <net/arp.h>
102 #include <net/tcp.h>
103 #include <net/icmp.h>
104 #include <net/xfrm.h>
105 #include <net/ip_mp_alg.h>
106 #include <net/netevent.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #endif
110
111 #define RT_FL_TOS(oldflp) \
112 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
113
114 #define IP_MAX_MTU 0xFFF0
115
116 #define RT_GC_TIMEOUT (300*HZ)
117
118 static int ip_rt_min_delay = 2 * HZ;
119 static int ip_rt_max_delay = 10 * HZ;
120 static int ip_rt_max_size;
121 static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
122 static int ip_rt_gc_interval = 60 * HZ;
123 static int ip_rt_gc_min_interval = HZ / 2;
124 static int ip_rt_redirect_number = 9;
125 static int ip_rt_redirect_load = HZ / 50;
126 static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
127 static int ip_rt_error_cost = HZ;
128 static int ip_rt_error_burst = 5 * HZ;
129 static int ip_rt_gc_elasticity = 8;
130 static int ip_rt_mtu_expires = 10 * 60 * HZ;
131 static int ip_rt_min_pmtu = 512 + 20 + 20;
132 static int ip_rt_min_advmss = 256;
133 static int ip_rt_secret_interval = 10 * 60 * HZ;
134 static unsigned long rt_deadline;
135
136 #define RTprint(a...) printk(KERN_DEBUG a)
137
138 static struct timer_list rt_flush_timer;
139 static struct timer_list rt_periodic_timer;
140 static struct timer_list rt_secret_timer;
141
142 /*
143 * Interface to generic destination cache.
144 */
145
146 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
147 static void ipv4_dst_destroy(struct dst_entry *dst);
148 static void ipv4_dst_ifdown(struct dst_entry *dst,
149 struct net_device *dev, int how);
150 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
151 static void ipv4_link_failure(struct sk_buff *skb);
152 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
153 static int rt_garbage_collect(void);
154
155
156 static struct dst_ops ipv4_dst_ops = {
157 .family = AF_INET,
158 .protocol = __constant_htons(ETH_P_IP),
159 .gc = rt_garbage_collect,
160 .check = ipv4_dst_check,
161 .destroy = ipv4_dst_destroy,
162 .ifdown = ipv4_dst_ifdown,
163 .negative_advice = ipv4_negative_advice,
164 .link_failure = ipv4_link_failure,
165 .update_pmtu = ip_rt_update_pmtu,
166 .entry_size = sizeof(struct rtable),
167 };
168
169 #define ECN_OR_COST(class) TC_PRIO_##class
170
171 __u8 ip_tos2prio[16] = {
172 TC_PRIO_BESTEFFORT,
173 ECN_OR_COST(FILLER),
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(BESTEFFORT),
176 TC_PRIO_BULK,
177 ECN_OR_COST(BULK),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_INTERACTIVE,
181 ECN_OR_COST(INTERACTIVE),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE_BULK,
185 ECN_OR_COST(INTERACTIVE_BULK),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK)
188 };
189
190
191 /*
192 * Route cache.
193 */
194
195 /* The locking scheme is rather straight forward:
196 *
197 * 1) Read-Copy Update protects the buckets of the central route hash.
198 * 2) Only writers remove entries, and they hold the lock
199 * as they look at rtable reference counts.
200 * 3) Only readers acquire references to rtable entries,
201 * they do so with atomic increments and with the
202 * lock held.
203 */
204
205 struct rt_hash_bucket {
206 struct rtable *chain;
207 };
208 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
209 defined(CONFIG_PROVE_LOCKING)
210 /*
211 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
212 * The size of this table is a power of two and depends on the number of CPUS.
213 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
214 */
215 #ifdef CONFIG_LOCKDEP
216 # define RT_HASH_LOCK_SZ 256
217 #else
218 # if NR_CPUS >= 32
219 # define RT_HASH_LOCK_SZ 4096
220 # elif NR_CPUS >= 16
221 # define RT_HASH_LOCK_SZ 2048
222 # elif NR_CPUS >= 8
223 # define RT_HASH_LOCK_SZ 1024
224 # elif NR_CPUS >= 4
225 # define RT_HASH_LOCK_SZ 512
226 # else
227 # define RT_HASH_LOCK_SZ 256
228 # endif
229 #endif
230
231 static spinlock_t *rt_hash_locks;
232 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
233 # define rt_hash_lock_init() { \
234 int i; \
235 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, GFP_KERNEL); \
236 if (!rt_hash_locks) panic("IP: failed to allocate rt_hash_locks\n"); \
237 for (i = 0; i < RT_HASH_LOCK_SZ; i++) \
238 spin_lock_init(&rt_hash_locks[i]); \
239 }
240 #else
241 # define rt_hash_lock_addr(slot) NULL
242 # define rt_hash_lock_init()
243 #endif
244
245 static struct rt_hash_bucket *rt_hash_table;
246 static unsigned rt_hash_mask;
247 static int rt_hash_log;
248 static unsigned int rt_hash_rnd;
249
250 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
251 #define RT_CACHE_STAT_INC(field) \
252 (__raw_get_cpu_var(rt_cache_stat).field++)
253
254 static int rt_intern_hash(unsigned hash, struct rtable *rth,
255 struct rtable **res);
256
257 static unsigned int rt_hash_code(u32 daddr, u32 saddr)
258 {
259 return (jhash_2words(daddr, saddr, rt_hash_rnd)
260 & rt_hash_mask);
261 }
262
263 #define rt_hash(daddr, saddr, idx) \
264 rt_hash_code((__force u32)(__be32)(daddr),\
265 (__force u32)(__be32)(saddr) ^ ((idx) << 5))
266
267 #ifdef CONFIG_PROC_FS
268 struct rt_cache_iter_state {
269 int bucket;
270 };
271
272 static struct rtable *rt_cache_get_first(struct seq_file *seq)
273 {
274 struct rtable *r = NULL;
275 struct rt_cache_iter_state *st = seq->private;
276
277 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
278 rcu_read_lock_bh();
279 r = rt_hash_table[st->bucket].chain;
280 if (r)
281 break;
282 rcu_read_unlock_bh();
283 }
284 return r;
285 }
286
287 static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
288 {
289 struct rt_cache_iter_state *st = rcu_dereference(seq->private);
290
291 r = r->u.dst.rt_next;
292 while (!r) {
293 rcu_read_unlock_bh();
294 if (--st->bucket < 0)
295 break;
296 rcu_read_lock_bh();
297 r = rt_hash_table[st->bucket].chain;
298 }
299 return r;
300 }
301
302 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
303 {
304 struct rtable *r = rt_cache_get_first(seq);
305
306 if (r)
307 while (pos && (r = rt_cache_get_next(seq, r)))
308 --pos;
309 return pos ? NULL : r;
310 }
311
312 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
313 {
314 return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
315 }
316
317 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
318 {
319 struct rtable *r = NULL;
320
321 if (v == SEQ_START_TOKEN)
322 r = rt_cache_get_first(seq);
323 else
324 r = rt_cache_get_next(seq, v);
325 ++*pos;
326 return r;
327 }
328
329 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
330 {
331 if (v && v != SEQ_START_TOKEN)
332 rcu_read_unlock_bh();
333 }
334
335 static int rt_cache_seq_show(struct seq_file *seq, void *v)
336 {
337 if (v == SEQ_START_TOKEN)
338 seq_printf(seq, "%-127s\n",
339 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
340 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
341 "HHUptod\tSpecDst");
342 else {
343 struct rtable *r = v;
344 char temp[256];
345
346 sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
347 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
348 r->u.dst.dev ? r->u.dst.dev->name : "*",
349 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
350 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
351 r->u.dst.__use, 0, (unsigned long)r->rt_src,
352 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
353 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
354 dst_metric(&r->u.dst, RTAX_WINDOW),
355 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
356 dst_metric(&r->u.dst, RTAX_RTTVAR)),
357 r->fl.fl4_tos,
358 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
359 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
360 dev_queue_xmit) : 0,
361 r->rt_spec_dst);
362 seq_printf(seq, "%-127s\n", temp);
363 }
364 return 0;
365 }
366
367 static struct seq_operations rt_cache_seq_ops = {
368 .start = rt_cache_seq_start,
369 .next = rt_cache_seq_next,
370 .stop = rt_cache_seq_stop,
371 .show = rt_cache_seq_show,
372 };
373
374 static int rt_cache_seq_open(struct inode *inode, struct file *file)
375 {
376 struct seq_file *seq;
377 int rc = -ENOMEM;
378 struct rt_cache_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
379
380 if (!s)
381 goto out;
382 rc = seq_open(file, &rt_cache_seq_ops);
383 if (rc)
384 goto out_kfree;
385 seq = file->private_data;
386 seq->private = s;
387 memset(s, 0, sizeof(*s));
388 out:
389 return rc;
390 out_kfree:
391 kfree(s);
392 goto out;
393 }
394
395 static const struct file_operations rt_cache_seq_fops = {
396 .owner = THIS_MODULE,
397 .open = rt_cache_seq_open,
398 .read = seq_read,
399 .llseek = seq_lseek,
400 .release = seq_release_private,
401 };
402
403
404 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
405 {
406 int cpu;
407
408 if (*pos == 0)
409 return SEQ_START_TOKEN;
410
411 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
412 if (!cpu_possible(cpu))
413 continue;
414 *pos = cpu+1;
415 return &per_cpu(rt_cache_stat, cpu);
416 }
417 return NULL;
418 }
419
420 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
421 {
422 int cpu;
423
424 for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
425 if (!cpu_possible(cpu))
426 continue;
427 *pos = cpu+1;
428 return &per_cpu(rt_cache_stat, cpu);
429 }
430 return NULL;
431
432 }
433
434 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
435 {
436
437 }
438
439 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
440 {
441 struct rt_cache_stat *st = v;
442
443 if (v == SEQ_START_TOKEN) {
444 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");
445 return 0;
446 }
447
448 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
449 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
450 atomic_read(&ipv4_dst_ops.entries),
451 st->in_hit,
452 st->in_slow_tot,
453 st->in_slow_mc,
454 st->in_no_route,
455 st->in_brd,
456 st->in_martian_dst,
457 st->in_martian_src,
458
459 st->out_hit,
460 st->out_slow_tot,
461 st->out_slow_mc,
462
463 st->gc_total,
464 st->gc_ignored,
465 st->gc_goal_miss,
466 st->gc_dst_overflow,
467 st->in_hlist_search,
468 st->out_hlist_search
469 );
470 return 0;
471 }
472
473 static struct seq_operations rt_cpu_seq_ops = {
474 .start = rt_cpu_seq_start,
475 .next = rt_cpu_seq_next,
476 .stop = rt_cpu_seq_stop,
477 .show = rt_cpu_seq_show,
478 };
479
480
481 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
482 {
483 return seq_open(file, &rt_cpu_seq_ops);
484 }
485
486 static const struct file_operations rt_cpu_seq_fops = {
487 .owner = THIS_MODULE,
488 .open = rt_cpu_seq_open,
489 .read = seq_read,
490 .llseek = seq_lseek,
491 .release = seq_release,
492 };
493
494 #endif /* CONFIG_PROC_FS */
495
496 static __inline__ void rt_free(struct rtable *rt)
497 {
498 multipath_remove(rt);
499 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
500 }
501
502 static __inline__ void rt_drop(struct rtable *rt)
503 {
504 multipath_remove(rt);
505 ip_rt_put(rt);
506 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
507 }
508
509 static __inline__ int rt_fast_clean(struct rtable *rth)
510 {
511 /* Kill broadcast/multicast entries very aggresively, if they
512 collide in hash table with more useful entries */
513 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
514 rth->fl.iif && rth->u.dst.rt_next;
515 }
516
517 static __inline__ int rt_valuable(struct rtable *rth)
518 {
519 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
520 rth->u.dst.expires;
521 }
522
523 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
524 {
525 unsigned long age;
526 int ret = 0;
527
528 if (atomic_read(&rth->u.dst.__refcnt))
529 goto out;
530
531 ret = 1;
532 if (rth->u.dst.expires &&
533 time_after_eq(jiffies, rth->u.dst.expires))
534 goto out;
535
536 age = jiffies - rth->u.dst.lastuse;
537 ret = 0;
538 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
539 (age <= tmo2 && rt_valuable(rth)))
540 goto out;
541 ret = 1;
542 out: return ret;
543 }
544
545 /* Bits of score are:
546 * 31: very valuable
547 * 30: not quite useless
548 * 29..0: usage counter
549 */
550 static inline u32 rt_score(struct rtable *rt)
551 {
552 u32 score = jiffies - rt->u.dst.lastuse;
553
554 score = ~score & ~(3<<30);
555
556 if (rt_valuable(rt))
557 score |= (1<<31);
558
559 if (!rt->fl.iif ||
560 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
561 score |= (1<<30);
562
563 return score;
564 }
565
566 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
567 {
568 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
569 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
570 (fl1->mark ^ fl2->mark) |
571 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
572 *(u16 *)&fl2->nl_u.ip4_u.tos) |
573 (fl1->oif ^ fl2->oif) |
574 (fl1->iif ^ fl2->iif)) == 0;
575 }
576
577 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
578 static struct rtable **rt_remove_balanced_route(struct rtable **chain_head,
579 struct rtable *expentry,
580 int *removed_count)
581 {
582 int passedexpired = 0;
583 struct rtable **nextstep = NULL;
584 struct rtable **rthp = chain_head;
585 struct rtable *rth;
586
587 if (removed_count)
588 *removed_count = 0;
589
590 while ((rth = *rthp) != NULL) {
591 if (rth == expentry)
592 passedexpired = 1;
593
594 if (((*rthp)->u.dst.flags & DST_BALANCED) != 0 &&
595 compare_keys(&(*rthp)->fl, &expentry->fl)) {
596 if (*rthp == expentry) {
597 *rthp = rth->u.dst.rt_next;
598 continue;
599 } else {
600 *rthp = rth->u.dst.rt_next;
601 rt_free(rth);
602 if (removed_count)
603 ++(*removed_count);
604 }
605 } else {
606 if (!((*rthp)->u.dst.flags & DST_BALANCED) &&
607 passedexpired && !nextstep)
608 nextstep = &rth->u.dst.rt_next;
609
610 rthp = &rth->u.dst.rt_next;
611 }
612 }
613
614 rt_free(expentry);
615 if (removed_count)
616 ++(*removed_count);
617
618 return nextstep;
619 }
620 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
621
622
623 /* This runs via a timer and thus is always in BH context. */
624 static void rt_check_expire(unsigned long dummy)
625 {
626 static unsigned int rover;
627 unsigned int i = rover, goal;
628 struct rtable *rth, **rthp;
629 unsigned long now = jiffies;
630 u64 mult;
631
632 mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
633 if (ip_rt_gc_timeout > 1)
634 do_div(mult, ip_rt_gc_timeout);
635 goal = (unsigned int)mult;
636 if (goal > rt_hash_mask) goal = rt_hash_mask + 1;
637 for (; goal > 0; goal--) {
638 unsigned long tmo = ip_rt_gc_timeout;
639
640 i = (i + 1) & rt_hash_mask;
641 rthp = &rt_hash_table[i].chain;
642
643 if (*rthp == 0)
644 continue;
645 spin_lock(rt_hash_lock_addr(i));
646 while ((rth = *rthp) != NULL) {
647 if (rth->u.dst.expires) {
648 /* Entry is expired even if it is in use */
649 if (time_before_eq(now, rth->u.dst.expires)) {
650 tmo >>= 1;
651 rthp = &rth->u.dst.rt_next;
652 continue;
653 }
654 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
655 tmo >>= 1;
656 rthp = &rth->u.dst.rt_next;
657 continue;
658 }
659
660 /* Cleanup aged off entries. */
661 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
662 /* remove all related balanced entries if necessary */
663 if (rth->u.dst.flags & DST_BALANCED) {
664 rthp = rt_remove_balanced_route(
665 &rt_hash_table[i].chain,
666 rth, NULL);
667 if (!rthp)
668 break;
669 } else {
670 *rthp = rth->u.dst.rt_next;
671 rt_free(rth);
672 }
673 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
674 *rthp = rth->u.dst.rt_next;
675 rt_free(rth);
676 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
677 }
678 spin_unlock(rt_hash_lock_addr(i));
679
680 /* Fallback loop breaker. */
681 if (time_after(jiffies, now))
682 break;
683 }
684 rover = i;
685 mod_timer(&rt_periodic_timer, jiffies + ip_rt_gc_interval);
686 }
687
688 /* This can run from both BH and non-BH contexts, the latter
689 * in the case of a forced flush event.
690 */
691 static void rt_run_flush(unsigned long dummy)
692 {
693 int i;
694 struct rtable *rth, *next;
695
696 rt_deadline = 0;
697
698 get_random_bytes(&rt_hash_rnd, 4);
699
700 for (i = rt_hash_mask; i >= 0; i--) {
701 spin_lock_bh(rt_hash_lock_addr(i));
702 rth = rt_hash_table[i].chain;
703 if (rth)
704 rt_hash_table[i].chain = NULL;
705 spin_unlock_bh(rt_hash_lock_addr(i));
706
707 for (; rth; rth = next) {
708 next = rth->u.dst.rt_next;
709 rt_free(rth);
710 }
711 }
712 }
713
714 static DEFINE_SPINLOCK(rt_flush_lock);
715
716 void rt_cache_flush(int delay)
717 {
718 unsigned long now = jiffies;
719 int user_mode = !in_softirq();
720
721 if (delay < 0)
722 delay = ip_rt_min_delay;
723
724 /* flush existing multipath state*/
725 multipath_flush();
726
727 spin_lock_bh(&rt_flush_lock);
728
729 if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
730 long tmo = (long)(rt_deadline - now);
731
732 /* If flush timer is already running
733 and flush request is not immediate (delay > 0):
734
735 if deadline is not achieved, prolongate timer to "delay",
736 otherwise fire it at deadline time.
737 */
738
739 if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
740 tmo = 0;
741
742 if (delay > tmo)
743 delay = tmo;
744 }
745
746 if (delay <= 0) {
747 spin_unlock_bh(&rt_flush_lock);
748 rt_run_flush(0);
749 return;
750 }
751
752 if (rt_deadline == 0)
753 rt_deadline = now + ip_rt_max_delay;
754
755 mod_timer(&rt_flush_timer, now+delay);
756 spin_unlock_bh(&rt_flush_lock);
757 }
758
759 static void rt_secret_rebuild(unsigned long dummy)
760 {
761 unsigned long now = jiffies;
762
763 rt_cache_flush(0);
764 mod_timer(&rt_secret_timer, now + ip_rt_secret_interval);
765 }
766
767 /*
768 Short description of GC goals.
769
770 We want to build algorithm, which will keep routing cache
771 at some equilibrium point, when number of aged off entries
772 is kept approximately equal to newly generated ones.
773
774 Current expiration strength is variable "expire".
775 We try to adjust it dynamically, so that if networking
776 is idle expires is large enough to keep enough of warm entries,
777 and when load increases it reduces to limit cache size.
778 */
779
780 static int rt_garbage_collect(void)
781 {
782 static unsigned long expire = RT_GC_TIMEOUT;
783 static unsigned long last_gc;
784 static int rover;
785 static int equilibrium;
786 struct rtable *rth, **rthp;
787 unsigned long now = jiffies;
788 int goal;
789
790 /*
791 * Garbage collection is pretty expensive,
792 * do not make it too frequently.
793 */
794
795 RT_CACHE_STAT_INC(gc_total);
796
797 if (now - last_gc < ip_rt_gc_min_interval &&
798 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
799 RT_CACHE_STAT_INC(gc_ignored);
800 goto out;
801 }
802
803 /* Calculate number of entries, which we want to expire now. */
804 goal = atomic_read(&ipv4_dst_ops.entries) -
805 (ip_rt_gc_elasticity << rt_hash_log);
806 if (goal <= 0) {
807 if (equilibrium < ipv4_dst_ops.gc_thresh)
808 equilibrium = ipv4_dst_ops.gc_thresh;
809 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
810 if (goal > 0) {
811 equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
812 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
813 }
814 } else {
815 /* We are in dangerous area. Try to reduce cache really
816 * aggressively.
817 */
818 goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
819 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
820 }
821
822 if (now - last_gc >= ip_rt_gc_min_interval)
823 last_gc = now;
824
825 if (goal <= 0) {
826 equilibrium += goal;
827 goto work_done;
828 }
829
830 do {
831 int i, k;
832
833 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
834 unsigned long tmo = expire;
835
836 k = (k + 1) & rt_hash_mask;
837 rthp = &rt_hash_table[k].chain;
838 spin_lock_bh(rt_hash_lock_addr(k));
839 while ((rth = *rthp) != NULL) {
840 if (!rt_may_expire(rth, tmo, expire)) {
841 tmo >>= 1;
842 rthp = &rth->u.dst.rt_next;
843 continue;
844 }
845 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
846 /* remove all related balanced entries
847 * if necessary
848 */
849 if (rth->u.dst.flags & DST_BALANCED) {
850 int r;
851
852 rthp = rt_remove_balanced_route(
853 &rt_hash_table[k].chain,
854 rth,
855 &r);
856 goal -= r;
857 if (!rthp)
858 break;
859 } else {
860 *rthp = rth->u.dst.rt_next;
861 rt_free(rth);
862 goal--;
863 }
864 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
865 *rthp = rth->u.dst.rt_next;
866 rt_free(rth);
867 goal--;
868 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
869 }
870 spin_unlock_bh(rt_hash_lock_addr(k));
871 if (goal <= 0)
872 break;
873 }
874 rover = k;
875
876 if (goal <= 0)
877 goto work_done;
878
879 /* Goal is not achieved. We stop process if:
880
881 - if expire reduced to zero. Otherwise, expire is halfed.
882 - if table is not full.
883 - if we are called from interrupt.
884 - jiffies check is just fallback/debug loop breaker.
885 We will not spin here for long time in any case.
886 */
887
888 RT_CACHE_STAT_INC(gc_goal_miss);
889
890 if (expire == 0)
891 break;
892
893 expire >>= 1;
894 #if RT_CACHE_DEBUG >= 2
895 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
896 atomic_read(&ipv4_dst_ops.entries), goal, i);
897 #endif
898
899 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
900 goto out;
901 } while (!in_softirq() && time_before_eq(jiffies, now));
902
903 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
904 goto out;
905 if (net_ratelimit())
906 printk(KERN_WARNING "dst cache overflow\n");
907 RT_CACHE_STAT_INC(gc_dst_overflow);
908 return 1;
909
910 work_done:
911 expire += ip_rt_gc_min_interval;
912 if (expire > ip_rt_gc_timeout ||
913 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
914 expire = ip_rt_gc_timeout;
915 #if RT_CACHE_DEBUG >= 2
916 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
917 atomic_read(&ipv4_dst_ops.entries), goal, rover);
918 #endif
919 out: return 0;
920 }
921
922 static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
923 {
924 struct rtable *rth, **rthp;
925 unsigned long now;
926 struct rtable *cand, **candp;
927 u32 min_score;
928 int chain_length;
929 int attempts = !in_softirq();
930
931 restart:
932 chain_length = 0;
933 min_score = ~(u32)0;
934 cand = NULL;
935 candp = NULL;
936 now = jiffies;
937
938 rthp = &rt_hash_table[hash].chain;
939
940 spin_lock_bh(rt_hash_lock_addr(hash));
941 while ((rth = *rthp) != NULL) {
942 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
943 if (!(rth->u.dst.flags & DST_BALANCED) &&
944 compare_keys(&rth->fl, &rt->fl)) {
945 #else
946 if (compare_keys(&rth->fl, &rt->fl)) {
947 #endif
948 /* Put it first */
949 *rthp = rth->u.dst.rt_next;
950 /*
951 * Since lookup is lockfree, the deletion
952 * must be visible to another weakly ordered CPU before
953 * the insertion at the start of the hash chain.
954 */
955 rcu_assign_pointer(rth->u.dst.rt_next,
956 rt_hash_table[hash].chain);
957 /*
958 * Since lookup is lockfree, the update writes
959 * must be ordered for consistency on SMP.
960 */
961 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
962
963 rth->u.dst.__use++;
964 dst_hold(&rth->u.dst);
965 rth->u.dst.lastuse = now;
966 spin_unlock_bh(rt_hash_lock_addr(hash));
967
968 rt_drop(rt);
969 *rp = rth;
970 return 0;
971 }
972
973 if (!atomic_read(&rth->u.dst.__refcnt)) {
974 u32 score = rt_score(rth);
975
976 if (score <= min_score) {
977 cand = rth;
978 candp = rthp;
979 min_score = score;
980 }
981 }
982
983 chain_length++;
984
985 rthp = &rth->u.dst.rt_next;
986 }
987
988 if (cand) {
989 /* ip_rt_gc_elasticity used to be average length of chain
990 * length, when exceeded gc becomes really aggressive.
991 *
992 * The second limit is less certain. At the moment it allows
993 * only 2 entries per bucket. We will see.
994 */
995 if (chain_length > ip_rt_gc_elasticity) {
996 *candp = cand->u.dst.rt_next;
997 rt_free(cand);
998 }
999 }
1000
1001 /* Try to bind route to arp only if it is output
1002 route or unicast forwarding path.
1003 */
1004 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
1005 int err = arp_bind_neighbour(&rt->u.dst);
1006 if (err) {
1007 spin_unlock_bh(rt_hash_lock_addr(hash));
1008
1009 if (err != -ENOBUFS) {
1010 rt_drop(rt);
1011 return err;
1012 }
1013
1014 /* Neighbour tables are full and nothing
1015 can be released. Try to shrink route cache,
1016 it is most likely it holds some neighbour records.
1017 */
1018 if (attempts-- > 0) {
1019 int saved_elasticity = ip_rt_gc_elasticity;
1020 int saved_int = ip_rt_gc_min_interval;
1021 ip_rt_gc_elasticity = 1;
1022 ip_rt_gc_min_interval = 0;
1023 rt_garbage_collect();
1024 ip_rt_gc_min_interval = saved_int;
1025 ip_rt_gc_elasticity = saved_elasticity;
1026 goto restart;
1027 }
1028
1029 if (net_ratelimit())
1030 printk(KERN_WARNING "Neighbour table overflow.\n");
1031 rt_drop(rt);
1032 return -ENOBUFS;
1033 }
1034 }
1035
1036 rt->u.dst.rt_next = rt_hash_table[hash].chain;
1037 #if RT_CACHE_DEBUG >= 2
1038 if (rt->u.dst.rt_next) {
1039 struct rtable *trt;
1040 printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
1041 NIPQUAD(rt->rt_dst));
1042 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
1043 printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
1044 printk("\n");
1045 }
1046 #endif
1047 rt_hash_table[hash].chain = rt;
1048 spin_unlock_bh(rt_hash_lock_addr(hash));
1049 *rp = rt;
1050 return 0;
1051 }
1052
1053 void rt_bind_peer(struct rtable *rt, int create)
1054 {
1055 static DEFINE_SPINLOCK(rt_peer_lock);
1056 struct inet_peer *peer;
1057
1058 peer = inet_getpeer(rt->rt_dst, create);
1059
1060 spin_lock_bh(&rt_peer_lock);
1061 if (rt->peer == NULL) {
1062 rt->peer = peer;
1063 peer = NULL;
1064 }
1065 spin_unlock_bh(&rt_peer_lock);
1066 if (peer)
1067 inet_putpeer(peer);
1068 }
1069
1070 /*
1071 * Peer allocation may fail only in serious out-of-memory conditions. However
1072 * we still can generate some output.
1073 * Random ID selection looks a bit dangerous because we have no chances to
1074 * select ID being unique in a reasonable period of time.
1075 * But broken packet identifier may be better than no packet at all.
1076 */
1077 static void ip_select_fb_ident(struct iphdr *iph)
1078 {
1079 static DEFINE_SPINLOCK(ip_fb_id_lock);
1080 static u32 ip_fallback_id;
1081 u32 salt;
1082
1083 spin_lock_bh(&ip_fb_id_lock);
1084 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1085 iph->id = htons(salt & 0xFFFF);
1086 ip_fallback_id = salt;
1087 spin_unlock_bh(&ip_fb_id_lock);
1088 }
1089
1090 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1091 {
1092 struct rtable *rt = (struct rtable *) dst;
1093
1094 if (rt) {
1095 if (rt->peer == NULL)
1096 rt_bind_peer(rt, 1);
1097
1098 /* If peer is attached to destination, it is never detached,
1099 so that we need not to grab a lock to dereference it.
1100 */
1101 if (rt->peer) {
1102 iph->id = htons(inet_getid(rt->peer, more));
1103 return;
1104 }
1105 } else
1106 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1107 __builtin_return_address(0));
1108
1109 ip_select_fb_ident(iph);
1110 }
1111
1112 static void rt_del(unsigned hash, struct rtable *rt)
1113 {
1114 struct rtable **rthp;
1115
1116 spin_lock_bh(rt_hash_lock_addr(hash));
1117 ip_rt_put(rt);
1118 for (rthp = &rt_hash_table[hash].chain; *rthp;
1119 rthp = &(*rthp)->u.dst.rt_next)
1120 if (*rthp == rt) {
1121 *rthp = rt->u.dst.rt_next;
1122 rt_free(rt);
1123 break;
1124 }
1125 spin_unlock_bh(rt_hash_lock_addr(hash));
1126 }
1127
1128 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1129 __be32 saddr, struct net_device *dev)
1130 {
1131 int i, k;
1132 struct in_device *in_dev = in_dev_get(dev);
1133 struct rtable *rth, **rthp;
1134 __be32 skeys[2] = { saddr, 0 };
1135 int ikeys[2] = { dev->ifindex, 0 };
1136 struct netevent_redirect netevent;
1137
1138 if (!in_dev)
1139 return;
1140
1141 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1142 || MULTICAST(new_gw) || BADCLASS(new_gw) || ZERONET(new_gw))
1143 goto reject_redirect;
1144
1145 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1146 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1147 goto reject_redirect;
1148 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1149 goto reject_redirect;
1150 } else {
1151 if (inet_addr_type(new_gw) != RTN_UNICAST)
1152 goto reject_redirect;
1153 }
1154
1155 for (i = 0; i < 2; i++) {
1156 for (k = 0; k < 2; k++) {
1157 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
1158
1159 rthp=&rt_hash_table[hash].chain;
1160
1161 rcu_read_lock();
1162 while ((rth = rcu_dereference(*rthp)) != NULL) {
1163 struct rtable *rt;
1164
1165 if (rth->fl.fl4_dst != daddr ||
1166 rth->fl.fl4_src != skeys[i] ||
1167 rth->fl.oif != ikeys[k] ||
1168 rth->fl.iif != 0) {
1169 rthp = &rth->u.dst.rt_next;
1170 continue;
1171 }
1172
1173 if (rth->rt_dst != daddr ||
1174 rth->rt_src != saddr ||
1175 rth->u.dst.error ||
1176 rth->rt_gateway != old_gw ||
1177 rth->u.dst.dev != dev)
1178 break;
1179
1180 dst_hold(&rth->u.dst);
1181 rcu_read_unlock();
1182
1183 rt = dst_alloc(&ipv4_dst_ops);
1184 if (rt == NULL) {
1185 ip_rt_put(rth);
1186 in_dev_put(in_dev);
1187 return;
1188 }
1189
1190 /* Copy all the information. */
1191 *rt = *rth;
1192 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1193 rt->u.dst.__use = 1;
1194 atomic_set(&rt->u.dst.__refcnt, 1);
1195 rt->u.dst.child = NULL;
1196 if (rt->u.dst.dev)
1197 dev_hold(rt->u.dst.dev);
1198 if (rt->idev)
1199 in_dev_hold(rt->idev);
1200 rt->u.dst.obsolete = 0;
1201 rt->u.dst.lastuse = jiffies;
1202 rt->u.dst.path = &rt->u.dst;
1203 rt->u.dst.neighbour = NULL;
1204 rt->u.dst.hh = NULL;
1205 rt->u.dst.xfrm = NULL;
1206
1207 rt->rt_flags |= RTCF_REDIRECTED;
1208
1209 /* Gateway is different ... */
1210 rt->rt_gateway = new_gw;
1211
1212 /* Redirect received -> path was valid */
1213 dst_confirm(&rth->u.dst);
1214
1215 if (rt->peer)
1216 atomic_inc(&rt->peer->refcnt);
1217
1218 if (arp_bind_neighbour(&rt->u.dst) ||
1219 !(rt->u.dst.neighbour->nud_state &
1220 NUD_VALID)) {
1221 if (rt->u.dst.neighbour)
1222 neigh_event_send(rt->u.dst.neighbour, NULL);
1223 ip_rt_put(rth);
1224 rt_drop(rt);
1225 goto do_next;
1226 }
1227
1228 netevent.old = &rth->u.dst;
1229 netevent.new = &rt->u.dst;
1230 call_netevent_notifiers(NETEVENT_REDIRECT,
1231 &netevent);
1232
1233 rt_del(hash, rth);
1234 if (!rt_intern_hash(hash, rt, &rt))
1235 ip_rt_put(rt);
1236 goto do_next;
1237 }
1238 rcu_read_unlock();
1239 do_next:
1240 ;
1241 }
1242 }
1243 in_dev_put(in_dev);
1244 return;
1245
1246 reject_redirect:
1247 #ifdef CONFIG_IP_ROUTE_VERBOSE
1248 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1249 printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
1250 "%u.%u.%u.%u ignored.\n"
1251 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n",
1252 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1253 NIPQUAD(saddr), NIPQUAD(daddr));
1254 #endif
1255 in_dev_put(in_dev);
1256 }
1257
1258 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1259 {
1260 struct rtable *rt = (struct rtable*)dst;
1261 struct dst_entry *ret = dst;
1262
1263 if (rt) {
1264 if (dst->obsolete) {
1265 ip_rt_put(rt);
1266 ret = NULL;
1267 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1268 rt->u.dst.expires) {
1269 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1270 rt->fl.oif);
1271 #if RT_CACHE_DEBUG >= 1
1272 printk(KERN_DEBUG "ip_rt_advice: redirect to "
1273 "%u.%u.%u.%u/%02x dropped\n",
1274 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1275 #endif
1276 rt_del(hash, rt);
1277 ret = NULL;
1278 }
1279 }
1280 return ret;
1281 }
1282
1283 /*
1284 * Algorithm:
1285 * 1. The first ip_rt_redirect_number redirects are sent
1286 * with exponential backoff, then we stop sending them at all,
1287 * assuming that the host ignores our redirects.
1288 * 2. If we did not see packets requiring redirects
1289 * during ip_rt_redirect_silence, we assume that the host
1290 * forgot redirected route and start to send redirects again.
1291 *
1292 * This algorithm is much cheaper and more intelligent than dumb load limiting
1293 * in icmp.c.
1294 *
1295 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1296 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1297 */
1298
1299 void ip_rt_send_redirect(struct sk_buff *skb)
1300 {
1301 struct rtable *rt = (struct rtable*)skb->dst;
1302 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1303
1304 if (!in_dev)
1305 return;
1306
1307 if (!IN_DEV_TX_REDIRECTS(in_dev))
1308 goto out;
1309
1310 /* No redirected packets during ip_rt_redirect_silence;
1311 * reset the algorithm.
1312 */
1313 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1314 rt->u.dst.rate_tokens = 0;
1315
1316 /* Too many ignored redirects; do not send anything
1317 * set u.dst.rate_last to the last seen redirected packet.
1318 */
1319 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1320 rt->u.dst.rate_last = jiffies;
1321 goto out;
1322 }
1323
1324 /* Check for load limit; set rate_last to the latest sent
1325 * redirect.
1326 */
1327 if (rt->u.dst.rate_tokens == 0 ||
1328 time_after(jiffies,
1329 (rt->u.dst.rate_last +
1330 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1331 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1332 rt->u.dst.rate_last = jiffies;
1333 ++rt->u.dst.rate_tokens;
1334 #ifdef CONFIG_IP_ROUTE_VERBOSE
1335 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1336 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1337 net_ratelimit())
1338 printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
1339 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1340 NIPQUAD(rt->rt_src), rt->rt_iif,
1341 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1342 #endif
1343 }
1344 out:
1345 in_dev_put(in_dev);
1346 }
1347
1348 static int ip_error(struct sk_buff *skb)
1349 {
1350 struct rtable *rt = (struct rtable*)skb->dst;
1351 unsigned long now;
1352 int code;
1353
1354 switch (rt->u.dst.error) {
1355 case EINVAL:
1356 default:
1357 goto out;
1358 case EHOSTUNREACH:
1359 code = ICMP_HOST_UNREACH;
1360 break;
1361 case ENETUNREACH:
1362 code = ICMP_NET_UNREACH;
1363 break;
1364 case EACCES:
1365 code = ICMP_PKT_FILTERED;
1366 break;
1367 }
1368
1369 now = jiffies;
1370 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1371 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1372 rt->u.dst.rate_tokens = ip_rt_error_burst;
1373 rt->u.dst.rate_last = now;
1374 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1375 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1376 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1377 }
1378
1379 out: kfree_skb(skb);
1380 return 0;
1381 }
1382
1383 /*
1384 * The last two values are not from the RFC but
1385 * are needed for AMPRnet AX.25 paths.
1386 */
1387
1388 static const unsigned short mtu_plateau[] =
1389 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1390
1391 static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
1392 {
1393 int i;
1394
1395 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1396 if (old_mtu > mtu_plateau[i])
1397 return mtu_plateau[i];
1398 return 68;
1399 }
1400
1401 unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
1402 {
1403 int i;
1404 unsigned short old_mtu = ntohs(iph->tot_len);
1405 struct rtable *rth;
1406 __be32 skeys[2] = { iph->saddr, 0, };
1407 __be32 daddr = iph->daddr;
1408 unsigned short est_mtu = 0;
1409
1410 if (ipv4_config.no_pmtu_disc)
1411 return 0;
1412
1413 for (i = 0; i < 2; i++) {
1414 unsigned hash = rt_hash(daddr, skeys[i], 0);
1415
1416 rcu_read_lock();
1417 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1418 rth = rcu_dereference(rth->u.dst.rt_next)) {
1419 if (rth->fl.fl4_dst == daddr &&
1420 rth->fl.fl4_src == skeys[i] &&
1421 rth->rt_dst == daddr &&
1422 rth->rt_src == iph->saddr &&
1423 rth->fl.iif == 0 &&
1424 !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
1425 unsigned short mtu = new_mtu;
1426
1427 if (new_mtu < 68 || new_mtu >= old_mtu) {
1428
1429 /* BSD 4.2 compatibility hack :-( */
1430 if (mtu == 0 &&
1431 old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
1432 old_mtu >= 68 + (iph->ihl << 2))
1433 old_mtu -= iph->ihl << 2;
1434
1435 mtu = guess_mtu(old_mtu);
1436 }
1437 if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1438 if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
1439 dst_confirm(&rth->u.dst);
1440 if (mtu < ip_rt_min_pmtu) {
1441 mtu = ip_rt_min_pmtu;
1442 rth->u.dst.metrics[RTAX_LOCK-1] |=
1443 (1 << RTAX_MTU);
1444 }
1445 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1446 dst_set_expires(&rth->u.dst,
1447 ip_rt_mtu_expires);
1448 }
1449 est_mtu = mtu;
1450 }
1451 }
1452 }
1453 rcu_read_unlock();
1454 }
1455 return est_mtu ? : new_mtu;
1456 }
1457
1458 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1459 {
1460 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
1461 !(dst_metric_locked(dst, RTAX_MTU))) {
1462 if (mtu < ip_rt_min_pmtu) {
1463 mtu = ip_rt_min_pmtu;
1464 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1465 }
1466 dst->metrics[RTAX_MTU-1] = mtu;
1467 dst_set_expires(dst, ip_rt_mtu_expires);
1468 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1469 }
1470 }
1471
1472 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1473 {
1474 return NULL;
1475 }
1476
1477 static void ipv4_dst_destroy(struct dst_entry *dst)
1478 {
1479 struct rtable *rt = (struct rtable *) dst;
1480 struct inet_peer *peer = rt->peer;
1481 struct in_device *idev = rt->idev;
1482
1483 if (peer) {
1484 rt->peer = NULL;
1485 inet_putpeer(peer);
1486 }
1487
1488 if (idev) {
1489 rt->idev = NULL;
1490 in_dev_put(idev);
1491 }
1492 }
1493
1494 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1495 int how)
1496 {
1497 struct rtable *rt = (struct rtable *) dst;
1498 struct in_device *idev = rt->idev;
1499 if (dev != &loopback_dev && idev && idev->dev == dev) {
1500 struct in_device *loopback_idev = in_dev_get(&loopback_dev);
1501 if (loopback_idev) {
1502 rt->idev = loopback_idev;
1503 in_dev_put(idev);
1504 }
1505 }
1506 }
1507
1508 static void ipv4_link_failure(struct sk_buff *skb)
1509 {
1510 struct rtable *rt;
1511
1512 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1513
1514 rt = (struct rtable *) skb->dst;
1515 if (rt)
1516 dst_set_expires(&rt->u.dst, 0);
1517 }
1518
1519 static int ip_rt_bug(struct sk_buff *skb)
1520 {
1521 printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1522 NIPQUAD(skb->nh.iph->saddr), NIPQUAD(skb->nh.iph->daddr),
1523 skb->dev ? skb->dev->name : "?");
1524 kfree_skb(skb);
1525 return 0;
1526 }
1527
1528 /*
1529 We do not cache source address of outgoing interface,
1530 because it is used only by IP RR, TS and SRR options,
1531 so that it out of fast path.
1532
1533 BTW remember: "addr" is allowed to be not aligned
1534 in IP options!
1535 */
1536
1537 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1538 {
1539 __be32 src;
1540 struct fib_result res;
1541
1542 if (rt->fl.iif == 0)
1543 src = rt->rt_src;
1544 else if (fib_lookup(&rt->fl, &res) == 0) {
1545 src = FIB_RES_PREFSRC(res);
1546 fib_res_put(&res);
1547 } else
1548 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1549 RT_SCOPE_UNIVERSE);
1550 memcpy(addr, &src, 4);
1551 }
1552
1553 #ifdef CONFIG_NET_CLS_ROUTE
1554 static void set_class_tag(struct rtable *rt, u32 tag)
1555 {
1556 if (!(rt->u.dst.tclassid & 0xFFFF))
1557 rt->u.dst.tclassid |= tag & 0xFFFF;
1558 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1559 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1560 }
1561 #endif
1562
1563 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1564 {
1565 struct fib_info *fi = res->fi;
1566
1567 if (fi) {
1568 if (FIB_RES_GW(*res) &&
1569 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1570 rt->rt_gateway = FIB_RES_GW(*res);
1571 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1572 sizeof(rt->u.dst.metrics));
1573 if (fi->fib_mtu == 0) {
1574 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1575 if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
1576 rt->rt_gateway != rt->rt_dst &&
1577 rt->u.dst.dev->mtu > 576)
1578 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1579 }
1580 #ifdef CONFIG_NET_CLS_ROUTE
1581 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1582 #endif
1583 } else
1584 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1585
1586 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1587 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1588 if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
1589 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1590 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
1591 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1592 ip_rt_min_advmss);
1593 if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
1594 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1595
1596 #ifdef CONFIG_NET_CLS_ROUTE
1597 #ifdef CONFIG_IP_MULTIPLE_TABLES
1598 set_class_tag(rt, fib_rules_tclass(res));
1599 #endif
1600 set_class_tag(rt, itag);
1601 #endif
1602 rt->rt_type = res->type;
1603 }
1604
1605 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1606 u8 tos, struct net_device *dev, int our)
1607 {
1608 unsigned hash;
1609 struct rtable *rth;
1610 __be32 spec_dst;
1611 struct in_device *in_dev = in_dev_get(dev);
1612 u32 itag = 0;
1613
1614 /* Primary sanity checks. */
1615
1616 if (in_dev == NULL)
1617 return -EINVAL;
1618
1619 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr) ||
1620 skb->protocol != htons(ETH_P_IP))
1621 goto e_inval;
1622
1623 if (ZERONET(saddr)) {
1624 if (!LOCAL_MCAST(daddr))
1625 goto e_inval;
1626 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1627 } else if (fib_validate_source(saddr, 0, tos, 0,
1628 dev, &spec_dst, &itag) < 0)
1629 goto e_inval;
1630
1631 rth = dst_alloc(&ipv4_dst_ops);
1632 if (!rth)
1633 goto e_nobufs;
1634
1635 rth->u.dst.output= ip_rt_bug;
1636
1637 atomic_set(&rth->u.dst.__refcnt, 1);
1638 rth->u.dst.flags= DST_HOST;
1639 if (in_dev->cnf.no_policy)
1640 rth->u.dst.flags |= DST_NOPOLICY;
1641 rth->fl.fl4_dst = daddr;
1642 rth->rt_dst = daddr;
1643 rth->fl.fl4_tos = tos;
1644 rth->fl.mark = skb->mark;
1645 rth->fl.fl4_src = saddr;
1646 rth->rt_src = saddr;
1647 #ifdef CONFIG_NET_CLS_ROUTE
1648 rth->u.dst.tclassid = itag;
1649 #endif
1650 rth->rt_iif =
1651 rth->fl.iif = dev->ifindex;
1652 rth->u.dst.dev = &loopback_dev;
1653 dev_hold(rth->u.dst.dev);
1654 rth->idev = in_dev_get(rth->u.dst.dev);
1655 rth->fl.oif = 0;
1656 rth->rt_gateway = daddr;
1657 rth->rt_spec_dst= spec_dst;
1658 rth->rt_type = RTN_MULTICAST;
1659 rth->rt_flags = RTCF_MULTICAST;
1660 if (our) {
1661 rth->u.dst.input= ip_local_deliver;
1662 rth->rt_flags |= RTCF_LOCAL;
1663 }
1664
1665 #ifdef CONFIG_IP_MROUTE
1666 if (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1667 rth->u.dst.input = ip_mr_input;
1668 #endif
1669 RT_CACHE_STAT_INC(in_slow_mc);
1670
1671 in_dev_put(in_dev);
1672 hash = rt_hash(daddr, saddr, dev->ifindex);
1673 return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
1674
1675 e_nobufs:
1676 in_dev_put(in_dev);
1677 return -ENOBUFS;
1678
1679 e_inval:
1680 in_dev_put(in_dev);
1681 return -EINVAL;
1682 }
1683
1684
1685 static void ip_handle_martian_source(struct net_device *dev,
1686 struct in_device *in_dev,
1687 struct sk_buff *skb,
1688 __be32 daddr,
1689 __be32 saddr)
1690 {
1691 RT_CACHE_STAT_INC(in_martian_src);
1692 #ifdef CONFIG_IP_ROUTE_VERBOSE
1693 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1694 /*
1695 * RFC1812 recommendation, if source is martian,
1696 * the only hint is MAC header.
1697 */
1698 printk(KERN_WARNING "martian source %u.%u.%u.%u from "
1699 "%u.%u.%u.%u, on dev %s\n",
1700 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1701 if (dev->hard_header_len && skb->mac.raw) {
1702 int i;
1703 unsigned char *p = skb->mac.raw;
1704 printk(KERN_WARNING "ll header: ");
1705 for (i = 0; i < dev->hard_header_len; i++, p++) {
1706 printk("%02x", *p);
1707 if (i < (dev->hard_header_len - 1))
1708 printk(":");
1709 }
1710 printk("\n");
1711 }
1712 }
1713 #endif
1714 }
1715
1716 static inline int __mkroute_input(struct sk_buff *skb,
1717 struct fib_result* res,
1718 struct in_device *in_dev,
1719 __be32 daddr, __be32 saddr, u32 tos,
1720 struct rtable **result)
1721 {
1722
1723 struct rtable *rth;
1724 int err;
1725 struct in_device *out_dev;
1726 unsigned flags = 0;
1727 __be32 spec_dst;
1728 u32 itag;
1729
1730 /* get a working reference to the output device */
1731 out_dev = in_dev_get(FIB_RES_DEV(*res));
1732 if (out_dev == NULL) {
1733 if (net_ratelimit())
1734 printk(KERN_CRIT "Bug in ip_route_input" \
1735 "_slow(). Please, report\n");
1736 return -EINVAL;
1737 }
1738
1739
1740 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1741 in_dev->dev, &spec_dst, &itag);
1742 if (err < 0) {
1743 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1744 saddr);
1745
1746 err = -EINVAL;
1747 goto cleanup;
1748 }
1749
1750 if (err)
1751 flags |= RTCF_DIRECTSRC;
1752
1753 if (out_dev == in_dev && err && !(flags & (RTCF_NAT | RTCF_MASQ)) &&
1754 (IN_DEV_SHARED_MEDIA(out_dev) ||
1755 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1756 flags |= RTCF_DOREDIRECT;
1757
1758 if (skb->protocol != htons(ETH_P_IP)) {
1759 /* Not IP (i.e. ARP). Do not create route, if it is
1760 * invalid for proxy arp. DNAT routes are always valid.
1761 */
1762 if (out_dev == in_dev && !(flags & RTCF_DNAT)) {
1763 err = -EINVAL;
1764 goto cleanup;
1765 }
1766 }
1767
1768
1769 rth = dst_alloc(&ipv4_dst_ops);
1770 if (!rth) {
1771 err = -ENOBUFS;
1772 goto cleanup;
1773 }
1774
1775 atomic_set(&rth->u.dst.__refcnt, 1);
1776 rth->u.dst.flags= DST_HOST;
1777 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1778 if (res->fi->fib_nhs > 1)
1779 rth->u.dst.flags |= DST_BALANCED;
1780 #endif
1781 if (in_dev->cnf.no_policy)
1782 rth->u.dst.flags |= DST_NOPOLICY;
1783 if (out_dev->cnf.no_xfrm)
1784 rth->u.dst.flags |= DST_NOXFRM;
1785 rth->fl.fl4_dst = daddr;
1786 rth->rt_dst = daddr;
1787 rth->fl.fl4_tos = tos;
1788 rth->fl.mark = skb->mark;
1789 rth->fl.fl4_src = saddr;
1790 rth->rt_src = saddr;
1791 rth->rt_gateway = daddr;
1792 rth->rt_iif =
1793 rth->fl.iif = in_dev->dev->ifindex;
1794 rth->u.dst.dev = (out_dev)->dev;
1795 dev_hold(rth->u.dst.dev);
1796 rth->idev = in_dev_get(rth->u.dst.dev);
1797 rth->fl.oif = 0;
1798 rth->rt_spec_dst= spec_dst;
1799
1800 rth->u.dst.input = ip_forward;
1801 rth->u.dst.output = ip_output;
1802
1803 rt_set_nexthop(rth, res, itag);
1804
1805 rth->rt_flags = flags;
1806
1807 *result = rth;
1808 err = 0;
1809 cleanup:
1810 /* release the working reference to the output device */
1811 in_dev_put(out_dev);
1812 return err;
1813 }
1814
1815 static inline int ip_mkroute_input_def(struct sk_buff *skb,
1816 struct fib_result* res,
1817 const struct flowi *fl,
1818 struct in_device *in_dev,
1819 __be32 daddr, __be32 saddr, u32 tos)
1820 {
1821 struct rtable* rth = NULL;
1822 int err;
1823 unsigned hash;
1824
1825 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1826 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
1827 fib_select_multipath(fl, res);
1828 #endif
1829
1830 /* create a routing cache entry */
1831 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1832 if (err)
1833 return err;
1834
1835 /* put it into the cache */
1836 hash = rt_hash(daddr, saddr, fl->iif);
1837 return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1838 }
1839
1840 static inline int ip_mkroute_input(struct sk_buff *skb,
1841 struct fib_result* res,
1842 const struct flowi *fl,
1843 struct in_device *in_dev,
1844 __be32 daddr, __be32 saddr, u32 tos)
1845 {
1846 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
1847 struct rtable* rth = NULL, *rtres;
1848 unsigned char hop, hopcount;
1849 int err = -EINVAL;
1850 unsigned int hash;
1851
1852 if (res->fi)
1853 hopcount = res->fi->fib_nhs;
1854 else
1855 hopcount = 1;
1856
1857 /* distinguish between multipath and singlepath */
1858 if (hopcount < 2)
1859 return ip_mkroute_input_def(skb, res, fl, in_dev, daddr,
1860 saddr, tos);
1861
1862 /* add all alternatives to the routing cache */
1863 for (hop = 0; hop < hopcount; hop++) {
1864 res->nh_sel = hop;
1865
1866 /* put reference to previous result */
1867 if (hop)
1868 ip_rt_put(rtres);
1869
1870 /* create a routing cache entry */
1871 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos,
1872 &rth);
1873 if (err)
1874 return err;
1875
1876 /* put it into the cache */
1877 hash = rt_hash(daddr, saddr, fl->iif);
1878 err = rt_intern_hash(hash, rth, &rtres);
1879 if (err)
1880 return err;
1881
1882 /* forward hop information to multipath impl. */
1883 multipath_set_nhinfo(rth,
1884 FIB_RES_NETWORK(*res),
1885 FIB_RES_NETMASK(*res),
1886 res->prefixlen,
1887 &FIB_RES_NH(*res));
1888 }
1889 skb->dst = &rtres->u.dst;
1890 return err;
1891 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1892 return ip_mkroute_input_def(skb, res, fl, in_dev, daddr, saddr, tos);
1893 #endif /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
1894 }
1895
1896
1897 /*
1898 * NOTE. We drop all the packets that has local source
1899 * addresses, because every properly looped back packet
1900 * must have correct destination already attached by output routine.
1901 *
1902 * Such approach solves two big problems:
1903 * 1. Not simplex devices are handled properly.
1904 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1905 */
1906
1907 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1908 u8 tos, struct net_device *dev)
1909 {
1910 struct fib_result res;
1911 struct in_device *in_dev = in_dev_get(dev);
1912 struct flowi fl = { .nl_u = { .ip4_u =
1913 { .daddr = daddr,
1914 .saddr = saddr,
1915 .tos = tos,
1916 .scope = RT_SCOPE_UNIVERSE,
1917 } },
1918 .mark = skb->mark,
1919 .iif = dev->ifindex };
1920 unsigned flags = 0;
1921 u32 itag = 0;
1922 struct rtable * rth;
1923 unsigned hash;
1924 __be32 spec_dst;
1925 int err = -EINVAL;
1926 int free_res = 0;
1927
1928 /* IP on this device is disabled. */
1929
1930 if (!in_dev)
1931 goto out;
1932
1933 /* Check for the most weird martians, which can be not detected
1934 by fib_lookup.
1935 */
1936
1937 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr))
1938 goto martian_source;
1939
1940 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
1941 goto brd_input;
1942
1943 /* Accept zero addresses only to limited broadcast;
1944 * I even do not know to fix it or not. Waiting for complains :-)
1945 */
1946 if (ZERONET(saddr))
1947 goto martian_source;
1948
1949 if (BADCLASS(daddr) || ZERONET(daddr) || LOOPBACK(daddr))
1950 goto martian_destination;
1951
1952 /*
1953 * Now we are ready to route packet.
1954 */
1955 if ((err = fib_lookup(&fl, &res)) != 0) {
1956 if (!IN_DEV_FORWARD(in_dev))
1957 goto e_hostunreach;
1958 goto no_route;
1959 }
1960 free_res = 1;
1961
1962 RT_CACHE_STAT_INC(in_slow_tot);
1963
1964 if (res.type == RTN_BROADCAST)
1965 goto brd_input;
1966
1967 if (res.type == RTN_LOCAL) {
1968 int result;
1969 result = fib_validate_source(saddr, daddr, tos,
1970 loopback_dev.ifindex,
1971 dev, &spec_dst, &itag);
1972 if (result < 0)
1973 goto martian_source;
1974 if (result)
1975 flags |= RTCF_DIRECTSRC;
1976 spec_dst = daddr;
1977 goto local_input;
1978 }
1979
1980 if (!IN_DEV_FORWARD(in_dev))
1981 goto e_hostunreach;
1982 if (res.type != RTN_UNICAST)
1983 goto martian_destination;
1984
1985 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
1986 if (err == -ENOBUFS)
1987 goto e_nobufs;
1988 if (err == -EINVAL)
1989 goto e_inval;
1990
1991 done:
1992 in_dev_put(in_dev);
1993 if (free_res)
1994 fib_res_put(&res);
1995 out: return err;
1996
1997 brd_input:
1998 if (skb->protocol != htons(ETH_P_IP))
1999 goto e_inval;
2000
2001 if (ZERONET(saddr))
2002 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2003 else {
2004 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
2005 &itag);
2006 if (err < 0)
2007 goto martian_source;
2008 if (err)
2009 flags |= RTCF_DIRECTSRC;
2010 }
2011 flags |= RTCF_BROADCAST;
2012 res.type = RTN_BROADCAST;
2013 RT_CACHE_STAT_INC(in_brd);
2014
2015 local_input:
2016 rth = dst_alloc(&ipv4_dst_ops);
2017 if (!rth)
2018 goto e_nobufs;
2019
2020 rth->u.dst.output= ip_rt_bug;
2021
2022 atomic_set(&rth->u.dst.__refcnt, 1);
2023 rth->u.dst.flags= DST_HOST;
2024 if (in_dev->cnf.no_policy)
2025 rth->u.dst.flags |= DST_NOPOLICY;
2026 rth->fl.fl4_dst = daddr;
2027 rth->rt_dst = daddr;
2028 rth->fl.fl4_tos = tos;
2029 rth->fl.mark = skb->mark;
2030 rth->fl.fl4_src = saddr;
2031 rth->rt_src = saddr;
2032 #ifdef CONFIG_NET_CLS_ROUTE
2033 rth->u.dst.tclassid = itag;
2034 #endif
2035 rth->rt_iif =
2036 rth->fl.iif = dev->ifindex;
2037 rth->u.dst.dev = &loopback_dev;
2038 dev_hold(rth->u.dst.dev);
2039 rth->idev = in_dev_get(rth->u.dst.dev);
2040 rth->rt_gateway = daddr;
2041 rth->rt_spec_dst= spec_dst;
2042 rth->u.dst.input= ip_local_deliver;
2043 rth->rt_flags = flags|RTCF_LOCAL;
2044 if (res.type == RTN_UNREACHABLE) {
2045 rth->u.dst.input= ip_error;
2046 rth->u.dst.error= -err;
2047 rth->rt_flags &= ~RTCF_LOCAL;
2048 }
2049 rth->rt_type = res.type;
2050 hash = rt_hash(daddr, saddr, fl.iif);
2051 err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
2052 goto done;
2053
2054 no_route:
2055 RT_CACHE_STAT_INC(in_no_route);
2056 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2057 res.type = RTN_UNREACHABLE;
2058 goto local_input;
2059
2060 /*
2061 * Do not cache martian addresses: they should be logged (RFC1812)
2062 */
2063 martian_destination:
2064 RT_CACHE_STAT_INC(in_martian_dst);
2065 #ifdef CONFIG_IP_ROUTE_VERBOSE
2066 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2067 printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
2068 "%u.%u.%u.%u, dev %s\n",
2069 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
2070 #endif
2071
2072 e_hostunreach:
2073 err = -EHOSTUNREACH;
2074 goto done;
2075
2076 e_inval:
2077 err = -EINVAL;
2078 goto done;
2079
2080 e_nobufs:
2081 err = -ENOBUFS;
2082 goto done;
2083
2084 martian_source:
2085 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2086 goto e_inval;
2087 }
2088
2089 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2090 u8 tos, struct net_device *dev)
2091 {
2092 struct rtable * rth;
2093 unsigned hash;
2094 int iif = dev->ifindex;
2095
2096 tos &= IPTOS_RT_MASK;
2097 hash = rt_hash(daddr, saddr, iif);
2098
2099 rcu_read_lock();
2100 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2101 rth = rcu_dereference(rth->u.dst.rt_next)) {
2102 if (rth->fl.fl4_dst == daddr &&
2103 rth->fl.fl4_src == saddr &&
2104 rth->fl.iif == iif &&
2105 rth->fl.oif == 0 &&
2106 rth->fl.mark == skb->mark &&
2107 rth->fl.fl4_tos == tos) {
2108 rth->u.dst.lastuse = jiffies;
2109 dst_hold(&rth->u.dst);
2110 rth->u.dst.__use++;
2111 RT_CACHE_STAT_INC(in_hit);
2112 rcu_read_unlock();
2113 skb->dst = (struct dst_entry*)rth;
2114 return 0;
2115 }
2116 RT_CACHE_STAT_INC(in_hlist_search);
2117 }
2118 rcu_read_unlock();
2119
2120 /* Multicast recognition logic is moved from route cache to here.
2121 The problem was that too many Ethernet cards have broken/missing
2122 hardware multicast filters :-( As result the host on multicasting
2123 network acquires a lot of useless route cache entries, sort of
2124 SDR messages from all the world. Now we try to get rid of them.
2125 Really, provided software IP multicast filter is organized
2126 reasonably (at least, hashed), it does not result in a slowdown
2127 comparing with route cache reject entries.
2128 Note, that multicast routers are not affected, because
2129 route cache entry is created eventually.
2130 */
2131 if (MULTICAST(daddr)) {
2132 struct in_device *in_dev;
2133
2134 rcu_read_lock();
2135 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
2136 int our = ip_check_mc(in_dev, daddr, saddr,
2137 skb->nh.iph->protocol);
2138 if (our
2139 #ifdef CONFIG_IP_MROUTE
2140 || (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
2141 #endif
2142 ) {
2143 rcu_read_unlock();
2144 return ip_route_input_mc(skb, daddr, saddr,
2145 tos, dev, our);
2146 }
2147 }
2148 rcu_read_unlock();
2149 return -EINVAL;
2150 }
2151 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
2152 }
2153
2154 static inline int __mkroute_output(struct rtable **result,
2155 struct fib_result* res,
2156 const struct flowi *fl,
2157 const struct flowi *oldflp,
2158 struct net_device *dev_out,
2159 unsigned flags)
2160 {
2161 struct rtable *rth;
2162 struct in_device *in_dev;
2163 u32 tos = RT_FL_TOS(oldflp);
2164 int err = 0;
2165
2166 if (LOOPBACK(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
2167 return -EINVAL;
2168
2169 if (fl->fl4_dst == htonl(0xFFFFFFFF))
2170 res->type = RTN_BROADCAST;
2171 else if (MULTICAST(fl->fl4_dst))
2172 res->type = RTN_MULTICAST;
2173 else if (BADCLASS(fl->fl4_dst) || ZERONET(fl->fl4_dst))
2174 return -EINVAL;
2175
2176 if (dev_out->flags & IFF_LOOPBACK)
2177 flags |= RTCF_LOCAL;
2178
2179 /* get work reference to inet device */
2180 in_dev = in_dev_get(dev_out);
2181 if (!in_dev)
2182 return -EINVAL;
2183
2184 if (res->type == RTN_BROADCAST) {
2185 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2186 if (res->fi) {
2187 fib_info_put(res->fi);
2188 res->fi = NULL;
2189 }
2190 } else if (res->type == RTN_MULTICAST) {
2191 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2192 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2193 oldflp->proto))
2194 flags &= ~RTCF_LOCAL;
2195 /* If multicast route do not exist use
2196 default one, but do not gateway in this case.
2197 Yes, it is hack.
2198 */
2199 if (res->fi && res->prefixlen < 4) {
2200 fib_info_put(res->fi);
2201 res->fi = NULL;
2202 }
2203 }
2204
2205
2206 rth = dst_alloc(&ipv4_dst_ops);
2207 if (!rth) {
2208 err = -ENOBUFS;
2209 goto cleanup;
2210 }
2211
2212 atomic_set(&rth->u.dst.__refcnt, 1);
2213 rth->u.dst.flags= DST_HOST;
2214 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2215 if (res->fi) {
2216 rth->rt_multipath_alg = res->fi->fib_mp_alg;
2217 if (res->fi->fib_nhs > 1)
2218 rth->u.dst.flags |= DST_BALANCED;
2219 }
2220 #endif
2221 if (in_dev->cnf.no_xfrm)
2222 rth->u.dst.flags |= DST_NOXFRM;
2223 if (in_dev->cnf.no_policy)
2224 rth->u.dst.flags |= DST_NOPOLICY;
2225
2226 rth->fl.fl4_dst = oldflp->fl4_dst;
2227 rth->fl.fl4_tos = tos;
2228 rth->fl.fl4_src = oldflp->fl4_src;
2229 rth->fl.oif = oldflp->oif;
2230 rth->fl.mark = oldflp->mark;
2231 rth->rt_dst = fl->fl4_dst;
2232 rth->rt_src = fl->fl4_src;
2233 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2234 /* get references to the devices that are to be hold by the routing
2235 cache entry */
2236 rth->u.dst.dev = dev_out;
2237 dev_hold(dev_out);
2238 rth->idev = in_dev_get(dev_out);
2239 rth->rt_gateway = fl->fl4_dst;
2240 rth->rt_spec_dst= fl->fl4_src;
2241
2242 rth->u.dst.output=ip_output;
2243
2244 RT_CACHE_STAT_INC(out_slow_tot);
2245
2246 if (flags & RTCF_LOCAL) {
2247 rth->u.dst.input = ip_local_deliver;
2248 rth->rt_spec_dst = fl->fl4_dst;
2249 }
2250 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2251 rth->rt_spec_dst = fl->fl4_src;
2252 if (flags & RTCF_LOCAL &&
2253 !(dev_out->flags & IFF_LOOPBACK)) {
2254 rth->u.dst.output = ip_mc_output;
2255 RT_CACHE_STAT_INC(out_slow_mc);
2256 }
2257 #ifdef CONFIG_IP_MROUTE
2258 if (res->type == RTN_MULTICAST) {
2259 if (IN_DEV_MFORWARD(in_dev) &&
2260 !LOCAL_MCAST(oldflp->fl4_dst)) {
2261 rth->u.dst.input = ip_mr_input;
2262 rth->u.dst.output = ip_mc_output;
2263 }
2264 }
2265 #endif
2266 }
2267
2268 rt_set_nexthop(rth, res, 0);
2269
2270 rth->rt_flags = flags;
2271
2272 *result = rth;
2273 cleanup:
2274 /* release work reference to inet device */
2275 in_dev_put(in_dev);
2276
2277 return err;
2278 }
2279
2280 static inline int ip_mkroute_output_def(struct rtable **rp,
2281 struct fib_result* res,
2282 const struct flowi *fl,
2283 const struct flowi *oldflp,
2284 struct net_device *dev_out,
2285 unsigned flags)
2286 {
2287 struct rtable *rth = NULL;
2288 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2289 unsigned hash;
2290 if (err == 0) {
2291 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
2292 err = rt_intern_hash(hash, rth, rp);
2293 }
2294
2295 return err;
2296 }
2297
2298 static inline int ip_mkroute_output(struct rtable** rp,
2299 struct fib_result* res,
2300 const struct flowi *fl,
2301 const struct flowi *oldflp,
2302 struct net_device *dev_out,
2303 unsigned flags)
2304 {
2305 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2306 unsigned char hop;
2307 unsigned hash;
2308 int err = -EINVAL;
2309 struct rtable *rth = NULL;
2310
2311 if (res->fi && res->fi->fib_nhs > 1) {
2312 unsigned char hopcount = res->fi->fib_nhs;
2313
2314 for (hop = 0; hop < hopcount; hop++) {
2315 struct net_device *dev2nexthop;
2316
2317 res->nh_sel = hop;
2318
2319 /* hold a work reference to the output device */
2320 dev2nexthop = FIB_RES_DEV(*res);
2321 dev_hold(dev2nexthop);
2322
2323 /* put reference to previous result */
2324 if (hop)
2325 ip_rt_put(*rp);
2326
2327 err = __mkroute_output(&rth, res, fl, oldflp,
2328 dev2nexthop, flags);
2329
2330 if (err != 0)
2331 goto cleanup;
2332
2333 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src,
2334 oldflp->oif);
2335 err = rt_intern_hash(hash, rth, rp);
2336
2337 /* forward hop information to multipath impl. */
2338 multipath_set_nhinfo(rth,
2339 FIB_RES_NETWORK(*res),
2340 FIB_RES_NETMASK(*res),
2341 res->prefixlen,
2342 &FIB_RES_NH(*res));
2343 cleanup:
2344 /* release work reference to output device */
2345 dev_put(dev2nexthop);
2346
2347 if (err != 0)
2348 return err;
2349 }
2350 return err;
2351 } else {
2352 return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out,
2353 flags);
2354 }
2355 #else /* CONFIG_IP_ROUTE_MULTIPATH_CACHED */
2356 return ip_mkroute_output_def(rp, res, fl, oldflp, dev_out, flags);
2357 #endif
2358 }
2359
2360 /*
2361 * Major route resolver routine.
2362 */
2363
2364 static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
2365 {
2366 u32 tos = RT_FL_TOS(oldflp);
2367 struct flowi fl = { .nl_u = { .ip4_u =
2368 { .daddr = oldflp->fl4_dst,
2369 .saddr = oldflp->fl4_src,
2370 .tos = tos & IPTOS_RT_MASK,
2371 .scope = ((tos & RTO_ONLINK) ?
2372 RT_SCOPE_LINK :
2373 RT_SCOPE_UNIVERSE),
2374 } },
2375 .mark = oldflp->mark,
2376 .iif = loopback_dev.ifindex,
2377 .oif = oldflp->oif };
2378 struct fib_result res;
2379 unsigned flags = 0;
2380 struct net_device *dev_out = NULL;
2381 int free_res = 0;
2382 int err;
2383
2384
2385 res.fi = NULL;
2386 #ifdef CONFIG_IP_MULTIPLE_TABLES
2387 res.r = NULL;
2388 #endif
2389
2390 if (oldflp->fl4_src) {
2391 err = -EINVAL;
2392 if (MULTICAST(oldflp->fl4_src) ||
2393 BADCLASS(oldflp->fl4_src) ||
2394 ZERONET(oldflp->fl4_src))
2395 goto out;
2396
2397 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2398 dev_out = ip_dev_find(oldflp->fl4_src);
2399 if (dev_out == NULL)
2400 goto out;
2401
2402 /* I removed check for oif == dev_out->oif here.
2403 It was wrong for two reasons:
2404 1. ip_dev_find(saddr) can return wrong iface, if saddr is
2405 assigned to multiple interfaces.
2406 2. Moreover, we are allowed to send packets with saddr
2407 of another iface. --ANK
2408 */
2409
2410 if (oldflp->oif == 0
2411 && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2412 /* Special hack: user can direct multicasts
2413 and limited broadcast via necessary interface
2414 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2415 This hack is not just for fun, it allows
2416 vic,vat and friends to work.
2417 They bind socket to loopback, set ttl to zero
2418 and expect that it will work.
2419 From the viewpoint of routing cache they are broken,
2420 because we are not allowed to build multicast path
2421 with loopback source addr (look, routing cache
2422 cannot know, that ttl is zero, so that packet
2423 will not leave this host and route is valid).
2424 Luckily, this hack is good workaround.
2425 */
2426
2427 fl.oif = dev_out->ifindex;
2428 goto make_route;
2429 }
2430 if (dev_out)
2431 dev_put(dev_out);
2432 dev_out = NULL;
2433 }
2434
2435
2436 if (oldflp->oif) {
2437 dev_out = dev_get_by_index(oldflp->oif);
2438 err = -ENODEV;
2439 if (dev_out == NULL)
2440 goto out;
2441
2442 /* RACE: Check return value of inet_select_addr instead. */
2443 if (__in_dev_get_rtnl(dev_out) == NULL) {
2444 dev_put(dev_out);
2445 goto out; /* Wrong error code */
2446 }
2447
2448 if (LOCAL_MCAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2449 if (!fl.fl4_src)
2450 fl.fl4_src = inet_select_addr(dev_out, 0,
2451 RT_SCOPE_LINK);
2452 goto make_route;
2453 }
2454 if (!fl.fl4_src) {
2455 if (MULTICAST(oldflp->fl4_dst))
2456 fl.fl4_src = inet_select_addr(dev_out, 0,
2457 fl.fl4_scope);
2458 else if (!oldflp->fl4_dst)
2459 fl.fl4_src = inet_select_addr(dev_out, 0,
2460 RT_SCOPE_HOST);
2461 }
2462 }
2463
2464 if (!fl.fl4_dst) {
2465 fl.fl4_dst = fl.fl4_src;
2466 if (!fl.fl4_dst)
2467 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2468 if (dev_out)
2469 dev_put(dev_out);
2470 dev_out = &loopback_dev;
2471 dev_hold(dev_out);
2472 fl.oif = loopback_dev.ifindex;
2473 res.type = RTN_LOCAL;
2474 flags |= RTCF_LOCAL;
2475 goto make_route;
2476 }
2477
2478 if (fib_lookup(&fl, &res)) {
2479 res.fi = NULL;
2480 if (oldflp->oif) {
2481 /* Apparently, routing tables are wrong. Assume,
2482 that the destination is on link.
2483
2484 WHY? DW.
2485 Because we are allowed to send to iface
2486 even if it has NO routes and NO assigned
2487 addresses. When oif is specified, routing
2488 tables are looked up with only one purpose:
2489 to catch if destination is gatewayed, rather than
2490 direct. Moreover, if MSG_DONTROUTE is set,
2491 we send packet, ignoring both routing tables
2492 and ifaddr state. --ANK
2493
2494
2495 We could make it even if oif is unknown,
2496 likely IPv6, but we do not.
2497 */
2498
2499 if (fl.fl4_src == 0)
2500 fl.fl4_src = inet_select_addr(dev_out, 0,
2501 RT_SCOPE_LINK);
2502 res.type = RTN_UNICAST;
2503 goto make_route;
2504 }
2505 if (dev_out)
2506 dev_put(dev_out);
2507 err = -ENETUNREACH;
2508 goto out;
2509 }
2510 free_res = 1;
2511
2512 if (res.type == RTN_LOCAL) {
2513 if (!fl.fl4_src)
2514 fl.fl4_src = fl.fl4_dst;
2515 if (dev_out)
2516 dev_put(dev_out);
2517 dev_out = &loopback_dev;
2518 dev_hold(dev_out);
2519 fl.oif = dev_out->ifindex;
2520 if (res.fi)
2521 fib_info_put(res.fi);
2522 res.fi = NULL;
2523 flags |= RTCF_LOCAL;
2524 goto make_route;
2525 }
2526
2527 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2528 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2529 fib_select_multipath(&fl, &res);
2530 else
2531 #endif
2532 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2533 fib_select_default(&fl, &res);
2534
2535 if (!fl.fl4_src)
2536 fl.fl4_src = FIB_RES_PREFSRC(res);
2537
2538 if (dev_out)
2539 dev_put(dev_out);
2540 dev_out = FIB_RES_DEV(res);
2541 dev_hold(dev_out);
2542 fl.oif = dev_out->ifindex;
2543
2544
2545 make_route:
2546 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2547
2548
2549 if (free_res)
2550 fib_res_put(&res);
2551 if (dev_out)
2552 dev_put(dev_out);
2553 out: return err;
2554 }
2555
2556 int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
2557 {
2558 unsigned hash;
2559 struct rtable *rth;
2560
2561 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
2562
2563 rcu_read_lock_bh();
2564 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2565 rth = rcu_dereference(rth->u.dst.rt_next)) {
2566 if (rth->fl.fl4_dst == flp->fl4_dst &&
2567 rth->fl.fl4_src == flp->fl4_src &&
2568 rth->fl.iif == 0 &&
2569 rth->fl.oif == flp->oif &&
2570 rth->fl.mark == flp->mark &&
2571 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2572 (IPTOS_RT_MASK | RTO_ONLINK))) {
2573
2574 /* check for multipath routes and choose one if
2575 * necessary
2576 */
2577 if (multipath_select_route(flp, rth, rp)) {
2578 dst_hold(&(*rp)->u.dst);
2579 RT_CACHE_STAT_INC(out_hit);
2580 rcu_read_unlock_bh();
2581 return 0;
2582 }
2583
2584 rth->u.dst.lastuse = jiffies;
2585 dst_hold(&rth->u.dst);
2586 rth->u.dst.__use++;
2587 RT_CACHE_STAT_INC(out_hit);
2588 rcu_read_unlock_bh();
2589 *rp = rth;
2590 return 0;
2591 }
2592 RT_CACHE_STAT_INC(out_hlist_search);
2593 }
2594 rcu_read_unlock_bh();
2595
2596 return ip_route_output_slow(rp, flp);
2597 }
2598
2599 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2600
2601 int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
2602 {
2603 int err;
2604
2605 if ((err = __ip_route_output_key(rp, flp)) != 0)
2606 return err;
2607
2608 if (flp->proto) {
2609 if (!flp->fl4_src)
2610 flp->fl4_src = (*rp)->rt_src;
2611 if (!flp->fl4_dst)
2612 flp->fl4_dst = (*rp)->rt_dst;
2613 return xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
2614 }
2615
2616 return 0;
2617 }
2618
2619 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2620
2621 int ip_route_output_key(struct rtable **rp, struct flowi *flp)
2622 {
2623 return ip_route_output_flow(rp, flp, NULL, 0);
2624 }
2625
2626 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2627 int nowait, unsigned int flags)
2628 {
2629 struct rtable *rt = (struct rtable*)skb->dst;
2630 struct rtmsg *r;
2631 struct nlmsghdr *nlh;
2632 long expires;
2633 u32 id = 0, ts = 0, tsage = 0, error;
2634
2635 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2636 if (nlh == NULL)
2637 return -EMSGSIZE;
2638
2639 r = nlmsg_data(nlh);
2640 r->rtm_family = AF_INET;
2641 r->rtm_dst_len = 32;
2642 r->rtm_src_len = 0;
2643 r->rtm_tos = rt->fl.fl4_tos;
2644 r->rtm_table = RT_TABLE_MAIN;
2645 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2646 r->rtm_type = rt->rt_type;
2647 r->rtm_scope = RT_SCOPE_UNIVERSE;
2648 r->rtm_protocol = RTPROT_UNSPEC;
2649 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2650 if (rt->rt_flags & RTCF_NOTIFY)
2651 r->rtm_flags |= RTM_F_NOTIFY;
2652
2653 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2654
2655 if (rt->fl.fl4_src) {
2656 r->rtm_src_len = 32;
2657 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2658 }
2659 if (rt->u.dst.dev)
2660 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2661 #ifdef CONFIG_NET_CLS_ROUTE
2662 if (rt->u.dst.tclassid)
2663 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2664 #endif
2665 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
2666 if (rt->rt_multipath_alg != IP_MP_ALG_NONE)
2667 NLA_PUT_U32(skb, RTA_MP_ALGO, rt->rt_multipath_alg);
2668 #endif
2669 if (rt->fl.iif)
2670 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2671 else if (rt->rt_src != rt->fl.fl4_src)
2672 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2673
2674 if (rt->rt_dst != rt->rt_gateway)
2675 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2676
2677 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2678 goto nla_put_failure;
2679
2680 error = rt->u.dst.error;
2681 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2682 if (rt->peer) {
2683 id = rt->peer->ip_id_count;
2684 if (rt->peer->tcp_ts_stamp) {
2685 ts = rt->peer->tcp_ts;
2686 tsage = xtime.tv_sec - rt->peer->tcp_ts_stamp;
2687 }
2688 }
2689
2690 if (rt->fl.iif) {
2691 #ifdef CONFIG_IP_MROUTE
2692 __be32 dst = rt->rt_dst;
2693
2694 if (MULTICAST(dst) && !LOCAL_MCAST(dst) &&
2695 ipv4_devconf.mc_forwarding) {
2696 int err = ipmr_get_route(skb, r, nowait);
2697 if (err <= 0) {
2698 if (!nowait) {
2699 if (err == 0)
2700 return 0;
2701 goto nla_put_failure;
2702 } else {
2703 if (err == -EMSGSIZE)
2704 goto nla_put_failure;
2705 error = err;
2706 }
2707 }
2708 } else
2709 #endif
2710 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2711 }
2712
2713 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2714 expires, error) < 0)
2715 goto nla_put_failure;
2716
2717 return nlmsg_end(skb, nlh);
2718
2719 nla_put_failure:
2720 nlmsg_cancel(skb, nlh);
2721 return -EMSGSIZE;
2722 }
2723
2724 int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2725 {
2726 struct rtmsg *rtm;
2727 struct nlattr *tb[RTA_MAX+1];
2728 struct rtable *rt = NULL;
2729 __be32 dst = 0;
2730 __be32 src = 0;
2731 u32 iif;
2732 int err;
2733 struct sk_buff *skb;
2734
2735 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2736 if (err < 0)
2737 goto errout;
2738
2739 rtm = nlmsg_data(nlh);
2740
2741 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2742 if (skb == NULL) {
2743 err = -ENOBUFS;
2744 goto errout;
2745 }
2746
2747 /* Reserve room for dummy headers, this skb can pass
2748 through good chunk of routing engine.
2749 */
2750 skb->mac.raw = skb->nh.raw = skb->data;
2751
2752 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2753 skb->nh.iph->protocol = IPPROTO_ICMP;
2754 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2755
2756 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2757 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2758 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2759
2760 if (iif) {
2761 struct net_device *dev;
2762
2763 dev = __dev_get_by_index(iif);
2764 if (dev == NULL) {
2765 err = -ENODEV;
2766 goto errout_free;
2767 }
2768
2769 skb->protocol = htons(ETH_P_IP);
2770 skb->dev = dev;
2771 local_bh_disable();
2772 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2773 local_bh_enable();
2774
2775 rt = (struct rtable*) skb->dst;
2776 if (err == 0 && rt->u.dst.error)
2777 err = -rt->u.dst.error;
2778 } else {
2779 struct flowi fl = {
2780 .nl_u = {
2781 .ip4_u = {
2782 .daddr = dst,
2783 .saddr = src,
2784 .tos = rtm->rtm_tos,
2785 },
2786 },
2787 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2788 };
2789 err = ip_route_output_key(&rt, &fl);
2790 }
2791
2792 if (err)
2793 goto errout_free;
2794
2795 skb->dst = &rt->u.dst;
2796 if (rtm->rtm_flags & RTM_F_NOTIFY)
2797 rt->rt_flags |= RTCF_NOTIFY;
2798
2799 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2800 RTM_NEWROUTE, 0, 0);
2801 if (err <= 0)
2802 goto errout_free;
2803
2804 err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
2805 errout:
2806 return err;
2807
2808 errout_free:
2809 kfree_skb(skb);
2810 goto errout;
2811 }
2812
2813 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2814 {
2815 struct rtable *rt;
2816 int h, s_h;
2817 int idx, s_idx;
2818
2819 s_h = cb->args[0];
2820 s_idx = idx = cb->args[1];
2821 for (h = 0; h <= rt_hash_mask; h++) {
2822 if (h < s_h) continue;
2823 if (h > s_h)
2824 s_idx = 0;
2825 rcu_read_lock_bh();
2826 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2827 rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
2828 if (idx < s_idx)
2829 continue;
2830 skb->dst = dst_clone(&rt->u.dst);
2831 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2832 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2833 1, NLM_F_MULTI) <= 0) {
2834 dst_release(xchg(&skb->dst, NULL));
2835 rcu_read_unlock_bh();
2836 goto done;
2837 }
2838 dst_release(xchg(&skb->dst, NULL));
2839 }
2840 rcu_read_unlock_bh();
2841 }
2842
2843 done:
2844 cb->args[0] = h;
2845 cb->args[1] = idx;
2846 return skb->len;
2847 }
2848
2849 void ip_rt_multicast_event(struct in_device *in_dev)
2850 {
2851 rt_cache_flush(0);
2852 }
2853
2854 #ifdef CONFIG_SYSCTL
2855 static int flush_delay;
2856
2857 static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
2858 struct file *filp, void __user *buffer,
2859 size_t *lenp, loff_t *ppos)
2860 {
2861 if (write) {
2862 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2863 rt_cache_flush(flush_delay);
2864 return 0;
2865 }
2866
2867 return -EINVAL;
2868 }
2869
2870 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2871 int __user *name,
2872 int nlen,
2873 void __user *oldval,
2874 size_t __user *oldlenp,
2875 void __user *newval,
2876 size_t newlen)
2877 {
2878 int delay;
2879 if (newlen != sizeof(int))
2880 return -EINVAL;
2881 if (get_user(delay, (int __user *)newval))
2882 return -EFAULT;
2883 rt_cache_flush(delay);
2884 return 0;
2885 }
2886
2887 ctl_table ipv4_route_table[] = {
2888 {
2889 .ctl_name = NET_IPV4_ROUTE_FLUSH,
2890 .procname = "flush",
2891 .data = &flush_delay,
2892 .maxlen = sizeof(int),
2893 .mode = 0200,
2894 .proc_handler = &ipv4_sysctl_rtcache_flush,
2895 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
2896 },
2897 {
2898 .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
2899 .procname = "min_delay",
2900 .data = &ip_rt_min_delay,
2901 .maxlen = sizeof(int),
2902 .mode = 0644,
2903 .proc_handler = &proc_dointvec_jiffies,
2904 .strategy = &sysctl_jiffies,
2905 },
2906 {
2907 .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
2908 .procname = "max_delay",
2909 .data = &ip_rt_max_delay,
2910 .maxlen = sizeof(int),
2911 .mode = 0644,
2912 .proc_handler = &proc_dointvec_jiffies,
2913 .strategy = &sysctl_jiffies,
2914 },
2915 {
2916 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2917 .procname = "gc_thresh",
2918 .data = &ipv4_dst_ops.gc_thresh,
2919 .maxlen = sizeof(int),
2920 .mode = 0644,
2921 .proc_handler = &proc_dointvec,
2922 },
2923 {
2924 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
2925 .procname = "max_size",
2926 .data = &ip_rt_max_size,
2927 .maxlen = sizeof(int),
2928 .mode = 0644,
2929 .proc_handler = &proc_dointvec,
2930 },
2931 {
2932 /* Deprecated. Use gc_min_interval_ms */
2933
2934 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
2935 .procname = "gc_min_interval",
2936 .data = &ip_rt_gc_min_interval,
2937 .maxlen = sizeof(int),
2938 .mode = 0644,
2939 .proc_handler = &proc_dointvec_jiffies,
2940 .strategy = &sysctl_jiffies,
2941 },
2942 {
2943 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
2944 .procname = "gc_min_interval_ms",
2945 .data = &ip_rt_gc_min_interval,
2946 .maxlen = sizeof(int),
2947 .mode = 0644,
2948 .proc_handler = &proc_dointvec_ms_jiffies,
2949 .strategy = &sysctl_ms_jiffies,
2950 },
2951 {
2952 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
2953 .procname = "gc_timeout",
2954 .data = &ip_rt_gc_timeout,
2955 .maxlen = sizeof(int),
2956 .mode = 0644,
2957 .proc_handler = &proc_dointvec_jiffies,
2958 .strategy = &sysctl_jiffies,
2959 },
2960 {
2961 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
2962 .procname = "gc_interval",
2963 .data = &ip_rt_gc_interval,
2964 .maxlen = sizeof(int),
2965 .mode = 0644,
2966 .proc_handler = &proc_dointvec_jiffies,
2967 .strategy = &sysctl_jiffies,
2968 },
2969 {
2970 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
2971 .procname = "redirect_load",
2972 .data = &ip_rt_redirect_load,
2973 .maxlen = sizeof(int),
2974 .mode = 0644,
2975 .proc_handler = &proc_dointvec,
2976 },
2977 {
2978 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
2979 .procname = "redirect_number",
2980 .data = &ip_rt_redirect_number,
2981 .maxlen = sizeof(int),
2982 .mode = 0644,
2983 .proc_handler = &proc_dointvec,
2984 },
2985 {
2986 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
2987 .procname = "redirect_silence",
2988 .data = &ip_rt_redirect_silence,
2989 .maxlen = sizeof(int),
2990 .mode = 0644,
2991 .proc_handler = &proc_dointvec,
2992 },
2993 {
2994 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
2995 .procname = "error_cost",
2996 .data = &ip_rt_error_cost,
2997 .maxlen = sizeof(int),
2998 .mode = 0644,
2999 .proc_handler = &proc_dointvec,
3000 },
3001 {
3002 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
3003 .procname = "error_burst",
3004 .data = &ip_rt_error_burst,
3005 .maxlen = sizeof(int),
3006 .mode = 0644,
3007 .proc_handler = &proc_dointvec,
3008 },
3009 {
3010 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
3011 .procname = "gc_elasticity",
3012 .data = &ip_rt_gc_elasticity,
3013 .maxlen = sizeof(int),
3014 .mode = 0644,
3015 .proc_handler = &proc_dointvec,
3016 },
3017 {
3018 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
3019 .procname = "mtu_expires",
3020 .data = &ip_rt_mtu_expires,
3021 .maxlen = sizeof(int),
3022 .mode = 0644,
3023 .proc_handler = &proc_dointvec_jiffies,
3024 .strategy = &sysctl_jiffies,
3025 },
3026 {
3027 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
3028 .procname = "min_pmtu",
3029 .data = &ip_rt_min_pmtu,
3030 .maxlen = sizeof(int),
3031 .mode = 0644,
3032 .proc_handler = &proc_dointvec,
3033 },
3034 {
3035 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
3036 .procname = "min_adv_mss",
3037 .data = &ip_rt_min_advmss,
3038 .maxlen = sizeof(int),
3039 .mode = 0644,
3040 .proc_handler = &proc_dointvec,
3041 },
3042 {
3043 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
3044 .procname = "secret_interval",
3045 .data = &ip_rt_secret_interval,
3046 .maxlen = sizeof(int),
3047 .mode = 0644,
3048 .proc_handler = &proc_dointvec_jiffies,
3049 .strategy = &sysctl_jiffies,
3050 },
3051 { .ctl_name = 0 }
3052 };
3053 #endif
3054
3055 #ifdef CONFIG_NET_CLS_ROUTE
3056 struct ip_rt_acct *ip_rt_acct;
3057
3058 /* This code sucks. But you should have seen it before! --RR */
3059
3060 /* IP route accounting ptr for this logical cpu number. */
3061 #define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
3062
3063 #ifdef CONFIG_PROC_FS
3064 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
3065 int length, int *eof, void *data)
3066 {
3067 unsigned int i;
3068
3069 if ((offset & 3) || (length & 3))
3070 return -EIO;
3071
3072 if (offset >= sizeof(struct ip_rt_acct) * 256) {
3073 *eof = 1;
3074 return 0;
3075 }
3076
3077 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
3078 length = sizeof(struct ip_rt_acct) * 256 - offset;
3079 *eof = 1;
3080 }
3081
3082 offset /= sizeof(u32);
3083
3084 if (length > 0) {
3085 u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
3086 u32 *dst = (u32 *) buffer;
3087
3088 /* Copy first cpu. */
3089 *start = buffer;
3090 memcpy(dst, src, length);
3091
3092 /* Add the other cpus in, one int at a time */
3093 for_each_possible_cpu(i) {
3094 unsigned int j;
3095
3096 src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
3097
3098 for (j = 0; j < length/4; j++)
3099 dst[j] += src[j];
3100 }
3101 }
3102 return length;
3103 }
3104 #endif /* CONFIG_PROC_FS */
3105 #endif /* CONFIG_NET_CLS_ROUTE */
3106
3107 static __initdata unsigned long rhash_entries;
3108 static int __init set_rhash_entries(char *str)
3109 {
3110 if (!str)
3111 return 0;
3112 rhash_entries = simple_strtoul(str, &str, 0);
3113 return 1;
3114 }
3115 __setup("rhash_entries=", set_rhash_entries);
3116
3117 int __init ip_rt_init(void)
3118 {
3119 int rc = 0;
3120
3121 rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
3122 (jiffies ^ (jiffies >> 7)));
3123
3124 #ifdef CONFIG_NET_CLS_ROUTE
3125 {
3126 int order;
3127 for (order = 0;
3128 (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
3129 /* NOTHING */;
3130 ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
3131 if (!ip_rt_acct)
3132 panic("IP: failed to allocate ip_rt_acct\n");
3133 memset(ip_rt_acct, 0, PAGE_SIZE << order);
3134 }
3135 #endif
3136
3137 ipv4_dst_ops.kmem_cachep =
3138 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3139 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
3140
3141 rt_hash_table = (struct rt_hash_bucket *)
3142 alloc_large_system_hash("IP route cache",
3143 sizeof(struct rt_hash_bucket),
3144 rhash_entries,
3145 (num_physpages >= 128 * 1024) ?
3146 15 : 17,
3147 0,
3148 &rt_hash_log,
3149 &rt_hash_mask,
3150 0);
3151 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3152 rt_hash_lock_init();
3153
3154 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3155 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3156
3157 devinet_init();
3158 ip_fib_init();
3159
3160 init_timer(&rt_flush_timer);
3161 rt_flush_timer.function = rt_run_flush;
3162 init_timer(&rt_periodic_timer);
3163 rt_periodic_timer.function = rt_check_expire;
3164 init_timer(&rt_secret_timer);
3165 rt_secret_timer.function = rt_secret_rebuild;
3166
3167 /* All the timers, started at system startup tend
3168 to synchronize. Perturb it a bit.
3169 */
3170 rt_periodic_timer.expires = jiffies + net_random() % ip_rt_gc_interval +
3171 ip_rt_gc_interval;
3172 add_timer(&rt_periodic_timer);
3173
3174 rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
3175 ip_rt_secret_interval;
3176 add_timer(&rt_secret_timer);
3177
3178 #ifdef CONFIG_PROC_FS
3179 {
3180 struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
3181 if (!proc_net_fops_create("rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
3182 !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
3183 proc_net_stat))) {
3184 return -ENOMEM;
3185 }
3186 rtstat_pde->proc_fops = &rt_cpu_seq_fops;
3187 }
3188 #ifdef CONFIG_NET_CLS_ROUTE
3189 create_proc_read_entry("rt_acct", 0, proc_net, ip_rt_acct_read, NULL);
3190 #endif
3191 #endif
3192 #ifdef CONFIG_XFRM
3193 xfrm_init();
3194 xfrm4_init();
3195 #endif
3196 return rc;
3197 }
3198
3199 EXPORT_SYMBOL(__ip_select_ident);
3200 EXPORT_SYMBOL(ip_route_input);
3201 EXPORT_SYMBOL(ip_route_output_key);
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