projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'v3.10.70' 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 net = dev_net(rt->dst.dev);
877 if (!IN_DEV_FORWARD(in_dev)) {
878 switch (rt->dst.error) {
879 case EHOSTUNREACH:
880 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
881 break;
882
883 case ENETUNREACH:
884 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
885 break;
886 }
887 goto out;
888 }
889
890 switch (rt->dst.error) {
891 case EINVAL:
892 default:
893 goto out;
894 case EHOSTUNREACH:
895 code = ICMP_HOST_UNREACH;
896 break;
897 case ENETUNREACH:
898 code = ICMP_NET_UNREACH;
899 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
900 break;
901 case EACCES:
902 code = ICMP_PKT_FILTERED;
903 break;
904 }
905
906 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
907
908 send = true;
909 if (peer) {
910 now = jiffies;
911 peer->rate_tokens += now - peer->rate_last;
912 if (peer->rate_tokens > ip_rt_error_burst)
913 peer->rate_tokens = ip_rt_error_burst;
914 peer->rate_last = now;
915 if (peer->rate_tokens >= ip_rt_error_cost)
916 peer->rate_tokens -= ip_rt_error_cost;
917 else
918 send = false;
919 inet_putpeer(peer);
920 }
921 if (send)
922 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
923
924 out: kfree_skb(skb);
925 return 0;
926 }
927
928 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
929 {
930 struct dst_entry *dst = &rt->dst;
931 struct fib_result res;
932
933 if (dst_metric_locked(dst, RTAX_MTU))
934 return;
935
936 if (dst->dev->mtu < mtu)
937 return;
938
939 if (mtu < ip_rt_min_pmtu)
940 mtu = ip_rt_min_pmtu;
941
942 if (!rt->rt_pmtu) {
943 dst->obsolete = DST_OBSOLETE_KILL;
944 } else {
945 rt->rt_pmtu = mtu;
946 dst->expires = max(1UL, jiffies + ip_rt_mtu_expires);
947 }
948
949 rcu_read_lock();
950 if (fib_lookup(dev_net(dst->dev), fl4, &res) == 0) {
951 struct fib_nh *nh = &FIB_RES_NH(res);
952
953 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
954 jiffies + ip_rt_mtu_expires);
955 }
956 rcu_read_unlock();
957 }
958
959 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
960 struct sk_buff *skb, u32 mtu)
961 {
962 struct rtable *rt = (struct rtable *) dst;
963 struct flowi4 fl4;
964
965 ip_rt_build_flow_key(&fl4, sk, skb);
966 __ip_rt_update_pmtu(rt, &fl4, mtu);
967 }
968
969 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
970 int oif, u32 mark, u8 protocol, int flow_flags)
971 {
972 const struct iphdr *iph = (const struct iphdr *) skb->data;
973 struct flowi4 fl4;
974 struct rtable *rt;
975
976 if (!mark)
977 mark = IP4_REPLY_MARK(net, skb->mark);
978
979 __build_flow_key(&fl4, NULL, iph, oif,
980 RT_TOS(iph->tos), protocol, mark, flow_flags);
981 rt = __ip_route_output_key(net, &fl4);
982 if (!IS_ERR(rt)) {
983 __ip_rt_update_pmtu(rt, &fl4, mtu);
984 ip_rt_put(rt);
985 }
986 }
987 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
988
989 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
990 {
991 const struct iphdr *iph = (const struct iphdr *) skb->data;
992 struct flowi4 fl4;
993 struct rtable *rt;
994
995 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
996
997 if (!fl4.flowi4_mark)
998 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
999
1000 rt = __ip_route_output_key(sock_net(sk), &fl4);
1001 if (!IS_ERR(rt)) {
1002 __ip_rt_update_pmtu(rt, &fl4, mtu);
1003 ip_rt_put(rt);
1004 }
1005 }
1006
1007 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1008 {
1009 const struct iphdr *iph = (const struct iphdr *) skb->data;
1010 struct flowi4 fl4;
1011 struct rtable *rt;
1012 struct dst_entry *odst = NULL;
1013 bool new = false;
1014
1015 bh_lock_sock(sk);
1016 odst = sk_dst_get(sk);
1017
1018 if (sock_owned_by_user(sk) || !odst) {
1019 __ipv4_sk_update_pmtu(skb, sk, mtu);
1020 goto out;
1021 }
1022
1023 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1024
1025 rt = (struct rtable *)odst;
1026 if (odst->obsolete && odst->ops->check(odst, 0) == NULL) {
1027 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1028 if (IS_ERR(rt))
1029 goto out;
1030
1031 new = true;
1032 }
1033
1034 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1035
1036 if (!dst_check(&rt->dst, 0)) {
1037 if (new)
1038 dst_release(&rt->dst);
1039
1040 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1041 if (IS_ERR(rt))
1042 goto out;
1043
1044 new = true;
1045 }
1046
1047 if (new)
1048 sk_dst_set(sk, &rt->dst);
1049
1050 out:
1051 bh_unlock_sock(sk);
1052 dst_release(odst);
1053 }
1054 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1055
1056 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1057 int oif, u32 mark, u8 protocol, int flow_flags)
1058 {
1059 const struct iphdr *iph = (const struct iphdr *) skb->data;
1060 struct flowi4 fl4;
1061 struct rtable *rt;
1062
1063 __build_flow_key(&fl4, NULL, iph, oif,
1064 RT_TOS(iph->tos), protocol, mark, flow_flags);
1065 rt = __ip_route_output_key(net, &fl4);
1066 if (!IS_ERR(rt)) {
1067 __ip_do_redirect(rt, skb, &fl4, false);
1068 ip_rt_put(rt);
1069 }
1070 }
1071 EXPORT_SYMBOL_GPL(ipv4_redirect);
1072
1073 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1074 {
1075 const struct iphdr *iph = (const struct iphdr *) skb->data;
1076 struct flowi4 fl4;
1077 struct rtable *rt;
1078
1079 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1080 rt = __ip_route_output_key(sock_net(sk), &fl4);
1081 if (!IS_ERR(rt)) {
1082 __ip_do_redirect(rt, skb, &fl4, false);
1083 ip_rt_put(rt);
1084 }
1085 }
1086 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1087
1088 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1089 {
1090 struct rtable *rt = (struct rtable *) dst;
1091
1092 /* All IPV4 dsts are created with ->obsolete set to the value
1093 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1094 * into this function always.
1095 *
1096 * When a PMTU/redirect information update invalidates a
1097 * route, this is indicated by setting obsolete to
1098 * DST_OBSOLETE_KILL.
1099 */
1100 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1101 return NULL;
1102 return dst;
1103 }
1104
1105 static void ipv4_link_failure(struct sk_buff *skb)
1106 {
1107 struct rtable *rt;
1108
1109 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1110
1111 rt = skb_rtable(skb);
1112 if (rt)
1113 dst_set_expires(&rt->dst, 0);
1114 }
1115
1116 static int ip_rt_bug(struct sk_buff *skb)
1117 {
1118 pr_debug("%s: %pI4 -> %pI4, %s\n",
1119 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1120 skb->dev ? skb->dev->name : "?");
1121 kfree_skb(skb);
1122 WARN_ON(1);
1123 return 0;
1124 }
1125
1126 /*
1127 We do not cache source address of outgoing interface,
1128 because it is used only by IP RR, TS and SRR options,
1129 so that it out of fast path.
1130
1131 BTW remember: "addr" is allowed to be not aligned
1132 in IP options!
1133 */
1134
1135 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1136 {
1137 __be32 src;
1138
1139 if (rt_is_output_route(rt))
1140 src = ip_hdr(skb)->saddr;
1141 else {
1142 struct fib_result res;
1143 struct flowi4 fl4;
1144 struct iphdr *iph;
1145
1146 iph = ip_hdr(skb);
1147
1148 memset(&fl4, 0, sizeof(fl4));
1149 fl4.daddr = iph->daddr;
1150 fl4.saddr = iph->saddr;
1151 fl4.flowi4_tos = RT_TOS(iph->tos);
1152 fl4.flowi4_oif = rt->dst.dev->ifindex;
1153 fl4.flowi4_iif = skb->dev->ifindex;
1154 fl4.flowi4_mark = skb->mark;
1155
1156 rcu_read_lock();
1157 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1158 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1159 else
1160 src = inet_select_addr(rt->dst.dev,
1161 rt_nexthop(rt, iph->daddr),
1162 RT_SCOPE_UNIVERSE);
1163 rcu_read_unlock();
1164 }
1165 memcpy(addr, &src, 4);
1166 }
1167
1168 #ifdef CONFIG_IP_ROUTE_CLASSID
1169 static void set_class_tag(struct rtable *rt, u32 tag)
1170 {
1171 if (!(rt->dst.tclassid & 0xFFFF))
1172 rt->dst.tclassid |= tag & 0xFFFF;
1173 if (!(rt->dst.tclassid & 0xFFFF0000))
1174 rt->dst.tclassid |= tag & 0xFFFF0000;
1175 }
1176 #endif
1177
1178 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1179 {
1180 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1181
1182 if (advmss == 0) {
1183 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1184 ip_rt_min_advmss);
1185 if (advmss > 65535 - 40)
1186 advmss = 65535 - 40;
1187 }
1188 return advmss;
1189 }
1190
1191 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1192 {
1193 const struct rtable *rt = (const struct rtable *) dst;
1194 unsigned int mtu = rt->rt_pmtu;
1195
1196 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1197 mtu = dst_metric_raw(dst, RTAX_MTU);
1198
1199 if (mtu)
1200 return mtu;
1201
1202 mtu = dst->dev->mtu;
1203
1204 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1205 if (rt->rt_uses_gateway && mtu > 576)
1206 mtu = 576;
1207 }
1208
1209 if (mtu > IP_MAX_MTU)
1210 mtu = IP_MAX_MTU;
1211
1212 return mtu;
1213 }
1214
1215 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1216 {
1217 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1218 struct fib_nh_exception *fnhe;
1219 u32 hval;
1220
1221 if (!hash)
1222 return NULL;
1223
1224 hval = fnhe_hashfun(daddr);
1225
1226 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1227 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1228 if (fnhe->fnhe_daddr == daddr)
1229 return fnhe;
1230 }
1231 return NULL;
1232 }
1233
1234 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1235 __be32 daddr)
1236 {
1237 bool ret = false;
1238
1239 spin_lock_bh(&fnhe_lock);
1240
1241 if (daddr == fnhe->fnhe_daddr) {
1242 struct rtable *orig = rcu_dereference(fnhe->fnhe_rth);
1243 if (orig && rt_is_expired(orig)) {
1244 fnhe->fnhe_gw = 0;
1245 fnhe->fnhe_pmtu = 0;
1246 fnhe->fnhe_expires = 0;
1247 }
1248 if (fnhe->fnhe_pmtu) {
1249 unsigned long expires = fnhe->fnhe_expires;
1250 unsigned long diff = expires - jiffies;
1251
1252 if (time_before(jiffies, expires)) {
1253 rt->rt_pmtu = fnhe->fnhe_pmtu;
1254 dst_set_expires(&rt->dst, diff);
1255 }
1256 }
1257 if (fnhe->fnhe_gw) {
1258 rt->rt_flags |= RTCF_REDIRECTED;
1259 rt->rt_gateway = fnhe->fnhe_gw;
1260 rt->rt_uses_gateway = 1;
1261 } else if (!rt->rt_gateway)
1262 rt->rt_gateway = daddr;
1263
1264 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1265 if (orig)
1266 rt_free(orig);
1267
1268 fnhe->fnhe_stamp = jiffies;
1269 ret = true;
1270 }
1271 spin_unlock_bh(&fnhe_lock);
1272
1273 return ret;
1274 }
1275
1276 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1277 {
1278 struct rtable *orig, *prev, **p;
1279 bool ret = true;
1280
1281 if (rt_is_input_route(rt)) {
1282 p = (struct rtable **)&nh->nh_rth_input;
1283 } else {
1284 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1285 }
1286 orig = *p;
1287
1288 prev = cmpxchg(p, orig, rt);
1289 if (prev == orig) {
1290 if (orig)
1291 rt_free(orig);
1292 } else
1293 ret = false;
1294
1295 return ret;
1296 }
1297
1298 static DEFINE_SPINLOCK(rt_uncached_lock);
1299 static LIST_HEAD(rt_uncached_list);
1300
1301 static void rt_add_uncached_list(struct rtable *rt)
1302 {
1303 spin_lock_bh(&rt_uncached_lock);
1304 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1305 spin_unlock_bh(&rt_uncached_lock);
1306 }
1307
1308 static void ipv4_dst_destroy(struct dst_entry *dst)
1309 {
1310 struct rtable *rt = (struct rtable *) dst;
1311
1312 if (!list_empty(&rt->rt_uncached)) {
1313 spin_lock_bh(&rt_uncached_lock);
1314 list_del(&rt->rt_uncached);
1315 spin_unlock_bh(&rt_uncached_lock);
1316 }
1317 }
1318
1319 void rt_flush_dev(struct net_device *dev)
1320 {
1321 if (!list_empty(&rt_uncached_list)) {
1322 struct net *net = dev_net(dev);
1323 struct rtable *rt;
1324
1325 spin_lock_bh(&rt_uncached_lock);
1326 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1327 if (rt->dst.dev != dev)
1328 continue;
1329 rt->dst.dev = net->loopback_dev;
1330 dev_hold(rt->dst.dev);
1331 dev_put(dev);
1332 }
1333 spin_unlock_bh(&rt_uncached_lock);
1334 }
1335 }
1336
1337 static bool rt_cache_valid(const struct rtable *rt)
1338 {
1339 return rt &&
1340 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1341 !rt_is_expired(rt);
1342 }
1343
1344 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1345 const struct fib_result *res,
1346 struct fib_nh_exception *fnhe,
1347 struct fib_info *fi, u16 type, u32 itag)
1348 {
1349 bool cached = false;
1350
1351 if (fi) {
1352 struct fib_nh *nh = &FIB_RES_NH(*res);
1353
1354 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1355 rt->rt_gateway = nh->nh_gw;
1356 rt->rt_uses_gateway = 1;
1357 }
1358 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1359 #ifdef CONFIG_IP_ROUTE_CLASSID
1360 rt->dst.tclassid = nh->nh_tclassid;
1361 #endif
1362 if (unlikely(fnhe))
1363 cached = rt_bind_exception(rt, fnhe, daddr);
1364 else if (!(rt->dst.flags & DST_NOCACHE))
1365 cached = rt_cache_route(nh, rt);
1366 if (unlikely(!cached)) {
1367 /* Routes we intend to cache in nexthop exception or
1368 * FIB nexthop have the DST_NOCACHE bit clear.
1369 * However, if we are unsuccessful at storing this
1370 * route into the cache we really need to set it.
1371 */
1372 rt->dst.flags |= DST_NOCACHE;
1373 if (!rt->rt_gateway)
1374 rt->rt_gateway = daddr;
1375 rt_add_uncached_list(rt);
1376 }
1377 } else
1378 rt_add_uncached_list(rt);
1379
1380 #ifdef CONFIG_IP_ROUTE_CLASSID
1381 #ifdef CONFIG_IP_MULTIPLE_TABLES
1382 set_class_tag(rt, res->tclassid);
1383 #endif
1384 set_class_tag(rt, itag);
1385 #endif
1386 }
1387
1388 static struct rtable *rt_dst_alloc(struct net_device *dev,
1389 bool nopolicy, bool noxfrm, bool will_cache)
1390 {
1391 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1392 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1393 (nopolicy ? DST_NOPOLICY : 0) |
1394 (noxfrm ? DST_NOXFRM : 0));
1395 }
1396
1397 /* called in rcu_read_lock() section */
1398 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1399 u8 tos, struct net_device *dev, int our)
1400 {
1401 struct rtable *rth;
1402 struct in_device *in_dev = __in_dev_get_rcu(dev);
1403 u32 itag = 0;
1404 int err;
1405
1406 /* Primary sanity checks. */
1407
1408 if (in_dev == NULL)
1409 return -EINVAL;
1410
1411 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1412 skb->protocol != htons(ETH_P_IP))
1413 goto e_inval;
1414
1415 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1416 if (ipv4_is_loopback(saddr))
1417 goto e_inval;
1418
1419 if (ipv4_is_zeronet(saddr)) {
1420 if (!ipv4_is_local_multicast(daddr))
1421 goto e_inval;
1422 } else {
1423 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1424 in_dev, &itag);
1425 if (err < 0)
1426 goto e_err;
1427 }
1428 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1429 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1430 if (!rth)
1431 goto e_nobufs;
1432
1433 #ifdef CONFIG_IP_ROUTE_CLASSID
1434 rth->dst.tclassid = itag;
1435 #endif
1436 rth->dst.output = ip_rt_bug;
1437
1438 rth->rt_genid = rt_genid(dev_net(dev));
1439 rth->rt_flags = RTCF_MULTICAST;
1440 rth->rt_type = RTN_MULTICAST;
1441 rth->rt_is_input= 1;
1442 rth->rt_iif = 0;
1443 rth->rt_pmtu = 0;
1444 rth->rt_gateway = 0;
1445 rth->rt_uses_gateway = 0;
1446 INIT_LIST_HEAD(&rth->rt_uncached);
1447 if (our) {
1448 rth->dst.input= ip_local_deliver;
1449 rth->rt_flags |= RTCF_LOCAL;
1450 }
1451
1452 #ifdef CONFIG_IP_MROUTE
1453 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1454 rth->dst.input = ip_mr_input;
1455 #endif
1456 RT_CACHE_STAT_INC(in_slow_mc);
1457
1458 skb_dst_set(skb, &rth->dst);
1459 return 0;
1460
1461 e_nobufs:
1462 return -ENOBUFS;
1463 e_inval:
1464 return -EINVAL;
1465 e_err:
1466 return err;
1467 }
1468
1469
1470 static void ip_handle_martian_source(struct net_device *dev,
1471 struct in_device *in_dev,
1472 struct sk_buff *skb,
1473 __be32 daddr,
1474 __be32 saddr)
1475 {
1476 RT_CACHE_STAT_INC(in_martian_src);
1477 #ifdef CONFIG_IP_ROUTE_VERBOSE
1478 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1479 /*
1480 * RFC1812 recommendation, if source is martian,
1481 * the only hint is MAC header.
1482 */
1483 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1484 &daddr, &saddr, dev->name);
1485 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1486 print_hex_dump(KERN_WARNING, "ll header: ",
1487 DUMP_PREFIX_OFFSET, 16, 1,
1488 skb_mac_header(skb),
1489 dev->hard_header_len, true);
1490 }
1491 }
1492 #endif
1493 }
1494
1495 /* called in rcu_read_lock() section */
1496 static int __mkroute_input(struct sk_buff *skb,
1497 const struct fib_result *res,
1498 struct in_device *in_dev,
1499 __be32 daddr, __be32 saddr, u32 tos)
1500 {
1501 struct rtable *rth;
1502 int err;
1503 struct in_device *out_dev;
1504 unsigned int flags = 0;
1505 bool do_cache;
1506 u32 itag = 0;
1507
1508 /* get a working reference to the output device */
1509 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1510 if (out_dev == NULL) {
1511 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1512 return -EINVAL;
1513 }
1514
1515 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1516 in_dev->dev, in_dev, &itag);
1517 if (err < 0) {
1518 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1519 saddr);
1520
1521 goto cleanup;
1522 }
1523
1524 do_cache = res->fi && !itag;
1525 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1526 skb->protocol == htons(ETH_P_IP) &&
1527 (IN_DEV_SHARED_MEDIA(out_dev) ||
1528 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1529 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1530
1531 if (skb->protocol != htons(ETH_P_IP)) {
1532 /* Not IP (i.e. ARP). Do not create route, if it is
1533 * invalid for proxy arp. DNAT routes are always valid.
1534 *
1535 * Proxy arp feature have been extended to allow, ARP
1536 * replies back to the same interface, to support
1537 * Private VLAN switch technologies. See arp.c.
1538 */
1539 if (out_dev == in_dev &&
1540 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1541 err = -EINVAL;
1542 goto cleanup;
1543 }
1544 }
1545
1546 if (do_cache) {
1547 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1548 if (rt_cache_valid(rth)) {
1549 skb_dst_set_noref(skb, &rth->dst);
1550 goto out;
1551 }
1552 }
1553
1554 rth = rt_dst_alloc(out_dev->dev,
1555 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1556 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1557 if (!rth) {
1558 err = -ENOBUFS;
1559 goto cleanup;
1560 }
1561
1562 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1563 rth->rt_flags = flags;
1564 rth->rt_type = res->type;
1565 rth->rt_is_input = 1;
1566 rth->rt_iif = 0;
1567 rth->rt_pmtu = 0;
1568 rth->rt_gateway = 0;
1569 rth->rt_uses_gateway = 0;
1570 INIT_LIST_HEAD(&rth->rt_uncached);
1571 RT_CACHE_STAT_INC(in_slow_tot);
1572
1573 rth->dst.input = ip_forward;
1574 rth->dst.output = ip_output;
1575
1576 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1577 skb_dst_set(skb, &rth->dst);
1578 out:
1579 err = 0;
1580 cleanup:
1581 return err;
1582 }
1583
1584 static int ip_mkroute_input(struct sk_buff *skb,
1585 struct fib_result *res,
1586 const struct flowi4 *fl4,
1587 struct in_device *in_dev,
1588 __be32 daddr, __be32 saddr, u32 tos)
1589 {
1590 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1591 if (res->fi && res->fi->fib_nhs > 1)
1592 fib_select_multipath(res);
1593 #endif
1594
1595 /* create a routing cache entry */
1596 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1597 }
1598
1599 /*
1600 * NOTE. We drop all the packets that has local source
1601 * addresses, because every properly looped back packet
1602 * must have correct destination already attached by output routine.
1603 *
1604 * Such approach solves two big problems:
1605 * 1. Not simplex devices are handled properly.
1606 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1607 * called with rcu_read_lock()
1608 */
1609
1610 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1611 u8 tos, struct net_device *dev)
1612 {
1613 struct fib_result res;
1614 struct in_device *in_dev = __in_dev_get_rcu(dev);
1615 struct flowi4 fl4;
1616 unsigned int flags = 0;
1617 u32 itag = 0;
1618 struct rtable *rth;
1619 int err = -EINVAL;
1620 struct net *net = dev_net(dev);
1621 bool do_cache;
1622
1623 /* IP on this device is disabled. */
1624
1625 if (!in_dev)
1626 goto out;
1627
1628 /* Check for the most weird martians, which can be not detected
1629 by fib_lookup.
1630 */
1631
1632 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1633 goto martian_source;
1634
1635 res.fi = NULL;
1636 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1637 goto brd_input;
1638
1639 /* Accept zero addresses only to limited broadcast;
1640 * I even do not know to fix it or not. Waiting for complains :-)
1641 */
1642 if (ipv4_is_zeronet(saddr))
1643 goto martian_source;
1644
1645 if (ipv4_is_zeronet(daddr))
1646 goto martian_destination;
1647
1648 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1649 * and call it once if daddr or/and saddr are loopback addresses
1650 */
1651 if (ipv4_is_loopback(daddr)) {
1652 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1653 goto martian_destination;
1654 } else if (ipv4_is_loopback(saddr)) {
1655 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1656 goto martian_source;
1657 }
1658
1659 /*
1660 * Now we are ready to route packet.
1661 */
1662 fl4.flowi4_oif = 0;
1663 fl4.flowi4_iif = dev->ifindex;
1664 fl4.flowi4_mark = skb->mark;
1665 fl4.flowi4_tos = tos;
1666 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1667 fl4.daddr = daddr;
1668 fl4.saddr = saddr;
1669 err = fib_lookup(net, &fl4, &res);
1670 if (err != 0)
1671 goto no_route;
1672
1673 if (res.type == RTN_BROADCAST)
1674 goto brd_input;
1675
1676 if (res.type == RTN_LOCAL) {
1677 err = fib_validate_source(skb, saddr, daddr, tos,
1678 LOOPBACK_IFINDEX,
1679 dev, in_dev, &itag);
1680 if (err < 0)
1681 goto martian_source_keep_err;
1682 goto local_input;
1683 }
1684
1685 if (!IN_DEV_FORWARD(in_dev))
1686 goto no_route;
1687 if (res.type != RTN_UNICAST)
1688 goto martian_destination;
1689
1690 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1691 out: return err;
1692
1693 brd_input:
1694 if (skb->protocol != htons(ETH_P_IP))
1695 goto e_inval;
1696
1697 if (!ipv4_is_zeronet(saddr)) {
1698 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1699 in_dev, &itag);
1700 if (err < 0)
1701 goto martian_source_keep_err;
1702 }
1703 flags |= RTCF_BROADCAST;
1704 res.type = RTN_BROADCAST;
1705 RT_CACHE_STAT_INC(in_brd);
1706
1707 local_input:
1708 do_cache = false;
1709 if (res.fi) {
1710 if (!itag) {
1711 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1712 if (rt_cache_valid(rth)) {
1713 skb_dst_set_noref(skb, &rth->dst);
1714 err = 0;
1715 goto out;
1716 }
1717 do_cache = true;
1718 }
1719 }
1720
1721 rth = rt_dst_alloc(net->loopback_dev,
1722 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1723 if (!rth)
1724 goto e_nobufs;
1725
1726 rth->dst.input= ip_local_deliver;
1727 rth->dst.output= ip_rt_bug;
1728 #ifdef CONFIG_IP_ROUTE_CLASSID
1729 rth->dst.tclassid = itag;
1730 #endif
1731
1732 rth->rt_genid = rt_genid(net);
1733 rth->rt_flags = flags|RTCF_LOCAL;
1734 rth->rt_type = res.type;
1735 rth->rt_is_input = 1;
1736 rth->rt_iif = 0;
1737 rth->rt_pmtu = 0;
1738 rth->rt_gateway = 0;
1739 rth->rt_uses_gateway = 0;
1740 INIT_LIST_HEAD(&rth->rt_uncached);
1741 RT_CACHE_STAT_INC(in_slow_tot);
1742 if (res.type == RTN_UNREACHABLE) {
1743 rth->dst.input= ip_error;
1744 rth->dst.error= -err;
1745 rth->rt_flags &= ~RTCF_LOCAL;
1746 }
1747 if (do_cache) {
1748 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1749 rth->dst.flags |= DST_NOCACHE;
1750 rt_add_uncached_list(rth);
1751 }
1752 }
1753 skb_dst_set(skb, &rth->dst);
1754 err = 0;
1755 goto out;
1756
1757 no_route:
1758 RT_CACHE_STAT_INC(in_no_route);
1759 res.type = RTN_UNREACHABLE;
1760 if (err == -ESRCH)
1761 err = -ENETUNREACH;
1762 goto local_input;
1763
1764 /*
1765 * Do not cache martian addresses: they should be logged (RFC1812)
1766 */
1767 martian_destination:
1768 RT_CACHE_STAT_INC(in_martian_dst);
1769 #ifdef CONFIG_IP_ROUTE_VERBOSE
1770 if (IN_DEV_LOG_MARTIANS(in_dev))
1771 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1772 &daddr, &saddr, dev->name);
1773 #endif
1774
1775 e_inval:
1776 err = -EINVAL;
1777 goto out;
1778
1779 e_nobufs:
1780 err = -ENOBUFS;
1781 goto out;
1782
1783 martian_source:
1784 err = -EINVAL;
1785 martian_source_keep_err:
1786 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1787 goto out;
1788 }
1789
1790 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1791 u8 tos, struct net_device *dev)
1792 {
1793 int res;
1794
1795 rcu_read_lock();
1796
1797 /* Multicast recognition logic is moved from route cache to here.
1798 The problem was that too many Ethernet cards have broken/missing
1799 hardware multicast filters :-( As result the host on multicasting
1800 network acquires a lot of useless route cache entries, sort of
1801 SDR messages from all the world. Now we try to get rid of them.
1802 Really, provided software IP multicast filter is organized
1803 reasonably (at least, hashed), it does not result in a slowdown
1804 comparing with route cache reject entries.
1805 Note, that multicast routers are not affected, because
1806 route cache entry is created eventually.
1807 */
1808 if (ipv4_is_multicast(daddr)) {
1809 struct in_device *in_dev = __in_dev_get_rcu(dev);
1810
1811 if (in_dev) {
1812 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1813 ip_hdr(skb)->protocol);
1814 if (our
1815 #ifdef CONFIG_IP_MROUTE
1816 ||
1817 (!ipv4_is_local_multicast(daddr) &&
1818 IN_DEV_MFORWARD(in_dev))
1819 #endif
1820 ) {
1821 int res = ip_route_input_mc(skb, daddr, saddr,
1822 tos, dev, our);
1823 rcu_read_unlock();
1824 return res;
1825 }
1826 }
1827 rcu_read_unlock();
1828 return -EINVAL;
1829 }
1830 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1831 rcu_read_unlock();
1832 return res;
1833 }
1834 EXPORT_SYMBOL(ip_route_input_noref);
1835
1836 /* called with rcu_read_lock() */
1837 static struct rtable *__mkroute_output(const struct fib_result *res,
1838 const struct flowi4 *fl4, int orig_oif,
1839 struct net_device *dev_out,
1840 unsigned int flags)
1841 {
1842 struct fib_info *fi = res->fi;
1843 struct fib_nh_exception *fnhe;
1844 struct in_device *in_dev;
1845 u16 type = res->type;
1846 struct rtable *rth;
1847 bool do_cache;
1848
1849 in_dev = __in_dev_get_rcu(dev_out);
1850 if (!in_dev)
1851 return ERR_PTR(-EINVAL);
1852
1853 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1854 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1855 return ERR_PTR(-EINVAL);
1856
1857 if (ipv4_is_lbcast(fl4->daddr))
1858 type = RTN_BROADCAST;
1859 else if (ipv4_is_multicast(fl4->daddr))
1860 type = RTN_MULTICAST;
1861 else if (ipv4_is_zeronet(fl4->daddr))
1862 return ERR_PTR(-EINVAL);
1863
1864 if (dev_out->flags & IFF_LOOPBACK)
1865 flags |= RTCF_LOCAL;
1866
1867 do_cache = true;
1868 if (type == RTN_BROADCAST) {
1869 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1870 fi = NULL;
1871 } else if (type == RTN_MULTICAST) {
1872 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1873 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1874 fl4->flowi4_proto))
1875 flags &= ~RTCF_LOCAL;
1876 else
1877 do_cache = false;
1878 /* If multicast route do not exist use
1879 * default one, but do not gateway in this case.
1880 * Yes, it is hack.
1881 */
1882 if (fi && res->prefixlen < 4)
1883 fi = NULL;
1884 }
1885
1886 fnhe = NULL;
1887 do_cache &= fi != NULL;
1888 if (do_cache) {
1889 struct rtable __rcu **prth;
1890 struct fib_nh *nh = &FIB_RES_NH(*res);
1891
1892 fnhe = find_exception(nh, fl4->daddr);
1893 if (fnhe)
1894 prth = &fnhe->fnhe_rth;
1895 else {
1896 if (unlikely(fl4->flowi4_flags &
1897 FLOWI_FLAG_KNOWN_NH &&
1898 !(nh->nh_gw &&
1899 nh->nh_scope == RT_SCOPE_LINK))) {
1900 do_cache = false;
1901 goto add;
1902 }
1903 prth = __this_cpu_ptr(nh->nh_pcpu_rth_output);
1904 }
1905 rth = rcu_dereference(*prth);
1906 if (rt_cache_valid(rth)) {
1907 dst_hold(&rth->dst);
1908 return rth;
1909 }
1910 }
1911
1912 add:
1913 rth = rt_dst_alloc(dev_out,
1914 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1915 IN_DEV_CONF_GET(in_dev, NOXFRM),
1916 do_cache);
1917 if (!rth)
1918 return ERR_PTR(-ENOBUFS);
1919
1920 rth->dst.output = ip_output;
1921
1922 rth->rt_genid = rt_genid(dev_net(dev_out));
1923 rth->rt_flags = flags;
1924 rth->rt_type = type;
1925 rth->rt_is_input = 0;
1926 rth->rt_iif = orig_oif ? : 0;
1927 rth->rt_pmtu = 0;
1928 rth->rt_gateway = 0;
1929 rth->rt_uses_gateway = 0;
1930 INIT_LIST_HEAD(&rth->rt_uncached);
1931
1932 RT_CACHE_STAT_INC(out_slow_tot);
1933
1934 if (flags & RTCF_LOCAL)
1935 rth->dst.input = ip_local_deliver;
1936 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1937 if (flags & RTCF_LOCAL &&
1938 !(dev_out->flags & IFF_LOOPBACK)) {
1939 rth->dst.output = ip_mc_output;
1940 RT_CACHE_STAT_INC(out_slow_mc);
1941 }
1942 #ifdef CONFIG_IP_MROUTE
1943 if (type == RTN_MULTICAST) {
1944 if (IN_DEV_MFORWARD(in_dev) &&
1945 !ipv4_is_local_multicast(fl4->daddr)) {
1946 rth->dst.input = ip_mr_input;
1947 rth->dst.output = ip_mc_output;
1948 }
1949 }
1950 #endif
1951 }
1952
1953 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1954
1955 return rth;
1956 }
1957
1958 /*
1959 * Major route resolver routine.
1960 */
1961
1962 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1963 {
1964 struct net_device *dev_out = NULL;
1965 __u8 tos = RT_FL_TOS(fl4);
1966 unsigned int flags = 0;
1967 struct fib_result res;
1968 struct rtable *rth;
1969 int orig_oif;
1970
1971 res.tclassid = 0;
1972 res.fi = NULL;
1973 res.table = NULL;
1974
1975 orig_oif = fl4->flowi4_oif;
1976
1977 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1978 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1979 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1980 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1981
1982 rcu_read_lock();
1983 if (fl4->saddr) {
1984 rth = ERR_PTR(-EINVAL);
1985 if (ipv4_is_multicast(fl4->saddr) ||
1986 ipv4_is_lbcast(fl4->saddr) ||
1987 ipv4_is_zeronet(fl4->saddr))
1988 goto out;
1989
1990 /* I removed check for oif == dev_out->oif here.
1991 It was wrong for two reasons:
1992 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1993 is assigned to multiple interfaces.
1994 2. Moreover, we are allowed to send packets with saddr
1995 of another iface. --ANK
1996 */
1997
1998 if (fl4->flowi4_oif == 0 &&
1999 (ipv4_is_multicast(fl4->daddr) ||
2000 ipv4_is_lbcast(fl4->daddr))) {
2001 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2002 dev_out = __ip_dev_find(net, fl4->saddr, false);
2003 if (dev_out == NULL)
2004 goto out;
2005
2006 /* Special hack: user can direct multicasts
2007 and limited broadcast via necessary interface
2008 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2009 This hack is not just for fun, it allows
2010 vic,vat and friends to work.
2011 They bind socket to loopback, set ttl to zero
2012 and expect that it will work.
2013 From the viewpoint of routing cache they are broken,
2014 because we are not allowed to build multicast path
2015 with loopback source addr (look, routing cache
2016 cannot know, that ttl is zero, so that packet
2017 will not leave this host and route is valid).
2018 Luckily, this hack is good workaround.
2019 */
2020
2021 fl4->flowi4_oif = dev_out->ifindex;
2022 goto make_route;
2023 }
2024
2025 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2026 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2027 if (!__ip_dev_find(net, fl4->saddr, false))
2028 goto out;
2029 }
2030 }
2031
2032
2033 if (fl4->flowi4_oif) {
2034 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2035 rth = ERR_PTR(-ENODEV);
2036 if (dev_out == NULL)
2037 goto out;
2038
2039 /* RACE: Check return value of inet_select_addr instead. */
2040 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2041 rth = ERR_PTR(-ENETUNREACH);
2042 goto out;
2043 }
2044 if (ipv4_is_local_multicast(fl4->daddr) ||
2045 ipv4_is_lbcast(fl4->daddr)) {
2046 if (!fl4->saddr)
2047 fl4->saddr = inet_select_addr(dev_out, 0,
2048 RT_SCOPE_LINK);
2049 goto make_route;
2050 }
2051 if (!fl4->saddr) {
2052 if (ipv4_is_multicast(fl4->daddr))
2053 fl4->saddr = inet_select_addr(dev_out, 0,
2054 fl4->flowi4_scope);
2055 else if (!fl4->daddr)
2056 fl4->saddr = inet_select_addr(dev_out, 0,
2057 RT_SCOPE_HOST);
2058 }
2059 }
2060
2061 if (!fl4->daddr) {
2062 fl4->daddr = fl4->saddr;
2063 if (!fl4->daddr)
2064 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2065 dev_out = net->loopback_dev;
2066 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2067 res.type = RTN_LOCAL;
2068 flags |= RTCF_LOCAL;
2069 goto make_route;
2070 }
2071
2072 if (fib_lookup(net, fl4, &res)) {
2073 res.fi = NULL;
2074 res.table = NULL;
2075 if (fl4->flowi4_oif) {
2076 /* Apparently, routing tables are wrong. Assume,
2077 that the destination is on link.
2078
2079 WHY? DW.
2080 Because we are allowed to send to iface
2081 even if it has NO routes and NO assigned
2082 addresses. When oif is specified, routing
2083 tables are looked up with only one purpose:
2084 to catch if destination is gatewayed, rather than
2085 direct. Moreover, if MSG_DONTROUTE is set,
2086 we send packet, ignoring both routing tables
2087 and ifaddr state. --ANK
2088
2089
2090 We could make it even if oif is unknown,
2091 likely IPv6, but we do not.
2092 */
2093
2094 if (fl4->saddr == 0)
2095 fl4->saddr = inet_select_addr(dev_out, 0,
2096 RT_SCOPE_LINK);
2097 res.type = RTN_UNICAST;
2098 goto make_route;
2099 }
2100 rth = ERR_PTR(-ENETUNREACH);
2101 goto out;
2102 }
2103
2104 if (res.type == RTN_LOCAL) {
2105 if (!fl4->saddr) {
2106 if (res.fi->fib_prefsrc)
2107 fl4->saddr = res.fi->fib_prefsrc;
2108 else
2109 fl4->saddr = fl4->daddr;
2110 }
2111 dev_out = net->loopback_dev;
2112 fl4->flowi4_oif = dev_out->ifindex;
2113 flags |= RTCF_LOCAL;
2114 goto make_route;
2115 }
2116
2117 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2118 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2119 fib_select_multipath(&res);
2120 else
2121 #endif
2122 if (!res.prefixlen &&
2123 res.table->tb_num_default > 1 &&
2124 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2125 fib_select_default(&res);
2126
2127 if (!fl4->saddr)
2128 fl4->saddr = FIB_RES_PREFSRC(net, res);
2129
2130 dev_out = FIB_RES_DEV(res);
2131 fl4->flowi4_oif = dev_out->ifindex;
2132
2133
2134 make_route:
2135 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2136
2137 out:
2138 rcu_read_unlock();
2139 return rth;
2140 }
2141 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2142
2143 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2144 {
2145 return NULL;
2146 }
2147
2148 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2149 {
2150 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2151
2152 return mtu ? : dst->dev->mtu;
2153 }
2154
2155 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2156 struct sk_buff *skb, u32 mtu)
2157 {
2158 }
2159
2160 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2161 struct sk_buff *skb)
2162 {
2163 }
2164
2165 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2166 unsigned long old)
2167 {
2168 return NULL;
2169 }
2170
2171 static struct dst_ops ipv4_dst_blackhole_ops = {
2172 .family = AF_INET,
2173 .protocol = cpu_to_be16(ETH_P_IP),
2174 .check = ipv4_blackhole_dst_check,
2175 .mtu = ipv4_blackhole_mtu,
2176 .default_advmss = ipv4_default_advmss,
2177 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2178 .redirect = ipv4_rt_blackhole_redirect,
2179 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2180 .neigh_lookup = ipv4_neigh_lookup,
2181 };
2182
2183 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2184 {
2185 struct rtable *ort = (struct rtable *) dst_orig;
2186 struct rtable *rt;
2187
2188 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2189 if (rt) {
2190 struct dst_entry *new = &rt->dst;
2191
2192 new->__use = 1;
2193 new->input = dst_discard;
2194 new->output = dst_discard;
2195
2196 new->dev = ort->dst.dev;
2197 if (new->dev)
2198 dev_hold(new->dev);
2199
2200 rt->rt_is_input = ort->rt_is_input;
2201 rt->rt_iif = ort->rt_iif;
2202 rt->rt_pmtu = ort->rt_pmtu;
2203
2204 rt->rt_genid = rt_genid(net);
2205 rt->rt_flags = ort->rt_flags;
2206 rt->rt_type = ort->rt_type;
2207 rt->rt_gateway = ort->rt_gateway;
2208 rt->rt_uses_gateway = ort->rt_uses_gateway;
2209
2210 INIT_LIST_HEAD(&rt->rt_uncached);
2211
2212 dst_free(new);
2213 }
2214
2215 dst_release(dst_orig);
2216
2217 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2218 }
2219
2220 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2221 struct sock *sk)
2222 {
2223 struct rtable *rt = __ip_route_output_key(net, flp4);
2224
2225 if (IS_ERR(rt))
2226 return rt;
2227
2228 if (flp4->flowi4_proto)
2229 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2230 flowi4_to_flowi(flp4),
2231 sk, 0);
2232
2233 return rt;
2234 }
2235 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2236
2237 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2238 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2239 u32 seq, int event, int nowait, unsigned int flags)
2240 {
2241 struct rtable *rt = skb_rtable(skb);
2242 struct rtmsg *r;
2243 struct nlmsghdr *nlh;
2244 unsigned long expires = 0;
2245 u32 error;
2246 u32 metrics[RTAX_MAX];
2247
2248 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2249 if (nlh == NULL)
2250 return -EMSGSIZE;
2251
2252 r = nlmsg_data(nlh);
2253 r->rtm_family = AF_INET;
2254 r->rtm_dst_len = 32;
2255 r->rtm_src_len = 0;
2256 r->rtm_tos = fl4->flowi4_tos;
2257 r->rtm_table = RT_TABLE_MAIN;
2258 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2259 goto nla_put_failure;
2260 r->rtm_type = rt->rt_type;
2261 r->rtm_scope = RT_SCOPE_UNIVERSE;
2262 r->rtm_protocol = RTPROT_UNSPEC;
2263 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2264 if (rt->rt_flags & RTCF_NOTIFY)
2265 r->rtm_flags |= RTM_F_NOTIFY;
2266 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2267 r->rtm_flags |= RTCF_DOREDIRECT;
2268
2269 if (nla_put_be32(skb, RTA_DST, dst))
2270 goto nla_put_failure;
2271 if (src) {
2272 r->rtm_src_len = 32;
2273 if (nla_put_be32(skb, RTA_SRC, src))
2274 goto nla_put_failure;
2275 }
2276 if (rt->dst.dev &&
2277 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2278 goto nla_put_failure;
2279 #ifdef CONFIG_IP_ROUTE_CLASSID
2280 if (rt->dst.tclassid &&
2281 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2282 goto nla_put_failure;
2283 #endif
2284 if (!rt_is_input_route(rt) &&
2285 fl4->saddr != src) {
2286 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2287 goto nla_put_failure;
2288 }
2289 if (rt->rt_uses_gateway &&
2290 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2291 goto nla_put_failure;
2292
2293 expires = rt->dst.expires;
2294 if (expires) {
2295 unsigned long now = jiffies;
2296
2297 if (time_before(now, expires))
2298 expires -= now;
2299 else
2300 expires = 0;
2301 }
2302
2303 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2304 if (rt->rt_pmtu && expires)
2305 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2306 if (rtnetlink_put_metrics(skb, metrics) < 0)
2307 goto nla_put_failure;
2308
2309 if (fl4->flowi4_mark &&
2310 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2311 goto nla_put_failure;
2312
2313 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2314 nla_put_u32(skb, RTA_UID,
2315 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2316 goto nla_put_failure;
2317
2318 error = rt->dst.error;
2319
2320 if (rt_is_input_route(rt)) {
2321 #ifdef CONFIG_IP_MROUTE
2322 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2323 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2324 int err = ipmr_get_route(net, skb,
2325 fl4->saddr, fl4->daddr,
2326 r, nowait);
2327 if (err <= 0) {
2328 if (!nowait) {
2329 if (err == 0)
2330 return 0;
2331 goto nla_put_failure;
2332 } else {
2333 if (err == -EMSGSIZE)
2334 goto nla_put_failure;
2335 error = err;
2336 }
2337 }
2338 } else
2339 #endif
2340 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2341 goto nla_put_failure;
2342 }
2343
2344 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2345 goto nla_put_failure;
2346
2347 return nlmsg_end(skb, nlh);
2348
2349 nla_put_failure:
2350 nlmsg_cancel(skb, nlh);
2351 return -EMSGSIZE;
2352 }
2353
2354 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2355 {
2356 struct net *net = sock_net(in_skb->sk);
2357 struct rtmsg *rtm;
2358 struct nlattr *tb[RTA_MAX+1];
2359 struct rtable *rt = NULL;
2360 struct flowi4 fl4;
2361 __be32 dst = 0;
2362 __be32 src = 0;
2363 u32 iif;
2364 int err;
2365 int mark;
2366 struct sk_buff *skb;
2367 kuid_t uid;
2368
2369 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2370 if (err < 0)
2371 goto errout;
2372
2373 rtm = nlmsg_data(nlh);
2374
2375 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2376 if (skb == NULL) {
2377 err = -ENOBUFS;
2378 goto errout;
2379 }
2380
2381 /* Reserve room for dummy headers, this skb can pass
2382 through good chunk of routing engine.
2383 */
2384 skb_reset_mac_header(skb);
2385 skb_reset_network_header(skb);
2386
2387 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2388 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2389 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2390
2391 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2392 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2393 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2394 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2395 if (tb[RTA_UID])
2396 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2397 else
2398 uid = (iif ? INVALID_UID : current_uid());
2399
2400 memset(&fl4, 0, sizeof(fl4));
2401 fl4.daddr = dst;
2402 fl4.saddr = src;
2403 fl4.flowi4_tos = rtm->rtm_tos;
2404 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2405 fl4.flowi4_mark = mark;
2406 fl4.flowi4_uid = uid;
2407
2408 if (iif) {
2409 struct net_device *dev;
2410
2411 dev = __dev_get_by_index(net, iif);
2412 if (dev == NULL) {
2413 err = -ENODEV;
2414 goto errout_free;
2415 }
2416
2417 skb->protocol = htons(ETH_P_IP);
2418 skb->dev = dev;
2419 skb->mark = mark;
2420 local_bh_disable();
2421 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2422 local_bh_enable();
2423
2424 rt = skb_rtable(skb);
2425 if (err == 0 && rt->dst.error)
2426 err = -rt->dst.error;
2427 } else {
2428 rt = ip_route_output_key(net, &fl4);
2429
2430 err = 0;
2431 if (IS_ERR(rt))
2432 err = PTR_ERR(rt);
2433 }
2434
2435 if (err)
2436 goto errout_free;
2437
2438 skb_dst_set(skb, &rt->dst);
2439 if (rtm->rtm_flags & RTM_F_NOTIFY)
2440 rt->rt_flags |= RTCF_NOTIFY;
2441
2442 err = rt_fill_info(net, dst, src, &fl4, skb,
2443 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2444 RTM_NEWROUTE, 0, 0);
2445 if (err <= 0)
2446 goto errout_free;
2447
2448 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2449 errout:
2450 return err;
2451
2452 errout_free:
2453 kfree_skb(skb);
2454 goto errout;
2455 }
2456
2457 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2458 {
2459 return skb->len;
2460 }
2461
2462 void ip_rt_multicast_event(struct in_device *in_dev)
2463 {
2464 rt_cache_flush(dev_net(in_dev->dev));
2465 }
2466
2467 #ifdef CONFIG_SYSCTL
2468 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
2469 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2470 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2471 static int ip_rt_gc_elasticity __read_mostly = 8;
2472
2473 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2474 void __user *buffer,
2475 size_t *lenp, loff_t *ppos)
2476 {
2477 if (write) {
2478 rt_cache_flush((struct net *)__ctl->extra1);
2479 return 0;
2480 }
2481
2482 return -EINVAL;
2483 }
2484
2485 static ctl_table ipv4_route_table[] = {
2486 {
2487 .procname = "gc_thresh",
2488 .data = &ipv4_dst_ops.gc_thresh,
2489 .maxlen = sizeof(int),
2490 .mode = 0644,
2491 .proc_handler = proc_dointvec,
2492 },
2493 {
2494 .procname = "max_size",
2495 .data = &ip_rt_max_size,
2496 .maxlen = sizeof(int),
2497 .mode = 0644,
2498 .proc_handler = proc_dointvec,
2499 },
2500 {
2501 /* Deprecated. Use gc_min_interval_ms */
2502
2503 .procname = "gc_min_interval",
2504 .data = &ip_rt_gc_min_interval,
2505 .maxlen = sizeof(int),
2506 .mode = 0644,
2507 .proc_handler = proc_dointvec_jiffies,
2508 },
2509 {
2510 .procname = "gc_min_interval_ms",
2511 .data = &ip_rt_gc_min_interval,
2512 .maxlen = sizeof(int),
2513 .mode = 0644,
2514 .proc_handler = proc_dointvec_ms_jiffies,
2515 },
2516 {
2517 .procname = "gc_timeout",
2518 .data = &ip_rt_gc_timeout,
2519 .maxlen = sizeof(int),
2520 .mode = 0644,
2521 .proc_handler = proc_dointvec_jiffies,
2522 },
2523 {
2524 .procname = "gc_interval",
2525 .data = &ip_rt_gc_interval,
2526 .maxlen = sizeof(int),
2527 .mode = 0644,
2528 .proc_handler = proc_dointvec_jiffies,
2529 },
2530 {
2531 .procname = "redirect_load",
2532 .data = &ip_rt_redirect_load,
2533 .maxlen = sizeof(int),
2534 .mode = 0644,
2535 .proc_handler = proc_dointvec,
2536 },
2537 {
2538 .procname = "redirect_number",
2539 .data = &ip_rt_redirect_number,
2540 .maxlen = sizeof(int),
2541 .mode = 0644,
2542 .proc_handler = proc_dointvec,
2543 },
2544 {
2545 .procname = "redirect_silence",
2546 .data = &ip_rt_redirect_silence,
2547 .maxlen = sizeof(int),
2548 .mode = 0644,
2549 .proc_handler = proc_dointvec,
2550 },
2551 {
2552 .procname = "error_cost",
2553 .data = &ip_rt_error_cost,
2554 .maxlen = sizeof(int),
2555 .mode = 0644,
2556 .proc_handler = proc_dointvec,
2557 },
2558 {
2559 .procname = "error_burst",
2560 .data = &ip_rt_error_burst,
2561 .maxlen = sizeof(int),
2562 .mode = 0644,
2563 .proc_handler = proc_dointvec,
2564 },
2565 {
2566 .procname = "gc_elasticity",
2567 .data = &ip_rt_gc_elasticity,
2568 .maxlen = sizeof(int),
2569 .mode = 0644,
2570 .proc_handler = proc_dointvec,
2571 },
2572 {
2573 .procname = "mtu_expires",
2574 .data = &ip_rt_mtu_expires,
2575 .maxlen = sizeof(int),
2576 .mode = 0644,
2577 .proc_handler = proc_dointvec_jiffies,
2578 },
2579 {
2580 .procname = "min_pmtu",
2581 .data = &ip_rt_min_pmtu,
2582 .maxlen = sizeof(int),
2583 .mode = 0644,
2584 .proc_handler = proc_dointvec,
2585 },
2586 {
2587 .procname = "min_adv_mss",
2588 .data = &ip_rt_min_advmss,
2589 .maxlen = sizeof(int),
2590 .mode = 0644,
2591 .proc_handler = proc_dointvec,
2592 },
2593 { }
2594 };
2595
2596 static struct ctl_table ipv4_route_flush_table[] = {
2597 {
2598 .procname = "flush",
2599 .maxlen = sizeof(int),
2600 .mode = 0200,
2601 .proc_handler = ipv4_sysctl_rtcache_flush,
2602 },
2603 { },
2604 };
2605
2606 static __net_init int sysctl_route_net_init(struct net *net)
2607 {
2608 struct ctl_table *tbl;
2609
2610 tbl = ipv4_route_flush_table;
2611 if (!net_eq(net, &init_net)) {
2612 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2613 if (tbl == NULL)
2614 goto err_dup;
2615
2616 /* Don't export sysctls to unprivileged users */
2617 if (net->user_ns != &init_user_ns)
2618 tbl[0].procname = NULL;
2619 }
2620 tbl[0].extra1 = net;
2621
2622 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2623 if (net->ipv4.route_hdr == NULL)
2624 goto err_reg;
2625 return 0;
2626
2627 err_reg:
2628 if (tbl != ipv4_route_flush_table)
2629 kfree(tbl);
2630 err_dup:
2631 return -ENOMEM;
2632 }
2633
2634 static __net_exit void sysctl_route_net_exit(struct net *net)
2635 {
2636 struct ctl_table *tbl;
2637
2638 tbl = net->ipv4.route_hdr->ctl_table_arg;
2639 unregister_net_sysctl_table(net->ipv4.route_hdr);
2640 BUG_ON(tbl == ipv4_route_flush_table);
2641 kfree(tbl);
2642 }
2643
2644 static __net_initdata struct pernet_operations sysctl_route_ops = {
2645 .init = sysctl_route_net_init,
2646 .exit = sysctl_route_net_exit,
2647 };
2648 #endif
2649
2650 static __net_init int rt_genid_init(struct net *net)
2651 {
2652 atomic_set(&net->rt_genid, 0);
2653 get_random_bytes(&net->ipv4.dev_addr_genid,
2654 sizeof(net->ipv4.dev_addr_genid));
2655 return 0;
2656 }
2657
2658 static __net_initdata struct pernet_operations rt_genid_ops = {
2659 .init = rt_genid_init,
2660 };
2661
2662 static int __net_init ipv4_inetpeer_init(struct net *net)
2663 {
2664 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2665
2666 if (!bp)
2667 return -ENOMEM;
2668 inet_peer_base_init(bp);
2669 net->ipv4.peers = bp;
2670 return 0;
2671 }
2672
2673 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2674 {
2675 struct inet_peer_base *bp = net->ipv4.peers;
2676
2677 net->ipv4.peers = NULL;
2678 inetpeer_invalidate_tree(bp);
2679 kfree(bp);
2680 }
2681
2682 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2683 .init = ipv4_inetpeer_init,
2684 .exit = ipv4_inetpeer_exit,
2685 };
2686
2687 #ifdef CONFIG_IP_ROUTE_CLASSID
2688 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2689 #endif /* CONFIG_IP_ROUTE_CLASSID */
2690
2691 int __init ip_rt_init(void)
2692 {
2693 int rc = 0;
2694
2695 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2696 if (!ip_idents)
2697 panic("IP: failed to allocate ip_idents\n");
2698
2699 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2700
2701 #ifdef CONFIG_IP_ROUTE_CLASSID
2702 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2703 if (!ip_rt_acct)
2704 panic("IP: failed to allocate ip_rt_acct\n");
2705 #endif
2706
2707 ipv4_dst_ops.kmem_cachep =
2708 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2709 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2710
2711 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2712
2713 if (dst_entries_init(&ipv4_dst_ops) < 0)
2714 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2715
2716 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2717 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2718
2719 ipv4_dst_ops.gc_thresh = ~0;
2720 ip_rt_max_size = INT_MAX;
2721
2722 devinet_init();
2723 ip_fib_init();
2724
2725 if (ip_rt_proc_init())
2726 pr_err("Unable to create route proc files\n");
2727 #ifdef CONFIG_XFRM
2728 xfrm_init();
2729 xfrm4_init();
2730 #endif
2731 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2732
2733 #ifdef CONFIG_SYSCTL
2734 register_pernet_subsys(&sysctl_route_ops);
2735 #endif
2736 register_pernet_subsys(&rt_genid_ops);
2737 register_pernet_subsys(&ipv4_inetpeer_ops);
2738 return rc;
2739 }
2740
2741 #ifdef CONFIG_SYSCTL
2742 /*
2743 * We really need to sanitize the damn ipv4 init order, then all
2744 * this nonsense will go away.
2745 */
2746 void __init ip_static_sysctl_init(void)
2747 {
2748 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2749 }
2750 #endif
kernel source for telekom puls (alcatel/mediatek)