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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/bitops.h>
65#include <linux/kernel.h>
66#include <linux/mm.h>
67#include <linux/memblock.h>
68#include <linux/socket.h>
69#include <linux/errno.h>
70#include <linux/in.h>
71#include <linux/inet.h>
72#include <linux/netdevice.h>
73#include <linux/proc_fs.h>
74#include <linux/init.h>
75#include <linux/skbuff.h>
76#include <linux/inetdevice.h>
77#include <linux/igmp.h>
78#include <linux/pkt_sched.h>
79#include <linux/mroute.h>
80#include <linux/netfilter_ipv4.h>
81#include <linux/random.h>
82#include <linux/rcupdate.h>
83#include <linux/slab.h>
84#include <linux/jhash.h>
85#include <net/dst.h>
86#include <net/dst_metadata.h>
87#include <net/inet_dscp.h>
88#include <net/net_namespace.h>
89#include <net/ip.h>
90#include <net/route.h>
91#include <net/inetpeer.h>
92#include <net/sock.h>
93#include <net/ip_fib.h>
94#include <net/nexthop.h>
95#include <net/tcp.h>
96#include <net/icmp.h>
97#include <net/xfrm.h>
98#include <net/lwtunnel.h>
99#include <net/netevent.h>
100#include <net/rtnetlink.h>
101#ifdef CONFIG_SYSCTL
102#include <linux/sysctl.h>
103#endif
104#include <net/secure_seq.h>
105#include <net/ip_tunnels.h>
106
107#include "fib_lookup.h"
108
109#define RT_GC_TIMEOUT (300*HZ)
110
111#define DEFAULT_MIN_PMTU (512 + 20 + 20)
112#define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
113#define DEFAULT_MIN_ADVMSS 256
114static int ip_rt_max_size;
115static int ip_rt_redirect_number __read_mostly = 9;
116static int ip_rt_redirect_load __read_mostly = HZ / 50;
117static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
118static int ip_rt_error_cost __read_mostly = HZ;
119static int ip_rt_error_burst __read_mostly = 5 * HZ;
120
121static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
122
123/*
124 * Interface to generic destination cache.
125 */
126
127INDIRECT_CALLABLE_SCOPE
128struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
129static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
130INDIRECT_CALLABLE_SCOPE
131unsigned int ipv4_mtu(const struct dst_entry *dst);
132static void ipv4_negative_advice(struct sock *sk,
133 struct dst_entry *dst);
134static void ipv4_link_failure(struct sk_buff *skb);
135static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
136 struct sk_buff *skb, u32 mtu,
137 bool confirm_neigh);
138static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb);
140static void ipv4_dst_destroy(struct dst_entry *dst);
141
142static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
143{
144 WARN_ON(1);
145 return NULL;
146}
147
148static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
149 struct sk_buff *skb,
150 const void *daddr);
151static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
152
153static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
157 .mtu = ipv4_mtu,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
166 .confirm_neigh = ipv4_confirm_neigh,
167};
168
169#define ECN_OR_COST(class) TC_PRIO_##class
170
171const __u8 ip_tos2prio[16] = {
172 TC_PRIO_BESTEFFORT,
173 ECN_OR_COST(BESTEFFORT),
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(BESTEFFORT),
176 TC_PRIO_BULK,
177 ECN_OR_COST(BULK),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_INTERACTIVE,
181 ECN_OR_COST(INTERACTIVE),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE_BULK,
185 ECN_OR_COST(INTERACTIVE_BULK),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK)
188};
189EXPORT_SYMBOL(ip_tos2prio);
190
191static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
192#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
193
194#ifdef CONFIG_PROC_FS
195static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
196{
197 if (*pos)
198 return NULL;
199 return SEQ_START_TOKEN;
200}
201
202static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
203{
204 ++*pos;
205 return NULL;
206}
207
208static void rt_cache_seq_stop(struct seq_file *seq, void *v)
209{
210}
211
212static int rt_cache_seq_show(struct seq_file *seq, void *v)
213{
214 if (v == SEQ_START_TOKEN)
215 seq_printf(seq, "%-127s\n",
216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
218 "HHUptod\tSpecDst");
219 return 0;
220}
221
222static const struct seq_operations rt_cache_seq_ops = {
223 .start = rt_cache_seq_start,
224 .next = rt_cache_seq_next,
225 .stop = rt_cache_seq_stop,
226 .show = rt_cache_seq_show,
227};
228
229static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
230{
231 int cpu;
232
233 if (*pos == 0)
234 return SEQ_START_TOKEN;
235
236 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
237 if (!cpu_possible(cpu))
238 continue;
239 *pos = cpu+1;
240 return &per_cpu(rt_cache_stat, cpu);
241 }
242 return NULL;
243}
244
245static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
246{
247 int cpu;
248
249 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
251 continue;
252 *pos = cpu+1;
253 return &per_cpu(rt_cache_stat, cpu);
254 }
255 (*pos)++;
256 return NULL;
257
258}
259
260static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
261{
262
263}
264
265static int rt_cpu_seq_show(struct seq_file *seq, void *v)
266{
267 struct rt_cache_stat *st = v;
268
269 if (v == SEQ_START_TOKEN) {
270 seq_puts(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");
271 return 0;
272 }
273
274 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x "
275 "%08x %08x %08x %08x %08x %08x "
276 "%08x %08x %08x %08x\n",
277 dst_entries_get_slow(&ipv4_dst_ops),
278 0, /* st->in_hit */
279 st->in_slow_tot,
280 st->in_slow_mc,
281 st->in_no_route,
282 st->in_brd,
283 st->in_martian_dst,
284 st->in_martian_src,
285
286 0, /* st->out_hit */
287 st->out_slow_tot,
288 st->out_slow_mc,
289
290 0, /* st->gc_total */
291 0, /* st->gc_ignored */
292 0, /* st->gc_goal_miss */
293 0, /* st->gc_dst_overflow */
294 0, /* st->in_hlist_search */
295 0 /* st->out_hlist_search */
296 );
297 return 0;
298}
299
300static const struct seq_operations rt_cpu_seq_ops = {
301 .start = rt_cpu_seq_start,
302 .next = rt_cpu_seq_next,
303 .stop = rt_cpu_seq_stop,
304 .show = rt_cpu_seq_show,
305};
306
307#ifdef CONFIG_IP_ROUTE_CLASSID
308static int rt_acct_proc_show(struct seq_file *m, void *v)
309{
310 struct ip_rt_acct *dst, *src;
311 unsigned int i, j;
312
313 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
314 if (!dst)
315 return -ENOMEM;
316
317 for_each_possible_cpu(i) {
318 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
319 for (j = 0; j < 256; j++) {
320 dst[j].o_bytes += src[j].o_bytes;
321 dst[j].o_packets += src[j].o_packets;
322 dst[j].i_bytes += src[j].i_bytes;
323 dst[j].i_packets += src[j].i_packets;
324 }
325 }
326
327 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
328 kfree(dst);
329 return 0;
330}
331#endif
332
333static int __net_init ip_rt_do_proc_init(struct net *net)
334{
335 struct proc_dir_entry *pde;
336
337 pde = proc_create_seq("rt_cache", 0444, net->proc_net,
338 &rt_cache_seq_ops);
339 if (!pde)
340 goto err1;
341
342 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat,
343 &rt_cpu_seq_ops);
344 if (!pde)
345 goto err2;
346
347#ifdef CONFIG_IP_ROUTE_CLASSID
348 pde = proc_create_single("rt_acct", 0, net->proc_net,
349 rt_acct_proc_show);
350 if (!pde)
351 goto err3;
352#endif
353 return 0;
354
355#ifdef CONFIG_IP_ROUTE_CLASSID
356err3:
357 remove_proc_entry("rt_cache", net->proc_net_stat);
358#endif
359err2:
360 remove_proc_entry("rt_cache", net->proc_net);
361err1:
362 return -ENOMEM;
363}
364
365static void __net_exit ip_rt_do_proc_exit(struct net *net)
366{
367 remove_proc_entry("rt_cache", net->proc_net_stat);
368 remove_proc_entry("rt_cache", net->proc_net);
369#ifdef CONFIG_IP_ROUTE_CLASSID
370 remove_proc_entry("rt_acct", net->proc_net);
371#endif
372}
373
374static struct pernet_operations ip_rt_proc_ops __net_initdata = {
375 .init = ip_rt_do_proc_init,
376 .exit = ip_rt_do_proc_exit,
377};
378
379static int __init ip_rt_proc_init(void)
380{
381 return register_pernet_subsys(&ip_rt_proc_ops);
382}
383
384#else
385static inline int ip_rt_proc_init(void)
386{
387 return 0;
388}
389#endif /* CONFIG_PROC_FS */
390
391static inline bool rt_is_expired(const struct rtable *rth)
392{
393 bool res;
394
395 rcu_read_lock();
396 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev));
397 rcu_read_unlock();
398
399 return res;
400}
401
402void rt_cache_flush(struct net *net)
403{
404 rt_genid_bump_ipv4(net);
405}
406
407static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
408 struct sk_buff *skb,
409 const void *daddr)
410{
411 const struct rtable *rt = container_of(dst, struct rtable, dst);
412 struct net_device *dev = dst->dev;
413 struct neighbour *n;
414
415 rcu_read_lock();
416
417 if (likely(rt->rt_gw_family == AF_INET)) {
418 n = ip_neigh_gw4(dev, rt->rt_gw4);
419 } else if (rt->rt_gw_family == AF_INET6) {
420 n = ip_neigh_gw6(dev, &rt->rt_gw6);
421 } else {
422 __be32 pkey;
423
424 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
425 n = ip_neigh_gw4(dev, pkey);
426 }
427
428 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
429 n = NULL;
430
431 rcu_read_unlock();
432
433 return n;
434}
435
436static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
437{
438 const struct rtable *rt = container_of(dst, struct rtable, dst);
439 struct net_device *dev = dst->dev;
440 const __be32 *pkey = daddr;
441
442 if (rt->rt_gw_family == AF_INET) {
443 pkey = (const __be32 *)&rt->rt_gw4;
444 } else if (rt->rt_gw_family == AF_INET6) {
445 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
446 } else if (!daddr ||
447 (rt->rt_flags &
448 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
449 return;
450 }
451 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
452}
453
454/* Hash tables of size 2048..262144 depending on RAM size.
455 * Each bucket uses 8 bytes.
456 */
457static u32 ip_idents_mask __read_mostly;
458static atomic_t *ip_idents __read_mostly;
459static u32 *ip_tstamps __read_mostly;
460
461/* In order to protect privacy, we add a perturbation to identifiers
462 * if one generator is seldom used. This makes hard for an attacker
463 * to infer how many packets were sent between two points in time.
464 */
465static u32 ip_idents_reserve(u32 hash, int segs)
466{
467 u32 bucket, old, now = (u32)jiffies;
468 atomic_t *p_id;
469 u32 *p_tstamp;
470 u32 delta = 0;
471
472 bucket = hash & ip_idents_mask;
473 p_tstamp = ip_tstamps + bucket;
474 p_id = ip_idents + bucket;
475 old = READ_ONCE(*p_tstamp);
476
477 if (old != now && cmpxchg(p_tstamp, old, now) == old)
478 delta = get_random_u32_below(now - old);
479
480 /* If UBSAN reports an error there, please make sure your compiler
481 * supports -fno-strict-overflow before reporting it that was a bug
482 * in UBSAN, and it has been fixed in GCC-8.
483 */
484 return atomic_add_return(segs + delta, p_id) - segs;
485}
486
487void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
488{
489 u32 hash, id;
490
491 /* Note the following code is not safe, but this is okay. */
492 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
493 get_random_bytes(&net->ipv4.ip_id_key,
494 sizeof(net->ipv4.ip_id_key));
495
496 hash = siphash_3u32((__force u32)iph->daddr,
497 (__force u32)iph->saddr,
498 iph->protocol,
499 &net->ipv4.ip_id_key);
500 id = ip_idents_reserve(hash, segs);
501 iph->id = htons(id);
502}
503EXPORT_SYMBOL(__ip_select_ident);
504
505static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
506 const struct sock *sk, const struct iphdr *iph,
507 int oif, __u8 tos, u8 prot, u32 mark,
508 int flow_flags)
509{
510 __u8 scope = RT_SCOPE_UNIVERSE;
511
512 if (sk) {
513 oif = sk->sk_bound_dev_if;
514 mark = READ_ONCE(sk->sk_mark);
515 tos = ip_sock_rt_tos(sk);
516 scope = ip_sock_rt_scope(sk);
517 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW :
518 sk->sk_protocol;
519 }
520
521 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope,
522 prot, flow_flags, iph->daddr, iph->saddr, 0, 0,
523 sock_net_uid(net, sk));
524}
525
526static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
527 const struct sock *sk)
528{
529 const struct net *net = dev_net(skb->dev);
530 const struct iphdr *iph = ip_hdr(skb);
531 int oif = skb->dev->ifindex;
532 u8 prot = iph->protocol;
533 u32 mark = skb->mark;
534 __u8 tos = iph->tos;
535
536 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
537}
538
539static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
540{
541 const struct inet_sock *inet = inet_sk(sk);
542 const struct ip_options_rcu *inet_opt;
543 __be32 daddr = inet->inet_daddr;
544
545 rcu_read_lock();
546 inet_opt = rcu_dereference(inet->inet_opt);
547 if (inet_opt && inet_opt->opt.srr)
548 daddr = inet_opt->opt.faddr;
549 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark),
550 ip_sock_rt_tos(sk),
551 ip_sock_rt_scope(sk),
552 inet_test_bit(HDRINCL, sk) ?
553 IPPROTO_RAW : sk->sk_protocol,
554 inet_sk_flowi_flags(sk),
555 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
556 rcu_read_unlock();
557}
558
559static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
560 const struct sk_buff *skb)
561{
562 if (skb)
563 build_skb_flow_key(fl4, skb, sk);
564 else
565 build_sk_flow_key(fl4, sk);
566}
567
568static DEFINE_SPINLOCK(fnhe_lock);
569
570static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
571{
572 struct rtable *rt;
573
574 rt = rcu_dereference(fnhe->fnhe_rth_input);
575 if (rt) {
576 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
577 dst_dev_put(&rt->dst);
578 dst_release(&rt->dst);
579 }
580 rt = rcu_dereference(fnhe->fnhe_rth_output);
581 if (rt) {
582 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
583 dst_dev_put(&rt->dst);
584 dst_release(&rt->dst);
585 }
586}
587
588static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
589{
590 struct fib_nh_exception __rcu **fnhe_p, **oldest_p;
591 struct fib_nh_exception *fnhe, *oldest = NULL;
592
593 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) {
594 fnhe = rcu_dereference_protected(*fnhe_p,
595 lockdep_is_held(&fnhe_lock));
596 if (!fnhe)
597 break;
598 if (!oldest ||
599 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) {
600 oldest = fnhe;
601 oldest_p = fnhe_p;
602 }
603 }
604 fnhe_flush_routes(oldest);
605 *oldest_p = oldest->fnhe_next;
606 kfree_rcu(oldest, rcu);
607}
608
609static u32 fnhe_hashfun(__be32 daddr)
610{
611 static siphash_aligned_key_t fnhe_hash_key;
612 u64 hval;
613
614 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));
615 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key);
616 return hash_64(hval, FNHE_HASH_SHIFT);
617}
618
619static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
620{
621 rt->rt_pmtu = fnhe->fnhe_pmtu;
622 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
623 rt->dst.expires = fnhe->fnhe_expires;
624
625 if (fnhe->fnhe_gw) {
626 rt->rt_flags |= RTCF_REDIRECTED;
627 rt->rt_uses_gateway = 1;
628 rt->rt_gw_family = AF_INET;
629 rt->rt_gw4 = fnhe->fnhe_gw;
630 }
631}
632
633static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
634 __be32 gw, u32 pmtu, bool lock,
635 unsigned long expires)
636{
637 struct fnhe_hash_bucket *hash;
638 struct fib_nh_exception *fnhe;
639 struct rtable *rt;
640 u32 genid, hval;
641 unsigned int i;
642 int depth;
643
644 genid = fnhe_genid(dev_net(nhc->nhc_dev));
645 hval = fnhe_hashfun(daddr);
646
647 spin_lock_bh(&fnhe_lock);
648
649 hash = rcu_dereference(nhc->nhc_exceptions);
650 if (!hash) {
651 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
652 if (!hash)
653 goto out_unlock;
654 rcu_assign_pointer(nhc->nhc_exceptions, hash);
655 }
656
657 hash += hval;
658
659 depth = 0;
660 for (fnhe = rcu_dereference(hash->chain); fnhe;
661 fnhe = rcu_dereference(fnhe->fnhe_next)) {
662 if (fnhe->fnhe_daddr == daddr)
663 break;
664 depth++;
665 }
666
667 if (fnhe) {
668 if (fnhe->fnhe_genid != genid)
669 fnhe->fnhe_genid = genid;
670 if (gw)
671 fnhe->fnhe_gw = gw;
672 if (pmtu) {
673 fnhe->fnhe_pmtu = pmtu;
674 fnhe->fnhe_mtu_locked = lock;
675 }
676 fnhe->fnhe_expires = max(1UL, expires);
677 /* Update all cached dsts too */
678 rt = rcu_dereference(fnhe->fnhe_rth_input);
679 if (rt)
680 fill_route_from_fnhe(rt, fnhe);
681 rt = rcu_dereference(fnhe->fnhe_rth_output);
682 if (rt)
683 fill_route_from_fnhe(rt, fnhe);
684 } else {
685 /* Randomize max depth to avoid some side channels attacks. */
686 int max_depth = FNHE_RECLAIM_DEPTH +
687 get_random_u32_below(FNHE_RECLAIM_DEPTH);
688
689 while (depth > max_depth) {
690 fnhe_remove_oldest(hash);
691 depth--;
692 }
693
694 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
695 if (!fnhe)
696 goto out_unlock;
697
698 fnhe->fnhe_next = hash->chain;
699
700 fnhe->fnhe_genid = genid;
701 fnhe->fnhe_daddr = daddr;
702 fnhe->fnhe_gw = gw;
703 fnhe->fnhe_pmtu = pmtu;
704 fnhe->fnhe_mtu_locked = lock;
705 fnhe->fnhe_expires = max(1UL, expires);
706
707 rcu_assign_pointer(hash->chain, fnhe);
708
709 /* Exception created; mark the cached routes for the nexthop
710 * stale, so anyone caching it rechecks if this exception
711 * applies to them.
712 */
713 rt = rcu_dereference(nhc->nhc_rth_input);
714 if (rt)
715 rt->dst.obsolete = DST_OBSOLETE_KILL;
716
717 for_each_possible_cpu(i) {
718 struct rtable __rcu **prt;
719
720 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
721 rt = rcu_dereference(*prt);
722 if (rt)
723 rt->dst.obsolete = DST_OBSOLETE_KILL;
724 }
725 }
726
727 fnhe->fnhe_stamp = jiffies;
728
729out_unlock:
730 spin_unlock_bh(&fnhe_lock);
731}
732
733static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
734 bool kill_route)
735{
736 __be32 new_gw = icmp_hdr(skb)->un.gateway;
737 __be32 old_gw = ip_hdr(skb)->saddr;
738 struct net_device *dev = skb->dev;
739 struct in_device *in_dev;
740 struct fib_result res;
741 struct neighbour *n;
742 struct net *net;
743
744 switch (icmp_hdr(skb)->code & 7) {
745 case ICMP_REDIR_NET:
746 case ICMP_REDIR_NETTOS:
747 case ICMP_REDIR_HOST:
748 case ICMP_REDIR_HOSTTOS:
749 break;
750
751 default:
752 return;
753 }
754
755 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
756 return;
757
758 in_dev = __in_dev_get_rcu(dev);
759 if (!in_dev)
760 return;
761
762 net = dev_net(dev);
763 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
764 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
765 ipv4_is_zeronet(new_gw))
766 goto reject_redirect;
767
768 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
769 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
770 goto reject_redirect;
771 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
772 goto reject_redirect;
773 } else {
774 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
775 goto reject_redirect;
776 }
777
778 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw);
779 if (!n)
780 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
781 if (!IS_ERR(n)) {
782 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) {
783 neigh_event_send(n, NULL);
784 } else {
785 if (fib_lookup(net, fl4, &res, 0) == 0) {
786 struct fib_nh_common *nhc;
787
788 fib_select_path(net, &res, fl4, skb);
789 nhc = FIB_RES_NHC(res);
790 update_or_create_fnhe(nhc, fl4->daddr, new_gw,
791 0, false,
792 jiffies + ip_rt_gc_timeout);
793 }
794 if (kill_route)
795 rt->dst.obsolete = DST_OBSOLETE_KILL;
796 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
797 }
798 neigh_release(n);
799 }
800 return;
801
802reject_redirect:
803#ifdef CONFIG_IP_ROUTE_VERBOSE
804 if (IN_DEV_LOG_MARTIANS(in_dev)) {
805 const struct iphdr *iph = (const struct iphdr *) skb->data;
806 __be32 daddr = iph->daddr;
807 __be32 saddr = iph->saddr;
808
809 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
810 " Advised path = %pI4 -> %pI4\n",
811 &old_gw, dev->name, &new_gw,
812 &saddr, &daddr);
813 }
814#endif
815 ;
816}
817
818static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
819{
820 struct rtable *rt;
821 struct flowi4 fl4;
822 const struct iphdr *iph = (const struct iphdr *) skb->data;
823 struct net *net = dev_net(skb->dev);
824 int oif = skb->dev->ifindex;
825 u8 prot = iph->protocol;
826 u32 mark = skb->mark;
827 __u8 tos = iph->tos;
828
829 rt = dst_rtable(dst);
830
831 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
832 __ip_do_redirect(rt, skb, &fl4, true);
833}
834
835static void ipv4_negative_advice(struct sock *sk,
836 struct dst_entry *dst)
837{
838 struct rtable *rt = dst_rtable(dst);
839
840 if ((dst->obsolete > 0) ||
841 (rt->rt_flags & RTCF_REDIRECTED) ||
842 rt->dst.expires)
843 sk_dst_reset(sk);
844}
845
846/*
847 * Algorithm:
848 * 1. The first ip_rt_redirect_number redirects are sent
849 * with exponential backoff, then we stop sending them at all,
850 * assuming that the host ignores our redirects.
851 * 2. If we did not see packets requiring redirects
852 * during ip_rt_redirect_silence, we assume that the host
853 * forgot redirected route and start to send redirects again.
854 *
855 * This algorithm is much cheaper and more intelligent than dumb load limiting
856 * in icmp.c.
857 *
858 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
859 * and "frag. need" (breaks PMTU discovery) in icmp.c.
860 */
861
862void ip_rt_send_redirect(struct sk_buff *skb)
863{
864 struct rtable *rt = skb_rtable(skb);
865 struct in_device *in_dev;
866 struct inet_peer *peer;
867 struct net *net;
868 int log_martians;
869 int vif;
870
871 rcu_read_lock();
872 in_dev = __in_dev_get_rcu(rt->dst.dev);
873 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
874 rcu_read_unlock();
875 return;
876 }
877 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
878 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
879
880 net = dev_net(rt->dst.dev);
881 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif);
882 if (!peer) {
883 rcu_read_unlock();
884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
885 rt_nexthop(rt, ip_hdr(skb)->daddr));
886 return;
887 }
888
889 /* No redirected packets during ip_rt_redirect_silence;
890 * reset the algorithm.
891 */
892 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
893 peer->rate_tokens = 0;
894 peer->n_redirects = 0;
895 }
896
897 /* Too many ignored redirects; do not send anything
898 * set dst.rate_last to the last seen redirected packet.
899 */
900 if (peer->n_redirects >= ip_rt_redirect_number) {
901 peer->rate_last = jiffies;
902 goto out_unlock;
903 }
904
905 /* Check for load limit; set rate_last to the latest sent
906 * redirect.
907 */
908 if (peer->n_redirects == 0 ||
909 time_after(jiffies,
910 (peer->rate_last +
911 (ip_rt_redirect_load << peer->n_redirects)))) {
912 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
913
914 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
915 peer->rate_last = jiffies;
916 ++peer->n_redirects;
917 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians &&
918 peer->n_redirects == ip_rt_redirect_number)
919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
920 &ip_hdr(skb)->saddr, inet_iif(skb),
921 &ip_hdr(skb)->daddr, &gw);
922 }
923out_unlock:
924 rcu_read_unlock();
925}
926
927static int ip_error(struct sk_buff *skb)
928{
929 struct rtable *rt = skb_rtable(skb);
930 struct net_device *dev = skb->dev;
931 struct in_device *in_dev;
932 struct inet_peer *peer;
933 unsigned long now;
934 struct net *net;
935 SKB_DR(reason);
936 bool send;
937 int code;
938
939 if (netif_is_l3_master(skb->dev)) {
940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
941 if (!dev)
942 goto out;
943 }
944
945 in_dev = __in_dev_get_rcu(dev);
946
947 /* IP on this device is disabled. */
948 if (!in_dev)
949 goto out;
950
951 net = dev_net(rt->dst.dev);
952 if (!IN_DEV_FORWARD(in_dev)) {
953 switch (rt->dst.error) {
954 case EHOSTUNREACH:
955 SKB_DR_SET(reason, IP_INADDRERRORS);
956 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
957 break;
958
959 case ENETUNREACH:
960 SKB_DR_SET(reason, IP_INNOROUTES);
961 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
962 break;
963 }
964 goto out;
965 }
966
967 switch (rt->dst.error) {
968 case EINVAL:
969 default:
970 goto out;
971 case EHOSTUNREACH:
972 code = ICMP_HOST_UNREACH;
973 break;
974 case ENETUNREACH:
975 code = ICMP_NET_UNREACH;
976 SKB_DR_SET(reason, IP_INNOROUTES);
977 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
978 break;
979 case EACCES:
980 code = ICMP_PKT_FILTERED;
981 break;
982 }
983
984 rcu_read_lock();
985 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
986 l3mdev_master_ifindex_rcu(skb->dev));
987 send = true;
988 if (peer) {
989 now = jiffies;
990 peer->rate_tokens += now - peer->rate_last;
991 if (peer->rate_tokens > ip_rt_error_burst)
992 peer->rate_tokens = ip_rt_error_burst;
993 peer->rate_last = now;
994 if (peer->rate_tokens >= ip_rt_error_cost)
995 peer->rate_tokens -= ip_rt_error_cost;
996 else
997 send = false;
998 }
999 rcu_read_unlock();
1000
1001 if (send)
1002 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1003
1004out: kfree_skb_reason(skb, reason);
1005 return 0;
1006}
1007
1008static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1009{
1010 struct dst_entry *dst = &rt->dst;
1011 struct fib_result res;
1012 bool lock = false;
1013 struct net *net;
1014 u32 old_mtu;
1015
1016 if (ip_mtu_locked(dst))
1017 return;
1018
1019 old_mtu = ipv4_mtu(dst);
1020 if (old_mtu < mtu)
1021 return;
1022
1023 rcu_read_lock();
1024 net = dev_net_rcu(dst->dev);
1025 if (mtu < net->ipv4.ip_rt_min_pmtu) {
1026 lock = true;
1027 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu);
1028 }
1029
1030 if (rt->rt_pmtu == mtu && !lock &&
1031 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2))
1032 goto out;
1033
1034 if (fib_lookup(net, fl4, &res, 0) == 0) {
1035 struct fib_nh_common *nhc;
1036
1037 fib_select_path(net, &res, fl4, NULL);
1038#ifdef CONFIG_IP_ROUTE_MULTIPATH
1039 if (fib_info_num_path(res.fi) > 1) {
1040 int nhsel;
1041
1042 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) {
1043 nhc = fib_info_nhc(res.fi, nhsel);
1044 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1045 jiffies + net->ipv4.ip_rt_mtu_expires);
1046 }
1047 goto out;
1048 }
1049#endif /* CONFIG_IP_ROUTE_MULTIPATH */
1050 nhc = FIB_RES_NHC(res);
1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1052 jiffies + net->ipv4.ip_rt_mtu_expires);
1053 }
1054out:
1055 rcu_read_unlock();
1056}
1057
1058static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1059 struct sk_buff *skb, u32 mtu,
1060 bool confirm_neigh)
1061{
1062 struct rtable *rt = dst_rtable(dst);
1063 struct flowi4 fl4;
1064
1065 ip_rt_build_flow_key(&fl4, sk, skb);
1066
1067 /* Don't make lookup fail for bridged encapsulations */
1068 if (skb && netif_is_any_bridge_port(skb->dev))
1069 fl4.flowi4_oif = 0;
1070
1071 __ip_rt_update_pmtu(rt, &fl4, mtu);
1072}
1073
1074void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1075 int oif, u8 protocol)
1076{
1077 const struct iphdr *iph = (const struct iphdr *)skb->data;
1078 struct flowi4 fl4;
1079 struct rtable *rt;
1080 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1081
1082 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark,
1083 0);
1084 rt = __ip_route_output_key(net, &fl4);
1085 if (!IS_ERR(rt)) {
1086 __ip_rt_update_pmtu(rt, &fl4, mtu);
1087 ip_rt_put(rt);
1088 }
1089}
1090EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1091
1092static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1093{
1094 const struct iphdr *iph = (const struct iphdr *)skb->data;
1095 struct flowi4 fl4;
1096 struct rtable *rt;
1097
1098 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1099
1100 if (!fl4.flowi4_mark)
1101 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1102
1103 rt = __ip_route_output_key(sock_net(sk), &fl4);
1104 if (!IS_ERR(rt)) {
1105 __ip_rt_update_pmtu(rt, &fl4, mtu);
1106 ip_rt_put(rt);
1107 }
1108}
1109
1110void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1111{
1112 const struct iphdr *iph = (const struct iphdr *)skb->data;
1113 struct flowi4 fl4;
1114 struct rtable *rt;
1115 struct dst_entry *odst = NULL;
1116 bool new = false;
1117 struct net *net = sock_net(sk);
1118
1119 bh_lock_sock(sk);
1120
1121 if (!ip_sk_accept_pmtu(sk))
1122 goto out;
1123
1124 odst = sk_dst_get(sk);
1125
1126 if (sock_owned_by_user(sk) || !odst) {
1127 __ipv4_sk_update_pmtu(skb, sk, mtu);
1128 goto out;
1129 }
1130
1131 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1132
1133 rt = dst_rtable(odst);
1134 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1135 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1136 if (IS_ERR(rt))
1137 goto out;
1138
1139 new = true;
1140 }
1141
1142 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu);
1143
1144 if (!dst_check(&rt->dst, 0)) {
1145 if (new)
1146 dst_release(&rt->dst);
1147
1148 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1149 if (IS_ERR(rt))
1150 goto out;
1151
1152 new = true;
1153 }
1154
1155 if (new)
1156 sk_dst_set(sk, &rt->dst);
1157
1158out:
1159 bh_unlock_sock(sk);
1160 dst_release(odst);
1161}
1162EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1163
1164void ipv4_redirect(struct sk_buff *skb, struct net *net,
1165 int oif, u8 protocol)
1166{
1167 const struct iphdr *iph = (const struct iphdr *)skb->data;
1168 struct flowi4 fl4;
1169 struct rtable *rt;
1170
1171 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0);
1172 rt = __ip_route_output_key(net, &fl4);
1173 if (!IS_ERR(rt)) {
1174 __ip_do_redirect(rt, skb, &fl4, false);
1175 ip_rt_put(rt);
1176 }
1177}
1178EXPORT_SYMBOL_GPL(ipv4_redirect);
1179
1180void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1181{
1182 const struct iphdr *iph = (const struct iphdr *)skb->data;
1183 struct flowi4 fl4;
1184 struct rtable *rt;
1185 struct net *net = sock_net(sk);
1186
1187 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1188 rt = __ip_route_output_key(net, &fl4);
1189 if (!IS_ERR(rt)) {
1190 __ip_do_redirect(rt, skb, &fl4, false);
1191 ip_rt_put(rt);
1192 }
1193}
1194EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1195
1196INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
1197 u32 cookie)
1198{
1199 struct rtable *rt = dst_rtable(dst);
1200
1201 /* All IPV4 dsts are created with ->obsolete set to the value
1202 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1203 * into this function always.
1204 *
1205 * When a PMTU/redirect information update invalidates a route,
1206 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1207 * DST_OBSOLETE_DEAD.
1208 */
1209 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1210 return NULL;
1211 return dst;
1212}
1213EXPORT_INDIRECT_CALLABLE(ipv4_dst_check);
1214
1215static void ipv4_send_dest_unreach(struct sk_buff *skb)
1216{
1217 struct net_device *dev;
1218 struct ip_options opt;
1219 int res;
1220
1221 /* Recompile ip options since IPCB may not be valid anymore.
1222 * Also check we have a reasonable ipv4 header.
1223 */
1224 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1225 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1226 return;
1227
1228 memset(&opt, 0, sizeof(opt));
1229 if (ip_hdr(skb)->ihl > 5) {
1230 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1231 return;
1232 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1233
1234 rcu_read_lock();
1235 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev;
1236 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL);
1237 rcu_read_unlock();
1238
1239 if (res)
1240 return;
1241 }
1242 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1243}
1244
1245static void ipv4_link_failure(struct sk_buff *skb)
1246{
1247 struct rtable *rt;
1248
1249 ipv4_send_dest_unreach(skb);
1250
1251 rt = skb_rtable(skb);
1252 if (rt)
1253 dst_set_expires(&rt->dst, 0);
1254}
1255
1256static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1257{
1258 pr_debug("%s: %pI4 -> %pI4, %s\n",
1259 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1260 skb->dev ? skb->dev->name : "?");
1261 kfree_skb(skb);
1262 WARN_ON(1);
1263 return 0;
1264}
1265
1266/*
1267 * We do not cache source address of outgoing interface,
1268 * because it is used only by IP RR, TS and SRR options,
1269 * so that it out of fast path.
1270 *
1271 * BTW remember: "addr" is allowed to be not aligned
1272 * in IP options!
1273 */
1274
1275void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1276{
1277 __be32 src;
1278
1279 if (rt_is_output_route(rt))
1280 src = ip_hdr(skb)->saddr;
1281 else {
1282 struct fib_result res;
1283 struct iphdr *iph = ip_hdr(skb);
1284 struct flowi4 fl4 = {
1285 .daddr = iph->daddr,
1286 .saddr = iph->saddr,
1287 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)),
1288 .flowi4_oif = rt->dst.dev->ifindex,
1289 .flowi4_iif = skb->dev->ifindex,
1290 .flowi4_mark = skb->mark,
1291 };
1292
1293 rcu_read_lock();
1294 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1295 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1296 else
1297 src = inet_select_addr(rt->dst.dev,
1298 rt_nexthop(rt, iph->daddr),
1299 RT_SCOPE_UNIVERSE);
1300 rcu_read_unlock();
1301 }
1302 memcpy(addr, &src, 4);
1303}
1304
1305#ifdef CONFIG_IP_ROUTE_CLASSID
1306static void set_class_tag(struct rtable *rt, u32 tag)
1307{
1308 if (!(rt->dst.tclassid & 0xFFFF))
1309 rt->dst.tclassid |= tag & 0xFFFF;
1310 if (!(rt->dst.tclassid & 0xFFFF0000))
1311 rt->dst.tclassid |= tag & 0xFFFF0000;
1312}
1313#endif
1314
1315static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1316{
1317 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1318 unsigned int advmss;
1319 struct net *net;
1320
1321 rcu_read_lock();
1322 net = dev_net_rcu(dst->dev);
1323 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1324 net->ipv4.ip_rt_min_advmss);
1325 rcu_read_unlock();
1326
1327 return min(advmss, IPV4_MAX_PMTU - header_size);
1328}
1329
1330INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
1331{
1332 return ip_dst_mtu_maybe_forward(dst, false);
1333}
1334EXPORT_INDIRECT_CALLABLE(ipv4_mtu);
1335
1336static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1337{
1338 struct fnhe_hash_bucket *hash;
1339 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1340 u32 hval = fnhe_hashfun(daddr);
1341
1342 spin_lock_bh(&fnhe_lock);
1343
1344 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1345 lockdep_is_held(&fnhe_lock));
1346 hash += hval;
1347
1348 fnhe_p = &hash->chain;
1349 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1350 while (fnhe) {
1351 if (fnhe->fnhe_daddr == daddr) {
1352 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1353 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1354 /* set fnhe_daddr to 0 to ensure it won't bind with
1355 * new dsts in rt_bind_exception().
1356 */
1357 fnhe->fnhe_daddr = 0;
1358 fnhe_flush_routes(fnhe);
1359 kfree_rcu(fnhe, rcu);
1360 break;
1361 }
1362 fnhe_p = &fnhe->fnhe_next;
1363 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1364 lockdep_is_held(&fnhe_lock));
1365 }
1366
1367 spin_unlock_bh(&fnhe_lock);
1368}
1369
1370static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1371 __be32 daddr)
1372{
1373 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1374 struct fib_nh_exception *fnhe;
1375 u32 hval;
1376
1377 if (!hash)
1378 return NULL;
1379
1380 hval = fnhe_hashfun(daddr);
1381
1382 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1383 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1384 if (fnhe->fnhe_daddr == daddr) {
1385 if (fnhe->fnhe_expires &&
1386 time_after(jiffies, fnhe->fnhe_expires)) {
1387 ip_del_fnhe(nhc, daddr);
1388 break;
1389 }
1390 return fnhe;
1391 }
1392 }
1393 return NULL;
1394}
1395
1396/* MTU selection:
1397 * 1. mtu on route is locked - use it
1398 * 2. mtu from nexthop exception
1399 * 3. mtu from egress device
1400 */
1401
1402u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1403{
1404 struct fib_nh_common *nhc = res->nhc;
1405 struct net_device *dev = nhc->nhc_dev;
1406 struct fib_info *fi = res->fi;
1407 u32 mtu = 0;
1408
1409 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) ||
1410 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1411 mtu = fi->fib_mtu;
1412
1413 if (likely(!mtu)) {
1414 struct fib_nh_exception *fnhe;
1415
1416 fnhe = find_exception(nhc, daddr);
1417 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1418 mtu = fnhe->fnhe_pmtu;
1419 }
1420
1421 if (likely(!mtu))
1422 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1423
1424 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1425}
1426
1427static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1428 __be32 daddr, const bool do_cache)
1429{
1430 bool ret = false;
1431
1432 spin_lock_bh(&fnhe_lock);
1433
1434 if (daddr == fnhe->fnhe_daddr) {
1435 struct rtable __rcu **porig;
1436 struct rtable *orig;
1437 int genid = fnhe_genid(dev_net(rt->dst.dev));
1438
1439 if (rt_is_input_route(rt))
1440 porig = &fnhe->fnhe_rth_input;
1441 else
1442 porig = &fnhe->fnhe_rth_output;
1443 orig = rcu_dereference(*porig);
1444
1445 if (fnhe->fnhe_genid != genid) {
1446 fnhe->fnhe_genid = genid;
1447 fnhe->fnhe_gw = 0;
1448 fnhe->fnhe_pmtu = 0;
1449 fnhe->fnhe_expires = 0;
1450 fnhe->fnhe_mtu_locked = false;
1451 fnhe_flush_routes(fnhe);
1452 orig = NULL;
1453 }
1454 fill_route_from_fnhe(rt, fnhe);
1455 if (!rt->rt_gw4) {
1456 rt->rt_gw4 = daddr;
1457 rt->rt_gw_family = AF_INET;
1458 }
1459
1460 if (do_cache) {
1461 dst_hold(&rt->dst);
1462 rcu_assign_pointer(*porig, rt);
1463 if (orig) {
1464 dst_dev_put(&orig->dst);
1465 dst_release(&orig->dst);
1466 }
1467 ret = true;
1468 }
1469
1470 fnhe->fnhe_stamp = jiffies;
1471 }
1472 spin_unlock_bh(&fnhe_lock);
1473
1474 return ret;
1475}
1476
1477static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1478{
1479 struct rtable *orig, *prev, **p;
1480 bool ret = true;
1481
1482 if (rt_is_input_route(rt)) {
1483 p = (struct rtable **)&nhc->nhc_rth_input;
1484 } else {
1485 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1486 }
1487 orig = *p;
1488
1489 /* hold dst before doing cmpxchg() to avoid race condition
1490 * on this dst
1491 */
1492 dst_hold(&rt->dst);
1493 prev = cmpxchg(p, orig, rt);
1494 if (prev == orig) {
1495 if (orig) {
1496 rt_add_uncached_list(orig);
1497 dst_release(&orig->dst);
1498 }
1499 } else {
1500 dst_release(&rt->dst);
1501 ret = false;
1502 }
1503
1504 return ret;
1505}
1506
1507struct uncached_list {
1508 spinlock_t lock;
1509 struct list_head head;
1510};
1511
1512static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1513
1514void rt_add_uncached_list(struct rtable *rt)
1515{
1516 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1517
1518 rt->dst.rt_uncached_list = ul;
1519
1520 spin_lock_bh(&ul->lock);
1521 list_add_tail(&rt->dst.rt_uncached, &ul->head);
1522 spin_unlock_bh(&ul->lock);
1523}
1524
1525void rt_del_uncached_list(struct rtable *rt)
1526{
1527 if (!list_empty(&rt->dst.rt_uncached)) {
1528 struct uncached_list *ul = rt->dst.rt_uncached_list;
1529
1530 spin_lock_bh(&ul->lock);
1531 list_del_init(&rt->dst.rt_uncached);
1532 spin_unlock_bh(&ul->lock);
1533 }
1534}
1535
1536static void ipv4_dst_destroy(struct dst_entry *dst)
1537{
1538 ip_dst_metrics_put(dst);
1539 rt_del_uncached_list(dst_rtable(dst));
1540}
1541
1542void rt_flush_dev(struct net_device *dev)
1543{
1544 struct rtable *rt, *safe;
1545 int cpu;
1546
1547 for_each_possible_cpu(cpu) {
1548 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1549
1550 if (list_empty(&ul->head))
1551 continue;
1552
1553 spin_lock_bh(&ul->lock);
1554 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
1555 if (rt->dst.dev != dev)
1556 continue;
1557 rt->dst.dev = blackhole_netdev;
1558 netdev_ref_replace(dev, blackhole_netdev,
1559 &rt->dst.dev_tracker, GFP_ATOMIC);
1560 list_del_init(&rt->dst.rt_uncached);
1561 }
1562 spin_unlock_bh(&ul->lock);
1563 }
1564}
1565
1566static bool rt_cache_valid(const struct rtable *rt)
1567{
1568 return rt &&
1569 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1570 !rt_is_expired(rt);
1571}
1572
1573static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1574 const struct fib_result *res,
1575 struct fib_nh_exception *fnhe,
1576 struct fib_info *fi, u16 type, u32 itag,
1577 const bool do_cache)
1578{
1579 bool cached = false;
1580
1581 if (fi) {
1582 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1583
1584 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1585 rt->rt_uses_gateway = 1;
1586 rt->rt_gw_family = nhc->nhc_gw_family;
1587 /* only INET and INET6 are supported */
1588 if (likely(nhc->nhc_gw_family == AF_INET))
1589 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1590 else
1591 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1592 }
1593
1594 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1595
1596#ifdef CONFIG_IP_ROUTE_CLASSID
1597 if (nhc->nhc_family == AF_INET) {
1598 struct fib_nh *nh;
1599
1600 nh = container_of(nhc, struct fib_nh, nh_common);
1601 rt->dst.tclassid = nh->nh_tclassid;
1602 }
1603#endif
1604 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1605 if (unlikely(fnhe))
1606 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1607 else if (do_cache)
1608 cached = rt_cache_route(nhc, rt);
1609 if (unlikely(!cached)) {
1610 /* Routes we intend to cache in nexthop exception or
1611 * FIB nexthop have the DST_NOCACHE bit clear.
1612 * However, if we are unsuccessful at storing this
1613 * route into the cache we really need to set it.
1614 */
1615 if (!rt->rt_gw4) {
1616 rt->rt_gw_family = AF_INET;
1617 rt->rt_gw4 = daddr;
1618 }
1619 rt_add_uncached_list(rt);
1620 }
1621 } else
1622 rt_add_uncached_list(rt);
1623
1624#ifdef CONFIG_IP_ROUTE_CLASSID
1625#ifdef CONFIG_IP_MULTIPLE_TABLES
1626 set_class_tag(rt, res->tclassid);
1627#endif
1628 set_class_tag(rt, itag);
1629#endif
1630}
1631
1632struct rtable *rt_dst_alloc(struct net_device *dev,
1633 unsigned int flags, u16 type,
1634 bool noxfrm)
1635{
1636 struct rtable *rt;
1637
1638 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1639 (noxfrm ? DST_NOXFRM : 0));
1640
1641 if (rt) {
1642 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1643 rt->rt_flags = flags;
1644 rt->rt_type = type;
1645 rt->rt_is_input = 0;
1646 rt->rt_iif = 0;
1647 rt->rt_pmtu = 0;
1648 rt->rt_mtu_locked = 0;
1649 rt->rt_uses_gateway = 0;
1650 rt->rt_gw_family = 0;
1651 rt->rt_gw4 = 0;
1652
1653 rt->dst.output = ip_output;
1654 if (flags & RTCF_LOCAL)
1655 rt->dst.input = ip_local_deliver;
1656 }
1657
1658 return rt;
1659}
1660EXPORT_SYMBOL(rt_dst_alloc);
1661
1662struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1663{
1664 struct rtable *new_rt;
1665
1666 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1667 rt->dst.flags);
1668
1669 if (new_rt) {
1670 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1671 new_rt->rt_flags = rt->rt_flags;
1672 new_rt->rt_type = rt->rt_type;
1673 new_rt->rt_is_input = rt->rt_is_input;
1674 new_rt->rt_iif = rt->rt_iif;
1675 new_rt->rt_pmtu = rt->rt_pmtu;
1676 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1677 new_rt->rt_gw_family = rt->rt_gw_family;
1678 if (rt->rt_gw_family == AF_INET)
1679 new_rt->rt_gw4 = rt->rt_gw4;
1680 else if (rt->rt_gw_family == AF_INET6)
1681 new_rt->rt_gw6 = rt->rt_gw6;
1682
1683 new_rt->dst.input = rt->dst.input;
1684 new_rt->dst.output = rt->dst.output;
1685 new_rt->dst.error = rt->dst.error;
1686 new_rt->dst.lastuse = jiffies;
1687 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1688 }
1689 return new_rt;
1690}
1691EXPORT_SYMBOL(rt_dst_clone);
1692
1693/* called in rcu_read_lock() section */
1694enum skb_drop_reason
1695ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1696 dscp_t dscp, struct net_device *dev,
1697 struct in_device *in_dev, u32 *itag)
1698{
1699 enum skb_drop_reason reason;
1700
1701 /* Primary sanity checks. */
1702 if (!in_dev)
1703 return SKB_DROP_REASON_NOT_SPECIFIED;
1704
1705 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1706 return SKB_DROP_REASON_IP_INVALID_SOURCE;
1707
1708 if (skb->protocol != htons(ETH_P_IP))
1709 return SKB_DROP_REASON_INVALID_PROTO;
1710
1711 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1712 return SKB_DROP_REASON_IP_LOCALNET;
1713
1714 if (ipv4_is_zeronet(saddr)) {
1715 if (!ipv4_is_local_multicast(daddr) &&
1716 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1717 return SKB_DROP_REASON_IP_INVALID_SOURCE;
1718 } else {
1719 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
1720 dev, in_dev, itag);
1721 if (reason)
1722 return reason;
1723 }
1724 return SKB_NOT_DROPPED_YET;
1725}
1726
1727/* called in rcu_read_lock() section */
1728static enum skb_drop_reason
1729ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1730 dscp_t dscp, struct net_device *dev, int our)
1731{
1732 struct in_device *in_dev = __in_dev_get_rcu(dev);
1733 unsigned int flags = RTCF_MULTICAST;
1734 enum skb_drop_reason reason;
1735 struct rtable *rth;
1736 u32 itag = 0;
1737
1738 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev,
1739 &itag);
1740 if (reason)
1741 return reason;
1742
1743 if (our)
1744 flags |= RTCF_LOCAL;
1745
1746 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1747 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1748
1749 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1750 false);
1751 if (!rth)
1752 return SKB_DROP_REASON_NOMEM;
1753
1754#ifdef CONFIG_IP_ROUTE_CLASSID
1755 rth->dst.tclassid = itag;
1756#endif
1757 rth->dst.output = ip_rt_bug;
1758 rth->rt_is_input= 1;
1759
1760#ifdef CONFIG_IP_MROUTE
1761 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1762 rth->dst.input = ip_mr_input;
1763#endif
1764 RT_CACHE_STAT_INC(in_slow_mc);
1765
1766 skb_dst_drop(skb);
1767 skb_dst_set(skb, &rth->dst);
1768 return SKB_NOT_DROPPED_YET;
1769}
1770
1771
1772static void ip_handle_martian_source(struct net_device *dev,
1773 struct in_device *in_dev,
1774 struct sk_buff *skb,
1775 __be32 daddr,
1776 __be32 saddr)
1777{
1778 RT_CACHE_STAT_INC(in_martian_src);
1779#ifdef CONFIG_IP_ROUTE_VERBOSE
1780 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1781 /*
1782 * RFC1812 recommendation, if source is martian,
1783 * the only hint is MAC header.
1784 */
1785 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1786 &daddr, &saddr, dev->name);
1787 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1788 print_hex_dump(KERN_WARNING, "ll header: ",
1789 DUMP_PREFIX_OFFSET, 16, 1,
1790 skb_mac_header(skb),
1791 dev->hard_header_len, false);
1792 }
1793 }
1794#endif
1795}
1796
1797/* called in rcu_read_lock() section */
1798static enum skb_drop_reason
1799__mkroute_input(struct sk_buff *skb, const struct fib_result *res,
1800 struct in_device *in_dev, __be32 daddr,
1801 __be32 saddr, dscp_t dscp)
1802{
1803 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
1804 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1805 struct net_device *dev = nhc->nhc_dev;
1806 struct fib_nh_exception *fnhe;
1807 struct rtable *rth;
1808 int err;
1809 struct in_device *out_dev;
1810 bool do_cache;
1811 u32 itag = 0;
1812
1813 /* get a working reference to the output device */
1814 out_dev = __in_dev_get_rcu(dev);
1815 if (!out_dev) {
1816 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1817 return reason;
1818 }
1819
1820 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res),
1821 in_dev->dev, in_dev, &itag);
1822 if (err < 0) {
1823 reason = -err;
1824 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1825 saddr);
1826
1827 goto cleanup;
1828 }
1829
1830 do_cache = res->fi && !itag;
1831 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1832 skb->protocol == htons(ETH_P_IP)) {
1833 __be32 gw;
1834
1835 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1836 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1837 inet_addr_onlink(out_dev, saddr, gw))
1838 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1839 }
1840
1841 if (skb->protocol != htons(ETH_P_IP)) {
1842 /* Not IP (i.e. ARP). Do not create route, if it is
1843 * invalid for proxy arp. DNAT routes are always valid.
1844 *
1845 * Proxy arp feature have been extended to allow, ARP
1846 * replies back to the same interface, to support
1847 * Private VLAN switch technologies. See arp.c.
1848 */
1849 if (out_dev == in_dev &&
1850 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1851 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE;
1852 goto cleanup;
1853 }
1854 }
1855
1856 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1857 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1858
1859 fnhe = find_exception(nhc, daddr);
1860 if (do_cache) {
1861 if (fnhe)
1862 rth = rcu_dereference(fnhe->fnhe_rth_input);
1863 else
1864 rth = rcu_dereference(nhc->nhc_rth_input);
1865 if (rt_cache_valid(rth)) {
1866 skb_dst_set_noref(skb, &rth->dst);
1867 goto out;
1868 }
1869 }
1870
1871 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1872 IN_DEV_ORCONF(out_dev, NOXFRM));
1873 if (!rth) {
1874 reason = SKB_DROP_REASON_NOMEM;
1875 goto cleanup;
1876 }
1877
1878 rth->rt_is_input = 1;
1879 RT_CACHE_STAT_INC(in_slow_tot);
1880
1881 rth->dst.input = ip_forward;
1882
1883 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1884 do_cache);
1885 lwtunnel_set_redirect(&rth->dst);
1886 skb_dst_set(skb, &rth->dst);
1887out:
1888 reason = SKB_NOT_DROPPED_YET;
1889cleanup:
1890 return reason;
1891}
1892
1893#ifdef CONFIG_IP_ROUTE_MULTIPATH
1894/* To make ICMP packets follow the right flow, the multipath hash is
1895 * calculated from the inner IP addresses.
1896 */
1897static void ip_multipath_l3_keys(const struct sk_buff *skb,
1898 struct flow_keys *hash_keys)
1899{
1900 const struct iphdr *outer_iph = ip_hdr(skb);
1901 const struct iphdr *key_iph = outer_iph;
1902 const struct iphdr *inner_iph;
1903 const struct icmphdr *icmph;
1904 struct iphdr _inner_iph;
1905 struct icmphdr _icmph;
1906
1907 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1908 goto out;
1909
1910 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1911 goto out;
1912
1913 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1914 &_icmph);
1915 if (!icmph)
1916 goto out;
1917
1918 if (!icmp_is_err(icmph->type))
1919 goto out;
1920
1921 inner_iph = skb_header_pointer(skb,
1922 outer_iph->ihl * 4 + sizeof(_icmph),
1923 sizeof(_inner_iph), &_inner_iph);
1924 if (!inner_iph)
1925 goto out;
1926
1927 key_iph = inner_iph;
1928out:
1929 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1930 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1931}
1932
1933static u32 fib_multipath_custom_hash_outer(const struct net *net,
1934 const struct sk_buff *skb,
1935 bool *p_has_inner)
1936{
1937 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1938 struct flow_keys keys, hash_keys;
1939
1940 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
1941 return 0;
1942
1943 memset(&hash_keys, 0, sizeof(hash_keys));
1944 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
1945
1946 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1947 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
1948 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1949 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
1950 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1951 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
1952 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1953 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
1954 hash_keys.ports.src = keys.ports.src;
1955 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
1956 hash_keys.ports.dst = keys.ports.dst;
1957
1958 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
1959 return fib_multipath_hash_from_keys(net, &hash_keys);
1960}
1961
1962static u32 fib_multipath_custom_hash_inner(const struct net *net,
1963 const struct sk_buff *skb,
1964 bool has_inner)
1965{
1966 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1967 struct flow_keys keys, hash_keys;
1968
1969 /* We assume the packet carries an encapsulation, but if none was
1970 * encountered during dissection of the outer flow, then there is no
1971 * point in calling the flow dissector again.
1972 */
1973 if (!has_inner)
1974 return 0;
1975
1976 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
1977 return 0;
1978
1979 memset(&hash_keys, 0, sizeof(hash_keys));
1980 skb_flow_dissect_flow_keys(skb, &keys, 0);
1981
1982 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
1983 return 0;
1984
1985 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1986 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1988 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1989 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1990 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1991 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1992 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1993 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1994 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1996 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
1998 hash_keys.tags.flow_label = keys.tags.flow_label;
1999 }
2000
2001 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2002 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2004 hash_keys.ports.src = keys.ports.src;
2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2006 hash_keys.ports.dst = keys.ports.dst;
2007
2008 return fib_multipath_hash_from_keys(net, &hash_keys);
2009}
2010
2011static u32 fib_multipath_custom_hash_skb(const struct net *net,
2012 const struct sk_buff *skb)
2013{
2014 u32 mhash, mhash_inner;
2015 bool has_inner = true;
2016
2017 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner);
2018 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner);
2019
2020 return jhash_2words(mhash, mhash_inner, 0);
2021}
2022
2023static u32 fib_multipath_custom_hash_fl4(const struct net *net,
2024 const struct flowi4 *fl4)
2025{
2026 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
2027 struct flow_keys hash_keys;
2028
2029 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2030 return 0;
2031
2032 memset(&hash_keys, 0, sizeof(hash_keys));
2033 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2034 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2035 hash_keys.addrs.v4addrs.src = fl4->saddr;
2036 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2037 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2038 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2039 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2040 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2041 hash_keys.ports.src = fl4->fl4_sport;
2042 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2043 hash_keys.ports.dst = fl4->fl4_dport;
2044
2045 return fib_multipath_hash_from_keys(net, &hash_keys);
2046}
2047
2048/* if skb is set it will be used and fl4 can be NULL */
2049int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
2050 const struct sk_buff *skb, struct flow_keys *flkeys)
2051{
2052 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
2053 struct flow_keys hash_keys;
2054 u32 mhash = 0;
2055
2056 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) {
2057 case 0:
2058 memset(&hash_keys, 0, sizeof(hash_keys));
2059 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2060 if (skb) {
2061 ip_multipath_l3_keys(skb, &hash_keys);
2062 } else {
2063 hash_keys.addrs.v4addrs.src = fl4->saddr;
2064 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2065 }
2066 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2067 break;
2068 case 1:
2069 /* skb is currently provided only when forwarding */
2070 if (skb) {
2071 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2072 struct flow_keys keys;
2073
2074 /* short-circuit if we already have L4 hash present */
2075 if (skb->l4_hash)
2076 return skb_get_hash_raw(skb) >> 1;
2077
2078 memset(&hash_keys, 0, sizeof(hash_keys));
2079
2080 if (!flkeys) {
2081 skb_flow_dissect_flow_keys(skb, &keys, flag);
2082 flkeys = &keys;
2083 }
2084
2085 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2086 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2087 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2088 hash_keys.ports.src = flkeys->ports.src;
2089 hash_keys.ports.dst = flkeys->ports.dst;
2090 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2091 } else {
2092 memset(&hash_keys, 0, sizeof(hash_keys));
2093 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2094 hash_keys.addrs.v4addrs.src = fl4->saddr;
2095 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2096 hash_keys.ports.src = fl4->fl4_sport;
2097 hash_keys.ports.dst = fl4->fl4_dport;
2098 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2099 }
2100 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2101 break;
2102 case 2:
2103 memset(&hash_keys, 0, sizeof(hash_keys));
2104 /* skb is currently provided only when forwarding */
2105 if (skb) {
2106 struct flow_keys keys;
2107
2108 skb_flow_dissect_flow_keys(skb, &keys, 0);
2109 /* Inner can be v4 or v6 */
2110 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2111 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2112 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2113 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2114 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2115 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2116 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2117 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2118 hash_keys.tags.flow_label = keys.tags.flow_label;
2119 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2120 } else {
2121 /* Same as case 0 */
2122 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2123 ip_multipath_l3_keys(skb, &hash_keys);
2124 }
2125 } else {
2126 /* Same as case 0 */
2127 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2128 hash_keys.addrs.v4addrs.src = fl4->saddr;
2129 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2130 }
2131 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2132 break;
2133 case 3:
2134 if (skb)
2135 mhash = fib_multipath_custom_hash_skb(net, skb);
2136 else
2137 mhash = fib_multipath_custom_hash_fl4(net, fl4);
2138 break;
2139 }
2140
2141 if (multipath_hash)
2142 mhash = jhash_2words(mhash, multipath_hash, 0);
2143
2144 return mhash >> 1;
2145}
2146#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2147
2148static enum skb_drop_reason
2149ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
2150 struct in_device *in_dev, __be32 daddr,
2151 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys)
2152{
2153#ifdef CONFIG_IP_ROUTE_MULTIPATH
2154 if (res->fi && fib_info_num_path(res->fi) > 1) {
2155 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2156
2157 fib_select_multipath(res, h);
2158 IPCB(skb)->flags |= IPSKB_MULTIPATH;
2159 }
2160#endif
2161
2162 /* create a routing cache entry */
2163 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp);
2164}
2165
2166/* Implements all the saddr-related checks as ip_route_input_slow(),
2167 * assuming daddr is valid and the destination is not a local broadcast one.
2168 * Uses the provided hint instead of performing a route lookup.
2169 */
2170enum skb_drop_reason
2171ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2172 dscp_t dscp, struct net_device *dev,
2173 const struct sk_buff *hint)
2174{
2175 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2176 struct in_device *in_dev = __in_dev_get_rcu(dev);
2177 struct rtable *rt = skb_rtable(hint);
2178 struct net *net = dev_net(dev);
2179 u32 tag = 0;
2180
2181 if (!in_dev)
2182 return reason;
2183
2184 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
2185 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2186 goto martian_source;
2187 }
2188
2189 if (ipv4_is_zeronet(saddr)) {
2190 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2191 goto martian_source;
2192 }
2193
2194 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2195 reason = SKB_DROP_REASON_IP_LOCALNET;
2196 goto martian_source;
2197 }
2198
2199 if (rt->rt_type != RTN_LOCAL)
2200 goto skip_validate_source;
2201
2202 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev,
2203 in_dev, &tag);
2204 if (reason)
2205 goto martian_source;
2206
2207skip_validate_source:
2208 skb_dst_copy(skb, hint);
2209 return SKB_NOT_DROPPED_YET;
2210
2211martian_source:
2212 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2213 return reason;
2214}
2215
2216/* get device for dst_alloc with local routes */
2217static struct net_device *ip_rt_get_dev(struct net *net,
2218 const struct fib_result *res)
2219{
2220 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL;
2221 struct net_device *dev = NULL;
2222
2223 if (nhc)
2224 dev = l3mdev_master_dev_rcu(nhc->nhc_dev);
2225
2226 return dev ? : net->loopback_dev;
2227}
2228
2229/*
2230 * NOTE. We drop all the packets that has local source
2231 * addresses, because every properly looped back packet
2232 * must have correct destination already attached by output routine.
2233 * Changes in the enforced policies must be applied also to
2234 * ip_route_use_hint().
2235 *
2236 * Such approach solves two big problems:
2237 * 1. Not simplex devices are handled properly.
2238 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2239 * called with rcu_read_lock()
2240 */
2241
2242static enum skb_drop_reason
2243ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2244 dscp_t dscp, struct net_device *dev,
2245 struct fib_result *res)
2246{
2247 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2248 struct in_device *in_dev = __in_dev_get_rcu(dev);
2249 struct flow_keys *flkeys = NULL, _flkeys;
2250 struct net *net = dev_net(dev);
2251 struct ip_tunnel_info *tun_info;
2252 int err = -EINVAL;
2253 unsigned int flags = 0;
2254 u32 itag = 0;
2255 struct rtable *rth;
2256 struct flowi4 fl4;
2257 bool do_cache = true;
2258
2259 /* IP on this device is disabled. */
2260
2261 if (!in_dev)
2262 goto out;
2263
2264 /* Check for the most weird martians, which can be not detected
2265 * by fib_lookup.
2266 */
2267
2268 tun_info = skb_tunnel_info(skb);
2269 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2270 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2271 else
2272 fl4.flowi4_tun_key.tun_id = 0;
2273 skb_dst_drop(skb);
2274
2275 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
2276 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2277 goto martian_source;
2278 }
2279
2280 res->fi = NULL;
2281 res->table = NULL;
2282 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2283 goto brd_input;
2284
2285 /* Accept zero addresses only to limited broadcast;
2286 * I even do not know to fix it or not. Waiting for complains :-)
2287 */
2288 if (ipv4_is_zeronet(saddr)) {
2289 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2290 goto martian_source;
2291 }
2292
2293 if (ipv4_is_zeronet(daddr)) {
2294 reason = SKB_DROP_REASON_IP_INVALID_DEST;
2295 goto martian_destination;
2296 }
2297
2298 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2299 * and call it once if daddr or/and saddr are loopback addresses
2300 */
2301 if (ipv4_is_loopback(daddr)) {
2302 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2303 reason = SKB_DROP_REASON_IP_LOCALNET;
2304 goto martian_destination;
2305 }
2306 } else if (ipv4_is_loopback(saddr)) {
2307 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2308 reason = SKB_DROP_REASON_IP_LOCALNET;
2309 goto martian_source;
2310 }
2311 }
2312
2313 /*
2314 * Now we are ready to route packet.
2315 */
2316 fl4.flowi4_l3mdev = 0;
2317 fl4.flowi4_oif = 0;
2318 fl4.flowi4_iif = dev->ifindex;
2319 fl4.flowi4_mark = skb->mark;
2320 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
2321 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2322 fl4.flowi4_flags = 0;
2323 fl4.daddr = daddr;
2324 fl4.saddr = saddr;
2325 fl4.flowi4_uid = sock_net_uid(net, NULL);
2326 fl4.flowi4_multipath_hash = 0;
2327
2328 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2329 flkeys = &_flkeys;
2330 } else {
2331 fl4.flowi4_proto = 0;
2332 fl4.fl4_sport = 0;
2333 fl4.fl4_dport = 0;
2334 }
2335
2336 err = fib_lookup(net, &fl4, res, 0);
2337 if (err != 0) {
2338 if (!IN_DEV_FORWARD(in_dev))
2339 err = -EHOSTUNREACH;
2340 goto no_route;
2341 }
2342
2343 if (res->type == RTN_BROADCAST) {
2344 if (IN_DEV_BFORWARD(in_dev))
2345 goto make_route;
2346 /* not do cache if bc_forwarding is enabled */
2347 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING))
2348 do_cache = false;
2349 goto brd_input;
2350 }
2351
2352 err = -EINVAL;
2353 if (res->type == RTN_LOCAL) {
2354 reason = fib_validate_source_reason(skb, saddr, daddr, dscp,
2355 0, dev, in_dev, &itag);
2356 if (reason)
2357 goto martian_source;
2358 goto local_input;
2359 }
2360
2361 if (!IN_DEV_FORWARD(in_dev)) {
2362 err = -EHOSTUNREACH;
2363 goto no_route;
2364 }
2365 if (res->type != RTN_UNICAST) {
2366 reason = SKB_DROP_REASON_IP_INVALID_DEST;
2367 goto martian_destination;
2368 }
2369
2370make_route:
2371 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp,
2372 flkeys);
2373
2374out:
2375 return reason;
2376
2377brd_input:
2378 if (skb->protocol != htons(ETH_P_IP)) {
2379 reason = SKB_DROP_REASON_INVALID_PROTO;
2380 goto out;
2381 }
2382
2383 if (!ipv4_is_zeronet(saddr)) {
2384 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
2385 dev, in_dev, &itag);
2386 if (reason)
2387 goto martian_source;
2388 }
2389 flags |= RTCF_BROADCAST;
2390 res->type = RTN_BROADCAST;
2391 RT_CACHE_STAT_INC(in_brd);
2392
2393local_input:
2394 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
2395 IPCB(skb)->flags |= IPSKB_NOPOLICY;
2396
2397 do_cache &= res->fi && !itag;
2398 if (do_cache) {
2399 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2400
2401 rth = rcu_dereference(nhc->nhc_rth_input);
2402 if (rt_cache_valid(rth)) {
2403 skb_dst_set_noref(skb, &rth->dst);
2404 reason = SKB_NOT_DROPPED_YET;
2405 goto out;
2406 }
2407 }
2408
2409 rth = rt_dst_alloc(ip_rt_get_dev(net, res),
2410 flags | RTCF_LOCAL, res->type, false);
2411 if (!rth)
2412 goto e_nobufs;
2413
2414 rth->dst.output= ip_rt_bug;
2415#ifdef CONFIG_IP_ROUTE_CLASSID
2416 rth->dst.tclassid = itag;
2417#endif
2418 rth->rt_is_input = 1;
2419
2420 RT_CACHE_STAT_INC(in_slow_tot);
2421 if (res->type == RTN_UNREACHABLE) {
2422 rth->dst.input= ip_error;
2423 rth->dst.error= -err;
2424 rth->rt_flags &= ~RTCF_LOCAL;
2425 }
2426
2427 if (do_cache) {
2428 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2429
2430 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2431 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2432 WARN_ON(rth->dst.input == lwtunnel_input);
2433 rth->dst.lwtstate->orig_input = rth->dst.input;
2434 rth->dst.input = lwtunnel_input;
2435 }
2436
2437 if (unlikely(!rt_cache_route(nhc, rth)))
2438 rt_add_uncached_list(rth);
2439 }
2440 skb_dst_set(skb, &rth->dst);
2441 reason = SKB_NOT_DROPPED_YET;
2442 goto out;
2443
2444no_route:
2445 RT_CACHE_STAT_INC(in_no_route);
2446 res->type = RTN_UNREACHABLE;
2447 res->fi = NULL;
2448 res->table = NULL;
2449 goto local_input;
2450
2451 /*
2452 * Do not cache martian addresses: they should be logged (RFC1812)
2453 */
2454martian_destination:
2455 RT_CACHE_STAT_INC(in_martian_dst);
2456#ifdef CONFIG_IP_ROUTE_VERBOSE
2457 if (IN_DEV_LOG_MARTIANS(in_dev))
2458 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2459 &daddr, &saddr, dev->name);
2460#endif
2461 goto out;
2462
2463e_nobufs:
2464 reason = SKB_DROP_REASON_NOMEM;
2465 goto out;
2466
2467martian_source:
2468 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2469 goto out;
2470}
2471
2472/* called with rcu_read_lock held */
2473static enum skb_drop_reason
2474ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2475 dscp_t dscp, struct net_device *dev,
2476 struct fib_result *res)
2477{
2478 /* Multicast recognition logic is moved from route cache to here.
2479 * The problem was that too many Ethernet cards have broken/missing
2480 * hardware multicast filters :-( As result the host on multicasting
2481 * network acquires a lot of useless route cache entries, sort of
2482 * SDR messages from all the world. Now we try to get rid of them.
2483 * Really, provided software IP multicast filter is organized
2484 * reasonably (at least, hashed), it does not result in a slowdown
2485 * comparing with route cache reject entries.
2486 * Note, that multicast routers are not affected, because
2487 * route cache entry is created eventually.
2488 */
2489 if (ipv4_is_multicast(daddr)) {
2490 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2491 struct in_device *in_dev = __in_dev_get_rcu(dev);
2492 int our = 0;
2493
2494 if (!in_dev)
2495 return reason;
2496
2497 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2498 ip_hdr(skb)->protocol);
2499
2500 /* check l3 master if no match yet */
2501 if (!our && netif_is_l3_slave(dev)) {
2502 struct in_device *l3_in_dev;
2503
2504 l3_in_dev = __in_dev_get_rcu(skb->dev);
2505 if (l3_in_dev)
2506 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2507 ip_hdr(skb)->protocol);
2508 }
2509
2510 if (our
2511#ifdef CONFIG_IP_MROUTE
2512 ||
2513 (!ipv4_is_local_multicast(daddr) &&
2514 IN_DEV_MFORWARD(in_dev))
2515#endif
2516 ) {
2517 reason = ip_route_input_mc(skb, daddr, saddr, dscp,
2518 dev, our);
2519 }
2520 return reason;
2521 }
2522
2523 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res);
2524}
2525
2526enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr,
2527 __be32 saddr, dscp_t dscp,
2528 struct net_device *dev)
2529{
2530 enum skb_drop_reason reason;
2531 struct fib_result res;
2532
2533 rcu_read_lock();
2534 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res);
2535 rcu_read_unlock();
2536
2537 return reason;
2538}
2539EXPORT_SYMBOL(ip_route_input_noref);
2540
2541/* called with rcu_read_lock() */
2542static struct rtable *__mkroute_output(const struct fib_result *res,
2543 const struct flowi4 *fl4, int orig_oif,
2544 struct net_device *dev_out,
2545 unsigned int flags)
2546{
2547 struct fib_info *fi = res->fi;
2548 struct fib_nh_exception *fnhe;
2549 struct in_device *in_dev;
2550 u16 type = res->type;
2551 struct rtable *rth;
2552 bool do_cache;
2553
2554 in_dev = __in_dev_get_rcu(dev_out);
2555 if (!in_dev)
2556 return ERR_PTR(-EINVAL);
2557
2558 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2559 if (ipv4_is_loopback(fl4->saddr) &&
2560 !(dev_out->flags & IFF_LOOPBACK) &&
2561 !netif_is_l3_master(dev_out))
2562 return ERR_PTR(-EINVAL);
2563
2564 if (ipv4_is_lbcast(fl4->daddr))
2565 type = RTN_BROADCAST;
2566 else if (ipv4_is_multicast(fl4->daddr))
2567 type = RTN_MULTICAST;
2568 else if (ipv4_is_zeronet(fl4->daddr))
2569 return ERR_PTR(-EINVAL);
2570
2571 if (dev_out->flags & IFF_LOOPBACK)
2572 flags |= RTCF_LOCAL;
2573
2574 do_cache = true;
2575 if (type == RTN_BROADCAST) {
2576 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2577 fi = NULL;
2578 } else if (type == RTN_MULTICAST) {
2579 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2580 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2581 fl4->flowi4_proto))
2582 flags &= ~RTCF_LOCAL;
2583 else
2584 do_cache = false;
2585 /* If multicast route do not exist use
2586 * default one, but do not gateway in this case.
2587 * Yes, it is hack.
2588 */
2589 if (fi && res->prefixlen < 4)
2590 fi = NULL;
2591 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2592 (orig_oif != dev_out->ifindex)) {
2593 /* For local routes that require a particular output interface
2594 * we do not want to cache the result. Caching the result
2595 * causes incorrect behaviour when there are multiple source
2596 * addresses on the interface, the end result being that if the
2597 * intended recipient is waiting on that interface for the
2598 * packet he won't receive it because it will be delivered on
2599 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2600 * be set to the loopback interface as well.
2601 */
2602 do_cache = false;
2603 }
2604
2605 fnhe = NULL;
2606 do_cache &= fi != NULL;
2607 if (fi) {
2608 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2609 struct rtable __rcu **prth;
2610
2611 fnhe = find_exception(nhc, fl4->daddr);
2612 if (!do_cache)
2613 goto add;
2614 if (fnhe) {
2615 prth = &fnhe->fnhe_rth_output;
2616 } else {
2617 if (unlikely(fl4->flowi4_flags &
2618 FLOWI_FLAG_KNOWN_NH &&
2619 !(nhc->nhc_gw_family &&
2620 nhc->nhc_scope == RT_SCOPE_LINK))) {
2621 do_cache = false;
2622 goto add;
2623 }
2624 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2625 }
2626 rth = rcu_dereference(*prth);
2627 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2628 return rth;
2629 }
2630
2631add:
2632 rth = rt_dst_alloc(dev_out, flags, type,
2633 IN_DEV_ORCONF(in_dev, NOXFRM));
2634 if (!rth)
2635 return ERR_PTR(-ENOBUFS);
2636
2637 rth->rt_iif = orig_oif;
2638
2639 RT_CACHE_STAT_INC(out_slow_tot);
2640
2641 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2642 if (flags & RTCF_LOCAL &&
2643 !(dev_out->flags & IFF_LOOPBACK)) {
2644 rth->dst.output = ip_mc_output;
2645 RT_CACHE_STAT_INC(out_slow_mc);
2646 }
2647#ifdef CONFIG_IP_MROUTE
2648 if (type == RTN_MULTICAST) {
2649 if (IN_DEV_MFORWARD(in_dev) &&
2650 !ipv4_is_local_multicast(fl4->daddr)) {
2651 rth->dst.input = ip_mr_input;
2652 rth->dst.output = ip_mc_output;
2653 }
2654 }
2655#endif
2656 }
2657
2658 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2659 lwtunnel_set_redirect(&rth->dst);
2660
2661 return rth;
2662}
2663
2664/*
2665 * Major route resolver routine.
2666 */
2667
2668struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2669 const struct sk_buff *skb)
2670{
2671 struct fib_result res = {
2672 .type = RTN_UNSPEC,
2673 .fi = NULL,
2674 .table = NULL,
2675 .tclassid = 0,
2676 };
2677 struct rtable *rth;
2678
2679 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2680 fl4->flowi4_tos &= INET_DSCP_MASK;
2681
2682 rcu_read_lock();
2683 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2684 rcu_read_unlock();
2685
2686 return rth;
2687}
2688EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2689
2690struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2691 struct fib_result *res,
2692 const struct sk_buff *skb)
2693{
2694 struct net_device *dev_out = NULL;
2695 int orig_oif = fl4->flowi4_oif;
2696 unsigned int flags = 0;
2697 struct rtable *rth;
2698 int err;
2699
2700 if (fl4->saddr) {
2701 if (ipv4_is_multicast(fl4->saddr) ||
2702 ipv4_is_lbcast(fl4->saddr) ||
2703 ipv4_is_zeronet(fl4->saddr)) {
2704 rth = ERR_PTR(-EINVAL);
2705 goto out;
2706 }
2707
2708 rth = ERR_PTR(-ENETUNREACH);
2709
2710 /* I removed check for oif == dev_out->oif here.
2711 * It was wrong for two reasons:
2712 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2713 * is assigned to multiple interfaces.
2714 * 2. Moreover, we are allowed to send packets with saddr
2715 * of another iface. --ANK
2716 */
2717
2718 if (fl4->flowi4_oif == 0 &&
2719 (ipv4_is_multicast(fl4->daddr) ||
2720 ipv4_is_lbcast(fl4->daddr))) {
2721 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2722 dev_out = __ip_dev_find(net, fl4->saddr, false);
2723 if (!dev_out)
2724 goto out;
2725
2726 /* Special hack: user can direct multicasts
2727 * and limited broadcast via necessary interface
2728 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2729 * This hack is not just for fun, it allows
2730 * vic,vat and friends to work.
2731 * They bind socket to loopback, set ttl to zero
2732 * and expect that it will work.
2733 * From the viewpoint of routing cache they are broken,
2734 * because we are not allowed to build multicast path
2735 * with loopback source addr (look, routing cache
2736 * cannot know, that ttl is zero, so that packet
2737 * will not leave this host and route is valid).
2738 * Luckily, this hack is good workaround.
2739 */
2740
2741 fl4->flowi4_oif = dev_out->ifindex;
2742 goto make_route;
2743 }
2744
2745 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2746 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2747 if (!__ip_dev_find(net, fl4->saddr, false))
2748 goto out;
2749 }
2750 }
2751
2752
2753 if (fl4->flowi4_oif) {
2754 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2755 rth = ERR_PTR(-ENODEV);
2756 if (!dev_out)
2757 goto out;
2758
2759 /* RACE: Check return value of inet_select_addr instead. */
2760 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2761 rth = ERR_PTR(-ENETUNREACH);
2762 goto out;
2763 }
2764 if (ipv4_is_local_multicast(fl4->daddr) ||
2765 ipv4_is_lbcast(fl4->daddr) ||
2766 fl4->flowi4_proto == IPPROTO_IGMP) {
2767 if (!fl4->saddr)
2768 fl4->saddr = inet_select_addr(dev_out, 0,
2769 RT_SCOPE_LINK);
2770 goto make_route;
2771 }
2772 if (!fl4->saddr) {
2773 if (ipv4_is_multicast(fl4->daddr))
2774 fl4->saddr = inet_select_addr(dev_out, 0,
2775 fl4->flowi4_scope);
2776 else if (!fl4->daddr)
2777 fl4->saddr = inet_select_addr(dev_out, 0,
2778 RT_SCOPE_HOST);
2779 }
2780 }
2781
2782 if (!fl4->daddr) {
2783 fl4->daddr = fl4->saddr;
2784 if (!fl4->daddr)
2785 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2786 dev_out = net->loopback_dev;
2787 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2788 res->type = RTN_LOCAL;
2789 flags |= RTCF_LOCAL;
2790 goto make_route;
2791 }
2792
2793 err = fib_lookup(net, fl4, res, 0);
2794 if (err) {
2795 res->fi = NULL;
2796 res->table = NULL;
2797 if (fl4->flowi4_oif &&
2798 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) {
2799 /* Apparently, routing tables are wrong. Assume,
2800 * that the destination is on link.
2801 *
2802 * WHY? DW.
2803 * Because we are allowed to send to iface
2804 * even if it has NO routes and NO assigned
2805 * addresses. When oif is specified, routing
2806 * tables are looked up with only one purpose:
2807 * to catch if destination is gatewayed, rather than
2808 * direct. Moreover, if MSG_DONTROUTE is set,
2809 * we send packet, ignoring both routing tables
2810 * and ifaddr state. --ANK
2811 *
2812 *
2813 * We could make it even if oif is unknown,
2814 * likely IPv6, but we do not.
2815 */
2816
2817 if (fl4->saddr == 0)
2818 fl4->saddr = inet_select_addr(dev_out, 0,
2819 RT_SCOPE_LINK);
2820 res->type = RTN_UNICAST;
2821 goto make_route;
2822 }
2823 rth = ERR_PTR(err);
2824 goto out;
2825 }
2826
2827 if (res->type == RTN_LOCAL) {
2828 if (!fl4->saddr) {
2829 if (res->fi->fib_prefsrc)
2830 fl4->saddr = res->fi->fib_prefsrc;
2831 else
2832 fl4->saddr = fl4->daddr;
2833 }
2834
2835 /* L3 master device is the loopback for that domain */
2836 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2837 net->loopback_dev;
2838
2839 /* make sure orig_oif points to fib result device even
2840 * though packet rx/tx happens over loopback or l3mdev
2841 */
2842 orig_oif = FIB_RES_OIF(*res);
2843
2844 fl4->flowi4_oif = dev_out->ifindex;
2845 flags |= RTCF_LOCAL;
2846 goto make_route;
2847 }
2848
2849 fib_select_path(net, res, fl4, skb);
2850
2851 dev_out = FIB_RES_DEV(*res);
2852
2853make_route:
2854 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2855
2856out:
2857 return rth;
2858}
2859
2860static struct dst_ops ipv4_dst_blackhole_ops = {
2861 .family = AF_INET,
2862 .default_advmss = ipv4_default_advmss,
2863 .neigh_lookup = ipv4_neigh_lookup,
2864 .check = dst_blackhole_check,
2865 .cow_metrics = dst_blackhole_cow_metrics,
2866 .update_pmtu = dst_blackhole_update_pmtu,
2867 .redirect = dst_blackhole_redirect,
2868 .mtu = dst_blackhole_mtu,
2869};
2870
2871struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2872{
2873 struct rtable *ort = dst_rtable(dst_orig);
2874 struct rtable *rt;
2875
2876 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0);
2877 if (rt) {
2878 struct dst_entry *new = &rt->dst;
2879
2880 new->__use = 1;
2881 new->input = dst_discard;
2882 new->output = dst_discard_out;
2883
2884 new->dev = net->loopback_dev;
2885 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC);
2886
2887 rt->rt_is_input = ort->rt_is_input;
2888 rt->rt_iif = ort->rt_iif;
2889 rt->rt_pmtu = ort->rt_pmtu;
2890 rt->rt_mtu_locked = ort->rt_mtu_locked;
2891
2892 rt->rt_genid = rt_genid_ipv4(net);
2893 rt->rt_flags = ort->rt_flags;
2894 rt->rt_type = ort->rt_type;
2895 rt->rt_uses_gateway = ort->rt_uses_gateway;
2896 rt->rt_gw_family = ort->rt_gw_family;
2897 if (rt->rt_gw_family == AF_INET)
2898 rt->rt_gw4 = ort->rt_gw4;
2899 else if (rt->rt_gw_family == AF_INET6)
2900 rt->rt_gw6 = ort->rt_gw6;
2901 }
2902
2903 dst_release(dst_orig);
2904
2905 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2906}
2907
2908struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2909 const struct sock *sk)
2910{
2911 struct rtable *rt = __ip_route_output_key(net, flp4);
2912
2913 if (IS_ERR(rt))
2914 return rt;
2915
2916 if (flp4->flowi4_proto) {
2917 flp4->flowi4_oif = rt->dst.dev->ifindex;
2918 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst,
2919 flowi4_to_flowi(flp4),
2920 sk, 0));
2921 }
2922
2923 return rt;
2924}
2925EXPORT_SYMBOL_GPL(ip_route_output_flow);
2926
2927/* called with rcu_read_lock held */
2928static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2929 struct rtable *rt, u32 table_id, dscp_t dscp,
2930 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2931 u32 seq, unsigned int flags)
2932{
2933 struct rtmsg *r;
2934 struct nlmsghdr *nlh;
2935 unsigned long expires = 0;
2936 u32 error;
2937 u32 metrics[RTAX_MAX];
2938
2939 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2940 if (!nlh)
2941 return -EMSGSIZE;
2942
2943 r = nlmsg_data(nlh);
2944 r->rtm_family = AF_INET;
2945 r->rtm_dst_len = 32;
2946 r->rtm_src_len = 0;
2947 r->rtm_tos = inet_dscp_to_dsfield(dscp);
2948 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2949 if (nla_put_u32(skb, RTA_TABLE, table_id))
2950 goto nla_put_failure;
2951 r->rtm_type = rt->rt_type;
2952 r->rtm_scope = RT_SCOPE_UNIVERSE;
2953 r->rtm_protocol = RTPROT_UNSPEC;
2954 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2955 if (rt->rt_flags & RTCF_NOTIFY)
2956 r->rtm_flags |= RTM_F_NOTIFY;
2957 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2958 r->rtm_flags |= RTCF_DOREDIRECT;
2959
2960 if (nla_put_in_addr(skb, RTA_DST, dst))
2961 goto nla_put_failure;
2962 if (src) {
2963 r->rtm_src_len = 32;
2964 if (nla_put_in_addr(skb, RTA_SRC, src))
2965 goto nla_put_failure;
2966 }
2967 if (rt->dst.dev &&
2968 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2969 goto nla_put_failure;
2970 if (rt->dst.lwtstate &&
2971 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
2972 goto nla_put_failure;
2973#ifdef CONFIG_IP_ROUTE_CLASSID
2974 if (rt->dst.tclassid &&
2975 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2976 goto nla_put_failure;
2977#endif
2978 if (fl4 && !rt_is_input_route(rt) &&
2979 fl4->saddr != src) {
2980 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2981 goto nla_put_failure;
2982 }
2983 if (rt->rt_uses_gateway) {
2984 if (rt->rt_gw_family == AF_INET &&
2985 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
2986 goto nla_put_failure;
2987 } else if (rt->rt_gw_family == AF_INET6) {
2988 int alen = sizeof(struct in6_addr);
2989 struct nlattr *nla;
2990 struct rtvia *via;
2991
2992 nla = nla_reserve(skb, RTA_VIA, alen + 2);
2993 if (!nla)
2994 goto nla_put_failure;
2995
2996 via = nla_data(nla);
2997 via->rtvia_family = AF_INET6;
2998 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
2999 }
3000 }
3001
3002 expires = rt->dst.expires;
3003 if (expires) {
3004 unsigned long now = jiffies;
3005
3006 if (time_before(now, expires))
3007 expires -= now;
3008 else
3009 expires = 0;
3010 }
3011
3012 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
3013 if (rt->rt_pmtu && expires)
3014 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
3015 if (rt->rt_mtu_locked && expires)
3016 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
3017 if (rtnetlink_put_metrics(skb, metrics) < 0)
3018 goto nla_put_failure;
3019
3020 if (fl4) {
3021 if (fl4->flowi4_mark &&
3022 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
3023 goto nla_put_failure;
3024
3025 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
3026 nla_put_u32(skb, RTA_UID,
3027 from_kuid_munged(current_user_ns(),
3028 fl4->flowi4_uid)))
3029 goto nla_put_failure;
3030
3031 if (rt_is_input_route(rt)) {
3032#ifdef CONFIG_IP_MROUTE
3033 if (ipv4_is_multicast(dst) &&
3034 !ipv4_is_local_multicast(dst) &&
3035 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) {
3036 int err = ipmr_get_route(net, skb,
3037 fl4->saddr, fl4->daddr,
3038 r, portid);
3039
3040 if (err <= 0) {
3041 if (err == 0)
3042 return 0;
3043 goto nla_put_failure;
3044 }
3045 } else
3046#endif
3047 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
3048 goto nla_put_failure;
3049 }
3050 }
3051
3052 error = rt->dst.error;
3053
3054 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
3055 goto nla_put_failure;
3056
3057 nlmsg_end(skb, nlh);
3058 return 0;
3059
3060nla_put_failure:
3061 nlmsg_cancel(skb, nlh);
3062 return -EMSGSIZE;
3063}
3064
3065static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
3066 struct netlink_callback *cb, u32 table_id,
3067 struct fnhe_hash_bucket *bucket, int genid,
3068 int *fa_index, int fa_start, unsigned int flags)
3069{
3070 int i;
3071
3072 for (i = 0; i < FNHE_HASH_SIZE; i++) {
3073 struct fib_nh_exception *fnhe;
3074
3075 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
3076 fnhe = rcu_dereference(fnhe->fnhe_next)) {
3077 struct rtable *rt;
3078 int err;
3079
3080 if (*fa_index < fa_start)
3081 goto next;
3082
3083 if (fnhe->fnhe_genid != genid)
3084 goto next;
3085
3086 if (fnhe->fnhe_expires &&
3087 time_after(jiffies, fnhe->fnhe_expires))
3088 goto next;
3089
3090 rt = rcu_dereference(fnhe->fnhe_rth_input);
3091 if (!rt)
3092 rt = rcu_dereference(fnhe->fnhe_rth_output);
3093 if (!rt)
3094 goto next;
3095
3096 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
3097 table_id, 0, NULL, skb,
3098 NETLINK_CB(cb->skb).portid,
3099 cb->nlh->nlmsg_seq, flags);
3100 if (err)
3101 return err;
3102next:
3103 (*fa_index)++;
3104 }
3105 }
3106
3107 return 0;
3108}
3109
3110int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
3111 u32 table_id, struct fib_info *fi,
3112 int *fa_index, int fa_start, unsigned int flags)
3113{
3114 struct net *net = sock_net(cb->skb->sk);
3115 int nhsel, genid = fnhe_genid(net);
3116
3117 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
3118 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
3119 struct fnhe_hash_bucket *bucket;
3120 int err;
3121
3122 if (nhc->nhc_flags & RTNH_F_DEAD)
3123 continue;
3124
3125 rcu_read_lock();
3126 bucket = rcu_dereference(nhc->nhc_exceptions);
3127 err = 0;
3128 if (bucket)
3129 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
3130 genid, fa_index, fa_start,
3131 flags);
3132 rcu_read_unlock();
3133 if (err)
3134 return err;
3135 }
3136
3137 return 0;
3138}
3139
3140static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
3141 u8 ip_proto, __be16 sport,
3142 __be16 dport)
3143{
3144 struct sk_buff *skb;
3145 struct iphdr *iph;
3146
3147 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3148 if (!skb)
3149 return NULL;
3150
3151 /* Reserve room for dummy headers, this skb can pass
3152 * through good chunk of routing engine.
3153 */
3154 skb_reset_mac_header(skb);
3155 skb_reset_network_header(skb);
3156 skb->protocol = htons(ETH_P_IP);
3157 iph = skb_put(skb, sizeof(struct iphdr));
3158 iph->protocol = ip_proto;
3159 iph->saddr = src;
3160 iph->daddr = dst;
3161 iph->version = 0x4;
3162 iph->frag_off = 0;
3163 iph->ihl = 0x5;
3164 skb_set_transport_header(skb, skb->len);
3165
3166 switch (iph->protocol) {
3167 case IPPROTO_UDP: {
3168 struct udphdr *udph;
3169
3170 udph = skb_put_zero(skb, sizeof(struct udphdr));
3171 udph->source = sport;
3172 udph->dest = dport;
3173 udph->len = htons(sizeof(struct udphdr));
3174 udph->check = 0;
3175 break;
3176 }
3177 case IPPROTO_TCP: {
3178 struct tcphdr *tcph;
3179
3180 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
3181 tcph->source = sport;
3182 tcph->dest = dport;
3183 tcph->doff = sizeof(struct tcphdr) / 4;
3184 tcph->rst = 1;
3185 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
3186 src, dst, 0);
3187 break;
3188 }
3189 case IPPROTO_ICMP: {
3190 struct icmphdr *icmph;
3191
3192 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
3193 icmph->type = ICMP_ECHO;
3194 icmph->code = 0;
3195 }
3196 }
3197
3198 return skb;
3199}
3200
3201static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3202 const struct nlmsghdr *nlh,
3203 struct nlattr **tb,
3204 struct netlink_ext_ack *extack)
3205{
3206 struct rtmsg *rtm;
3207 int i, err;
3208
3209 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3210 NL_SET_ERR_MSG(extack,
3211 "ipv4: Invalid header for route get request");
3212 return -EINVAL;
3213 }
3214
3215 if (!netlink_strict_get_check(skb))
3216 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3217 rtm_ipv4_policy, extack);
3218
3219 rtm = nlmsg_data(nlh);
3220 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3221 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3222 rtm->rtm_table || rtm->rtm_protocol ||
3223 rtm->rtm_scope || rtm->rtm_type) {
3224 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3225 return -EINVAL;
3226 }
3227
3228 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3229 RTM_F_LOOKUP_TABLE |
3230 RTM_F_FIB_MATCH)) {
3231 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3232 return -EINVAL;
3233 }
3234
3235 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3236 rtm_ipv4_policy, extack);
3237 if (err)
3238 return err;
3239
3240 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3241 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3242 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3243 return -EINVAL;
3244 }
3245
3246 for (i = 0; i <= RTA_MAX; i++) {
3247 if (!tb[i])
3248 continue;
3249
3250 switch (i) {
3251 case RTA_IIF:
3252 case RTA_OIF:
3253 case RTA_SRC:
3254 case RTA_DST:
3255 case RTA_IP_PROTO:
3256 case RTA_SPORT:
3257 case RTA_DPORT:
3258 case RTA_MARK:
3259 case RTA_UID:
3260 break;
3261 default:
3262 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3263 return -EINVAL;
3264 }
3265 }
3266
3267 return 0;
3268}
3269
3270static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3271 struct netlink_ext_ack *extack)
3272{
3273 struct net *net = sock_net(in_skb->sk);
3274 struct nlattr *tb[RTA_MAX+1];
3275 u32 table_id = RT_TABLE_MAIN;
3276 __be16 sport = 0, dport = 0;
3277 struct fib_result res = {};
3278 u8 ip_proto = IPPROTO_UDP;
3279 struct rtable *rt = NULL;
3280 struct sk_buff *skb;
3281 struct rtmsg *rtm;
3282 struct flowi4 fl4 = {};
3283 __be32 dst = 0;
3284 __be32 src = 0;
3285 kuid_t uid;
3286 u32 iif;
3287 int err;
3288 int mark;
3289
3290 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3291 if (err < 0)
3292 return err;
3293
3294 rtm = nlmsg_data(nlh);
3295 src = nla_get_in_addr_default(tb[RTA_SRC], 0);
3296 dst = nla_get_in_addr_default(tb[RTA_DST], 0);
3297 iif = nla_get_u32_default(tb[RTA_IIF], 0);
3298 mark = nla_get_u32_default(tb[RTA_MARK], 0);
3299 if (tb[RTA_UID])
3300 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3301 else
3302 uid = (iif ? INVALID_UID : current_uid());
3303
3304 if (tb[RTA_IP_PROTO]) {
3305 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3306 &ip_proto, AF_INET, extack);
3307 if (err)
3308 return err;
3309 }
3310
3311 if (tb[RTA_SPORT])
3312 sport = nla_get_be16(tb[RTA_SPORT]);
3313
3314 if (tb[RTA_DPORT])
3315 dport = nla_get_be16(tb[RTA_DPORT]);
3316
3317 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3318 if (!skb)
3319 return -ENOBUFS;
3320
3321 fl4.daddr = dst;
3322 fl4.saddr = src;
3323 fl4.flowi4_tos = rtm->rtm_tos & INET_DSCP_MASK;
3324 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0);
3325 fl4.flowi4_mark = mark;
3326 fl4.flowi4_uid = uid;
3327 if (sport)
3328 fl4.fl4_sport = sport;
3329 if (dport)
3330 fl4.fl4_dport = dport;
3331 fl4.flowi4_proto = ip_proto;
3332
3333 rcu_read_lock();
3334
3335 if (iif) {
3336 struct net_device *dev;
3337
3338 dev = dev_get_by_index_rcu(net, iif);
3339 if (!dev) {
3340 err = -ENODEV;
3341 goto errout_rcu;
3342 }
3343
3344 fl4.flowi4_iif = iif; /* for rt_fill_info */
3345 skb->dev = dev;
3346 skb->mark = mark;
3347 err = ip_route_input_rcu(skb, dst, src,
3348 inet_dsfield_to_dscp(rtm->rtm_tos),
3349 dev, &res) ? -EINVAL : 0;
3350
3351 rt = skb_rtable(skb);
3352 if (err == 0 && rt->dst.error)
3353 err = -rt->dst.error;
3354 } else {
3355 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3356 skb->dev = net->loopback_dev;
3357 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3358 err = 0;
3359 if (IS_ERR(rt))
3360 err = PTR_ERR(rt);
3361 else
3362 skb_dst_set(skb, &rt->dst);
3363 }
3364
3365 if (err)
3366 goto errout_rcu;
3367
3368 if (rtm->rtm_flags & RTM_F_NOTIFY)
3369 rt->rt_flags |= RTCF_NOTIFY;
3370
3371 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3372 table_id = res.table ? res.table->tb_id : 0;
3373
3374 /* reset skb for netlink reply msg */
3375 skb_trim(skb, 0);
3376 skb_reset_network_header(skb);
3377 skb_reset_transport_header(skb);
3378 skb_reset_mac_header(skb);
3379
3380 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3381 struct fib_rt_info fri;
3382
3383 if (!res.fi) {
3384 err = fib_props[res.type].error;
3385 if (!err)
3386 err = -EHOSTUNREACH;
3387 goto errout_rcu;
3388 }
3389 fri.fi = res.fi;
3390 fri.tb_id = table_id;
3391 fri.dst = res.prefix;
3392 fri.dst_len = res.prefixlen;
3393 fri.dscp = res.dscp;
3394 fri.type = rt->rt_type;
3395 fri.offload = 0;
3396 fri.trap = 0;
3397 fri.offload_failed = 0;
3398 if (res.fa_head) {
3399 struct fib_alias *fa;
3400
3401 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) {
3402 u8 slen = 32 - fri.dst_len;
3403
3404 if (fa->fa_slen == slen &&
3405 fa->tb_id == fri.tb_id &&
3406 fa->fa_dscp == fri.dscp &&
3407 fa->fa_info == res.fi &&
3408 fa->fa_type == fri.type) {
3409 fri.offload = READ_ONCE(fa->offload);
3410 fri.trap = READ_ONCE(fa->trap);
3411 fri.offload_failed =
3412 READ_ONCE(fa->offload_failed);
3413 break;
3414 }
3415 }
3416 }
3417 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3418 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0);
3419 } else {
3420 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4,
3421 skb, NETLINK_CB(in_skb).portid,
3422 nlh->nlmsg_seq, 0);
3423 }
3424 if (err < 0)
3425 goto errout_rcu;
3426
3427 rcu_read_unlock();
3428
3429 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3430
3431errout_free:
3432 return err;
3433errout_rcu:
3434 rcu_read_unlock();
3435 kfree_skb(skb);
3436 goto errout_free;
3437}
3438
3439void ip_rt_multicast_event(struct in_device *in_dev)
3440{
3441 rt_cache_flush(dev_net(in_dev->dev));
3442}
3443
3444#ifdef CONFIG_SYSCTL
3445static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3446static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3447static int ip_rt_gc_elasticity __read_mostly = 8;
3448static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3449
3450static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write,
3451 void *buffer, size_t *lenp, loff_t *ppos)
3452{
3453 struct net *net = (struct net *)__ctl->extra1;
3454
3455 if (write) {
3456 rt_cache_flush(net);
3457 fnhe_genid_bump(net);
3458 return 0;
3459 }
3460
3461 return -EINVAL;
3462}
3463
3464static struct ctl_table ipv4_route_table[] = {
3465 {
3466 .procname = "gc_thresh",
3467 .data = &ipv4_dst_ops.gc_thresh,
3468 .maxlen = sizeof(int),
3469 .mode = 0644,
3470 .proc_handler = proc_dointvec,
3471 },
3472 {
3473 .procname = "max_size",
3474 .data = &ip_rt_max_size,
3475 .maxlen = sizeof(int),
3476 .mode = 0644,
3477 .proc_handler = proc_dointvec,
3478 },
3479 {
3480 /* Deprecated. Use gc_min_interval_ms */
3481
3482 .procname = "gc_min_interval",
3483 .data = &ip_rt_gc_min_interval,
3484 .maxlen = sizeof(int),
3485 .mode = 0644,
3486 .proc_handler = proc_dointvec_jiffies,
3487 },
3488 {
3489 .procname = "gc_min_interval_ms",
3490 .data = &ip_rt_gc_min_interval,
3491 .maxlen = sizeof(int),
3492 .mode = 0644,
3493 .proc_handler = proc_dointvec_ms_jiffies,
3494 },
3495 {
3496 .procname = "gc_timeout",
3497 .data = &ip_rt_gc_timeout,
3498 .maxlen = sizeof(int),
3499 .mode = 0644,
3500 .proc_handler = proc_dointvec_jiffies,
3501 },
3502 {
3503 .procname = "gc_interval",
3504 .data = &ip_rt_gc_interval,
3505 .maxlen = sizeof(int),
3506 .mode = 0644,
3507 .proc_handler = proc_dointvec_jiffies,
3508 },
3509 {
3510 .procname = "redirect_load",
3511 .data = &ip_rt_redirect_load,
3512 .maxlen = sizeof(int),
3513 .mode = 0644,
3514 .proc_handler = proc_dointvec,
3515 },
3516 {
3517 .procname = "redirect_number",
3518 .data = &ip_rt_redirect_number,
3519 .maxlen = sizeof(int),
3520 .mode = 0644,
3521 .proc_handler = proc_dointvec,
3522 },
3523 {
3524 .procname = "redirect_silence",
3525 .data = &ip_rt_redirect_silence,
3526 .maxlen = sizeof(int),
3527 .mode = 0644,
3528 .proc_handler = proc_dointvec,
3529 },
3530 {
3531 .procname = "error_cost",
3532 .data = &ip_rt_error_cost,
3533 .maxlen = sizeof(int),
3534 .mode = 0644,
3535 .proc_handler = proc_dointvec,
3536 },
3537 {
3538 .procname = "error_burst",
3539 .data = &ip_rt_error_burst,
3540 .maxlen = sizeof(int),
3541 .mode = 0644,
3542 .proc_handler = proc_dointvec,
3543 },
3544 {
3545 .procname = "gc_elasticity",
3546 .data = &ip_rt_gc_elasticity,
3547 .maxlen = sizeof(int),
3548 .mode = 0644,
3549 .proc_handler = proc_dointvec,
3550 },
3551};
3552
3553static const char ipv4_route_flush_procname[] = "flush";
3554
3555static struct ctl_table ipv4_route_netns_table[] = {
3556 {
3557 .procname = ipv4_route_flush_procname,
3558 .maxlen = sizeof(int),
3559 .mode = 0200,
3560 .proc_handler = ipv4_sysctl_rtcache_flush,
3561 },
3562 {
3563 .procname = "min_pmtu",
3564 .data = &init_net.ipv4.ip_rt_min_pmtu,
3565 .maxlen = sizeof(int),
3566 .mode = 0644,
3567 .proc_handler = proc_dointvec_minmax,
3568 .extra1 = &ip_min_valid_pmtu,
3569 },
3570 {
3571 .procname = "mtu_expires",
3572 .data = &init_net.ipv4.ip_rt_mtu_expires,
3573 .maxlen = sizeof(int),
3574 .mode = 0644,
3575 .proc_handler = proc_dointvec_jiffies,
3576 },
3577 {
3578 .procname = "min_adv_mss",
3579 .data = &init_net.ipv4.ip_rt_min_advmss,
3580 .maxlen = sizeof(int),
3581 .mode = 0644,
3582 .proc_handler = proc_dointvec,
3583 },
3584};
3585
3586static __net_init int sysctl_route_net_init(struct net *net)
3587{
3588 struct ctl_table *tbl;
3589 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table);
3590
3591 tbl = ipv4_route_netns_table;
3592 if (!net_eq(net, &init_net)) {
3593 int i;
3594
3595 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL);
3596 if (!tbl)
3597 goto err_dup;
3598
3599 /* Don't export non-whitelisted sysctls to unprivileged users */
3600 if (net->user_ns != &init_user_ns) {
3601 if (tbl[0].procname != ipv4_route_flush_procname)
3602 table_size = 0;
3603 }
3604
3605 /* Update the variables to point into the current struct net
3606 * except for the first element flush
3607 */
3608 for (i = 1; i < table_size; i++)
3609 tbl[i].data += (void *)net - (void *)&init_net;
3610 }
3611 tbl[0].extra1 = net;
3612
3613 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route",
3614 tbl, table_size);
3615 if (!net->ipv4.route_hdr)
3616 goto err_reg;
3617 return 0;
3618
3619err_reg:
3620 if (tbl != ipv4_route_netns_table)
3621 kfree(tbl);
3622err_dup:
3623 return -ENOMEM;
3624}
3625
3626static __net_exit void sysctl_route_net_exit(struct net *net)
3627{
3628 const struct ctl_table *tbl;
3629
3630 tbl = net->ipv4.route_hdr->ctl_table_arg;
3631 unregister_net_sysctl_table(net->ipv4.route_hdr);
3632 BUG_ON(tbl == ipv4_route_netns_table);
3633 kfree(tbl);
3634}
3635
3636static __net_initdata struct pernet_operations sysctl_route_ops = {
3637 .init = sysctl_route_net_init,
3638 .exit = sysctl_route_net_exit,
3639};
3640#endif
3641
3642static __net_init int netns_ip_rt_init(struct net *net)
3643{
3644 /* Set default value for namespaceified sysctls */
3645 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU;
3646 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
3647 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
3648 return 0;
3649}
3650
3651static struct pernet_operations __net_initdata ip_rt_ops = {
3652 .init = netns_ip_rt_init,
3653};
3654
3655static __net_init int rt_genid_init(struct net *net)
3656{
3657 atomic_set(&net->ipv4.rt_genid, 0);
3658 atomic_set(&net->fnhe_genid, 0);
3659 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32());
3660 return 0;
3661}
3662
3663static __net_initdata struct pernet_operations rt_genid_ops = {
3664 .init = rt_genid_init,
3665};
3666
3667static int __net_init ipv4_inetpeer_init(struct net *net)
3668{
3669 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3670
3671 if (!bp)
3672 return -ENOMEM;
3673 inet_peer_base_init(bp);
3674 net->ipv4.peers = bp;
3675 return 0;
3676}
3677
3678static void __net_exit ipv4_inetpeer_exit(struct net *net)
3679{
3680 struct inet_peer_base *bp = net->ipv4.peers;
3681
3682 net->ipv4.peers = NULL;
3683 inetpeer_invalidate_tree(bp);
3684 kfree(bp);
3685}
3686
3687static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3688 .init = ipv4_inetpeer_init,
3689 .exit = ipv4_inetpeer_exit,
3690};
3691
3692#ifdef CONFIG_IP_ROUTE_CLASSID
3693struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3694#endif /* CONFIG_IP_ROUTE_CLASSID */
3695
3696static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = {
3697 {.protocol = PF_INET, .msgtype = RTM_GETROUTE,
3698 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED},
3699};
3700
3701int __init ip_rt_init(void)
3702{
3703 void *idents_hash;
3704 int cpu;
3705
3706 /* For modern hosts, this will use 2 MB of memory */
3707 idents_hash = alloc_large_system_hash("IP idents",
3708 sizeof(*ip_idents) + sizeof(*ip_tstamps),
3709 0,
3710 16, /* one bucket per 64 KB */
3711 HASH_ZERO,
3712 NULL,
3713 &ip_idents_mask,
3714 2048,
3715 256*1024);
3716
3717 ip_idents = idents_hash;
3718
3719 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents));
3720
3721 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents);
3722
3723 for_each_possible_cpu(cpu) {
3724 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3725
3726 INIT_LIST_HEAD(&ul->head);
3727 spin_lock_init(&ul->lock);
3728 }
3729#ifdef CONFIG_IP_ROUTE_CLASSID
3730 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3731 if (!ip_rt_acct)
3732 panic("IP: failed to allocate ip_rt_acct\n");
3733#endif
3734
3735 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable,
3736 SLAB_HWCACHE_ALIGN | SLAB_PANIC);
3737
3738 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3739
3740 if (dst_entries_init(&ipv4_dst_ops) < 0)
3741 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3742
3743 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3744 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3745
3746 ipv4_dst_ops.gc_thresh = ~0;
3747 ip_rt_max_size = INT_MAX;
3748
3749 devinet_init();
3750 ip_fib_init();
3751
3752 if (ip_rt_proc_init())
3753 pr_err("Unable to create route proc files\n");
3754#ifdef CONFIG_XFRM
3755 xfrm_init();
3756 xfrm4_init();
3757#endif
3758 rtnl_register_many(ip_rt_rtnl_msg_handlers);
3759
3760#ifdef CONFIG_SYSCTL
3761 register_pernet_subsys(&sysctl_route_ops);
3762#endif
3763 register_pernet_subsys(&ip_rt_ops);
3764 register_pernet_subsys(&rt_genid_ops);
3765 register_pernet_subsys(&ipv4_inetpeer_ops);
3766 return 0;
3767}
3768
3769#ifdef CONFIG_SYSCTL
3770/*
3771 * We really need to sanitize the damn ipv4 init order, then all
3772 * this nonsense will go away.
3773 */
3774void __init ip_static_sysctl_init(void)
3775{
3776 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3777}
3778#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/memblock.h>
70#include <linux/string.h>
71#include <linux/socket.h>
72#include <linux/sockios.h>
73#include <linux/errno.h>
74#include <linux/in.h>
75#include <linux/inet.h>
76#include <linux/netdevice.h>
77#include <linux/proc_fs.h>
78#include <linux/init.h>
79#include <linux/skbuff.h>
80#include <linux/inetdevice.h>
81#include <linux/igmp.h>
82#include <linux/pkt_sched.h>
83#include <linux/mroute.h>
84#include <linux/netfilter_ipv4.h>
85#include <linux/random.h>
86#include <linux/rcupdate.h>
87#include <linux/times.h>
88#include <linux/slab.h>
89#include <linux/jhash.h>
90#include <net/dst.h>
91#include <net/dst_metadata.h>
92#include <net/net_namespace.h>
93#include <net/protocol.h>
94#include <net/ip.h>
95#include <net/route.h>
96#include <net/inetpeer.h>
97#include <net/sock.h>
98#include <net/ip_fib.h>
99#include <net/nexthop.h>
100#include <net/arp.h>
101#include <net/tcp.h>
102#include <net/icmp.h>
103#include <net/xfrm.h>
104#include <net/lwtunnel.h>
105#include <net/netevent.h>
106#include <net/rtnetlink.h>
107#ifdef CONFIG_SYSCTL
108#include <linux/sysctl.h>
109#endif
110#include <net/secure_seq.h>
111#include <net/ip_tunnels.h>
112#include <net/l3mdev.h>
113
114#include "fib_lookup.h"
115
116#define RT_FL_TOS(oldflp4) \
117 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
118
119#define RT_GC_TIMEOUT (300*HZ)
120
121static int ip_rt_max_size;
122static int ip_rt_redirect_number __read_mostly = 9;
123static int ip_rt_redirect_load __read_mostly = HZ / 50;
124static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
125static int ip_rt_error_cost __read_mostly = HZ;
126static int ip_rt_error_burst __read_mostly = 5 * HZ;
127static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
128static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
129static int ip_rt_min_advmss __read_mostly = 256;
130
131static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
132
133/*
134 * Interface to generic destination cache.
135 */
136
137INDIRECT_CALLABLE_SCOPE
138struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
139static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
140INDIRECT_CALLABLE_SCOPE
141unsigned 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,
146 bool confirm_neigh);
147static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
148 struct sk_buff *skb);
149static void ipv4_dst_destroy(struct dst_entry *dst);
150
151static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
152{
153 WARN_ON(1);
154 return NULL;
155}
156
157static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
158 struct sk_buff *skb,
159 const void *daddr);
160static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
161
162static struct dst_ops ipv4_dst_ops = {
163 .family = AF_INET,
164 .check = ipv4_dst_check,
165 .default_advmss = ipv4_default_advmss,
166 .mtu = ipv4_mtu,
167 .cow_metrics = ipv4_cow_metrics,
168 .destroy = ipv4_dst_destroy,
169 .negative_advice = ipv4_negative_advice,
170 .link_failure = ipv4_link_failure,
171 .update_pmtu = ip_rt_update_pmtu,
172 .redirect = ip_do_redirect,
173 .local_out = __ip_local_out,
174 .neigh_lookup = ipv4_neigh_lookup,
175 .confirm_neigh = ipv4_confirm_neigh,
176};
177
178#define ECN_OR_COST(class) TC_PRIO_##class
179
180const __u8 ip_tos2prio[16] = {
181 TC_PRIO_BESTEFFORT,
182 ECN_OR_COST(BESTEFFORT),
183 TC_PRIO_BESTEFFORT,
184 ECN_OR_COST(BESTEFFORT),
185 TC_PRIO_BULK,
186 ECN_OR_COST(BULK),
187 TC_PRIO_BULK,
188 ECN_OR_COST(BULK),
189 TC_PRIO_INTERACTIVE,
190 ECN_OR_COST(INTERACTIVE),
191 TC_PRIO_INTERACTIVE,
192 ECN_OR_COST(INTERACTIVE),
193 TC_PRIO_INTERACTIVE_BULK,
194 ECN_OR_COST(INTERACTIVE_BULK),
195 TC_PRIO_INTERACTIVE_BULK,
196 ECN_OR_COST(INTERACTIVE_BULK)
197};
198EXPORT_SYMBOL(ip_tos2prio);
199
200static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
201#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
202
203#ifdef CONFIG_PROC_FS
204static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
205{
206 if (*pos)
207 return NULL;
208 return SEQ_START_TOKEN;
209}
210
211static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
212{
213 ++*pos;
214 return NULL;
215}
216
217static void rt_cache_seq_stop(struct seq_file *seq, void *v)
218{
219}
220
221static int rt_cache_seq_show(struct seq_file *seq, void *v)
222{
223 if (v == SEQ_START_TOKEN)
224 seq_printf(seq, "%-127s\n",
225 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
226 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
227 "HHUptod\tSpecDst");
228 return 0;
229}
230
231static const struct seq_operations rt_cache_seq_ops = {
232 .start = rt_cache_seq_start,
233 .next = rt_cache_seq_next,
234 .stop = rt_cache_seq_stop,
235 .show = rt_cache_seq_show,
236};
237
238static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
239{
240 int cpu;
241
242 if (*pos == 0)
243 return SEQ_START_TOKEN;
244
245 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
246 if (!cpu_possible(cpu))
247 continue;
248 *pos = cpu+1;
249 return &per_cpu(rt_cache_stat, cpu);
250 }
251 return NULL;
252}
253
254static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
255{
256 int cpu;
257
258 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
259 if (!cpu_possible(cpu))
260 continue;
261 *pos = cpu+1;
262 return &per_cpu(rt_cache_stat, cpu);
263 }
264 (*pos)++;
265 return NULL;
266
267}
268
269static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
270{
271
272}
273
274static int rt_cpu_seq_show(struct seq_file *seq, void *v)
275{
276 struct rt_cache_stat *st = v;
277
278 if (v == SEQ_START_TOKEN) {
279 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");
280 return 0;
281 }
282
283 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
284 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
285 dst_entries_get_slow(&ipv4_dst_ops),
286 0, /* st->in_hit */
287 st->in_slow_tot,
288 st->in_slow_mc,
289 st->in_no_route,
290 st->in_brd,
291 st->in_martian_dst,
292 st->in_martian_src,
293
294 0, /* st->out_hit */
295 st->out_slow_tot,
296 st->out_slow_mc,
297
298 0, /* st->gc_total */
299 0, /* st->gc_ignored */
300 0, /* st->gc_goal_miss */
301 0, /* st->gc_dst_overflow */
302 0, /* st->in_hlist_search */
303 0 /* st->out_hlist_search */
304 );
305 return 0;
306}
307
308static const struct seq_operations rt_cpu_seq_ops = {
309 .start = rt_cpu_seq_start,
310 .next = rt_cpu_seq_next,
311 .stop = rt_cpu_seq_stop,
312 .show = rt_cpu_seq_show,
313};
314
315#ifdef CONFIG_IP_ROUTE_CLASSID
316static int rt_acct_proc_show(struct seq_file *m, void *v)
317{
318 struct ip_rt_acct *dst, *src;
319 unsigned int i, j;
320
321 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
322 if (!dst)
323 return -ENOMEM;
324
325 for_each_possible_cpu(i) {
326 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
327 for (j = 0; j < 256; j++) {
328 dst[j].o_bytes += src[j].o_bytes;
329 dst[j].o_packets += src[j].o_packets;
330 dst[j].i_bytes += src[j].i_bytes;
331 dst[j].i_packets += src[j].i_packets;
332 }
333 }
334
335 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
336 kfree(dst);
337 return 0;
338}
339#endif
340
341static int __net_init ip_rt_do_proc_init(struct net *net)
342{
343 struct proc_dir_entry *pde;
344
345 pde = proc_create_seq("rt_cache", 0444, net->proc_net,
346 &rt_cache_seq_ops);
347 if (!pde)
348 goto err1;
349
350 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat,
351 &rt_cpu_seq_ops);
352 if (!pde)
353 goto err2;
354
355#ifdef CONFIG_IP_ROUTE_CLASSID
356 pde = proc_create_single("rt_acct", 0, net->proc_net,
357 rt_acct_proc_show);
358 if (!pde)
359 goto err3;
360#endif
361 return 0;
362
363#ifdef CONFIG_IP_ROUTE_CLASSID
364err3:
365 remove_proc_entry("rt_cache", net->proc_net_stat);
366#endif
367err2:
368 remove_proc_entry("rt_cache", net->proc_net);
369err1:
370 return -ENOMEM;
371}
372
373static void __net_exit ip_rt_do_proc_exit(struct net *net)
374{
375 remove_proc_entry("rt_cache", net->proc_net_stat);
376 remove_proc_entry("rt_cache", net->proc_net);
377#ifdef CONFIG_IP_ROUTE_CLASSID
378 remove_proc_entry("rt_acct", net->proc_net);
379#endif
380}
381
382static struct pernet_operations ip_rt_proc_ops __net_initdata = {
383 .init = ip_rt_do_proc_init,
384 .exit = ip_rt_do_proc_exit,
385};
386
387static int __init ip_rt_proc_init(void)
388{
389 return register_pernet_subsys(&ip_rt_proc_ops);
390}
391
392#else
393static inline int ip_rt_proc_init(void)
394{
395 return 0;
396}
397#endif /* CONFIG_PROC_FS */
398
399static inline bool rt_is_expired(const struct rtable *rth)
400{
401 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
402}
403
404void rt_cache_flush(struct net *net)
405{
406 rt_genid_bump_ipv4(net);
407}
408
409static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
410 struct sk_buff *skb,
411 const void *daddr)
412{
413 const struct rtable *rt = container_of(dst, struct rtable, dst);
414 struct net_device *dev = dst->dev;
415 struct neighbour *n;
416
417 rcu_read_lock_bh();
418
419 if (likely(rt->rt_gw_family == AF_INET)) {
420 n = ip_neigh_gw4(dev, rt->rt_gw4);
421 } else if (rt->rt_gw_family == AF_INET6) {
422 n = ip_neigh_gw6(dev, &rt->rt_gw6);
423 } else {
424 __be32 pkey;
425
426 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
427 n = ip_neigh_gw4(dev, pkey);
428 }
429
430 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
431 n = NULL;
432
433 rcu_read_unlock_bh();
434
435 return n;
436}
437
438static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
439{
440 const struct rtable *rt = container_of(dst, struct rtable, dst);
441 struct net_device *dev = dst->dev;
442 const __be32 *pkey = daddr;
443
444 if (rt->rt_gw_family == AF_INET) {
445 pkey = (const __be32 *)&rt->rt_gw4;
446 } else if (rt->rt_gw_family == AF_INET6) {
447 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
448 } else if (!daddr ||
449 (rt->rt_flags &
450 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
451 return;
452 }
453 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
454}
455
456/* Hash tables of size 2048..262144 depending on RAM size.
457 * Each bucket uses 8 bytes.
458 */
459static u32 ip_idents_mask __read_mostly;
460static atomic_t *ip_idents __read_mostly;
461static u32 *ip_tstamps __read_mostly;
462
463/* In order to protect privacy, we add a perturbation to identifiers
464 * if one generator is seldom used. This makes hard for an attacker
465 * to infer how many packets were sent between two points in time.
466 */
467u32 ip_idents_reserve(u32 hash, int segs)
468{
469 u32 bucket, old, now = (u32)jiffies;
470 atomic_t *p_id;
471 u32 *p_tstamp;
472 u32 delta = 0;
473
474 bucket = hash & ip_idents_mask;
475 p_tstamp = ip_tstamps + bucket;
476 p_id = ip_idents + bucket;
477 old = READ_ONCE(*p_tstamp);
478
479 if (old != now && cmpxchg(p_tstamp, old, now) == old)
480 delta = prandom_u32_max(now - old);
481
482 /* If UBSAN reports an error there, please make sure your compiler
483 * supports -fno-strict-overflow before reporting it that was a bug
484 * in UBSAN, and it has been fixed in GCC-8.
485 */
486 return atomic_add_return(segs + delta, p_id) - segs;
487}
488EXPORT_SYMBOL(ip_idents_reserve);
489
490void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
491{
492 u32 hash, id;
493
494 /* Note the following code is not safe, but this is okay. */
495 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
496 get_random_bytes(&net->ipv4.ip_id_key,
497 sizeof(net->ipv4.ip_id_key));
498
499 hash = siphash_3u32((__force u32)iph->daddr,
500 (__force u32)iph->saddr,
501 iph->protocol,
502 &net->ipv4.ip_id_key);
503 id = ip_idents_reserve(hash, segs);
504 iph->id = htons(id);
505}
506EXPORT_SYMBOL(__ip_select_ident);
507
508static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
509 const struct sock *sk,
510 const struct iphdr *iph,
511 int oif, u8 tos,
512 u8 prot, u32 mark, int flow_flags)
513{
514 if (sk) {
515 const struct inet_sock *inet = inet_sk(sk);
516
517 oif = sk->sk_bound_dev_if;
518 mark = sk->sk_mark;
519 tos = RT_CONN_FLAGS(sk);
520 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
521 }
522 flowi4_init_output(fl4, oif, mark, tos,
523 RT_SCOPE_UNIVERSE, prot,
524 flow_flags,
525 iph->daddr, iph->saddr, 0, 0,
526 sock_net_uid(net, sk));
527}
528
529static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
530 const struct sock *sk)
531{
532 const struct net *net = dev_net(skb->dev);
533 const struct iphdr *iph = ip_hdr(skb);
534 int oif = skb->dev->ifindex;
535 u8 tos = RT_TOS(iph->tos);
536 u8 prot = iph->protocol;
537 u32 mark = skb->mark;
538
539 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
540}
541
542static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
543{
544 const struct inet_sock *inet = inet_sk(sk);
545 const struct ip_options_rcu *inet_opt;
546 __be32 daddr = inet->inet_daddr;
547
548 rcu_read_lock();
549 inet_opt = rcu_dereference(inet->inet_opt);
550 if (inet_opt && inet_opt->opt.srr)
551 daddr = inet_opt->opt.faddr;
552 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
553 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
554 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
555 inet_sk_flowi_flags(sk),
556 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
557 rcu_read_unlock();
558}
559
560static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
561 const struct sk_buff *skb)
562{
563 if (skb)
564 build_skb_flow_key(fl4, skb, sk);
565 else
566 build_sk_flow_key(fl4, sk);
567}
568
569static DEFINE_SPINLOCK(fnhe_lock);
570
571static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
572{
573 struct rtable *rt;
574
575 rt = rcu_dereference(fnhe->fnhe_rth_input);
576 if (rt) {
577 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
578 dst_dev_put(&rt->dst);
579 dst_release(&rt->dst);
580 }
581 rt = rcu_dereference(fnhe->fnhe_rth_output);
582 if (rt) {
583 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
584 dst_dev_put(&rt->dst);
585 dst_release(&rt->dst);
586 }
587}
588
589static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
590{
591 struct fib_nh_exception __rcu **fnhe_p, **oldest_p;
592 struct fib_nh_exception *fnhe, *oldest = NULL;
593
594 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) {
595 fnhe = rcu_dereference_protected(*fnhe_p,
596 lockdep_is_held(&fnhe_lock));
597 if (!fnhe)
598 break;
599 if (!oldest ||
600 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) {
601 oldest = fnhe;
602 oldest_p = fnhe_p;
603 }
604 }
605 fnhe_flush_routes(oldest);
606 *oldest_p = oldest->fnhe_next;
607 kfree_rcu(oldest, rcu);
608}
609
610static u32 fnhe_hashfun(__be32 daddr)
611{
612 static siphash_key_t fnhe_hash_key __read_mostly;
613 u64 hval;
614
615 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));
616 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key);
617 return hash_64(hval, FNHE_HASH_SHIFT);
618}
619
620static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
621{
622 rt->rt_pmtu = fnhe->fnhe_pmtu;
623 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
624 rt->dst.expires = fnhe->fnhe_expires;
625
626 if (fnhe->fnhe_gw) {
627 rt->rt_flags |= RTCF_REDIRECTED;
628 rt->rt_uses_gateway = 1;
629 rt->rt_gw_family = AF_INET;
630 rt->rt_gw4 = fnhe->fnhe_gw;
631 }
632}
633
634static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
635 __be32 gw, u32 pmtu, bool lock,
636 unsigned long expires)
637{
638 struct fnhe_hash_bucket *hash;
639 struct fib_nh_exception *fnhe;
640 struct rtable *rt;
641 u32 genid, hval;
642 unsigned int i;
643 int depth;
644
645 genid = fnhe_genid(dev_net(nhc->nhc_dev));
646 hval = fnhe_hashfun(daddr);
647
648 spin_lock_bh(&fnhe_lock);
649
650 hash = rcu_dereference(nhc->nhc_exceptions);
651 if (!hash) {
652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
653 if (!hash)
654 goto out_unlock;
655 rcu_assign_pointer(nhc->nhc_exceptions, hash);
656 }
657
658 hash += hval;
659
660 depth = 0;
661 for (fnhe = rcu_dereference(hash->chain); fnhe;
662 fnhe = rcu_dereference(fnhe->fnhe_next)) {
663 if (fnhe->fnhe_daddr == daddr)
664 break;
665 depth++;
666 }
667
668 if (fnhe) {
669 if (fnhe->fnhe_genid != genid)
670 fnhe->fnhe_genid = genid;
671 if (gw)
672 fnhe->fnhe_gw = gw;
673 if (pmtu) {
674 fnhe->fnhe_pmtu = pmtu;
675 fnhe->fnhe_mtu_locked = lock;
676 }
677 fnhe->fnhe_expires = max(1UL, expires);
678 /* Update all cached dsts too */
679 rt = rcu_dereference(fnhe->fnhe_rth_input);
680 if (rt)
681 fill_route_from_fnhe(rt, fnhe);
682 rt = rcu_dereference(fnhe->fnhe_rth_output);
683 if (rt)
684 fill_route_from_fnhe(rt, fnhe);
685 } else {
686 /* Randomize max depth to avoid some side channels attacks. */
687 int max_depth = FNHE_RECLAIM_DEPTH +
688 prandom_u32_max(FNHE_RECLAIM_DEPTH);
689
690 while (depth > max_depth) {
691 fnhe_remove_oldest(hash);
692 depth--;
693 }
694
695 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
696 if (!fnhe)
697 goto out_unlock;
698
699 fnhe->fnhe_next = hash->chain;
700
701 fnhe->fnhe_genid = genid;
702 fnhe->fnhe_daddr = daddr;
703 fnhe->fnhe_gw = gw;
704 fnhe->fnhe_pmtu = pmtu;
705 fnhe->fnhe_mtu_locked = lock;
706 fnhe->fnhe_expires = max(1UL, expires);
707
708 rcu_assign_pointer(hash->chain, fnhe);
709
710 /* Exception created; mark the cached routes for the nexthop
711 * stale, so anyone caching it rechecks if this exception
712 * applies to them.
713 */
714 rt = rcu_dereference(nhc->nhc_rth_input);
715 if (rt)
716 rt->dst.obsolete = DST_OBSOLETE_KILL;
717
718 for_each_possible_cpu(i) {
719 struct rtable __rcu **prt;
720
721 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
722 rt = rcu_dereference(*prt);
723 if (rt)
724 rt->dst.obsolete = DST_OBSOLETE_KILL;
725 }
726 }
727
728 fnhe->fnhe_stamp = jiffies;
729
730out_unlock:
731 spin_unlock_bh(&fnhe_lock);
732}
733
734static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
735 bool kill_route)
736{
737 __be32 new_gw = icmp_hdr(skb)->un.gateway;
738 __be32 old_gw = ip_hdr(skb)->saddr;
739 struct net_device *dev = skb->dev;
740 struct in_device *in_dev;
741 struct fib_result res;
742 struct neighbour *n;
743 struct net *net;
744
745 switch (icmp_hdr(skb)->code & 7) {
746 case ICMP_REDIR_NET:
747 case ICMP_REDIR_NETTOS:
748 case ICMP_REDIR_HOST:
749 case ICMP_REDIR_HOSTTOS:
750 break;
751
752 default:
753 return;
754 }
755
756 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
757 return;
758
759 in_dev = __in_dev_get_rcu(dev);
760 if (!in_dev)
761 return;
762
763 net = dev_net(dev);
764 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
765 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
766 ipv4_is_zeronet(new_gw))
767 goto reject_redirect;
768
769 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
770 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
771 goto reject_redirect;
772 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
773 goto reject_redirect;
774 } else {
775 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
776 goto reject_redirect;
777 }
778
779 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
780 if (!n)
781 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
782 if (!IS_ERR(n)) {
783 if (!(n->nud_state & NUD_VALID)) {
784 neigh_event_send(n, NULL);
785 } else {
786 if (fib_lookup(net, fl4, &res, 0) == 0) {
787 struct fib_nh_common *nhc;
788
789 fib_select_path(net, &res, fl4, skb);
790 nhc = FIB_RES_NHC(res);
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->n_redirects == 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 struct net *net = dev_net(dst->dev);
1017 struct fib_result res;
1018 bool lock = false;
1019 u32 old_mtu;
1020
1021 if (ip_mtu_locked(dst))
1022 return;
1023
1024 old_mtu = ipv4_mtu(dst);
1025 if (old_mtu < mtu)
1026 return;
1027
1028 if (mtu < ip_rt_min_pmtu) {
1029 lock = true;
1030 mtu = min(old_mtu, ip_rt_min_pmtu);
1031 }
1032
1033 if (rt->rt_pmtu == mtu && !lock &&
1034 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1035 return;
1036
1037 rcu_read_lock();
1038 if (fib_lookup(net, fl4, &res, 0) == 0) {
1039 struct fib_nh_common *nhc;
1040
1041 fib_select_path(net, &res, fl4, NULL);
1042 nhc = FIB_RES_NHC(res);
1043 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1044 jiffies + ip_rt_mtu_expires);
1045 }
1046 rcu_read_unlock();
1047}
1048
1049static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1050 struct sk_buff *skb, u32 mtu,
1051 bool confirm_neigh)
1052{
1053 struct rtable *rt = (struct rtable *) dst;
1054 struct flowi4 fl4;
1055
1056 ip_rt_build_flow_key(&fl4, sk, skb);
1057
1058 /* Don't make lookup fail for bridged encapsulations */
1059 if (skb && netif_is_any_bridge_port(skb->dev))
1060 fl4.flowi4_oif = 0;
1061
1062 __ip_rt_update_pmtu(rt, &fl4, mtu);
1063}
1064
1065void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1066 int oif, u8 protocol)
1067{
1068 const struct iphdr *iph = (const struct iphdr *)skb->data;
1069 struct flowi4 fl4;
1070 struct rtable *rt;
1071 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1072
1073 __build_flow_key(net, &fl4, NULL, iph, oif,
1074 RT_TOS(iph->tos), protocol, mark, 0);
1075 rt = __ip_route_output_key(net, &fl4);
1076 if (!IS_ERR(rt)) {
1077 __ip_rt_update_pmtu(rt, &fl4, mtu);
1078 ip_rt_put(rt);
1079 }
1080}
1081EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1082
1083static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1084{
1085 const struct iphdr *iph = (const struct iphdr *)skb->data;
1086 struct flowi4 fl4;
1087 struct rtable *rt;
1088
1089 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1090
1091 if (!fl4.flowi4_mark)
1092 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1093
1094 rt = __ip_route_output_key(sock_net(sk), &fl4);
1095 if (!IS_ERR(rt)) {
1096 __ip_rt_update_pmtu(rt, &fl4, mtu);
1097 ip_rt_put(rt);
1098 }
1099}
1100
1101void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1102{
1103 const struct iphdr *iph = (const struct iphdr *)skb->data;
1104 struct flowi4 fl4;
1105 struct rtable *rt;
1106 struct dst_entry *odst = NULL;
1107 bool new = false;
1108 struct net *net = sock_net(sk);
1109
1110 bh_lock_sock(sk);
1111
1112 if (!ip_sk_accept_pmtu(sk))
1113 goto out;
1114
1115 odst = sk_dst_get(sk);
1116
1117 if (sock_owned_by_user(sk) || !odst) {
1118 __ipv4_sk_update_pmtu(skb, sk, mtu);
1119 goto out;
1120 }
1121
1122 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1123
1124 rt = (struct rtable *)odst;
1125 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1126 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1127 if (IS_ERR(rt))
1128 goto out;
1129
1130 new = true;
1131 }
1132
1133 __ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu);
1134
1135 if (!dst_check(&rt->dst, 0)) {
1136 if (new)
1137 dst_release(&rt->dst);
1138
1139 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1140 if (IS_ERR(rt))
1141 goto out;
1142
1143 new = true;
1144 }
1145
1146 if (new)
1147 sk_dst_set(sk, &rt->dst);
1148
1149out:
1150 bh_unlock_sock(sk);
1151 dst_release(odst);
1152}
1153EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1154
1155void ipv4_redirect(struct sk_buff *skb, struct net *net,
1156 int oif, u8 protocol)
1157{
1158 const struct iphdr *iph = (const struct iphdr *)skb->data;
1159 struct flowi4 fl4;
1160 struct rtable *rt;
1161
1162 __build_flow_key(net, &fl4, NULL, iph, oif,
1163 RT_TOS(iph->tos), protocol, 0, 0);
1164 rt = __ip_route_output_key(net, &fl4);
1165 if (!IS_ERR(rt)) {
1166 __ip_do_redirect(rt, skb, &fl4, false);
1167 ip_rt_put(rt);
1168 }
1169}
1170EXPORT_SYMBOL_GPL(ipv4_redirect);
1171
1172void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1173{
1174 const struct iphdr *iph = (const struct iphdr *)skb->data;
1175 struct flowi4 fl4;
1176 struct rtable *rt;
1177 struct net *net = sock_net(sk);
1178
1179 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1180 rt = __ip_route_output_key(net, &fl4);
1181 if (!IS_ERR(rt)) {
1182 __ip_do_redirect(rt, skb, &fl4, false);
1183 ip_rt_put(rt);
1184 }
1185}
1186EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1187
1188INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
1189 u32 cookie)
1190{
1191 struct rtable *rt = (struct rtable *) dst;
1192
1193 /* All IPV4 dsts are created with ->obsolete set to the value
1194 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1195 * into this function always.
1196 *
1197 * When a PMTU/redirect information update invalidates a route,
1198 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1199 * DST_OBSOLETE_DEAD.
1200 */
1201 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1202 return NULL;
1203 return dst;
1204}
1205EXPORT_INDIRECT_CALLABLE(ipv4_dst_check);
1206
1207static void ipv4_send_dest_unreach(struct sk_buff *skb)
1208{
1209 struct ip_options opt;
1210 int res;
1211
1212 /* Recompile ip options since IPCB may not be valid anymore.
1213 * Also check we have a reasonable ipv4 header.
1214 */
1215 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1216 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1217 return;
1218
1219 memset(&opt, 0, sizeof(opt));
1220 if (ip_hdr(skb)->ihl > 5) {
1221 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1222 return;
1223 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1224
1225 rcu_read_lock();
1226 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
1227 rcu_read_unlock();
1228
1229 if (res)
1230 return;
1231 }
1232 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1233}
1234
1235static void ipv4_link_failure(struct sk_buff *skb)
1236{
1237 struct rtable *rt;
1238
1239 ipv4_send_dest_unreach(skb);
1240
1241 rt = skb_rtable(skb);
1242 if (rt)
1243 dst_set_expires(&rt->dst, 0);
1244}
1245
1246static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1247{
1248 pr_debug("%s: %pI4 -> %pI4, %s\n",
1249 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1250 skb->dev ? skb->dev->name : "?");
1251 kfree_skb(skb);
1252 WARN_ON(1);
1253 return 0;
1254}
1255
1256/*
1257 * We do not cache source address of outgoing interface,
1258 * because it is used only by IP RR, TS and SRR options,
1259 * so that it out of fast path.
1260 *
1261 * BTW remember: "addr" is allowed to be not aligned
1262 * in IP options!
1263 */
1264
1265void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1266{
1267 __be32 src;
1268
1269 if (rt_is_output_route(rt))
1270 src = ip_hdr(skb)->saddr;
1271 else {
1272 struct fib_result res;
1273 struct iphdr *iph = ip_hdr(skb);
1274 struct flowi4 fl4 = {
1275 .daddr = iph->daddr,
1276 .saddr = iph->saddr,
1277 .flowi4_tos = RT_TOS(iph->tos),
1278 .flowi4_oif = rt->dst.dev->ifindex,
1279 .flowi4_iif = skb->dev->ifindex,
1280 .flowi4_mark = skb->mark,
1281 };
1282
1283 rcu_read_lock();
1284 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1285 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1286 else
1287 src = inet_select_addr(rt->dst.dev,
1288 rt_nexthop(rt, iph->daddr),
1289 RT_SCOPE_UNIVERSE);
1290 rcu_read_unlock();
1291 }
1292 memcpy(addr, &src, 4);
1293}
1294
1295#ifdef CONFIG_IP_ROUTE_CLASSID
1296static void set_class_tag(struct rtable *rt, u32 tag)
1297{
1298 if (!(rt->dst.tclassid & 0xFFFF))
1299 rt->dst.tclassid |= tag & 0xFFFF;
1300 if (!(rt->dst.tclassid & 0xFFFF0000))
1301 rt->dst.tclassid |= tag & 0xFFFF0000;
1302}
1303#endif
1304
1305static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1306{
1307 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1308 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1309 ip_rt_min_advmss);
1310
1311 return min(advmss, IPV4_MAX_PMTU - header_size);
1312}
1313
1314INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
1315{
1316 const struct rtable *rt = (const struct rtable *)dst;
1317 unsigned int mtu = rt->rt_pmtu;
1318
1319 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1320 mtu = dst_metric_raw(dst, RTAX_MTU);
1321
1322 if (mtu)
1323 goto out;
1324
1325 mtu = READ_ONCE(dst->dev->mtu);
1326
1327 if (unlikely(ip_mtu_locked(dst))) {
1328 if (rt->rt_uses_gateway && mtu > 576)
1329 mtu = 576;
1330 }
1331
1332out:
1333 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1334
1335 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1336}
1337EXPORT_INDIRECT_CALLABLE(ipv4_mtu);
1338
1339static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1340{
1341 struct fnhe_hash_bucket *hash;
1342 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1343 u32 hval = fnhe_hashfun(daddr);
1344
1345 spin_lock_bh(&fnhe_lock);
1346
1347 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1348 lockdep_is_held(&fnhe_lock));
1349 hash += hval;
1350
1351 fnhe_p = &hash->chain;
1352 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1353 while (fnhe) {
1354 if (fnhe->fnhe_daddr == daddr) {
1355 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1356 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1357 /* set fnhe_daddr to 0 to ensure it won't bind with
1358 * new dsts in rt_bind_exception().
1359 */
1360 fnhe->fnhe_daddr = 0;
1361 fnhe_flush_routes(fnhe);
1362 kfree_rcu(fnhe, rcu);
1363 break;
1364 }
1365 fnhe_p = &fnhe->fnhe_next;
1366 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1367 lockdep_is_held(&fnhe_lock));
1368 }
1369
1370 spin_unlock_bh(&fnhe_lock);
1371}
1372
1373static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1374 __be32 daddr)
1375{
1376 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1377 struct fib_nh_exception *fnhe;
1378 u32 hval;
1379
1380 if (!hash)
1381 return NULL;
1382
1383 hval = fnhe_hashfun(daddr);
1384
1385 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1386 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1387 if (fnhe->fnhe_daddr == daddr) {
1388 if (fnhe->fnhe_expires &&
1389 time_after(jiffies, fnhe->fnhe_expires)) {
1390 ip_del_fnhe(nhc, daddr);
1391 break;
1392 }
1393 return fnhe;
1394 }
1395 }
1396 return NULL;
1397}
1398
1399/* MTU selection:
1400 * 1. mtu on route is locked - use it
1401 * 2. mtu from nexthop exception
1402 * 3. mtu from egress device
1403 */
1404
1405u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1406{
1407 struct fib_nh_common *nhc = res->nhc;
1408 struct net_device *dev = nhc->nhc_dev;
1409 struct fib_info *fi = res->fi;
1410 u32 mtu = 0;
1411
1412 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1413 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1414 mtu = fi->fib_mtu;
1415
1416 if (likely(!mtu)) {
1417 struct fib_nh_exception *fnhe;
1418
1419 fnhe = find_exception(nhc, daddr);
1420 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1421 mtu = fnhe->fnhe_pmtu;
1422 }
1423
1424 if (likely(!mtu))
1425 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1426
1427 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1428}
1429
1430static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1431 __be32 daddr, const bool do_cache)
1432{
1433 bool ret = false;
1434
1435 spin_lock_bh(&fnhe_lock);
1436
1437 if (daddr == fnhe->fnhe_daddr) {
1438 struct rtable __rcu **porig;
1439 struct rtable *orig;
1440 int genid = fnhe_genid(dev_net(rt->dst.dev));
1441
1442 if (rt_is_input_route(rt))
1443 porig = &fnhe->fnhe_rth_input;
1444 else
1445 porig = &fnhe->fnhe_rth_output;
1446 orig = rcu_dereference(*porig);
1447
1448 if (fnhe->fnhe_genid != genid) {
1449 fnhe->fnhe_genid = genid;
1450 fnhe->fnhe_gw = 0;
1451 fnhe->fnhe_pmtu = 0;
1452 fnhe->fnhe_expires = 0;
1453 fnhe->fnhe_mtu_locked = false;
1454 fnhe_flush_routes(fnhe);
1455 orig = NULL;
1456 }
1457 fill_route_from_fnhe(rt, fnhe);
1458 if (!rt->rt_gw4) {
1459 rt->rt_gw4 = daddr;
1460 rt->rt_gw_family = AF_INET;
1461 }
1462
1463 if (do_cache) {
1464 dst_hold(&rt->dst);
1465 rcu_assign_pointer(*porig, rt);
1466 if (orig) {
1467 dst_dev_put(&orig->dst);
1468 dst_release(&orig->dst);
1469 }
1470 ret = true;
1471 }
1472
1473 fnhe->fnhe_stamp = jiffies;
1474 }
1475 spin_unlock_bh(&fnhe_lock);
1476
1477 return ret;
1478}
1479
1480static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1481{
1482 struct rtable *orig, *prev, **p;
1483 bool ret = true;
1484
1485 if (rt_is_input_route(rt)) {
1486 p = (struct rtable **)&nhc->nhc_rth_input;
1487 } else {
1488 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1489 }
1490 orig = *p;
1491
1492 /* hold dst before doing cmpxchg() to avoid race condition
1493 * on this dst
1494 */
1495 dst_hold(&rt->dst);
1496 prev = cmpxchg(p, orig, rt);
1497 if (prev == orig) {
1498 if (orig) {
1499 rt_add_uncached_list(orig);
1500 dst_release(&orig->dst);
1501 }
1502 } else {
1503 dst_release(&rt->dst);
1504 ret = false;
1505 }
1506
1507 return ret;
1508}
1509
1510struct uncached_list {
1511 spinlock_t lock;
1512 struct list_head head;
1513};
1514
1515static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1516
1517void rt_add_uncached_list(struct rtable *rt)
1518{
1519 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1520
1521 rt->rt_uncached_list = ul;
1522
1523 spin_lock_bh(&ul->lock);
1524 list_add_tail(&rt->rt_uncached, &ul->head);
1525 spin_unlock_bh(&ul->lock);
1526}
1527
1528void rt_del_uncached_list(struct rtable *rt)
1529{
1530 if (!list_empty(&rt->rt_uncached)) {
1531 struct uncached_list *ul = rt->rt_uncached_list;
1532
1533 spin_lock_bh(&ul->lock);
1534 list_del(&rt->rt_uncached);
1535 spin_unlock_bh(&ul->lock);
1536 }
1537}
1538
1539static void ipv4_dst_destroy(struct dst_entry *dst)
1540{
1541 struct rtable *rt = (struct rtable *)dst;
1542
1543 ip_dst_metrics_put(dst);
1544 rt_del_uncached_list(rt);
1545}
1546
1547void rt_flush_dev(struct net_device *dev)
1548{
1549 struct rtable *rt;
1550 int cpu;
1551
1552 for_each_possible_cpu(cpu) {
1553 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1554
1555 spin_lock_bh(&ul->lock);
1556 list_for_each_entry(rt, &ul->head, rt_uncached) {
1557 if (rt->dst.dev != dev)
1558 continue;
1559 rt->dst.dev = blackhole_netdev;
1560 dev_hold(rt->dst.dev);
1561 dev_put(dev);
1562 }
1563 spin_unlock_bh(&ul->lock);
1564 }
1565}
1566
1567static bool rt_cache_valid(const struct rtable *rt)
1568{
1569 return rt &&
1570 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1571 !rt_is_expired(rt);
1572}
1573
1574static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1575 const struct fib_result *res,
1576 struct fib_nh_exception *fnhe,
1577 struct fib_info *fi, u16 type, u32 itag,
1578 const bool do_cache)
1579{
1580 bool cached = false;
1581
1582 if (fi) {
1583 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1584
1585 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1586 rt->rt_uses_gateway = 1;
1587 rt->rt_gw_family = nhc->nhc_gw_family;
1588 /* only INET and INET6 are supported */
1589 if (likely(nhc->nhc_gw_family == AF_INET))
1590 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1591 else
1592 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1593 }
1594
1595 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1596
1597#ifdef CONFIG_IP_ROUTE_CLASSID
1598 if (nhc->nhc_family == AF_INET) {
1599 struct fib_nh *nh;
1600
1601 nh = container_of(nhc, struct fib_nh, nh_common);
1602 rt->dst.tclassid = nh->nh_tclassid;
1603 }
1604#endif
1605 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1606 if (unlikely(fnhe))
1607 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1608 else if (do_cache)
1609 cached = rt_cache_route(nhc, rt);
1610 if (unlikely(!cached)) {
1611 /* Routes we intend to cache in nexthop exception or
1612 * FIB nexthop have the DST_NOCACHE bit clear.
1613 * However, if we are unsuccessful at storing this
1614 * route into the cache we really need to set it.
1615 */
1616 if (!rt->rt_gw4) {
1617 rt->rt_gw_family = AF_INET;
1618 rt->rt_gw4 = daddr;
1619 }
1620 rt_add_uncached_list(rt);
1621 }
1622 } else
1623 rt_add_uncached_list(rt);
1624
1625#ifdef CONFIG_IP_ROUTE_CLASSID
1626#ifdef CONFIG_IP_MULTIPLE_TABLES
1627 set_class_tag(rt, res->tclassid);
1628#endif
1629 set_class_tag(rt, itag);
1630#endif
1631}
1632
1633struct rtable *rt_dst_alloc(struct net_device *dev,
1634 unsigned int flags, u16 type,
1635 bool nopolicy, bool noxfrm)
1636{
1637 struct rtable *rt;
1638
1639 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1640 (nopolicy ? DST_NOPOLICY : 0) |
1641 (noxfrm ? DST_NOXFRM : 0));
1642
1643 if (rt) {
1644 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1645 rt->rt_flags = flags;
1646 rt->rt_type = type;
1647 rt->rt_is_input = 0;
1648 rt->rt_iif = 0;
1649 rt->rt_pmtu = 0;
1650 rt->rt_mtu_locked = 0;
1651 rt->rt_uses_gateway = 0;
1652 rt->rt_gw_family = 0;
1653 rt->rt_gw4 = 0;
1654 INIT_LIST_HEAD(&rt->rt_uncached);
1655
1656 rt->dst.output = ip_output;
1657 if (flags & RTCF_LOCAL)
1658 rt->dst.input = ip_local_deliver;
1659 }
1660
1661 return rt;
1662}
1663EXPORT_SYMBOL(rt_dst_alloc);
1664
1665struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1666{
1667 struct rtable *new_rt;
1668
1669 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1670 rt->dst.flags);
1671
1672 if (new_rt) {
1673 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1674 new_rt->rt_flags = rt->rt_flags;
1675 new_rt->rt_type = rt->rt_type;
1676 new_rt->rt_is_input = rt->rt_is_input;
1677 new_rt->rt_iif = rt->rt_iif;
1678 new_rt->rt_pmtu = rt->rt_pmtu;
1679 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1680 new_rt->rt_gw_family = rt->rt_gw_family;
1681 if (rt->rt_gw_family == AF_INET)
1682 new_rt->rt_gw4 = rt->rt_gw4;
1683 else if (rt->rt_gw_family == AF_INET6)
1684 new_rt->rt_gw6 = rt->rt_gw6;
1685 INIT_LIST_HEAD(&new_rt->rt_uncached);
1686
1687 new_rt->dst.input = rt->dst.input;
1688 new_rt->dst.output = rt->dst.output;
1689 new_rt->dst.error = rt->dst.error;
1690 new_rt->dst.lastuse = jiffies;
1691 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1692 }
1693 return new_rt;
1694}
1695EXPORT_SYMBOL(rt_dst_clone);
1696
1697/* called in rcu_read_lock() section */
1698int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1699 u8 tos, struct net_device *dev,
1700 struct in_device *in_dev, u32 *itag)
1701{
1702 int err;
1703
1704 /* Primary sanity checks. */
1705 if (!in_dev)
1706 return -EINVAL;
1707
1708 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1709 skb->protocol != htons(ETH_P_IP))
1710 return -EINVAL;
1711
1712 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1713 return -EINVAL;
1714
1715 if (ipv4_is_zeronet(saddr)) {
1716 if (!ipv4_is_local_multicast(daddr) &&
1717 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1718 return -EINVAL;
1719 } else {
1720 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1721 in_dev, itag);
1722 if (err < 0)
1723 return err;
1724 }
1725 return 0;
1726}
1727
1728/* called in rcu_read_lock() section */
1729static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1730 u8 tos, struct net_device *dev, int our)
1731{
1732 struct in_device *in_dev = __in_dev_get_rcu(dev);
1733 unsigned int flags = RTCF_MULTICAST;
1734 struct rtable *rth;
1735 u32 itag = 0;
1736 int err;
1737
1738 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1739 if (err)
1740 return err;
1741
1742 if (our)
1743 flags |= RTCF_LOCAL;
1744
1745 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1746 IN_DEV_ORCONF(in_dev, NOPOLICY), false);
1747 if (!rth)
1748 return -ENOBUFS;
1749
1750#ifdef CONFIG_IP_ROUTE_CLASSID
1751 rth->dst.tclassid = itag;
1752#endif
1753 rth->dst.output = ip_rt_bug;
1754 rth->rt_is_input= 1;
1755
1756#ifdef CONFIG_IP_MROUTE
1757 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1758 rth->dst.input = ip_mr_input;
1759#endif
1760 RT_CACHE_STAT_INC(in_slow_mc);
1761
1762 skb_dst_set(skb, &rth->dst);
1763 return 0;
1764}
1765
1766
1767static void ip_handle_martian_source(struct net_device *dev,
1768 struct in_device *in_dev,
1769 struct sk_buff *skb,
1770 __be32 daddr,
1771 __be32 saddr)
1772{
1773 RT_CACHE_STAT_INC(in_martian_src);
1774#ifdef CONFIG_IP_ROUTE_VERBOSE
1775 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1776 /*
1777 * RFC1812 recommendation, if source is martian,
1778 * the only hint is MAC header.
1779 */
1780 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1781 &daddr, &saddr, dev->name);
1782 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1783 print_hex_dump(KERN_WARNING, "ll header: ",
1784 DUMP_PREFIX_OFFSET, 16, 1,
1785 skb_mac_header(skb),
1786 dev->hard_header_len, false);
1787 }
1788 }
1789#endif
1790}
1791
1792/* called in rcu_read_lock() section */
1793static int __mkroute_input(struct sk_buff *skb,
1794 const struct fib_result *res,
1795 struct in_device *in_dev,
1796 __be32 daddr, __be32 saddr, u32 tos)
1797{
1798 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1799 struct net_device *dev = nhc->nhc_dev;
1800 struct fib_nh_exception *fnhe;
1801 struct rtable *rth;
1802 int err;
1803 struct in_device *out_dev;
1804 bool do_cache;
1805 u32 itag = 0;
1806
1807 /* get a working reference to the output device */
1808 out_dev = __in_dev_get_rcu(dev);
1809 if (!out_dev) {
1810 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1811 return -EINVAL;
1812 }
1813
1814 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1815 in_dev->dev, in_dev, &itag);
1816 if (err < 0) {
1817 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1818 saddr);
1819
1820 goto cleanup;
1821 }
1822
1823 do_cache = res->fi && !itag;
1824 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1825 skb->protocol == htons(ETH_P_IP)) {
1826 __be32 gw;
1827
1828 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1829 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1830 inet_addr_onlink(out_dev, saddr, gw))
1831 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1832 }
1833
1834 if (skb->protocol != htons(ETH_P_IP)) {
1835 /* Not IP (i.e. ARP). Do not create route, if it is
1836 * invalid for proxy arp. DNAT routes are always valid.
1837 *
1838 * Proxy arp feature have been extended to allow, ARP
1839 * replies back to the same interface, to support
1840 * Private VLAN switch technologies. See arp.c.
1841 */
1842 if (out_dev == in_dev &&
1843 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1844 err = -EINVAL;
1845 goto cleanup;
1846 }
1847 }
1848
1849 fnhe = find_exception(nhc, daddr);
1850 if (do_cache) {
1851 if (fnhe)
1852 rth = rcu_dereference(fnhe->fnhe_rth_input);
1853 else
1854 rth = rcu_dereference(nhc->nhc_rth_input);
1855 if (rt_cache_valid(rth)) {
1856 skb_dst_set_noref(skb, &rth->dst);
1857 goto out;
1858 }
1859 }
1860
1861 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1862 IN_DEV_ORCONF(in_dev, NOPOLICY),
1863 IN_DEV_ORCONF(out_dev, NOXFRM));
1864 if (!rth) {
1865 err = -ENOBUFS;
1866 goto cleanup;
1867 }
1868
1869 rth->rt_is_input = 1;
1870 RT_CACHE_STAT_INC(in_slow_tot);
1871
1872 rth->dst.input = ip_forward;
1873
1874 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1875 do_cache);
1876 lwtunnel_set_redirect(&rth->dst);
1877 skb_dst_set(skb, &rth->dst);
1878out:
1879 err = 0;
1880 cleanup:
1881 return err;
1882}
1883
1884#ifdef CONFIG_IP_ROUTE_MULTIPATH
1885/* To make ICMP packets follow the right flow, the multipath hash is
1886 * calculated from the inner IP addresses.
1887 */
1888static void ip_multipath_l3_keys(const struct sk_buff *skb,
1889 struct flow_keys *hash_keys)
1890{
1891 const struct iphdr *outer_iph = ip_hdr(skb);
1892 const struct iphdr *key_iph = outer_iph;
1893 const struct iphdr *inner_iph;
1894 const struct icmphdr *icmph;
1895 struct iphdr _inner_iph;
1896 struct icmphdr _icmph;
1897
1898 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1899 goto out;
1900
1901 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1902 goto out;
1903
1904 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1905 &_icmph);
1906 if (!icmph)
1907 goto out;
1908
1909 if (!icmp_is_err(icmph->type))
1910 goto out;
1911
1912 inner_iph = skb_header_pointer(skb,
1913 outer_iph->ihl * 4 + sizeof(_icmph),
1914 sizeof(_inner_iph), &_inner_iph);
1915 if (!inner_iph)
1916 goto out;
1917
1918 key_iph = inner_iph;
1919out:
1920 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1921 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1922}
1923
1924static u32 fib_multipath_custom_hash_outer(const struct net *net,
1925 const struct sk_buff *skb,
1926 bool *p_has_inner)
1927{
1928 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
1929 struct flow_keys keys, hash_keys;
1930
1931 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
1932 return 0;
1933
1934 memset(&hash_keys, 0, sizeof(hash_keys));
1935 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
1936
1937 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1938 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
1939 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1940 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
1941 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1942 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
1943 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1944 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
1945 hash_keys.ports.src = keys.ports.src;
1946 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
1947 hash_keys.ports.dst = keys.ports.dst;
1948
1949 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
1950 return flow_hash_from_keys(&hash_keys);
1951}
1952
1953static u32 fib_multipath_custom_hash_inner(const struct net *net,
1954 const struct sk_buff *skb,
1955 bool has_inner)
1956{
1957 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
1958 struct flow_keys keys, hash_keys;
1959
1960 /* We assume the packet carries an encapsulation, but if none was
1961 * encountered during dissection of the outer flow, then there is no
1962 * point in calling the flow dissector again.
1963 */
1964 if (!has_inner)
1965 return 0;
1966
1967 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
1968 return 0;
1969
1970 memset(&hash_keys, 0, sizeof(hash_keys));
1971 skb_flow_dissect_flow_keys(skb, &keys, 0);
1972
1973 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
1974 return 0;
1975
1976 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1977 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1978 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1979 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1980 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1981 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1982 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1983 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1984 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1985 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1986 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1987 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1988 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
1989 hash_keys.tags.flow_label = keys.tags.flow_label;
1990 }
1991
1992 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
1993 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1994 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
1995 hash_keys.ports.src = keys.ports.src;
1996 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
1997 hash_keys.ports.dst = keys.ports.dst;
1998
1999 return flow_hash_from_keys(&hash_keys);
2000}
2001
2002static u32 fib_multipath_custom_hash_skb(const struct net *net,
2003 const struct sk_buff *skb)
2004{
2005 u32 mhash, mhash_inner;
2006 bool has_inner = true;
2007
2008 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner);
2009 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner);
2010
2011 return jhash_2words(mhash, mhash_inner, 0);
2012}
2013
2014static u32 fib_multipath_custom_hash_fl4(const struct net *net,
2015 const struct flowi4 *fl4)
2016{
2017 u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
2018 struct flow_keys hash_keys;
2019
2020 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2021 return 0;
2022
2023 memset(&hash_keys, 0, sizeof(hash_keys));
2024 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2025 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2026 hash_keys.addrs.v4addrs.src = fl4->saddr;
2027 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2028 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2029 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2030 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2031 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2032 hash_keys.ports.src = fl4->fl4_sport;
2033 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2034 hash_keys.ports.dst = fl4->fl4_dport;
2035
2036 return flow_hash_from_keys(&hash_keys);
2037}
2038
2039/* if skb is set it will be used and fl4 can be NULL */
2040int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
2041 const struct sk_buff *skb, struct flow_keys *flkeys)
2042{
2043 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
2044 struct flow_keys hash_keys;
2045 u32 mhash = 0;
2046
2047 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
2048 case 0:
2049 memset(&hash_keys, 0, sizeof(hash_keys));
2050 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2051 if (skb) {
2052 ip_multipath_l3_keys(skb, &hash_keys);
2053 } else {
2054 hash_keys.addrs.v4addrs.src = fl4->saddr;
2055 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2056 }
2057 mhash = flow_hash_from_keys(&hash_keys);
2058 break;
2059 case 1:
2060 /* skb is currently provided only when forwarding */
2061 if (skb) {
2062 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2063 struct flow_keys keys;
2064
2065 /* short-circuit if we already have L4 hash present */
2066 if (skb->l4_hash)
2067 return skb_get_hash_raw(skb) >> 1;
2068
2069 memset(&hash_keys, 0, sizeof(hash_keys));
2070
2071 if (!flkeys) {
2072 skb_flow_dissect_flow_keys(skb, &keys, flag);
2073 flkeys = &keys;
2074 }
2075
2076 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2077 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2078 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2079 hash_keys.ports.src = flkeys->ports.src;
2080 hash_keys.ports.dst = flkeys->ports.dst;
2081 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2082 } else {
2083 memset(&hash_keys, 0, sizeof(hash_keys));
2084 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2085 hash_keys.addrs.v4addrs.src = fl4->saddr;
2086 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2087 hash_keys.ports.src = fl4->fl4_sport;
2088 hash_keys.ports.dst = fl4->fl4_dport;
2089 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2090 }
2091 mhash = flow_hash_from_keys(&hash_keys);
2092 break;
2093 case 2:
2094 memset(&hash_keys, 0, sizeof(hash_keys));
2095 /* skb is currently provided only when forwarding */
2096 if (skb) {
2097 struct flow_keys keys;
2098
2099 skb_flow_dissect_flow_keys(skb, &keys, 0);
2100 /* Inner can be v4 or v6 */
2101 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2102 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2103 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2104 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2105 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2106 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2107 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2108 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2109 hash_keys.tags.flow_label = keys.tags.flow_label;
2110 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2111 } else {
2112 /* Same as case 0 */
2113 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2114 ip_multipath_l3_keys(skb, &hash_keys);
2115 }
2116 } else {
2117 /* Same as case 0 */
2118 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2119 hash_keys.addrs.v4addrs.src = fl4->saddr;
2120 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2121 }
2122 mhash = flow_hash_from_keys(&hash_keys);
2123 break;
2124 case 3:
2125 if (skb)
2126 mhash = fib_multipath_custom_hash_skb(net, skb);
2127 else
2128 mhash = fib_multipath_custom_hash_fl4(net, fl4);
2129 break;
2130 }
2131
2132 if (multipath_hash)
2133 mhash = jhash_2words(mhash, multipath_hash, 0);
2134
2135 return mhash >> 1;
2136}
2137#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2138
2139static int ip_mkroute_input(struct sk_buff *skb,
2140 struct fib_result *res,
2141 struct in_device *in_dev,
2142 __be32 daddr, __be32 saddr, u32 tos,
2143 struct flow_keys *hkeys)
2144{
2145#ifdef CONFIG_IP_ROUTE_MULTIPATH
2146 if (res->fi && fib_info_num_path(res->fi) > 1) {
2147 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2148
2149 fib_select_multipath(res, h);
2150 }
2151#endif
2152
2153 /* create a routing cache entry */
2154 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
2155}
2156
2157/* Implements all the saddr-related checks as ip_route_input_slow(),
2158 * assuming daddr is valid and the destination is not a local broadcast one.
2159 * Uses the provided hint instead of performing a route lookup.
2160 */
2161int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2162 u8 tos, struct net_device *dev,
2163 const struct sk_buff *hint)
2164{
2165 struct in_device *in_dev = __in_dev_get_rcu(dev);
2166 struct rtable *rt = skb_rtable(hint);
2167 struct net *net = dev_net(dev);
2168 int err = -EINVAL;
2169 u32 tag = 0;
2170
2171 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2172 goto martian_source;
2173
2174 if (ipv4_is_zeronet(saddr))
2175 goto martian_source;
2176
2177 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2178 goto martian_source;
2179
2180 if (rt->rt_type != RTN_LOCAL)
2181 goto skip_validate_source;
2182
2183 tos &= IPTOS_RT_MASK;
2184 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag);
2185 if (err < 0)
2186 goto martian_source;
2187
2188skip_validate_source:
2189 skb_dst_copy(skb, hint);
2190 return 0;
2191
2192martian_source:
2193 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2194 return err;
2195}
2196
2197/* get device for dst_alloc with local routes */
2198static struct net_device *ip_rt_get_dev(struct net *net,
2199 const struct fib_result *res)
2200{
2201 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL;
2202 struct net_device *dev = NULL;
2203
2204 if (nhc)
2205 dev = l3mdev_master_dev_rcu(nhc->nhc_dev);
2206
2207 return dev ? : net->loopback_dev;
2208}
2209
2210/*
2211 * NOTE. We drop all the packets that has local source
2212 * addresses, because every properly looped back packet
2213 * must have correct destination already attached by output routine.
2214 * Changes in the enforced policies must be applied also to
2215 * ip_route_use_hint().
2216 *
2217 * Such approach solves two big problems:
2218 * 1. Not simplex devices are handled properly.
2219 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2220 * called with rcu_read_lock()
2221 */
2222
2223static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2224 u8 tos, struct net_device *dev,
2225 struct fib_result *res)
2226{
2227 struct in_device *in_dev = __in_dev_get_rcu(dev);
2228 struct flow_keys *flkeys = NULL, _flkeys;
2229 struct net *net = dev_net(dev);
2230 struct ip_tunnel_info *tun_info;
2231 int err = -EINVAL;
2232 unsigned int flags = 0;
2233 u32 itag = 0;
2234 struct rtable *rth;
2235 struct flowi4 fl4;
2236 bool do_cache = true;
2237
2238 /* IP on this device is disabled. */
2239
2240 if (!in_dev)
2241 goto out;
2242
2243 /* Check for the most weird martians, which can be not detected
2244 * by fib_lookup.
2245 */
2246
2247 tun_info = skb_tunnel_info(skb);
2248 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2249 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2250 else
2251 fl4.flowi4_tun_key.tun_id = 0;
2252 skb_dst_drop(skb);
2253
2254 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2255 goto martian_source;
2256
2257 res->fi = NULL;
2258 res->table = NULL;
2259 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2260 goto brd_input;
2261
2262 /* Accept zero addresses only to limited broadcast;
2263 * I even do not know to fix it or not. Waiting for complains :-)
2264 */
2265 if (ipv4_is_zeronet(saddr))
2266 goto martian_source;
2267
2268 if (ipv4_is_zeronet(daddr))
2269 goto martian_destination;
2270
2271 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2272 * and call it once if daddr or/and saddr are loopback addresses
2273 */
2274 if (ipv4_is_loopback(daddr)) {
2275 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2276 goto martian_destination;
2277 } else if (ipv4_is_loopback(saddr)) {
2278 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2279 goto martian_source;
2280 }
2281
2282 /*
2283 * Now we are ready to route packet.
2284 */
2285 fl4.flowi4_oif = 0;
2286 fl4.flowi4_iif = dev->ifindex;
2287 fl4.flowi4_mark = skb->mark;
2288 fl4.flowi4_tos = tos;
2289 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2290 fl4.flowi4_flags = 0;
2291 fl4.daddr = daddr;
2292 fl4.saddr = saddr;
2293 fl4.flowi4_uid = sock_net_uid(net, NULL);
2294 fl4.flowi4_multipath_hash = 0;
2295
2296 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2297 flkeys = &_flkeys;
2298 } else {
2299 fl4.flowi4_proto = 0;
2300 fl4.fl4_sport = 0;
2301 fl4.fl4_dport = 0;
2302 }
2303
2304 err = fib_lookup(net, &fl4, res, 0);
2305 if (err != 0) {
2306 if (!IN_DEV_FORWARD(in_dev))
2307 err = -EHOSTUNREACH;
2308 goto no_route;
2309 }
2310
2311 if (res->type == RTN_BROADCAST) {
2312 if (IN_DEV_BFORWARD(in_dev))
2313 goto make_route;
2314 /* not do cache if bc_forwarding is enabled */
2315 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING))
2316 do_cache = false;
2317 goto brd_input;
2318 }
2319
2320 if (res->type == RTN_LOCAL) {
2321 err = fib_validate_source(skb, saddr, daddr, tos,
2322 0, dev, in_dev, &itag);
2323 if (err < 0)
2324 goto martian_source;
2325 goto local_input;
2326 }
2327
2328 if (!IN_DEV_FORWARD(in_dev)) {
2329 err = -EHOSTUNREACH;
2330 goto no_route;
2331 }
2332 if (res->type != RTN_UNICAST)
2333 goto martian_destination;
2334
2335make_route:
2336 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2337out: return err;
2338
2339brd_input:
2340 if (skb->protocol != htons(ETH_P_IP))
2341 goto e_inval;
2342
2343 if (!ipv4_is_zeronet(saddr)) {
2344 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2345 in_dev, &itag);
2346 if (err < 0)
2347 goto martian_source;
2348 }
2349 flags |= RTCF_BROADCAST;
2350 res->type = RTN_BROADCAST;
2351 RT_CACHE_STAT_INC(in_brd);
2352
2353local_input:
2354 do_cache &= res->fi && !itag;
2355 if (do_cache) {
2356 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2357
2358 rth = rcu_dereference(nhc->nhc_rth_input);
2359 if (rt_cache_valid(rth)) {
2360 skb_dst_set_noref(skb, &rth->dst);
2361 err = 0;
2362 goto out;
2363 }
2364 }
2365
2366 rth = rt_dst_alloc(ip_rt_get_dev(net, res),
2367 flags | RTCF_LOCAL, res->type,
2368 IN_DEV_ORCONF(in_dev, NOPOLICY), false);
2369 if (!rth)
2370 goto e_nobufs;
2371
2372 rth->dst.output= ip_rt_bug;
2373#ifdef CONFIG_IP_ROUTE_CLASSID
2374 rth->dst.tclassid = itag;
2375#endif
2376 rth->rt_is_input = 1;
2377
2378 RT_CACHE_STAT_INC(in_slow_tot);
2379 if (res->type == RTN_UNREACHABLE) {
2380 rth->dst.input= ip_error;
2381 rth->dst.error= -err;
2382 rth->rt_flags &= ~RTCF_LOCAL;
2383 }
2384
2385 if (do_cache) {
2386 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2387
2388 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2389 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2390 WARN_ON(rth->dst.input == lwtunnel_input);
2391 rth->dst.lwtstate->orig_input = rth->dst.input;
2392 rth->dst.input = lwtunnel_input;
2393 }
2394
2395 if (unlikely(!rt_cache_route(nhc, rth)))
2396 rt_add_uncached_list(rth);
2397 }
2398 skb_dst_set(skb, &rth->dst);
2399 err = 0;
2400 goto out;
2401
2402no_route:
2403 RT_CACHE_STAT_INC(in_no_route);
2404 res->type = RTN_UNREACHABLE;
2405 res->fi = NULL;
2406 res->table = NULL;
2407 goto local_input;
2408
2409 /*
2410 * Do not cache martian addresses: they should be logged (RFC1812)
2411 */
2412martian_destination:
2413 RT_CACHE_STAT_INC(in_martian_dst);
2414#ifdef CONFIG_IP_ROUTE_VERBOSE
2415 if (IN_DEV_LOG_MARTIANS(in_dev))
2416 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2417 &daddr, &saddr, dev->name);
2418#endif
2419
2420e_inval:
2421 err = -EINVAL;
2422 goto out;
2423
2424e_nobufs:
2425 err = -ENOBUFS;
2426 goto out;
2427
2428martian_source:
2429 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2430 goto out;
2431}
2432
2433int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2434 u8 tos, struct net_device *dev)
2435{
2436 struct fib_result res;
2437 int err;
2438
2439 tos &= IPTOS_RT_MASK;
2440 rcu_read_lock();
2441 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2442 rcu_read_unlock();
2443
2444 return err;
2445}
2446EXPORT_SYMBOL(ip_route_input_noref);
2447
2448/* called with rcu_read_lock held */
2449int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2450 u8 tos, struct net_device *dev, struct fib_result *res)
2451{
2452 /* Multicast recognition logic is moved from route cache to here.
2453 * The problem was that too many Ethernet cards have broken/missing
2454 * hardware multicast filters :-( As result the host on multicasting
2455 * network acquires a lot of useless route cache entries, sort of
2456 * SDR messages from all the world. Now we try to get rid of them.
2457 * Really, provided software IP multicast filter is organized
2458 * reasonably (at least, hashed), it does not result in a slowdown
2459 * comparing with route cache reject entries.
2460 * Note, that multicast routers are not affected, because
2461 * route cache entry is created eventually.
2462 */
2463 if (ipv4_is_multicast(daddr)) {
2464 struct in_device *in_dev = __in_dev_get_rcu(dev);
2465 int our = 0;
2466 int err = -EINVAL;
2467
2468 if (!in_dev)
2469 return err;
2470 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2471 ip_hdr(skb)->protocol);
2472
2473 /* check l3 master if no match yet */
2474 if (!our && netif_is_l3_slave(dev)) {
2475 struct in_device *l3_in_dev;
2476
2477 l3_in_dev = __in_dev_get_rcu(skb->dev);
2478 if (l3_in_dev)
2479 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2480 ip_hdr(skb)->protocol);
2481 }
2482
2483 if (our
2484#ifdef CONFIG_IP_MROUTE
2485 ||
2486 (!ipv4_is_local_multicast(daddr) &&
2487 IN_DEV_MFORWARD(in_dev))
2488#endif
2489 ) {
2490 err = ip_route_input_mc(skb, daddr, saddr,
2491 tos, dev, our);
2492 }
2493 return err;
2494 }
2495
2496 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2497}
2498
2499/* called with rcu_read_lock() */
2500static struct rtable *__mkroute_output(const struct fib_result *res,
2501 const struct flowi4 *fl4, int orig_oif,
2502 struct net_device *dev_out,
2503 unsigned int flags)
2504{
2505 struct fib_info *fi = res->fi;
2506 struct fib_nh_exception *fnhe;
2507 struct in_device *in_dev;
2508 u16 type = res->type;
2509 struct rtable *rth;
2510 bool do_cache;
2511
2512 in_dev = __in_dev_get_rcu(dev_out);
2513 if (!in_dev)
2514 return ERR_PTR(-EINVAL);
2515
2516 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2517 if (ipv4_is_loopback(fl4->saddr) &&
2518 !(dev_out->flags & IFF_LOOPBACK) &&
2519 !netif_is_l3_master(dev_out))
2520 return ERR_PTR(-EINVAL);
2521
2522 if (ipv4_is_lbcast(fl4->daddr))
2523 type = RTN_BROADCAST;
2524 else if (ipv4_is_multicast(fl4->daddr))
2525 type = RTN_MULTICAST;
2526 else if (ipv4_is_zeronet(fl4->daddr))
2527 return ERR_PTR(-EINVAL);
2528
2529 if (dev_out->flags & IFF_LOOPBACK)
2530 flags |= RTCF_LOCAL;
2531
2532 do_cache = true;
2533 if (type == RTN_BROADCAST) {
2534 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2535 fi = NULL;
2536 } else if (type == RTN_MULTICAST) {
2537 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2538 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2539 fl4->flowi4_proto))
2540 flags &= ~RTCF_LOCAL;
2541 else
2542 do_cache = false;
2543 /* If multicast route do not exist use
2544 * default one, but do not gateway in this case.
2545 * Yes, it is hack.
2546 */
2547 if (fi && res->prefixlen < 4)
2548 fi = NULL;
2549 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2550 (orig_oif != dev_out->ifindex)) {
2551 /* For local routes that require a particular output interface
2552 * we do not want to cache the result. Caching the result
2553 * causes incorrect behaviour when there are multiple source
2554 * addresses on the interface, the end result being that if the
2555 * intended recipient is waiting on that interface for the
2556 * packet he won't receive it because it will be delivered on
2557 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2558 * be set to the loopback interface as well.
2559 */
2560 do_cache = false;
2561 }
2562
2563 fnhe = NULL;
2564 do_cache &= fi != NULL;
2565 if (fi) {
2566 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2567 struct rtable __rcu **prth;
2568
2569 fnhe = find_exception(nhc, fl4->daddr);
2570 if (!do_cache)
2571 goto add;
2572 if (fnhe) {
2573 prth = &fnhe->fnhe_rth_output;
2574 } else {
2575 if (unlikely(fl4->flowi4_flags &
2576 FLOWI_FLAG_KNOWN_NH &&
2577 !(nhc->nhc_gw_family &&
2578 nhc->nhc_scope == RT_SCOPE_LINK))) {
2579 do_cache = false;
2580 goto add;
2581 }
2582 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2583 }
2584 rth = rcu_dereference(*prth);
2585 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2586 return rth;
2587 }
2588
2589add:
2590 rth = rt_dst_alloc(dev_out, flags, type,
2591 IN_DEV_ORCONF(in_dev, NOPOLICY),
2592 IN_DEV_ORCONF(in_dev, NOXFRM));
2593 if (!rth)
2594 return ERR_PTR(-ENOBUFS);
2595
2596 rth->rt_iif = orig_oif;
2597
2598 RT_CACHE_STAT_INC(out_slow_tot);
2599
2600 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2601 if (flags & RTCF_LOCAL &&
2602 !(dev_out->flags & IFF_LOOPBACK)) {
2603 rth->dst.output = ip_mc_output;
2604 RT_CACHE_STAT_INC(out_slow_mc);
2605 }
2606#ifdef CONFIG_IP_MROUTE
2607 if (type == RTN_MULTICAST) {
2608 if (IN_DEV_MFORWARD(in_dev) &&
2609 !ipv4_is_local_multicast(fl4->daddr)) {
2610 rth->dst.input = ip_mr_input;
2611 rth->dst.output = ip_mc_output;
2612 }
2613 }
2614#endif
2615 }
2616
2617 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2618 lwtunnel_set_redirect(&rth->dst);
2619
2620 return rth;
2621}
2622
2623/*
2624 * Major route resolver routine.
2625 */
2626
2627struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2628 const struct sk_buff *skb)
2629{
2630 __u8 tos = RT_FL_TOS(fl4);
2631 struct fib_result res = {
2632 .type = RTN_UNSPEC,
2633 .fi = NULL,
2634 .table = NULL,
2635 .tclassid = 0,
2636 };
2637 struct rtable *rth;
2638
2639 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2640 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2641 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2642 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2643
2644 rcu_read_lock();
2645 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2646 rcu_read_unlock();
2647
2648 return rth;
2649}
2650EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2651
2652struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2653 struct fib_result *res,
2654 const struct sk_buff *skb)
2655{
2656 struct net_device *dev_out = NULL;
2657 int orig_oif = fl4->flowi4_oif;
2658 unsigned int flags = 0;
2659 struct rtable *rth;
2660 int err;
2661
2662 if (fl4->saddr) {
2663 if (ipv4_is_multicast(fl4->saddr) ||
2664 ipv4_is_lbcast(fl4->saddr) ||
2665 ipv4_is_zeronet(fl4->saddr)) {
2666 rth = ERR_PTR(-EINVAL);
2667 goto out;
2668 }
2669
2670 rth = ERR_PTR(-ENETUNREACH);
2671
2672 /* I removed check for oif == dev_out->oif here.
2673 * It was wrong for two reasons:
2674 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2675 * is assigned to multiple interfaces.
2676 * 2. Moreover, we are allowed to send packets with saddr
2677 * of another iface. --ANK
2678 */
2679
2680 if (fl4->flowi4_oif == 0 &&
2681 (ipv4_is_multicast(fl4->daddr) ||
2682 ipv4_is_lbcast(fl4->daddr))) {
2683 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2684 dev_out = __ip_dev_find(net, fl4->saddr, false);
2685 if (!dev_out)
2686 goto out;
2687
2688 /* Special hack: user can direct multicasts
2689 * and limited broadcast via necessary interface
2690 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2691 * This hack is not just for fun, it allows
2692 * vic,vat and friends to work.
2693 * They bind socket to loopback, set ttl to zero
2694 * and expect that it will work.
2695 * From the viewpoint of routing cache they are broken,
2696 * because we are not allowed to build multicast path
2697 * with loopback source addr (look, routing cache
2698 * cannot know, that ttl is zero, so that packet
2699 * will not leave this host and route is valid).
2700 * Luckily, this hack is good workaround.
2701 */
2702
2703 fl4->flowi4_oif = dev_out->ifindex;
2704 goto make_route;
2705 }
2706
2707 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2708 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2709 if (!__ip_dev_find(net, fl4->saddr, false))
2710 goto out;
2711 }
2712 }
2713
2714
2715 if (fl4->flowi4_oif) {
2716 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2717 rth = ERR_PTR(-ENODEV);
2718 if (!dev_out)
2719 goto out;
2720
2721 /* RACE: Check return value of inet_select_addr instead. */
2722 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2723 rth = ERR_PTR(-ENETUNREACH);
2724 goto out;
2725 }
2726 if (ipv4_is_local_multicast(fl4->daddr) ||
2727 ipv4_is_lbcast(fl4->daddr) ||
2728 fl4->flowi4_proto == IPPROTO_IGMP) {
2729 if (!fl4->saddr)
2730 fl4->saddr = inet_select_addr(dev_out, 0,
2731 RT_SCOPE_LINK);
2732 goto make_route;
2733 }
2734 if (!fl4->saddr) {
2735 if (ipv4_is_multicast(fl4->daddr))
2736 fl4->saddr = inet_select_addr(dev_out, 0,
2737 fl4->flowi4_scope);
2738 else if (!fl4->daddr)
2739 fl4->saddr = inet_select_addr(dev_out, 0,
2740 RT_SCOPE_HOST);
2741 }
2742 }
2743
2744 if (!fl4->daddr) {
2745 fl4->daddr = fl4->saddr;
2746 if (!fl4->daddr)
2747 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2748 dev_out = net->loopback_dev;
2749 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2750 res->type = RTN_LOCAL;
2751 flags |= RTCF_LOCAL;
2752 goto make_route;
2753 }
2754
2755 err = fib_lookup(net, fl4, res, 0);
2756 if (err) {
2757 res->fi = NULL;
2758 res->table = NULL;
2759 if (fl4->flowi4_oif &&
2760 (ipv4_is_multicast(fl4->daddr) ||
2761 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2762 /* Apparently, routing tables are wrong. Assume,
2763 * that the destination is on link.
2764 *
2765 * WHY? DW.
2766 * Because we are allowed to send to iface
2767 * even if it has NO routes and NO assigned
2768 * addresses. When oif is specified, routing
2769 * tables are looked up with only one purpose:
2770 * to catch if destination is gatewayed, rather than
2771 * direct. Moreover, if MSG_DONTROUTE is set,
2772 * we send packet, ignoring both routing tables
2773 * and ifaddr state. --ANK
2774 *
2775 *
2776 * We could make it even if oif is unknown,
2777 * likely IPv6, but we do not.
2778 */
2779
2780 if (fl4->saddr == 0)
2781 fl4->saddr = inet_select_addr(dev_out, 0,
2782 RT_SCOPE_LINK);
2783 res->type = RTN_UNICAST;
2784 goto make_route;
2785 }
2786 rth = ERR_PTR(err);
2787 goto out;
2788 }
2789
2790 if (res->type == RTN_LOCAL) {
2791 if (!fl4->saddr) {
2792 if (res->fi->fib_prefsrc)
2793 fl4->saddr = res->fi->fib_prefsrc;
2794 else
2795 fl4->saddr = fl4->daddr;
2796 }
2797
2798 /* L3 master device is the loopback for that domain */
2799 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2800 net->loopback_dev;
2801
2802 /* make sure orig_oif points to fib result device even
2803 * though packet rx/tx happens over loopback or l3mdev
2804 */
2805 orig_oif = FIB_RES_OIF(*res);
2806
2807 fl4->flowi4_oif = dev_out->ifindex;
2808 flags |= RTCF_LOCAL;
2809 goto make_route;
2810 }
2811
2812 fib_select_path(net, res, fl4, skb);
2813
2814 dev_out = FIB_RES_DEV(*res);
2815
2816make_route:
2817 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2818
2819out:
2820 return rth;
2821}
2822
2823static struct dst_ops ipv4_dst_blackhole_ops = {
2824 .family = AF_INET,
2825 .default_advmss = ipv4_default_advmss,
2826 .neigh_lookup = ipv4_neigh_lookup,
2827 .check = dst_blackhole_check,
2828 .cow_metrics = dst_blackhole_cow_metrics,
2829 .update_pmtu = dst_blackhole_update_pmtu,
2830 .redirect = dst_blackhole_redirect,
2831 .mtu = dst_blackhole_mtu,
2832};
2833
2834struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2835{
2836 struct rtable *ort = (struct rtable *) dst_orig;
2837 struct rtable *rt;
2838
2839 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2840 if (rt) {
2841 struct dst_entry *new = &rt->dst;
2842
2843 new->__use = 1;
2844 new->input = dst_discard;
2845 new->output = dst_discard_out;
2846
2847 new->dev = net->loopback_dev;
2848 if (new->dev)
2849 dev_hold(new->dev);
2850
2851 rt->rt_is_input = ort->rt_is_input;
2852 rt->rt_iif = ort->rt_iif;
2853 rt->rt_pmtu = ort->rt_pmtu;
2854 rt->rt_mtu_locked = ort->rt_mtu_locked;
2855
2856 rt->rt_genid = rt_genid_ipv4(net);
2857 rt->rt_flags = ort->rt_flags;
2858 rt->rt_type = ort->rt_type;
2859 rt->rt_uses_gateway = ort->rt_uses_gateway;
2860 rt->rt_gw_family = ort->rt_gw_family;
2861 if (rt->rt_gw_family == AF_INET)
2862 rt->rt_gw4 = ort->rt_gw4;
2863 else if (rt->rt_gw_family == AF_INET6)
2864 rt->rt_gw6 = ort->rt_gw6;
2865
2866 INIT_LIST_HEAD(&rt->rt_uncached);
2867 }
2868
2869 dst_release(dst_orig);
2870
2871 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2872}
2873
2874struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2875 const struct sock *sk)
2876{
2877 struct rtable *rt = __ip_route_output_key(net, flp4);
2878
2879 if (IS_ERR(rt))
2880 return rt;
2881
2882 if (flp4->flowi4_proto) {
2883 flp4->flowi4_oif = rt->dst.dev->ifindex;
2884 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2885 flowi4_to_flowi(flp4),
2886 sk, 0);
2887 }
2888
2889 return rt;
2890}
2891EXPORT_SYMBOL_GPL(ip_route_output_flow);
2892
2893struct rtable *ip_route_output_tunnel(struct sk_buff *skb,
2894 struct net_device *dev,
2895 struct net *net, __be32 *saddr,
2896 const struct ip_tunnel_info *info,
2897 u8 protocol, bool use_cache)
2898{
2899#ifdef CONFIG_DST_CACHE
2900 struct dst_cache *dst_cache;
2901#endif
2902 struct rtable *rt = NULL;
2903 struct flowi4 fl4;
2904 __u8 tos;
2905
2906#ifdef CONFIG_DST_CACHE
2907 dst_cache = (struct dst_cache *)&info->dst_cache;
2908 if (use_cache) {
2909 rt = dst_cache_get_ip4(dst_cache, saddr);
2910 if (rt)
2911 return rt;
2912 }
2913#endif
2914 memset(&fl4, 0, sizeof(fl4));
2915 fl4.flowi4_mark = skb->mark;
2916 fl4.flowi4_proto = protocol;
2917 fl4.daddr = info->key.u.ipv4.dst;
2918 fl4.saddr = info->key.u.ipv4.src;
2919 tos = info->key.tos;
2920 fl4.flowi4_tos = RT_TOS(tos);
2921
2922 rt = ip_route_output_key(net, &fl4);
2923 if (IS_ERR(rt)) {
2924 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
2925 return ERR_PTR(-ENETUNREACH);
2926 }
2927 if (rt->dst.dev == dev) { /* is this necessary? */
2928 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
2929 ip_rt_put(rt);
2930 return ERR_PTR(-ELOOP);
2931 }
2932#ifdef CONFIG_DST_CACHE
2933 if (use_cache)
2934 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
2935#endif
2936 *saddr = fl4.saddr;
2937 return rt;
2938}
2939EXPORT_SYMBOL_GPL(ip_route_output_tunnel);
2940
2941/* called with rcu_read_lock held */
2942static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2943 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2944 struct sk_buff *skb, u32 portid, u32 seq,
2945 unsigned int flags)
2946{
2947 struct rtmsg *r;
2948 struct nlmsghdr *nlh;
2949 unsigned long expires = 0;
2950 u32 error;
2951 u32 metrics[RTAX_MAX];
2952
2953 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2954 if (!nlh)
2955 return -EMSGSIZE;
2956
2957 r = nlmsg_data(nlh);
2958 r->rtm_family = AF_INET;
2959 r->rtm_dst_len = 32;
2960 r->rtm_src_len = 0;
2961 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0;
2962 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2963 if (nla_put_u32(skb, RTA_TABLE, table_id))
2964 goto nla_put_failure;
2965 r->rtm_type = rt->rt_type;
2966 r->rtm_scope = RT_SCOPE_UNIVERSE;
2967 r->rtm_protocol = RTPROT_UNSPEC;
2968 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2969 if (rt->rt_flags & RTCF_NOTIFY)
2970 r->rtm_flags |= RTM_F_NOTIFY;
2971 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2972 r->rtm_flags |= RTCF_DOREDIRECT;
2973
2974 if (nla_put_in_addr(skb, RTA_DST, dst))
2975 goto nla_put_failure;
2976 if (src) {
2977 r->rtm_src_len = 32;
2978 if (nla_put_in_addr(skb, RTA_SRC, src))
2979 goto nla_put_failure;
2980 }
2981 if (rt->dst.dev &&
2982 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2983 goto nla_put_failure;
2984 if (rt->dst.lwtstate &&
2985 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
2986 goto nla_put_failure;
2987#ifdef CONFIG_IP_ROUTE_CLASSID
2988 if (rt->dst.tclassid &&
2989 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2990 goto nla_put_failure;
2991#endif
2992 if (fl4 && !rt_is_input_route(rt) &&
2993 fl4->saddr != src) {
2994 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2995 goto nla_put_failure;
2996 }
2997 if (rt->rt_uses_gateway) {
2998 if (rt->rt_gw_family == AF_INET &&
2999 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
3000 goto nla_put_failure;
3001 } else if (rt->rt_gw_family == AF_INET6) {
3002 int alen = sizeof(struct in6_addr);
3003 struct nlattr *nla;
3004 struct rtvia *via;
3005
3006 nla = nla_reserve(skb, RTA_VIA, alen + 2);
3007 if (!nla)
3008 goto nla_put_failure;
3009
3010 via = nla_data(nla);
3011 via->rtvia_family = AF_INET6;
3012 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
3013 }
3014 }
3015
3016 expires = rt->dst.expires;
3017 if (expires) {
3018 unsigned long now = jiffies;
3019
3020 if (time_before(now, expires))
3021 expires -= now;
3022 else
3023 expires = 0;
3024 }
3025
3026 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
3027 if (rt->rt_pmtu && expires)
3028 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
3029 if (rt->rt_mtu_locked && expires)
3030 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
3031 if (rtnetlink_put_metrics(skb, metrics) < 0)
3032 goto nla_put_failure;
3033
3034 if (fl4) {
3035 if (fl4->flowi4_mark &&
3036 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
3037 goto nla_put_failure;
3038
3039 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
3040 nla_put_u32(skb, RTA_UID,
3041 from_kuid_munged(current_user_ns(),
3042 fl4->flowi4_uid)))
3043 goto nla_put_failure;
3044
3045 if (rt_is_input_route(rt)) {
3046#ifdef CONFIG_IP_MROUTE
3047 if (ipv4_is_multicast(dst) &&
3048 !ipv4_is_local_multicast(dst) &&
3049 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
3050 int err = ipmr_get_route(net, skb,
3051 fl4->saddr, fl4->daddr,
3052 r, portid);
3053
3054 if (err <= 0) {
3055 if (err == 0)
3056 return 0;
3057 goto nla_put_failure;
3058 }
3059 } else
3060#endif
3061 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
3062 goto nla_put_failure;
3063 }
3064 }
3065
3066 error = rt->dst.error;
3067
3068 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
3069 goto nla_put_failure;
3070
3071 nlmsg_end(skb, nlh);
3072 return 0;
3073
3074nla_put_failure:
3075 nlmsg_cancel(skb, nlh);
3076 return -EMSGSIZE;
3077}
3078
3079static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
3080 struct netlink_callback *cb, u32 table_id,
3081 struct fnhe_hash_bucket *bucket, int genid,
3082 int *fa_index, int fa_start, unsigned int flags)
3083{
3084 int i;
3085
3086 for (i = 0; i < FNHE_HASH_SIZE; i++) {
3087 struct fib_nh_exception *fnhe;
3088
3089 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
3090 fnhe = rcu_dereference(fnhe->fnhe_next)) {
3091 struct rtable *rt;
3092 int err;
3093
3094 if (*fa_index < fa_start)
3095 goto next;
3096
3097 if (fnhe->fnhe_genid != genid)
3098 goto next;
3099
3100 if (fnhe->fnhe_expires &&
3101 time_after(jiffies, fnhe->fnhe_expires))
3102 goto next;
3103
3104 rt = rcu_dereference(fnhe->fnhe_rth_input);
3105 if (!rt)
3106 rt = rcu_dereference(fnhe->fnhe_rth_output);
3107 if (!rt)
3108 goto next;
3109
3110 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
3111 table_id, NULL, skb,
3112 NETLINK_CB(cb->skb).portid,
3113 cb->nlh->nlmsg_seq, flags);
3114 if (err)
3115 return err;
3116next:
3117 (*fa_index)++;
3118 }
3119 }
3120
3121 return 0;
3122}
3123
3124int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
3125 u32 table_id, struct fib_info *fi,
3126 int *fa_index, int fa_start, unsigned int flags)
3127{
3128 struct net *net = sock_net(cb->skb->sk);
3129 int nhsel, genid = fnhe_genid(net);
3130
3131 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
3132 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
3133 struct fnhe_hash_bucket *bucket;
3134 int err;
3135
3136 if (nhc->nhc_flags & RTNH_F_DEAD)
3137 continue;
3138
3139 rcu_read_lock();
3140 bucket = rcu_dereference(nhc->nhc_exceptions);
3141 err = 0;
3142 if (bucket)
3143 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
3144 genid, fa_index, fa_start,
3145 flags);
3146 rcu_read_unlock();
3147 if (err)
3148 return err;
3149 }
3150
3151 return 0;
3152}
3153
3154static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
3155 u8 ip_proto, __be16 sport,
3156 __be16 dport)
3157{
3158 struct sk_buff *skb;
3159 struct iphdr *iph;
3160
3161 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3162 if (!skb)
3163 return NULL;
3164
3165 /* Reserve room for dummy headers, this skb can pass
3166 * through good chunk of routing engine.
3167 */
3168 skb_reset_mac_header(skb);
3169 skb_reset_network_header(skb);
3170 skb->protocol = htons(ETH_P_IP);
3171 iph = skb_put(skb, sizeof(struct iphdr));
3172 iph->protocol = ip_proto;
3173 iph->saddr = src;
3174 iph->daddr = dst;
3175 iph->version = 0x4;
3176 iph->frag_off = 0;
3177 iph->ihl = 0x5;
3178 skb_set_transport_header(skb, skb->len);
3179
3180 switch (iph->protocol) {
3181 case IPPROTO_UDP: {
3182 struct udphdr *udph;
3183
3184 udph = skb_put_zero(skb, sizeof(struct udphdr));
3185 udph->source = sport;
3186 udph->dest = dport;
3187 udph->len = htons(sizeof(struct udphdr));
3188 udph->check = 0;
3189 break;
3190 }
3191 case IPPROTO_TCP: {
3192 struct tcphdr *tcph;
3193
3194 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
3195 tcph->source = sport;
3196 tcph->dest = dport;
3197 tcph->doff = sizeof(struct tcphdr) / 4;
3198 tcph->rst = 1;
3199 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
3200 src, dst, 0);
3201 break;
3202 }
3203 case IPPROTO_ICMP: {
3204 struct icmphdr *icmph;
3205
3206 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
3207 icmph->type = ICMP_ECHO;
3208 icmph->code = 0;
3209 }
3210 }
3211
3212 return skb;
3213}
3214
3215static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3216 const struct nlmsghdr *nlh,
3217 struct nlattr **tb,
3218 struct netlink_ext_ack *extack)
3219{
3220 struct rtmsg *rtm;
3221 int i, err;
3222
3223 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3224 NL_SET_ERR_MSG(extack,
3225 "ipv4: Invalid header for route get request");
3226 return -EINVAL;
3227 }
3228
3229 if (!netlink_strict_get_check(skb))
3230 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3231 rtm_ipv4_policy, extack);
3232
3233 rtm = nlmsg_data(nlh);
3234 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3235 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3236 rtm->rtm_table || rtm->rtm_protocol ||
3237 rtm->rtm_scope || rtm->rtm_type) {
3238 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3239 return -EINVAL;
3240 }
3241
3242 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3243 RTM_F_LOOKUP_TABLE |
3244 RTM_F_FIB_MATCH)) {
3245 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3246 return -EINVAL;
3247 }
3248
3249 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3250 rtm_ipv4_policy, extack);
3251 if (err)
3252 return err;
3253
3254 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3255 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3256 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3257 return -EINVAL;
3258 }
3259
3260 for (i = 0; i <= RTA_MAX; i++) {
3261 if (!tb[i])
3262 continue;
3263
3264 switch (i) {
3265 case RTA_IIF:
3266 case RTA_OIF:
3267 case RTA_SRC:
3268 case RTA_DST:
3269 case RTA_IP_PROTO:
3270 case RTA_SPORT:
3271 case RTA_DPORT:
3272 case RTA_MARK:
3273 case RTA_UID:
3274 break;
3275 default:
3276 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3277 return -EINVAL;
3278 }
3279 }
3280
3281 return 0;
3282}
3283
3284static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3285 struct netlink_ext_ack *extack)
3286{
3287 struct net *net = sock_net(in_skb->sk);
3288 struct nlattr *tb[RTA_MAX+1];
3289 u32 table_id = RT_TABLE_MAIN;
3290 __be16 sport = 0, dport = 0;
3291 struct fib_result res = {};
3292 u8 ip_proto = IPPROTO_UDP;
3293 struct rtable *rt = NULL;
3294 struct sk_buff *skb;
3295 struct rtmsg *rtm;
3296 struct flowi4 fl4 = {};
3297 __be32 dst = 0;
3298 __be32 src = 0;
3299 kuid_t uid;
3300 u32 iif;
3301 int err;
3302 int mark;
3303
3304 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3305 if (err < 0)
3306 return err;
3307
3308 rtm = nlmsg_data(nlh);
3309 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
3310 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
3311 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3312 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3313 if (tb[RTA_UID])
3314 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3315 else
3316 uid = (iif ? INVALID_UID : current_uid());
3317
3318 if (tb[RTA_IP_PROTO]) {
3319 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3320 &ip_proto, AF_INET, extack);
3321 if (err)
3322 return err;
3323 }
3324
3325 if (tb[RTA_SPORT])
3326 sport = nla_get_be16(tb[RTA_SPORT]);
3327
3328 if (tb[RTA_DPORT])
3329 dport = nla_get_be16(tb[RTA_DPORT]);
3330
3331 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3332 if (!skb)
3333 return -ENOBUFS;
3334
3335 fl4.daddr = dst;
3336 fl4.saddr = src;
3337 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK;
3338 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
3339 fl4.flowi4_mark = mark;
3340 fl4.flowi4_uid = uid;
3341 if (sport)
3342 fl4.fl4_sport = sport;
3343 if (dport)
3344 fl4.fl4_dport = dport;
3345 fl4.flowi4_proto = ip_proto;
3346
3347 rcu_read_lock();
3348
3349 if (iif) {
3350 struct net_device *dev;
3351
3352 dev = dev_get_by_index_rcu(net, iif);
3353 if (!dev) {
3354 err = -ENODEV;
3355 goto errout_rcu;
3356 }
3357
3358 fl4.flowi4_iif = iif; /* for rt_fill_info */
3359 skb->dev = dev;
3360 skb->mark = mark;
3361 err = ip_route_input_rcu(skb, dst, src,
3362 rtm->rtm_tos & IPTOS_RT_MASK, dev,
3363 &res);
3364
3365 rt = skb_rtable(skb);
3366 if (err == 0 && rt->dst.error)
3367 err = -rt->dst.error;
3368 } else {
3369 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3370 skb->dev = net->loopback_dev;
3371 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3372 err = 0;
3373 if (IS_ERR(rt))
3374 err = PTR_ERR(rt);
3375 else
3376 skb_dst_set(skb, &rt->dst);
3377 }
3378
3379 if (err)
3380 goto errout_rcu;
3381
3382 if (rtm->rtm_flags & RTM_F_NOTIFY)
3383 rt->rt_flags |= RTCF_NOTIFY;
3384
3385 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3386 table_id = res.table ? res.table->tb_id : 0;
3387
3388 /* reset skb for netlink reply msg */
3389 skb_trim(skb, 0);
3390 skb_reset_network_header(skb);
3391 skb_reset_transport_header(skb);
3392 skb_reset_mac_header(skb);
3393
3394 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3395 struct fib_rt_info fri;
3396
3397 if (!res.fi) {
3398 err = fib_props[res.type].error;
3399 if (!err)
3400 err = -EHOSTUNREACH;
3401 goto errout_rcu;
3402 }
3403 fri.fi = res.fi;
3404 fri.tb_id = table_id;
3405 fri.dst = res.prefix;
3406 fri.dst_len = res.prefixlen;
3407 fri.tos = fl4.flowi4_tos;
3408 fri.type = rt->rt_type;
3409 fri.offload = 0;
3410 fri.trap = 0;
3411 fri.offload_failed = 0;
3412 if (res.fa_head) {
3413 struct fib_alias *fa;
3414
3415 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) {
3416 u8 slen = 32 - fri.dst_len;
3417
3418 if (fa->fa_slen == slen &&
3419 fa->tb_id == fri.tb_id &&
3420 fa->fa_tos == fri.tos &&
3421 fa->fa_info == res.fi &&
3422 fa->fa_type == fri.type) {
3423 fri.offload = fa->offload;
3424 fri.trap = fa->trap;
3425 break;
3426 }
3427 }
3428 }
3429 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3430 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0);
3431 } else {
3432 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
3433 NETLINK_CB(in_skb).portid,
3434 nlh->nlmsg_seq, 0);
3435 }
3436 if (err < 0)
3437 goto errout_rcu;
3438
3439 rcu_read_unlock();
3440
3441 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3442
3443errout_free:
3444 return err;
3445errout_rcu:
3446 rcu_read_unlock();
3447 kfree_skb(skb);
3448 goto errout_free;
3449}
3450
3451void ip_rt_multicast_event(struct in_device *in_dev)
3452{
3453 rt_cache_flush(dev_net(in_dev->dev));
3454}
3455
3456#ifdef CONFIG_SYSCTL
3457static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3458static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3459static int ip_rt_gc_elasticity __read_mostly = 8;
3460static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3461
3462static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
3463 void *buffer, size_t *lenp, loff_t *ppos)
3464{
3465 struct net *net = (struct net *)__ctl->extra1;
3466
3467 if (write) {
3468 rt_cache_flush(net);
3469 fnhe_genid_bump(net);
3470 return 0;
3471 }
3472
3473 return -EINVAL;
3474}
3475
3476static struct ctl_table ipv4_route_table[] = {
3477 {
3478 .procname = "gc_thresh",
3479 .data = &ipv4_dst_ops.gc_thresh,
3480 .maxlen = sizeof(int),
3481 .mode = 0644,
3482 .proc_handler = proc_dointvec,
3483 },
3484 {
3485 .procname = "max_size",
3486 .data = &ip_rt_max_size,
3487 .maxlen = sizeof(int),
3488 .mode = 0644,
3489 .proc_handler = proc_dointvec,
3490 },
3491 {
3492 /* Deprecated. Use gc_min_interval_ms */
3493
3494 .procname = "gc_min_interval",
3495 .data = &ip_rt_gc_min_interval,
3496 .maxlen = sizeof(int),
3497 .mode = 0644,
3498 .proc_handler = proc_dointvec_jiffies,
3499 },
3500 {
3501 .procname = "gc_min_interval_ms",
3502 .data = &ip_rt_gc_min_interval,
3503 .maxlen = sizeof(int),
3504 .mode = 0644,
3505 .proc_handler = proc_dointvec_ms_jiffies,
3506 },
3507 {
3508 .procname = "gc_timeout",
3509 .data = &ip_rt_gc_timeout,
3510 .maxlen = sizeof(int),
3511 .mode = 0644,
3512 .proc_handler = proc_dointvec_jiffies,
3513 },
3514 {
3515 .procname = "gc_interval",
3516 .data = &ip_rt_gc_interval,
3517 .maxlen = sizeof(int),
3518 .mode = 0644,
3519 .proc_handler = proc_dointvec_jiffies,
3520 },
3521 {
3522 .procname = "redirect_load",
3523 .data = &ip_rt_redirect_load,
3524 .maxlen = sizeof(int),
3525 .mode = 0644,
3526 .proc_handler = proc_dointvec,
3527 },
3528 {
3529 .procname = "redirect_number",
3530 .data = &ip_rt_redirect_number,
3531 .maxlen = sizeof(int),
3532 .mode = 0644,
3533 .proc_handler = proc_dointvec,
3534 },
3535 {
3536 .procname = "redirect_silence",
3537 .data = &ip_rt_redirect_silence,
3538 .maxlen = sizeof(int),
3539 .mode = 0644,
3540 .proc_handler = proc_dointvec,
3541 },
3542 {
3543 .procname = "error_cost",
3544 .data = &ip_rt_error_cost,
3545 .maxlen = sizeof(int),
3546 .mode = 0644,
3547 .proc_handler = proc_dointvec,
3548 },
3549 {
3550 .procname = "error_burst",
3551 .data = &ip_rt_error_burst,
3552 .maxlen = sizeof(int),
3553 .mode = 0644,
3554 .proc_handler = proc_dointvec,
3555 },
3556 {
3557 .procname = "gc_elasticity",
3558 .data = &ip_rt_gc_elasticity,
3559 .maxlen = sizeof(int),
3560 .mode = 0644,
3561 .proc_handler = proc_dointvec,
3562 },
3563 {
3564 .procname = "mtu_expires",
3565 .data = &ip_rt_mtu_expires,
3566 .maxlen = sizeof(int),
3567 .mode = 0644,
3568 .proc_handler = proc_dointvec_jiffies,
3569 },
3570 {
3571 .procname = "min_pmtu",
3572 .data = &ip_rt_min_pmtu,
3573 .maxlen = sizeof(int),
3574 .mode = 0644,
3575 .proc_handler = proc_dointvec_minmax,
3576 .extra1 = &ip_min_valid_pmtu,
3577 },
3578 {
3579 .procname = "min_adv_mss",
3580 .data = &ip_rt_min_advmss,
3581 .maxlen = sizeof(int),
3582 .mode = 0644,
3583 .proc_handler = proc_dointvec,
3584 },
3585 { }
3586};
3587
3588static const char ipv4_route_flush_procname[] = "flush";
3589
3590static struct ctl_table ipv4_route_flush_table[] = {
3591 {
3592 .procname = ipv4_route_flush_procname,
3593 .maxlen = sizeof(int),
3594 .mode = 0200,
3595 .proc_handler = ipv4_sysctl_rtcache_flush,
3596 },
3597 { },
3598};
3599
3600static __net_init int sysctl_route_net_init(struct net *net)
3601{
3602 struct ctl_table *tbl;
3603
3604 tbl = ipv4_route_flush_table;
3605 if (!net_eq(net, &init_net)) {
3606 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3607 if (!tbl)
3608 goto err_dup;
3609
3610 /* Don't export non-whitelisted sysctls to unprivileged users */
3611 if (net->user_ns != &init_user_ns) {
3612 if (tbl[0].procname != ipv4_route_flush_procname)
3613 tbl[0].procname = NULL;
3614 }
3615 }
3616 tbl[0].extra1 = net;
3617
3618 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3619 if (!net->ipv4.route_hdr)
3620 goto err_reg;
3621 return 0;
3622
3623err_reg:
3624 if (tbl != ipv4_route_flush_table)
3625 kfree(tbl);
3626err_dup:
3627 return -ENOMEM;
3628}
3629
3630static __net_exit void sysctl_route_net_exit(struct net *net)
3631{
3632 struct ctl_table *tbl;
3633
3634 tbl = net->ipv4.route_hdr->ctl_table_arg;
3635 unregister_net_sysctl_table(net->ipv4.route_hdr);
3636 BUG_ON(tbl == ipv4_route_flush_table);
3637 kfree(tbl);
3638}
3639
3640static __net_initdata struct pernet_operations sysctl_route_ops = {
3641 .init = sysctl_route_net_init,
3642 .exit = sysctl_route_net_exit,
3643};
3644#endif
3645
3646static __net_init int rt_genid_init(struct net *net)
3647{
3648 atomic_set(&net->ipv4.rt_genid, 0);
3649 atomic_set(&net->fnhe_genid, 0);
3650 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3651 return 0;
3652}
3653
3654static __net_initdata struct pernet_operations rt_genid_ops = {
3655 .init = rt_genid_init,
3656};
3657
3658static int __net_init ipv4_inetpeer_init(struct net *net)
3659{
3660 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3661
3662 if (!bp)
3663 return -ENOMEM;
3664 inet_peer_base_init(bp);
3665 net->ipv4.peers = bp;
3666 return 0;
3667}
3668
3669static void __net_exit ipv4_inetpeer_exit(struct net *net)
3670{
3671 struct inet_peer_base *bp = net->ipv4.peers;
3672
3673 net->ipv4.peers = NULL;
3674 inetpeer_invalidate_tree(bp);
3675 kfree(bp);
3676}
3677
3678static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3679 .init = ipv4_inetpeer_init,
3680 .exit = ipv4_inetpeer_exit,
3681};
3682
3683#ifdef CONFIG_IP_ROUTE_CLASSID
3684struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3685#endif /* CONFIG_IP_ROUTE_CLASSID */
3686
3687int __init ip_rt_init(void)
3688{
3689 void *idents_hash;
3690 int cpu;
3691
3692 /* For modern hosts, this will use 2 MB of memory */
3693 idents_hash = alloc_large_system_hash("IP idents",
3694 sizeof(*ip_idents) + sizeof(*ip_tstamps),
3695 0,
3696 16, /* one bucket per 64 KB */
3697 HASH_ZERO,
3698 NULL,
3699 &ip_idents_mask,
3700 2048,
3701 256*1024);
3702
3703 ip_idents = idents_hash;
3704
3705 prandom_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents));
3706
3707 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents);
3708
3709 for_each_possible_cpu(cpu) {
3710 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3711
3712 INIT_LIST_HEAD(&ul->head);
3713 spin_lock_init(&ul->lock);
3714 }
3715#ifdef CONFIG_IP_ROUTE_CLASSID
3716 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3717 if (!ip_rt_acct)
3718 panic("IP: failed to allocate ip_rt_acct\n");
3719#endif
3720
3721 ipv4_dst_ops.kmem_cachep =
3722 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3723 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3724
3725 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3726
3727 if (dst_entries_init(&ipv4_dst_ops) < 0)
3728 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3729
3730 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3731 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3732
3733 ipv4_dst_ops.gc_thresh = ~0;
3734 ip_rt_max_size = INT_MAX;
3735
3736 devinet_init();
3737 ip_fib_init();
3738
3739 if (ip_rt_proc_init())
3740 pr_err("Unable to create route proc files\n");
3741#ifdef CONFIG_XFRM
3742 xfrm_init();
3743 xfrm4_init();
3744#endif
3745 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3746 RTNL_FLAG_DOIT_UNLOCKED);
3747
3748#ifdef CONFIG_SYSCTL
3749 register_pernet_subsys(&sysctl_route_ops);
3750#endif
3751 register_pernet_subsys(&rt_genid_ops);
3752 register_pernet_subsys(&ipv4_inetpeer_ops);
3753 return 0;
3754}
3755
3756#ifdef CONFIG_SYSCTL
3757/*
3758 * We really need to sanitize the damn ipv4 init order, then all
3759 * this nonsense will go away.
3760 */
3761void __init ip_static_sysctl_init(void)
3762{
3763 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3764}
3765#endif