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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_FL_TOS(oldflp4) \
110 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
111
112#define RT_GC_TIMEOUT (300*HZ)
113
114#define DEFAULT_MIN_PMTU (512 + 20 + 20)
115#define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
116#define DEFAULT_MIN_ADVMSS 256
117static int ip_rt_max_size;
118static int ip_rt_redirect_number __read_mostly = 9;
119static int ip_rt_redirect_load __read_mostly = HZ / 50;
120static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
121static int ip_rt_error_cost __read_mostly = HZ;
122static int ip_rt_error_burst __read_mostly = 5 * HZ;
123
124static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
125
126/*
127 * Interface to generic destination cache.
128 */
129
130INDIRECT_CALLABLE_SCOPE
131struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
132static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
133INDIRECT_CALLABLE_SCOPE
134unsigned int ipv4_mtu(const struct dst_entry *dst);
135static void ipv4_negative_advice(struct sock *sk,
136 struct dst_entry *dst);
137static void ipv4_link_failure(struct sk_buff *skb);
138static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb, u32 mtu,
140 bool confirm_neigh);
141static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb);
143static void ipv4_dst_destroy(struct dst_entry *dst);
144
145static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
146{
147 WARN_ON(1);
148 return NULL;
149}
150
151static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
152 struct sk_buff *skb,
153 const void *daddr);
154static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
155
156static struct dst_ops ipv4_dst_ops = {
157 .family = AF_INET,
158 .check = ipv4_dst_check,
159 .default_advmss = ipv4_default_advmss,
160 .mtu = ipv4_mtu,
161 .cow_metrics = ipv4_cow_metrics,
162 .destroy = ipv4_dst_destroy,
163 .negative_advice = ipv4_negative_advice,
164 .link_failure = ipv4_link_failure,
165 .update_pmtu = ip_rt_update_pmtu,
166 .redirect = ip_do_redirect,
167 .local_out = __ip_local_out,
168 .neigh_lookup = ipv4_neigh_lookup,
169 .confirm_neigh = ipv4_confirm_neigh,
170};
171
172#define ECN_OR_COST(class) TC_PRIO_##class
173
174const __u8 ip_tos2prio[16] = {
175 TC_PRIO_BESTEFFORT,
176 ECN_OR_COST(BESTEFFORT),
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BULK,
180 ECN_OR_COST(BULK),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_INTERACTIVE,
184 ECN_OR_COST(INTERACTIVE),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE_BULK,
188 ECN_OR_COST(INTERACTIVE_BULK),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK)
191};
192EXPORT_SYMBOL(ip_tos2prio);
193
194static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
195#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
196
197#ifdef CONFIG_PROC_FS
198static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
199{
200 if (*pos)
201 return NULL;
202 return SEQ_START_TOKEN;
203}
204
205static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
206{
207 ++*pos;
208 return NULL;
209}
210
211static void rt_cache_seq_stop(struct seq_file *seq, void *v)
212{
213}
214
215static int rt_cache_seq_show(struct seq_file *seq, void *v)
216{
217 if (v == SEQ_START_TOKEN)
218 seq_printf(seq, "%-127s\n",
219 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
220 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
221 "HHUptod\tSpecDst");
222 return 0;
223}
224
225static const struct seq_operations rt_cache_seq_ops = {
226 .start = rt_cache_seq_start,
227 .next = rt_cache_seq_next,
228 .stop = rt_cache_seq_stop,
229 .show = rt_cache_seq_show,
230};
231
232static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
233{
234 int cpu;
235
236 if (*pos == 0)
237 return SEQ_START_TOKEN;
238
239 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
240 if (!cpu_possible(cpu))
241 continue;
242 *pos = cpu+1;
243 return &per_cpu(rt_cache_stat, cpu);
244 }
245 return NULL;
246}
247
248static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
249{
250 int cpu;
251
252 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
253 if (!cpu_possible(cpu))
254 continue;
255 *pos = cpu+1;
256 return &per_cpu(rt_cache_stat, cpu);
257 }
258 (*pos)++;
259 return NULL;
260
261}
262
263static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
264{
265
266}
267
268static int rt_cpu_seq_show(struct seq_file *seq, void *v)
269{
270 struct rt_cache_stat *st = v;
271
272 if (v == SEQ_START_TOKEN) {
273 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");
274 return 0;
275 }
276
277 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x "
278 "%08x %08x %08x %08x %08x %08x "
279 "%08x %08x %08x %08x\n",
280 dst_entries_get_slow(&ipv4_dst_ops),
281 0, /* st->in_hit */
282 st->in_slow_tot,
283 st->in_slow_mc,
284 st->in_no_route,
285 st->in_brd,
286 st->in_martian_dst,
287 st->in_martian_src,
288
289 0, /* st->out_hit */
290 st->out_slow_tot,
291 st->out_slow_mc,
292
293 0, /* st->gc_total */
294 0, /* st->gc_ignored */
295 0, /* st->gc_goal_miss */
296 0, /* st->gc_dst_overflow */
297 0, /* st->in_hlist_search */
298 0 /* st->out_hlist_search */
299 );
300 return 0;
301}
302
303static const struct seq_operations rt_cpu_seq_ops = {
304 .start = rt_cpu_seq_start,
305 .next = rt_cpu_seq_next,
306 .stop = rt_cpu_seq_stop,
307 .show = rt_cpu_seq_show,
308};
309
310#ifdef CONFIG_IP_ROUTE_CLASSID
311static int rt_acct_proc_show(struct seq_file *m, void *v)
312{
313 struct ip_rt_acct *dst, *src;
314 unsigned int i, j;
315
316 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
317 if (!dst)
318 return -ENOMEM;
319
320 for_each_possible_cpu(i) {
321 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
322 for (j = 0; j < 256; j++) {
323 dst[j].o_bytes += src[j].o_bytes;
324 dst[j].o_packets += src[j].o_packets;
325 dst[j].i_bytes += src[j].i_bytes;
326 dst[j].i_packets += src[j].i_packets;
327 }
328 }
329
330 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
331 kfree(dst);
332 return 0;
333}
334#endif
335
336static int __net_init ip_rt_do_proc_init(struct net *net)
337{
338 struct proc_dir_entry *pde;
339
340 pde = proc_create_seq("rt_cache", 0444, net->proc_net,
341 &rt_cache_seq_ops);
342 if (!pde)
343 goto err1;
344
345 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat,
346 &rt_cpu_seq_ops);
347 if (!pde)
348 goto err2;
349
350#ifdef CONFIG_IP_ROUTE_CLASSID
351 pde = proc_create_single("rt_acct", 0, net->proc_net,
352 rt_acct_proc_show);
353 if (!pde)
354 goto err3;
355#endif
356 return 0;
357
358#ifdef CONFIG_IP_ROUTE_CLASSID
359err3:
360 remove_proc_entry("rt_cache", net->proc_net_stat);
361#endif
362err2:
363 remove_proc_entry("rt_cache", net->proc_net);
364err1:
365 return -ENOMEM;
366}
367
368static void __net_exit ip_rt_do_proc_exit(struct net *net)
369{
370 remove_proc_entry("rt_cache", net->proc_net_stat);
371 remove_proc_entry("rt_cache", net->proc_net);
372#ifdef CONFIG_IP_ROUTE_CLASSID
373 remove_proc_entry("rt_acct", net->proc_net);
374#endif
375}
376
377static struct pernet_operations ip_rt_proc_ops __net_initdata = {
378 .init = ip_rt_do_proc_init,
379 .exit = ip_rt_do_proc_exit,
380};
381
382static int __init ip_rt_proc_init(void)
383{
384 return register_pernet_subsys(&ip_rt_proc_ops);
385}
386
387#else
388static inline int ip_rt_proc_init(void)
389{
390 return 0;
391}
392#endif /* CONFIG_PROC_FS */
393
394static inline bool rt_is_expired(const struct rtable *rth)
395{
396 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
397}
398
399void rt_cache_flush(struct net *net)
400{
401 rt_genid_bump_ipv4(net);
402}
403
404static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
405 struct sk_buff *skb,
406 const void *daddr)
407{
408 const struct rtable *rt = container_of(dst, struct rtable, dst);
409 struct net_device *dev = dst->dev;
410 struct neighbour *n;
411
412 rcu_read_lock();
413
414 if (likely(rt->rt_gw_family == AF_INET)) {
415 n = ip_neigh_gw4(dev, rt->rt_gw4);
416 } else if (rt->rt_gw_family == AF_INET6) {
417 n = ip_neigh_gw6(dev, &rt->rt_gw6);
418 } else {
419 __be32 pkey;
420
421 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
422 n = ip_neigh_gw4(dev, pkey);
423 }
424
425 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
426 n = NULL;
427
428 rcu_read_unlock();
429
430 return n;
431}
432
433static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
434{
435 const struct rtable *rt = container_of(dst, struct rtable, dst);
436 struct net_device *dev = dst->dev;
437 const __be32 *pkey = daddr;
438
439 if (rt->rt_gw_family == AF_INET) {
440 pkey = (const __be32 *)&rt->rt_gw4;
441 } else if (rt->rt_gw_family == AF_INET6) {
442 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
443 } else if (!daddr ||
444 (rt->rt_flags &
445 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
446 return;
447 }
448 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
449}
450
451/* Hash tables of size 2048..262144 depending on RAM size.
452 * Each bucket uses 8 bytes.
453 */
454static u32 ip_idents_mask __read_mostly;
455static atomic_t *ip_idents __read_mostly;
456static u32 *ip_tstamps __read_mostly;
457
458/* In order to protect privacy, we add a perturbation to identifiers
459 * if one generator is seldom used. This makes hard for an attacker
460 * to infer how many packets were sent between two points in time.
461 */
462static u32 ip_idents_reserve(u32 hash, int segs)
463{
464 u32 bucket, old, now = (u32)jiffies;
465 atomic_t *p_id;
466 u32 *p_tstamp;
467 u32 delta = 0;
468
469 bucket = hash & ip_idents_mask;
470 p_tstamp = ip_tstamps + bucket;
471 p_id = ip_idents + bucket;
472 old = READ_ONCE(*p_tstamp);
473
474 if (old != now && cmpxchg(p_tstamp, old, now) == old)
475 delta = get_random_u32_below(now - old);
476
477 /* If UBSAN reports an error there, please make sure your compiler
478 * supports -fno-strict-overflow before reporting it that was a bug
479 * in UBSAN, and it has been fixed in GCC-8.
480 */
481 return atomic_add_return(segs + delta, p_id) - segs;
482}
483
484void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
485{
486 u32 hash, id;
487
488 /* Note the following code is not safe, but this is okay. */
489 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
490 get_random_bytes(&net->ipv4.ip_id_key,
491 sizeof(net->ipv4.ip_id_key));
492
493 hash = siphash_3u32((__force u32)iph->daddr,
494 (__force u32)iph->saddr,
495 iph->protocol,
496 &net->ipv4.ip_id_key);
497 id = ip_idents_reserve(hash, segs);
498 iph->id = htons(id);
499}
500EXPORT_SYMBOL(__ip_select_ident);
501
502static void ip_rt_fix_tos(struct flowi4 *fl4)
503{
504 __u8 tos = RT_FL_TOS(fl4);
505
506 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
507 if (tos & RTO_ONLINK)
508 fl4->flowi4_scope = RT_SCOPE_LINK;
509}
510
511static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
512 const struct sock *sk, const struct iphdr *iph,
513 int oif, __u8 tos, u8 prot, u32 mark,
514 int flow_flags)
515{
516 __u8 scope = RT_SCOPE_UNIVERSE;
517
518 if (sk) {
519 oif = sk->sk_bound_dev_if;
520 mark = READ_ONCE(sk->sk_mark);
521 tos = ip_sock_rt_tos(sk);
522 scope = ip_sock_rt_scope(sk);
523 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW :
524 sk->sk_protocol;
525 }
526
527 flowi4_init_output(fl4, oif, mark, tos & IPTOS_RT_MASK, scope,
528 prot, flow_flags, iph->daddr, iph->saddr, 0, 0,
529 sock_net_uid(net, sk));
530}
531
532static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
533 const struct sock *sk)
534{
535 const struct net *net = dev_net(skb->dev);
536 const struct iphdr *iph = ip_hdr(skb);
537 int oif = skb->dev->ifindex;
538 u8 prot = iph->protocol;
539 u32 mark = skb->mark;
540 __u8 tos = iph->tos;
541
542 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
543}
544
545static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
546{
547 const struct inet_sock *inet = inet_sk(sk);
548 const struct ip_options_rcu *inet_opt;
549 __be32 daddr = inet->inet_daddr;
550
551 rcu_read_lock();
552 inet_opt = rcu_dereference(inet->inet_opt);
553 if (inet_opt && inet_opt->opt.srr)
554 daddr = inet_opt->opt.faddr;
555 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark),
556 ip_sock_rt_tos(sk) & IPTOS_RT_MASK,
557 ip_sock_rt_scope(sk),
558 inet_test_bit(HDRINCL, sk) ?
559 IPPROTO_RAW : sk->sk_protocol,
560 inet_sk_flowi_flags(sk),
561 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
562 rcu_read_unlock();
563}
564
565static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
566 const struct sk_buff *skb)
567{
568 if (skb)
569 build_skb_flow_key(fl4, skb, sk);
570 else
571 build_sk_flow_key(fl4, sk);
572}
573
574static DEFINE_SPINLOCK(fnhe_lock);
575
576static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
577{
578 struct rtable *rt;
579
580 rt = rcu_dereference(fnhe->fnhe_rth_input);
581 if (rt) {
582 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
583 dst_dev_put(&rt->dst);
584 dst_release(&rt->dst);
585 }
586 rt = rcu_dereference(fnhe->fnhe_rth_output);
587 if (rt) {
588 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
589 dst_dev_put(&rt->dst);
590 dst_release(&rt->dst);
591 }
592}
593
594static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
595{
596 struct fib_nh_exception __rcu **fnhe_p, **oldest_p;
597 struct fib_nh_exception *fnhe, *oldest = NULL;
598
599 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) {
600 fnhe = rcu_dereference_protected(*fnhe_p,
601 lockdep_is_held(&fnhe_lock));
602 if (!fnhe)
603 break;
604 if (!oldest ||
605 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) {
606 oldest = fnhe;
607 oldest_p = fnhe_p;
608 }
609 }
610 fnhe_flush_routes(oldest);
611 *oldest_p = oldest->fnhe_next;
612 kfree_rcu(oldest, rcu);
613}
614
615static u32 fnhe_hashfun(__be32 daddr)
616{
617 static siphash_aligned_key_t fnhe_hash_key;
618 u64 hval;
619
620 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));
621 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key);
622 return hash_64(hval, FNHE_HASH_SHIFT);
623}
624
625static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
626{
627 rt->rt_pmtu = fnhe->fnhe_pmtu;
628 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
629 rt->dst.expires = fnhe->fnhe_expires;
630
631 if (fnhe->fnhe_gw) {
632 rt->rt_flags |= RTCF_REDIRECTED;
633 rt->rt_uses_gateway = 1;
634 rt->rt_gw_family = AF_INET;
635 rt->rt_gw4 = fnhe->fnhe_gw;
636 }
637}
638
639static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
640 __be32 gw, u32 pmtu, bool lock,
641 unsigned long expires)
642{
643 struct fnhe_hash_bucket *hash;
644 struct fib_nh_exception *fnhe;
645 struct rtable *rt;
646 u32 genid, hval;
647 unsigned int i;
648 int depth;
649
650 genid = fnhe_genid(dev_net(nhc->nhc_dev));
651 hval = fnhe_hashfun(daddr);
652
653 spin_lock_bh(&fnhe_lock);
654
655 hash = rcu_dereference(nhc->nhc_exceptions);
656 if (!hash) {
657 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
658 if (!hash)
659 goto out_unlock;
660 rcu_assign_pointer(nhc->nhc_exceptions, hash);
661 }
662
663 hash += hval;
664
665 depth = 0;
666 for (fnhe = rcu_dereference(hash->chain); fnhe;
667 fnhe = rcu_dereference(fnhe->fnhe_next)) {
668 if (fnhe->fnhe_daddr == daddr)
669 break;
670 depth++;
671 }
672
673 if (fnhe) {
674 if (fnhe->fnhe_genid != genid)
675 fnhe->fnhe_genid = genid;
676 if (gw)
677 fnhe->fnhe_gw = gw;
678 if (pmtu) {
679 fnhe->fnhe_pmtu = pmtu;
680 fnhe->fnhe_mtu_locked = lock;
681 }
682 fnhe->fnhe_expires = max(1UL, expires);
683 /* Update all cached dsts too */
684 rt = rcu_dereference(fnhe->fnhe_rth_input);
685 if (rt)
686 fill_route_from_fnhe(rt, fnhe);
687 rt = rcu_dereference(fnhe->fnhe_rth_output);
688 if (rt)
689 fill_route_from_fnhe(rt, fnhe);
690 } else {
691 /* Randomize max depth to avoid some side channels attacks. */
692 int max_depth = FNHE_RECLAIM_DEPTH +
693 get_random_u32_below(FNHE_RECLAIM_DEPTH);
694
695 while (depth > max_depth) {
696 fnhe_remove_oldest(hash);
697 depth--;
698 }
699
700 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
701 if (!fnhe)
702 goto out_unlock;
703
704 fnhe->fnhe_next = hash->chain;
705
706 fnhe->fnhe_genid = genid;
707 fnhe->fnhe_daddr = daddr;
708 fnhe->fnhe_gw = gw;
709 fnhe->fnhe_pmtu = pmtu;
710 fnhe->fnhe_mtu_locked = lock;
711 fnhe->fnhe_expires = max(1UL, expires);
712
713 rcu_assign_pointer(hash->chain, fnhe);
714
715 /* Exception created; mark the cached routes for the nexthop
716 * stale, so anyone caching it rechecks if this exception
717 * applies to them.
718 */
719 rt = rcu_dereference(nhc->nhc_rth_input);
720 if (rt)
721 rt->dst.obsolete = DST_OBSOLETE_KILL;
722
723 for_each_possible_cpu(i) {
724 struct rtable __rcu **prt;
725
726 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
727 rt = rcu_dereference(*prt);
728 if (rt)
729 rt->dst.obsolete = DST_OBSOLETE_KILL;
730 }
731 }
732
733 fnhe->fnhe_stamp = jiffies;
734
735out_unlock:
736 spin_unlock_bh(&fnhe_lock);
737}
738
739static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
740 bool kill_route)
741{
742 __be32 new_gw = icmp_hdr(skb)->un.gateway;
743 __be32 old_gw = ip_hdr(skb)->saddr;
744 struct net_device *dev = skb->dev;
745 struct in_device *in_dev;
746 struct fib_result res;
747 struct neighbour *n;
748 struct net *net;
749
750 switch (icmp_hdr(skb)->code & 7) {
751 case ICMP_REDIR_NET:
752 case ICMP_REDIR_NETTOS:
753 case ICMP_REDIR_HOST:
754 case ICMP_REDIR_HOSTTOS:
755 break;
756
757 default:
758 return;
759 }
760
761 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
762 return;
763
764 in_dev = __in_dev_get_rcu(dev);
765 if (!in_dev)
766 return;
767
768 net = dev_net(dev);
769 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
770 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
771 ipv4_is_zeronet(new_gw))
772 goto reject_redirect;
773
774 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
775 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
776 goto reject_redirect;
777 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
778 goto reject_redirect;
779 } else {
780 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
781 goto reject_redirect;
782 }
783
784 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw);
785 if (!n)
786 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
787 if (!IS_ERR(n)) {
788 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) {
789 neigh_event_send(n, NULL);
790 } else {
791 if (fib_lookup(net, fl4, &res, 0) == 0) {
792 struct fib_nh_common *nhc;
793
794 fib_select_path(net, &res, fl4, skb);
795 nhc = FIB_RES_NHC(res);
796 update_or_create_fnhe(nhc, fl4->daddr, new_gw,
797 0, false,
798 jiffies + ip_rt_gc_timeout);
799 }
800 if (kill_route)
801 rt->dst.obsolete = DST_OBSOLETE_KILL;
802 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
803 }
804 neigh_release(n);
805 }
806 return;
807
808reject_redirect:
809#ifdef CONFIG_IP_ROUTE_VERBOSE
810 if (IN_DEV_LOG_MARTIANS(in_dev)) {
811 const struct iphdr *iph = (const struct iphdr *) skb->data;
812 __be32 daddr = iph->daddr;
813 __be32 saddr = iph->saddr;
814
815 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
816 " Advised path = %pI4 -> %pI4\n",
817 &old_gw, dev->name, &new_gw,
818 &saddr, &daddr);
819 }
820#endif
821 ;
822}
823
824static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
825{
826 struct rtable *rt;
827 struct flowi4 fl4;
828 const struct iphdr *iph = (const struct iphdr *) skb->data;
829 struct net *net = dev_net(skb->dev);
830 int oif = skb->dev->ifindex;
831 u8 prot = iph->protocol;
832 u32 mark = skb->mark;
833 __u8 tos = iph->tos;
834
835 rt = dst_rtable(dst);
836
837 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
838 __ip_do_redirect(rt, skb, &fl4, true);
839}
840
841static void ipv4_negative_advice(struct sock *sk,
842 struct dst_entry *dst)
843{
844 struct rtable *rt = dst_rtable(dst);
845
846 if ((dst->obsolete > 0) ||
847 (rt->rt_flags & RTCF_REDIRECTED) ||
848 rt->dst.expires)
849 sk_dst_reset(sk);
850}
851
852/*
853 * Algorithm:
854 * 1. The first ip_rt_redirect_number redirects are sent
855 * with exponential backoff, then we stop sending them at all,
856 * assuming that the host ignores our redirects.
857 * 2. If we did not see packets requiring redirects
858 * during ip_rt_redirect_silence, we assume that the host
859 * forgot redirected route and start to send redirects again.
860 *
861 * This algorithm is much cheaper and more intelligent than dumb load limiting
862 * in icmp.c.
863 *
864 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
865 * and "frag. need" (breaks PMTU discovery) in icmp.c.
866 */
867
868void ip_rt_send_redirect(struct sk_buff *skb)
869{
870 struct rtable *rt = skb_rtable(skb);
871 struct in_device *in_dev;
872 struct inet_peer *peer;
873 struct net *net;
874 int log_martians;
875 int vif;
876
877 rcu_read_lock();
878 in_dev = __in_dev_get_rcu(rt->dst.dev);
879 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
880 rcu_read_unlock();
881 return;
882 }
883 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
884 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
885 rcu_read_unlock();
886
887 net = dev_net(rt->dst.dev);
888 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
889 if (!peer) {
890 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
891 rt_nexthop(rt, ip_hdr(skb)->daddr));
892 return;
893 }
894
895 /* No redirected packets during ip_rt_redirect_silence;
896 * reset the algorithm.
897 */
898 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
899 peer->rate_tokens = 0;
900 peer->n_redirects = 0;
901 }
902
903 /* Too many ignored redirects; do not send anything
904 * set dst.rate_last to the last seen redirected packet.
905 */
906 if (peer->n_redirects >= ip_rt_redirect_number) {
907 peer->rate_last = jiffies;
908 goto out_put_peer;
909 }
910
911 /* Check for load limit; set rate_last to the latest sent
912 * redirect.
913 */
914 if (peer->n_redirects == 0 ||
915 time_after(jiffies,
916 (peer->rate_last +
917 (ip_rt_redirect_load << peer->n_redirects)))) {
918 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
919
920 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
921 peer->rate_last = jiffies;
922 ++peer->n_redirects;
923 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians &&
924 peer->n_redirects == ip_rt_redirect_number)
925 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
926 &ip_hdr(skb)->saddr, inet_iif(skb),
927 &ip_hdr(skb)->daddr, &gw);
928 }
929out_put_peer:
930 inet_putpeer(peer);
931}
932
933static int ip_error(struct sk_buff *skb)
934{
935 struct rtable *rt = skb_rtable(skb);
936 struct net_device *dev = skb->dev;
937 struct in_device *in_dev;
938 struct inet_peer *peer;
939 unsigned long now;
940 struct net *net;
941 SKB_DR(reason);
942 bool send;
943 int code;
944
945 if (netif_is_l3_master(skb->dev)) {
946 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
947 if (!dev)
948 goto out;
949 }
950
951 in_dev = __in_dev_get_rcu(dev);
952
953 /* IP on this device is disabled. */
954 if (!in_dev)
955 goto out;
956
957 net = dev_net(rt->dst.dev);
958 if (!IN_DEV_FORWARD(in_dev)) {
959 switch (rt->dst.error) {
960 case EHOSTUNREACH:
961 SKB_DR_SET(reason, IP_INADDRERRORS);
962 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
963 break;
964
965 case ENETUNREACH:
966 SKB_DR_SET(reason, IP_INNOROUTES);
967 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
968 break;
969 }
970 goto out;
971 }
972
973 switch (rt->dst.error) {
974 case EINVAL:
975 default:
976 goto out;
977 case EHOSTUNREACH:
978 code = ICMP_HOST_UNREACH;
979 break;
980 case ENETUNREACH:
981 code = ICMP_NET_UNREACH;
982 SKB_DR_SET(reason, IP_INNOROUTES);
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_reason(skb, reason);
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 < net->ipv4.ip_rt_min_pmtu) {
1029 lock = true;
1030 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu);
1031 }
1032
1033 if (rt->rt_pmtu == mtu && !lock &&
1034 time_before(jiffies, dst->expires - net->ipv4.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 + net->ipv4.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 = dst_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, iph->tos, protocol, mark,
1074 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 = dst_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(dst_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, iph->tos, protocol, 0, 0);
1163 rt = __ip_route_output_key(net, &fl4);
1164 if (!IS_ERR(rt)) {
1165 __ip_do_redirect(rt, skb, &fl4, false);
1166 ip_rt_put(rt);
1167 }
1168}
1169EXPORT_SYMBOL_GPL(ipv4_redirect);
1170
1171void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1172{
1173 const struct iphdr *iph = (const struct iphdr *)skb->data;
1174 struct flowi4 fl4;
1175 struct rtable *rt;
1176 struct net *net = sock_net(sk);
1177
1178 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1179 rt = __ip_route_output_key(net, &fl4);
1180 if (!IS_ERR(rt)) {
1181 __ip_do_redirect(rt, skb, &fl4, false);
1182 ip_rt_put(rt);
1183 }
1184}
1185EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1186
1187INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
1188 u32 cookie)
1189{
1190 struct rtable *rt = dst_rtable(dst);
1191
1192 /* All IPV4 dsts are created with ->obsolete set to the value
1193 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1194 * into this function always.
1195 *
1196 * When a PMTU/redirect information update invalidates a route,
1197 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1198 * DST_OBSOLETE_DEAD.
1199 */
1200 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1201 return NULL;
1202 return dst;
1203}
1204EXPORT_INDIRECT_CALLABLE(ipv4_dst_check);
1205
1206static void ipv4_send_dest_unreach(struct sk_buff *skb)
1207{
1208 struct net_device *dev;
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 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev;
1227 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL);
1228 rcu_read_unlock();
1229
1230 if (res)
1231 return;
1232 }
1233 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1234}
1235
1236static void ipv4_link_failure(struct sk_buff *skb)
1237{
1238 struct rtable *rt;
1239
1240 ipv4_send_dest_unreach(skb);
1241
1242 rt = skb_rtable(skb);
1243 if (rt)
1244 dst_set_expires(&rt->dst, 0);
1245}
1246
1247static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1248{
1249 pr_debug("%s: %pI4 -> %pI4, %s\n",
1250 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1251 skb->dev ? skb->dev->name : "?");
1252 kfree_skb(skb);
1253 WARN_ON(1);
1254 return 0;
1255}
1256
1257/*
1258 * We do not cache source address of outgoing interface,
1259 * because it is used only by IP RR, TS and SRR options,
1260 * so that it out of fast path.
1261 *
1262 * BTW remember: "addr" is allowed to be not aligned
1263 * in IP options!
1264 */
1265
1266void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1267{
1268 __be32 src;
1269
1270 if (rt_is_output_route(rt))
1271 src = ip_hdr(skb)->saddr;
1272 else {
1273 struct fib_result res;
1274 struct iphdr *iph = ip_hdr(skb);
1275 struct flowi4 fl4 = {
1276 .daddr = iph->daddr,
1277 .saddr = iph->saddr,
1278 .flowi4_tos = RT_TOS(iph->tos),
1279 .flowi4_oif = rt->dst.dev->ifindex,
1280 .flowi4_iif = skb->dev->ifindex,
1281 .flowi4_mark = skb->mark,
1282 };
1283
1284 rcu_read_lock();
1285 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1286 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1287 else
1288 src = inet_select_addr(rt->dst.dev,
1289 rt_nexthop(rt, iph->daddr),
1290 RT_SCOPE_UNIVERSE);
1291 rcu_read_unlock();
1292 }
1293 memcpy(addr, &src, 4);
1294}
1295
1296#ifdef CONFIG_IP_ROUTE_CLASSID
1297static void set_class_tag(struct rtable *rt, u32 tag)
1298{
1299 if (!(rt->dst.tclassid & 0xFFFF))
1300 rt->dst.tclassid |= tag & 0xFFFF;
1301 if (!(rt->dst.tclassid & 0xFFFF0000))
1302 rt->dst.tclassid |= tag & 0xFFFF0000;
1303}
1304#endif
1305
1306static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1307{
1308 struct net *net = dev_net(dst->dev);
1309 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1310 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1311 net->ipv4.ip_rt_min_advmss);
1312
1313 return min(advmss, IPV4_MAX_PMTU - header_size);
1314}
1315
1316INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
1317{
1318 return ip_dst_mtu_maybe_forward(dst, false);
1319}
1320EXPORT_INDIRECT_CALLABLE(ipv4_mtu);
1321
1322static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1323{
1324 struct fnhe_hash_bucket *hash;
1325 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1326 u32 hval = fnhe_hashfun(daddr);
1327
1328 spin_lock_bh(&fnhe_lock);
1329
1330 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1331 lockdep_is_held(&fnhe_lock));
1332 hash += hval;
1333
1334 fnhe_p = &hash->chain;
1335 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1336 while (fnhe) {
1337 if (fnhe->fnhe_daddr == daddr) {
1338 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1339 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1340 /* set fnhe_daddr to 0 to ensure it won't bind with
1341 * new dsts in rt_bind_exception().
1342 */
1343 fnhe->fnhe_daddr = 0;
1344 fnhe_flush_routes(fnhe);
1345 kfree_rcu(fnhe, rcu);
1346 break;
1347 }
1348 fnhe_p = &fnhe->fnhe_next;
1349 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1350 lockdep_is_held(&fnhe_lock));
1351 }
1352
1353 spin_unlock_bh(&fnhe_lock);
1354}
1355
1356static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1357 __be32 daddr)
1358{
1359 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1360 struct fib_nh_exception *fnhe;
1361 u32 hval;
1362
1363 if (!hash)
1364 return NULL;
1365
1366 hval = fnhe_hashfun(daddr);
1367
1368 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1369 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1370 if (fnhe->fnhe_daddr == daddr) {
1371 if (fnhe->fnhe_expires &&
1372 time_after(jiffies, fnhe->fnhe_expires)) {
1373 ip_del_fnhe(nhc, daddr);
1374 break;
1375 }
1376 return fnhe;
1377 }
1378 }
1379 return NULL;
1380}
1381
1382/* MTU selection:
1383 * 1. mtu on route is locked - use it
1384 * 2. mtu from nexthop exception
1385 * 3. mtu from egress device
1386 */
1387
1388u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1389{
1390 struct fib_nh_common *nhc = res->nhc;
1391 struct net_device *dev = nhc->nhc_dev;
1392 struct fib_info *fi = res->fi;
1393 u32 mtu = 0;
1394
1395 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) ||
1396 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1397 mtu = fi->fib_mtu;
1398
1399 if (likely(!mtu)) {
1400 struct fib_nh_exception *fnhe;
1401
1402 fnhe = find_exception(nhc, daddr);
1403 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1404 mtu = fnhe->fnhe_pmtu;
1405 }
1406
1407 if (likely(!mtu))
1408 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1409
1410 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1411}
1412
1413static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1414 __be32 daddr, const bool do_cache)
1415{
1416 bool ret = false;
1417
1418 spin_lock_bh(&fnhe_lock);
1419
1420 if (daddr == fnhe->fnhe_daddr) {
1421 struct rtable __rcu **porig;
1422 struct rtable *orig;
1423 int genid = fnhe_genid(dev_net(rt->dst.dev));
1424
1425 if (rt_is_input_route(rt))
1426 porig = &fnhe->fnhe_rth_input;
1427 else
1428 porig = &fnhe->fnhe_rth_output;
1429 orig = rcu_dereference(*porig);
1430
1431 if (fnhe->fnhe_genid != genid) {
1432 fnhe->fnhe_genid = genid;
1433 fnhe->fnhe_gw = 0;
1434 fnhe->fnhe_pmtu = 0;
1435 fnhe->fnhe_expires = 0;
1436 fnhe->fnhe_mtu_locked = false;
1437 fnhe_flush_routes(fnhe);
1438 orig = NULL;
1439 }
1440 fill_route_from_fnhe(rt, fnhe);
1441 if (!rt->rt_gw4) {
1442 rt->rt_gw4 = daddr;
1443 rt->rt_gw_family = AF_INET;
1444 }
1445
1446 if (do_cache) {
1447 dst_hold(&rt->dst);
1448 rcu_assign_pointer(*porig, rt);
1449 if (orig) {
1450 dst_dev_put(&orig->dst);
1451 dst_release(&orig->dst);
1452 }
1453 ret = true;
1454 }
1455
1456 fnhe->fnhe_stamp = jiffies;
1457 }
1458 spin_unlock_bh(&fnhe_lock);
1459
1460 return ret;
1461}
1462
1463static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1464{
1465 struct rtable *orig, *prev, **p;
1466 bool ret = true;
1467
1468 if (rt_is_input_route(rt)) {
1469 p = (struct rtable **)&nhc->nhc_rth_input;
1470 } else {
1471 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1472 }
1473 orig = *p;
1474
1475 /* hold dst before doing cmpxchg() to avoid race condition
1476 * on this dst
1477 */
1478 dst_hold(&rt->dst);
1479 prev = cmpxchg(p, orig, rt);
1480 if (prev == orig) {
1481 if (orig) {
1482 rt_add_uncached_list(orig);
1483 dst_release(&orig->dst);
1484 }
1485 } else {
1486 dst_release(&rt->dst);
1487 ret = false;
1488 }
1489
1490 return ret;
1491}
1492
1493struct uncached_list {
1494 spinlock_t lock;
1495 struct list_head head;
1496 struct list_head quarantine;
1497};
1498
1499static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1500
1501void rt_add_uncached_list(struct rtable *rt)
1502{
1503 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1504
1505 rt->dst.rt_uncached_list = ul;
1506
1507 spin_lock_bh(&ul->lock);
1508 list_add_tail(&rt->dst.rt_uncached, &ul->head);
1509 spin_unlock_bh(&ul->lock);
1510}
1511
1512void rt_del_uncached_list(struct rtable *rt)
1513{
1514 if (!list_empty(&rt->dst.rt_uncached)) {
1515 struct uncached_list *ul = rt->dst.rt_uncached_list;
1516
1517 spin_lock_bh(&ul->lock);
1518 list_del_init(&rt->dst.rt_uncached);
1519 spin_unlock_bh(&ul->lock);
1520 }
1521}
1522
1523static void ipv4_dst_destroy(struct dst_entry *dst)
1524{
1525 ip_dst_metrics_put(dst);
1526 rt_del_uncached_list(dst_rtable(dst));
1527}
1528
1529void rt_flush_dev(struct net_device *dev)
1530{
1531 struct rtable *rt, *safe;
1532 int cpu;
1533
1534 for_each_possible_cpu(cpu) {
1535 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1536
1537 if (list_empty(&ul->head))
1538 continue;
1539
1540 spin_lock_bh(&ul->lock);
1541 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
1542 if (rt->dst.dev != dev)
1543 continue;
1544 rt->dst.dev = blackhole_netdev;
1545 netdev_ref_replace(dev, blackhole_netdev,
1546 &rt->dst.dev_tracker, GFP_ATOMIC);
1547 list_move(&rt->dst.rt_uncached, &ul->quarantine);
1548 }
1549 spin_unlock_bh(&ul->lock);
1550 }
1551}
1552
1553static bool rt_cache_valid(const struct rtable *rt)
1554{
1555 return rt &&
1556 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1557 !rt_is_expired(rt);
1558}
1559
1560static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1561 const struct fib_result *res,
1562 struct fib_nh_exception *fnhe,
1563 struct fib_info *fi, u16 type, u32 itag,
1564 const bool do_cache)
1565{
1566 bool cached = false;
1567
1568 if (fi) {
1569 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1570
1571 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1572 rt->rt_uses_gateway = 1;
1573 rt->rt_gw_family = nhc->nhc_gw_family;
1574 /* only INET and INET6 are supported */
1575 if (likely(nhc->nhc_gw_family == AF_INET))
1576 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1577 else
1578 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1579 }
1580
1581 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1582
1583#ifdef CONFIG_IP_ROUTE_CLASSID
1584 if (nhc->nhc_family == AF_INET) {
1585 struct fib_nh *nh;
1586
1587 nh = container_of(nhc, struct fib_nh, nh_common);
1588 rt->dst.tclassid = nh->nh_tclassid;
1589 }
1590#endif
1591 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1592 if (unlikely(fnhe))
1593 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1594 else if (do_cache)
1595 cached = rt_cache_route(nhc, rt);
1596 if (unlikely(!cached)) {
1597 /* Routes we intend to cache in nexthop exception or
1598 * FIB nexthop have the DST_NOCACHE bit clear.
1599 * However, if we are unsuccessful at storing this
1600 * route into the cache we really need to set it.
1601 */
1602 if (!rt->rt_gw4) {
1603 rt->rt_gw_family = AF_INET;
1604 rt->rt_gw4 = daddr;
1605 }
1606 rt_add_uncached_list(rt);
1607 }
1608 } else
1609 rt_add_uncached_list(rt);
1610
1611#ifdef CONFIG_IP_ROUTE_CLASSID
1612#ifdef CONFIG_IP_MULTIPLE_TABLES
1613 set_class_tag(rt, res->tclassid);
1614#endif
1615 set_class_tag(rt, itag);
1616#endif
1617}
1618
1619struct rtable *rt_dst_alloc(struct net_device *dev,
1620 unsigned int flags, u16 type,
1621 bool noxfrm)
1622{
1623 struct rtable *rt;
1624
1625 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1626 (noxfrm ? DST_NOXFRM : 0));
1627
1628 if (rt) {
1629 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1630 rt->rt_flags = flags;
1631 rt->rt_type = type;
1632 rt->rt_is_input = 0;
1633 rt->rt_iif = 0;
1634 rt->rt_pmtu = 0;
1635 rt->rt_mtu_locked = 0;
1636 rt->rt_uses_gateway = 0;
1637 rt->rt_gw_family = 0;
1638 rt->rt_gw4 = 0;
1639
1640 rt->dst.output = ip_output;
1641 if (flags & RTCF_LOCAL)
1642 rt->dst.input = ip_local_deliver;
1643 }
1644
1645 return rt;
1646}
1647EXPORT_SYMBOL(rt_dst_alloc);
1648
1649struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1650{
1651 struct rtable *new_rt;
1652
1653 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1654 rt->dst.flags);
1655
1656 if (new_rt) {
1657 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1658 new_rt->rt_flags = rt->rt_flags;
1659 new_rt->rt_type = rt->rt_type;
1660 new_rt->rt_is_input = rt->rt_is_input;
1661 new_rt->rt_iif = rt->rt_iif;
1662 new_rt->rt_pmtu = rt->rt_pmtu;
1663 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1664 new_rt->rt_gw_family = rt->rt_gw_family;
1665 if (rt->rt_gw_family == AF_INET)
1666 new_rt->rt_gw4 = rt->rt_gw4;
1667 else if (rt->rt_gw_family == AF_INET6)
1668 new_rt->rt_gw6 = rt->rt_gw6;
1669
1670 new_rt->dst.input = rt->dst.input;
1671 new_rt->dst.output = rt->dst.output;
1672 new_rt->dst.error = rt->dst.error;
1673 new_rt->dst.lastuse = jiffies;
1674 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1675 }
1676 return new_rt;
1677}
1678EXPORT_SYMBOL(rt_dst_clone);
1679
1680/* called in rcu_read_lock() section */
1681int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1682 u8 tos, struct net_device *dev,
1683 struct in_device *in_dev, u32 *itag)
1684{
1685 int err;
1686
1687 /* Primary sanity checks. */
1688 if (!in_dev)
1689 return -EINVAL;
1690
1691 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1692 skb->protocol != htons(ETH_P_IP))
1693 return -EINVAL;
1694
1695 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1696 return -EINVAL;
1697
1698 if (ipv4_is_zeronet(saddr)) {
1699 if (!ipv4_is_local_multicast(daddr) &&
1700 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1701 return -EINVAL;
1702 } else {
1703 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1704 in_dev, itag);
1705 if (err < 0)
1706 return err;
1707 }
1708 return 0;
1709}
1710
1711/* called in rcu_read_lock() section */
1712static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1713 u8 tos, struct net_device *dev, int our)
1714{
1715 struct in_device *in_dev = __in_dev_get_rcu(dev);
1716 unsigned int flags = RTCF_MULTICAST;
1717 struct rtable *rth;
1718 u32 itag = 0;
1719 int err;
1720
1721 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1722 if (err)
1723 return err;
1724
1725 if (our)
1726 flags |= RTCF_LOCAL;
1727
1728 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1729 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1730
1731 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1732 false);
1733 if (!rth)
1734 return -ENOBUFS;
1735
1736#ifdef CONFIG_IP_ROUTE_CLASSID
1737 rth->dst.tclassid = itag;
1738#endif
1739 rth->dst.output = ip_rt_bug;
1740 rth->rt_is_input= 1;
1741
1742#ifdef CONFIG_IP_MROUTE
1743 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1744 rth->dst.input = ip_mr_input;
1745#endif
1746 RT_CACHE_STAT_INC(in_slow_mc);
1747
1748 skb_dst_drop(skb);
1749 skb_dst_set(skb, &rth->dst);
1750 return 0;
1751}
1752
1753
1754static void ip_handle_martian_source(struct net_device *dev,
1755 struct in_device *in_dev,
1756 struct sk_buff *skb,
1757 __be32 daddr,
1758 __be32 saddr)
1759{
1760 RT_CACHE_STAT_INC(in_martian_src);
1761#ifdef CONFIG_IP_ROUTE_VERBOSE
1762 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1763 /*
1764 * RFC1812 recommendation, if source is martian,
1765 * the only hint is MAC header.
1766 */
1767 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1768 &daddr, &saddr, dev->name);
1769 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1770 print_hex_dump(KERN_WARNING, "ll header: ",
1771 DUMP_PREFIX_OFFSET, 16, 1,
1772 skb_mac_header(skb),
1773 dev->hard_header_len, false);
1774 }
1775 }
1776#endif
1777}
1778
1779/* called in rcu_read_lock() section */
1780static int __mkroute_input(struct sk_buff *skb,
1781 const struct fib_result *res,
1782 struct in_device *in_dev,
1783 __be32 daddr, __be32 saddr, u32 tos)
1784{
1785 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1786 struct net_device *dev = nhc->nhc_dev;
1787 struct fib_nh_exception *fnhe;
1788 struct rtable *rth;
1789 int err;
1790 struct in_device *out_dev;
1791 bool do_cache;
1792 u32 itag = 0;
1793
1794 /* get a working reference to the output device */
1795 out_dev = __in_dev_get_rcu(dev);
1796 if (!out_dev) {
1797 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1798 return -EINVAL;
1799 }
1800
1801 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1802 in_dev->dev, in_dev, &itag);
1803 if (err < 0) {
1804 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1805 saddr);
1806
1807 goto cleanup;
1808 }
1809
1810 do_cache = res->fi && !itag;
1811 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1812 skb->protocol == htons(ETH_P_IP)) {
1813 __be32 gw;
1814
1815 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1816 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1817 inet_addr_onlink(out_dev, saddr, gw))
1818 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1819 }
1820
1821 if (skb->protocol != htons(ETH_P_IP)) {
1822 /* Not IP (i.e. ARP). Do not create route, if it is
1823 * invalid for proxy arp. DNAT routes are always valid.
1824 *
1825 * Proxy arp feature have been extended to allow, ARP
1826 * replies back to the same interface, to support
1827 * Private VLAN switch technologies. See arp.c.
1828 */
1829 if (out_dev == in_dev &&
1830 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1831 err = -EINVAL;
1832 goto cleanup;
1833 }
1834 }
1835
1836 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1837 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1838
1839 fnhe = find_exception(nhc, daddr);
1840 if (do_cache) {
1841 if (fnhe)
1842 rth = rcu_dereference(fnhe->fnhe_rth_input);
1843 else
1844 rth = rcu_dereference(nhc->nhc_rth_input);
1845 if (rt_cache_valid(rth)) {
1846 skb_dst_set_noref(skb, &rth->dst);
1847 goto out;
1848 }
1849 }
1850
1851 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1852 IN_DEV_ORCONF(out_dev, NOXFRM));
1853 if (!rth) {
1854 err = -ENOBUFS;
1855 goto cleanup;
1856 }
1857
1858 rth->rt_is_input = 1;
1859 RT_CACHE_STAT_INC(in_slow_tot);
1860
1861 rth->dst.input = ip_forward;
1862
1863 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1864 do_cache);
1865 lwtunnel_set_redirect(&rth->dst);
1866 skb_dst_set(skb, &rth->dst);
1867out:
1868 err = 0;
1869 cleanup:
1870 return err;
1871}
1872
1873#ifdef CONFIG_IP_ROUTE_MULTIPATH
1874/* To make ICMP packets follow the right flow, the multipath hash is
1875 * calculated from the inner IP addresses.
1876 */
1877static void ip_multipath_l3_keys(const struct sk_buff *skb,
1878 struct flow_keys *hash_keys)
1879{
1880 const struct iphdr *outer_iph = ip_hdr(skb);
1881 const struct iphdr *key_iph = outer_iph;
1882 const struct iphdr *inner_iph;
1883 const struct icmphdr *icmph;
1884 struct iphdr _inner_iph;
1885 struct icmphdr _icmph;
1886
1887 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1888 goto out;
1889
1890 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1891 goto out;
1892
1893 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1894 &_icmph);
1895 if (!icmph)
1896 goto out;
1897
1898 if (!icmp_is_err(icmph->type))
1899 goto out;
1900
1901 inner_iph = skb_header_pointer(skb,
1902 outer_iph->ihl * 4 + sizeof(_icmph),
1903 sizeof(_inner_iph), &_inner_iph);
1904 if (!inner_iph)
1905 goto out;
1906
1907 key_iph = inner_iph;
1908out:
1909 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1910 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1911}
1912
1913static u32 fib_multipath_custom_hash_outer(const struct net *net,
1914 const struct sk_buff *skb,
1915 bool *p_has_inner)
1916{
1917 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1918 struct flow_keys keys, hash_keys;
1919
1920 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
1921 return 0;
1922
1923 memset(&hash_keys, 0, sizeof(hash_keys));
1924 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
1925
1926 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1927 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
1928 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1929 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
1930 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1931 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
1932 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1933 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
1934 hash_keys.ports.src = keys.ports.src;
1935 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
1936 hash_keys.ports.dst = keys.ports.dst;
1937
1938 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
1939 return flow_hash_from_keys(&hash_keys);
1940}
1941
1942static u32 fib_multipath_custom_hash_inner(const struct net *net,
1943 const struct sk_buff *skb,
1944 bool has_inner)
1945{
1946 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1947 struct flow_keys keys, hash_keys;
1948
1949 /* We assume the packet carries an encapsulation, but if none was
1950 * encountered during dissection of the outer flow, then there is no
1951 * point in calling the flow dissector again.
1952 */
1953 if (!has_inner)
1954 return 0;
1955
1956 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
1957 return 0;
1958
1959 memset(&hash_keys, 0, sizeof(hash_keys));
1960 skb_flow_dissect_flow_keys(skb, &keys, 0);
1961
1962 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
1963 return 0;
1964
1965 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1966 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1967 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1968 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1969 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1970 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1971 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1972 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1973 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1974 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1975 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1976 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1977 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
1978 hash_keys.tags.flow_label = keys.tags.flow_label;
1979 }
1980
1981 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
1982 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1983 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
1984 hash_keys.ports.src = keys.ports.src;
1985 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
1986 hash_keys.ports.dst = keys.ports.dst;
1987
1988 return flow_hash_from_keys(&hash_keys);
1989}
1990
1991static u32 fib_multipath_custom_hash_skb(const struct net *net,
1992 const struct sk_buff *skb)
1993{
1994 u32 mhash, mhash_inner;
1995 bool has_inner = true;
1996
1997 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner);
1998 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner);
1999
2000 return jhash_2words(mhash, mhash_inner, 0);
2001}
2002
2003static u32 fib_multipath_custom_hash_fl4(const struct net *net,
2004 const struct flowi4 *fl4)
2005{
2006 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
2007 struct flow_keys hash_keys;
2008
2009 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2010 return 0;
2011
2012 memset(&hash_keys, 0, sizeof(hash_keys));
2013 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2014 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2015 hash_keys.addrs.v4addrs.src = fl4->saddr;
2016 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2017 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2018 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2019 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2020 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2021 hash_keys.ports.src = fl4->fl4_sport;
2022 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2023 hash_keys.ports.dst = fl4->fl4_dport;
2024
2025 return flow_hash_from_keys(&hash_keys);
2026}
2027
2028/* if skb is set it will be used and fl4 can be NULL */
2029int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
2030 const struct sk_buff *skb, struct flow_keys *flkeys)
2031{
2032 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
2033 struct flow_keys hash_keys;
2034 u32 mhash = 0;
2035
2036 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) {
2037 case 0:
2038 memset(&hash_keys, 0, sizeof(hash_keys));
2039 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2040 if (skb) {
2041 ip_multipath_l3_keys(skb, &hash_keys);
2042 } else {
2043 hash_keys.addrs.v4addrs.src = fl4->saddr;
2044 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2045 }
2046 mhash = flow_hash_from_keys(&hash_keys);
2047 break;
2048 case 1:
2049 /* skb is currently provided only when forwarding */
2050 if (skb) {
2051 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2052 struct flow_keys keys;
2053
2054 /* short-circuit if we already have L4 hash present */
2055 if (skb->l4_hash)
2056 return skb_get_hash_raw(skb) >> 1;
2057
2058 memset(&hash_keys, 0, sizeof(hash_keys));
2059
2060 if (!flkeys) {
2061 skb_flow_dissect_flow_keys(skb, &keys, flag);
2062 flkeys = &keys;
2063 }
2064
2065 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2066 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2067 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2068 hash_keys.ports.src = flkeys->ports.src;
2069 hash_keys.ports.dst = flkeys->ports.dst;
2070 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2071 } else {
2072 memset(&hash_keys, 0, sizeof(hash_keys));
2073 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2074 hash_keys.addrs.v4addrs.src = fl4->saddr;
2075 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2076 hash_keys.ports.src = fl4->fl4_sport;
2077 hash_keys.ports.dst = fl4->fl4_dport;
2078 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2079 }
2080 mhash = flow_hash_from_keys(&hash_keys);
2081 break;
2082 case 2:
2083 memset(&hash_keys, 0, sizeof(hash_keys));
2084 /* skb is currently provided only when forwarding */
2085 if (skb) {
2086 struct flow_keys keys;
2087
2088 skb_flow_dissect_flow_keys(skb, &keys, 0);
2089 /* Inner can be v4 or v6 */
2090 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2091 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2092 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2093 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2094 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2095 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2096 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2097 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2098 hash_keys.tags.flow_label = keys.tags.flow_label;
2099 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2100 } else {
2101 /* Same as case 0 */
2102 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2103 ip_multipath_l3_keys(skb, &hash_keys);
2104 }
2105 } else {
2106 /* Same as case 0 */
2107 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2108 hash_keys.addrs.v4addrs.src = fl4->saddr;
2109 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2110 }
2111 mhash = flow_hash_from_keys(&hash_keys);
2112 break;
2113 case 3:
2114 if (skb)
2115 mhash = fib_multipath_custom_hash_skb(net, skb);
2116 else
2117 mhash = fib_multipath_custom_hash_fl4(net, fl4);
2118 break;
2119 }
2120
2121 if (multipath_hash)
2122 mhash = jhash_2words(mhash, multipath_hash, 0);
2123
2124 return mhash >> 1;
2125}
2126#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2127
2128static int ip_mkroute_input(struct sk_buff *skb,
2129 struct fib_result *res,
2130 struct in_device *in_dev,
2131 __be32 daddr, __be32 saddr, u32 tos,
2132 struct flow_keys *hkeys)
2133{
2134#ifdef CONFIG_IP_ROUTE_MULTIPATH
2135 if (res->fi && fib_info_num_path(res->fi) > 1) {
2136 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2137
2138 fib_select_multipath(res, h);
2139 IPCB(skb)->flags |= IPSKB_MULTIPATH;
2140 }
2141#endif
2142
2143 /* create a routing cache entry */
2144 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
2145}
2146
2147/* Implements all the saddr-related checks as ip_route_input_slow(),
2148 * assuming daddr is valid and the destination is not a local broadcast one.
2149 * Uses the provided hint instead of performing a route lookup.
2150 */
2151int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2152 u8 tos, struct net_device *dev,
2153 const struct sk_buff *hint)
2154{
2155 struct in_device *in_dev = __in_dev_get_rcu(dev);
2156 struct rtable *rt = skb_rtable(hint);
2157 struct net *net = dev_net(dev);
2158 int err = -EINVAL;
2159 u32 tag = 0;
2160
2161 if (!in_dev)
2162 return -EINVAL;
2163
2164 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2165 goto martian_source;
2166
2167 if (ipv4_is_zeronet(saddr))
2168 goto martian_source;
2169
2170 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2171 goto martian_source;
2172
2173 if (rt->rt_type != RTN_LOCAL)
2174 goto skip_validate_source;
2175
2176 tos &= IPTOS_RT_MASK;
2177 err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag);
2178 if (err < 0)
2179 goto martian_source;
2180
2181skip_validate_source:
2182 skb_dst_copy(skb, hint);
2183 return 0;
2184
2185martian_source:
2186 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2187 return err;
2188}
2189
2190/* get device for dst_alloc with local routes */
2191static struct net_device *ip_rt_get_dev(struct net *net,
2192 const struct fib_result *res)
2193{
2194 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL;
2195 struct net_device *dev = NULL;
2196
2197 if (nhc)
2198 dev = l3mdev_master_dev_rcu(nhc->nhc_dev);
2199
2200 return dev ? : net->loopback_dev;
2201}
2202
2203/*
2204 * NOTE. We drop all the packets that has local source
2205 * addresses, because every properly looped back packet
2206 * must have correct destination already attached by output routine.
2207 * Changes in the enforced policies must be applied also to
2208 * ip_route_use_hint().
2209 *
2210 * Such approach solves two big problems:
2211 * 1. Not simplex devices are handled properly.
2212 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2213 * called with rcu_read_lock()
2214 */
2215
2216static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2217 u8 tos, struct net_device *dev,
2218 struct fib_result *res)
2219{
2220 struct in_device *in_dev = __in_dev_get_rcu(dev);
2221 struct flow_keys *flkeys = NULL, _flkeys;
2222 struct net *net = dev_net(dev);
2223 struct ip_tunnel_info *tun_info;
2224 int err = -EINVAL;
2225 unsigned int flags = 0;
2226 u32 itag = 0;
2227 struct rtable *rth;
2228 struct flowi4 fl4;
2229 bool do_cache = true;
2230
2231 /* IP on this device is disabled. */
2232
2233 if (!in_dev)
2234 goto out;
2235
2236 /* Check for the most weird martians, which can be not detected
2237 * by fib_lookup.
2238 */
2239
2240 tun_info = skb_tunnel_info(skb);
2241 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2242 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2243 else
2244 fl4.flowi4_tun_key.tun_id = 0;
2245 skb_dst_drop(skb);
2246
2247 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2248 goto martian_source;
2249
2250 res->fi = NULL;
2251 res->table = NULL;
2252 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2253 goto brd_input;
2254
2255 /* Accept zero addresses only to limited broadcast;
2256 * I even do not know to fix it or not. Waiting for complains :-)
2257 */
2258 if (ipv4_is_zeronet(saddr))
2259 goto martian_source;
2260
2261 if (ipv4_is_zeronet(daddr))
2262 goto martian_destination;
2263
2264 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2265 * and call it once if daddr or/and saddr are loopback addresses
2266 */
2267 if (ipv4_is_loopback(daddr)) {
2268 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2269 goto martian_destination;
2270 } else if (ipv4_is_loopback(saddr)) {
2271 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2272 goto martian_source;
2273 }
2274
2275 /*
2276 * Now we are ready to route packet.
2277 */
2278 fl4.flowi4_l3mdev = 0;
2279 fl4.flowi4_oif = 0;
2280 fl4.flowi4_iif = dev->ifindex;
2281 fl4.flowi4_mark = skb->mark;
2282 fl4.flowi4_tos = tos;
2283 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2284 fl4.flowi4_flags = 0;
2285 fl4.daddr = daddr;
2286 fl4.saddr = saddr;
2287 fl4.flowi4_uid = sock_net_uid(net, NULL);
2288 fl4.flowi4_multipath_hash = 0;
2289
2290 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2291 flkeys = &_flkeys;
2292 } else {
2293 fl4.flowi4_proto = 0;
2294 fl4.fl4_sport = 0;
2295 fl4.fl4_dport = 0;
2296 }
2297
2298 err = fib_lookup(net, &fl4, res, 0);
2299 if (err != 0) {
2300 if (!IN_DEV_FORWARD(in_dev))
2301 err = -EHOSTUNREACH;
2302 goto no_route;
2303 }
2304
2305 if (res->type == RTN_BROADCAST) {
2306 if (IN_DEV_BFORWARD(in_dev))
2307 goto make_route;
2308 /* not do cache if bc_forwarding is enabled */
2309 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING))
2310 do_cache = false;
2311 goto brd_input;
2312 }
2313
2314 if (res->type == RTN_LOCAL) {
2315 err = fib_validate_source(skb, saddr, daddr, tos,
2316 0, dev, in_dev, &itag);
2317 if (err < 0)
2318 goto martian_source;
2319 goto local_input;
2320 }
2321
2322 if (!IN_DEV_FORWARD(in_dev)) {
2323 err = -EHOSTUNREACH;
2324 goto no_route;
2325 }
2326 if (res->type != RTN_UNICAST)
2327 goto martian_destination;
2328
2329make_route:
2330 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2331out: return err;
2332
2333brd_input:
2334 if (skb->protocol != htons(ETH_P_IP))
2335 goto e_inval;
2336
2337 if (!ipv4_is_zeronet(saddr)) {
2338 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2339 in_dev, &itag);
2340 if (err < 0)
2341 goto martian_source;
2342 }
2343 flags |= RTCF_BROADCAST;
2344 res->type = RTN_BROADCAST;
2345 RT_CACHE_STAT_INC(in_brd);
2346
2347local_input:
2348 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
2349 IPCB(skb)->flags |= IPSKB_NOPOLICY;
2350
2351 do_cache &= res->fi && !itag;
2352 if (do_cache) {
2353 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2354
2355 rth = rcu_dereference(nhc->nhc_rth_input);
2356 if (rt_cache_valid(rth)) {
2357 skb_dst_set_noref(skb, &rth->dst);
2358 err = 0;
2359 goto out;
2360 }
2361 }
2362
2363 rth = rt_dst_alloc(ip_rt_get_dev(net, res),
2364 flags | RTCF_LOCAL, res->type, false);
2365 if (!rth)
2366 goto e_nobufs;
2367
2368 rth->dst.output= ip_rt_bug;
2369#ifdef CONFIG_IP_ROUTE_CLASSID
2370 rth->dst.tclassid = itag;
2371#endif
2372 rth->rt_is_input = 1;
2373
2374 RT_CACHE_STAT_INC(in_slow_tot);
2375 if (res->type == RTN_UNREACHABLE) {
2376 rth->dst.input= ip_error;
2377 rth->dst.error= -err;
2378 rth->rt_flags &= ~RTCF_LOCAL;
2379 }
2380
2381 if (do_cache) {
2382 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2383
2384 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2385 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2386 WARN_ON(rth->dst.input == lwtunnel_input);
2387 rth->dst.lwtstate->orig_input = rth->dst.input;
2388 rth->dst.input = lwtunnel_input;
2389 }
2390
2391 if (unlikely(!rt_cache_route(nhc, rth)))
2392 rt_add_uncached_list(rth);
2393 }
2394 skb_dst_set(skb, &rth->dst);
2395 err = 0;
2396 goto out;
2397
2398no_route:
2399 RT_CACHE_STAT_INC(in_no_route);
2400 res->type = RTN_UNREACHABLE;
2401 res->fi = NULL;
2402 res->table = NULL;
2403 goto local_input;
2404
2405 /*
2406 * Do not cache martian addresses: they should be logged (RFC1812)
2407 */
2408martian_destination:
2409 RT_CACHE_STAT_INC(in_martian_dst);
2410#ifdef CONFIG_IP_ROUTE_VERBOSE
2411 if (IN_DEV_LOG_MARTIANS(in_dev))
2412 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2413 &daddr, &saddr, dev->name);
2414#endif
2415
2416e_inval:
2417 err = -EINVAL;
2418 goto out;
2419
2420e_nobufs:
2421 err = -ENOBUFS;
2422 goto out;
2423
2424martian_source:
2425 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2426 goto out;
2427}
2428
2429/* called with rcu_read_lock held */
2430static int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2431 u8 tos, struct net_device *dev, struct fib_result *res)
2432{
2433 /* Multicast recognition logic is moved from route cache to here.
2434 * The problem was that too many Ethernet cards have broken/missing
2435 * hardware multicast filters :-( As result the host on multicasting
2436 * network acquires a lot of useless route cache entries, sort of
2437 * SDR messages from all the world. Now we try to get rid of them.
2438 * Really, provided software IP multicast filter is organized
2439 * reasonably (at least, hashed), it does not result in a slowdown
2440 * comparing with route cache reject entries.
2441 * Note, that multicast routers are not affected, because
2442 * route cache entry is created eventually.
2443 */
2444 if (ipv4_is_multicast(daddr)) {
2445 struct in_device *in_dev = __in_dev_get_rcu(dev);
2446 int our = 0;
2447 int err = -EINVAL;
2448
2449 if (!in_dev)
2450 return err;
2451 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2452 ip_hdr(skb)->protocol);
2453
2454 /* check l3 master if no match yet */
2455 if (!our && netif_is_l3_slave(dev)) {
2456 struct in_device *l3_in_dev;
2457
2458 l3_in_dev = __in_dev_get_rcu(skb->dev);
2459 if (l3_in_dev)
2460 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2461 ip_hdr(skb)->protocol);
2462 }
2463
2464 if (our
2465#ifdef CONFIG_IP_MROUTE
2466 ||
2467 (!ipv4_is_local_multicast(daddr) &&
2468 IN_DEV_MFORWARD(in_dev))
2469#endif
2470 ) {
2471 err = ip_route_input_mc(skb, daddr, saddr,
2472 tos, dev, our);
2473 }
2474 return err;
2475 }
2476
2477 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2478}
2479
2480int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2481 u8 tos, struct net_device *dev)
2482{
2483 struct fib_result res;
2484 int err;
2485
2486 tos &= IPTOS_RT_MASK;
2487 rcu_read_lock();
2488 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2489 rcu_read_unlock();
2490
2491 return err;
2492}
2493EXPORT_SYMBOL(ip_route_input_noref);
2494
2495/* called with rcu_read_lock() */
2496static struct rtable *__mkroute_output(const struct fib_result *res,
2497 const struct flowi4 *fl4, int orig_oif,
2498 struct net_device *dev_out,
2499 unsigned int flags)
2500{
2501 struct fib_info *fi = res->fi;
2502 struct fib_nh_exception *fnhe;
2503 struct in_device *in_dev;
2504 u16 type = res->type;
2505 struct rtable *rth;
2506 bool do_cache;
2507
2508 in_dev = __in_dev_get_rcu(dev_out);
2509 if (!in_dev)
2510 return ERR_PTR(-EINVAL);
2511
2512 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2513 if (ipv4_is_loopback(fl4->saddr) &&
2514 !(dev_out->flags & IFF_LOOPBACK) &&
2515 !netif_is_l3_master(dev_out))
2516 return ERR_PTR(-EINVAL);
2517
2518 if (ipv4_is_lbcast(fl4->daddr))
2519 type = RTN_BROADCAST;
2520 else if (ipv4_is_multicast(fl4->daddr))
2521 type = RTN_MULTICAST;
2522 else if (ipv4_is_zeronet(fl4->daddr))
2523 return ERR_PTR(-EINVAL);
2524
2525 if (dev_out->flags & IFF_LOOPBACK)
2526 flags |= RTCF_LOCAL;
2527
2528 do_cache = true;
2529 if (type == RTN_BROADCAST) {
2530 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2531 fi = NULL;
2532 } else if (type == RTN_MULTICAST) {
2533 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2534 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2535 fl4->flowi4_proto))
2536 flags &= ~RTCF_LOCAL;
2537 else
2538 do_cache = false;
2539 /* If multicast route do not exist use
2540 * default one, but do not gateway in this case.
2541 * Yes, it is hack.
2542 */
2543 if (fi && res->prefixlen < 4)
2544 fi = NULL;
2545 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2546 (orig_oif != dev_out->ifindex)) {
2547 /* For local routes that require a particular output interface
2548 * we do not want to cache the result. Caching the result
2549 * causes incorrect behaviour when there are multiple source
2550 * addresses on the interface, the end result being that if the
2551 * intended recipient is waiting on that interface for the
2552 * packet he won't receive it because it will be delivered on
2553 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2554 * be set to the loopback interface as well.
2555 */
2556 do_cache = false;
2557 }
2558
2559 fnhe = NULL;
2560 do_cache &= fi != NULL;
2561 if (fi) {
2562 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2563 struct rtable __rcu **prth;
2564
2565 fnhe = find_exception(nhc, fl4->daddr);
2566 if (!do_cache)
2567 goto add;
2568 if (fnhe) {
2569 prth = &fnhe->fnhe_rth_output;
2570 } else {
2571 if (unlikely(fl4->flowi4_flags &
2572 FLOWI_FLAG_KNOWN_NH &&
2573 !(nhc->nhc_gw_family &&
2574 nhc->nhc_scope == RT_SCOPE_LINK))) {
2575 do_cache = false;
2576 goto add;
2577 }
2578 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2579 }
2580 rth = rcu_dereference(*prth);
2581 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2582 return rth;
2583 }
2584
2585add:
2586 rth = rt_dst_alloc(dev_out, flags, type,
2587 IN_DEV_ORCONF(in_dev, NOXFRM));
2588 if (!rth)
2589 return ERR_PTR(-ENOBUFS);
2590
2591 rth->rt_iif = orig_oif;
2592
2593 RT_CACHE_STAT_INC(out_slow_tot);
2594
2595 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2596 if (flags & RTCF_LOCAL &&
2597 !(dev_out->flags & IFF_LOOPBACK)) {
2598 rth->dst.output = ip_mc_output;
2599 RT_CACHE_STAT_INC(out_slow_mc);
2600 }
2601#ifdef CONFIG_IP_MROUTE
2602 if (type == RTN_MULTICAST) {
2603 if (IN_DEV_MFORWARD(in_dev) &&
2604 !ipv4_is_local_multicast(fl4->daddr)) {
2605 rth->dst.input = ip_mr_input;
2606 rth->dst.output = ip_mc_output;
2607 }
2608 }
2609#endif
2610 }
2611
2612 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2613 lwtunnel_set_redirect(&rth->dst);
2614
2615 return rth;
2616}
2617
2618/*
2619 * Major route resolver routine.
2620 */
2621
2622struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2623 const struct sk_buff *skb)
2624{
2625 struct fib_result res = {
2626 .type = RTN_UNSPEC,
2627 .fi = NULL,
2628 .table = NULL,
2629 .tclassid = 0,
2630 };
2631 struct rtable *rth;
2632
2633 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2634 ip_rt_fix_tos(fl4);
2635
2636 rcu_read_lock();
2637 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2638 rcu_read_unlock();
2639
2640 return rth;
2641}
2642EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2643
2644struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2645 struct fib_result *res,
2646 const struct sk_buff *skb)
2647{
2648 struct net_device *dev_out = NULL;
2649 int orig_oif = fl4->flowi4_oif;
2650 unsigned int flags = 0;
2651 struct rtable *rth;
2652 int err;
2653
2654 if (fl4->saddr) {
2655 if (ipv4_is_multicast(fl4->saddr) ||
2656 ipv4_is_lbcast(fl4->saddr) ||
2657 ipv4_is_zeronet(fl4->saddr)) {
2658 rth = ERR_PTR(-EINVAL);
2659 goto out;
2660 }
2661
2662 rth = ERR_PTR(-ENETUNREACH);
2663
2664 /* I removed check for oif == dev_out->oif here.
2665 * It was wrong for two reasons:
2666 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2667 * is assigned to multiple interfaces.
2668 * 2. Moreover, we are allowed to send packets with saddr
2669 * of another iface. --ANK
2670 */
2671
2672 if (fl4->flowi4_oif == 0 &&
2673 (ipv4_is_multicast(fl4->daddr) ||
2674 ipv4_is_lbcast(fl4->daddr))) {
2675 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2676 dev_out = __ip_dev_find(net, fl4->saddr, false);
2677 if (!dev_out)
2678 goto out;
2679
2680 /* Special hack: user can direct multicasts
2681 * and limited broadcast via necessary interface
2682 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2683 * This hack is not just for fun, it allows
2684 * vic,vat and friends to work.
2685 * They bind socket to loopback, set ttl to zero
2686 * and expect that it will work.
2687 * From the viewpoint of routing cache they are broken,
2688 * because we are not allowed to build multicast path
2689 * with loopback source addr (look, routing cache
2690 * cannot know, that ttl is zero, so that packet
2691 * will not leave this host and route is valid).
2692 * Luckily, this hack is good workaround.
2693 */
2694
2695 fl4->flowi4_oif = dev_out->ifindex;
2696 goto make_route;
2697 }
2698
2699 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2700 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2701 if (!__ip_dev_find(net, fl4->saddr, false))
2702 goto out;
2703 }
2704 }
2705
2706
2707 if (fl4->flowi4_oif) {
2708 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2709 rth = ERR_PTR(-ENODEV);
2710 if (!dev_out)
2711 goto out;
2712
2713 /* RACE: Check return value of inet_select_addr instead. */
2714 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2715 rth = ERR_PTR(-ENETUNREACH);
2716 goto out;
2717 }
2718 if (ipv4_is_local_multicast(fl4->daddr) ||
2719 ipv4_is_lbcast(fl4->daddr) ||
2720 fl4->flowi4_proto == IPPROTO_IGMP) {
2721 if (!fl4->saddr)
2722 fl4->saddr = inet_select_addr(dev_out, 0,
2723 RT_SCOPE_LINK);
2724 goto make_route;
2725 }
2726 if (!fl4->saddr) {
2727 if (ipv4_is_multicast(fl4->daddr))
2728 fl4->saddr = inet_select_addr(dev_out, 0,
2729 fl4->flowi4_scope);
2730 else if (!fl4->daddr)
2731 fl4->saddr = inet_select_addr(dev_out, 0,
2732 RT_SCOPE_HOST);
2733 }
2734 }
2735
2736 if (!fl4->daddr) {
2737 fl4->daddr = fl4->saddr;
2738 if (!fl4->daddr)
2739 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2740 dev_out = net->loopback_dev;
2741 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2742 res->type = RTN_LOCAL;
2743 flags |= RTCF_LOCAL;
2744 goto make_route;
2745 }
2746
2747 err = fib_lookup(net, fl4, res, 0);
2748 if (err) {
2749 res->fi = NULL;
2750 res->table = NULL;
2751 if (fl4->flowi4_oif &&
2752 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) {
2753 /* Apparently, routing tables are wrong. Assume,
2754 * that the destination is on link.
2755 *
2756 * WHY? DW.
2757 * Because we are allowed to send to iface
2758 * even if it has NO routes and NO assigned
2759 * addresses. When oif is specified, routing
2760 * tables are looked up with only one purpose:
2761 * to catch if destination is gatewayed, rather than
2762 * direct. Moreover, if MSG_DONTROUTE is set,
2763 * we send packet, ignoring both routing tables
2764 * and ifaddr state. --ANK
2765 *
2766 *
2767 * We could make it even if oif is unknown,
2768 * likely IPv6, but we do not.
2769 */
2770
2771 if (fl4->saddr == 0)
2772 fl4->saddr = inet_select_addr(dev_out, 0,
2773 RT_SCOPE_LINK);
2774 res->type = RTN_UNICAST;
2775 goto make_route;
2776 }
2777 rth = ERR_PTR(err);
2778 goto out;
2779 }
2780
2781 if (res->type == RTN_LOCAL) {
2782 if (!fl4->saddr) {
2783 if (res->fi->fib_prefsrc)
2784 fl4->saddr = res->fi->fib_prefsrc;
2785 else
2786 fl4->saddr = fl4->daddr;
2787 }
2788
2789 /* L3 master device is the loopback for that domain */
2790 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2791 net->loopback_dev;
2792
2793 /* make sure orig_oif points to fib result device even
2794 * though packet rx/tx happens over loopback or l3mdev
2795 */
2796 orig_oif = FIB_RES_OIF(*res);
2797
2798 fl4->flowi4_oif = dev_out->ifindex;
2799 flags |= RTCF_LOCAL;
2800 goto make_route;
2801 }
2802
2803 fib_select_path(net, res, fl4, skb);
2804
2805 dev_out = FIB_RES_DEV(*res);
2806
2807make_route:
2808 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2809
2810out:
2811 return rth;
2812}
2813
2814static struct dst_ops ipv4_dst_blackhole_ops = {
2815 .family = AF_INET,
2816 .default_advmss = ipv4_default_advmss,
2817 .neigh_lookup = ipv4_neigh_lookup,
2818 .check = dst_blackhole_check,
2819 .cow_metrics = dst_blackhole_cow_metrics,
2820 .update_pmtu = dst_blackhole_update_pmtu,
2821 .redirect = dst_blackhole_redirect,
2822 .mtu = dst_blackhole_mtu,
2823};
2824
2825struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2826{
2827 struct rtable *ort = dst_rtable(dst_orig);
2828 struct rtable *rt;
2829
2830 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0);
2831 if (rt) {
2832 struct dst_entry *new = &rt->dst;
2833
2834 new->__use = 1;
2835 new->input = dst_discard;
2836 new->output = dst_discard_out;
2837
2838 new->dev = net->loopback_dev;
2839 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC);
2840
2841 rt->rt_is_input = ort->rt_is_input;
2842 rt->rt_iif = ort->rt_iif;
2843 rt->rt_pmtu = ort->rt_pmtu;
2844 rt->rt_mtu_locked = ort->rt_mtu_locked;
2845
2846 rt->rt_genid = rt_genid_ipv4(net);
2847 rt->rt_flags = ort->rt_flags;
2848 rt->rt_type = ort->rt_type;
2849 rt->rt_uses_gateway = ort->rt_uses_gateway;
2850 rt->rt_gw_family = ort->rt_gw_family;
2851 if (rt->rt_gw_family == AF_INET)
2852 rt->rt_gw4 = ort->rt_gw4;
2853 else if (rt->rt_gw_family == AF_INET6)
2854 rt->rt_gw6 = ort->rt_gw6;
2855 }
2856
2857 dst_release(dst_orig);
2858
2859 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2860}
2861
2862struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2863 const struct sock *sk)
2864{
2865 struct rtable *rt = __ip_route_output_key(net, flp4);
2866
2867 if (IS_ERR(rt))
2868 return rt;
2869
2870 if (flp4->flowi4_proto) {
2871 flp4->flowi4_oif = rt->dst.dev->ifindex;
2872 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst,
2873 flowi4_to_flowi(flp4),
2874 sk, 0));
2875 }
2876
2877 return rt;
2878}
2879EXPORT_SYMBOL_GPL(ip_route_output_flow);
2880
2881/* called with rcu_read_lock held */
2882static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2883 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2884 struct sk_buff *skb, u32 portid, u32 seq,
2885 unsigned int flags)
2886{
2887 struct rtmsg *r;
2888 struct nlmsghdr *nlh;
2889 unsigned long expires = 0;
2890 u32 error;
2891 u32 metrics[RTAX_MAX];
2892
2893 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2894 if (!nlh)
2895 return -EMSGSIZE;
2896
2897 r = nlmsg_data(nlh);
2898 r->rtm_family = AF_INET;
2899 r->rtm_dst_len = 32;
2900 r->rtm_src_len = 0;
2901 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0;
2902 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2903 if (nla_put_u32(skb, RTA_TABLE, table_id))
2904 goto nla_put_failure;
2905 r->rtm_type = rt->rt_type;
2906 r->rtm_scope = RT_SCOPE_UNIVERSE;
2907 r->rtm_protocol = RTPROT_UNSPEC;
2908 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2909 if (rt->rt_flags & RTCF_NOTIFY)
2910 r->rtm_flags |= RTM_F_NOTIFY;
2911 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2912 r->rtm_flags |= RTCF_DOREDIRECT;
2913
2914 if (nla_put_in_addr(skb, RTA_DST, dst))
2915 goto nla_put_failure;
2916 if (src) {
2917 r->rtm_src_len = 32;
2918 if (nla_put_in_addr(skb, RTA_SRC, src))
2919 goto nla_put_failure;
2920 }
2921 if (rt->dst.dev &&
2922 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2923 goto nla_put_failure;
2924 if (rt->dst.lwtstate &&
2925 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
2926 goto nla_put_failure;
2927#ifdef CONFIG_IP_ROUTE_CLASSID
2928 if (rt->dst.tclassid &&
2929 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2930 goto nla_put_failure;
2931#endif
2932 if (fl4 && !rt_is_input_route(rt) &&
2933 fl4->saddr != src) {
2934 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2935 goto nla_put_failure;
2936 }
2937 if (rt->rt_uses_gateway) {
2938 if (rt->rt_gw_family == AF_INET &&
2939 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
2940 goto nla_put_failure;
2941 } else if (rt->rt_gw_family == AF_INET6) {
2942 int alen = sizeof(struct in6_addr);
2943 struct nlattr *nla;
2944 struct rtvia *via;
2945
2946 nla = nla_reserve(skb, RTA_VIA, alen + 2);
2947 if (!nla)
2948 goto nla_put_failure;
2949
2950 via = nla_data(nla);
2951 via->rtvia_family = AF_INET6;
2952 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
2953 }
2954 }
2955
2956 expires = rt->dst.expires;
2957 if (expires) {
2958 unsigned long now = jiffies;
2959
2960 if (time_before(now, expires))
2961 expires -= now;
2962 else
2963 expires = 0;
2964 }
2965
2966 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2967 if (rt->rt_pmtu && expires)
2968 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2969 if (rt->rt_mtu_locked && expires)
2970 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2971 if (rtnetlink_put_metrics(skb, metrics) < 0)
2972 goto nla_put_failure;
2973
2974 if (fl4) {
2975 if (fl4->flowi4_mark &&
2976 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2977 goto nla_put_failure;
2978
2979 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2980 nla_put_u32(skb, RTA_UID,
2981 from_kuid_munged(current_user_ns(),
2982 fl4->flowi4_uid)))
2983 goto nla_put_failure;
2984
2985 if (rt_is_input_route(rt)) {
2986#ifdef CONFIG_IP_MROUTE
2987 if (ipv4_is_multicast(dst) &&
2988 !ipv4_is_local_multicast(dst) &&
2989 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) {
2990 int err = ipmr_get_route(net, skb,
2991 fl4->saddr, fl4->daddr,
2992 r, portid);
2993
2994 if (err <= 0) {
2995 if (err == 0)
2996 return 0;
2997 goto nla_put_failure;
2998 }
2999 } else
3000#endif
3001 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
3002 goto nla_put_failure;
3003 }
3004 }
3005
3006 error = rt->dst.error;
3007
3008 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
3009 goto nla_put_failure;
3010
3011 nlmsg_end(skb, nlh);
3012 return 0;
3013
3014nla_put_failure:
3015 nlmsg_cancel(skb, nlh);
3016 return -EMSGSIZE;
3017}
3018
3019static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
3020 struct netlink_callback *cb, u32 table_id,
3021 struct fnhe_hash_bucket *bucket, int genid,
3022 int *fa_index, int fa_start, unsigned int flags)
3023{
3024 int i;
3025
3026 for (i = 0; i < FNHE_HASH_SIZE; i++) {
3027 struct fib_nh_exception *fnhe;
3028
3029 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
3030 fnhe = rcu_dereference(fnhe->fnhe_next)) {
3031 struct rtable *rt;
3032 int err;
3033
3034 if (*fa_index < fa_start)
3035 goto next;
3036
3037 if (fnhe->fnhe_genid != genid)
3038 goto next;
3039
3040 if (fnhe->fnhe_expires &&
3041 time_after(jiffies, fnhe->fnhe_expires))
3042 goto next;
3043
3044 rt = rcu_dereference(fnhe->fnhe_rth_input);
3045 if (!rt)
3046 rt = rcu_dereference(fnhe->fnhe_rth_output);
3047 if (!rt)
3048 goto next;
3049
3050 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
3051 table_id, NULL, skb,
3052 NETLINK_CB(cb->skb).portid,
3053 cb->nlh->nlmsg_seq, flags);
3054 if (err)
3055 return err;
3056next:
3057 (*fa_index)++;
3058 }
3059 }
3060
3061 return 0;
3062}
3063
3064int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
3065 u32 table_id, struct fib_info *fi,
3066 int *fa_index, int fa_start, unsigned int flags)
3067{
3068 struct net *net = sock_net(cb->skb->sk);
3069 int nhsel, genid = fnhe_genid(net);
3070
3071 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
3072 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
3073 struct fnhe_hash_bucket *bucket;
3074 int err;
3075
3076 if (nhc->nhc_flags & RTNH_F_DEAD)
3077 continue;
3078
3079 rcu_read_lock();
3080 bucket = rcu_dereference(nhc->nhc_exceptions);
3081 err = 0;
3082 if (bucket)
3083 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
3084 genid, fa_index, fa_start,
3085 flags);
3086 rcu_read_unlock();
3087 if (err)
3088 return err;
3089 }
3090
3091 return 0;
3092}
3093
3094static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
3095 u8 ip_proto, __be16 sport,
3096 __be16 dport)
3097{
3098 struct sk_buff *skb;
3099 struct iphdr *iph;
3100
3101 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3102 if (!skb)
3103 return NULL;
3104
3105 /* Reserve room for dummy headers, this skb can pass
3106 * through good chunk of routing engine.
3107 */
3108 skb_reset_mac_header(skb);
3109 skb_reset_network_header(skb);
3110 skb->protocol = htons(ETH_P_IP);
3111 iph = skb_put(skb, sizeof(struct iphdr));
3112 iph->protocol = ip_proto;
3113 iph->saddr = src;
3114 iph->daddr = dst;
3115 iph->version = 0x4;
3116 iph->frag_off = 0;
3117 iph->ihl = 0x5;
3118 skb_set_transport_header(skb, skb->len);
3119
3120 switch (iph->protocol) {
3121 case IPPROTO_UDP: {
3122 struct udphdr *udph;
3123
3124 udph = skb_put_zero(skb, sizeof(struct udphdr));
3125 udph->source = sport;
3126 udph->dest = dport;
3127 udph->len = htons(sizeof(struct udphdr));
3128 udph->check = 0;
3129 break;
3130 }
3131 case IPPROTO_TCP: {
3132 struct tcphdr *tcph;
3133
3134 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
3135 tcph->source = sport;
3136 tcph->dest = dport;
3137 tcph->doff = sizeof(struct tcphdr) / 4;
3138 tcph->rst = 1;
3139 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
3140 src, dst, 0);
3141 break;
3142 }
3143 case IPPROTO_ICMP: {
3144 struct icmphdr *icmph;
3145
3146 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
3147 icmph->type = ICMP_ECHO;
3148 icmph->code = 0;
3149 }
3150 }
3151
3152 return skb;
3153}
3154
3155static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3156 const struct nlmsghdr *nlh,
3157 struct nlattr **tb,
3158 struct netlink_ext_ack *extack)
3159{
3160 struct rtmsg *rtm;
3161 int i, err;
3162
3163 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3164 NL_SET_ERR_MSG(extack,
3165 "ipv4: Invalid header for route get request");
3166 return -EINVAL;
3167 }
3168
3169 if (!netlink_strict_get_check(skb))
3170 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3171 rtm_ipv4_policy, extack);
3172
3173 rtm = nlmsg_data(nlh);
3174 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3175 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3176 rtm->rtm_table || rtm->rtm_protocol ||
3177 rtm->rtm_scope || rtm->rtm_type) {
3178 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3179 return -EINVAL;
3180 }
3181
3182 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3183 RTM_F_LOOKUP_TABLE |
3184 RTM_F_FIB_MATCH)) {
3185 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3186 return -EINVAL;
3187 }
3188
3189 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3190 rtm_ipv4_policy, extack);
3191 if (err)
3192 return err;
3193
3194 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3195 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3196 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3197 return -EINVAL;
3198 }
3199
3200 for (i = 0; i <= RTA_MAX; i++) {
3201 if (!tb[i])
3202 continue;
3203
3204 switch (i) {
3205 case RTA_IIF:
3206 case RTA_OIF:
3207 case RTA_SRC:
3208 case RTA_DST:
3209 case RTA_IP_PROTO:
3210 case RTA_SPORT:
3211 case RTA_DPORT:
3212 case RTA_MARK:
3213 case RTA_UID:
3214 break;
3215 default:
3216 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3217 return -EINVAL;
3218 }
3219 }
3220
3221 return 0;
3222}
3223
3224static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3225 struct netlink_ext_ack *extack)
3226{
3227 struct net *net = sock_net(in_skb->sk);
3228 struct nlattr *tb[RTA_MAX+1];
3229 u32 table_id = RT_TABLE_MAIN;
3230 __be16 sport = 0, dport = 0;
3231 struct fib_result res = {};
3232 u8 ip_proto = IPPROTO_UDP;
3233 struct rtable *rt = NULL;
3234 struct sk_buff *skb;
3235 struct rtmsg *rtm;
3236 struct flowi4 fl4 = {};
3237 __be32 dst = 0;
3238 __be32 src = 0;
3239 kuid_t uid;
3240 u32 iif;
3241 int err;
3242 int mark;
3243
3244 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3245 if (err < 0)
3246 return err;
3247
3248 rtm = nlmsg_data(nlh);
3249 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
3250 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
3251 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3252 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3253 if (tb[RTA_UID])
3254 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3255 else
3256 uid = (iif ? INVALID_UID : current_uid());
3257
3258 if (tb[RTA_IP_PROTO]) {
3259 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3260 &ip_proto, AF_INET, extack);
3261 if (err)
3262 return err;
3263 }
3264
3265 if (tb[RTA_SPORT])
3266 sport = nla_get_be16(tb[RTA_SPORT]);
3267
3268 if (tb[RTA_DPORT])
3269 dport = nla_get_be16(tb[RTA_DPORT]);
3270
3271 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3272 if (!skb)
3273 return -ENOBUFS;
3274
3275 fl4.daddr = dst;
3276 fl4.saddr = src;
3277 fl4.flowi4_tos = rtm->rtm_tos & IPTOS_RT_MASK;
3278 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
3279 fl4.flowi4_mark = mark;
3280 fl4.flowi4_uid = uid;
3281 if (sport)
3282 fl4.fl4_sport = sport;
3283 if (dport)
3284 fl4.fl4_dport = dport;
3285 fl4.flowi4_proto = ip_proto;
3286
3287 rcu_read_lock();
3288
3289 if (iif) {
3290 struct net_device *dev;
3291
3292 dev = dev_get_by_index_rcu(net, iif);
3293 if (!dev) {
3294 err = -ENODEV;
3295 goto errout_rcu;
3296 }
3297
3298 fl4.flowi4_iif = iif; /* for rt_fill_info */
3299 skb->dev = dev;
3300 skb->mark = mark;
3301 err = ip_route_input_rcu(skb, dst, src,
3302 rtm->rtm_tos & IPTOS_RT_MASK, dev,
3303 &res);
3304
3305 rt = skb_rtable(skb);
3306 if (err == 0 && rt->dst.error)
3307 err = -rt->dst.error;
3308 } else {
3309 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3310 skb->dev = net->loopback_dev;
3311 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3312 err = 0;
3313 if (IS_ERR(rt))
3314 err = PTR_ERR(rt);
3315 else
3316 skb_dst_set(skb, &rt->dst);
3317 }
3318
3319 if (err)
3320 goto errout_rcu;
3321
3322 if (rtm->rtm_flags & RTM_F_NOTIFY)
3323 rt->rt_flags |= RTCF_NOTIFY;
3324
3325 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3326 table_id = res.table ? res.table->tb_id : 0;
3327
3328 /* reset skb for netlink reply msg */
3329 skb_trim(skb, 0);
3330 skb_reset_network_header(skb);
3331 skb_reset_transport_header(skb);
3332 skb_reset_mac_header(skb);
3333
3334 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3335 struct fib_rt_info fri;
3336
3337 if (!res.fi) {
3338 err = fib_props[res.type].error;
3339 if (!err)
3340 err = -EHOSTUNREACH;
3341 goto errout_rcu;
3342 }
3343 fri.fi = res.fi;
3344 fri.tb_id = table_id;
3345 fri.dst = res.prefix;
3346 fri.dst_len = res.prefixlen;
3347 fri.dscp = inet_dsfield_to_dscp(fl4.flowi4_tos);
3348 fri.type = rt->rt_type;
3349 fri.offload = 0;
3350 fri.trap = 0;
3351 fri.offload_failed = 0;
3352 if (res.fa_head) {
3353 struct fib_alias *fa;
3354
3355 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) {
3356 u8 slen = 32 - fri.dst_len;
3357
3358 if (fa->fa_slen == slen &&
3359 fa->tb_id == fri.tb_id &&
3360 fa->fa_dscp == fri.dscp &&
3361 fa->fa_info == res.fi &&
3362 fa->fa_type == fri.type) {
3363 fri.offload = READ_ONCE(fa->offload);
3364 fri.trap = READ_ONCE(fa->trap);
3365 fri.offload_failed =
3366 READ_ONCE(fa->offload_failed);
3367 break;
3368 }
3369 }
3370 }
3371 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3372 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0);
3373 } else {
3374 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
3375 NETLINK_CB(in_skb).portid,
3376 nlh->nlmsg_seq, 0);
3377 }
3378 if (err < 0)
3379 goto errout_rcu;
3380
3381 rcu_read_unlock();
3382
3383 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3384
3385errout_free:
3386 return err;
3387errout_rcu:
3388 rcu_read_unlock();
3389 kfree_skb(skb);
3390 goto errout_free;
3391}
3392
3393void ip_rt_multicast_event(struct in_device *in_dev)
3394{
3395 rt_cache_flush(dev_net(in_dev->dev));
3396}
3397
3398#ifdef CONFIG_SYSCTL
3399static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3400static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3401static int ip_rt_gc_elasticity __read_mostly = 8;
3402static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3403
3404static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
3405 void *buffer, size_t *lenp, loff_t *ppos)
3406{
3407 struct net *net = (struct net *)__ctl->extra1;
3408
3409 if (write) {
3410 rt_cache_flush(net);
3411 fnhe_genid_bump(net);
3412 return 0;
3413 }
3414
3415 return -EINVAL;
3416}
3417
3418static struct ctl_table ipv4_route_table[] = {
3419 {
3420 .procname = "gc_thresh",
3421 .data = &ipv4_dst_ops.gc_thresh,
3422 .maxlen = sizeof(int),
3423 .mode = 0644,
3424 .proc_handler = proc_dointvec,
3425 },
3426 {
3427 .procname = "max_size",
3428 .data = &ip_rt_max_size,
3429 .maxlen = sizeof(int),
3430 .mode = 0644,
3431 .proc_handler = proc_dointvec,
3432 },
3433 {
3434 /* Deprecated. Use gc_min_interval_ms */
3435
3436 .procname = "gc_min_interval",
3437 .data = &ip_rt_gc_min_interval,
3438 .maxlen = sizeof(int),
3439 .mode = 0644,
3440 .proc_handler = proc_dointvec_jiffies,
3441 },
3442 {
3443 .procname = "gc_min_interval_ms",
3444 .data = &ip_rt_gc_min_interval,
3445 .maxlen = sizeof(int),
3446 .mode = 0644,
3447 .proc_handler = proc_dointvec_ms_jiffies,
3448 },
3449 {
3450 .procname = "gc_timeout",
3451 .data = &ip_rt_gc_timeout,
3452 .maxlen = sizeof(int),
3453 .mode = 0644,
3454 .proc_handler = proc_dointvec_jiffies,
3455 },
3456 {
3457 .procname = "gc_interval",
3458 .data = &ip_rt_gc_interval,
3459 .maxlen = sizeof(int),
3460 .mode = 0644,
3461 .proc_handler = proc_dointvec_jiffies,
3462 },
3463 {
3464 .procname = "redirect_load",
3465 .data = &ip_rt_redirect_load,
3466 .maxlen = sizeof(int),
3467 .mode = 0644,
3468 .proc_handler = proc_dointvec,
3469 },
3470 {
3471 .procname = "redirect_number",
3472 .data = &ip_rt_redirect_number,
3473 .maxlen = sizeof(int),
3474 .mode = 0644,
3475 .proc_handler = proc_dointvec,
3476 },
3477 {
3478 .procname = "redirect_silence",
3479 .data = &ip_rt_redirect_silence,
3480 .maxlen = sizeof(int),
3481 .mode = 0644,
3482 .proc_handler = proc_dointvec,
3483 },
3484 {
3485 .procname = "error_cost",
3486 .data = &ip_rt_error_cost,
3487 .maxlen = sizeof(int),
3488 .mode = 0644,
3489 .proc_handler = proc_dointvec,
3490 },
3491 {
3492 .procname = "error_burst",
3493 .data = &ip_rt_error_burst,
3494 .maxlen = sizeof(int),
3495 .mode = 0644,
3496 .proc_handler = proc_dointvec,
3497 },
3498 {
3499 .procname = "gc_elasticity",
3500 .data = &ip_rt_gc_elasticity,
3501 .maxlen = sizeof(int),
3502 .mode = 0644,
3503 .proc_handler = proc_dointvec,
3504 },
3505 { }
3506};
3507
3508static const char ipv4_route_flush_procname[] = "flush";
3509
3510static struct ctl_table ipv4_route_netns_table[] = {
3511 {
3512 .procname = ipv4_route_flush_procname,
3513 .maxlen = sizeof(int),
3514 .mode = 0200,
3515 .proc_handler = ipv4_sysctl_rtcache_flush,
3516 },
3517 {
3518 .procname = "min_pmtu",
3519 .data = &init_net.ipv4.ip_rt_min_pmtu,
3520 .maxlen = sizeof(int),
3521 .mode = 0644,
3522 .proc_handler = proc_dointvec_minmax,
3523 .extra1 = &ip_min_valid_pmtu,
3524 },
3525 {
3526 .procname = "mtu_expires",
3527 .data = &init_net.ipv4.ip_rt_mtu_expires,
3528 .maxlen = sizeof(int),
3529 .mode = 0644,
3530 .proc_handler = proc_dointvec_jiffies,
3531 },
3532 {
3533 .procname = "min_adv_mss",
3534 .data = &init_net.ipv4.ip_rt_min_advmss,
3535 .maxlen = sizeof(int),
3536 .mode = 0644,
3537 .proc_handler = proc_dointvec,
3538 },
3539 { },
3540};
3541
3542static __net_init int sysctl_route_net_init(struct net *net)
3543{
3544 struct ctl_table *tbl;
3545 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table);
3546
3547 tbl = ipv4_route_netns_table;
3548 if (!net_eq(net, &init_net)) {
3549 int i;
3550
3551 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL);
3552 if (!tbl)
3553 goto err_dup;
3554
3555 /* Don't export non-whitelisted sysctls to unprivileged users */
3556 if (net->user_ns != &init_user_ns) {
3557 if (tbl[0].procname != ipv4_route_flush_procname) {
3558 tbl[0].procname = NULL;
3559 table_size = 0;
3560 }
3561 }
3562
3563 /* Update the variables to point into the current struct net
3564 * except for the first element flush
3565 */
3566 for (i = 1; i < ARRAY_SIZE(ipv4_route_netns_table) - 1; i++)
3567 tbl[i].data += (void *)net - (void *)&init_net;
3568 }
3569 tbl[0].extra1 = net;
3570
3571 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route",
3572 tbl, table_size);
3573 if (!net->ipv4.route_hdr)
3574 goto err_reg;
3575 return 0;
3576
3577err_reg:
3578 if (tbl != ipv4_route_netns_table)
3579 kfree(tbl);
3580err_dup:
3581 return -ENOMEM;
3582}
3583
3584static __net_exit void sysctl_route_net_exit(struct net *net)
3585{
3586 struct ctl_table *tbl;
3587
3588 tbl = net->ipv4.route_hdr->ctl_table_arg;
3589 unregister_net_sysctl_table(net->ipv4.route_hdr);
3590 BUG_ON(tbl == ipv4_route_netns_table);
3591 kfree(tbl);
3592}
3593
3594static __net_initdata struct pernet_operations sysctl_route_ops = {
3595 .init = sysctl_route_net_init,
3596 .exit = sysctl_route_net_exit,
3597};
3598#endif
3599
3600static __net_init int netns_ip_rt_init(struct net *net)
3601{
3602 /* Set default value for namespaceified sysctls */
3603 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU;
3604 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
3605 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
3606 return 0;
3607}
3608
3609static struct pernet_operations __net_initdata ip_rt_ops = {
3610 .init = netns_ip_rt_init,
3611};
3612
3613static __net_init int rt_genid_init(struct net *net)
3614{
3615 atomic_set(&net->ipv4.rt_genid, 0);
3616 atomic_set(&net->fnhe_genid, 0);
3617 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32());
3618 return 0;
3619}
3620
3621static __net_initdata struct pernet_operations rt_genid_ops = {
3622 .init = rt_genid_init,
3623};
3624
3625static int __net_init ipv4_inetpeer_init(struct net *net)
3626{
3627 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3628
3629 if (!bp)
3630 return -ENOMEM;
3631 inet_peer_base_init(bp);
3632 net->ipv4.peers = bp;
3633 return 0;
3634}
3635
3636static void __net_exit ipv4_inetpeer_exit(struct net *net)
3637{
3638 struct inet_peer_base *bp = net->ipv4.peers;
3639
3640 net->ipv4.peers = NULL;
3641 inetpeer_invalidate_tree(bp);
3642 kfree(bp);
3643}
3644
3645static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3646 .init = ipv4_inetpeer_init,
3647 .exit = ipv4_inetpeer_exit,
3648};
3649
3650#ifdef CONFIG_IP_ROUTE_CLASSID
3651struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3652#endif /* CONFIG_IP_ROUTE_CLASSID */
3653
3654int __init ip_rt_init(void)
3655{
3656 void *idents_hash;
3657 int cpu;
3658
3659 /* For modern hosts, this will use 2 MB of memory */
3660 idents_hash = alloc_large_system_hash("IP idents",
3661 sizeof(*ip_idents) + sizeof(*ip_tstamps),
3662 0,
3663 16, /* one bucket per 64 KB */
3664 HASH_ZERO,
3665 NULL,
3666 &ip_idents_mask,
3667 2048,
3668 256*1024);
3669
3670 ip_idents = idents_hash;
3671
3672 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents));
3673
3674 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents);
3675
3676 for_each_possible_cpu(cpu) {
3677 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3678
3679 INIT_LIST_HEAD(&ul->head);
3680 INIT_LIST_HEAD(&ul->quarantine);
3681 spin_lock_init(&ul->lock);
3682 }
3683#ifdef CONFIG_IP_ROUTE_CLASSID
3684 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3685 if (!ip_rt_acct)
3686 panic("IP: failed to allocate ip_rt_acct\n");
3687#endif
3688
3689 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable,
3690 SLAB_HWCACHE_ALIGN | SLAB_PANIC);
3691
3692 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3693
3694 if (dst_entries_init(&ipv4_dst_ops) < 0)
3695 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3696
3697 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3698 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3699
3700 ipv4_dst_ops.gc_thresh = ~0;
3701 ip_rt_max_size = INT_MAX;
3702
3703 devinet_init();
3704 ip_fib_init();
3705
3706 if (ip_rt_proc_init())
3707 pr_err("Unable to create route proc files\n");
3708#ifdef CONFIG_XFRM
3709 xfrm_init();
3710 xfrm4_init();
3711#endif
3712 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3713 RTNL_FLAG_DOIT_UNLOCKED);
3714
3715#ifdef CONFIG_SYSCTL
3716 register_pernet_subsys(&sysctl_route_ops);
3717#endif
3718 register_pernet_subsys(&ip_rt_ops);
3719 register_pernet_subsys(&rt_genid_ops);
3720 register_pernet_subsys(&ipv4_inetpeer_ops);
3721 return 0;
3722}
3723
3724#ifdef CONFIG_SYSCTL
3725/*
3726 * We really need to sanitize the damn ipv4 init order, then all
3727 * this nonsense will go away.
3728 */
3729void __init ip_static_sysctl_init(void)
3730{
3731 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3732}
3733#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * ROUTE - implementation of the IP router.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
14 *
15 * Fixes:
16 * Alan Cox : Verify area fixes.
17 * Alan Cox : cli() protects routing changes
18 * Rui Oliveira : ICMP routing table updates
19 * (rco@di.uminho.pt) Routing table insertion and update
20 * Linus Torvalds : Rewrote bits to be sensible
21 * Alan Cox : Added BSD route gw semantics
22 * Alan Cox : Super /proc >4K
23 * Alan Cox : MTU in route table
24 * Alan Cox : MSS actually. Also added the window
25 * clamper.
26 * Sam Lantinga : Fixed route matching in rt_del()
27 * Alan Cox : Routing cache support.
28 * Alan Cox : Removed compatibility cruft.
29 * Alan Cox : RTF_REJECT support.
30 * Alan Cox : TCP irtt support.
31 * Jonathan Naylor : Added Metric support.
32 * Miquel van Smoorenburg : BSD API fixes.
33 * Miquel van Smoorenburg : Metrics.
34 * Alan Cox : Use __u32 properly
35 * Alan Cox : Aligned routing errors more closely with BSD
36 * our system is still very different.
37 * Alan Cox : Faster /proc handling
38 * Alexey Kuznetsov : Massive rework to support tree based routing,
39 * routing caches and better behaviour.
40 *
41 * Olaf Erb : irtt wasn't being copied right.
42 * Bjorn Ekwall : Kerneld route support.
43 * Alan Cox : Multicast fixed (I hope)
44 * Pavel Krauz : Limited broadcast fixed
45 * Mike McLagan : Routing by source
46 * Alexey Kuznetsov : End of old history. Split to fib.c and
47 * route.c and rewritten from scratch.
48 * Andi Kleen : Load-limit warning messages.
49 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
53 * Marc Boucher : routing by fwmark
54 * Robert Olsson : Added rt_cache statistics
55 * Arnaldo C. Melo : Convert proc stuff to seq_file
56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
58 * Ilia Sotnikov : Removed TOS from hash calculations
59 */
60
61#define pr_fmt(fmt) "IPv4: " fmt
62
63#include <linux/module.h>
64#include <linux/uaccess.h>
65#include <linux/bitops.h>
66#include <linux/types.h>
67#include <linux/kernel.h>
68#include <linux/mm.h>
69#include <linux/string.h>
70#include <linux/socket.h>
71#include <linux/sockios.h>
72#include <linux/errno.h>
73#include <linux/in.h>
74#include <linux/inet.h>
75#include <linux/netdevice.h>
76#include <linux/proc_fs.h>
77#include <linux/init.h>
78#include <linux/skbuff.h>
79#include <linux/inetdevice.h>
80#include <linux/igmp.h>
81#include <linux/pkt_sched.h>
82#include <linux/mroute.h>
83#include <linux/netfilter_ipv4.h>
84#include <linux/random.h>
85#include <linux/rcupdate.h>
86#include <linux/times.h>
87#include <linux/slab.h>
88#include <linux/jhash.h>
89#include <net/dst.h>
90#include <net/dst_metadata.h>
91#include <net/net_namespace.h>
92#include <net/protocol.h>
93#include <net/ip.h>
94#include <net/route.h>
95#include <net/inetpeer.h>
96#include <net/sock.h>
97#include <net/ip_fib.h>
98#include <net/nexthop.h>
99#include <net/arp.h>
100#include <net/tcp.h>
101#include <net/icmp.h>
102#include <net/xfrm.h>
103#include <net/lwtunnel.h>
104#include <net/netevent.h>
105#include <net/rtnetlink.h>
106#ifdef CONFIG_SYSCTL
107#include <linux/sysctl.h>
108#endif
109#include <net/secure_seq.h>
110#include <net/ip_tunnels.h>
111#include <net/l3mdev.h>
112
113#include "fib_lookup.h"
114
115#define RT_FL_TOS(oldflp4) \
116 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
117
118#define RT_GC_TIMEOUT (300*HZ)
119
120static int ip_rt_max_size;
121static int ip_rt_redirect_number __read_mostly = 9;
122static int ip_rt_redirect_load __read_mostly = HZ / 50;
123static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
124static int ip_rt_error_cost __read_mostly = HZ;
125static int ip_rt_error_burst __read_mostly = 5 * HZ;
126static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
127static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
128static int ip_rt_min_advmss __read_mostly = 256;
129
130static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
131
132/*
133 * Interface to generic destination cache.
134 */
135
136static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
137static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
138static unsigned int ipv4_mtu(const struct dst_entry *dst);
139static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
140static void ipv4_link_failure(struct sk_buff *skb);
141static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
142 struct sk_buff *skb, u32 mtu);
143static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
144 struct sk_buff *skb);
145static void ipv4_dst_destroy(struct dst_entry *dst);
146
147static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
148{
149 WARN_ON(1);
150 return NULL;
151}
152
153static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
154 struct sk_buff *skb,
155 const void *daddr);
156static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
157
158static struct dst_ops ipv4_dst_ops = {
159 .family = AF_INET,
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .negative_advice = ipv4_negative_advice,
166 .link_failure = ipv4_link_failure,
167 .update_pmtu = ip_rt_update_pmtu,
168 .redirect = ip_do_redirect,
169 .local_out = __ip_local_out,
170 .neigh_lookup = ipv4_neigh_lookup,
171 .confirm_neigh = ipv4_confirm_neigh,
172};
173
174#define ECN_OR_COST(class) TC_PRIO_##class
175
176const __u8 ip_tos2prio[16] = {
177 TC_PRIO_BESTEFFORT,
178 ECN_OR_COST(BESTEFFORT),
179 TC_PRIO_BESTEFFORT,
180 ECN_OR_COST(BESTEFFORT),
181 TC_PRIO_BULK,
182 ECN_OR_COST(BULK),
183 TC_PRIO_BULK,
184 ECN_OR_COST(BULK),
185 TC_PRIO_INTERACTIVE,
186 ECN_OR_COST(INTERACTIVE),
187 TC_PRIO_INTERACTIVE,
188 ECN_OR_COST(INTERACTIVE),
189 TC_PRIO_INTERACTIVE_BULK,
190 ECN_OR_COST(INTERACTIVE_BULK),
191 TC_PRIO_INTERACTIVE_BULK,
192 ECN_OR_COST(INTERACTIVE_BULK)
193};
194EXPORT_SYMBOL(ip_tos2prio);
195
196static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
197#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
198
199#ifdef CONFIG_PROC_FS
200static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
201{
202 if (*pos)
203 return NULL;
204 return SEQ_START_TOKEN;
205}
206
207static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
208{
209 ++*pos;
210 return NULL;
211}
212
213static void rt_cache_seq_stop(struct seq_file *seq, void *v)
214{
215}
216
217static int rt_cache_seq_show(struct seq_file *seq, void *v)
218{
219 if (v == SEQ_START_TOKEN)
220 seq_printf(seq, "%-127s\n",
221 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
222 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
223 "HHUptod\tSpecDst");
224 return 0;
225}
226
227static const struct seq_operations rt_cache_seq_ops = {
228 .start = rt_cache_seq_start,
229 .next = rt_cache_seq_next,
230 .stop = rt_cache_seq_stop,
231 .show = rt_cache_seq_show,
232};
233
234static int rt_cache_seq_open(struct inode *inode, struct file *file)
235{
236 return seq_open(file, &rt_cache_seq_ops);
237}
238
239static const struct file_operations rt_cache_seq_fops = {
240 .open = rt_cache_seq_open,
241 .read = seq_read,
242 .llseek = seq_lseek,
243 .release = seq_release,
244};
245
246
247static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
248{
249 int cpu;
250
251 if (*pos == 0)
252 return SEQ_START_TOKEN;
253
254 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
255 if (!cpu_possible(cpu))
256 continue;
257 *pos = cpu+1;
258 return &per_cpu(rt_cache_stat, cpu);
259 }
260 return NULL;
261}
262
263static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
264{
265 int cpu;
266
267 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
268 if (!cpu_possible(cpu))
269 continue;
270 *pos = cpu+1;
271 return &per_cpu(rt_cache_stat, cpu);
272 }
273 return NULL;
274
275}
276
277static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
278{
279
280}
281
282static int rt_cpu_seq_show(struct seq_file *seq, void *v)
283{
284 struct rt_cache_stat *st = v;
285
286 if (v == SEQ_START_TOKEN) {
287 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
288 return 0;
289 }
290
291 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
292 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
293 dst_entries_get_slow(&ipv4_dst_ops),
294 0, /* st->in_hit */
295 st->in_slow_tot,
296 st->in_slow_mc,
297 st->in_no_route,
298 st->in_brd,
299 st->in_martian_dst,
300 st->in_martian_src,
301
302 0, /* st->out_hit */
303 st->out_slow_tot,
304 st->out_slow_mc,
305
306 0, /* st->gc_total */
307 0, /* st->gc_ignored */
308 0, /* st->gc_goal_miss */
309 0, /* st->gc_dst_overflow */
310 0, /* st->in_hlist_search */
311 0 /* st->out_hlist_search */
312 );
313 return 0;
314}
315
316static const struct seq_operations rt_cpu_seq_ops = {
317 .start = rt_cpu_seq_start,
318 .next = rt_cpu_seq_next,
319 .stop = rt_cpu_seq_stop,
320 .show = rt_cpu_seq_show,
321};
322
323
324static int rt_cpu_seq_open(struct inode *inode, struct file *file)
325{
326 return seq_open(file, &rt_cpu_seq_ops);
327}
328
329static const struct file_operations rt_cpu_seq_fops = {
330 .open = rt_cpu_seq_open,
331 .read = seq_read,
332 .llseek = seq_lseek,
333 .release = seq_release,
334};
335
336#ifdef CONFIG_IP_ROUTE_CLASSID
337static int rt_acct_proc_show(struct seq_file *m, void *v)
338{
339 struct ip_rt_acct *dst, *src;
340 unsigned int i, j;
341
342 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
343 if (!dst)
344 return -ENOMEM;
345
346 for_each_possible_cpu(i) {
347 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
348 for (j = 0; j < 256; j++) {
349 dst[j].o_bytes += src[j].o_bytes;
350 dst[j].o_packets += src[j].o_packets;
351 dst[j].i_bytes += src[j].i_bytes;
352 dst[j].i_packets += src[j].i_packets;
353 }
354 }
355
356 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
357 kfree(dst);
358 return 0;
359}
360#endif
361
362static int __net_init ip_rt_do_proc_init(struct net *net)
363{
364 struct proc_dir_entry *pde;
365
366 pde = proc_create("rt_cache", 0444, net->proc_net,
367 &rt_cache_seq_fops);
368 if (!pde)
369 goto err1;
370
371 pde = proc_create("rt_cache", 0444,
372 net->proc_net_stat, &rt_cpu_seq_fops);
373 if (!pde)
374 goto err2;
375
376#ifdef CONFIG_IP_ROUTE_CLASSID
377 pde = proc_create_single("rt_acct", 0, net->proc_net,
378 rt_acct_proc_show);
379 if (!pde)
380 goto err3;
381#endif
382 return 0;
383
384#ifdef CONFIG_IP_ROUTE_CLASSID
385err3:
386 remove_proc_entry("rt_cache", net->proc_net_stat);
387#endif
388err2:
389 remove_proc_entry("rt_cache", net->proc_net);
390err1:
391 return -ENOMEM;
392}
393
394static void __net_exit ip_rt_do_proc_exit(struct net *net)
395{
396 remove_proc_entry("rt_cache", net->proc_net_stat);
397 remove_proc_entry("rt_cache", net->proc_net);
398#ifdef CONFIG_IP_ROUTE_CLASSID
399 remove_proc_entry("rt_acct", net->proc_net);
400#endif
401}
402
403static struct pernet_operations ip_rt_proc_ops __net_initdata = {
404 .init = ip_rt_do_proc_init,
405 .exit = ip_rt_do_proc_exit,
406};
407
408static int __init ip_rt_proc_init(void)
409{
410 return register_pernet_subsys(&ip_rt_proc_ops);
411}
412
413#else
414static inline int ip_rt_proc_init(void)
415{
416 return 0;
417}
418#endif /* CONFIG_PROC_FS */
419
420static inline bool rt_is_expired(const struct rtable *rth)
421{
422 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
423}
424
425void rt_cache_flush(struct net *net)
426{
427 rt_genid_bump_ipv4(net);
428}
429
430static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
431 struct sk_buff *skb,
432 const void *daddr)
433{
434 const struct rtable *rt = container_of(dst, struct rtable, dst);
435 struct net_device *dev = dst->dev;
436 struct neighbour *n;
437
438 rcu_read_lock_bh();
439
440 if (likely(rt->rt_gw_family == AF_INET)) {
441 n = ip_neigh_gw4(dev, rt->rt_gw4);
442 } else if (rt->rt_gw_family == AF_INET6) {
443 n = ip_neigh_gw6(dev, &rt->rt_gw6);
444 } else {
445 __be32 pkey;
446
447 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
448 n = ip_neigh_gw4(dev, pkey);
449 }
450
451 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
452 n = NULL;
453
454 rcu_read_unlock_bh();
455
456 return n;
457}
458
459static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
460{
461 const struct rtable *rt = container_of(dst, struct rtable, dst);
462 struct net_device *dev = dst->dev;
463 const __be32 *pkey = daddr;
464
465 if (rt->rt_gw_family == AF_INET) {
466 pkey = (const __be32 *)&rt->rt_gw4;
467 } else if (rt->rt_gw_family == AF_INET6) {
468 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
469 } else if (!daddr ||
470 (rt->rt_flags &
471 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
472 return;
473 }
474 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
475}
476
477#define IP_IDENTS_SZ 2048u
478
479static atomic_t *ip_idents __read_mostly;
480static u32 *ip_tstamps __read_mostly;
481
482/* In order to protect privacy, we add a perturbation to identifiers
483 * if one generator is seldom used. This makes hard for an attacker
484 * to infer how many packets were sent between two points in time.
485 */
486u32 ip_idents_reserve(u32 hash, int segs)
487{
488 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
489 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
490 u32 old = READ_ONCE(*p_tstamp);
491 u32 now = (u32)jiffies;
492 u32 new, delta = 0;
493
494 if (old != now && cmpxchg(p_tstamp, old, now) == old)
495 delta = prandom_u32_max(now - old);
496
497 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
498 do {
499 old = (u32)atomic_read(p_id);
500 new = old + delta + segs;
501 } while (atomic_cmpxchg(p_id, old, new) != old);
502
503 return new - segs;
504}
505EXPORT_SYMBOL(ip_idents_reserve);
506
507void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
508{
509 u32 hash, id;
510
511 /* Note the following code is not safe, but this is okay. */
512 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
513 get_random_bytes(&net->ipv4.ip_id_key,
514 sizeof(net->ipv4.ip_id_key));
515
516 hash = siphash_3u32((__force u32)iph->daddr,
517 (__force u32)iph->saddr,
518 iph->protocol,
519 &net->ipv4.ip_id_key);
520 id = ip_idents_reserve(hash, segs);
521 iph->id = htons(id);
522}
523EXPORT_SYMBOL(__ip_select_ident);
524
525static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
526 const struct sock *sk,
527 const struct iphdr *iph,
528 int oif, u8 tos,
529 u8 prot, u32 mark, int flow_flags)
530{
531 if (sk) {
532 const struct inet_sock *inet = inet_sk(sk);
533
534 oif = sk->sk_bound_dev_if;
535 mark = sk->sk_mark;
536 tos = RT_CONN_FLAGS(sk);
537 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
538 }
539 flowi4_init_output(fl4, oif, mark, tos,
540 RT_SCOPE_UNIVERSE, prot,
541 flow_flags,
542 iph->daddr, iph->saddr, 0, 0,
543 sock_net_uid(net, sk));
544}
545
546static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
547 const struct sock *sk)
548{
549 const struct net *net = dev_net(skb->dev);
550 const struct iphdr *iph = ip_hdr(skb);
551 int oif = skb->dev->ifindex;
552 u8 tos = RT_TOS(iph->tos);
553 u8 prot = iph->protocol;
554 u32 mark = skb->mark;
555
556 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
557}
558
559static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
560{
561 const struct inet_sock *inet = inet_sk(sk);
562 const struct ip_options_rcu *inet_opt;
563 __be32 daddr = inet->inet_daddr;
564
565 rcu_read_lock();
566 inet_opt = rcu_dereference(inet->inet_opt);
567 if (inet_opt && inet_opt->opt.srr)
568 daddr = inet_opt->opt.faddr;
569 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
570 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
571 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
572 inet_sk_flowi_flags(sk),
573 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
574 rcu_read_unlock();
575}
576
577static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
578 const struct sk_buff *skb)
579{
580 if (skb)
581 build_skb_flow_key(fl4, skb, sk);
582 else
583 build_sk_flow_key(fl4, sk);
584}
585
586static DEFINE_SPINLOCK(fnhe_lock);
587
588static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
589{
590 struct rtable *rt;
591
592 rt = rcu_dereference(fnhe->fnhe_rth_input);
593 if (rt) {
594 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
595 dst_dev_put(&rt->dst);
596 dst_release(&rt->dst);
597 }
598 rt = rcu_dereference(fnhe->fnhe_rth_output);
599 if (rt) {
600 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
601 dst_dev_put(&rt->dst);
602 dst_release(&rt->dst);
603 }
604}
605
606static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
607{
608 struct fib_nh_exception *fnhe, *oldest;
609
610 oldest = rcu_dereference(hash->chain);
611 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
612 fnhe = rcu_dereference(fnhe->fnhe_next)) {
613 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
614 oldest = fnhe;
615 }
616 fnhe_flush_routes(oldest);
617 return oldest;
618}
619
620static inline u32 fnhe_hashfun(__be32 daddr)
621{
622 static u32 fnhe_hashrnd __read_mostly;
623 u32 hval;
624
625 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
626 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
627 return hash_32(hval, FNHE_HASH_SHIFT);
628}
629
630static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
631{
632 rt->rt_pmtu = fnhe->fnhe_pmtu;
633 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
634 rt->dst.expires = fnhe->fnhe_expires;
635
636 if (fnhe->fnhe_gw) {
637 rt->rt_flags |= RTCF_REDIRECTED;
638 rt->rt_uses_gateway = 1;
639 rt->rt_gw_family = AF_INET;
640 rt->rt_gw4 = fnhe->fnhe_gw;
641 }
642}
643
644static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
645 __be32 gw, u32 pmtu, bool lock,
646 unsigned long expires)
647{
648 struct fnhe_hash_bucket *hash;
649 struct fib_nh_exception *fnhe;
650 struct rtable *rt;
651 u32 genid, hval;
652 unsigned int i;
653 int depth;
654
655 genid = fnhe_genid(dev_net(nhc->nhc_dev));
656 hval = fnhe_hashfun(daddr);
657
658 spin_lock_bh(&fnhe_lock);
659
660 hash = rcu_dereference(nhc->nhc_exceptions);
661 if (!hash) {
662 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
663 if (!hash)
664 goto out_unlock;
665 rcu_assign_pointer(nhc->nhc_exceptions, hash);
666 }
667
668 hash += hval;
669
670 depth = 0;
671 for (fnhe = rcu_dereference(hash->chain); fnhe;
672 fnhe = rcu_dereference(fnhe->fnhe_next)) {
673 if (fnhe->fnhe_daddr == daddr)
674 break;
675 depth++;
676 }
677
678 if (fnhe) {
679 if (fnhe->fnhe_genid != genid)
680 fnhe->fnhe_genid = genid;
681 if (gw)
682 fnhe->fnhe_gw = gw;
683 if (pmtu) {
684 fnhe->fnhe_pmtu = pmtu;
685 fnhe->fnhe_mtu_locked = lock;
686 }
687 fnhe->fnhe_expires = max(1UL, expires);
688 /* Update all cached dsts too */
689 rt = rcu_dereference(fnhe->fnhe_rth_input);
690 if (rt)
691 fill_route_from_fnhe(rt, fnhe);
692 rt = rcu_dereference(fnhe->fnhe_rth_output);
693 if (rt)
694 fill_route_from_fnhe(rt, fnhe);
695 } else {
696 if (depth > FNHE_RECLAIM_DEPTH)
697 fnhe = fnhe_oldest(hash);
698 else {
699 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
700 if (!fnhe)
701 goto out_unlock;
702
703 fnhe->fnhe_next = hash->chain;
704 rcu_assign_pointer(hash->chain, fnhe);
705 }
706 fnhe->fnhe_genid = genid;
707 fnhe->fnhe_daddr = daddr;
708 fnhe->fnhe_gw = gw;
709 fnhe->fnhe_pmtu = pmtu;
710 fnhe->fnhe_mtu_locked = lock;
711 fnhe->fnhe_expires = max(1UL, expires);
712
713 /* Exception created; mark the cached routes for the nexthop
714 * stale, so anyone caching it rechecks if this exception
715 * applies to them.
716 */
717 rt = rcu_dereference(nhc->nhc_rth_input);
718 if (rt)
719 rt->dst.obsolete = DST_OBSOLETE_KILL;
720
721 for_each_possible_cpu(i) {
722 struct rtable __rcu **prt;
723 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
724 rt = rcu_dereference(*prt);
725 if (rt)
726 rt->dst.obsolete = DST_OBSOLETE_KILL;
727 }
728 }
729
730 fnhe->fnhe_stamp = jiffies;
731
732out_unlock:
733 spin_unlock_bh(&fnhe_lock);
734}
735
736static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
737 bool kill_route)
738{
739 __be32 new_gw = icmp_hdr(skb)->un.gateway;
740 __be32 old_gw = ip_hdr(skb)->saddr;
741 struct net_device *dev = skb->dev;
742 struct in_device *in_dev;
743 struct fib_result res;
744 struct neighbour *n;
745 struct net *net;
746
747 switch (icmp_hdr(skb)->code & 7) {
748 case ICMP_REDIR_NET:
749 case ICMP_REDIR_NETTOS:
750 case ICMP_REDIR_HOST:
751 case ICMP_REDIR_HOSTTOS:
752 break;
753
754 default:
755 return;
756 }
757
758 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
759 return;
760
761 in_dev = __in_dev_get_rcu(dev);
762 if (!in_dev)
763 return;
764
765 net = dev_net(dev);
766 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
767 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
768 ipv4_is_zeronet(new_gw))
769 goto reject_redirect;
770
771 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
772 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
773 goto reject_redirect;
774 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
775 goto reject_redirect;
776 } else {
777 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
778 goto reject_redirect;
779 }
780
781 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
782 if (!n)
783 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
784 if (!IS_ERR(n)) {
785 if (!(n->nud_state & NUD_VALID)) {
786 neigh_event_send(n, NULL);
787 } else {
788 if (fib_lookup(net, fl4, &res, 0) == 0) {
789 struct fib_nh_common *nhc = FIB_RES_NHC(res);
790
791 update_or_create_fnhe(nhc, fl4->daddr, new_gw,
792 0, false,
793 jiffies + ip_rt_gc_timeout);
794 }
795 if (kill_route)
796 rt->dst.obsolete = DST_OBSOLETE_KILL;
797 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
798 }
799 neigh_release(n);
800 }
801 return;
802
803reject_redirect:
804#ifdef CONFIG_IP_ROUTE_VERBOSE
805 if (IN_DEV_LOG_MARTIANS(in_dev)) {
806 const struct iphdr *iph = (const struct iphdr *) skb->data;
807 __be32 daddr = iph->daddr;
808 __be32 saddr = iph->saddr;
809
810 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
811 " Advised path = %pI4 -> %pI4\n",
812 &old_gw, dev->name, &new_gw,
813 &saddr, &daddr);
814 }
815#endif
816 ;
817}
818
819static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
820{
821 struct rtable *rt;
822 struct flowi4 fl4;
823 const struct iphdr *iph = (const struct iphdr *) skb->data;
824 struct net *net = dev_net(skb->dev);
825 int oif = skb->dev->ifindex;
826 u8 tos = RT_TOS(iph->tos);
827 u8 prot = iph->protocol;
828 u32 mark = skb->mark;
829
830 rt = (struct rtable *) dst;
831
832 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
833 __ip_do_redirect(rt, skb, &fl4, true);
834}
835
836static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
837{
838 struct rtable *rt = (struct rtable *)dst;
839 struct dst_entry *ret = dst;
840
841 if (rt) {
842 if (dst->obsolete > 0) {
843 ip_rt_put(rt);
844 ret = NULL;
845 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
846 rt->dst.expires) {
847 ip_rt_put(rt);
848 ret = NULL;
849 }
850 }
851 return ret;
852}
853
854/*
855 * Algorithm:
856 * 1. The first ip_rt_redirect_number redirects are sent
857 * with exponential backoff, then we stop sending them at all,
858 * assuming that the host ignores our redirects.
859 * 2. If we did not see packets requiring redirects
860 * during ip_rt_redirect_silence, we assume that the host
861 * forgot redirected route and start to send redirects again.
862 *
863 * This algorithm is much cheaper and more intelligent than dumb load limiting
864 * in icmp.c.
865 *
866 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
867 * and "frag. need" (breaks PMTU discovery) in icmp.c.
868 */
869
870void ip_rt_send_redirect(struct sk_buff *skb)
871{
872 struct rtable *rt = skb_rtable(skb);
873 struct in_device *in_dev;
874 struct inet_peer *peer;
875 struct net *net;
876 int log_martians;
877 int vif;
878
879 rcu_read_lock();
880 in_dev = __in_dev_get_rcu(rt->dst.dev);
881 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
882 rcu_read_unlock();
883 return;
884 }
885 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
886 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
887 rcu_read_unlock();
888
889 net = dev_net(rt->dst.dev);
890 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
891 if (!peer) {
892 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
893 rt_nexthop(rt, ip_hdr(skb)->daddr));
894 return;
895 }
896
897 /* No redirected packets during ip_rt_redirect_silence;
898 * reset the algorithm.
899 */
900 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
901 peer->rate_tokens = 0;
902 peer->n_redirects = 0;
903 }
904
905 /* Too many ignored redirects; do not send anything
906 * set dst.rate_last to the last seen redirected packet.
907 */
908 if (peer->n_redirects >= ip_rt_redirect_number) {
909 peer->rate_last = jiffies;
910 goto out_put_peer;
911 }
912
913 /* Check for load limit; set rate_last to the latest sent
914 * redirect.
915 */
916 if (peer->rate_tokens == 0 ||
917 time_after(jiffies,
918 (peer->rate_last +
919 (ip_rt_redirect_load << peer->n_redirects)))) {
920 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
921
922 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
923 peer->rate_last = jiffies;
924 ++peer->n_redirects;
925#ifdef CONFIG_IP_ROUTE_VERBOSE
926 if (log_martians &&
927 peer->n_redirects == ip_rt_redirect_number)
928 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
929 &ip_hdr(skb)->saddr, inet_iif(skb),
930 &ip_hdr(skb)->daddr, &gw);
931#endif
932 }
933out_put_peer:
934 inet_putpeer(peer);
935}
936
937static int ip_error(struct sk_buff *skb)
938{
939 struct rtable *rt = skb_rtable(skb);
940 struct net_device *dev = skb->dev;
941 struct in_device *in_dev;
942 struct inet_peer *peer;
943 unsigned long now;
944 struct net *net;
945 bool send;
946 int code;
947
948 if (netif_is_l3_master(skb->dev)) {
949 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
950 if (!dev)
951 goto out;
952 }
953
954 in_dev = __in_dev_get_rcu(dev);
955
956 /* IP on this device is disabled. */
957 if (!in_dev)
958 goto out;
959
960 net = dev_net(rt->dst.dev);
961 if (!IN_DEV_FORWARD(in_dev)) {
962 switch (rt->dst.error) {
963 case EHOSTUNREACH:
964 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
965 break;
966
967 case ENETUNREACH:
968 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
969 break;
970 }
971 goto out;
972 }
973
974 switch (rt->dst.error) {
975 case EINVAL:
976 default:
977 goto out;
978 case EHOSTUNREACH:
979 code = ICMP_HOST_UNREACH;
980 break;
981 case ENETUNREACH:
982 code = ICMP_NET_UNREACH;
983 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
984 break;
985 case EACCES:
986 code = ICMP_PKT_FILTERED;
987 break;
988 }
989
990 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
991 l3mdev_master_ifindex(skb->dev), 1);
992
993 send = true;
994 if (peer) {
995 now = jiffies;
996 peer->rate_tokens += now - peer->rate_last;
997 if (peer->rate_tokens > ip_rt_error_burst)
998 peer->rate_tokens = ip_rt_error_burst;
999 peer->rate_last = now;
1000 if (peer->rate_tokens >= ip_rt_error_cost)
1001 peer->rate_tokens -= ip_rt_error_cost;
1002 else
1003 send = false;
1004 inet_putpeer(peer);
1005 }
1006 if (send)
1007 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1008
1009out: kfree_skb(skb);
1010 return 0;
1011}
1012
1013static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1014{
1015 struct dst_entry *dst = &rt->dst;
1016 u32 old_mtu = ipv4_mtu(dst);
1017 struct fib_result res;
1018 bool lock = false;
1019
1020 if (ip_mtu_locked(dst))
1021 return;
1022
1023 if (old_mtu < mtu)
1024 return;
1025
1026 if (mtu < ip_rt_min_pmtu) {
1027 lock = true;
1028 mtu = min(old_mtu, ip_rt_min_pmtu);
1029 }
1030
1031 if (rt->rt_pmtu == mtu && !lock &&
1032 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1033 return;
1034
1035 rcu_read_lock();
1036 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1037 struct fib_nh_common *nhc = FIB_RES_NHC(res);
1038
1039 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1040 jiffies + ip_rt_mtu_expires);
1041 }
1042 rcu_read_unlock();
1043}
1044
1045static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1046 struct sk_buff *skb, u32 mtu)
1047{
1048 struct rtable *rt = (struct rtable *) dst;
1049 struct flowi4 fl4;
1050
1051 ip_rt_build_flow_key(&fl4, sk, skb);
1052 __ip_rt_update_pmtu(rt, &fl4, mtu);
1053}
1054
1055void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1056 int oif, u8 protocol)
1057{
1058 const struct iphdr *iph = (const struct iphdr *) skb->data;
1059 struct flowi4 fl4;
1060 struct rtable *rt;
1061 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1062
1063 __build_flow_key(net, &fl4, NULL, iph, oif,
1064 RT_TOS(iph->tos), protocol, mark, 0);
1065 rt = __ip_route_output_key(net, &fl4);
1066 if (!IS_ERR(rt)) {
1067 __ip_rt_update_pmtu(rt, &fl4, mtu);
1068 ip_rt_put(rt);
1069 }
1070}
1071EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1072
1073static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1074{
1075 const struct iphdr *iph = (const struct iphdr *) skb->data;
1076 struct flowi4 fl4;
1077 struct rtable *rt;
1078
1079 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1080
1081 if (!fl4.flowi4_mark)
1082 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1083
1084 rt = __ip_route_output_key(sock_net(sk), &fl4);
1085 if (!IS_ERR(rt)) {
1086 __ip_rt_update_pmtu(rt, &fl4, mtu);
1087 ip_rt_put(rt);
1088 }
1089}
1090
1091void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1092{
1093 const struct iphdr *iph = (const struct iphdr *) skb->data;
1094 struct flowi4 fl4;
1095 struct rtable *rt;
1096 struct dst_entry *odst = NULL;
1097 bool new = false;
1098 struct net *net = sock_net(sk);
1099
1100 bh_lock_sock(sk);
1101
1102 if (!ip_sk_accept_pmtu(sk))
1103 goto out;
1104
1105 odst = sk_dst_get(sk);
1106
1107 if (sock_owned_by_user(sk) || !odst) {
1108 __ipv4_sk_update_pmtu(skb, sk, mtu);
1109 goto out;
1110 }
1111
1112 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1113
1114 rt = (struct rtable *)odst;
1115 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1116 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1117 if (IS_ERR(rt))
1118 goto out;
1119
1120 new = true;
1121 }
1122
1123 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1124
1125 if (!dst_check(&rt->dst, 0)) {
1126 if (new)
1127 dst_release(&rt->dst);
1128
1129 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1130 if (IS_ERR(rt))
1131 goto out;
1132
1133 new = true;
1134 }
1135
1136 if (new)
1137 sk_dst_set(sk, &rt->dst);
1138
1139out:
1140 bh_unlock_sock(sk);
1141 dst_release(odst);
1142}
1143EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1144
1145void ipv4_redirect(struct sk_buff *skb, struct net *net,
1146 int oif, u8 protocol)
1147{
1148 const struct iphdr *iph = (const struct iphdr *) skb->data;
1149 struct flowi4 fl4;
1150 struct rtable *rt;
1151
1152 __build_flow_key(net, &fl4, NULL, iph, oif,
1153 RT_TOS(iph->tos), protocol, 0, 0);
1154 rt = __ip_route_output_key(net, &fl4);
1155 if (!IS_ERR(rt)) {
1156 __ip_do_redirect(rt, skb, &fl4, false);
1157 ip_rt_put(rt);
1158 }
1159}
1160EXPORT_SYMBOL_GPL(ipv4_redirect);
1161
1162void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1163{
1164 const struct iphdr *iph = (const struct iphdr *) skb->data;
1165 struct flowi4 fl4;
1166 struct rtable *rt;
1167 struct net *net = sock_net(sk);
1168
1169 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1170 rt = __ip_route_output_key(net, &fl4);
1171 if (!IS_ERR(rt)) {
1172 __ip_do_redirect(rt, skb, &fl4, false);
1173 ip_rt_put(rt);
1174 }
1175}
1176EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1177
1178static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1179{
1180 struct rtable *rt = (struct rtable *) dst;
1181
1182 /* All IPV4 dsts are created with ->obsolete set to the value
1183 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1184 * into this function always.
1185 *
1186 * When a PMTU/redirect information update invalidates a route,
1187 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1188 * DST_OBSOLETE_DEAD.
1189 */
1190 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1191 return NULL;
1192 return dst;
1193}
1194
1195static void ipv4_send_dest_unreach(struct sk_buff *skb)
1196{
1197 struct ip_options opt;
1198 int res;
1199
1200 /* Recompile ip options since IPCB may not be valid anymore.
1201 * Also check we have a reasonable ipv4 header.
1202 */
1203 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1204 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1205 return;
1206
1207 memset(&opt, 0, sizeof(opt));
1208 if (ip_hdr(skb)->ihl > 5) {
1209 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1210 return;
1211 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1212
1213 rcu_read_lock();
1214 res = __ip_options_compile(dev_net(skb->dev), &opt, skb, NULL);
1215 rcu_read_unlock();
1216
1217 if (res)
1218 return;
1219 }
1220 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1221}
1222
1223static void ipv4_link_failure(struct sk_buff *skb)
1224{
1225 struct rtable *rt;
1226
1227 ipv4_send_dest_unreach(skb);
1228
1229 rt = skb_rtable(skb);
1230 if (rt)
1231 dst_set_expires(&rt->dst, 0);
1232}
1233
1234static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1235{
1236 pr_debug("%s: %pI4 -> %pI4, %s\n",
1237 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1238 skb->dev ? skb->dev->name : "?");
1239 kfree_skb(skb);
1240 WARN_ON(1);
1241 return 0;
1242}
1243
1244/*
1245 We do not cache source address of outgoing interface,
1246 because it is used only by IP RR, TS and SRR options,
1247 so that it out of fast path.
1248
1249 BTW remember: "addr" is allowed to be not aligned
1250 in IP options!
1251 */
1252
1253void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1254{
1255 __be32 src;
1256
1257 if (rt_is_output_route(rt))
1258 src = ip_hdr(skb)->saddr;
1259 else {
1260 struct fib_result res;
1261 struct iphdr *iph = ip_hdr(skb);
1262 struct flowi4 fl4 = {
1263 .daddr = iph->daddr,
1264 .saddr = iph->saddr,
1265 .flowi4_tos = RT_TOS(iph->tos),
1266 .flowi4_oif = rt->dst.dev->ifindex,
1267 .flowi4_iif = skb->dev->ifindex,
1268 .flowi4_mark = skb->mark,
1269 };
1270
1271 rcu_read_lock();
1272 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1273 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1274 else
1275 src = inet_select_addr(rt->dst.dev,
1276 rt_nexthop(rt, iph->daddr),
1277 RT_SCOPE_UNIVERSE);
1278 rcu_read_unlock();
1279 }
1280 memcpy(addr, &src, 4);
1281}
1282
1283#ifdef CONFIG_IP_ROUTE_CLASSID
1284static void set_class_tag(struct rtable *rt, u32 tag)
1285{
1286 if (!(rt->dst.tclassid & 0xFFFF))
1287 rt->dst.tclassid |= tag & 0xFFFF;
1288 if (!(rt->dst.tclassid & 0xFFFF0000))
1289 rt->dst.tclassid |= tag & 0xFFFF0000;
1290}
1291#endif
1292
1293static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1294{
1295 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1296 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1297 ip_rt_min_advmss);
1298
1299 return min(advmss, IPV4_MAX_PMTU - header_size);
1300}
1301
1302static unsigned int ipv4_mtu(const struct dst_entry *dst)
1303{
1304 const struct rtable *rt = (const struct rtable *) dst;
1305 unsigned int mtu = rt->rt_pmtu;
1306
1307 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1308 mtu = dst_metric_raw(dst, RTAX_MTU);
1309
1310 if (mtu)
1311 return mtu;
1312
1313 mtu = READ_ONCE(dst->dev->mtu);
1314
1315 if (unlikely(ip_mtu_locked(dst))) {
1316 if (rt->rt_uses_gateway && mtu > 576)
1317 mtu = 576;
1318 }
1319
1320 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1321
1322 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1323}
1324
1325static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1326{
1327 struct fnhe_hash_bucket *hash;
1328 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1329 u32 hval = fnhe_hashfun(daddr);
1330
1331 spin_lock_bh(&fnhe_lock);
1332
1333 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1334 lockdep_is_held(&fnhe_lock));
1335 hash += hval;
1336
1337 fnhe_p = &hash->chain;
1338 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1339 while (fnhe) {
1340 if (fnhe->fnhe_daddr == daddr) {
1341 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1342 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1343 /* set fnhe_daddr to 0 to ensure it won't bind with
1344 * new dsts in rt_bind_exception().
1345 */
1346 fnhe->fnhe_daddr = 0;
1347 fnhe_flush_routes(fnhe);
1348 kfree_rcu(fnhe, rcu);
1349 break;
1350 }
1351 fnhe_p = &fnhe->fnhe_next;
1352 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1353 lockdep_is_held(&fnhe_lock));
1354 }
1355
1356 spin_unlock_bh(&fnhe_lock);
1357}
1358
1359static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1360 __be32 daddr)
1361{
1362 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1363 struct fib_nh_exception *fnhe;
1364 u32 hval;
1365
1366 if (!hash)
1367 return NULL;
1368
1369 hval = fnhe_hashfun(daddr);
1370
1371 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1372 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1373 if (fnhe->fnhe_daddr == daddr) {
1374 if (fnhe->fnhe_expires &&
1375 time_after(jiffies, fnhe->fnhe_expires)) {
1376 ip_del_fnhe(nhc, daddr);
1377 break;
1378 }
1379 return fnhe;
1380 }
1381 }
1382 return NULL;
1383}
1384
1385/* MTU selection:
1386 * 1. mtu on route is locked - use it
1387 * 2. mtu from nexthop exception
1388 * 3. mtu from egress device
1389 */
1390
1391u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1392{
1393 struct fib_nh_common *nhc = res->nhc;
1394 struct net_device *dev = nhc->nhc_dev;
1395 struct fib_info *fi = res->fi;
1396 u32 mtu = 0;
1397
1398 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1399 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1400 mtu = fi->fib_mtu;
1401
1402 if (likely(!mtu)) {
1403 struct fib_nh_exception *fnhe;
1404
1405 fnhe = find_exception(nhc, daddr);
1406 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1407 mtu = fnhe->fnhe_pmtu;
1408 }
1409
1410 if (likely(!mtu))
1411 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1412
1413 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1414}
1415
1416static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1417 __be32 daddr, const bool do_cache)
1418{
1419 bool ret = false;
1420
1421 spin_lock_bh(&fnhe_lock);
1422
1423 if (daddr == fnhe->fnhe_daddr) {
1424 struct rtable __rcu **porig;
1425 struct rtable *orig;
1426 int genid = fnhe_genid(dev_net(rt->dst.dev));
1427
1428 if (rt_is_input_route(rt))
1429 porig = &fnhe->fnhe_rth_input;
1430 else
1431 porig = &fnhe->fnhe_rth_output;
1432 orig = rcu_dereference(*porig);
1433
1434 if (fnhe->fnhe_genid != genid) {
1435 fnhe->fnhe_genid = genid;
1436 fnhe->fnhe_gw = 0;
1437 fnhe->fnhe_pmtu = 0;
1438 fnhe->fnhe_expires = 0;
1439 fnhe->fnhe_mtu_locked = false;
1440 fnhe_flush_routes(fnhe);
1441 orig = NULL;
1442 }
1443 fill_route_from_fnhe(rt, fnhe);
1444 if (!rt->rt_gw4) {
1445 rt->rt_gw4 = daddr;
1446 rt->rt_gw_family = AF_INET;
1447 }
1448
1449 if (do_cache) {
1450 dst_hold(&rt->dst);
1451 rcu_assign_pointer(*porig, rt);
1452 if (orig) {
1453 dst_dev_put(&orig->dst);
1454 dst_release(&orig->dst);
1455 }
1456 ret = true;
1457 }
1458
1459 fnhe->fnhe_stamp = jiffies;
1460 }
1461 spin_unlock_bh(&fnhe_lock);
1462
1463 return ret;
1464}
1465
1466static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1467{
1468 struct rtable *orig, *prev, **p;
1469 bool ret = true;
1470
1471 if (rt_is_input_route(rt)) {
1472 p = (struct rtable **)&nhc->nhc_rth_input;
1473 } else {
1474 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1475 }
1476 orig = *p;
1477
1478 /* hold dst before doing cmpxchg() to avoid race condition
1479 * on this dst
1480 */
1481 dst_hold(&rt->dst);
1482 prev = cmpxchg(p, orig, rt);
1483 if (prev == orig) {
1484 if (orig) {
1485 rt_add_uncached_list(orig);
1486 dst_release(&orig->dst);
1487 }
1488 } else {
1489 dst_release(&rt->dst);
1490 ret = false;
1491 }
1492
1493 return ret;
1494}
1495
1496struct uncached_list {
1497 spinlock_t lock;
1498 struct list_head head;
1499};
1500
1501static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1502
1503void rt_add_uncached_list(struct rtable *rt)
1504{
1505 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1506
1507 rt->rt_uncached_list = ul;
1508
1509 spin_lock_bh(&ul->lock);
1510 list_add_tail(&rt->rt_uncached, &ul->head);
1511 spin_unlock_bh(&ul->lock);
1512}
1513
1514void rt_del_uncached_list(struct rtable *rt)
1515{
1516 if (!list_empty(&rt->rt_uncached)) {
1517 struct uncached_list *ul = rt->rt_uncached_list;
1518
1519 spin_lock_bh(&ul->lock);
1520 list_del(&rt->rt_uncached);
1521 spin_unlock_bh(&ul->lock);
1522 }
1523}
1524
1525static void ipv4_dst_destroy(struct dst_entry *dst)
1526{
1527 struct rtable *rt = (struct rtable *)dst;
1528
1529 ip_dst_metrics_put(dst);
1530 rt_del_uncached_list(rt);
1531}
1532
1533void rt_flush_dev(struct net_device *dev)
1534{
1535 struct rtable *rt;
1536 int cpu;
1537
1538 for_each_possible_cpu(cpu) {
1539 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1540
1541 spin_lock_bh(&ul->lock);
1542 list_for_each_entry(rt, &ul->head, rt_uncached) {
1543 if (rt->dst.dev != dev)
1544 continue;
1545 rt->dst.dev = blackhole_netdev;
1546 dev_hold(rt->dst.dev);
1547 dev_put(dev);
1548 }
1549 spin_unlock_bh(&ul->lock);
1550 }
1551}
1552
1553static bool rt_cache_valid(const struct rtable *rt)
1554{
1555 return rt &&
1556 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1557 !rt_is_expired(rt);
1558}
1559
1560static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1561 const struct fib_result *res,
1562 struct fib_nh_exception *fnhe,
1563 struct fib_info *fi, u16 type, u32 itag,
1564 const bool do_cache)
1565{
1566 bool cached = false;
1567
1568 if (fi) {
1569 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1570
1571 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1572 rt->rt_uses_gateway = 1;
1573 rt->rt_gw_family = nhc->nhc_gw_family;
1574 /* only INET and INET6 are supported */
1575 if (likely(nhc->nhc_gw_family == AF_INET))
1576 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1577 else
1578 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1579 }
1580
1581 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1582
1583#ifdef CONFIG_IP_ROUTE_CLASSID
1584 if (nhc->nhc_family == AF_INET) {
1585 struct fib_nh *nh;
1586
1587 nh = container_of(nhc, struct fib_nh, nh_common);
1588 rt->dst.tclassid = nh->nh_tclassid;
1589 }
1590#endif
1591 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1592 if (unlikely(fnhe))
1593 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1594 else if (do_cache)
1595 cached = rt_cache_route(nhc, rt);
1596 if (unlikely(!cached)) {
1597 /* Routes we intend to cache in nexthop exception or
1598 * FIB nexthop have the DST_NOCACHE bit clear.
1599 * However, if we are unsuccessful at storing this
1600 * route into the cache we really need to set it.
1601 */
1602 if (!rt->rt_gw4) {
1603 rt->rt_gw_family = AF_INET;
1604 rt->rt_gw4 = daddr;
1605 }
1606 rt_add_uncached_list(rt);
1607 }
1608 } else
1609 rt_add_uncached_list(rt);
1610
1611#ifdef CONFIG_IP_ROUTE_CLASSID
1612#ifdef CONFIG_IP_MULTIPLE_TABLES
1613 set_class_tag(rt, res->tclassid);
1614#endif
1615 set_class_tag(rt, itag);
1616#endif
1617}
1618
1619struct rtable *rt_dst_alloc(struct net_device *dev,
1620 unsigned int flags, u16 type,
1621 bool nopolicy, bool noxfrm, bool will_cache)
1622{
1623 struct rtable *rt;
1624
1625 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1626 (will_cache ? 0 : DST_HOST) |
1627 (nopolicy ? DST_NOPOLICY : 0) |
1628 (noxfrm ? DST_NOXFRM : 0));
1629
1630 if (rt) {
1631 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1632 rt->rt_flags = flags;
1633 rt->rt_type = type;
1634 rt->rt_is_input = 0;
1635 rt->rt_iif = 0;
1636 rt->rt_pmtu = 0;
1637 rt->rt_mtu_locked = 0;
1638 rt->rt_uses_gateway = 0;
1639 rt->rt_gw_family = 0;
1640 rt->rt_gw4 = 0;
1641 INIT_LIST_HEAD(&rt->rt_uncached);
1642
1643 rt->dst.output = ip_output;
1644 if (flags & RTCF_LOCAL)
1645 rt->dst.input = ip_local_deliver;
1646 }
1647
1648 return rt;
1649}
1650EXPORT_SYMBOL(rt_dst_alloc);
1651
1652struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1653{
1654 struct rtable *new_rt;
1655
1656 new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1657 rt->dst.flags);
1658
1659 if (new_rt) {
1660 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1661 new_rt->rt_flags = rt->rt_flags;
1662 new_rt->rt_type = rt->rt_type;
1663 new_rt->rt_is_input = rt->rt_is_input;
1664 new_rt->rt_iif = rt->rt_iif;
1665 new_rt->rt_pmtu = rt->rt_pmtu;
1666 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1667 new_rt->rt_gw_family = rt->rt_gw_family;
1668 if (rt->rt_gw_family == AF_INET)
1669 new_rt->rt_gw4 = rt->rt_gw4;
1670 else if (rt->rt_gw_family == AF_INET6)
1671 new_rt->rt_gw6 = rt->rt_gw6;
1672 INIT_LIST_HEAD(&new_rt->rt_uncached);
1673
1674 new_rt->dst.flags |= DST_HOST;
1675 new_rt->dst.input = rt->dst.input;
1676 new_rt->dst.output = rt->dst.output;
1677 new_rt->dst.error = rt->dst.error;
1678 new_rt->dst.lastuse = jiffies;
1679 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1680 }
1681 return new_rt;
1682}
1683EXPORT_SYMBOL(rt_dst_clone);
1684
1685/* called in rcu_read_lock() section */
1686int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1687 u8 tos, struct net_device *dev,
1688 struct in_device *in_dev, u32 *itag)
1689{
1690 int err;
1691
1692 /* Primary sanity checks. */
1693 if (!in_dev)
1694 return -EINVAL;
1695
1696 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1697 skb->protocol != htons(ETH_P_IP))
1698 return -EINVAL;
1699
1700 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1701 return -EINVAL;
1702
1703 if (ipv4_is_zeronet(saddr)) {
1704 if (!ipv4_is_local_multicast(daddr) &&
1705 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1706 return -EINVAL;
1707 } else {
1708 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1709 in_dev, itag);
1710 if (err < 0)
1711 return err;
1712 }
1713 return 0;
1714}
1715
1716/* called in rcu_read_lock() section */
1717static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1718 u8 tos, struct net_device *dev, int our)
1719{
1720 struct in_device *in_dev = __in_dev_get_rcu(dev);
1721 unsigned int flags = RTCF_MULTICAST;
1722 struct rtable *rth;
1723 u32 itag = 0;
1724 int err;
1725
1726 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1727 if (err)
1728 return err;
1729
1730 if (our)
1731 flags |= RTCF_LOCAL;
1732
1733 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1734 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1735 if (!rth)
1736 return -ENOBUFS;
1737
1738#ifdef CONFIG_IP_ROUTE_CLASSID
1739 rth->dst.tclassid = itag;
1740#endif
1741 rth->dst.output = ip_rt_bug;
1742 rth->rt_is_input= 1;
1743
1744#ifdef CONFIG_IP_MROUTE
1745 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1746 rth->dst.input = ip_mr_input;
1747#endif
1748 RT_CACHE_STAT_INC(in_slow_mc);
1749
1750 skb_dst_set(skb, &rth->dst);
1751 return 0;
1752}
1753
1754
1755static void ip_handle_martian_source(struct net_device *dev,
1756 struct in_device *in_dev,
1757 struct sk_buff *skb,
1758 __be32 daddr,
1759 __be32 saddr)
1760{
1761 RT_CACHE_STAT_INC(in_martian_src);
1762#ifdef CONFIG_IP_ROUTE_VERBOSE
1763 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1764 /*
1765 * RFC1812 recommendation, if source is martian,
1766 * the only hint is MAC header.
1767 */
1768 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1769 &daddr, &saddr, dev->name);
1770 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1771 print_hex_dump(KERN_WARNING, "ll header: ",
1772 DUMP_PREFIX_OFFSET, 16, 1,
1773 skb_mac_header(skb),
1774 dev->hard_header_len, false);
1775 }
1776 }
1777#endif
1778}
1779
1780/* called in rcu_read_lock() section */
1781static int __mkroute_input(struct sk_buff *skb,
1782 const struct fib_result *res,
1783 struct in_device *in_dev,
1784 __be32 daddr, __be32 saddr, u32 tos)
1785{
1786 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1787 struct net_device *dev = nhc->nhc_dev;
1788 struct fib_nh_exception *fnhe;
1789 struct rtable *rth;
1790 int err;
1791 struct in_device *out_dev;
1792 bool do_cache;
1793 u32 itag = 0;
1794
1795 /* get a working reference to the output device */
1796 out_dev = __in_dev_get_rcu(dev);
1797 if (!out_dev) {
1798 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1799 return -EINVAL;
1800 }
1801
1802 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1803 in_dev->dev, in_dev, &itag);
1804 if (err < 0) {
1805 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1806 saddr);
1807
1808 goto cleanup;
1809 }
1810
1811 do_cache = res->fi && !itag;
1812 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1813 skb->protocol == htons(ETH_P_IP)) {
1814 __be32 gw;
1815
1816 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1817 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1818 inet_addr_onlink(out_dev, saddr, gw))
1819 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1820 }
1821
1822 if (skb->protocol != htons(ETH_P_IP)) {
1823 /* Not IP (i.e. ARP). Do not create route, if it is
1824 * invalid for proxy arp. DNAT routes are always valid.
1825 *
1826 * Proxy arp feature have been extended to allow, ARP
1827 * replies back to the same interface, to support
1828 * Private VLAN switch technologies. See arp.c.
1829 */
1830 if (out_dev == in_dev &&
1831 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1832 err = -EINVAL;
1833 goto cleanup;
1834 }
1835 }
1836
1837 fnhe = find_exception(nhc, daddr);
1838 if (do_cache) {
1839 if (fnhe)
1840 rth = rcu_dereference(fnhe->fnhe_rth_input);
1841 else
1842 rth = rcu_dereference(nhc->nhc_rth_input);
1843 if (rt_cache_valid(rth)) {
1844 skb_dst_set_noref(skb, &rth->dst);
1845 goto out;
1846 }
1847 }
1848
1849 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1850 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1851 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1852 if (!rth) {
1853 err = -ENOBUFS;
1854 goto cleanup;
1855 }
1856
1857 rth->rt_is_input = 1;
1858 RT_CACHE_STAT_INC(in_slow_tot);
1859
1860 rth->dst.input = ip_forward;
1861
1862 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1863 do_cache);
1864 lwtunnel_set_redirect(&rth->dst);
1865 skb_dst_set(skb, &rth->dst);
1866out:
1867 err = 0;
1868 cleanup:
1869 return err;
1870}
1871
1872#ifdef CONFIG_IP_ROUTE_MULTIPATH
1873/* To make ICMP packets follow the right flow, the multipath hash is
1874 * calculated from the inner IP addresses.
1875 */
1876static void ip_multipath_l3_keys(const struct sk_buff *skb,
1877 struct flow_keys *hash_keys)
1878{
1879 const struct iphdr *outer_iph = ip_hdr(skb);
1880 const struct iphdr *key_iph = outer_iph;
1881 const struct iphdr *inner_iph;
1882 const struct icmphdr *icmph;
1883 struct iphdr _inner_iph;
1884 struct icmphdr _icmph;
1885
1886 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1887 goto out;
1888
1889 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1890 goto out;
1891
1892 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1893 &_icmph);
1894 if (!icmph)
1895 goto out;
1896
1897 if (icmph->type != ICMP_DEST_UNREACH &&
1898 icmph->type != ICMP_REDIRECT &&
1899 icmph->type != ICMP_TIME_EXCEEDED &&
1900 icmph->type != ICMP_PARAMETERPROB)
1901 goto out;
1902
1903 inner_iph = skb_header_pointer(skb,
1904 outer_iph->ihl * 4 + sizeof(_icmph),
1905 sizeof(_inner_iph), &_inner_iph);
1906 if (!inner_iph)
1907 goto out;
1908
1909 key_iph = inner_iph;
1910out:
1911 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1912 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1913}
1914
1915/* if skb is set it will be used and fl4 can be NULL */
1916int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1917 const struct sk_buff *skb, struct flow_keys *flkeys)
1918{
1919 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
1920 struct flow_keys hash_keys;
1921 u32 mhash;
1922
1923 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1924 case 0:
1925 memset(&hash_keys, 0, sizeof(hash_keys));
1926 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1927 if (skb) {
1928 ip_multipath_l3_keys(skb, &hash_keys);
1929 } else {
1930 hash_keys.addrs.v4addrs.src = fl4->saddr;
1931 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1932 }
1933 break;
1934 case 1:
1935 /* skb is currently provided only when forwarding */
1936 if (skb) {
1937 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1938 struct flow_keys keys;
1939
1940 /* short-circuit if we already have L4 hash present */
1941 if (skb->l4_hash)
1942 return skb_get_hash_raw(skb) >> 1;
1943
1944 memset(&hash_keys, 0, sizeof(hash_keys));
1945
1946 if (!flkeys) {
1947 skb_flow_dissect_flow_keys(skb, &keys, flag);
1948 flkeys = &keys;
1949 }
1950
1951 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1952 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1953 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1954 hash_keys.ports.src = flkeys->ports.src;
1955 hash_keys.ports.dst = flkeys->ports.dst;
1956 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1957 } else {
1958 memset(&hash_keys, 0, sizeof(hash_keys));
1959 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1960 hash_keys.addrs.v4addrs.src = fl4->saddr;
1961 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1962 hash_keys.ports.src = fl4->fl4_sport;
1963 hash_keys.ports.dst = fl4->fl4_dport;
1964 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1965 }
1966 break;
1967 case 2:
1968 memset(&hash_keys, 0, sizeof(hash_keys));
1969 /* skb is currently provided only when forwarding */
1970 if (skb) {
1971 struct flow_keys keys;
1972
1973 skb_flow_dissect_flow_keys(skb, &keys, 0);
1974 /* Inner can be v4 or v6 */
1975 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1976 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1977 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1978 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1979 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1980 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1981 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1982 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1983 hash_keys.tags.flow_label = keys.tags.flow_label;
1984 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1985 } else {
1986 /* Same as case 0 */
1987 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1988 ip_multipath_l3_keys(skb, &hash_keys);
1989 }
1990 } else {
1991 /* Same as case 0 */
1992 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1993 hash_keys.addrs.v4addrs.src = fl4->saddr;
1994 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1995 }
1996 break;
1997 }
1998 mhash = flow_hash_from_keys(&hash_keys);
1999
2000 if (multipath_hash)
2001 mhash = jhash_2words(mhash, multipath_hash, 0);
2002
2003 return mhash >> 1;
2004}
2005#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2006
2007static int ip_mkroute_input(struct sk_buff *skb,
2008 struct fib_result *res,
2009 struct in_device *in_dev,
2010 __be32 daddr, __be32 saddr, u32 tos,
2011 struct flow_keys *hkeys)
2012{
2013#ifdef CONFIG_IP_ROUTE_MULTIPATH
2014 if (res->fi && fib_info_num_path(res->fi) > 1) {
2015 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2016
2017 fib_select_multipath(res, h);
2018 }
2019#endif
2020
2021 /* create a routing cache entry */
2022 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
2023}
2024
2025/*
2026 * NOTE. We drop all the packets that has local source
2027 * addresses, because every properly looped back packet
2028 * must have correct destination already attached by output routine.
2029 *
2030 * Such approach solves two big problems:
2031 * 1. Not simplex devices are handled properly.
2032 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2033 * called with rcu_read_lock()
2034 */
2035
2036static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2037 u8 tos, struct net_device *dev,
2038 struct fib_result *res)
2039{
2040 struct in_device *in_dev = __in_dev_get_rcu(dev);
2041 struct flow_keys *flkeys = NULL, _flkeys;
2042 struct net *net = dev_net(dev);
2043 struct ip_tunnel_info *tun_info;
2044 int err = -EINVAL;
2045 unsigned int flags = 0;
2046 u32 itag = 0;
2047 struct rtable *rth;
2048 struct flowi4 fl4;
2049 bool do_cache = true;
2050
2051 /* IP on this device is disabled. */
2052
2053 if (!in_dev)
2054 goto out;
2055
2056 /* Check for the most weird martians, which can be not detected
2057 by fib_lookup.
2058 */
2059
2060 tun_info = skb_tunnel_info(skb);
2061 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2062 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2063 else
2064 fl4.flowi4_tun_key.tun_id = 0;
2065 skb_dst_drop(skb);
2066
2067 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
2068 goto martian_source;
2069
2070 res->fi = NULL;
2071 res->table = NULL;
2072 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2073 goto brd_input;
2074
2075 /* Accept zero addresses only to limited broadcast;
2076 * I even do not know to fix it or not. Waiting for complains :-)
2077 */
2078 if (ipv4_is_zeronet(saddr))
2079 goto martian_source;
2080
2081 if (ipv4_is_zeronet(daddr))
2082 goto martian_destination;
2083
2084 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2085 * and call it once if daddr or/and saddr are loopback addresses
2086 */
2087 if (ipv4_is_loopback(daddr)) {
2088 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2089 goto martian_destination;
2090 } else if (ipv4_is_loopback(saddr)) {
2091 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
2092 goto martian_source;
2093 }
2094
2095 /*
2096 * Now we are ready to route packet.
2097 */
2098 fl4.flowi4_oif = 0;
2099 fl4.flowi4_iif = dev->ifindex;
2100 fl4.flowi4_mark = skb->mark;
2101 fl4.flowi4_tos = tos;
2102 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2103 fl4.flowi4_flags = 0;
2104 fl4.daddr = daddr;
2105 fl4.saddr = saddr;
2106 fl4.flowi4_uid = sock_net_uid(net, NULL);
2107
2108 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2109 flkeys = &_flkeys;
2110 } else {
2111 fl4.flowi4_proto = 0;
2112 fl4.fl4_sport = 0;
2113 fl4.fl4_dport = 0;
2114 }
2115
2116 err = fib_lookup(net, &fl4, res, 0);
2117 if (err != 0) {
2118 if (!IN_DEV_FORWARD(in_dev))
2119 err = -EHOSTUNREACH;
2120 goto no_route;
2121 }
2122
2123 if (res->type == RTN_BROADCAST) {
2124 if (IN_DEV_BFORWARD(in_dev))
2125 goto make_route;
2126 /* not do cache if bc_forwarding is enabled */
2127 if (IPV4_DEVCONF_ALL(net, BC_FORWARDING))
2128 do_cache = false;
2129 goto brd_input;
2130 }
2131
2132 if (res->type == RTN_LOCAL) {
2133 err = fib_validate_source(skb, saddr, daddr, tos,
2134 0, dev, in_dev, &itag);
2135 if (err < 0)
2136 goto martian_source;
2137 goto local_input;
2138 }
2139
2140 if (!IN_DEV_FORWARD(in_dev)) {
2141 err = -EHOSTUNREACH;
2142 goto no_route;
2143 }
2144 if (res->type != RTN_UNICAST)
2145 goto martian_destination;
2146
2147make_route:
2148 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2149out: return err;
2150
2151brd_input:
2152 if (skb->protocol != htons(ETH_P_IP))
2153 goto e_inval;
2154
2155 if (!ipv4_is_zeronet(saddr)) {
2156 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2157 in_dev, &itag);
2158 if (err < 0)
2159 goto martian_source;
2160 }
2161 flags |= RTCF_BROADCAST;
2162 res->type = RTN_BROADCAST;
2163 RT_CACHE_STAT_INC(in_brd);
2164
2165local_input:
2166 do_cache &= res->fi && !itag;
2167 if (do_cache) {
2168 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2169
2170 rth = rcu_dereference(nhc->nhc_rth_input);
2171 if (rt_cache_valid(rth)) {
2172 skb_dst_set_noref(skb, &rth->dst);
2173 err = 0;
2174 goto out;
2175 }
2176 }
2177
2178 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2179 flags | RTCF_LOCAL, res->type,
2180 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2181 if (!rth)
2182 goto e_nobufs;
2183
2184 rth->dst.output= ip_rt_bug;
2185#ifdef CONFIG_IP_ROUTE_CLASSID
2186 rth->dst.tclassid = itag;
2187#endif
2188 rth->rt_is_input = 1;
2189
2190 RT_CACHE_STAT_INC(in_slow_tot);
2191 if (res->type == RTN_UNREACHABLE) {
2192 rth->dst.input= ip_error;
2193 rth->dst.error= -err;
2194 rth->rt_flags &= ~RTCF_LOCAL;
2195 }
2196
2197 if (do_cache) {
2198 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2199
2200 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2201 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2202 WARN_ON(rth->dst.input == lwtunnel_input);
2203 rth->dst.lwtstate->orig_input = rth->dst.input;
2204 rth->dst.input = lwtunnel_input;
2205 }
2206
2207 if (unlikely(!rt_cache_route(nhc, rth)))
2208 rt_add_uncached_list(rth);
2209 }
2210 skb_dst_set(skb, &rth->dst);
2211 err = 0;
2212 goto out;
2213
2214no_route:
2215 RT_CACHE_STAT_INC(in_no_route);
2216 res->type = RTN_UNREACHABLE;
2217 res->fi = NULL;
2218 res->table = NULL;
2219 goto local_input;
2220
2221 /*
2222 * Do not cache martian addresses: they should be logged (RFC1812)
2223 */
2224martian_destination:
2225 RT_CACHE_STAT_INC(in_martian_dst);
2226#ifdef CONFIG_IP_ROUTE_VERBOSE
2227 if (IN_DEV_LOG_MARTIANS(in_dev))
2228 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2229 &daddr, &saddr, dev->name);
2230#endif
2231
2232e_inval:
2233 err = -EINVAL;
2234 goto out;
2235
2236e_nobufs:
2237 err = -ENOBUFS;
2238 goto out;
2239
2240martian_source:
2241 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2242 goto out;
2243}
2244
2245int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2246 u8 tos, struct net_device *dev)
2247{
2248 struct fib_result res;
2249 int err;
2250
2251 tos &= IPTOS_RT_MASK;
2252 rcu_read_lock();
2253 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2254 rcu_read_unlock();
2255
2256 return err;
2257}
2258EXPORT_SYMBOL(ip_route_input_noref);
2259
2260/* called with rcu_read_lock held */
2261int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2262 u8 tos, struct net_device *dev, struct fib_result *res)
2263{
2264 /* Multicast recognition logic is moved from route cache to here.
2265 The problem was that too many Ethernet cards have broken/missing
2266 hardware multicast filters :-( As result the host on multicasting
2267 network acquires a lot of useless route cache entries, sort of
2268 SDR messages from all the world. Now we try to get rid of them.
2269 Really, provided software IP multicast filter is organized
2270 reasonably (at least, hashed), it does not result in a slowdown
2271 comparing with route cache reject entries.
2272 Note, that multicast routers are not affected, because
2273 route cache entry is created eventually.
2274 */
2275 if (ipv4_is_multicast(daddr)) {
2276 struct in_device *in_dev = __in_dev_get_rcu(dev);
2277 int our = 0;
2278 int err = -EINVAL;
2279
2280 if (!in_dev)
2281 return err;
2282 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2283 ip_hdr(skb)->protocol);
2284
2285 /* check l3 master if no match yet */
2286 if (!our && netif_is_l3_slave(dev)) {
2287 struct in_device *l3_in_dev;
2288
2289 l3_in_dev = __in_dev_get_rcu(skb->dev);
2290 if (l3_in_dev)
2291 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2292 ip_hdr(skb)->protocol);
2293 }
2294
2295 if (our
2296#ifdef CONFIG_IP_MROUTE
2297 ||
2298 (!ipv4_is_local_multicast(daddr) &&
2299 IN_DEV_MFORWARD(in_dev))
2300#endif
2301 ) {
2302 err = ip_route_input_mc(skb, daddr, saddr,
2303 tos, dev, our);
2304 }
2305 return err;
2306 }
2307
2308 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2309}
2310
2311/* called with rcu_read_lock() */
2312static struct rtable *__mkroute_output(const struct fib_result *res,
2313 const struct flowi4 *fl4, int orig_oif,
2314 struct net_device *dev_out,
2315 unsigned int flags)
2316{
2317 struct fib_info *fi = res->fi;
2318 struct fib_nh_exception *fnhe;
2319 struct in_device *in_dev;
2320 u16 type = res->type;
2321 struct rtable *rth;
2322 bool do_cache;
2323
2324 in_dev = __in_dev_get_rcu(dev_out);
2325 if (!in_dev)
2326 return ERR_PTR(-EINVAL);
2327
2328 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2329 if (ipv4_is_loopback(fl4->saddr) &&
2330 !(dev_out->flags & IFF_LOOPBACK) &&
2331 !netif_is_l3_master(dev_out))
2332 return ERR_PTR(-EINVAL);
2333
2334 if (ipv4_is_lbcast(fl4->daddr))
2335 type = RTN_BROADCAST;
2336 else if (ipv4_is_multicast(fl4->daddr))
2337 type = RTN_MULTICAST;
2338 else if (ipv4_is_zeronet(fl4->daddr))
2339 return ERR_PTR(-EINVAL);
2340
2341 if (dev_out->flags & IFF_LOOPBACK)
2342 flags |= RTCF_LOCAL;
2343
2344 do_cache = true;
2345 if (type == RTN_BROADCAST) {
2346 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2347 fi = NULL;
2348 } else if (type == RTN_MULTICAST) {
2349 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2350 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2351 fl4->flowi4_proto))
2352 flags &= ~RTCF_LOCAL;
2353 else
2354 do_cache = false;
2355 /* If multicast route do not exist use
2356 * default one, but do not gateway in this case.
2357 * Yes, it is hack.
2358 */
2359 if (fi && res->prefixlen < 4)
2360 fi = NULL;
2361 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2362 (orig_oif != dev_out->ifindex)) {
2363 /* For local routes that require a particular output interface
2364 * we do not want to cache the result. Caching the result
2365 * causes incorrect behaviour when there are multiple source
2366 * addresses on the interface, the end result being that if the
2367 * intended recipient is waiting on that interface for the
2368 * packet he won't receive it because it will be delivered on
2369 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2370 * be set to the loopback interface as well.
2371 */
2372 do_cache = false;
2373 }
2374
2375 fnhe = NULL;
2376 do_cache &= fi != NULL;
2377 if (fi) {
2378 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2379 struct rtable __rcu **prth;
2380
2381 fnhe = find_exception(nhc, fl4->daddr);
2382 if (!do_cache)
2383 goto add;
2384 if (fnhe) {
2385 prth = &fnhe->fnhe_rth_output;
2386 } else {
2387 if (unlikely(fl4->flowi4_flags &
2388 FLOWI_FLAG_KNOWN_NH &&
2389 !(nhc->nhc_gw_family &&
2390 nhc->nhc_scope == RT_SCOPE_LINK))) {
2391 do_cache = false;
2392 goto add;
2393 }
2394 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2395 }
2396 rth = rcu_dereference(*prth);
2397 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2398 return rth;
2399 }
2400
2401add:
2402 rth = rt_dst_alloc(dev_out, flags, type,
2403 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2404 IN_DEV_CONF_GET(in_dev, NOXFRM),
2405 do_cache);
2406 if (!rth)
2407 return ERR_PTR(-ENOBUFS);
2408
2409 rth->rt_iif = orig_oif;
2410
2411 RT_CACHE_STAT_INC(out_slow_tot);
2412
2413 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2414 if (flags & RTCF_LOCAL &&
2415 !(dev_out->flags & IFF_LOOPBACK)) {
2416 rth->dst.output = ip_mc_output;
2417 RT_CACHE_STAT_INC(out_slow_mc);
2418 }
2419#ifdef CONFIG_IP_MROUTE
2420 if (type == RTN_MULTICAST) {
2421 if (IN_DEV_MFORWARD(in_dev) &&
2422 !ipv4_is_local_multicast(fl4->daddr)) {
2423 rth->dst.input = ip_mr_input;
2424 rth->dst.output = ip_mc_output;
2425 }
2426 }
2427#endif
2428 }
2429
2430 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2431 lwtunnel_set_redirect(&rth->dst);
2432
2433 return rth;
2434}
2435
2436/*
2437 * Major route resolver routine.
2438 */
2439
2440struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2441 const struct sk_buff *skb)
2442{
2443 __u8 tos = RT_FL_TOS(fl4);
2444 struct fib_result res = {
2445 .type = RTN_UNSPEC,
2446 .fi = NULL,
2447 .table = NULL,
2448 .tclassid = 0,
2449 };
2450 struct rtable *rth;
2451
2452 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2453 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2454 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2455 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2456
2457 rcu_read_lock();
2458 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2459 rcu_read_unlock();
2460
2461 return rth;
2462}
2463EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2464
2465struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2466 struct fib_result *res,
2467 const struct sk_buff *skb)
2468{
2469 struct net_device *dev_out = NULL;
2470 int orig_oif = fl4->flowi4_oif;
2471 unsigned int flags = 0;
2472 struct rtable *rth;
2473 int err;
2474
2475 if (fl4->saddr) {
2476 if (ipv4_is_multicast(fl4->saddr) ||
2477 ipv4_is_lbcast(fl4->saddr) ||
2478 ipv4_is_zeronet(fl4->saddr)) {
2479 rth = ERR_PTR(-EINVAL);
2480 goto out;
2481 }
2482
2483 rth = ERR_PTR(-ENETUNREACH);
2484
2485 /* I removed check for oif == dev_out->oif here.
2486 It was wrong for two reasons:
2487 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2488 is assigned to multiple interfaces.
2489 2. Moreover, we are allowed to send packets with saddr
2490 of another iface. --ANK
2491 */
2492
2493 if (fl4->flowi4_oif == 0 &&
2494 (ipv4_is_multicast(fl4->daddr) ||
2495 ipv4_is_lbcast(fl4->daddr))) {
2496 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2497 dev_out = __ip_dev_find(net, fl4->saddr, false);
2498 if (!dev_out)
2499 goto out;
2500
2501 /* Special hack: user can direct multicasts
2502 and limited broadcast via necessary interface
2503 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2504 This hack is not just for fun, it allows
2505 vic,vat and friends to work.
2506 They bind socket to loopback, set ttl to zero
2507 and expect that it will work.
2508 From the viewpoint of routing cache they are broken,
2509 because we are not allowed to build multicast path
2510 with loopback source addr (look, routing cache
2511 cannot know, that ttl is zero, so that packet
2512 will not leave this host and route is valid).
2513 Luckily, this hack is good workaround.
2514 */
2515
2516 fl4->flowi4_oif = dev_out->ifindex;
2517 goto make_route;
2518 }
2519
2520 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2521 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2522 if (!__ip_dev_find(net, fl4->saddr, false))
2523 goto out;
2524 }
2525 }
2526
2527
2528 if (fl4->flowi4_oif) {
2529 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2530 rth = ERR_PTR(-ENODEV);
2531 if (!dev_out)
2532 goto out;
2533
2534 /* RACE: Check return value of inet_select_addr instead. */
2535 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2536 rth = ERR_PTR(-ENETUNREACH);
2537 goto out;
2538 }
2539 if (ipv4_is_local_multicast(fl4->daddr) ||
2540 ipv4_is_lbcast(fl4->daddr) ||
2541 fl4->flowi4_proto == IPPROTO_IGMP) {
2542 if (!fl4->saddr)
2543 fl4->saddr = inet_select_addr(dev_out, 0,
2544 RT_SCOPE_LINK);
2545 goto make_route;
2546 }
2547 if (!fl4->saddr) {
2548 if (ipv4_is_multicast(fl4->daddr))
2549 fl4->saddr = inet_select_addr(dev_out, 0,
2550 fl4->flowi4_scope);
2551 else if (!fl4->daddr)
2552 fl4->saddr = inet_select_addr(dev_out, 0,
2553 RT_SCOPE_HOST);
2554 }
2555 }
2556
2557 if (!fl4->daddr) {
2558 fl4->daddr = fl4->saddr;
2559 if (!fl4->daddr)
2560 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2561 dev_out = net->loopback_dev;
2562 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2563 res->type = RTN_LOCAL;
2564 flags |= RTCF_LOCAL;
2565 goto make_route;
2566 }
2567
2568 err = fib_lookup(net, fl4, res, 0);
2569 if (err) {
2570 res->fi = NULL;
2571 res->table = NULL;
2572 if (fl4->flowi4_oif &&
2573 (ipv4_is_multicast(fl4->daddr) ||
2574 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2575 /* Apparently, routing tables are wrong. Assume,
2576 that the destination is on link.
2577
2578 WHY? DW.
2579 Because we are allowed to send to iface
2580 even if it has NO routes and NO assigned
2581 addresses. When oif is specified, routing
2582 tables are looked up with only one purpose:
2583 to catch if destination is gatewayed, rather than
2584 direct. Moreover, if MSG_DONTROUTE is set,
2585 we send packet, ignoring both routing tables
2586 and ifaddr state. --ANK
2587
2588
2589 We could make it even if oif is unknown,
2590 likely IPv6, but we do not.
2591 */
2592
2593 if (fl4->saddr == 0)
2594 fl4->saddr = inet_select_addr(dev_out, 0,
2595 RT_SCOPE_LINK);
2596 res->type = RTN_UNICAST;
2597 goto make_route;
2598 }
2599 rth = ERR_PTR(err);
2600 goto out;
2601 }
2602
2603 if (res->type == RTN_LOCAL) {
2604 if (!fl4->saddr) {
2605 if (res->fi->fib_prefsrc)
2606 fl4->saddr = res->fi->fib_prefsrc;
2607 else
2608 fl4->saddr = fl4->daddr;
2609 }
2610
2611 /* L3 master device is the loopback for that domain */
2612 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2613 net->loopback_dev;
2614
2615 /* make sure orig_oif points to fib result device even
2616 * though packet rx/tx happens over loopback or l3mdev
2617 */
2618 orig_oif = FIB_RES_OIF(*res);
2619
2620 fl4->flowi4_oif = dev_out->ifindex;
2621 flags |= RTCF_LOCAL;
2622 goto make_route;
2623 }
2624
2625 fib_select_path(net, res, fl4, skb);
2626
2627 dev_out = FIB_RES_DEV(*res);
2628 fl4->flowi4_oif = dev_out->ifindex;
2629
2630
2631make_route:
2632 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2633
2634out:
2635 return rth;
2636}
2637
2638static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2639{
2640 return NULL;
2641}
2642
2643static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2644{
2645 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2646
2647 return mtu ? : dst->dev->mtu;
2648}
2649
2650static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2651 struct sk_buff *skb, u32 mtu)
2652{
2653}
2654
2655static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2656 struct sk_buff *skb)
2657{
2658}
2659
2660static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2661 unsigned long old)
2662{
2663 return NULL;
2664}
2665
2666static struct dst_ops ipv4_dst_blackhole_ops = {
2667 .family = AF_INET,
2668 .check = ipv4_blackhole_dst_check,
2669 .mtu = ipv4_blackhole_mtu,
2670 .default_advmss = ipv4_default_advmss,
2671 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2672 .redirect = ipv4_rt_blackhole_redirect,
2673 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2674 .neigh_lookup = ipv4_neigh_lookup,
2675};
2676
2677struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2678{
2679 struct rtable *ort = (struct rtable *) dst_orig;
2680 struct rtable *rt;
2681
2682 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2683 if (rt) {
2684 struct dst_entry *new = &rt->dst;
2685
2686 new->__use = 1;
2687 new->input = dst_discard;
2688 new->output = dst_discard_out;
2689
2690 new->dev = net->loopback_dev;
2691 if (new->dev)
2692 dev_hold(new->dev);
2693
2694 rt->rt_is_input = ort->rt_is_input;
2695 rt->rt_iif = ort->rt_iif;
2696 rt->rt_pmtu = ort->rt_pmtu;
2697 rt->rt_mtu_locked = ort->rt_mtu_locked;
2698
2699 rt->rt_genid = rt_genid_ipv4(net);
2700 rt->rt_flags = ort->rt_flags;
2701 rt->rt_type = ort->rt_type;
2702 rt->rt_uses_gateway = ort->rt_uses_gateway;
2703 rt->rt_gw_family = ort->rt_gw_family;
2704 if (rt->rt_gw_family == AF_INET)
2705 rt->rt_gw4 = ort->rt_gw4;
2706 else if (rt->rt_gw_family == AF_INET6)
2707 rt->rt_gw6 = ort->rt_gw6;
2708
2709 INIT_LIST_HEAD(&rt->rt_uncached);
2710 }
2711
2712 dst_release(dst_orig);
2713
2714 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2715}
2716
2717struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2718 const struct sock *sk)
2719{
2720 struct rtable *rt = __ip_route_output_key(net, flp4);
2721
2722 if (IS_ERR(rt))
2723 return rt;
2724
2725 if (flp4->flowi4_proto)
2726 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2727 flowi4_to_flowi(flp4),
2728 sk, 0);
2729
2730 return rt;
2731}
2732EXPORT_SYMBOL_GPL(ip_route_output_flow);
2733
2734/* called with rcu_read_lock held */
2735static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2736 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2737 struct sk_buff *skb, u32 portid, u32 seq,
2738 unsigned int flags)
2739{
2740 struct rtmsg *r;
2741 struct nlmsghdr *nlh;
2742 unsigned long expires = 0;
2743 u32 error;
2744 u32 metrics[RTAX_MAX];
2745
2746 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2747 if (!nlh)
2748 return -EMSGSIZE;
2749
2750 r = nlmsg_data(nlh);
2751 r->rtm_family = AF_INET;
2752 r->rtm_dst_len = 32;
2753 r->rtm_src_len = 0;
2754 r->rtm_tos = fl4 ? fl4->flowi4_tos : 0;
2755 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2756 if (nla_put_u32(skb, RTA_TABLE, table_id))
2757 goto nla_put_failure;
2758 r->rtm_type = rt->rt_type;
2759 r->rtm_scope = RT_SCOPE_UNIVERSE;
2760 r->rtm_protocol = RTPROT_UNSPEC;
2761 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2762 if (rt->rt_flags & RTCF_NOTIFY)
2763 r->rtm_flags |= RTM_F_NOTIFY;
2764 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2765 r->rtm_flags |= RTCF_DOREDIRECT;
2766
2767 if (nla_put_in_addr(skb, RTA_DST, dst))
2768 goto nla_put_failure;
2769 if (src) {
2770 r->rtm_src_len = 32;
2771 if (nla_put_in_addr(skb, RTA_SRC, src))
2772 goto nla_put_failure;
2773 }
2774 if (rt->dst.dev &&
2775 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2776 goto nla_put_failure;
2777#ifdef CONFIG_IP_ROUTE_CLASSID
2778 if (rt->dst.tclassid &&
2779 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2780 goto nla_put_failure;
2781#endif
2782 if (fl4 && !rt_is_input_route(rt) &&
2783 fl4->saddr != src) {
2784 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2785 goto nla_put_failure;
2786 }
2787 if (rt->rt_uses_gateway) {
2788 if (rt->rt_gw_family == AF_INET &&
2789 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
2790 goto nla_put_failure;
2791 } else if (rt->rt_gw_family == AF_INET6) {
2792 int alen = sizeof(struct in6_addr);
2793 struct nlattr *nla;
2794 struct rtvia *via;
2795
2796 nla = nla_reserve(skb, RTA_VIA, alen + 2);
2797 if (!nla)
2798 goto nla_put_failure;
2799
2800 via = nla_data(nla);
2801 via->rtvia_family = AF_INET6;
2802 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
2803 }
2804 }
2805
2806 expires = rt->dst.expires;
2807 if (expires) {
2808 unsigned long now = jiffies;
2809
2810 if (time_before(now, expires))
2811 expires -= now;
2812 else
2813 expires = 0;
2814 }
2815
2816 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2817 if (rt->rt_pmtu && expires)
2818 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2819 if (rt->rt_mtu_locked && expires)
2820 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2821 if (rtnetlink_put_metrics(skb, metrics) < 0)
2822 goto nla_put_failure;
2823
2824 if (fl4) {
2825 if (fl4->flowi4_mark &&
2826 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2827 goto nla_put_failure;
2828
2829 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2830 nla_put_u32(skb, RTA_UID,
2831 from_kuid_munged(current_user_ns(),
2832 fl4->flowi4_uid)))
2833 goto nla_put_failure;
2834
2835 if (rt_is_input_route(rt)) {
2836#ifdef CONFIG_IP_MROUTE
2837 if (ipv4_is_multicast(dst) &&
2838 !ipv4_is_local_multicast(dst) &&
2839 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2840 int err = ipmr_get_route(net, skb,
2841 fl4->saddr, fl4->daddr,
2842 r, portid);
2843
2844 if (err <= 0) {
2845 if (err == 0)
2846 return 0;
2847 goto nla_put_failure;
2848 }
2849 } else
2850#endif
2851 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
2852 goto nla_put_failure;
2853 }
2854 }
2855
2856 error = rt->dst.error;
2857
2858 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2859 goto nla_put_failure;
2860
2861 nlmsg_end(skb, nlh);
2862 return 0;
2863
2864nla_put_failure:
2865 nlmsg_cancel(skb, nlh);
2866 return -EMSGSIZE;
2867}
2868
2869static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
2870 struct netlink_callback *cb, u32 table_id,
2871 struct fnhe_hash_bucket *bucket, int genid,
2872 int *fa_index, int fa_start, unsigned int flags)
2873{
2874 int i;
2875
2876 for (i = 0; i < FNHE_HASH_SIZE; i++) {
2877 struct fib_nh_exception *fnhe;
2878
2879 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
2880 fnhe = rcu_dereference(fnhe->fnhe_next)) {
2881 struct rtable *rt;
2882 int err;
2883
2884 if (*fa_index < fa_start)
2885 goto next;
2886
2887 if (fnhe->fnhe_genid != genid)
2888 goto next;
2889
2890 if (fnhe->fnhe_expires &&
2891 time_after(jiffies, fnhe->fnhe_expires))
2892 goto next;
2893
2894 rt = rcu_dereference(fnhe->fnhe_rth_input);
2895 if (!rt)
2896 rt = rcu_dereference(fnhe->fnhe_rth_output);
2897 if (!rt)
2898 goto next;
2899
2900 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
2901 table_id, NULL, skb,
2902 NETLINK_CB(cb->skb).portid,
2903 cb->nlh->nlmsg_seq, flags);
2904 if (err)
2905 return err;
2906next:
2907 (*fa_index)++;
2908 }
2909 }
2910
2911 return 0;
2912}
2913
2914int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
2915 u32 table_id, struct fib_info *fi,
2916 int *fa_index, int fa_start, unsigned int flags)
2917{
2918 struct net *net = sock_net(cb->skb->sk);
2919 int nhsel, genid = fnhe_genid(net);
2920
2921 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
2922 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
2923 struct fnhe_hash_bucket *bucket;
2924 int err;
2925
2926 if (nhc->nhc_flags & RTNH_F_DEAD)
2927 continue;
2928
2929 rcu_read_lock();
2930 bucket = rcu_dereference(nhc->nhc_exceptions);
2931 err = 0;
2932 if (bucket)
2933 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
2934 genid, fa_index, fa_start,
2935 flags);
2936 rcu_read_unlock();
2937 if (err)
2938 return err;
2939 }
2940
2941 return 0;
2942}
2943
2944static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
2945 u8 ip_proto, __be16 sport,
2946 __be16 dport)
2947{
2948 struct sk_buff *skb;
2949 struct iphdr *iph;
2950
2951 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2952 if (!skb)
2953 return NULL;
2954
2955 /* Reserve room for dummy headers, this skb can pass
2956 * through good chunk of routing engine.
2957 */
2958 skb_reset_mac_header(skb);
2959 skb_reset_network_header(skb);
2960 skb->protocol = htons(ETH_P_IP);
2961 iph = skb_put(skb, sizeof(struct iphdr));
2962 iph->protocol = ip_proto;
2963 iph->saddr = src;
2964 iph->daddr = dst;
2965 iph->version = 0x4;
2966 iph->frag_off = 0;
2967 iph->ihl = 0x5;
2968 skb_set_transport_header(skb, skb->len);
2969
2970 switch (iph->protocol) {
2971 case IPPROTO_UDP: {
2972 struct udphdr *udph;
2973
2974 udph = skb_put_zero(skb, sizeof(struct udphdr));
2975 udph->source = sport;
2976 udph->dest = dport;
2977 udph->len = sizeof(struct udphdr);
2978 udph->check = 0;
2979 break;
2980 }
2981 case IPPROTO_TCP: {
2982 struct tcphdr *tcph;
2983
2984 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
2985 tcph->source = sport;
2986 tcph->dest = dport;
2987 tcph->doff = sizeof(struct tcphdr) / 4;
2988 tcph->rst = 1;
2989 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
2990 src, dst, 0);
2991 break;
2992 }
2993 case IPPROTO_ICMP: {
2994 struct icmphdr *icmph;
2995
2996 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
2997 icmph->type = ICMP_ECHO;
2998 icmph->code = 0;
2999 }
3000 }
3001
3002 return skb;
3003}
3004
3005static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3006 const struct nlmsghdr *nlh,
3007 struct nlattr **tb,
3008 struct netlink_ext_ack *extack)
3009{
3010 struct rtmsg *rtm;
3011 int i, err;
3012
3013 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3014 NL_SET_ERR_MSG(extack,
3015 "ipv4: Invalid header for route get request");
3016 return -EINVAL;
3017 }
3018
3019 if (!netlink_strict_get_check(skb))
3020 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3021 rtm_ipv4_policy, extack);
3022
3023 rtm = nlmsg_data(nlh);
3024 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3025 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3026 rtm->rtm_table || rtm->rtm_protocol ||
3027 rtm->rtm_scope || rtm->rtm_type) {
3028 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3029 return -EINVAL;
3030 }
3031
3032 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3033 RTM_F_LOOKUP_TABLE |
3034 RTM_F_FIB_MATCH)) {
3035 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3036 return -EINVAL;
3037 }
3038
3039 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3040 rtm_ipv4_policy, extack);
3041 if (err)
3042 return err;
3043
3044 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3045 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3046 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3047 return -EINVAL;
3048 }
3049
3050 for (i = 0; i <= RTA_MAX; i++) {
3051 if (!tb[i])
3052 continue;
3053
3054 switch (i) {
3055 case RTA_IIF:
3056 case RTA_OIF:
3057 case RTA_SRC:
3058 case RTA_DST:
3059 case RTA_IP_PROTO:
3060 case RTA_SPORT:
3061 case RTA_DPORT:
3062 case RTA_MARK:
3063 case RTA_UID:
3064 break;
3065 default:
3066 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3067 return -EINVAL;
3068 }
3069 }
3070
3071 return 0;
3072}
3073
3074static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3075 struct netlink_ext_ack *extack)
3076{
3077 struct net *net = sock_net(in_skb->sk);
3078 struct nlattr *tb[RTA_MAX+1];
3079 u32 table_id = RT_TABLE_MAIN;
3080 __be16 sport = 0, dport = 0;
3081 struct fib_result res = {};
3082 u8 ip_proto = IPPROTO_UDP;
3083 struct rtable *rt = NULL;
3084 struct sk_buff *skb;
3085 struct rtmsg *rtm;
3086 struct flowi4 fl4 = {};
3087 __be32 dst = 0;
3088 __be32 src = 0;
3089 kuid_t uid;
3090 u32 iif;
3091 int err;
3092 int mark;
3093
3094 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3095 if (err < 0)
3096 return err;
3097
3098 rtm = nlmsg_data(nlh);
3099 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
3100 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
3101 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3102 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3103 if (tb[RTA_UID])
3104 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3105 else
3106 uid = (iif ? INVALID_UID : current_uid());
3107
3108 if (tb[RTA_IP_PROTO]) {
3109 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3110 &ip_proto, AF_INET, extack);
3111 if (err)
3112 return err;
3113 }
3114
3115 if (tb[RTA_SPORT])
3116 sport = nla_get_be16(tb[RTA_SPORT]);
3117
3118 if (tb[RTA_DPORT])
3119 dport = nla_get_be16(tb[RTA_DPORT]);
3120
3121 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3122 if (!skb)
3123 return -ENOBUFS;
3124
3125 fl4.daddr = dst;
3126 fl4.saddr = src;
3127 fl4.flowi4_tos = rtm->rtm_tos;
3128 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
3129 fl4.flowi4_mark = mark;
3130 fl4.flowi4_uid = uid;
3131 if (sport)
3132 fl4.fl4_sport = sport;
3133 if (dport)
3134 fl4.fl4_dport = dport;
3135 fl4.flowi4_proto = ip_proto;
3136
3137 rcu_read_lock();
3138
3139 if (iif) {
3140 struct net_device *dev;
3141
3142 dev = dev_get_by_index_rcu(net, iif);
3143 if (!dev) {
3144 err = -ENODEV;
3145 goto errout_rcu;
3146 }
3147
3148 fl4.flowi4_iif = iif; /* for rt_fill_info */
3149 skb->dev = dev;
3150 skb->mark = mark;
3151 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
3152 dev, &res);
3153
3154 rt = skb_rtable(skb);
3155 if (err == 0 && rt->dst.error)
3156 err = -rt->dst.error;
3157 } else {
3158 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3159 skb->dev = net->loopback_dev;
3160 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3161 err = 0;
3162 if (IS_ERR(rt))
3163 err = PTR_ERR(rt);
3164 else
3165 skb_dst_set(skb, &rt->dst);
3166 }
3167
3168 if (err)
3169 goto errout_rcu;
3170
3171 if (rtm->rtm_flags & RTM_F_NOTIFY)
3172 rt->rt_flags |= RTCF_NOTIFY;
3173
3174 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3175 table_id = res.table ? res.table->tb_id : 0;
3176
3177 /* reset skb for netlink reply msg */
3178 skb_trim(skb, 0);
3179 skb_reset_network_header(skb);
3180 skb_reset_transport_header(skb);
3181 skb_reset_mac_header(skb);
3182
3183 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3184 if (!res.fi) {
3185 err = fib_props[res.type].error;
3186 if (!err)
3187 err = -EHOSTUNREACH;
3188 goto errout_rcu;
3189 }
3190 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3191 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
3192 rt->rt_type, res.prefix, res.prefixlen,
3193 fl4.flowi4_tos, res.fi, 0);
3194 } else {
3195 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
3196 NETLINK_CB(in_skb).portid,
3197 nlh->nlmsg_seq, 0);
3198 }
3199 if (err < 0)
3200 goto errout_rcu;
3201
3202 rcu_read_unlock();
3203
3204 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3205
3206errout_free:
3207 return err;
3208errout_rcu:
3209 rcu_read_unlock();
3210 kfree_skb(skb);
3211 goto errout_free;
3212}
3213
3214void ip_rt_multicast_event(struct in_device *in_dev)
3215{
3216 rt_cache_flush(dev_net(in_dev->dev));
3217}
3218
3219#ifdef CONFIG_SYSCTL
3220static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3221static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3222static int ip_rt_gc_elasticity __read_mostly = 8;
3223static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3224
3225static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
3226 void __user *buffer,
3227 size_t *lenp, loff_t *ppos)
3228{
3229 struct net *net = (struct net *)__ctl->extra1;
3230
3231 if (write) {
3232 rt_cache_flush(net);
3233 fnhe_genid_bump(net);
3234 return 0;
3235 }
3236
3237 return -EINVAL;
3238}
3239
3240static struct ctl_table ipv4_route_table[] = {
3241 {
3242 .procname = "gc_thresh",
3243 .data = &ipv4_dst_ops.gc_thresh,
3244 .maxlen = sizeof(int),
3245 .mode = 0644,
3246 .proc_handler = proc_dointvec,
3247 },
3248 {
3249 .procname = "max_size",
3250 .data = &ip_rt_max_size,
3251 .maxlen = sizeof(int),
3252 .mode = 0644,
3253 .proc_handler = proc_dointvec,
3254 },
3255 {
3256 /* Deprecated. Use gc_min_interval_ms */
3257
3258 .procname = "gc_min_interval",
3259 .data = &ip_rt_gc_min_interval,
3260 .maxlen = sizeof(int),
3261 .mode = 0644,
3262 .proc_handler = proc_dointvec_jiffies,
3263 },
3264 {
3265 .procname = "gc_min_interval_ms",
3266 .data = &ip_rt_gc_min_interval,
3267 .maxlen = sizeof(int),
3268 .mode = 0644,
3269 .proc_handler = proc_dointvec_ms_jiffies,
3270 },
3271 {
3272 .procname = "gc_timeout",
3273 .data = &ip_rt_gc_timeout,
3274 .maxlen = sizeof(int),
3275 .mode = 0644,
3276 .proc_handler = proc_dointvec_jiffies,
3277 },
3278 {
3279 .procname = "gc_interval",
3280 .data = &ip_rt_gc_interval,
3281 .maxlen = sizeof(int),
3282 .mode = 0644,
3283 .proc_handler = proc_dointvec_jiffies,
3284 },
3285 {
3286 .procname = "redirect_load",
3287 .data = &ip_rt_redirect_load,
3288 .maxlen = sizeof(int),
3289 .mode = 0644,
3290 .proc_handler = proc_dointvec,
3291 },
3292 {
3293 .procname = "redirect_number",
3294 .data = &ip_rt_redirect_number,
3295 .maxlen = sizeof(int),
3296 .mode = 0644,
3297 .proc_handler = proc_dointvec,
3298 },
3299 {
3300 .procname = "redirect_silence",
3301 .data = &ip_rt_redirect_silence,
3302 .maxlen = sizeof(int),
3303 .mode = 0644,
3304 .proc_handler = proc_dointvec,
3305 },
3306 {
3307 .procname = "error_cost",
3308 .data = &ip_rt_error_cost,
3309 .maxlen = sizeof(int),
3310 .mode = 0644,
3311 .proc_handler = proc_dointvec,
3312 },
3313 {
3314 .procname = "error_burst",
3315 .data = &ip_rt_error_burst,
3316 .maxlen = sizeof(int),
3317 .mode = 0644,
3318 .proc_handler = proc_dointvec,
3319 },
3320 {
3321 .procname = "gc_elasticity",
3322 .data = &ip_rt_gc_elasticity,
3323 .maxlen = sizeof(int),
3324 .mode = 0644,
3325 .proc_handler = proc_dointvec,
3326 },
3327 {
3328 .procname = "mtu_expires",
3329 .data = &ip_rt_mtu_expires,
3330 .maxlen = sizeof(int),
3331 .mode = 0644,
3332 .proc_handler = proc_dointvec_jiffies,
3333 },
3334 {
3335 .procname = "min_pmtu",
3336 .data = &ip_rt_min_pmtu,
3337 .maxlen = sizeof(int),
3338 .mode = 0644,
3339 .proc_handler = proc_dointvec_minmax,
3340 .extra1 = &ip_min_valid_pmtu,
3341 },
3342 {
3343 .procname = "min_adv_mss",
3344 .data = &ip_rt_min_advmss,
3345 .maxlen = sizeof(int),
3346 .mode = 0644,
3347 .proc_handler = proc_dointvec,
3348 },
3349 { }
3350};
3351
3352static const char ipv4_route_flush_procname[] = "flush";
3353
3354static struct ctl_table ipv4_route_flush_table[] = {
3355 {
3356 .procname = ipv4_route_flush_procname,
3357 .maxlen = sizeof(int),
3358 .mode = 0200,
3359 .proc_handler = ipv4_sysctl_rtcache_flush,
3360 },
3361 { },
3362};
3363
3364static __net_init int sysctl_route_net_init(struct net *net)
3365{
3366 struct ctl_table *tbl;
3367
3368 tbl = ipv4_route_flush_table;
3369 if (!net_eq(net, &init_net)) {
3370 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3371 if (!tbl)
3372 goto err_dup;
3373
3374 /* Don't export non-whitelisted sysctls to unprivileged users */
3375 if (net->user_ns != &init_user_ns) {
3376 if (tbl[0].procname != ipv4_route_flush_procname)
3377 tbl[0].procname = NULL;
3378 }
3379 }
3380 tbl[0].extra1 = net;
3381
3382 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3383 if (!net->ipv4.route_hdr)
3384 goto err_reg;
3385 return 0;
3386
3387err_reg:
3388 if (tbl != ipv4_route_flush_table)
3389 kfree(tbl);
3390err_dup:
3391 return -ENOMEM;
3392}
3393
3394static __net_exit void sysctl_route_net_exit(struct net *net)
3395{
3396 struct ctl_table *tbl;
3397
3398 tbl = net->ipv4.route_hdr->ctl_table_arg;
3399 unregister_net_sysctl_table(net->ipv4.route_hdr);
3400 BUG_ON(tbl == ipv4_route_flush_table);
3401 kfree(tbl);
3402}
3403
3404static __net_initdata struct pernet_operations sysctl_route_ops = {
3405 .init = sysctl_route_net_init,
3406 .exit = sysctl_route_net_exit,
3407};
3408#endif
3409
3410static __net_init int rt_genid_init(struct net *net)
3411{
3412 atomic_set(&net->ipv4.rt_genid, 0);
3413 atomic_set(&net->fnhe_genid, 0);
3414 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3415 return 0;
3416}
3417
3418static __net_initdata struct pernet_operations rt_genid_ops = {
3419 .init = rt_genid_init,
3420};
3421
3422static int __net_init ipv4_inetpeer_init(struct net *net)
3423{
3424 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3425
3426 if (!bp)
3427 return -ENOMEM;
3428 inet_peer_base_init(bp);
3429 net->ipv4.peers = bp;
3430 return 0;
3431}
3432
3433static void __net_exit ipv4_inetpeer_exit(struct net *net)
3434{
3435 struct inet_peer_base *bp = net->ipv4.peers;
3436
3437 net->ipv4.peers = NULL;
3438 inetpeer_invalidate_tree(bp);
3439 kfree(bp);
3440}
3441
3442static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3443 .init = ipv4_inetpeer_init,
3444 .exit = ipv4_inetpeer_exit,
3445};
3446
3447#ifdef CONFIG_IP_ROUTE_CLASSID
3448struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3449#endif /* CONFIG_IP_ROUTE_CLASSID */
3450
3451int __init ip_rt_init(void)
3452{
3453 int cpu;
3454
3455 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents),
3456 GFP_KERNEL);
3457 if (!ip_idents)
3458 panic("IP: failed to allocate ip_idents\n");
3459
3460 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3461
3462 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3463 if (!ip_tstamps)
3464 panic("IP: failed to allocate ip_tstamps\n");
3465
3466 for_each_possible_cpu(cpu) {
3467 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3468
3469 INIT_LIST_HEAD(&ul->head);
3470 spin_lock_init(&ul->lock);
3471 }
3472#ifdef CONFIG_IP_ROUTE_CLASSID
3473 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3474 if (!ip_rt_acct)
3475 panic("IP: failed to allocate ip_rt_acct\n");
3476#endif
3477
3478 ipv4_dst_ops.kmem_cachep =
3479 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3480 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3481
3482 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3483
3484 if (dst_entries_init(&ipv4_dst_ops) < 0)
3485 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3486
3487 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3488 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3489
3490 ipv4_dst_ops.gc_thresh = ~0;
3491 ip_rt_max_size = INT_MAX;
3492
3493 devinet_init();
3494 ip_fib_init();
3495
3496 if (ip_rt_proc_init())
3497 pr_err("Unable to create route proc files\n");
3498#ifdef CONFIG_XFRM
3499 xfrm_init();
3500 xfrm4_init();
3501#endif
3502 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3503 RTNL_FLAG_DOIT_UNLOCKED);
3504
3505#ifdef CONFIG_SYSCTL
3506 register_pernet_subsys(&sysctl_route_ops);
3507#endif
3508 register_pernet_subsys(&rt_genid_ops);
3509 register_pernet_subsys(&ipv4_inetpeer_ops);
3510 return 0;
3511}
3512
3513#ifdef CONFIG_SYSCTL
3514/*
3515 * We really need to sanitize the damn ipv4 init order, then all
3516 * this nonsense will go away.
3517 */
3518void __init ip_static_sysctl_init(void)
3519{
3520 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3521}
3522#endif