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Merge tag 'v3.10.81' into update
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <asm/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/net_namespace.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/netevent.h>
106 #include <net/rtnetlink.h>
107 #ifdef CONFIG_SYSCTL
108 #include <linux/sysctl.h>
109 #include <linux/kmemleak.h>
110 #endif
111 #include <net/secure_seq.h>
112
113 #define RT_FL_TOS(oldflp4) \
114 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
115
116 #define IP_MAX_MTU 0xFFF0
117
118 #define RT_GC_TIMEOUT (300*HZ)
119
120 static int ip_rt_max_size;
121 static int ip_rt_redirect_number __read_mostly = 9;
122 static int ip_rt_redirect_load __read_mostly = HZ / 50;
123 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
124 static int ip_rt_error_cost __read_mostly = HZ;
125 static int ip_rt_error_burst __read_mostly = 5 * HZ;
126 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
127 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
128 static int ip_rt_min_advmss __read_mostly = 256;
129
130 /*
131 * Interface to generic destination cache.
132 */
133
134 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
135 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
136 static unsigned int ipv4_mtu(const struct dst_entry *dst);
137 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
138 static void ipv4_link_failure(struct sk_buff *skb);
139 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
140 struct sk_buff *skb, u32 mtu);
141 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb);
143 static void ipv4_dst_destroy(struct dst_entry *dst);
144
145 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
146 int how)
147 {
148 }
149
150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
151 {
152 WARN_ON(1);
153 return NULL;
154 }
155
156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
157 struct sk_buff *skb,
158 const void *daddr);
159
160 static struct dst_ops ipv4_dst_ops = {
161 .family = AF_INET,
162 .protocol = cpu_to_be16(ETH_P_IP),
163 .check = ipv4_dst_check,
164 .default_advmss = ipv4_default_advmss,
165 .mtu = ipv4_mtu,
166 .cow_metrics = ipv4_cow_metrics,
167 .destroy = ipv4_dst_destroy,
168 .ifdown = ipv4_dst_ifdown,
169 .negative_advice = ipv4_negative_advice,
170 .link_failure = ipv4_link_failure,
171 .update_pmtu = ip_rt_update_pmtu,
172 .redirect = ip_do_redirect,
173 .local_out = __ip_local_out,
174 .neigh_lookup = ipv4_neigh_lookup,
175 };
176
177 #define ECN_OR_COST(class) TC_PRIO_##class
178
179 const __u8 ip_tos2prio[16] = {
180 TC_PRIO_BESTEFFORT,
181 ECN_OR_COST(BESTEFFORT),
182 TC_PRIO_BESTEFFORT,
183 ECN_OR_COST(BESTEFFORT),
184 TC_PRIO_BULK,
185 ECN_OR_COST(BULK),
186 TC_PRIO_BULK,
187 ECN_OR_COST(BULK),
188 TC_PRIO_INTERACTIVE,
189 ECN_OR_COST(INTERACTIVE),
190 TC_PRIO_INTERACTIVE,
191 ECN_OR_COST(INTERACTIVE),
192 TC_PRIO_INTERACTIVE_BULK,
193 ECN_OR_COST(INTERACTIVE_BULK),
194 TC_PRIO_INTERACTIVE_BULK,
195 ECN_OR_COST(INTERACTIVE_BULK)
196 };
197 EXPORT_SYMBOL(ip_tos2prio);
198
199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
200 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
201
202 #ifdef CONFIG_PROC_FS
203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
204 {
205 if (*pos)
206 return NULL;
207 return SEQ_START_TOKEN;
208 }
209
210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
211 {
212 ++*pos;
213 return NULL;
214 }
215
216 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
217 {
218 }
219
220 static int rt_cache_seq_show(struct seq_file *seq, void *v)
221 {
222 if (v == SEQ_START_TOKEN)
223 seq_printf(seq, "%-127s\n",
224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
226 "HHUptod\tSpecDst");
227 return 0;
228 }
229
230 static const struct seq_operations rt_cache_seq_ops = {
231 .start = rt_cache_seq_start,
232 .next = rt_cache_seq_next,
233 .stop = rt_cache_seq_stop,
234 .show = rt_cache_seq_show,
235 };
236
237 static int rt_cache_seq_open(struct inode *inode, struct file *file)
238 {
239 return seq_open(file, &rt_cache_seq_ops);
240 }
241
242 static const struct file_operations rt_cache_seq_fops = {
243 .owner = THIS_MODULE,
244 .open = rt_cache_seq_open,
245 .read = seq_read,
246 .llseek = seq_lseek,
247 .release = seq_release,
248 };
249
250
251 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
252 {
253 int cpu;
254
255 if (*pos == 0)
256 return SEQ_START_TOKEN;
257
258 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
259 if (!cpu_possible(cpu))
260 continue;
261 *pos = cpu+1;
262 return &per_cpu(rt_cache_stat, cpu);
263 }
264 return NULL;
265 }
266
267 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
268 {
269 int cpu;
270
271 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
272 if (!cpu_possible(cpu))
273 continue;
274 *pos = cpu+1;
275 return &per_cpu(rt_cache_stat, cpu);
276 }
277 return NULL;
278
279 }
280
281 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
282 {
283
284 }
285
286 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
287 {
288 struct rt_cache_stat *st = v;
289
290 if (v == SEQ_START_TOKEN) {
291 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");
292 return 0;
293 }
294
295 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
296 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
297 dst_entries_get_slow(&ipv4_dst_ops),
298 st->in_hit,
299 st->in_slow_tot,
300 st->in_slow_mc,
301 st->in_no_route,
302 st->in_brd,
303 st->in_martian_dst,
304 st->in_martian_src,
305
306 st->out_hit,
307 st->out_slow_tot,
308 st->out_slow_mc,
309
310 st->gc_total,
311 st->gc_ignored,
312 st->gc_goal_miss,
313 st->gc_dst_overflow,
314 st->in_hlist_search,
315 st->out_hlist_search
316 );
317 return 0;
318 }
319
320 static const struct seq_operations rt_cpu_seq_ops = {
321 .start = rt_cpu_seq_start,
322 .next = rt_cpu_seq_next,
323 .stop = rt_cpu_seq_stop,
324 .show = rt_cpu_seq_show,
325 };
326
327
328 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
329 {
330 return seq_open(file, &rt_cpu_seq_ops);
331 }
332
333 static const struct file_operations rt_cpu_seq_fops = {
334 .owner = THIS_MODULE,
335 .open = rt_cpu_seq_open,
336 .read = seq_read,
337 .llseek = seq_lseek,
338 .release = seq_release,
339 };
340
341 #ifdef CONFIG_IP_ROUTE_CLASSID
342 static int rt_acct_proc_show(struct seq_file *m, void *v)
343 {
344 struct ip_rt_acct *dst, *src;
345 unsigned int i, j;
346
347 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
348 if (!dst)
349 return -ENOMEM;
350
351 for_each_possible_cpu(i) {
352 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
353 for (j = 0; j < 256; j++) {
354 dst[j].o_bytes += src[j].o_bytes;
355 dst[j].o_packets += src[j].o_packets;
356 dst[j].i_bytes += src[j].i_bytes;
357 dst[j].i_packets += src[j].i_packets;
358 }
359 }
360
361 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
362 kfree(dst);
363 return 0;
364 }
365
366 static int rt_acct_proc_open(struct inode *inode, struct file *file)
367 {
368 return single_open(file, rt_acct_proc_show, NULL);
369 }
370
371 static const struct file_operations rt_acct_proc_fops = {
372 .owner = THIS_MODULE,
373 .open = rt_acct_proc_open,
374 .read = seq_read,
375 .llseek = seq_lseek,
376 .release = single_release,
377 };
378 #endif
379
380 static int __net_init ip_rt_do_proc_init(struct net *net)
381 {
382 struct proc_dir_entry *pde;
383
384 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
385 &rt_cache_seq_fops);
386 if (!pde)
387 goto err1;
388
389 pde = proc_create("rt_cache", S_IRUGO,
390 net->proc_net_stat, &rt_cpu_seq_fops);
391 if (!pde)
392 goto err2;
393
394 #ifdef CONFIG_IP_ROUTE_CLASSID
395 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
396 if (!pde)
397 goto err3;
398 #endif
399 return 0;
400
401 #ifdef CONFIG_IP_ROUTE_CLASSID
402 err3:
403 remove_proc_entry("rt_cache", net->proc_net_stat);
404 #endif
405 err2:
406 remove_proc_entry("rt_cache", net->proc_net);
407 err1:
408 return -ENOMEM;
409 }
410
411 static void __net_exit ip_rt_do_proc_exit(struct net *net)
412 {
413 remove_proc_entry("rt_cache", net->proc_net_stat);
414 remove_proc_entry("rt_cache", net->proc_net);
415 #ifdef CONFIG_IP_ROUTE_CLASSID
416 remove_proc_entry("rt_acct", net->proc_net);
417 #endif
418 }
419
420 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
421 .init = ip_rt_do_proc_init,
422 .exit = ip_rt_do_proc_exit,
423 };
424
425 static int __init ip_rt_proc_init(void)
426 {
427 return register_pernet_subsys(&ip_rt_proc_ops);
428 }
429
430 #else
431 static inline int ip_rt_proc_init(void)
432 {
433 return 0;
434 }
435 #endif /* CONFIG_PROC_FS */
436
437 static inline bool rt_is_expired(const struct rtable *rth)
438 {
439 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
440 }
441
442 void rt_cache_flush(struct net *net)
443 {
444 rt_genid_bump(net);
445 }
446
447 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
448 struct sk_buff *skb,
449 const void *daddr)
450 {
451 struct net_device *dev = dst->dev;
452 const __be32 *pkey = daddr;
453 const struct rtable *rt;
454 struct neighbour *n;
455
456 rt = (const struct rtable *) dst;
457 if (rt->rt_gateway)
458 pkey = (const __be32 *) &rt->rt_gateway;
459 else if (skb)
460 pkey = &ip_hdr(skb)->daddr;
461
462 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
463 if (n)
464 return n;
465 return neigh_create(&arp_tbl, pkey, dev);
466 }
467
468 #define IP_IDENTS_SZ 2048u
469 struct ip_ident_bucket {
470 atomic_t id;
471 u32 stamp32;
472 };
473
474 static struct ip_ident_bucket *ip_idents __read_mostly;
475
476 /* In order to protect privacy, we add a perturbation to identifiers
477 * if one generator is seldom used. This makes hard for an attacker
478 * to infer how many packets were sent between two points in time.
479 */
480 u32 ip_idents_reserve(u32 hash, int segs)
481 {
482 struct ip_ident_bucket *bucket = ip_idents + hash % IP_IDENTS_SZ;
483 u32 old = ACCESS_ONCE(bucket->stamp32);
484 u32 now = (u32)jiffies;
485 u32 delta = 0;
486
487 if (old != now && cmpxchg(&bucket->stamp32, old, now) == old) {
488 u64 x = prandom_u32();
489
490 x *= (now - old);
491 delta = (u32)(x >> 32);
492 }
493
494 return atomic_add_return(segs + delta, &bucket->id) - segs;
495 }
496 EXPORT_SYMBOL(ip_idents_reserve);
497
498 void __ip_select_ident(struct iphdr *iph, int segs)
499 {
500 static u32 ip_idents_hashrnd __read_mostly;
501 static bool hashrnd_initialized = false;
502 u32 hash, id;
503
504 if (unlikely(!hashrnd_initialized)) {
505 hashrnd_initialized = true;
506 get_random_bytes(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
507 }
508
509 hash = jhash_3words((__force u32)iph->daddr,
510 (__force u32)iph->saddr,
511 iph->protocol,
512 ip_idents_hashrnd);
513 id = ip_idents_reserve(hash, segs);
514 iph->id = htons(id);
515 }
516 EXPORT_SYMBOL(__ip_select_ident);
517
518 static void __build_flow_key(struct flowi4 *fl4, struct sock *sk,
519 const struct iphdr *iph,
520 int oif, u8 tos,
521 u8 prot, u32 mark, int flow_flags)
522 {
523 if (sk) {
524 const struct inet_sock *inet = inet_sk(sk);
525
526 oif = sk->sk_bound_dev_if;
527 mark = sk->sk_mark;
528 tos = RT_CONN_FLAGS(sk);
529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
530 }
531 flowi4_init_output(fl4, oif, mark, tos,
532 RT_SCOPE_UNIVERSE, prot,
533 flow_flags,
534 iph->daddr, iph->saddr, 0, 0,
535 sk ? sock_i_uid(sk) : 0);
536 }
537
538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
539 struct sock *sk)
540 {
541 const struct iphdr *iph = ip_hdr(skb);
542 int oif = skb->dev->ifindex;
543 u8 tos = RT_TOS(iph->tos);
544 u8 prot = iph->protocol;
545 u32 mark = skb->mark;
546
547 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
548 }
549
550 static void build_sk_flow_key(struct flowi4 *fl4, struct sock *sk)
551 {
552 const struct inet_sock *inet = inet_sk(sk);
553 const struct ip_options_rcu *inet_opt;
554 __be32 daddr = inet->inet_daddr;
555
556 rcu_read_lock();
557 inet_opt = rcu_dereference(inet->inet_opt);
558 if (inet_opt && inet_opt->opt.srr)
559 daddr = inet_opt->opt.faddr;
560 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
561 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
562 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
563 inet_sk_flowi_flags(sk),
564 daddr, inet->inet_saddr, 0, 0,
565 sock_i_uid(sk));
566 rcu_read_unlock();
567 }
568
569 static void ip_rt_build_flow_key(struct flowi4 *fl4, struct sock *sk,
570 const struct sk_buff *skb)
571 {
572 if (skb)
573 build_skb_flow_key(fl4, skb, sk);
574 else
575 build_sk_flow_key(fl4, sk);
576 }
577
578 static inline void rt_free(struct rtable *rt)
579 {
580 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
581 }
582
583 static DEFINE_SPINLOCK(fnhe_lock);
584
585 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
586 {
587 struct fib_nh_exception *fnhe, *oldest;
588 struct rtable *orig;
589
590 oldest = rcu_dereference(hash->chain);
591 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
592 fnhe = rcu_dereference(fnhe->fnhe_next)) {
593 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
594 oldest = fnhe;
595 }
596 orig = rcu_dereference(oldest->fnhe_rth);
597 if (orig) {
598 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
599 rt_free(orig);
600 }
601 return oldest;
602 }
603
604 static inline u32 fnhe_hashfun(__be32 daddr)
605 {
606 u32 hval;
607
608 hval = (__force u32) daddr;
609 hval ^= (hval >> 11) ^ (hval >> 22);
610
611 return hval & (FNHE_HASH_SIZE - 1);
612 }
613
614 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
615 u32 pmtu, unsigned long expires)
616 {
617 struct fnhe_hash_bucket *hash;
618 struct fib_nh_exception *fnhe;
619 int depth;
620 u32 hval = fnhe_hashfun(daddr);
621
622 spin_lock_bh(&fnhe_lock);
623
624 hash = nh->nh_exceptions;
625 if (!hash) {
626 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
627 if (!hash)
628 goto out_unlock;
629 nh->nh_exceptions = hash;
630 }
631
632 hash += hval;
633
634 depth = 0;
635 for (fnhe = rcu_dereference(hash->chain); fnhe;
636 fnhe = rcu_dereference(fnhe->fnhe_next)) {
637 if (fnhe->fnhe_daddr == daddr)
638 break;
639 depth++;
640 }
641
642 if (fnhe) {
643 if (gw)
644 fnhe->fnhe_gw = gw;
645 if (pmtu) {
646 fnhe->fnhe_pmtu = pmtu;
647 fnhe->fnhe_expires = expires;
648 }
649 } else {
650 if (depth > FNHE_RECLAIM_DEPTH)
651 fnhe = fnhe_oldest(hash);
652 else {
653 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
654 if (!fnhe)
655 goto out_unlock;
656
657 fnhe->fnhe_next = hash->chain;
658 rcu_assign_pointer(hash->chain, fnhe);
659 }
660 fnhe->fnhe_daddr = daddr;
661 fnhe->fnhe_gw = gw;
662 fnhe->fnhe_pmtu = pmtu;
663 fnhe->fnhe_expires = expires;
664 }
665
666 fnhe->fnhe_stamp = jiffies;
667
668 out_unlock:
669 spin_unlock_bh(&fnhe_lock);
670 return;
671 }
672
673 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
674 bool kill_route)
675 {
676 __be32 new_gw = icmp_hdr(skb)->un.gateway;
677 __be32 old_gw = ip_hdr(skb)->saddr;
678 struct net_device *dev = skb->dev;
679 struct in_device *in_dev;
680 struct fib_result res;
681 struct neighbour *n;
682 struct net *net;
683
684 switch (icmp_hdr(skb)->code & 7) {
685 case ICMP_REDIR_NET:
686 case ICMP_REDIR_NETTOS:
687 case ICMP_REDIR_HOST:
688 case ICMP_REDIR_HOSTTOS:
689 break;
690
691 default:
692 return;
693 }
694
695 if (rt->rt_gateway != old_gw)
696 return;
697
698 in_dev = __in_dev_get_rcu(dev);
699 if (!in_dev)
700 return;
701
702 net = dev_net(dev);
703 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
704 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
705 ipv4_is_zeronet(new_gw))
706 goto reject_redirect;
707
708 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
709 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
710 goto reject_redirect;
711 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
712 goto reject_redirect;
713 } else {
714 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
715 goto reject_redirect;
716 }
717
718 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
719 if (n) {
720 if (!(n->nud_state & NUD_VALID)) {
721 neigh_event_send(n, NULL);
722 } else {
723 if (fib_lookup(net, fl4, &res) == 0) {
724 struct fib_nh *nh = &FIB_RES_NH(res);
725
726 update_or_create_fnhe(nh, fl4->daddr, new_gw,
727 0, 0);
728 }
729 if (kill_route)
730 rt->dst.obsolete = DST_OBSOLETE_KILL;
731 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
732 }
733 neigh_release(n);
734 }
735 return;
736
737 reject_redirect:
738 #ifdef CONFIG_IP_ROUTE_VERBOSE
739 if (IN_DEV_LOG_MARTIANS(in_dev)) {
740 const struct iphdr *iph = (const struct iphdr *) skb->data;
741 __be32 daddr = iph->daddr;
742 __be32 saddr = iph->saddr;
743
744 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
745 " Advised path = %pI4 -> %pI4\n",
746 &old_gw, dev->name, &new_gw,
747 &saddr, &daddr);
748 }
749 #endif
750 ;
751 }
752
753 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
754 {
755 struct rtable *rt;
756 struct flowi4 fl4;
757 const struct iphdr *iph = (const struct iphdr *) skb->data;
758 int oif = skb->dev->ifindex;
759 u8 tos = RT_TOS(iph->tos);
760 u8 prot = iph->protocol;
761 u32 mark = skb->mark;
762
763 rt = (struct rtable *) dst;
764
765 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
766 __ip_do_redirect(rt, skb, &fl4, true);
767 }
768
769 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
770 {
771 struct rtable *rt = (struct rtable *)dst;
772 struct dst_entry *ret = dst;
773
774 if (rt) {
775 if (dst->obsolete > 0) {
776 ip_rt_put(rt);
777 ret = NULL;
778 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
779 rt->dst.expires) {
780 ip_rt_put(rt);
781 ret = NULL;
782 }
783 }
784 return ret;
785 }
786
787 /*
788 * Algorithm:
789 * 1. The first ip_rt_redirect_number redirects are sent
790 * with exponential backoff, then we stop sending them at all,
791 * assuming that the host ignores our redirects.
792 * 2. If we did not see packets requiring redirects
793 * during ip_rt_redirect_silence, we assume that the host
794 * forgot redirected route and start to send redirects again.
795 *
796 * This algorithm is much cheaper and more intelligent than dumb load limiting
797 * in icmp.c.
798 *
799 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
800 * and "frag. need" (breaks PMTU discovery) in icmp.c.
801 */
802
803 void ip_rt_send_redirect(struct sk_buff *skb)
804 {
805 struct rtable *rt = skb_rtable(skb);
806 struct in_device *in_dev;
807 struct inet_peer *peer;
808 struct net *net;
809 int log_martians;
810
811 rcu_read_lock();
812 in_dev = __in_dev_get_rcu(rt->dst.dev);
813 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
814 rcu_read_unlock();
815 return;
816 }
817 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
818 rcu_read_unlock();
819
820 net = dev_net(rt->dst.dev);
821 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
822 if (!peer) {
823 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
824 rt_nexthop(rt, ip_hdr(skb)->daddr));
825 return;
826 }
827
828 /* No redirected packets during ip_rt_redirect_silence;
829 * reset the algorithm.
830 */
831 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
832 peer->rate_tokens = 0;
833
834 /* Too many ignored redirects; do not send anything
835 * set dst.rate_last to the last seen redirected packet.
836 */
837 if (peer->rate_tokens >= ip_rt_redirect_number) {
838 peer->rate_last = jiffies;
839 goto out_put_peer;
840 }
841
842 /* Check for load limit; set rate_last to the latest sent
843 * redirect.
844 */
845 if (peer->rate_tokens == 0 ||
846 time_after(jiffies,
847 (peer->rate_last +
848 (ip_rt_redirect_load << peer->rate_tokens)))) {
849 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
850
851 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
852 peer->rate_last = jiffies;
853 ++peer->rate_tokens;
854 #ifdef CONFIG_IP_ROUTE_VERBOSE
855 if (log_martians &&
856 peer->rate_tokens == ip_rt_redirect_number)
857 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
858 &ip_hdr(skb)->saddr, inet_iif(skb),
859 &ip_hdr(skb)->daddr, &gw);
860 #endif
861 }
862 out_put_peer:
863 inet_putpeer(peer);
864 }
865
866 static int ip_error(struct sk_buff *skb)
867 {
868 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
869 struct rtable *rt = skb_rtable(skb);
870 struct inet_peer *peer;
871 unsigned long now;
872 struct net *net;
873 bool send;
874 int code;
875
876 /* IP on this device is disabled. */
877 if (!in_dev)
878 goto out;
879
880 net = dev_net(rt->dst.dev);
881 if (!IN_DEV_FORWARD(in_dev)) {
882 switch (rt->dst.error) {
883 case EHOSTUNREACH:
884 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
885 break;
886
887 case ENETUNREACH:
888 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
889 break;
890 }
891 goto out;
892 }
893
894 switch (rt->dst.error) {
895 case EINVAL:
896 default:
897 goto out;
898 case EHOSTUNREACH:
899 code = ICMP_HOST_UNREACH;
900 break;
901 case ENETUNREACH:
902 code = ICMP_NET_UNREACH;
903 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
904 break;
905 case EACCES:
906 code = ICMP_PKT_FILTERED;
907 break;
908 }
909
910 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
911
912 send = true;
913 if (peer) {
914 now = jiffies;
915 peer->rate_tokens += now - peer->rate_last;
916 if (peer->rate_tokens > ip_rt_error_burst)
917 peer->rate_tokens = ip_rt_error_burst;
918 peer->rate_last = now;
919 if (peer->rate_tokens >= ip_rt_error_cost)
920 peer->rate_tokens -= ip_rt_error_cost;
921 else
922 send = false;
923 inet_putpeer(peer);
924 }
925 if (send)
926 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
927
928 out: kfree_skb(skb);
929 return 0;
930 }
931
932 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
933 {
934 struct dst_entry *dst = &rt->dst;
935 struct fib_result res;
936
937 if (dst_metric_locked(dst, RTAX_MTU))
938 return;
939
940 if (dst->dev->mtu < mtu)
941 return;
942
943 if (mtu < ip_rt_min_pmtu)
944 mtu = ip_rt_min_pmtu;
945
946 if (!rt->rt_pmtu) {
947 dst->obsolete = DST_OBSOLETE_KILL;
948 } else {
949 rt->rt_pmtu = mtu;
950 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
951 }
952
953 rcu_read_lock();
954 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
955 struct fib_nh *nh = &FIB_RES_NH(res);
956
957 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
958 jiffies + ip_rt_mtu_expires);
959 }
960 rcu_read_unlock();
961 }
962
963 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
964 struct sk_buff *skb, u32 mtu)
965 {
966 struct rtable *rt = (struct rtable *) dst;
967 struct flowi4 fl4;
968
969 ip_rt_build_flow_key(&fl4, sk, skb);
970 __ip_rt_update_pmtu(rt, &fl4, mtu);
971 }
972
973 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
974 int oif, u32 mark, u8 protocol, int flow_flags)
975 {
976 const struct iphdr *iph = (const struct iphdr *) skb->data;
977 struct flowi4 fl4;
978 struct rtable *rt;
979
980 if (!mark)
981 mark = IP4_REPLY_MARK(net, skb->mark);
982
983 __build_flow_key(&fl4, NULL, iph, oif,
984 RT_TOS(iph->tos), protocol, mark, flow_flags);
985 rt = __ip_route_output_key(net, &fl4);
986 if (!IS_ERR(rt)) {
987 __ip_rt_update_pmtu(rt, &fl4, mtu);
988 ip_rt_put(rt);
989 }
990 }
991 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
992
993 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
994 {
995 const struct iphdr *iph = (const struct iphdr *) skb->data;
996 struct flowi4 fl4;
997 struct rtable *rt;
998
999 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1000
1001 if (!fl4.flowi4_mark)
1002 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1003
1004 rt = __ip_route_output_key(sock_net(sk), &fl4);
1005 if (!IS_ERR(rt)) {
1006 __ip_rt_update_pmtu(rt, &fl4, mtu);
1007 ip_rt_put(rt);
1008 }
1009 }
1010
1011 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1012 {
1013 const struct iphdr *iph = (const struct iphdr *) skb->data;
1014 struct flowi4 fl4;
1015 struct rtable *rt;
1016 struct dst_entry *odst = NULL;
1017 bool new = false;
1018
1019 bh_lock_sock(sk);
1020 odst = sk_dst_get(sk);
1021
1022 if (sock_owned_by_user(sk) || !odst) {
1023 __ipv4_sk_update_pmtu(skb, sk, mtu);
1024 goto out;
1025 }
1026
1027 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1028
1029 rt = (struct rtable *)odst;
1030 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1031 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1032 if (IS_ERR(rt))
1033 goto out;
1034
1035 new = true;
1036 }
1037
1038 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1039
1040 if (!dst_check(&rt->dst, 0)) {
1041 if (new)
1042 dst_release(&rt->dst);
1043
1044 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1045 if (IS_ERR(rt))
1046 goto out;
1047
1048 new = true;
1049 }
1050
1051 if (new)
1052 sk_dst_set(sk, &rt->dst);
1053
1054 out:
1055 bh_unlock_sock(sk);
1056 dst_release(odst);
1057 }
1058 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1059
1060 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1061 int oif, u32 mark, u8 protocol, int flow_flags)
1062 {
1063 const struct iphdr *iph = (const struct iphdr *) skb->data;
1064 struct flowi4 fl4;
1065 struct rtable *rt;
1066
1067 __build_flow_key(&fl4, NULL, iph, oif,
1068 RT_TOS(iph->tos), protocol, mark, flow_flags);
1069 rt = __ip_route_output_key(net, &fl4);
1070 if (!IS_ERR(rt)) {
1071 __ip_do_redirect(rt, skb, &fl4, false);
1072 ip_rt_put(rt);
1073 }
1074 }
1075 EXPORT_SYMBOL_GPL(ipv4_redirect);
1076
1077 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1078 {
1079 const struct iphdr *iph = (const struct iphdr *) skb->data;
1080 struct flowi4 fl4;
1081 struct rtable *rt;
1082
1083 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1084 rt = __ip_route_output_key(sock_net(sk), &fl4);
1085 if (!IS_ERR(rt)) {
1086 __ip_do_redirect(rt, skb, &fl4, false);
1087 ip_rt_put(rt);
1088 }
1089 }
1090 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1091
1092 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1093 {
1094 struct rtable *rt = (struct rtable *) dst;
1095
1096 /* All IPV4 dsts are created with ->obsolete set to the value
1097 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1098 * into this function always.
1099 *
1100 * When a PMTU/redirect information update invalidates a
1101 * route, this is indicated by setting obsolete to
1102 * DST_OBSOLETE_KILL.
1103 */
1104 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1105 return NULL;
1106 return dst;
1107 }
1108
1109 static void ipv4_link_failure(struct sk_buff *skb)
1110 {
1111 struct rtable *rt;
1112
1113 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1114
1115 rt = skb_rtable(skb);
1116 if (rt)
1117 dst_set_expires(&rt->dst, 0);
1118 }
1119
1120 static int ip_rt_bug(struct sk_buff *skb)
1121 {
1122 pr_debug("%s: %pI4 -> %pI4, %s\n",
1123 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1124 skb->dev ? skb->dev->name : "?");
1125 kfree_skb(skb);
1126 WARN_ON(1);
1127 return 0;
1128 }
1129
1130 /*
1131 We do not cache source address of outgoing interface,
1132 because it is used only by IP RR, TS and SRR options,
1133 so that it out of fast path.
1134
1135 BTW remember: "addr" is allowed to be not aligned
1136 in IP options!
1137 */
1138
1139 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1140 {
1141 __be32 src;
1142
1143 if (rt_is_output_route(rt))
1144 src = ip_hdr(skb)->saddr;
1145 else {
1146 struct fib_result res;
1147 struct flowi4 fl4;
1148 struct iphdr *iph;
1149
1150 iph = ip_hdr(skb);
1151
1152 memset(&fl4, 0, sizeof(fl4));
1153 fl4.daddr = iph->daddr;
1154 fl4.saddr = iph->saddr;
1155 fl4.flowi4_tos = RT_TOS(iph->tos);
1156 fl4.flowi4_oif = rt->dst.dev->ifindex;
1157 fl4.flowi4_iif = skb->dev->ifindex;
1158 fl4.flowi4_mark = skb->mark;
1159
1160 rcu_read_lock();
1161 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1162 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1163 else
1164 src = inet_select_addr(rt->dst.dev,
1165 rt_nexthop(rt, iph->daddr),
1166 RT_SCOPE_UNIVERSE);
1167 rcu_read_unlock();
1168 }
1169 memcpy(addr, &src, 4);
1170 }
1171
1172 #ifdef CONFIG_IP_ROUTE_CLASSID
1173 static void set_class_tag(struct rtable *rt, u32 tag)
1174 {
1175 if (!(rt->dst.tclassid & 0xFFFF))
1176 rt->dst.tclassid |= tag & 0xFFFF;
1177 if (!(rt->dst.tclassid & 0xFFFF0000))
1178 rt->dst.tclassid |= tag & 0xFFFF0000;
1179 }
1180 #endif
1181
1182 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1183 {
1184 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1185
1186 if (advmss == 0) {
1187 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1188 ip_rt_min_advmss);
1189 if (advmss > 65535 - 40)
1190 advmss = 65535 - 40;
1191 }
1192 return advmss;
1193 }
1194
1195 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1196 {
1197 const struct rtable *rt = (const struct rtable *) dst;
1198 unsigned int mtu = rt->rt_pmtu;
1199
1200 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1201 mtu = dst_metric_raw(dst, RTAX_MTU);
1202
1203 if (mtu)
1204 return mtu;
1205
1206 mtu = dst->dev->mtu;
1207
1208 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1209 if (rt->rt_uses_gateway && mtu > 576)
1210 mtu = 576;
1211 }
1212
1213 if (mtu > IP_MAX_MTU)
1214 mtu = IP_MAX_MTU;
1215
1216 return mtu;
1217 }
1218
1219 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1220 {
1221 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1222 struct fib_nh_exception *fnhe;
1223 u32 hval;
1224
1225 if (!hash)
1226 return NULL;
1227
1228 hval = fnhe_hashfun(daddr);
1229
1230 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1231 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1232 if (fnhe->fnhe_daddr == daddr)
1233 return fnhe;
1234 }
1235 return NULL;
1236 }
1237
1238 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1239 __be32 daddr)
1240 {
1241 bool ret = false;
1242
1243 spin_lock_bh(&fnhe_lock);
1244
1245 if (daddr == fnhe->fnhe_daddr) {
1246 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth);
1247 if (orig && rt_is_expired(orig)) {
1248 fnhe->fnhe_gw = 0;
1249 fnhe->fnhe_pmtu = 0;
1250 fnhe->fnhe_expires = 0;
1251 }
1252 if (fnhe->fnhe_pmtu) {
1253 unsigned long expires = fnhe->fnhe_expires;
1254 unsigned long diff = expires - jiffies;
1255
1256 if (time_before(jiffies, expires)) {
1257 rt->rt_pmtu = fnhe->fnhe_pmtu;
1258 dst_set_expires(&rt->dst, diff);
1259 }
1260 }
1261 if (fnhe->fnhe_gw) {
1262 rt->rt_flags |= RTCF_REDIRECTED;
1263 rt->rt_gateway = fnhe->fnhe_gw;
1264 rt->rt_uses_gateway = 1;
1265 } else if (!rt->rt_gateway)
1266 rt->rt_gateway = daddr;
1267
1268 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1269 if (orig)
1270 rt_free(orig);
1271
1272 fnhe->fnhe_stamp = jiffies;
1273 ret = true;
1274 }
1275 spin_unlock_bh(&fnhe_lock);
1276
1277 return ret;
1278 }
1279
1280 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1281 {
1282 struct rtable *orig, *prev, **p;
1283 bool ret = true;
1284
1285 if (rt_is_input_route(rt)) {
1286 p = (struct rtable **)&nh->nh_rth_input;
1287 } else {
1288 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1289 }
1290 orig = *p;
1291
1292 prev = cmpxchg(p, orig, rt);
1293 if (prev == orig) {
1294 if (orig)
1295 rt_free(orig);
1296 } else
1297 ret = false;
1298
1299 return ret;
1300 }
1301
1302 static DEFINE_SPINLOCK(rt_uncached_lock);
1303 static LIST_HEAD(rt_uncached_list);
1304
1305 static void rt_add_uncached_list(struct rtable *rt)
1306 {
1307 spin_lock_bh(&rt_uncached_lock);
1308 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1309 spin_unlock_bh(&rt_uncached_lock);
1310 }
1311
1312 static void ipv4_dst_destroy(struct dst_entry *dst)
1313 {
1314 struct rtable *rt = (struct rtable *) dst;
1315
1316 if (!list_empty(&rt->rt_uncached)) {
1317 spin_lock_bh(&rt_uncached_lock);
1318 list_del(&rt->rt_uncached);
1319 spin_unlock_bh(&rt_uncached_lock);
1320 }
1321 }
1322
1323 void rt_flush_dev(struct net_device *dev)
1324 {
1325 if (!list_empty(&rt_uncached_list)) {
1326 struct net *net = dev_net(dev);
1327 struct rtable *rt;
1328
1329 spin_lock_bh(&rt_uncached_lock);
1330 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1331 if (rt->dst.dev != dev)
1332 continue;
1333 rt->dst.dev = net->loopback_dev;
1334 dev_hold(rt->dst.dev);
1335 dev_put(dev);
1336 }
1337 spin_unlock_bh(&rt_uncached_lock);
1338 }
1339 }
1340
1341 static bool rt_cache_valid(const struct rtable *rt)
1342 {
1343 return rt &&
1344 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1345 !rt_is_expired(rt);
1346 }
1347
1348 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1349 const struct fib_result *res,
1350 struct fib_nh_exception *fnhe,
1351 struct fib_info *fi, u16 type, u32 itag)
1352 {
1353 bool cached = false;
1354
1355 if (fi) {
1356 struct fib_nh *nh = &FIB_RES_NH(*res);
1357
1358 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1359 rt->rt_gateway = nh->nh_gw;
1360 rt->rt_uses_gateway = 1;
1361 }
1362 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1363 #ifdef CONFIG_IP_ROUTE_CLASSID
1364 rt->dst.tclassid = nh->nh_tclassid;
1365 #endif
1366 if (unlikely(fnhe))
1367 cached = rt_bind_exception(rt, fnhe, daddr);
1368 else if (!(rt->dst.flags & DST_NOCACHE))
1369 cached = rt_cache_route(nh, rt);
1370 if (unlikely(!cached)) {
1371 /* Routes we intend to cache in nexthop exception or
1372 * FIB nexthop have the DST_NOCACHE bit clear.
1373 * However, if we are unsuccessful at storing this
1374 * route into the cache we really need to set it.
1375 */
1376 rt->dst.flags |= DST_NOCACHE;
1377 if (!rt->rt_gateway)
1378 rt->rt_gateway = daddr;
1379 rt_add_uncached_list(rt);
1380 }
1381 } else
1382 rt_add_uncached_list(rt);
1383
1384 #ifdef CONFIG_IP_ROUTE_CLASSID
1385 #ifdef CONFIG_IP_MULTIPLE_TABLES
1386 set_class_tag(rt, res->tclassid);
1387 #endif
1388 set_class_tag(rt, itag);
1389 #endif
1390 }
1391
1392 static struct rtable *rt_dst_alloc(struct net_device *dev,
1393 bool nopolicy, bool noxfrm, bool will_cache)
1394 {
1395 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1396 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1397 (nopolicy ? DST_NOPOLICY : 0) |
1398 (noxfrm ? DST_NOXFRM : 0));
1399 }
1400
1401 /* called in rcu_read_lock() section */
1402 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1403 u8 tos, struct net_device *dev, int our)
1404 {
1405 struct rtable *rth;
1406 struct in_device *in_dev = __in_dev_get_rcu(dev);
1407 u32 itag = 0;
1408 int err;
1409
1410 /* Primary sanity checks. */
1411
1412 if (in_dev == NULL)
1413 return -EINVAL;
1414
1415 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1416 skb->protocol != htons(ETH_P_IP))
1417 goto e_inval;
1418
1419 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1420 if (ipv4_is_loopback(saddr))
1421 goto e_inval;
1422
1423 if (ipv4_is_zeronet(saddr)) {
1424 if (!ipv4_is_local_multicast(daddr))
1425 goto e_inval;
1426 } else {
1427 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1428 in_dev, &itag);
1429 if (err < 0)
1430 goto e_err;
1431 }
1432 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1433 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1434 if (!rth)
1435 goto e_nobufs;
1436
1437 #ifdef CONFIG_IP_ROUTE_CLASSID
1438 rth->dst.tclassid = itag;
1439 #endif
1440 rth->dst.output = ip_rt_bug;
1441
1442 rth->rt_genid = rt_genid(dev_net(dev));
1443 rth->rt_flags = RTCF_MULTICAST;
1444 rth->rt_type = RTN_MULTICAST;
1445 rth->rt_is_input= 1;
1446 rth->rt_iif = 0;
1447 rth->rt_pmtu = 0;
1448 rth->rt_gateway = 0;
1449 rth->rt_uses_gateway = 0;
1450 INIT_LIST_HEAD(&rth->rt_uncached);
1451 if (our) {
1452 rth->dst.input= ip_local_deliver;
1453 rth->rt_flags |= RTCF_LOCAL;
1454 }
1455
1456 #ifdef CONFIG_IP_MROUTE
1457 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1458 rth->dst.input = ip_mr_input;
1459 #endif
1460 RT_CACHE_STAT_INC(in_slow_mc);
1461
1462 skb_dst_set(skb, &rth->dst);
1463 return 0;
1464
1465 e_nobufs:
1466 return -ENOBUFS;
1467 e_inval:
1468 return -EINVAL;
1469 e_err:
1470 return err;
1471 }
1472
1473
1474 static void ip_handle_martian_source(struct net_device *dev,
1475 struct in_device *in_dev,
1476 struct sk_buff *skb,
1477 __be32 daddr,
1478 __be32 saddr)
1479 {
1480 RT_CACHE_STAT_INC(in_martian_src);
1481 #ifdef CONFIG_IP_ROUTE_VERBOSE
1482 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1483 /*
1484 * RFC1812 recommendation, if source is martian,
1485 * the only hint is MAC header.
1486 */
1487 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1488 &daddr, &saddr, dev->name);
1489 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1490 print_hex_dump(KERN_WARNING, "ll header: ",
1491 DUMP_PREFIX_OFFSET, 16, 1,
1492 skb_mac_header(skb),
1493 dev->hard_header_len, true);
1494 }
1495 }
1496 #endif
1497 }
1498
1499 /* called in rcu_read_lock() section */
1500 static int __mkroute_input(struct sk_buff *skb,
1501 const struct fib_result *res,
1502 struct in_device *in_dev,
1503 __be32 daddr, __be32 saddr, u32 tos)
1504 {
1505 struct rtable *rth;
1506 int err;
1507 struct in_device *out_dev;
1508 unsigned int flags = 0;
1509 bool do_cache;
1510 u32 itag = 0;
1511
1512 /* get a working reference to the output device */
1513 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1514 if (out_dev == NULL) {
1515 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1516 return -EINVAL;
1517 }
1518
1519 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1520 in_dev->dev, in_dev, &itag);
1521 if (err < 0) {
1522 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1523 saddr);
1524
1525 goto cleanup;
1526 }
1527
1528 do_cache = res->fi && !itag;
1529 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1530 skb->protocol == htons(ETH_P_IP) &&
1531 (IN_DEV_SHARED_MEDIA(out_dev) ||
1532 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1533 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1534
1535 if (skb->protocol != htons(ETH_P_IP)) {
1536 /* Not IP (i.e. ARP). Do not create route, if it is
1537 * invalid for proxy arp. DNAT routes are always valid.
1538 *
1539 * Proxy arp feature have been extended to allow, ARP
1540 * replies back to the same interface, to support
1541 * Private VLAN switch technologies. See arp.c.
1542 */
1543 if (out_dev == in_dev &&
1544 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1545 err = -EINVAL;
1546 goto cleanup;
1547 }
1548 }
1549
1550 if (do_cache) {
1551 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1552 if (rt_cache_valid(rth)) {
1553 skb_dst_set_noref(skb, &rth->dst);
1554 goto out;
1555 }
1556 }
1557
1558 rth = rt_dst_alloc(out_dev->dev,
1559 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1560 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1561 if (!rth) {
1562 err = -ENOBUFS;
1563 goto cleanup;
1564 }
1565
1566 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1567 rth->rt_flags = flags;
1568 rth->rt_type = res->type;
1569 rth->rt_is_input = 1;
1570 rth->rt_iif = 0;
1571 rth->rt_pmtu = 0;
1572 rth->rt_gateway = 0;
1573 rth->rt_uses_gateway = 0;
1574 INIT_LIST_HEAD(&rth->rt_uncached);
1575 RT_CACHE_STAT_INC(in_slow_tot);
1576
1577 rth->dst.input = ip_forward;
1578 rth->dst.output = ip_output;
1579
1580 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1581 skb_dst_set(skb, &rth->dst);
1582 out:
1583 err = 0;
1584 cleanup:
1585 return err;
1586 }
1587
1588 static int ip_mkroute_input(struct sk_buff *skb,
1589 struct fib_result *res,
1590 const struct flowi4 *fl4,
1591 struct in_device *in_dev,
1592 __be32 daddr, __be32 saddr, u32 tos)
1593 {
1594 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1595 if (res->fi && res->fi->fib_nhs > 1)
1596 fib_select_multipath(res);
1597 #endif
1598
1599 /* create a routing cache entry */
1600 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1601 }
1602
1603 /*
1604 * NOTE. We drop all the packets that has local source
1605 * addresses, because every properly looped back packet
1606 * must have correct destination already attached by output routine.
1607 *
1608 * Such approach solves two big problems:
1609 * 1. Not simplex devices are handled properly.
1610 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1611 * called with rcu_read_lock()
1612 */
1613
1614 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1615 u8 tos, struct net_device *dev)
1616 {
1617 struct fib_result res;
1618 struct in_device *in_dev = __in_dev_get_rcu(dev);
1619 struct flowi4 fl4;
1620 unsigned int flags = 0;
1621 u32 itag = 0;
1622 struct rtable *rth;
1623 int err = -EINVAL;
1624 struct net *net = dev_net(dev);
1625 bool do_cache;
1626
1627 /* IP on this device is disabled. */
1628
1629 if (!in_dev)
1630 goto out;
1631
1632 /* Check for the most weird martians, which can be not detected
1633 by fib_lookup.
1634 */
1635
1636 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1637 goto martian_source;
1638
1639 res.fi = NULL;
1640 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1641 goto brd_input;
1642
1643 /* Accept zero addresses only to limited broadcast;
1644 * I even do not know to fix it or not. Waiting for complains :-)
1645 */
1646 if (ipv4_is_zeronet(saddr))
1647 goto martian_source;
1648
1649 if (ipv4_is_zeronet(daddr))
1650 goto martian_destination;
1651
1652 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1653 * and call it once if daddr or/and saddr are loopback addresses
1654 */
1655 if (ipv4_is_loopback(daddr)) {
1656 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1657 goto martian_destination;
1658 } else if (ipv4_is_loopback(saddr)) {
1659 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1660 goto martian_source;
1661 }
1662
1663 /*
1664 * Now we are ready to route packet.
1665 */
1666 fl4.flowi4_oif = 0;
1667 fl4.flowi4_iif = dev->ifindex;
1668 fl4.flowi4_mark = skb->mark;
1669 fl4.flowi4_tos = tos;
1670 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1671 fl4.daddr = daddr;
1672 fl4.saddr = saddr;
1673 err = fib_lookup(net, &fl4, &res);
1674 if (err != 0)
1675 goto no_route;
1676
1677 if (res.type == RTN_BROADCAST)
1678 goto brd_input;
1679
1680 if (res.type == RTN_LOCAL) {
1681 err = fib_validate_source(skb, saddr, daddr, tos,
1682 LOOPBACK_IFINDEX,
1683 dev, in_dev, &itag);
1684 if (err < 0)
1685 goto martian_source_keep_err;
1686 goto local_input;
1687 }
1688
1689 if (!IN_DEV_FORWARD(in_dev))
1690 goto no_route;
1691 if (res.type != RTN_UNICAST)
1692 goto martian_destination;
1693
1694 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1695 out: return err;
1696
1697 brd_input:
1698 if (skb->protocol != htons(ETH_P_IP))
1699 goto e_inval;
1700
1701 if (!ipv4_is_zeronet(saddr)) {
1702 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1703 in_dev, &itag);
1704 if (err < 0)
1705 goto martian_source_keep_err;
1706 }
1707 flags |= RTCF_BROADCAST;
1708 res.type = RTN_BROADCAST;
1709 RT_CACHE_STAT_INC(in_brd);
1710
1711 local_input:
1712 do_cache = false;
1713 if (res.fi) {
1714 if (!itag) {
1715 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1716 if (rt_cache_valid(rth)) {
1717 skb_dst_set_noref(skb, &rth->dst);
1718 err = 0;
1719 goto out;
1720 }
1721 do_cache = true;
1722 }
1723 }
1724
1725 rth = rt_dst_alloc(net->loopback_dev,
1726 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1727 if (!rth)
1728 goto e_nobufs;
1729
1730 rth->dst.input= ip_local_deliver;
1731 rth->dst.output= ip_rt_bug;
1732 #ifdef CONFIG_IP_ROUTE_CLASSID
1733 rth->dst.tclassid = itag;
1734 #endif
1735
1736 rth->rt_genid = rt_genid(net);
1737 rth->rt_flags = flags|RTCF_LOCAL;
1738 rth->rt_type = res.type;
1739 rth->rt_is_input = 1;
1740 rth->rt_iif = 0;
1741 rth->rt_pmtu = 0;
1742 rth->rt_gateway = 0;
1743 rth->rt_uses_gateway = 0;
1744 INIT_LIST_HEAD(&rth->rt_uncached);
1745 RT_CACHE_STAT_INC(in_slow_tot);
1746 if (res.type == RTN_UNREACHABLE) {
1747 rth->dst.input= ip_error;
1748 rth->dst.error= -err;
1749 rth->rt_flags &= ~RTCF_LOCAL;
1750 }
1751 if (do_cache) {
1752 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1753 rth->dst.flags |= DST_NOCACHE;
1754 rt_add_uncached_list(rth);
1755 }
1756 }
1757 skb_dst_set(skb, &rth->dst);
1758 err = 0;
1759 goto out;
1760
1761 no_route:
1762 RT_CACHE_STAT_INC(in_no_route);
1763 res.type = RTN_UNREACHABLE;
1764 if (err == -ESRCH)
1765 err = -ENETUNREACH;
1766 goto local_input;
1767
1768 /*
1769 * Do not cache martian addresses: they should be logged (RFC1812)
1770 */
1771 martian_destination:
1772 RT_CACHE_STAT_INC(in_martian_dst);
1773 #ifdef CONFIG_IP_ROUTE_VERBOSE
1774 if (IN_DEV_LOG_MARTIANS(in_dev))
1775 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1776 &daddr, &saddr, dev->name);
1777 #endif
1778
1779 e_inval:
1780 err = -EINVAL;
1781 goto out;
1782
1783 e_nobufs:
1784 err = -ENOBUFS;
1785 goto out;
1786
1787 martian_source:
1788 err = -EINVAL;
1789 martian_source_keep_err:
1790 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1791 goto out;
1792 }
1793
1794 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1795 u8 tos, struct net_device *dev)
1796 {
1797 int res;
1798
1799 rcu_read_lock();
1800
1801 /* Multicast recognition logic is moved from route cache to here.
1802 The problem was that too many Ethernet cards have broken/missing
1803 hardware multicast filters :-( As result the host on multicasting
1804 network acquires a lot of useless route cache entries, sort of
1805 SDR messages from all the world. Now we try to get rid of them.
1806 Really, provided software IP multicast filter is organized
1807 reasonably (at least, hashed), it does not result in a slowdown
1808 comparing with route cache reject entries.
1809 Note, that multicast routers are not affected, because
1810 route cache entry is created eventually.
1811 */
1812 if (ipv4_is_multicast(daddr)) {
1813 struct in_device *in_dev = __in_dev_get_rcu(dev);
1814
1815 if (in_dev) {
1816 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1817 ip_hdr(skb)->protocol);
1818 if (our
1819 #ifdef CONFIG_IP_MROUTE
1820 ||
1821 (!ipv4_is_local_multicast(daddr) &&
1822 IN_DEV_MFORWARD(in_dev))
1823 #endif
1824 ) {
1825 int res = ip_route_input_mc(skb, daddr, saddr,
1826 tos, dev, our);
1827 rcu_read_unlock();
1828 return res;
1829 }
1830 }
1831 rcu_read_unlock();
1832 return -EINVAL;
1833 }
1834 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1835 rcu_read_unlock();
1836 return res;
1837 }
1838 EXPORT_SYMBOL(ip_route_input_noref);
1839
1840 /* called with rcu_read_lock() */
1841 static struct rtable *__mkroute_output(const struct fib_result *res,
1842 const struct flowi4 *fl4, int orig_oif,
1843 struct net_device *dev_out,
1844 unsigned int flags)
1845 {
1846 struct fib_info *fi = res->fi;
1847 struct fib_nh_exception *fnhe;
1848 struct in_device *in_dev;
1849 u16 type = res->type;
1850 struct rtable *rth;
1851 bool do_cache;
1852
1853 in_dev = __in_dev_get_rcu(dev_out);
1854 if (!in_dev)
1855 return ERR_PTR(-EINVAL);
1856
1857 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1858 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1859 return ERR_PTR(-EINVAL);
1860
1861 if (ipv4_is_lbcast(fl4->daddr))
1862 type = RTN_BROADCAST;
1863 else if (ipv4_is_multicast(fl4->daddr))
1864 type = RTN_MULTICAST;
1865 else if (ipv4_is_zeronet(fl4->daddr))
1866 return ERR_PTR(-EINVAL);
1867
1868 if (dev_out->flags & IFF_LOOPBACK)
1869 flags |= RTCF_LOCAL;
1870
1871 do_cache = true;
1872 if (type == RTN_BROADCAST) {
1873 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1874 fi = NULL;
1875 } else if (type == RTN_MULTICAST) {
1876 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1877 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1878 fl4->flowi4_proto))
1879 flags &= ~RTCF_LOCAL;
1880 else
1881 do_cache = false;
1882 /* If multicast route do not exist use
1883 * default one, but do not gateway in this case.
1884 * Yes, it is hack.
1885 */
1886 if (fi && res->prefixlen < 4)
1887 fi = NULL;
1888 }
1889
1890 fnhe = NULL;
1891 do_cache &= fi != NULL;
1892 if (do_cache) {
1893 struct rtable __rcu **prth;
1894 struct fib_nh *nh = &FIB_RES_NH(*res);
1895
1896 fnhe = find_exception(nh, fl4->daddr);
1897 if (fnhe)
1898 prth = &fnhe->fnhe_rth;
1899 else {
1900 if (unlikely(fl4->flowi4_flags &
1901 FLOWI_FLAG_KNOWN_NH &&
1902 !(nh->nh_gw &&
1903 nh->nh_scope == RT_SCOPE_LINK))) {
1904 do_cache = false;
1905 goto add;
1906 }
1907 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1908 }
1909 rth = rcu_dereference(*prth);
1910 if (rt_cache_valid(rth)) {
1911 dst_hold(&rth->dst);
1912 return rth;
1913 }
1914 }
1915
1916 add:
1917 rth = rt_dst_alloc(dev_out,
1918 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1919 IN_DEV_CONF_GET(in_dev, NOXFRM),
1920 do_cache);
1921 if (!rth)
1922 return ERR_PTR(-ENOBUFS);
1923
1924 rth->dst.output = ip_output;
1925
1926 rth->rt_genid = rt_genid(dev_net(dev_out));
1927 rth->rt_flags = flags;
1928 rth->rt_type = type;
1929 rth->rt_is_input = 0;
1930 rth->rt_iif = orig_oif ? : 0;
1931 rth->rt_pmtu = 0;
1932 rth->rt_gateway = 0;
1933 rth->rt_uses_gateway = 0;
1934 INIT_LIST_HEAD(&rth->rt_uncached);
1935
1936 RT_CACHE_STAT_INC(out_slow_tot);
1937
1938 if (flags & RTCF_LOCAL)
1939 rth->dst.input = ip_local_deliver;
1940 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1941 if (flags & RTCF_LOCAL &&
1942 !(dev_out->flags & IFF_LOOPBACK)) {
1943 rth->dst.output = ip_mc_output;
1944 RT_CACHE_STAT_INC(out_slow_mc);
1945 }
1946 #ifdef CONFIG_IP_MROUTE
1947 if (type == RTN_MULTICAST) {
1948 if (IN_DEV_MFORWARD(in_dev) &&
1949 !ipv4_is_local_multicast(fl4->daddr)) {
1950 rth->dst.input = ip_mr_input;
1951 rth->dst.output = ip_mc_output;
1952 }
1953 }
1954 #endif
1955 }
1956
1957 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1958
1959 return rth;
1960 }
1961
1962 /*
1963 * Major route resolver routine.
1964 */
1965
1966 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1967 {
1968 struct net_device *dev_out = NULL;
1969 __u8 tos = RT_FL_TOS(fl4);
1970 unsigned int flags = 0;
1971 struct fib_result res;
1972 struct rtable *rth;
1973 int orig_oif;
1974
1975 res.tclassid = 0;
1976 res.fi = NULL;
1977 res.table = NULL;
1978
1979 orig_oif = fl4->flowi4_oif;
1980
1981 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1982 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1983 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1984 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1985
1986 rcu_read_lock();
1987 if (fl4->saddr) {
1988 rth = ERR_PTR(-EINVAL);
1989 if (ipv4_is_multicast(fl4->saddr) ||
1990 ipv4_is_lbcast(fl4->saddr) ||
1991 ipv4_is_zeronet(fl4->saddr))
1992 goto out;
1993
1994 /* I removed check for oif == dev_out->oif here.
1995 It was wrong for two reasons:
1996 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1997 is assigned to multiple interfaces.
1998 2. Moreover, we are allowed to send packets with saddr
1999 of another iface. --ANK
2000 */
2001
2002 if (fl4->flowi4_oif == 0 &&
2003 (ipv4_is_multicast(fl4->daddr) ||
2004 ipv4_is_lbcast(fl4->daddr))) {
2005 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2006 dev_out = __ip_dev_find(net, fl4->saddr, false);
2007 if (dev_out == NULL)
2008 goto out;
2009
2010 /* Special hack: user can direct multicasts
2011 and limited broadcast via necessary interface
2012 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2013 This hack is not just for fun, it allows
2014 vic,vat and friends to work.
2015 They bind socket to loopback, set ttl to zero
2016 and expect that it will work.
2017 From the viewpoint of routing cache they are broken,
2018 because we are not allowed to build multicast path
2019 with loopback source addr (look, routing cache
2020 cannot know, that ttl is zero, so that packet
2021 will not leave this host and route is valid).
2022 Luckily, this hack is good workaround.
2023 */
2024
2025 fl4->flowi4_oif = dev_out->ifindex;
2026 goto make_route;
2027 }
2028
2029 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2030 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2031 if (!__ip_dev_find(net, fl4->saddr, false))
2032 goto out;
2033 }
2034 }
2035
2036
2037 if (fl4->flowi4_oif) {
2038 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2039 rth = ERR_PTR(-ENODEV);
2040 if (dev_out == NULL)
2041 goto out;
2042
2043 /* RACE: Check return value of inet_select_addr instead. */
2044 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2045 rth = ERR_PTR(-ENETUNREACH);
2046 goto out;
2047 }
2048 if (ipv4_is_local_multicast(fl4->daddr) ||
2049 ipv4_is_lbcast(fl4->daddr)) {
2050 if (!fl4->saddr)
2051 fl4->saddr = inet_select_addr(dev_out, 0,
2052 RT_SCOPE_LINK);
2053 goto make_route;
2054 }
2055 if (!fl4->saddr) {
2056 if (ipv4_is_multicast(fl4->daddr))
2057 fl4->saddr = inet_select_addr(dev_out, 0,
2058 fl4->flowi4_scope);
2059 else if (!fl4->daddr)
2060 fl4->saddr = inet_select_addr(dev_out, 0,
2061 RT_SCOPE_HOST);
2062 }
2063 }
2064
2065 if (!fl4->daddr) {
2066 fl4->daddr = fl4->saddr;
2067 if (!fl4->daddr)
2068 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2069 dev_out = net->loopback_dev;
2070 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2071 res.type = RTN_LOCAL;
2072 flags |= RTCF_LOCAL;
2073 goto make_route;
2074 }
2075
2076 if (fib_lookup(net, fl4, &res)) {
2077 res.fi = NULL;
2078 res.table = NULL;
2079 if (fl4->flowi4_oif) {
2080 /* Apparently, routing tables are wrong. Assume,
2081 that the destination is on link.
2082
2083 WHY? DW.
2084 Because we are allowed to send to iface
2085 even if it has NO routes and NO assigned
2086 addresses. When oif is specified, routing
2087 tables are looked up with only one purpose:
2088 to catch if destination is gatewayed, rather than
2089 direct. Moreover, if MSG_DONTROUTE is set,
2090 we send packet, ignoring both routing tables
2091 and ifaddr state. --ANK
2092
2093
2094 We could make it even if oif is unknown,
2095 likely IPv6, but we do not.
2096 */
2097
2098 if (fl4->saddr == 0)
2099 fl4->saddr = inet_select_addr(dev_out, 0,
2100 RT_SCOPE_LINK);
2101 res.type = RTN_UNICAST;
2102 goto make_route;
2103 }
2104 rth = ERR_PTR(-ENETUNREACH);
2105 goto out;
2106 }
2107
2108 if (res.type == RTN_LOCAL) {
2109 if (!fl4->saddr) {
2110 if (res.fi->fib_prefsrc)
2111 fl4->saddr = res.fi->fib_prefsrc;
2112 else
2113 fl4->saddr = fl4->daddr;
2114 }
2115 dev_out = net->loopback_dev;
2116 fl4->flowi4_oif = dev_out->ifindex;
2117 flags |= RTCF_LOCAL;
2118 goto make_route;
2119 }
2120
2121 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2122 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2123 fib_select_multipath(&res);
2124 else
2125 #endif
2126 if (!res.prefixlen &&
2127 res.table->tb_num_default > 1 &&
2128 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2129 fib_select_default(&res);
2130
2131 if (!fl4->saddr)
2132 fl4->saddr = FIB_RES_PREFSRC(net, res);
2133
2134 dev_out = FIB_RES_DEV(res);
2135 fl4->flowi4_oif = dev_out->ifindex;
2136
2137
2138 make_route:
2139 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2140
2141 out:
2142 rcu_read_unlock();
2143 return rth;
2144 }
2145 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2146
2147 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2148 {
2149 return NULL;
2150 }
2151
2152 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2153 {
2154 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2155
2156 return mtu ? : dst->dev->mtu;
2157 }
2158
2159 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2160 struct sk_buff *skb, u32 mtu)
2161 {
2162 }
2163
2164 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2165 struct sk_buff *skb)
2166 {
2167 }
2168
2169 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2170 unsigned long old)
2171 {
2172 return NULL;
2173 }
2174
2175 static struct dst_ops ipv4_dst_blackhole_ops = {
2176 .family = AF_INET,
2177 .protocol = cpu_to_be16(ETH_P_IP),
2178 .check = ipv4_blackhole_dst_check,
2179 .mtu = ipv4_blackhole_mtu,
2180 .default_advmss = ipv4_default_advmss,
2181 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2182 .redirect = ipv4_rt_blackhole_redirect,
2183 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2184 .neigh_lookup = ipv4_neigh_lookup,
2185 };
2186
2187 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2188 {
2189 struct rtable *ort = (struct rtable *) dst_orig;
2190 struct rtable *rt;
2191
2192 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2193 if (rt) {
2194 struct dst_entry *new = &rt->dst;
2195
2196 new->__use = 1;
2197 new->input = dst_discard;
2198 new->output = dst_discard;
2199
2200 new->dev = ort->dst.dev;
2201 if (new->dev)
2202 dev_hold(new->dev);
2203
2204 rt->rt_is_input = ort->rt_is_input;
2205 rt->rt_iif = ort->rt_iif;
2206 rt->rt_pmtu = ort->rt_pmtu;
2207
2208 rt->rt_genid = rt_genid(net);
2209 rt->rt_flags = ort->rt_flags;
2210 rt->rt_type = ort->rt_type;
2211 rt->rt_gateway = ort->rt_gateway;
2212 rt->rt_uses_gateway = ort->rt_uses_gateway;
2213
2214 INIT_LIST_HEAD(&rt->rt_uncached);
2215
2216 dst_free(new);
2217 }
2218
2219 dst_release(dst_orig);
2220
2221 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2222 }
2223
2224 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2225 struct sock *sk)
2226 {
2227 struct rtable *rt = __ip_route_output_key(net, flp4);
2228
2229 if (IS_ERR(rt))
2230 return rt;
2231
2232 if (flp4->flowi4_proto)
2233 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2234 flowi4_to_flowi(flp4),
2235 sk, 0);
2236
2237 return rt;
2238 }
2239 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2240
2241 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2242 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2243 u32 seq, int event, int nowait, unsigned int flags)
2244 {
2245 struct rtable *rt = skb_rtable(skb);
2246 struct rtmsg *r;
2247 struct nlmsghdr *nlh;
2248 unsigned long expires = 0;
2249 u32 error;
2250 u32 metrics[RTAX_MAX];
2251
2252 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2253 if (nlh == NULL)
2254 return -EMSGSIZE;
2255
2256 r = nlmsg_data(nlh);
2257 r->rtm_family = AF_INET;
2258 r->rtm_dst_len = 32;
2259 r->rtm_src_len = 0;
2260 r->rtm_tos = fl4->flowi4_tos;
2261 r->rtm_table = RT_TABLE_MAIN;
2262 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2263 goto nla_put_failure;
2264 r->rtm_type = rt->rt_type;
2265 r->rtm_scope = RT_SCOPE_UNIVERSE;
2266 r->rtm_protocol = RTPROT_UNSPEC;
2267 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2268 if (rt->rt_flags & RTCF_NOTIFY)
2269 r->rtm_flags |= RTM_F_NOTIFY;
2270 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2271 r->rtm_flags |= RTCF_DOREDIRECT;
2272
2273 if (nla_put_be32(skb, RTA_DST, dst))
2274 goto nla_put_failure;
2275 if (src) {
2276 r->rtm_src_len = 32;
2277 if (nla_put_be32(skb, RTA_SRC, src))
2278 goto nla_put_failure;
2279 }
2280 if (rt->dst.dev &&
2281 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2282 goto nla_put_failure;
2283 #ifdef CONFIG_IP_ROUTE_CLASSID
2284 if (rt->dst.tclassid &&
2285 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2286 goto nla_put_failure;
2287 #endif
2288 if (!rt_is_input_route(rt) &&
2289 fl4->saddr != src) {
2290 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2291 goto nla_put_failure;
2292 }
2293 if (rt->rt_uses_gateway &&
2294 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2295 goto nla_put_failure;
2296
2297 expires = rt->dst.expires;
2298 if (expires) {
2299 unsigned long now = jiffies;
2300
2301 if (time_before(now, expires))
2302 expires -= now;
2303 else
2304 expires = 0;
2305 }
2306
2307 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2308 if (rt->rt_pmtu && expires)
2309 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2310 if (rtnetlink_put_metrics(skb, metrics) < 0)
2311 goto nla_put_failure;
2312
2313 if (fl4->flowi4_mark &&
2314 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2315 goto nla_put_failure;
2316
2317 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2318 nla_put_u32(skb, RTA_UID,
2319 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2320 goto nla_put_failure;
2321
2322 error = rt->dst.error;
2323
2324 if (rt_is_input_route(rt)) {
2325 #ifdef CONFIG_IP_MROUTE
2326 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2327 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2328 int err = ipmr_get_route(net, skb,
2329 fl4->saddr, fl4->daddr,
2330 r, nowait);
2331 if (err <= 0) {
2332 if (!nowait) {
2333 if (err == 0)
2334 return 0;
2335 goto nla_put_failure;
2336 } else {
2337 if (err == -EMSGSIZE)
2338 goto nla_put_failure;
2339 error = err;
2340 }
2341 }
2342 } else
2343 #endif
2344 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2345 goto nla_put_failure;
2346 }
2347
2348 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2349 goto nla_put_failure;
2350
2351 return nlmsg_end(skb, nlh);
2352
2353 nla_put_failure:
2354 nlmsg_cancel(skb, nlh);
2355 return -EMSGSIZE;
2356 }
2357
2358 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2359 {
2360 struct net *net = sock_net(in_skb->sk);
2361 struct rtmsg *rtm;
2362 struct nlattr *tb[RTA_MAX+1];
2363 struct rtable *rt = NULL;
2364 struct flowi4 fl4;
2365 __be32 dst = 0;
2366 __be32 src = 0;
2367 u32 iif;
2368 int err;
2369 int mark;
2370 struct sk_buff *skb;
2371 kuid_t uid;
2372
2373 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2374 if (err < 0)
2375 goto errout;
2376
2377 rtm = nlmsg_data(nlh);
2378
2379 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2380 if (skb == NULL) {
2381 err = -ENOBUFS;
2382 goto errout;
2383 }
2384
2385 /* Reserve room for dummy headers, this skb can pass
2386 through good chunk of routing engine.
2387 */
2388 skb_reset_mac_header(skb);
2389 skb_reset_network_header(skb);
2390
2391 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2392 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2393 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2394
2395 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2396 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2397 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2398 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2399 if (tb[RTA_UID])
2400 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2401 else
2402 uid = (iif ? INVALID_UID : current_uid());
2403
2404 memset(&fl4, 0, sizeof(fl4));
2405 fl4.daddr = dst;
2406 fl4.saddr = src;
2407 fl4.flowi4_tos = rtm->rtm_tos;
2408 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2409 fl4.flowi4_mark = mark;
2410 fl4.flowi4_uid = uid;
2411
2412 if (iif) {
2413 struct net_device *dev;
2414
2415 dev = __dev_get_by_index(net, iif);
2416 if (dev == NULL) {
2417 err = -ENODEV;
2418 goto errout_free;
2419 }
2420
2421 skb->protocol = htons(ETH_P_IP);
2422 skb->dev = dev;
2423 skb->mark = mark;
2424 local_bh_disable();
2425 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2426 local_bh_enable();
2427
2428 rt = skb_rtable(skb);
2429 if (err == 0 && rt->dst.error)
2430 err = -rt->dst.error;
2431 } else {
2432 rt = ip_route_output_key(net, &fl4);
2433
2434 err = 0;
2435 if (IS_ERR(rt))
2436 err = PTR_ERR(rt);
2437 }
2438
2439 if (err)
2440 goto errout_free;
2441
2442 skb_dst_set(skb, &rt->dst);
2443 if (rtm->rtm_flags & RTM_F_NOTIFY)
2444 rt->rt_flags |= RTCF_NOTIFY;
2445
2446 err = rt_fill_info(net, dst, src, &fl4, skb,
2447 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2448 RTM_NEWROUTE, 0, 0);
2449 if (err <= 0)
2450 goto errout_free;
2451
2452 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2453 errout:
2454 return err;
2455
2456 errout_free:
2457 kfree_skb(skb);
2458 goto errout;
2459 }
2460
2461 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2462 {
2463 return skb->len;
2464 }
2465
2466 void ip_rt_multicast_event(struct in_device *in_dev)
2467 {
2468 rt_cache_flush(dev_net(in_dev->dev));
2469 }
2470
2471 #ifdef CONFIG_SYSCTL
2472 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2473 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2474 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2475 static int ip_rt_gc_elasticity __read_mostly = 8;
2476
2477 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2478 void __user *buffer,
2479 size_t *lenp, loff_t *ppos)
2480 {
2481 if (write) {
2482 rt_cache_flush((struct net *)__ctl->extra1);
2483 return 0;
2484 }
2485
2486 return -EINVAL;
2487 }
2488
2489 static ctl_table ipv4_route_table[] = {
2490 {
2491 .procname = "gc_thresh",
2492 .data = &ipv4_dst_ops.gc_thresh,
2493 .maxlen = sizeof(int),
2494 .mode = 0644,
2495 .proc_handler = proc_dointvec,
2496 },
2497 {
2498 .procname = "max_size",
2499 .data = &ip_rt_max_size,
2500 .maxlen = sizeof(int),
2501 .mode = 0644,
2502 .proc_handler = proc_dointvec,
2503 },
2504 {
2505 /* Deprecated. Use gc_min_interval_ms */
2506
2507 .procname = "gc_min_interval",
2508 .data = &ip_rt_gc_min_interval,
2509 .maxlen = sizeof(int),
2510 .mode = 0644,
2511 .proc_handler = proc_dointvec_jiffies,
2512 },
2513 {
2514 .procname = "gc_min_interval_ms",
2515 .data = &ip_rt_gc_min_interval,
2516 .maxlen = sizeof(int),
2517 .mode = 0644,
2518 .proc_handler = proc_dointvec_ms_jiffies,
2519 },
2520 {
2521 .procname = "gc_timeout",
2522 .data = &ip_rt_gc_timeout,
2523 .maxlen = sizeof(int),
2524 .mode = 0644,
2525 .proc_handler = proc_dointvec_jiffies,
2526 },
2527 {
2528 .procname = "gc_interval",
2529 .data = &ip_rt_gc_interval,
2530 .maxlen = sizeof(int),
2531 .mode = 0644,
2532 .proc_handler = proc_dointvec_jiffies,
2533 },
2534 {
2535 .procname = "redirect_load",
2536 .data = &ip_rt_redirect_load,
2537 .maxlen = sizeof(int),
2538 .mode = 0644,
2539 .proc_handler = proc_dointvec,
2540 },
2541 {
2542 .procname = "redirect_number",
2543 .data = &ip_rt_redirect_number,
2544 .maxlen = sizeof(int),
2545 .mode = 0644,
2546 .proc_handler = proc_dointvec,
2547 },
2548 {
2549 .procname = "redirect_silence",
2550 .data = &ip_rt_redirect_silence,
2551 .maxlen = sizeof(int),
2552 .mode = 0644,
2553 .proc_handler = proc_dointvec,
2554 },
2555 {
2556 .procname = "error_cost",
2557 .data = &ip_rt_error_cost,
2558 .maxlen = sizeof(int),
2559 .mode = 0644,
2560 .proc_handler = proc_dointvec,
2561 },
2562 {
2563 .procname = "error_burst",
2564 .data = &ip_rt_error_burst,
2565 .maxlen = sizeof(int),
2566 .mode = 0644,
2567 .proc_handler = proc_dointvec,
2568 },
2569 {
2570 .procname = "gc_elasticity",
2571 .data = &ip_rt_gc_elasticity,
2572 .maxlen = sizeof(int),
2573 .mode = 0644,
2574 .proc_handler = proc_dointvec,
2575 },
2576 {
2577 .procname = "mtu_expires",
2578 .data = &ip_rt_mtu_expires,
2579 .maxlen = sizeof(int),
2580 .mode = 0644,
2581 .proc_handler = proc_dointvec_jiffies,
2582 },
2583 {
2584 .procname = "min_pmtu",
2585 .data = &ip_rt_min_pmtu,
2586 .maxlen = sizeof(int),
2587 .mode = 0644,
2588 .proc_handler = proc_dointvec,
2589 },
2590 {
2591 .procname = "min_adv_mss",
2592 .data = &ip_rt_min_advmss,
2593 .maxlen = sizeof(int),
2594 .mode = 0644,
2595 .proc_handler = proc_dointvec,
2596 },
2597 { }
2598 };
2599
2600 static struct ctl_table ipv4_route_flush_table[] = {
2601 {
2602 .procname = "flush",
2603 .maxlen = sizeof(int),
2604 .mode = 0200,
2605 .proc_handler = ipv4_sysctl_rtcache_flush,
2606 },
2607 { },
2608 };
2609
2610 static __net_init int sysctl_route_net_init(struct net *net)
2611 {
2612 struct ctl_table *tbl;
2613
2614 tbl = ipv4_route_flush_table;
2615 if (!net_eq(net, &init_net)) {
2616 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2617 if (tbl == NULL)
2618 goto err_dup;
2619
2620 /* Don't export sysctls to unprivileged users */
2621 if (net->user_ns != &init_user_ns)
2622 tbl[0].procname = NULL;
2623 }
2624 tbl[0].extra1 = net;
2625
2626 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2627 if (net->ipv4.route_hdr == NULL)
2628 goto err_reg;
2629 return 0;
2630
2631 err_reg:
2632 if (tbl != ipv4_route_flush_table)
2633 kfree(tbl);
2634 err_dup:
2635 return -ENOMEM;
2636 }
2637
2638 static __net_exit void sysctl_route_net_exit(struct net *net)
2639 {
2640 struct ctl_table *tbl;
2641
2642 tbl = net->ipv4.route_hdr->ctl_table_arg;
2643 unregister_net_sysctl_table(net->ipv4.route_hdr);
2644 BUG_ON(tbl == ipv4_route_flush_table);
2645 kfree(tbl);
2646 }
2647
2648 static __net_initdata struct pernet_operations sysctl_route_ops = {
2649 .init = sysctl_route_net_init,
2650 .exit = sysctl_route_net_exit,
2651 };
2652 #endif
2653
2654 static __net_init int rt_genid_init(struct net *net)
2655 {
2656 atomic_set(&net->rt_genid, 0);
2657 get_random_bytes(&net->ipv4.dev_addr_genid,
2658 sizeof(net->ipv4.dev_addr_genid));
2659 return 0;
2660 }
2661
2662 static __net_initdata struct pernet_operations rt_genid_ops = {
2663 .init = rt_genid_init,
2664 };
2665
2666 static int __net_init ipv4_inetpeer_init(struct net *net)
2667 {
2668 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2669
2670 if (!bp)
2671 return -ENOMEM;
2672 inet_peer_base_init(bp);
2673 net->ipv4.peers = bp;
2674 return 0;
2675 }
2676
2677 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2678 {
2679 struct inet_peer_base *bp = net->ipv4.peers;
2680
2681 net->ipv4.peers = NULL;
2682 inetpeer_invalidate_tree(bp);
2683 kfree(bp);
2684 }
2685
2686 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2687 .init = ipv4_inetpeer_init,
2688 .exit = ipv4_inetpeer_exit,
2689 };
2690
2691 #ifdef CONFIG_IP_ROUTE_CLASSID
2692 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2693 #endif /* CONFIG_IP_ROUTE_CLASSID */
2694
2695 int __init ip_rt_init(void)
2696 {
2697 int rc = 0;
2698
2699 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2700 if (!ip_idents)
2701 panic("IP: failed to allocate ip_idents\n");
2702
2703 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2704
2705 #ifdef CONFIG_IP_ROUTE_CLASSID
2706 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2707 if (!ip_rt_acct)
2708 panic("IP: failed to allocate ip_rt_acct\n");
2709 #endif
2710
2711 ipv4_dst_ops.kmem_cachep =
2712 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2713 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2714
2715 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2716
2717 if (dst_entries_init(&ipv4_dst_ops) < 0)
2718 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2719
2720 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2721 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2722
2723 ipv4_dst_ops.gc_thresh = ~0;
2724 ip_rt_max_size = INT_MAX;
2725
2726 devinet_init();
2727 ip_fib_init();
2728
2729 if (ip_rt_proc_init())
2730 pr_err("Unable to create route proc files\n");
2731 #ifdef CONFIG_XFRM
2732 xfrm_init();
2733 xfrm4_init();
2734 #endif
2735 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2736
2737 #ifdef CONFIG_SYSCTL
2738 register_pernet_subsys(&sysctl_route_ops);
2739 #endif
2740 register_pernet_subsys(&rt_genid_ops);
2741 register_pernet_subsys(&ipv4_inetpeer_ops);
2742 return rc;
2743 }
2744
2745 #ifdef CONFIG_SYSCTL
2746 /*
2747 * We really need to sanitize the damn ipv4 init order, then all
2748 * this nonsense will go away.
2749 */
2750 void __init ip_static_sysctl_init(void)
2751 {
2752 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2753 }
2754 #endif
kernel source for telekom puls (alcatel/mediatek)