projects / GitHub / LineageOS / android_kernel_samsung_universal7580.git / blame_incremental
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (non-incremental) | history | HEAD
ipv4: Really ignore ICMP address requests/replies.
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / net / ipv4 / route.c
... / ...
CommitLineData
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/bootmem.h>
74#include <linux/string.h>
75#include <linux/socket.h>
76#include <linux/sockios.h>
77#include <linux/errno.h>
78#include <linux/in.h>
79#include <linux/inet.h>
80#include <linux/netdevice.h>
81#include <linux/proc_fs.h>
82#include <linux/init.h>
83#include <linux/workqueue.h>
84#include <linux/skbuff.h>
85#include <linux/inetdevice.h>
86#include <linux/igmp.h>
87#include <linux/pkt_sched.h>
88#include <linux/mroute.h>
89#include <linux/netfilter_ipv4.h>
90#include <linux/random.h>
91#include <linux/jhash.h>
92#include <linux/rcupdate.h>
93#include <linux/times.h>
94#include <linux/slab.h>
95#include <linux/prefetch.h>
96#include <net/dst.h>
97#include <net/net_namespace.h>
98#include <net/protocol.h>
99#include <net/ip.h>
100#include <net/route.h>
101#include <net/inetpeer.h>
102#include <net/sock.h>
103#include <net/ip_fib.h>
104#include <net/arp.h>
105#include <net/tcp.h>
106#include <net/icmp.h>
107#include <net/xfrm.h>
108#include <net/netevent.h>
109#include <net/rtnetlink.h>
110#ifdef CONFIG_SYSCTL
111#include <linux/sysctl.h>
112#include <linux/kmemleak.h>
113#endif
114#include <net/secure_seq.h>
115
116#define RT_FL_TOS(oldflp4) \
117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
118
119#define IP_MAX_MTU 0xFFF0
120
121#define RT_GC_TIMEOUT (300*HZ)
122
123static int ip_rt_max_size;
124static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
125static int ip_rt_gc_interval __read_mostly = 60 * HZ;
126static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
127static int ip_rt_redirect_number __read_mostly = 9;
128static int ip_rt_redirect_load __read_mostly = HZ / 50;
129static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
130static int ip_rt_error_cost __read_mostly = HZ;
131static int ip_rt_error_burst __read_mostly = 5 * HZ;
132static int ip_rt_gc_elasticity __read_mostly = 8;
133static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
134static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
135static int ip_rt_min_advmss __read_mostly = 256;
136
137/*
138 * Interface to generic destination cache.
139 */
140
141static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
142static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
143static unsigned int ipv4_mtu(const struct dst_entry *dst);
144static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145static void ipv4_link_failure(struct sk_buff *skb);
146static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
147 struct sk_buff *skb, u32 mtu);
148static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
149 struct sk_buff *skb);
150
151static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
152 int how)
153{
154}
155
156static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
157{
158 WARN_ON(1);
159 return NULL;
160}
161
162static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
163 struct sk_buff *skb,
164 const void *daddr);
165
166static struct dst_ops ipv4_dst_ops = {
167 .family = AF_INET,
168 .protocol = cpu_to_be16(ETH_P_IP),
169 .check = ipv4_dst_check,
170 .default_advmss = ipv4_default_advmss,
171 .mtu = ipv4_mtu,
172 .cow_metrics = ipv4_cow_metrics,
173 .ifdown = ipv4_dst_ifdown,
174 .negative_advice = ipv4_negative_advice,
175 .link_failure = ipv4_link_failure,
176 .update_pmtu = ip_rt_update_pmtu,
177 .redirect = ip_do_redirect,
178 .local_out = __ip_local_out,
179 .neigh_lookup = ipv4_neigh_lookup,
180};
181
182#define ECN_OR_COST(class) TC_PRIO_##class
183
184const __u8 ip_tos2prio[16] = {
185 TC_PRIO_BESTEFFORT,
186 ECN_OR_COST(BESTEFFORT),
187 TC_PRIO_BESTEFFORT,
188 ECN_OR_COST(BESTEFFORT),
189 TC_PRIO_BULK,
190 ECN_OR_COST(BULK),
191 TC_PRIO_BULK,
192 ECN_OR_COST(BULK),
193 TC_PRIO_INTERACTIVE,
194 ECN_OR_COST(INTERACTIVE),
195 TC_PRIO_INTERACTIVE,
196 ECN_OR_COST(INTERACTIVE),
197 TC_PRIO_INTERACTIVE_BULK,
198 ECN_OR_COST(INTERACTIVE_BULK),
199 TC_PRIO_INTERACTIVE_BULK,
200 ECN_OR_COST(INTERACTIVE_BULK)
201};
202EXPORT_SYMBOL(ip_tos2prio);
203
204static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
205#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
206
207static inline int rt_genid(struct net *net)
208{
209 return atomic_read(&net->ipv4.rt_genid);
210}
211
212#ifdef CONFIG_PROC_FS
213static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
214{
215 if (*pos)
216 return NULL;
217 return SEQ_START_TOKEN;
218}
219
220static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
221{
222 ++*pos;
223 return NULL;
224}
225
226static void rt_cache_seq_stop(struct seq_file *seq, void *v)
227{
228}
229
230static int rt_cache_seq_show(struct seq_file *seq, void *v)
231{
232 if (v == SEQ_START_TOKEN)
233 seq_printf(seq, "%-127s\n",
234 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
235 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
236 "HHUptod\tSpecDst");
237 return 0;
238}
239
240static const struct seq_operations rt_cache_seq_ops = {
241 .start = rt_cache_seq_start,
242 .next = rt_cache_seq_next,
243 .stop = rt_cache_seq_stop,
244 .show = rt_cache_seq_show,
245};
246
247static int rt_cache_seq_open(struct inode *inode, struct file *file)
248{
249 return seq_open(file, &rt_cache_seq_ops);
250}
251
252static const struct file_operations rt_cache_seq_fops = {
253 .owner = THIS_MODULE,
254 .open = rt_cache_seq_open,
255 .read = seq_read,
256 .llseek = seq_lseek,
257 .release = seq_release,
258};
259
260
261static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
262{
263 int cpu;
264
265 if (*pos == 0)
266 return SEQ_START_TOKEN;
267
268 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
269 if (!cpu_possible(cpu))
270 continue;
271 *pos = cpu+1;
272 return &per_cpu(rt_cache_stat, cpu);
273 }
274 return NULL;
275}
276
277static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
278{
279 int cpu;
280
281 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
282 if (!cpu_possible(cpu))
283 continue;
284 *pos = cpu+1;
285 return &per_cpu(rt_cache_stat, cpu);
286 }
287 return NULL;
288
289}
290
291static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
292{
293
294}
295
296static int rt_cpu_seq_show(struct seq_file *seq, void *v)
297{
298 struct rt_cache_stat *st = v;
299
300 if (v == SEQ_START_TOKEN) {
301 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");
302 return 0;
303 }
304
305 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
306 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
307 dst_entries_get_slow(&ipv4_dst_ops),
308 st->in_hit,
309 st->in_slow_tot,
310 st->in_slow_mc,
311 st->in_no_route,
312 st->in_brd,
313 st->in_martian_dst,
314 st->in_martian_src,
315
316 st->out_hit,
317 st->out_slow_tot,
318 st->out_slow_mc,
319
320 st->gc_total,
321 st->gc_ignored,
322 st->gc_goal_miss,
323 st->gc_dst_overflow,
324 st->in_hlist_search,
325 st->out_hlist_search
326 );
327 return 0;
328}
329
330static const struct seq_operations rt_cpu_seq_ops = {
331 .start = rt_cpu_seq_start,
332 .next = rt_cpu_seq_next,
333 .stop = rt_cpu_seq_stop,
334 .show = rt_cpu_seq_show,
335};
336
337
338static int rt_cpu_seq_open(struct inode *inode, struct file *file)
339{
340 return seq_open(file, &rt_cpu_seq_ops);
341}
342
343static const struct file_operations rt_cpu_seq_fops = {
344 .owner = THIS_MODULE,
345 .open = rt_cpu_seq_open,
346 .read = seq_read,
347 .llseek = seq_lseek,
348 .release = seq_release,
349};
350
351#ifdef CONFIG_IP_ROUTE_CLASSID
352static int rt_acct_proc_show(struct seq_file *m, void *v)
353{
354 struct ip_rt_acct *dst, *src;
355 unsigned int i, j;
356
357 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
358 if (!dst)
359 return -ENOMEM;
360
361 for_each_possible_cpu(i) {
362 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
363 for (j = 0; j < 256; j++) {
364 dst[j].o_bytes += src[j].o_bytes;
365 dst[j].o_packets += src[j].o_packets;
366 dst[j].i_bytes += src[j].i_bytes;
367 dst[j].i_packets += src[j].i_packets;
368 }
369 }
370
371 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
372 kfree(dst);
373 return 0;
374}
375
376static int rt_acct_proc_open(struct inode *inode, struct file *file)
377{
378 return single_open(file, rt_acct_proc_show, NULL);
379}
380
381static const struct file_operations rt_acct_proc_fops = {
382 .owner = THIS_MODULE,
383 .open = rt_acct_proc_open,
384 .read = seq_read,
385 .llseek = seq_lseek,
386 .release = single_release,
387};
388#endif
389
390static int __net_init ip_rt_do_proc_init(struct net *net)
391{
392 struct proc_dir_entry *pde;
393
394 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
395 &rt_cache_seq_fops);
396 if (!pde)
397 goto err1;
398
399 pde = proc_create("rt_cache", S_IRUGO,
400 net->proc_net_stat, &rt_cpu_seq_fops);
401 if (!pde)
402 goto err2;
403
404#ifdef CONFIG_IP_ROUTE_CLASSID
405 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
406 if (!pde)
407 goto err3;
408#endif
409 return 0;
410
411#ifdef CONFIG_IP_ROUTE_CLASSID
412err3:
413 remove_proc_entry("rt_cache", net->proc_net_stat);
414#endif
415err2:
416 remove_proc_entry("rt_cache", net->proc_net);
417err1:
418 return -ENOMEM;
419}
420
421static void __net_exit ip_rt_do_proc_exit(struct net *net)
422{
423 remove_proc_entry("rt_cache", net->proc_net_stat);
424 remove_proc_entry("rt_cache", net->proc_net);
425#ifdef CONFIG_IP_ROUTE_CLASSID
426 remove_proc_entry("rt_acct", net->proc_net);
427#endif
428}
429
430static struct pernet_operations ip_rt_proc_ops __net_initdata = {
431 .init = ip_rt_do_proc_init,
432 .exit = ip_rt_do_proc_exit,
433};
434
435static int __init ip_rt_proc_init(void)
436{
437 return register_pernet_subsys(&ip_rt_proc_ops);
438}
439
440#else
441static inline int ip_rt_proc_init(void)
442{
443 return 0;
444}
445#endif /* CONFIG_PROC_FS */
446
447static inline int rt_is_expired(struct rtable *rth)
448{
449 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
450}
451
452/*
453 * Perturbation of rt_genid by a small quantity [1..256]
454 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
455 * many times (2^24) without giving recent rt_genid.
456 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
457 */
458static void rt_cache_invalidate(struct net *net)
459{
460 unsigned char shuffle;
461
462 get_random_bytes(&shuffle, sizeof(shuffle));
463 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
464}
465
466/*
467 * delay < 0 : invalidate cache (fast : entries will be deleted later)
468 * delay >= 0 : invalidate & flush cache (can be long)
469 */
470void rt_cache_flush(struct net *net, int delay)
471{
472 rt_cache_invalidate(net);
473}
474
475static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
476 struct sk_buff *skb,
477 const void *daddr)
478{
479 struct net_device *dev = dst->dev;
480 const __be32 *pkey = daddr;
481 const struct rtable *rt;
482 struct neighbour *n;
483
484 rt = (const struct rtable *) dst;
485 if (rt->rt_gateway)
486 pkey = (const __be32 *) &rt->rt_gateway;
487 else if (skb)
488 pkey = &ip_hdr(skb)->daddr;
489
490 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
491 if (n)
492 return n;
493 return neigh_create(&arp_tbl, pkey, dev);
494}
495
496/*
497 * Peer allocation may fail only in serious out-of-memory conditions. However
498 * we still can generate some output.
499 * Random ID selection looks a bit dangerous because we have no chances to
500 * select ID being unique in a reasonable period of time.
501 * But broken packet identifier may be better than no packet at all.
502 */
503static void ip_select_fb_ident(struct iphdr *iph)
504{
505 static DEFINE_SPINLOCK(ip_fb_id_lock);
506 static u32 ip_fallback_id;
507 u32 salt;
508
509 spin_lock_bh(&ip_fb_id_lock);
510 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
511 iph->id = htons(salt & 0xFFFF);
512 ip_fallback_id = salt;
513 spin_unlock_bh(&ip_fb_id_lock);
514}
515
516void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
517{
518 struct net *net = dev_net(dst->dev);
519 struct inet_peer *peer;
520
521 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
522 if (peer) {
523 iph->id = htons(inet_getid(peer, more));
524 inet_putpeer(peer);
525 return;
526 }
527
528 ip_select_fb_ident(iph);
529}
530EXPORT_SYMBOL(__ip_select_ident);
531
532static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
533 const struct iphdr *iph,
534 int oif, u8 tos,
535 u8 prot, u32 mark, int flow_flags)
536{
537 if (sk) {
538 const struct inet_sock *inet = inet_sk(sk);
539
540 oif = sk->sk_bound_dev_if;
541 mark = sk->sk_mark;
542 tos = RT_CONN_FLAGS(sk);
543 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
544 }
545 flowi4_init_output(fl4, oif, mark, tos,
546 RT_SCOPE_UNIVERSE, prot,
547 flow_flags,
548 iph->daddr, iph->saddr, 0, 0);
549}
550
551static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
552 const struct sock *sk)
553{
554 const struct iphdr *iph = ip_hdr(skb);
555 int oif = skb->dev->ifindex;
556 u8 tos = RT_TOS(iph->tos);
557 u8 prot = iph->protocol;
558 u32 mark = skb->mark;
559
560 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
561}
562
563static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
564{
565 const struct inet_sock *inet = inet_sk(sk);
566 const struct ip_options_rcu *inet_opt;
567 __be32 daddr = inet->inet_daddr;
568
569 rcu_read_lock();
570 inet_opt = rcu_dereference(inet->inet_opt);
571 if (inet_opt && inet_opt->opt.srr)
572 daddr = inet_opt->opt.faddr;
573 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
574 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
575 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
576 inet_sk_flowi_flags(sk),
577 daddr, inet->inet_saddr, 0, 0);
578 rcu_read_unlock();
579}
580
581static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
582 const struct sk_buff *skb)
583{
584 if (skb)
585 build_skb_flow_key(fl4, skb, sk);
586 else
587 build_sk_flow_key(fl4, sk);
588}
589
590static DEFINE_SEQLOCK(fnhe_seqlock);
591
592static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
593{
594 struct fib_nh_exception *fnhe, *oldest;
595
596 oldest = rcu_dereference(hash->chain);
597 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
598 fnhe = rcu_dereference(fnhe->fnhe_next)) {
599 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
600 oldest = fnhe;
601 }
602 return oldest;
603}
604
605static inline u32 fnhe_hashfun(__be32 daddr)
606{
607 u32 hval;
608
609 hval = (__force u32) daddr;
610 hval ^= (hval >> 11) ^ (hval >> 22);
611
612 return hval & (FNHE_HASH_SIZE - 1);
613}
614
615static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
616 u32 pmtu, unsigned long expires)
617{
618 struct fnhe_hash_bucket *hash;
619 struct fib_nh_exception *fnhe;
620 int depth;
621 u32 hval = fnhe_hashfun(daddr);
622
623 write_seqlock_bh(&fnhe_seqlock);
624
625 hash = nh->nh_exceptions;
626 if (!hash) {
627 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
628 if (!hash)
629 goto out_unlock;
630 nh->nh_exceptions = hash;
631 }
632
633 hash += hval;
634
635 depth = 0;
636 for (fnhe = rcu_dereference(hash->chain); fnhe;
637 fnhe = rcu_dereference(fnhe->fnhe_next)) {
638 if (fnhe->fnhe_daddr == daddr)
639 break;
640 depth++;
641 }
642
643 if (fnhe) {
644 if (gw)
645 fnhe->fnhe_gw = gw;
646 if (pmtu) {
647 fnhe->fnhe_pmtu = pmtu;
648 fnhe->fnhe_expires = expires;
649 }
650 } else {
651 if (depth > FNHE_RECLAIM_DEPTH)
652 fnhe = fnhe_oldest(hash);
653 else {
654 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
655 if (!fnhe)
656 goto out_unlock;
657
658 fnhe->fnhe_next = hash->chain;
659 rcu_assign_pointer(hash->chain, fnhe);
660 }
661 fnhe->fnhe_daddr = daddr;
662 fnhe->fnhe_gw = gw;
663 fnhe->fnhe_pmtu = pmtu;
664 fnhe->fnhe_expires = expires;
665 }
666
667 fnhe->fnhe_stamp = jiffies;
668
669out_unlock:
670 write_sequnlock_bh(&fnhe_seqlock);
671 return;
672}
673
674static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
675 bool kill_route)
676{
677 __be32 new_gw = icmp_hdr(skb)->un.gateway;
678 __be32 old_gw = ip_hdr(skb)->saddr;
679 struct net_device *dev = skb->dev;
680 struct in_device *in_dev;
681 struct fib_result res;
682 struct neighbour *n;
683 struct net *net;
684
685 switch (icmp_hdr(skb)->code & 7) {
686 case ICMP_REDIR_NET:
687 case ICMP_REDIR_NETTOS:
688 case ICMP_REDIR_HOST:
689 case ICMP_REDIR_HOSTTOS:
690 break;
691
692 default:
693 return;
694 }
695
696 if (rt->rt_gateway != old_gw)
697 return;
698
699 in_dev = __in_dev_get_rcu(dev);
700 if (!in_dev)
701 return;
702
703 net = dev_net(dev);
704 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
705 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
706 ipv4_is_zeronet(new_gw))
707 goto reject_redirect;
708
709 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
710 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
711 goto reject_redirect;
712 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
713 goto reject_redirect;
714 } else {
715 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
716 goto reject_redirect;
717 }
718
719 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
720 if (n) {
721 if (!(n->nud_state & NUD_VALID)) {
722 neigh_event_send(n, NULL);
723 } else {
724 if (fib_lookup(net, fl4, &res) == 0) {
725 struct fib_nh *nh = &FIB_RES_NH(res);
726
727 update_or_create_fnhe(nh, fl4->daddr, new_gw,
728 0, 0);
729 }
730 if (kill_route)
731 rt->dst.obsolete = DST_OBSOLETE_KILL;
732 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
733 }
734 neigh_release(n);
735 }
736 return;
737
738reject_redirect:
739#ifdef CONFIG_IP_ROUTE_VERBOSE
740 if (IN_DEV_LOG_MARTIANS(in_dev)) {
741 const struct iphdr *iph = (const struct iphdr *) skb->data;
742 __be32 daddr = iph->daddr;
743 __be32 saddr = iph->saddr;
744
745 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
746 " Advised path = %pI4 -> %pI4\n",
747 &old_gw, dev->name, &new_gw,
748 &saddr, &daddr);
749 }
750#endif
751 ;
752}
753
754static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
755{
756 struct rtable *rt;
757 struct flowi4 fl4;
758
759 rt = (struct rtable *) dst;
760
761 ip_rt_build_flow_key(&fl4, sk, skb);
762 __ip_do_redirect(rt, skb, &fl4, true);
763}
764
765static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
766{
767 struct rtable *rt = (struct rtable *)dst;
768 struct dst_entry *ret = dst;
769
770 if (rt) {
771 if (dst->obsolete > 0) {
772 ip_rt_put(rt);
773 ret = NULL;
774 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
775 rt->dst.expires) {
776 ip_rt_put(rt);
777 ret = NULL;
778 }
779 }
780 return ret;
781}
782
783/*
784 * Algorithm:
785 * 1. The first ip_rt_redirect_number redirects are sent
786 * with exponential backoff, then we stop sending them at all,
787 * assuming that the host ignores our redirects.
788 * 2. If we did not see packets requiring redirects
789 * during ip_rt_redirect_silence, we assume that the host
790 * forgot redirected route and start to send redirects again.
791 *
792 * This algorithm is much cheaper and more intelligent than dumb load limiting
793 * in icmp.c.
794 *
795 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
796 * and "frag. need" (breaks PMTU discovery) in icmp.c.
797 */
798
799void ip_rt_send_redirect(struct sk_buff *skb)
800{
801 struct rtable *rt = skb_rtable(skb);
802 struct in_device *in_dev;
803 struct inet_peer *peer;
804 struct net *net;
805 int log_martians;
806
807 rcu_read_lock();
808 in_dev = __in_dev_get_rcu(rt->dst.dev);
809 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
810 rcu_read_unlock();
811 return;
812 }
813 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
814 rcu_read_unlock();
815
816 net = dev_net(rt->dst.dev);
817 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
818 if (!peer) {
819 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
820 return;
821 }
822
823 /* No redirected packets during ip_rt_redirect_silence;
824 * reset the algorithm.
825 */
826 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
827 peer->rate_tokens = 0;
828
829 /* Too many ignored redirects; do not send anything
830 * set dst.rate_last to the last seen redirected packet.
831 */
832 if (peer->rate_tokens >= ip_rt_redirect_number) {
833 peer->rate_last = jiffies;
834 goto out_put_peer;
835 }
836
837 /* Check for load limit; set rate_last to the latest sent
838 * redirect.
839 */
840 if (peer->rate_tokens == 0 ||
841 time_after(jiffies,
842 (peer->rate_last +
843 (ip_rt_redirect_load << peer->rate_tokens)))) {
844 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
845 peer->rate_last = jiffies;
846 ++peer->rate_tokens;
847#ifdef CONFIG_IP_ROUTE_VERBOSE
848 if (log_martians &&
849 peer->rate_tokens == ip_rt_redirect_number)
850 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
851 &ip_hdr(skb)->saddr, rt->rt_iif,
852 &ip_hdr(skb)->daddr, &rt->rt_gateway);
853#endif
854 }
855out_put_peer:
856 inet_putpeer(peer);
857}
858
859static int ip_error(struct sk_buff *skb)
860{
861 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
862 struct rtable *rt = skb_rtable(skb);
863 struct inet_peer *peer;
864 unsigned long now;
865 struct net *net;
866 bool send;
867 int code;
868
869 net = dev_net(rt->dst.dev);
870 if (!IN_DEV_FORWARD(in_dev)) {
871 switch (rt->dst.error) {
872 case EHOSTUNREACH:
873 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
874 break;
875
876 case ENETUNREACH:
877 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
878 break;
879 }
880 goto out;
881 }
882
883 switch (rt->dst.error) {
884 case EINVAL:
885 default:
886 goto out;
887 case EHOSTUNREACH:
888 code = ICMP_HOST_UNREACH;
889 break;
890 case ENETUNREACH:
891 code = ICMP_NET_UNREACH;
892 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
893 break;
894 case EACCES:
895 code = ICMP_PKT_FILTERED;
896 break;
897 }
898
899 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
900
901 send = true;
902 if (peer) {
903 now = jiffies;
904 peer->rate_tokens += now - peer->rate_last;
905 if (peer->rate_tokens > ip_rt_error_burst)
906 peer->rate_tokens = ip_rt_error_burst;
907 peer->rate_last = now;
908 if (peer->rate_tokens >= ip_rt_error_cost)
909 peer->rate_tokens -= ip_rt_error_cost;
910 else
911 send = false;
912 inet_putpeer(peer);
913 }
914 if (send)
915 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
916
917out: kfree_skb(skb);
918 return 0;
919}
920
921static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
922{
923 struct fib_result res;
924
925 if (mtu < ip_rt_min_pmtu)
926 mtu = ip_rt_min_pmtu;
927
928 if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) {
929 struct fib_nh *nh = &FIB_RES_NH(res);
930
931 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
932 jiffies + ip_rt_mtu_expires);
933 }
934 return mtu;
935}
936
937static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
938 struct sk_buff *skb, u32 mtu)
939{
940 struct rtable *rt = (struct rtable *) dst;
941 struct flowi4 fl4;
942
943 ip_rt_build_flow_key(&fl4, sk, skb);
944 mtu = __ip_rt_update_pmtu(rt, &fl4, mtu);
945
946 if (!rt->rt_pmtu) {
947 dst->obsolete = DST_OBSOLETE_KILL;
948 } else {
949 rt->rt_pmtu = mtu;
950 dst_set_expires(&rt->dst, ip_rt_mtu_expires);
951 }
952}
953
954void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
955 int oif, u32 mark, u8 protocol, int flow_flags)
956{
957 const struct iphdr *iph = (const struct iphdr *) skb->data;
958 struct flowi4 fl4;
959 struct rtable *rt;
960
961 __build_flow_key(&fl4, NULL, iph, oif,
962 RT_TOS(iph->tos), protocol, mark, flow_flags);
963 rt = __ip_route_output_key(net, &fl4);
964 if (!IS_ERR(rt)) {
965 __ip_rt_update_pmtu(rt, &fl4, mtu);
966 ip_rt_put(rt);
967 }
968}
969EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
970
971void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
972{
973 const struct iphdr *iph = (const struct iphdr *) skb->data;
974 struct flowi4 fl4;
975 struct rtable *rt;
976
977 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
978 rt = __ip_route_output_key(sock_net(sk), &fl4);
979 if (!IS_ERR(rt)) {
980 __ip_rt_update_pmtu(rt, &fl4, mtu);
981 ip_rt_put(rt);
982 }
983}
984EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
985
986void ipv4_redirect(struct sk_buff *skb, struct net *net,
987 int oif, u32 mark, u8 protocol, int flow_flags)
988{
989 const struct iphdr *iph = (const struct iphdr *) skb->data;
990 struct flowi4 fl4;
991 struct rtable *rt;
992
993 __build_flow_key(&fl4, NULL, iph, oif,
994 RT_TOS(iph->tos), protocol, mark, flow_flags);
995 rt = __ip_route_output_key(net, &fl4);
996 if (!IS_ERR(rt)) {
997 __ip_do_redirect(rt, skb, &fl4, false);
998 ip_rt_put(rt);
999 }
1000}
1001EXPORT_SYMBOL_GPL(ipv4_redirect);
1002
1003void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1004{
1005 const struct iphdr *iph = (const struct iphdr *) skb->data;
1006 struct flowi4 fl4;
1007 struct rtable *rt;
1008
1009 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1010 rt = __ip_route_output_key(sock_net(sk), &fl4);
1011 if (!IS_ERR(rt)) {
1012 __ip_do_redirect(rt, skb, &fl4, false);
1013 ip_rt_put(rt);
1014 }
1015}
1016EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1017
1018static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1019{
1020 struct rtable *rt = (struct rtable *) dst;
1021
1022 /* All IPV4 dsts are created with ->obsolete set to the value
1023 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1024 * into this function always.
1025 *
1026 * When a PMTU/redirect information update invalidates a
1027 * route, this is indicated by setting obsolete to
1028 * DST_OBSOLETE_KILL.
1029 */
1030 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1031 return NULL;
1032 return dst;
1033}
1034
1035static void ipv4_link_failure(struct sk_buff *skb)
1036{
1037 struct rtable *rt;
1038
1039 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1040
1041 rt = skb_rtable(skb);
1042 if (rt)
1043 dst_set_expires(&rt->dst, 0);
1044}
1045
1046static int ip_rt_bug(struct sk_buff *skb)
1047{
1048 pr_debug("%s: %pI4 -> %pI4, %s\n",
1049 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1050 skb->dev ? skb->dev->name : "?");
1051 kfree_skb(skb);
1052 WARN_ON(1);
1053 return 0;
1054}
1055
1056/*
1057 We do not cache source address of outgoing interface,
1058 because it is used only by IP RR, TS and SRR options,
1059 so that it out of fast path.
1060
1061 BTW remember: "addr" is allowed to be not aligned
1062 in IP options!
1063 */
1064
1065void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1066{
1067 __be32 src;
1068
1069 if (rt_is_output_route(rt))
1070 src = ip_hdr(skb)->saddr;
1071 else {
1072 struct fib_result res;
1073 struct flowi4 fl4;
1074 struct iphdr *iph;
1075
1076 iph = ip_hdr(skb);
1077
1078 memset(&fl4, 0, sizeof(fl4));
1079 fl4.daddr = iph->daddr;
1080 fl4.saddr = iph->saddr;
1081 fl4.flowi4_tos = RT_TOS(iph->tos);
1082 fl4.flowi4_oif = rt->dst.dev->ifindex;
1083 fl4.flowi4_iif = skb->dev->ifindex;
1084 fl4.flowi4_mark = skb->mark;
1085
1086 rcu_read_lock();
1087 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1088 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1089 else
1090 src = inet_select_addr(rt->dst.dev,
1091 rt_nexthop(rt, iph->daddr),
1092 RT_SCOPE_UNIVERSE);
1093 rcu_read_unlock();
1094 }
1095 memcpy(addr, &src, 4);
1096}
1097
1098#ifdef CONFIG_IP_ROUTE_CLASSID
1099static void set_class_tag(struct rtable *rt, u32 tag)
1100{
1101 if (!(rt->dst.tclassid & 0xFFFF))
1102 rt->dst.tclassid |= tag & 0xFFFF;
1103 if (!(rt->dst.tclassid & 0xFFFF0000))
1104 rt->dst.tclassid |= tag & 0xFFFF0000;
1105}
1106#endif
1107
1108static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1109{
1110 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1111
1112 if (advmss == 0) {
1113 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1114 ip_rt_min_advmss);
1115 if (advmss > 65535 - 40)
1116 advmss = 65535 - 40;
1117 }
1118 return advmss;
1119}
1120
1121static unsigned int ipv4_mtu(const struct dst_entry *dst)
1122{
1123 const struct rtable *rt = (const struct rtable *) dst;
1124 unsigned int mtu = rt->rt_pmtu;
1125
1126 if (mtu && time_after_eq(jiffies, rt->dst.expires))
1127 mtu = 0;
1128
1129 if (!mtu)
1130 mtu = dst_metric_raw(dst, RTAX_MTU);
1131
1132 if (mtu && rt_is_output_route(rt))
1133 return mtu;
1134
1135 mtu = dst->dev->mtu;
1136
1137 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1138 if (rt->rt_gateway && mtu > 576)
1139 mtu = 576;
1140 }
1141
1142 if (mtu > IP_MAX_MTU)
1143 mtu = IP_MAX_MTU;
1144
1145 return mtu;
1146}
1147
1148static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1149{
1150 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1151 struct fib_nh_exception *fnhe;
1152 u32 hval;
1153
1154 if (!hash)
1155 return NULL;
1156
1157 hval = fnhe_hashfun(daddr);
1158
1159 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1160 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1161 if (fnhe->fnhe_daddr == daddr)
1162 return fnhe;
1163 }
1164 return NULL;
1165}
1166
1167static void rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1168 __be32 daddr)
1169{
1170 __be32 fnhe_daddr, gw;
1171 unsigned long expires;
1172 unsigned int seq;
1173 u32 pmtu;
1174
1175restart:
1176 seq = read_seqbegin(&fnhe_seqlock);
1177 fnhe_daddr = fnhe->fnhe_daddr;
1178 gw = fnhe->fnhe_gw;
1179 pmtu = fnhe->fnhe_pmtu;
1180 expires = fnhe->fnhe_expires;
1181 if (read_seqretry(&fnhe_seqlock, seq))
1182 goto restart;
1183
1184 if (daddr != fnhe_daddr)
1185 return;
1186
1187 if (pmtu) {
1188 unsigned long diff = expires - jiffies;
1189
1190 if (time_before(jiffies, expires)) {
1191 rt->rt_pmtu = pmtu;
1192 dst_set_expires(&rt->dst, diff);
1193 }
1194 }
1195 if (gw) {
1196 rt->rt_flags |= RTCF_REDIRECTED;
1197 rt->rt_gateway = gw;
1198 }
1199 fnhe->fnhe_stamp = jiffies;
1200}
1201
1202static inline void rt_release_rcu(struct rcu_head *head)
1203{
1204 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
1205 dst_release(dst);
1206}
1207
1208static void rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1209{
1210 struct rtable *orig, *prev, **p = &nh->nh_rth_output;
1211
1212 if (rt_is_input_route(rt))
1213 p = &nh->nh_rth_input;
1214
1215 orig = *p;
1216
1217 prev = cmpxchg(p, orig, rt);
1218 if (prev == orig) {
1219 dst_clone(&rt->dst);
1220 if (orig)
1221 call_rcu_bh(&orig->dst.rcu_head, rt_release_rcu);
1222 }
1223}
1224
1225static bool rt_cache_valid(struct rtable *rt)
1226{
1227 return (rt && rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK);
1228}
1229
1230static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1231 const struct fib_result *res,
1232 struct fib_nh_exception *fnhe,
1233 struct fib_info *fi, u16 type, u32 itag)
1234{
1235 if (fi) {
1236 struct fib_nh *nh = &FIB_RES_NH(*res);
1237
1238 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
1239 rt->rt_gateway = nh->nh_gw;
1240 if (unlikely(fnhe))
1241 rt_bind_exception(rt, fnhe, daddr);
1242 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1243#ifdef CONFIG_IP_ROUTE_CLASSID
1244 rt->dst.tclassid = nh->nh_tclassid;
1245#endif
1246 if (!(rt->dst.flags & DST_HOST))
1247 rt_cache_route(nh, rt);
1248 }
1249
1250#ifdef CONFIG_IP_ROUTE_CLASSID
1251#ifdef CONFIG_IP_MULTIPLE_TABLES
1252 set_class_tag(rt, res->tclassid);
1253#endif
1254 set_class_tag(rt, itag);
1255#endif
1256}
1257
1258static struct rtable *rt_dst_alloc(struct net_device *dev,
1259 bool nopolicy, bool noxfrm, bool will_cache)
1260{
1261 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1262 (will_cache ? 0 : DST_HOST) | DST_NOCACHE |
1263 (nopolicy ? DST_NOPOLICY : 0) |
1264 (noxfrm ? DST_NOXFRM : 0));
1265}
1266
1267/* called in rcu_read_lock() section */
1268static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1269 u8 tos, struct net_device *dev, int our)
1270{
1271 struct rtable *rth;
1272 struct in_device *in_dev = __in_dev_get_rcu(dev);
1273 u32 itag = 0;
1274 int err;
1275
1276 /* Primary sanity checks. */
1277
1278 if (in_dev == NULL)
1279 return -EINVAL;
1280
1281 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1282 skb->protocol != htons(ETH_P_IP))
1283 goto e_inval;
1284
1285 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1286 if (ipv4_is_loopback(saddr))
1287 goto e_inval;
1288
1289 if (ipv4_is_zeronet(saddr)) {
1290 if (!ipv4_is_local_multicast(daddr))
1291 goto e_inval;
1292 } else {
1293 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1294 in_dev, &itag);
1295 if (err < 0)
1296 goto e_err;
1297 }
1298 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1299 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1300 if (!rth)
1301 goto e_nobufs;
1302
1303#ifdef CONFIG_IP_ROUTE_CLASSID
1304 rth->dst.tclassid = itag;
1305#endif
1306 rth->dst.output = ip_rt_bug;
1307
1308 rth->rt_genid = rt_genid(dev_net(dev));
1309 rth->rt_flags = RTCF_MULTICAST;
1310 rth->rt_type = RTN_MULTICAST;
1311 rth->rt_is_input= 1;
1312 rth->rt_iif = dev->ifindex;
1313 rth->rt_pmtu = 0;
1314 rth->rt_gateway = 0;
1315 if (our) {
1316 rth->dst.input= ip_local_deliver;
1317 rth->rt_flags |= RTCF_LOCAL;
1318 }
1319
1320#ifdef CONFIG_IP_MROUTE
1321 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1322 rth->dst.input = ip_mr_input;
1323#endif
1324 RT_CACHE_STAT_INC(in_slow_mc);
1325
1326 skb_dst_set(skb, &rth->dst);
1327 return 0;
1328
1329e_nobufs:
1330 return -ENOBUFS;
1331e_inval:
1332 return -EINVAL;
1333e_err:
1334 return err;
1335}
1336
1337
1338static void ip_handle_martian_source(struct net_device *dev,
1339 struct in_device *in_dev,
1340 struct sk_buff *skb,
1341 __be32 daddr,
1342 __be32 saddr)
1343{
1344 RT_CACHE_STAT_INC(in_martian_src);
1345#ifdef CONFIG_IP_ROUTE_VERBOSE
1346 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1347 /*
1348 * RFC1812 recommendation, if source is martian,
1349 * the only hint is MAC header.
1350 */
1351 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1352 &daddr, &saddr, dev->name);
1353 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1354 print_hex_dump(KERN_WARNING, "ll header: ",
1355 DUMP_PREFIX_OFFSET, 16, 1,
1356 skb_mac_header(skb),
1357 dev->hard_header_len, true);
1358 }
1359 }
1360#endif
1361}
1362
1363/* called in rcu_read_lock() section */
1364static int __mkroute_input(struct sk_buff *skb,
1365 const struct fib_result *res,
1366 struct in_device *in_dev,
1367 __be32 daddr, __be32 saddr, u32 tos,
1368 struct rtable **result)
1369{
1370 struct rtable *rth;
1371 int err;
1372 struct in_device *out_dev;
1373 unsigned int flags = 0;
1374 bool do_cache;
1375 u32 itag;
1376
1377 /* get a working reference to the output device */
1378 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1379 if (out_dev == NULL) {
1380 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1381 return -EINVAL;
1382 }
1383
1384
1385 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1386 in_dev->dev, in_dev, &itag);
1387 if (err < 0) {
1388 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1389 saddr);
1390
1391 goto cleanup;
1392 }
1393
1394 if (err)
1395 flags |= RTCF_DIRECTSRC;
1396
1397 if (out_dev == in_dev && err &&
1398 (IN_DEV_SHARED_MEDIA(out_dev) ||
1399 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1400 flags |= RTCF_DOREDIRECT;
1401
1402 if (skb->protocol != htons(ETH_P_IP)) {
1403 /* Not IP (i.e. ARP). Do not create route, if it is
1404 * invalid for proxy arp. DNAT routes are always valid.
1405 *
1406 * Proxy arp feature have been extended to allow, ARP
1407 * replies back to the same interface, to support
1408 * Private VLAN switch technologies. See arp.c.
1409 */
1410 if (out_dev == in_dev &&
1411 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1412 err = -EINVAL;
1413 goto cleanup;
1414 }
1415 }
1416
1417 do_cache = false;
1418 if (res->fi) {
1419 if (!(flags & RTCF_DIRECTSRC) && !itag) {
1420 rth = FIB_RES_NH(*res).nh_rth_input;
1421 if (rt_cache_valid(rth)) {
1422 dst_hold(&rth->dst);
1423 goto out;
1424 }
1425 do_cache = true;
1426 }
1427 }
1428
1429 rth = rt_dst_alloc(out_dev->dev,
1430 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1431 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1432 if (!rth) {
1433 err = -ENOBUFS;
1434 goto cleanup;
1435 }
1436
1437 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1438 rth->rt_flags = flags;
1439 rth->rt_type = res->type;
1440 rth->rt_is_input = 1;
1441 rth->rt_iif = in_dev->dev->ifindex;
1442 rth->rt_pmtu = 0;
1443 rth->rt_gateway = 0;
1444
1445 rth->dst.input = ip_forward;
1446 rth->dst.output = ip_output;
1447
1448 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1449out:
1450 *result = rth;
1451 err = 0;
1452 cleanup:
1453 return err;
1454}
1455
1456static int ip_mkroute_input(struct sk_buff *skb,
1457 struct fib_result *res,
1458 const struct flowi4 *fl4,
1459 struct in_device *in_dev,
1460 __be32 daddr, __be32 saddr, u32 tos)
1461{
1462 struct rtable *rth = NULL;
1463 int err;
1464
1465#ifdef CONFIG_IP_ROUTE_MULTIPATH
1466 if (res->fi && res->fi->fib_nhs > 1)
1467 fib_select_multipath(res);
1468#endif
1469
1470 /* create a routing cache entry */
1471 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
1472 if (err)
1473 return err;
1474
1475 skb_dst_set(skb, &rth->dst);
1476 return 0;
1477}
1478
1479/*
1480 * NOTE. We drop all the packets that has local source
1481 * addresses, because every properly looped back packet
1482 * must have correct destination already attached by output routine.
1483 *
1484 * Such approach solves two big problems:
1485 * 1. Not simplex devices are handled properly.
1486 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1487 * called with rcu_read_lock()
1488 */
1489
1490static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1491 u8 tos, struct net_device *dev)
1492{
1493 struct fib_result res;
1494 struct in_device *in_dev = __in_dev_get_rcu(dev);
1495 struct flowi4 fl4;
1496 unsigned int flags = 0;
1497 u32 itag = 0;
1498 struct rtable *rth;
1499 int err = -EINVAL;
1500 struct net *net = dev_net(dev);
1501 bool do_cache;
1502
1503 /* IP on this device is disabled. */
1504
1505 if (!in_dev)
1506 goto out;
1507
1508 /* Check for the most weird martians, which can be not detected
1509 by fib_lookup.
1510 */
1511
1512 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1513 goto martian_source;
1514
1515 res.fi = NULL;
1516 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1517 goto brd_input;
1518
1519 /* Accept zero addresses only to limited broadcast;
1520 * I even do not know to fix it or not. Waiting for complains :-)
1521 */
1522 if (ipv4_is_zeronet(saddr))
1523 goto martian_source;
1524
1525 if (ipv4_is_zeronet(daddr))
1526 goto martian_destination;
1527
1528 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) {
1529 if (ipv4_is_loopback(daddr))
1530 goto martian_destination;
1531
1532 if (ipv4_is_loopback(saddr))
1533 goto martian_source;
1534 }
1535
1536 /*
1537 * Now we are ready to route packet.
1538 */
1539 fl4.flowi4_oif = 0;
1540 fl4.flowi4_iif = dev->ifindex;
1541 fl4.flowi4_mark = skb->mark;
1542 fl4.flowi4_tos = tos;
1543 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1544 fl4.daddr = daddr;
1545 fl4.saddr = saddr;
1546 err = fib_lookup(net, &fl4, &res);
1547 if (err != 0)
1548 goto no_route;
1549
1550 RT_CACHE_STAT_INC(in_slow_tot);
1551
1552 if (res.type == RTN_BROADCAST)
1553 goto brd_input;
1554
1555 if (res.type == RTN_LOCAL) {
1556 err = fib_validate_source(skb, saddr, daddr, tos,
1557 net->loopback_dev->ifindex,
1558 dev, in_dev, &itag);
1559 if (err < 0)
1560 goto martian_source_keep_err;
1561 if (err)
1562 flags |= RTCF_DIRECTSRC;
1563 goto local_input;
1564 }
1565
1566 if (!IN_DEV_FORWARD(in_dev))
1567 goto no_route;
1568 if (res.type != RTN_UNICAST)
1569 goto martian_destination;
1570
1571 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1572out: return err;
1573
1574brd_input:
1575 if (skb->protocol != htons(ETH_P_IP))
1576 goto e_inval;
1577
1578 if (!ipv4_is_zeronet(saddr)) {
1579 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1580 in_dev, &itag);
1581 if (err < 0)
1582 goto martian_source_keep_err;
1583 if (err)
1584 flags |= RTCF_DIRECTSRC;
1585 }
1586 flags |= RTCF_BROADCAST;
1587 res.type = RTN_BROADCAST;
1588 RT_CACHE_STAT_INC(in_brd);
1589
1590local_input:
1591 do_cache = false;
1592 if (res.fi) {
1593 if (!(flags & RTCF_DIRECTSRC) && !itag) {
1594 rth = FIB_RES_NH(res).nh_rth_input;
1595 if (rt_cache_valid(rth)) {
1596 dst_hold(&rth->dst);
1597 goto set_and_out;
1598 }
1599 do_cache = true;
1600 }
1601 }
1602
1603 rth = rt_dst_alloc(net->loopback_dev,
1604 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1605 if (!rth)
1606 goto e_nobufs;
1607
1608 rth->dst.input= ip_local_deliver;
1609 rth->dst.output= ip_rt_bug;
1610#ifdef CONFIG_IP_ROUTE_CLASSID
1611 rth->dst.tclassid = itag;
1612#endif
1613
1614 rth->rt_genid = rt_genid(net);
1615 rth->rt_flags = flags|RTCF_LOCAL;
1616 rth->rt_type = res.type;
1617 rth->rt_is_input = 1;
1618 rth->rt_iif = dev->ifindex;
1619 rth->rt_pmtu = 0;
1620 rth->rt_gateway = 0;
1621 if (res.type == RTN_UNREACHABLE) {
1622 rth->dst.input= ip_error;
1623 rth->dst.error= -err;
1624 rth->rt_flags &= ~RTCF_LOCAL;
1625 }
1626 if (do_cache)
1627 rt_cache_route(&FIB_RES_NH(res), rth);
1628set_and_out:
1629 skb_dst_set(skb, &rth->dst);
1630 err = 0;
1631 goto out;
1632
1633no_route:
1634 RT_CACHE_STAT_INC(in_no_route);
1635 res.type = RTN_UNREACHABLE;
1636 if (err == -ESRCH)
1637 err = -ENETUNREACH;
1638 goto local_input;
1639
1640 /*
1641 * Do not cache martian addresses: they should be logged (RFC1812)
1642 */
1643martian_destination:
1644 RT_CACHE_STAT_INC(in_martian_dst);
1645#ifdef CONFIG_IP_ROUTE_VERBOSE
1646 if (IN_DEV_LOG_MARTIANS(in_dev))
1647 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1648 &daddr, &saddr, dev->name);
1649#endif
1650
1651e_inval:
1652 err = -EINVAL;
1653 goto out;
1654
1655e_nobufs:
1656 err = -ENOBUFS;
1657 goto out;
1658
1659martian_source:
1660 err = -EINVAL;
1661martian_source_keep_err:
1662 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1663 goto out;
1664}
1665
1666int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1667 u8 tos, struct net_device *dev)
1668{
1669 int res;
1670
1671 rcu_read_lock();
1672
1673 /* Multicast recognition logic is moved from route cache to here.
1674 The problem was that too many Ethernet cards have broken/missing
1675 hardware multicast filters :-( As result the host on multicasting
1676 network acquires a lot of useless route cache entries, sort of
1677 SDR messages from all the world. Now we try to get rid of them.
1678 Really, provided software IP multicast filter is organized
1679 reasonably (at least, hashed), it does not result in a slowdown
1680 comparing with route cache reject entries.
1681 Note, that multicast routers are not affected, because
1682 route cache entry is created eventually.
1683 */
1684 if (ipv4_is_multicast(daddr)) {
1685 struct in_device *in_dev = __in_dev_get_rcu(dev);
1686
1687 if (in_dev) {
1688 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1689 ip_hdr(skb)->protocol);
1690 if (our
1691#ifdef CONFIG_IP_MROUTE
1692 ||
1693 (!ipv4_is_local_multicast(daddr) &&
1694 IN_DEV_MFORWARD(in_dev))
1695#endif
1696 ) {
1697 int res = ip_route_input_mc(skb, daddr, saddr,
1698 tos, dev, our);
1699 rcu_read_unlock();
1700 return res;
1701 }
1702 }
1703 rcu_read_unlock();
1704 return -EINVAL;
1705 }
1706 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1707 rcu_read_unlock();
1708 return res;
1709}
1710EXPORT_SYMBOL(ip_route_input);
1711
1712/* called with rcu_read_lock() */
1713static struct rtable *__mkroute_output(const struct fib_result *res,
1714 const struct flowi4 *fl4, int orig_oif,
1715 struct net_device *dev_out,
1716 unsigned int flags)
1717{
1718 struct fib_info *fi = res->fi;
1719 struct fib_nh_exception *fnhe;
1720 struct in_device *in_dev;
1721 u16 type = res->type;
1722 struct rtable *rth;
1723
1724 in_dev = __in_dev_get_rcu(dev_out);
1725 if (!in_dev)
1726 return ERR_PTR(-EINVAL);
1727
1728 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1729 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1730 return ERR_PTR(-EINVAL);
1731
1732 if (ipv4_is_lbcast(fl4->daddr))
1733 type = RTN_BROADCAST;
1734 else if (ipv4_is_multicast(fl4->daddr))
1735 type = RTN_MULTICAST;
1736 else if (ipv4_is_zeronet(fl4->daddr))
1737 return ERR_PTR(-EINVAL);
1738
1739 if (dev_out->flags & IFF_LOOPBACK)
1740 flags |= RTCF_LOCAL;
1741
1742 if (type == RTN_BROADCAST) {
1743 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1744 fi = NULL;
1745 } else if (type == RTN_MULTICAST) {
1746 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1747 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1748 fl4->flowi4_proto))
1749 flags &= ~RTCF_LOCAL;
1750 /* If multicast route do not exist use
1751 * default one, but do not gateway in this case.
1752 * Yes, it is hack.
1753 */
1754 if (fi && res->prefixlen < 4)
1755 fi = NULL;
1756 }
1757
1758 fnhe = NULL;
1759 if (fi) {
1760 fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
1761 if (!fnhe) {
1762 rth = FIB_RES_NH(*res).nh_rth_output;
1763 if (rt_cache_valid(rth)) {
1764 dst_hold(&rth->dst);
1765 return rth;
1766 }
1767 }
1768 }
1769 rth = rt_dst_alloc(dev_out,
1770 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1771 IN_DEV_CONF_GET(in_dev, NOXFRM),
1772 fi && !fnhe);
1773 if (!rth)
1774 return ERR_PTR(-ENOBUFS);
1775
1776 rth->dst.output = ip_output;
1777
1778 rth->rt_genid = rt_genid(dev_net(dev_out));
1779 rth->rt_flags = flags;
1780 rth->rt_type = type;
1781 rth->rt_is_input = 0;
1782 rth->rt_iif = orig_oif ? : dev_out->ifindex;
1783 rth->rt_pmtu = 0;
1784 rth->rt_gateway = 0;
1785
1786 RT_CACHE_STAT_INC(out_slow_tot);
1787
1788 if (flags & RTCF_LOCAL)
1789 rth->dst.input = ip_local_deliver;
1790 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1791 if (flags & RTCF_LOCAL &&
1792 !(dev_out->flags & IFF_LOOPBACK)) {
1793 rth->dst.output = ip_mc_output;
1794 RT_CACHE_STAT_INC(out_slow_mc);
1795 }
1796#ifdef CONFIG_IP_MROUTE
1797 if (type == RTN_MULTICAST) {
1798 if (IN_DEV_MFORWARD(in_dev) &&
1799 !ipv4_is_local_multicast(fl4->daddr)) {
1800 rth->dst.input = ip_mr_input;
1801 rth->dst.output = ip_mc_output;
1802 }
1803 }
1804#endif
1805 }
1806
1807 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1808
1809 return rth;
1810}
1811
1812/*
1813 * Major route resolver routine.
1814 */
1815
1816struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1817{
1818 struct net_device *dev_out = NULL;
1819 __u8 tos = RT_FL_TOS(fl4);
1820 unsigned int flags = 0;
1821 struct fib_result res;
1822 struct rtable *rth;
1823 int orig_oif;
1824
1825 res.tclassid = 0;
1826 res.fi = NULL;
1827 res.table = NULL;
1828
1829 orig_oif = fl4->flowi4_oif;
1830
1831 fl4->flowi4_iif = net->loopback_dev->ifindex;
1832 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1833 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1834 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1835
1836 rcu_read_lock();
1837 if (fl4->saddr) {
1838 rth = ERR_PTR(-EINVAL);
1839 if (ipv4_is_multicast(fl4->saddr) ||
1840 ipv4_is_lbcast(fl4->saddr) ||
1841 ipv4_is_zeronet(fl4->saddr))
1842 goto out;
1843
1844 /* I removed check for oif == dev_out->oif here.
1845 It was wrong for two reasons:
1846 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1847 is assigned to multiple interfaces.
1848 2. Moreover, we are allowed to send packets with saddr
1849 of another iface. --ANK
1850 */
1851
1852 if (fl4->flowi4_oif == 0 &&
1853 (ipv4_is_multicast(fl4->daddr) ||
1854 ipv4_is_lbcast(fl4->daddr))) {
1855 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1856 dev_out = __ip_dev_find(net, fl4->saddr, false);
1857 if (dev_out == NULL)
1858 goto out;
1859
1860 /* Special hack: user can direct multicasts
1861 and limited broadcast via necessary interface
1862 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1863 This hack is not just for fun, it allows
1864 vic,vat and friends to work.
1865 They bind socket to loopback, set ttl to zero
1866 and expect that it will work.
1867 From the viewpoint of routing cache they are broken,
1868 because we are not allowed to build multicast path
1869 with loopback source addr (look, routing cache
1870 cannot know, that ttl is zero, so that packet
1871 will not leave this host and route is valid).
1872 Luckily, this hack is good workaround.
1873 */
1874
1875 fl4->flowi4_oif = dev_out->ifindex;
1876 goto make_route;
1877 }
1878
1879 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1880 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1881 if (!__ip_dev_find(net, fl4->saddr, false))
1882 goto out;
1883 }
1884 }
1885
1886
1887 if (fl4->flowi4_oif) {
1888 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
1889 rth = ERR_PTR(-ENODEV);
1890 if (dev_out == NULL)
1891 goto out;
1892
1893 /* RACE: Check return value of inet_select_addr instead. */
1894 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
1895 rth = ERR_PTR(-ENETUNREACH);
1896 goto out;
1897 }
1898 if (ipv4_is_local_multicast(fl4->daddr) ||
1899 ipv4_is_lbcast(fl4->daddr)) {
1900 if (!fl4->saddr)
1901 fl4->saddr = inet_select_addr(dev_out, 0,
1902 RT_SCOPE_LINK);
1903 goto make_route;
1904 }
1905 if (fl4->saddr) {
1906 if (ipv4_is_multicast(fl4->daddr))
1907 fl4->saddr = inet_select_addr(dev_out, 0,
1908 fl4->flowi4_scope);
1909 else if (!fl4->daddr)
1910 fl4->saddr = inet_select_addr(dev_out, 0,
1911 RT_SCOPE_HOST);
1912 }
1913 }
1914
1915 if (!fl4->daddr) {
1916 fl4->daddr = fl4->saddr;
1917 if (!fl4->daddr)
1918 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
1919 dev_out = net->loopback_dev;
1920 fl4->flowi4_oif = net->loopback_dev->ifindex;
1921 res.type = RTN_LOCAL;
1922 flags |= RTCF_LOCAL;
1923 goto make_route;
1924 }
1925
1926 if (fib_lookup(net, fl4, &res)) {
1927 res.fi = NULL;
1928 res.table = NULL;
1929 if (fl4->flowi4_oif) {
1930 /* Apparently, routing tables are wrong. Assume,
1931 that the destination is on link.
1932
1933 WHY? DW.
1934 Because we are allowed to send to iface
1935 even if it has NO routes and NO assigned
1936 addresses. When oif is specified, routing
1937 tables are looked up with only one purpose:
1938 to catch if destination is gatewayed, rather than
1939 direct. Moreover, if MSG_DONTROUTE is set,
1940 we send packet, ignoring both routing tables
1941 and ifaddr state. --ANK
1942
1943
1944 We could make it even if oif is unknown,
1945 likely IPv6, but we do not.
1946 */
1947
1948 if (fl4->saddr == 0)
1949 fl4->saddr = inet_select_addr(dev_out, 0,
1950 RT_SCOPE_LINK);
1951 res.type = RTN_UNICAST;
1952 goto make_route;
1953 }
1954 rth = ERR_PTR(-ENETUNREACH);
1955 goto out;
1956 }
1957
1958 if (res.type == RTN_LOCAL) {
1959 if (!fl4->saddr) {
1960 if (res.fi->fib_prefsrc)
1961 fl4->saddr = res.fi->fib_prefsrc;
1962 else
1963 fl4->saddr = fl4->daddr;
1964 }
1965 dev_out = net->loopback_dev;
1966 fl4->flowi4_oif = dev_out->ifindex;
1967 res.fi = NULL;
1968 flags |= RTCF_LOCAL;
1969 goto make_route;
1970 }
1971
1972#ifdef CONFIG_IP_ROUTE_MULTIPATH
1973 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
1974 fib_select_multipath(&res);
1975 else
1976#endif
1977 if (!res.prefixlen &&
1978 res.table->tb_num_default > 1 &&
1979 res.type == RTN_UNICAST && !fl4->flowi4_oif)
1980 fib_select_default(&res);
1981
1982 if (!fl4->saddr)
1983 fl4->saddr = FIB_RES_PREFSRC(net, res);
1984
1985 dev_out = FIB_RES_DEV(res);
1986 fl4->flowi4_oif = dev_out->ifindex;
1987
1988
1989make_route:
1990 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
1991
1992out:
1993 rcu_read_unlock();
1994 return rth;
1995}
1996EXPORT_SYMBOL_GPL(__ip_route_output_key);
1997
1998static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
1999{
2000 return NULL;
2001}
2002
2003static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2004{
2005 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2006
2007 return mtu ? : dst->dev->mtu;
2008}
2009
2010static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2011 struct sk_buff *skb, u32 mtu)
2012{
2013}
2014
2015static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2016 struct sk_buff *skb)
2017{
2018}
2019
2020static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2021 unsigned long old)
2022{
2023 return NULL;
2024}
2025
2026static struct dst_ops ipv4_dst_blackhole_ops = {
2027 .family = AF_INET,
2028 .protocol = cpu_to_be16(ETH_P_IP),
2029 .check = ipv4_blackhole_dst_check,
2030 .mtu = ipv4_blackhole_mtu,
2031 .default_advmss = ipv4_default_advmss,
2032 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2033 .redirect = ipv4_rt_blackhole_redirect,
2034 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2035 .neigh_lookup = ipv4_neigh_lookup,
2036};
2037
2038struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2039{
2040 struct rtable *ort = (struct rtable *) dst_orig;
2041 struct rtable *rt;
2042
2043 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2044 if (rt) {
2045 struct dst_entry *new = &rt->dst;
2046
2047 new->__use = 1;
2048 new->input = dst_discard;
2049 new->output = dst_discard;
2050
2051 new->dev = ort->dst.dev;
2052 if (new->dev)
2053 dev_hold(new->dev);
2054
2055 rt->rt_is_input = ort->rt_is_input;
2056 rt->rt_iif = ort->rt_iif;
2057 rt->rt_pmtu = ort->rt_pmtu;
2058
2059 rt->rt_genid = rt_genid(net);
2060 rt->rt_flags = ort->rt_flags;
2061 rt->rt_type = ort->rt_type;
2062 rt->rt_gateway = ort->rt_gateway;
2063
2064 dst_free(new);
2065 }
2066
2067 dst_release(dst_orig);
2068
2069 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2070}
2071
2072struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2073 struct sock *sk)
2074{
2075 struct rtable *rt = __ip_route_output_key(net, flp4);
2076
2077 if (IS_ERR(rt))
2078 return rt;
2079
2080 if (flp4->flowi4_proto)
2081 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2082 flowi4_to_flowi(flp4),
2083 sk, 0);
2084
2085 return rt;
2086}
2087EXPORT_SYMBOL_GPL(ip_route_output_flow);
2088
2089static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2090 struct flowi4 *fl4, struct sk_buff *skb, u32 pid,
2091 u32 seq, int event, int nowait, unsigned int flags)
2092{
2093 struct rtable *rt = skb_rtable(skb);
2094 struct rtmsg *r;
2095 struct nlmsghdr *nlh;
2096 unsigned long expires = 0;
2097 u32 error;
2098 u32 metrics[RTAX_MAX];
2099
2100 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2101 if (nlh == NULL)
2102 return -EMSGSIZE;
2103
2104 r = nlmsg_data(nlh);
2105 r->rtm_family = AF_INET;
2106 r->rtm_dst_len = 32;
2107 r->rtm_src_len = 0;
2108 r->rtm_tos = fl4->flowi4_tos;
2109 r->rtm_table = RT_TABLE_MAIN;
2110 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2111 goto nla_put_failure;
2112 r->rtm_type = rt->rt_type;
2113 r->rtm_scope = RT_SCOPE_UNIVERSE;
2114 r->rtm_protocol = RTPROT_UNSPEC;
2115 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2116 if (rt->rt_flags & RTCF_NOTIFY)
2117 r->rtm_flags |= RTM_F_NOTIFY;
2118
2119 if (nla_put_be32(skb, RTA_DST, dst))
2120 goto nla_put_failure;
2121 if (src) {
2122 r->rtm_src_len = 32;
2123 if (nla_put_be32(skb, RTA_SRC, src))
2124 goto nla_put_failure;
2125 }
2126 if (rt->dst.dev &&
2127 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2128 goto nla_put_failure;
2129#ifdef CONFIG_IP_ROUTE_CLASSID
2130 if (rt->dst.tclassid &&
2131 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2132 goto nla_put_failure;
2133#endif
2134 if (!rt_is_input_route(rt) &&
2135 fl4->saddr != src) {
2136 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2137 goto nla_put_failure;
2138 }
2139 if (rt->rt_gateway &&
2140 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2141 goto nla_put_failure;
2142
2143 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2144 if (rt->rt_pmtu)
2145 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2146 if (rtnetlink_put_metrics(skb, metrics) < 0)
2147 goto nla_put_failure;
2148
2149 if (fl4->flowi4_mark &&
2150 nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark))
2151 goto nla_put_failure;
2152
2153 error = rt->dst.error;
2154 expires = rt->dst.expires;
2155 if (expires) {
2156 if (time_before(jiffies, expires))
2157 expires -= jiffies;
2158 else
2159 expires = 0;
2160 }
2161
2162 if (rt_is_input_route(rt)) {
2163 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2164 goto nla_put_failure;
2165 }
2166
2167 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2168 goto nla_put_failure;
2169
2170 return nlmsg_end(skb, nlh);
2171
2172nla_put_failure:
2173 nlmsg_cancel(skb, nlh);
2174 return -EMSGSIZE;
2175}
2176
2177static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
2178{
2179 struct net *net = sock_net(in_skb->sk);
2180 struct rtmsg *rtm;
2181 struct nlattr *tb[RTA_MAX+1];
2182 struct rtable *rt = NULL;
2183 struct flowi4 fl4;
2184 __be32 dst = 0;
2185 __be32 src = 0;
2186 u32 iif;
2187 int err;
2188 int mark;
2189 struct sk_buff *skb;
2190
2191 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2192 if (err < 0)
2193 goto errout;
2194
2195 rtm = nlmsg_data(nlh);
2196
2197 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2198 if (skb == NULL) {
2199 err = -ENOBUFS;
2200 goto errout;
2201 }
2202
2203 /* Reserve room for dummy headers, this skb can pass
2204 through good chunk of routing engine.
2205 */
2206 skb_reset_mac_header(skb);
2207 skb_reset_network_header(skb);
2208
2209 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2210 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2211 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2212
2213 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2214 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2215 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2216 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2217
2218 memset(&fl4, 0, sizeof(fl4));
2219 fl4.daddr = dst;
2220 fl4.saddr = src;
2221 fl4.flowi4_tos = rtm->rtm_tos;
2222 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2223 fl4.flowi4_mark = mark;
2224
2225 if (iif) {
2226 struct net_device *dev;
2227
2228 dev = __dev_get_by_index(net, iif);
2229 if (dev == NULL) {
2230 err = -ENODEV;
2231 goto errout_free;
2232 }
2233
2234 skb->protocol = htons(ETH_P_IP);
2235 skb->dev = dev;
2236 skb->mark = mark;
2237 local_bh_disable();
2238 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2239 local_bh_enable();
2240
2241 rt = skb_rtable(skb);
2242 if (err == 0 && rt->dst.error)
2243 err = -rt->dst.error;
2244 } else {
2245 rt = ip_route_output_key(net, &fl4);
2246
2247 err = 0;
2248 if (IS_ERR(rt))
2249 err = PTR_ERR(rt);
2250 }
2251
2252 if (err)
2253 goto errout_free;
2254
2255 skb_dst_set(skb, &rt->dst);
2256 if (rtm->rtm_flags & RTM_F_NOTIFY)
2257 rt->rt_flags |= RTCF_NOTIFY;
2258
2259 err = rt_fill_info(net, dst, src, &fl4, skb,
2260 NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
2261 RTM_NEWROUTE, 0, 0);
2262 if (err <= 0)
2263 goto errout_free;
2264
2265 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2266errout:
2267 return err;
2268
2269errout_free:
2270 kfree_skb(skb);
2271 goto errout;
2272}
2273
2274int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2275{
2276 return skb->len;
2277}
2278
2279void ip_rt_multicast_event(struct in_device *in_dev)
2280{
2281 rt_cache_flush(dev_net(in_dev->dev), 0);
2282}
2283
2284#ifdef CONFIG_SYSCTL
2285static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2286 void __user *buffer,
2287 size_t *lenp, loff_t *ppos)
2288{
2289 if (write) {
2290 int flush_delay;
2291 ctl_table ctl;
2292 struct net *net;
2293
2294 memcpy(&ctl, __ctl, sizeof(ctl));
2295 ctl.data = &flush_delay;
2296 proc_dointvec(&ctl, write, buffer, lenp, ppos);
2297
2298 net = (struct net *)__ctl->extra1;
2299 rt_cache_flush(net, flush_delay);
2300 return 0;
2301 }
2302
2303 return -EINVAL;
2304}
2305
2306static ctl_table ipv4_route_table[] = {
2307 {
2308 .procname = "gc_thresh",
2309 .data = &ipv4_dst_ops.gc_thresh,
2310 .maxlen = sizeof(int),
2311 .mode = 0644,
2312 .proc_handler = proc_dointvec,
2313 },
2314 {
2315 .procname = "max_size",
2316 .data = &ip_rt_max_size,
2317 .maxlen = sizeof(int),
2318 .mode = 0644,
2319 .proc_handler = proc_dointvec,
2320 },
2321 {
2322 /* Deprecated. Use gc_min_interval_ms */
2323
2324 .procname = "gc_min_interval",
2325 .data = &ip_rt_gc_min_interval,
2326 .maxlen = sizeof(int),
2327 .mode = 0644,
2328 .proc_handler = proc_dointvec_jiffies,
2329 },
2330 {
2331 .procname = "gc_min_interval_ms",
2332 .data = &ip_rt_gc_min_interval,
2333 .maxlen = sizeof(int),
2334 .mode = 0644,
2335 .proc_handler = proc_dointvec_ms_jiffies,
2336 },
2337 {
2338 .procname = "gc_timeout",
2339 .data = &ip_rt_gc_timeout,
2340 .maxlen = sizeof(int),
2341 .mode = 0644,
2342 .proc_handler = proc_dointvec_jiffies,
2343 },
2344 {
2345 .procname = "gc_interval",
2346 .data = &ip_rt_gc_interval,
2347 .maxlen = sizeof(int),
2348 .mode = 0644,
2349 .proc_handler = proc_dointvec_jiffies,
2350 },
2351 {
2352 .procname = "redirect_load",
2353 .data = &ip_rt_redirect_load,
2354 .maxlen = sizeof(int),
2355 .mode = 0644,
2356 .proc_handler = proc_dointvec,
2357 },
2358 {
2359 .procname = "redirect_number",
2360 .data = &ip_rt_redirect_number,
2361 .maxlen = sizeof(int),
2362 .mode = 0644,
2363 .proc_handler = proc_dointvec,
2364 },
2365 {
2366 .procname = "redirect_silence",
2367 .data = &ip_rt_redirect_silence,
2368 .maxlen = sizeof(int),
2369 .mode = 0644,
2370 .proc_handler = proc_dointvec,
2371 },
2372 {
2373 .procname = "error_cost",
2374 .data = &ip_rt_error_cost,
2375 .maxlen = sizeof(int),
2376 .mode = 0644,
2377 .proc_handler = proc_dointvec,
2378 },
2379 {
2380 .procname = "error_burst",
2381 .data = &ip_rt_error_burst,
2382 .maxlen = sizeof(int),
2383 .mode = 0644,
2384 .proc_handler = proc_dointvec,
2385 },
2386 {
2387 .procname = "gc_elasticity",
2388 .data = &ip_rt_gc_elasticity,
2389 .maxlen = sizeof(int),
2390 .mode = 0644,
2391 .proc_handler = proc_dointvec,
2392 },
2393 {
2394 .procname = "mtu_expires",
2395 .data = &ip_rt_mtu_expires,
2396 .maxlen = sizeof(int),
2397 .mode = 0644,
2398 .proc_handler = proc_dointvec_jiffies,
2399 },
2400 {
2401 .procname = "min_pmtu",
2402 .data = &ip_rt_min_pmtu,
2403 .maxlen = sizeof(int),
2404 .mode = 0644,
2405 .proc_handler = proc_dointvec,
2406 },
2407 {
2408 .procname = "min_adv_mss",
2409 .data = &ip_rt_min_advmss,
2410 .maxlen = sizeof(int),
2411 .mode = 0644,
2412 .proc_handler = proc_dointvec,
2413 },
2414 { }
2415};
2416
2417static struct ctl_table ipv4_route_flush_table[] = {
2418 {
2419 .procname = "flush",
2420 .maxlen = sizeof(int),
2421 .mode = 0200,
2422 .proc_handler = ipv4_sysctl_rtcache_flush,
2423 },
2424 { },
2425};
2426
2427static __net_init int sysctl_route_net_init(struct net *net)
2428{
2429 struct ctl_table *tbl;
2430
2431 tbl = ipv4_route_flush_table;
2432 if (!net_eq(net, &init_net)) {
2433 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2434 if (tbl == NULL)
2435 goto err_dup;
2436 }
2437 tbl[0].extra1 = net;
2438
2439 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2440 if (net->ipv4.route_hdr == NULL)
2441 goto err_reg;
2442 return 0;
2443
2444err_reg:
2445 if (tbl != ipv4_route_flush_table)
2446 kfree(tbl);
2447err_dup:
2448 return -ENOMEM;
2449}
2450
2451static __net_exit void sysctl_route_net_exit(struct net *net)
2452{
2453 struct ctl_table *tbl;
2454
2455 tbl = net->ipv4.route_hdr->ctl_table_arg;
2456 unregister_net_sysctl_table(net->ipv4.route_hdr);
2457 BUG_ON(tbl == ipv4_route_flush_table);
2458 kfree(tbl);
2459}
2460
2461static __net_initdata struct pernet_operations sysctl_route_ops = {
2462 .init = sysctl_route_net_init,
2463 .exit = sysctl_route_net_exit,
2464};
2465#endif
2466
2467static __net_init int rt_genid_init(struct net *net)
2468{
2469 get_random_bytes(&net->ipv4.rt_genid,
2470 sizeof(net->ipv4.rt_genid));
2471 get_random_bytes(&net->ipv4.dev_addr_genid,
2472 sizeof(net->ipv4.dev_addr_genid));
2473 return 0;
2474}
2475
2476static __net_initdata struct pernet_operations rt_genid_ops = {
2477 .init = rt_genid_init,
2478};
2479
2480static int __net_init ipv4_inetpeer_init(struct net *net)
2481{
2482 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2483
2484 if (!bp)
2485 return -ENOMEM;
2486 inet_peer_base_init(bp);
2487 net->ipv4.peers = bp;
2488 return 0;
2489}
2490
2491static void __net_exit ipv4_inetpeer_exit(struct net *net)
2492{
2493 struct inet_peer_base *bp = net->ipv4.peers;
2494
2495 net->ipv4.peers = NULL;
2496 inetpeer_invalidate_tree(bp);
2497 kfree(bp);
2498}
2499
2500static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2501 .init = ipv4_inetpeer_init,
2502 .exit = ipv4_inetpeer_exit,
2503};
2504
2505#ifdef CONFIG_IP_ROUTE_CLASSID
2506struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2507#endif /* CONFIG_IP_ROUTE_CLASSID */
2508
2509int __init ip_rt_init(void)
2510{
2511 int rc = 0;
2512
2513#ifdef CONFIG_IP_ROUTE_CLASSID
2514 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2515 if (!ip_rt_acct)
2516 panic("IP: failed to allocate ip_rt_acct\n");
2517#endif
2518
2519 ipv4_dst_ops.kmem_cachep =
2520 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2521 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2522
2523 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2524
2525 if (dst_entries_init(&ipv4_dst_ops) < 0)
2526 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2527
2528 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2529 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2530
2531 ipv4_dst_ops.gc_thresh = ~0;
2532 ip_rt_max_size = INT_MAX;
2533
2534 devinet_init();
2535 ip_fib_init();
2536
2537 if (ip_rt_proc_init())
2538 pr_err("Unable to create route proc files\n");
2539#ifdef CONFIG_XFRM
2540 xfrm_init();
2541 xfrm4_init(ip_rt_max_size);
2542#endif
2543 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2544
2545#ifdef CONFIG_SYSCTL
2546 register_pernet_subsys(&sysctl_route_ops);
2547#endif
2548 register_pernet_subsys(&rt_genid_ops);
2549 register_pernet_subsys(&ipv4_inetpeer_ops);
2550 return rc;
2551}
2552
2553#ifdef CONFIG_SYSCTL
2554/*
2555 * We really need to sanitize the damn ipv4 init order, then all
2556 * this nonsense will go away.
2557 */
2558void __init ip_static_sysctl_init(void)
2559{
2560 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2561}
2562#endif