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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * ROUTE - implementation of the IP router.
8 *
9 * Authors: Ross Biro
10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 * Alan Cox, <gw4pts@gw4pts.ampr.org>
12 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
13 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
14 *
15 * Fixes:
16 * Alan Cox : Verify area fixes.
17 * Alan Cox : cli() protects routing changes
18 * Rui Oliveira : ICMP routing table updates
19 * (rco@di.uminho.pt) Routing table insertion and update
20 * Linus Torvalds : Rewrote bits to be sensible
21 * Alan Cox : Added BSD route gw semantics
22 * Alan Cox : Super /proc >4K
23 * Alan Cox : MTU in route table
24 * Alan Cox : MSS actually. Also added the window
25 * clamper.
26 * Sam Lantinga : Fixed route matching in rt_del()
27 * Alan Cox : Routing cache support.
28 * Alan Cox : Removed compatibility cruft.
29 * Alan Cox : RTF_REJECT support.
30 * Alan Cox : TCP irtt support.
31 * Jonathan Naylor : Added Metric support.
32 * Miquel van Smoorenburg : BSD API fixes.
33 * Miquel van Smoorenburg : Metrics.
34 * Alan Cox : Use __u32 properly
35 * Alan Cox : Aligned routing errors more closely with BSD
36 * our system is still very different.
37 * Alan Cox : Faster /proc handling
38 * Alexey Kuznetsov : Massive rework to support tree based routing,
39 * routing caches and better behaviour.
40 *
41 * Olaf Erb : irtt wasn't being copied right.
42 * Bjorn Ekwall : Kerneld route support.
43 * Alan Cox : Multicast fixed (I hope)
44 * Pavel Krauz : Limited broadcast fixed
45 * Mike McLagan : Routing by source
46 * Alexey Kuznetsov : End of old history. Split to fib.c and
47 * route.c and rewritten from scratch.
48 * Andi Kleen : Load-limit warning messages.
49 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
50 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
51 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
52 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
53 * Marc Boucher : routing by fwmark
54 * Robert Olsson : Added rt_cache statistics
55 * Arnaldo C. Melo : Convert proc stuff to seq_file
56 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
57 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
58 * Ilia Sotnikov : Removed TOS from hash calculations
59 */
60
61#define pr_fmt(fmt) "IPv4: " fmt
62
63#include <linux/module.h>
64#include <linux/bitops.h>
65#include <linux/kernel.h>
66#include <linux/mm.h>
67#include <linux/memblock.h>
68#include <linux/socket.h>
69#include <linux/errno.h>
70#include <linux/in.h>
71#include <linux/inet.h>
72#include <linux/netdevice.h>
73#include <linux/proc_fs.h>
74#include <linux/init.h>
75#include <linux/skbuff.h>
76#include <linux/inetdevice.h>
77#include <linux/igmp.h>
78#include <linux/pkt_sched.h>
79#include <linux/mroute.h>
80#include <linux/netfilter_ipv4.h>
81#include <linux/random.h>
82#include <linux/rcupdate.h>
83#include <linux/slab.h>
84#include <linux/jhash.h>
85#include <net/dst.h>
86#include <net/dst_metadata.h>
87#include <net/inet_dscp.h>
88#include <net/net_namespace.h>
89#include <net/ip.h>
90#include <net/route.h>
91#include <net/inetpeer.h>
92#include <net/sock.h>
93#include <net/ip_fib.h>
94#include <net/nexthop.h>
95#include <net/tcp.h>
96#include <net/icmp.h>
97#include <net/xfrm.h>
98#include <net/lwtunnel.h>
99#include <net/netevent.h>
100#include <net/rtnetlink.h>
101#ifdef CONFIG_SYSCTL
102#include <linux/sysctl.h>
103#endif
104#include <net/secure_seq.h>
105#include <net/ip_tunnels.h>
106
107#include "fib_lookup.h"
108
109#define RT_GC_TIMEOUT (300*HZ)
110
111#define DEFAULT_MIN_PMTU (512 + 20 + 20)
112#define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
113#define DEFAULT_MIN_ADVMSS 256
114static int ip_rt_max_size;
115static int ip_rt_redirect_number __read_mostly = 9;
116static int ip_rt_redirect_load __read_mostly = HZ / 50;
117static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
118static int ip_rt_error_cost __read_mostly = HZ;
119static int ip_rt_error_burst __read_mostly = 5 * HZ;
120
121static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
122
123/*
124 * Interface to generic destination cache.
125 */
126
127INDIRECT_CALLABLE_SCOPE
128struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
129static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
130INDIRECT_CALLABLE_SCOPE
131unsigned int ipv4_mtu(const struct dst_entry *dst);
132static void ipv4_negative_advice(struct sock *sk,
133 struct dst_entry *dst);
134static void ipv4_link_failure(struct sk_buff *skb);
135static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
136 struct sk_buff *skb, u32 mtu,
137 bool confirm_neigh);
138static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
139 struct sk_buff *skb);
140static void ipv4_dst_destroy(struct dst_entry *dst);
141
142static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
143{
144 WARN_ON(1);
145 return NULL;
146}
147
148static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
149 struct sk_buff *skb,
150 const void *daddr);
151static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
152
153static struct dst_ops ipv4_dst_ops = {
154 .family = AF_INET,
155 .check = ipv4_dst_check,
156 .default_advmss = ipv4_default_advmss,
157 .mtu = ipv4_mtu,
158 .cow_metrics = ipv4_cow_metrics,
159 .destroy = ipv4_dst_destroy,
160 .negative_advice = ipv4_negative_advice,
161 .link_failure = ipv4_link_failure,
162 .update_pmtu = ip_rt_update_pmtu,
163 .redirect = ip_do_redirect,
164 .local_out = __ip_local_out,
165 .neigh_lookup = ipv4_neigh_lookup,
166 .confirm_neigh = ipv4_confirm_neigh,
167};
168
169#define ECN_OR_COST(class) TC_PRIO_##class
170
171const __u8 ip_tos2prio[16] = {
172 TC_PRIO_BESTEFFORT,
173 ECN_OR_COST(BESTEFFORT),
174 TC_PRIO_BESTEFFORT,
175 ECN_OR_COST(BESTEFFORT),
176 TC_PRIO_BULK,
177 ECN_OR_COST(BULK),
178 TC_PRIO_BULK,
179 ECN_OR_COST(BULK),
180 TC_PRIO_INTERACTIVE,
181 ECN_OR_COST(INTERACTIVE),
182 TC_PRIO_INTERACTIVE,
183 ECN_OR_COST(INTERACTIVE),
184 TC_PRIO_INTERACTIVE_BULK,
185 ECN_OR_COST(INTERACTIVE_BULK),
186 TC_PRIO_INTERACTIVE_BULK,
187 ECN_OR_COST(INTERACTIVE_BULK)
188};
189EXPORT_SYMBOL(ip_tos2prio);
190
191static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
192#define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
193
194#ifdef CONFIG_PROC_FS
195static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
196{
197 if (*pos)
198 return NULL;
199 return SEQ_START_TOKEN;
200}
201
202static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
203{
204 ++*pos;
205 return NULL;
206}
207
208static void rt_cache_seq_stop(struct seq_file *seq, void *v)
209{
210}
211
212static int rt_cache_seq_show(struct seq_file *seq, void *v)
213{
214 if (v == SEQ_START_TOKEN)
215 seq_printf(seq, "%-127s\n",
216 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
217 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
218 "HHUptod\tSpecDst");
219 return 0;
220}
221
222static const struct seq_operations rt_cache_seq_ops = {
223 .start = rt_cache_seq_start,
224 .next = rt_cache_seq_next,
225 .stop = rt_cache_seq_stop,
226 .show = rt_cache_seq_show,
227};
228
229static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
230{
231 int cpu;
232
233 if (*pos == 0)
234 return SEQ_START_TOKEN;
235
236 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
237 if (!cpu_possible(cpu))
238 continue;
239 *pos = cpu+1;
240 return &per_cpu(rt_cache_stat, cpu);
241 }
242 return NULL;
243}
244
245static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
246{
247 int cpu;
248
249 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
250 if (!cpu_possible(cpu))
251 continue;
252 *pos = cpu+1;
253 return &per_cpu(rt_cache_stat, cpu);
254 }
255 (*pos)++;
256 return NULL;
257
258}
259
260static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
261{
262
263}
264
265static int rt_cpu_seq_show(struct seq_file *seq, void *v)
266{
267 struct rt_cache_stat *st = v;
268
269 if (v == SEQ_START_TOKEN) {
270 seq_puts(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
271 return 0;
272 }
273
274 seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x "
275 "%08x %08x %08x %08x %08x %08x "
276 "%08x %08x %08x %08x\n",
277 dst_entries_get_slow(&ipv4_dst_ops),
278 0, /* st->in_hit */
279 st->in_slow_tot,
280 st->in_slow_mc,
281 st->in_no_route,
282 st->in_brd,
283 st->in_martian_dst,
284 st->in_martian_src,
285
286 0, /* st->out_hit */
287 st->out_slow_tot,
288 st->out_slow_mc,
289
290 0, /* st->gc_total */
291 0, /* st->gc_ignored */
292 0, /* st->gc_goal_miss */
293 0, /* st->gc_dst_overflow */
294 0, /* st->in_hlist_search */
295 0 /* st->out_hlist_search */
296 );
297 return 0;
298}
299
300static const struct seq_operations rt_cpu_seq_ops = {
301 .start = rt_cpu_seq_start,
302 .next = rt_cpu_seq_next,
303 .stop = rt_cpu_seq_stop,
304 .show = rt_cpu_seq_show,
305};
306
307#ifdef CONFIG_IP_ROUTE_CLASSID
308static int rt_acct_proc_show(struct seq_file *m, void *v)
309{
310 struct ip_rt_acct *dst, *src;
311 unsigned int i, j;
312
313 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
314 if (!dst)
315 return -ENOMEM;
316
317 for_each_possible_cpu(i) {
318 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
319 for (j = 0; j < 256; j++) {
320 dst[j].o_bytes += src[j].o_bytes;
321 dst[j].o_packets += src[j].o_packets;
322 dst[j].i_bytes += src[j].i_bytes;
323 dst[j].i_packets += src[j].i_packets;
324 }
325 }
326
327 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
328 kfree(dst);
329 return 0;
330}
331#endif
332
333static int __net_init ip_rt_do_proc_init(struct net *net)
334{
335 struct proc_dir_entry *pde;
336
337 pde = proc_create_seq("rt_cache", 0444, net->proc_net,
338 &rt_cache_seq_ops);
339 if (!pde)
340 goto err1;
341
342 pde = proc_create_seq("rt_cache", 0444, net->proc_net_stat,
343 &rt_cpu_seq_ops);
344 if (!pde)
345 goto err2;
346
347#ifdef CONFIG_IP_ROUTE_CLASSID
348 pde = proc_create_single("rt_acct", 0, net->proc_net,
349 rt_acct_proc_show);
350 if (!pde)
351 goto err3;
352#endif
353 return 0;
354
355#ifdef CONFIG_IP_ROUTE_CLASSID
356err3:
357 remove_proc_entry("rt_cache", net->proc_net_stat);
358#endif
359err2:
360 remove_proc_entry("rt_cache", net->proc_net);
361err1:
362 return -ENOMEM;
363}
364
365static void __net_exit ip_rt_do_proc_exit(struct net *net)
366{
367 remove_proc_entry("rt_cache", net->proc_net_stat);
368 remove_proc_entry("rt_cache", net->proc_net);
369#ifdef CONFIG_IP_ROUTE_CLASSID
370 remove_proc_entry("rt_acct", net->proc_net);
371#endif
372}
373
374static struct pernet_operations ip_rt_proc_ops __net_initdata = {
375 .init = ip_rt_do_proc_init,
376 .exit = ip_rt_do_proc_exit,
377};
378
379static int __init ip_rt_proc_init(void)
380{
381 return register_pernet_subsys(&ip_rt_proc_ops);
382}
383
384#else
385static inline int ip_rt_proc_init(void)
386{
387 return 0;
388}
389#endif /* CONFIG_PROC_FS */
390
391static inline bool rt_is_expired(const struct rtable *rth)
392{
393 bool res;
394
395 rcu_read_lock();
396 res = rth->rt_genid != rt_genid_ipv4(dev_net_rcu(rth->dst.dev));
397 rcu_read_unlock();
398
399 return res;
400}
401
402void rt_cache_flush(struct net *net)
403{
404 rt_genid_bump_ipv4(net);
405}
406
407static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
408 struct sk_buff *skb,
409 const void *daddr)
410{
411 const struct rtable *rt = container_of(dst, struct rtable, dst);
412 struct net_device *dev = dst->dev;
413 struct neighbour *n;
414
415 rcu_read_lock();
416
417 if (likely(rt->rt_gw_family == AF_INET)) {
418 n = ip_neigh_gw4(dev, rt->rt_gw4);
419 } else if (rt->rt_gw_family == AF_INET6) {
420 n = ip_neigh_gw6(dev, &rt->rt_gw6);
421 } else {
422 __be32 pkey;
423
424 pkey = skb ? ip_hdr(skb)->daddr : *((__be32 *) daddr);
425 n = ip_neigh_gw4(dev, pkey);
426 }
427
428 if (!IS_ERR(n) && !refcount_inc_not_zero(&n->refcnt))
429 n = NULL;
430
431 rcu_read_unlock();
432
433 return n;
434}
435
436static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
437{
438 const struct rtable *rt = container_of(dst, struct rtable, dst);
439 struct net_device *dev = dst->dev;
440 const __be32 *pkey = daddr;
441
442 if (rt->rt_gw_family == AF_INET) {
443 pkey = (const __be32 *)&rt->rt_gw4;
444 } else if (rt->rt_gw_family == AF_INET6) {
445 return __ipv6_confirm_neigh_stub(dev, &rt->rt_gw6);
446 } else if (!daddr ||
447 (rt->rt_flags &
448 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL))) {
449 return;
450 }
451 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
452}
453
454/* Hash tables of size 2048..262144 depending on RAM size.
455 * Each bucket uses 8 bytes.
456 */
457static u32 ip_idents_mask __read_mostly;
458static atomic_t *ip_idents __read_mostly;
459static u32 *ip_tstamps __read_mostly;
460
461/* In order to protect privacy, we add a perturbation to identifiers
462 * if one generator is seldom used. This makes hard for an attacker
463 * to infer how many packets were sent between two points in time.
464 */
465static u32 ip_idents_reserve(u32 hash, int segs)
466{
467 u32 bucket, old, now = (u32)jiffies;
468 atomic_t *p_id;
469 u32 *p_tstamp;
470 u32 delta = 0;
471
472 bucket = hash & ip_idents_mask;
473 p_tstamp = ip_tstamps + bucket;
474 p_id = ip_idents + bucket;
475 old = READ_ONCE(*p_tstamp);
476
477 if (old != now && cmpxchg(p_tstamp, old, now) == old)
478 delta = get_random_u32_below(now - old);
479
480 /* If UBSAN reports an error there, please make sure your compiler
481 * supports -fno-strict-overflow before reporting it that was a bug
482 * in UBSAN, and it has been fixed in GCC-8.
483 */
484 return atomic_add_return(segs + delta, p_id) - segs;
485}
486
487void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
488{
489 u32 hash, id;
490
491 /* Note the following code is not safe, but this is okay. */
492 if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key)))
493 get_random_bytes(&net->ipv4.ip_id_key,
494 sizeof(net->ipv4.ip_id_key));
495
496 hash = siphash_3u32((__force u32)iph->daddr,
497 (__force u32)iph->saddr,
498 iph->protocol,
499 &net->ipv4.ip_id_key);
500 id = ip_idents_reserve(hash, segs);
501 iph->id = htons(id);
502}
503EXPORT_SYMBOL(__ip_select_ident);
504
505static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
506 const struct sock *sk, const struct iphdr *iph,
507 int oif, __u8 tos, u8 prot, u32 mark,
508 int flow_flags)
509{
510 __u8 scope = RT_SCOPE_UNIVERSE;
511
512 if (sk) {
513 oif = sk->sk_bound_dev_if;
514 mark = READ_ONCE(sk->sk_mark);
515 tos = ip_sock_rt_tos(sk);
516 scope = ip_sock_rt_scope(sk);
517 prot = inet_test_bit(HDRINCL, sk) ? IPPROTO_RAW :
518 sk->sk_protocol;
519 }
520
521 flowi4_init_output(fl4, oif, mark, tos & INET_DSCP_MASK, scope,
522 prot, flow_flags, iph->daddr, iph->saddr, 0, 0,
523 sock_net_uid(net, sk));
524}
525
526static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
527 const struct sock *sk)
528{
529 const struct net *net = dev_net(skb->dev);
530 const struct iphdr *iph = ip_hdr(skb);
531 int oif = skb->dev->ifindex;
532 u8 prot = iph->protocol;
533 u32 mark = skb->mark;
534 __u8 tos = iph->tos;
535
536 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
537}
538
539static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
540{
541 const struct inet_sock *inet = inet_sk(sk);
542 const struct ip_options_rcu *inet_opt;
543 __be32 daddr = inet->inet_daddr;
544
545 rcu_read_lock();
546 inet_opt = rcu_dereference(inet->inet_opt);
547 if (inet_opt && inet_opt->opt.srr)
548 daddr = inet_opt->opt.faddr;
549 flowi4_init_output(fl4, sk->sk_bound_dev_if, READ_ONCE(sk->sk_mark),
550 ip_sock_rt_tos(sk),
551 ip_sock_rt_scope(sk),
552 inet_test_bit(HDRINCL, sk) ?
553 IPPROTO_RAW : sk->sk_protocol,
554 inet_sk_flowi_flags(sk),
555 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
556 rcu_read_unlock();
557}
558
559static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
560 const struct sk_buff *skb)
561{
562 if (skb)
563 build_skb_flow_key(fl4, skb, sk);
564 else
565 build_sk_flow_key(fl4, sk);
566}
567
568static DEFINE_SPINLOCK(fnhe_lock);
569
570static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
571{
572 struct rtable *rt;
573
574 rt = rcu_dereference(fnhe->fnhe_rth_input);
575 if (rt) {
576 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
577 dst_dev_put(&rt->dst);
578 dst_release(&rt->dst);
579 }
580 rt = rcu_dereference(fnhe->fnhe_rth_output);
581 if (rt) {
582 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
583 dst_dev_put(&rt->dst);
584 dst_release(&rt->dst);
585 }
586}
587
588static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
589{
590 struct fib_nh_exception __rcu **fnhe_p, **oldest_p;
591 struct fib_nh_exception *fnhe, *oldest = NULL;
592
593 for (fnhe_p = &hash->chain; ; fnhe_p = &fnhe->fnhe_next) {
594 fnhe = rcu_dereference_protected(*fnhe_p,
595 lockdep_is_held(&fnhe_lock));
596 if (!fnhe)
597 break;
598 if (!oldest ||
599 time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) {
600 oldest = fnhe;
601 oldest_p = fnhe_p;
602 }
603 }
604 fnhe_flush_routes(oldest);
605 *oldest_p = oldest->fnhe_next;
606 kfree_rcu(oldest, rcu);
607}
608
609static u32 fnhe_hashfun(__be32 daddr)
610{
611 static siphash_aligned_key_t fnhe_hash_key;
612 u64 hval;
613
614 net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));
615 hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key);
616 return hash_64(hval, FNHE_HASH_SHIFT);
617}
618
619static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
620{
621 rt->rt_pmtu = fnhe->fnhe_pmtu;
622 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
623 rt->dst.expires = fnhe->fnhe_expires;
624
625 if (fnhe->fnhe_gw) {
626 rt->rt_flags |= RTCF_REDIRECTED;
627 rt->rt_uses_gateway = 1;
628 rt->rt_gw_family = AF_INET;
629 rt->rt_gw4 = fnhe->fnhe_gw;
630 }
631}
632
633static void update_or_create_fnhe(struct fib_nh_common *nhc, __be32 daddr,
634 __be32 gw, u32 pmtu, bool lock,
635 unsigned long expires)
636{
637 struct fnhe_hash_bucket *hash;
638 struct fib_nh_exception *fnhe;
639 struct rtable *rt;
640 u32 genid, hval;
641 unsigned int i;
642 int depth;
643
644 genid = fnhe_genid(dev_net(nhc->nhc_dev));
645 hval = fnhe_hashfun(daddr);
646
647 spin_lock_bh(&fnhe_lock);
648
649 hash = rcu_dereference(nhc->nhc_exceptions);
650 if (!hash) {
651 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
652 if (!hash)
653 goto out_unlock;
654 rcu_assign_pointer(nhc->nhc_exceptions, hash);
655 }
656
657 hash += hval;
658
659 depth = 0;
660 for (fnhe = rcu_dereference(hash->chain); fnhe;
661 fnhe = rcu_dereference(fnhe->fnhe_next)) {
662 if (fnhe->fnhe_daddr == daddr)
663 break;
664 depth++;
665 }
666
667 if (fnhe) {
668 if (fnhe->fnhe_genid != genid)
669 fnhe->fnhe_genid = genid;
670 if (gw)
671 fnhe->fnhe_gw = gw;
672 if (pmtu) {
673 fnhe->fnhe_pmtu = pmtu;
674 fnhe->fnhe_mtu_locked = lock;
675 }
676 fnhe->fnhe_expires = max(1UL, expires);
677 /* Update all cached dsts too */
678 rt = rcu_dereference(fnhe->fnhe_rth_input);
679 if (rt)
680 fill_route_from_fnhe(rt, fnhe);
681 rt = rcu_dereference(fnhe->fnhe_rth_output);
682 if (rt)
683 fill_route_from_fnhe(rt, fnhe);
684 } else {
685 /* Randomize max depth to avoid some side channels attacks. */
686 int max_depth = FNHE_RECLAIM_DEPTH +
687 get_random_u32_below(FNHE_RECLAIM_DEPTH);
688
689 while (depth > max_depth) {
690 fnhe_remove_oldest(hash);
691 depth--;
692 }
693
694 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
695 if (!fnhe)
696 goto out_unlock;
697
698 fnhe->fnhe_next = hash->chain;
699
700 fnhe->fnhe_genid = genid;
701 fnhe->fnhe_daddr = daddr;
702 fnhe->fnhe_gw = gw;
703 fnhe->fnhe_pmtu = pmtu;
704 fnhe->fnhe_mtu_locked = lock;
705 fnhe->fnhe_expires = max(1UL, expires);
706
707 rcu_assign_pointer(hash->chain, fnhe);
708
709 /* Exception created; mark the cached routes for the nexthop
710 * stale, so anyone caching it rechecks if this exception
711 * applies to them.
712 */
713 rt = rcu_dereference(nhc->nhc_rth_input);
714 if (rt)
715 rt->dst.obsolete = DST_OBSOLETE_KILL;
716
717 for_each_possible_cpu(i) {
718 struct rtable __rcu **prt;
719
720 prt = per_cpu_ptr(nhc->nhc_pcpu_rth_output, i);
721 rt = rcu_dereference(*prt);
722 if (rt)
723 rt->dst.obsolete = DST_OBSOLETE_KILL;
724 }
725 }
726
727 fnhe->fnhe_stamp = jiffies;
728
729out_unlock:
730 spin_unlock_bh(&fnhe_lock);
731}
732
733static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
734 bool kill_route)
735{
736 __be32 new_gw = icmp_hdr(skb)->un.gateway;
737 __be32 old_gw = ip_hdr(skb)->saddr;
738 struct net_device *dev = skb->dev;
739 struct in_device *in_dev;
740 struct fib_result res;
741 struct neighbour *n;
742 struct net *net;
743
744 switch (icmp_hdr(skb)->code & 7) {
745 case ICMP_REDIR_NET:
746 case ICMP_REDIR_NETTOS:
747 case ICMP_REDIR_HOST:
748 case ICMP_REDIR_HOSTTOS:
749 break;
750
751 default:
752 return;
753 }
754
755 if (rt->rt_gw_family != AF_INET || rt->rt_gw4 != old_gw)
756 return;
757
758 in_dev = __in_dev_get_rcu(dev);
759 if (!in_dev)
760 return;
761
762 net = dev_net(dev);
763 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
764 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
765 ipv4_is_zeronet(new_gw))
766 goto reject_redirect;
767
768 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
769 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
770 goto reject_redirect;
771 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
772 goto reject_redirect;
773 } else {
774 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
775 goto reject_redirect;
776 }
777
778 n = __ipv4_neigh_lookup(rt->dst.dev, (__force u32)new_gw);
779 if (!n)
780 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
781 if (!IS_ERR(n)) {
782 if (!(READ_ONCE(n->nud_state) & NUD_VALID)) {
783 neigh_event_send(n, NULL);
784 } else {
785 if (fib_lookup(net, fl4, &res, 0) == 0) {
786 struct fib_nh_common *nhc;
787
788 fib_select_path(net, &res, fl4, skb);
789 nhc = FIB_RES_NHC(res);
790 update_or_create_fnhe(nhc, fl4->daddr, new_gw,
791 0, false,
792 jiffies + ip_rt_gc_timeout);
793 }
794 if (kill_route)
795 rt->dst.obsolete = DST_OBSOLETE_KILL;
796 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
797 }
798 neigh_release(n);
799 }
800 return;
801
802reject_redirect:
803#ifdef CONFIG_IP_ROUTE_VERBOSE
804 if (IN_DEV_LOG_MARTIANS(in_dev)) {
805 const struct iphdr *iph = (const struct iphdr *) skb->data;
806 __be32 daddr = iph->daddr;
807 __be32 saddr = iph->saddr;
808
809 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
810 " Advised path = %pI4 -> %pI4\n",
811 &old_gw, dev->name, &new_gw,
812 &saddr, &daddr);
813 }
814#endif
815 ;
816}
817
818static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
819{
820 struct rtable *rt;
821 struct flowi4 fl4;
822 const struct iphdr *iph = (const struct iphdr *) skb->data;
823 struct net *net = dev_net(skb->dev);
824 int oif = skb->dev->ifindex;
825 u8 prot = iph->protocol;
826 u32 mark = skb->mark;
827 __u8 tos = iph->tos;
828
829 rt = dst_rtable(dst);
830
831 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
832 __ip_do_redirect(rt, skb, &fl4, true);
833}
834
835static void ipv4_negative_advice(struct sock *sk,
836 struct dst_entry *dst)
837{
838 struct rtable *rt = dst_rtable(dst);
839
840 if ((dst->obsolete > 0) ||
841 (rt->rt_flags & RTCF_REDIRECTED) ||
842 rt->dst.expires)
843 sk_dst_reset(sk);
844}
845
846/*
847 * Algorithm:
848 * 1. The first ip_rt_redirect_number redirects are sent
849 * with exponential backoff, then we stop sending them at all,
850 * assuming that the host ignores our redirects.
851 * 2. If we did not see packets requiring redirects
852 * during ip_rt_redirect_silence, we assume that the host
853 * forgot redirected route and start to send redirects again.
854 *
855 * This algorithm is much cheaper and more intelligent than dumb load limiting
856 * in icmp.c.
857 *
858 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
859 * and "frag. need" (breaks PMTU discovery) in icmp.c.
860 */
861
862void ip_rt_send_redirect(struct sk_buff *skb)
863{
864 struct rtable *rt = skb_rtable(skb);
865 struct in_device *in_dev;
866 struct inet_peer *peer;
867 struct net *net;
868 int log_martians;
869 int vif;
870
871 rcu_read_lock();
872 in_dev = __in_dev_get_rcu(rt->dst.dev);
873 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
874 rcu_read_unlock();
875 return;
876 }
877 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
878 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
879
880 net = dev_net(rt->dst.dev);
881 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif);
882 if (!peer) {
883 rcu_read_unlock();
884 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
885 rt_nexthop(rt, ip_hdr(skb)->daddr));
886 return;
887 }
888
889 /* No redirected packets during ip_rt_redirect_silence;
890 * reset the algorithm.
891 */
892 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence)) {
893 peer->rate_tokens = 0;
894 peer->n_redirects = 0;
895 }
896
897 /* Too many ignored redirects; do not send anything
898 * set dst.rate_last to the last seen redirected packet.
899 */
900 if (peer->n_redirects >= ip_rt_redirect_number) {
901 peer->rate_last = jiffies;
902 goto out_unlock;
903 }
904
905 /* Check for load limit; set rate_last to the latest sent
906 * redirect.
907 */
908 if (peer->n_redirects == 0 ||
909 time_after(jiffies,
910 (peer->rate_last +
911 (ip_rt_redirect_load << peer->n_redirects)))) {
912 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
913
914 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
915 peer->rate_last = jiffies;
916 ++peer->n_redirects;
917 if (IS_ENABLED(CONFIG_IP_ROUTE_VERBOSE) && log_martians &&
918 peer->n_redirects == ip_rt_redirect_number)
919 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
920 &ip_hdr(skb)->saddr, inet_iif(skb),
921 &ip_hdr(skb)->daddr, &gw);
922 }
923out_unlock:
924 rcu_read_unlock();
925}
926
927static int ip_error(struct sk_buff *skb)
928{
929 struct rtable *rt = skb_rtable(skb);
930 struct net_device *dev = skb->dev;
931 struct in_device *in_dev;
932 struct inet_peer *peer;
933 unsigned long now;
934 struct net *net;
935 SKB_DR(reason);
936 bool send;
937 int code;
938
939 if (netif_is_l3_master(skb->dev)) {
940 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
941 if (!dev)
942 goto out;
943 }
944
945 in_dev = __in_dev_get_rcu(dev);
946
947 /* IP on this device is disabled. */
948 if (!in_dev)
949 goto out;
950
951 net = dev_net(rt->dst.dev);
952 if (!IN_DEV_FORWARD(in_dev)) {
953 switch (rt->dst.error) {
954 case EHOSTUNREACH:
955 SKB_DR_SET(reason, IP_INADDRERRORS);
956 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
957 break;
958
959 case ENETUNREACH:
960 SKB_DR_SET(reason, IP_INNOROUTES);
961 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
962 break;
963 }
964 goto out;
965 }
966
967 switch (rt->dst.error) {
968 case EINVAL:
969 default:
970 goto out;
971 case EHOSTUNREACH:
972 code = ICMP_HOST_UNREACH;
973 break;
974 case ENETUNREACH:
975 code = ICMP_NET_UNREACH;
976 SKB_DR_SET(reason, IP_INNOROUTES);
977 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
978 break;
979 case EACCES:
980 code = ICMP_PKT_FILTERED;
981 break;
982 }
983
984 rcu_read_lock();
985 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
986 l3mdev_master_ifindex_rcu(skb->dev));
987 send = true;
988 if (peer) {
989 now = jiffies;
990 peer->rate_tokens += now - peer->rate_last;
991 if (peer->rate_tokens > ip_rt_error_burst)
992 peer->rate_tokens = ip_rt_error_burst;
993 peer->rate_last = now;
994 if (peer->rate_tokens >= ip_rt_error_cost)
995 peer->rate_tokens -= ip_rt_error_cost;
996 else
997 send = false;
998 }
999 rcu_read_unlock();
1000
1001 if (send)
1002 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1003
1004out: kfree_skb_reason(skb, reason);
1005 return 0;
1006}
1007
1008static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1009{
1010 struct dst_entry *dst = &rt->dst;
1011 struct fib_result res;
1012 bool lock = false;
1013 struct net *net;
1014 u32 old_mtu;
1015
1016 if (ip_mtu_locked(dst))
1017 return;
1018
1019 old_mtu = ipv4_mtu(dst);
1020 if (old_mtu < mtu)
1021 return;
1022
1023 rcu_read_lock();
1024 net = dev_net_rcu(dst->dev);
1025 if (mtu < net->ipv4.ip_rt_min_pmtu) {
1026 lock = true;
1027 mtu = min(old_mtu, net->ipv4.ip_rt_min_pmtu);
1028 }
1029
1030 if (rt->rt_pmtu == mtu && !lock &&
1031 time_before(jiffies, dst->expires - net->ipv4.ip_rt_mtu_expires / 2))
1032 goto out;
1033
1034 if (fib_lookup(net, fl4, &res, 0) == 0) {
1035 struct fib_nh_common *nhc;
1036
1037 fib_select_path(net, &res, fl4, NULL);
1038#ifdef CONFIG_IP_ROUTE_MULTIPATH
1039 if (fib_info_num_path(res.fi) > 1) {
1040 int nhsel;
1041
1042 for (nhsel = 0; nhsel < fib_info_num_path(res.fi); nhsel++) {
1043 nhc = fib_info_nhc(res.fi, nhsel);
1044 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1045 jiffies + net->ipv4.ip_rt_mtu_expires);
1046 }
1047 goto out;
1048 }
1049#endif /* CONFIG_IP_ROUTE_MULTIPATH */
1050 nhc = FIB_RES_NHC(res);
1051 update_or_create_fnhe(nhc, fl4->daddr, 0, mtu, lock,
1052 jiffies + net->ipv4.ip_rt_mtu_expires);
1053 }
1054out:
1055 rcu_read_unlock();
1056}
1057
1058static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1059 struct sk_buff *skb, u32 mtu,
1060 bool confirm_neigh)
1061{
1062 struct rtable *rt = dst_rtable(dst);
1063 struct flowi4 fl4;
1064
1065 ip_rt_build_flow_key(&fl4, sk, skb);
1066
1067 /* Don't make lookup fail for bridged encapsulations */
1068 if (skb && netif_is_any_bridge_port(skb->dev))
1069 fl4.flowi4_oif = 0;
1070
1071 __ip_rt_update_pmtu(rt, &fl4, mtu);
1072}
1073
1074void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1075 int oif, u8 protocol)
1076{
1077 const struct iphdr *iph = (const struct iphdr *)skb->data;
1078 struct flowi4 fl4;
1079 struct rtable *rt;
1080 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1081
1082 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, mark,
1083 0);
1084 rt = __ip_route_output_key(net, &fl4);
1085 if (!IS_ERR(rt)) {
1086 __ip_rt_update_pmtu(rt, &fl4, mtu);
1087 ip_rt_put(rt);
1088 }
1089}
1090EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1091
1092static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1093{
1094 const struct iphdr *iph = (const struct iphdr *)skb->data;
1095 struct flowi4 fl4;
1096 struct rtable *rt;
1097
1098 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1099
1100 if (!fl4.flowi4_mark)
1101 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1102
1103 rt = __ip_route_output_key(sock_net(sk), &fl4);
1104 if (!IS_ERR(rt)) {
1105 __ip_rt_update_pmtu(rt, &fl4, mtu);
1106 ip_rt_put(rt);
1107 }
1108}
1109
1110void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1111{
1112 const struct iphdr *iph = (const struct iphdr *)skb->data;
1113 struct flowi4 fl4;
1114 struct rtable *rt;
1115 struct dst_entry *odst = NULL;
1116 bool new = false;
1117 struct net *net = sock_net(sk);
1118
1119 bh_lock_sock(sk);
1120
1121 if (!ip_sk_accept_pmtu(sk))
1122 goto out;
1123
1124 odst = sk_dst_get(sk);
1125
1126 if (sock_owned_by_user(sk) || !odst) {
1127 __ipv4_sk_update_pmtu(skb, sk, mtu);
1128 goto out;
1129 }
1130
1131 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1132
1133 rt = dst_rtable(odst);
1134 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1135 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1136 if (IS_ERR(rt))
1137 goto out;
1138
1139 new = true;
1140 }
1141
1142 __ip_rt_update_pmtu(dst_rtable(xfrm_dst_path(&rt->dst)), &fl4, mtu);
1143
1144 if (!dst_check(&rt->dst, 0)) {
1145 if (new)
1146 dst_release(&rt->dst);
1147
1148 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1149 if (IS_ERR(rt))
1150 goto out;
1151
1152 new = true;
1153 }
1154
1155 if (new)
1156 sk_dst_set(sk, &rt->dst);
1157
1158out:
1159 bh_unlock_sock(sk);
1160 dst_release(odst);
1161}
1162EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1163
1164void ipv4_redirect(struct sk_buff *skb, struct net *net,
1165 int oif, u8 protocol)
1166{
1167 const struct iphdr *iph = (const struct iphdr *)skb->data;
1168 struct flowi4 fl4;
1169 struct rtable *rt;
1170
1171 __build_flow_key(net, &fl4, NULL, iph, oif, iph->tos, protocol, 0, 0);
1172 rt = __ip_route_output_key(net, &fl4);
1173 if (!IS_ERR(rt)) {
1174 __ip_do_redirect(rt, skb, &fl4, false);
1175 ip_rt_put(rt);
1176 }
1177}
1178EXPORT_SYMBOL_GPL(ipv4_redirect);
1179
1180void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1181{
1182 const struct iphdr *iph = (const struct iphdr *)skb->data;
1183 struct flowi4 fl4;
1184 struct rtable *rt;
1185 struct net *net = sock_net(sk);
1186
1187 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1188 rt = __ip_route_output_key(net, &fl4);
1189 if (!IS_ERR(rt)) {
1190 __ip_do_redirect(rt, skb, &fl4, false);
1191 ip_rt_put(rt);
1192 }
1193}
1194EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1195
1196INDIRECT_CALLABLE_SCOPE struct dst_entry *ipv4_dst_check(struct dst_entry *dst,
1197 u32 cookie)
1198{
1199 struct rtable *rt = dst_rtable(dst);
1200
1201 /* All IPV4 dsts are created with ->obsolete set to the value
1202 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1203 * into this function always.
1204 *
1205 * When a PMTU/redirect information update invalidates a route,
1206 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1207 * DST_OBSOLETE_DEAD.
1208 */
1209 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1210 return NULL;
1211 return dst;
1212}
1213EXPORT_INDIRECT_CALLABLE(ipv4_dst_check);
1214
1215static void ipv4_send_dest_unreach(struct sk_buff *skb)
1216{
1217 struct net_device *dev;
1218 struct ip_options opt;
1219 int res;
1220
1221 /* Recompile ip options since IPCB may not be valid anymore.
1222 * Also check we have a reasonable ipv4 header.
1223 */
1224 if (!pskb_network_may_pull(skb, sizeof(struct iphdr)) ||
1225 ip_hdr(skb)->version != 4 || ip_hdr(skb)->ihl < 5)
1226 return;
1227
1228 memset(&opt, 0, sizeof(opt));
1229 if (ip_hdr(skb)->ihl > 5) {
1230 if (!pskb_network_may_pull(skb, ip_hdr(skb)->ihl * 4))
1231 return;
1232 opt.optlen = ip_hdr(skb)->ihl * 4 - sizeof(struct iphdr);
1233
1234 rcu_read_lock();
1235 dev = skb->dev ? skb->dev : skb_rtable(skb)->dst.dev;
1236 res = __ip_options_compile(dev_net(dev), &opt, skb, NULL);
1237 rcu_read_unlock();
1238
1239 if (res)
1240 return;
1241 }
1242 __icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, &opt);
1243}
1244
1245static void ipv4_link_failure(struct sk_buff *skb)
1246{
1247 struct rtable *rt;
1248
1249 ipv4_send_dest_unreach(skb);
1250
1251 rt = skb_rtable(skb);
1252 if (rt)
1253 dst_set_expires(&rt->dst, 0);
1254}
1255
1256static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1257{
1258 pr_debug("%s: %pI4 -> %pI4, %s\n",
1259 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1260 skb->dev ? skb->dev->name : "?");
1261 kfree_skb(skb);
1262 WARN_ON(1);
1263 return 0;
1264}
1265
1266/*
1267 * We do not cache source address of outgoing interface,
1268 * because it is used only by IP RR, TS and SRR options,
1269 * so that it out of fast path.
1270 *
1271 * BTW remember: "addr" is allowed to be not aligned
1272 * in IP options!
1273 */
1274
1275void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1276{
1277 __be32 src;
1278
1279 if (rt_is_output_route(rt))
1280 src = ip_hdr(skb)->saddr;
1281 else {
1282 struct fib_result res;
1283 struct iphdr *iph = ip_hdr(skb);
1284 struct flowi4 fl4 = {
1285 .daddr = iph->daddr,
1286 .saddr = iph->saddr,
1287 .flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)),
1288 .flowi4_oif = rt->dst.dev->ifindex,
1289 .flowi4_iif = skb->dev->ifindex,
1290 .flowi4_mark = skb->mark,
1291 };
1292
1293 rcu_read_lock();
1294 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1295 src = fib_result_prefsrc(dev_net(rt->dst.dev), &res);
1296 else
1297 src = inet_select_addr(rt->dst.dev,
1298 rt_nexthop(rt, iph->daddr),
1299 RT_SCOPE_UNIVERSE);
1300 rcu_read_unlock();
1301 }
1302 memcpy(addr, &src, 4);
1303}
1304
1305#ifdef CONFIG_IP_ROUTE_CLASSID
1306static void set_class_tag(struct rtable *rt, u32 tag)
1307{
1308 if (!(rt->dst.tclassid & 0xFFFF))
1309 rt->dst.tclassid |= tag & 0xFFFF;
1310 if (!(rt->dst.tclassid & 0xFFFF0000))
1311 rt->dst.tclassid |= tag & 0xFFFF0000;
1312}
1313#endif
1314
1315static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1316{
1317 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1318 unsigned int advmss;
1319 struct net *net;
1320
1321 rcu_read_lock();
1322 net = dev_net_rcu(dst->dev);
1323 advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1324 net->ipv4.ip_rt_min_advmss);
1325 rcu_read_unlock();
1326
1327 return min(advmss, IPV4_MAX_PMTU - header_size);
1328}
1329
1330INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst)
1331{
1332 return ip_dst_mtu_maybe_forward(dst, false);
1333}
1334EXPORT_INDIRECT_CALLABLE(ipv4_mtu);
1335
1336static void ip_del_fnhe(struct fib_nh_common *nhc, __be32 daddr)
1337{
1338 struct fnhe_hash_bucket *hash;
1339 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1340 u32 hval = fnhe_hashfun(daddr);
1341
1342 spin_lock_bh(&fnhe_lock);
1343
1344 hash = rcu_dereference_protected(nhc->nhc_exceptions,
1345 lockdep_is_held(&fnhe_lock));
1346 hash += hval;
1347
1348 fnhe_p = &hash->chain;
1349 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1350 while (fnhe) {
1351 if (fnhe->fnhe_daddr == daddr) {
1352 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1353 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1354 /* set fnhe_daddr to 0 to ensure it won't bind with
1355 * new dsts in rt_bind_exception().
1356 */
1357 fnhe->fnhe_daddr = 0;
1358 fnhe_flush_routes(fnhe);
1359 kfree_rcu(fnhe, rcu);
1360 break;
1361 }
1362 fnhe_p = &fnhe->fnhe_next;
1363 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1364 lockdep_is_held(&fnhe_lock));
1365 }
1366
1367 spin_unlock_bh(&fnhe_lock);
1368}
1369
1370static struct fib_nh_exception *find_exception(struct fib_nh_common *nhc,
1371 __be32 daddr)
1372{
1373 struct fnhe_hash_bucket *hash = rcu_dereference(nhc->nhc_exceptions);
1374 struct fib_nh_exception *fnhe;
1375 u32 hval;
1376
1377 if (!hash)
1378 return NULL;
1379
1380 hval = fnhe_hashfun(daddr);
1381
1382 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1383 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1384 if (fnhe->fnhe_daddr == daddr) {
1385 if (fnhe->fnhe_expires &&
1386 time_after(jiffies, fnhe->fnhe_expires)) {
1387 ip_del_fnhe(nhc, daddr);
1388 break;
1389 }
1390 return fnhe;
1391 }
1392 }
1393 return NULL;
1394}
1395
1396/* MTU selection:
1397 * 1. mtu on route is locked - use it
1398 * 2. mtu from nexthop exception
1399 * 3. mtu from egress device
1400 */
1401
1402u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1403{
1404 struct fib_nh_common *nhc = res->nhc;
1405 struct net_device *dev = nhc->nhc_dev;
1406 struct fib_info *fi = res->fi;
1407 u32 mtu = 0;
1408
1409 if (READ_ONCE(dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu) ||
1410 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1411 mtu = fi->fib_mtu;
1412
1413 if (likely(!mtu)) {
1414 struct fib_nh_exception *fnhe;
1415
1416 fnhe = find_exception(nhc, daddr);
1417 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1418 mtu = fnhe->fnhe_pmtu;
1419 }
1420
1421 if (likely(!mtu))
1422 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1423
1424 return mtu - lwtunnel_headroom(nhc->nhc_lwtstate, mtu);
1425}
1426
1427static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1428 __be32 daddr, const bool do_cache)
1429{
1430 bool ret = false;
1431
1432 spin_lock_bh(&fnhe_lock);
1433
1434 if (daddr == fnhe->fnhe_daddr) {
1435 struct rtable __rcu **porig;
1436 struct rtable *orig;
1437 int genid = fnhe_genid(dev_net(rt->dst.dev));
1438
1439 if (rt_is_input_route(rt))
1440 porig = &fnhe->fnhe_rth_input;
1441 else
1442 porig = &fnhe->fnhe_rth_output;
1443 orig = rcu_dereference(*porig);
1444
1445 if (fnhe->fnhe_genid != genid) {
1446 fnhe->fnhe_genid = genid;
1447 fnhe->fnhe_gw = 0;
1448 fnhe->fnhe_pmtu = 0;
1449 fnhe->fnhe_expires = 0;
1450 fnhe->fnhe_mtu_locked = false;
1451 fnhe_flush_routes(fnhe);
1452 orig = NULL;
1453 }
1454 fill_route_from_fnhe(rt, fnhe);
1455 if (!rt->rt_gw4) {
1456 rt->rt_gw4 = daddr;
1457 rt->rt_gw_family = AF_INET;
1458 }
1459
1460 if (do_cache) {
1461 dst_hold(&rt->dst);
1462 rcu_assign_pointer(*porig, rt);
1463 if (orig) {
1464 dst_dev_put(&orig->dst);
1465 dst_release(&orig->dst);
1466 }
1467 ret = true;
1468 }
1469
1470 fnhe->fnhe_stamp = jiffies;
1471 }
1472 spin_unlock_bh(&fnhe_lock);
1473
1474 return ret;
1475}
1476
1477static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt)
1478{
1479 struct rtable *orig, *prev, **p;
1480 bool ret = true;
1481
1482 if (rt_is_input_route(rt)) {
1483 p = (struct rtable **)&nhc->nhc_rth_input;
1484 } else {
1485 p = (struct rtable **)raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
1486 }
1487 orig = *p;
1488
1489 /* hold dst before doing cmpxchg() to avoid race condition
1490 * on this dst
1491 */
1492 dst_hold(&rt->dst);
1493 prev = cmpxchg(p, orig, rt);
1494 if (prev == orig) {
1495 if (orig) {
1496 rt_add_uncached_list(orig);
1497 dst_release(&orig->dst);
1498 }
1499 } else {
1500 dst_release(&rt->dst);
1501 ret = false;
1502 }
1503
1504 return ret;
1505}
1506
1507struct uncached_list {
1508 spinlock_t lock;
1509 struct list_head head;
1510};
1511
1512static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1513
1514void rt_add_uncached_list(struct rtable *rt)
1515{
1516 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1517
1518 rt->dst.rt_uncached_list = ul;
1519
1520 spin_lock_bh(&ul->lock);
1521 list_add_tail(&rt->dst.rt_uncached, &ul->head);
1522 spin_unlock_bh(&ul->lock);
1523}
1524
1525void rt_del_uncached_list(struct rtable *rt)
1526{
1527 if (!list_empty(&rt->dst.rt_uncached)) {
1528 struct uncached_list *ul = rt->dst.rt_uncached_list;
1529
1530 spin_lock_bh(&ul->lock);
1531 list_del_init(&rt->dst.rt_uncached);
1532 spin_unlock_bh(&ul->lock);
1533 }
1534}
1535
1536static void ipv4_dst_destroy(struct dst_entry *dst)
1537{
1538 ip_dst_metrics_put(dst);
1539 rt_del_uncached_list(dst_rtable(dst));
1540}
1541
1542void rt_flush_dev(struct net_device *dev)
1543{
1544 struct rtable *rt, *safe;
1545 int cpu;
1546
1547 for_each_possible_cpu(cpu) {
1548 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1549
1550 if (list_empty(&ul->head))
1551 continue;
1552
1553 spin_lock_bh(&ul->lock);
1554 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
1555 if (rt->dst.dev != dev)
1556 continue;
1557 rt->dst.dev = blackhole_netdev;
1558 netdev_ref_replace(dev, blackhole_netdev,
1559 &rt->dst.dev_tracker, GFP_ATOMIC);
1560 list_del_init(&rt->dst.rt_uncached);
1561 }
1562 spin_unlock_bh(&ul->lock);
1563 }
1564}
1565
1566static bool rt_cache_valid(const struct rtable *rt)
1567{
1568 return rt &&
1569 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1570 !rt_is_expired(rt);
1571}
1572
1573static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1574 const struct fib_result *res,
1575 struct fib_nh_exception *fnhe,
1576 struct fib_info *fi, u16 type, u32 itag,
1577 const bool do_cache)
1578{
1579 bool cached = false;
1580
1581 if (fi) {
1582 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1583
1584 if (nhc->nhc_gw_family && nhc->nhc_scope == RT_SCOPE_LINK) {
1585 rt->rt_uses_gateway = 1;
1586 rt->rt_gw_family = nhc->nhc_gw_family;
1587 /* only INET and INET6 are supported */
1588 if (likely(nhc->nhc_gw_family == AF_INET))
1589 rt->rt_gw4 = nhc->nhc_gw.ipv4;
1590 else
1591 rt->rt_gw6 = nhc->nhc_gw.ipv6;
1592 }
1593
1594 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1595
1596#ifdef CONFIG_IP_ROUTE_CLASSID
1597 if (nhc->nhc_family == AF_INET) {
1598 struct fib_nh *nh;
1599
1600 nh = container_of(nhc, struct fib_nh, nh_common);
1601 rt->dst.tclassid = nh->nh_tclassid;
1602 }
1603#endif
1604 rt->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
1605 if (unlikely(fnhe))
1606 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1607 else if (do_cache)
1608 cached = rt_cache_route(nhc, rt);
1609 if (unlikely(!cached)) {
1610 /* Routes we intend to cache in nexthop exception or
1611 * FIB nexthop have the DST_NOCACHE bit clear.
1612 * However, if we are unsuccessful at storing this
1613 * route into the cache we really need to set it.
1614 */
1615 if (!rt->rt_gw4) {
1616 rt->rt_gw_family = AF_INET;
1617 rt->rt_gw4 = daddr;
1618 }
1619 rt_add_uncached_list(rt);
1620 }
1621 } else
1622 rt_add_uncached_list(rt);
1623
1624#ifdef CONFIG_IP_ROUTE_CLASSID
1625#ifdef CONFIG_IP_MULTIPLE_TABLES
1626 set_class_tag(rt, res->tclassid);
1627#endif
1628 set_class_tag(rt, itag);
1629#endif
1630}
1631
1632struct rtable *rt_dst_alloc(struct net_device *dev,
1633 unsigned int flags, u16 type,
1634 bool noxfrm)
1635{
1636 struct rtable *rt;
1637
1638 rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1639 (noxfrm ? DST_NOXFRM : 0));
1640
1641 if (rt) {
1642 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1643 rt->rt_flags = flags;
1644 rt->rt_type = type;
1645 rt->rt_is_input = 0;
1646 rt->rt_iif = 0;
1647 rt->rt_pmtu = 0;
1648 rt->rt_mtu_locked = 0;
1649 rt->rt_uses_gateway = 0;
1650 rt->rt_gw_family = 0;
1651 rt->rt_gw4 = 0;
1652
1653 rt->dst.output = ip_output;
1654 if (flags & RTCF_LOCAL)
1655 rt->dst.input = ip_local_deliver;
1656 }
1657
1658 return rt;
1659}
1660EXPORT_SYMBOL(rt_dst_alloc);
1661
1662struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
1663{
1664 struct rtable *new_rt;
1665
1666 new_rt = dst_alloc(&ipv4_dst_ops, dev, DST_OBSOLETE_FORCE_CHK,
1667 rt->dst.flags);
1668
1669 if (new_rt) {
1670 new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1671 new_rt->rt_flags = rt->rt_flags;
1672 new_rt->rt_type = rt->rt_type;
1673 new_rt->rt_is_input = rt->rt_is_input;
1674 new_rt->rt_iif = rt->rt_iif;
1675 new_rt->rt_pmtu = rt->rt_pmtu;
1676 new_rt->rt_mtu_locked = rt->rt_mtu_locked;
1677 new_rt->rt_gw_family = rt->rt_gw_family;
1678 if (rt->rt_gw_family == AF_INET)
1679 new_rt->rt_gw4 = rt->rt_gw4;
1680 else if (rt->rt_gw_family == AF_INET6)
1681 new_rt->rt_gw6 = rt->rt_gw6;
1682
1683 new_rt->dst.input = rt->dst.input;
1684 new_rt->dst.output = rt->dst.output;
1685 new_rt->dst.error = rt->dst.error;
1686 new_rt->dst.lastuse = jiffies;
1687 new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
1688 }
1689 return new_rt;
1690}
1691EXPORT_SYMBOL(rt_dst_clone);
1692
1693/* called in rcu_read_lock() section */
1694enum skb_drop_reason
1695ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1696 dscp_t dscp, struct net_device *dev,
1697 struct in_device *in_dev, u32 *itag)
1698{
1699 enum skb_drop_reason reason;
1700
1701 /* Primary sanity checks. */
1702 if (!in_dev)
1703 return SKB_DROP_REASON_NOT_SPECIFIED;
1704
1705 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1706 return SKB_DROP_REASON_IP_INVALID_SOURCE;
1707
1708 if (skb->protocol != htons(ETH_P_IP))
1709 return SKB_DROP_REASON_INVALID_PROTO;
1710
1711 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1712 return SKB_DROP_REASON_IP_LOCALNET;
1713
1714 if (ipv4_is_zeronet(saddr)) {
1715 if (!ipv4_is_local_multicast(daddr) &&
1716 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1717 return SKB_DROP_REASON_IP_INVALID_SOURCE;
1718 } else {
1719 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
1720 dev, in_dev, itag);
1721 if (reason)
1722 return reason;
1723 }
1724 return SKB_NOT_DROPPED_YET;
1725}
1726
1727/* called in rcu_read_lock() section */
1728static enum skb_drop_reason
1729ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1730 dscp_t dscp, struct net_device *dev, int our)
1731{
1732 struct in_device *in_dev = __in_dev_get_rcu(dev);
1733 unsigned int flags = RTCF_MULTICAST;
1734 enum skb_drop_reason reason;
1735 struct rtable *rth;
1736 u32 itag = 0;
1737
1738 reason = ip_mc_validate_source(skb, daddr, saddr, dscp, dev, in_dev,
1739 &itag);
1740 if (reason)
1741 return reason;
1742
1743 if (our)
1744 flags |= RTCF_LOCAL;
1745
1746 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1747 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1748
1749 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1750 false);
1751 if (!rth)
1752 return SKB_DROP_REASON_NOMEM;
1753
1754#ifdef CONFIG_IP_ROUTE_CLASSID
1755 rth->dst.tclassid = itag;
1756#endif
1757 rth->dst.output = ip_rt_bug;
1758 rth->rt_is_input= 1;
1759
1760#ifdef CONFIG_IP_MROUTE
1761 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1762 rth->dst.input = ip_mr_input;
1763#endif
1764 RT_CACHE_STAT_INC(in_slow_mc);
1765
1766 skb_dst_drop(skb);
1767 skb_dst_set(skb, &rth->dst);
1768 return SKB_NOT_DROPPED_YET;
1769}
1770
1771
1772static void ip_handle_martian_source(struct net_device *dev,
1773 struct in_device *in_dev,
1774 struct sk_buff *skb,
1775 __be32 daddr,
1776 __be32 saddr)
1777{
1778 RT_CACHE_STAT_INC(in_martian_src);
1779#ifdef CONFIG_IP_ROUTE_VERBOSE
1780 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1781 /*
1782 * RFC1812 recommendation, if source is martian,
1783 * the only hint is MAC header.
1784 */
1785 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1786 &daddr, &saddr, dev->name);
1787 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1788 print_hex_dump(KERN_WARNING, "ll header: ",
1789 DUMP_PREFIX_OFFSET, 16, 1,
1790 skb_mac_header(skb),
1791 dev->hard_header_len, false);
1792 }
1793 }
1794#endif
1795}
1796
1797/* called in rcu_read_lock() section */
1798static enum skb_drop_reason
1799__mkroute_input(struct sk_buff *skb, const struct fib_result *res,
1800 struct in_device *in_dev, __be32 daddr,
1801 __be32 saddr, dscp_t dscp)
1802{
1803 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
1804 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
1805 struct net_device *dev = nhc->nhc_dev;
1806 struct fib_nh_exception *fnhe;
1807 struct rtable *rth;
1808 int err;
1809 struct in_device *out_dev;
1810 bool do_cache;
1811 u32 itag = 0;
1812
1813 /* get a working reference to the output device */
1814 out_dev = __in_dev_get_rcu(dev);
1815 if (!out_dev) {
1816 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1817 return reason;
1818 }
1819
1820 err = fib_validate_source(skb, saddr, daddr, dscp, FIB_RES_OIF(*res),
1821 in_dev->dev, in_dev, &itag);
1822 if (err < 0) {
1823 reason = -err;
1824 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1825 saddr);
1826
1827 goto cleanup;
1828 }
1829
1830 do_cache = res->fi && !itag;
1831 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1832 skb->protocol == htons(ETH_P_IP)) {
1833 __be32 gw;
1834
1835 gw = nhc->nhc_gw_family == AF_INET ? nhc->nhc_gw.ipv4 : 0;
1836 if (IN_DEV_SHARED_MEDIA(out_dev) ||
1837 inet_addr_onlink(out_dev, saddr, gw))
1838 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1839 }
1840
1841 if (skb->protocol != htons(ETH_P_IP)) {
1842 /* Not IP (i.e. ARP). Do not create route, if it is
1843 * invalid for proxy arp. DNAT routes are always valid.
1844 *
1845 * Proxy arp feature have been extended to allow, ARP
1846 * replies back to the same interface, to support
1847 * Private VLAN switch technologies. See arp.c.
1848 */
1849 if (out_dev == in_dev &&
1850 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1851 reason = SKB_DROP_REASON_ARP_PVLAN_DISABLE;
1852 goto cleanup;
1853 }
1854 }
1855
1856 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
1857 IPCB(skb)->flags |= IPSKB_NOPOLICY;
1858
1859 fnhe = find_exception(nhc, daddr);
1860 if (do_cache) {
1861 if (fnhe)
1862 rth = rcu_dereference(fnhe->fnhe_rth_input);
1863 else
1864 rth = rcu_dereference(nhc->nhc_rth_input);
1865 if (rt_cache_valid(rth)) {
1866 skb_dst_set_noref(skb, &rth->dst);
1867 goto out;
1868 }
1869 }
1870
1871 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1872 IN_DEV_ORCONF(out_dev, NOXFRM));
1873 if (!rth) {
1874 reason = SKB_DROP_REASON_NOMEM;
1875 goto cleanup;
1876 }
1877
1878 rth->rt_is_input = 1;
1879 RT_CACHE_STAT_INC(in_slow_tot);
1880
1881 rth->dst.input = ip_forward;
1882
1883 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1884 do_cache);
1885 lwtunnel_set_redirect(&rth->dst);
1886 skb_dst_set(skb, &rth->dst);
1887out:
1888 reason = SKB_NOT_DROPPED_YET;
1889cleanup:
1890 return reason;
1891}
1892
1893#ifdef CONFIG_IP_ROUTE_MULTIPATH
1894/* To make ICMP packets follow the right flow, the multipath hash is
1895 * calculated from the inner IP addresses.
1896 */
1897static void ip_multipath_l3_keys(const struct sk_buff *skb,
1898 struct flow_keys *hash_keys)
1899{
1900 const struct iphdr *outer_iph = ip_hdr(skb);
1901 const struct iphdr *key_iph = outer_iph;
1902 const struct iphdr *inner_iph;
1903 const struct icmphdr *icmph;
1904 struct iphdr _inner_iph;
1905 struct icmphdr _icmph;
1906
1907 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1908 goto out;
1909
1910 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1911 goto out;
1912
1913 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1914 &_icmph);
1915 if (!icmph)
1916 goto out;
1917
1918 if (!icmp_is_err(icmph->type))
1919 goto out;
1920
1921 inner_iph = skb_header_pointer(skb,
1922 outer_iph->ihl * 4 + sizeof(_icmph),
1923 sizeof(_inner_iph), &_inner_iph);
1924 if (!inner_iph)
1925 goto out;
1926
1927 key_iph = inner_iph;
1928out:
1929 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1930 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1931}
1932
1933static u32 fib_multipath_custom_hash_outer(const struct net *net,
1934 const struct sk_buff *skb,
1935 bool *p_has_inner)
1936{
1937 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1938 struct flow_keys keys, hash_keys;
1939
1940 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
1941 return 0;
1942
1943 memset(&hash_keys, 0, sizeof(hash_keys));
1944 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
1945
1946 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1947 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
1948 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1949 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
1950 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1951 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
1952 hash_keys.basic.ip_proto = keys.basic.ip_proto;
1953 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
1954 hash_keys.ports.src = keys.ports.src;
1955 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
1956 hash_keys.ports.dst = keys.ports.dst;
1957
1958 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
1959 return fib_multipath_hash_from_keys(net, &hash_keys);
1960}
1961
1962static u32 fib_multipath_custom_hash_inner(const struct net *net,
1963 const struct sk_buff *skb,
1964 bool has_inner)
1965{
1966 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
1967 struct flow_keys keys, hash_keys;
1968
1969 /* We assume the packet carries an encapsulation, but if none was
1970 * encountered during dissection of the outer flow, then there is no
1971 * point in calling the flow dissector again.
1972 */
1973 if (!has_inner)
1974 return 0;
1975
1976 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
1977 return 0;
1978
1979 memset(&hash_keys, 0, sizeof(hash_keys));
1980 skb_flow_dissect_flow_keys(skb, &keys, 0);
1981
1982 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
1983 return 0;
1984
1985 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
1986 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1987 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1988 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
1989 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1990 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
1991 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
1992 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1993 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
1994 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
1995 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
1996 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
1997 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
1998 hash_keys.tags.flow_label = keys.tags.flow_label;
1999 }
2000
2001 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
2002 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2003 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
2004 hash_keys.ports.src = keys.ports.src;
2005 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
2006 hash_keys.ports.dst = keys.ports.dst;
2007
2008 return fib_multipath_hash_from_keys(net, &hash_keys);
2009}
2010
2011static u32 fib_multipath_custom_hash_skb(const struct net *net,
2012 const struct sk_buff *skb)
2013{
2014 u32 mhash, mhash_inner;
2015 bool has_inner = true;
2016
2017 mhash = fib_multipath_custom_hash_outer(net, skb, &has_inner);
2018 mhash_inner = fib_multipath_custom_hash_inner(net, skb, has_inner);
2019
2020 return jhash_2words(mhash, mhash_inner, 0);
2021}
2022
2023static u32 fib_multipath_custom_hash_fl4(const struct net *net,
2024 const struct flowi4 *fl4)
2025{
2026 u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
2027 struct flow_keys hash_keys;
2028
2029 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
2030 return 0;
2031
2032 memset(&hash_keys, 0, sizeof(hash_keys));
2033 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2034 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
2035 hash_keys.addrs.v4addrs.src = fl4->saddr;
2036 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
2037 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2038 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
2039 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2040 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
2041 hash_keys.ports.src = fl4->fl4_sport;
2042 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
2043 hash_keys.ports.dst = fl4->fl4_dport;
2044
2045 return fib_multipath_hash_from_keys(net, &hash_keys);
2046}
2047
2048/* if skb is set it will be used and fl4 can be NULL */
2049int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
2050 const struct sk_buff *skb, struct flow_keys *flkeys)
2051{
2052 u32 multipath_hash = fl4 ? fl4->flowi4_multipath_hash : 0;
2053 struct flow_keys hash_keys;
2054 u32 mhash = 0;
2055
2056 switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) {
2057 case 0:
2058 memset(&hash_keys, 0, sizeof(hash_keys));
2059 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2060 if (skb) {
2061 ip_multipath_l3_keys(skb, &hash_keys);
2062 } else {
2063 hash_keys.addrs.v4addrs.src = fl4->saddr;
2064 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2065 }
2066 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2067 break;
2068 case 1:
2069 /* skb is currently provided only when forwarding */
2070 if (skb) {
2071 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
2072 struct flow_keys keys;
2073
2074 /* short-circuit if we already have L4 hash present */
2075 if (skb->l4_hash)
2076 return skb_get_hash_raw(skb) >> 1;
2077
2078 memset(&hash_keys, 0, sizeof(hash_keys));
2079
2080 if (!flkeys) {
2081 skb_flow_dissect_flow_keys(skb, &keys, flag);
2082 flkeys = &keys;
2083 }
2084
2085 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2086 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
2087 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
2088 hash_keys.ports.src = flkeys->ports.src;
2089 hash_keys.ports.dst = flkeys->ports.dst;
2090 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
2091 } else {
2092 memset(&hash_keys, 0, sizeof(hash_keys));
2093 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2094 hash_keys.addrs.v4addrs.src = fl4->saddr;
2095 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2096 hash_keys.ports.src = fl4->fl4_sport;
2097 hash_keys.ports.dst = fl4->fl4_dport;
2098 hash_keys.basic.ip_proto = fl4->flowi4_proto;
2099 }
2100 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2101 break;
2102 case 2:
2103 memset(&hash_keys, 0, sizeof(hash_keys));
2104 /* skb is currently provided only when forwarding */
2105 if (skb) {
2106 struct flow_keys keys;
2107
2108 skb_flow_dissect_flow_keys(skb, &keys, 0);
2109 /* Inner can be v4 or v6 */
2110 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
2111 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2112 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
2113 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
2114 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
2115 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
2116 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
2117 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
2118 hash_keys.tags.flow_label = keys.tags.flow_label;
2119 hash_keys.basic.ip_proto = keys.basic.ip_proto;
2120 } else {
2121 /* Same as case 0 */
2122 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2123 ip_multipath_l3_keys(skb, &hash_keys);
2124 }
2125 } else {
2126 /* Same as case 0 */
2127 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
2128 hash_keys.addrs.v4addrs.src = fl4->saddr;
2129 hash_keys.addrs.v4addrs.dst = fl4->daddr;
2130 }
2131 mhash = fib_multipath_hash_from_keys(net, &hash_keys);
2132 break;
2133 case 3:
2134 if (skb)
2135 mhash = fib_multipath_custom_hash_skb(net, skb);
2136 else
2137 mhash = fib_multipath_custom_hash_fl4(net, fl4);
2138 break;
2139 }
2140
2141 if (multipath_hash)
2142 mhash = jhash_2words(mhash, multipath_hash, 0);
2143
2144 return mhash >> 1;
2145}
2146#endif /* CONFIG_IP_ROUTE_MULTIPATH */
2147
2148static enum skb_drop_reason
2149ip_mkroute_input(struct sk_buff *skb, struct fib_result *res,
2150 struct in_device *in_dev, __be32 daddr,
2151 __be32 saddr, dscp_t dscp, struct flow_keys *hkeys)
2152{
2153#ifdef CONFIG_IP_ROUTE_MULTIPATH
2154 if (res->fi && fib_info_num_path(res->fi) > 1) {
2155 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
2156
2157 fib_select_multipath(res, h);
2158 IPCB(skb)->flags |= IPSKB_MULTIPATH;
2159 }
2160#endif
2161
2162 /* create a routing cache entry */
2163 return __mkroute_input(skb, res, in_dev, daddr, saddr, dscp);
2164}
2165
2166/* Implements all the saddr-related checks as ip_route_input_slow(),
2167 * assuming daddr is valid and the destination is not a local broadcast one.
2168 * Uses the provided hint instead of performing a route lookup.
2169 */
2170enum skb_drop_reason
2171ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2172 dscp_t dscp, struct net_device *dev,
2173 const struct sk_buff *hint)
2174{
2175 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2176 struct in_device *in_dev = __in_dev_get_rcu(dev);
2177 struct rtable *rt = skb_rtable(hint);
2178 struct net *net = dev_net(dev);
2179 u32 tag = 0;
2180
2181 if (!in_dev)
2182 return reason;
2183
2184 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
2185 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2186 goto martian_source;
2187 }
2188
2189 if (ipv4_is_zeronet(saddr)) {
2190 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2191 goto martian_source;
2192 }
2193
2194 if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2195 reason = SKB_DROP_REASON_IP_LOCALNET;
2196 goto martian_source;
2197 }
2198
2199 if (rt->rt_type != RTN_LOCAL)
2200 goto skip_validate_source;
2201
2202 reason = fib_validate_source_reason(skb, saddr, daddr, dscp, 0, dev,
2203 in_dev, &tag);
2204 if (reason)
2205 goto martian_source;
2206
2207skip_validate_source:
2208 skb_dst_copy(skb, hint);
2209 return SKB_NOT_DROPPED_YET;
2210
2211martian_source:
2212 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2213 return reason;
2214}
2215
2216/* get device for dst_alloc with local routes */
2217static struct net_device *ip_rt_get_dev(struct net *net,
2218 const struct fib_result *res)
2219{
2220 struct fib_nh_common *nhc = res->fi ? res->nhc : NULL;
2221 struct net_device *dev = NULL;
2222
2223 if (nhc)
2224 dev = l3mdev_master_dev_rcu(nhc->nhc_dev);
2225
2226 return dev ? : net->loopback_dev;
2227}
2228
2229/*
2230 * NOTE. We drop all the packets that has local source
2231 * addresses, because every properly looped back packet
2232 * must have correct destination already attached by output routine.
2233 * Changes in the enforced policies must be applied also to
2234 * ip_route_use_hint().
2235 *
2236 * Such approach solves two big problems:
2237 * 1. Not simplex devices are handled properly.
2238 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2239 * called with rcu_read_lock()
2240 */
2241
2242static enum skb_drop_reason
2243ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2244 dscp_t dscp, struct net_device *dev,
2245 struct fib_result *res)
2246{
2247 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2248 struct in_device *in_dev = __in_dev_get_rcu(dev);
2249 struct flow_keys *flkeys = NULL, _flkeys;
2250 struct net *net = dev_net(dev);
2251 struct ip_tunnel_info *tun_info;
2252 int err = -EINVAL;
2253 unsigned int flags = 0;
2254 u32 itag = 0;
2255 struct rtable *rth;
2256 struct flowi4 fl4;
2257 bool do_cache = true;
2258
2259 /* IP on this device is disabled. */
2260
2261 if (!in_dev)
2262 goto out;
2263
2264 /* Check for the most weird martians, which can be not detected
2265 * by fib_lookup.
2266 */
2267
2268 tun_info = skb_tunnel_info(skb);
2269 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
2270 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
2271 else
2272 fl4.flowi4_tun_key.tun_id = 0;
2273 skb_dst_drop(skb);
2274
2275 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) {
2276 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2277 goto martian_source;
2278 }
2279
2280 res->fi = NULL;
2281 res->table = NULL;
2282 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2283 goto brd_input;
2284
2285 /* Accept zero addresses only to limited broadcast;
2286 * I even do not know to fix it or not. Waiting for complains :-)
2287 */
2288 if (ipv4_is_zeronet(saddr)) {
2289 reason = SKB_DROP_REASON_IP_INVALID_SOURCE;
2290 goto martian_source;
2291 }
2292
2293 if (ipv4_is_zeronet(daddr)) {
2294 reason = SKB_DROP_REASON_IP_INVALID_DEST;
2295 goto martian_destination;
2296 }
2297
2298 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
2299 * and call it once if daddr or/and saddr are loopback addresses
2300 */
2301 if (ipv4_is_loopback(daddr)) {
2302 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2303 reason = SKB_DROP_REASON_IP_LOCALNET;
2304 goto martian_destination;
2305 }
2306 } else if (ipv4_is_loopback(saddr)) {
2307 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) {
2308 reason = SKB_DROP_REASON_IP_LOCALNET;
2309 goto martian_source;
2310 }
2311 }
2312
2313 /*
2314 * Now we are ready to route packet.
2315 */
2316 fl4.flowi4_l3mdev = 0;
2317 fl4.flowi4_oif = 0;
2318 fl4.flowi4_iif = dev->ifindex;
2319 fl4.flowi4_mark = skb->mark;
2320 fl4.flowi4_tos = inet_dscp_to_dsfield(dscp);
2321 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2322 fl4.flowi4_flags = 0;
2323 fl4.daddr = daddr;
2324 fl4.saddr = saddr;
2325 fl4.flowi4_uid = sock_net_uid(net, NULL);
2326 fl4.flowi4_multipath_hash = 0;
2327
2328 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
2329 flkeys = &_flkeys;
2330 } else {
2331 fl4.flowi4_proto = 0;
2332 fl4.fl4_sport = 0;
2333 fl4.fl4_dport = 0;
2334 }
2335
2336 err = fib_lookup(net, &fl4, res, 0);
2337 if (err != 0) {
2338 if (!IN_DEV_FORWARD(in_dev))
2339 err = -EHOSTUNREACH;
2340 goto no_route;
2341 }
2342
2343 if (res->type == RTN_BROADCAST) {
2344 if (IN_DEV_BFORWARD(in_dev))
2345 goto make_route;
2346 /* not do cache if bc_forwarding is enabled */
2347 if (IPV4_DEVCONF_ALL_RO(net, BC_FORWARDING))
2348 do_cache = false;
2349 goto brd_input;
2350 }
2351
2352 err = -EINVAL;
2353 if (res->type == RTN_LOCAL) {
2354 reason = fib_validate_source_reason(skb, saddr, daddr, dscp,
2355 0, dev, in_dev, &itag);
2356 if (reason)
2357 goto martian_source;
2358 goto local_input;
2359 }
2360
2361 if (!IN_DEV_FORWARD(in_dev)) {
2362 err = -EHOSTUNREACH;
2363 goto no_route;
2364 }
2365 if (res->type != RTN_UNICAST) {
2366 reason = SKB_DROP_REASON_IP_INVALID_DEST;
2367 goto martian_destination;
2368 }
2369
2370make_route:
2371 reason = ip_mkroute_input(skb, res, in_dev, daddr, saddr, dscp,
2372 flkeys);
2373
2374out:
2375 return reason;
2376
2377brd_input:
2378 if (skb->protocol != htons(ETH_P_IP)) {
2379 reason = SKB_DROP_REASON_INVALID_PROTO;
2380 goto out;
2381 }
2382
2383 if (!ipv4_is_zeronet(saddr)) {
2384 reason = fib_validate_source_reason(skb, saddr, 0, dscp, 0,
2385 dev, in_dev, &itag);
2386 if (reason)
2387 goto martian_source;
2388 }
2389 flags |= RTCF_BROADCAST;
2390 res->type = RTN_BROADCAST;
2391 RT_CACHE_STAT_INC(in_brd);
2392
2393local_input:
2394 if (IN_DEV_ORCONF(in_dev, NOPOLICY))
2395 IPCB(skb)->flags |= IPSKB_NOPOLICY;
2396
2397 do_cache &= res->fi && !itag;
2398 if (do_cache) {
2399 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2400
2401 rth = rcu_dereference(nhc->nhc_rth_input);
2402 if (rt_cache_valid(rth)) {
2403 skb_dst_set_noref(skb, &rth->dst);
2404 reason = SKB_NOT_DROPPED_YET;
2405 goto out;
2406 }
2407 }
2408
2409 rth = rt_dst_alloc(ip_rt_get_dev(net, res),
2410 flags | RTCF_LOCAL, res->type, false);
2411 if (!rth)
2412 goto e_nobufs;
2413
2414 rth->dst.output= ip_rt_bug;
2415#ifdef CONFIG_IP_ROUTE_CLASSID
2416 rth->dst.tclassid = itag;
2417#endif
2418 rth->rt_is_input = 1;
2419
2420 RT_CACHE_STAT_INC(in_slow_tot);
2421 if (res->type == RTN_UNREACHABLE) {
2422 rth->dst.input= ip_error;
2423 rth->dst.error= -err;
2424 rth->rt_flags &= ~RTCF_LOCAL;
2425 }
2426
2427 if (do_cache) {
2428 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2429
2430 rth->dst.lwtstate = lwtstate_get(nhc->nhc_lwtstate);
2431 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2432 WARN_ON(rth->dst.input == lwtunnel_input);
2433 rth->dst.lwtstate->orig_input = rth->dst.input;
2434 rth->dst.input = lwtunnel_input;
2435 }
2436
2437 if (unlikely(!rt_cache_route(nhc, rth)))
2438 rt_add_uncached_list(rth);
2439 }
2440 skb_dst_set(skb, &rth->dst);
2441 reason = SKB_NOT_DROPPED_YET;
2442 goto out;
2443
2444no_route:
2445 RT_CACHE_STAT_INC(in_no_route);
2446 res->type = RTN_UNREACHABLE;
2447 res->fi = NULL;
2448 res->table = NULL;
2449 goto local_input;
2450
2451 /*
2452 * Do not cache martian addresses: they should be logged (RFC1812)
2453 */
2454martian_destination:
2455 RT_CACHE_STAT_INC(in_martian_dst);
2456#ifdef CONFIG_IP_ROUTE_VERBOSE
2457 if (IN_DEV_LOG_MARTIANS(in_dev))
2458 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2459 &daddr, &saddr, dev->name);
2460#endif
2461 goto out;
2462
2463e_nobufs:
2464 reason = SKB_DROP_REASON_NOMEM;
2465 goto out;
2466
2467martian_source:
2468 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2469 goto out;
2470}
2471
2472/* called with rcu_read_lock held */
2473static enum skb_drop_reason
2474ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2475 dscp_t dscp, struct net_device *dev,
2476 struct fib_result *res)
2477{
2478 /* Multicast recognition logic is moved from route cache to here.
2479 * The problem was that too many Ethernet cards have broken/missing
2480 * hardware multicast filters :-( As result the host on multicasting
2481 * network acquires a lot of useless route cache entries, sort of
2482 * SDR messages from all the world. Now we try to get rid of them.
2483 * Really, provided software IP multicast filter is organized
2484 * reasonably (at least, hashed), it does not result in a slowdown
2485 * comparing with route cache reject entries.
2486 * Note, that multicast routers are not affected, because
2487 * route cache entry is created eventually.
2488 */
2489 if (ipv4_is_multicast(daddr)) {
2490 enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
2491 struct in_device *in_dev = __in_dev_get_rcu(dev);
2492 int our = 0;
2493
2494 if (!in_dev)
2495 return reason;
2496
2497 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2498 ip_hdr(skb)->protocol);
2499
2500 /* check l3 master if no match yet */
2501 if (!our && netif_is_l3_slave(dev)) {
2502 struct in_device *l3_in_dev;
2503
2504 l3_in_dev = __in_dev_get_rcu(skb->dev);
2505 if (l3_in_dev)
2506 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2507 ip_hdr(skb)->protocol);
2508 }
2509
2510 if (our
2511#ifdef CONFIG_IP_MROUTE
2512 ||
2513 (!ipv4_is_local_multicast(daddr) &&
2514 IN_DEV_MFORWARD(in_dev))
2515#endif
2516 ) {
2517 reason = ip_route_input_mc(skb, daddr, saddr, dscp,
2518 dev, our);
2519 }
2520 return reason;
2521 }
2522
2523 return ip_route_input_slow(skb, daddr, saddr, dscp, dev, res);
2524}
2525
2526enum skb_drop_reason ip_route_input_noref(struct sk_buff *skb, __be32 daddr,
2527 __be32 saddr, dscp_t dscp,
2528 struct net_device *dev)
2529{
2530 enum skb_drop_reason reason;
2531 struct fib_result res;
2532
2533 rcu_read_lock();
2534 reason = ip_route_input_rcu(skb, daddr, saddr, dscp, dev, &res);
2535 rcu_read_unlock();
2536
2537 return reason;
2538}
2539EXPORT_SYMBOL(ip_route_input_noref);
2540
2541/* called with rcu_read_lock() */
2542static struct rtable *__mkroute_output(const struct fib_result *res,
2543 const struct flowi4 *fl4, int orig_oif,
2544 struct net_device *dev_out,
2545 unsigned int flags)
2546{
2547 struct fib_info *fi = res->fi;
2548 struct fib_nh_exception *fnhe;
2549 struct in_device *in_dev;
2550 u16 type = res->type;
2551 struct rtable *rth;
2552 bool do_cache;
2553
2554 in_dev = __in_dev_get_rcu(dev_out);
2555 if (!in_dev)
2556 return ERR_PTR(-EINVAL);
2557
2558 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2559 if (ipv4_is_loopback(fl4->saddr) &&
2560 !(dev_out->flags & IFF_LOOPBACK) &&
2561 !netif_is_l3_master(dev_out))
2562 return ERR_PTR(-EINVAL);
2563
2564 if (ipv4_is_lbcast(fl4->daddr))
2565 type = RTN_BROADCAST;
2566 else if (ipv4_is_multicast(fl4->daddr))
2567 type = RTN_MULTICAST;
2568 else if (ipv4_is_zeronet(fl4->daddr))
2569 return ERR_PTR(-EINVAL);
2570
2571 if (dev_out->flags & IFF_LOOPBACK)
2572 flags |= RTCF_LOCAL;
2573
2574 do_cache = true;
2575 if (type == RTN_BROADCAST) {
2576 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2577 fi = NULL;
2578 } else if (type == RTN_MULTICAST) {
2579 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2580 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2581 fl4->flowi4_proto))
2582 flags &= ~RTCF_LOCAL;
2583 else
2584 do_cache = false;
2585 /* If multicast route do not exist use
2586 * default one, but do not gateway in this case.
2587 * Yes, it is hack.
2588 */
2589 if (fi && res->prefixlen < 4)
2590 fi = NULL;
2591 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2592 (orig_oif != dev_out->ifindex)) {
2593 /* For local routes that require a particular output interface
2594 * we do not want to cache the result. Caching the result
2595 * causes incorrect behaviour when there are multiple source
2596 * addresses on the interface, the end result being that if the
2597 * intended recipient is waiting on that interface for the
2598 * packet he won't receive it because it will be delivered on
2599 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2600 * be set to the loopback interface as well.
2601 */
2602 do_cache = false;
2603 }
2604
2605 fnhe = NULL;
2606 do_cache &= fi != NULL;
2607 if (fi) {
2608 struct fib_nh_common *nhc = FIB_RES_NHC(*res);
2609 struct rtable __rcu **prth;
2610
2611 fnhe = find_exception(nhc, fl4->daddr);
2612 if (!do_cache)
2613 goto add;
2614 if (fnhe) {
2615 prth = &fnhe->fnhe_rth_output;
2616 } else {
2617 if (unlikely(fl4->flowi4_flags &
2618 FLOWI_FLAG_KNOWN_NH &&
2619 !(nhc->nhc_gw_family &&
2620 nhc->nhc_scope == RT_SCOPE_LINK))) {
2621 do_cache = false;
2622 goto add;
2623 }
2624 prth = raw_cpu_ptr(nhc->nhc_pcpu_rth_output);
2625 }
2626 rth = rcu_dereference(*prth);
2627 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2628 return rth;
2629 }
2630
2631add:
2632 rth = rt_dst_alloc(dev_out, flags, type,
2633 IN_DEV_ORCONF(in_dev, NOXFRM));
2634 if (!rth)
2635 return ERR_PTR(-ENOBUFS);
2636
2637 rth->rt_iif = orig_oif;
2638
2639 RT_CACHE_STAT_INC(out_slow_tot);
2640
2641 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2642 if (flags & RTCF_LOCAL &&
2643 !(dev_out->flags & IFF_LOOPBACK)) {
2644 rth->dst.output = ip_mc_output;
2645 RT_CACHE_STAT_INC(out_slow_mc);
2646 }
2647#ifdef CONFIG_IP_MROUTE
2648 if (type == RTN_MULTICAST) {
2649 if (IN_DEV_MFORWARD(in_dev) &&
2650 !ipv4_is_local_multicast(fl4->daddr)) {
2651 rth->dst.input = ip_mr_input;
2652 rth->dst.output = ip_mc_output;
2653 }
2654 }
2655#endif
2656 }
2657
2658 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2659 lwtunnel_set_redirect(&rth->dst);
2660
2661 return rth;
2662}
2663
2664/*
2665 * Major route resolver routine.
2666 */
2667
2668struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2669 const struct sk_buff *skb)
2670{
2671 struct fib_result res = {
2672 .type = RTN_UNSPEC,
2673 .fi = NULL,
2674 .table = NULL,
2675 .tclassid = 0,
2676 };
2677 struct rtable *rth;
2678
2679 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2680 fl4->flowi4_tos &= INET_DSCP_MASK;
2681
2682 rcu_read_lock();
2683 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2684 rcu_read_unlock();
2685
2686 return rth;
2687}
2688EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2689
2690struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2691 struct fib_result *res,
2692 const struct sk_buff *skb)
2693{
2694 struct net_device *dev_out = NULL;
2695 int orig_oif = fl4->flowi4_oif;
2696 unsigned int flags = 0;
2697 struct rtable *rth;
2698 int err;
2699
2700 if (fl4->saddr) {
2701 if (ipv4_is_multicast(fl4->saddr) ||
2702 ipv4_is_lbcast(fl4->saddr) ||
2703 ipv4_is_zeronet(fl4->saddr)) {
2704 rth = ERR_PTR(-EINVAL);
2705 goto out;
2706 }
2707
2708 rth = ERR_PTR(-ENETUNREACH);
2709
2710 /* I removed check for oif == dev_out->oif here.
2711 * It was wrong for two reasons:
2712 * 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2713 * is assigned to multiple interfaces.
2714 * 2. Moreover, we are allowed to send packets with saddr
2715 * of another iface. --ANK
2716 */
2717
2718 if (fl4->flowi4_oif == 0 &&
2719 (ipv4_is_multicast(fl4->daddr) ||
2720 ipv4_is_lbcast(fl4->daddr))) {
2721 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2722 dev_out = __ip_dev_find(net, fl4->saddr, false);
2723 if (!dev_out)
2724 goto out;
2725
2726 /* Special hack: user can direct multicasts
2727 * and limited broadcast via necessary interface
2728 * without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2729 * This hack is not just for fun, it allows
2730 * vic,vat and friends to work.
2731 * They bind socket to loopback, set ttl to zero
2732 * and expect that it will work.
2733 * From the viewpoint of routing cache they are broken,
2734 * because we are not allowed to build multicast path
2735 * with loopback source addr (look, routing cache
2736 * cannot know, that ttl is zero, so that packet
2737 * will not leave this host and route is valid).
2738 * Luckily, this hack is good workaround.
2739 */
2740
2741 fl4->flowi4_oif = dev_out->ifindex;
2742 goto make_route;
2743 }
2744
2745 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2746 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2747 if (!__ip_dev_find(net, fl4->saddr, false))
2748 goto out;
2749 }
2750 }
2751
2752
2753 if (fl4->flowi4_oif) {
2754 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2755 rth = ERR_PTR(-ENODEV);
2756 if (!dev_out)
2757 goto out;
2758
2759 /* RACE: Check return value of inet_select_addr instead. */
2760 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2761 rth = ERR_PTR(-ENETUNREACH);
2762 goto out;
2763 }
2764 if (ipv4_is_local_multicast(fl4->daddr) ||
2765 ipv4_is_lbcast(fl4->daddr) ||
2766 fl4->flowi4_proto == IPPROTO_IGMP) {
2767 if (!fl4->saddr)
2768 fl4->saddr = inet_select_addr(dev_out, 0,
2769 RT_SCOPE_LINK);
2770 goto make_route;
2771 }
2772 if (!fl4->saddr) {
2773 if (ipv4_is_multicast(fl4->daddr))
2774 fl4->saddr = inet_select_addr(dev_out, 0,
2775 fl4->flowi4_scope);
2776 else if (!fl4->daddr)
2777 fl4->saddr = inet_select_addr(dev_out, 0,
2778 RT_SCOPE_HOST);
2779 }
2780 }
2781
2782 if (!fl4->daddr) {
2783 fl4->daddr = fl4->saddr;
2784 if (!fl4->daddr)
2785 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2786 dev_out = net->loopback_dev;
2787 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2788 res->type = RTN_LOCAL;
2789 flags |= RTCF_LOCAL;
2790 goto make_route;
2791 }
2792
2793 err = fib_lookup(net, fl4, res, 0);
2794 if (err) {
2795 res->fi = NULL;
2796 res->table = NULL;
2797 if (fl4->flowi4_oif &&
2798 (ipv4_is_multicast(fl4->daddr) || !fl4->flowi4_l3mdev)) {
2799 /* Apparently, routing tables are wrong. Assume,
2800 * that the destination is on link.
2801 *
2802 * WHY? DW.
2803 * Because we are allowed to send to iface
2804 * even if it has NO routes and NO assigned
2805 * addresses. When oif is specified, routing
2806 * tables are looked up with only one purpose:
2807 * to catch if destination is gatewayed, rather than
2808 * direct. Moreover, if MSG_DONTROUTE is set,
2809 * we send packet, ignoring both routing tables
2810 * and ifaddr state. --ANK
2811 *
2812 *
2813 * We could make it even if oif is unknown,
2814 * likely IPv6, but we do not.
2815 */
2816
2817 if (fl4->saddr == 0)
2818 fl4->saddr = inet_select_addr(dev_out, 0,
2819 RT_SCOPE_LINK);
2820 res->type = RTN_UNICAST;
2821 goto make_route;
2822 }
2823 rth = ERR_PTR(err);
2824 goto out;
2825 }
2826
2827 if (res->type == RTN_LOCAL) {
2828 if (!fl4->saddr) {
2829 if (res->fi->fib_prefsrc)
2830 fl4->saddr = res->fi->fib_prefsrc;
2831 else
2832 fl4->saddr = fl4->daddr;
2833 }
2834
2835 /* L3 master device is the loopback for that domain */
2836 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2837 net->loopback_dev;
2838
2839 /* make sure orig_oif points to fib result device even
2840 * though packet rx/tx happens over loopback or l3mdev
2841 */
2842 orig_oif = FIB_RES_OIF(*res);
2843
2844 fl4->flowi4_oif = dev_out->ifindex;
2845 flags |= RTCF_LOCAL;
2846 goto make_route;
2847 }
2848
2849 fib_select_path(net, res, fl4, skb);
2850
2851 dev_out = FIB_RES_DEV(*res);
2852
2853make_route:
2854 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2855
2856out:
2857 return rth;
2858}
2859
2860static struct dst_ops ipv4_dst_blackhole_ops = {
2861 .family = AF_INET,
2862 .default_advmss = ipv4_default_advmss,
2863 .neigh_lookup = ipv4_neigh_lookup,
2864 .check = dst_blackhole_check,
2865 .cow_metrics = dst_blackhole_cow_metrics,
2866 .update_pmtu = dst_blackhole_update_pmtu,
2867 .redirect = dst_blackhole_redirect,
2868 .mtu = dst_blackhole_mtu,
2869};
2870
2871struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2872{
2873 struct rtable *ort = dst_rtable(dst_orig);
2874 struct rtable *rt;
2875
2876 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, DST_OBSOLETE_DEAD, 0);
2877 if (rt) {
2878 struct dst_entry *new = &rt->dst;
2879
2880 new->__use = 1;
2881 new->input = dst_discard;
2882 new->output = dst_discard_out;
2883
2884 new->dev = net->loopback_dev;
2885 netdev_hold(new->dev, &new->dev_tracker, GFP_ATOMIC);
2886
2887 rt->rt_is_input = ort->rt_is_input;
2888 rt->rt_iif = ort->rt_iif;
2889 rt->rt_pmtu = ort->rt_pmtu;
2890 rt->rt_mtu_locked = ort->rt_mtu_locked;
2891
2892 rt->rt_genid = rt_genid_ipv4(net);
2893 rt->rt_flags = ort->rt_flags;
2894 rt->rt_type = ort->rt_type;
2895 rt->rt_uses_gateway = ort->rt_uses_gateway;
2896 rt->rt_gw_family = ort->rt_gw_family;
2897 if (rt->rt_gw_family == AF_INET)
2898 rt->rt_gw4 = ort->rt_gw4;
2899 else if (rt->rt_gw_family == AF_INET6)
2900 rt->rt_gw6 = ort->rt_gw6;
2901 }
2902
2903 dst_release(dst_orig);
2904
2905 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2906}
2907
2908struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2909 const struct sock *sk)
2910{
2911 struct rtable *rt = __ip_route_output_key(net, flp4);
2912
2913 if (IS_ERR(rt))
2914 return rt;
2915
2916 if (flp4->flowi4_proto) {
2917 flp4->flowi4_oif = rt->dst.dev->ifindex;
2918 rt = dst_rtable(xfrm_lookup_route(net, &rt->dst,
2919 flowi4_to_flowi(flp4),
2920 sk, 0));
2921 }
2922
2923 return rt;
2924}
2925EXPORT_SYMBOL_GPL(ip_route_output_flow);
2926
2927/* called with rcu_read_lock held */
2928static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2929 struct rtable *rt, u32 table_id, dscp_t dscp,
2930 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2931 u32 seq, unsigned int flags)
2932{
2933 struct rtmsg *r;
2934 struct nlmsghdr *nlh;
2935 unsigned long expires = 0;
2936 u32 error;
2937 u32 metrics[RTAX_MAX];
2938
2939 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), flags);
2940 if (!nlh)
2941 return -EMSGSIZE;
2942
2943 r = nlmsg_data(nlh);
2944 r->rtm_family = AF_INET;
2945 r->rtm_dst_len = 32;
2946 r->rtm_src_len = 0;
2947 r->rtm_tos = inet_dscp_to_dsfield(dscp);
2948 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2949 if (nla_put_u32(skb, RTA_TABLE, table_id))
2950 goto nla_put_failure;
2951 r->rtm_type = rt->rt_type;
2952 r->rtm_scope = RT_SCOPE_UNIVERSE;
2953 r->rtm_protocol = RTPROT_UNSPEC;
2954 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2955 if (rt->rt_flags & RTCF_NOTIFY)
2956 r->rtm_flags |= RTM_F_NOTIFY;
2957 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2958 r->rtm_flags |= RTCF_DOREDIRECT;
2959
2960 if (nla_put_in_addr(skb, RTA_DST, dst))
2961 goto nla_put_failure;
2962 if (src) {
2963 r->rtm_src_len = 32;
2964 if (nla_put_in_addr(skb, RTA_SRC, src))
2965 goto nla_put_failure;
2966 }
2967 if (rt->dst.dev &&
2968 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2969 goto nla_put_failure;
2970 if (rt->dst.lwtstate &&
2971 lwtunnel_fill_encap(skb, rt->dst.lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
2972 goto nla_put_failure;
2973#ifdef CONFIG_IP_ROUTE_CLASSID
2974 if (rt->dst.tclassid &&
2975 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2976 goto nla_put_failure;
2977#endif
2978 if (fl4 && !rt_is_input_route(rt) &&
2979 fl4->saddr != src) {
2980 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2981 goto nla_put_failure;
2982 }
2983 if (rt->rt_uses_gateway) {
2984 if (rt->rt_gw_family == AF_INET &&
2985 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gw4)) {
2986 goto nla_put_failure;
2987 } else if (rt->rt_gw_family == AF_INET6) {
2988 int alen = sizeof(struct in6_addr);
2989 struct nlattr *nla;
2990 struct rtvia *via;
2991
2992 nla = nla_reserve(skb, RTA_VIA, alen + 2);
2993 if (!nla)
2994 goto nla_put_failure;
2995
2996 via = nla_data(nla);
2997 via->rtvia_family = AF_INET6;
2998 memcpy(via->rtvia_addr, &rt->rt_gw6, alen);
2999 }
3000 }
3001
3002 expires = rt->dst.expires;
3003 if (expires) {
3004 unsigned long now = jiffies;
3005
3006 if (time_before(now, expires))
3007 expires -= now;
3008 else
3009 expires = 0;
3010 }
3011
3012 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
3013 if (rt->rt_pmtu && expires)
3014 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
3015 if (rt->rt_mtu_locked && expires)
3016 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
3017 if (rtnetlink_put_metrics(skb, metrics) < 0)
3018 goto nla_put_failure;
3019
3020 if (fl4) {
3021 if (fl4->flowi4_mark &&
3022 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
3023 goto nla_put_failure;
3024
3025 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
3026 nla_put_u32(skb, RTA_UID,
3027 from_kuid_munged(current_user_ns(),
3028 fl4->flowi4_uid)))
3029 goto nla_put_failure;
3030
3031 if (rt_is_input_route(rt)) {
3032#ifdef CONFIG_IP_MROUTE
3033 if (ipv4_is_multicast(dst) &&
3034 !ipv4_is_local_multicast(dst) &&
3035 IPV4_DEVCONF_ALL_RO(net, MC_FORWARDING)) {
3036 int err = ipmr_get_route(net, skb,
3037 fl4->saddr, fl4->daddr,
3038 r, portid);
3039
3040 if (err <= 0) {
3041 if (err == 0)
3042 return 0;
3043 goto nla_put_failure;
3044 }
3045 } else
3046#endif
3047 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
3048 goto nla_put_failure;
3049 }
3050 }
3051
3052 error = rt->dst.error;
3053
3054 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
3055 goto nla_put_failure;
3056
3057 nlmsg_end(skb, nlh);
3058 return 0;
3059
3060nla_put_failure:
3061 nlmsg_cancel(skb, nlh);
3062 return -EMSGSIZE;
3063}
3064
3065static int fnhe_dump_bucket(struct net *net, struct sk_buff *skb,
3066 struct netlink_callback *cb, u32 table_id,
3067 struct fnhe_hash_bucket *bucket, int genid,
3068 int *fa_index, int fa_start, unsigned int flags)
3069{
3070 int i;
3071
3072 for (i = 0; i < FNHE_HASH_SIZE; i++) {
3073 struct fib_nh_exception *fnhe;
3074
3075 for (fnhe = rcu_dereference(bucket[i].chain); fnhe;
3076 fnhe = rcu_dereference(fnhe->fnhe_next)) {
3077 struct rtable *rt;
3078 int err;
3079
3080 if (*fa_index < fa_start)
3081 goto next;
3082
3083 if (fnhe->fnhe_genid != genid)
3084 goto next;
3085
3086 if (fnhe->fnhe_expires &&
3087 time_after(jiffies, fnhe->fnhe_expires))
3088 goto next;
3089
3090 rt = rcu_dereference(fnhe->fnhe_rth_input);
3091 if (!rt)
3092 rt = rcu_dereference(fnhe->fnhe_rth_output);
3093 if (!rt)
3094 goto next;
3095
3096 err = rt_fill_info(net, fnhe->fnhe_daddr, 0, rt,
3097 table_id, 0, NULL, skb,
3098 NETLINK_CB(cb->skb).portid,
3099 cb->nlh->nlmsg_seq, flags);
3100 if (err)
3101 return err;
3102next:
3103 (*fa_index)++;
3104 }
3105 }
3106
3107 return 0;
3108}
3109
3110int fib_dump_info_fnhe(struct sk_buff *skb, struct netlink_callback *cb,
3111 u32 table_id, struct fib_info *fi,
3112 int *fa_index, int fa_start, unsigned int flags)
3113{
3114 struct net *net = sock_net(cb->skb->sk);
3115 int nhsel, genid = fnhe_genid(net);
3116
3117 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
3118 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
3119 struct fnhe_hash_bucket *bucket;
3120 int err;
3121
3122 if (nhc->nhc_flags & RTNH_F_DEAD)
3123 continue;
3124
3125 rcu_read_lock();
3126 bucket = rcu_dereference(nhc->nhc_exceptions);
3127 err = 0;
3128 if (bucket)
3129 err = fnhe_dump_bucket(net, skb, cb, table_id, bucket,
3130 genid, fa_index, fa_start,
3131 flags);
3132 rcu_read_unlock();
3133 if (err)
3134 return err;
3135 }
3136
3137 return 0;
3138}
3139
3140static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
3141 u8 ip_proto, __be16 sport,
3142 __be16 dport)
3143{
3144 struct sk_buff *skb;
3145 struct iphdr *iph;
3146
3147 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3148 if (!skb)
3149 return NULL;
3150
3151 /* Reserve room for dummy headers, this skb can pass
3152 * through good chunk of routing engine.
3153 */
3154 skb_reset_mac_header(skb);
3155 skb_reset_network_header(skb);
3156 skb->protocol = htons(ETH_P_IP);
3157 iph = skb_put(skb, sizeof(struct iphdr));
3158 iph->protocol = ip_proto;
3159 iph->saddr = src;
3160 iph->daddr = dst;
3161 iph->version = 0x4;
3162 iph->frag_off = 0;
3163 iph->ihl = 0x5;
3164 skb_set_transport_header(skb, skb->len);
3165
3166 switch (iph->protocol) {
3167 case IPPROTO_UDP: {
3168 struct udphdr *udph;
3169
3170 udph = skb_put_zero(skb, sizeof(struct udphdr));
3171 udph->source = sport;
3172 udph->dest = dport;
3173 udph->len = htons(sizeof(struct udphdr));
3174 udph->check = 0;
3175 break;
3176 }
3177 case IPPROTO_TCP: {
3178 struct tcphdr *tcph;
3179
3180 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
3181 tcph->source = sport;
3182 tcph->dest = dport;
3183 tcph->doff = sizeof(struct tcphdr) / 4;
3184 tcph->rst = 1;
3185 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
3186 src, dst, 0);
3187 break;
3188 }
3189 case IPPROTO_ICMP: {
3190 struct icmphdr *icmph;
3191
3192 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
3193 icmph->type = ICMP_ECHO;
3194 icmph->code = 0;
3195 }
3196 }
3197
3198 return skb;
3199}
3200
3201static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
3202 const struct nlmsghdr *nlh,
3203 struct nlattr **tb,
3204 struct netlink_ext_ack *extack)
3205{
3206 struct rtmsg *rtm;
3207 int i, err;
3208
3209 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
3210 NL_SET_ERR_MSG(extack,
3211 "ipv4: Invalid header for route get request");
3212 return -EINVAL;
3213 }
3214
3215 if (!netlink_strict_get_check(skb))
3216 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
3217 rtm_ipv4_policy, extack);
3218
3219 rtm = nlmsg_data(nlh);
3220 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
3221 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
3222 rtm->rtm_table || rtm->rtm_protocol ||
3223 rtm->rtm_scope || rtm->rtm_type) {
3224 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
3225 return -EINVAL;
3226 }
3227
3228 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
3229 RTM_F_LOOKUP_TABLE |
3230 RTM_F_FIB_MATCH)) {
3231 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
3232 return -EINVAL;
3233 }
3234
3235 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
3236 rtm_ipv4_policy, extack);
3237 if (err)
3238 return err;
3239
3240 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
3241 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
3242 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
3243 return -EINVAL;
3244 }
3245
3246 for (i = 0; i <= RTA_MAX; i++) {
3247 if (!tb[i])
3248 continue;
3249
3250 switch (i) {
3251 case RTA_IIF:
3252 case RTA_OIF:
3253 case RTA_SRC:
3254 case RTA_DST:
3255 case RTA_IP_PROTO:
3256 case RTA_SPORT:
3257 case RTA_DPORT:
3258 case RTA_MARK:
3259 case RTA_UID:
3260 break;
3261 default:
3262 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
3263 return -EINVAL;
3264 }
3265 }
3266
3267 return 0;
3268}
3269
3270static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
3271 struct netlink_ext_ack *extack)
3272{
3273 struct net *net = sock_net(in_skb->sk);
3274 struct nlattr *tb[RTA_MAX+1];
3275 u32 table_id = RT_TABLE_MAIN;
3276 __be16 sport = 0, dport = 0;
3277 struct fib_result res = {};
3278 u8 ip_proto = IPPROTO_UDP;
3279 struct rtable *rt = NULL;
3280 struct sk_buff *skb;
3281 struct rtmsg *rtm;
3282 struct flowi4 fl4 = {};
3283 __be32 dst = 0;
3284 __be32 src = 0;
3285 kuid_t uid;
3286 u32 iif;
3287 int err;
3288 int mark;
3289
3290 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
3291 if (err < 0)
3292 return err;
3293
3294 rtm = nlmsg_data(nlh);
3295 src = nla_get_in_addr_default(tb[RTA_SRC], 0);
3296 dst = nla_get_in_addr_default(tb[RTA_DST], 0);
3297 iif = nla_get_u32_default(tb[RTA_IIF], 0);
3298 mark = nla_get_u32_default(tb[RTA_MARK], 0);
3299 if (tb[RTA_UID])
3300 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
3301 else
3302 uid = (iif ? INVALID_UID : current_uid());
3303
3304 if (tb[RTA_IP_PROTO]) {
3305 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
3306 &ip_proto, AF_INET, extack);
3307 if (err)
3308 return err;
3309 }
3310
3311 if (tb[RTA_SPORT])
3312 sport = nla_get_be16(tb[RTA_SPORT]);
3313
3314 if (tb[RTA_DPORT])
3315 dport = nla_get_be16(tb[RTA_DPORT]);
3316
3317 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
3318 if (!skb)
3319 return -ENOBUFS;
3320
3321 fl4.daddr = dst;
3322 fl4.saddr = src;
3323 fl4.flowi4_tos = rtm->rtm_tos & INET_DSCP_MASK;
3324 fl4.flowi4_oif = nla_get_u32_default(tb[RTA_OIF], 0);
3325 fl4.flowi4_mark = mark;
3326 fl4.flowi4_uid = uid;
3327 if (sport)
3328 fl4.fl4_sport = sport;
3329 if (dport)
3330 fl4.fl4_dport = dport;
3331 fl4.flowi4_proto = ip_proto;
3332
3333 rcu_read_lock();
3334
3335 if (iif) {
3336 struct net_device *dev;
3337
3338 dev = dev_get_by_index_rcu(net, iif);
3339 if (!dev) {
3340 err = -ENODEV;
3341 goto errout_rcu;
3342 }
3343
3344 fl4.flowi4_iif = iif; /* for rt_fill_info */
3345 skb->dev = dev;
3346 skb->mark = mark;
3347 err = ip_route_input_rcu(skb, dst, src,
3348 inet_dsfield_to_dscp(rtm->rtm_tos),
3349 dev, &res) ? -EINVAL : 0;
3350
3351 rt = skb_rtable(skb);
3352 if (err == 0 && rt->dst.error)
3353 err = -rt->dst.error;
3354 } else {
3355 fl4.flowi4_iif = LOOPBACK_IFINDEX;
3356 skb->dev = net->loopback_dev;
3357 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
3358 err = 0;
3359 if (IS_ERR(rt))
3360 err = PTR_ERR(rt);
3361 else
3362 skb_dst_set(skb, &rt->dst);
3363 }
3364
3365 if (err)
3366 goto errout_rcu;
3367
3368 if (rtm->rtm_flags & RTM_F_NOTIFY)
3369 rt->rt_flags |= RTCF_NOTIFY;
3370
3371 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
3372 table_id = res.table ? res.table->tb_id : 0;
3373
3374 /* reset skb for netlink reply msg */
3375 skb_trim(skb, 0);
3376 skb_reset_network_header(skb);
3377 skb_reset_transport_header(skb);
3378 skb_reset_mac_header(skb);
3379
3380 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
3381 struct fib_rt_info fri;
3382
3383 if (!res.fi) {
3384 err = fib_props[res.type].error;
3385 if (!err)
3386 err = -EHOSTUNREACH;
3387 goto errout_rcu;
3388 }
3389 fri.fi = res.fi;
3390 fri.tb_id = table_id;
3391 fri.dst = res.prefix;
3392 fri.dst_len = res.prefixlen;
3393 fri.dscp = res.dscp;
3394 fri.type = rt->rt_type;
3395 fri.offload = 0;
3396 fri.trap = 0;
3397 fri.offload_failed = 0;
3398 if (res.fa_head) {
3399 struct fib_alias *fa;
3400
3401 hlist_for_each_entry_rcu(fa, res.fa_head, fa_list) {
3402 u8 slen = 32 - fri.dst_len;
3403
3404 if (fa->fa_slen == slen &&
3405 fa->tb_id == fri.tb_id &&
3406 fa->fa_dscp == fri.dscp &&
3407 fa->fa_info == res.fi &&
3408 fa->fa_type == fri.type) {
3409 fri.offload = READ_ONCE(fa->offload);
3410 fri.trap = READ_ONCE(fa->trap);
3411 fri.offload_failed =
3412 READ_ONCE(fa->offload_failed);
3413 break;
3414 }
3415 }
3416 }
3417 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
3418 nlh->nlmsg_seq, RTM_NEWROUTE, &fri, 0);
3419 } else {
3420 err = rt_fill_info(net, dst, src, rt, table_id, res.dscp, &fl4,
3421 skb, NETLINK_CB(in_skb).portid,
3422 nlh->nlmsg_seq, 0);
3423 }
3424 if (err < 0)
3425 goto errout_rcu;
3426
3427 rcu_read_unlock();
3428
3429 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
3430
3431errout_free:
3432 return err;
3433errout_rcu:
3434 rcu_read_unlock();
3435 kfree_skb(skb);
3436 goto errout_free;
3437}
3438
3439void ip_rt_multicast_event(struct in_device *in_dev)
3440{
3441 rt_cache_flush(dev_net(in_dev->dev));
3442}
3443
3444#ifdef CONFIG_SYSCTL
3445static int ip_rt_gc_interval __read_mostly = 60 * HZ;
3446static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
3447static int ip_rt_gc_elasticity __read_mostly = 8;
3448static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
3449
3450static int ipv4_sysctl_rtcache_flush(const struct ctl_table *__ctl, int write,
3451 void *buffer, size_t *lenp, loff_t *ppos)
3452{
3453 struct net *net = (struct net *)__ctl->extra1;
3454
3455 if (write) {
3456 rt_cache_flush(net);
3457 fnhe_genid_bump(net);
3458 return 0;
3459 }
3460
3461 return -EINVAL;
3462}
3463
3464static struct ctl_table ipv4_route_table[] = {
3465 {
3466 .procname = "gc_thresh",
3467 .data = &ipv4_dst_ops.gc_thresh,
3468 .maxlen = sizeof(int),
3469 .mode = 0644,
3470 .proc_handler = proc_dointvec,
3471 },
3472 {
3473 .procname = "max_size",
3474 .data = &ip_rt_max_size,
3475 .maxlen = sizeof(int),
3476 .mode = 0644,
3477 .proc_handler = proc_dointvec,
3478 },
3479 {
3480 /* Deprecated. Use gc_min_interval_ms */
3481
3482 .procname = "gc_min_interval",
3483 .data = &ip_rt_gc_min_interval,
3484 .maxlen = sizeof(int),
3485 .mode = 0644,
3486 .proc_handler = proc_dointvec_jiffies,
3487 },
3488 {
3489 .procname = "gc_min_interval_ms",
3490 .data = &ip_rt_gc_min_interval,
3491 .maxlen = sizeof(int),
3492 .mode = 0644,
3493 .proc_handler = proc_dointvec_ms_jiffies,
3494 },
3495 {
3496 .procname = "gc_timeout",
3497 .data = &ip_rt_gc_timeout,
3498 .maxlen = sizeof(int),
3499 .mode = 0644,
3500 .proc_handler = proc_dointvec_jiffies,
3501 },
3502 {
3503 .procname = "gc_interval",
3504 .data = &ip_rt_gc_interval,
3505 .maxlen = sizeof(int),
3506 .mode = 0644,
3507 .proc_handler = proc_dointvec_jiffies,
3508 },
3509 {
3510 .procname = "redirect_load",
3511 .data = &ip_rt_redirect_load,
3512 .maxlen = sizeof(int),
3513 .mode = 0644,
3514 .proc_handler = proc_dointvec,
3515 },
3516 {
3517 .procname = "redirect_number",
3518 .data = &ip_rt_redirect_number,
3519 .maxlen = sizeof(int),
3520 .mode = 0644,
3521 .proc_handler = proc_dointvec,
3522 },
3523 {
3524 .procname = "redirect_silence",
3525 .data = &ip_rt_redirect_silence,
3526 .maxlen = sizeof(int),
3527 .mode = 0644,
3528 .proc_handler = proc_dointvec,
3529 },
3530 {
3531 .procname = "error_cost",
3532 .data = &ip_rt_error_cost,
3533 .maxlen = sizeof(int),
3534 .mode = 0644,
3535 .proc_handler = proc_dointvec,
3536 },
3537 {
3538 .procname = "error_burst",
3539 .data = &ip_rt_error_burst,
3540 .maxlen = sizeof(int),
3541 .mode = 0644,
3542 .proc_handler = proc_dointvec,
3543 },
3544 {
3545 .procname = "gc_elasticity",
3546 .data = &ip_rt_gc_elasticity,
3547 .maxlen = sizeof(int),
3548 .mode = 0644,
3549 .proc_handler = proc_dointvec,
3550 },
3551};
3552
3553static const char ipv4_route_flush_procname[] = "flush";
3554
3555static struct ctl_table ipv4_route_netns_table[] = {
3556 {
3557 .procname = ipv4_route_flush_procname,
3558 .maxlen = sizeof(int),
3559 .mode = 0200,
3560 .proc_handler = ipv4_sysctl_rtcache_flush,
3561 },
3562 {
3563 .procname = "min_pmtu",
3564 .data = &init_net.ipv4.ip_rt_min_pmtu,
3565 .maxlen = sizeof(int),
3566 .mode = 0644,
3567 .proc_handler = proc_dointvec_minmax,
3568 .extra1 = &ip_min_valid_pmtu,
3569 },
3570 {
3571 .procname = "mtu_expires",
3572 .data = &init_net.ipv4.ip_rt_mtu_expires,
3573 .maxlen = sizeof(int),
3574 .mode = 0644,
3575 .proc_handler = proc_dointvec_jiffies,
3576 },
3577 {
3578 .procname = "min_adv_mss",
3579 .data = &init_net.ipv4.ip_rt_min_advmss,
3580 .maxlen = sizeof(int),
3581 .mode = 0644,
3582 .proc_handler = proc_dointvec,
3583 },
3584};
3585
3586static __net_init int sysctl_route_net_init(struct net *net)
3587{
3588 struct ctl_table *tbl;
3589 size_t table_size = ARRAY_SIZE(ipv4_route_netns_table);
3590
3591 tbl = ipv4_route_netns_table;
3592 if (!net_eq(net, &init_net)) {
3593 int i;
3594
3595 tbl = kmemdup(tbl, sizeof(ipv4_route_netns_table), GFP_KERNEL);
3596 if (!tbl)
3597 goto err_dup;
3598
3599 /* Don't export non-whitelisted sysctls to unprivileged users */
3600 if (net->user_ns != &init_user_ns) {
3601 if (tbl[0].procname != ipv4_route_flush_procname)
3602 table_size = 0;
3603 }
3604
3605 /* Update the variables to point into the current struct net
3606 * except for the first element flush
3607 */
3608 for (i = 1; i < table_size; i++)
3609 tbl[i].data += (void *)net - (void *)&init_net;
3610 }
3611 tbl[0].extra1 = net;
3612
3613 net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route",
3614 tbl, table_size);
3615 if (!net->ipv4.route_hdr)
3616 goto err_reg;
3617 return 0;
3618
3619err_reg:
3620 if (tbl != ipv4_route_netns_table)
3621 kfree(tbl);
3622err_dup:
3623 return -ENOMEM;
3624}
3625
3626static __net_exit void sysctl_route_net_exit(struct net *net)
3627{
3628 const struct ctl_table *tbl;
3629
3630 tbl = net->ipv4.route_hdr->ctl_table_arg;
3631 unregister_net_sysctl_table(net->ipv4.route_hdr);
3632 BUG_ON(tbl == ipv4_route_netns_table);
3633 kfree(tbl);
3634}
3635
3636static __net_initdata struct pernet_operations sysctl_route_ops = {
3637 .init = sysctl_route_net_init,
3638 .exit = sysctl_route_net_exit,
3639};
3640#endif
3641
3642static __net_init int netns_ip_rt_init(struct net *net)
3643{
3644 /* Set default value for namespaceified sysctls */
3645 net->ipv4.ip_rt_min_pmtu = DEFAULT_MIN_PMTU;
3646 net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
3647 net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
3648 return 0;
3649}
3650
3651static struct pernet_operations __net_initdata ip_rt_ops = {
3652 .init = netns_ip_rt_init,
3653};
3654
3655static __net_init int rt_genid_init(struct net *net)
3656{
3657 atomic_set(&net->ipv4.rt_genid, 0);
3658 atomic_set(&net->fnhe_genid, 0);
3659 atomic_set(&net->ipv4.dev_addr_genid, get_random_u32());
3660 return 0;
3661}
3662
3663static __net_initdata struct pernet_operations rt_genid_ops = {
3664 .init = rt_genid_init,
3665};
3666
3667static int __net_init ipv4_inetpeer_init(struct net *net)
3668{
3669 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3670
3671 if (!bp)
3672 return -ENOMEM;
3673 inet_peer_base_init(bp);
3674 net->ipv4.peers = bp;
3675 return 0;
3676}
3677
3678static void __net_exit ipv4_inetpeer_exit(struct net *net)
3679{
3680 struct inet_peer_base *bp = net->ipv4.peers;
3681
3682 net->ipv4.peers = NULL;
3683 inetpeer_invalidate_tree(bp);
3684 kfree(bp);
3685}
3686
3687static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3688 .init = ipv4_inetpeer_init,
3689 .exit = ipv4_inetpeer_exit,
3690};
3691
3692#ifdef CONFIG_IP_ROUTE_CLASSID
3693struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3694#endif /* CONFIG_IP_ROUTE_CLASSID */
3695
3696static const struct rtnl_msg_handler ip_rt_rtnl_msg_handlers[] __initconst = {
3697 {.protocol = PF_INET, .msgtype = RTM_GETROUTE,
3698 .doit = inet_rtm_getroute, .flags = RTNL_FLAG_DOIT_UNLOCKED},
3699};
3700
3701int __init ip_rt_init(void)
3702{
3703 void *idents_hash;
3704 int cpu;
3705
3706 /* For modern hosts, this will use 2 MB of memory */
3707 idents_hash = alloc_large_system_hash("IP idents",
3708 sizeof(*ip_idents) + sizeof(*ip_tstamps),
3709 0,
3710 16, /* one bucket per 64 KB */
3711 HASH_ZERO,
3712 NULL,
3713 &ip_idents_mask,
3714 2048,
3715 256*1024);
3716
3717 ip_idents = idents_hash;
3718
3719 get_random_bytes(ip_idents, (ip_idents_mask + 1) * sizeof(*ip_idents));
3720
3721 ip_tstamps = idents_hash + (ip_idents_mask + 1) * sizeof(*ip_idents);
3722
3723 for_each_possible_cpu(cpu) {
3724 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3725
3726 INIT_LIST_HEAD(&ul->head);
3727 spin_lock_init(&ul->lock);
3728 }
3729#ifdef CONFIG_IP_ROUTE_CLASSID
3730 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3731 if (!ip_rt_acct)
3732 panic("IP: failed to allocate ip_rt_acct\n");
3733#endif
3734
3735 ipv4_dst_ops.kmem_cachep = KMEM_CACHE(rtable,
3736 SLAB_HWCACHE_ALIGN | SLAB_PANIC);
3737
3738 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3739
3740 if (dst_entries_init(&ipv4_dst_ops) < 0)
3741 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3742
3743 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3744 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3745
3746 ipv4_dst_ops.gc_thresh = ~0;
3747 ip_rt_max_size = INT_MAX;
3748
3749 devinet_init();
3750 ip_fib_init();
3751
3752 if (ip_rt_proc_init())
3753 pr_err("Unable to create route proc files\n");
3754#ifdef CONFIG_XFRM
3755 xfrm_init();
3756 xfrm4_init();
3757#endif
3758 rtnl_register_many(ip_rt_rtnl_msg_handlers);
3759
3760#ifdef CONFIG_SYSCTL
3761 register_pernet_subsys(&sysctl_route_ops);
3762#endif
3763 register_pernet_subsys(&ip_rt_ops);
3764 register_pernet_subsys(&rt_genid_ops);
3765 register_pernet_subsys(&ipv4_inetpeer_ops);
3766 return 0;
3767}
3768
3769#ifdef CONFIG_SYSCTL
3770/*
3771 * We really need to sanitize the damn ipv4 init order, then all
3772 * this nonsense will go away.
3773 */
3774void __init ip_static_sysctl_init(void)
3775{
3776 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3777}
3778#endif
1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65#include <linux/module.h>
66#include <asm/uaccess.h>
67#include <asm/system.h>
68#include <linux/bitops.h>
69#include <linux/types.h>
70#include <linux/kernel.h>
71#include <linux/mm.h>
72#include <linux/bootmem.h>
73#include <linux/string.h>
74#include <linux/socket.h>
75#include <linux/sockios.h>
76#include <linux/errno.h>
77#include <linux/in.h>
78#include <linux/inet.h>
79#include <linux/netdevice.h>
80#include <linux/proc_fs.h>
81#include <linux/init.h>
82#include <linux/workqueue.h>
83#include <linux/skbuff.h>
84#include <linux/inetdevice.h>
85#include <linux/igmp.h>
86#include <linux/pkt_sched.h>
87#include <linux/mroute.h>
88#include <linux/netfilter_ipv4.h>
89#include <linux/random.h>
90#include <linux/jhash.h>
91#include <linux/rcupdate.h>
92#include <linux/times.h>
93#include <linux/slab.h>
94#include <net/dst.h>
95#include <net/net_namespace.h>
96#include <net/protocol.h>
97#include <net/ip.h>
98#include <net/route.h>
99#include <net/inetpeer.h>
100#include <net/sock.h>
101#include <net/ip_fib.h>
102#include <net/arp.h>
103#include <net/tcp.h>
104#include <net/icmp.h>
105#include <net/xfrm.h>
106#include <net/netevent.h>
107#include <net/rtnetlink.h>
108#ifdef CONFIG_SYSCTL
109#include <linux/sysctl.h>
110#endif
111#include <net/atmclip.h>
112#include <net/secure_seq.h>
113
114#define RT_FL_TOS(oldflp4) \
115 ((u32)(oldflp4->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
116
117#define IP_MAX_MTU 0xFFF0
118
119#define RT_GC_TIMEOUT (300*HZ)
120
121static int ip_rt_max_size;
122static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
123static int ip_rt_gc_interval __read_mostly = 60 * HZ;
124static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
125static int ip_rt_redirect_number __read_mostly = 9;
126static int ip_rt_redirect_load __read_mostly = HZ / 50;
127static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
128static int ip_rt_error_cost __read_mostly = HZ;
129static int ip_rt_error_burst __read_mostly = 5 * HZ;
130static int ip_rt_gc_elasticity __read_mostly = 8;
131static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
132static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
133static int ip_rt_min_advmss __read_mostly = 256;
134static int rt_chain_length_max __read_mostly = 20;
135
136/*
137 * Interface to generic destination cache.
138 */
139
140static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
141static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
142static unsigned int ipv4_default_mtu(const struct dst_entry *dst);
143static void ipv4_dst_destroy(struct dst_entry *dst);
144static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
145static void ipv4_link_failure(struct sk_buff *skb);
146static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
147static int rt_garbage_collect(struct dst_ops *ops);
148
149static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
150 int how)
151{
152}
153
154static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
155{
156 struct rtable *rt = (struct rtable *) dst;
157 struct inet_peer *peer;
158 u32 *p = NULL;
159
160 if (!rt->peer)
161 rt_bind_peer(rt, rt->rt_dst, 1);
162
163 peer = rt->peer;
164 if (peer) {
165 u32 *old_p = __DST_METRICS_PTR(old);
166 unsigned long prev, new;
167
168 p = peer->metrics;
169 if (inet_metrics_new(peer))
170 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
171
172 new = (unsigned long) p;
173 prev = cmpxchg(&dst->_metrics, old, new);
174
175 if (prev != old) {
176 p = __DST_METRICS_PTR(prev);
177 if (prev & DST_METRICS_READ_ONLY)
178 p = NULL;
179 } else {
180 if (rt->fi) {
181 fib_info_put(rt->fi);
182 rt->fi = NULL;
183 }
184 }
185 }
186 return p;
187}
188
189static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
190
191static struct dst_ops ipv4_dst_ops = {
192 .family = AF_INET,
193 .protocol = cpu_to_be16(ETH_P_IP),
194 .gc = rt_garbage_collect,
195 .check = ipv4_dst_check,
196 .default_advmss = ipv4_default_advmss,
197 .default_mtu = ipv4_default_mtu,
198 .cow_metrics = ipv4_cow_metrics,
199 .destroy = ipv4_dst_destroy,
200 .ifdown = ipv4_dst_ifdown,
201 .negative_advice = ipv4_negative_advice,
202 .link_failure = ipv4_link_failure,
203 .update_pmtu = ip_rt_update_pmtu,
204 .local_out = __ip_local_out,
205 .neigh_lookup = ipv4_neigh_lookup,
206};
207
208#define ECN_OR_COST(class) TC_PRIO_##class
209
210const __u8 ip_tos2prio[16] = {
211 TC_PRIO_BESTEFFORT,
212 ECN_OR_COST(BESTEFFORT),
213 TC_PRIO_BESTEFFORT,
214 ECN_OR_COST(BESTEFFORT),
215 TC_PRIO_BULK,
216 ECN_OR_COST(BULK),
217 TC_PRIO_BULK,
218 ECN_OR_COST(BULK),
219 TC_PRIO_INTERACTIVE,
220 ECN_OR_COST(INTERACTIVE),
221 TC_PRIO_INTERACTIVE,
222 ECN_OR_COST(INTERACTIVE),
223 TC_PRIO_INTERACTIVE_BULK,
224 ECN_OR_COST(INTERACTIVE_BULK),
225 TC_PRIO_INTERACTIVE_BULK,
226 ECN_OR_COST(INTERACTIVE_BULK)
227};
228
229
230/*
231 * Route cache.
232 */
233
234/* The locking scheme is rather straight forward:
235 *
236 * 1) Read-Copy Update protects the buckets of the central route hash.
237 * 2) Only writers remove entries, and they hold the lock
238 * as they look at rtable reference counts.
239 * 3) Only readers acquire references to rtable entries,
240 * they do so with atomic increments and with the
241 * lock held.
242 */
243
244struct rt_hash_bucket {
245 struct rtable __rcu *chain;
246};
247
248#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
249 defined(CONFIG_PROVE_LOCKING)
250/*
251 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
252 * The size of this table is a power of two and depends on the number of CPUS.
253 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
254 */
255#ifdef CONFIG_LOCKDEP
256# define RT_HASH_LOCK_SZ 256
257#else
258# if NR_CPUS >= 32
259# define RT_HASH_LOCK_SZ 4096
260# elif NR_CPUS >= 16
261# define RT_HASH_LOCK_SZ 2048
262# elif NR_CPUS >= 8
263# define RT_HASH_LOCK_SZ 1024
264# elif NR_CPUS >= 4
265# define RT_HASH_LOCK_SZ 512
266# else
267# define RT_HASH_LOCK_SZ 256
268# endif
269#endif
270
271static spinlock_t *rt_hash_locks;
272# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
273
274static __init void rt_hash_lock_init(void)
275{
276 int i;
277
278 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
279 GFP_KERNEL);
280 if (!rt_hash_locks)
281 panic("IP: failed to allocate rt_hash_locks\n");
282
283 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
284 spin_lock_init(&rt_hash_locks[i]);
285}
286#else
287# define rt_hash_lock_addr(slot) NULL
288
289static inline void rt_hash_lock_init(void)
290{
291}
292#endif
293
294static struct rt_hash_bucket *rt_hash_table __read_mostly;
295static unsigned rt_hash_mask __read_mostly;
296static unsigned int rt_hash_log __read_mostly;
297
298static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
299#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
300
301static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
302 int genid)
303{
304 return jhash_3words((__force u32)daddr, (__force u32)saddr,
305 idx, genid)
306 & rt_hash_mask;
307}
308
309static inline int rt_genid(struct net *net)
310{
311 return atomic_read(&net->ipv4.rt_genid);
312}
313
314#ifdef CONFIG_PROC_FS
315struct rt_cache_iter_state {
316 struct seq_net_private p;
317 int bucket;
318 int genid;
319};
320
321static struct rtable *rt_cache_get_first(struct seq_file *seq)
322{
323 struct rt_cache_iter_state *st = seq->private;
324 struct rtable *r = NULL;
325
326 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
327 if (!rcu_dereference_raw(rt_hash_table[st->bucket].chain))
328 continue;
329 rcu_read_lock_bh();
330 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
331 while (r) {
332 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
333 r->rt_genid == st->genid)
334 return r;
335 r = rcu_dereference_bh(r->dst.rt_next);
336 }
337 rcu_read_unlock_bh();
338 }
339 return r;
340}
341
342static struct rtable *__rt_cache_get_next(struct seq_file *seq,
343 struct rtable *r)
344{
345 struct rt_cache_iter_state *st = seq->private;
346
347 r = rcu_dereference_bh(r->dst.rt_next);
348 while (!r) {
349 rcu_read_unlock_bh();
350 do {
351 if (--st->bucket < 0)
352 return NULL;
353 } while (!rcu_dereference_raw(rt_hash_table[st->bucket].chain));
354 rcu_read_lock_bh();
355 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
356 }
357 return r;
358}
359
360static struct rtable *rt_cache_get_next(struct seq_file *seq,
361 struct rtable *r)
362{
363 struct rt_cache_iter_state *st = seq->private;
364 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
365 if (dev_net(r->dst.dev) != seq_file_net(seq))
366 continue;
367 if (r->rt_genid == st->genid)
368 break;
369 }
370 return r;
371}
372
373static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
374{
375 struct rtable *r = rt_cache_get_first(seq);
376
377 if (r)
378 while (pos && (r = rt_cache_get_next(seq, r)))
379 --pos;
380 return pos ? NULL : r;
381}
382
383static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
384{
385 struct rt_cache_iter_state *st = seq->private;
386 if (*pos)
387 return rt_cache_get_idx(seq, *pos - 1);
388 st->genid = rt_genid(seq_file_net(seq));
389 return SEQ_START_TOKEN;
390}
391
392static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
393{
394 struct rtable *r;
395
396 if (v == SEQ_START_TOKEN)
397 r = rt_cache_get_first(seq);
398 else
399 r = rt_cache_get_next(seq, v);
400 ++*pos;
401 return r;
402}
403
404static void rt_cache_seq_stop(struct seq_file *seq, void *v)
405{
406 if (v && v != SEQ_START_TOKEN)
407 rcu_read_unlock_bh();
408}
409
410static int rt_cache_seq_show(struct seq_file *seq, void *v)
411{
412 if (v == SEQ_START_TOKEN)
413 seq_printf(seq, "%-127s\n",
414 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
415 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
416 "HHUptod\tSpecDst");
417 else {
418 struct rtable *r = v;
419 struct neighbour *n;
420 int len;
421
422 n = dst_get_neighbour(&r->dst);
423 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
424 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
425 r->dst.dev ? r->dst.dev->name : "*",
426 (__force u32)r->rt_dst,
427 (__force u32)r->rt_gateway,
428 r->rt_flags, atomic_read(&r->dst.__refcnt),
429 r->dst.__use, 0, (__force u32)r->rt_src,
430 dst_metric_advmss(&r->dst) + 40,
431 dst_metric(&r->dst, RTAX_WINDOW),
432 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
433 dst_metric(&r->dst, RTAX_RTTVAR)),
434 r->rt_key_tos,
435 -1,
436 (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0,
437 r->rt_spec_dst, &len);
438
439 seq_printf(seq, "%*s\n", 127 - len, "");
440 }
441 return 0;
442}
443
444static const struct seq_operations rt_cache_seq_ops = {
445 .start = rt_cache_seq_start,
446 .next = rt_cache_seq_next,
447 .stop = rt_cache_seq_stop,
448 .show = rt_cache_seq_show,
449};
450
451static int rt_cache_seq_open(struct inode *inode, struct file *file)
452{
453 return seq_open_net(inode, file, &rt_cache_seq_ops,
454 sizeof(struct rt_cache_iter_state));
455}
456
457static const struct file_operations rt_cache_seq_fops = {
458 .owner = THIS_MODULE,
459 .open = rt_cache_seq_open,
460 .read = seq_read,
461 .llseek = seq_lseek,
462 .release = seq_release_net,
463};
464
465
466static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
467{
468 int cpu;
469
470 if (*pos == 0)
471 return SEQ_START_TOKEN;
472
473 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
474 if (!cpu_possible(cpu))
475 continue;
476 *pos = cpu+1;
477 return &per_cpu(rt_cache_stat, cpu);
478 }
479 return NULL;
480}
481
482static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
483{
484 int cpu;
485
486 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
487 if (!cpu_possible(cpu))
488 continue;
489 *pos = cpu+1;
490 return &per_cpu(rt_cache_stat, cpu);
491 }
492 return NULL;
493
494}
495
496static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
497{
498
499}
500
501static int rt_cpu_seq_show(struct seq_file *seq, void *v)
502{
503 struct rt_cache_stat *st = v;
504
505 if (v == SEQ_START_TOKEN) {
506 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");
507 return 0;
508 }
509
510 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
511 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
512 dst_entries_get_slow(&ipv4_dst_ops),
513 st->in_hit,
514 st->in_slow_tot,
515 st->in_slow_mc,
516 st->in_no_route,
517 st->in_brd,
518 st->in_martian_dst,
519 st->in_martian_src,
520
521 st->out_hit,
522 st->out_slow_tot,
523 st->out_slow_mc,
524
525 st->gc_total,
526 st->gc_ignored,
527 st->gc_goal_miss,
528 st->gc_dst_overflow,
529 st->in_hlist_search,
530 st->out_hlist_search
531 );
532 return 0;
533}
534
535static const struct seq_operations rt_cpu_seq_ops = {
536 .start = rt_cpu_seq_start,
537 .next = rt_cpu_seq_next,
538 .stop = rt_cpu_seq_stop,
539 .show = rt_cpu_seq_show,
540};
541
542
543static int rt_cpu_seq_open(struct inode *inode, struct file *file)
544{
545 return seq_open(file, &rt_cpu_seq_ops);
546}
547
548static const struct file_operations rt_cpu_seq_fops = {
549 .owner = THIS_MODULE,
550 .open = rt_cpu_seq_open,
551 .read = seq_read,
552 .llseek = seq_lseek,
553 .release = seq_release,
554};
555
556#ifdef CONFIG_IP_ROUTE_CLASSID
557static int rt_acct_proc_show(struct seq_file *m, void *v)
558{
559 struct ip_rt_acct *dst, *src;
560 unsigned int i, j;
561
562 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
563 if (!dst)
564 return -ENOMEM;
565
566 for_each_possible_cpu(i) {
567 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
568 for (j = 0; j < 256; j++) {
569 dst[j].o_bytes += src[j].o_bytes;
570 dst[j].o_packets += src[j].o_packets;
571 dst[j].i_bytes += src[j].i_bytes;
572 dst[j].i_packets += src[j].i_packets;
573 }
574 }
575
576 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
577 kfree(dst);
578 return 0;
579}
580
581static int rt_acct_proc_open(struct inode *inode, struct file *file)
582{
583 return single_open(file, rt_acct_proc_show, NULL);
584}
585
586static const struct file_operations rt_acct_proc_fops = {
587 .owner = THIS_MODULE,
588 .open = rt_acct_proc_open,
589 .read = seq_read,
590 .llseek = seq_lseek,
591 .release = single_release,
592};
593#endif
594
595static int __net_init ip_rt_do_proc_init(struct net *net)
596{
597 struct proc_dir_entry *pde;
598
599 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
600 &rt_cache_seq_fops);
601 if (!pde)
602 goto err1;
603
604 pde = proc_create("rt_cache", S_IRUGO,
605 net->proc_net_stat, &rt_cpu_seq_fops);
606 if (!pde)
607 goto err2;
608
609#ifdef CONFIG_IP_ROUTE_CLASSID
610 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
611 if (!pde)
612 goto err3;
613#endif
614 return 0;
615
616#ifdef CONFIG_IP_ROUTE_CLASSID
617err3:
618 remove_proc_entry("rt_cache", net->proc_net_stat);
619#endif
620err2:
621 remove_proc_entry("rt_cache", net->proc_net);
622err1:
623 return -ENOMEM;
624}
625
626static void __net_exit ip_rt_do_proc_exit(struct net *net)
627{
628 remove_proc_entry("rt_cache", net->proc_net_stat);
629 remove_proc_entry("rt_cache", net->proc_net);
630#ifdef CONFIG_IP_ROUTE_CLASSID
631 remove_proc_entry("rt_acct", net->proc_net);
632#endif
633}
634
635static struct pernet_operations ip_rt_proc_ops __net_initdata = {
636 .init = ip_rt_do_proc_init,
637 .exit = ip_rt_do_proc_exit,
638};
639
640static int __init ip_rt_proc_init(void)
641{
642 return register_pernet_subsys(&ip_rt_proc_ops);
643}
644
645#else
646static inline int ip_rt_proc_init(void)
647{
648 return 0;
649}
650#endif /* CONFIG_PROC_FS */
651
652static inline void rt_free(struct rtable *rt)
653{
654 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
655}
656
657static inline void rt_drop(struct rtable *rt)
658{
659 ip_rt_put(rt);
660 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
661}
662
663static inline int rt_fast_clean(struct rtable *rth)
664{
665 /* Kill broadcast/multicast entries very aggresively, if they
666 collide in hash table with more useful entries */
667 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
668 rt_is_input_route(rth) && rth->dst.rt_next;
669}
670
671static inline int rt_valuable(struct rtable *rth)
672{
673 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
674 (rth->peer && rth->peer->pmtu_expires);
675}
676
677static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
678{
679 unsigned long age;
680 int ret = 0;
681
682 if (atomic_read(&rth->dst.__refcnt))
683 goto out;
684
685 age = jiffies - rth->dst.lastuse;
686 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
687 (age <= tmo2 && rt_valuable(rth)))
688 goto out;
689 ret = 1;
690out: return ret;
691}
692
693/* Bits of score are:
694 * 31: very valuable
695 * 30: not quite useless
696 * 29..0: usage counter
697 */
698static inline u32 rt_score(struct rtable *rt)
699{
700 u32 score = jiffies - rt->dst.lastuse;
701
702 score = ~score & ~(3<<30);
703
704 if (rt_valuable(rt))
705 score |= (1<<31);
706
707 if (rt_is_output_route(rt) ||
708 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
709 score |= (1<<30);
710
711 return score;
712}
713
714static inline bool rt_caching(const struct net *net)
715{
716 return net->ipv4.current_rt_cache_rebuild_count <=
717 net->ipv4.sysctl_rt_cache_rebuild_count;
718}
719
720static inline bool compare_hash_inputs(const struct rtable *rt1,
721 const struct rtable *rt2)
722{
723 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
724 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
725 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
726}
727
728static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
729{
730 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
731 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
732 (rt1->rt_mark ^ rt2->rt_mark) |
733 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
734 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
735 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
736}
737
738static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
739{
740 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
741}
742
743static inline int rt_is_expired(struct rtable *rth)
744{
745 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
746}
747
748/*
749 * Perform a full scan of hash table and free all entries.
750 * Can be called by a softirq or a process.
751 * In the later case, we want to be reschedule if necessary
752 */
753static void rt_do_flush(struct net *net, int process_context)
754{
755 unsigned int i;
756 struct rtable *rth, *next;
757
758 for (i = 0; i <= rt_hash_mask; i++) {
759 struct rtable __rcu **pprev;
760 struct rtable *list;
761
762 if (process_context && need_resched())
763 cond_resched();
764 rth = rcu_dereference_raw(rt_hash_table[i].chain);
765 if (!rth)
766 continue;
767
768 spin_lock_bh(rt_hash_lock_addr(i));
769
770 list = NULL;
771 pprev = &rt_hash_table[i].chain;
772 rth = rcu_dereference_protected(*pprev,
773 lockdep_is_held(rt_hash_lock_addr(i)));
774
775 while (rth) {
776 next = rcu_dereference_protected(rth->dst.rt_next,
777 lockdep_is_held(rt_hash_lock_addr(i)));
778
779 if (!net ||
780 net_eq(dev_net(rth->dst.dev), net)) {
781 rcu_assign_pointer(*pprev, next);
782 rcu_assign_pointer(rth->dst.rt_next, list);
783 list = rth;
784 } else {
785 pprev = &rth->dst.rt_next;
786 }
787 rth = next;
788 }
789
790 spin_unlock_bh(rt_hash_lock_addr(i));
791
792 for (; list; list = next) {
793 next = rcu_dereference_protected(list->dst.rt_next, 1);
794 rt_free(list);
795 }
796 }
797}
798
799/*
800 * While freeing expired entries, we compute average chain length
801 * and standard deviation, using fixed-point arithmetic.
802 * This to have an estimation of rt_chain_length_max
803 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
804 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
805 */
806
807#define FRACT_BITS 3
808#define ONE (1UL << FRACT_BITS)
809
810/*
811 * Given a hash chain and an item in this hash chain,
812 * find if a previous entry has the same hash_inputs
813 * (but differs on tos, mark or oif)
814 * Returns 0 if an alias is found.
815 * Returns ONE if rth has no alias before itself.
816 */
817static int has_noalias(const struct rtable *head, const struct rtable *rth)
818{
819 const struct rtable *aux = head;
820
821 while (aux != rth) {
822 if (compare_hash_inputs(aux, rth))
823 return 0;
824 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
825 }
826 return ONE;
827}
828
829/*
830 * Perturbation of rt_genid by a small quantity [1..256]
831 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
832 * many times (2^24) without giving recent rt_genid.
833 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
834 */
835static void rt_cache_invalidate(struct net *net)
836{
837 unsigned char shuffle;
838
839 get_random_bytes(&shuffle, sizeof(shuffle));
840 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
841}
842
843/*
844 * delay < 0 : invalidate cache (fast : entries will be deleted later)
845 * delay >= 0 : invalidate & flush cache (can be long)
846 */
847void rt_cache_flush(struct net *net, int delay)
848{
849 rt_cache_invalidate(net);
850 if (delay >= 0)
851 rt_do_flush(net, !in_softirq());
852}
853
854/* Flush previous cache invalidated entries from the cache */
855void rt_cache_flush_batch(struct net *net)
856{
857 rt_do_flush(net, !in_softirq());
858}
859
860static void rt_emergency_hash_rebuild(struct net *net)
861{
862 if (net_ratelimit())
863 printk(KERN_WARNING "Route hash chain too long!\n");
864 rt_cache_invalidate(net);
865}
866
867/*
868 Short description of GC goals.
869
870 We want to build algorithm, which will keep routing cache
871 at some equilibrium point, when number of aged off entries
872 is kept approximately equal to newly generated ones.
873
874 Current expiration strength is variable "expire".
875 We try to adjust it dynamically, so that if networking
876 is idle expires is large enough to keep enough of warm entries,
877 and when load increases it reduces to limit cache size.
878 */
879
880static int rt_garbage_collect(struct dst_ops *ops)
881{
882 static unsigned long expire = RT_GC_TIMEOUT;
883 static unsigned long last_gc;
884 static int rover;
885 static int equilibrium;
886 struct rtable *rth;
887 struct rtable __rcu **rthp;
888 unsigned long now = jiffies;
889 int goal;
890 int entries = dst_entries_get_fast(&ipv4_dst_ops);
891
892 /*
893 * Garbage collection is pretty expensive,
894 * do not make it too frequently.
895 */
896
897 RT_CACHE_STAT_INC(gc_total);
898
899 if (now - last_gc < ip_rt_gc_min_interval &&
900 entries < ip_rt_max_size) {
901 RT_CACHE_STAT_INC(gc_ignored);
902 goto out;
903 }
904
905 entries = dst_entries_get_slow(&ipv4_dst_ops);
906 /* Calculate number of entries, which we want to expire now. */
907 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
908 if (goal <= 0) {
909 if (equilibrium < ipv4_dst_ops.gc_thresh)
910 equilibrium = ipv4_dst_ops.gc_thresh;
911 goal = entries - equilibrium;
912 if (goal > 0) {
913 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
914 goal = entries - equilibrium;
915 }
916 } else {
917 /* We are in dangerous area. Try to reduce cache really
918 * aggressively.
919 */
920 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
921 equilibrium = entries - goal;
922 }
923
924 if (now - last_gc >= ip_rt_gc_min_interval)
925 last_gc = now;
926
927 if (goal <= 0) {
928 equilibrium += goal;
929 goto work_done;
930 }
931
932 do {
933 int i, k;
934
935 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
936 unsigned long tmo = expire;
937
938 k = (k + 1) & rt_hash_mask;
939 rthp = &rt_hash_table[k].chain;
940 spin_lock_bh(rt_hash_lock_addr(k));
941 while ((rth = rcu_dereference_protected(*rthp,
942 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
943 if (!rt_is_expired(rth) &&
944 !rt_may_expire(rth, tmo, expire)) {
945 tmo >>= 1;
946 rthp = &rth->dst.rt_next;
947 continue;
948 }
949 *rthp = rth->dst.rt_next;
950 rt_free(rth);
951 goal--;
952 }
953 spin_unlock_bh(rt_hash_lock_addr(k));
954 if (goal <= 0)
955 break;
956 }
957 rover = k;
958
959 if (goal <= 0)
960 goto work_done;
961
962 /* Goal is not achieved. We stop process if:
963
964 - if expire reduced to zero. Otherwise, expire is halfed.
965 - if table is not full.
966 - if we are called from interrupt.
967 - jiffies check is just fallback/debug loop breaker.
968 We will not spin here for long time in any case.
969 */
970
971 RT_CACHE_STAT_INC(gc_goal_miss);
972
973 if (expire == 0)
974 break;
975
976 expire >>= 1;
977
978 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
979 goto out;
980 } while (!in_softirq() && time_before_eq(jiffies, now));
981
982 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
983 goto out;
984 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
985 goto out;
986 if (net_ratelimit())
987 printk(KERN_WARNING "dst cache overflow\n");
988 RT_CACHE_STAT_INC(gc_dst_overflow);
989 return 1;
990
991work_done:
992 expire += ip_rt_gc_min_interval;
993 if (expire > ip_rt_gc_timeout ||
994 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
995 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
996 expire = ip_rt_gc_timeout;
997out: return 0;
998}
999
1000/*
1001 * Returns number of entries in a hash chain that have different hash_inputs
1002 */
1003static int slow_chain_length(const struct rtable *head)
1004{
1005 int length = 0;
1006 const struct rtable *rth = head;
1007
1008 while (rth) {
1009 length += has_noalias(head, rth);
1010 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1011 }
1012 return length >> FRACT_BITS;
1013}
1014
1015static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1016{
1017 struct neigh_table *tbl = &arp_tbl;
1018 static const __be32 inaddr_any = 0;
1019 struct net_device *dev = dst->dev;
1020 const __be32 *pkey = daddr;
1021 struct neighbour *n;
1022
1023#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
1024 if (dev->type == ARPHRD_ATM)
1025 tbl = clip_tbl_hook;
1026#endif
1027 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1028 pkey = &inaddr_any;
1029
1030 n = __ipv4_neigh_lookup(tbl, dev, *(__force u32 *)pkey);
1031 if (n)
1032 return n;
1033 return neigh_create(tbl, pkey, dev);
1034}
1035
1036static int rt_bind_neighbour(struct rtable *rt)
1037{
1038 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1039 if (IS_ERR(n))
1040 return PTR_ERR(n);
1041 dst_set_neighbour(&rt->dst, n);
1042
1043 return 0;
1044}
1045
1046static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1047 struct sk_buff *skb, int ifindex)
1048{
1049 struct rtable *rth, *cand;
1050 struct rtable __rcu **rthp, **candp;
1051 unsigned long now;
1052 u32 min_score;
1053 int chain_length;
1054 int attempts = !in_softirq();
1055
1056restart:
1057 chain_length = 0;
1058 min_score = ~(u32)0;
1059 cand = NULL;
1060 candp = NULL;
1061 now = jiffies;
1062
1063 if (!rt_caching(dev_net(rt->dst.dev))) {
1064 /*
1065 * If we're not caching, just tell the caller we
1066 * were successful and don't touch the route. The
1067 * caller hold the sole reference to the cache entry, and
1068 * it will be released when the caller is done with it.
1069 * If we drop it here, the callers have no way to resolve routes
1070 * when we're not caching. Instead, just point *rp at rt, so
1071 * the caller gets a single use out of the route
1072 * Note that we do rt_free on this new route entry, so that
1073 * once its refcount hits zero, we are still able to reap it
1074 * (Thanks Alexey)
1075 * Note: To avoid expensive rcu stuff for this uncached dst,
1076 * we set DST_NOCACHE so that dst_release() can free dst without
1077 * waiting a grace period.
1078 */
1079
1080 rt->dst.flags |= DST_NOCACHE;
1081 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1082 int err = rt_bind_neighbour(rt);
1083 if (err) {
1084 if (net_ratelimit())
1085 printk(KERN_WARNING
1086 "Neighbour table failure & not caching routes.\n");
1087 ip_rt_put(rt);
1088 return ERR_PTR(err);
1089 }
1090 }
1091
1092 goto skip_hashing;
1093 }
1094
1095 rthp = &rt_hash_table[hash].chain;
1096
1097 spin_lock_bh(rt_hash_lock_addr(hash));
1098 while ((rth = rcu_dereference_protected(*rthp,
1099 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1100 if (rt_is_expired(rth)) {
1101 *rthp = rth->dst.rt_next;
1102 rt_free(rth);
1103 continue;
1104 }
1105 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1106 /* Put it first */
1107 *rthp = rth->dst.rt_next;
1108 /*
1109 * Since lookup is lockfree, the deletion
1110 * must be visible to another weakly ordered CPU before
1111 * the insertion at the start of the hash chain.
1112 */
1113 rcu_assign_pointer(rth->dst.rt_next,
1114 rt_hash_table[hash].chain);
1115 /*
1116 * Since lookup is lockfree, the update writes
1117 * must be ordered for consistency on SMP.
1118 */
1119 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1120
1121 dst_use(&rth->dst, now);
1122 spin_unlock_bh(rt_hash_lock_addr(hash));
1123
1124 rt_drop(rt);
1125 if (skb)
1126 skb_dst_set(skb, &rth->dst);
1127 return rth;
1128 }
1129
1130 if (!atomic_read(&rth->dst.__refcnt)) {
1131 u32 score = rt_score(rth);
1132
1133 if (score <= min_score) {
1134 cand = rth;
1135 candp = rthp;
1136 min_score = score;
1137 }
1138 }
1139
1140 chain_length++;
1141
1142 rthp = &rth->dst.rt_next;
1143 }
1144
1145 if (cand) {
1146 /* ip_rt_gc_elasticity used to be average length of chain
1147 * length, when exceeded gc becomes really aggressive.
1148 *
1149 * The second limit is less certain. At the moment it allows
1150 * only 2 entries per bucket. We will see.
1151 */
1152 if (chain_length > ip_rt_gc_elasticity) {
1153 *candp = cand->dst.rt_next;
1154 rt_free(cand);
1155 }
1156 } else {
1157 if (chain_length > rt_chain_length_max &&
1158 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1159 struct net *net = dev_net(rt->dst.dev);
1160 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1161 if (!rt_caching(net)) {
1162 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1163 rt->dst.dev->name, num);
1164 }
1165 rt_emergency_hash_rebuild(net);
1166 spin_unlock_bh(rt_hash_lock_addr(hash));
1167
1168 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1169 ifindex, rt_genid(net));
1170 goto restart;
1171 }
1172 }
1173
1174 /* Try to bind route to arp only if it is output
1175 route or unicast forwarding path.
1176 */
1177 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1178 int err = rt_bind_neighbour(rt);
1179 if (err) {
1180 spin_unlock_bh(rt_hash_lock_addr(hash));
1181
1182 if (err != -ENOBUFS) {
1183 rt_drop(rt);
1184 return ERR_PTR(err);
1185 }
1186
1187 /* Neighbour tables are full and nothing
1188 can be released. Try to shrink route cache,
1189 it is most likely it holds some neighbour records.
1190 */
1191 if (attempts-- > 0) {
1192 int saved_elasticity = ip_rt_gc_elasticity;
1193 int saved_int = ip_rt_gc_min_interval;
1194 ip_rt_gc_elasticity = 1;
1195 ip_rt_gc_min_interval = 0;
1196 rt_garbage_collect(&ipv4_dst_ops);
1197 ip_rt_gc_min_interval = saved_int;
1198 ip_rt_gc_elasticity = saved_elasticity;
1199 goto restart;
1200 }
1201
1202 if (net_ratelimit())
1203 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1204 rt_drop(rt);
1205 return ERR_PTR(-ENOBUFS);
1206 }
1207 }
1208
1209 rt->dst.rt_next = rt_hash_table[hash].chain;
1210
1211 /*
1212 * Since lookup is lockfree, we must make sure
1213 * previous writes to rt are committed to memory
1214 * before making rt visible to other CPUS.
1215 */
1216 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1217
1218 spin_unlock_bh(rt_hash_lock_addr(hash));
1219
1220skip_hashing:
1221 if (skb)
1222 skb_dst_set(skb, &rt->dst);
1223 return rt;
1224}
1225
1226static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1227
1228static u32 rt_peer_genid(void)
1229{
1230 return atomic_read(&__rt_peer_genid);
1231}
1232
1233void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1234{
1235 struct inet_peer *peer;
1236
1237 peer = inet_getpeer_v4(daddr, create);
1238
1239 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1240 inet_putpeer(peer);
1241 else
1242 rt->rt_peer_genid = rt_peer_genid();
1243}
1244
1245/*
1246 * Peer allocation may fail only in serious out-of-memory conditions. However
1247 * we still can generate some output.
1248 * Random ID selection looks a bit dangerous because we have no chances to
1249 * select ID being unique in a reasonable period of time.
1250 * But broken packet identifier may be better than no packet at all.
1251 */
1252static void ip_select_fb_ident(struct iphdr *iph)
1253{
1254 static DEFINE_SPINLOCK(ip_fb_id_lock);
1255 static u32 ip_fallback_id;
1256 u32 salt;
1257
1258 spin_lock_bh(&ip_fb_id_lock);
1259 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1260 iph->id = htons(salt & 0xFFFF);
1261 ip_fallback_id = salt;
1262 spin_unlock_bh(&ip_fb_id_lock);
1263}
1264
1265void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1266{
1267 struct rtable *rt = (struct rtable *) dst;
1268
1269 if (rt) {
1270 if (rt->peer == NULL)
1271 rt_bind_peer(rt, rt->rt_dst, 1);
1272
1273 /* If peer is attached to destination, it is never detached,
1274 so that we need not to grab a lock to dereference it.
1275 */
1276 if (rt->peer) {
1277 iph->id = htons(inet_getid(rt->peer, more));
1278 return;
1279 }
1280 } else
1281 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1282 __builtin_return_address(0));
1283
1284 ip_select_fb_ident(iph);
1285}
1286EXPORT_SYMBOL(__ip_select_ident);
1287
1288static void rt_del(unsigned hash, struct rtable *rt)
1289{
1290 struct rtable __rcu **rthp;
1291 struct rtable *aux;
1292
1293 rthp = &rt_hash_table[hash].chain;
1294 spin_lock_bh(rt_hash_lock_addr(hash));
1295 ip_rt_put(rt);
1296 while ((aux = rcu_dereference_protected(*rthp,
1297 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1298 if (aux == rt || rt_is_expired(aux)) {
1299 *rthp = aux->dst.rt_next;
1300 rt_free(aux);
1301 continue;
1302 }
1303 rthp = &aux->dst.rt_next;
1304 }
1305 spin_unlock_bh(rt_hash_lock_addr(hash));
1306}
1307
1308/* called in rcu_read_lock() section */
1309void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1310 __be32 saddr, struct net_device *dev)
1311{
1312 struct in_device *in_dev = __in_dev_get_rcu(dev);
1313 struct inet_peer *peer;
1314 struct net *net;
1315
1316 if (!in_dev)
1317 return;
1318
1319 net = dev_net(dev);
1320 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1321 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1322 ipv4_is_zeronet(new_gw))
1323 goto reject_redirect;
1324
1325 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1326 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1327 goto reject_redirect;
1328 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1329 goto reject_redirect;
1330 } else {
1331 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1332 goto reject_redirect;
1333 }
1334
1335 peer = inet_getpeer_v4(daddr, 1);
1336 if (peer) {
1337 peer->redirect_learned.a4 = new_gw;
1338
1339 inet_putpeer(peer);
1340
1341 atomic_inc(&__rt_peer_genid);
1342 }
1343 return;
1344
1345reject_redirect:
1346#ifdef CONFIG_IP_ROUTE_VERBOSE
1347 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1348 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1349 " Advised path = %pI4 -> %pI4\n",
1350 &old_gw, dev->name, &new_gw,
1351 &saddr, &daddr);
1352#endif
1353 ;
1354}
1355
1356static bool peer_pmtu_expired(struct inet_peer *peer)
1357{
1358 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1359
1360 return orig &&
1361 time_after_eq(jiffies, orig) &&
1362 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1363}
1364
1365static bool peer_pmtu_cleaned(struct inet_peer *peer)
1366{
1367 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1368
1369 return orig &&
1370 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1371}
1372
1373static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1374{
1375 struct rtable *rt = (struct rtable *)dst;
1376 struct dst_entry *ret = dst;
1377
1378 if (rt) {
1379 if (dst->obsolete > 0) {
1380 ip_rt_put(rt);
1381 ret = NULL;
1382 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1383 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1384 rt->rt_oif,
1385 rt_genid(dev_net(dst->dev)));
1386 rt_del(hash, rt);
1387 ret = NULL;
1388 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1389 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1390 }
1391 }
1392 return ret;
1393}
1394
1395/*
1396 * Algorithm:
1397 * 1. The first ip_rt_redirect_number redirects are sent
1398 * with exponential backoff, then we stop sending them at all,
1399 * assuming that the host ignores our redirects.
1400 * 2. If we did not see packets requiring redirects
1401 * during ip_rt_redirect_silence, we assume that the host
1402 * forgot redirected route and start to send redirects again.
1403 *
1404 * This algorithm is much cheaper and more intelligent than dumb load limiting
1405 * in icmp.c.
1406 *
1407 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1408 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1409 */
1410
1411void ip_rt_send_redirect(struct sk_buff *skb)
1412{
1413 struct rtable *rt = skb_rtable(skb);
1414 struct in_device *in_dev;
1415 struct inet_peer *peer;
1416 int log_martians;
1417
1418 rcu_read_lock();
1419 in_dev = __in_dev_get_rcu(rt->dst.dev);
1420 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1421 rcu_read_unlock();
1422 return;
1423 }
1424 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1425 rcu_read_unlock();
1426
1427 if (!rt->peer)
1428 rt_bind_peer(rt, rt->rt_dst, 1);
1429 peer = rt->peer;
1430 if (!peer) {
1431 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1432 return;
1433 }
1434
1435 /* No redirected packets during ip_rt_redirect_silence;
1436 * reset the algorithm.
1437 */
1438 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1439 peer->rate_tokens = 0;
1440
1441 /* Too many ignored redirects; do not send anything
1442 * set dst.rate_last to the last seen redirected packet.
1443 */
1444 if (peer->rate_tokens >= ip_rt_redirect_number) {
1445 peer->rate_last = jiffies;
1446 return;
1447 }
1448
1449 /* Check for load limit; set rate_last to the latest sent
1450 * redirect.
1451 */
1452 if (peer->rate_tokens == 0 ||
1453 time_after(jiffies,
1454 (peer->rate_last +
1455 (ip_rt_redirect_load << peer->rate_tokens)))) {
1456 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1457 peer->rate_last = jiffies;
1458 ++peer->rate_tokens;
1459#ifdef CONFIG_IP_ROUTE_VERBOSE
1460 if (log_martians &&
1461 peer->rate_tokens == ip_rt_redirect_number &&
1462 net_ratelimit())
1463 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1464 &ip_hdr(skb)->saddr, rt->rt_iif,
1465 &rt->rt_dst, &rt->rt_gateway);
1466#endif
1467 }
1468}
1469
1470static int ip_error(struct sk_buff *skb)
1471{
1472 struct rtable *rt = skb_rtable(skb);
1473 struct inet_peer *peer;
1474 unsigned long now;
1475 bool send;
1476 int code;
1477
1478 switch (rt->dst.error) {
1479 case EINVAL:
1480 default:
1481 goto out;
1482 case EHOSTUNREACH:
1483 code = ICMP_HOST_UNREACH;
1484 break;
1485 case ENETUNREACH:
1486 code = ICMP_NET_UNREACH;
1487 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1488 IPSTATS_MIB_INNOROUTES);
1489 break;
1490 case EACCES:
1491 code = ICMP_PKT_FILTERED;
1492 break;
1493 }
1494
1495 if (!rt->peer)
1496 rt_bind_peer(rt, rt->rt_dst, 1);
1497 peer = rt->peer;
1498
1499 send = true;
1500 if (peer) {
1501 now = jiffies;
1502 peer->rate_tokens += now - peer->rate_last;
1503 if (peer->rate_tokens > ip_rt_error_burst)
1504 peer->rate_tokens = ip_rt_error_burst;
1505 peer->rate_last = now;
1506 if (peer->rate_tokens >= ip_rt_error_cost)
1507 peer->rate_tokens -= ip_rt_error_cost;
1508 else
1509 send = false;
1510 }
1511 if (send)
1512 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1513
1514out: kfree_skb(skb);
1515 return 0;
1516}
1517
1518/*
1519 * The last two values are not from the RFC but
1520 * are needed for AMPRnet AX.25 paths.
1521 */
1522
1523static const unsigned short mtu_plateau[] =
1524{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1525
1526static inline unsigned short guess_mtu(unsigned short old_mtu)
1527{
1528 int i;
1529
1530 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1531 if (old_mtu > mtu_plateau[i])
1532 return mtu_plateau[i];
1533 return 68;
1534}
1535
1536unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1537 unsigned short new_mtu,
1538 struct net_device *dev)
1539{
1540 unsigned short old_mtu = ntohs(iph->tot_len);
1541 unsigned short est_mtu = 0;
1542 struct inet_peer *peer;
1543
1544 peer = inet_getpeer_v4(iph->daddr, 1);
1545 if (peer) {
1546 unsigned short mtu = new_mtu;
1547
1548 if (new_mtu < 68 || new_mtu >= old_mtu) {
1549 /* BSD 4.2 derived systems incorrectly adjust
1550 * tot_len by the IP header length, and report
1551 * a zero MTU in the ICMP message.
1552 */
1553 if (mtu == 0 &&
1554 old_mtu >= 68 + (iph->ihl << 2))
1555 old_mtu -= iph->ihl << 2;
1556 mtu = guess_mtu(old_mtu);
1557 }
1558
1559 if (mtu < ip_rt_min_pmtu)
1560 mtu = ip_rt_min_pmtu;
1561 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1562 unsigned long pmtu_expires;
1563
1564 pmtu_expires = jiffies + ip_rt_mtu_expires;
1565 if (!pmtu_expires)
1566 pmtu_expires = 1UL;
1567
1568 est_mtu = mtu;
1569 peer->pmtu_learned = mtu;
1570 peer->pmtu_expires = pmtu_expires;
1571 }
1572
1573 inet_putpeer(peer);
1574
1575 atomic_inc(&__rt_peer_genid);
1576 }
1577 return est_mtu ? : new_mtu;
1578}
1579
1580static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1581{
1582 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1583
1584 if (!expires)
1585 return;
1586 if (time_before(jiffies, expires)) {
1587 u32 orig_dst_mtu = dst_mtu(dst);
1588 if (peer->pmtu_learned < orig_dst_mtu) {
1589 if (!peer->pmtu_orig)
1590 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1591 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1592 }
1593 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1594 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1595}
1596
1597static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1598{
1599 struct rtable *rt = (struct rtable *) dst;
1600 struct inet_peer *peer;
1601
1602 dst_confirm(dst);
1603
1604 if (!rt->peer)
1605 rt_bind_peer(rt, rt->rt_dst, 1);
1606 peer = rt->peer;
1607 if (peer) {
1608 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1609
1610 if (mtu < ip_rt_min_pmtu)
1611 mtu = ip_rt_min_pmtu;
1612 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1613
1614 pmtu_expires = jiffies + ip_rt_mtu_expires;
1615 if (!pmtu_expires)
1616 pmtu_expires = 1UL;
1617
1618 peer->pmtu_learned = mtu;
1619 peer->pmtu_expires = pmtu_expires;
1620
1621 atomic_inc(&__rt_peer_genid);
1622 rt->rt_peer_genid = rt_peer_genid();
1623 }
1624 check_peer_pmtu(dst, peer);
1625 }
1626}
1627
1628static int check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1629{
1630 struct rtable *rt = (struct rtable *) dst;
1631 __be32 orig_gw = rt->rt_gateway;
1632 struct neighbour *n, *old_n;
1633
1634 dst_confirm(&rt->dst);
1635
1636 rt->rt_gateway = peer->redirect_learned.a4;
1637
1638 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1639 if (IS_ERR(n))
1640 return PTR_ERR(n);
1641 old_n = xchg(&rt->dst._neighbour, n);
1642 if (old_n)
1643 neigh_release(old_n);
1644 if (!n || !(n->nud_state & NUD_VALID)) {
1645 if (n)
1646 neigh_event_send(n, NULL);
1647 rt->rt_gateway = orig_gw;
1648 return -EAGAIN;
1649 } else {
1650 rt->rt_flags |= RTCF_REDIRECTED;
1651 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1652 }
1653 return 0;
1654}
1655
1656static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1657{
1658 struct rtable *rt = (struct rtable *) dst;
1659
1660 if (rt_is_expired(rt))
1661 return NULL;
1662 if (rt->rt_peer_genid != rt_peer_genid()) {
1663 struct inet_peer *peer;
1664
1665 if (!rt->peer)
1666 rt_bind_peer(rt, rt->rt_dst, 0);
1667
1668 peer = rt->peer;
1669 if (peer) {
1670 check_peer_pmtu(dst, peer);
1671
1672 if (peer->redirect_learned.a4 &&
1673 peer->redirect_learned.a4 != rt->rt_gateway) {
1674 if (check_peer_redir(dst, peer))
1675 return NULL;
1676 }
1677 }
1678
1679 rt->rt_peer_genid = rt_peer_genid();
1680 }
1681 return dst;
1682}
1683
1684static void ipv4_dst_destroy(struct dst_entry *dst)
1685{
1686 struct rtable *rt = (struct rtable *) dst;
1687 struct inet_peer *peer = rt->peer;
1688
1689 if (rt->fi) {
1690 fib_info_put(rt->fi);
1691 rt->fi = NULL;
1692 }
1693 if (peer) {
1694 rt->peer = NULL;
1695 inet_putpeer(peer);
1696 }
1697}
1698
1699
1700static void ipv4_link_failure(struct sk_buff *skb)
1701{
1702 struct rtable *rt;
1703
1704 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1705
1706 rt = skb_rtable(skb);
1707 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1708 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1709}
1710
1711static int ip_rt_bug(struct sk_buff *skb)
1712{
1713 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1714 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1715 skb->dev ? skb->dev->name : "?");
1716 kfree_skb(skb);
1717 WARN_ON(1);
1718 return 0;
1719}
1720
1721/*
1722 We do not cache source address of outgoing interface,
1723 because it is used only by IP RR, TS and SRR options,
1724 so that it out of fast path.
1725
1726 BTW remember: "addr" is allowed to be not aligned
1727 in IP options!
1728 */
1729
1730void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1731{
1732 __be32 src;
1733
1734 if (rt_is_output_route(rt))
1735 src = ip_hdr(skb)->saddr;
1736 else {
1737 struct fib_result res;
1738 struct flowi4 fl4;
1739 struct iphdr *iph;
1740
1741 iph = ip_hdr(skb);
1742
1743 memset(&fl4, 0, sizeof(fl4));
1744 fl4.daddr = iph->daddr;
1745 fl4.saddr = iph->saddr;
1746 fl4.flowi4_tos = RT_TOS(iph->tos);
1747 fl4.flowi4_oif = rt->dst.dev->ifindex;
1748 fl4.flowi4_iif = skb->dev->ifindex;
1749 fl4.flowi4_mark = skb->mark;
1750
1751 rcu_read_lock();
1752 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1753 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1754 else
1755 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1756 RT_SCOPE_UNIVERSE);
1757 rcu_read_unlock();
1758 }
1759 memcpy(addr, &src, 4);
1760}
1761
1762#ifdef CONFIG_IP_ROUTE_CLASSID
1763static void set_class_tag(struct rtable *rt, u32 tag)
1764{
1765 if (!(rt->dst.tclassid & 0xFFFF))
1766 rt->dst.tclassid |= tag & 0xFFFF;
1767 if (!(rt->dst.tclassid & 0xFFFF0000))
1768 rt->dst.tclassid |= tag & 0xFFFF0000;
1769}
1770#endif
1771
1772static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1773{
1774 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1775
1776 if (advmss == 0) {
1777 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1778 ip_rt_min_advmss);
1779 if (advmss > 65535 - 40)
1780 advmss = 65535 - 40;
1781 }
1782 return advmss;
1783}
1784
1785static unsigned int ipv4_default_mtu(const struct dst_entry *dst)
1786{
1787 unsigned int mtu = dst->dev->mtu;
1788
1789 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1790 const struct rtable *rt = (const struct rtable *) dst;
1791
1792 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1793 mtu = 576;
1794 }
1795
1796 if (mtu > IP_MAX_MTU)
1797 mtu = IP_MAX_MTU;
1798
1799 return mtu;
1800}
1801
1802static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1803 struct fib_info *fi)
1804{
1805 struct inet_peer *peer;
1806 int create = 0;
1807
1808 /* If a peer entry exists for this destination, we must hook
1809 * it up in order to get at cached metrics.
1810 */
1811 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1812 create = 1;
1813
1814 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1815 if (peer) {
1816 rt->rt_peer_genid = rt_peer_genid();
1817 if (inet_metrics_new(peer))
1818 memcpy(peer->metrics, fi->fib_metrics,
1819 sizeof(u32) * RTAX_MAX);
1820 dst_init_metrics(&rt->dst, peer->metrics, false);
1821
1822 check_peer_pmtu(&rt->dst, peer);
1823 if (peer->redirect_learned.a4 &&
1824 peer->redirect_learned.a4 != rt->rt_gateway) {
1825 rt->rt_gateway = peer->redirect_learned.a4;
1826 rt->rt_flags |= RTCF_REDIRECTED;
1827 }
1828 } else {
1829 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1830 rt->fi = fi;
1831 atomic_inc(&fi->fib_clntref);
1832 }
1833 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1834 }
1835}
1836
1837static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1838 const struct fib_result *res,
1839 struct fib_info *fi, u16 type, u32 itag)
1840{
1841 struct dst_entry *dst = &rt->dst;
1842
1843 if (fi) {
1844 if (FIB_RES_GW(*res) &&
1845 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1846 rt->rt_gateway = FIB_RES_GW(*res);
1847 rt_init_metrics(rt, fl4, fi);
1848#ifdef CONFIG_IP_ROUTE_CLASSID
1849 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1850#endif
1851 }
1852
1853 if (dst_mtu(dst) > IP_MAX_MTU)
1854 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1855 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1856 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1857
1858#ifdef CONFIG_IP_ROUTE_CLASSID
1859#ifdef CONFIG_IP_MULTIPLE_TABLES
1860 set_class_tag(rt, fib_rules_tclass(res));
1861#endif
1862 set_class_tag(rt, itag);
1863#endif
1864}
1865
1866static struct rtable *rt_dst_alloc(struct net_device *dev,
1867 bool nopolicy, bool noxfrm)
1868{
1869 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
1870 DST_HOST |
1871 (nopolicy ? DST_NOPOLICY : 0) |
1872 (noxfrm ? DST_NOXFRM : 0));
1873}
1874
1875/* called in rcu_read_lock() section */
1876static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1877 u8 tos, struct net_device *dev, int our)
1878{
1879 unsigned int hash;
1880 struct rtable *rth;
1881 __be32 spec_dst;
1882 struct in_device *in_dev = __in_dev_get_rcu(dev);
1883 u32 itag = 0;
1884 int err;
1885
1886 /* Primary sanity checks. */
1887
1888 if (in_dev == NULL)
1889 return -EINVAL;
1890
1891 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1892 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
1893 goto e_inval;
1894
1895 if (ipv4_is_zeronet(saddr)) {
1896 if (!ipv4_is_local_multicast(daddr))
1897 goto e_inval;
1898 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
1899 } else {
1900 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
1901 &itag);
1902 if (err < 0)
1903 goto e_err;
1904 }
1905 rth = rt_dst_alloc(init_net.loopback_dev,
1906 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
1907 if (!rth)
1908 goto e_nobufs;
1909
1910#ifdef CONFIG_IP_ROUTE_CLASSID
1911 rth->dst.tclassid = itag;
1912#endif
1913 rth->dst.output = ip_rt_bug;
1914
1915 rth->rt_key_dst = daddr;
1916 rth->rt_key_src = saddr;
1917 rth->rt_genid = rt_genid(dev_net(dev));
1918 rth->rt_flags = RTCF_MULTICAST;
1919 rth->rt_type = RTN_MULTICAST;
1920 rth->rt_key_tos = tos;
1921 rth->rt_dst = daddr;
1922 rth->rt_src = saddr;
1923 rth->rt_route_iif = dev->ifindex;
1924 rth->rt_iif = dev->ifindex;
1925 rth->rt_oif = 0;
1926 rth->rt_mark = skb->mark;
1927 rth->rt_gateway = daddr;
1928 rth->rt_spec_dst= spec_dst;
1929 rth->rt_peer_genid = 0;
1930 rth->peer = NULL;
1931 rth->fi = NULL;
1932 if (our) {
1933 rth->dst.input= ip_local_deliver;
1934 rth->rt_flags |= RTCF_LOCAL;
1935 }
1936
1937#ifdef CONFIG_IP_MROUTE
1938 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1939 rth->dst.input = ip_mr_input;
1940#endif
1941 RT_CACHE_STAT_INC(in_slow_mc);
1942
1943 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
1944 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
1945 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
1946
1947e_nobufs:
1948 return -ENOBUFS;
1949e_inval:
1950 return -EINVAL;
1951e_err:
1952 return err;
1953}
1954
1955
1956static void ip_handle_martian_source(struct net_device *dev,
1957 struct in_device *in_dev,
1958 struct sk_buff *skb,
1959 __be32 daddr,
1960 __be32 saddr)
1961{
1962 RT_CACHE_STAT_INC(in_martian_src);
1963#ifdef CONFIG_IP_ROUTE_VERBOSE
1964 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1965 /*
1966 * RFC1812 recommendation, if source is martian,
1967 * the only hint is MAC header.
1968 */
1969 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
1970 &daddr, &saddr, dev->name);
1971 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1972 int i;
1973 const unsigned char *p = skb_mac_header(skb);
1974 printk(KERN_WARNING "ll header: ");
1975 for (i = 0; i < dev->hard_header_len; i++, p++) {
1976 printk("%02x", *p);
1977 if (i < (dev->hard_header_len - 1))
1978 printk(":");
1979 }
1980 printk("\n");
1981 }
1982 }
1983#endif
1984}
1985
1986/* called in rcu_read_lock() section */
1987static int __mkroute_input(struct sk_buff *skb,
1988 const struct fib_result *res,
1989 struct in_device *in_dev,
1990 __be32 daddr, __be32 saddr, u32 tos,
1991 struct rtable **result)
1992{
1993 struct rtable *rth;
1994 int err;
1995 struct in_device *out_dev;
1996 unsigned int flags = 0;
1997 __be32 spec_dst;
1998 u32 itag;
1999
2000 /* get a working reference to the output device */
2001 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2002 if (out_dev == NULL) {
2003 if (net_ratelimit())
2004 printk(KERN_CRIT "Bug in ip_route_input" \
2005 "_slow(). Please, report\n");
2006 return -EINVAL;
2007 }
2008
2009
2010 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2011 in_dev->dev, &spec_dst, &itag);
2012 if (err < 0) {
2013 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2014 saddr);
2015
2016 goto cleanup;
2017 }
2018
2019 if (err)
2020 flags |= RTCF_DIRECTSRC;
2021
2022 if (out_dev == in_dev && err &&
2023 (IN_DEV_SHARED_MEDIA(out_dev) ||
2024 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2025 flags |= RTCF_DOREDIRECT;
2026
2027 if (skb->protocol != htons(ETH_P_IP)) {
2028 /* Not IP (i.e. ARP). Do not create route, if it is
2029 * invalid for proxy arp. DNAT routes are always valid.
2030 *
2031 * Proxy arp feature have been extended to allow, ARP
2032 * replies back to the same interface, to support
2033 * Private VLAN switch technologies. See arp.c.
2034 */
2035 if (out_dev == in_dev &&
2036 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2037 err = -EINVAL;
2038 goto cleanup;
2039 }
2040 }
2041
2042 rth = rt_dst_alloc(out_dev->dev,
2043 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2044 IN_DEV_CONF_GET(out_dev, NOXFRM));
2045 if (!rth) {
2046 err = -ENOBUFS;
2047 goto cleanup;
2048 }
2049
2050 rth->rt_key_dst = daddr;
2051 rth->rt_key_src = saddr;
2052 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2053 rth->rt_flags = flags;
2054 rth->rt_type = res->type;
2055 rth->rt_key_tos = tos;
2056 rth->rt_dst = daddr;
2057 rth->rt_src = saddr;
2058 rth->rt_route_iif = in_dev->dev->ifindex;
2059 rth->rt_iif = in_dev->dev->ifindex;
2060 rth->rt_oif = 0;
2061 rth->rt_mark = skb->mark;
2062 rth->rt_gateway = daddr;
2063 rth->rt_spec_dst= spec_dst;
2064 rth->rt_peer_genid = 0;
2065 rth->peer = NULL;
2066 rth->fi = NULL;
2067
2068 rth->dst.input = ip_forward;
2069 rth->dst.output = ip_output;
2070
2071 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2072
2073 *result = rth;
2074 err = 0;
2075 cleanup:
2076 return err;
2077}
2078
2079static int ip_mkroute_input(struct sk_buff *skb,
2080 struct fib_result *res,
2081 const struct flowi4 *fl4,
2082 struct in_device *in_dev,
2083 __be32 daddr, __be32 saddr, u32 tos)
2084{
2085 struct rtable* rth = NULL;
2086 int err;
2087 unsigned hash;
2088
2089#ifdef CONFIG_IP_ROUTE_MULTIPATH
2090 if (res->fi && res->fi->fib_nhs > 1)
2091 fib_select_multipath(res);
2092#endif
2093
2094 /* create a routing cache entry */
2095 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2096 if (err)
2097 return err;
2098
2099 /* put it into the cache */
2100 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2101 rt_genid(dev_net(rth->dst.dev)));
2102 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2103 if (IS_ERR(rth))
2104 return PTR_ERR(rth);
2105 return 0;
2106}
2107
2108/*
2109 * NOTE. We drop all the packets that has local source
2110 * addresses, because every properly looped back packet
2111 * must have correct destination already attached by output routine.
2112 *
2113 * Such approach solves two big problems:
2114 * 1. Not simplex devices are handled properly.
2115 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2116 * called with rcu_read_lock()
2117 */
2118
2119static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2120 u8 tos, struct net_device *dev)
2121{
2122 struct fib_result res;
2123 struct in_device *in_dev = __in_dev_get_rcu(dev);
2124 struct flowi4 fl4;
2125 unsigned flags = 0;
2126 u32 itag = 0;
2127 struct rtable * rth;
2128 unsigned hash;
2129 __be32 spec_dst;
2130 int err = -EINVAL;
2131 struct net * net = dev_net(dev);
2132
2133 /* IP on this device is disabled. */
2134
2135 if (!in_dev)
2136 goto out;
2137
2138 /* Check for the most weird martians, which can be not detected
2139 by fib_lookup.
2140 */
2141
2142 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2143 ipv4_is_loopback(saddr))
2144 goto martian_source;
2145
2146 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2147 goto brd_input;
2148
2149 /* Accept zero addresses only to limited broadcast;
2150 * I even do not know to fix it or not. Waiting for complains :-)
2151 */
2152 if (ipv4_is_zeronet(saddr))
2153 goto martian_source;
2154
2155 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2156 goto martian_destination;
2157
2158 /*
2159 * Now we are ready to route packet.
2160 */
2161 fl4.flowi4_oif = 0;
2162 fl4.flowi4_iif = dev->ifindex;
2163 fl4.flowi4_mark = skb->mark;
2164 fl4.flowi4_tos = tos;
2165 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2166 fl4.daddr = daddr;
2167 fl4.saddr = saddr;
2168 err = fib_lookup(net, &fl4, &res);
2169 if (err != 0) {
2170 if (!IN_DEV_FORWARD(in_dev))
2171 goto e_hostunreach;
2172 goto no_route;
2173 }
2174
2175 RT_CACHE_STAT_INC(in_slow_tot);
2176
2177 if (res.type == RTN_BROADCAST)
2178 goto brd_input;
2179
2180 if (res.type == RTN_LOCAL) {
2181 err = fib_validate_source(skb, saddr, daddr, tos,
2182 net->loopback_dev->ifindex,
2183 dev, &spec_dst, &itag);
2184 if (err < 0)
2185 goto martian_source_keep_err;
2186 if (err)
2187 flags |= RTCF_DIRECTSRC;
2188 spec_dst = daddr;
2189 goto local_input;
2190 }
2191
2192 if (!IN_DEV_FORWARD(in_dev))
2193 goto e_hostunreach;
2194 if (res.type != RTN_UNICAST)
2195 goto martian_destination;
2196
2197 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2198out: return err;
2199
2200brd_input:
2201 if (skb->protocol != htons(ETH_P_IP))
2202 goto e_inval;
2203
2204 if (ipv4_is_zeronet(saddr))
2205 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2206 else {
2207 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2208 &itag);
2209 if (err < 0)
2210 goto martian_source_keep_err;
2211 if (err)
2212 flags |= RTCF_DIRECTSRC;
2213 }
2214 flags |= RTCF_BROADCAST;
2215 res.type = RTN_BROADCAST;
2216 RT_CACHE_STAT_INC(in_brd);
2217
2218local_input:
2219 rth = rt_dst_alloc(net->loopback_dev,
2220 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2221 if (!rth)
2222 goto e_nobufs;
2223
2224 rth->dst.input= ip_local_deliver;
2225 rth->dst.output= ip_rt_bug;
2226#ifdef CONFIG_IP_ROUTE_CLASSID
2227 rth->dst.tclassid = itag;
2228#endif
2229
2230 rth->rt_key_dst = daddr;
2231 rth->rt_key_src = saddr;
2232 rth->rt_genid = rt_genid(net);
2233 rth->rt_flags = flags|RTCF_LOCAL;
2234 rth->rt_type = res.type;
2235 rth->rt_key_tos = tos;
2236 rth->rt_dst = daddr;
2237 rth->rt_src = saddr;
2238#ifdef CONFIG_IP_ROUTE_CLASSID
2239 rth->dst.tclassid = itag;
2240#endif
2241 rth->rt_route_iif = dev->ifindex;
2242 rth->rt_iif = dev->ifindex;
2243 rth->rt_oif = 0;
2244 rth->rt_mark = skb->mark;
2245 rth->rt_gateway = daddr;
2246 rth->rt_spec_dst= spec_dst;
2247 rth->rt_peer_genid = 0;
2248 rth->peer = NULL;
2249 rth->fi = NULL;
2250 if (res.type == RTN_UNREACHABLE) {
2251 rth->dst.input= ip_error;
2252 rth->dst.error= -err;
2253 rth->rt_flags &= ~RTCF_LOCAL;
2254 }
2255 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2256 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2257 err = 0;
2258 if (IS_ERR(rth))
2259 err = PTR_ERR(rth);
2260 goto out;
2261
2262no_route:
2263 RT_CACHE_STAT_INC(in_no_route);
2264 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2265 res.type = RTN_UNREACHABLE;
2266 if (err == -ESRCH)
2267 err = -ENETUNREACH;
2268 goto local_input;
2269
2270 /*
2271 * Do not cache martian addresses: they should be logged (RFC1812)
2272 */
2273martian_destination:
2274 RT_CACHE_STAT_INC(in_martian_dst);
2275#ifdef CONFIG_IP_ROUTE_VERBOSE
2276 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2277 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2278 &daddr, &saddr, dev->name);
2279#endif
2280
2281e_hostunreach:
2282 err = -EHOSTUNREACH;
2283 goto out;
2284
2285e_inval:
2286 err = -EINVAL;
2287 goto out;
2288
2289e_nobufs:
2290 err = -ENOBUFS;
2291 goto out;
2292
2293martian_source:
2294 err = -EINVAL;
2295martian_source_keep_err:
2296 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2297 goto out;
2298}
2299
2300int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2301 u8 tos, struct net_device *dev, bool noref)
2302{
2303 struct rtable * rth;
2304 unsigned hash;
2305 int iif = dev->ifindex;
2306 struct net *net;
2307 int res;
2308
2309 net = dev_net(dev);
2310
2311 rcu_read_lock();
2312
2313 if (!rt_caching(net))
2314 goto skip_cache;
2315
2316 tos &= IPTOS_RT_MASK;
2317 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2318
2319 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2320 rth = rcu_dereference(rth->dst.rt_next)) {
2321 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2322 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2323 (rth->rt_route_iif ^ iif) |
2324 (rth->rt_key_tos ^ tos)) == 0 &&
2325 rth->rt_mark == skb->mark &&
2326 net_eq(dev_net(rth->dst.dev), net) &&
2327 !rt_is_expired(rth)) {
2328 if (noref) {
2329 dst_use_noref(&rth->dst, jiffies);
2330 skb_dst_set_noref(skb, &rth->dst);
2331 } else {
2332 dst_use(&rth->dst, jiffies);
2333 skb_dst_set(skb, &rth->dst);
2334 }
2335 RT_CACHE_STAT_INC(in_hit);
2336 rcu_read_unlock();
2337 return 0;
2338 }
2339 RT_CACHE_STAT_INC(in_hlist_search);
2340 }
2341
2342skip_cache:
2343 /* Multicast recognition logic is moved from route cache to here.
2344 The problem was that too many Ethernet cards have broken/missing
2345 hardware multicast filters :-( As result the host on multicasting
2346 network acquires a lot of useless route cache entries, sort of
2347 SDR messages from all the world. Now we try to get rid of them.
2348 Really, provided software IP multicast filter is organized
2349 reasonably (at least, hashed), it does not result in a slowdown
2350 comparing with route cache reject entries.
2351 Note, that multicast routers are not affected, because
2352 route cache entry is created eventually.
2353 */
2354 if (ipv4_is_multicast(daddr)) {
2355 struct in_device *in_dev = __in_dev_get_rcu(dev);
2356
2357 if (in_dev) {
2358 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2359 ip_hdr(skb)->protocol);
2360 if (our
2361#ifdef CONFIG_IP_MROUTE
2362 ||
2363 (!ipv4_is_local_multicast(daddr) &&
2364 IN_DEV_MFORWARD(in_dev))
2365#endif
2366 ) {
2367 int res = ip_route_input_mc(skb, daddr, saddr,
2368 tos, dev, our);
2369 rcu_read_unlock();
2370 return res;
2371 }
2372 }
2373 rcu_read_unlock();
2374 return -EINVAL;
2375 }
2376 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2377 rcu_read_unlock();
2378 return res;
2379}
2380EXPORT_SYMBOL(ip_route_input_common);
2381
2382/* called with rcu_read_lock() */
2383static struct rtable *__mkroute_output(const struct fib_result *res,
2384 const struct flowi4 *fl4,
2385 __be32 orig_daddr, __be32 orig_saddr,
2386 int orig_oif, struct net_device *dev_out,
2387 unsigned int flags)
2388{
2389 struct fib_info *fi = res->fi;
2390 u32 tos = RT_FL_TOS(fl4);
2391 struct in_device *in_dev;
2392 u16 type = res->type;
2393 struct rtable *rth;
2394
2395 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2396 return ERR_PTR(-EINVAL);
2397
2398 if (ipv4_is_lbcast(fl4->daddr))
2399 type = RTN_BROADCAST;
2400 else if (ipv4_is_multicast(fl4->daddr))
2401 type = RTN_MULTICAST;
2402 else if (ipv4_is_zeronet(fl4->daddr))
2403 return ERR_PTR(-EINVAL);
2404
2405 if (dev_out->flags & IFF_LOOPBACK)
2406 flags |= RTCF_LOCAL;
2407
2408 in_dev = __in_dev_get_rcu(dev_out);
2409 if (!in_dev)
2410 return ERR_PTR(-EINVAL);
2411
2412 if (type == RTN_BROADCAST) {
2413 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2414 fi = NULL;
2415 } else if (type == RTN_MULTICAST) {
2416 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2417 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2418 fl4->flowi4_proto))
2419 flags &= ~RTCF_LOCAL;
2420 /* If multicast route do not exist use
2421 * default one, but do not gateway in this case.
2422 * Yes, it is hack.
2423 */
2424 if (fi && res->prefixlen < 4)
2425 fi = NULL;
2426 }
2427
2428 rth = rt_dst_alloc(dev_out,
2429 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2430 IN_DEV_CONF_GET(in_dev, NOXFRM));
2431 if (!rth)
2432 return ERR_PTR(-ENOBUFS);
2433
2434 rth->dst.output = ip_output;
2435
2436 rth->rt_key_dst = orig_daddr;
2437 rth->rt_key_src = orig_saddr;
2438 rth->rt_genid = rt_genid(dev_net(dev_out));
2439 rth->rt_flags = flags;
2440 rth->rt_type = type;
2441 rth->rt_key_tos = tos;
2442 rth->rt_dst = fl4->daddr;
2443 rth->rt_src = fl4->saddr;
2444 rth->rt_route_iif = 0;
2445 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2446 rth->rt_oif = orig_oif;
2447 rth->rt_mark = fl4->flowi4_mark;
2448 rth->rt_gateway = fl4->daddr;
2449 rth->rt_spec_dst= fl4->saddr;
2450 rth->rt_peer_genid = 0;
2451 rth->peer = NULL;
2452 rth->fi = NULL;
2453
2454 RT_CACHE_STAT_INC(out_slow_tot);
2455
2456 if (flags & RTCF_LOCAL) {
2457 rth->dst.input = ip_local_deliver;
2458 rth->rt_spec_dst = fl4->daddr;
2459 }
2460 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2461 rth->rt_spec_dst = fl4->saddr;
2462 if (flags & RTCF_LOCAL &&
2463 !(dev_out->flags & IFF_LOOPBACK)) {
2464 rth->dst.output = ip_mc_output;
2465 RT_CACHE_STAT_INC(out_slow_mc);
2466 }
2467#ifdef CONFIG_IP_MROUTE
2468 if (type == RTN_MULTICAST) {
2469 if (IN_DEV_MFORWARD(in_dev) &&
2470 !ipv4_is_local_multicast(fl4->daddr)) {
2471 rth->dst.input = ip_mr_input;
2472 rth->dst.output = ip_mc_output;
2473 }
2474 }
2475#endif
2476 }
2477
2478 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2479
2480 return rth;
2481}
2482
2483/*
2484 * Major route resolver routine.
2485 * called with rcu_read_lock();
2486 */
2487
2488static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2489{
2490 struct net_device *dev_out = NULL;
2491 u32 tos = RT_FL_TOS(fl4);
2492 unsigned int flags = 0;
2493 struct fib_result res;
2494 struct rtable *rth;
2495 __be32 orig_daddr;
2496 __be32 orig_saddr;
2497 int orig_oif;
2498
2499 res.fi = NULL;
2500#ifdef CONFIG_IP_MULTIPLE_TABLES
2501 res.r = NULL;
2502#endif
2503
2504 orig_daddr = fl4->daddr;
2505 orig_saddr = fl4->saddr;
2506 orig_oif = fl4->flowi4_oif;
2507
2508 fl4->flowi4_iif = net->loopback_dev->ifindex;
2509 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2510 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2511 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2512
2513 rcu_read_lock();
2514 if (fl4->saddr) {
2515 rth = ERR_PTR(-EINVAL);
2516 if (ipv4_is_multicast(fl4->saddr) ||
2517 ipv4_is_lbcast(fl4->saddr) ||
2518 ipv4_is_zeronet(fl4->saddr))
2519 goto out;
2520
2521 /* I removed check for oif == dev_out->oif here.
2522 It was wrong for two reasons:
2523 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2524 is assigned to multiple interfaces.
2525 2. Moreover, we are allowed to send packets with saddr
2526 of another iface. --ANK
2527 */
2528
2529 if (fl4->flowi4_oif == 0 &&
2530 (ipv4_is_multicast(fl4->daddr) ||
2531 ipv4_is_lbcast(fl4->daddr))) {
2532 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2533 dev_out = __ip_dev_find(net, fl4->saddr, false);
2534 if (dev_out == NULL)
2535 goto out;
2536
2537 /* Special hack: user can direct multicasts
2538 and limited broadcast via necessary interface
2539 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2540 This hack is not just for fun, it allows
2541 vic,vat and friends to work.
2542 They bind socket to loopback, set ttl to zero
2543 and expect that it will work.
2544 From the viewpoint of routing cache they are broken,
2545 because we are not allowed to build multicast path
2546 with loopback source addr (look, routing cache
2547 cannot know, that ttl is zero, so that packet
2548 will not leave this host and route is valid).
2549 Luckily, this hack is good workaround.
2550 */
2551
2552 fl4->flowi4_oif = dev_out->ifindex;
2553 goto make_route;
2554 }
2555
2556 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2557 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2558 if (!__ip_dev_find(net, fl4->saddr, false))
2559 goto out;
2560 }
2561 }
2562
2563
2564 if (fl4->flowi4_oif) {
2565 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2566 rth = ERR_PTR(-ENODEV);
2567 if (dev_out == NULL)
2568 goto out;
2569
2570 /* RACE: Check return value of inet_select_addr instead. */
2571 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2572 rth = ERR_PTR(-ENETUNREACH);
2573 goto out;
2574 }
2575 if (ipv4_is_local_multicast(fl4->daddr) ||
2576 ipv4_is_lbcast(fl4->daddr)) {
2577 if (!fl4->saddr)
2578 fl4->saddr = inet_select_addr(dev_out, 0,
2579 RT_SCOPE_LINK);
2580 goto make_route;
2581 }
2582 if (fl4->saddr) {
2583 if (ipv4_is_multicast(fl4->daddr))
2584 fl4->saddr = inet_select_addr(dev_out, 0,
2585 fl4->flowi4_scope);
2586 else if (!fl4->daddr)
2587 fl4->saddr = inet_select_addr(dev_out, 0,
2588 RT_SCOPE_HOST);
2589 }
2590 }
2591
2592 if (!fl4->daddr) {
2593 fl4->daddr = fl4->saddr;
2594 if (!fl4->daddr)
2595 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2596 dev_out = net->loopback_dev;
2597 fl4->flowi4_oif = net->loopback_dev->ifindex;
2598 res.type = RTN_LOCAL;
2599 flags |= RTCF_LOCAL;
2600 goto make_route;
2601 }
2602
2603 if (fib_lookup(net, fl4, &res)) {
2604 res.fi = NULL;
2605 if (fl4->flowi4_oif) {
2606 /* Apparently, routing tables are wrong. Assume,
2607 that the destination is on link.
2608
2609 WHY? DW.
2610 Because we are allowed to send to iface
2611 even if it has NO routes and NO assigned
2612 addresses. When oif is specified, routing
2613 tables are looked up with only one purpose:
2614 to catch if destination is gatewayed, rather than
2615 direct. Moreover, if MSG_DONTROUTE is set,
2616 we send packet, ignoring both routing tables
2617 and ifaddr state. --ANK
2618
2619
2620 We could make it even if oif is unknown,
2621 likely IPv6, but we do not.
2622 */
2623
2624 if (fl4->saddr == 0)
2625 fl4->saddr = inet_select_addr(dev_out, 0,
2626 RT_SCOPE_LINK);
2627 res.type = RTN_UNICAST;
2628 goto make_route;
2629 }
2630 rth = ERR_PTR(-ENETUNREACH);
2631 goto out;
2632 }
2633
2634 if (res.type == RTN_LOCAL) {
2635 if (!fl4->saddr) {
2636 if (res.fi->fib_prefsrc)
2637 fl4->saddr = res.fi->fib_prefsrc;
2638 else
2639 fl4->saddr = fl4->daddr;
2640 }
2641 dev_out = net->loopback_dev;
2642 fl4->flowi4_oif = dev_out->ifindex;
2643 res.fi = NULL;
2644 flags |= RTCF_LOCAL;
2645 goto make_route;
2646 }
2647
2648#ifdef CONFIG_IP_ROUTE_MULTIPATH
2649 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2650 fib_select_multipath(&res);
2651 else
2652#endif
2653 if (!res.prefixlen &&
2654 res.table->tb_num_default > 1 &&
2655 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2656 fib_select_default(&res);
2657
2658 if (!fl4->saddr)
2659 fl4->saddr = FIB_RES_PREFSRC(net, res);
2660
2661 dev_out = FIB_RES_DEV(res);
2662 fl4->flowi4_oif = dev_out->ifindex;
2663
2664
2665make_route:
2666 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2667 dev_out, flags);
2668 if (!IS_ERR(rth)) {
2669 unsigned int hash;
2670
2671 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2672 rt_genid(dev_net(dev_out)));
2673 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2674 }
2675
2676out:
2677 rcu_read_unlock();
2678 return rth;
2679}
2680
2681struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2682{
2683 struct rtable *rth;
2684 unsigned int hash;
2685
2686 if (!rt_caching(net))
2687 goto slow_output;
2688
2689 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2690
2691 rcu_read_lock_bh();
2692 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2693 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2694 if (rth->rt_key_dst == flp4->daddr &&
2695 rth->rt_key_src == flp4->saddr &&
2696 rt_is_output_route(rth) &&
2697 rth->rt_oif == flp4->flowi4_oif &&
2698 rth->rt_mark == flp4->flowi4_mark &&
2699 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2700 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2701 net_eq(dev_net(rth->dst.dev), net) &&
2702 !rt_is_expired(rth)) {
2703 dst_use(&rth->dst, jiffies);
2704 RT_CACHE_STAT_INC(out_hit);
2705 rcu_read_unlock_bh();
2706 if (!flp4->saddr)
2707 flp4->saddr = rth->rt_src;
2708 if (!flp4->daddr)
2709 flp4->daddr = rth->rt_dst;
2710 return rth;
2711 }
2712 RT_CACHE_STAT_INC(out_hlist_search);
2713 }
2714 rcu_read_unlock_bh();
2715
2716slow_output:
2717 return ip_route_output_slow(net, flp4);
2718}
2719EXPORT_SYMBOL_GPL(__ip_route_output_key);
2720
2721static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2722{
2723 return NULL;
2724}
2725
2726static unsigned int ipv4_blackhole_default_mtu(const struct dst_entry *dst)
2727{
2728 return 0;
2729}
2730
2731static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2732{
2733}
2734
2735static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2736 unsigned long old)
2737{
2738 return NULL;
2739}
2740
2741static struct dst_ops ipv4_dst_blackhole_ops = {
2742 .family = AF_INET,
2743 .protocol = cpu_to_be16(ETH_P_IP),
2744 .destroy = ipv4_dst_destroy,
2745 .check = ipv4_blackhole_dst_check,
2746 .default_mtu = ipv4_blackhole_default_mtu,
2747 .default_advmss = ipv4_default_advmss,
2748 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2749 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2750 .neigh_lookup = ipv4_neigh_lookup,
2751};
2752
2753struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2754{
2755 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2756 struct rtable *ort = (struct rtable *) dst_orig;
2757
2758 if (rt) {
2759 struct dst_entry *new = &rt->dst;
2760
2761 new->__use = 1;
2762 new->input = dst_discard;
2763 new->output = dst_discard;
2764 dst_copy_metrics(new, &ort->dst);
2765
2766 new->dev = ort->dst.dev;
2767 if (new->dev)
2768 dev_hold(new->dev);
2769
2770 rt->rt_key_dst = ort->rt_key_dst;
2771 rt->rt_key_src = ort->rt_key_src;
2772 rt->rt_key_tos = ort->rt_key_tos;
2773 rt->rt_route_iif = ort->rt_route_iif;
2774 rt->rt_iif = ort->rt_iif;
2775 rt->rt_oif = ort->rt_oif;
2776 rt->rt_mark = ort->rt_mark;
2777
2778 rt->rt_genid = rt_genid(net);
2779 rt->rt_flags = ort->rt_flags;
2780 rt->rt_type = ort->rt_type;
2781 rt->rt_dst = ort->rt_dst;
2782 rt->rt_src = ort->rt_src;
2783 rt->rt_gateway = ort->rt_gateway;
2784 rt->rt_spec_dst = ort->rt_spec_dst;
2785 rt->peer = ort->peer;
2786 if (rt->peer)
2787 atomic_inc(&rt->peer->refcnt);
2788 rt->fi = ort->fi;
2789 if (rt->fi)
2790 atomic_inc(&rt->fi->fib_clntref);
2791
2792 dst_free(new);
2793 }
2794
2795 dst_release(dst_orig);
2796
2797 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2798}
2799
2800struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2801 struct sock *sk)
2802{
2803 struct rtable *rt = __ip_route_output_key(net, flp4);
2804
2805 if (IS_ERR(rt))
2806 return rt;
2807
2808 if (flp4->flowi4_proto)
2809 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2810 flowi4_to_flowi(flp4),
2811 sk, 0);
2812
2813 return rt;
2814}
2815EXPORT_SYMBOL_GPL(ip_route_output_flow);
2816
2817static int rt_fill_info(struct net *net,
2818 struct sk_buff *skb, u32 pid, u32 seq, int event,
2819 int nowait, unsigned int flags)
2820{
2821 struct rtable *rt = skb_rtable(skb);
2822 struct rtmsg *r;
2823 struct nlmsghdr *nlh;
2824 long expires = 0;
2825 const struct inet_peer *peer = rt->peer;
2826 u32 id = 0, ts = 0, tsage = 0, error;
2827
2828 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2829 if (nlh == NULL)
2830 return -EMSGSIZE;
2831
2832 r = nlmsg_data(nlh);
2833 r->rtm_family = AF_INET;
2834 r->rtm_dst_len = 32;
2835 r->rtm_src_len = 0;
2836 r->rtm_tos = rt->rt_key_tos;
2837 r->rtm_table = RT_TABLE_MAIN;
2838 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2839 r->rtm_type = rt->rt_type;
2840 r->rtm_scope = RT_SCOPE_UNIVERSE;
2841 r->rtm_protocol = RTPROT_UNSPEC;
2842 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2843 if (rt->rt_flags & RTCF_NOTIFY)
2844 r->rtm_flags |= RTM_F_NOTIFY;
2845
2846 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2847
2848 if (rt->rt_key_src) {
2849 r->rtm_src_len = 32;
2850 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2851 }
2852 if (rt->dst.dev)
2853 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2854#ifdef CONFIG_IP_ROUTE_CLASSID
2855 if (rt->dst.tclassid)
2856 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2857#endif
2858 if (rt_is_input_route(rt))
2859 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2860 else if (rt->rt_src != rt->rt_key_src)
2861 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
2862
2863 if (rt->rt_dst != rt->rt_gateway)
2864 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
2865
2866 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2867 goto nla_put_failure;
2868
2869 if (rt->rt_mark)
2870 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
2871
2872 error = rt->dst.error;
2873 if (peer) {
2874 inet_peer_refcheck(rt->peer);
2875 id = atomic_read(&peer->ip_id_count) & 0xffff;
2876 if (peer->tcp_ts_stamp) {
2877 ts = peer->tcp_ts;
2878 tsage = get_seconds() - peer->tcp_ts_stamp;
2879 }
2880 expires = ACCESS_ONCE(peer->pmtu_expires);
2881 if (expires)
2882 expires -= jiffies;
2883 }
2884
2885 if (rt_is_input_route(rt)) {
2886#ifdef CONFIG_IP_MROUTE
2887 __be32 dst = rt->rt_dst;
2888
2889 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2890 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2891 int err = ipmr_get_route(net, skb,
2892 rt->rt_src, rt->rt_dst,
2893 r, nowait);
2894 if (err <= 0) {
2895 if (!nowait) {
2896 if (err == 0)
2897 return 0;
2898 goto nla_put_failure;
2899 } else {
2900 if (err == -EMSGSIZE)
2901 goto nla_put_failure;
2902 error = err;
2903 }
2904 }
2905 } else
2906#endif
2907 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
2908 }
2909
2910 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
2911 expires, error) < 0)
2912 goto nla_put_failure;
2913
2914 return nlmsg_end(skb, nlh);
2915
2916nla_put_failure:
2917 nlmsg_cancel(skb, nlh);
2918 return -EMSGSIZE;
2919}
2920
2921static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2922{
2923 struct net *net = sock_net(in_skb->sk);
2924 struct rtmsg *rtm;
2925 struct nlattr *tb[RTA_MAX+1];
2926 struct rtable *rt = NULL;
2927 __be32 dst = 0;
2928 __be32 src = 0;
2929 u32 iif;
2930 int err;
2931 int mark;
2932 struct sk_buff *skb;
2933
2934 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2935 if (err < 0)
2936 goto errout;
2937
2938 rtm = nlmsg_data(nlh);
2939
2940 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2941 if (skb == NULL) {
2942 err = -ENOBUFS;
2943 goto errout;
2944 }
2945
2946 /* Reserve room for dummy headers, this skb can pass
2947 through good chunk of routing engine.
2948 */
2949 skb_reset_mac_header(skb);
2950 skb_reset_network_header(skb);
2951
2952 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2953 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2954 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2955
2956 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2957 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2958 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2959 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2960
2961 if (iif) {
2962 struct net_device *dev;
2963
2964 dev = __dev_get_by_index(net, iif);
2965 if (dev == NULL) {
2966 err = -ENODEV;
2967 goto errout_free;
2968 }
2969
2970 skb->protocol = htons(ETH_P_IP);
2971 skb->dev = dev;
2972 skb->mark = mark;
2973 local_bh_disable();
2974 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2975 local_bh_enable();
2976
2977 rt = skb_rtable(skb);
2978 if (err == 0 && rt->dst.error)
2979 err = -rt->dst.error;
2980 } else {
2981 struct flowi4 fl4 = {
2982 .daddr = dst,
2983 .saddr = src,
2984 .flowi4_tos = rtm->rtm_tos,
2985 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
2986 .flowi4_mark = mark,
2987 };
2988 rt = ip_route_output_key(net, &fl4);
2989
2990 err = 0;
2991 if (IS_ERR(rt))
2992 err = PTR_ERR(rt);
2993 }
2994
2995 if (err)
2996 goto errout_free;
2997
2998 skb_dst_set(skb, &rt->dst);
2999 if (rtm->rtm_flags & RTM_F_NOTIFY)
3000 rt->rt_flags |= RTCF_NOTIFY;
3001
3002 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3003 RTM_NEWROUTE, 0, 0);
3004 if (err <= 0)
3005 goto errout_free;
3006
3007 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3008errout:
3009 return err;
3010
3011errout_free:
3012 kfree_skb(skb);
3013 goto errout;
3014}
3015
3016int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3017{
3018 struct rtable *rt;
3019 int h, s_h;
3020 int idx, s_idx;
3021 struct net *net;
3022
3023 net = sock_net(skb->sk);
3024
3025 s_h = cb->args[0];
3026 if (s_h < 0)
3027 s_h = 0;
3028 s_idx = idx = cb->args[1];
3029 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3030 if (!rt_hash_table[h].chain)
3031 continue;
3032 rcu_read_lock_bh();
3033 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3034 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3035 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3036 continue;
3037 if (rt_is_expired(rt))
3038 continue;
3039 skb_dst_set_noref(skb, &rt->dst);
3040 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3041 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3042 1, NLM_F_MULTI) <= 0) {
3043 skb_dst_drop(skb);
3044 rcu_read_unlock_bh();
3045 goto done;
3046 }
3047 skb_dst_drop(skb);
3048 }
3049 rcu_read_unlock_bh();
3050 }
3051
3052done:
3053 cb->args[0] = h;
3054 cb->args[1] = idx;
3055 return skb->len;
3056}
3057
3058void ip_rt_multicast_event(struct in_device *in_dev)
3059{
3060 rt_cache_flush(dev_net(in_dev->dev), 0);
3061}
3062
3063#ifdef CONFIG_SYSCTL
3064static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3065 void __user *buffer,
3066 size_t *lenp, loff_t *ppos)
3067{
3068 if (write) {
3069 int flush_delay;
3070 ctl_table ctl;
3071 struct net *net;
3072
3073 memcpy(&ctl, __ctl, sizeof(ctl));
3074 ctl.data = &flush_delay;
3075 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3076
3077 net = (struct net *)__ctl->extra1;
3078 rt_cache_flush(net, flush_delay);
3079 return 0;
3080 }
3081
3082 return -EINVAL;
3083}
3084
3085static ctl_table ipv4_route_table[] = {
3086 {
3087 .procname = "gc_thresh",
3088 .data = &ipv4_dst_ops.gc_thresh,
3089 .maxlen = sizeof(int),
3090 .mode = 0644,
3091 .proc_handler = proc_dointvec,
3092 },
3093 {
3094 .procname = "max_size",
3095 .data = &ip_rt_max_size,
3096 .maxlen = sizeof(int),
3097 .mode = 0644,
3098 .proc_handler = proc_dointvec,
3099 },
3100 {
3101 /* Deprecated. Use gc_min_interval_ms */
3102
3103 .procname = "gc_min_interval",
3104 .data = &ip_rt_gc_min_interval,
3105 .maxlen = sizeof(int),
3106 .mode = 0644,
3107 .proc_handler = proc_dointvec_jiffies,
3108 },
3109 {
3110 .procname = "gc_min_interval_ms",
3111 .data = &ip_rt_gc_min_interval,
3112 .maxlen = sizeof(int),
3113 .mode = 0644,
3114 .proc_handler = proc_dointvec_ms_jiffies,
3115 },
3116 {
3117 .procname = "gc_timeout",
3118 .data = &ip_rt_gc_timeout,
3119 .maxlen = sizeof(int),
3120 .mode = 0644,
3121 .proc_handler = proc_dointvec_jiffies,
3122 },
3123 {
3124 .procname = "gc_interval",
3125 .data = &ip_rt_gc_interval,
3126 .maxlen = sizeof(int),
3127 .mode = 0644,
3128 .proc_handler = proc_dointvec_jiffies,
3129 },
3130 {
3131 .procname = "redirect_load",
3132 .data = &ip_rt_redirect_load,
3133 .maxlen = sizeof(int),
3134 .mode = 0644,
3135 .proc_handler = proc_dointvec,
3136 },
3137 {
3138 .procname = "redirect_number",
3139 .data = &ip_rt_redirect_number,
3140 .maxlen = sizeof(int),
3141 .mode = 0644,
3142 .proc_handler = proc_dointvec,
3143 },
3144 {
3145 .procname = "redirect_silence",
3146 .data = &ip_rt_redirect_silence,
3147 .maxlen = sizeof(int),
3148 .mode = 0644,
3149 .proc_handler = proc_dointvec,
3150 },
3151 {
3152 .procname = "error_cost",
3153 .data = &ip_rt_error_cost,
3154 .maxlen = sizeof(int),
3155 .mode = 0644,
3156 .proc_handler = proc_dointvec,
3157 },
3158 {
3159 .procname = "error_burst",
3160 .data = &ip_rt_error_burst,
3161 .maxlen = sizeof(int),
3162 .mode = 0644,
3163 .proc_handler = proc_dointvec,
3164 },
3165 {
3166 .procname = "gc_elasticity",
3167 .data = &ip_rt_gc_elasticity,
3168 .maxlen = sizeof(int),
3169 .mode = 0644,
3170 .proc_handler = proc_dointvec,
3171 },
3172 {
3173 .procname = "mtu_expires",
3174 .data = &ip_rt_mtu_expires,
3175 .maxlen = sizeof(int),
3176 .mode = 0644,
3177 .proc_handler = proc_dointvec_jiffies,
3178 },
3179 {
3180 .procname = "min_pmtu",
3181 .data = &ip_rt_min_pmtu,
3182 .maxlen = sizeof(int),
3183 .mode = 0644,
3184 .proc_handler = proc_dointvec,
3185 },
3186 {
3187 .procname = "min_adv_mss",
3188 .data = &ip_rt_min_advmss,
3189 .maxlen = sizeof(int),
3190 .mode = 0644,
3191 .proc_handler = proc_dointvec,
3192 },
3193 { }
3194};
3195
3196static struct ctl_table empty[1];
3197
3198static struct ctl_table ipv4_skeleton[] =
3199{
3200 { .procname = "route",
3201 .mode = 0555, .child = ipv4_route_table},
3202 { .procname = "neigh",
3203 .mode = 0555, .child = empty},
3204 { }
3205};
3206
3207static __net_initdata struct ctl_path ipv4_path[] = {
3208 { .procname = "net", },
3209 { .procname = "ipv4", },
3210 { },
3211};
3212
3213static struct ctl_table ipv4_route_flush_table[] = {
3214 {
3215 .procname = "flush",
3216 .maxlen = sizeof(int),
3217 .mode = 0200,
3218 .proc_handler = ipv4_sysctl_rtcache_flush,
3219 },
3220 { },
3221};
3222
3223static __net_initdata struct ctl_path ipv4_route_path[] = {
3224 { .procname = "net", },
3225 { .procname = "ipv4", },
3226 { .procname = "route", },
3227 { },
3228};
3229
3230static __net_init int sysctl_route_net_init(struct net *net)
3231{
3232 struct ctl_table *tbl;
3233
3234 tbl = ipv4_route_flush_table;
3235 if (!net_eq(net, &init_net)) {
3236 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3237 if (tbl == NULL)
3238 goto err_dup;
3239 }
3240 tbl[0].extra1 = net;
3241
3242 net->ipv4.route_hdr =
3243 register_net_sysctl_table(net, ipv4_route_path, tbl);
3244 if (net->ipv4.route_hdr == NULL)
3245 goto err_reg;
3246 return 0;
3247
3248err_reg:
3249 if (tbl != ipv4_route_flush_table)
3250 kfree(tbl);
3251err_dup:
3252 return -ENOMEM;
3253}
3254
3255static __net_exit void sysctl_route_net_exit(struct net *net)
3256{
3257 struct ctl_table *tbl;
3258
3259 tbl = net->ipv4.route_hdr->ctl_table_arg;
3260 unregister_net_sysctl_table(net->ipv4.route_hdr);
3261 BUG_ON(tbl == ipv4_route_flush_table);
3262 kfree(tbl);
3263}
3264
3265static __net_initdata struct pernet_operations sysctl_route_ops = {
3266 .init = sysctl_route_net_init,
3267 .exit = sysctl_route_net_exit,
3268};
3269#endif
3270
3271static __net_init int rt_genid_init(struct net *net)
3272{
3273 get_random_bytes(&net->ipv4.rt_genid,
3274 sizeof(net->ipv4.rt_genid));
3275 get_random_bytes(&net->ipv4.dev_addr_genid,
3276 sizeof(net->ipv4.dev_addr_genid));
3277 return 0;
3278}
3279
3280static __net_initdata struct pernet_operations rt_genid_ops = {
3281 .init = rt_genid_init,
3282};
3283
3284
3285#ifdef CONFIG_IP_ROUTE_CLASSID
3286struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3287#endif /* CONFIG_IP_ROUTE_CLASSID */
3288
3289static __initdata unsigned long rhash_entries;
3290static int __init set_rhash_entries(char *str)
3291{
3292 if (!str)
3293 return 0;
3294 rhash_entries = simple_strtoul(str, &str, 0);
3295 return 1;
3296}
3297__setup("rhash_entries=", set_rhash_entries);
3298
3299int __init ip_rt_init(void)
3300{
3301 int rc = 0;
3302
3303#ifdef CONFIG_IP_ROUTE_CLASSID
3304 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3305 if (!ip_rt_acct)
3306 panic("IP: failed to allocate ip_rt_acct\n");
3307#endif
3308
3309 ipv4_dst_ops.kmem_cachep =
3310 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3311 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3312
3313 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3314
3315 if (dst_entries_init(&ipv4_dst_ops) < 0)
3316 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3317
3318 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3319 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3320
3321 rt_hash_table = (struct rt_hash_bucket *)
3322 alloc_large_system_hash("IP route cache",
3323 sizeof(struct rt_hash_bucket),
3324 rhash_entries,
3325 (totalram_pages >= 128 * 1024) ?
3326 15 : 17,
3327 0,
3328 &rt_hash_log,
3329 &rt_hash_mask,
3330 rhash_entries ? 0 : 512 * 1024);
3331 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3332 rt_hash_lock_init();
3333
3334 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3335 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3336
3337 devinet_init();
3338 ip_fib_init();
3339
3340 if (ip_rt_proc_init())
3341 printk(KERN_ERR "Unable to create route proc files\n");
3342#ifdef CONFIG_XFRM
3343 xfrm_init();
3344 xfrm4_init(ip_rt_max_size);
3345#endif
3346 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3347
3348#ifdef CONFIG_SYSCTL
3349 register_pernet_subsys(&sysctl_route_ops);
3350#endif
3351 register_pernet_subsys(&rt_genid_ops);
3352 return rc;
3353}
3354
3355#ifdef CONFIG_SYSCTL
3356/*
3357 * We really need to sanitize the damn ipv4 init order, then all
3358 * this nonsense will go away.
3359 */
3360void __init ip_static_sysctl_init(void)
3361{
3362 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3363}
3364#endif