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[IPV4]: Remove bugus goto-s from ip_route_input_slow
[linux-2.6/x86.git] / net / ipv4 / route.c
blobc95b270ba3501698fa635ce6d8f5821fd5af5c0d
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/workqueue.h>
85 #include <linux/skbuff.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/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/netevent.h>
107 #include <net/rtnetlink.h>
108 #ifdef CONFIG_SYSCTL
109 #include <linux/sysctl.h>
110 #endif
111
112 #define RT_FL_TOS(oldflp) \
113 ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_min_delay = 2 * HZ;
120 static int ip_rt_max_delay = 10 * HZ;
121 static int ip_rt_max_size;
122 static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
123 static int ip_rt_gc_interval = 60 * HZ;
124 static int ip_rt_gc_min_interval = HZ / 2;
125 static int ip_rt_redirect_number = 9;
126 static int ip_rt_redirect_load = HZ / 50;
127 static int ip_rt_redirect_silence = ((HZ / 50) << (9 + 1));
128 static int ip_rt_error_cost = HZ;
129 static int ip_rt_error_burst = 5 * HZ;
130 static int ip_rt_gc_elasticity = 8;
131 static int ip_rt_mtu_expires = 10 * 60 * HZ;
132 static int ip_rt_min_pmtu = 512 + 20 + 20;
133 static int ip_rt_min_advmss = 256;
134 static int ip_rt_secret_interval = 10 * 60 * HZ;
135 static unsigned long rt_deadline;
136
137 #define RTprint(a...) printk(KERN_DEBUG a)
138
139 static struct timer_list rt_flush_timer;
140 static void rt_check_expire(struct work_struct *work);
141 static DECLARE_DELAYED_WORK(expires_work, rt_check_expire);
142 static struct timer_list rt_secret_timer;
143
144 /*
145 * Interface to generic destination cache.
146 */
147
148 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
149 static void ipv4_dst_destroy(struct dst_entry *dst);
150 static void ipv4_dst_ifdown(struct dst_entry *dst,
151 struct net_device *dev, int how);
152 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
153 static void ipv4_link_failure(struct sk_buff *skb);
154 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
155 static int rt_garbage_collect(void);
156
157
158 static struct dst_ops ipv4_dst_ops = {
159 .family = AF_INET,
160 .protocol = __constant_htons(ETH_P_IP),
161 .gc = rt_garbage_collect,
162 .check = ipv4_dst_check,
163 .destroy = ipv4_dst_destroy,
164 .ifdown = ipv4_dst_ifdown,
165 .negative_advice = ipv4_negative_advice,
166 .link_failure = ipv4_link_failure,
167 .update_pmtu = ip_rt_update_pmtu,
168 .entry_size = sizeof(struct rtable),
169 };
170
171 #define ECN_OR_COST(class) TC_PRIO_##class
172
173 const __u8 ip_tos2prio[16] = {
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(FILLER),
176 TC_PRIO_BESTEFFORT,
177 ECN_OR_COST(BESTEFFORT),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_BULK,
181 ECN_OR_COST(BULK),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE,
185 ECN_OR_COST(INTERACTIVE),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK),
188 TC_PRIO_INTERACTIVE_BULK,
189 ECN_OR_COST(INTERACTIVE_BULK)
190 };
191
192
193 /*
194 * Route cache.
195 */
196
197 /* The locking scheme is rather straight forward:
198 *
199 * 1) Read-Copy Update protects the buckets of the central route hash.
200 * 2) Only writers remove entries, and they hold the lock
201 * as they look at rtable reference counts.
202 * 3) Only readers acquire references to rtable entries,
203 * they do so with atomic increments and with the
204 * lock held.
205 */
206
207 struct rt_hash_bucket {
208 struct rtable *chain;
209 };
210 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
211 defined(CONFIG_PROVE_LOCKING)
212 /*
213 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
214 * The size of this table is a power of two and depends on the number of CPUS.
215 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
216 */
217 #ifdef CONFIG_LOCKDEP
218 # define RT_HASH_LOCK_SZ 256
219 #else
220 # if NR_CPUS >= 32
221 # define RT_HASH_LOCK_SZ 4096
222 # elif NR_CPUS >= 16
223 # define RT_HASH_LOCK_SZ 2048
224 # elif NR_CPUS >= 8
225 # define RT_HASH_LOCK_SZ 1024
226 # elif NR_CPUS >= 4
227 # define RT_HASH_LOCK_SZ 512
228 # else
229 # define RT_HASH_LOCK_SZ 256
230 # endif
231 #endif
232
233 static spinlock_t *rt_hash_locks;
234 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
235 # define rt_hash_lock_init() { \
236 int i; \
237 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ, GFP_KERNEL); \
238 if (!rt_hash_locks) panic("IP: failed to allocate rt_hash_locks\n"); \
239 for (i = 0; i < RT_HASH_LOCK_SZ; i++) \
240 spin_lock_init(&rt_hash_locks[i]); \
241 }
242 #else
243 # define rt_hash_lock_addr(slot) NULL
244 # define rt_hash_lock_init()
245 #endif
246
247 static struct rt_hash_bucket *rt_hash_table;
248 static unsigned rt_hash_mask;
249 static unsigned int rt_hash_log;
250 static unsigned int rt_hash_rnd;
251
252 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
253 #define RT_CACHE_STAT_INC(field) \
254 (__raw_get_cpu_var(rt_cache_stat).field++)
255
256 static int rt_intern_hash(unsigned hash, struct rtable *rth,
257 struct rtable **res);
258
259 static unsigned int rt_hash_code(u32 daddr, u32 saddr)
260 {
261 return (jhash_2words(daddr, saddr, rt_hash_rnd)
262 & rt_hash_mask);
263 }
264
265 #define rt_hash(daddr, saddr, idx) \
266 rt_hash_code((__force u32)(__be32)(daddr),\
267 (__force u32)(__be32)(saddr) ^ ((idx) << 5))
268
269 #ifdef CONFIG_PROC_FS
270 struct rt_cache_iter_state {
271 int bucket;
272 };
273
274 static struct rtable *rt_cache_get_first(struct seq_file *seq)
275 {
276 struct rtable *r = NULL;
277 struct rt_cache_iter_state *st = seq->private;
278
279 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
280 rcu_read_lock_bh();
281 r = rt_hash_table[st->bucket].chain;
282 if (r)
283 break;
284 rcu_read_unlock_bh();
285 }
286 return r;
287 }
288
289 static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
290 {
291 struct rt_cache_iter_state *st = rcu_dereference(seq->private);
292
293 r = r->u.dst.rt_next;
294 while (!r) {
295 rcu_read_unlock_bh();
296 if (--st->bucket < 0)
297 break;
298 rcu_read_lock_bh();
299 r = rt_hash_table[st->bucket].chain;
300 }
301 return r;
302 }
303
304 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
305 {
306 struct rtable *r = rt_cache_get_first(seq);
307
308 if (r)
309 while (pos && (r = rt_cache_get_next(seq, r)))
310 --pos;
311 return pos ? NULL : r;
312 }
313
314 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
315 {
316 return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
317 }
318
319 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
320 {
321 struct rtable *r = NULL;
322
323 if (v == SEQ_START_TOKEN)
324 r = rt_cache_get_first(seq);
325 else
326 r = rt_cache_get_next(seq, v);
327 ++*pos;
328 return r;
329 }
330
331 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
332 {
333 if (v && v != SEQ_START_TOKEN)
334 rcu_read_unlock_bh();
335 }
336
337 static int rt_cache_seq_show(struct seq_file *seq, void *v)
338 {
339 if (v == SEQ_START_TOKEN)
340 seq_printf(seq, "%-127s\n",
341 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
342 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
343 "HHUptod\tSpecDst");
344 else {
345 struct rtable *r = v;
346 char temp[256];
347
348 sprintf(temp, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
349 "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X",
350 r->u.dst.dev ? r->u.dst.dev->name : "*",
351 (unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
352 r->rt_flags, atomic_read(&r->u.dst.__refcnt),
353 r->u.dst.__use, 0, (unsigned long)r->rt_src,
354 (dst_metric(&r->u.dst, RTAX_ADVMSS) ?
355 (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
356 dst_metric(&r->u.dst, RTAX_WINDOW),
357 (int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
358 dst_metric(&r->u.dst, RTAX_RTTVAR)),
359 r->fl.fl4_tos,
360 r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
361 r->u.dst.hh ? (r->u.dst.hh->hh_output ==
362 dev_queue_xmit) : 0,
363 r->rt_spec_dst);
364 seq_printf(seq, "%-127s\n", temp);
365 }
366 return 0;
367 }
368
369 static const struct seq_operations rt_cache_seq_ops = {
370 .start = rt_cache_seq_start,
371 .next = rt_cache_seq_next,
372 .stop = rt_cache_seq_stop,
373 .show = rt_cache_seq_show,
374 };
375
376 static int rt_cache_seq_open(struct inode *inode, struct file *file)
377 {
378 return seq_open_private(file, &rt_cache_seq_ops,
379 sizeof(struct rt_cache_iter_state));
380 }
381
382 static const struct file_operations rt_cache_seq_fops = {
383 .owner = THIS_MODULE,
384 .open = rt_cache_seq_open,
385 .read = seq_read,
386 .llseek = seq_lseek,
387 .release = seq_release_private,
388 };
389
390
391 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
392 {
393 int cpu;
394
395 if (*pos == 0)
396 return SEQ_START_TOKEN;
397
398 for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
399 if (!cpu_possible(cpu))
400 continue;
401 *pos = cpu+1;
402 return &per_cpu(rt_cache_stat, cpu);
403 }
404 return NULL;
405 }
406
407 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
408 {
409 int cpu;
410
411 for (cpu = *pos; 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
421 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
422 {
423
424 }
425
426 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
427 {
428 struct rt_cache_stat *st = v;
429
430 if (v == SEQ_START_TOKEN) {
431 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");
432 return 0;
433 }
434
435 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
436 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
437 atomic_read(&ipv4_dst_ops.entries),
438 st->in_hit,
439 st->in_slow_tot,
440 st->in_slow_mc,
441 st->in_no_route,
442 st->in_brd,
443 st->in_martian_dst,
444 st->in_martian_src,
445
446 st->out_hit,
447 st->out_slow_tot,
448 st->out_slow_mc,
449
450 st->gc_total,
451 st->gc_ignored,
452 st->gc_goal_miss,
453 st->gc_dst_overflow,
454 st->in_hlist_search,
455 st->out_hlist_search
456 );
457 return 0;
458 }
459
460 static const struct seq_operations rt_cpu_seq_ops = {
461 .start = rt_cpu_seq_start,
462 .next = rt_cpu_seq_next,
463 .stop = rt_cpu_seq_stop,
464 .show = rt_cpu_seq_show,
465 };
466
467
468 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
469 {
470 return seq_open(file, &rt_cpu_seq_ops);
471 }
472
473 static const struct file_operations rt_cpu_seq_fops = {
474 .owner = THIS_MODULE,
475 .open = rt_cpu_seq_open,
476 .read = seq_read,
477 .llseek = seq_lseek,
478 .release = seq_release,
479 };
480
481 #endif /* CONFIG_PROC_FS */
482
483 static __inline__ void rt_free(struct rtable *rt)
484 {
485 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
486 }
487
488 static __inline__ void rt_drop(struct rtable *rt)
489 {
490 ip_rt_put(rt);
491 call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
492 }
493
494 static __inline__ int rt_fast_clean(struct rtable *rth)
495 {
496 /* Kill broadcast/multicast entries very aggresively, if they
497 collide in hash table with more useful entries */
498 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
499 rth->fl.iif && rth->u.dst.rt_next;
500 }
501
502 static __inline__ int rt_valuable(struct rtable *rth)
503 {
504 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
505 rth->u.dst.expires;
506 }
507
508 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
509 {
510 unsigned long age;
511 int ret = 0;
512
513 if (atomic_read(&rth->u.dst.__refcnt))
514 goto out;
515
516 ret = 1;
517 if (rth->u.dst.expires &&
518 time_after_eq(jiffies, rth->u.dst.expires))
519 goto out;
520
521 age = jiffies - rth->u.dst.lastuse;
522 ret = 0;
523 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
524 (age <= tmo2 && rt_valuable(rth)))
525 goto out;
526 ret = 1;
527 out: return ret;
528 }
529
530 /* Bits of score are:
531 * 31: very valuable
532 * 30: not quite useless
533 * 29..0: usage counter
534 */
535 static inline u32 rt_score(struct rtable *rt)
536 {
537 u32 score = jiffies - rt->u.dst.lastuse;
538
539 score = ~score & ~(3<<30);
540
541 if (rt_valuable(rt))
542 score |= (1<<31);
543
544 if (!rt->fl.iif ||
545 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
546 score |= (1<<30);
547
548 return score;
549 }
550
551 static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
552 {
553 return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
554 (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
555 (fl1->mark ^ fl2->mark) |
556 (*(u16 *)&fl1->nl_u.ip4_u.tos ^
557 *(u16 *)&fl2->nl_u.ip4_u.tos) |
558 (fl1->oif ^ fl2->oif) |
559 (fl1->iif ^ fl2->iif)) == 0;
560 }
561
562 static void rt_check_expire(struct work_struct *work)
563 {
564 static unsigned int rover;
565 unsigned int i = rover, goal;
566 struct rtable *rth, **rthp;
567 u64 mult;
568
569 mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
570 if (ip_rt_gc_timeout > 1)
571 do_div(mult, ip_rt_gc_timeout);
572 goal = (unsigned int)mult;
573 if (goal > rt_hash_mask)
574 goal = rt_hash_mask + 1;
575 for (; goal > 0; goal--) {
576 unsigned long tmo = ip_rt_gc_timeout;
577
578 i = (i + 1) & rt_hash_mask;
579 rthp = &rt_hash_table[i].chain;
580
581 if (*rthp == NULL)
582 continue;
583 spin_lock_bh(rt_hash_lock_addr(i));
584 while ((rth = *rthp) != NULL) {
585 if (rth->u.dst.expires) {
586 /* Entry is expired even if it is in use */
587 if (time_before_eq(jiffies, rth->u.dst.expires)) {
588 tmo >>= 1;
589 rthp = &rth->u.dst.rt_next;
590 continue;
591 }
592 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
593 tmo >>= 1;
594 rthp = &rth->u.dst.rt_next;
595 continue;
596 }
597
598 /* Cleanup aged off entries. */
599 *rthp = rth->u.dst.rt_next;
600 rt_free(rth);
601 }
602 spin_unlock_bh(rt_hash_lock_addr(i));
603 }
604 rover = i;
605 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
606 }
607
608 /* This can run from both BH and non-BH contexts, the latter
609 * in the case of a forced flush event.
610 */
611 static void rt_run_flush(unsigned long dummy)
612 {
613 int i;
614 struct rtable *rth, *next;
615
616 rt_deadline = 0;
617
618 get_random_bytes(&rt_hash_rnd, 4);
619
620 for (i = rt_hash_mask; i >= 0; i--) {
621 spin_lock_bh(rt_hash_lock_addr(i));
622 rth = rt_hash_table[i].chain;
623 if (rth)
624 rt_hash_table[i].chain = NULL;
625 spin_unlock_bh(rt_hash_lock_addr(i));
626
627 for (; rth; rth = next) {
628 next = rth->u.dst.rt_next;
629 rt_free(rth);
630 }
631 }
632 }
633
634 static DEFINE_SPINLOCK(rt_flush_lock);
635
636 void rt_cache_flush(int delay)
637 {
638 unsigned long now = jiffies;
639 int user_mode = !in_softirq();
640
641 if (delay < 0)
642 delay = ip_rt_min_delay;
643
644 spin_lock_bh(&rt_flush_lock);
645
646 if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
647 long tmo = (long)(rt_deadline - now);
648
649 /* If flush timer is already running
650 and flush request is not immediate (delay > 0):
651
652 if deadline is not achieved, prolongate timer to "delay",
653 otherwise fire it at deadline time.
654 */
655
656 if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
657 tmo = 0;
658
659 if (delay > tmo)
660 delay = tmo;
661 }
662
663 if (delay <= 0) {
664 spin_unlock_bh(&rt_flush_lock);
665 rt_run_flush(0);
666 return;
667 }
668
669 if (rt_deadline == 0)
670 rt_deadline = now + ip_rt_max_delay;
671
672 mod_timer(&rt_flush_timer, now+delay);
673 spin_unlock_bh(&rt_flush_lock);
674 }
675
676 static void rt_secret_rebuild(unsigned long dummy)
677 {
678 unsigned long now = jiffies;
679
680 rt_cache_flush(0);
681 mod_timer(&rt_secret_timer, now + ip_rt_secret_interval);
682 }
683
684 /*
685 Short description of GC goals.
686
687 We want to build algorithm, which will keep routing cache
688 at some equilibrium point, when number of aged off entries
689 is kept approximately equal to newly generated ones.
690
691 Current expiration strength is variable "expire".
692 We try to adjust it dynamically, so that if networking
693 is idle expires is large enough to keep enough of warm entries,
694 and when load increases it reduces to limit cache size.
695 */
696
697 static int rt_garbage_collect(void)
698 {
699 static unsigned long expire = RT_GC_TIMEOUT;
700 static unsigned long last_gc;
701 static int rover;
702 static int equilibrium;
703 struct rtable *rth, **rthp;
704 unsigned long now = jiffies;
705 int goal;
706
707 /*
708 * Garbage collection is pretty expensive,
709 * do not make it too frequently.
710 */
711
712 RT_CACHE_STAT_INC(gc_total);
713
714 if (now - last_gc < ip_rt_gc_min_interval &&
715 atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
716 RT_CACHE_STAT_INC(gc_ignored);
717 goto out;
718 }
719
720 /* Calculate number of entries, which we want to expire now. */
721 goal = atomic_read(&ipv4_dst_ops.entries) -
722 (ip_rt_gc_elasticity << rt_hash_log);
723 if (goal <= 0) {
724 if (equilibrium < ipv4_dst_ops.gc_thresh)
725 equilibrium = ipv4_dst_ops.gc_thresh;
726 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
727 if (goal > 0) {
728 equilibrium += min_t(unsigned int, goal / 2, rt_hash_mask + 1);
729 goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
730 }
731 } else {
732 /* We are in dangerous area. Try to reduce cache really
733 * aggressively.
734 */
735 goal = max_t(unsigned int, goal / 2, rt_hash_mask + 1);
736 equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
737 }
738
739 if (now - last_gc >= ip_rt_gc_min_interval)
740 last_gc = now;
741
742 if (goal <= 0) {
743 equilibrium += goal;
744 goto work_done;
745 }
746
747 do {
748 int i, k;
749
750 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
751 unsigned long tmo = expire;
752
753 k = (k + 1) & rt_hash_mask;
754 rthp = &rt_hash_table[k].chain;
755 spin_lock_bh(rt_hash_lock_addr(k));
756 while ((rth = *rthp) != NULL) {
757 if (!rt_may_expire(rth, tmo, expire)) {
758 tmo >>= 1;
759 rthp = &rth->u.dst.rt_next;
760 continue;
761 }
762 *rthp = rth->u.dst.rt_next;
763 rt_free(rth);
764 goal--;
765 }
766 spin_unlock_bh(rt_hash_lock_addr(k));
767 if (goal <= 0)
768 break;
769 }
770 rover = k;
771
772 if (goal <= 0)
773 goto work_done;
774
775 /* Goal is not achieved. We stop process if:
776
777 - if expire reduced to zero. Otherwise, expire is halfed.
778 - if table is not full.
779 - if we are called from interrupt.
780 - jiffies check is just fallback/debug loop breaker.
781 We will not spin here for long time in any case.
782 */
783
784 RT_CACHE_STAT_INC(gc_goal_miss);
785
786 if (expire == 0)
787 break;
788
789 expire >>= 1;
790 #if RT_CACHE_DEBUG >= 2
791 printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
792 atomic_read(&ipv4_dst_ops.entries), goal, i);
793 #endif
794
795 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
796 goto out;
797 } while (!in_softirq() && time_before_eq(jiffies, now));
798
799 if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
800 goto out;
801 if (net_ratelimit())
802 printk(KERN_WARNING "dst cache overflow\n");
803 RT_CACHE_STAT_INC(gc_dst_overflow);
804 return 1;
805
806 work_done:
807 expire += ip_rt_gc_min_interval;
808 if (expire > ip_rt_gc_timeout ||
809 atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
810 expire = ip_rt_gc_timeout;
811 #if RT_CACHE_DEBUG >= 2
812 printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
813 atomic_read(&ipv4_dst_ops.entries), goal, rover);
814 #endif
815 out: return 0;
816 }
817
818 static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
819 {
820 struct rtable *rth, **rthp;
821 unsigned long now;
822 struct rtable *cand, **candp;
823 u32 min_score;
824 int chain_length;
825 int attempts = !in_softirq();
826
827 restart:
828 chain_length = 0;
829 min_score = ~(u32)0;
830 cand = NULL;
831 candp = NULL;
832 now = jiffies;
833
834 rthp = &rt_hash_table[hash].chain;
835
836 spin_lock_bh(rt_hash_lock_addr(hash));
837 while ((rth = *rthp) != NULL) {
838 if (compare_keys(&rth->fl, &rt->fl)) {
839 /* Put it first */
840 *rthp = rth->u.dst.rt_next;
841 /*
842 * Since lookup is lockfree, the deletion
843 * must be visible to another weakly ordered CPU before
844 * the insertion at the start of the hash chain.
845 */
846 rcu_assign_pointer(rth->u.dst.rt_next,
847 rt_hash_table[hash].chain);
848 /*
849 * Since lookup is lockfree, the update writes
850 * must be ordered for consistency on SMP.
851 */
852 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
853
854 rth->u.dst.__use++;
855 dst_hold(&rth->u.dst);
856 rth->u.dst.lastuse = now;
857 spin_unlock_bh(rt_hash_lock_addr(hash));
858
859 rt_drop(rt);
860 *rp = rth;
861 return 0;
862 }
863
864 if (!atomic_read(&rth->u.dst.__refcnt)) {
865 u32 score = rt_score(rth);
866
867 if (score <= min_score) {
868 cand = rth;
869 candp = rthp;
870 min_score = score;
871 }
872 }
873
874 chain_length++;
875
876 rthp = &rth->u.dst.rt_next;
877 }
878
879 if (cand) {
880 /* ip_rt_gc_elasticity used to be average length of chain
881 * length, when exceeded gc becomes really aggressive.
882 *
883 * The second limit is less certain. At the moment it allows
884 * only 2 entries per bucket. We will see.
885 */
886 if (chain_length > ip_rt_gc_elasticity) {
887 *candp = cand->u.dst.rt_next;
888 rt_free(cand);
889 }
890 }
891
892 /* Try to bind route to arp only if it is output
893 route or unicast forwarding path.
894 */
895 if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
896 int err = arp_bind_neighbour(&rt->u.dst);
897 if (err) {
898 spin_unlock_bh(rt_hash_lock_addr(hash));
899
900 if (err != -ENOBUFS) {
901 rt_drop(rt);
902 return err;
903 }
904
905 /* Neighbour tables are full and nothing
906 can be released. Try to shrink route cache,
907 it is most likely it holds some neighbour records.
908 */
909 if (attempts-- > 0) {
910 int saved_elasticity = ip_rt_gc_elasticity;
911 int saved_int = ip_rt_gc_min_interval;
912 ip_rt_gc_elasticity = 1;
913 ip_rt_gc_min_interval = 0;
914 rt_garbage_collect();
915 ip_rt_gc_min_interval = saved_int;
916 ip_rt_gc_elasticity = saved_elasticity;
917 goto restart;
918 }
919
920 if (net_ratelimit())
921 printk(KERN_WARNING "Neighbour table overflow.\n");
922 rt_drop(rt);
923 return -ENOBUFS;
924 }
925 }
926
927 rt->u.dst.rt_next = rt_hash_table[hash].chain;
928 #if RT_CACHE_DEBUG >= 2
929 if (rt->u.dst.rt_next) {
930 struct rtable *trt;
931 printk(KERN_DEBUG "rt_cache @%02x: %u.%u.%u.%u", hash,
932 NIPQUAD(rt->rt_dst));
933 for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
934 printk(" . %u.%u.%u.%u", NIPQUAD(trt->rt_dst));
935 printk("\n");
936 }
937 #endif
938 rt_hash_table[hash].chain = rt;
939 spin_unlock_bh(rt_hash_lock_addr(hash));
940 *rp = rt;
941 return 0;
942 }
943
944 void rt_bind_peer(struct rtable *rt, int create)
945 {
946 static DEFINE_SPINLOCK(rt_peer_lock);
947 struct inet_peer *peer;
948
949 peer = inet_getpeer(rt->rt_dst, create);
950
951 spin_lock_bh(&rt_peer_lock);
952 if (rt->peer == NULL) {
953 rt->peer = peer;
954 peer = NULL;
955 }
956 spin_unlock_bh(&rt_peer_lock);
957 if (peer)
958 inet_putpeer(peer);
959 }
960
961 /*
962 * Peer allocation may fail only in serious out-of-memory conditions. However
963 * we still can generate some output.
964 * Random ID selection looks a bit dangerous because we have no chances to
965 * select ID being unique in a reasonable period of time.
966 * But broken packet identifier may be better than no packet at all.
967 */
968 static void ip_select_fb_ident(struct iphdr *iph)
969 {
970 static DEFINE_SPINLOCK(ip_fb_id_lock);
971 static u32 ip_fallback_id;
972 u32 salt;
973
974 spin_lock_bh(&ip_fb_id_lock);
975 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
976 iph->id = htons(salt & 0xFFFF);
977 ip_fallback_id = salt;
978 spin_unlock_bh(&ip_fb_id_lock);
979 }
980
981 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
982 {
983 struct rtable *rt = (struct rtable *) dst;
984
985 if (rt) {
986 if (rt->peer == NULL)
987 rt_bind_peer(rt, 1);
988
989 /* If peer is attached to destination, it is never detached,
990 so that we need not to grab a lock to dereference it.
991 */
992 if (rt->peer) {
993 iph->id = htons(inet_getid(rt->peer, more));
994 return;
995 }
996 } else
997 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
998 __builtin_return_address(0));
999
1000 ip_select_fb_ident(iph);
1001 }
1002
1003 static void rt_del(unsigned hash, struct rtable *rt)
1004 {
1005 struct rtable **rthp;
1006
1007 spin_lock_bh(rt_hash_lock_addr(hash));
1008 ip_rt_put(rt);
1009 for (rthp = &rt_hash_table[hash].chain; *rthp;
1010 rthp = &(*rthp)->u.dst.rt_next)
1011 if (*rthp == rt) {
1012 *rthp = rt->u.dst.rt_next;
1013 rt_free(rt);
1014 break;
1015 }
1016 spin_unlock_bh(rt_hash_lock_addr(hash));
1017 }
1018
1019 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1020 __be32 saddr, struct net_device *dev)
1021 {
1022 int i, k;
1023 struct in_device *in_dev = in_dev_get(dev);
1024 struct rtable *rth, **rthp;
1025 __be32 skeys[2] = { saddr, 0 };
1026 int ikeys[2] = { dev->ifindex, 0 };
1027 struct netevent_redirect netevent;
1028
1029 if (!in_dev)
1030 return;
1031
1032 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
1033 || MULTICAST(new_gw) || BADCLASS(new_gw) || ZERONET(new_gw))
1034 goto reject_redirect;
1035
1036 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1037 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1038 goto reject_redirect;
1039 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1040 goto reject_redirect;
1041 } else {
1042 if (inet_addr_type(new_gw) != RTN_UNICAST)
1043 goto reject_redirect;
1044 }
1045
1046 for (i = 0; i < 2; i++) {
1047 for (k = 0; k < 2; k++) {
1048 unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
1049
1050 rthp=&rt_hash_table[hash].chain;
1051
1052 rcu_read_lock();
1053 while ((rth = rcu_dereference(*rthp)) != NULL) {
1054 struct rtable *rt;
1055
1056 if (rth->fl.fl4_dst != daddr ||
1057 rth->fl.fl4_src != skeys[i] ||
1058 rth->fl.oif != ikeys[k] ||
1059 rth->fl.iif != 0) {
1060 rthp = &rth->u.dst.rt_next;
1061 continue;
1062 }
1063
1064 if (rth->rt_dst != daddr ||
1065 rth->rt_src != saddr ||
1066 rth->u.dst.error ||
1067 rth->rt_gateway != old_gw ||
1068 rth->u.dst.dev != dev)
1069 break;
1070
1071 dst_hold(&rth->u.dst);
1072 rcu_read_unlock();
1073
1074 rt = dst_alloc(&ipv4_dst_ops);
1075 if (rt == NULL) {
1076 ip_rt_put(rth);
1077 in_dev_put(in_dev);
1078 return;
1079 }
1080
1081 /* Copy all the information. */
1082 *rt = *rth;
1083 INIT_RCU_HEAD(&rt->u.dst.rcu_head);
1084 rt->u.dst.__use = 1;
1085 atomic_set(&rt->u.dst.__refcnt, 1);
1086 rt->u.dst.child = NULL;
1087 if (rt->u.dst.dev)
1088 dev_hold(rt->u.dst.dev);
1089 if (rt->idev)
1090 in_dev_hold(rt->idev);
1091 rt->u.dst.obsolete = 0;
1092 rt->u.dst.lastuse = jiffies;
1093 rt->u.dst.path = &rt->u.dst;
1094 rt->u.dst.neighbour = NULL;
1095 rt->u.dst.hh = NULL;
1096 rt->u.dst.xfrm = NULL;
1097
1098 rt->rt_flags |= RTCF_REDIRECTED;
1099
1100 /* Gateway is different ... */
1101 rt->rt_gateway = new_gw;
1102
1103 /* Redirect received -> path was valid */
1104 dst_confirm(&rth->u.dst);
1105
1106 if (rt->peer)
1107 atomic_inc(&rt->peer->refcnt);
1108
1109 if (arp_bind_neighbour(&rt->u.dst) ||
1110 !(rt->u.dst.neighbour->nud_state &
1111 NUD_VALID)) {
1112 if (rt->u.dst.neighbour)
1113 neigh_event_send(rt->u.dst.neighbour, NULL);
1114 ip_rt_put(rth);
1115 rt_drop(rt);
1116 goto do_next;
1117 }
1118
1119 netevent.old = &rth->u.dst;
1120 netevent.new = &rt->u.dst;
1121 call_netevent_notifiers(NETEVENT_REDIRECT,
1122 &netevent);
1123
1124 rt_del(hash, rth);
1125 if (!rt_intern_hash(hash, rt, &rt))
1126 ip_rt_put(rt);
1127 goto do_next;
1128 }
1129 rcu_read_unlock();
1130 do_next:
1131 ;
1132 }
1133 }
1134 in_dev_put(in_dev);
1135 return;
1136
1137 reject_redirect:
1138 #ifdef CONFIG_IP_ROUTE_VERBOSE
1139 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1140 printk(KERN_INFO "Redirect from %u.%u.%u.%u on %s about "
1141 "%u.%u.%u.%u ignored.\n"
1142 " Advised path = %u.%u.%u.%u -> %u.%u.%u.%u\n",
1143 NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
1144 NIPQUAD(saddr), NIPQUAD(daddr));
1145 #endif
1146 in_dev_put(in_dev);
1147 }
1148
1149 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1150 {
1151 struct rtable *rt = (struct rtable*)dst;
1152 struct dst_entry *ret = dst;
1153
1154 if (rt) {
1155 if (dst->obsolete) {
1156 ip_rt_put(rt);
1157 ret = NULL;
1158 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
1159 rt->u.dst.expires) {
1160 unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
1161 rt->fl.oif);
1162 #if RT_CACHE_DEBUG >= 1
1163 printk(KERN_DEBUG "ip_rt_advice: redirect to "
1164 "%u.%u.%u.%u/%02x dropped\n",
1165 NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
1166 #endif
1167 rt_del(hash, rt);
1168 ret = NULL;
1169 }
1170 }
1171 return ret;
1172 }
1173
1174 /*
1175 * Algorithm:
1176 * 1. The first ip_rt_redirect_number redirects are sent
1177 * with exponential backoff, then we stop sending them at all,
1178 * assuming that the host ignores our redirects.
1179 * 2. If we did not see packets requiring redirects
1180 * during ip_rt_redirect_silence, we assume that the host
1181 * forgot redirected route and start to send redirects again.
1182 *
1183 * This algorithm is much cheaper and more intelligent than dumb load limiting
1184 * in icmp.c.
1185 *
1186 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1187 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1188 */
1189
1190 void ip_rt_send_redirect(struct sk_buff *skb)
1191 {
1192 struct rtable *rt = (struct rtable*)skb->dst;
1193 struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
1194
1195 if (!in_dev)
1196 return;
1197
1198 if (!IN_DEV_TX_REDIRECTS(in_dev))
1199 goto out;
1200
1201 /* No redirected packets during ip_rt_redirect_silence;
1202 * reset the algorithm.
1203 */
1204 if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
1205 rt->u.dst.rate_tokens = 0;
1206
1207 /* Too many ignored redirects; do not send anything
1208 * set u.dst.rate_last to the last seen redirected packet.
1209 */
1210 if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
1211 rt->u.dst.rate_last = jiffies;
1212 goto out;
1213 }
1214
1215 /* Check for load limit; set rate_last to the latest sent
1216 * redirect.
1217 */
1218 if (rt->u.dst.rate_tokens == 0 ||
1219 time_after(jiffies,
1220 (rt->u.dst.rate_last +
1221 (ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
1222 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1223 rt->u.dst.rate_last = jiffies;
1224 ++rt->u.dst.rate_tokens;
1225 #ifdef CONFIG_IP_ROUTE_VERBOSE
1226 if (IN_DEV_LOG_MARTIANS(in_dev) &&
1227 rt->u.dst.rate_tokens == ip_rt_redirect_number &&
1228 net_ratelimit())
1229 printk(KERN_WARNING "host %u.%u.%u.%u/if%d ignores "
1230 "redirects for %u.%u.%u.%u to %u.%u.%u.%u.\n",
1231 NIPQUAD(rt->rt_src), rt->rt_iif,
1232 NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
1233 #endif
1234 }
1235 out:
1236 in_dev_put(in_dev);
1237 }
1238
1239 static int ip_error(struct sk_buff *skb)
1240 {
1241 struct rtable *rt = (struct rtable*)skb->dst;
1242 unsigned long now;
1243 int code;
1244
1245 switch (rt->u.dst.error) {
1246 case EINVAL:
1247 default:
1248 goto out;
1249 case EHOSTUNREACH:
1250 code = ICMP_HOST_UNREACH;
1251 break;
1252 case ENETUNREACH:
1253 code = ICMP_NET_UNREACH;
1254 break;
1255 case EACCES:
1256 code = ICMP_PKT_FILTERED;
1257 break;
1258 }
1259
1260 now = jiffies;
1261 rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
1262 if (rt->u.dst.rate_tokens > ip_rt_error_burst)
1263 rt->u.dst.rate_tokens = ip_rt_error_burst;
1264 rt->u.dst.rate_last = now;
1265 if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
1266 rt->u.dst.rate_tokens -= ip_rt_error_cost;
1267 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1268 }
1269
1270 out: kfree_skb(skb);
1271 return 0;
1272 }
1273
1274 /*
1275 * The last two values are not from the RFC but
1276 * are needed for AMPRnet AX.25 paths.
1277 */
1278
1279 static const unsigned short mtu_plateau[] =
1280 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1281
1282 static __inline__ unsigned short guess_mtu(unsigned short old_mtu)
1283 {
1284 int i;
1285
1286 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1287 if (old_mtu > mtu_plateau[i])
1288 return mtu_plateau[i];
1289 return 68;
1290 }
1291
1292 unsigned short ip_rt_frag_needed(struct iphdr *iph, unsigned short new_mtu)
1293 {
1294 int i;
1295 unsigned short old_mtu = ntohs(iph->tot_len);
1296 struct rtable *rth;
1297 __be32 skeys[2] = { iph->saddr, 0, };
1298 __be32 daddr = iph->daddr;
1299 unsigned short est_mtu = 0;
1300
1301 if (ipv4_config.no_pmtu_disc)
1302 return 0;
1303
1304 for (i = 0; i < 2; i++) {
1305 unsigned hash = rt_hash(daddr, skeys[i], 0);
1306
1307 rcu_read_lock();
1308 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1309 rth = rcu_dereference(rth->u.dst.rt_next)) {
1310 if (rth->fl.fl4_dst == daddr &&
1311 rth->fl.fl4_src == skeys[i] &&
1312 rth->rt_dst == daddr &&
1313 rth->rt_src == iph->saddr &&
1314 rth->fl.iif == 0 &&
1315 !(dst_metric_locked(&rth->u.dst, RTAX_MTU))) {
1316 unsigned short mtu = new_mtu;
1317
1318 if (new_mtu < 68 || new_mtu >= old_mtu) {
1319
1320 /* BSD 4.2 compatibility hack :-( */
1321 if (mtu == 0 &&
1322 old_mtu >= rth->u.dst.metrics[RTAX_MTU-1] &&
1323 old_mtu >= 68 + (iph->ihl << 2))
1324 old_mtu -= iph->ihl << 2;
1325
1326 mtu = guess_mtu(old_mtu);
1327 }
1328 if (mtu <= rth->u.dst.metrics[RTAX_MTU-1]) {
1329 if (mtu < rth->u.dst.metrics[RTAX_MTU-1]) {
1330 dst_confirm(&rth->u.dst);
1331 if (mtu < ip_rt_min_pmtu) {
1332 mtu = ip_rt_min_pmtu;
1333 rth->u.dst.metrics[RTAX_LOCK-1] |=
1334 (1 << RTAX_MTU);
1335 }
1336 rth->u.dst.metrics[RTAX_MTU-1] = mtu;
1337 dst_set_expires(&rth->u.dst,
1338 ip_rt_mtu_expires);
1339 }
1340 est_mtu = mtu;
1341 }
1342 }
1343 }
1344 rcu_read_unlock();
1345 }
1346 return est_mtu ? : new_mtu;
1347 }
1348
1349 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1350 {
1351 if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= 68 &&
1352 !(dst_metric_locked(dst, RTAX_MTU))) {
1353 if (mtu < ip_rt_min_pmtu) {
1354 mtu = ip_rt_min_pmtu;
1355 dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
1356 }
1357 dst->metrics[RTAX_MTU-1] = mtu;
1358 dst_set_expires(dst, ip_rt_mtu_expires);
1359 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
1360 }
1361 }
1362
1363 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1364 {
1365 return NULL;
1366 }
1367
1368 static void ipv4_dst_destroy(struct dst_entry *dst)
1369 {
1370 struct rtable *rt = (struct rtable *) dst;
1371 struct inet_peer *peer = rt->peer;
1372 struct in_device *idev = rt->idev;
1373
1374 if (peer) {
1375 rt->peer = NULL;
1376 inet_putpeer(peer);
1377 }
1378
1379 if (idev) {
1380 rt->idev = NULL;
1381 in_dev_put(idev);
1382 }
1383 }
1384
1385 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
1386 int how)
1387 {
1388 struct rtable *rt = (struct rtable *) dst;
1389 struct in_device *idev = rt->idev;
1390 if (dev != init_net.loopback_dev && idev && idev->dev == dev) {
1391 struct in_device *loopback_idev = in_dev_get(init_net.loopback_dev);
1392 if (loopback_idev) {
1393 rt->idev = loopback_idev;
1394 in_dev_put(idev);
1395 }
1396 }
1397 }
1398
1399 static void ipv4_link_failure(struct sk_buff *skb)
1400 {
1401 struct rtable *rt;
1402
1403 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1404
1405 rt = (struct rtable *) skb->dst;
1406 if (rt)
1407 dst_set_expires(&rt->u.dst, 0);
1408 }
1409
1410 static int ip_rt_bug(struct sk_buff *skb)
1411 {
1412 printk(KERN_DEBUG "ip_rt_bug: %u.%u.%u.%u -> %u.%u.%u.%u, %s\n",
1413 NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(ip_hdr(skb)->daddr),
1414 skb->dev ? skb->dev->name : "?");
1415 kfree_skb(skb);
1416 return 0;
1417 }
1418
1419 /*
1420 We do not cache source address of outgoing interface,
1421 because it is used only by IP RR, TS and SRR options,
1422 so that it out of fast path.
1423
1424 BTW remember: "addr" is allowed to be not aligned
1425 in IP options!
1426 */
1427
1428 void ip_rt_get_source(u8 *addr, struct rtable *rt)
1429 {
1430 __be32 src;
1431 struct fib_result res;
1432
1433 if (rt->fl.iif == 0)
1434 src = rt->rt_src;
1435 else if (fib_lookup(&rt->fl, &res) == 0) {
1436 src = FIB_RES_PREFSRC(res);
1437 fib_res_put(&res);
1438 } else
1439 src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
1440 RT_SCOPE_UNIVERSE);
1441 memcpy(addr, &src, 4);
1442 }
1443
1444 #ifdef CONFIG_NET_CLS_ROUTE
1445 static void set_class_tag(struct rtable *rt, u32 tag)
1446 {
1447 if (!(rt->u.dst.tclassid & 0xFFFF))
1448 rt->u.dst.tclassid |= tag & 0xFFFF;
1449 if (!(rt->u.dst.tclassid & 0xFFFF0000))
1450 rt->u.dst.tclassid |= tag & 0xFFFF0000;
1451 }
1452 #endif
1453
1454 static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
1455 {
1456 struct fib_info *fi = res->fi;
1457
1458 if (fi) {
1459 if (FIB_RES_GW(*res) &&
1460 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1461 rt->rt_gateway = FIB_RES_GW(*res);
1462 memcpy(rt->u.dst.metrics, fi->fib_metrics,
1463 sizeof(rt->u.dst.metrics));
1464 if (fi->fib_mtu == 0) {
1465 rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
1466 if (rt->u.dst.metrics[RTAX_LOCK-1] & (1 << RTAX_MTU) &&
1467 rt->rt_gateway != rt->rt_dst &&
1468 rt->u.dst.dev->mtu > 576)
1469 rt->u.dst.metrics[RTAX_MTU-1] = 576;
1470 }
1471 #ifdef CONFIG_NET_CLS_ROUTE
1472 rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
1473 #endif
1474 } else
1475 rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
1476
1477 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0)
1478 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
1479 if (rt->u.dst.metrics[RTAX_MTU-1] > IP_MAX_MTU)
1480 rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
1481 if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0)
1482 rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
1483 ip_rt_min_advmss);
1484 if (rt->u.dst.metrics[RTAX_ADVMSS-1] > 65535 - 40)
1485 rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
1486
1487 #ifdef CONFIG_NET_CLS_ROUTE
1488 #ifdef CONFIG_IP_MULTIPLE_TABLES
1489 set_class_tag(rt, fib_rules_tclass(res));
1490 #endif
1491 set_class_tag(rt, itag);
1492 #endif
1493 rt->rt_type = res->type;
1494 }
1495
1496 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1497 u8 tos, struct net_device *dev, int our)
1498 {
1499 unsigned hash;
1500 struct rtable *rth;
1501 __be32 spec_dst;
1502 struct in_device *in_dev = in_dev_get(dev);
1503 u32 itag = 0;
1504
1505 /* Primary sanity checks. */
1506
1507 if (in_dev == NULL)
1508 return -EINVAL;
1509
1510 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr) ||
1511 skb->protocol != htons(ETH_P_IP))
1512 goto e_inval;
1513
1514 if (ZERONET(saddr)) {
1515 if (!LOCAL_MCAST(daddr))
1516 goto e_inval;
1517 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1518 } else if (fib_validate_source(saddr, 0, tos, 0,
1519 dev, &spec_dst, &itag) < 0)
1520 goto e_inval;
1521
1522 rth = dst_alloc(&ipv4_dst_ops);
1523 if (!rth)
1524 goto e_nobufs;
1525
1526 rth->u.dst.output= ip_rt_bug;
1527
1528 atomic_set(&rth->u.dst.__refcnt, 1);
1529 rth->u.dst.flags= DST_HOST;
1530 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1531 rth->u.dst.flags |= DST_NOPOLICY;
1532 rth->fl.fl4_dst = daddr;
1533 rth->rt_dst = daddr;
1534 rth->fl.fl4_tos = tos;
1535 rth->fl.mark = skb->mark;
1536 rth->fl.fl4_src = saddr;
1537 rth->rt_src = saddr;
1538 #ifdef CONFIG_NET_CLS_ROUTE
1539 rth->u.dst.tclassid = itag;
1540 #endif
1541 rth->rt_iif =
1542 rth->fl.iif = dev->ifindex;
1543 rth->u.dst.dev = init_net.loopback_dev;
1544 dev_hold(rth->u.dst.dev);
1545 rth->idev = in_dev_get(rth->u.dst.dev);
1546 rth->fl.oif = 0;
1547 rth->rt_gateway = daddr;
1548 rth->rt_spec_dst= spec_dst;
1549 rth->rt_type = RTN_MULTICAST;
1550 rth->rt_flags = RTCF_MULTICAST;
1551 if (our) {
1552 rth->u.dst.input= ip_local_deliver;
1553 rth->rt_flags |= RTCF_LOCAL;
1554 }
1555
1556 #ifdef CONFIG_IP_MROUTE
1557 if (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1558 rth->u.dst.input = ip_mr_input;
1559 #endif
1560 RT_CACHE_STAT_INC(in_slow_mc);
1561
1562 in_dev_put(in_dev);
1563 hash = rt_hash(daddr, saddr, dev->ifindex);
1564 return rt_intern_hash(hash, rth, (struct rtable**) &skb->dst);
1565
1566 e_nobufs:
1567 in_dev_put(in_dev);
1568 return -ENOBUFS;
1569
1570 e_inval:
1571 in_dev_put(in_dev);
1572 return -EINVAL;
1573 }
1574
1575
1576 static void ip_handle_martian_source(struct net_device *dev,
1577 struct in_device *in_dev,
1578 struct sk_buff *skb,
1579 __be32 daddr,
1580 __be32 saddr)
1581 {
1582 RT_CACHE_STAT_INC(in_martian_src);
1583 #ifdef CONFIG_IP_ROUTE_VERBOSE
1584 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1585 /*
1586 * RFC1812 recommendation, if source is martian,
1587 * the only hint is MAC header.
1588 */
1589 printk(KERN_WARNING "martian source %u.%u.%u.%u from "
1590 "%u.%u.%u.%u, on dev %s\n",
1591 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1592 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1593 int i;
1594 const unsigned char *p = skb_mac_header(skb);
1595 printk(KERN_WARNING "ll header: ");
1596 for (i = 0; i < dev->hard_header_len; i++, p++) {
1597 printk("%02x", *p);
1598 if (i < (dev->hard_header_len - 1))
1599 printk(":");
1600 }
1601 printk("\n");
1602 }
1603 }
1604 #endif
1605 }
1606
1607 static inline int __mkroute_input(struct sk_buff *skb,
1608 struct fib_result* res,
1609 struct in_device *in_dev,
1610 __be32 daddr, __be32 saddr, u32 tos,
1611 struct rtable **result)
1612 {
1613
1614 struct rtable *rth;
1615 int err;
1616 struct in_device *out_dev;
1617 unsigned flags = 0;
1618 __be32 spec_dst;
1619 u32 itag;
1620
1621 /* get a working reference to the output device */
1622 out_dev = in_dev_get(FIB_RES_DEV(*res));
1623 if (out_dev == NULL) {
1624 if (net_ratelimit())
1625 printk(KERN_CRIT "Bug in ip_route_input" \
1626 "_slow(). Please, report\n");
1627 return -EINVAL;
1628 }
1629
1630
1631 err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
1632 in_dev->dev, &spec_dst, &itag);
1633 if (err < 0) {
1634 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1635 saddr);
1636
1637 err = -EINVAL;
1638 goto cleanup;
1639 }
1640
1641 if (err)
1642 flags |= RTCF_DIRECTSRC;
1643
1644 if (out_dev == in_dev && err && !(flags & (RTCF_NAT | RTCF_MASQ)) &&
1645 (IN_DEV_SHARED_MEDIA(out_dev) ||
1646 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1647 flags |= RTCF_DOREDIRECT;
1648
1649 if (skb->protocol != htons(ETH_P_IP)) {
1650 /* Not IP (i.e. ARP). Do not create route, if it is
1651 * invalid for proxy arp. DNAT routes are always valid.
1652 */
1653 if (out_dev == in_dev && !(flags & RTCF_DNAT)) {
1654 err = -EINVAL;
1655 goto cleanup;
1656 }
1657 }
1658
1659
1660 rth = dst_alloc(&ipv4_dst_ops);
1661 if (!rth) {
1662 err = -ENOBUFS;
1663 goto cleanup;
1664 }
1665
1666 atomic_set(&rth->u.dst.__refcnt, 1);
1667 rth->u.dst.flags= DST_HOST;
1668 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1669 rth->u.dst.flags |= DST_NOPOLICY;
1670 if (IN_DEV_CONF_GET(out_dev, NOXFRM))
1671 rth->u.dst.flags |= DST_NOXFRM;
1672 rth->fl.fl4_dst = daddr;
1673 rth->rt_dst = daddr;
1674 rth->fl.fl4_tos = tos;
1675 rth->fl.mark = skb->mark;
1676 rth->fl.fl4_src = saddr;
1677 rth->rt_src = saddr;
1678 rth->rt_gateway = daddr;
1679 rth->rt_iif =
1680 rth->fl.iif = in_dev->dev->ifindex;
1681 rth->u.dst.dev = (out_dev)->dev;
1682 dev_hold(rth->u.dst.dev);
1683 rth->idev = in_dev_get(rth->u.dst.dev);
1684 rth->fl.oif = 0;
1685 rth->rt_spec_dst= spec_dst;
1686
1687 rth->u.dst.input = ip_forward;
1688 rth->u.dst.output = ip_output;
1689
1690 rt_set_nexthop(rth, res, itag);
1691
1692 rth->rt_flags = flags;
1693
1694 *result = rth;
1695 err = 0;
1696 cleanup:
1697 /* release the working reference to the output device */
1698 in_dev_put(out_dev);
1699 return err;
1700 }
1701
1702 static inline int ip_mkroute_input(struct sk_buff *skb,
1703 struct fib_result* res,
1704 const struct flowi *fl,
1705 struct in_device *in_dev,
1706 __be32 daddr, __be32 saddr, u32 tos)
1707 {
1708 struct rtable* rth = NULL;
1709 int err;
1710 unsigned hash;
1711
1712 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1713 if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
1714 fib_select_multipath(fl, res);
1715 #endif
1716
1717 /* create a routing cache entry */
1718 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1719 if (err)
1720 return err;
1721
1722 /* put it into the cache */
1723 hash = rt_hash(daddr, saddr, fl->iif);
1724 return rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1725 }
1726
1727 /*
1728 * NOTE. We drop all the packets that has local source
1729 * addresses, because every properly looped back packet
1730 * must have correct destination already attached by output routine.
1731 *
1732 * Such approach solves two big problems:
1733 * 1. Not simplex devices are handled properly.
1734 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1735 */
1736
1737 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1738 u8 tos, struct net_device *dev)
1739 {
1740 struct fib_result res;
1741 struct in_device *in_dev = in_dev_get(dev);
1742 struct flowi fl = { .nl_u = { .ip4_u =
1743 { .daddr = daddr,
1744 .saddr = saddr,
1745 .tos = tos,
1746 .scope = RT_SCOPE_UNIVERSE,
1747 } },
1748 .mark = skb->mark,
1749 .iif = dev->ifindex };
1750 unsigned flags = 0;
1751 u32 itag = 0;
1752 struct rtable * rth;
1753 unsigned hash;
1754 __be32 spec_dst;
1755 int err = -EINVAL;
1756 int free_res = 0;
1757
1758 /* IP on this device is disabled. */
1759
1760 if (!in_dev)
1761 goto out;
1762
1763 /* Check for the most weird martians, which can be not detected
1764 by fib_lookup.
1765 */
1766
1767 if (MULTICAST(saddr) || BADCLASS(saddr) || LOOPBACK(saddr))
1768 goto martian_source;
1769
1770 if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
1771 goto brd_input;
1772
1773 /* Accept zero addresses only to limited broadcast;
1774 * I even do not know to fix it or not. Waiting for complains :-)
1775 */
1776 if (ZERONET(saddr))
1777 goto martian_source;
1778
1779 if (BADCLASS(daddr) || ZERONET(daddr) || LOOPBACK(daddr))
1780 goto martian_destination;
1781
1782 /*
1783 * Now we are ready to route packet.
1784 */
1785 if ((err = fib_lookup(&fl, &res)) != 0) {
1786 if (!IN_DEV_FORWARD(in_dev))
1787 goto e_hostunreach;
1788 goto no_route;
1789 }
1790 free_res = 1;
1791
1792 RT_CACHE_STAT_INC(in_slow_tot);
1793
1794 if (res.type == RTN_BROADCAST)
1795 goto brd_input;
1796
1797 if (res.type == RTN_LOCAL) {
1798 int result;
1799 result = fib_validate_source(saddr, daddr, tos,
1800 init_net.loopback_dev->ifindex,
1801 dev, &spec_dst, &itag);
1802 if (result < 0)
1803 goto martian_source;
1804 if (result)
1805 flags |= RTCF_DIRECTSRC;
1806 spec_dst = daddr;
1807 goto local_input;
1808 }
1809
1810 if (!IN_DEV_FORWARD(in_dev))
1811 goto e_hostunreach;
1812 if (res.type != RTN_UNICAST)
1813 goto martian_destination;
1814
1815 err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
1816 done:
1817 in_dev_put(in_dev);
1818 if (free_res)
1819 fib_res_put(&res);
1820 out: return err;
1821
1822 brd_input:
1823 if (skb->protocol != htons(ETH_P_IP))
1824 goto e_inval;
1825
1826 if (ZERONET(saddr))
1827 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1828 else {
1829 err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
1830 &itag);
1831 if (err < 0)
1832 goto martian_source;
1833 if (err)
1834 flags |= RTCF_DIRECTSRC;
1835 }
1836 flags |= RTCF_BROADCAST;
1837 res.type = RTN_BROADCAST;
1838 RT_CACHE_STAT_INC(in_brd);
1839
1840 local_input:
1841 rth = dst_alloc(&ipv4_dst_ops);
1842 if (!rth)
1843 goto e_nobufs;
1844
1845 rth->u.dst.output= ip_rt_bug;
1846
1847 atomic_set(&rth->u.dst.__refcnt, 1);
1848 rth->u.dst.flags= DST_HOST;
1849 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
1850 rth->u.dst.flags |= DST_NOPOLICY;
1851 rth->fl.fl4_dst = daddr;
1852 rth->rt_dst = daddr;
1853 rth->fl.fl4_tos = tos;
1854 rth->fl.mark = skb->mark;
1855 rth->fl.fl4_src = saddr;
1856 rth->rt_src = saddr;
1857 #ifdef CONFIG_NET_CLS_ROUTE
1858 rth->u.dst.tclassid = itag;
1859 #endif
1860 rth->rt_iif =
1861 rth->fl.iif = dev->ifindex;
1862 rth->u.dst.dev = init_net.loopback_dev;
1863 dev_hold(rth->u.dst.dev);
1864 rth->idev = in_dev_get(rth->u.dst.dev);
1865 rth->rt_gateway = daddr;
1866 rth->rt_spec_dst= spec_dst;
1867 rth->u.dst.input= ip_local_deliver;
1868 rth->rt_flags = flags|RTCF_LOCAL;
1869 if (res.type == RTN_UNREACHABLE) {
1870 rth->u.dst.input= ip_error;
1871 rth->u.dst.error= -err;
1872 rth->rt_flags &= ~RTCF_LOCAL;
1873 }
1874 rth->rt_type = res.type;
1875 hash = rt_hash(daddr, saddr, fl.iif);
1876 err = rt_intern_hash(hash, rth, (struct rtable**)&skb->dst);
1877 goto done;
1878
1879 no_route:
1880 RT_CACHE_STAT_INC(in_no_route);
1881 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
1882 res.type = RTN_UNREACHABLE;
1883 goto local_input;
1884
1885 /*
1886 * Do not cache martian addresses: they should be logged (RFC1812)
1887 */
1888 martian_destination:
1889 RT_CACHE_STAT_INC(in_martian_dst);
1890 #ifdef CONFIG_IP_ROUTE_VERBOSE
1891 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1892 printk(KERN_WARNING "martian destination %u.%u.%u.%u from "
1893 "%u.%u.%u.%u, dev %s\n",
1894 NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
1895 #endif
1896
1897 e_hostunreach:
1898 err = -EHOSTUNREACH;
1899 goto done;
1900
1901 e_inval:
1902 err = -EINVAL;
1903 goto done;
1904
1905 e_nobufs:
1906 err = -ENOBUFS;
1907 goto done;
1908
1909 martian_source:
1910 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1911 goto e_inval;
1912 }
1913
1914 int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1915 u8 tos, struct net_device *dev)
1916 {
1917 struct rtable * rth;
1918 unsigned hash;
1919 int iif = dev->ifindex;
1920
1921 tos &= IPTOS_RT_MASK;
1922 hash = rt_hash(daddr, saddr, iif);
1923
1924 rcu_read_lock();
1925 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
1926 rth = rcu_dereference(rth->u.dst.rt_next)) {
1927 if (rth->fl.fl4_dst == daddr &&
1928 rth->fl.fl4_src == saddr &&
1929 rth->fl.iif == iif &&
1930 rth->fl.oif == 0 &&
1931 rth->fl.mark == skb->mark &&
1932 rth->fl.fl4_tos == tos) {
1933 rth->u.dst.lastuse = jiffies;
1934 dst_hold(&rth->u.dst);
1935 rth->u.dst.__use++;
1936 RT_CACHE_STAT_INC(in_hit);
1937 rcu_read_unlock();
1938 skb->dst = (struct dst_entry*)rth;
1939 return 0;
1940 }
1941 RT_CACHE_STAT_INC(in_hlist_search);
1942 }
1943 rcu_read_unlock();
1944
1945 /* Multicast recognition logic is moved from route cache to here.
1946 The problem was that too many Ethernet cards have broken/missing
1947 hardware multicast filters :-( As result the host on multicasting
1948 network acquires a lot of useless route cache entries, sort of
1949 SDR messages from all the world. Now we try to get rid of them.
1950 Really, provided software IP multicast filter is organized
1951 reasonably (at least, hashed), it does not result in a slowdown
1952 comparing with route cache reject entries.
1953 Note, that multicast routers are not affected, because
1954 route cache entry is created eventually.
1955 */
1956 if (MULTICAST(daddr)) {
1957 struct in_device *in_dev;
1958
1959 rcu_read_lock();
1960 if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
1961 int our = ip_check_mc(in_dev, daddr, saddr,
1962 ip_hdr(skb)->protocol);
1963 if (our
1964 #ifdef CONFIG_IP_MROUTE
1965 || (!LOCAL_MCAST(daddr) && IN_DEV_MFORWARD(in_dev))
1966 #endif
1967 ) {
1968 rcu_read_unlock();
1969 return ip_route_input_mc(skb, daddr, saddr,
1970 tos, dev, our);
1971 }
1972 }
1973 rcu_read_unlock();
1974 return -EINVAL;
1975 }
1976 return ip_route_input_slow(skb, daddr, saddr, tos, dev);
1977 }
1978
1979 static inline int __mkroute_output(struct rtable **result,
1980 struct fib_result* res,
1981 const struct flowi *fl,
1982 const struct flowi *oldflp,
1983 struct net_device *dev_out,
1984 unsigned flags)
1985 {
1986 struct rtable *rth;
1987 struct in_device *in_dev;
1988 u32 tos = RT_FL_TOS(oldflp);
1989 int err = 0;
1990
1991 if (LOOPBACK(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
1992 return -EINVAL;
1993
1994 if (fl->fl4_dst == htonl(0xFFFFFFFF))
1995 res->type = RTN_BROADCAST;
1996 else if (MULTICAST(fl->fl4_dst))
1997 res->type = RTN_MULTICAST;
1998 else if (BADCLASS(fl->fl4_dst) || ZERONET(fl->fl4_dst))
1999 return -EINVAL;
2000
2001 if (dev_out->flags & IFF_LOOPBACK)
2002 flags |= RTCF_LOCAL;
2003
2004 /* get work reference to inet device */
2005 in_dev = in_dev_get(dev_out);
2006 if (!in_dev)
2007 return -EINVAL;
2008
2009 if (res->type == RTN_BROADCAST) {
2010 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2011 if (res->fi) {
2012 fib_info_put(res->fi);
2013 res->fi = NULL;
2014 }
2015 } else if (res->type == RTN_MULTICAST) {
2016 flags |= RTCF_MULTICAST|RTCF_LOCAL;
2017 if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
2018 oldflp->proto))
2019 flags &= ~RTCF_LOCAL;
2020 /* If multicast route do not exist use
2021 default one, but do not gateway in this case.
2022 Yes, it is hack.
2023 */
2024 if (res->fi && res->prefixlen < 4) {
2025 fib_info_put(res->fi);
2026 res->fi = NULL;
2027 }
2028 }
2029
2030
2031 rth = dst_alloc(&ipv4_dst_ops);
2032 if (!rth) {
2033 err = -ENOBUFS;
2034 goto cleanup;
2035 }
2036
2037 atomic_set(&rth->u.dst.__refcnt, 1);
2038 rth->u.dst.flags= DST_HOST;
2039 if (IN_DEV_CONF_GET(in_dev, NOXFRM))
2040 rth->u.dst.flags |= DST_NOXFRM;
2041 if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
2042 rth->u.dst.flags |= DST_NOPOLICY;
2043
2044 rth->fl.fl4_dst = oldflp->fl4_dst;
2045 rth->fl.fl4_tos = tos;
2046 rth->fl.fl4_src = oldflp->fl4_src;
2047 rth->fl.oif = oldflp->oif;
2048 rth->fl.mark = oldflp->mark;
2049 rth->rt_dst = fl->fl4_dst;
2050 rth->rt_src = fl->fl4_src;
2051 rth->rt_iif = oldflp->oif ? : dev_out->ifindex;
2052 /* get references to the devices that are to be hold by the routing
2053 cache entry */
2054 rth->u.dst.dev = dev_out;
2055 dev_hold(dev_out);
2056 rth->idev = in_dev_get(dev_out);
2057 rth->rt_gateway = fl->fl4_dst;
2058 rth->rt_spec_dst= fl->fl4_src;
2059
2060 rth->u.dst.output=ip_output;
2061
2062 RT_CACHE_STAT_INC(out_slow_tot);
2063
2064 if (flags & RTCF_LOCAL) {
2065 rth->u.dst.input = ip_local_deliver;
2066 rth->rt_spec_dst = fl->fl4_dst;
2067 }
2068 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2069 rth->rt_spec_dst = fl->fl4_src;
2070 if (flags & RTCF_LOCAL &&
2071 !(dev_out->flags & IFF_LOOPBACK)) {
2072 rth->u.dst.output = ip_mc_output;
2073 RT_CACHE_STAT_INC(out_slow_mc);
2074 }
2075 #ifdef CONFIG_IP_MROUTE
2076 if (res->type == RTN_MULTICAST) {
2077 if (IN_DEV_MFORWARD(in_dev) &&
2078 !LOCAL_MCAST(oldflp->fl4_dst)) {
2079 rth->u.dst.input = ip_mr_input;
2080 rth->u.dst.output = ip_mc_output;
2081 }
2082 }
2083 #endif
2084 }
2085
2086 rt_set_nexthop(rth, res, 0);
2087
2088 rth->rt_flags = flags;
2089
2090 *result = rth;
2091 cleanup:
2092 /* release work reference to inet device */
2093 in_dev_put(in_dev);
2094
2095 return err;
2096 }
2097
2098 static inline int ip_mkroute_output(struct rtable **rp,
2099 struct fib_result* res,
2100 const struct flowi *fl,
2101 const struct flowi *oldflp,
2102 struct net_device *dev_out,
2103 unsigned flags)
2104 {
2105 struct rtable *rth = NULL;
2106 int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
2107 unsigned hash;
2108 if (err == 0) {
2109 hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
2110 err = rt_intern_hash(hash, rth, rp);
2111 }
2112
2113 return err;
2114 }
2115
2116 /*
2117 * Major route resolver routine.
2118 */
2119
2120 static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
2121 {
2122 u32 tos = RT_FL_TOS(oldflp);
2123 struct flowi fl = { .nl_u = { .ip4_u =
2124 { .daddr = oldflp->fl4_dst,
2125 .saddr = oldflp->fl4_src,
2126 .tos = tos & IPTOS_RT_MASK,
2127 .scope = ((tos & RTO_ONLINK) ?
2128 RT_SCOPE_LINK :
2129 RT_SCOPE_UNIVERSE),
2130 } },
2131 .mark = oldflp->mark,
2132 .iif = init_net.loopback_dev->ifindex,
2133 .oif = oldflp->oif };
2134 struct fib_result res;
2135 unsigned flags = 0;
2136 struct net_device *dev_out = NULL;
2137 int free_res = 0;
2138 int err;
2139
2140
2141 res.fi = NULL;
2142 #ifdef CONFIG_IP_MULTIPLE_TABLES
2143 res.r = NULL;
2144 #endif
2145
2146 if (oldflp->fl4_src) {
2147 err = -EINVAL;
2148 if (MULTICAST(oldflp->fl4_src) ||
2149 BADCLASS(oldflp->fl4_src) ||
2150 ZERONET(oldflp->fl4_src))
2151 goto out;
2152
2153 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2154 dev_out = ip_dev_find(oldflp->fl4_src);
2155 if (dev_out == NULL)
2156 goto out;
2157
2158 /* I removed check for oif == dev_out->oif here.
2159 It was wrong for two reasons:
2160 1. ip_dev_find(saddr) can return wrong iface, if saddr is
2161 assigned to multiple interfaces.
2162 2. Moreover, we are allowed to send packets with saddr
2163 of another iface. --ANK
2164 */
2165
2166 if (oldflp->oif == 0
2167 && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
2168 /* Special hack: user can direct multicasts
2169 and limited broadcast via necessary interface
2170 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2171 This hack is not just for fun, it allows
2172 vic,vat and friends to work.
2173 They bind socket to loopback, set ttl to zero
2174 and expect that it will work.
2175 From the viewpoint of routing cache they are broken,
2176 because we are not allowed to build multicast path
2177 with loopback source addr (look, routing cache
2178 cannot know, that ttl is zero, so that packet
2179 will not leave this host and route is valid).
2180 Luckily, this hack is good workaround.
2181 */
2182
2183 fl.oif = dev_out->ifindex;
2184 goto make_route;
2185 }
2186 if (dev_out)
2187 dev_put(dev_out);
2188 dev_out = NULL;
2189 }
2190
2191
2192 if (oldflp->oif) {
2193 dev_out = dev_get_by_index(&init_net, oldflp->oif);
2194 err = -ENODEV;
2195 if (dev_out == NULL)
2196 goto out;
2197
2198 /* RACE: Check return value of inet_select_addr instead. */
2199 if (__in_dev_get_rtnl(dev_out) == NULL) {
2200 dev_put(dev_out);
2201 goto out; /* Wrong error code */
2202 }
2203
2204 if (LOCAL_MCAST(oldflp->fl4_dst) || oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
2205 if (!fl.fl4_src)
2206 fl.fl4_src = inet_select_addr(dev_out, 0,
2207 RT_SCOPE_LINK);
2208 goto make_route;
2209 }
2210 if (!fl.fl4_src) {
2211 if (MULTICAST(oldflp->fl4_dst))
2212 fl.fl4_src = inet_select_addr(dev_out, 0,
2213 fl.fl4_scope);
2214 else if (!oldflp->fl4_dst)
2215 fl.fl4_src = inet_select_addr(dev_out, 0,
2216 RT_SCOPE_HOST);
2217 }
2218 }
2219
2220 if (!fl.fl4_dst) {
2221 fl.fl4_dst = fl.fl4_src;
2222 if (!fl.fl4_dst)
2223 fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
2224 if (dev_out)
2225 dev_put(dev_out);
2226 dev_out = init_net.loopback_dev;
2227 dev_hold(dev_out);
2228 fl.oif = init_net.loopback_dev->ifindex;
2229 res.type = RTN_LOCAL;
2230 flags |= RTCF_LOCAL;
2231 goto make_route;
2232 }
2233
2234 if (fib_lookup(&fl, &res)) {
2235 res.fi = NULL;
2236 if (oldflp->oif) {
2237 /* Apparently, routing tables are wrong. Assume,
2238 that the destination is on link.
2239
2240 WHY? DW.
2241 Because we are allowed to send to iface
2242 even if it has NO routes and NO assigned
2243 addresses. When oif is specified, routing
2244 tables are looked up with only one purpose:
2245 to catch if destination is gatewayed, rather than
2246 direct. Moreover, if MSG_DONTROUTE is set,
2247 we send packet, ignoring both routing tables
2248 and ifaddr state. --ANK
2249
2250
2251 We could make it even if oif is unknown,
2252 likely IPv6, but we do not.
2253 */
2254
2255 if (fl.fl4_src == 0)
2256 fl.fl4_src = inet_select_addr(dev_out, 0,
2257 RT_SCOPE_LINK);
2258 res.type = RTN_UNICAST;
2259 goto make_route;
2260 }
2261 if (dev_out)
2262 dev_put(dev_out);
2263 err = -ENETUNREACH;
2264 goto out;
2265 }
2266 free_res = 1;
2267
2268 if (res.type == RTN_LOCAL) {
2269 if (!fl.fl4_src)
2270 fl.fl4_src = fl.fl4_dst;
2271 if (dev_out)
2272 dev_put(dev_out);
2273 dev_out = init_net.loopback_dev;
2274 dev_hold(dev_out);
2275 fl.oif = dev_out->ifindex;
2276 if (res.fi)
2277 fib_info_put(res.fi);
2278 res.fi = NULL;
2279 flags |= RTCF_LOCAL;
2280 goto make_route;
2281 }
2282
2283 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2284 if (res.fi->fib_nhs > 1 && fl.oif == 0)
2285 fib_select_multipath(&fl, &res);
2286 else
2287 #endif
2288 if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
2289 fib_select_default(&fl, &res);
2290
2291 if (!fl.fl4_src)
2292 fl.fl4_src = FIB_RES_PREFSRC(res);
2293
2294 if (dev_out)
2295 dev_put(dev_out);
2296 dev_out = FIB_RES_DEV(res);
2297 dev_hold(dev_out);
2298 fl.oif = dev_out->ifindex;
2299
2300
2301 make_route:
2302 err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
2303
2304
2305 if (free_res)
2306 fib_res_put(&res);
2307 if (dev_out)
2308 dev_put(dev_out);
2309 out: return err;
2310 }
2311
2312 int __ip_route_output_key(struct rtable **rp, const struct flowi *flp)
2313 {
2314 unsigned hash;
2315 struct rtable *rth;
2316
2317 hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
2318
2319 rcu_read_lock_bh();
2320 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2321 rth = rcu_dereference(rth->u.dst.rt_next)) {
2322 if (rth->fl.fl4_dst == flp->fl4_dst &&
2323 rth->fl.fl4_src == flp->fl4_src &&
2324 rth->fl.iif == 0 &&
2325 rth->fl.oif == flp->oif &&
2326 rth->fl.mark == flp->mark &&
2327 !((rth->fl.fl4_tos ^ flp->fl4_tos) &
2328 (IPTOS_RT_MASK | RTO_ONLINK))) {
2329 rth->u.dst.lastuse = jiffies;
2330 dst_hold(&rth->u.dst);
2331 rth->u.dst.__use++;
2332 RT_CACHE_STAT_INC(out_hit);
2333 rcu_read_unlock_bh();
2334 *rp = rth;
2335 return 0;
2336 }
2337 RT_CACHE_STAT_INC(out_hlist_search);
2338 }
2339 rcu_read_unlock_bh();
2340
2341 return ip_route_output_slow(rp, flp);
2342 }
2343
2344 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2345
2346 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2347 {
2348 }
2349
2350 static struct dst_ops ipv4_dst_blackhole_ops = {
2351 .family = AF_INET,
2352 .protocol = __constant_htons(ETH_P_IP),
2353 .destroy = ipv4_dst_destroy,
2354 .check = ipv4_dst_check,
2355 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2356 .entry_size = sizeof(struct rtable),
2357 };
2358
2359
2360 static int ipv4_blackhole_output(struct sk_buff *skb)
2361 {
2362 kfree_skb(skb);
2363 return 0;
2364 }
2365
2366 static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp, struct sock *sk)
2367 {
2368 struct rtable *ort = *rp;
2369 struct rtable *rt = (struct rtable *)
2370 dst_alloc(&ipv4_dst_blackhole_ops);
2371
2372 if (rt) {
2373 struct dst_entry *new = &rt->u.dst;
2374
2375 atomic_set(&new->__refcnt, 1);
2376 new->__use = 1;
2377 new->input = ipv4_blackhole_output;
2378 new->output = ipv4_blackhole_output;
2379 memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
2380
2381 new->dev = ort->u.dst.dev;
2382 if (new->dev)
2383 dev_hold(new->dev);
2384
2385 rt->fl = ort->fl;
2386
2387 rt->idev = ort->idev;
2388 if (rt->idev)
2389 in_dev_hold(rt->idev);
2390 rt->rt_flags = ort->rt_flags;
2391 rt->rt_type = ort->rt_type;
2392 rt->rt_dst = ort->rt_dst;
2393 rt->rt_src = ort->rt_src;
2394 rt->rt_iif = ort->rt_iif;
2395 rt->rt_gateway = ort->rt_gateway;
2396 rt->rt_spec_dst = ort->rt_spec_dst;
2397 rt->peer = ort->peer;
2398 if (rt->peer)
2399 atomic_inc(&rt->peer->refcnt);
2400
2401 dst_free(new);
2402 }
2403
2404 dst_release(&(*rp)->u.dst);
2405 *rp = rt;
2406 return (rt ? 0 : -ENOMEM);
2407 }
2408
2409 int ip_route_output_flow(struct rtable **rp, struct flowi *flp, struct sock *sk, int flags)
2410 {
2411 int err;
2412
2413 if ((err = __ip_route_output_key(rp, flp)) != 0)
2414 return err;
2415
2416 if (flp->proto) {
2417 if (!flp->fl4_src)
2418 flp->fl4_src = (*rp)->rt_src;
2419 if (!flp->fl4_dst)
2420 flp->fl4_dst = (*rp)->rt_dst;
2421 err = __xfrm_lookup((struct dst_entry **)rp, flp, sk, flags);
2422 if (err == -EREMOTE)
2423 err = ipv4_dst_blackhole(rp, flp, sk);
2424
2425 return err;
2426 }
2427
2428 return 0;
2429 }
2430
2431 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2432
2433 int ip_route_output_key(struct rtable **rp, struct flowi *flp)
2434 {
2435 return ip_route_output_flow(rp, flp, NULL, 0);
2436 }
2437
2438 static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
2439 int nowait, unsigned int flags)
2440 {
2441 struct rtable *rt = (struct rtable*)skb->dst;
2442 struct rtmsg *r;
2443 struct nlmsghdr *nlh;
2444 long expires;
2445 u32 id = 0, ts = 0, tsage = 0, error;
2446
2447 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2448 if (nlh == NULL)
2449 return -EMSGSIZE;
2450
2451 r = nlmsg_data(nlh);
2452 r->rtm_family = AF_INET;
2453 r->rtm_dst_len = 32;
2454 r->rtm_src_len = 0;
2455 r->rtm_tos = rt->fl.fl4_tos;
2456 r->rtm_table = RT_TABLE_MAIN;
2457 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2458 r->rtm_type = rt->rt_type;
2459 r->rtm_scope = RT_SCOPE_UNIVERSE;
2460 r->rtm_protocol = RTPROT_UNSPEC;
2461 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2462 if (rt->rt_flags & RTCF_NOTIFY)
2463 r->rtm_flags |= RTM_F_NOTIFY;
2464
2465 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2466
2467 if (rt->fl.fl4_src) {
2468 r->rtm_src_len = 32;
2469 NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
2470 }
2471 if (rt->u.dst.dev)
2472 NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
2473 #ifdef CONFIG_NET_CLS_ROUTE
2474 if (rt->u.dst.tclassid)
2475 NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
2476 #endif
2477 if (rt->fl.iif)
2478 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2479 else if (rt->rt_src != rt->fl.fl4_src)
2480 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2481
2482 if (rt->rt_dst != rt->rt_gateway)
2483 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2484
2485 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
2486 goto nla_put_failure;
2487
2488 error = rt->u.dst.error;
2489 expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
2490 if (rt->peer) {
2491 id = rt->peer->ip_id_count;
2492 if (rt->peer->tcp_ts_stamp) {
2493 ts = rt->peer->tcp_ts;
2494 tsage = get_seconds() - rt->peer->tcp_ts_stamp;
2495 }
2496 }
2497
2498 if (rt->fl.iif) {
2499 #ifdef CONFIG_IP_MROUTE
2500 __be32 dst = rt->rt_dst;
2501
2502 if (MULTICAST(dst) && !LOCAL_MCAST(dst) &&
2503 IPV4_DEVCONF_ALL(MC_FORWARDING)) {
2504 int err = ipmr_get_route(skb, r, nowait);
2505 if (err <= 0) {
2506 if (!nowait) {
2507 if (err == 0)
2508 return 0;
2509 goto nla_put_failure;
2510 } else {
2511 if (err == -EMSGSIZE)
2512 goto nla_put_failure;
2513 error = err;
2514 }
2515 }
2516 } else
2517 #endif
2518 NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
2519 }
2520
2521 if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
2522 expires, error) < 0)
2523 goto nla_put_failure;
2524
2525 return nlmsg_end(skb, nlh);
2526
2527 nla_put_failure:
2528 nlmsg_cancel(skb, nlh);
2529 return -EMSGSIZE;
2530 }
2531
2532 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2533 {
2534 struct rtmsg *rtm;
2535 struct nlattr *tb[RTA_MAX+1];
2536 struct rtable *rt = NULL;
2537 __be32 dst = 0;
2538 __be32 src = 0;
2539 u32 iif;
2540 int err;
2541 struct sk_buff *skb;
2542
2543 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2544 if (err < 0)
2545 goto errout;
2546
2547 rtm = nlmsg_data(nlh);
2548
2549 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2550 if (skb == NULL) {
2551 err = -ENOBUFS;
2552 goto errout;
2553 }
2554
2555 /* Reserve room for dummy headers, this skb can pass
2556 through good chunk of routing engine.
2557 */
2558 skb_reset_mac_header(skb);
2559 skb_reset_network_header(skb);
2560
2561 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2562 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2563 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2564
2565 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2566 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2567 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2568
2569 if (iif) {
2570 struct net_device *dev;
2571
2572 dev = __dev_get_by_index(&init_net, iif);
2573 if (dev == NULL) {
2574 err = -ENODEV;
2575 goto errout_free;
2576 }
2577
2578 skb->protocol = htons(ETH_P_IP);
2579 skb->dev = dev;
2580 local_bh_disable();
2581 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2582 local_bh_enable();
2583
2584 rt = (struct rtable*) skb->dst;
2585 if (err == 0 && rt->u.dst.error)
2586 err = -rt->u.dst.error;
2587 } else {
2588 struct flowi fl = {
2589 .nl_u = {
2590 .ip4_u = {
2591 .daddr = dst,
2592 .saddr = src,
2593 .tos = rtm->rtm_tos,
2594 },
2595 },
2596 .oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2597 };
2598 err = ip_route_output_key(&rt, &fl);
2599 }
2600
2601 if (err)
2602 goto errout_free;
2603
2604 skb->dst = &rt->u.dst;
2605 if (rtm->rtm_flags & RTM_F_NOTIFY)
2606 rt->rt_flags |= RTCF_NOTIFY;
2607
2608 err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2609 RTM_NEWROUTE, 0, 0);
2610 if (err <= 0)
2611 goto errout_free;
2612
2613 err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
2614 errout:
2615 return err;
2616
2617 errout_free:
2618 kfree_skb(skb);
2619 goto errout;
2620 }
2621
2622 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2623 {
2624 struct rtable *rt;
2625 int h, s_h;
2626 int idx, s_idx;
2627
2628 s_h = cb->args[0];
2629 s_idx = idx = cb->args[1];
2630 for (h = 0; h <= rt_hash_mask; h++) {
2631 if (h < s_h) continue;
2632 if (h > s_h)
2633 s_idx = 0;
2634 rcu_read_lock_bh();
2635 for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
2636 rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
2637 if (idx < s_idx)
2638 continue;
2639 skb->dst = dst_clone(&rt->u.dst);
2640 if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
2641 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2642 1, NLM_F_MULTI) <= 0) {
2643 dst_release(xchg(&skb->dst, NULL));
2644 rcu_read_unlock_bh();
2645 goto done;
2646 }
2647 dst_release(xchg(&skb->dst, NULL));
2648 }
2649 rcu_read_unlock_bh();
2650 }
2651
2652 done:
2653 cb->args[0] = h;
2654 cb->args[1] = idx;
2655 return skb->len;
2656 }
2657
2658 void ip_rt_multicast_event(struct in_device *in_dev)
2659 {
2660 rt_cache_flush(0);
2661 }
2662
2663 #ifdef CONFIG_SYSCTL
2664 static int flush_delay;
2665
2666 static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
2667 struct file *filp, void __user *buffer,
2668 size_t *lenp, loff_t *ppos)
2669 {
2670 if (write) {
2671 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
2672 rt_cache_flush(flush_delay);
2673 return 0;
2674 }
2675
2676 return -EINVAL;
2677 }
2678
2679 static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
2680 int __user *name,
2681 int nlen,
2682 void __user *oldval,
2683 size_t __user *oldlenp,
2684 void __user *newval,
2685 size_t newlen)
2686 {
2687 int delay;
2688 if (newlen != sizeof(int))
2689 return -EINVAL;
2690 if (get_user(delay, (int __user *)newval))
2691 return -EFAULT;
2692 rt_cache_flush(delay);
2693 return 0;
2694 }
2695
2696 ctl_table ipv4_route_table[] = {
2697 {
2698 .ctl_name = NET_IPV4_ROUTE_FLUSH,
2699 .procname = "flush",
2700 .data = &flush_delay,
2701 .maxlen = sizeof(int),
2702 .mode = 0200,
2703 .proc_handler = &ipv4_sysctl_rtcache_flush,
2704 .strategy = &ipv4_sysctl_rtcache_flush_strategy,
2705 },
2706 {
2707 .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
2708 .procname = "min_delay",
2709 .data = &ip_rt_min_delay,
2710 .maxlen = sizeof(int),
2711 .mode = 0644,
2712 .proc_handler = &proc_dointvec_jiffies,
2713 .strategy = &sysctl_jiffies,
2714 },
2715 {
2716 .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
2717 .procname = "max_delay",
2718 .data = &ip_rt_max_delay,
2719 .maxlen = sizeof(int),
2720 .mode = 0644,
2721 .proc_handler = &proc_dointvec_jiffies,
2722 .strategy = &sysctl_jiffies,
2723 },
2724 {
2725 .ctl_name = NET_IPV4_ROUTE_GC_THRESH,
2726 .procname = "gc_thresh",
2727 .data = &ipv4_dst_ops.gc_thresh,
2728 .maxlen = sizeof(int),
2729 .mode = 0644,
2730 .proc_handler = &proc_dointvec,
2731 },
2732 {
2733 .ctl_name = NET_IPV4_ROUTE_MAX_SIZE,
2734 .procname = "max_size",
2735 .data = &ip_rt_max_size,
2736 .maxlen = sizeof(int),
2737 .mode = 0644,
2738 .proc_handler = &proc_dointvec,
2739 },
2740 {
2741 /* Deprecated. Use gc_min_interval_ms */
2742
2743 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL,
2744 .procname = "gc_min_interval",
2745 .data = &ip_rt_gc_min_interval,
2746 .maxlen = sizeof(int),
2747 .mode = 0644,
2748 .proc_handler = &proc_dointvec_jiffies,
2749 .strategy = &sysctl_jiffies,
2750 },
2751 {
2752 .ctl_name = NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
2753 .procname = "gc_min_interval_ms",
2754 .data = &ip_rt_gc_min_interval,
2755 .maxlen = sizeof(int),
2756 .mode = 0644,
2757 .proc_handler = &proc_dointvec_ms_jiffies,
2758 .strategy = &sysctl_ms_jiffies,
2759 },
2760 {
2761 .ctl_name = NET_IPV4_ROUTE_GC_TIMEOUT,
2762 .procname = "gc_timeout",
2763 .data = &ip_rt_gc_timeout,
2764 .maxlen = sizeof(int),
2765 .mode = 0644,
2766 .proc_handler = &proc_dointvec_jiffies,
2767 .strategy = &sysctl_jiffies,
2768 },
2769 {
2770 .ctl_name = NET_IPV4_ROUTE_GC_INTERVAL,
2771 .procname = "gc_interval",
2772 .data = &ip_rt_gc_interval,
2773 .maxlen = sizeof(int),
2774 .mode = 0644,
2775 .proc_handler = &proc_dointvec_jiffies,
2776 .strategy = &sysctl_jiffies,
2777 },
2778 {
2779 .ctl_name = NET_IPV4_ROUTE_REDIRECT_LOAD,
2780 .procname = "redirect_load",
2781 .data = &ip_rt_redirect_load,
2782 .maxlen = sizeof(int),
2783 .mode = 0644,
2784 .proc_handler = &proc_dointvec,
2785 },
2786 {
2787 .ctl_name = NET_IPV4_ROUTE_REDIRECT_NUMBER,
2788 .procname = "redirect_number",
2789 .data = &ip_rt_redirect_number,
2790 .maxlen = sizeof(int),
2791 .mode = 0644,
2792 .proc_handler = &proc_dointvec,
2793 },
2794 {
2795 .ctl_name = NET_IPV4_ROUTE_REDIRECT_SILENCE,
2796 .procname = "redirect_silence",
2797 .data = &ip_rt_redirect_silence,
2798 .maxlen = sizeof(int),
2799 .mode = 0644,
2800 .proc_handler = &proc_dointvec,
2801 },
2802 {
2803 .ctl_name = NET_IPV4_ROUTE_ERROR_COST,
2804 .procname = "error_cost",
2805 .data = &ip_rt_error_cost,
2806 .maxlen = sizeof(int),
2807 .mode = 0644,
2808 .proc_handler = &proc_dointvec,
2809 },
2810 {
2811 .ctl_name = NET_IPV4_ROUTE_ERROR_BURST,
2812 .procname = "error_burst",
2813 .data = &ip_rt_error_burst,
2814 .maxlen = sizeof(int),
2815 .mode = 0644,
2816 .proc_handler = &proc_dointvec,
2817 },
2818 {
2819 .ctl_name = NET_IPV4_ROUTE_GC_ELASTICITY,
2820 .procname = "gc_elasticity",
2821 .data = &ip_rt_gc_elasticity,
2822 .maxlen = sizeof(int),
2823 .mode = 0644,
2824 .proc_handler = &proc_dointvec,
2825 },
2826 {
2827 .ctl_name = NET_IPV4_ROUTE_MTU_EXPIRES,
2828 .procname = "mtu_expires",
2829 .data = &ip_rt_mtu_expires,
2830 .maxlen = sizeof(int),
2831 .mode = 0644,
2832 .proc_handler = &proc_dointvec_jiffies,
2833 .strategy = &sysctl_jiffies,
2834 },
2835 {
2836 .ctl_name = NET_IPV4_ROUTE_MIN_PMTU,
2837 .procname = "min_pmtu",
2838 .data = &ip_rt_min_pmtu,
2839 .maxlen = sizeof(int),
2840 .mode = 0644,
2841 .proc_handler = &proc_dointvec,
2842 },
2843 {
2844 .ctl_name = NET_IPV4_ROUTE_MIN_ADVMSS,
2845 .procname = "min_adv_mss",
2846 .data = &ip_rt_min_advmss,
2847 .maxlen = sizeof(int),
2848 .mode = 0644,
2849 .proc_handler = &proc_dointvec,
2850 },
2851 {
2852 .ctl_name = NET_IPV4_ROUTE_SECRET_INTERVAL,
2853 .procname = "secret_interval",
2854 .data = &ip_rt_secret_interval,
2855 .maxlen = sizeof(int),
2856 .mode = 0644,
2857 .proc_handler = &proc_dointvec_jiffies,
2858 .strategy = &sysctl_jiffies,
2859 },
2860 { .ctl_name = 0 }
2861 };
2862 #endif
2863
2864 #ifdef CONFIG_NET_CLS_ROUTE
2865 struct ip_rt_acct *ip_rt_acct;
2866
2867 /* This code sucks. But you should have seen it before! --RR */
2868
2869 /* IP route accounting ptr for this logical cpu number. */
2870 #define IP_RT_ACCT_CPU(i) (ip_rt_acct + i * 256)
2871
2872 #ifdef CONFIG_PROC_FS
2873 static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
2874 int length, int *eof, void *data)
2875 {
2876 unsigned int i;
2877
2878 if ((offset & 3) || (length & 3))
2879 return -EIO;
2880
2881 if (offset >= sizeof(struct ip_rt_acct) * 256) {
2882 *eof = 1;
2883 return 0;
2884 }
2885
2886 if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
2887 length = sizeof(struct ip_rt_acct) * 256 - offset;
2888 *eof = 1;
2889 }
2890
2891 offset /= sizeof(u32);
2892
2893 if (length > 0) {
2894 u32 *src = ((u32 *) IP_RT_ACCT_CPU(0)) + offset;
2895 u32 *dst = (u32 *) buffer;
2896
2897 /* Copy first cpu. */
2898 *start = buffer;
2899 memcpy(dst, src, length);
2900
2901 /* Add the other cpus in, one int at a time */
2902 for_each_possible_cpu(i) {
2903 unsigned int j;
2904
2905 src = ((u32 *) IP_RT_ACCT_CPU(i)) + offset;
2906
2907 for (j = 0; j < length/4; j++)
2908 dst[j] += src[j];
2909 }
2910 }
2911 return length;
2912 }
2913 #endif /* CONFIG_PROC_FS */
2914 #endif /* CONFIG_NET_CLS_ROUTE */
2915
2916 static __initdata unsigned long rhash_entries;
2917 static int __init set_rhash_entries(char *str)
2918 {
2919 if (!str)
2920 return 0;
2921 rhash_entries = simple_strtoul(str, &str, 0);
2922 return 1;
2923 }
2924 __setup("rhash_entries=", set_rhash_entries);
2925
2926 int __init ip_rt_init(void)
2927 {
2928 int rc = 0;
2929
2930 rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
2931 (jiffies ^ (jiffies >> 7)));
2932
2933 #ifdef CONFIG_NET_CLS_ROUTE
2934 {
2935 int order;
2936 for (order = 0;
2937 (PAGE_SIZE << order) < 256 * sizeof(struct ip_rt_acct) * NR_CPUS; order++)
2938 /* NOTHING */;
2939 ip_rt_acct = (struct ip_rt_acct *)__get_free_pages(GFP_KERNEL, order);
2940 if (!ip_rt_acct)
2941 panic("IP: failed to allocate ip_rt_acct\n");
2942 memset(ip_rt_acct, 0, PAGE_SIZE << order);
2943 }
2944 #endif
2945
2946 ipv4_dst_ops.kmem_cachep =
2947 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2948 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2949
2950 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2951
2952 rt_hash_table = (struct rt_hash_bucket *)
2953 alloc_large_system_hash("IP route cache",
2954 sizeof(struct rt_hash_bucket),
2955 rhash_entries,
2956 (num_physpages >= 128 * 1024) ?
2957 15 : 17,
2958 0,
2959 &rt_hash_log,
2960 &rt_hash_mask,
2961 0);
2962 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
2963 rt_hash_lock_init();
2964
2965 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
2966 ip_rt_max_size = (rt_hash_mask + 1) * 16;
2967
2968 devinet_init();
2969 ip_fib_init();
2970
2971 init_timer(&rt_flush_timer);
2972 rt_flush_timer.function = rt_run_flush;
2973 init_timer(&rt_secret_timer);
2974 rt_secret_timer.function = rt_secret_rebuild;
2975
2976 /* All the timers, started at system startup tend
2977 to synchronize. Perturb it a bit.
2978 */
2979 schedule_delayed_work(&expires_work,
2980 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
2981
2982 rt_secret_timer.expires = jiffies + net_random() % ip_rt_secret_interval +
2983 ip_rt_secret_interval;
2984 add_timer(&rt_secret_timer);
2985
2986 #ifdef CONFIG_PROC_FS
2987 {
2988 struct proc_dir_entry *rtstat_pde = NULL; /* keep gcc happy */
2989 if (!proc_net_fops_create(&init_net, "rt_cache", S_IRUGO, &rt_cache_seq_fops) ||
2990 !(rtstat_pde = create_proc_entry("rt_cache", S_IRUGO,
2991 init_net.proc_net_stat))) {
2992 return -ENOMEM;
2993 }
2994 rtstat_pde->proc_fops = &rt_cpu_seq_fops;
2995 }
2996 #ifdef CONFIG_NET_CLS_ROUTE
2997 create_proc_read_entry("rt_acct", 0, init_net.proc_net, ip_rt_acct_read, NULL);
2998 #endif
2999 #endif
3000 #ifdef CONFIG_XFRM
3001 xfrm_init();
3002 xfrm4_init();
3003 #endif
3004 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
3005
3006 return rc;
3007 }
3008
3009 EXPORT_SYMBOL(__ip_select_ident);
3010 EXPORT_SYMBOL(ip_route_input);
3011 EXPORT_SYMBOL(ip_route_output_key);
x86 "subsystem" repository