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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 <linux/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/dst_metadata.h>
95#include <net/net_namespace.h>
96#include <net/protocol.h>
97#include <net/ip.h>
98#include <net/route.h>
99#include <net/inetpeer.h>
100#include <net/sock.h>
101#include <net/ip_fib.h>
102#include <net/arp.h>
103#include <net/tcp.h>
104#include <net/icmp.h>
105#include <net/xfrm.h>
106#include <net/lwtunnel.h>
107#include <net/netevent.h>
108#include <net/rtnetlink.h>
109#ifdef CONFIG_SYSCTL
110#include <linux/sysctl.h>
111#endif
112#include <net/secure_seq.h>
113#include <net/ip_tunnels.h>
114#include <net/l3mdev.h>
115
116#include "fib_lookup.h"
117
118#define RT_FL_TOS(oldflp4) \
119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
120
121#define RT_GC_TIMEOUT (300*HZ)
122
123static int ip_rt_max_size;
124static int ip_rt_redirect_number __read_mostly = 9;
125static int ip_rt_redirect_load __read_mostly = HZ / 50;
126static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
127static int ip_rt_error_cost __read_mostly = HZ;
128static int ip_rt_error_burst __read_mostly = 5 * HZ;
129static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131static int ip_rt_min_advmss __read_mostly = 256;
132
133static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
134
135/*
136 * Interface to generic destination cache.
137 */
138
139static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
140static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
141static unsigned int ipv4_mtu(const struct dst_entry *dst);
142static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143static void ipv4_link_failure(struct sk_buff *skb);
144static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb, u32 mtu);
146static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
147 struct sk_buff *skb);
148static void ipv4_dst_destroy(struct dst_entry *dst);
149
150static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
151{
152 WARN_ON(1);
153 return NULL;
154}
155
156static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
157 struct sk_buff *skb,
158 const void *daddr);
159static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
160
161static struct dst_ops ipv4_dst_ops = {
162 .family = AF_INET,
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 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
174 .confirm_neigh = ipv4_confirm_neigh,
175};
176
177#define ECN_OR_COST(class) TC_PRIO_##class
178
179const __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};
197EXPORT_SYMBOL(ip_tos2prio);
198
199static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
200#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
201
202#ifdef CONFIG_PROC_FS
203static 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
210static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
211{
212 ++*pos;
213 return NULL;
214}
215
216static void rt_cache_seq_stop(struct seq_file *seq, void *v)
217{
218}
219
220static 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
230static 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
237static int rt_cache_seq_open(struct inode *inode, struct file *file)
238{
239 return seq_open(file, &rt_cache_seq_ops);
240}
241
242static const struct file_operations rt_cache_seq_fops = {
243 .open = rt_cache_seq_open,
244 .read = seq_read,
245 .llseek = seq_lseek,
246 .release = seq_release,
247};
248
249
250static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
251{
252 int cpu;
253
254 if (*pos == 0)
255 return SEQ_START_TOKEN;
256
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
259 continue;
260 *pos = cpu+1;
261 return &per_cpu(rt_cache_stat, cpu);
262 }
263 return NULL;
264}
265
266static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
267{
268 int cpu;
269
270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
272 continue;
273 *pos = cpu+1;
274 return &per_cpu(rt_cache_stat, cpu);
275 }
276 return NULL;
277
278}
279
280static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
281{
282
283}
284
285static int rt_cpu_seq_show(struct seq_file *seq, void *v)
286{
287 struct rt_cache_stat *st = v;
288
289 if (v == SEQ_START_TOKEN) {
290 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");
291 return 0;
292 }
293
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
297 0, /* st->in_hit */
298 st->in_slow_tot,
299 st->in_slow_mc,
300 st->in_no_route,
301 st->in_brd,
302 st->in_martian_dst,
303 st->in_martian_src,
304
305 0, /* st->out_hit */
306 st->out_slow_tot,
307 st->out_slow_mc,
308
309 0, /* st->gc_total */
310 0, /* st->gc_ignored */
311 0, /* st->gc_goal_miss */
312 0, /* st->gc_dst_overflow */
313 0, /* st->in_hlist_search */
314 0 /* st->out_hlist_search */
315 );
316 return 0;
317}
318
319static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
324};
325
326
327static int rt_cpu_seq_open(struct inode *inode, struct file *file)
328{
329 return seq_open(file, &rt_cpu_seq_ops);
330}
331
332static const struct file_operations rt_cpu_seq_fops = {
333 .open = rt_cpu_seq_open,
334 .read = seq_read,
335 .llseek = seq_lseek,
336 .release = seq_release,
337};
338
339#ifdef CONFIG_IP_ROUTE_CLASSID
340static int rt_acct_proc_show(struct seq_file *m, void *v)
341{
342 struct ip_rt_acct *dst, *src;
343 unsigned int i, j;
344
345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
346 if (!dst)
347 return -ENOMEM;
348
349 for_each_possible_cpu(i) {
350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
351 for (j = 0; j < 256; j++) {
352 dst[j].o_bytes += src[j].o_bytes;
353 dst[j].o_packets += src[j].o_packets;
354 dst[j].i_bytes += src[j].i_bytes;
355 dst[j].i_packets += src[j].i_packets;
356 }
357 }
358
359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
360 kfree(dst);
361 return 0;
362}
363
364static int rt_acct_proc_open(struct inode *inode, struct file *file)
365{
366 return single_open(file, rt_acct_proc_show, NULL);
367}
368
369static const struct file_operations rt_acct_proc_fops = {
370 .open = rt_acct_proc_open,
371 .read = seq_read,
372 .llseek = seq_lseek,
373 .release = single_release,
374};
375#endif
376
377static int __net_init ip_rt_do_proc_init(struct net *net)
378{
379 struct proc_dir_entry *pde;
380
381 pde = proc_create("rt_cache", 0444, net->proc_net,
382 &rt_cache_seq_fops);
383 if (!pde)
384 goto err1;
385
386 pde = proc_create("rt_cache", 0444,
387 net->proc_net_stat, &rt_cpu_seq_fops);
388 if (!pde)
389 goto err2;
390
391#ifdef CONFIG_IP_ROUTE_CLASSID
392 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
393 if (!pde)
394 goto err3;
395#endif
396 return 0;
397
398#ifdef CONFIG_IP_ROUTE_CLASSID
399err3:
400 remove_proc_entry("rt_cache", net->proc_net_stat);
401#endif
402err2:
403 remove_proc_entry("rt_cache", net->proc_net);
404err1:
405 return -ENOMEM;
406}
407
408static void __net_exit ip_rt_do_proc_exit(struct net *net)
409{
410 remove_proc_entry("rt_cache", net->proc_net_stat);
411 remove_proc_entry("rt_cache", net->proc_net);
412#ifdef CONFIG_IP_ROUTE_CLASSID
413 remove_proc_entry("rt_acct", net->proc_net);
414#endif
415}
416
417static struct pernet_operations ip_rt_proc_ops __net_initdata = {
418 .init = ip_rt_do_proc_init,
419 .exit = ip_rt_do_proc_exit,
420};
421
422static int __init ip_rt_proc_init(void)
423{
424 return register_pernet_subsys(&ip_rt_proc_ops);
425}
426
427#else
428static inline int ip_rt_proc_init(void)
429{
430 return 0;
431}
432#endif /* CONFIG_PROC_FS */
433
434static inline bool rt_is_expired(const struct rtable *rth)
435{
436 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
437}
438
439void rt_cache_flush(struct net *net)
440{
441 rt_genid_bump_ipv4(net);
442}
443
444static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
445 struct sk_buff *skb,
446 const void *daddr)
447{
448 struct net_device *dev = dst->dev;
449 const __be32 *pkey = daddr;
450 const struct rtable *rt;
451 struct neighbour *n;
452
453 rt = (const struct rtable *) dst;
454 if (rt->rt_gateway)
455 pkey = (const __be32 *) &rt->rt_gateway;
456 else if (skb)
457 pkey = &ip_hdr(skb)->daddr;
458
459 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
460 if (n)
461 return n;
462 return neigh_create(&arp_tbl, pkey, dev);
463}
464
465static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
466{
467 struct net_device *dev = dst->dev;
468 const __be32 *pkey = daddr;
469 const struct rtable *rt;
470
471 rt = (const struct rtable *)dst;
472 if (rt->rt_gateway)
473 pkey = (const __be32 *)&rt->rt_gateway;
474 else if (!daddr ||
475 (rt->rt_flags &
476 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL)))
477 return;
478
479 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
480}
481
482#define IP_IDENTS_SZ 2048u
483
484static atomic_t *ip_idents __read_mostly;
485static u32 *ip_tstamps __read_mostly;
486
487/* In order to protect privacy, we add a perturbation to identifiers
488 * if one generator is seldom used. This makes hard for an attacker
489 * to infer how many packets were sent between two points in time.
490 */
491u32 ip_idents_reserve(u32 hash, int segs)
492{
493 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
494 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
495 u32 old = READ_ONCE(*p_tstamp);
496 u32 now = (u32)jiffies;
497 u32 new, delta = 0;
498
499 if (old != now && cmpxchg(p_tstamp, old, now) == old)
500 delta = prandom_u32_max(now - old);
501
502 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
503 do {
504 old = (u32)atomic_read(p_id);
505 new = old + delta + segs;
506 } while (atomic_cmpxchg(p_id, old, new) != old);
507
508 return new - segs;
509}
510EXPORT_SYMBOL(ip_idents_reserve);
511
512void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
513{
514 static u32 ip_idents_hashrnd __read_mostly;
515 u32 hash, id;
516
517 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
518
519 hash = jhash_3words((__force u32)iph->daddr,
520 (__force u32)iph->saddr,
521 iph->protocol ^ net_hash_mix(net),
522 ip_idents_hashrnd);
523 id = ip_idents_reserve(hash, segs);
524 iph->id = htons(id);
525}
526EXPORT_SYMBOL(__ip_select_ident);
527
528static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
529 const struct sock *sk,
530 const struct iphdr *iph,
531 int oif, u8 tos,
532 u8 prot, u32 mark, int flow_flags)
533{
534 if (sk) {
535 const struct inet_sock *inet = inet_sk(sk);
536
537 oif = sk->sk_bound_dev_if;
538 mark = sk->sk_mark;
539 tos = RT_CONN_FLAGS(sk);
540 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
541 }
542 flowi4_init_output(fl4, oif, mark, tos,
543 RT_SCOPE_UNIVERSE, prot,
544 flow_flags,
545 iph->daddr, iph->saddr, 0, 0,
546 sock_net_uid(net, sk));
547}
548
549static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
550 const struct sock *sk)
551{
552 const struct net *net = dev_net(skb->dev);
553 const struct iphdr *iph = ip_hdr(skb);
554 int oif = skb->dev->ifindex;
555 u8 tos = RT_TOS(iph->tos);
556 u8 prot = iph->protocol;
557 u32 mark = skb->mark;
558
559 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
560}
561
562static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
563{
564 const struct inet_sock *inet = inet_sk(sk);
565 const struct ip_options_rcu *inet_opt;
566 __be32 daddr = inet->inet_daddr;
567
568 rcu_read_lock();
569 inet_opt = rcu_dereference(inet->inet_opt);
570 if (inet_opt && inet_opt->opt.srr)
571 daddr = inet_opt->opt.faddr;
572 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
573 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
574 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
575 inet_sk_flowi_flags(sk),
576 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
577 rcu_read_unlock();
578}
579
580static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
581 const struct sk_buff *skb)
582{
583 if (skb)
584 build_skb_flow_key(fl4, skb, sk);
585 else
586 build_sk_flow_key(fl4, sk);
587}
588
589static DEFINE_SPINLOCK(fnhe_lock);
590
591static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
592{
593 struct rtable *rt;
594
595 rt = rcu_dereference(fnhe->fnhe_rth_input);
596 if (rt) {
597 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
598 dst_dev_put(&rt->dst);
599 dst_release(&rt->dst);
600 }
601 rt = rcu_dereference(fnhe->fnhe_rth_output);
602 if (rt) {
603 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
604 dst_dev_put(&rt->dst);
605 dst_release(&rt->dst);
606 }
607}
608
609static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
610{
611 struct fib_nh_exception *fnhe, *oldest;
612
613 oldest = rcu_dereference(hash->chain);
614 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
615 fnhe = rcu_dereference(fnhe->fnhe_next)) {
616 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
617 oldest = fnhe;
618 }
619 fnhe_flush_routes(oldest);
620 return oldest;
621}
622
623static inline u32 fnhe_hashfun(__be32 daddr)
624{
625 static u32 fnhe_hashrnd __read_mostly;
626 u32 hval;
627
628 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
629 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
630 return hash_32(hval, FNHE_HASH_SHIFT);
631}
632
633static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
634{
635 rt->rt_pmtu = fnhe->fnhe_pmtu;
636 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
637 rt->dst.expires = fnhe->fnhe_expires;
638
639 if (fnhe->fnhe_gw) {
640 rt->rt_flags |= RTCF_REDIRECTED;
641 rt->rt_gateway = fnhe->fnhe_gw;
642 rt->rt_uses_gateway = 1;
643 }
644}
645
646static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
647 u32 pmtu, bool lock, unsigned long expires)
648{
649 struct fnhe_hash_bucket *hash;
650 struct fib_nh_exception *fnhe;
651 struct rtable *rt;
652 u32 genid, hval;
653 unsigned int i;
654 int depth;
655
656 genid = fnhe_genid(dev_net(nh->nh_dev));
657 hval = fnhe_hashfun(daddr);
658
659 spin_lock_bh(&fnhe_lock);
660
661 hash = rcu_dereference(nh->nh_exceptions);
662 if (!hash) {
663 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
664 if (!hash)
665 goto out_unlock;
666 rcu_assign_pointer(nh->nh_exceptions, hash);
667 }
668
669 hash += hval;
670
671 depth = 0;
672 for (fnhe = rcu_dereference(hash->chain); fnhe;
673 fnhe = rcu_dereference(fnhe->fnhe_next)) {
674 if (fnhe->fnhe_daddr == daddr)
675 break;
676 depth++;
677 }
678
679 if (fnhe) {
680 if (fnhe->fnhe_genid != genid)
681 fnhe->fnhe_genid = genid;
682 if (gw)
683 fnhe->fnhe_gw = gw;
684 if (pmtu) {
685 fnhe->fnhe_pmtu = pmtu;
686 fnhe->fnhe_mtu_locked = lock;
687 }
688 fnhe->fnhe_expires = max(1UL, expires);
689 /* Update all cached dsts too */
690 rt = rcu_dereference(fnhe->fnhe_rth_input);
691 if (rt)
692 fill_route_from_fnhe(rt, fnhe);
693 rt = rcu_dereference(fnhe->fnhe_rth_output);
694 if (rt)
695 fill_route_from_fnhe(rt, fnhe);
696 } else {
697 if (depth > FNHE_RECLAIM_DEPTH)
698 fnhe = fnhe_oldest(hash);
699 else {
700 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
701 if (!fnhe)
702 goto out_unlock;
703
704 fnhe->fnhe_next = hash->chain;
705 rcu_assign_pointer(hash->chain, fnhe);
706 }
707 fnhe->fnhe_genid = genid;
708 fnhe->fnhe_daddr = daddr;
709 fnhe->fnhe_gw = gw;
710 fnhe->fnhe_pmtu = pmtu;
711 fnhe->fnhe_mtu_locked = lock;
712 fnhe->fnhe_expires = max(1UL, expires);
713
714 /* Exception created; mark the cached routes for the nexthop
715 * stale, so anyone caching it rechecks if this exception
716 * applies to them.
717 */
718 rt = rcu_dereference(nh->nh_rth_input);
719 if (rt)
720 rt->dst.obsolete = DST_OBSOLETE_KILL;
721
722 for_each_possible_cpu(i) {
723 struct rtable __rcu **prt;
724 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
725 rt = rcu_dereference(*prt);
726 if (rt)
727 rt->dst.obsolete = DST_OBSOLETE_KILL;
728 }
729 }
730
731 fnhe->fnhe_stamp = jiffies;
732
733out_unlock:
734 spin_unlock_bh(&fnhe_lock);
735}
736
737static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
738 bool kill_route)
739{
740 __be32 new_gw = icmp_hdr(skb)->un.gateway;
741 __be32 old_gw = ip_hdr(skb)->saddr;
742 struct net_device *dev = skb->dev;
743 struct in_device *in_dev;
744 struct fib_result res;
745 struct neighbour *n;
746 struct net *net;
747
748 switch (icmp_hdr(skb)->code & 7) {
749 case ICMP_REDIR_NET:
750 case ICMP_REDIR_NETTOS:
751 case ICMP_REDIR_HOST:
752 case ICMP_REDIR_HOSTTOS:
753 break;
754
755 default:
756 return;
757 }
758
759 if (rt->rt_gateway != old_gw)
760 return;
761
762 in_dev = __in_dev_get_rcu(dev);
763 if (!in_dev)
764 return;
765
766 net = dev_net(dev);
767 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
768 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
769 ipv4_is_zeronet(new_gw))
770 goto reject_redirect;
771
772 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
773 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
774 goto reject_redirect;
775 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
776 goto reject_redirect;
777 } else {
778 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
779 goto reject_redirect;
780 }
781
782 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
783 if (!n)
784 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
785 if (!IS_ERR(n)) {
786 if (!(n->nud_state & NUD_VALID)) {
787 neigh_event_send(n, NULL);
788 } else {
789 if (fib_lookup(net, fl4, &res, 0) == 0) {
790 struct fib_nh *nh = &FIB_RES_NH(res);
791
792 update_or_create_fnhe(nh, fl4->daddr, new_gw,
793 0, false,
794 jiffies + ip_rt_gc_timeout);
795 }
796 if (kill_route)
797 rt->dst.obsolete = DST_OBSOLETE_KILL;
798 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
799 }
800 neigh_release(n);
801 }
802 return;
803
804reject_redirect:
805#ifdef CONFIG_IP_ROUTE_VERBOSE
806 if (IN_DEV_LOG_MARTIANS(in_dev)) {
807 const struct iphdr *iph = (const struct iphdr *) skb->data;
808 __be32 daddr = iph->daddr;
809 __be32 saddr = iph->saddr;
810
811 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
812 " Advised path = %pI4 -> %pI4\n",
813 &old_gw, dev->name, &new_gw,
814 &saddr, &daddr);
815 }
816#endif
817 ;
818}
819
820static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
821{
822 struct rtable *rt;
823 struct flowi4 fl4;
824 const struct iphdr *iph = (const struct iphdr *) skb->data;
825 struct net *net = dev_net(skb->dev);
826 int oif = skb->dev->ifindex;
827 u8 tos = RT_TOS(iph->tos);
828 u8 prot = iph->protocol;
829 u32 mark = skb->mark;
830
831 rt = (struct rtable *) dst;
832
833 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
834 __ip_do_redirect(rt, skb, &fl4, true);
835}
836
837static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
838{
839 struct rtable *rt = (struct rtable *)dst;
840 struct dst_entry *ret = dst;
841
842 if (rt) {
843 if (dst->obsolete > 0) {
844 ip_rt_put(rt);
845 ret = NULL;
846 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
847 rt->dst.expires) {
848 ip_rt_put(rt);
849 ret = NULL;
850 }
851 }
852 return ret;
853}
854
855/*
856 * Algorithm:
857 * 1. The first ip_rt_redirect_number redirects are sent
858 * with exponential backoff, then we stop sending them at all,
859 * assuming that the host ignores our redirects.
860 * 2. If we did not see packets requiring redirects
861 * during ip_rt_redirect_silence, we assume that the host
862 * forgot redirected route and start to send redirects again.
863 *
864 * This algorithm is much cheaper and more intelligent than dumb load limiting
865 * in icmp.c.
866 *
867 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
868 * and "frag. need" (breaks PMTU discovery) in icmp.c.
869 */
870
871void ip_rt_send_redirect(struct sk_buff *skb)
872{
873 struct rtable *rt = skb_rtable(skb);
874 struct in_device *in_dev;
875 struct inet_peer *peer;
876 struct net *net;
877 int log_martians;
878 int vif;
879
880 rcu_read_lock();
881 in_dev = __in_dev_get_rcu(rt->dst.dev);
882 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
883 rcu_read_unlock();
884 return;
885 }
886 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
887 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
888 rcu_read_unlock();
889
890 net = dev_net(rt->dst.dev);
891 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
892 if (!peer) {
893 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
894 rt_nexthop(rt, ip_hdr(skb)->daddr));
895 return;
896 }
897
898 /* No redirected packets during ip_rt_redirect_silence;
899 * reset the algorithm.
900 */
901 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
902 peer->rate_tokens = 0;
903
904 /* Too many ignored redirects; do not send anything
905 * set dst.rate_last to the last seen redirected packet.
906 */
907 if (peer->rate_tokens >= ip_rt_redirect_number) {
908 peer->rate_last = jiffies;
909 goto out_put_peer;
910 }
911
912 /* Check for load limit; set rate_last to the latest sent
913 * redirect.
914 */
915 if (peer->rate_tokens == 0 ||
916 time_after(jiffies,
917 (peer->rate_last +
918 (ip_rt_redirect_load << peer->rate_tokens)))) {
919 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
920
921 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
922 peer->rate_last = jiffies;
923 ++peer->rate_tokens;
924#ifdef CONFIG_IP_ROUTE_VERBOSE
925 if (log_martians &&
926 peer->rate_tokens == ip_rt_redirect_number)
927 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
928 &ip_hdr(skb)->saddr, inet_iif(skb),
929 &ip_hdr(skb)->daddr, &gw);
930#endif
931 }
932out_put_peer:
933 inet_putpeer(peer);
934}
935
936static int ip_error(struct sk_buff *skb)
937{
938 struct rtable *rt = skb_rtable(skb);
939 struct net_device *dev = skb->dev;
940 struct in_device *in_dev;
941 struct inet_peer *peer;
942 unsigned long now;
943 struct net *net;
944 bool send;
945 int code;
946
947 if (netif_is_l3_master(skb->dev)) {
948 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
949 if (!dev)
950 goto out;
951 }
952
953 in_dev = __in_dev_get_rcu(dev);
954
955 /* IP on this device is disabled. */
956 if (!in_dev)
957 goto out;
958
959 net = dev_net(rt->dst.dev);
960 if (!IN_DEV_FORWARD(in_dev)) {
961 switch (rt->dst.error) {
962 case EHOSTUNREACH:
963 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
964 break;
965
966 case ENETUNREACH:
967 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
968 break;
969 }
970 goto out;
971 }
972
973 switch (rt->dst.error) {
974 case EINVAL:
975 default:
976 goto out;
977 case EHOSTUNREACH:
978 code = ICMP_HOST_UNREACH;
979 break;
980 case ENETUNREACH:
981 code = ICMP_NET_UNREACH;
982 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
983 break;
984 case EACCES:
985 code = ICMP_PKT_FILTERED;
986 break;
987 }
988
989 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
990 l3mdev_master_ifindex(skb->dev), 1);
991
992 send = true;
993 if (peer) {
994 now = jiffies;
995 peer->rate_tokens += now - peer->rate_last;
996 if (peer->rate_tokens > ip_rt_error_burst)
997 peer->rate_tokens = ip_rt_error_burst;
998 peer->rate_last = now;
999 if (peer->rate_tokens >= ip_rt_error_cost)
1000 peer->rate_tokens -= ip_rt_error_cost;
1001 else
1002 send = false;
1003 inet_putpeer(peer);
1004 }
1005 if (send)
1006 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1007
1008out: kfree_skb(skb);
1009 return 0;
1010}
1011
1012static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1013{
1014 struct dst_entry *dst = &rt->dst;
1015 struct fib_result res;
1016 bool lock = false;
1017
1018 if (ip_mtu_locked(dst))
1019 return;
1020
1021 if (ipv4_mtu(dst) < mtu)
1022 return;
1023
1024 if (mtu < ip_rt_min_pmtu) {
1025 lock = true;
1026 mtu = ip_rt_min_pmtu;
1027 }
1028
1029 if (rt->rt_pmtu == mtu &&
1030 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1031 return;
1032
1033 rcu_read_lock();
1034 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1035 struct fib_nh *nh = &FIB_RES_NH(res);
1036
1037 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
1038 jiffies + ip_rt_mtu_expires);
1039 }
1040 rcu_read_unlock();
1041}
1042
1043static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1044 struct sk_buff *skb, u32 mtu)
1045{
1046 struct rtable *rt = (struct rtable *) dst;
1047 struct flowi4 fl4;
1048
1049 ip_rt_build_flow_key(&fl4, sk, skb);
1050 __ip_rt_update_pmtu(rt, &fl4, mtu);
1051}
1052
1053void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1054 int oif, u32 mark, u8 protocol, int flow_flags)
1055{
1056 const struct iphdr *iph = (const struct iphdr *) skb->data;
1057 struct flowi4 fl4;
1058 struct rtable *rt;
1059
1060 if (!mark)
1061 mark = IP4_REPLY_MARK(net, skb->mark);
1062
1063 __build_flow_key(net, &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_rt_update_pmtu(rt, &fl4, mtu);
1068 ip_rt_put(rt);
1069 }
1070}
1071EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1072
1073static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1074{
1075 const struct iphdr *iph = (const struct iphdr *) skb->data;
1076 struct flowi4 fl4;
1077 struct rtable *rt;
1078
1079 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1080
1081 if (!fl4.flowi4_mark)
1082 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1083
1084 rt = __ip_route_output_key(sock_net(sk), &fl4);
1085 if (!IS_ERR(rt)) {
1086 __ip_rt_update_pmtu(rt, &fl4, mtu);
1087 ip_rt_put(rt);
1088 }
1089}
1090
1091void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1092{
1093 const struct iphdr *iph = (const struct iphdr *) skb->data;
1094 struct flowi4 fl4;
1095 struct rtable *rt;
1096 struct dst_entry *odst = NULL;
1097 bool new = false;
1098 struct net *net = sock_net(sk);
1099
1100 bh_lock_sock(sk);
1101
1102 if (!ip_sk_accept_pmtu(sk))
1103 goto out;
1104
1105 odst = sk_dst_get(sk);
1106
1107 if (sock_owned_by_user(sk) || !odst) {
1108 __ipv4_sk_update_pmtu(skb, sk, mtu);
1109 goto out;
1110 }
1111
1112 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1113
1114 rt = (struct rtable *)odst;
1115 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1116 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1117 if (IS_ERR(rt))
1118 goto out;
1119
1120 new = true;
1121 }
1122
1123 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1124
1125 if (!dst_check(&rt->dst, 0)) {
1126 if (new)
1127 dst_release(&rt->dst);
1128
1129 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1130 if (IS_ERR(rt))
1131 goto out;
1132
1133 new = true;
1134 }
1135
1136 if (new)
1137 sk_dst_set(sk, &rt->dst);
1138
1139out:
1140 bh_unlock_sock(sk);
1141 dst_release(odst);
1142}
1143EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1144
1145void ipv4_redirect(struct sk_buff *skb, struct net *net,
1146 int oif, u32 mark, u8 protocol, int flow_flags)
1147{
1148 const struct iphdr *iph = (const struct iphdr *) skb->data;
1149 struct flowi4 fl4;
1150 struct rtable *rt;
1151
1152 __build_flow_key(net, &fl4, NULL, iph, oif,
1153 RT_TOS(iph->tos), protocol, mark, flow_flags);
1154 rt = __ip_route_output_key(net, &fl4);
1155 if (!IS_ERR(rt)) {
1156 __ip_do_redirect(rt, skb, &fl4, false);
1157 ip_rt_put(rt);
1158 }
1159}
1160EXPORT_SYMBOL_GPL(ipv4_redirect);
1161
1162void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1163{
1164 const struct iphdr *iph = (const struct iphdr *) skb->data;
1165 struct flowi4 fl4;
1166 struct rtable *rt;
1167 struct net *net = sock_net(sk);
1168
1169 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1170 rt = __ip_route_output_key(net, &fl4);
1171 if (!IS_ERR(rt)) {
1172 __ip_do_redirect(rt, skb, &fl4, false);
1173 ip_rt_put(rt);
1174 }
1175}
1176EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1177
1178static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1179{
1180 struct rtable *rt = (struct rtable *) dst;
1181
1182 /* All IPV4 dsts are created with ->obsolete set to the value
1183 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1184 * into this function always.
1185 *
1186 * When a PMTU/redirect information update invalidates a route,
1187 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1188 * DST_OBSOLETE_DEAD by dst_free().
1189 */
1190 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1191 return NULL;
1192 return dst;
1193}
1194
1195static void ipv4_link_failure(struct sk_buff *skb)
1196{
1197 struct rtable *rt;
1198
1199 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1200
1201 rt = skb_rtable(skb);
1202 if (rt)
1203 dst_set_expires(&rt->dst, 0);
1204}
1205
1206static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1207{
1208 pr_debug("%s: %pI4 -> %pI4, %s\n",
1209 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1210 skb->dev ? skb->dev->name : "?");
1211 kfree_skb(skb);
1212 WARN_ON(1);
1213 return 0;
1214}
1215
1216/*
1217 We do not cache source address of outgoing interface,
1218 because it is used only by IP RR, TS and SRR options,
1219 so that it out of fast path.
1220
1221 BTW remember: "addr" is allowed to be not aligned
1222 in IP options!
1223 */
1224
1225void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1226{
1227 __be32 src;
1228
1229 if (rt_is_output_route(rt))
1230 src = ip_hdr(skb)->saddr;
1231 else {
1232 struct fib_result res;
1233 struct flowi4 fl4;
1234 struct iphdr *iph;
1235
1236 iph = ip_hdr(skb);
1237
1238 memset(&fl4, 0, sizeof(fl4));
1239 fl4.daddr = iph->daddr;
1240 fl4.saddr = iph->saddr;
1241 fl4.flowi4_tos = RT_TOS(iph->tos);
1242 fl4.flowi4_oif = rt->dst.dev->ifindex;
1243 fl4.flowi4_iif = skb->dev->ifindex;
1244 fl4.flowi4_mark = skb->mark;
1245
1246 rcu_read_lock();
1247 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1248 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1249 else
1250 src = inet_select_addr(rt->dst.dev,
1251 rt_nexthop(rt, iph->daddr),
1252 RT_SCOPE_UNIVERSE);
1253 rcu_read_unlock();
1254 }
1255 memcpy(addr, &src, 4);
1256}
1257
1258#ifdef CONFIG_IP_ROUTE_CLASSID
1259static void set_class_tag(struct rtable *rt, u32 tag)
1260{
1261 if (!(rt->dst.tclassid & 0xFFFF))
1262 rt->dst.tclassid |= tag & 0xFFFF;
1263 if (!(rt->dst.tclassid & 0xFFFF0000))
1264 rt->dst.tclassid |= tag & 0xFFFF0000;
1265}
1266#endif
1267
1268static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1269{
1270 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1271 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1272 ip_rt_min_advmss);
1273
1274 return min(advmss, IPV4_MAX_PMTU - header_size);
1275}
1276
1277static unsigned int ipv4_mtu(const struct dst_entry *dst)
1278{
1279 const struct rtable *rt = (const struct rtable *) dst;
1280 unsigned int mtu = rt->rt_pmtu;
1281
1282 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1283 mtu = dst_metric_raw(dst, RTAX_MTU);
1284
1285 if (mtu)
1286 return mtu;
1287
1288 mtu = READ_ONCE(dst->dev->mtu);
1289
1290 if (unlikely(ip_mtu_locked(dst))) {
1291 if (rt->rt_uses_gateway && mtu > 576)
1292 mtu = 576;
1293 }
1294
1295 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1296
1297 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1298}
1299
1300static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1301{
1302 struct fnhe_hash_bucket *hash;
1303 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1304 u32 hval = fnhe_hashfun(daddr);
1305
1306 spin_lock_bh(&fnhe_lock);
1307
1308 hash = rcu_dereference_protected(nh->nh_exceptions,
1309 lockdep_is_held(&fnhe_lock));
1310 hash += hval;
1311
1312 fnhe_p = &hash->chain;
1313 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1314 while (fnhe) {
1315 if (fnhe->fnhe_daddr == daddr) {
1316 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1317 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1318 fnhe_flush_routes(fnhe);
1319 kfree_rcu(fnhe, rcu);
1320 break;
1321 }
1322 fnhe_p = &fnhe->fnhe_next;
1323 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1324 lockdep_is_held(&fnhe_lock));
1325 }
1326
1327 spin_unlock_bh(&fnhe_lock);
1328}
1329
1330static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1331{
1332 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1333 struct fib_nh_exception *fnhe;
1334 u32 hval;
1335
1336 if (!hash)
1337 return NULL;
1338
1339 hval = fnhe_hashfun(daddr);
1340
1341 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1342 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1343 if (fnhe->fnhe_daddr == daddr) {
1344 if (fnhe->fnhe_expires &&
1345 time_after(jiffies, fnhe->fnhe_expires)) {
1346 ip_del_fnhe(nh, daddr);
1347 break;
1348 }
1349 return fnhe;
1350 }
1351 }
1352 return NULL;
1353}
1354
1355static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1356 __be32 daddr, const bool do_cache)
1357{
1358 bool ret = false;
1359
1360 spin_lock_bh(&fnhe_lock);
1361
1362 if (daddr == fnhe->fnhe_daddr) {
1363 struct rtable __rcu **porig;
1364 struct rtable *orig;
1365 int genid = fnhe_genid(dev_net(rt->dst.dev));
1366
1367 if (rt_is_input_route(rt))
1368 porig = &fnhe->fnhe_rth_input;
1369 else
1370 porig = &fnhe->fnhe_rth_output;
1371 orig = rcu_dereference(*porig);
1372
1373 if (fnhe->fnhe_genid != genid) {
1374 fnhe->fnhe_genid = genid;
1375 fnhe->fnhe_gw = 0;
1376 fnhe->fnhe_pmtu = 0;
1377 fnhe->fnhe_expires = 0;
1378 fnhe->fnhe_mtu_locked = false;
1379 fnhe_flush_routes(fnhe);
1380 orig = NULL;
1381 }
1382 fill_route_from_fnhe(rt, fnhe);
1383 if (!rt->rt_gateway)
1384 rt->rt_gateway = daddr;
1385
1386 if (do_cache) {
1387 dst_hold(&rt->dst);
1388 rcu_assign_pointer(*porig, rt);
1389 if (orig) {
1390 dst_dev_put(&orig->dst);
1391 dst_release(&orig->dst);
1392 }
1393 ret = true;
1394 }
1395
1396 fnhe->fnhe_stamp = jiffies;
1397 }
1398 spin_unlock_bh(&fnhe_lock);
1399
1400 return ret;
1401}
1402
1403static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1404{
1405 struct rtable *orig, *prev, **p;
1406 bool ret = true;
1407
1408 if (rt_is_input_route(rt)) {
1409 p = (struct rtable **)&nh->nh_rth_input;
1410 } else {
1411 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1412 }
1413 orig = *p;
1414
1415 /* hold dst before doing cmpxchg() to avoid race condition
1416 * on this dst
1417 */
1418 dst_hold(&rt->dst);
1419 prev = cmpxchg(p, orig, rt);
1420 if (prev == orig) {
1421 if (orig) {
1422 dst_dev_put(&orig->dst);
1423 dst_release(&orig->dst);
1424 }
1425 } else {
1426 dst_release(&rt->dst);
1427 ret = false;
1428 }
1429
1430 return ret;
1431}
1432
1433struct uncached_list {
1434 spinlock_t lock;
1435 struct list_head head;
1436};
1437
1438static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1439
1440void rt_add_uncached_list(struct rtable *rt)
1441{
1442 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1443
1444 rt->rt_uncached_list = ul;
1445
1446 spin_lock_bh(&ul->lock);
1447 list_add_tail(&rt->rt_uncached, &ul->head);
1448 spin_unlock_bh(&ul->lock);
1449}
1450
1451void rt_del_uncached_list(struct rtable *rt)
1452{
1453 if (!list_empty(&rt->rt_uncached)) {
1454 struct uncached_list *ul = rt->rt_uncached_list;
1455
1456 spin_lock_bh(&ul->lock);
1457 list_del(&rt->rt_uncached);
1458 spin_unlock_bh(&ul->lock);
1459 }
1460}
1461
1462static void ipv4_dst_destroy(struct dst_entry *dst)
1463{
1464 struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
1465 struct rtable *rt = (struct rtable *)dst;
1466
1467 if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
1468 kfree(p);
1469
1470 rt_del_uncached_list(rt);
1471}
1472
1473void rt_flush_dev(struct net_device *dev)
1474{
1475 struct net *net = dev_net(dev);
1476 struct rtable *rt;
1477 int cpu;
1478
1479 for_each_possible_cpu(cpu) {
1480 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1481
1482 spin_lock_bh(&ul->lock);
1483 list_for_each_entry(rt, &ul->head, rt_uncached) {
1484 if (rt->dst.dev != dev)
1485 continue;
1486 rt->dst.dev = net->loopback_dev;
1487 dev_hold(rt->dst.dev);
1488 dev_put(dev);
1489 }
1490 spin_unlock_bh(&ul->lock);
1491 }
1492}
1493
1494static bool rt_cache_valid(const struct rtable *rt)
1495{
1496 return rt &&
1497 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1498 !rt_is_expired(rt);
1499}
1500
1501static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1502 const struct fib_result *res,
1503 struct fib_nh_exception *fnhe,
1504 struct fib_info *fi, u16 type, u32 itag,
1505 const bool do_cache)
1506{
1507 bool cached = false;
1508
1509 if (fi) {
1510 struct fib_nh *nh = &FIB_RES_NH(*res);
1511
1512 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1513 rt->rt_gateway = nh->nh_gw;
1514 rt->rt_uses_gateway = 1;
1515 }
1516 dst_init_metrics(&rt->dst, fi->fib_metrics->metrics, true);
1517 if (fi->fib_metrics != &dst_default_metrics) {
1518 rt->dst._metrics |= DST_METRICS_REFCOUNTED;
1519 refcount_inc(&fi->fib_metrics->refcnt);
1520 }
1521#ifdef CONFIG_IP_ROUTE_CLASSID
1522 rt->dst.tclassid = nh->nh_tclassid;
1523#endif
1524 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1525 if (unlikely(fnhe))
1526 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1527 else if (do_cache)
1528 cached = rt_cache_route(nh, rt);
1529 if (unlikely(!cached)) {
1530 /* Routes we intend to cache in nexthop exception or
1531 * FIB nexthop have the DST_NOCACHE bit clear.
1532 * However, if we are unsuccessful at storing this
1533 * route into the cache we really need to set it.
1534 */
1535 if (!rt->rt_gateway)
1536 rt->rt_gateway = daddr;
1537 rt_add_uncached_list(rt);
1538 }
1539 } else
1540 rt_add_uncached_list(rt);
1541
1542#ifdef CONFIG_IP_ROUTE_CLASSID
1543#ifdef CONFIG_IP_MULTIPLE_TABLES
1544 set_class_tag(rt, res->tclassid);
1545#endif
1546 set_class_tag(rt, itag);
1547#endif
1548}
1549
1550struct rtable *rt_dst_alloc(struct net_device *dev,
1551 unsigned int flags, u16 type,
1552 bool nopolicy, bool noxfrm, bool will_cache)
1553{
1554 struct rtable *rt;
1555
1556 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1557 (will_cache ? 0 : DST_HOST) |
1558 (nopolicy ? DST_NOPOLICY : 0) |
1559 (noxfrm ? DST_NOXFRM : 0));
1560
1561 if (rt) {
1562 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1563 rt->rt_flags = flags;
1564 rt->rt_type = type;
1565 rt->rt_is_input = 0;
1566 rt->rt_iif = 0;
1567 rt->rt_pmtu = 0;
1568 rt->rt_mtu_locked = 0;
1569 rt->rt_gateway = 0;
1570 rt->rt_uses_gateway = 0;
1571 INIT_LIST_HEAD(&rt->rt_uncached);
1572
1573 rt->dst.output = ip_output;
1574 if (flags & RTCF_LOCAL)
1575 rt->dst.input = ip_local_deliver;
1576 }
1577
1578 return rt;
1579}
1580EXPORT_SYMBOL(rt_dst_alloc);
1581
1582/* called in rcu_read_lock() section */
1583int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1584 u8 tos, struct net_device *dev,
1585 struct in_device *in_dev, u32 *itag)
1586{
1587 int err;
1588
1589 /* Primary sanity checks. */
1590 if (!in_dev)
1591 return -EINVAL;
1592
1593 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1594 skb->protocol != htons(ETH_P_IP))
1595 return -EINVAL;
1596
1597 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1598 return -EINVAL;
1599
1600 if (ipv4_is_zeronet(saddr)) {
1601 if (!ipv4_is_local_multicast(daddr))
1602 return -EINVAL;
1603 } else {
1604 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1605 in_dev, itag);
1606 if (err < 0)
1607 return err;
1608 }
1609 return 0;
1610}
1611
1612/* called in rcu_read_lock() section */
1613static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1614 u8 tos, struct net_device *dev, int our)
1615{
1616 struct in_device *in_dev = __in_dev_get_rcu(dev);
1617 unsigned int flags = RTCF_MULTICAST;
1618 struct rtable *rth;
1619 u32 itag = 0;
1620 int err;
1621
1622 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1623 if (err)
1624 return err;
1625
1626 if (our)
1627 flags |= RTCF_LOCAL;
1628
1629 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1630 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1631 if (!rth)
1632 return -ENOBUFS;
1633
1634#ifdef CONFIG_IP_ROUTE_CLASSID
1635 rth->dst.tclassid = itag;
1636#endif
1637 rth->dst.output = ip_rt_bug;
1638 rth->rt_is_input= 1;
1639
1640#ifdef CONFIG_IP_MROUTE
1641 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1642 rth->dst.input = ip_mr_input;
1643#endif
1644 RT_CACHE_STAT_INC(in_slow_mc);
1645
1646 skb_dst_set(skb, &rth->dst);
1647 return 0;
1648}
1649
1650
1651static void ip_handle_martian_source(struct net_device *dev,
1652 struct in_device *in_dev,
1653 struct sk_buff *skb,
1654 __be32 daddr,
1655 __be32 saddr)
1656{
1657 RT_CACHE_STAT_INC(in_martian_src);
1658#ifdef CONFIG_IP_ROUTE_VERBOSE
1659 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1660 /*
1661 * RFC1812 recommendation, if source is martian,
1662 * the only hint is MAC header.
1663 */
1664 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1665 &daddr, &saddr, dev->name);
1666 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1667 print_hex_dump(KERN_WARNING, "ll header: ",
1668 DUMP_PREFIX_OFFSET, 16, 1,
1669 skb_mac_header(skb),
1670 dev->hard_header_len, true);
1671 }
1672 }
1673#endif
1674}
1675
1676/* called in rcu_read_lock() section */
1677static int __mkroute_input(struct sk_buff *skb,
1678 const struct fib_result *res,
1679 struct in_device *in_dev,
1680 __be32 daddr, __be32 saddr, u32 tos)
1681{
1682 struct fib_nh_exception *fnhe;
1683 struct rtable *rth;
1684 int err;
1685 struct in_device *out_dev;
1686 bool do_cache;
1687 u32 itag = 0;
1688
1689 /* get a working reference to the output device */
1690 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1691 if (!out_dev) {
1692 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1693 return -EINVAL;
1694 }
1695
1696 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1697 in_dev->dev, in_dev, &itag);
1698 if (err < 0) {
1699 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1700 saddr);
1701
1702 goto cleanup;
1703 }
1704
1705 do_cache = res->fi && !itag;
1706 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1707 skb->protocol == htons(ETH_P_IP) &&
1708 (IN_DEV_SHARED_MEDIA(out_dev) ||
1709 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1710 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1711
1712 if (skb->protocol != htons(ETH_P_IP)) {
1713 /* Not IP (i.e. ARP). Do not create route, if it is
1714 * invalid for proxy arp. DNAT routes are always valid.
1715 *
1716 * Proxy arp feature have been extended to allow, ARP
1717 * replies back to the same interface, to support
1718 * Private VLAN switch technologies. See arp.c.
1719 */
1720 if (out_dev == in_dev &&
1721 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1722 err = -EINVAL;
1723 goto cleanup;
1724 }
1725 }
1726
1727 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1728 if (do_cache) {
1729 if (fnhe)
1730 rth = rcu_dereference(fnhe->fnhe_rth_input);
1731 else
1732 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1733 if (rt_cache_valid(rth)) {
1734 skb_dst_set_noref(skb, &rth->dst);
1735 goto out;
1736 }
1737 }
1738
1739 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1740 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1741 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1742 if (!rth) {
1743 err = -ENOBUFS;
1744 goto cleanup;
1745 }
1746
1747 rth->rt_is_input = 1;
1748 RT_CACHE_STAT_INC(in_slow_tot);
1749
1750 rth->dst.input = ip_forward;
1751
1752 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1753 do_cache);
1754 lwtunnel_set_redirect(&rth->dst);
1755 skb_dst_set(skb, &rth->dst);
1756out:
1757 err = 0;
1758 cleanup:
1759 return err;
1760}
1761
1762#ifdef CONFIG_IP_ROUTE_MULTIPATH
1763/* To make ICMP packets follow the right flow, the multipath hash is
1764 * calculated from the inner IP addresses.
1765 */
1766static void ip_multipath_l3_keys(const struct sk_buff *skb,
1767 struct flow_keys *hash_keys)
1768{
1769 const struct iphdr *outer_iph = ip_hdr(skb);
1770 const struct iphdr *key_iph = outer_iph;
1771 const struct iphdr *inner_iph;
1772 const struct icmphdr *icmph;
1773 struct iphdr _inner_iph;
1774 struct icmphdr _icmph;
1775
1776 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1777 goto out;
1778
1779 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1780 goto out;
1781
1782 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1783 &_icmph);
1784 if (!icmph)
1785 goto out;
1786
1787 if (icmph->type != ICMP_DEST_UNREACH &&
1788 icmph->type != ICMP_REDIRECT &&
1789 icmph->type != ICMP_TIME_EXCEEDED &&
1790 icmph->type != ICMP_PARAMETERPROB)
1791 goto out;
1792
1793 inner_iph = skb_header_pointer(skb,
1794 outer_iph->ihl * 4 + sizeof(_icmph),
1795 sizeof(_inner_iph), &_inner_iph);
1796 if (!inner_iph)
1797 goto out;
1798
1799 key_iph = inner_iph;
1800out:
1801 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1802 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1803}
1804
1805/* if skb is set it will be used and fl4 can be NULL */
1806int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1807 const struct sk_buff *skb, struct flow_keys *flkeys)
1808{
1809 struct flow_keys hash_keys;
1810 u32 mhash;
1811
1812 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1813 case 0:
1814 memset(&hash_keys, 0, sizeof(hash_keys));
1815 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1816 if (skb) {
1817 ip_multipath_l3_keys(skb, &hash_keys);
1818 } else {
1819 hash_keys.addrs.v4addrs.src = fl4->saddr;
1820 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1821 }
1822 break;
1823 case 1:
1824 /* skb is currently provided only when forwarding */
1825 if (skb) {
1826 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1827 struct flow_keys keys;
1828
1829 /* short-circuit if we already have L4 hash present */
1830 if (skb->l4_hash)
1831 return skb_get_hash_raw(skb) >> 1;
1832
1833 memset(&hash_keys, 0, sizeof(hash_keys));
1834
1835 if (!flkeys) {
1836 skb_flow_dissect_flow_keys(skb, &keys, flag);
1837 flkeys = &keys;
1838 }
1839
1840 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1841 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1842 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1843 hash_keys.ports.src = flkeys->ports.src;
1844 hash_keys.ports.dst = flkeys->ports.dst;
1845 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1846 } else {
1847 memset(&hash_keys, 0, sizeof(hash_keys));
1848 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1849 hash_keys.addrs.v4addrs.src = fl4->saddr;
1850 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1851 hash_keys.ports.src = fl4->fl4_sport;
1852 hash_keys.ports.dst = fl4->fl4_dport;
1853 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1854 }
1855 break;
1856 }
1857 mhash = flow_hash_from_keys(&hash_keys);
1858
1859 return mhash >> 1;
1860}
1861#endif /* CONFIG_IP_ROUTE_MULTIPATH */
1862
1863static int ip_mkroute_input(struct sk_buff *skb,
1864 struct fib_result *res,
1865 struct in_device *in_dev,
1866 __be32 daddr, __be32 saddr, u32 tos,
1867 struct flow_keys *hkeys)
1868{
1869#ifdef CONFIG_IP_ROUTE_MULTIPATH
1870 if (res->fi && res->fi->fib_nhs > 1) {
1871 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
1872
1873 fib_select_multipath(res, h);
1874 }
1875#endif
1876
1877 /* create a routing cache entry */
1878 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1879}
1880
1881/*
1882 * NOTE. We drop all the packets that has local source
1883 * addresses, because every properly looped back packet
1884 * must have correct destination already attached by output routine.
1885 *
1886 * Such approach solves two big problems:
1887 * 1. Not simplex devices are handled properly.
1888 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1889 * called with rcu_read_lock()
1890 */
1891
1892static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1893 u8 tos, struct net_device *dev,
1894 struct fib_result *res)
1895{
1896 struct in_device *in_dev = __in_dev_get_rcu(dev);
1897 struct flow_keys *flkeys = NULL, _flkeys;
1898 struct net *net = dev_net(dev);
1899 struct ip_tunnel_info *tun_info;
1900 int err = -EINVAL;
1901 unsigned int flags = 0;
1902 u32 itag = 0;
1903 struct rtable *rth;
1904 struct flowi4 fl4;
1905 bool do_cache;
1906
1907 /* IP on this device is disabled. */
1908
1909 if (!in_dev)
1910 goto out;
1911
1912 /* Check for the most weird martians, which can be not detected
1913 by fib_lookup.
1914 */
1915
1916 tun_info = skb_tunnel_info(skb);
1917 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1918 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1919 else
1920 fl4.flowi4_tun_key.tun_id = 0;
1921 skb_dst_drop(skb);
1922
1923 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1924 goto martian_source;
1925
1926 res->fi = NULL;
1927 res->table = NULL;
1928 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1929 goto brd_input;
1930
1931 /* Accept zero addresses only to limited broadcast;
1932 * I even do not know to fix it or not. Waiting for complains :-)
1933 */
1934 if (ipv4_is_zeronet(saddr))
1935 goto martian_source;
1936
1937 if (ipv4_is_zeronet(daddr))
1938 goto martian_destination;
1939
1940 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1941 * and call it once if daddr or/and saddr are loopback addresses
1942 */
1943 if (ipv4_is_loopback(daddr)) {
1944 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1945 goto martian_destination;
1946 } else if (ipv4_is_loopback(saddr)) {
1947 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1948 goto martian_source;
1949 }
1950
1951 /*
1952 * Now we are ready to route packet.
1953 */
1954 fl4.flowi4_oif = 0;
1955 fl4.flowi4_iif = dev->ifindex;
1956 fl4.flowi4_mark = skb->mark;
1957 fl4.flowi4_tos = tos;
1958 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1959 fl4.flowi4_flags = 0;
1960 fl4.daddr = daddr;
1961 fl4.saddr = saddr;
1962 fl4.flowi4_uid = sock_net_uid(net, NULL);
1963
1964 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
1965 flkeys = &_flkeys;
1966 } else {
1967 fl4.flowi4_proto = 0;
1968 fl4.fl4_sport = 0;
1969 fl4.fl4_dport = 0;
1970 }
1971
1972 err = fib_lookup(net, &fl4, res, 0);
1973 if (err != 0) {
1974 if (!IN_DEV_FORWARD(in_dev))
1975 err = -EHOSTUNREACH;
1976 goto no_route;
1977 }
1978
1979 if (res->type == RTN_BROADCAST)
1980 goto brd_input;
1981
1982 if (res->type == RTN_LOCAL) {
1983 err = fib_validate_source(skb, saddr, daddr, tos,
1984 0, dev, in_dev, &itag);
1985 if (err < 0)
1986 goto martian_source;
1987 goto local_input;
1988 }
1989
1990 if (!IN_DEV_FORWARD(in_dev)) {
1991 err = -EHOSTUNREACH;
1992 goto no_route;
1993 }
1994 if (res->type != RTN_UNICAST)
1995 goto martian_destination;
1996
1997 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
1998out: return err;
1999
2000brd_input:
2001 if (skb->protocol != htons(ETH_P_IP))
2002 goto e_inval;
2003
2004 if (!ipv4_is_zeronet(saddr)) {
2005 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2006 in_dev, &itag);
2007 if (err < 0)
2008 goto martian_source;
2009 }
2010 flags |= RTCF_BROADCAST;
2011 res->type = RTN_BROADCAST;
2012 RT_CACHE_STAT_INC(in_brd);
2013
2014local_input:
2015 do_cache = false;
2016 if (res->fi) {
2017 if (!itag) {
2018 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
2019 if (rt_cache_valid(rth)) {
2020 skb_dst_set_noref(skb, &rth->dst);
2021 err = 0;
2022 goto out;
2023 }
2024 do_cache = true;
2025 }
2026 }
2027
2028 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2029 flags | RTCF_LOCAL, res->type,
2030 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2031 if (!rth)
2032 goto e_nobufs;
2033
2034 rth->dst.output= ip_rt_bug;
2035#ifdef CONFIG_IP_ROUTE_CLASSID
2036 rth->dst.tclassid = itag;
2037#endif
2038 rth->rt_is_input = 1;
2039
2040 RT_CACHE_STAT_INC(in_slow_tot);
2041 if (res->type == RTN_UNREACHABLE) {
2042 rth->dst.input= ip_error;
2043 rth->dst.error= -err;
2044 rth->rt_flags &= ~RTCF_LOCAL;
2045 }
2046
2047 if (do_cache) {
2048 struct fib_nh *nh = &FIB_RES_NH(*res);
2049
2050 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
2051 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2052 WARN_ON(rth->dst.input == lwtunnel_input);
2053 rth->dst.lwtstate->orig_input = rth->dst.input;
2054 rth->dst.input = lwtunnel_input;
2055 }
2056
2057 if (unlikely(!rt_cache_route(nh, rth)))
2058 rt_add_uncached_list(rth);
2059 }
2060 skb_dst_set(skb, &rth->dst);
2061 err = 0;
2062 goto out;
2063
2064no_route:
2065 RT_CACHE_STAT_INC(in_no_route);
2066 res->type = RTN_UNREACHABLE;
2067 res->fi = NULL;
2068 res->table = NULL;
2069 goto local_input;
2070
2071 /*
2072 * Do not cache martian addresses: they should be logged (RFC1812)
2073 */
2074martian_destination:
2075 RT_CACHE_STAT_INC(in_martian_dst);
2076#ifdef CONFIG_IP_ROUTE_VERBOSE
2077 if (IN_DEV_LOG_MARTIANS(in_dev))
2078 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2079 &daddr, &saddr, dev->name);
2080#endif
2081
2082e_inval:
2083 err = -EINVAL;
2084 goto out;
2085
2086e_nobufs:
2087 err = -ENOBUFS;
2088 goto out;
2089
2090martian_source:
2091 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2092 goto out;
2093}
2094
2095int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2096 u8 tos, struct net_device *dev)
2097{
2098 struct fib_result res;
2099 int err;
2100
2101 tos &= IPTOS_RT_MASK;
2102 rcu_read_lock();
2103 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2104 rcu_read_unlock();
2105
2106 return err;
2107}
2108EXPORT_SYMBOL(ip_route_input_noref);
2109
2110/* called with rcu_read_lock held */
2111int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2112 u8 tos, struct net_device *dev, struct fib_result *res)
2113{
2114 /* Multicast recognition logic is moved from route cache to here.
2115 The problem was that too many Ethernet cards have broken/missing
2116 hardware multicast filters :-( As result the host on multicasting
2117 network acquires a lot of useless route cache entries, sort of
2118 SDR messages from all the world. Now we try to get rid of them.
2119 Really, provided software IP multicast filter is organized
2120 reasonably (at least, hashed), it does not result in a slowdown
2121 comparing with route cache reject entries.
2122 Note, that multicast routers are not affected, because
2123 route cache entry is created eventually.
2124 */
2125 if (ipv4_is_multicast(daddr)) {
2126 struct in_device *in_dev = __in_dev_get_rcu(dev);
2127 int our = 0;
2128 int err = -EINVAL;
2129
2130 if (in_dev)
2131 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2132 ip_hdr(skb)->protocol);
2133
2134 /* check l3 master if no match yet */
2135 if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
2136 struct in_device *l3_in_dev;
2137
2138 l3_in_dev = __in_dev_get_rcu(skb->dev);
2139 if (l3_in_dev)
2140 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2141 ip_hdr(skb)->protocol);
2142 }
2143
2144 if (our
2145#ifdef CONFIG_IP_MROUTE
2146 ||
2147 (!ipv4_is_local_multicast(daddr) &&
2148 IN_DEV_MFORWARD(in_dev))
2149#endif
2150 ) {
2151 err = ip_route_input_mc(skb, daddr, saddr,
2152 tos, dev, our);
2153 }
2154 return err;
2155 }
2156
2157 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2158}
2159
2160/* called with rcu_read_lock() */
2161static struct rtable *__mkroute_output(const struct fib_result *res,
2162 const struct flowi4 *fl4, int orig_oif,
2163 struct net_device *dev_out,
2164 unsigned int flags)
2165{
2166 struct fib_info *fi = res->fi;
2167 struct fib_nh_exception *fnhe;
2168 struct in_device *in_dev;
2169 u16 type = res->type;
2170 struct rtable *rth;
2171 bool do_cache;
2172
2173 in_dev = __in_dev_get_rcu(dev_out);
2174 if (!in_dev)
2175 return ERR_PTR(-EINVAL);
2176
2177 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2178 if (ipv4_is_loopback(fl4->saddr) &&
2179 !(dev_out->flags & IFF_LOOPBACK) &&
2180 !netif_is_l3_master(dev_out))
2181 return ERR_PTR(-EINVAL);
2182
2183 if (ipv4_is_lbcast(fl4->daddr))
2184 type = RTN_BROADCAST;
2185 else if (ipv4_is_multicast(fl4->daddr))
2186 type = RTN_MULTICAST;
2187 else if (ipv4_is_zeronet(fl4->daddr))
2188 return ERR_PTR(-EINVAL);
2189
2190 if (dev_out->flags & IFF_LOOPBACK)
2191 flags |= RTCF_LOCAL;
2192
2193 do_cache = true;
2194 if (type == RTN_BROADCAST) {
2195 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2196 fi = NULL;
2197 } else if (type == RTN_MULTICAST) {
2198 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2199 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2200 fl4->flowi4_proto))
2201 flags &= ~RTCF_LOCAL;
2202 else
2203 do_cache = false;
2204 /* If multicast route do not exist use
2205 * default one, but do not gateway in this case.
2206 * Yes, it is hack.
2207 */
2208 if (fi && res->prefixlen < 4)
2209 fi = NULL;
2210 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2211 (orig_oif != dev_out->ifindex)) {
2212 /* For local routes that require a particular output interface
2213 * we do not want to cache the result. Caching the result
2214 * causes incorrect behaviour when there are multiple source
2215 * addresses on the interface, the end result being that if the
2216 * intended recipient is waiting on that interface for the
2217 * packet he won't receive it because it will be delivered on
2218 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2219 * be set to the loopback interface as well.
2220 */
2221 do_cache = false;
2222 }
2223
2224 fnhe = NULL;
2225 do_cache &= fi != NULL;
2226 if (fi) {
2227 struct rtable __rcu **prth;
2228 struct fib_nh *nh = &FIB_RES_NH(*res);
2229
2230 fnhe = find_exception(nh, fl4->daddr);
2231 if (!do_cache)
2232 goto add;
2233 if (fnhe) {
2234 prth = &fnhe->fnhe_rth_output;
2235 } else {
2236 if (unlikely(fl4->flowi4_flags &
2237 FLOWI_FLAG_KNOWN_NH &&
2238 !(nh->nh_gw &&
2239 nh->nh_scope == RT_SCOPE_LINK))) {
2240 do_cache = false;
2241 goto add;
2242 }
2243 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2244 }
2245 rth = rcu_dereference(*prth);
2246 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2247 return rth;
2248 }
2249
2250add:
2251 rth = rt_dst_alloc(dev_out, flags, type,
2252 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2253 IN_DEV_CONF_GET(in_dev, NOXFRM),
2254 do_cache);
2255 if (!rth)
2256 return ERR_PTR(-ENOBUFS);
2257
2258 rth->rt_iif = orig_oif;
2259
2260 RT_CACHE_STAT_INC(out_slow_tot);
2261
2262 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2263 if (flags & RTCF_LOCAL &&
2264 !(dev_out->flags & IFF_LOOPBACK)) {
2265 rth->dst.output = ip_mc_output;
2266 RT_CACHE_STAT_INC(out_slow_mc);
2267 }
2268#ifdef CONFIG_IP_MROUTE
2269 if (type == RTN_MULTICAST) {
2270 if (IN_DEV_MFORWARD(in_dev) &&
2271 !ipv4_is_local_multicast(fl4->daddr)) {
2272 rth->dst.input = ip_mr_input;
2273 rth->dst.output = ip_mc_output;
2274 }
2275 }
2276#endif
2277 }
2278
2279 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2280 lwtunnel_set_redirect(&rth->dst);
2281
2282 return rth;
2283}
2284
2285/*
2286 * Major route resolver routine.
2287 */
2288
2289struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2290 const struct sk_buff *skb)
2291{
2292 __u8 tos = RT_FL_TOS(fl4);
2293 struct fib_result res = {
2294 .type = RTN_UNSPEC,
2295 .fi = NULL,
2296 .table = NULL,
2297 .tclassid = 0,
2298 };
2299 struct rtable *rth;
2300
2301 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2302 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2303 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2304 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2305
2306 rcu_read_lock();
2307 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2308 rcu_read_unlock();
2309
2310 return rth;
2311}
2312EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2313
2314struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2315 struct fib_result *res,
2316 const struct sk_buff *skb)
2317{
2318 struct net_device *dev_out = NULL;
2319 int orig_oif = fl4->flowi4_oif;
2320 unsigned int flags = 0;
2321 struct rtable *rth;
2322 int err = -ENETUNREACH;
2323
2324 if (fl4->saddr) {
2325 rth = ERR_PTR(-EINVAL);
2326 if (ipv4_is_multicast(fl4->saddr) ||
2327 ipv4_is_lbcast(fl4->saddr) ||
2328 ipv4_is_zeronet(fl4->saddr))
2329 goto out;
2330
2331 /* I removed check for oif == dev_out->oif here.
2332 It was wrong for two reasons:
2333 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2334 is assigned to multiple interfaces.
2335 2. Moreover, we are allowed to send packets with saddr
2336 of another iface. --ANK
2337 */
2338
2339 if (fl4->flowi4_oif == 0 &&
2340 (ipv4_is_multicast(fl4->daddr) ||
2341 ipv4_is_lbcast(fl4->daddr))) {
2342 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2343 dev_out = __ip_dev_find(net, fl4->saddr, false);
2344 if (!dev_out)
2345 goto out;
2346
2347 /* Special hack: user can direct multicasts
2348 and limited broadcast via necessary interface
2349 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2350 This hack is not just for fun, it allows
2351 vic,vat and friends to work.
2352 They bind socket to loopback, set ttl to zero
2353 and expect that it will work.
2354 From the viewpoint of routing cache they are broken,
2355 because we are not allowed to build multicast path
2356 with loopback source addr (look, routing cache
2357 cannot know, that ttl is zero, so that packet
2358 will not leave this host and route is valid).
2359 Luckily, this hack is good workaround.
2360 */
2361
2362 fl4->flowi4_oif = dev_out->ifindex;
2363 goto make_route;
2364 }
2365
2366 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2367 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2368 if (!__ip_dev_find(net, fl4->saddr, false))
2369 goto out;
2370 }
2371 }
2372
2373
2374 if (fl4->flowi4_oif) {
2375 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2376 rth = ERR_PTR(-ENODEV);
2377 if (!dev_out)
2378 goto out;
2379
2380 /* RACE: Check return value of inet_select_addr instead. */
2381 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2382 rth = ERR_PTR(-ENETUNREACH);
2383 goto out;
2384 }
2385 if (ipv4_is_local_multicast(fl4->daddr) ||
2386 ipv4_is_lbcast(fl4->daddr) ||
2387 fl4->flowi4_proto == IPPROTO_IGMP) {
2388 if (!fl4->saddr)
2389 fl4->saddr = inet_select_addr(dev_out, 0,
2390 RT_SCOPE_LINK);
2391 goto make_route;
2392 }
2393 if (!fl4->saddr) {
2394 if (ipv4_is_multicast(fl4->daddr))
2395 fl4->saddr = inet_select_addr(dev_out, 0,
2396 fl4->flowi4_scope);
2397 else if (!fl4->daddr)
2398 fl4->saddr = inet_select_addr(dev_out, 0,
2399 RT_SCOPE_HOST);
2400 }
2401 }
2402
2403 if (!fl4->daddr) {
2404 fl4->daddr = fl4->saddr;
2405 if (!fl4->daddr)
2406 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2407 dev_out = net->loopback_dev;
2408 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2409 res->type = RTN_LOCAL;
2410 flags |= RTCF_LOCAL;
2411 goto make_route;
2412 }
2413
2414 err = fib_lookup(net, fl4, res, 0);
2415 if (err) {
2416 res->fi = NULL;
2417 res->table = NULL;
2418 if (fl4->flowi4_oif &&
2419 (ipv4_is_multicast(fl4->daddr) ||
2420 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2421 /* Apparently, routing tables are wrong. Assume,
2422 that the destination is on link.
2423
2424 WHY? DW.
2425 Because we are allowed to send to iface
2426 even if it has NO routes and NO assigned
2427 addresses. When oif is specified, routing
2428 tables are looked up with only one purpose:
2429 to catch if destination is gatewayed, rather than
2430 direct. Moreover, if MSG_DONTROUTE is set,
2431 we send packet, ignoring both routing tables
2432 and ifaddr state. --ANK
2433
2434
2435 We could make it even if oif is unknown,
2436 likely IPv6, but we do not.
2437 */
2438
2439 if (fl4->saddr == 0)
2440 fl4->saddr = inet_select_addr(dev_out, 0,
2441 RT_SCOPE_LINK);
2442 res->type = RTN_UNICAST;
2443 goto make_route;
2444 }
2445 rth = ERR_PTR(err);
2446 goto out;
2447 }
2448
2449 if (res->type == RTN_LOCAL) {
2450 if (!fl4->saddr) {
2451 if (res->fi->fib_prefsrc)
2452 fl4->saddr = res->fi->fib_prefsrc;
2453 else
2454 fl4->saddr = fl4->daddr;
2455 }
2456
2457 /* L3 master device is the loopback for that domain */
2458 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2459 net->loopback_dev;
2460
2461 /* make sure orig_oif points to fib result device even
2462 * though packet rx/tx happens over loopback or l3mdev
2463 */
2464 orig_oif = FIB_RES_OIF(*res);
2465
2466 fl4->flowi4_oif = dev_out->ifindex;
2467 flags |= RTCF_LOCAL;
2468 goto make_route;
2469 }
2470
2471 fib_select_path(net, res, fl4, skb);
2472
2473 dev_out = FIB_RES_DEV(*res);
2474 fl4->flowi4_oif = dev_out->ifindex;
2475
2476
2477make_route:
2478 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2479
2480out:
2481 return rth;
2482}
2483
2484static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2485{
2486 return NULL;
2487}
2488
2489static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2490{
2491 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2492
2493 return mtu ? : dst->dev->mtu;
2494}
2495
2496static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2497 struct sk_buff *skb, u32 mtu)
2498{
2499}
2500
2501static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2502 struct sk_buff *skb)
2503{
2504}
2505
2506static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2507 unsigned long old)
2508{
2509 return NULL;
2510}
2511
2512static struct dst_ops ipv4_dst_blackhole_ops = {
2513 .family = AF_INET,
2514 .check = ipv4_blackhole_dst_check,
2515 .mtu = ipv4_blackhole_mtu,
2516 .default_advmss = ipv4_default_advmss,
2517 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2518 .redirect = ipv4_rt_blackhole_redirect,
2519 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2520 .neigh_lookup = ipv4_neigh_lookup,
2521};
2522
2523struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2524{
2525 struct rtable *ort = (struct rtable *) dst_orig;
2526 struct rtable *rt;
2527
2528 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2529 if (rt) {
2530 struct dst_entry *new = &rt->dst;
2531
2532 new->__use = 1;
2533 new->input = dst_discard;
2534 new->output = dst_discard_out;
2535
2536 new->dev = net->loopback_dev;
2537 if (new->dev)
2538 dev_hold(new->dev);
2539
2540 rt->rt_is_input = ort->rt_is_input;
2541 rt->rt_iif = ort->rt_iif;
2542 rt->rt_pmtu = ort->rt_pmtu;
2543 rt->rt_mtu_locked = ort->rt_mtu_locked;
2544
2545 rt->rt_genid = rt_genid_ipv4(net);
2546 rt->rt_flags = ort->rt_flags;
2547 rt->rt_type = ort->rt_type;
2548 rt->rt_gateway = ort->rt_gateway;
2549 rt->rt_uses_gateway = ort->rt_uses_gateway;
2550
2551 INIT_LIST_HEAD(&rt->rt_uncached);
2552 }
2553
2554 dst_release(dst_orig);
2555
2556 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2557}
2558
2559struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2560 const struct sock *sk)
2561{
2562 struct rtable *rt = __ip_route_output_key(net, flp4);
2563
2564 if (IS_ERR(rt))
2565 return rt;
2566
2567 if (flp4->flowi4_proto)
2568 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2569 flowi4_to_flowi(flp4),
2570 sk, 0);
2571
2572 return rt;
2573}
2574EXPORT_SYMBOL_GPL(ip_route_output_flow);
2575
2576/* called with rcu_read_lock held */
2577static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2578 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2579 u32 seq)
2580{
2581 struct rtable *rt = skb_rtable(skb);
2582 struct rtmsg *r;
2583 struct nlmsghdr *nlh;
2584 unsigned long expires = 0;
2585 u32 error;
2586 u32 metrics[RTAX_MAX];
2587
2588 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0);
2589 if (!nlh)
2590 return -EMSGSIZE;
2591
2592 r = nlmsg_data(nlh);
2593 r->rtm_family = AF_INET;
2594 r->rtm_dst_len = 32;
2595 r->rtm_src_len = 0;
2596 r->rtm_tos = fl4->flowi4_tos;
2597 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2598 if (nla_put_u32(skb, RTA_TABLE, table_id))
2599 goto nla_put_failure;
2600 r->rtm_type = rt->rt_type;
2601 r->rtm_scope = RT_SCOPE_UNIVERSE;
2602 r->rtm_protocol = RTPROT_UNSPEC;
2603 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2604 if (rt->rt_flags & RTCF_NOTIFY)
2605 r->rtm_flags |= RTM_F_NOTIFY;
2606 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2607 r->rtm_flags |= RTCF_DOREDIRECT;
2608
2609 if (nla_put_in_addr(skb, RTA_DST, dst))
2610 goto nla_put_failure;
2611 if (src) {
2612 r->rtm_src_len = 32;
2613 if (nla_put_in_addr(skb, RTA_SRC, src))
2614 goto nla_put_failure;
2615 }
2616 if (rt->dst.dev &&
2617 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2618 goto nla_put_failure;
2619#ifdef CONFIG_IP_ROUTE_CLASSID
2620 if (rt->dst.tclassid &&
2621 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2622 goto nla_put_failure;
2623#endif
2624 if (!rt_is_input_route(rt) &&
2625 fl4->saddr != src) {
2626 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2627 goto nla_put_failure;
2628 }
2629 if (rt->rt_uses_gateway &&
2630 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2631 goto nla_put_failure;
2632
2633 expires = rt->dst.expires;
2634 if (expires) {
2635 unsigned long now = jiffies;
2636
2637 if (time_before(now, expires))
2638 expires -= now;
2639 else
2640 expires = 0;
2641 }
2642
2643 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2644 if (rt->rt_pmtu && expires)
2645 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2646 if (rt->rt_mtu_locked && expires)
2647 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2648 if (rtnetlink_put_metrics(skb, metrics) < 0)
2649 goto nla_put_failure;
2650
2651 if (fl4->flowi4_mark &&
2652 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2653 goto nla_put_failure;
2654
2655 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2656 nla_put_u32(skb, RTA_UID,
2657 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2658 goto nla_put_failure;
2659
2660 error = rt->dst.error;
2661
2662 if (rt_is_input_route(rt)) {
2663#ifdef CONFIG_IP_MROUTE
2664 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2665 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2666 int err = ipmr_get_route(net, skb,
2667 fl4->saddr, fl4->daddr,
2668 r, portid);
2669
2670 if (err <= 0) {
2671 if (err == 0)
2672 return 0;
2673 goto nla_put_failure;
2674 }
2675 } else
2676#endif
2677 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2678 goto nla_put_failure;
2679 }
2680
2681 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2682 goto nla_put_failure;
2683
2684 nlmsg_end(skb, nlh);
2685 return 0;
2686
2687nla_put_failure:
2688 nlmsg_cancel(skb, nlh);
2689 return -EMSGSIZE;
2690}
2691
2692static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2693 struct netlink_ext_ack *extack)
2694{
2695 struct net *net = sock_net(in_skb->sk);
2696 struct rtmsg *rtm;
2697 struct nlattr *tb[RTA_MAX+1];
2698 struct fib_result res = {};
2699 struct rtable *rt = NULL;
2700 struct flowi4 fl4;
2701 __be32 dst = 0;
2702 __be32 src = 0;
2703 u32 iif;
2704 int err;
2705 int mark;
2706 struct sk_buff *skb;
2707 u32 table_id = RT_TABLE_MAIN;
2708 kuid_t uid;
2709
2710 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy,
2711 extack);
2712 if (err < 0)
2713 goto errout;
2714
2715 rtm = nlmsg_data(nlh);
2716
2717 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2718 if (!skb) {
2719 err = -ENOBUFS;
2720 goto errout;
2721 }
2722
2723 /* Reserve room for dummy headers, this skb can pass
2724 through good chunk of routing engine.
2725 */
2726 skb_reset_mac_header(skb);
2727 skb_reset_network_header(skb);
2728
2729 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2730 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2731 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2732 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2733 if (tb[RTA_UID])
2734 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2735 else
2736 uid = (iif ? INVALID_UID : current_uid());
2737
2738 /* Bugfix: need to give ip_route_input enough of an IP header to
2739 * not gag.
2740 */
2741 ip_hdr(skb)->protocol = IPPROTO_UDP;
2742 ip_hdr(skb)->saddr = src;
2743 ip_hdr(skb)->daddr = dst;
2744
2745 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2746
2747 memset(&fl4, 0, sizeof(fl4));
2748 fl4.daddr = dst;
2749 fl4.saddr = src;
2750 fl4.flowi4_tos = rtm->rtm_tos;
2751 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2752 fl4.flowi4_mark = mark;
2753 fl4.flowi4_uid = uid;
2754
2755 rcu_read_lock();
2756
2757 if (iif) {
2758 struct net_device *dev;
2759
2760 dev = dev_get_by_index_rcu(net, iif);
2761 if (!dev) {
2762 err = -ENODEV;
2763 goto errout_free;
2764 }
2765
2766 skb->protocol = htons(ETH_P_IP);
2767 skb->dev = dev;
2768 skb->mark = mark;
2769 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
2770 dev, &res);
2771
2772 rt = skb_rtable(skb);
2773 if (err == 0 && rt->dst.error)
2774 err = -rt->dst.error;
2775 } else {
2776 fl4.flowi4_iif = LOOPBACK_IFINDEX;
2777 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
2778 err = 0;
2779 if (IS_ERR(rt))
2780 err = PTR_ERR(rt);
2781 else
2782 skb_dst_set(skb, &rt->dst);
2783 }
2784
2785 if (err)
2786 goto errout_free;
2787
2788 if (rtm->rtm_flags & RTM_F_NOTIFY)
2789 rt->rt_flags |= RTCF_NOTIFY;
2790
2791 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2792 table_id = res.table ? res.table->tb_id : 0;
2793
2794 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2795 if (!res.fi) {
2796 err = fib_props[res.type].error;
2797 if (!err)
2798 err = -EHOSTUNREACH;
2799 goto errout_free;
2800 }
2801 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
2802 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
2803 rt->rt_type, res.prefix, res.prefixlen,
2804 fl4.flowi4_tos, res.fi, 0);
2805 } else {
2806 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2807 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
2808 }
2809 if (err < 0)
2810 goto errout_free;
2811
2812 rcu_read_unlock();
2813
2814 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2815errout:
2816 return err;
2817
2818errout_free:
2819 rcu_read_unlock();
2820 kfree_skb(skb);
2821 goto errout;
2822}
2823
2824void ip_rt_multicast_event(struct in_device *in_dev)
2825{
2826 rt_cache_flush(dev_net(in_dev->dev));
2827}
2828
2829#ifdef CONFIG_SYSCTL
2830static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2831static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2832static int ip_rt_gc_elasticity __read_mostly = 8;
2833static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
2834
2835static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2836 void __user *buffer,
2837 size_t *lenp, loff_t *ppos)
2838{
2839 struct net *net = (struct net *)__ctl->extra1;
2840
2841 if (write) {
2842 rt_cache_flush(net);
2843 fnhe_genid_bump(net);
2844 return 0;
2845 }
2846
2847 return -EINVAL;
2848}
2849
2850static struct ctl_table ipv4_route_table[] = {
2851 {
2852 .procname = "gc_thresh",
2853 .data = &ipv4_dst_ops.gc_thresh,
2854 .maxlen = sizeof(int),
2855 .mode = 0644,
2856 .proc_handler = proc_dointvec,
2857 },
2858 {
2859 .procname = "max_size",
2860 .data = &ip_rt_max_size,
2861 .maxlen = sizeof(int),
2862 .mode = 0644,
2863 .proc_handler = proc_dointvec,
2864 },
2865 {
2866 /* Deprecated. Use gc_min_interval_ms */
2867
2868 .procname = "gc_min_interval",
2869 .data = &ip_rt_gc_min_interval,
2870 .maxlen = sizeof(int),
2871 .mode = 0644,
2872 .proc_handler = proc_dointvec_jiffies,
2873 },
2874 {
2875 .procname = "gc_min_interval_ms",
2876 .data = &ip_rt_gc_min_interval,
2877 .maxlen = sizeof(int),
2878 .mode = 0644,
2879 .proc_handler = proc_dointvec_ms_jiffies,
2880 },
2881 {
2882 .procname = "gc_timeout",
2883 .data = &ip_rt_gc_timeout,
2884 .maxlen = sizeof(int),
2885 .mode = 0644,
2886 .proc_handler = proc_dointvec_jiffies,
2887 },
2888 {
2889 .procname = "gc_interval",
2890 .data = &ip_rt_gc_interval,
2891 .maxlen = sizeof(int),
2892 .mode = 0644,
2893 .proc_handler = proc_dointvec_jiffies,
2894 },
2895 {
2896 .procname = "redirect_load",
2897 .data = &ip_rt_redirect_load,
2898 .maxlen = sizeof(int),
2899 .mode = 0644,
2900 .proc_handler = proc_dointvec,
2901 },
2902 {
2903 .procname = "redirect_number",
2904 .data = &ip_rt_redirect_number,
2905 .maxlen = sizeof(int),
2906 .mode = 0644,
2907 .proc_handler = proc_dointvec,
2908 },
2909 {
2910 .procname = "redirect_silence",
2911 .data = &ip_rt_redirect_silence,
2912 .maxlen = sizeof(int),
2913 .mode = 0644,
2914 .proc_handler = proc_dointvec,
2915 },
2916 {
2917 .procname = "error_cost",
2918 .data = &ip_rt_error_cost,
2919 .maxlen = sizeof(int),
2920 .mode = 0644,
2921 .proc_handler = proc_dointvec,
2922 },
2923 {
2924 .procname = "error_burst",
2925 .data = &ip_rt_error_burst,
2926 .maxlen = sizeof(int),
2927 .mode = 0644,
2928 .proc_handler = proc_dointvec,
2929 },
2930 {
2931 .procname = "gc_elasticity",
2932 .data = &ip_rt_gc_elasticity,
2933 .maxlen = sizeof(int),
2934 .mode = 0644,
2935 .proc_handler = proc_dointvec,
2936 },
2937 {
2938 .procname = "mtu_expires",
2939 .data = &ip_rt_mtu_expires,
2940 .maxlen = sizeof(int),
2941 .mode = 0644,
2942 .proc_handler = proc_dointvec_jiffies,
2943 },
2944 {
2945 .procname = "min_pmtu",
2946 .data = &ip_rt_min_pmtu,
2947 .maxlen = sizeof(int),
2948 .mode = 0644,
2949 .proc_handler = proc_dointvec_minmax,
2950 .extra1 = &ip_min_valid_pmtu,
2951 },
2952 {
2953 .procname = "min_adv_mss",
2954 .data = &ip_rt_min_advmss,
2955 .maxlen = sizeof(int),
2956 .mode = 0644,
2957 .proc_handler = proc_dointvec,
2958 },
2959 { }
2960};
2961
2962static struct ctl_table ipv4_route_flush_table[] = {
2963 {
2964 .procname = "flush",
2965 .maxlen = sizeof(int),
2966 .mode = 0200,
2967 .proc_handler = ipv4_sysctl_rtcache_flush,
2968 },
2969 { },
2970};
2971
2972static __net_init int sysctl_route_net_init(struct net *net)
2973{
2974 struct ctl_table *tbl;
2975
2976 tbl = ipv4_route_flush_table;
2977 if (!net_eq(net, &init_net)) {
2978 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2979 if (!tbl)
2980 goto err_dup;
2981
2982 /* Don't export sysctls to unprivileged users */
2983 if (net->user_ns != &init_user_ns)
2984 tbl[0].procname = NULL;
2985 }
2986 tbl[0].extra1 = net;
2987
2988 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2989 if (!net->ipv4.route_hdr)
2990 goto err_reg;
2991 return 0;
2992
2993err_reg:
2994 if (tbl != ipv4_route_flush_table)
2995 kfree(tbl);
2996err_dup:
2997 return -ENOMEM;
2998}
2999
3000static __net_exit void sysctl_route_net_exit(struct net *net)
3001{
3002 struct ctl_table *tbl;
3003
3004 tbl = net->ipv4.route_hdr->ctl_table_arg;
3005 unregister_net_sysctl_table(net->ipv4.route_hdr);
3006 BUG_ON(tbl == ipv4_route_flush_table);
3007 kfree(tbl);
3008}
3009
3010static __net_initdata struct pernet_operations sysctl_route_ops = {
3011 .init = sysctl_route_net_init,
3012 .exit = sysctl_route_net_exit,
3013};
3014#endif
3015
3016static __net_init int rt_genid_init(struct net *net)
3017{
3018 atomic_set(&net->ipv4.rt_genid, 0);
3019 atomic_set(&net->fnhe_genid, 0);
3020 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3021 return 0;
3022}
3023
3024static __net_initdata struct pernet_operations rt_genid_ops = {
3025 .init = rt_genid_init,
3026};
3027
3028static int __net_init ipv4_inetpeer_init(struct net *net)
3029{
3030 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3031
3032 if (!bp)
3033 return -ENOMEM;
3034 inet_peer_base_init(bp);
3035 net->ipv4.peers = bp;
3036 return 0;
3037}
3038
3039static void __net_exit ipv4_inetpeer_exit(struct net *net)
3040{
3041 struct inet_peer_base *bp = net->ipv4.peers;
3042
3043 net->ipv4.peers = NULL;
3044 inetpeer_invalidate_tree(bp);
3045 kfree(bp);
3046}
3047
3048static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3049 .init = ipv4_inetpeer_init,
3050 .exit = ipv4_inetpeer_exit,
3051};
3052
3053#ifdef CONFIG_IP_ROUTE_CLASSID
3054struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3055#endif /* CONFIG_IP_ROUTE_CLASSID */
3056
3057int __init ip_rt_init(void)
3058{
3059 int cpu;
3060
3061 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
3062 if (!ip_idents)
3063 panic("IP: failed to allocate ip_idents\n");
3064
3065 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3066
3067 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3068 if (!ip_tstamps)
3069 panic("IP: failed to allocate ip_tstamps\n");
3070
3071 for_each_possible_cpu(cpu) {
3072 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3073
3074 INIT_LIST_HEAD(&ul->head);
3075 spin_lock_init(&ul->lock);
3076 }
3077#ifdef CONFIG_IP_ROUTE_CLASSID
3078 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3079 if (!ip_rt_acct)
3080 panic("IP: failed to allocate ip_rt_acct\n");
3081#endif
3082
3083 ipv4_dst_ops.kmem_cachep =
3084 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3085 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3086
3087 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3088
3089 if (dst_entries_init(&ipv4_dst_ops) < 0)
3090 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3091
3092 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3093 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3094
3095 ipv4_dst_ops.gc_thresh = ~0;
3096 ip_rt_max_size = INT_MAX;
3097
3098 devinet_init();
3099 ip_fib_init();
3100
3101 if (ip_rt_proc_init())
3102 pr_err("Unable to create route proc files\n");
3103#ifdef CONFIG_XFRM
3104 xfrm_init();
3105 xfrm4_init();
3106#endif
3107 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3108 RTNL_FLAG_DOIT_UNLOCKED);
3109
3110#ifdef CONFIG_SYSCTL
3111 register_pernet_subsys(&sysctl_route_ops);
3112#endif
3113 register_pernet_subsys(&rt_genid_ops);
3114 register_pernet_subsys(&ipv4_inetpeer_ops);
3115 return 0;
3116}
3117
3118#ifdef CONFIG_SYSCTL
3119/*
3120 * We really need to sanitize the damn ipv4 init order, then all
3121 * this nonsense will go away.
3122 */
3123void __init ip_static_sysctl_init(void)
3124{
3125 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3126}
3127#endif
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/dst_metadata.h>
95#include <net/net_namespace.h>
96#include <net/protocol.h>
97#include <net/ip.h>
98#include <net/route.h>
99#include <net/inetpeer.h>
100#include <net/sock.h>
101#include <net/ip_fib.h>
102#include <net/arp.h>
103#include <net/tcp.h>
104#include <net/icmp.h>
105#include <net/xfrm.h>
106#include <net/lwtunnel.h>
107#include <net/netevent.h>
108#include <net/rtnetlink.h>
109#ifdef CONFIG_SYSCTL
110#include <linux/sysctl.h>
111#include <linux/kmemleak.h>
112#endif
113#include <net/secure_seq.h>
114#include <net/ip_tunnels.h>
115#include <net/l3mdev.h>
116
117#define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119
120#define RT_GC_TIMEOUT (300*HZ)
121
122static int ip_rt_max_size;
123static int ip_rt_redirect_number __read_mostly = 9;
124static int ip_rt_redirect_load __read_mostly = HZ / 50;
125static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126static int ip_rt_error_cost __read_mostly = HZ;
127static int ip_rt_error_burst __read_mostly = 5 * HZ;
128static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130static int ip_rt_min_advmss __read_mostly = 256;
131
132static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
133/*
134 * Interface to generic destination cache.
135 */
136
137static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
138static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
139static unsigned int ipv4_mtu(const struct dst_entry *dst);
140static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
141static void ipv4_link_failure(struct sk_buff *skb);
142static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
143 struct sk_buff *skb, u32 mtu);
144static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb);
146static void ipv4_dst_destroy(struct dst_entry *dst);
147
148static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
149{
150 WARN_ON(1);
151 return NULL;
152}
153
154static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
155 struct sk_buff *skb,
156 const void *daddr);
157
158static struct dst_ops ipv4_dst_ops = {
159 .family = AF_INET,
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .negative_advice = ipv4_negative_advice,
166 .link_failure = ipv4_link_failure,
167 .update_pmtu = ip_rt_update_pmtu,
168 .redirect = ip_do_redirect,
169 .local_out = __ip_local_out,
170 .neigh_lookup = ipv4_neigh_lookup,
171};
172
173#define ECN_OR_COST(class) TC_PRIO_##class
174
175const __u8 ip_tos2prio[16] = {
176 TC_PRIO_BESTEFFORT,
177 ECN_OR_COST(BESTEFFORT),
178 TC_PRIO_BESTEFFORT,
179 ECN_OR_COST(BESTEFFORT),
180 TC_PRIO_BULK,
181 ECN_OR_COST(BULK),
182 TC_PRIO_BULK,
183 ECN_OR_COST(BULK),
184 TC_PRIO_INTERACTIVE,
185 ECN_OR_COST(INTERACTIVE),
186 TC_PRIO_INTERACTIVE,
187 ECN_OR_COST(INTERACTIVE),
188 TC_PRIO_INTERACTIVE_BULK,
189 ECN_OR_COST(INTERACTIVE_BULK),
190 TC_PRIO_INTERACTIVE_BULK,
191 ECN_OR_COST(INTERACTIVE_BULK)
192};
193EXPORT_SYMBOL(ip_tos2prio);
194
195static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
196#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
197
198#ifdef CONFIG_PROC_FS
199static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
200{
201 if (*pos)
202 return NULL;
203 return SEQ_START_TOKEN;
204}
205
206static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
207{
208 ++*pos;
209 return NULL;
210}
211
212static void rt_cache_seq_stop(struct seq_file *seq, void *v)
213{
214}
215
216static int rt_cache_seq_show(struct seq_file *seq, void *v)
217{
218 if (v == SEQ_START_TOKEN)
219 seq_printf(seq, "%-127s\n",
220 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
221 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
222 "HHUptod\tSpecDst");
223 return 0;
224}
225
226static const struct seq_operations rt_cache_seq_ops = {
227 .start = rt_cache_seq_start,
228 .next = rt_cache_seq_next,
229 .stop = rt_cache_seq_stop,
230 .show = rt_cache_seq_show,
231};
232
233static int rt_cache_seq_open(struct inode *inode, struct file *file)
234{
235 return seq_open(file, &rt_cache_seq_ops);
236}
237
238static const struct file_operations rt_cache_seq_fops = {
239 .owner = THIS_MODULE,
240 .open = rt_cache_seq_open,
241 .read = seq_read,
242 .llseek = seq_lseek,
243 .release = seq_release,
244};
245
246
247static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
248{
249 int cpu;
250
251 if (*pos == 0)
252 return SEQ_START_TOKEN;
253
254 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
255 if (!cpu_possible(cpu))
256 continue;
257 *pos = cpu+1;
258 return &per_cpu(rt_cache_stat, cpu);
259 }
260 return NULL;
261}
262
263static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
264{
265 int cpu;
266
267 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
268 if (!cpu_possible(cpu))
269 continue;
270 *pos = cpu+1;
271 return &per_cpu(rt_cache_stat, cpu);
272 }
273 return NULL;
274
275}
276
277static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
278{
279
280}
281
282static int rt_cpu_seq_show(struct seq_file *seq, void *v)
283{
284 struct rt_cache_stat *st = v;
285
286 if (v == SEQ_START_TOKEN) {
287 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");
288 return 0;
289 }
290
291 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
292 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
293 dst_entries_get_slow(&ipv4_dst_ops),
294 0, /* st->in_hit */
295 st->in_slow_tot,
296 st->in_slow_mc,
297 st->in_no_route,
298 st->in_brd,
299 st->in_martian_dst,
300 st->in_martian_src,
301
302 0, /* st->out_hit */
303 st->out_slow_tot,
304 st->out_slow_mc,
305
306 0, /* st->gc_total */
307 0, /* st->gc_ignored */
308 0, /* st->gc_goal_miss */
309 0, /* st->gc_dst_overflow */
310 0, /* st->in_hlist_search */
311 0 /* st->out_hlist_search */
312 );
313 return 0;
314}
315
316static const struct seq_operations rt_cpu_seq_ops = {
317 .start = rt_cpu_seq_start,
318 .next = rt_cpu_seq_next,
319 .stop = rt_cpu_seq_stop,
320 .show = rt_cpu_seq_show,
321};
322
323
324static int rt_cpu_seq_open(struct inode *inode, struct file *file)
325{
326 return seq_open(file, &rt_cpu_seq_ops);
327}
328
329static const struct file_operations rt_cpu_seq_fops = {
330 .owner = THIS_MODULE,
331 .open = rt_cpu_seq_open,
332 .read = seq_read,
333 .llseek = seq_lseek,
334 .release = seq_release,
335};
336
337#ifdef CONFIG_IP_ROUTE_CLASSID
338static int rt_acct_proc_show(struct seq_file *m, void *v)
339{
340 struct ip_rt_acct *dst, *src;
341 unsigned int i, j;
342
343 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
344 if (!dst)
345 return -ENOMEM;
346
347 for_each_possible_cpu(i) {
348 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
349 for (j = 0; j < 256; j++) {
350 dst[j].o_bytes += src[j].o_bytes;
351 dst[j].o_packets += src[j].o_packets;
352 dst[j].i_bytes += src[j].i_bytes;
353 dst[j].i_packets += src[j].i_packets;
354 }
355 }
356
357 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
358 kfree(dst);
359 return 0;
360}
361
362static int rt_acct_proc_open(struct inode *inode, struct file *file)
363{
364 return single_open(file, rt_acct_proc_show, NULL);
365}
366
367static const struct file_operations rt_acct_proc_fops = {
368 .owner = THIS_MODULE,
369 .open = rt_acct_proc_open,
370 .read = seq_read,
371 .llseek = seq_lseek,
372 .release = single_release,
373};
374#endif
375
376static int __net_init ip_rt_do_proc_init(struct net *net)
377{
378 struct proc_dir_entry *pde;
379
380 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
381 &rt_cache_seq_fops);
382 if (!pde)
383 goto err1;
384
385 pde = proc_create("rt_cache", S_IRUGO,
386 net->proc_net_stat, &rt_cpu_seq_fops);
387 if (!pde)
388 goto err2;
389
390#ifdef CONFIG_IP_ROUTE_CLASSID
391 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
392 if (!pde)
393 goto err3;
394#endif
395 return 0;
396
397#ifdef CONFIG_IP_ROUTE_CLASSID
398err3:
399 remove_proc_entry("rt_cache", net->proc_net_stat);
400#endif
401err2:
402 remove_proc_entry("rt_cache", net->proc_net);
403err1:
404 return -ENOMEM;
405}
406
407static void __net_exit ip_rt_do_proc_exit(struct net *net)
408{
409 remove_proc_entry("rt_cache", net->proc_net_stat);
410 remove_proc_entry("rt_cache", net->proc_net);
411#ifdef CONFIG_IP_ROUTE_CLASSID
412 remove_proc_entry("rt_acct", net->proc_net);
413#endif
414}
415
416static struct pernet_operations ip_rt_proc_ops __net_initdata = {
417 .init = ip_rt_do_proc_init,
418 .exit = ip_rt_do_proc_exit,
419};
420
421static int __init ip_rt_proc_init(void)
422{
423 return register_pernet_subsys(&ip_rt_proc_ops);
424}
425
426#else
427static inline int ip_rt_proc_init(void)
428{
429 return 0;
430}
431#endif /* CONFIG_PROC_FS */
432
433static inline bool rt_is_expired(const struct rtable *rth)
434{
435 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
436}
437
438void rt_cache_flush(struct net *net)
439{
440 rt_genid_bump_ipv4(net);
441}
442
443static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
444 struct sk_buff *skb,
445 const void *daddr)
446{
447 struct net_device *dev = dst->dev;
448 const __be32 *pkey = daddr;
449 const struct rtable *rt;
450 struct neighbour *n;
451
452 rt = (const struct rtable *) dst;
453 if (rt->rt_gateway)
454 pkey = (const __be32 *) &rt->rt_gateway;
455 else if (skb)
456 pkey = &ip_hdr(skb)->daddr;
457
458 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
459 if (n)
460 return n;
461 return neigh_create(&arp_tbl, pkey, dev);
462}
463
464#define IP_IDENTS_SZ 2048u
465
466static atomic_t *ip_idents __read_mostly;
467static u32 *ip_tstamps __read_mostly;
468
469/* In order to protect privacy, we add a perturbation to identifiers
470 * if one generator is seldom used. This makes hard for an attacker
471 * to infer how many packets were sent between two points in time.
472 */
473u32 ip_idents_reserve(u32 hash, int segs)
474{
475 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
476 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
477 u32 old = ACCESS_ONCE(*p_tstamp);
478 u32 now = (u32)jiffies;
479 u32 delta = 0;
480
481 if (old != now && cmpxchg(p_tstamp, old, now) == old)
482 delta = prandom_u32_max(now - old);
483
484 return atomic_add_return(segs + delta, p_id) - segs;
485}
486EXPORT_SYMBOL(ip_idents_reserve);
487
488void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
489{
490 static u32 ip_idents_hashrnd __read_mostly;
491 u32 hash, id;
492
493 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
494
495 hash = jhash_3words((__force u32)iph->daddr,
496 (__force u32)iph->saddr,
497 iph->protocol ^ net_hash_mix(net),
498 ip_idents_hashrnd);
499 id = ip_idents_reserve(hash, segs);
500 iph->id = htons(id);
501}
502EXPORT_SYMBOL(__ip_select_ident);
503
504static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
505 const struct iphdr *iph,
506 int oif, u8 tos,
507 u8 prot, u32 mark, int flow_flags)
508{
509 if (sk) {
510 const struct inet_sock *inet = inet_sk(sk);
511
512 oif = sk->sk_bound_dev_if;
513 mark = sk->sk_mark;
514 tos = RT_CONN_FLAGS(sk);
515 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
516 }
517 flowi4_init_output(fl4, oif, mark, tos,
518 RT_SCOPE_UNIVERSE, prot,
519 flow_flags,
520 iph->daddr, iph->saddr, 0, 0);
521}
522
523static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
524 const struct sock *sk)
525{
526 const struct iphdr *iph = ip_hdr(skb);
527 int oif = skb->dev->ifindex;
528 u8 tos = RT_TOS(iph->tos);
529 u8 prot = iph->protocol;
530 u32 mark = skb->mark;
531
532 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
533}
534
535static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
536{
537 const struct inet_sock *inet = inet_sk(sk);
538 const struct ip_options_rcu *inet_opt;
539 __be32 daddr = inet->inet_daddr;
540
541 rcu_read_lock();
542 inet_opt = rcu_dereference(inet->inet_opt);
543 if (inet_opt && inet_opt->opt.srr)
544 daddr = inet_opt->opt.faddr;
545 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
546 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
547 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
548 inet_sk_flowi_flags(sk),
549 daddr, inet->inet_saddr, 0, 0);
550 rcu_read_unlock();
551}
552
553static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
554 const struct sk_buff *skb)
555{
556 if (skb)
557 build_skb_flow_key(fl4, skb, sk);
558 else
559 build_sk_flow_key(fl4, sk);
560}
561
562static inline void rt_free(struct rtable *rt)
563{
564 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
565}
566
567static DEFINE_SPINLOCK(fnhe_lock);
568
569static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
570{
571 struct rtable *rt;
572
573 rt = rcu_dereference(fnhe->fnhe_rth_input);
574 if (rt) {
575 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
576 rt_free(rt);
577 }
578 rt = rcu_dereference(fnhe->fnhe_rth_output);
579 if (rt) {
580 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
581 rt_free(rt);
582 }
583}
584
585static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
586{
587 struct fib_nh_exception *fnhe, *oldest;
588
589 oldest = rcu_dereference(hash->chain);
590 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
591 fnhe = rcu_dereference(fnhe->fnhe_next)) {
592 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
593 oldest = fnhe;
594 }
595 fnhe_flush_routes(oldest);
596 return oldest;
597}
598
599static inline u32 fnhe_hashfun(__be32 daddr)
600{
601 static u32 fnhe_hashrnd __read_mostly;
602 u32 hval;
603
604 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
605 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
606 return hash_32(hval, FNHE_HASH_SHIFT);
607}
608
609static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
610{
611 rt->rt_pmtu = fnhe->fnhe_pmtu;
612 rt->dst.expires = fnhe->fnhe_expires;
613
614 if (fnhe->fnhe_gw) {
615 rt->rt_flags |= RTCF_REDIRECTED;
616 rt->rt_gateway = fnhe->fnhe_gw;
617 rt->rt_uses_gateway = 1;
618 }
619}
620
621static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
622 u32 pmtu, unsigned long expires)
623{
624 struct fnhe_hash_bucket *hash;
625 struct fib_nh_exception *fnhe;
626 struct rtable *rt;
627 unsigned int i;
628 int depth;
629 u32 hval = fnhe_hashfun(daddr);
630
631 spin_lock_bh(&fnhe_lock);
632
633 hash = rcu_dereference(nh->nh_exceptions);
634 if (!hash) {
635 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
636 if (!hash)
637 goto out_unlock;
638 rcu_assign_pointer(nh->nh_exceptions, hash);
639 }
640
641 hash += hval;
642
643 depth = 0;
644 for (fnhe = rcu_dereference(hash->chain); fnhe;
645 fnhe = rcu_dereference(fnhe->fnhe_next)) {
646 if (fnhe->fnhe_daddr == daddr)
647 break;
648 depth++;
649 }
650
651 if (fnhe) {
652 if (gw)
653 fnhe->fnhe_gw = gw;
654 if (pmtu) {
655 fnhe->fnhe_pmtu = pmtu;
656 fnhe->fnhe_expires = max(1UL, expires);
657 }
658 /* Update all cached dsts too */
659 rt = rcu_dereference(fnhe->fnhe_rth_input);
660 if (rt)
661 fill_route_from_fnhe(rt, fnhe);
662 rt = rcu_dereference(fnhe->fnhe_rth_output);
663 if (rt)
664 fill_route_from_fnhe(rt, fnhe);
665 } else {
666 if (depth > FNHE_RECLAIM_DEPTH)
667 fnhe = fnhe_oldest(hash);
668 else {
669 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
670 if (!fnhe)
671 goto out_unlock;
672
673 fnhe->fnhe_next = hash->chain;
674 rcu_assign_pointer(hash->chain, fnhe);
675 }
676 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
677 fnhe->fnhe_daddr = daddr;
678 fnhe->fnhe_gw = gw;
679 fnhe->fnhe_pmtu = pmtu;
680 fnhe->fnhe_expires = expires;
681
682 /* Exception created; mark the cached routes for the nexthop
683 * stale, so anyone caching it rechecks if this exception
684 * applies to them.
685 */
686 rt = rcu_dereference(nh->nh_rth_input);
687 if (rt)
688 rt->dst.obsolete = DST_OBSOLETE_KILL;
689
690 for_each_possible_cpu(i) {
691 struct rtable __rcu **prt;
692 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
693 rt = rcu_dereference(*prt);
694 if (rt)
695 rt->dst.obsolete = DST_OBSOLETE_KILL;
696 }
697 }
698
699 fnhe->fnhe_stamp = jiffies;
700
701out_unlock:
702 spin_unlock_bh(&fnhe_lock);
703}
704
705static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
706 bool kill_route)
707{
708 __be32 new_gw = icmp_hdr(skb)->un.gateway;
709 __be32 old_gw = ip_hdr(skb)->saddr;
710 struct net_device *dev = skb->dev;
711 struct in_device *in_dev;
712 struct fib_result res;
713 struct neighbour *n;
714 struct net *net;
715
716 switch (icmp_hdr(skb)->code & 7) {
717 case ICMP_REDIR_NET:
718 case ICMP_REDIR_NETTOS:
719 case ICMP_REDIR_HOST:
720 case ICMP_REDIR_HOSTTOS:
721 break;
722
723 default:
724 return;
725 }
726
727 if (rt->rt_gateway != old_gw)
728 return;
729
730 in_dev = __in_dev_get_rcu(dev);
731 if (!in_dev)
732 return;
733
734 net = dev_net(dev);
735 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
736 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
737 ipv4_is_zeronet(new_gw))
738 goto reject_redirect;
739
740 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
741 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
742 goto reject_redirect;
743 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
744 goto reject_redirect;
745 } else {
746 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
747 goto reject_redirect;
748 }
749
750 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
751 if (!IS_ERR(n)) {
752 if (!(n->nud_state & NUD_VALID)) {
753 neigh_event_send(n, NULL);
754 } else {
755 if (fib_lookup(net, fl4, &res, 0) == 0) {
756 struct fib_nh *nh = &FIB_RES_NH(res);
757
758 update_or_create_fnhe(nh, fl4->daddr, new_gw,
759 0, jiffies + ip_rt_gc_timeout);
760 }
761 if (kill_route)
762 rt->dst.obsolete = DST_OBSOLETE_KILL;
763 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
764 }
765 neigh_release(n);
766 }
767 return;
768
769reject_redirect:
770#ifdef CONFIG_IP_ROUTE_VERBOSE
771 if (IN_DEV_LOG_MARTIANS(in_dev)) {
772 const struct iphdr *iph = (const struct iphdr *) skb->data;
773 __be32 daddr = iph->daddr;
774 __be32 saddr = iph->saddr;
775
776 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
777 " Advised path = %pI4 -> %pI4\n",
778 &old_gw, dev->name, &new_gw,
779 &saddr, &daddr);
780 }
781#endif
782 ;
783}
784
785static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
786{
787 struct rtable *rt;
788 struct flowi4 fl4;
789 const struct iphdr *iph = (const struct iphdr *) skb->data;
790 int oif = skb->dev->ifindex;
791 u8 tos = RT_TOS(iph->tos);
792 u8 prot = iph->protocol;
793 u32 mark = skb->mark;
794
795 rt = (struct rtable *) dst;
796
797 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
798 __ip_do_redirect(rt, skb, &fl4, true);
799}
800
801static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
802{
803 struct rtable *rt = (struct rtable *)dst;
804 struct dst_entry *ret = dst;
805
806 if (rt) {
807 if (dst->obsolete > 0) {
808 ip_rt_put(rt);
809 ret = NULL;
810 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
811 rt->dst.expires) {
812 ip_rt_put(rt);
813 ret = NULL;
814 }
815 }
816 return ret;
817}
818
819/*
820 * Algorithm:
821 * 1. The first ip_rt_redirect_number redirects are sent
822 * with exponential backoff, then we stop sending them at all,
823 * assuming that the host ignores our redirects.
824 * 2. If we did not see packets requiring redirects
825 * during ip_rt_redirect_silence, we assume that the host
826 * forgot redirected route and start to send redirects again.
827 *
828 * This algorithm is much cheaper and more intelligent than dumb load limiting
829 * in icmp.c.
830 *
831 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
832 * and "frag. need" (breaks PMTU discovery) in icmp.c.
833 */
834
835void ip_rt_send_redirect(struct sk_buff *skb)
836{
837 struct rtable *rt = skb_rtable(skb);
838 struct in_device *in_dev;
839 struct inet_peer *peer;
840 struct net *net;
841 int log_martians;
842 int vif;
843
844 rcu_read_lock();
845 in_dev = __in_dev_get_rcu(rt->dst.dev);
846 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
847 rcu_read_unlock();
848 return;
849 }
850 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
851 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
852 rcu_read_unlock();
853
854 net = dev_net(rt->dst.dev);
855 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
856 if (!peer) {
857 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
858 rt_nexthop(rt, ip_hdr(skb)->daddr));
859 return;
860 }
861
862 /* No redirected packets during ip_rt_redirect_silence;
863 * reset the algorithm.
864 */
865 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
866 peer->rate_tokens = 0;
867
868 /* Too many ignored redirects; do not send anything
869 * set dst.rate_last to the last seen redirected packet.
870 */
871 if (peer->rate_tokens >= ip_rt_redirect_number) {
872 peer->rate_last = jiffies;
873 goto out_put_peer;
874 }
875
876 /* Check for load limit; set rate_last to the latest sent
877 * redirect.
878 */
879 if (peer->rate_tokens == 0 ||
880 time_after(jiffies,
881 (peer->rate_last +
882 (ip_rt_redirect_load << peer->rate_tokens)))) {
883 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
884
885 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
886 peer->rate_last = jiffies;
887 ++peer->rate_tokens;
888#ifdef CONFIG_IP_ROUTE_VERBOSE
889 if (log_martians &&
890 peer->rate_tokens == ip_rt_redirect_number)
891 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
892 &ip_hdr(skb)->saddr, inet_iif(skb),
893 &ip_hdr(skb)->daddr, &gw);
894#endif
895 }
896out_put_peer:
897 inet_putpeer(peer);
898}
899
900static int ip_error(struct sk_buff *skb)
901{
902 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
903 struct rtable *rt = skb_rtable(skb);
904 struct inet_peer *peer;
905 unsigned long now;
906 struct net *net;
907 bool send;
908 int code;
909
910 /* IP on this device is disabled. */
911 if (!in_dev)
912 goto out;
913
914 net = dev_net(rt->dst.dev);
915 if (!IN_DEV_FORWARD(in_dev)) {
916 switch (rt->dst.error) {
917 case EHOSTUNREACH:
918 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
919 break;
920
921 case ENETUNREACH:
922 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
923 break;
924 }
925 goto out;
926 }
927
928 switch (rt->dst.error) {
929 case EINVAL:
930 default:
931 goto out;
932 case EHOSTUNREACH:
933 code = ICMP_HOST_UNREACH;
934 break;
935 case ENETUNREACH:
936 code = ICMP_NET_UNREACH;
937 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
938 break;
939 case EACCES:
940 code = ICMP_PKT_FILTERED;
941 break;
942 }
943
944 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
945 l3mdev_master_ifindex(skb->dev), 1);
946
947 send = true;
948 if (peer) {
949 now = jiffies;
950 peer->rate_tokens += now - peer->rate_last;
951 if (peer->rate_tokens > ip_rt_error_burst)
952 peer->rate_tokens = ip_rt_error_burst;
953 peer->rate_last = now;
954 if (peer->rate_tokens >= ip_rt_error_cost)
955 peer->rate_tokens -= ip_rt_error_cost;
956 else
957 send = false;
958 inet_putpeer(peer);
959 }
960 if (send)
961 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
962
963out: kfree_skb(skb);
964 return 0;
965}
966
967static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
968{
969 struct dst_entry *dst = &rt->dst;
970 struct fib_result res;
971
972 if (dst_metric_locked(dst, RTAX_MTU))
973 return;
974
975 if (ipv4_mtu(dst) < mtu)
976 return;
977
978 if (mtu < ip_rt_min_pmtu)
979 mtu = ip_rt_min_pmtu;
980
981 if (rt->rt_pmtu == mtu &&
982 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
983 return;
984
985 rcu_read_lock();
986 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
987 struct fib_nh *nh = &FIB_RES_NH(res);
988
989 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
990 jiffies + ip_rt_mtu_expires);
991 }
992 rcu_read_unlock();
993}
994
995static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
996 struct sk_buff *skb, u32 mtu)
997{
998 struct rtable *rt = (struct rtable *) dst;
999 struct flowi4 fl4;
1000
1001 ip_rt_build_flow_key(&fl4, sk, skb);
1002 __ip_rt_update_pmtu(rt, &fl4, mtu);
1003}
1004
1005void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1006 int oif, u32 mark, u8 protocol, int flow_flags)
1007{
1008 const struct iphdr *iph = (const struct iphdr *) skb->data;
1009 struct flowi4 fl4;
1010 struct rtable *rt;
1011
1012 if (!mark)
1013 mark = IP4_REPLY_MARK(net, skb->mark);
1014
1015 __build_flow_key(&fl4, NULL, iph, oif,
1016 RT_TOS(iph->tos), protocol, mark, flow_flags);
1017 rt = __ip_route_output_key(net, &fl4);
1018 if (!IS_ERR(rt)) {
1019 __ip_rt_update_pmtu(rt, &fl4, mtu);
1020 ip_rt_put(rt);
1021 }
1022}
1023EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1024
1025static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1026{
1027 const struct iphdr *iph = (const struct iphdr *) skb->data;
1028 struct flowi4 fl4;
1029 struct rtable *rt;
1030
1031 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1032
1033 if (!fl4.flowi4_mark)
1034 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1035
1036 rt = __ip_route_output_key(sock_net(sk), &fl4);
1037 if (!IS_ERR(rt)) {
1038 __ip_rt_update_pmtu(rt, &fl4, mtu);
1039 ip_rt_put(rt);
1040 }
1041}
1042
1043void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1044{
1045 const struct iphdr *iph = (const struct iphdr *) skb->data;
1046 struct flowi4 fl4;
1047 struct rtable *rt;
1048 struct dst_entry *odst = NULL;
1049 bool new = false;
1050
1051 bh_lock_sock(sk);
1052
1053 if (!ip_sk_accept_pmtu(sk))
1054 goto out;
1055
1056 odst = sk_dst_get(sk);
1057
1058 if (sock_owned_by_user(sk) || !odst) {
1059 __ipv4_sk_update_pmtu(skb, sk, mtu);
1060 goto out;
1061 }
1062
1063 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1064
1065 rt = (struct rtable *)odst;
1066 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1067 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1068 if (IS_ERR(rt))
1069 goto out;
1070
1071 new = true;
1072 }
1073
1074 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1075
1076 if (!dst_check(&rt->dst, 0)) {
1077 if (new)
1078 dst_release(&rt->dst);
1079
1080 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1081 if (IS_ERR(rt))
1082 goto out;
1083
1084 new = true;
1085 }
1086
1087 if (new)
1088 sk_dst_set(sk, &rt->dst);
1089
1090out:
1091 bh_unlock_sock(sk);
1092 dst_release(odst);
1093}
1094EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1095
1096void ipv4_redirect(struct sk_buff *skb, struct net *net,
1097 int oif, u32 mark, u8 protocol, int flow_flags)
1098{
1099 const struct iphdr *iph = (const struct iphdr *) skb->data;
1100 struct flowi4 fl4;
1101 struct rtable *rt;
1102
1103 __build_flow_key(&fl4, NULL, iph, oif,
1104 RT_TOS(iph->tos), protocol, mark, flow_flags);
1105 rt = __ip_route_output_key(net, &fl4);
1106 if (!IS_ERR(rt)) {
1107 __ip_do_redirect(rt, skb, &fl4, false);
1108 ip_rt_put(rt);
1109 }
1110}
1111EXPORT_SYMBOL_GPL(ipv4_redirect);
1112
1113void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1114{
1115 const struct iphdr *iph = (const struct iphdr *) skb->data;
1116 struct flowi4 fl4;
1117 struct rtable *rt;
1118
1119 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1120 rt = __ip_route_output_key(sock_net(sk), &fl4);
1121 if (!IS_ERR(rt)) {
1122 __ip_do_redirect(rt, skb, &fl4, false);
1123 ip_rt_put(rt);
1124 }
1125}
1126EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1127
1128static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1129{
1130 struct rtable *rt = (struct rtable *) dst;
1131
1132 /* All IPV4 dsts are created with ->obsolete set to the value
1133 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1134 * into this function always.
1135 *
1136 * When a PMTU/redirect information update invalidates a route,
1137 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1138 * DST_OBSOLETE_DEAD by dst_free().
1139 */
1140 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1141 return NULL;
1142 return dst;
1143}
1144
1145static void ipv4_link_failure(struct sk_buff *skb)
1146{
1147 struct rtable *rt;
1148
1149 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1150
1151 rt = skb_rtable(skb);
1152 if (rt)
1153 dst_set_expires(&rt->dst, 0);
1154}
1155
1156static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1157{
1158 pr_debug("%s: %pI4 -> %pI4, %s\n",
1159 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1160 skb->dev ? skb->dev->name : "?");
1161 kfree_skb(skb);
1162 WARN_ON(1);
1163 return 0;
1164}
1165
1166/*
1167 We do not cache source address of outgoing interface,
1168 because it is used only by IP RR, TS and SRR options,
1169 so that it out of fast path.
1170
1171 BTW remember: "addr" is allowed to be not aligned
1172 in IP options!
1173 */
1174
1175void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1176{
1177 __be32 src;
1178
1179 if (rt_is_output_route(rt))
1180 src = ip_hdr(skb)->saddr;
1181 else {
1182 struct fib_result res;
1183 struct flowi4 fl4;
1184 struct iphdr *iph;
1185
1186 iph = ip_hdr(skb);
1187
1188 memset(&fl4, 0, sizeof(fl4));
1189 fl4.daddr = iph->daddr;
1190 fl4.saddr = iph->saddr;
1191 fl4.flowi4_tos = RT_TOS(iph->tos);
1192 fl4.flowi4_oif = rt->dst.dev->ifindex;
1193 fl4.flowi4_iif = skb->dev->ifindex;
1194 fl4.flowi4_mark = skb->mark;
1195
1196 rcu_read_lock();
1197 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1198 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1199 else
1200 src = inet_select_addr(rt->dst.dev,
1201 rt_nexthop(rt, iph->daddr),
1202 RT_SCOPE_UNIVERSE);
1203 rcu_read_unlock();
1204 }
1205 memcpy(addr, &src, 4);
1206}
1207
1208#ifdef CONFIG_IP_ROUTE_CLASSID
1209static void set_class_tag(struct rtable *rt, u32 tag)
1210{
1211 if (!(rt->dst.tclassid & 0xFFFF))
1212 rt->dst.tclassid |= tag & 0xFFFF;
1213 if (!(rt->dst.tclassid & 0xFFFF0000))
1214 rt->dst.tclassid |= tag & 0xFFFF0000;
1215}
1216#endif
1217
1218static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1219{
1220 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1221
1222 if (advmss == 0) {
1223 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1224 ip_rt_min_advmss);
1225 if (advmss > 65535 - 40)
1226 advmss = 65535 - 40;
1227 }
1228 return advmss;
1229}
1230
1231static unsigned int ipv4_mtu(const struct dst_entry *dst)
1232{
1233 const struct rtable *rt = (const struct rtable *) dst;
1234 unsigned int mtu = rt->rt_pmtu;
1235
1236 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1237 mtu = dst_metric_raw(dst, RTAX_MTU);
1238
1239 if (mtu)
1240 return mtu;
1241
1242 mtu = dst->dev->mtu;
1243
1244 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1245 if (rt->rt_uses_gateway && mtu > 576)
1246 mtu = 576;
1247 }
1248
1249 return min_t(unsigned int, mtu, IP_MAX_MTU);
1250}
1251
1252static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1253{
1254 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1255 struct fib_nh_exception *fnhe;
1256 u32 hval;
1257
1258 if (!hash)
1259 return NULL;
1260
1261 hval = fnhe_hashfun(daddr);
1262
1263 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1264 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1265 if (fnhe->fnhe_daddr == daddr)
1266 return fnhe;
1267 }
1268 return NULL;
1269}
1270
1271static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1272 __be32 daddr)
1273{
1274 bool ret = false;
1275
1276 spin_lock_bh(&fnhe_lock);
1277
1278 if (daddr == fnhe->fnhe_daddr) {
1279 struct rtable __rcu **porig;
1280 struct rtable *orig;
1281 int genid = fnhe_genid(dev_net(rt->dst.dev));
1282
1283 if (rt_is_input_route(rt))
1284 porig = &fnhe->fnhe_rth_input;
1285 else
1286 porig = &fnhe->fnhe_rth_output;
1287 orig = rcu_dereference(*porig);
1288
1289 if (fnhe->fnhe_genid != genid) {
1290 fnhe->fnhe_genid = genid;
1291 fnhe->fnhe_gw = 0;
1292 fnhe->fnhe_pmtu = 0;
1293 fnhe->fnhe_expires = 0;
1294 fnhe_flush_routes(fnhe);
1295 orig = NULL;
1296 }
1297 fill_route_from_fnhe(rt, fnhe);
1298 if (!rt->rt_gateway)
1299 rt->rt_gateway = daddr;
1300
1301 if (!(rt->dst.flags & DST_NOCACHE)) {
1302 rcu_assign_pointer(*porig, rt);
1303 if (orig)
1304 rt_free(orig);
1305 ret = true;
1306 }
1307
1308 fnhe->fnhe_stamp = jiffies;
1309 }
1310 spin_unlock_bh(&fnhe_lock);
1311
1312 return ret;
1313}
1314
1315static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1316{
1317 struct rtable *orig, *prev, **p;
1318 bool ret = true;
1319
1320 if (rt_is_input_route(rt)) {
1321 p = (struct rtable **)&nh->nh_rth_input;
1322 } else {
1323 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1324 }
1325 orig = *p;
1326
1327 prev = cmpxchg(p, orig, rt);
1328 if (prev == orig) {
1329 if (orig)
1330 rt_free(orig);
1331 } else
1332 ret = false;
1333
1334 return ret;
1335}
1336
1337struct uncached_list {
1338 spinlock_t lock;
1339 struct list_head head;
1340};
1341
1342static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1343
1344static void rt_add_uncached_list(struct rtable *rt)
1345{
1346 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1347
1348 rt->rt_uncached_list = ul;
1349
1350 spin_lock_bh(&ul->lock);
1351 list_add_tail(&rt->rt_uncached, &ul->head);
1352 spin_unlock_bh(&ul->lock);
1353}
1354
1355static void ipv4_dst_destroy(struct dst_entry *dst)
1356{
1357 struct rtable *rt = (struct rtable *) dst;
1358
1359 if (!list_empty(&rt->rt_uncached)) {
1360 struct uncached_list *ul = rt->rt_uncached_list;
1361
1362 spin_lock_bh(&ul->lock);
1363 list_del(&rt->rt_uncached);
1364 spin_unlock_bh(&ul->lock);
1365 }
1366}
1367
1368void rt_flush_dev(struct net_device *dev)
1369{
1370 struct net *net = dev_net(dev);
1371 struct rtable *rt;
1372 int cpu;
1373
1374 for_each_possible_cpu(cpu) {
1375 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1376
1377 spin_lock_bh(&ul->lock);
1378 list_for_each_entry(rt, &ul->head, rt_uncached) {
1379 if (rt->dst.dev != dev)
1380 continue;
1381 rt->dst.dev = net->loopback_dev;
1382 dev_hold(rt->dst.dev);
1383 dev_put(dev);
1384 }
1385 spin_unlock_bh(&ul->lock);
1386 }
1387}
1388
1389static bool rt_cache_valid(const struct rtable *rt)
1390{
1391 return rt &&
1392 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1393 !rt_is_expired(rt);
1394}
1395
1396static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1397 const struct fib_result *res,
1398 struct fib_nh_exception *fnhe,
1399 struct fib_info *fi, u16 type, u32 itag)
1400{
1401 bool cached = false;
1402
1403 if (fi) {
1404 struct fib_nh *nh = &FIB_RES_NH(*res);
1405
1406 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1407 rt->rt_gateway = nh->nh_gw;
1408 rt->rt_uses_gateway = 1;
1409 }
1410 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1411#ifdef CONFIG_IP_ROUTE_CLASSID
1412 rt->dst.tclassid = nh->nh_tclassid;
1413#endif
1414 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1415 if (unlikely(fnhe))
1416 cached = rt_bind_exception(rt, fnhe, daddr);
1417 else if (!(rt->dst.flags & DST_NOCACHE))
1418 cached = rt_cache_route(nh, rt);
1419 if (unlikely(!cached)) {
1420 /* Routes we intend to cache in nexthop exception or
1421 * FIB nexthop have the DST_NOCACHE bit clear.
1422 * However, if we are unsuccessful at storing this
1423 * route into the cache we really need to set it.
1424 */
1425 rt->dst.flags |= DST_NOCACHE;
1426 if (!rt->rt_gateway)
1427 rt->rt_gateway = daddr;
1428 rt_add_uncached_list(rt);
1429 }
1430 } else
1431 rt_add_uncached_list(rt);
1432
1433#ifdef CONFIG_IP_ROUTE_CLASSID
1434#ifdef CONFIG_IP_MULTIPLE_TABLES
1435 set_class_tag(rt, res->tclassid);
1436#endif
1437 set_class_tag(rt, itag);
1438#endif
1439}
1440
1441struct rtable *rt_dst_alloc(struct net_device *dev,
1442 unsigned int flags, u16 type,
1443 bool nopolicy, bool noxfrm, bool will_cache)
1444{
1445 struct rtable *rt;
1446
1447 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1448 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1449 (nopolicy ? DST_NOPOLICY : 0) |
1450 (noxfrm ? DST_NOXFRM : 0));
1451
1452 if (rt) {
1453 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1454 rt->rt_flags = flags;
1455 rt->rt_type = type;
1456 rt->rt_is_input = 0;
1457 rt->rt_iif = 0;
1458 rt->rt_pmtu = 0;
1459 rt->rt_gateway = 0;
1460 rt->rt_uses_gateway = 0;
1461 rt->rt_table_id = 0;
1462 INIT_LIST_HEAD(&rt->rt_uncached);
1463
1464 rt->dst.output = ip_output;
1465 if (flags & RTCF_LOCAL)
1466 rt->dst.input = ip_local_deliver;
1467 }
1468
1469 return rt;
1470}
1471EXPORT_SYMBOL(rt_dst_alloc);
1472
1473/* called in rcu_read_lock() section */
1474static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1475 u8 tos, struct net_device *dev, int our)
1476{
1477 struct rtable *rth;
1478 struct in_device *in_dev = __in_dev_get_rcu(dev);
1479 unsigned int flags = RTCF_MULTICAST;
1480 u32 itag = 0;
1481 int err;
1482
1483 /* Primary sanity checks. */
1484
1485 if (!in_dev)
1486 return -EINVAL;
1487
1488 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1489 skb->protocol != htons(ETH_P_IP))
1490 goto e_inval;
1491
1492 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1493 goto e_inval;
1494
1495 if (ipv4_is_zeronet(saddr)) {
1496 if (!ipv4_is_local_multicast(daddr))
1497 goto e_inval;
1498 } else {
1499 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1500 in_dev, &itag);
1501 if (err < 0)
1502 goto e_err;
1503 }
1504 if (our)
1505 flags |= RTCF_LOCAL;
1506
1507 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1508 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1509 if (!rth)
1510 goto e_nobufs;
1511
1512#ifdef CONFIG_IP_ROUTE_CLASSID
1513 rth->dst.tclassid = itag;
1514#endif
1515 rth->dst.output = ip_rt_bug;
1516 rth->rt_is_input= 1;
1517
1518#ifdef CONFIG_IP_MROUTE
1519 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1520 rth->dst.input = ip_mr_input;
1521#endif
1522 RT_CACHE_STAT_INC(in_slow_mc);
1523
1524 skb_dst_set(skb, &rth->dst);
1525 return 0;
1526
1527e_nobufs:
1528 return -ENOBUFS;
1529e_inval:
1530 return -EINVAL;
1531e_err:
1532 return err;
1533}
1534
1535
1536static void ip_handle_martian_source(struct net_device *dev,
1537 struct in_device *in_dev,
1538 struct sk_buff *skb,
1539 __be32 daddr,
1540 __be32 saddr)
1541{
1542 RT_CACHE_STAT_INC(in_martian_src);
1543#ifdef CONFIG_IP_ROUTE_VERBOSE
1544 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1545 /*
1546 * RFC1812 recommendation, if source is martian,
1547 * the only hint is MAC header.
1548 */
1549 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1550 &daddr, &saddr, dev->name);
1551 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1552 print_hex_dump(KERN_WARNING, "ll header: ",
1553 DUMP_PREFIX_OFFSET, 16, 1,
1554 skb_mac_header(skb),
1555 dev->hard_header_len, true);
1556 }
1557 }
1558#endif
1559}
1560
1561static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1562{
1563 struct fnhe_hash_bucket *hash;
1564 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1565 u32 hval = fnhe_hashfun(daddr);
1566
1567 spin_lock_bh(&fnhe_lock);
1568
1569 hash = rcu_dereference_protected(nh->nh_exceptions,
1570 lockdep_is_held(&fnhe_lock));
1571 hash += hval;
1572
1573 fnhe_p = &hash->chain;
1574 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1575 while (fnhe) {
1576 if (fnhe->fnhe_daddr == daddr) {
1577 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1578 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1579 fnhe_flush_routes(fnhe);
1580 kfree_rcu(fnhe, rcu);
1581 break;
1582 }
1583 fnhe_p = &fnhe->fnhe_next;
1584 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1585 lockdep_is_held(&fnhe_lock));
1586 }
1587
1588 spin_unlock_bh(&fnhe_lock);
1589}
1590
1591/* called in rcu_read_lock() section */
1592static int __mkroute_input(struct sk_buff *skb,
1593 const struct fib_result *res,
1594 struct in_device *in_dev,
1595 __be32 daddr, __be32 saddr, u32 tos)
1596{
1597 struct fib_nh_exception *fnhe;
1598 struct rtable *rth;
1599 int err;
1600 struct in_device *out_dev;
1601 bool do_cache;
1602 u32 itag = 0;
1603
1604 /* get a working reference to the output device */
1605 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1606 if (!out_dev) {
1607 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1608 return -EINVAL;
1609 }
1610
1611 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1612 in_dev->dev, in_dev, &itag);
1613 if (err < 0) {
1614 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1615 saddr);
1616
1617 goto cleanup;
1618 }
1619
1620 do_cache = res->fi && !itag;
1621 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1622 skb->protocol == htons(ETH_P_IP) &&
1623 (IN_DEV_SHARED_MEDIA(out_dev) ||
1624 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1625 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1626
1627 if (skb->protocol != htons(ETH_P_IP)) {
1628 /* Not IP (i.e. ARP). Do not create route, if it is
1629 * invalid for proxy arp. DNAT routes are always valid.
1630 *
1631 * Proxy arp feature have been extended to allow, ARP
1632 * replies back to the same interface, to support
1633 * Private VLAN switch technologies. See arp.c.
1634 */
1635 if (out_dev == in_dev &&
1636 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1637 err = -EINVAL;
1638 goto cleanup;
1639 }
1640 }
1641
1642 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1643 if (do_cache) {
1644 if (fnhe) {
1645 rth = rcu_dereference(fnhe->fnhe_rth_input);
1646 if (rth && rth->dst.expires &&
1647 time_after(jiffies, rth->dst.expires)) {
1648 ip_del_fnhe(&FIB_RES_NH(*res), daddr);
1649 fnhe = NULL;
1650 } else {
1651 goto rt_cache;
1652 }
1653 }
1654
1655 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1656
1657rt_cache:
1658 if (rt_cache_valid(rth)) {
1659 skb_dst_set_noref(skb, &rth->dst);
1660 goto out;
1661 }
1662 }
1663
1664 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1665 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1666 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1667 if (!rth) {
1668 err = -ENOBUFS;
1669 goto cleanup;
1670 }
1671
1672 rth->rt_is_input = 1;
1673 if (res->table)
1674 rth->rt_table_id = res->table->tb_id;
1675 RT_CACHE_STAT_INC(in_slow_tot);
1676
1677 rth->dst.input = ip_forward;
1678
1679 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1680 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1681 rth->dst.lwtstate->orig_output = rth->dst.output;
1682 rth->dst.output = lwtunnel_output;
1683 }
1684 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1685 rth->dst.lwtstate->orig_input = rth->dst.input;
1686 rth->dst.input = lwtunnel_input;
1687 }
1688 skb_dst_set(skb, &rth->dst);
1689out:
1690 err = 0;
1691 cleanup:
1692 return err;
1693}
1694
1695#ifdef CONFIG_IP_ROUTE_MULTIPATH
1696
1697/* To make ICMP packets follow the right flow, the multipath hash is
1698 * calculated from the inner IP addresses in reverse order.
1699 */
1700static int ip_multipath_icmp_hash(struct sk_buff *skb)
1701{
1702 const struct iphdr *outer_iph = ip_hdr(skb);
1703 struct icmphdr _icmph;
1704 const struct icmphdr *icmph;
1705 struct iphdr _inner_iph;
1706 const struct iphdr *inner_iph;
1707
1708 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1709 goto standard_hash;
1710
1711 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1712 &_icmph);
1713 if (!icmph)
1714 goto standard_hash;
1715
1716 if (icmph->type != ICMP_DEST_UNREACH &&
1717 icmph->type != ICMP_REDIRECT &&
1718 icmph->type != ICMP_TIME_EXCEEDED &&
1719 icmph->type != ICMP_PARAMETERPROB) {
1720 goto standard_hash;
1721 }
1722
1723 inner_iph = skb_header_pointer(skb,
1724 outer_iph->ihl * 4 + sizeof(_icmph),
1725 sizeof(_inner_iph), &_inner_iph);
1726 if (!inner_iph)
1727 goto standard_hash;
1728
1729 return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
1730
1731standard_hash:
1732 return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
1733}
1734
1735#endif /* CONFIG_IP_ROUTE_MULTIPATH */
1736
1737static int ip_mkroute_input(struct sk_buff *skb,
1738 struct fib_result *res,
1739 const struct flowi4 *fl4,
1740 struct in_device *in_dev,
1741 __be32 daddr, __be32 saddr, u32 tos)
1742{
1743#ifdef CONFIG_IP_ROUTE_MULTIPATH
1744 if (res->fi && res->fi->fib_nhs > 1) {
1745 int h;
1746
1747 if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
1748 h = ip_multipath_icmp_hash(skb);
1749 else
1750 h = fib_multipath_hash(saddr, daddr);
1751 fib_select_multipath(res, h);
1752 }
1753#endif
1754
1755 /* create a routing cache entry */
1756 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1757}
1758
1759/*
1760 * NOTE. We drop all the packets that has local source
1761 * addresses, because every properly looped back packet
1762 * must have correct destination already attached by output routine.
1763 *
1764 * Such approach solves two big problems:
1765 * 1. Not simplex devices are handled properly.
1766 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1767 * called with rcu_read_lock()
1768 */
1769
1770static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1771 u8 tos, struct net_device *dev)
1772{
1773 struct fib_result res;
1774 struct in_device *in_dev = __in_dev_get_rcu(dev);
1775 struct ip_tunnel_info *tun_info;
1776 struct flowi4 fl4;
1777 unsigned int flags = 0;
1778 u32 itag = 0;
1779 struct rtable *rth;
1780 int err = -EINVAL;
1781 struct net *net = dev_net(dev);
1782 bool do_cache;
1783
1784 /* IP on this device is disabled. */
1785
1786 if (!in_dev)
1787 goto out;
1788
1789 /* Check for the most weird martians, which can be not detected
1790 by fib_lookup.
1791 */
1792
1793 tun_info = skb_tunnel_info(skb);
1794 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1795 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1796 else
1797 fl4.flowi4_tun_key.tun_id = 0;
1798 skb_dst_drop(skb);
1799
1800 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1801 goto martian_source;
1802
1803 res.fi = NULL;
1804 res.table = NULL;
1805 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1806 goto brd_input;
1807
1808 /* Accept zero addresses only to limited broadcast;
1809 * I even do not know to fix it or not. Waiting for complains :-)
1810 */
1811 if (ipv4_is_zeronet(saddr))
1812 goto martian_source;
1813
1814 if (ipv4_is_zeronet(daddr))
1815 goto martian_destination;
1816
1817 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1818 * and call it once if daddr or/and saddr are loopback addresses
1819 */
1820 if (ipv4_is_loopback(daddr)) {
1821 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1822 goto martian_destination;
1823 } else if (ipv4_is_loopback(saddr)) {
1824 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1825 goto martian_source;
1826 }
1827
1828 /*
1829 * Now we are ready to route packet.
1830 */
1831 fl4.flowi4_oif = 0;
1832 fl4.flowi4_iif = l3mdev_fib_oif_rcu(dev);
1833 fl4.flowi4_mark = skb->mark;
1834 fl4.flowi4_tos = tos;
1835 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1836 fl4.flowi4_flags = 0;
1837 fl4.daddr = daddr;
1838 fl4.saddr = saddr;
1839 err = fib_lookup(net, &fl4, &res, 0);
1840 if (err != 0) {
1841 if (!IN_DEV_FORWARD(in_dev))
1842 err = -EHOSTUNREACH;
1843 goto no_route;
1844 }
1845
1846 if (res.type == RTN_BROADCAST)
1847 goto brd_input;
1848
1849 if (res.type == RTN_LOCAL) {
1850 err = fib_validate_source(skb, saddr, daddr, tos,
1851 0, dev, in_dev, &itag);
1852 if (err < 0)
1853 goto martian_source;
1854 goto local_input;
1855 }
1856
1857 if (!IN_DEV_FORWARD(in_dev)) {
1858 err = -EHOSTUNREACH;
1859 goto no_route;
1860 }
1861 if (res.type != RTN_UNICAST)
1862 goto martian_destination;
1863
1864 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1865out: return err;
1866
1867brd_input:
1868 if (skb->protocol != htons(ETH_P_IP))
1869 goto e_inval;
1870
1871 if (!ipv4_is_zeronet(saddr)) {
1872 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1873 in_dev, &itag);
1874 if (err < 0)
1875 goto martian_source;
1876 }
1877 flags |= RTCF_BROADCAST;
1878 res.type = RTN_BROADCAST;
1879 RT_CACHE_STAT_INC(in_brd);
1880
1881local_input:
1882 do_cache = false;
1883 if (res.fi) {
1884 if (!itag) {
1885 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1886 if (rt_cache_valid(rth)) {
1887 skb_dst_set_noref(skb, &rth->dst);
1888 err = 0;
1889 goto out;
1890 }
1891 do_cache = true;
1892 }
1893 }
1894
1895 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1896 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1897 if (!rth)
1898 goto e_nobufs;
1899
1900 rth->dst.output= ip_rt_bug;
1901#ifdef CONFIG_IP_ROUTE_CLASSID
1902 rth->dst.tclassid = itag;
1903#endif
1904 rth->rt_is_input = 1;
1905 if (res.table)
1906 rth->rt_table_id = res.table->tb_id;
1907
1908 RT_CACHE_STAT_INC(in_slow_tot);
1909 if (res.type == RTN_UNREACHABLE) {
1910 rth->dst.input= ip_error;
1911 rth->dst.error= -err;
1912 rth->rt_flags &= ~RTCF_LOCAL;
1913 }
1914 if (do_cache) {
1915 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1916 rth->dst.flags |= DST_NOCACHE;
1917 rt_add_uncached_list(rth);
1918 }
1919 }
1920 skb_dst_set(skb, &rth->dst);
1921 err = 0;
1922 goto out;
1923
1924no_route:
1925 RT_CACHE_STAT_INC(in_no_route);
1926 res.type = RTN_UNREACHABLE;
1927 res.fi = NULL;
1928 res.table = NULL;
1929 goto local_input;
1930
1931 /*
1932 * Do not cache martian addresses: they should be logged (RFC1812)
1933 */
1934martian_destination:
1935 RT_CACHE_STAT_INC(in_martian_dst);
1936#ifdef CONFIG_IP_ROUTE_VERBOSE
1937 if (IN_DEV_LOG_MARTIANS(in_dev))
1938 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1939 &daddr, &saddr, dev->name);
1940#endif
1941
1942e_inval:
1943 err = -EINVAL;
1944 goto out;
1945
1946e_nobufs:
1947 err = -ENOBUFS;
1948 goto out;
1949
1950martian_source:
1951 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1952 goto out;
1953}
1954
1955int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1956 u8 tos, struct net_device *dev)
1957{
1958 int res;
1959
1960 rcu_read_lock();
1961
1962 /* Multicast recognition logic is moved from route cache to here.
1963 The problem was that too many Ethernet cards have broken/missing
1964 hardware multicast filters :-( As result the host on multicasting
1965 network acquires a lot of useless route cache entries, sort of
1966 SDR messages from all the world. Now we try to get rid of them.
1967 Really, provided software IP multicast filter is organized
1968 reasonably (at least, hashed), it does not result in a slowdown
1969 comparing with route cache reject entries.
1970 Note, that multicast routers are not affected, because
1971 route cache entry is created eventually.
1972 */
1973 if (ipv4_is_multicast(daddr)) {
1974 struct in_device *in_dev = __in_dev_get_rcu(dev);
1975
1976 if (in_dev) {
1977 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1978 ip_hdr(skb)->protocol);
1979 if (our
1980#ifdef CONFIG_IP_MROUTE
1981 ||
1982 (!ipv4_is_local_multicast(daddr) &&
1983 IN_DEV_MFORWARD(in_dev))
1984#endif
1985 ) {
1986 int res = ip_route_input_mc(skb, daddr, saddr,
1987 tos, dev, our);
1988 rcu_read_unlock();
1989 return res;
1990 }
1991 }
1992 rcu_read_unlock();
1993 return -EINVAL;
1994 }
1995 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1996 rcu_read_unlock();
1997 return res;
1998}
1999EXPORT_SYMBOL(ip_route_input_noref);
2000
2001/* called with rcu_read_lock() */
2002static struct rtable *__mkroute_output(const struct fib_result *res,
2003 const struct flowi4 *fl4, int orig_oif,
2004 struct net_device *dev_out,
2005 unsigned int flags)
2006{
2007 struct fib_info *fi = res->fi;
2008 struct fib_nh_exception *fnhe;
2009 struct in_device *in_dev;
2010 u16 type = res->type;
2011 struct rtable *rth;
2012 bool do_cache;
2013
2014 in_dev = __in_dev_get_rcu(dev_out);
2015 if (!in_dev)
2016 return ERR_PTR(-EINVAL);
2017
2018 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2019 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2020 return ERR_PTR(-EINVAL);
2021
2022 if (ipv4_is_lbcast(fl4->daddr))
2023 type = RTN_BROADCAST;
2024 else if (ipv4_is_multicast(fl4->daddr))
2025 type = RTN_MULTICAST;
2026 else if (ipv4_is_zeronet(fl4->daddr))
2027 return ERR_PTR(-EINVAL);
2028
2029 if (dev_out->flags & IFF_LOOPBACK)
2030 flags |= RTCF_LOCAL;
2031
2032 do_cache = true;
2033 if (type == RTN_BROADCAST) {
2034 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2035 fi = NULL;
2036 } else if (type == RTN_MULTICAST) {
2037 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2038 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2039 fl4->flowi4_proto))
2040 flags &= ~RTCF_LOCAL;
2041 else
2042 do_cache = false;
2043 /* If multicast route do not exist use
2044 * default one, but do not gateway in this case.
2045 * Yes, it is hack.
2046 */
2047 if (fi && res->prefixlen < 4)
2048 fi = NULL;
2049 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2050 (orig_oif != dev_out->ifindex)) {
2051 /* For local routes that require a particular output interface
2052 * we do not want to cache the result. Caching the result
2053 * causes incorrect behaviour when there are multiple source
2054 * addresses on the interface, the end result being that if the
2055 * intended recipient is waiting on that interface for the
2056 * packet he won't receive it because it will be delivered on
2057 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2058 * be set to the loopback interface as well.
2059 */
2060 fi = NULL;
2061 }
2062
2063 fnhe = NULL;
2064 do_cache &= fi != NULL;
2065 if (do_cache) {
2066 struct rtable __rcu **prth;
2067 struct fib_nh *nh = &FIB_RES_NH(*res);
2068
2069 fnhe = find_exception(nh, fl4->daddr);
2070 if (fnhe) {
2071 prth = &fnhe->fnhe_rth_output;
2072 rth = rcu_dereference(*prth);
2073 if (rth && rth->dst.expires &&
2074 time_after(jiffies, rth->dst.expires)) {
2075 ip_del_fnhe(nh, fl4->daddr);
2076 fnhe = NULL;
2077 } else {
2078 goto rt_cache;
2079 }
2080 }
2081
2082 if (unlikely(fl4->flowi4_flags &
2083 FLOWI_FLAG_KNOWN_NH &&
2084 !(nh->nh_gw &&
2085 nh->nh_scope == RT_SCOPE_LINK))) {
2086 do_cache = false;
2087 goto add;
2088 }
2089 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2090 rth = rcu_dereference(*prth);
2091
2092rt_cache:
2093 if (rt_cache_valid(rth)) {
2094 dst_hold(&rth->dst);
2095 return rth;
2096 }
2097 }
2098
2099add:
2100 rth = rt_dst_alloc(dev_out, flags, type,
2101 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2102 IN_DEV_CONF_GET(in_dev, NOXFRM),
2103 do_cache);
2104 if (!rth)
2105 return ERR_PTR(-ENOBUFS);
2106
2107 rth->rt_iif = orig_oif ? : 0;
2108 if (res->table)
2109 rth->rt_table_id = res->table->tb_id;
2110
2111 RT_CACHE_STAT_INC(out_slow_tot);
2112
2113 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2114 if (flags & RTCF_LOCAL &&
2115 !(dev_out->flags & IFF_LOOPBACK)) {
2116 rth->dst.output = ip_mc_output;
2117 RT_CACHE_STAT_INC(out_slow_mc);
2118 }
2119#ifdef CONFIG_IP_MROUTE
2120 if (type == RTN_MULTICAST) {
2121 if (IN_DEV_MFORWARD(in_dev) &&
2122 !ipv4_is_local_multicast(fl4->daddr)) {
2123 rth->dst.input = ip_mr_input;
2124 rth->dst.output = ip_mc_output;
2125 }
2126 }
2127#endif
2128 }
2129
2130 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2131 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2132 rth->dst.output = lwtunnel_output;
2133
2134 return rth;
2135}
2136
2137/*
2138 * Major route resolver routine.
2139 */
2140
2141struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2142 int mp_hash)
2143{
2144 struct net_device *dev_out = NULL;
2145 __u8 tos = RT_FL_TOS(fl4);
2146 unsigned int flags = 0;
2147 struct fib_result res;
2148 struct rtable *rth;
2149 int orig_oif;
2150 int err = -ENETUNREACH;
2151
2152 res.tclassid = 0;
2153 res.fi = NULL;
2154 res.table = NULL;
2155
2156 orig_oif = fl4->flowi4_oif;
2157
2158 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2159 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2160 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2161 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2162
2163 rcu_read_lock();
2164 if (fl4->saddr) {
2165 rth = ERR_PTR(-EINVAL);
2166 if (ipv4_is_multicast(fl4->saddr) ||
2167 ipv4_is_lbcast(fl4->saddr) ||
2168 ipv4_is_zeronet(fl4->saddr))
2169 goto out;
2170
2171 /* I removed check for oif == dev_out->oif here.
2172 It was wrong for two reasons:
2173 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2174 is assigned to multiple interfaces.
2175 2. Moreover, we are allowed to send packets with saddr
2176 of another iface. --ANK
2177 */
2178
2179 if (fl4->flowi4_oif == 0 &&
2180 (ipv4_is_multicast(fl4->daddr) ||
2181 ipv4_is_lbcast(fl4->daddr))) {
2182 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2183 dev_out = __ip_dev_find(net, fl4->saddr, false);
2184 if (!dev_out)
2185 goto out;
2186
2187 /* Special hack: user can direct multicasts
2188 and limited broadcast via necessary interface
2189 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2190 This hack is not just for fun, it allows
2191 vic,vat and friends to work.
2192 They bind socket to loopback, set ttl to zero
2193 and expect that it will work.
2194 From the viewpoint of routing cache they are broken,
2195 because we are not allowed to build multicast path
2196 with loopback source addr (look, routing cache
2197 cannot know, that ttl is zero, so that packet
2198 will not leave this host and route is valid).
2199 Luckily, this hack is good workaround.
2200 */
2201
2202 fl4->flowi4_oif = dev_out->ifindex;
2203 goto make_route;
2204 }
2205
2206 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2207 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2208 if (!__ip_dev_find(net, fl4->saddr, false))
2209 goto out;
2210 }
2211 }
2212
2213
2214 if (fl4->flowi4_oif) {
2215 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2216 rth = ERR_PTR(-ENODEV);
2217 if (!dev_out)
2218 goto out;
2219
2220 /* RACE: Check return value of inet_select_addr instead. */
2221 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2222 rth = ERR_PTR(-ENETUNREACH);
2223 goto out;
2224 }
2225 if (ipv4_is_local_multicast(fl4->daddr) ||
2226 ipv4_is_lbcast(fl4->daddr) ||
2227 fl4->flowi4_proto == IPPROTO_IGMP) {
2228 if (!fl4->saddr)
2229 fl4->saddr = inet_select_addr(dev_out, 0,
2230 RT_SCOPE_LINK);
2231 goto make_route;
2232 }
2233 if (!fl4->saddr) {
2234 if (ipv4_is_multicast(fl4->daddr))
2235 fl4->saddr = inet_select_addr(dev_out, 0,
2236 fl4->flowi4_scope);
2237 else if (!fl4->daddr)
2238 fl4->saddr = inet_select_addr(dev_out, 0,
2239 RT_SCOPE_HOST);
2240 }
2241
2242 rth = l3mdev_get_rtable(dev_out, fl4);
2243 if (rth)
2244 goto out;
2245 }
2246
2247 if (!fl4->daddr) {
2248 fl4->daddr = fl4->saddr;
2249 if (!fl4->daddr)
2250 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2251 dev_out = net->loopback_dev;
2252 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2253 res.type = RTN_LOCAL;
2254 flags |= RTCF_LOCAL;
2255 goto make_route;
2256 }
2257
2258 err = fib_lookup(net, fl4, &res, 0);
2259 if (err) {
2260 res.fi = NULL;
2261 res.table = NULL;
2262 if (fl4->flowi4_oif &&
2263 !netif_index_is_l3_master(net, fl4->flowi4_oif)) {
2264 /* Apparently, routing tables are wrong. Assume,
2265 that the destination is on link.
2266
2267 WHY? DW.
2268 Because we are allowed to send to iface
2269 even if it has NO routes and NO assigned
2270 addresses. When oif is specified, routing
2271 tables are looked up with only one purpose:
2272 to catch if destination is gatewayed, rather than
2273 direct. Moreover, if MSG_DONTROUTE is set,
2274 we send packet, ignoring both routing tables
2275 and ifaddr state. --ANK
2276
2277
2278 We could make it even if oif is unknown,
2279 likely IPv6, but we do not.
2280 */
2281
2282 if (fl4->saddr == 0)
2283 fl4->saddr = inet_select_addr(dev_out, 0,
2284 RT_SCOPE_LINK);
2285 res.type = RTN_UNICAST;
2286 goto make_route;
2287 }
2288 rth = ERR_PTR(err);
2289 goto out;
2290 }
2291
2292 if (res.type == RTN_LOCAL) {
2293 if (!fl4->saddr) {
2294 if (res.fi->fib_prefsrc)
2295 fl4->saddr = res.fi->fib_prefsrc;
2296 else
2297 fl4->saddr = fl4->daddr;
2298 }
2299 dev_out = net->loopback_dev;
2300 fl4->flowi4_oif = dev_out->ifindex;
2301 flags |= RTCF_LOCAL;
2302 goto make_route;
2303 }
2304
2305 fib_select_path(net, &res, fl4, mp_hash);
2306
2307 dev_out = FIB_RES_DEV(res);
2308 fl4->flowi4_oif = dev_out->ifindex;
2309
2310
2311make_route:
2312 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2313
2314out:
2315 rcu_read_unlock();
2316 return rth;
2317}
2318EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
2319
2320static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2321{
2322 return NULL;
2323}
2324
2325static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2326{
2327 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2328
2329 return mtu ? : dst->dev->mtu;
2330}
2331
2332static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2333 struct sk_buff *skb, u32 mtu)
2334{
2335}
2336
2337static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2338 struct sk_buff *skb)
2339{
2340}
2341
2342static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2343 unsigned long old)
2344{
2345 return NULL;
2346}
2347
2348static struct dst_ops ipv4_dst_blackhole_ops = {
2349 .family = AF_INET,
2350 .check = ipv4_blackhole_dst_check,
2351 .mtu = ipv4_blackhole_mtu,
2352 .default_advmss = ipv4_default_advmss,
2353 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2354 .redirect = ipv4_rt_blackhole_redirect,
2355 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2356 .neigh_lookup = ipv4_neigh_lookup,
2357};
2358
2359struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2360{
2361 struct rtable *ort = (struct rtable *) dst_orig;
2362 struct rtable *rt;
2363
2364 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2365 if (rt) {
2366 struct dst_entry *new = &rt->dst;
2367
2368 new->__use = 1;
2369 new->input = dst_discard;
2370 new->output = dst_discard_out;
2371
2372 new->dev = ort->dst.dev;
2373 if (new->dev)
2374 dev_hold(new->dev);
2375
2376 rt->rt_is_input = ort->rt_is_input;
2377 rt->rt_iif = ort->rt_iif;
2378 rt->rt_pmtu = ort->rt_pmtu;
2379
2380 rt->rt_genid = rt_genid_ipv4(net);
2381 rt->rt_flags = ort->rt_flags;
2382 rt->rt_type = ort->rt_type;
2383 rt->rt_gateway = ort->rt_gateway;
2384 rt->rt_uses_gateway = ort->rt_uses_gateway;
2385
2386 INIT_LIST_HEAD(&rt->rt_uncached);
2387 dst_free(new);
2388 }
2389
2390 dst_release(dst_orig);
2391
2392 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2393}
2394
2395struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2396 const struct sock *sk)
2397{
2398 struct rtable *rt = __ip_route_output_key(net, flp4);
2399
2400 if (IS_ERR(rt))
2401 return rt;
2402
2403 if (flp4->flowi4_proto)
2404 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2405 flowi4_to_flowi(flp4),
2406 sk, 0);
2407
2408 return rt;
2409}
2410EXPORT_SYMBOL_GPL(ip_route_output_flow);
2411
2412static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2413 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2414 u32 seq, int event, int nowait, unsigned int flags)
2415{
2416 struct rtable *rt = skb_rtable(skb);
2417 struct rtmsg *r;
2418 struct nlmsghdr *nlh;
2419 unsigned long expires = 0;
2420 u32 error;
2421 u32 metrics[RTAX_MAX];
2422
2423 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2424 if (!nlh)
2425 return -EMSGSIZE;
2426
2427 r = nlmsg_data(nlh);
2428 r->rtm_family = AF_INET;
2429 r->rtm_dst_len = 32;
2430 r->rtm_src_len = 0;
2431 r->rtm_tos = fl4->flowi4_tos;
2432 r->rtm_table = table_id;
2433 if (nla_put_u32(skb, RTA_TABLE, table_id))
2434 goto nla_put_failure;
2435 r->rtm_type = rt->rt_type;
2436 r->rtm_scope = RT_SCOPE_UNIVERSE;
2437 r->rtm_protocol = RTPROT_UNSPEC;
2438 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2439 if (rt->rt_flags & RTCF_NOTIFY)
2440 r->rtm_flags |= RTM_F_NOTIFY;
2441 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2442 r->rtm_flags |= RTCF_DOREDIRECT;
2443
2444 if (nla_put_in_addr(skb, RTA_DST, dst))
2445 goto nla_put_failure;
2446 if (src) {
2447 r->rtm_src_len = 32;
2448 if (nla_put_in_addr(skb, RTA_SRC, src))
2449 goto nla_put_failure;
2450 }
2451 if (rt->dst.dev &&
2452 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2453 goto nla_put_failure;
2454#ifdef CONFIG_IP_ROUTE_CLASSID
2455 if (rt->dst.tclassid &&
2456 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2457 goto nla_put_failure;
2458#endif
2459 if (!rt_is_input_route(rt) &&
2460 fl4->saddr != src) {
2461 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2462 goto nla_put_failure;
2463 }
2464 if (rt->rt_uses_gateway &&
2465 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2466 goto nla_put_failure;
2467
2468 expires = rt->dst.expires;
2469 if (expires) {
2470 unsigned long now = jiffies;
2471
2472 if (time_before(now, expires))
2473 expires -= now;
2474 else
2475 expires = 0;
2476 }
2477
2478 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2479 if (rt->rt_pmtu && expires)
2480 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2481 if (rtnetlink_put_metrics(skb, metrics) < 0)
2482 goto nla_put_failure;
2483
2484 if (fl4->flowi4_mark &&
2485 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2486 goto nla_put_failure;
2487
2488 error = rt->dst.error;
2489
2490 if (rt_is_input_route(rt)) {
2491#ifdef CONFIG_IP_MROUTE
2492 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2493 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2494 int err = ipmr_get_route(net, skb,
2495 fl4->saddr, fl4->daddr,
2496 r, nowait);
2497 if (err <= 0) {
2498 if (!nowait) {
2499 if (err == 0)
2500 return 0;
2501 goto nla_put_failure;
2502 } else {
2503 if (err == -EMSGSIZE)
2504 goto nla_put_failure;
2505 error = err;
2506 }
2507 }
2508 } else
2509#endif
2510 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2511 goto nla_put_failure;
2512 }
2513
2514 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2515 goto nla_put_failure;
2516
2517 nlmsg_end(skb, nlh);
2518 return 0;
2519
2520nla_put_failure:
2521 nlmsg_cancel(skb, nlh);
2522 return -EMSGSIZE;
2523}
2524
2525static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2526{
2527 struct net *net = sock_net(in_skb->sk);
2528 struct rtmsg *rtm;
2529 struct nlattr *tb[RTA_MAX+1];
2530 struct rtable *rt = NULL;
2531 struct flowi4 fl4;
2532 __be32 dst = 0;
2533 __be32 src = 0;
2534 u32 iif;
2535 int err;
2536 int mark;
2537 struct sk_buff *skb;
2538 u32 table_id = RT_TABLE_MAIN;
2539
2540 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2541 if (err < 0)
2542 goto errout;
2543
2544 rtm = nlmsg_data(nlh);
2545
2546 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2547 if (!skb) {
2548 err = -ENOBUFS;
2549 goto errout;
2550 }
2551
2552 /* Reserve room for dummy headers, this skb can pass
2553 through good chunk of routing engine.
2554 */
2555 skb_reset_mac_header(skb);
2556 skb_reset_network_header(skb);
2557
2558 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2559 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2560 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2561
2562 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2563 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2564 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2565 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2566
2567 memset(&fl4, 0, sizeof(fl4));
2568 fl4.daddr = dst;
2569 fl4.saddr = src;
2570 fl4.flowi4_tos = rtm->rtm_tos;
2571 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2572 fl4.flowi4_mark = mark;
2573
2574 if (netif_index_is_l3_master(net, fl4.flowi4_oif))
2575 fl4.flowi4_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF;
2576
2577 if (iif) {
2578 struct net_device *dev;
2579
2580 dev = __dev_get_by_index(net, iif);
2581 if (!dev) {
2582 err = -ENODEV;
2583 goto errout_free;
2584 }
2585
2586 skb->protocol = htons(ETH_P_IP);
2587 skb->dev = dev;
2588 skb->mark = mark;
2589 local_bh_disable();
2590 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2591 local_bh_enable();
2592
2593 rt = skb_rtable(skb);
2594 if (err == 0 && rt->dst.error)
2595 err = -rt->dst.error;
2596 } else {
2597 rt = ip_route_output_key(net, &fl4);
2598
2599 err = 0;
2600 if (IS_ERR(rt))
2601 err = PTR_ERR(rt);
2602 }
2603
2604 if (err)
2605 goto errout_free;
2606
2607 skb_dst_set(skb, &rt->dst);
2608 if (rtm->rtm_flags & RTM_F_NOTIFY)
2609 rt->rt_flags |= RTCF_NOTIFY;
2610
2611 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2612 table_id = rt->rt_table_id;
2613
2614 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2615 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2616 RTM_NEWROUTE, 0, 0);
2617 if (err < 0)
2618 goto errout_free;
2619
2620 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2621errout:
2622 return err;
2623
2624errout_free:
2625 kfree_skb(skb);
2626 goto errout;
2627}
2628
2629void ip_rt_multicast_event(struct in_device *in_dev)
2630{
2631 rt_cache_flush(dev_net(in_dev->dev));
2632}
2633
2634#ifdef CONFIG_SYSCTL
2635static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2636static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2637static int ip_rt_gc_elasticity __read_mostly = 8;
2638
2639static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2640 void __user *buffer,
2641 size_t *lenp, loff_t *ppos)
2642{
2643 struct net *net = (struct net *)__ctl->extra1;
2644
2645 if (write) {
2646 rt_cache_flush(net);
2647 fnhe_genid_bump(net);
2648 return 0;
2649 }
2650
2651 return -EINVAL;
2652}
2653
2654static struct ctl_table ipv4_route_table[] = {
2655 {
2656 .procname = "gc_thresh",
2657 .data = &ipv4_dst_ops.gc_thresh,
2658 .maxlen = sizeof(int),
2659 .mode = 0644,
2660 .proc_handler = proc_dointvec,
2661 },
2662 {
2663 .procname = "max_size",
2664 .data = &ip_rt_max_size,
2665 .maxlen = sizeof(int),
2666 .mode = 0644,
2667 .proc_handler = proc_dointvec,
2668 },
2669 {
2670 /* Deprecated. Use gc_min_interval_ms */
2671
2672 .procname = "gc_min_interval",
2673 .data = &ip_rt_gc_min_interval,
2674 .maxlen = sizeof(int),
2675 .mode = 0644,
2676 .proc_handler = proc_dointvec_jiffies,
2677 },
2678 {
2679 .procname = "gc_min_interval_ms",
2680 .data = &ip_rt_gc_min_interval,
2681 .maxlen = sizeof(int),
2682 .mode = 0644,
2683 .proc_handler = proc_dointvec_ms_jiffies,
2684 },
2685 {
2686 .procname = "gc_timeout",
2687 .data = &ip_rt_gc_timeout,
2688 .maxlen = sizeof(int),
2689 .mode = 0644,
2690 .proc_handler = proc_dointvec_jiffies,
2691 },
2692 {
2693 .procname = "gc_interval",
2694 .data = &ip_rt_gc_interval,
2695 .maxlen = sizeof(int),
2696 .mode = 0644,
2697 .proc_handler = proc_dointvec_jiffies,
2698 },
2699 {
2700 .procname = "redirect_load",
2701 .data = &ip_rt_redirect_load,
2702 .maxlen = sizeof(int),
2703 .mode = 0644,
2704 .proc_handler = proc_dointvec,
2705 },
2706 {
2707 .procname = "redirect_number",
2708 .data = &ip_rt_redirect_number,
2709 .maxlen = sizeof(int),
2710 .mode = 0644,
2711 .proc_handler = proc_dointvec,
2712 },
2713 {
2714 .procname = "redirect_silence",
2715 .data = &ip_rt_redirect_silence,
2716 .maxlen = sizeof(int),
2717 .mode = 0644,
2718 .proc_handler = proc_dointvec,
2719 },
2720 {
2721 .procname = "error_cost",
2722 .data = &ip_rt_error_cost,
2723 .maxlen = sizeof(int),
2724 .mode = 0644,
2725 .proc_handler = proc_dointvec,
2726 },
2727 {
2728 .procname = "error_burst",
2729 .data = &ip_rt_error_burst,
2730 .maxlen = sizeof(int),
2731 .mode = 0644,
2732 .proc_handler = proc_dointvec,
2733 },
2734 {
2735 .procname = "gc_elasticity",
2736 .data = &ip_rt_gc_elasticity,
2737 .maxlen = sizeof(int),
2738 .mode = 0644,
2739 .proc_handler = proc_dointvec,
2740 },
2741 {
2742 .procname = "mtu_expires",
2743 .data = &ip_rt_mtu_expires,
2744 .maxlen = sizeof(int),
2745 .mode = 0644,
2746 .proc_handler = proc_dointvec_jiffies,
2747 },
2748 {
2749 .procname = "min_pmtu",
2750 .data = &ip_rt_min_pmtu,
2751 .maxlen = sizeof(int),
2752 .mode = 0644,
2753 .proc_handler = proc_dointvec,
2754 },
2755 {
2756 .procname = "min_adv_mss",
2757 .data = &ip_rt_min_advmss,
2758 .maxlen = sizeof(int),
2759 .mode = 0644,
2760 .proc_handler = proc_dointvec,
2761 },
2762 { }
2763};
2764
2765static struct ctl_table ipv4_route_flush_table[] = {
2766 {
2767 .procname = "flush",
2768 .maxlen = sizeof(int),
2769 .mode = 0200,
2770 .proc_handler = ipv4_sysctl_rtcache_flush,
2771 },
2772 { },
2773};
2774
2775static __net_init int sysctl_route_net_init(struct net *net)
2776{
2777 struct ctl_table *tbl;
2778
2779 tbl = ipv4_route_flush_table;
2780 if (!net_eq(net, &init_net)) {
2781 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2782 if (!tbl)
2783 goto err_dup;
2784
2785 /* Don't export sysctls to unprivileged users */
2786 if (net->user_ns != &init_user_ns)
2787 tbl[0].procname = NULL;
2788 }
2789 tbl[0].extra1 = net;
2790
2791 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2792 if (!net->ipv4.route_hdr)
2793 goto err_reg;
2794 return 0;
2795
2796err_reg:
2797 if (tbl != ipv4_route_flush_table)
2798 kfree(tbl);
2799err_dup:
2800 return -ENOMEM;
2801}
2802
2803static __net_exit void sysctl_route_net_exit(struct net *net)
2804{
2805 struct ctl_table *tbl;
2806
2807 tbl = net->ipv4.route_hdr->ctl_table_arg;
2808 unregister_net_sysctl_table(net->ipv4.route_hdr);
2809 BUG_ON(tbl == ipv4_route_flush_table);
2810 kfree(tbl);
2811}
2812
2813static __net_initdata struct pernet_operations sysctl_route_ops = {
2814 .init = sysctl_route_net_init,
2815 .exit = sysctl_route_net_exit,
2816};
2817#endif
2818
2819static __net_init int rt_genid_init(struct net *net)
2820{
2821 atomic_set(&net->ipv4.rt_genid, 0);
2822 atomic_set(&net->fnhe_genid, 0);
2823 get_random_bytes(&net->ipv4.dev_addr_genid,
2824 sizeof(net->ipv4.dev_addr_genid));
2825 return 0;
2826}
2827
2828static __net_initdata struct pernet_operations rt_genid_ops = {
2829 .init = rt_genid_init,
2830};
2831
2832static int __net_init ipv4_inetpeer_init(struct net *net)
2833{
2834 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2835
2836 if (!bp)
2837 return -ENOMEM;
2838 inet_peer_base_init(bp);
2839 net->ipv4.peers = bp;
2840 return 0;
2841}
2842
2843static void __net_exit ipv4_inetpeer_exit(struct net *net)
2844{
2845 struct inet_peer_base *bp = net->ipv4.peers;
2846
2847 net->ipv4.peers = NULL;
2848 inetpeer_invalidate_tree(bp);
2849 kfree(bp);
2850}
2851
2852static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2853 .init = ipv4_inetpeer_init,
2854 .exit = ipv4_inetpeer_exit,
2855};
2856
2857#ifdef CONFIG_IP_ROUTE_CLASSID
2858struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2859#endif /* CONFIG_IP_ROUTE_CLASSID */
2860
2861int __init ip_rt_init(void)
2862{
2863 int rc = 0;
2864 int cpu;
2865
2866 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2867 if (!ip_idents)
2868 panic("IP: failed to allocate ip_idents\n");
2869
2870 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2871
2872 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2873 if (!ip_tstamps)
2874 panic("IP: failed to allocate ip_tstamps\n");
2875
2876 for_each_possible_cpu(cpu) {
2877 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2878
2879 INIT_LIST_HEAD(&ul->head);
2880 spin_lock_init(&ul->lock);
2881 }
2882#ifdef CONFIG_IP_ROUTE_CLASSID
2883 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2884 if (!ip_rt_acct)
2885 panic("IP: failed to allocate ip_rt_acct\n");
2886#endif
2887
2888 ipv4_dst_ops.kmem_cachep =
2889 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2890 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2891
2892 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2893
2894 if (dst_entries_init(&ipv4_dst_ops) < 0)
2895 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2896
2897 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2898 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2899
2900 ipv4_dst_ops.gc_thresh = ~0;
2901 ip_rt_max_size = INT_MAX;
2902
2903 devinet_init();
2904 ip_fib_init();
2905
2906 if (ip_rt_proc_init())
2907 pr_err("Unable to create route proc files\n");
2908#ifdef CONFIG_XFRM
2909 xfrm_init();
2910 xfrm4_init();
2911#endif
2912 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2913
2914#ifdef CONFIG_SYSCTL
2915 register_pernet_subsys(&sysctl_route_ops);
2916#endif
2917 register_pernet_subsys(&rt_genid_ops);
2918 register_pernet_subsys(&ipv4_inetpeer_ops);
2919 return rc;
2920}
2921
2922#ifdef CONFIG_SYSCTL
2923/*
2924 * We really need to sanitize the damn ipv4 init order, then all
2925 * this nonsense will go away.
2926 */
2927void __init ip_static_sysctl_init(void)
2928{
2929 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2930}
2931#endif