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Merge branch 'mlx5-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox...
[thirdparty/kernel/stable.git] / net / ipv4 / route.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #define pr_fmt(fmt) "IPv4: " fmt
66
67 #include <linux/module.h>
68 #include <linux/uaccess.h>
69 #include <linux/bitops.h>
70 #include <linux/types.h>
71 #include <linux/kernel.h>
72 #include <linux/mm.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/skbuff.h>
83 #include <linux/inetdevice.h>
84 #include <linux/igmp.h>
85 #include <linux/pkt_sched.h>
86 #include <linux/mroute.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 #include <linux/rcupdate.h>
90 #include <linux/times.h>
91 #include <linux/slab.h>
92 #include <linux/jhash.h>
93 #include <net/dst.h>
94 #include <net/dst_metadata.h>
95 #include <net/net_namespace.h>
96 #include <net/protocol.h>
97 #include <net/ip.h>
98 #include <net/route.h>
99 #include <net/inetpeer.h>
100 #include <net/sock.h>
101 #include <net/ip_fib.h>
102 #include <net/arp.h>
103 #include <net/tcp.h>
104 #include <net/icmp.h>
105 #include <net/xfrm.h>
106 #include <net/lwtunnel.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #endif
112 #include <net/secure_seq.h>
113 #include <net/ip_tunnels.h>
114 #include <net/l3mdev.h>
115
116 #include "fib_lookup.h"
117
118 #define RT_FL_TOS(oldflp4) \
119 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
120
121 #define RT_GC_TIMEOUT (300*HZ)
122
123 static int ip_rt_max_size;
124 static int ip_rt_redirect_number __read_mostly = 9;
125 static int ip_rt_redirect_load __read_mostly = HZ / 50;
126 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
127 static int ip_rt_error_cost __read_mostly = HZ;
128 static int ip_rt_error_burst __read_mostly = 5 * HZ;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static u32 ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132
133 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
134
135 /*
136 * Interface to generic destination cache.
137 */
138
139 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
140 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
141 static unsigned int ipv4_mtu(const struct dst_entry *dst);
142 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
143 static void ipv4_link_failure(struct sk_buff *skb);
144 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb, u32 mtu);
146 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
147 struct sk_buff *skb);
148 static void ipv4_dst_destroy(struct dst_entry *dst);
149
150 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
151 {
152 WARN_ON(1);
153 return NULL;
154 }
155
156 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
157 struct sk_buff *skb,
158 const void *daddr);
159 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr);
160
161 static struct dst_ops ipv4_dst_ops = {
162 .family = AF_INET,
163 .check = ipv4_dst_check,
164 .default_advmss = ipv4_default_advmss,
165 .mtu = ipv4_mtu,
166 .cow_metrics = ipv4_cow_metrics,
167 .destroy = ipv4_dst_destroy,
168 .negative_advice = ipv4_negative_advice,
169 .link_failure = ipv4_link_failure,
170 .update_pmtu = ip_rt_update_pmtu,
171 .redirect = ip_do_redirect,
172 .local_out = __ip_local_out,
173 .neigh_lookup = ipv4_neigh_lookup,
174 .confirm_neigh = ipv4_confirm_neigh,
175 };
176
177 #define ECN_OR_COST(class) TC_PRIO_##class
178
179 const __u8 ip_tos2prio[16] = {
180 TC_PRIO_BESTEFFORT,
181 ECN_OR_COST(BESTEFFORT),
182 TC_PRIO_BESTEFFORT,
183 ECN_OR_COST(BESTEFFORT),
184 TC_PRIO_BULK,
185 ECN_OR_COST(BULK),
186 TC_PRIO_BULK,
187 ECN_OR_COST(BULK),
188 TC_PRIO_INTERACTIVE,
189 ECN_OR_COST(INTERACTIVE),
190 TC_PRIO_INTERACTIVE,
191 ECN_OR_COST(INTERACTIVE),
192 TC_PRIO_INTERACTIVE_BULK,
193 ECN_OR_COST(INTERACTIVE_BULK),
194 TC_PRIO_INTERACTIVE_BULK,
195 ECN_OR_COST(INTERACTIVE_BULK)
196 };
197 EXPORT_SYMBOL(ip_tos2prio);
198
199 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
200 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
201
202 #ifdef CONFIG_PROC_FS
203 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
204 {
205 if (*pos)
206 return NULL;
207 return SEQ_START_TOKEN;
208 }
209
210 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
211 {
212 ++*pos;
213 return NULL;
214 }
215
216 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
217 {
218 }
219
220 static int rt_cache_seq_show(struct seq_file *seq, void *v)
221 {
222 if (v == SEQ_START_TOKEN)
223 seq_printf(seq, "%-127s\n",
224 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
225 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
226 "HHUptod\tSpecDst");
227 return 0;
228 }
229
230 static const struct seq_operations rt_cache_seq_ops = {
231 .start = rt_cache_seq_start,
232 .next = rt_cache_seq_next,
233 .stop = rt_cache_seq_stop,
234 .show = rt_cache_seq_show,
235 };
236
237 static int rt_cache_seq_open(struct inode *inode, struct file *file)
238 {
239 return seq_open(file, &rt_cache_seq_ops);
240 }
241
242 static const struct file_operations rt_cache_seq_fops = {
243 .open = rt_cache_seq_open,
244 .read = seq_read,
245 .llseek = seq_lseek,
246 .release = seq_release,
247 };
248
249
250 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
251 {
252 int cpu;
253
254 if (*pos == 0)
255 return SEQ_START_TOKEN;
256
257 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
258 if (!cpu_possible(cpu))
259 continue;
260 *pos = cpu+1;
261 return &per_cpu(rt_cache_stat, cpu);
262 }
263 return NULL;
264 }
265
266 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
267 {
268 int cpu;
269
270 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
271 if (!cpu_possible(cpu))
272 continue;
273 *pos = cpu+1;
274 return &per_cpu(rt_cache_stat, cpu);
275 }
276 return NULL;
277
278 }
279
280 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
281 {
282
283 }
284
285 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
286 {
287 struct rt_cache_stat *st = v;
288
289 if (v == SEQ_START_TOKEN) {
290 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
291 return 0;
292 }
293
294 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
295 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
296 dst_entries_get_slow(&ipv4_dst_ops),
297 0, /* st->in_hit */
298 st->in_slow_tot,
299 st->in_slow_mc,
300 st->in_no_route,
301 st->in_brd,
302 st->in_martian_dst,
303 st->in_martian_src,
304
305 0, /* st->out_hit */
306 st->out_slow_tot,
307 st->out_slow_mc,
308
309 0, /* st->gc_total */
310 0, /* st->gc_ignored */
311 0, /* st->gc_goal_miss */
312 0, /* st->gc_dst_overflow */
313 0, /* st->in_hlist_search */
314 0 /* st->out_hlist_search */
315 );
316 return 0;
317 }
318
319 static const struct seq_operations rt_cpu_seq_ops = {
320 .start = rt_cpu_seq_start,
321 .next = rt_cpu_seq_next,
322 .stop = rt_cpu_seq_stop,
323 .show = rt_cpu_seq_show,
324 };
325
326
327 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
328 {
329 return seq_open(file, &rt_cpu_seq_ops);
330 }
331
332 static const struct file_operations rt_cpu_seq_fops = {
333 .open = rt_cpu_seq_open,
334 .read = seq_read,
335 .llseek = seq_lseek,
336 .release = seq_release,
337 };
338
339 #ifdef CONFIG_IP_ROUTE_CLASSID
340 static int rt_acct_proc_show(struct seq_file *m, void *v)
341 {
342 struct ip_rt_acct *dst, *src;
343 unsigned int i, j;
344
345 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
346 if (!dst)
347 return -ENOMEM;
348
349 for_each_possible_cpu(i) {
350 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
351 for (j = 0; j < 256; j++) {
352 dst[j].o_bytes += src[j].o_bytes;
353 dst[j].o_packets += src[j].o_packets;
354 dst[j].i_bytes += src[j].i_bytes;
355 dst[j].i_packets += src[j].i_packets;
356 }
357 }
358
359 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
360 kfree(dst);
361 return 0;
362 }
363 #endif
364
365 static int __net_init ip_rt_do_proc_init(struct net *net)
366 {
367 struct proc_dir_entry *pde;
368
369 pde = proc_create("rt_cache", 0444, net->proc_net,
370 &rt_cache_seq_fops);
371 if (!pde)
372 goto err1;
373
374 pde = proc_create("rt_cache", 0444,
375 net->proc_net_stat, &rt_cpu_seq_fops);
376 if (!pde)
377 goto err2;
378
379 #ifdef CONFIG_IP_ROUTE_CLASSID
380 pde = proc_create_single("rt_acct", 0, net->proc_net,
381 rt_acct_proc_show);
382 if (!pde)
383 goto err3;
384 #endif
385 return 0;
386
387 #ifdef CONFIG_IP_ROUTE_CLASSID
388 err3:
389 remove_proc_entry("rt_cache", net->proc_net_stat);
390 #endif
391 err2:
392 remove_proc_entry("rt_cache", net->proc_net);
393 err1:
394 return -ENOMEM;
395 }
396
397 static void __net_exit ip_rt_do_proc_exit(struct net *net)
398 {
399 remove_proc_entry("rt_cache", net->proc_net_stat);
400 remove_proc_entry("rt_cache", net->proc_net);
401 #ifdef CONFIG_IP_ROUTE_CLASSID
402 remove_proc_entry("rt_acct", net->proc_net);
403 #endif
404 }
405
406 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
407 .init = ip_rt_do_proc_init,
408 .exit = ip_rt_do_proc_exit,
409 };
410
411 static int __init ip_rt_proc_init(void)
412 {
413 return register_pernet_subsys(&ip_rt_proc_ops);
414 }
415
416 #else
417 static inline int ip_rt_proc_init(void)
418 {
419 return 0;
420 }
421 #endif /* CONFIG_PROC_FS */
422
423 static inline bool rt_is_expired(const struct rtable *rth)
424 {
425 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
426 }
427
428 void rt_cache_flush(struct net *net)
429 {
430 rt_genid_bump_ipv4(net);
431 }
432
433 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
434 struct sk_buff *skb,
435 const void *daddr)
436 {
437 struct net_device *dev = dst->dev;
438 const __be32 *pkey = daddr;
439 const struct rtable *rt;
440 struct neighbour *n;
441
442 rt = (const struct rtable *) dst;
443 if (rt->rt_gateway)
444 pkey = (const __be32 *) &rt->rt_gateway;
445 else if (skb)
446 pkey = &ip_hdr(skb)->daddr;
447
448 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
449 if (n)
450 return n;
451 return neigh_create(&arp_tbl, pkey, dev);
452 }
453
454 static void ipv4_confirm_neigh(const struct dst_entry *dst, const void *daddr)
455 {
456 struct net_device *dev = dst->dev;
457 const __be32 *pkey = daddr;
458 const struct rtable *rt;
459
460 rt = (const struct rtable *)dst;
461 if (rt->rt_gateway)
462 pkey = (const __be32 *)&rt->rt_gateway;
463 else if (!daddr ||
464 (rt->rt_flags &
465 (RTCF_MULTICAST | RTCF_BROADCAST | RTCF_LOCAL)))
466 return;
467
468 __ipv4_confirm_neigh(dev, *(__force u32 *)pkey);
469 }
470
471 #define IP_IDENTS_SZ 2048u
472
473 static atomic_t *ip_idents __read_mostly;
474 static u32 *ip_tstamps __read_mostly;
475
476 /* In order to protect privacy, we add a perturbation to identifiers
477 * if one generator is seldom used. This makes hard for an attacker
478 * to infer how many packets were sent between two points in time.
479 */
480 u32 ip_idents_reserve(u32 hash, int segs)
481 {
482 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
483 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
484 u32 old = READ_ONCE(*p_tstamp);
485 u32 now = (u32)jiffies;
486 u32 new, delta = 0;
487
488 if (old != now && cmpxchg(p_tstamp, old, now) == old)
489 delta = prandom_u32_max(now - old);
490
491 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
492 do {
493 old = (u32)atomic_read(p_id);
494 new = old + delta + segs;
495 } while (atomic_cmpxchg(p_id, old, new) != old);
496
497 return new - segs;
498 }
499 EXPORT_SYMBOL(ip_idents_reserve);
500
501 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
502 {
503 static u32 ip_idents_hashrnd __read_mostly;
504 u32 hash, id;
505
506 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
507
508 hash = jhash_3words((__force u32)iph->daddr,
509 (__force u32)iph->saddr,
510 iph->protocol ^ net_hash_mix(net),
511 ip_idents_hashrnd);
512 id = ip_idents_reserve(hash, segs);
513 iph->id = htons(id);
514 }
515 EXPORT_SYMBOL(__ip_select_ident);
516
517 static void __build_flow_key(const struct net *net, struct flowi4 *fl4,
518 const struct sock *sk,
519 const struct iphdr *iph,
520 int oif, u8 tos,
521 u8 prot, u32 mark, int flow_flags)
522 {
523 if (sk) {
524 const struct inet_sock *inet = inet_sk(sk);
525
526 oif = sk->sk_bound_dev_if;
527 mark = sk->sk_mark;
528 tos = RT_CONN_FLAGS(sk);
529 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
530 }
531 flowi4_init_output(fl4, oif, mark, tos,
532 RT_SCOPE_UNIVERSE, prot,
533 flow_flags,
534 iph->daddr, iph->saddr, 0, 0,
535 sock_net_uid(net, sk));
536 }
537
538 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
539 const struct sock *sk)
540 {
541 const struct net *net = dev_net(skb->dev);
542 const struct iphdr *iph = ip_hdr(skb);
543 int oif = skb->dev->ifindex;
544 u8 tos = RT_TOS(iph->tos);
545 u8 prot = iph->protocol;
546 u32 mark = skb->mark;
547
548 __build_flow_key(net, fl4, sk, iph, oif, tos, prot, mark, 0);
549 }
550
551 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
552 {
553 const struct inet_sock *inet = inet_sk(sk);
554 const struct ip_options_rcu *inet_opt;
555 __be32 daddr = inet->inet_daddr;
556
557 rcu_read_lock();
558 inet_opt = rcu_dereference(inet->inet_opt);
559 if (inet_opt && inet_opt->opt.srr)
560 daddr = inet_opt->opt.faddr;
561 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
562 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
563 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
564 inet_sk_flowi_flags(sk),
565 daddr, inet->inet_saddr, 0, 0, sk->sk_uid);
566 rcu_read_unlock();
567 }
568
569 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
570 const struct sk_buff *skb)
571 {
572 if (skb)
573 build_skb_flow_key(fl4, skb, sk);
574 else
575 build_sk_flow_key(fl4, sk);
576 }
577
578 static DEFINE_SPINLOCK(fnhe_lock);
579
580 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
581 {
582 struct rtable *rt;
583
584 rt = rcu_dereference(fnhe->fnhe_rth_input);
585 if (rt) {
586 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
587 dst_dev_put(&rt->dst);
588 dst_release(&rt->dst);
589 }
590 rt = rcu_dereference(fnhe->fnhe_rth_output);
591 if (rt) {
592 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
593 dst_dev_put(&rt->dst);
594 dst_release(&rt->dst);
595 }
596 }
597
598 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
599 {
600 struct fib_nh_exception *fnhe, *oldest;
601
602 oldest = rcu_dereference(hash->chain);
603 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
604 fnhe = rcu_dereference(fnhe->fnhe_next)) {
605 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
606 oldest = fnhe;
607 }
608 fnhe_flush_routes(oldest);
609 return oldest;
610 }
611
612 static inline u32 fnhe_hashfun(__be32 daddr)
613 {
614 static u32 fnhe_hashrnd __read_mostly;
615 u32 hval;
616
617 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
618 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
619 return hash_32(hval, FNHE_HASH_SHIFT);
620 }
621
622 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
623 {
624 rt->rt_pmtu = fnhe->fnhe_pmtu;
625 rt->rt_mtu_locked = fnhe->fnhe_mtu_locked;
626 rt->dst.expires = fnhe->fnhe_expires;
627
628 if (fnhe->fnhe_gw) {
629 rt->rt_flags |= RTCF_REDIRECTED;
630 rt->rt_gateway = fnhe->fnhe_gw;
631 rt->rt_uses_gateway = 1;
632 }
633 }
634
635 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
636 u32 pmtu, bool lock, unsigned long expires)
637 {
638 struct fnhe_hash_bucket *hash;
639 struct fib_nh_exception *fnhe;
640 struct rtable *rt;
641 u32 genid, hval;
642 unsigned int i;
643 int depth;
644
645 genid = fnhe_genid(dev_net(nh->nh_dev));
646 hval = fnhe_hashfun(daddr);
647
648 spin_lock_bh(&fnhe_lock);
649
650 hash = rcu_dereference(nh->nh_exceptions);
651 if (!hash) {
652 hash = kcalloc(FNHE_HASH_SIZE, sizeof(*hash), GFP_ATOMIC);
653 if (!hash)
654 goto out_unlock;
655 rcu_assign_pointer(nh->nh_exceptions, hash);
656 }
657
658 hash += hval;
659
660 depth = 0;
661 for (fnhe = rcu_dereference(hash->chain); fnhe;
662 fnhe = rcu_dereference(fnhe->fnhe_next)) {
663 if (fnhe->fnhe_daddr == daddr)
664 break;
665 depth++;
666 }
667
668 if (fnhe) {
669 if (fnhe->fnhe_genid != genid)
670 fnhe->fnhe_genid = genid;
671 if (gw)
672 fnhe->fnhe_gw = gw;
673 if (pmtu) {
674 fnhe->fnhe_pmtu = pmtu;
675 fnhe->fnhe_mtu_locked = lock;
676 }
677 fnhe->fnhe_expires = max(1UL, expires);
678 /* Update all cached dsts too */
679 rt = rcu_dereference(fnhe->fnhe_rth_input);
680 if (rt)
681 fill_route_from_fnhe(rt, fnhe);
682 rt = rcu_dereference(fnhe->fnhe_rth_output);
683 if (rt)
684 fill_route_from_fnhe(rt, fnhe);
685 } else {
686 if (depth > FNHE_RECLAIM_DEPTH)
687 fnhe = fnhe_oldest(hash);
688 else {
689 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
690 if (!fnhe)
691 goto out_unlock;
692
693 fnhe->fnhe_next = hash->chain;
694 rcu_assign_pointer(hash->chain, fnhe);
695 }
696 fnhe->fnhe_genid = genid;
697 fnhe->fnhe_daddr = daddr;
698 fnhe->fnhe_gw = gw;
699 fnhe->fnhe_pmtu = pmtu;
700 fnhe->fnhe_mtu_locked = lock;
701 fnhe->fnhe_expires = max(1UL, expires);
702
703 /* Exception created; mark the cached routes for the nexthop
704 * stale, so anyone caching it rechecks if this exception
705 * applies to them.
706 */
707 rt = rcu_dereference(nh->nh_rth_input);
708 if (rt)
709 rt->dst.obsolete = DST_OBSOLETE_KILL;
710
711 for_each_possible_cpu(i) {
712 struct rtable __rcu **prt;
713 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
714 rt = rcu_dereference(*prt);
715 if (rt)
716 rt->dst.obsolete = DST_OBSOLETE_KILL;
717 }
718 }
719
720 fnhe->fnhe_stamp = jiffies;
721
722 out_unlock:
723 spin_unlock_bh(&fnhe_lock);
724 }
725
726 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
727 bool kill_route)
728 {
729 __be32 new_gw = icmp_hdr(skb)->un.gateway;
730 __be32 old_gw = ip_hdr(skb)->saddr;
731 struct net_device *dev = skb->dev;
732 struct in_device *in_dev;
733 struct fib_result res;
734 struct neighbour *n;
735 struct net *net;
736
737 switch (icmp_hdr(skb)->code & 7) {
738 case ICMP_REDIR_NET:
739 case ICMP_REDIR_NETTOS:
740 case ICMP_REDIR_HOST:
741 case ICMP_REDIR_HOSTTOS:
742 break;
743
744 default:
745 return;
746 }
747
748 if (rt->rt_gateway != old_gw)
749 return;
750
751 in_dev = __in_dev_get_rcu(dev);
752 if (!in_dev)
753 return;
754
755 net = dev_net(dev);
756 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
757 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
758 ipv4_is_zeronet(new_gw))
759 goto reject_redirect;
760
761 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
762 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
763 goto reject_redirect;
764 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
765 goto reject_redirect;
766 } else {
767 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
768 goto reject_redirect;
769 }
770
771 n = __ipv4_neigh_lookup(rt->dst.dev, new_gw);
772 if (!n)
773 n = neigh_create(&arp_tbl, &new_gw, rt->dst.dev);
774 if (!IS_ERR(n)) {
775 if (!(n->nud_state & NUD_VALID)) {
776 neigh_event_send(n, NULL);
777 } else {
778 if (fib_lookup(net, fl4, &res, 0) == 0) {
779 struct fib_nh *nh = &FIB_RES_NH(res);
780
781 update_or_create_fnhe(nh, fl4->daddr, new_gw,
782 0, false,
783 jiffies + ip_rt_gc_timeout);
784 }
785 if (kill_route)
786 rt->dst.obsolete = DST_OBSOLETE_KILL;
787 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
788 }
789 neigh_release(n);
790 }
791 return;
792
793 reject_redirect:
794 #ifdef CONFIG_IP_ROUTE_VERBOSE
795 if (IN_DEV_LOG_MARTIANS(in_dev)) {
796 const struct iphdr *iph = (const struct iphdr *) skb->data;
797 __be32 daddr = iph->daddr;
798 __be32 saddr = iph->saddr;
799
800 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
801 " Advised path = %pI4 -> %pI4\n",
802 &old_gw, dev->name, &new_gw,
803 &saddr, &daddr);
804 }
805 #endif
806 ;
807 }
808
809 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
810 {
811 struct rtable *rt;
812 struct flowi4 fl4;
813 const struct iphdr *iph = (const struct iphdr *) skb->data;
814 struct net *net = dev_net(skb->dev);
815 int oif = skb->dev->ifindex;
816 u8 tos = RT_TOS(iph->tos);
817 u8 prot = iph->protocol;
818 u32 mark = skb->mark;
819
820 rt = (struct rtable *) dst;
821
822 __build_flow_key(net, &fl4, sk, iph, oif, tos, prot, mark, 0);
823 __ip_do_redirect(rt, skb, &fl4, true);
824 }
825
826 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
827 {
828 struct rtable *rt = (struct rtable *)dst;
829 struct dst_entry *ret = dst;
830
831 if (rt) {
832 if (dst->obsolete > 0) {
833 ip_rt_put(rt);
834 ret = NULL;
835 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
836 rt->dst.expires) {
837 ip_rt_put(rt);
838 ret = NULL;
839 }
840 }
841 return ret;
842 }
843
844 /*
845 * Algorithm:
846 * 1. The first ip_rt_redirect_number redirects are sent
847 * with exponential backoff, then we stop sending them at all,
848 * assuming that the host ignores our redirects.
849 * 2. If we did not see packets requiring redirects
850 * during ip_rt_redirect_silence, we assume that the host
851 * forgot redirected route and start to send redirects again.
852 *
853 * This algorithm is much cheaper and more intelligent than dumb load limiting
854 * in icmp.c.
855 *
856 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
857 * and "frag. need" (breaks PMTU discovery) in icmp.c.
858 */
859
860 void ip_rt_send_redirect(struct sk_buff *skb)
861 {
862 struct rtable *rt = skb_rtable(skb);
863 struct in_device *in_dev;
864 struct inet_peer *peer;
865 struct net *net;
866 int log_martians;
867 int vif;
868
869 rcu_read_lock();
870 in_dev = __in_dev_get_rcu(rt->dst.dev);
871 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
872 rcu_read_unlock();
873 return;
874 }
875 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
876 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
877 rcu_read_unlock();
878
879 net = dev_net(rt->dst.dev);
880 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
881 if (!peer) {
882 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
883 rt_nexthop(rt, ip_hdr(skb)->daddr));
884 return;
885 }
886
887 /* No redirected packets during ip_rt_redirect_silence;
888 * reset the algorithm.
889 */
890 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
891 peer->rate_tokens = 0;
892
893 /* Too many ignored redirects; do not send anything
894 * set dst.rate_last to the last seen redirected packet.
895 */
896 if (peer->rate_tokens >= ip_rt_redirect_number) {
897 peer->rate_last = jiffies;
898 goto out_put_peer;
899 }
900
901 /* Check for load limit; set rate_last to the latest sent
902 * redirect.
903 */
904 if (peer->rate_tokens == 0 ||
905 time_after(jiffies,
906 (peer->rate_last +
907 (ip_rt_redirect_load << peer->rate_tokens)))) {
908 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
909
910 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
911 peer->rate_last = jiffies;
912 ++peer->rate_tokens;
913 #ifdef CONFIG_IP_ROUTE_VERBOSE
914 if (log_martians &&
915 peer->rate_tokens == ip_rt_redirect_number)
916 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
917 &ip_hdr(skb)->saddr, inet_iif(skb),
918 &ip_hdr(skb)->daddr, &gw);
919 #endif
920 }
921 out_put_peer:
922 inet_putpeer(peer);
923 }
924
925 static int ip_error(struct sk_buff *skb)
926 {
927 struct rtable *rt = skb_rtable(skb);
928 struct net_device *dev = skb->dev;
929 struct in_device *in_dev;
930 struct inet_peer *peer;
931 unsigned long now;
932 struct net *net;
933 bool send;
934 int code;
935
936 if (netif_is_l3_master(skb->dev)) {
937 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
938 if (!dev)
939 goto out;
940 }
941
942 in_dev = __in_dev_get_rcu(dev);
943
944 /* IP on this device is disabled. */
945 if (!in_dev)
946 goto out;
947
948 net = dev_net(rt->dst.dev);
949 if (!IN_DEV_FORWARD(in_dev)) {
950 switch (rt->dst.error) {
951 case EHOSTUNREACH:
952 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
953 break;
954
955 case ENETUNREACH:
956 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
957 break;
958 }
959 goto out;
960 }
961
962 switch (rt->dst.error) {
963 case EINVAL:
964 default:
965 goto out;
966 case EHOSTUNREACH:
967 code = ICMP_HOST_UNREACH;
968 break;
969 case ENETUNREACH:
970 code = ICMP_NET_UNREACH;
971 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
972 break;
973 case EACCES:
974 code = ICMP_PKT_FILTERED;
975 break;
976 }
977
978 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
979 l3mdev_master_ifindex(skb->dev), 1);
980
981 send = true;
982 if (peer) {
983 now = jiffies;
984 peer->rate_tokens += now - peer->rate_last;
985 if (peer->rate_tokens > ip_rt_error_burst)
986 peer->rate_tokens = ip_rt_error_burst;
987 peer->rate_last = now;
988 if (peer->rate_tokens >= ip_rt_error_cost)
989 peer->rate_tokens -= ip_rt_error_cost;
990 else
991 send = false;
992 inet_putpeer(peer);
993 }
994 if (send)
995 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
996
997 out: kfree_skb(skb);
998 return 0;
999 }
1000
1001 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1002 {
1003 struct dst_entry *dst = &rt->dst;
1004 u32 old_mtu = ipv4_mtu(dst);
1005 struct fib_result res;
1006 bool lock = false;
1007
1008 if (ip_mtu_locked(dst))
1009 return;
1010
1011 if (old_mtu < mtu)
1012 return;
1013
1014 if (mtu < ip_rt_min_pmtu) {
1015 lock = true;
1016 mtu = min(old_mtu, ip_rt_min_pmtu);
1017 }
1018
1019 if (rt->rt_pmtu == mtu && !lock &&
1020 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1021 return;
1022
1023 rcu_read_lock();
1024 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1025 struct fib_nh *nh = &FIB_RES_NH(res);
1026
1027 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
1028 jiffies + ip_rt_mtu_expires);
1029 }
1030 rcu_read_unlock();
1031 }
1032
1033 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1034 struct sk_buff *skb, u32 mtu)
1035 {
1036 struct rtable *rt = (struct rtable *) dst;
1037 struct flowi4 fl4;
1038
1039 ip_rt_build_flow_key(&fl4, sk, skb);
1040 __ip_rt_update_pmtu(rt, &fl4, mtu);
1041 }
1042
1043 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1044 int oif, u8 protocol)
1045 {
1046 const struct iphdr *iph = (const struct iphdr *) skb->data;
1047 struct flowi4 fl4;
1048 struct rtable *rt;
1049 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1050
1051 __build_flow_key(net, &fl4, NULL, iph, oif,
1052 RT_TOS(iph->tos), protocol, mark, 0);
1053 rt = __ip_route_output_key(net, &fl4);
1054 if (!IS_ERR(rt)) {
1055 __ip_rt_update_pmtu(rt, &fl4, mtu);
1056 ip_rt_put(rt);
1057 }
1058 }
1059 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1060
1061 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1062 {
1063 const struct iphdr *iph = (const struct iphdr *) skb->data;
1064 struct flowi4 fl4;
1065 struct rtable *rt;
1066
1067 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1068
1069 if (!fl4.flowi4_mark)
1070 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1071
1072 rt = __ip_route_output_key(sock_net(sk), &fl4);
1073 if (!IS_ERR(rt)) {
1074 __ip_rt_update_pmtu(rt, &fl4, mtu);
1075 ip_rt_put(rt);
1076 }
1077 }
1078
1079 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1080 {
1081 const struct iphdr *iph = (const struct iphdr *) skb->data;
1082 struct flowi4 fl4;
1083 struct rtable *rt;
1084 struct dst_entry *odst = NULL;
1085 bool new = false;
1086 struct net *net = sock_net(sk);
1087
1088 bh_lock_sock(sk);
1089
1090 if (!ip_sk_accept_pmtu(sk))
1091 goto out;
1092
1093 odst = sk_dst_get(sk);
1094
1095 if (sock_owned_by_user(sk) || !odst) {
1096 __ipv4_sk_update_pmtu(skb, sk, mtu);
1097 goto out;
1098 }
1099
1100 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1101
1102 rt = (struct rtable *)odst;
1103 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1104 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1105 if (IS_ERR(rt))
1106 goto out;
1107
1108 new = true;
1109 }
1110
1111 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1112
1113 if (!dst_check(&rt->dst, 0)) {
1114 if (new)
1115 dst_release(&rt->dst);
1116
1117 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1118 if (IS_ERR(rt))
1119 goto out;
1120
1121 new = true;
1122 }
1123
1124 if (new)
1125 sk_dst_set(sk, &rt->dst);
1126
1127 out:
1128 bh_unlock_sock(sk);
1129 dst_release(odst);
1130 }
1131 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1132
1133 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1134 int oif, u8 protocol)
1135 {
1136 const struct iphdr *iph = (const struct iphdr *) skb->data;
1137 struct flowi4 fl4;
1138 struct rtable *rt;
1139
1140 __build_flow_key(net, &fl4, NULL, iph, oif,
1141 RT_TOS(iph->tos), protocol, 0, 0);
1142 rt = __ip_route_output_key(net, &fl4);
1143 if (!IS_ERR(rt)) {
1144 __ip_do_redirect(rt, skb, &fl4, false);
1145 ip_rt_put(rt);
1146 }
1147 }
1148 EXPORT_SYMBOL_GPL(ipv4_redirect);
1149
1150 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1151 {
1152 const struct iphdr *iph = (const struct iphdr *) skb->data;
1153 struct flowi4 fl4;
1154 struct rtable *rt;
1155 struct net *net = sock_net(sk);
1156
1157 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1158 rt = __ip_route_output_key(net, &fl4);
1159 if (!IS_ERR(rt)) {
1160 __ip_do_redirect(rt, skb, &fl4, false);
1161 ip_rt_put(rt);
1162 }
1163 }
1164 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1165
1166 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1167 {
1168 struct rtable *rt = (struct rtable *) dst;
1169
1170 /* All IPV4 dsts are created with ->obsolete set to the value
1171 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1172 * into this function always.
1173 *
1174 * When a PMTU/redirect information update invalidates a route,
1175 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1176 * DST_OBSOLETE_DEAD by dst_free().
1177 */
1178 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1179 return NULL;
1180 return dst;
1181 }
1182
1183 static void ipv4_link_failure(struct sk_buff *skb)
1184 {
1185 struct rtable *rt;
1186
1187 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1188
1189 rt = skb_rtable(skb);
1190 if (rt)
1191 dst_set_expires(&rt->dst, 0);
1192 }
1193
1194 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1195 {
1196 pr_debug("%s: %pI4 -> %pI4, %s\n",
1197 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1198 skb->dev ? skb->dev->name : "?");
1199 kfree_skb(skb);
1200 WARN_ON(1);
1201 return 0;
1202 }
1203
1204 /*
1205 We do not cache source address of outgoing interface,
1206 because it is used only by IP RR, TS and SRR options,
1207 so that it out of fast path.
1208
1209 BTW remember: "addr" is allowed to be not aligned
1210 in IP options!
1211 */
1212
1213 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1214 {
1215 __be32 src;
1216
1217 if (rt_is_output_route(rt))
1218 src = ip_hdr(skb)->saddr;
1219 else {
1220 struct fib_result res;
1221 struct iphdr *iph = ip_hdr(skb);
1222 struct flowi4 fl4 = {
1223 .daddr = iph->daddr,
1224 .saddr = iph->saddr,
1225 .flowi4_tos = RT_TOS(iph->tos),
1226 .flowi4_oif = rt->dst.dev->ifindex,
1227 .flowi4_iif = skb->dev->ifindex,
1228 .flowi4_mark = skb->mark,
1229 };
1230
1231 rcu_read_lock();
1232 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1233 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1234 else
1235 src = inet_select_addr(rt->dst.dev,
1236 rt_nexthop(rt, iph->daddr),
1237 RT_SCOPE_UNIVERSE);
1238 rcu_read_unlock();
1239 }
1240 memcpy(addr, &src, 4);
1241 }
1242
1243 #ifdef CONFIG_IP_ROUTE_CLASSID
1244 static void set_class_tag(struct rtable *rt, u32 tag)
1245 {
1246 if (!(rt->dst.tclassid & 0xFFFF))
1247 rt->dst.tclassid |= tag & 0xFFFF;
1248 if (!(rt->dst.tclassid & 0xFFFF0000))
1249 rt->dst.tclassid |= tag & 0xFFFF0000;
1250 }
1251 #endif
1252
1253 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1254 {
1255 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1256 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1257 ip_rt_min_advmss);
1258
1259 return min(advmss, IPV4_MAX_PMTU - header_size);
1260 }
1261
1262 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1263 {
1264 const struct rtable *rt = (const struct rtable *) dst;
1265 unsigned int mtu = rt->rt_pmtu;
1266
1267 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1268 mtu = dst_metric_raw(dst, RTAX_MTU);
1269
1270 if (mtu)
1271 return mtu;
1272
1273 mtu = READ_ONCE(dst->dev->mtu);
1274
1275 if (unlikely(ip_mtu_locked(dst))) {
1276 if (rt->rt_uses_gateway && mtu > 576)
1277 mtu = 576;
1278 }
1279
1280 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1281
1282 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1283 }
1284
1285 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1286 {
1287 struct fnhe_hash_bucket *hash;
1288 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1289 u32 hval = fnhe_hashfun(daddr);
1290
1291 spin_lock_bh(&fnhe_lock);
1292
1293 hash = rcu_dereference_protected(nh->nh_exceptions,
1294 lockdep_is_held(&fnhe_lock));
1295 hash += hval;
1296
1297 fnhe_p = &hash->chain;
1298 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1299 while (fnhe) {
1300 if (fnhe->fnhe_daddr == daddr) {
1301 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1302 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1303 fnhe_flush_routes(fnhe);
1304 kfree_rcu(fnhe, rcu);
1305 break;
1306 }
1307 fnhe_p = &fnhe->fnhe_next;
1308 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1309 lockdep_is_held(&fnhe_lock));
1310 }
1311
1312 spin_unlock_bh(&fnhe_lock);
1313 }
1314
1315 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1316 {
1317 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1318 struct fib_nh_exception *fnhe;
1319 u32 hval;
1320
1321 if (!hash)
1322 return NULL;
1323
1324 hval = fnhe_hashfun(daddr);
1325
1326 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1327 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1328 if (fnhe->fnhe_daddr == daddr) {
1329 if (fnhe->fnhe_expires &&
1330 time_after(jiffies, fnhe->fnhe_expires)) {
1331 ip_del_fnhe(nh, daddr);
1332 break;
1333 }
1334 return fnhe;
1335 }
1336 }
1337 return NULL;
1338 }
1339
1340 /* MTU selection:
1341 * 1. mtu on route is locked - use it
1342 * 2. mtu from nexthop exception
1343 * 3. mtu from egress device
1344 */
1345
1346 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1347 {
1348 struct fib_info *fi = res->fi;
1349 struct fib_nh *nh = &fi->fib_nh[res->nh_sel];
1350 struct net_device *dev = nh->nh_dev;
1351 u32 mtu = 0;
1352
1353 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1354 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1355 mtu = fi->fib_mtu;
1356
1357 if (likely(!mtu)) {
1358 struct fib_nh_exception *fnhe;
1359
1360 fnhe = find_exception(nh, daddr);
1361 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1362 mtu = fnhe->fnhe_pmtu;
1363 }
1364
1365 if (likely(!mtu))
1366 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1367
1368 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu);
1369 }
1370
1371 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1372 __be32 daddr, const bool do_cache)
1373 {
1374 bool ret = false;
1375
1376 spin_lock_bh(&fnhe_lock);
1377
1378 if (daddr == fnhe->fnhe_daddr) {
1379 struct rtable __rcu **porig;
1380 struct rtable *orig;
1381 int genid = fnhe_genid(dev_net(rt->dst.dev));
1382
1383 if (rt_is_input_route(rt))
1384 porig = &fnhe->fnhe_rth_input;
1385 else
1386 porig = &fnhe->fnhe_rth_output;
1387 orig = rcu_dereference(*porig);
1388
1389 if (fnhe->fnhe_genid != genid) {
1390 fnhe->fnhe_genid = genid;
1391 fnhe->fnhe_gw = 0;
1392 fnhe->fnhe_pmtu = 0;
1393 fnhe->fnhe_expires = 0;
1394 fnhe->fnhe_mtu_locked = false;
1395 fnhe_flush_routes(fnhe);
1396 orig = NULL;
1397 }
1398 fill_route_from_fnhe(rt, fnhe);
1399 if (!rt->rt_gateway)
1400 rt->rt_gateway = daddr;
1401
1402 if (do_cache) {
1403 dst_hold(&rt->dst);
1404 rcu_assign_pointer(*porig, rt);
1405 if (orig) {
1406 dst_dev_put(&orig->dst);
1407 dst_release(&orig->dst);
1408 }
1409 ret = true;
1410 }
1411
1412 fnhe->fnhe_stamp = jiffies;
1413 }
1414 spin_unlock_bh(&fnhe_lock);
1415
1416 return ret;
1417 }
1418
1419 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1420 {
1421 struct rtable *orig, *prev, **p;
1422 bool ret = true;
1423
1424 if (rt_is_input_route(rt)) {
1425 p = (struct rtable **)&nh->nh_rth_input;
1426 } else {
1427 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1428 }
1429 orig = *p;
1430
1431 /* hold dst before doing cmpxchg() to avoid race condition
1432 * on this dst
1433 */
1434 dst_hold(&rt->dst);
1435 prev = cmpxchg(p, orig, rt);
1436 if (prev == orig) {
1437 if (orig) {
1438 dst_dev_put(&orig->dst);
1439 dst_release(&orig->dst);
1440 }
1441 } else {
1442 dst_release(&rt->dst);
1443 ret = false;
1444 }
1445
1446 return ret;
1447 }
1448
1449 struct uncached_list {
1450 spinlock_t lock;
1451 struct list_head head;
1452 };
1453
1454 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1455
1456 void rt_add_uncached_list(struct rtable *rt)
1457 {
1458 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1459
1460 rt->rt_uncached_list = ul;
1461
1462 spin_lock_bh(&ul->lock);
1463 list_add_tail(&rt->rt_uncached, &ul->head);
1464 spin_unlock_bh(&ul->lock);
1465 }
1466
1467 void rt_del_uncached_list(struct rtable *rt)
1468 {
1469 if (!list_empty(&rt->rt_uncached)) {
1470 struct uncached_list *ul = rt->rt_uncached_list;
1471
1472 spin_lock_bh(&ul->lock);
1473 list_del(&rt->rt_uncached);
1474 spin_unlock_bh(&ul->lock);
1475 }
1476 }
1477
1478 static void ipv4_dst_destroy(struct dst_entry *dst)
1479 {
1480 struct rtable *rt = (struct rtable *)dst;
1481
1482 ip_dst_metrics_put(dst);
1483 rt_del_uncached_list(rt);
1484 }
1485
1486 void rt_flush_dev(struct net_device *dev)
1487 {
1488 struct net *net = dev_net(dev);
1489 struct rtable *rt;
1490 int cpu;
1491
1492 for_each_possible_cpu(cpu) {
1493 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1494
1495 spin_lock_bh(&ul->lock);
1496 list_for_each_entry(rt, &ul->head, rt_uncached) {
1497 if (rt->dst.dev != dev)
1498 continue;
1499 rt->dst.dev = net->loopback_dev;
1500 dev_hold(rt->dst.dev);
1501 dev_put(dev);
1502 }
1503 spin_unlock_bh(&ul->lock);
1504 }
1505 }
1506
1507 static bool rt_cache_valid(const struct rtable *rt)
1508 {
1509 return rt &&
1510 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1511 !rt_is_expired(rt);
1512 }
1513
1514 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1515 const struct fib_result *res,
1516 struct fib_nh_exception *fnhe,
1517 struct fib_info *fi, u16 type, u32 itag,
1518 const bool do_cache)
1519 {
1520 bool cached = false;
1521
1522 if (fi) {
1523 struct fib_nh *nh = &FIB_RES_NH(*res);
1524
1525 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1526 rt->rt_gateway = nh->nh_gw;
1527 rt->rt_uses_gateway = 1;
1528 }
1529 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1530
1531 #ifdef CONFIG_IP_ROUTE_CLASSID
1532 rt->dst.tclassid = nh->nh_tclassid;
1533 #endif
1534 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1535 if (unlikely(fnhe))
1536 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1537 else if (do_cache)
1538 cached = rt_cache_route(nh, rt);
1539 if (unlikely(!cached)) {
1540 /* Routes we intend to cache in nexthop exception or
1541 * FIB nexthop have the DST_NOCACHE bit clear.
1542 * However, if we are unsuccessful at storing this
1543 * route into the cache we really need to set it.
1544 */
1545 if (!rt->rt_gateway)
1546 rt->rt_gateway = daddr;
1547 rt_add_uncached_list(rt);
1548 }
1549 } else
1550 rt_add_uncached_list(rt);
1551
1552 #ifdef CONFIG_IP_ROUTE_CLASSID
1553 #ifdef CONFIG_IP_MULTIPLE_TABLES
1554 set_class_tag(rt, res->tclassid);
1555 #endif
1556 set_class_tag(rt, itag);
1557 #endif
1558 }
1559
1560 struct rtable *rt_dst_alloc(struct net_device *dev,
1561 unsigned int flags, u16 type,
1562 bool nopolicy, bool noxfrm, bool will_cache)
1563 {
1564 struct rtable *rt;
1565
1566 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1567 (will_cache ? 0 : DST_HOST) |
1568 (nopolicy ? DST_NOPOLICY : 0) |
1569 (noxfrm ? DST_NOXFRM : 0));
1570
1571 if (rt) {
1572 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1573 rt->rt_flags = flags;
1574 rt->rt_type = type;
1575 rt->rt_is_input = 0;
1576 rt->rt_iif = 0;
1577 rt->rt_pmtu = 0;
1578 rt->rt_mtu_locked = 0;
1579 rt->rt_gateway = 0;
1580 rt->rt_uses_gateway = 0;
1581 INIT_LIST_HEAD(&rt->rt_uncached);
1582
1583 rt->dst.output = ip_output;
1584 if (flags & RTCF_LOCAL)
1585 rt->dst.input = ip_local_deliver;
1586 }
1587
1588 return rt;
1589 }
1590 EXPORT_SYMBOL(rt_dst_alloc);
1591
1592 /* called in rcu_read_lock() section */
1593 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1594 u8 tos, struct net_device *dev,
1595 struct in_device *in_dev, u32 *itag)
1596 {
1597 int err;
1598
1599 /* Primary sanity checks. */
1600 if (!in_dev)
1601 return -EINVAL;
1602
1603 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1604 skb->protocol != htons(ETH_P_IP))
1605 return -EINVAL;
1606
1607 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1608 return -EINVAL;
1609
1610 if (ipv4_is_zeronet(saddr)) {
1611 if (!ipv4_is_local_multicast(daddr) &&
1612 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1613 return -EINVAL;
1614 } else {
1615 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1616 in_dev, itag);
1617 if (err < 0)
1618 return err;
1619 }
1620 return 0;
1621 }
1622
1623 /* called in rcu_read_lock() section */
1624 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1625 u8 tos, struct net_device *dev, int our)
1626 {
1627 struct in_device *in_dev = __in_dev_get_rcu(dev);
1628 unsigned int flags = RTCF_MULTICAST;
1629 struct rtable *rth;
1630 u32 itag = 0;
1631 int err;
1632
1633 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1634 if (err)
1635 return err;
1636
1637 if (our)
1638 flags |= RTCF_LOCAL;
1639
1640 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1641 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1642 if (!rth)
1643 return -ENOBUFS;
1644
1645 #ifdef CONFIG_IP_ROUTE_CLASSID
1646 rth->dst.tclassid = itag;
1647 #endif
1648 rth->dst.output = ip_rt_bug;
1649 rth->rt_is_input= 1;
1650
1651 #ifdef CONFIG_IP_MROUTE
1652 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1653 rth->dst.input = ip_mr_input;
1654 #endif
1655 RT_CACHE_STAT_INC(in_slow_mc);
1656
1657 skb_dst_set(skb, &rth->dst);
1658 return 0;
1659 }
1660
1661
1662 static void ip_handle_martian_source(struct net_device *dev,
1663 struct in_device *in_dev,
1664 struct sk_buff *skb,
1665 __be32 daddr,
1666 __be32 saddr)
1667 {
1668 RT_CACHE_STAT_INC(in_martian_src);
1669 #ifdef CONFIG_IP_ROUTE_VERBOSE
1670 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1671 /*
1672 * RFC1812 recommendation, if source is martian,
1673 * the only hint is MAC header.
1674 */
1675 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1676 &daddr, &saddr, dev->name);
1677 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1678 print_hex_dump(KERN_WARNING, "ll header: ",
1679 DUMP_PREFIX_OFFSET, 16, 1,
1680 skb_mac_header(skb),
1681 dev->hard_header_len, false);
1682 }
1683 }
1684 #endif
1685 }
1686
1687 /* called in rcu_read_lock() section */
1688 static int __mkroute_input(struct sk_buff *skb,
1689 const struct fib_result *res,
1690 struct in_device *in_dev,
1691 __be32 daddr, __be32 saddr, u32 tos)
1692 {
1693 struct fib_nh_exception *fnhe;
1694 struct rtable *rth;
1695 int err;
1696 struct in_device *out_dev;
1697 bool do_cache;
1698 u32 itag = 0;
1699
1700 /* get a working reference to the output device */
1701 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1702 if (!out_dev) {
1703 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1704 return -EINVAL;
1705 }
1706
1707 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1708 in_dev->dev, in_dev, &itag);
1709 if (err < 0) {
1710 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1711 saddr);
1712
1713 goto cleanup;
1714 }
1715
1716 do_cache = res->fi && !itag;
1717 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1718 skb->protocol == htons(ETH_P_IP) &&
1719 (IN_DEV_SHARED_MEDIA(out_dev) ||
1720 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1721 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1722
1723 if (skb->protocol != htons(ETH_P_IP)) {
1724 /* Not IP (i.e. ARP). Do not create route, if it is
1725 * invalid for proxy arp. DNAT routes are always valid.
1726 *
1727 * Proxy arp feature have been extended to allow, ARP
1728 * replies back to the same interface, to support
1729 * Private VLAN switch technologies. See arp.c.
1730 */
1731 if (out_dev == in_dev &&
1732 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1733 err = -EINVAL;
1734 goto cleanup;
1735 }
1736 }
1737
1738 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1739 if (do_cache) {
1740 if (fnhe)
1741 rth = rcu_dereference(fnhe->fnhe_rth_input);
1742 else
1743 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1744 if (rt_cache_valid(rth)) {
1745 skb_dst_set_noref(skb, &rth->dst);
1746 goto out;
1747 }
1748 }
1749
1750 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1751 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1752 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1753 if (!rth) {
1754 err = -ENOBUFS;
1755 goto cleanup;
1756 }
1757
1758 rth->rt_is_input = 1;
1759 RT_CACHE_STAT_INC(in_slow_tot);
1760
1761 rth->dst.input = ip_forward;
1762
1763 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1764 do_cache);
1765 lwtunnel_set_redirect(&rth->dst);
1766 skb_dst_set(skb, &rth->dst);
1767 out:
1768 err = 0;
1769 cleanup:
1770 return err;
1771 }
1772
1773 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1774 /* To make ICMP packets follow the right flow, the multipath hash is
1775 * calculated from the inner IP addresses.
1776 */
1777 static void ip_multipath_l3_keys(const struct sk_buff *skb,
1778 struct flow_keys *hash_keys)
1779 {
1780 const struct iphdr *outer_iph = ip_hdr(skb);
1781 const struct iphdr *key_iph = outer_iph;
1782 const struct iphdr *inner_iph;
1783 const struct icmphdr *icmph;
1784 struct iphdr _inner_iph;
1785 struct icmphdr _icmph;
1786
1787 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1788 goto out;
1789
1790 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1791 goto out;
1792
1793 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1794 &_icmph);
1795 if (!icmph)
1796 goto out;
1797
1798 if (icmph->type != ICMP_DEST_UNREACH &&
1799 icmph->type != ICMP_REDIRECT &&
1800 icmph->type != ICMP_TIME_EXCEEDED &&
1801 icmph->type != ICMP_PARAMETERPROB)
1802 goto out;
1803
1804 inner_iph = skb_header_pointer(skb,
1805 outer_iph->ihl * 4 + sizeof(_icmph),
1806 sizeof(_inner_iph), &_inner_iph);
1807 if (!inner_iph)
1808 goto out;
1809
1810 key_iph = inner_iph;
1811 out:
1812 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1813 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1814 }
1815
1816 /* if skb is set it will be used and fl4 can be NULL */
1817 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1818 const struct sk_buff *skb, struct flow_keys *flkeys)
1819 {
1820 struct flow_keys hash_keys;
1821 u32 mhash;
1822
1823 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1824 case 0:
1825 memset(&hash_keys, 0, sizeof(hash_keys));
1826 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1827 if (skb) {
1828 ip_multipath_l3_keys(skb, &hash_keys);
1829 } else {
1830 hash_keys.addrs.v4addrs.src = fl4->saddr;
1831 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1832 }
1833 break;
1834 case 1:
1835 /* skb is currently provided only when forwarding */
1836 if (skb) {
1837 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1838 struct flow_keys keys;
1839
1840 /* short-circuit if we already have L4 hash present */
1841 if (skb->l4_hash)
1842 return skb_get_hash_raw(skb) >> 1;
1843
1844 memset(&hash_keys, 0, sizeof(hash_keys));
1845
1846 if (!flkeys) {
1847 skb_flow_dissect_flow_keys(skb, &keys, flag);
1848 flkeys = &keys;
1849 }
1850
1851 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1852 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1853 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1854 hash_keys.ports.src = flkeys->ports.src;
1855 hash_keys.ports.dst = flkeys->ports.dst;
1856 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1857 } else {
1858 memset(&hash_keys, 0, sizeof(hash_keys));
1859 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1860 hash_keys.addrs.v4addrs.src = fl4->saddr;
1861 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1862 hash_keys.ports.src = fl4->fl4_sport;
1863 hash_keys.ports.dst = fl4->fl4_dport;
1864 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1865 }
1866 break;
1867 }
1868 mhash = flow_hash_from_keys(&hash_keys);
1869
1870 return mhash >> 1;
1871 }
1872 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1873
1874 static int ip_mkroute_input(struct sk_buff *skb,
1875 struct fib_result *res,
1876 struct in_device *in_dev,
1877 __be32 daddr, __be32 saddr, u32 tos,
1878 struct flow_keys *hkeys)
1879 {
1880 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1881 if (res->fi && res->fi->fib_nhs > 1) {
1882 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
1883
1884 fib_select_multipath(res, h);
1885 }
1886 #endif
1887
1888 /* create a routing cache entry */
1889 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1890 }
1891
1892 /*
1893 * NOTE. We drop all the packets that has local source
1894 * addresses, because every properly looped back packet
1895 * must have correct destination already attached by output routine.
1896 *
1897 * Such approach solves two big problems:
1898 * 1. Not simplex devices are handled properly.
1899 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1900 * called with rcu_read_lock()
1901 */
1902
1903 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1904 u8 tos, struct net_device *dev,
1905 struct fib_result *res)
1906 {
1907 struct in_device *in_dev = __in_dev_get_rcu(dev);
1908 struct flow_keys *flkeys = NULL, _flkeys;
1909 struct net *net = dev_net(dev);
1910 struct ip_tunnel_info *tun_info;
1911 int err = -EINVAL;
1912 unsigned int flags = 0;
1913 u32 itag = 0;
1914 struct rtable *rth;
1915 struct flowi4 fl4;
1916 bool do_cache;
1917
1918 /* IP on this device is disabled. */
1919
1920 if (!in_dev)
1921 goto out;
1922
1923 /* Check for the most weird martians, which can be not detected
1924 by fib_lookup.
1925 */
1926
1927 tun_info = skb_tunnel_info(skb);
1928 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1929 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1930 else
1931 fl4.flowi4_tun_key.tun_id = 0;
1932 skb_dst_drop(skb);
1933
1934 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1935 goto martian_source;
1936
1937 res->fi = NULL;
1938 res->table = NULL;
1939 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1940 goto brd_input;
1941
1942 /* Accept zero addresses only to limited broadcast;
1943 * I even do not know to fix it or not. Waiting for complains :-)
1944 */
1945 if (ipv4_is_zeronet(saddr))
1946 goto martian_source;
1947
1948 if (ipv4_is_zeronet(daddr))
1949 goto martian_destination;
1950
1951 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1952 * and call it once if daddr or/and saddr are loopback addresses
1953 */
1954 if (ipv4_is_loopback(daddr)) {
1955 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1956 goto martian_destination;
1957 } else if (ipv4_is_loopback(saddr)) {
1958 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1959 goto martian_source;
1960 }
1961
1962 /*
1963 * Now we are ready to route packet.
1964 */
1965 fl4.flowi4_oif = 0;
1966 fl4.flowi4_iif = dev->ifindex;
1967 fl4.flowi4_mark = skb->mark;
1968 fl4.flowi4_tos = tos;
1969 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1970 fl4.flowi4_flags = 0;
1971 fl4.daddr = daddr;
1972 fl4.saddr = saddr;
1973 fl4.flowi4_uid = sock_net_uid(net, NULL);
1974
1975 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
1976 flkeys = &_flkeys;
1977 } else {
1978 fl4.flowi4_proto = 0;
1979 fl4.fl4_sport = 0;
1980 fl4.fl4_dport = 0;
1981 }
1982
1983 err = fib_lookup(net, &fl4, res, 0);
1984 if (err != 0) {
1985 if (!IN_DEV_FORWARD(in_dev))
1986 err = -EHOSTUNREACH;
1987 goto no_route;
1988 }
1989
1990 if (res->type == RTN_BROADCAST) {
1991 if (IN_DEV_BFORWARD(in_dev))
1992 goto make_route;
1993 goto brd_input;
1994 }
1995
1996 if (res->type == RTN_LOCAL) {
1997 err = fib_validate_source(skb, saddr, daddr, tos,
1998 0, dev, in_dev, &itag);
1999 if (err < 0)
2000 goto martian_source;
2001 goto local_input;
2002 }
2003
2004 if (!IN_DEV_FORWARD(in_dev)) {
2005 err = -EHOSTUNREACH;
2006 goto no_route;
2007 }
2008 if (res->type != RTN_UNICAST)
2009 goto martian_destination;
2010
2011 make_route:
2012 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2013 out: return err;
2014
2015 brd_input:
2016 if (skb->protocol != htons(ETH_P_IP))
2017 goto e_inval;
2018
2019 if (!ipv4_is_zeronet(saddr)) {
2020 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2021 in_dev, &itag);
2022 if (err < 0)
2023 goto martian_source;
2024 }
2025 flags |= RTCF_BROADCAST;
2026 res->type = RTN_BROADCAST;
2027 RT_CACHE_STAT_INC(in_brd);
2028
2029 local_input:
2030 do_cache = false;
2031 if (res->fi) {
2032 if (!itag) {
2033 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
2034 if (rt_cache_valid(rth)) {
2035 skb_dst_set_noref(skb, &rth->dst);
2036 err = 0;
2037 goto out;
2038 }
2039 do_cache = true;
2040 }
2041 }
2042
2043 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2044 flags | RTCF_LOCAL, res->type,
2045 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2046 if (!rth)
2047 goto e_nobufs;
2048
2049 rth->dst.output= ip_rt_bug;
2050 #ifdef CONFIG_IP_ROUTE_CLASSID
2051 rth->dst.tclassid = itag;
2052 #endif
2053 rth->rt_is_input = 1;
2054
2055 RT_CACHE_STAT_INC(in_slow_tot);
2056 if (res->type == RTN_UNREACHABLE) {
2057 rth->dst.input= ip_error;
2058 rth->dst.error= -err;
2059 rth->rt_flags &= ~RTCF_LOCAL;
2060 }
2061
2062 if (do_cache) {
2063 struct fib_nh *nh = &FIB_RES_NH(*res);
2064
2065 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
2066 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2067 WARN_ON(rth->dst.input == lwtunnel_input);
2068 rth->dst.lwtstate->orig_input = rth->dst.input;
2069 rth->dst.input = lwtunnel_input;
2070 }
2071
2072 if (unlikely(!rt_cache_route(nh, rth)))
2073 rt_add_uncached_list(rth);
2074 }
2075 skb_dst_set(skb, &rth->dst);
2076 err = 0;
2077 goto out;
2078
2079 no_route:
2080 RT_CACHE_STAT_INC(in_no_route);
2081 res->type = RTN_UNREACHABLE;
2082 res->fi = NULL;
2083 res->table = NULL;
2084 goto local_input;
2085
2086 /*
2087 * Do not cache martian addresses: they should be logged (RFC1812)
2088 */
2089 martian_destination:
2090 RT_CACHE_STAT_INC(in_martian_dst);
2091 #ifdef CONFIG_IP_ROUTE_VERBOSE
2092 if (IN_DEV_LOG_MARTIANS(in_dev))
2093 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2094 &daddr, &saddr, dev->name);
2095 #endif
2096
2097 e_inval:
2098 err = -EINVAL;
2099 goto out;
2100
2101 e_nobufs:
2102 err = -ENOBUFS;
2103 goto out;
2104
2105 martian_source:
2106 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2107 goto out;
2108 }
2109
2110 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2111 u8 tos, struct net_device *dev)
2112 {
2113 struct fib_result res;
2114 int err;
2115
2116 tos &= IPTOS_RT_MASK;
2117 rcu_read_lock();
2118 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2119 rcu_read_unlock();
2120
2121 return err;
2122 }
2123 EXPORT_SYMBOL(ip_route_input_noref);
2124
2125 /* called with rcu_read_lock held */
2126 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2127 u8 tos, struct net_device *dev, struct fib_result *res)
2128 {
2129 /* Multicast recognition logic is moved from route cache to here.
2130 The problem was that too many Ethernet cards have broken/missing
2131 hardware multicast filters :-( As result the host on multicasting
2132 network acquires a lot of useless route cache entries, sort of
2133 SDR messages from all the world. Now we try to get rid of them.
2134 Really, provided software IP multicast filter is organized
2135 reasonably (at least, hashed), it does not result in a slowdown
2136 comparing with route cache reject entries.
2137 Note, that multicast routers are not affected, because
2138 route cache entry is created eventually.
2139 */
2140 if (ipv4_is_multicast(daddr)) {
2141 struct in_device *in_dev = __in_dev_get_rcu(dev);
2142 int our = 0;
2143 int err = -EINVAL;
2144
2145 if (in_dev)
2146 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2147 ip_hdr(skb)->protocol);
2148
2149 /* check l3 master if no match yet */
2150 if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
2151 struct in_device *l3_in_dev;
2152
2153 l3_in_dev = __in_dev_get_rcu(skb->dev);
2154 if (l3_in_dev)
2155 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2156 ip_hdr(skb)->protocol);
2157 }
2158
2159 if (our
2160 #ifdef CONFIG_IP_MROUTE
2161 ||
2162 (!ipv4_is_local_multicast(daddr) &&
2163 IN_DEV_MFORWARD(in_dev))
2164 #endif
2165 ) {
2166 err = ip_route_input_mc(skb, daddr, saddr,
2167 tos, dev, our);
2168 }
2169 return err;
2170 }
2171
2172 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2173 }
2174
2175 /* called with rcu_read_lock() */
2176 static struct rtable *__mkroute_output(const struct fib_result *res,
2177 const struct flowi4 *fl4, int orig_oif,
2178 struct net_device *dev_out,
2179 unsigned int flags)
2180 {
2181 struct fib_info *fi = res->fi;
2182 struct fib_nh_exception *fnhe;
2183 struct in_device *in_dev;
2184 u16 type = res->type;
2185 struct rtable *rth;
2186 bool do_cache;
2187
2188 in_dev = __in_dev_get_rcu(dev_out);
2189 if (!in_dev)
2190 return ERR_PTR(-EINVAL);
2191
2192 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2193 if (ipv4_is_loopback(fl4->saddr) &&
2194 !(dev_out->flags & IFF_LOOPBACK) &&
2195 !netif_is_l3_master(dev_out))
2196 return ERR_PTR(-EINVAL);
2197
2198 if (ipv4_is_lbcast(fl4->daddr))
2199 type = RTN_BROADCAST;
2200 else if (ipv4_is_multicast(fl4->daddr))
2201 type = RTN_MULTICAST;
2202 else if (ipv4_is_zeronet(fl4->daddr))
2203 return ERR_PTR(-EINVAL);
2204
2205 if (dev_out->flags & IFF_LOOPBACK)
2206 flags |= RTCF_LOCAL;
2207
2208 do_cache = true;
2209 if (type == RTN_BROADCAST) {
2210 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2211 fi = NULL;
2212 } else if (type == RTN_MULTICAST) {
2213 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2214 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2215 fl4->flowi4_proto))
2216 flags &= ~RTCF_LOCAL;
2217 else
2218 do_cache = false;
2219 /* If multicast route do not exist use
2220 * default one, but do not gateway in this case.
2221 * Yes, it is hack.
2222 */
2223 if (fi && res->prefixlen < 4)
2224 fi = NULL;
2225 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2226 (orig_oif != dev_out->ifindex)) {
2227 /* For local routes that require a particular output interface
2228 * we do not want to cache the result. Caching the result
2229 * causes incorrect behaviour when there are multiple source
2230 * addresses on the interface, the end result being that if the
2231 * intended recipient is waiting on that interface for the
2232 * packet he won't receive it because it will be delivered on
2233 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2234 * be set to the loopback interface as well.
2235 */
2236 do_cache = false;
2237 }
2238
2239 fnhe = NULL;
2240 do_cache &= fi != NULL;
2241 if (fi) {
2242 struct rtable __rcu **prth;
2243 struct fib_nh *nh = &FIB_RES_NH(*res);
2244
2245 fnhe = find_exception(nh, fl4->daddr);
2246 if (!do_cache)
2247 goto add;
2248 if (fnhe) {
2249 prth = &fnhe->fnhe_rth_output;
2250 } else {
2251 if (unlikely(fl4->flowi4_flags &
2252 FLOWI_FLAG_KNOWN_NH &&
2253 !(nh->nh_gw &&
2254 nh->nh_scope == RT_SCOPE_LINK))) {
2255 do_cache = false;
2256 goto add;
2257 }
2258 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2259 }
2260 rth = rcu_dereference(*prth);
2261 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2262 return rth;
2263 }
2264
2265 add:
2266 rth = rt_dst_alloc(dev_out, flags, type,
2267 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2268 IN_DEV_CONF_GET(in_dev, NOXFRM),
2269 do_cache);
2270 if (!rth)
2271 return ERR_PTR(-ENOBUFS);
2272
2273 rth->rt_iif = orig_oif;
2274
2275 RT_CACHE_STAT_INC(out_slow_tot);
2276
2277 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2278 if (flags & RTCF_LOCAL &&
2279 !(dev_out->flags & IFF_LOOPBACK)) {
2280 rth->dst.output = ip_mc_output;
2281 RT_CACHE_STAT_INC(out_slow_mc);
2282 }
2283 #ifdef CONFIG_IP_MROUTE
2284 if (type == RTN_MULTICAST) {
2285 if (IN_DEV_MFORWARD(in_dev) &&
2286 !ipv4_is_local_multicast(fl4->daddr)) {
2287 rth->dst.input = ip_mr_input;
2288 rth->dst.output = ip_mc_output;
2289 }
2290 }
2291 #endif
2292 }
2293
2294 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2295 lwtunnel_set_redirect(&rth->dst);
2296
2297 return rth;
2298 }
2299
2300 /*
2301 * Major route resolver routine.
2302 */
2303
2304 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2305 const struct sk_buff *skb)
2306 {
2307 __u8 tos = RT_FL_TOS(fl4);
2308 struct fib_result res = {
2309 .type = RTN_UNSPEC,
2310 .fi = NULL,
2311 .table = NULL,
2312 .tclassid = 0,
2313 };
2314 struct rtable *rth;
2315
2316 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2317 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2318 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2319 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2320
2321 rcu_read_lock();
2322 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2323 rcu_read_unlock();
2324
2325 return rth;
2326 }
2327 EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2328
2329 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2330 struct fib_result *res,
2331 const struct sk_buff *skb)
2332 {
2333 struct net_device *dev_out = NULL;
2334 int orig_oif = fl4->flowi4_oif;
2335 unsigned int flags = 0;
2336 struct rtable *rth;
2337 int err = -ENETUNREACH;
2338
2339 if (fl4->saddr) {
2340 rth = ERR_PTR(-EINVAL);
2341 if (ipv4_is_multicast(fl4->saddr) ||
2342 ipv4_is_lbcast(fl4->saddr) ||
2343 ipv4_is_zeronet(fl4->saddr))
2344 goto out;
2345
2346 /* I removed check for oif == dev_out->oif here.
2347 It was wrong for two reasons:
2348 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2349 is assigned to multiple interfaces.
2350 2. Moreover, we are allowed to send packets with saddr
2351 of another iface. --ANK
2352 */
2353
2354 if (fl4->flowi4_oif == 0 &&
2355 (ipv4_is_multicast(fl4->daddr) ||
2356 ipv4_is_lbcast(fl4->daddr))) {
2357 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2358 dev_out = __ip_dev_find(net, fl4->saddr, false);
2359 if (!dev_out)
2360 goto out;
2361
2362 /* Special hack: user can direct multicasts
2363 and limited broadcast via necessary interface
2364 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2365 This hack is not just for fun, it allows
2366 vic,vat and friends to work.
2367 They bind socket to loopback, set ttl to zero
2368 and expect that it will work.
2369 From the viewpoint of routing cache they are broken,
2370 because we are not allowed to build multicast path
2371 with loopback source addr (look, routing cache
2372 cannot know, that ttl is zero, so that packet
2373 will not leave this host and route is valid).
2374 Luckily, this hack is good workaround.
2375 */
2376
2377 fl4->flowi4_oif = dev_out->ifindex;
2378 goto make_route;
2379 }
2380
2381 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2382 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2383 if (!__ip_dev_find(net, fl4->saddr, false))
2384 goto out;
2385 }
2386 }
2387
2388
2389 if (fl4->flowi4_oif) {
2390 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2391 rth = ERR_PTR(-ENODEV);
2392 if (!dev_out)
2393 goto out;
2394
2395 /* RACE: Check return value of inet_select_addr instead. */
2396 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2397 rth = ERR_PTR(-ENETUNREACH);
2398 goto out;
2399 }
2400 if (ipv4_is_local_multicast(fl4->daddr) ||
2401 ipv4_is_lbcast(fl4->daddr) ||
2402 fl4->flowi4_proto == IPPROTO_IGMP) {
2403 if (!fl4->saddr)
2404 fl4->saddr = inet_select_addr(dev_out, 0,
2405 RT_SCOPE_LINK);
2406 goto make_route;
2407 }
2408 if (!fl4->saddr) {
2409 if (ipv4_is_multicast(fl4->daddr))
2410 fl4->saddr = inet_select_addr(dev_out, 0,
2411 fl4->flowi4_scope);
2412 else if (!fl4->daddr)
2413 fl4->saddr = inet_select_addr(dev_out, 0,
2414 RT_SCOPE_HOST);
2415 }
2416 }
2417
2418 if (!fl4->daddr) {
2419 fl4->daddr = fl4->saddr;
2420 if (!fl4->daddr)
2421 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2422 dev_out = net->loopback_dev;
2423 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2424 res->type = RTN_LOCAL;
2425 flags |= RTCF_LOCAL;
2426 goto make_route;
2427 }
2428
2429 err = fib_lookup(net, fl4, res, 0);
2430 if (err) {
2431 res->fi = NULL;
2432 res->table = NULL;
2433 if (fl4->flowi4_oif &&
2434 (ipv4_is_multicast(fl4->daddr) ||
2435 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2436 /* Apparently, routing tables are wrong. Assume,
2437 that the destination is on link.
2438
2439 WHY? DW.
2440 Because we are allowed to send to iface
2441 even if it has NO routes and NO assigned
2442 addresses. When oif is specified, routing
2443 tables are looked up with only one purpose:
2444 to catch if destination is gatewayed, rather than
2445 direct. Moreover, if MSG_DONTROUTE is set,
2446 we send packet, ignoring both routing tables
2447 and ifaddr state. --ANK
2448
2449
2450 We could make it even if oif is unknown,
2451 likely IPv6, but we do not.
2452 */
2453
2454 if (fl4->saddr == 0)
2455 fl4->saddr = inet_select_addr(dev_out, 0,
2456 RT_SCOPE_LINK);
2457 res->type = RTN_UNICAST;
2458 goto make_route;
2459 }
2460 rth = ERR_PTR(err);
2461 goto out;
2462 }
2463
2464 if (res->type == RTN_LOCAL) {
2465 if (!fl4->saddr) {
2466 if (res->fi->fib_prefsrc)
2467 fl4->saddr = res->fi->fib_prefsrc;
2468 else
2469 fl4->saddr = fl4->daddr;
2470 }
2471
2472 /* L3 master device is the loopback for that domain */
2473 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2474 net->loopback_dev;
2475
2476 /* make sure orig_oif points to fib result device even
2477 * though packet rx/tx happens over loopback or l3mdev
2478 */
2479 orig_oif = FIB_RES_OIF(*res);
2480
2481 fl4->flowi4_oif = dev_out->ifindex;
2482 flags |= RTCF_LOCAL;
2483 goto make_route;
2484 }
2485
2486 fib_select_path(net, res, fl4, skb);
2487
2488 dev_out = FIB_RES_DEV(*res);
2489 fl4->flowi4_oif = dev_out->ifindex;
2490
2491
2492 make_route:
2493 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2494
2495 out:
2496 return rth;
2497 }
2498
2499 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2500 {
2501 return NULL;
2502 }
2503
2504 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2505 {
2506 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2507
2508 return mtu ? : dst->dev->mtu;
2509 }
2510
2511 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2512 struct sk_buff *skb, u32 mtu)
2513 {
2514 }
2515
2516 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2517 struct sk_buff *skb)
2518 {
2519 }
2520
2521 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2522 unsigned long old)
2523 {
2524 return NULL;
2525 }
2526
2527 static struct dst_ops ipv4_dst_blackhole_ops = {
2528 .family = AF_INET,
2529 .check = ipv4_blackhole_dst_check,
2530 .mtu = ipv4_blackhole_mtu,
2531 .default_advmss = ipv4_default_advmss,
2532 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2533 .redirect = ipv4_rt_blackhole_redirect,
2534 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2535 .neigh_lookup = ipv4_neigh_lookup,
2536 };
2537
2538 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2539 {
2540 struct rtable *ort = (struct rtable *) dst_orig;
2541 struct rtable *rt;
2542
2543 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2544 if (rt) {
2545 struct dst_entry *new = &rt->dst;
2546
2547 new->__use = 1;
2548 new->input = dst_discard;
2549 new->output = dst_discard_out;
2550
2551 new->dev = net->loopback_dev;
2552 if (new->dev)
2553 dev_hold(new->dev);
2554
2555 rt->rt_is_input = ort->rt_is_input;
2556 rt->rt_iif = ort->rt_iif;
2557 rt->rt_pmtu = ort->rt_pmtu;
2558 rt->rt_mtu_locked = ort->rt_mtu_locked;
2559
2560 rt->rt_genid = rt_genid_ipv4(net);
2561 rt->rt_flags = ort->rt_flags;
2562 rt->rt_type = ort->rt_type;
2563 rt->rt_gateway = ort->rt_gateway;
2564 rt->rt_uses_gateway = ort->rt_uses_gateway;
2565
2566 INIT_LIST_HEAD(&rt->rt_uncached);
2567 }
2568
2569 dst_release(dst_orig);
2570
2571 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2572 }
2573
2574 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2575 const struct sock *sk)
2576 {
2577 struct rtable *rt = __ip_route_output_key(net, flp4);
2578
2579 if (IS_ERR(rt))
2580 return rt;
2581
2582 if (flp4->flowi4_proto)
2583 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2584 flowi4_to_flowi(flp4),
2585 sk, 0);
2586
2587 return rt;
2588 }
2589 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2590
2591 /* called with rcu_read_lock held */
2592 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2593 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2594 struct sk_buff *skb, u32 portid, u32 seq)
2595 {
2596 struct rtmsg *r;
2597 struct nlmsghdr *nlh;
2598 unsigned long expires = 0;
2599 u32 error;
2600 u32 metrics[RTAX_MAX];
2601
2602 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0);
2603 if (!nlh)
2604 return -EMSGSIZE;
2605
2606 r = nlmsg_data(nlh);
2607 r->rtm_family = AF_INET;
2608 r->rtm_dst_len = 32;
2609 r->rtm_src_len = 0;
2610 r->rtm_tos = fl4->flowi4_tos;
2611 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2612 if (nla_put_u32(skb, RTA_TABLE, table_id))
2613 goto nla_put_failure;
2614 r->rtm_type = rt->rt_type;
2615 r->rtm_scope = RT_SCOPE_UNIVERSE;
2616 r->rtm_protocol = RTPROT_UNSPEC;
2617 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2618 if (rt->rt_flags & RTCF_NOTIFY)
2619 r->rtm_flags |= RTM_F_NOTIFY;
2620 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2621 r->rtm_flags |= RTCF_DOREDIRECT;
2622
2623 if (nla_put_in_addr(skb, RTA_DST, dst))
2624 goto nla_put_failure;
2625 if (src) {
2626 r->rtm_src_len = 32;
2627 if (nla_put_in_addr(skb, RTA_SRC, src))
2628 goto nla_put_failure;
2629 }
2630 if (rt->dst.dev &&
2631 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2632 goto nla_put_failure;
2633 #ifdef CONFIG_IP_ROUTE_CLASSID
2634 if (rt->dst.tclassid &&
2635 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2636 goto nla_put_failure;
2637 #endif
2638 if (!rt_is_input_route(rt) &&
2639 fl4->saddr != src) {
2640 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2641 goto nla_put_failure;
2642 }
2643 if (rt->rt_uses_gateway &&
2644 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2645 goto nla_put_failure;
2646
2647 expires = rt->dst.expires;
2648 if (expires) {
2649 unsigned long now = jiffies;
2650
2651 if (time_before(now, expires))
2652 expires -= now;
2653 else
2654 expires = 0;
2655 }
2656
2657 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2658 if (rt->rt_pmtu && expires)
2659 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2660 if (rt->rt_mtu_locked && expires)
2661 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2662 if (rtnetlink_put_metrics(skb, metrics) < 0)
2663 goto nla_put_failure;
2664
2665 if (fl4->flowi4_mark &&
2666 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2667 goto nla_put_failure;
2668
2669 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2670 nla_put_u32(skb, RTA_UID,
2671 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2672 goto nla_put_failure;
2673
2674 error = rt->dst.error;
2675
2676 if (rt_is_input_route(rt)) {
2677 #ifdef CONFIG_IP_MROUTE
2678 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2679 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2680 int err = ipmr_get_route(net, skb,
2681 fl4->saddr, fl4->daddr,
2682 r, portid);
2683
2684 if (err <= 0) {
2685 if (err == 0)
2686 return 0;
2687 goto nla_put_failure;
2688 }
2689 } else
2690 #endif
2691 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
2692 goto nla_put_failure;
2693 }
2694
2695 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2696 goto nla_put_failure;
2697
2698 nlmsg_end(skb, nlh);
2699 return 0;
2700
2701 nla_put_failure:
2702 nlmsg_cancel(skb, nlh);
2703 return -EMSGSIZE;
2704 }
2705
2706 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
2707 u8 ip_proto, __be16 sport,
2708 __be16 dport)
2709 {
2710 struct sk_buff *skb;
2711 struct iphdr *iph;
2712
2713 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2714 if (!skb)
2715 return NULL;
2716
2717 /* Reserve room for dummy headers, this skb can pass
2718 * through good chunk of routing engine.
2719 */
2720 skb_reset_mac_header(skb);
2721 skb_reset_network_header(skb);
2722 skb->protocol = htons(ETH_P_IP);
2723 iph = skb_put(skb, sizeof(struct iphdr));
2724 iph->protocol = ip_proto;
2725 iph->saddr = src;
2726 iph->daddr = dst;
2727 iph->version = 0x4;
2728 iph->frag_off = 0;
2729 iph->ihl = 0x5;
2730 skb_set_transport_header(skb, skb->len);
2731
2732 switch (iph->protocol) {
2733 case IPPROTO_UDP: {
2734 struct udphdr *udph;
2735
2736 udph = skb_put_zero(skb, sizeof(struct udphdr));
2737 udph->source = sport;
2738 udph->dest = dport;
2739 udph->len = sizeof(struct udphdr);
2740 udph->check = 0;
2741 break;
2742 }
2743 case IPPROTO_TCP: {
2744 struct tcphdr *tcph;
2745
2746 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
2747 tcph->source = sport;
2748 tcph->dest = dport;
2749 tcph->doff = sizeof(struct tcphdr) / 4;
2750 tcph->rst = 1;
2751 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
2752 src, dst, 0);
2753 break;
2754 }
2755 case IPPROTO_ICMP: {
2756 struct icmphdr *icmph;
2757
2758 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
2759 icmph->type = ICMP_ECHO;
2760 icmph->code = 0;
2761 }
2762 }
2763
2764 return skb;
2765 }
2766
2767 static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
2768 const struct nlmsghdr *nlh,
2769 struct nlattr **tb,
2770 struct netlink_ext_ack *extack)
2771 {
2772 struct rtmsg *rtm;
2773 int i, err;
2774
2775 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2776 NL_SET_ERR_MSG(extack,
2777 "ipv4: Invalid header for route get request");
2778 return -EINVAL;
2779 }
2780
2781 if (!netlink_strict_get_check(skb))
2782 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2783 rtm_ipv4_policy, extack);
2784
2785 rtm = nlmsg_data(nlh);
2786 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2787 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2788 rtm->rtm_table || rtm->rtm_protocol ||
2789 rtm->rtm_scope || rtm->rtm_type) {
2790 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
2791 return -EINVAL;
2792 }
2793
2794 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
2795 RTM_F_LOOKUP_TABLE |
2796 RTM_F_FIB_MATCH)) {
2797 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
2798 return -EINVAL;
2799 }
2800
2801 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2802 rtm_ipv4_policy, extack);
2803 if (err)
2804 return err;
2805
2806 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2807 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2808 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2809 return -EINVAL;
2810 }
2811
2812 for (i = 0; i <= RTA_MAX; i++) {
2813 if (!tb[i])
2814 continue;
2815
2816 switch (i) {
2817 case RTA_IIF:
2818 case RTA_OIF:
2819 case RTA_SRC:
2820 case RTA_DST:
2821 case RTA_IP_PROTO:
2822 case RTA_SPORT:
2823 case RTA_DPORT:
2824 case RTA_MARK:
2825 case RTA_UID:
2826 break;
2827 default:
2828 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
2829 return -EINVAL;
2830 }
2831 }
2832
2833 return 0;
2834 }
2835
2836 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2837 struct netlink_ext_ack *extack)
2838 {
2839 struct net *net = sock_net(in_skb->sk);
2840 struct nlattr *tb[RTA_MAX+1];
2841 u32 table_id = RT_TABLE_MAIN;
2842 __be16 sport = 0, dport = 0;
2843 struct fib_result res = {};
2844 u8 ip_proto = IPPROTO_UDP;
2845 struct rtable *rt = NULL;
2846 struct sk_buff *skb;
2847 struct rtmsg *rtm;
2848 struct flowi4 fl4 = {};
2849 __be32 dst = 0;
2850 __be32 src = 0;
2851 kuid_t uid;
2852 u32 iif;
2853 int err;
2854 int mark;
2855
2856 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2857 if (err < 0)
2858 return err;
2859
2860 rtm = nlmsg_data(nlh);
2861 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2862 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2863 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2864 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2865 if (tb[RTA_UID])
2866 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2867 else
2868 uid = (iif ? INVALID_UID : current_uid());
2869
2870 if (tb[RTA_IP_PROTO]) {
2871 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
2872 &ip_proto, extack);
2873 if (err)
2874 return err;
2875 }
2876
2877 if (tb[RTA_SPORT])
2878 sport = nla_get_be16(tb[RTA_SPORT]);
2879
2880 if (tb[RTA_DPORT])
2881 dport = nla_get_be16(tb[RTA_DPORT]);
2882
2883 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
2884 if (!skb)
2885 return -ENOBUFS;
2886
2887 fl4.daddr = dst;
2888 fl4.saddr = src;
2889 fl4.flowi4_tos = rtm->rtm_tos;
2890 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2891 fl4.flowi4_mark = mark;
2892 fl4.flowi4_uid = uid;
2893 if (sport)
2894 fl4.fl4_sport = sport;
2895 if (dport)
2896 fl4.fl4_dport = dport;
2897 fl4.flowi4_proto = ip_proto;
2898
2899 rcu_read_lock();
2900
2901 if (iif) {
2902 struct net_device *dev;
2903
2904 dev = dev_get_by_index_rcu(net, iif);
2905 if (!dev) {
2906 err = -ENODEV;
2907 goto errout_rcu;
2908 }
2909
2910 fl4.flowi4_iif = iif; /* for rt_fill_info */
2911 skb->dev = dev;
2912 skb->mark = mark;
2913 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
2914 dev, &res);
2915
2916 rt = skb_rtable(skb);
2917 if (err == 0 && rt->dst.error)
2918 err = -rt->dst.error;
2919 } else {
2920 fl4.flowi4_iif = LOOPBACK_IFINDEX;
2921 skb->dev = net->loopback_dev;
2922 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
2923 err = 0;
2924 if (IS_ERR(rt))
2925 err = PTR_ERR(rt);
2926 else
2927 skb_dst_set(skb, &rt->dst);
2928 }
2929
2930 if (err)
2931 goto errout_rcu;
2932
2933 if (rtm->rtm_flags & RTM_F_NOTIFY)
2934 rt->rt_flags |= RTCF_NOTIFY;
2935
2936 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2937 table_id = res.table ? res.table->tb_id : 0;
2938
2939 /* reset skb for netlink reply msg */
2940 skb_trim(skb, 0);
2941 skb_reset_network_header(skb);
2942 skb_reset_transport_header(skb);
2943 skb_reset_mac_header(skb);
2944
2945 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2946 if (!res.fi) {
2947 err = fib_props[res.type].error;
2948 if (!err)
2949 err = -EHOSTUNREACH;
2950 goto errout_rcu;
2951 }
2952 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
2953 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
2954 rt->rt_type, res.prefix, res.prefixlen,
2955 fl4.flowi4_tos, res.fi, 0);
2956 } else {
2957 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
2958 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
2959 }
2960 if (err < 0)
2961 goto errout_rcu;
2962
2963 rcu_read_unlock();
2964
2965 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2966
2967 errout_free:
2968 return err;
2969 errout_rcu:
2970 rcu_read_unlock();
2971 kfree_skb(skb);
2972 goto errout_free;
2973 }
2974
2975 void ip_rt_multicast_event(struct in_device *in_dev)
2976 {
2977 rt_cache_flush(dev_net(in_dev->dev));
2978 }
2979
2980 #ifdef CONFIG_SYSCTL
2981 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2982 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2983 static int ip_rt_gc_elasticity __read_mostly = 8;
2984 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
2985
2986 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2987 void __user *buffer,
2988 size_t *lenp, loff_t *ppos)
2989 {
2990 struct net *net = (struct net *)__ctl->extra1;
2991
2992 if (write) {
2993 rt_cache_flush(net);
2994 fnhe_genid_bump(net);
2995 return 0;
2996 }
2997
2998 return -EINVAL;
2999 }
3000
3001 static struct ctl_table ipv4_route_table[] = {
3002 {
3003 .procname = "gc_thresh",
3004 .data = &ipv4_dst_ops.gc_thresh,
3005 .maxlen = sizeof(int),
3006 .mode = 0644,
3007 .proc_handler = proc_dointvec,
3008 },
3009 {
3010 .procname = "max_size",
3011 .data = &ip_rt_max_size,
3012 .maxlen = sizeof(int),
3013 .mode = 0644,
3014 .proc_handler = proc_dointvec,
3015 },
3016 {
3017 /* Deprecated. Use gc_min_interval_ms */
3018
3019 .procname = "gc_min_interval",
3020 .data = &ip_rt_gc_min_interval,
3021 .maxlen = sizeof(int),
3022 .mode = 0644,
3023 .proc_handler = proc_dointvec_jiffies,
3024 },
3025 {
3026 .procname = "gc_min_interval_ms",
3027 .data = &ip_rt_gc_min_interval,
3028 .maxlen = sizeof(int),
3029 .mode = 0644,
3030 .proc_handler = proc_dointvec_ms_jiffies,
3031 },
3032 {
3033 .procname = "gc_timeout",
3034 .data = &ip_rt_gc_timeout,
3035 .maxlen = sizeof(int),
3036 .mode = 0644,
3037 .proc_handler = proc_dointvec_jiffies,
3038 },
3039 {
3040 .procname = "gc_interval",
3041 .data = &ip_rt_gc_interval,
3042 .maxlen = sizeof(int),
3043 .mode = 0644,
3044 .proc_handler = proc_dointvec_jiffies,
3045 },
3046 {
3047 .procname = "redirect_load",
3048 .data = &ip_rt_redirect_load,
3049 .maxlen = sizeof(int),
3050 .mode = 0644,
3051 .proc_handler = proc_dointvec,
3052 },
3053 {
3054 .procname = "redirect_number",
3055 .data = &ip_rt_redirect_number,
3056 .maxlen = sizeof(int),
3057 .mode = 0644,
3058 .proc_handler = proc_dointvec,
3059 },
3060 {
3061 .procname = "redirect_silence",
3062 .data = &ip_rt_redirect_silence,
3063 .maxlen = sizeof(int),
3064 .mode = 0644,
3065 .proc_handler = proc_dointvec,
3066 },
3067 {
3068 .procname = "error_cost",
3069 .data = &ip_rt_error_cost,
3070 .maxlen = sizeof(int),
3071 .mode = 0644,
3072 .proc_handler = proc_dointvec,
3073 },
3074 {
3075 .procname = "error_burst",
3076 .data = &ip_rt_error_burst,
3077 .maxlen = sizeof(int),
3078 .mode = 0644,
3079 .proc_handler = proc_dointvec,
3080 },
3081 {
3082 .procname = "gc_elasticity",
3083 .data = &ip_rt_gc_elasticity,
3084 .maxlen = sizeof(int),
3085 .mode = 0644,
3086 .proc_handler = proc_dointvec,
3087 },
3088 {
3089 .procname = "mtu_expires",
3090 .data = &ip_rt_mtu_expires,
3091 .maxlen = sizeof(int),
3092 .mode = 0644,
3093 .proc_handler = proc_dointvec_jiffies,
3094 },
3095 {
3096 .procname = "min_pmtu",
3097 .data = &ip_rt_min_pmtu,
3098 .maxlen = sizeof(int),
3099 .mode = 0644,
3100 .proc_handler = proc_dointvec_minmax,
3101 .extra1 = &ip_min_valid_pmtu,
3102 },
3103 {
3104 .procname = "min_adv_mss",
3105 .data = &ip_rt_min_advmss,
3106 .maxlen = sizeof(int),
3107 .mode = 0644,
3108 .proc_handler = proc_dointvec,
3109 },
3110 { }
3111 };
3112
3113 static struct ctl_table ipv4_route_flush_table[] = {
3114 {
3115 .procname = "flush",
3116 .maxlen = sizeof(int),
3117 .mode = 0200,
3118 .proc_handler = ipv4_sysctl_rtcache_flush,
3119 },
3120 { },
3121 };
3122
3123 static __net_init int sysctl_route_net_init(struct net *net)
3124 {
3125 struct ctl_table *tbl;
3126
3127 tbl = ipv4_route_flush_table;
3128 if (!net_eq(net, &init_net)) {
3129 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3130 if (!tbl)
3131 goto err_dup;
3132
3133 /* Don't export sysctls to unprivileged users */
3134 if (net->user_ns != &init_user_ns)
3135 tbl[0].procname = NULL;
3136 }
3137 tbl[0].extra1 = net;
3138
3139 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3140 if (!net->ipv4.route_hdr)
3141 goto err_reg;
3142 return 0;
3143
3144 err_reg:
3145 if (tbl != ipv4_route_flush_table)
3146 kfree(tbl);
3147 err_dup:
3148 return -ENOMEM;
3149 }
3150
3151 static __net_exit void sysctl_route_net_exit(struct net *net)
3152 {
3153 struct ctl_table *tbl;
3154
3155 tbl = net->ipv4.route_hdr->ctl_table_arg;
3156 unregister_net_sysctl_table(net->ipv4.route_hdr);
3157 BUG_ON(tbl == ipv4_route_flush_table);
3158 kfree(tbl);
3159 }
3160
3161 static __net_initdata struct pernet_operations sysctl_route_ops = {
3162 .init = sysctl_route_net_init,
3163 .exit = sysctl_route_net_exit,
3164 };
3165 #endif
3166
3167 static __net_init int rt_genid_init(struct net *net)
3168 {
3169 atomic_set(&net->ipv4.rt_genid, 0);
3170 atomic_set(&net->fnhe_genid, 0);
3171 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3172 return 0;
3173 }
3174
3175 static __net_initdata struct pernet_operations rt_genid_ops = {
3176 .init = rt_genid_init,
3177 };
3178
3179 static int __net_init ipv4_inetpeer_init(struct net *net)
3180 {
3181 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3182
3183 if (!bp)
3184 return -ENOMEM;
3185 inet_peer_base_init(bp);
3186 net->ipv4.peers = bp;
3187 return 0;
3188 }
3189
3190 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3191 {
3192 struct inet_peer_base *bp = net->ipv4.peers;
3193
3194 net->ipv4.peers = NULL;
3195 inetpeer_invalidate_tree(bp);
3196 kfree(bp);
3197 }
3198
3199 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3200 .init = ipv4_inetpeer_init,
3201 .exit = ipv4_inetpeer_exit,
3202 };
3203
3204 #ifdef CONFIG_IP_ROUTE_CLASSID
3205 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3206 #endif /* CONFIG_IP_ROUTE_CLASSID */
3207
3208 int __init ip_rt_init(void)
3209 {
3210 int cpu;
3211
3212 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents),
3213 GFP_KERNEL);
3214 if (!ip_idents)
3215 panic("IP: failed to allocate ip_idents\n");
3216
3217 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3218
3219 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3220 if (!ip_tstamps)
3221 panic("IP: failed to allocate ip_tstamps\n");
3222
3223 for_each_possible_cpu(cpu) {
3224 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3225
3226 INIT_LIST_HEAD(&ul->head);
3227 spin_lock_init(&ul->lock);
3228 }
3229 #ifdef CONFIG_IP_ROUTE_CLASSID
3230 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3231 if (!ip_rt_acct)
3232 panic("IP: failed to allocate ip_rt_acct\n");
3233 #endif
3234
3235 ipv4_dst_ops.kmem_cachep =
3236 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3237 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3238
3239 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3240
3241 if (dst_entries_init(&ipv4_dst_ops) < 0)
3242 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3243
3244 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3245 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3246
3247 ipv4_dst_ops.gc_thresh = ~0;
3248 ip_rt_max_size = INT_MAX;
3249
3250 devinet_init();
3251 ip_fib_init();
3252
3253 if (ip_rt_proc_init())
3254 pr_err("Unable to create route proc files\n");
3255 #ifdef CONFIG_XFRM
3256 xfrm_init();
3257 xfrm4_init();
3258 #endif
3259 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3260 RTNL_FLAG_DOIT_UNLOCKED);
3261
3262 #ifdef CONFIG_SYSCTL
3263 register_pernet_subsys(&sysctl_route_ops);
3264 #endif
3265 register_pernet_subsys(&rt_genid_ops);
3266 register_pernet_subsys(&ipv4_inetpeer_ops);
3267 return 0;
3268 }
3269
3270 #ifdef CONFIG_SYSCTL
3271 /*
3272 * We really need to sanitize the damn ipv4 init order, then all
3273 * this nonsense will go away.
3274 */
3275 void __init ip_static_sysctl_init(void)
3276 {
3277 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3278 }
3279 #endif
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git