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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * ROUTE - implementation of the IP router.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
14 *
15 * Fixes:
16 * Alan Cox : Verify area fixes.
17 * Alan Cox : cli() protects routing changes
18 * Rui Oliveira : ICMP routing table updates
19 * (rco@di.uminho.pt) Routing table insertion and update
20 * Linus Torvalds : Rewrote bits to be sensible
21 * Alan Cox : Added BSD route gw semantics
22 * Alan Cox : Super /proc >4K
23 * Alan Cox : MTU in route table
24 * Alan Cox : MSS actually. Also added the window
25 * clamper.
26 * Sam Lantinga : Fixed route matching in rt_del()
27 * Alan Cox : Routing cache support.
28 * Alan Cox : Removed compatibility cruft.
29 * Alan Cox : RTF_REJECT support.
30 * Alan Cox : TCP irtt support.
31 * Jonathan Naylor : Added Metric support.
32 * Miquel van Smoorenburg : BSD API fixes.
33 * Miquel van Smoorenburg : Metrics.
34 * Alan Cox : Use __u32 properly
35 * Alan Cox : Aligned routing errors more closely with BSD
36 * our system is still very different.
37 * Alan Cox : Faster /proc handling
38 * Alexey Kuznetsov : Massive rework to support tree based routing,
39 * routing caches and better behaviour.
40 *
41 * Olaf Erb : irtt wasn't being copied right.
42 * Bjorn Ekwall : Kerneld route support.
43 * Alan Cox : Multicast fixed (I hope)
44 * Pavel Krauz : Limited broadcast fixed
45 * Mike McLagan : Routing by source
46 * Alexey Kuznetsov : End of old history. Split to fib.c and
47 * route.c and rewritten from scratch.
48 * Andi Kleen : Load-limit warning messages.
49 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
53 * Marc Boucher : routing by fwmark
54 * Robert Olsson : Added rt_cache statistics
55 * Arnaldo C. Melo : Convert proc stuff to seq_file
56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
58 * Ilia Sotnikov : Removed TOS from hash calculations
59 */
60
61#define pr_fmt(fmt) "IPv4: " fmt
62
63#include <linux/module.h>
64#include <linux/uaccess.h>
65#include <linux/bitops.h>
66#include <linux/types.h>
67#include <linux/kernel.h>
68#include <linux/mm.h>
69#include <linux/string.h>
70#include <linux/socket.h>
71#include <linux/sockios.h>
72#include <linux/errno.h>
73#include <linux/in.h>
74#include <linux/inet.h>
75#include <linux/netdevice.h>
76#include <linux/proc_fs.h>
77#include <linux/init.h>
78#include <linux/skbuff.h>
79#include <linux/inetdevice.h>
80#include <linux/igmp.h>
81#include <linux/pkt_sched.h>
82#include <linux/mroute.h>
83#include <linux/netfilter_ipv4.h>
84#include <linux/random.h>
85#include <linux/rcupdate.h>
86#include <linux/times.h>
87#include <linux/slab.h>
88#include <linux/jhash.h>
89#include <net/dst.h>
90#include <net/dst_metadata.h>
91#include <net/net_namespace.h>
92#include <net/protocol.h>
93#include <net/ip.h>
94#include <net/route.h>
95#include <net/inetpeer.h>
96#include <net/sock.h>
97#include <net/ip_fib.h>
98#include <net/nexthop.h>
99#include <net/arp.h>
100#include <net/tcp.h>
101#include <net/icmp.h>
102#include <net/xfrm.h>
103#include <net/lwtunnel.h>
104#include <net/netevent.h>
105#include <net/rtnetlink.h>
106#ifdef CONFIG_SYSCTL
107#include <linux/sysctl.h>
108#endif
109#include <net/secure_seq.h>
110#include <net/ip_tunnels.h>
111#include <net/l3mdev.h>
112
113#include "fib_lookup.h"
114
115#define RT_FL_TOS(oldflp4) \
116 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
117
118#define RT_GC_TIMEOUT (300*HZ)
119
120static int ip_rt_max_size;
121static int ip_rt_redirect_number __read_mostly = 9;
122static int ip_rt_redirect_load __read_mostly = HZ / 50;
123static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
124static int ip_rt_error_cost __read_mostly = HZ;
125static int ip_rt_error_burst __read_mostly = 5 * HZ;
126static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
127static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
128static int ip_rt_min_advmss __read_mostly = 256;
129
130static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
131
132/*
133 * Interface to generic destination cache.
134 */
135
136static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138static unsigned int ipv4_mtu(const struct dst_entry *dst);
139static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140static void ipv4_link_failure(struct sk_buff *skb);
141static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145static void ipv4_dst_destroy(struct dst_entry *dst);
146
147static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148{
149 WARN_ON(1);
150 return NULL;
151}
152
153static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156static void ipv4_confirm_neigh(const struct dst_entry *dst, 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 .confirm_neigh = ipv4_confirm_neigh,
172};
173
174#define ECN_OR_COST(class) TC_PRIO_##class
175
176const __u8 ip_tos2prio[16] = {
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK)
193};
194EXPORT_SYMBOL(ip_tos2prio);
195
196static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
197#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
198
199#ifdef CONFIG_PROC_FS
200static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
201{
202 if (*pos)
203 return NULL;
204 return SEQ_START_TOKEN;
205}
206
207static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
208{
209 ++*pos;
210 return NULL;
211}
212
213static void rt_cache_seq_stop(struct seq_file *seq, void *v)
214{
215}
216
217static int rt_cache_seq_show(struct seq_file *seq, void *v)
218{
219 if (v == SEQ_START_TOKEN)
220 seq_printf(seq, "%-127s\n",
221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
223 "HHUptod\tSpecDst");
224 return 0;
225}
226
227static const struct seq_operations rt_cache_seq_ops = {
228 .start = rt_cache_seq_start,
229 .next = rt_cache_seq_next,
230 .stop = rt_cache_seq_stop,
231 .show = rt_cache_seq_show,
232};
233
234static int rt_cache_seq_open(struct inode *inode, struct file *file)
235{
236 return seq_open(file, &rt_cache_seq_ops);
237}
238
239static const struct file_operations rt_cache_seq_fops = {
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 .open = rt_cpu_seq_open,
331 .read = seq_read,
332 .llseek = seq_lseek,
333 .release = seq_release,
334};
335
336#ifdef CONFIG_IP_ROUTE_CLASSID
337static int rt_acct_proc_show(struct seq_file *m, void *v)
338{
339 struct ip_rt_acct *dst, *src;
340 unsigned int i, j;
341
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
343 if (!dst)
344 return -ENOMEM;
345
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
353 }
354 }
355
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 kfree(dst);
358 return 0;
359}
360#endif
361
362static int __net_init ip_rt_do_proc_init(struct net *net)
363{
364 struct proc_dir_entry *pde;
365
366 pde = proc_create("rt_cache", 0444, net->proc_net,
367 &rt_cache_seq_fops);
368 if (!pde)
369 goto err1;
370
371 pde = proc_create("rt_cache", 0444,
372 net->proc_net_stat, &rt_cpu_seq_fops);
373 if (!pde)
374 goto err2;
375
376#ifdef CONFIG_IP_ROUTE_CLASSID
377 pde = proc_create_single("rt_acct", 0, net->proc_net,
378 rt_acct_proc_show);
379 if (!pde)
380 goto err3;
381#endif
382 return 0;
383
384#ifdef CONFIG_IP_ROUTE_CLASSID
385err3:
386 remove_proc_entry("rt_cache", net->proc_net_stat);
387#endif
388err2:
389 remove_proc_entry("rt_cache", net->proc_net);
390err1:
391 return -ENOMEM;
392}
393
394static void __net_exit ip_rt_do_proc_exit(struct net *net)
395{
396 remove_proc_entry("rt_cache", net->proc_net_stat);
397 remove_proc_entry("rt_cache", net->proc_net);
398#ifdef CONFIG_IP_ROUTE_CLASSID
399 remove_proc_entry("rt_acct", net->proc_net);
400#endif
401}
402
403static struct pernet_operations ip_rt_proc_ops __net_initdata = {
404 .init = ip_rt_do_proc_init,
405 .exit = ip_rt_do_proc_exit,
406};
407
408static int __init ip_rt_proc_init(void)
409{
410 return register_pernet_subsys(&ip_rt_proc_ops);
411}
412
413#else
414static inline int ip_rt_proc_init(void)
415{
416 return 0;
417}
418#endif /* CONFIG_PROC_FS */
419
420static inline bool rt_is_expired(const struct rtable *rth)
421{
422 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
423}
424
425void rt_cache_flush(struct net *net)
426{
427 rt_genid_bump_ipv4(net);
428}
429
430static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
431 struct sk_buff *skb,
432 const void *daddr)
433{
434 const struct rtable *rt = container_of(dst, struct rtable, dst);
435 struct net_device *dev = dst->dev;
436 struct neighbour *n;
437
438 rcu_read_lock_bh();
439
440 if (likely(rt->rt_gw_family == AF_INET)) {
441 n = ip_neigh_gw4(dev, rt->rt_gw4);
442 } else if (rt->rt_gw_family == AF_INET6) {
443 n = ip_neigh_gw6(dev, &rt->rt_gw6);
444 } else {
445 __be32 pkey;
446
447 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
448 n = ip_neigh_gw4(dev, pkey);
449 }
450
451 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
452 n = NULL;
453
454 rcu_read_unlock_bh();
455
456 return n;
457}
458
459static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
460{
461 const struct rtable *rt = container_of(dst, struct rtable, dst);
462 struct net_device *dev = dst->dev;
463 const __be32 *pkey = daddr;
464
465 if (rt->rt_gw_family == AF_INET) {
466 pkey = (const __be32 *)&rt->rt_gw4;
467 } else if (rt->rt_gw_family == AF_INET6) {
468 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
469 } else if (!daddr ||
470 (rt->rt_flags &
471 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
472 return;
473 }
474 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
475}
476
477#define IP_IDENTS_SZ 2048u
478
479static atomic_t *ip_idents __read_mostly;
480static u32 *ip_tstamps __read_mostly;
481
482/* In order to protect privacy, we add a perturbation to identifiers
483 * if one generator is seldom used. This makes hard for an attacker
484 * to infer how many packets were sent between two points in time.
485 */
486u32 ip_idents_reserve(u32 hash, int segs)
487{
488 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
489 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
490 u32 old = READ_ONCE(*p_tstamp);
491 u32 now = (u32)jiffies;
492 u32 new, delta = 0;
493
494 if (old != now && cmpxchg(p_tstamp, old, now) == old)
495 delta = prandom_u32_max(now - old);
496
497 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
498 do {
499 old = (u32)atomic_read(p_id);
500 new = old + delta + segs;
501 } while (atomic_cmpxchg(p_id, old, new) != old);
502
503 return new - segs;
504}
505EXPORT_SYMBOL(ip_idents_reserve);
506
507void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
508{
509 u32 hash, id;
510
511 /* Note the following code is not safe, but this is okay. */
512 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
513 get_random_bytes(&net->ipv4.ip_id_key,
514 sizeof(net->ipv4.ip_id_key));
515
516 hash = siphash_3u32((__force u32)iph->daddr,
517 (__force u32)iph->saddr,
518 iph->protocol,
519 &net->ipv4.ip_id_key);
520 id = ip_idents_reserve(hash, segs);
521 iph->id = htons(id);
522}
523EXPORT_SYMBOL(__ip_select_ident);
524
525static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
526 const struct sock *sk,
527 const struct iphdr *iph,
528 int oif, u8 tos,
529 u8 prot, u32 mark, int flow_flags)
530{
531 if (sk) {
532 const struct inet_sock *inet = inet_sk(sk);
533
534 oif = sk->sk_bound_dev_if;
535 mark = sk->sk_mark;
536 tos = RT_CONN_FLAGS(sk);
537 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
538 }
539 flowi4_init_output(fl4, oif, mark, tos,
540 RT_SCOPE_UNIVERSE, prot,
541 flow_flags,
542 iph->daddr, iph->saddr, 0, 0,
543 sock_net_uid(net, sk));
544}
545
546static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
547 const struct sock *sk)
548{
549 const struct net *net = dev_net(skb->dev);
550 const struct iphdr *iph = ip_hdr(skb);
551 int oif = skb->dev->ifindex;
552 u8 tos = RT_TOS(iph->tos);
553 u8 prot = iph->protocol;
554 u32 mark = skb->mark;
555
556 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
557}
558
559static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
560{
561 const struct inet_sock *inet = inet_sk(sk);
562 const struct ip_options_rcu *inet_opt;
563 __be32 daddr = inet->inet_daddr;
564
565 rcu_read_lock();
566 inet_opt = rcu_dereference(inet->inet_opt);
567 if (inet_opt && inet_opt->opt.srr)
568 daddr = inet_opt->opt.faddr;
569 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
570 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
571 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
572 inet_sk_flowi_flags(sk),
573 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
574 rcu_read_unlock();
575}
576
577static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
578 const struct sk_buff *skb)
579{
580 if (skb)
581 build_skb_flow_key(fl4, skb, sk);
582 else
583 build_sk_flow_key(fl4, sk);
584}
585
586static DEFINE_SPINLOCK(fnhe_lock);
587
588static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
589{
590 struct rtable *rt;
591
592 rt = rcu_dereference(fnhe->fnhe_rth_input);
593 if (rt) {
594 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
595 dst_dev_put(&rt->dst);
596 dst_release(&rt->dst);
597 }
598 rt = rcu_dereference(fnhe->fnhe_rth_output);
599 if (rt) {
600 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
601 dst_dev_put(&rt->dst);
602 dst_release(&rt->dst);
603 }
604}
605
606static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
607{
608 struct fib_nh_exception *fnhe, *oldest;
609
610 oldest = rcu_dereference(hash->chain);
611 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
612 fnhe = rcu_dereference(fnhe->fnhe_next)) {
613 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
614 oldest = fnhe;
615 }
616 fnhe_flush_routes(oldest);
617 return oldest;
618}
619
620static inline u32 fnhe_hashfun(__be32 daddr)
621{
622 static u32 fnhe_hashrnd __read_mostly;
623 u32 hval;
624
625 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
626 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
627 return hash_32(hval, FNHE_HASH_SHIFT);
628}
629
630static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
631{
632 rt->rt_pmtu = fnhe->fnhe_pmtu;
633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
634 rt->dst.expires = fnhe->fnhe_expires;
635
636 if (fnhe->fnhe_gw) {
637 rt->rt_flags |= RTCF_REDIRECTED;
638 rt->rt_uses_gateway = 1;
639 rt->rt_gw_family = AF_INET;
640 rt->rt_gw4 = fnhe->fnhe_gw;
641 }
642}
643
644static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
645 __be32 gw, u32 pmtu, bool lock,
646 unsigned long expires)
647{
648 struct fnhe_hash_bucket *hash;
649 struct fib_nh_exception *fnhe;
650 struct rtable *rt;
651 u32 genid, hval;
652 unsigned int i;
653 int depth;
654
655 genid = fnhe_genid(dev_net(nhc->nhc_dev));
656 hval = fnhe_hashfun(daddr);
657
658 spin_lock_bh(&fnhe_lock);
659
660 hash = rcu_dereference(nhc->nhc_exceptions);
661 if (!hash) {
662 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
663 if (!hash)
664 goto out_unlock;
665 rcu_assign_pointer(nhc->nhc_exceptions, hash);
666 }
667
668 hash += hval;
669
670 depth = 0;
671 for (fnhe = rcu_dereference(hash->chain); fnhe;
672 fnhe = rcu_dereference(fnhe->fnhe_next)) {
673 if (fnhe->fnhe_daddr == daddr)
674 break;
675 depth++;
676 }
677
678 if (fnhe) {
679 if (fnhe->fnhe_genid != genid)
680 fnhe->fnhe_genid = genid;
681 if (gw)
682 fnhe->fnhe_gw = gw;
683 if (pmtu) {
684 fnhe->fnhe_pmtu = pmtu;
685 fnhe->fnhe_mtu_locked = lock;
686 }
687 fnhe->fnhe_expires = max(1UL, expires);
688 /* Update all cached dsts too */
689 rt = rcu_dereference(fnhe->fnhe_rth_input);
690 if (rt)
691 fill_route_from_fnhe(rt, fnhe);
692 rt = rcu_dereference(fnhe->fnhe_rth_output);
693 if (rt)
694 fill_route_from_fnhe(rt, fnhe);
695 } else {
696 if (depth > FNHE_RECLAIM_DEPTH)
697 fnhe = fnhe_oldest(hash);
698 else {
699 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
700 if (!fnhe)
701 goto out_unlock;
702
703 fnhe->fnhe_next = hash->chain;
704 rcu_assign_pointer(hash->chain, fnhe);
705 }
706 fnhe->fnhe_genid = genid;
707 fnhe->fnhe_daddr = daddr;
708 fnhe->fnhe_gw = gw;
709 fnhe->fnhe_pmtu = pmtu;
710 fnhe->fnhe_mtu_locked = lock;
711 fnhe->fnhe_expires = max(1UL, expires);
712
713 /* Exception created; mark the cached routes for the nexthop
714 * stale, so anyone caching it rechecks if this exception
715 * applies to them.
716 */
717 rt = rcu_dereference(nhc->nhc_rth_input);
718 if (rt)
719 rt->dst.obsolete = DST_OBSOLETE_KILL;
720
721 for_each_possible_cpu(i) {
722 struct rtable __rcu **prt;
723 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
724 rt = rcu_dereference(*prt);
725 if (rt)
726 rt->dst.obsolete = DST_OBSOLETE_KILL;
727 }
728 }
729
730 fnhe->fnhe_stamp = jiffies;
731
732out_unlock:
733 spin_unlock_bh(&fnhe_lock);
734}
735
736static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
737 bool kill_route)
738{
739 __be32 new_gw = icmp_hdr(skb)->un.gateway;
740 __be32 old_gw = ip_hdr(skb)->saddr;
741 struct net_device *dev = skb->dev;
742 struct in_device *in_dev;
743 struct fib_result res;
744 struct neighbour *n;
745 struct net *net;
746
747 switch (icmp_hdr(skb)->code & 7) {
748 case ICMP_REDIR_NET:
749 case ICMP_REDIR_NETTOS:
750 case ICMP_REDIR_HOST:
751 case ICMP_REDIR_HOSTTOS:
752 break;
753
754 default:
755 return;
756 }
757
758 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
759 return;
760
761 in_dev = __in_dev_get_rcu(dev);
762 if (!in_dev)
763 return;
764
765 net = dev_net(dev);
766 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
767 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
768 ipv4_is_zeronet(new_gw))
769 goto reject_redirect;
770
771 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
772 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
773 goto reject_redirect;
774 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
775 goto reject_redirect;
776 } else {
777 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
778 goto reject_redirect;
779 }
780
781 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
782 if (!n)
783 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
784 if (!IS_ERR(n)) {
785 if (!(n->nud_state & NUD_VALID)) {
786 neigh_event_send(n, NULL);
787 } else {
788 if (fib_lookup(net, fl4, &res, 0) == 0) {
789 struct fib_nh_common *nhc = FIB_RES_NHC(res);
790
791 update_or_create_fnhe(nhc, fl4->daddr, new_gw,
792 0, false,
793 jiffies + ip_rt_gc_timeout);
794 }
795 if (kill_route)
796 rt->dst.obsolete = DST_OBSOLETE_KILL;
797 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
798 }
799 neigh_release(n);
800 }
801 return;
802
803reject_redirect:
804#ifdef CONFIG_IP_ROUTE_VERBOSE
805 if (IN_DEV_LOG_MARTIANS(in_dev)) {
806 const struct iphdr *iph = (const struct iphdr *) skb->data;
807 __be32 daddr = iph->daddr;
808 __be32 saddr = iph->saddr;
809
810 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
811 " Advised path = %pI4 -> %pI4\n",
812 &old_gw, dev->name, &new_gw,
813 &saddr, &daddr);
814 }
815#endif
816 ;
817}
818
819static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
820{
821 struct rtable *rt;
822 struct flowi4 fl4;
823 const struct iphdr *iph = (const struct iphdr *) skb->data;
824 struct net *net = dev_net(skb->dev);
825 int oif = skb->dev->ifindex;
826 u8 tos = RT_TOS(iph->tos);
827 u8 prot = iph->protocol;
828 u32 mark = skb->mark;
829
830 rt = (struct rtable *) dst;
831
832 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
833 __ip_do_redirect(rt, skb, &fl4, true);
834}
835
836static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
837{
838 struct rtable *rt = (struct rtable *)dst;
839 struct dst_entry *ret = dst;
840
841 if (rt) {
842 if (dst->obsolete > 0) {
843 ip_rt_put(rt);
844 ret = NULL;
845 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
846 rt->dst.expires) {
847 ip_rt_put(rt);
848 ret = NULL;
849 }
850 }
851 return ret;
852}
853
854/*
855 * Algorithm:
856 * 1. The first ip_rt_redirect_number redirects are sent
857 * with exponential backoff, then we stop sending them at all,
858 * assuming that the host ignores our redirects.
859 * 2. If we did not see packets requiring redirects
860 * during ip_rt_redirect_silence, we assume that the host
861 * forgot redirected route and start to send redirects again.
862 *
863 * This algorithm is much cheaper and more intelligent than dumb load limiting
864 * in icmp.c.
865 *
866 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
867 * and "frag. need" (breaks PMTU discovery) in icmp.c.
868 */
869
870void ip_rt_send_redirect(struct sk_buff *skb)
871{
872 struct rtable *rt = skb_rtable(skb);
873 struct in_device *in_dev;
874 struct inet_peer *peer;
875 struct net *net;
876 int log_martians;
877 int vif;
878
879 rcu_read_lock();
880 in_dev = __in_dev_get_rcu(rt->dst.dev);
881 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
882 rcu_read_unlock();
883 return;
884 }
885 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
886 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
887 rcu_read_unlock();
888
889 net = dev_net(rt->dst.dev);
890 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
891 if (!peer) {
892 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
893 rt_nexthop(rt, ip_hdr(skb)->daddr));
894 return;
895 }
896
897 /* No redirected packets during ip_rt_redirect_silence;
898 * reset the algorithm.
899 */
900 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
901 peer->rate_tokens = 0;
902 peer->n_redirects = 0;
903 }
904
905 /* Too many ignored redirects; do not send anything
906 * set dst.rate_last to the last seen redirected packet.
907 */
908 if (peer->n_redirects >= ip_rt_redirect_number) {
909 peer->rate_last = jiffies;
910 goto out_put_peer;
911 }
912
913 /* Check for load limit; set rate_last to the latest sent
914 * redirect.
915 */
916 if (peer->rate_tokens == 0 ||
917 time_after(jiffies,
918 (peer->rate_last +
919 (ip_rt_redirect_load << peer->n_redirects)))) {
920 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
921
922 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
923 peer->rate_last = jiffies;
924 ++peer->n_redirects;
925#ifdef CONFIG_IP_ROUTE_VERBOSE
926 if (log_martians &&
927 peer->n_redirects == ip_rt_redirect_number)
928 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
929 &ip_hdr(skb)->saddr, inet_iif(skb),
930 &ip_hdr(skb)->daddr, &gw);
931#endif
932 }
933out_put_peer:
934 inet_putpeer(peer);
935}
936
937static int ip_error(struct sk_buff *skb)
938{
939 struct rtable *rt = skb_rtable(skb);
940 struct net_device *dev = skb->dev;
941 struct in_device *in_dev;
942 struct inet_peer *peer;
943 unsigned long now;
944 struct net *net;
945 bool send;
946 int code;
947
948 if (netif_is_l3_master(skb->dev)) {
949 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
950 if (!dev)
951 goto out;
952 }
953
954 in_dev = __in_dev_get_rcu(dev);
955
956 /* IP on this device is disabled. */
957 if (!in_dev)
958 goto out;
959
960 net = dev_net(rt->dst.dev);
961 if (!IN_DEV_FORWARD(in_dev)) {
962 switch (rt->dst.error) {
963 case EHOSTUNREACH:
964 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
965 break;
966
967 case ENETUNREACH:
968 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
969 break;
970 }
971 goto out;
972 }
973
974 switch (rt->dst.error) {
975 case EINVAL:
976 default:
977 goto out;
978 case EHOSTUNREACH:
979 code = ICMP_HOST_UNREACH;
980 break;
981 case ENETUNREACH:
982 code = ICMP_NET_UNREACH;
983 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
984 break;
985 case EACCES:
986 code = ICMP_PKT_FILTERED;
987 break;
988 }
989
990 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
991 l3mdev_master_ifindex(skb->dev), 1);
992
993 send = true;
994 if (peer) {
995 now = jiffies;
996 peer->rate_tokens += now - peer->rate_last;
997 if (peer->rate_tokens > ip_rt_error_burst)
998 peer->rate_tokens = ip_rt_error_burst;
999 peer->rate_last = now;
1000 if (peer->rate_tokens >= ip_rt_error_cost)
1001 peer->rate_tokens -= ip_rt_error_cost;
1002 else
1003 send = false;
1004 inet_putpeer(peer);
1005 }
1006 if (send)
1007 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1008
1009out: kfree_skb(skb);
1010 return 0;
1011}
1012
1013static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1014{
1015 struct dst_entry *dst = &rt->dst;
1016 u32 old_mtu = ipv4_mtu(dst);
1017 struct fib_result res;
1018 bool lock = false;
1019
1020 if (ip_mtu_locked(dst))
1021 return;
1022
1023 if (old_mtu < mtu)
1024 return;
1025
1026 if (mtu < ip_rt_min_pmtu) {
1027 lock = true;
1028 mtu = min(old_mtu, ip_rt_min_pmtu);
1029 }
1030
1031 if (rt->rt_pmtu == mtu && !lock &&
1032 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1033 return;
1034
1035 rcu_read_lock();
1036 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1037 struct fib_nh_common *nhc = FIB_RES_NHC(res);
1038
1039 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1040 jiffies + ip_rt_mtu_expires);
1041 }
1042 rcu_read_unlock();
1043}
1044
1045static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1046 struct sk_buff *skb, u32 mtu)
1047{
1048 struct rtable *rt = (struct rtable *) dst;
1049 struct flowi4 fl4;
1050
1051 ip_rt_build_flow_key(&fl4, sk, skb);
1052 __ip_rt_update_pmtu(rt, &fl4, mtu);
1053}
1054
1055void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1056 int oif, u8 protocol)
1057{
1058 const struct iphdr *iph = (const struct iphdr *) skb->data;
1059 struct flowi4 fl4;
1060 struct rtable *rt;
1061 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1062
1063 __build_flow_key(net, &fl4, NULL, iph, oif,
1064 RT_TOS(iph->tos), protocol, mark, 0);
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, u8 protocol)
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, 0, 0);
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.
1189 */
1190 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1191 return NULL;
1192 return dst;
1193}
1194
1195static void ipv4_send_dest_unreach(struct sk_buff *skb)
1196{
1197 struct ip_options opt;
1198 int res;
1199
1200 /* Recompile ip options since IPCB may not be valid anymore.
1201 * Also check we have a reasonable ipv4 header.
1202 */
1203 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1204 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1205 return;
1206
1207 memset(&opt, 0, sizeof(opt));
1208 if (ip_hdr(skb)->ihl > 5) {
1209 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1210 return;
1211 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1212
1213 rcu_read_lock();
1214 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
1215 rcu_read_unlock();
1216
1217 if (res)
1218 return;
1219 }
1220 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1221}
1222
1223static void ipv4_link_failure(struct sk_buff *skb)
1224{
1225 struct rtable *rt;
1226
1227 ipv4_send_dest_unreach(skb);
1228
1229 rt = skb_rtable(skb);
1230 if (rt)
1231 dst_set_expires(&rt->dst, 0);
1232}
1233
1234static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1235{
1236 pr_debug("%s: %pI4 -> %pI4, %s\n",
1237 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1238 skb->dev ? skb->dev->name : "?");
1239 kfree_skb(skb);
1240 WARN_ON(1);
1241 return 0;
1242}
1243
1244/*
1245 We do not cache source address of outgoing interface,
1246 because it is used only by IP RR, TS and SRR options,
1247 so that it out of fast path.
1248
1249 BTW remember: "addr" is allowed to be not aligned
1250 in IP options!
1251 */
1252
1253void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1254{
1255 __be32 src;
1256
1257 if (rt_is_output_route(rt))
1258 src = ip_hdr(skb)->saddr;
1259 else {
1260 struct fib_result res;
1261 struct iphdr *iph = ip_hdr(skb);
1262 struct flowi4 fl4 = {
1263 .daddr = iph->daddr,
1264 .saddr = iph->saddr,
1265 .flowi4_tos = RT_TOS(iph->tos),
1266 .flowi4_oif = rt->dst.dev->ifindex,
1267 .flowi4_iif = skb->dev->ifindex,
1268 .flowi4_mark = skb->mark,
1269 };
1270
1271 rcu_read_lock();
1272 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1273 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1274 else
1275 src = inet_select_addr(rt->dst.dev,
1276 rt_nexthop(rt, iph->daddr),
1277 RT_SCOPE_UNIVERSE);
1278 rcu_read_unlock();
1279 }
1280 memcpy(addr, &src, 4);
1281}
1282
1283#ifdef CONFIG_IP_ROUTE_CLASSID
1284static void set_class_tag(struct rtable *rt, u32 tag)
1285{
1286 if (!(rt->dst.tclassid & 0xFFFF))
1287 rt->dst.tclassid |= tag & 0xFFFF;
1288 if (!(rt->dst.tclassid & 0xFFFF0000))
1289 rt->dst.tclassid |= tag & 0xFFFF0000;
1290}
1291#endif
1292
1293static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1294{
1295 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1296 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1297 ip_rt_min_advmss);
1298
1299 return min(advmss, IPV4_MAX_PMTU - header_size);
1300}
1301
1302static unsigned int ipv4_mtu(const struct dst_entry *dst)
1303{
1304 const struct rtable *rt = (const struct rtable *) dst;
1305 unsigned int mtu = rt->rt_pmtu;
1306
1307 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1308 mtu = dst_metric_raw(dst, RTAX_MTU);
1309
1310 if (mtu)
1311 return mtu;
1312
1313 mtu = READ_ONCE(dst->dev->mtu);
1314
1315 if (unlikely(ip_mtu_locked(dst))) {
1316 if (rt->rt_uses_gateway && mtu > 576)
1317 mtu = 576;
1318 }
1319
1320 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1321
1322 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1323}
1324
1325static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1326{
1327 struct fnhe_hash_bucket *hash;
1328 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1329 u32 hval = fnhe_hashfun(daddr);
1330
1331 spin_lock_bh(&fnhe_lock);
1332
1333 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1334 lockdep_is_held(&fnhe_lock));
1335 hash += hval;
1336
1337 fnhe_p = &hash->chain;
1338 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1339 while (fnhe) {
1340 if (fnhe->fnhe_daddr == daddr) {
1341 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1342 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1343 /* set fnhe_daddr to 0 to ensure it won't bind with
1344 * new dsts in rt_bind_exception().
1345 */
1346 fnhe->fnhe_daddr = 0;
1347 fnhe_flush_routes(fnhe);
1348 kfree_rcu(fnhe, rcu);
1349 break;
1350 }
1351 fnhe_p = &fnhe->fnhe_next;
1352 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1353 lockdep_is_held(&fnhe_lock));
1354 }
1355
1356 spin_unlock_bh(&fnhe_lock);
1357}
1358
1359static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1360 __be32 daddr)
1361{
1362 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1363 struct fib_nh_exception *fnhe;
1364 u32 hval;
1365
1366 if (!hash)
1367 return NULL;
1368
1369 hval = fnhe_hashfun(daddr);
1370
1371 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1372 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1373 if (fnhe->fnhe_daddr == daddr) {
1374 if (fnhe->fnhe_expires &&
1375 time_after(jiffies, fnhe->fnhe_expires)) {
1376 ip_del_fnhe(nhc, daddr);
1377 break;
1378 }
1379 return fnhe;
1380 }
1381 }
1382 return NULL;
1383}
1384
1385/* MTU selection:
1386 * 1. mtu on route is locked - use it
1387 * 2. mtu from nexthop exception
1388 * 3. mtu from egress device
1389 */
1390
1391u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1392{
1393 struct fib_nh_common *nhc = res->nhc;
1394 struct net_device *dev = nhc->nhc_dev;
1395 struct fib_info *fi = res->fi;
1396 u32 mtu = 0;
1397
1398 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1399 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1400 mtu = fi->fib_mtu;
1401
1402 if (likely(!mtu)) {
1403 struct fib_nh_exception *fnhe;
1404
1405 fnhe = find_exception(nhc, daddr);
1406 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1407 mtu = fnhe->fnhe_pmtu;
1408 }
1409
1410 if (likely(!mtu))
1411 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1412
1413 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1414}
1415
1416static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1417 __be32 daddr, const bool do_cache)
1418{
1419 bool ret = false;
1420
1421 spin_lock_bh(&fnhe_lock);
1422
1423 if (daddr == fnhe->fnhe_daddr) {
1424 struct rtable __rcu **porig;
1425 struct rtable *orig;
1426 int genid = fnhe_genid(dev_net(rt->dst.dev));
1427
1428 if (rt_is_input_route(rt))
1429 porig = &fnhe->fnhe_rth_input;
1430 else
1431 porig = &fnhe->fnhe_rth_output;
1432 orig = rcu_dereference(*porig);
1433
1434 if (fnhe->fnhe_genid != genid) {
1435 fnhe->fnhe_genid = genid;
1436 fnhe->fnhe_gw = 0;
1437 fnhe->fnhe_pmtu = 0;
1438 fnhe->fnhe_expires = 0;
1439 fnhe->fnhe_mtu_locked = false;
1440 fnhe_flush_routes(fnhe);
1441 orig = NULL;
1442 }
1443 fill_route_from_fnhe(rt, fnhe);
1444 if (!rt->rt_gw4) {
1445 rt->rt_gw4 = daddr;
1446 rt->rt_gw_family = AF_INET;
1447 }
1448
1449 if (do_cache) {
1450 dst_hold(&rt->dst);
1451 rcu_assign_pointer(*porig, rt);
1452 if (orig) {
1453 dst_dev_put(&orig->dst);
1454 dst_release(&orig->dst);
1455 }
1456 ret = true;
1457 }
1458
1459 fnhe->fnhe_stamp = jiffies;
1460 }
1461 spin_unlock_bh(&fnhe_lock);
1462
1463 return ret;
1464}
1465
1466static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1467{
1468 struct rtable *orig, *prev, **p;
1469 bool ret = true;
1470
1471 if (rt_is_input_route(rt)) {
1472 p = (struct rtable **)&nhc->nhc_rth_input;
1473 } else {
1474 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1475 }
1476 orig = *p;
1477
1478 /* hold dst before doing cmpxchg() to avoid race condition
1479 * on this dst
1480 */
1481 dst_hold(&rt->dst);
1482 prev = cmpxchg(p, orig, rt);
1483 if (prev == orig) {
1484 if (orig) {
1485 rt_add_uncached_list(orig);
1486 dst_release(&orig->dst);
1487 }
1488 } else {
1489 dst_release(&rt->dst);
1490 ret = false;
1491 }
1492
1493 return ret;
1494}
1495
1496struct uncached_list {
1497 spinlock_t lock;
1498 struct list_head head;
1499};
1500
1501static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1502
1503void rt_add_uncached_list(struct rtable *rt)
1504{
1505 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1506
1507 rt->rt_uncached_list = ul;
1508
1509 spin_lock_bh(&ul->lock);
1510 list_add_tail(&rt->rt_uncached, &ul->head);
1511 spin_unlock_bh(&ul->lock);
1512}
1513
1514void rt_del_uncached_list(struct rtable *rt)
1515{
1516 if (!list_empty(&rt->rt_uncached)) {
1517 struct uncached_list *ul = rt->rt_uncached_list;
1518
1519 spin_lock_bh(&ul->lock);
1520 list_del(&rt->rt_uncached);
1521 spin_unlock_bh(&ul->lock);
1522 }
1523}
1524
1525static void ipv4_dst_destroy(struct dst_entry *dst)
1526{
1527 struct rtable *rt = (struct rtable *)dst;
1528
1529 ip_dst_metrics_put(dst);
1530 rt_del_uncached_list(rt);
1531}
1532
1533void rt_flush_dev(struct net_device *dev)
1534{
1535 struct rtable *rt;
1536 int cpu;
1537
1538 for_each_possible_cpu(cpu) {
1539 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1540
1541 spin_lock_bh(&ul->lock);
1542 list_for_each_entry(rt, &ul->head, rt_uncached) {
1543 if (rt->dst.dev != dev)
1544 continue;
1545 rt->dst.dev = blackhole_netdev;
1546 dev_hold(rt->dst.dev);
1547 dev_put(dev);
1548 }
1549 spin_unlock_bh(&ul->lock);
1550 }
1551}
1552
1553static bool rt_cache_valid(const struct rtable *rt)
1554{
1555 return rt &&
1556 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1557 !rt_is_expired(rt);
1558}
1559
1560static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1561 const struct fib_result *res,
1562 struct fib_nh_exception *fnhe,
1563 struct fib_info *fi, u16 type, u32 itag,
1564 const bool do_cache)
1565{
1566 bool cached = false;
1567
1568 if (fi) {
1569 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1570
1571 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1572 rt->rt_uses_gateway = 1;
1573 rt->rt_gw_family = nhc->nhc_gw_family;
1574 /* only INET and INET6 are supported */
1575 if (likely(nhc->nhc_gw_family == AF_INET))
1576 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1577 else
1578 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1579 }
1580
1581 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1582
1583#ifdef CONFIG_IP_ROUTE_CLASSID
1584 if (nhc->nhc_family == AF_INET) {
1585 struct fib_nh *nh;
1586
1587 nh = container_of(nhc, struct fib_nh, nh_common);
1588 rt->dst.tclassid = nh->nh_tclassid;
1589 }
1590#endif
1591 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1592 if (unlikely(fnhe))
1593 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1594 else if (do_cache)
1595 cached = rt_cache_route(nhc, rt);
1596 if (unlikely(!cached)) {
1597 /* Routes we intend to cache in nexthop exception or
1598 * FIB nexthop have the DST_NOCACHE bit clear.
1599 * However, if we are unsuccessful at storing this
1600 * route into the cache we really need to set it.
1601 */
1602 if (!rt->rt_gw4) {
1603 rt->rt_gw_family = AF_INET;
1604 rt->rt_gw4 = daddr;
1605 }
1606 rt_add_uncached_list(rt);
1607 }
1608 } else
1609 rt_add_uncached_list(rt);
1610
1611#ifdef CONFIG_IP_ROUTE_CLASSID
1612#ifdef CONFIG_IP_MULTIPLE_TABLES
1613 set_class_tag(rt, res->tclassid);
1614#endif
1615 set_class_tag(rt, itag);
1616#endif
1617}
1618
1619struct rtable *rt_dst_alloc(struct net_device *dev,
1620 unsigned int flags, u16 type,
1621 bool nopolicy, bool noxfrm, bool will_cache)
1622{
1623 struct rtable *rt;
1624
1625 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1626 (will_cache ? 0 : DST_HOST) |
1627 (nopolicy ? DST_NOPOLICY : 0) |
1628 (noxfrm ? DST_NOXFRM : 0));
1629
1630 if (rt) {
1631 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1632 rt->rt_flags = flags;
1633 rt->rt_type = type;
1634 rt->rt_is_input = 0;
1635 rt->rt_iif = 0;
1636 rt->rt_pmtu = 0;
1637 rt->rt_mtu_locked = 0;
1638 rt->rt_uses_gateway = 0;
1639 rt->rt_gw_family = 0;
1640 rt->rt_gw4 = 0;
1641 INIT_LIST_HEAD(&rt->rt_uncached);
1642
1643 rt->dst.output = ip_output;
1644 if (flags & RTCF_LOCAL)
1645 rt->dst.input = ip_local_deliver;
1646 }
1647
1648 return rt;
1649}
1650EXPORT_SYMBOL(rt_dst_alloc);
1651
1652struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1653{
1654 struct rtable *new_rt;
1655
1656 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1657 rt->dst.flags);
1658
1659 if (new_rt) {
1660 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1661 new_rt->rt_flags = rt->rt_flags;
1662 new_rt->rt_type = rt->rt_type;
1663 new_rt->rt_is_input = rt->rt_is_input;
1664 new_rt->rt_iif = rt->rt_iif;
1665 new_rt->rt_pmtu = rt->rt_pmtu;
1666 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1667 new_rt->rt_gw_family = rt->rt_gw_family;
1668 if (rt->rt_gw_family == AF_INET)
1669 new_rt->rt_gw4 = rt->rt_gw4;
1670 else if (rt->rt_gw_family == AF_INET6)
1671 new_rt->rt_gw6 = rt->rt_gw6;
1672 INIT_LIST_HEAD(&new_rt->rt_uncached);
1673
1674 new_rt->dst.flags |= DST_HOST;
1675 new_rt->dst.input = rt->dst.input;
1676 new_rt->dst.output = rt->dst.output;
1677 new_rt->dst.error = rt->dst.error;
1678 new_rt->dst.lastuse = jiffies;
1679 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1680 }
1681 return new_rt;
1682}
1683EXPORT_SYMBOL(rt_dst_clone);
1684
1685/* called in rcu_read_lock() section */
1686int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1687 u8 tos, struct net_device *dev,
1688 struct in_device *in_dev, u32 *itag)
1689{
1690 int err;
1691
1692 /* Primary sanity checks. */
1693 if (!in_dev)
1694 return -EINVAL;
1695
1696 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1697 skb->protocol != htons(ETH_P_IP))
1698 return -EINVAL;
1699
1700 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1701 return -EINVAL;
1702
1703 if (ipv4_is_zeronet(saddr)) {
1704 if (!ipv4_is_local_multicast(daddr) &&
1705 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1706 return -EINVAL;
1707 } else {
1708 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1709 in_dev, itag);
1710 if (err < 0)
1711 return err;
1712 }
1713 return 0;
1714}
1715
1716/* called in rcu_read_lock() section */
1717static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1718 u8 tos, struct net_device *dev, int our)
1719{
1720 struct in_device *in_dev = __in_dev_get_rcu(dev);
1721 unsigned int flags = RTCF_MULTICAST;
1722 struct rtable *rth;
1723 u32 itag = 0;
1724 int err;
1725
1726 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1727 if (err)
1728 return err;
1729
1730 if (our)
1731 flags |= RTCF_LOCAL;
1732
1733 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1734 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1735 if (!rth)
1736 return -ENOBUFS;
1737
1738#ifdef CONFIG_IP_ROUTE_CLASSID
1739 rth->dst.tclassid = itag;
1740#endif
1741 rth->dst.output = ip_rt_bug;
1742 rth->rt_is_input= 1;
1743
1744#ifdef CONFIG_IP_MROUTE
1745 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1746 rth->dst.input = ip_mr_input;
1747#endif
1748 RT_CACHE_STAT_INC(in_slow_mc);
1749
1750 skb_dst_set(skb, &rth->dst);
1751 return 0;
1752}
1753
1754
1755static void ip_handle_martian_source(struct net_device *dev,
1756 struct in_device *in_dev,
1757 struct sk_buff *skb,
1758 __be32 daddr,
1759 __be32 saddr)
1760{
1761 RT_CACHE_STAT_INC(in_martian_src);
1762#ifdef CONFIG_IP_ROUTE_VERBOSE
1763 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1764 /*
1765 * RFC1812 recommendation, if source is martian,
1766 * the only hint is MAC header.
1767 */
1768 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1769 &daddr, &saddr, dev->name);
1770 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1771 print_hex_dump(KERN_WARNING, "ll header: ",
1772 DUMP_PREFIX_OFFSET, 16, 1,
1773 skb_mac_header(skb),
1774 dev->hard_header_len, false);
1775 }
1776 }
1777#endif
1778}
1779
1780/* called in rcu_read_lock() section */
1781static int __mkroute_input(struct sk_buff *skb,
1782 const struct fib_result *res,
1783 struct in_device *in_dev,
1784 __be32 daddr, __be32 saddr, u32 tos)
1785{
1786 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1787 struct net_device *dev = nhc->nhc_dev;
1788 struct fib_nh_exception *fnhe;
1789 struct rtable *rth;
1790 int err;
1791 struct in_device *out_dev;
1792 bool do_cache;
1793 u32 itag = 0;
1794
1795 /* get a working reference to the output device */
1796 out_dev = __in_dev_get_rcu(dev);
1797 if (!out_dev) {
1798 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1799 return -EINVAL;
1800 }
1801
1802 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1803 in_dev->dev, in_dev, &itag);
1804 if (err < 0) {
1805 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1806 saddr);
1807
1808 goto cleanup;
1809 }
1810
1811 do_cache = res->fi && !itag;
1812 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1813 skb->protocol == htons(ETH_P_IP)) {
1814 __be32 gw;
1815
1816 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1817 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1818 inet_addr_onlink(out_dev, saddr, gw))
1819 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1820 }
1821
1822 if (skb->protocol != htons(ETH_P_IP)) {
1823 /* Not IP (i.e. ARP). Do not create route, if it is
1824 * invalid for proxy arp. DNAT routes are always valid.
1825 *
1826 * Proxy arp feature have been extended to allow, ARP
1827 * replies back to the same interface, to support
1828 * Private VLAN switch technologies. See arp.c.
1829 */
1830 if (out_dev == in_dev &&
1831 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1832 err = -EINVAL;
1833 goto cleanup;
1834 }
1835 }
1836
1837 fnhe = find_exception(nhc, daddr);
1838 if (do_cache) {
1839 if (fnhe)
1840 rth = rcu_dereference(fnhe->fnhe_rth_input);
1841 else
1842 rth = rcu_dereference(nhc->nhc_rth_input);
1843 if (rt_cache_valid(rth)) {
1844 skb_dst_set_noref(skb, &rth->dst);
1845 goto out;
1846 }
1847 }
1848
1849 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1850 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1851 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1852 if (!rth) {
1853 err = -ENOBUFS;
1854 goto cleanup;
1855 }
1856
1857 rth->rt_is_input = 1;
1858 RT_CACHE_STAT_INC(in_slow_tot);
1859
1860 rth->dst.input = ip_forward;
1861
1862 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1863 do_cache);
1864 lwtunnel_set_redirect(&rth->dst);
1865 skb_dst_set(skb, &rth->dst);
1866out:
1867 err = 0;
1868 cleanup:
1869 return err;
1870}
1871
1872#ifdef CONFIG_IP_ROUTE_MULTIPATH
1873/* To make ICMP packets follow the right flow, the multipath hash is
1874 * calculated from the inner IP addresses.
1875 */
1876static void ip_multipath_l3_keys(const struct sk_buff *skb,
1877 struct flow_keys *hash_keys)
1878{
1879 const struct iphdr *outer_iph = ip_hdr(skb);
1880 const struct iphdr *key_iph = outer_iph;
1881 const struct iphdr *inner_iph;
1882 const struct icmphdr *icmph;
1883 struct iphdr _inner_iph;
1884 struct icmphdr _icmph;
1885
1886 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1887 goto out;
1888
1889 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1890 goto out;
1891
1892 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1893 &_icmph);
1894 if (!icmph)
1895 goto out;
1896
1897 if (icmph->type != ICMP_DEST_UNREACH &&
1898 icmph->type != ICMP_REDIRECT &&
1899 icmph->type != ICMP_TIME_EXCEEDED &&
1900 icmph->type != ICMP_PARAMETERPROB)
1901 goto out;
1902
1903 inner_iph = skb_header_pointer(skb,
1904 outer_iph->ihl * 4 + sizeof(_icmph),
1905 sizeof(_inner_iph), &_inner_iph);
1906 if (!inner_iph)
1907 goto out;
1908
1909 key_iph = inner_iph;
1910out:
1911 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1912 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1913}
1914
1915/* if skb is set it will be used and fl4 can be NULL */
1916int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1917 const struct sk_buff *skb, struct flow_keys *flkeys)
1918{
1919 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
1920 struct flow_keys hash_keys;
1921 u32 mhash;
1922
1923 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1924 case 0:
1925 memset(&hash_keys, 0, sizeof(hash_keys));
1926 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1927 if (skb) {
1928 ip_multipath_l3_keys(skb, &hash_keys);
1929 } else {
1930 hash_keys.addrs.v4addrs.src = fl4->saddr;
1931 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1932 }
1933 break;
1934 case 1:
1935 /* skb is currently provided only when forwarding */
1936 if (skb) {
1937 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1938 struct flow_keys keys;
1939
1940 /* short-circuit if we already have L4 hash present */
1941 if (skb->l4_hash)
1942 return skb_get_hash_raw(skb) >> 1;
1943
1944 memset(&hash_keys, 0, sizeof(hash_keys));
1945
1946 if (!flkeys) {
1947 skb_flow_dissect_flow_keys(skb, &keys, flag);
1948 flkeys = &keys;
1949 }
1950
1951 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1952 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1953 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1954 hash_keys.ports.src = flkeys->ports.src;
1955 hash_keys.ports.dst = flkeys->ports.dst;
1956 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1957 } else {
1958 memset(&hash_keys, 0, sizeof(hash_keys));
1959 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1960 hash_keys.addrs.v4addrs.src = fl4->saddr;
1961 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1962 hash_keys.ports.src = fl4->fl4_sport;
1963 hash_keys.ports.dst = fl4->fl4_dport;
1964 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1965 }
1966 break;
1967 case 2:
1968 memset(&hash_keys, 0, sizeof(hash_keys));
1969 /* skb is currently provided only when forwarding */
1970 if (skb) {
1971 struct flow_keys keys;
1972
1973 skb_flow_dissect_flow_keys(skb, &keys, 0);
1974 /* Inner can be v4 or v6 */
1975 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1976 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1977 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1978 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1979 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1980 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1981 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1982 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1983 hash_keys.tags.flow_label = keys.tags.flow_label;
1984 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1985 } else {
1986 /* Same as case 0 */
1987 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1988 ip_multipath_l3_keys(skb, &hash_keys);
1989 }
1990 } else {
1991 /* Same as case 0 */
1992 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1993 hash_keys.addrs.v4addrs.src = fl4->saddr;
1994 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1995 }
1996 break;
1997 }
1998 mhash = flow_hash_from_keys(&hash_keys);
1999
2000 if (multipath_hash)
2001 mhash = jhash_2words(mhash, multipath_hash, 0);
2002
2003 return mhash >> 1;
2004}
2005#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2006
2007static int ip_mkroute_input(struct sk_buff *skb,
2008 struct fib_result *res,
2009 struct in_device *in_dev,
2010 __be32 daddr, __be32 saddr, u32 tos,
2011 struct flow_keys *hkeys)
2012{
2013#ifdef CONFIG_IP_ROUTE_MULTIPATH
2014 if (res->fi && fib_info_num_path(res->fi) > 1) {
2015 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2016
2017 fib_select_multipath(res, h);
2018 }
2019#endif
2020
2021 /* create a routing cache entry */
2022 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
2023}
2024
2025/*
2026 * NOTE. We drop all the packets that has local source
2027 * addresses, because every properly looped back packet
2028 * must have correct destination already attached by output routine.
2029 *
2030 * Such approach solves two big problems:
2031 * 1. Not simplex devices are handled properly.
2032 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2033 * called with rcu_read_lock()
2034 */
2035
2036static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2037 u8 tos, struct net_device *dev,
2038 struct fib_result *res)
2039{
2040 struct in_device *in_dev = __in_dev_get_rcu(dev);
2041 struct flow_keys *flkeys = NULL, _flkeys;
2042 struct net *net = dev_net(dev);
2043 struct ip_tunnel_info *tun_info;
2044 int err = -EINVAL;
2045 unsigned int flags = 0;
2046 u32 itag = 0;
2047 struct rtable *rth;
2048 struct flowi4 fl4;
2049 bool do_cache = true;
2050
2051 /* IP on this device is disabled. */
2052
2053 if (!in_dev)
2054 goto out;
2055
2056 /* Check for the most weird martians, which can be not detected
2057 by fib_lookup.
2058 */
2059
2060 tun_info = skb_tunnel_info(skb);
2061 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2062 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2063 else
2064 fl4.flowi4_tun_key.tun_id = 0;
2065 skb_dst_drop(skb);
2066
2067 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2068 goto martian_source;
2069
2070 res->fi = NULL;
2071 res->table = NULL;
2072 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2073 goto brd_input;
2074
2075 /* Accept zero addresses only to limited broadcast;
2076 * I even do not know to fix it or not. Waiting for complains :-)
2077 */
2078 if (ipv4_is_zeronet(saddr))
2079 goto martian_source;
2080
2081 if (ipv4_is_zeronet(daddr))
2082 goto martian_destination;
2083
2084 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2085 * and call it once if daddr or/and saddr are loopback addresses
2086 */
2087 if (ipv4_is_loopback(daddr)) {
2088 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2089 goto martian_destination;
2090 } else if (ipv4_is_loopback(saddr)) {
2091 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2092 goto martian_source;
2093 }
2094
2095 /*
2096 * Now we are ready to route packet.
2097 */
2098 fl4.flowi4_oif = 0;
2099 fl4.flowi4_iif = dev->ifindex;
2100 fl4.flowi4_mark = skb->mark;
2101 fl4.flowi4_tos = tos;
2102 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2103 fl4.flowi4_flags = 0;
2104 fl4.daddr = daddr;
2105 fl4.saddr = saddr;
2106 fl4.flowi4_uid = sock_net_uid(net, NULL);
2107
2108 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2109 flkeys = &_flkeys;
2110 } else {
2111 fl4.flowi4_proto = 0;
2112 fl4.fl4_sport = 0;
2113 fl4.fl4_dport = 0;
2114 }
2115
2116 err = fib_lookup(net, &fl4, res, 0);
2117 if (err != 0) {
2118 if (!IN_DEV_FORWARD(in_dev))
2119 err = -EHOSTUNREACH;
2120 goto no_route;
2121 }
2122
2123 if (res->type == RTN_BROADCAST) {
2124 if (IN_DEV_BFORWARD(in_dev))
2125 goto make_route;
2126 /* not do cache if bc_forwarding is enabled */
2127 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING))
2128 do_cache = false;
2129 goto brd_input;
2130 }
2131
2132 if (res->type == RTN_LOCAL) {
2133 err = fib_validate_source(skb, saddr, daddr, tos,
2134 0, dev, in_dev, &itag);
2135 if (err < 0)
2136 goto martian_source;
2137 goto local_input;
2138 }
2139
2140 if (!IN_DEV_FORWARD(in_dev)) {
2141 err = -EHOSTUNREACH;
2142 goto no_route;
2143 }
2144 if (res->type != RTN_UNICAST)
2145 goto martian_destination;
2146
2147make_route:
2148 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2149out: return err;
2150
2151brd_input:
2152 if (skb->protocol != htons(ETH_P_IP))
2153 goto e_inval;
2154
2155 if (!ipv4_is_zeronet(saddr)) {
2156 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2157 in_dev, &itag);
2158 if (err < 0)
2159 goto martian_source;
2160 }
2161 flags |= RTCF_BROADCAST;
2162 res->type = RTN_BROADCAST;
2163 RT_CACHE_STAT_INC(in_brd);
2164
2165local_input:
2166 do_cache &= res->fi && !itag;
2167 if (do_cache) {
2168 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2169
2170 rth = rcu_dereference(nhc->nhc_rth_input);
2171 if (rt_cache_valid(rth)) {
2172 skb_dst_set_noref(skb, &rth->dst);
2173 err = 0;
2174 goto out;
2175 }
2176 }
2177
2178 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2179 flags | RTCF_LOCAL, res->type,
2180 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2181 if (!rth)
2182 goto e_nobufs;
2183
2184 rth->dst.output= ip_rt_bug;
2185#ifdef CONFIG_IP_ROUTE_CLASSID
2186 rth->dst.tclassid = itag;
2187#endif
2188 rth->rt_is_input = 1;
2189
2190 RT_CACHE_STAT_INC(in_slow_tot);
2191 if (res->type == RTN_UNREACHABLE) {
2192 rth->dst.input= ip_error;
2193 rth->dst.error= -err;
2194 rth->rt_flags &= ~RTCF_LOCAL;
2195 }
2196
2197 if (do_cache) {
2198 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2199
2200 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2201 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2202 WARN_ON(rth->dst.input == lwtunnel_input);
2203 rth->dst.lwtstate->orig_input = rth->dst.input;
2204 rth->dst.input = lwtunnel_input;
2205 }
2206
2207 if (unlikely(!rt_cache_route(nhc, rth)))
2208 rt_add_uncached_list(rth);
2209 }
2210 skb_dst_set(skb, &rth->dst);
2211 err = 0;
2212 goto out;
2213
2214no_route:
2215 RT_CACHE_STAT_INC(in_no_route);
2216 res->type = RTN_UNREACHABLE;
2217 res->fi = NULL;
2218 res->table = NULL;
2219 goto local_input;
2220
2221 /*
2222 * Do not cache martian addresses: they should be logged (RFC1812)
2223 */
2224martian_destination:
2225 RT_CACHE_STAT_INC(in_martian_dst);
2226#ifdef CONFIG_IP_ROUTE_VERBOSE
2227 if (IN_DEV_LOG_MARTIANS(in_dev))
2228 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2229 &daddr, &saddr, dev->name);
2230#endif
2231
2232e_inval:
2233 err = -EINVAL;
2234 goto out;
2235
2236e_nobufs:
2237 err = -ENOBUFS;
2238 goto out;
2239
2240martian_source:
2241 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2242 goto out;
2243}
2244
2245int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2246 u8 tos, struct net_device *dev)
2247{
2248 struct fib_result res;
2249 int err;
2250
2251 tos &= IPTOS_RT_MASK;
2252 rcu_read_lock();
2253 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2254 rcu_read_unlock();
2255
2256 return err;
2257}
2258EXPORT_SYMBOL(ip_route_input_noref);
2259
2260/* called with rcu_read_lock held */
2261int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2262 u8 tos, struct net_device *dev, struct fib_result *res)
2263{
2264 /* Multicast recognition logic is moved from route cache to here.
2265 The problem was that too many Ethernet cards have broken/missing
2266 hardware multicast filters :-( As result the host on multicasting
2267 network acquires a lot of useless route cache entries, sort of
2268 SDR messages from all the world. Now we try to get rid of them.
2269 Really, provided software IP multicast filter is organized
2270 reasonably (at least, hashed), it does not result in a slowdown
2271 comparing with route cache reject entries.
2272 Note, that multicast routers are not affected, because
2273 route cache entry is created eventually.
2274 */
2275 if (ipv4_is_multicast(daddr)) {
2276 struct in_device *in_dev = __in_dev_get_rcu(dev);
2277 int our = 0;
2278 int err = -EINVAL;
2279
2280 if (!in_dev)
2281 return err;
2282 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2283 ip_hdr(skb)->protocol);
2284
2285 /* check l3 master if no match yet */
2286 if (!our && netif_is_l3_slave(dev)) {
2287 struct in_device *l3_in_dev;
2288
2289 l3_in_dev = __in_dev_get_rcu(skb->dev);
2290 if (l3_in_dev)
2291 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2292 ip_hdr(skb)->protocol);
2293 }
2294
2295 if (our
2296#ifdef CONFIG_IP_MROUTE
2297 ||
2298 (!ipv4_is_local_multicast(daddr) &&
2299 IN_DEV_MFORWARD(in_dev))
2300#endif
2301 ) {
2302 err = ip_route_input_mc(skb, daddr, saddr,
2303 tos, dev, our);
2304 }
2305 return err;
2306 }
2307
2308 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2309}
2310
2311/* called with rcu_read_lock() */
2312static struct rtable *__mkroute_output(const struct fib_result *res,
2313 const struct flowi4 *fl4, int orig_oif,
2314 struct net_device *dev_out,
2315 unsigned int flags)
2316{
2317 struct fib_info *fi = res->fi;
2318 struct fib_nh_exception *fnhe;
2319 struct in_device *in_dev;
2320 u16 type = res->type;
2321 struct rtable *rth;
2322 bool do_cache;
2323
2324 in_dev = __in_dev_get_rcu(dev_out);
2325 if (!in_dev)
2326 return ERR_PTR(-EINVAL);
2327
2328 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2329 if (ipv4_is_loopback(fl4->saddr) &&
2330 !(dev_out->flags & IFF_LOOPBACK) &&
2331 !netif_is_l3_master(dev_out))
2332 return ERR_PTR(-EINVAL);
2333
2334 if (ipv4_is_lbcast(fl4->daddr))
2335 type = RTN_BROADCAST;
2336 else if (ipv4_is_multicast(fl4->daddr))
2337 type = RTN_MULTICAST;
2338 else if (ipv4_is_zeronet(fl4->daddr))
2339 return ERR_PTR(-EINVAL);
2340
2341 if (dev_out->flags & IFF_LOOPBACK)
2342 flags |= RTCF_LOCAL;
2343
2344 do_cache = true;
2345 if (type == RTN_BROADCAST) {
2346 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2347 fi = NULL;
2348 } else if (type == RTN_MULTICAST) {
2349 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2350 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2351 fl4->flowi4_proto))
2352 flags &= ~RTCF_LOCAL;
2353 else
2354 do_cache = false;
2355 /* If multicast route do not exist use
2356 * default one, but do not gateway in this case.
2357 * Yes, it is hack.
2358 */
2359 if (fi && res->prefixlen < 4)
2360 fi = NULL;
2361 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2362 (orig_oif != dev_out->ifindex)) {
2363 /* For local routes that require a particular output interface
2364 * we do not want to cache the result. Caching the result
2365 * causes incorrect behaviour when there are multiple source
2366 * addresses on the interface, the end result being that if the
2367 * intended recipient is waiting on that interface for the
2368 * packet he won't receive it because it will be delivered on
2369 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2370 * be set to the loopback interface as well.
2371 */
2372 do_cache = false;
2373 }
2374
2375 fnhe = NULL;
2376 do_cache &= fi != NULL;
2377 if (fi) {
2378 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2379 struct rtable __rcu **prth;
2380
2381 fnhe = find_exception(nhc, fl4->daddr);
2382 if (!do_cache)
2383 goto add;
2384 if (fnhe) {
2385 prth = &fnhe->fnhe_rth_output;
2386 } else {
2387 if (unlikely(fl4->flowi4_flags &
2388 FLOWI_FLAG_KNOWN_NH &&
2389 !(nhc->nhc_gw_family &&
2390 nhc->nhc_scope == RT_SCOPE_LINK))) {
2391 do_cache = false;
2392 goto add;
2393 }
2394 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2395 }
2396 rth = rcu_dereference(*prth);
2397 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2398 return rth;
2399 }
2400
2401add:
2402 rth = rt_dst_alloc(dev_out, flags, type,
2403 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2404 IN_DEV_CONF_GET(in_dev, NOXFRM),
2405 do_cache);
2406 if (!rth)
2407 return ERR_PTR(-ENOBUFS);
2408
2409 rth->rt_iif = orig_oif;
2410
2411 RT_CACHE_STAT_INC(out_slow_tot);
2412
2413 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2414 if (flags & RTCF_LOCAL &&
2415 !(dev_out->flags & IFF_LOOPBACK)) {
2416 rth->dst.output = ip_mc_output;
2417 RT_CACHE_STAT_INC(out_slow_mc);
2418 }
2419#ifdef CONFIG_IP_MROUTE
2420 if (type == RTN_MULTICAST) {
2421 if (IN_DEV_MFORWARD(in_dev) &&
2422 !ipv4_is_local_multicast(fl4->daddr)) {
2423 rth->dst.input = ip_mr_input;
2424 rth->dst.output = ip_mc_output;
2425 }
2426 }
2427#endif
2428 }
2429
2430 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2431 lwtunnel_set_redirect(&rth->dst);
2432
2433 return rth;
2434}
2435
2436/*
2437 * Major route resolver routine.
2438 */
2439
2440struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2441 const struct sk_buff *skb)
2442{
2443 __u8 tos = RT_FL_TOS(fl4);
2444 struct fib_result res = {
2445 .type = RTN_UNSPEC,
2446 .fi = NULL,
2447 .table = NULL,
2448 .tclassid = 0,
2449 };
2450 struct rtable *rth;
2451
2452 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2453 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2454 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2455 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2456
2457 rcu_read_lock();
2458 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2459 rcu_read_unlock();
2460
2461 return rth;
2462}
2463EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2464
2465struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2466 struct fib_result *res,
2467 const struct sk_buff *skb)
2468{
2469 struct net_device *dev_out = NULL;
2470 int orig_oif = fl4->flowi4_oif;
2471 unsigned int flags = 0;
2472 struct rtable *rth;
2473 int err;
2474
2475 if (fl4->saddr) {
2476 if (ipv4_is_multicast(fl4->saddr) ||
2477 ipv4_is_lbcast(fl4->saddr) ||
2478 ipv4_is_zeronet(fl4->saddr)) {
2479 rth = ERR_PTR(-EINVAL);
2480 goto out;
2481 }
2482
2483 rth = ERR_PTR(-ENETUNREACH);
2484
2485 /* I removed check for oif == dev_out->oif here.
2486 It was wrong for two reasons:
2487 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2488 is assigned to multiple interfaces.
2489 2. Moreover, we are allowed to send packets with saddr
2490 of another iface. --ANK
2491 */
2492
2493 if (fl4->flowi4_oif == 0 &&
2494 (ipv4_is_multicast(fl4->daddr) ||
2495 ipv4_is_lbcast(fl4->daddr))) {
2496 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2497 dev_out = __ip_dev_find(net, fl4->saddr, false);
2498 if (!dev_out)
2499 goto out;
2500
2501 /* Special hack: user can direct multicasts
2502 and limited broadcast via necessary interface
2503 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2504 This hack is not just for fun, it allows
2505 vic,vat and friends to work.
2506 They bind socket to loopback, set ttl to zero
2507 and expect that it will work.
2508 From the viewpoint of routing cache they are broken,
2509 because we are not allowed to build multicast path
2510 with loopback source addr (look, routing cache
2511 cannot know, that ttl is zero, so that packet
2512 will not leave this host and route is valid).
2513 Luckily, this hack is good workaround.
2514 */
2515
2516 fl4->flowi4_oif = dev_out->ifindex;
2517 goto make_route;
2518 }
2519
2520 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2521 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2522 if (!__ip_dev_find(net, fl4->saddr, false))
2523 goto out;
2524 }
2525 }
2526
2527
2528 if (fl4->flowi4_oif) {
2529 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2530 rth = ERR_PTR(-ENODEV);
2531 if (!dev_out)
2532 goto out;
2533
2534 /* RACE: Check return value of inet_select_addr instead. */
2535 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2536 rth = ERR_PTR(-ENETUNREACH);
2537 goto out;
2538 }
2539 if (ipv4_is_local_multicast(fl4->daddr) ||
2540 ipv4_is_lbcast(fl4->daddr) ||
2541 fl4->flowi4_proto == IPPROTO_IGMP) {
2542 if (!fl4->saddr)
2543 fl4->saddr = inet_select_addr(dev_out, 0,
2544 RT_SCOPE_LINK);
2545 goto make_route;
2546 }
2547 if (!fl4->saddr) {
2548 if (ipv4_is_multicast(fl4->daddr))
2549 fl4->saddr = inet_select_addr(dev_out, 0,
2550 fl4->flowi4_scope);
2551 else if (!fl4->daddr)
2552 fl4->saddr = inet_select_addr(dev_out, 0,
2553 RT_SCOPE_HOST);
2554 }
2555 }
2556
2557 if (!fl4->daddr) {
2558 fl4->daddr = fl4->saddr;
2559 if (!fl4->daddr)
2560 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2561 dev_out = net->loopback_dev;
2562 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2563 res->type = RTN_LOCAL;
2564 flags |= RTCF_LOCAL;
2565 goto make_route;
2566 }
2567
2568 err = fib_lookup(net, fl4, res, 0);
2569 if (err) {
2570 res->fi = NULL;
2571 res->table = NULL;
2572 if (fl4->flowi4_oif &&
2573 (ipv4_is_multicast(fl4->daddr) ||
2574 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2575 /* Apparently, routing tables are wrong. Assume,
2576 that the destination is on link.
2577
2578 WHY? DW.
2579 Because we are allowed to send to iface
2580 even if it has NO routes and NO assigned
2581 addresses. When oif is specified, routing
2582 tables are looked up with only one purpose:
2583 to catch if destination is gatewayed, rather than
2584 direct. Moreover, if MSG_DONTROUTE is set,
2585 we send packet, ignoring both routing tables
2586 and ifaddr state. --ANK
2587
2588
2589 We could make it even if oif is unknown,
2590 likely IPv6, but we do not.
2591 */
2592
2593 if (fl4->saddr == 0)
2594 fl4->saddr = inet_select_addr(dev_out, 0,
2595 RT_SCOPE_LINK);
2596 res->type = RTN_UNICAST;
2597 goto make_route;
2598 }
2599 rth = ERR_PTR(err);
2600 goto out;
2601 }
2602
2603 if (res->type == RTN_LOCAL) {
2604 if (!fl4->saddr) {
2605 if (res->fi->fib_prefsrc)
2606 fl4->saddr = res->fi->fib_prefsrc;
2607 else
2608 fl4->saddr = fl4->daddr;
2609 }
2610
2611 /* L3 master device is the loopback for that domain */
2612 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2613 net->loopback_dev;
2614
2615 /* make sure orig_oif points to fib result device even
2616 * though packet rx/tx happens over loopback or l3mdev
2617 */
2618 orig_oif = FIB_RES_OIF(*res);
2619
2620 fl4->flowi4_oif = dev_out->ifindex;
2621 flags |= RTCF_LOCAL;
2622 goto make_route;
2623 }
2624
2625 fib_select_path(net, res, fl4, skb);
2626
2627 dev_out = FIB_RES_DEV(*res);
2628 fl4->flowi4_oif = dev_out->ifindex;
2629
2630
2631make_route:
2632 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2633
2634out:
2635 return rth;
2636}
2637
2638static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2639{
2640 return NULL;
2641}
2642
2643static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2644{
2645 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2646
2647 return mtu ? : dst->dev->mtu;
2648}
2649
2650static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2651 struct sk_buff *skb, u32 mtu)
2652{
2653}
2654
2655static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2656 struct sk_buff *skb)
2657{
2658}
2659
2660static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2661 unsigned long old)
2662{
2663 return NULL;
2664}
2665
2666static struct dst_ops ipv4_dst_blackhole_ops = {
2667 .family = AF_INET,
2668 .check = ipv4_blackhole_dst_check,
2669 .mtu = ipv4_blackhole_mtu,
2670 .default_advmss = ipv4_default_advmss,
2671 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2672 .redirect = ipv4_rt_blackhole_redirect,
2673 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2674 .neigh_lookup = ipv4_neigh_lookup,
2675};
2676
2677struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2678{
2679 struct rtable *ort = (struct rtable *) dst_orig;
2680 struct rtable *rt;
2681
2682 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2683 if (rt) {
2684 struct dst_entry *new = &rt->dst;
2685
2686 new->__use = 1;
2687 new->input = dst_discard;
2688 new->output = dst_discard_out;
2689
2690 new->dev = net->loopback_dev;
2691 if (new->dev)
2692 dev_hold(new->dev);
2693
2694 rt->rt_is_input = ort->rt_is_input;
2695 rt->rt_iif = ort->rt_iif;
2696 rt->rt_pmtu = ort->rt_pmtu;
2697 rt->rt_mtu_locked = ort->rt_mtu_locked;
2698
2699 rt->rt_genid = rt_genid_ipv4(net);
2700 rt->rt_flags = ort->rt_flags;
2701 rt->rt_type = ort->rt_type;
2702 rt->rt_uses_gateway = ort->rt_uses_gateway;
2703 rt->rt_gw_family = ort->rt_gw_family;
2704 if (rt->rt_gw_family == AF_INET)
2705 rt->rt_gw4 = ort->rt_gw4;
2706 else if (rt->rt_gw_family == AF_INET6)
2707 rt->rt_gw6 = ort->rt_gw6;
2708
2709 INIT_LIST_HEAD(&rt->rt_uncached);
2710 }
2711
2712 dst_release(dst_orig);
2713
2714 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2715}
2716
2717struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2718 const struct sock *sk)
2719{
2720 struct rtable *rt = __ip_route_output_key(net, flp4);
2721
2722 if (IS_ERR(rt))
2723 return rt;
2724
2725 if (flp4->flowi4_proto)
2726 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2727 flowi4_to_flowi(flp4),
2728 sk, 0);
2729
2730 return rt;
2731}
2732EXPORT_SYMBOL_GPL(ip_route_output_flow);
2733
2734/* called with rcu_read_lock held */
2735static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2736 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2737 struct sk_buff *skb, u32 portid, u32 seq,
2738 unsigned int flags)
2739{
2740 struct rtmsg *r;
2741 struct nlmsghdr *nlh;
2742 unsigned long expires = 0;
2743 u32 error;
2744 u32 metrics[RTAX_MAX];
2745
2746 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2747 if (!nlh)
2748 return -EMSGSIZE;
2749
2750 r = nlmsg_data(nlh);
2751 r->rtm_family = AF_INET;
2752 r->rtm_dst_len = 32;
2753 r->rtm_src_len = 0;
2754 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0;
2755 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2756 if (nla_put_u32(skb, RTA_TABLE, table_id))
2757 goto nla_put_failure;
2758 r->rtm_type = rt->rt_type;
2759 r->rtm_scope = RT_SCOPE_UNIVERSE;
2760 r->rtm_protocol = RTPROT_UNSPEC;
2761 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2762 if (rt->rt_flags & RTCF_NOTIFY)
2763 r->rtm_flags |= RTM_F_NOTIFY;
2764 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2765 r->rtm_flags |= RTCF_DOREDIRECT;
2766
2767 if (nla_put_in_addr(skb, RTA_DST, dst))
2768 goto nla_put_failure;
2769 if (src) {
2770 r->rtm_src_len = 32;
2771 if (nla_put_in_addr(skb, RTA_SRC, src))
2772 goto nla_put_failure;
2773 }
2774 if (rt->dst.dev &&
2775 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2776 goto nla_put_failure;
2777#ifdef CONFIG_IP_ROUTE_CLASSID
2778 if (rt->dst.tclassid &&
2779 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2780 goto nla_put_failure;
2781#endif
2782 if (fl4 && !rt_is_input_route(rt) &&
2783 fl4->saddr != src) {
2784 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2785 goto nla_put_failure;
2786 }
2787 if (rt->rt_uses_gateway) {
2788 if (rt->rt_gw_family == AF_INET &&
2789 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
2790 goto nla_put_failure;
2791 } else if (rt->rt_gw_family == AF_INET6) {
2792 int alen = sizeof(struct in6_addr);
2793 struct nlattr *nla;
2794 struct rtvia *via;
2795
2796 nla = nla_reserve(skb, RTA_VIA, alen + 2);
2797 if (!nla)
2798 goto nla_put_failure;
2799
2800 via = nla_data(nla);
2801 via->rtvia_family = AF_INET6;
2802 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
2803 }
2804 }
2805
2806 expires = rt->dst.expires;
2807 if (expires) {
2808 unsigned long now = jiffies;
2809
2810 if (time_before(now, expires))
2811 expires -= now;
2812 else
2813 expires = 0;
2814 }
2815
2816 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2817 if (rt->rt_pmtu && expires)
2818 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2819 if (rt->rt_mtu_locked && expires)
2820 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2821 if (rtnetlink_put_metrics(skb, metrics) < 0)
2822 goto nla_put_failure;
2823
2824 if (fl4) {
2825 if (fl4->flowi4_mark &&
2826 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2827 goto nla_put_failure;
2828
2829 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2830 nla_put_u32(skb, RTA_UID,
2831 from_kuid_munged(current_user_ns(),
2832 fl4->flowi4_uid)))
2833 goto nla_put_failure;
2834
2835 if (rt_is_input_route(rt)) {
2836#ifdef CONFIG_IP_MROUTE
2837 if (ipv4_is_multicast(dst) &&
2838 !ipv4_is_local_multicast(dst) &&
2839 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2840 int err = ipmr_get_route(net, skb,
2841 fl4->saddr, fl4->daddr,
2842 r, portid);
2843
2844 if (err <= 0) {
2845 if (err == 0)
2846 return 0;
2847 goto nla_put_failure;
2848 }
2849 } else
2850#endif
2851 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
2852 goto nla_put_failure;
2853 }
2854 }
2855
2856 error = rt->dst.error;
2857
2858 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2859 goto nla_put_failure;
2860
2861 nlmsg_end(skb, nlh);
2862 return 0;
2863
2864nla_put_failure:
2865 nlmsg_cancel(skb, nlh);
2866 return -EMSGSIZE;
2867}
2868
2869static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
2870 struct netlink_callback *cb, u32 table_id,
2871 struct fnhe_hash_bucket *bucket, int genid,
2872 int *fa_index, int fa_start, unsigned int flags)
2873{
2874 int i;
2875
2876 for (i = 0; i < FNHE_HASH_SIZE; i++) {
2877 struct fib_nh_exception *fnhe;
2878
2879 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
2880 fnhe = rcu_dereference(fnhe->fnhe_next)) {
2881 struct rtable *rt;
2882 int err;
2883
2884 if (*fa_index < fa_start)
2885 goto next;
2886
2887 if (fnhe->fnhe_genid != genid)
2888 goto next;
2889
2890 if (fnhe->fnhe_expires &&
2891 time_after(jiffies, fnhe->fnhe_expires))
2892 goto next;
2893
2894 rt = rcu_dereference(fnhe->fnhe_rth_input);
2895 if (!rt)
2896 rt = rcu_dereference(fnhe->fnhe_rth_output);
2897 if (!rt)
2898 goto next;
2899
2900 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
2901 table_id, NULL, skb,
2902 NETLINK_CB(cb->skb).portid,
2903 cb->nlh->nlmsg_seq, flags);
2904 if (err)
2905 return err;
2906next:
2907 (*fa_index)++;
2908 }
2909 }
2910
2911 return 0;
2912}
2913
2914int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
2915 u32 table_id, struct fib_info *fi,
2916 int *fa_index, int fa_start, unsigned int flags)
2917{
2918 struct net *net = sock_net(cb->skb->sk);
2919 int nhsel, genid = fnhe_genid(net);
2920
2921 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
2922 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
2923 struct fnhe_hash_bucket *bucket;
2924 int err;
2925
2926 if (nhc->nhc_flags & RTNH_F_DEAD)
2927 continue;
2928
2929 rcu_read_lock();
2930 bucket = rcu_dereference(nhc->nhc_exceptions);
2931 err = 0;
2932 if (bucket)
2933 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
2934 genid, fa_index, fa_start,
2935 flags);
2936 rcu_read_unlock();
2937 if (err)
2938 return err;
2939 }
2940
2941 return 0;
2942}
2943
2944static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
2945 u8 ip_proto, __be16 sport,
2946 __be16 dport)
2947{
2948 struct sk_buff *skb;
2949 struct iphdr *iph;
2950
2951 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2952 if (!skb)
2953 return NULL;
2954
2955 /* Reserve room for dummy headers, this skb can pass
2956 * through good chunk of routing engine.
2957 */
2958 skb_reset_mac_header(skb);
2959 skb_reset_network_header(skb);
2960 skb->protocol = htons(ETH_P_IP);
2961 iph = skb_put(skb, sizeof(struct iphdr));
2962 iph->protocol = ip_proto;
2963 iph->saddr = src;
2964 iph->daddr = dst;
2965 iph->version = 0x4;
2966 iph->frag_off = 0;
2967 iph->ihl = 0x5;
2968 skb_set_transport_header(skb, skb->len);
2969
2970 switch (iph->protocol) {
2971 case IPPROTO_UDP: {
2972 struct udphdr *udph;
2973
2974 udph = skb_put_zero(skb, sizeof(struct udphdr));
2975 udph->source = sport;
2976 udph->dest = dport;
2977 udph->len = sizeof(struct udphdr);
2978 udph->check = 0;
2979 break;
2980 }
2981 case IPPROTO_TCP: {
2982 struct tcphdr *tcph;
2983
2984 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
2985 tcph->source = sport;
2986 tcph->dest = dport;
2987 tcph->doff = sizeof(struct tcphdr) / 4;
2988 tcph->rst = 1;
2989 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
2990 src, dst, 0);
2991 break;
2992 }
2993 case IPPROTO_ICMP: {
2994 struct icmphdr *icmph;
2995
2996 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
2997 icmph->type = ICMP_ECHO;
2998 icmph->code = 0;
2999 }
3000 }
3001
3002 return skb;
3003}
3004
3005static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3006 const struct nlmsghdr *nlh,
3007 struct nlattr **tb,
3008 struct netlink_ext_ack *extack)
3009{
3010 struct rtmsg *rtm;
3011 int i, err;
3012
3013 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3014 NL_SET_ERR_MSG(extack,
3015 "ipv4: Invalid header for route get request");
3016 return -EINVAL;
3017 }
3018
3019 if (!netlink_strict_get_check(skb))
3020 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3021 rtm_ipv4_policy, extack);
3022
3023 rtm = nlmsg_data(nlh);
3024 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3025 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3026 rtm->rtm_table || rtm->rtm_protocol ||
3027 rtm->rtm_scope || rtm->rtm_type) {
3028 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3029 return -EINVAL;
3030 }
3031
3032 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3033 RTM_F_LOOKUP_TABLE |
3034 RTM_F_FIB_MATCH)) {
3035 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3036 return -EINVAL;
3037 }
3038
3039 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3040 rtm_ipv4_policy, extack);
3041 if (err)
3042 return err;
3043
3044 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3045 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3046 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3047 return -EINVAL;
3048 }
3049
3050 for (i = 0; i <= RTA_MAX; i++) {
3051 if (!tb[i])
3052 continue;
3053
3054 switch (i) {
3055 case RTA_IIF:
3056 case RTA_OIF:
3057 case RTA_SRC:
3058 case RTA_DST:
3059 case RTA_IP_PROTO:
3060 case RTA_SPORT:
3061 case RTA_DPORT:
3062 case RTA_MARK:
3063 case RTA_UID:
3064 break;
3065 default:
3066 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3067 return -EINVAL;
3068 }
3069 }
3070
3071 return 0;
3072}
3073
3074static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3075 struct netlink_ext_ack *extack)
3076{
3077 struct net *net = sock_net(in_skb->sk);
3078 struct nlattr *tb[RTA_MAX+1];
3079 u32 table_id = RT_TABLE_MAIN;
3080 __be16 sport = 0, dport = 0;
3081 struct fib_result res = {};
3082 u8 ip_proto = IPPROTO_UDP;
3083 struct rtable *rt = NULL;
3084 struct sk_buff *skb;
3085 struct rtmsg *rtm;
3086 struct flowi4 fl4 = {};
3087 __be32 dst = 0;
3088 __be32 src = 0;
3089 kuid_t uid;
3090 u32 iif;
3091 int err;
3092 int mark;
3093
3094 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3095 if (err < 0)
3096 return err;
3097
3098 rtm = nlmsg_data(nlh);
3099 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
3100 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
3101 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3102 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3103 if (tb[RTA_UID])
3104 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3105 else
3106 uid = (iif ? INVALID_UID : current_uid());
3107
3108 if (tb[RTA_IP_PROTO]) {
3109 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3110 &ip_proto, AF_INET, extack);
3111 if (err)
3112 return err;
3113 }
3114
3115 if (tb[RTA_SPORT])
3116 sport = nla_get_be16(tb[RTA_SPORT]);
3117
3118 if (tb[RTA_DPORT])
3119 dport = nla_get_be16(tb[RTA_DPORT]);
3120
3121 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3122 if (!skb)
3123 return -ENOBUFS;
3124
3125 fl4.daddr = dst;
3126 fl4.saddr = src;
3127 fl4.flowi4_tos = rtm->rtm_tos;
3128 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
3129 fl4.flowi4_mark = mark;
3130 fl4.flowi4_uid = uid;
3131 if (sport)
3132 fl4.fl4_sport = sport;
3133 if (dport)
3134 fl4.fl4_dport = dport;
3135 fl4.flowi4_proto = ip_proto;
3136
3137 rcu_read_lock();
3138
3139 if (iif) {
3140 struct net_device *dev;
3141
3142 dev = dev_get_by_index_rcu(net, iif);
3143 if (!dev) {
3144 err = -ENODEV;
3145 goto errout_rcu;
3146 }
3147
3148 fl4.flowi4_iif = iif; /* for rt_fill_info */
3149 skb->dev = dev;
3150 skb->mark = mark;
3151 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
3152 dev, &res);
3153
3154 rt = skb_rtable(skb);
3155 if (err == 0 && rt->dst.error)
3156 err = -rt->dst.error;
3157 } else {
3158 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3159 skb->dev = net->loopback_dev;
3160 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3161 err = 0;
3162 if (IS_ERR(rt))
3163 err = PTR_ERR(rt);
3164 else
3165 skb_dst_set(skb, &rt->dst);
3166 }
3167
3168 if (err)
3169 goto errout_rcu;
3170
3171 if (rtm->rtm_flags & RTM_F_NOTIFY)
3172 rt->rt_flags |= RTCF_NOTIFY;
3173
3174 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3175 table_id = res.table ? res.table->tb_id : 0;
3176
3177 /* reset skb for netlink reply msg */
3178 skb_trim(skb, 0);
3179 skb_reset_network_header(skb);
3180 skb_reset_transport_header(skb);
3181 skb_reset_mac_header(skb);
3182
3183 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3184 if (!res.fi) {
3185 err = fib_props[res.type].error;
3186 if (!err)
3187 err = -EHOSTUNREACH;
3188 goto errout_rcu;
3189 }
3190 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3191 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
3192 rt->rt_type, res.prefix, res.prefixlen,
3193 fl4.flowi4_tos, res.fi, 0);
3194 } else {
3195 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
3196 NETLINK_CB(in_skb).portid,
3197 nlh->nlmsg_seq, 0);
3198 }
3199 if (err < 0)
3200 goto errout_rcu;
3201
3202 rcu_read_unlock();
3203
3204 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3205
3206errout_free:
3207 return err;
3208errout_rcu:
3209 rcu_read_unlock();
3210 kfree_skb(skb);
3211 goto errout_free;
3212}
3213
3214void ip_rt_multicast_event(struct in_device *in_dev)
3215{
3216 rt_cache_flush(dev_net(in_dev->dev));
3217}
3218
3219#ifdef CONFIG_SYSCTL
3220static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3221static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3222static int ip_rt_gc_elasticity __read_mostly = 8;
3223static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3224
3225static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
3226 void __user *buffer,
3227 size_t *lenp, loff_t *ppos)
3228{
3229 struct net *net = (struct net *)__ctl->extra1;
3230
3231 if (write) {
3232 rt_cache_flush(net);
3233 fnhe_genid_bump(net);
3234 return 0;
3235 }
3236
3237 return -EINVAL;
3238}
3239
3240static struct ctl_table ipv4_route_table[] = {
3241 {
3242 .procname = "gc_thresh",
3243 .data = &ipv4_dst_ops.gc_thresh,
3244 .maxlen = sizeof(int),
3245 .mode = 0644,
3246 .proc_handler = proc_dointvec,
3247 },
3248 {
3249 .procname = "max_size",
3250 .data = &ip_rt_max_size,
3251 .maxlen = sizeof(int),
3252 .mode = 0644,
3253 .proc_handler = proc_dointvec,
3254 },
3255 {
3256 /* Deprecated. Use gc_min_interval_ms */
3257
3258 .procname = "gc_min_interval",
3259 .data = &ip_rt_gc_min_interval,
3260 .maxlen = sizeof(int),
3261 .mode = 0644,
3262 .proc_handler = proc_dointvec_jiffies,
3263 },
3264 {
3265 .procname = "gc_min_interval_ms",
3266 .data = &ip_rt_gc_min_interval,
3267 .maxlen = sizeof(int),
3268 .mode = 0644,
3269 .proc_handler = proc_dointvec_ms_jiffies,
3270 },
3271 {
3272 .procname = "gc_timeout",
3273 .data = &ip_rt_gc_timeout,
3274 .maxlen = sizeof(int),
3275 .mode = 0644,
3276 .proc_handler = proc_dointvec_jiffies,
3277 },
3278 {
3279 .procname = "gc_interval",
3280 .data = &ip_rt_gc_interval,
3281 .maxlen = sizeof(int),
3282 .mode = 0644,
3283 .proc_handler = proc_dointvec_jiffies,
3284 },
3285 {
3286 .procname = "redirect_load",
3287 .data = &ip_rt_redirect_load,
3288 .maxlen = sizeof(int),
3289 .mode = 0644,
3290 .proc_handler = proc_dointvec,
3291 },
3292 {
3293 .procname = "redirect_number",
3294 .data = &ip_rt_redirect_number,
3295 .maxlen = sizeof(int),
3296 .mode = 0644,
3297 .proc_handler = proc_dointvec,
3298 },
3299 {
3300 .procname = "redirect_silence",
3301 .data = &ip_rt_redirect_silence,
3302 .maxlen = sizeof(int),
3303 .mode = 0644,
3304 .proc_handler = proc_dointvec,
3305 },
3306 {
3307 .procname = "error_cost",
3308 .data = &ip_rt_error_cost,
3309 .maxlen = sizeof(int),
3310 .mode = 0644,
3311 .proc_handler = proc_dointvec,
3312 },
3313 {
3314 .procname = "error_burst",
3315 .data = &ip_rt_error_burst,
3316 .maxlen = sizeof(int),
3317 .mode = 0644,
3318 .proc_handler = proc_dointvec,
3319 },
3320 {
3321 .procname = "gc_elasticity",
3322 .data = &ip_rt_gc_elasticity,
3323 .maxlen = sizeof(int),
3324 .mode = 0644,
3325 .proc_handler = proc_dointvec,
3326 },
3327 {
3328 .procname = "mtu_expires",
3329 .data = &ip_rt_mtu_expires,
3330 .maxlen = sizeof(int),
3331 .mode = 0644,
3332 .proc_handler = proc_dointvec_jiffies,
3333 },
3334 {
3335 .procname = "min_pmtu",
3336 .data = &ip_rt_min_pmtu,
3337 .maxlen = sizeof(int),
3338 .mode = 0644,
3339 .proc_handler = proc_dointvec_minmax,
3340 .extra1 = &ip_min_valid_pmtu,
3341 },
3342 {
3343 .procname = "min_adv_mss",
3344 .data = &ip_rt_min_advmss,
3345 .maxlen = sizeof(int),
3346 .mode = 0644,
3347 .proc_handler = proc_dointvec,
3348 },
3349 { }
3350};
3351
3352static const char ipv4_route_flush_procname[] = "flush";
3353
3354static struct ctl_table ipv4_route_flush_table[] = {
3355 {
3356 .procname = ipv4_route_flush_procname,
3357 .maxlen = sizeof(int),
3358 .mode = 0200,
3359 .proc_handler = ipv4_sysctl_rtcache_flush,
3360 },
3361 { },
3362};
3363
3364static __net_init int sysctl_route_net_init(struct net *net)
3365{
3366 struct ctl_table *tbl;
3367
3368 tbl = ipv4_route_flush_table;
3369 if (!net_eq(net, &init_net)) {
3370 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3371 if (!tbl)
3372 goto err_dup;
3373
3374 /* Don't export non-whitelisted sysctls to unprivileged users */
3375 if (net->user_ns != &init_user_ns) {
3376 if (tbl[0].procname != ipv4_route_flush_procname)
3377 tbl[0].procname = NULL;
3378 }
3379 }
3380 tbl[0].extra1 = net;
3381
3382 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3383 if (!net->ipv4.route_hdr)
3384 goto err_reg;
3385 return 0;
3386
3387err_reg:
3388 if (tbl != ipv4_route_flush_table)
3389 kfree(tbl);
3390err_dup:
3391 return -ENOMEM;
3392}
3393
3394static __net_exit void sysctl_route_net_exit(struct net *net)
3395{
3396 struct ctl_table *tbl;
3397
3398 tbl = net->ipv4.route_hdr->ctl_table_arg;
3399 unregister_net_sysctl_table(net->ipv4.route_hdr);
3400 BUG_ON(tbl == ipv4_route_flush_table);
3401 kfree(tbl);
3402}
3403
3404static __net_initdata struct pernet_operations sysctl_route_ops = {
3405 .init = sysctl_route_net_init,
3406 .exit = sysctl_route_net_exit,
3407};
3408#endif
3409
3410static __net_init int rt_genid_init(struct net *net)
3411{
3412 atomic_set(&net->ipv4.rt_genid, 0);
3413 atomic_set(&net->fnhe_genid, 0);
3414 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3415 return 0;
3416}
3417
3418static __net_initdata struct pernet_operations rt_genid_ops = {
3419 .init = rt_genid_init,
3420};
3421
3422static int __net_init ipv4_inetpeer_init(struct net *net)
3423{
3424 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3425
3426 if (!bp)
3427 return -ENOMEM;
3428 inet_peer_base_init(bp);
3429 net->ipv4.peers = bp;
3430 return 0;
3431}
3432
3433static void __net_exit ipv4_inetpeer_exit(struct net *net)
3434{
3435 struct inet_peer_base *bp = net->ipv4.peers;
3436
3437 net->ipv4.peers = NULL;
3438 inetpeer_invalidate_tree(bp);
3439 kfree(bp);
3440}
3441
3442static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3443 .init = ipv4_inetpeer_init,
3444 .exit = ipv4_inetpeer_exit,
3445};
3446
3447#ifdef CONFIG_IP_ROUTE_CLASSID
3448struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3449#endif /* CONFIG_IP_ROUTE_CLASSID */
3450
3451int __init ip_rt_init(void)
3452{
3453 int cpu;
3454
3455 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents),
3456 GFP_KERNEL);
3457 if (!ip_idents)
3458 panic("IP: failed to allocate ip_idents\n");
3459
3460 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3461
3462 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3463 if (!ip_tstamps)
3464 panic("IP: failed to allocate ip_tstamps\n");
3465
3466 for_each_possible_cpu(cpu) {
3467 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3468
3469 INIT_LIST_HEAD(&ul->head);
3470 spin_lock_init(&ul->lock);
3471 }
3472#ifdef CONFIG_IP_ROUTE_CLASSID
3473 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3474 if (!ip_rt_acct)
3475 panic("IP: failed to allocate ip_rt_acct\n");
3476#endif
3477
3478 ipv4_dst_ops.kmem_cachep =
3479 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3480 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3481
3482 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3483
3484 if (dst_entries_init(&ipv4_dst_ops) < 0)
3485 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3486
3487 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3488 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3489
3490 ipv4_dst_ops.gc_thresh = ~0;
3491 ip_rt_max_size = INT_MAX;
3492
3493 devinet_init();
3494 ip_fib_init();
3495
3496 if (ip_rt_proc_init())
3497 pr_err("Unable to create route proc files\n");
3498#ifdef CONFIG_XFRM
3499 xfrm_init();
3500 xfrm4_init();
3501#endif
3502 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3503 RTNL_FLAG_DOIT_UNLOCKED);
3504
3505#ifdef CONFIG_SYSCTL
3506 register_pernet_subsys(&sysctl_route_ops);
3507#endif
3508 register_pernet_subsys(&rt_genid_ops);
3509 register_pernet_subsys(&ipv4_inetpeer_ops);
3510 return 0;
3511}
3512
3513#ifdef CONFIG_SYSCTL
3514/*
3515 * We really need to sanitize the damn ipv4 init order, then all
3516 * this nonsense will go away.
3517 */
3518void __init ip_static_sysctl_init(void)
3519{
3520 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3521}
3522#endif