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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[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 peer->n_redirects = 0;
893 }
894
895 /* Too many ignored redirects; do not send anything
896 * set dst.rate_last to the last seen redirected packet.
897 */
898 if (peer->n_redirects >= ip_rt_redirect_number) {
899 peer->rate_last = jiffies;
900 goto out_put_peer;
901 }
902
903 /* Check for load limit; set rate_last to the latest sent
904 * redirect.
905 */
906 if (peer->rate_tokens == 0 ||
907 time_after(jiffies,
908 (peer->rate_last +
909 (ip_rt_redirect_load << peer->rate_tokens)))) {
910 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
911
912 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
913 peer->rate_last = jiffies;
914 ++peer->rate_tokens;
915 ++peer->n_redirects;
916 #ifdef CONFIG_IP_ROUTE_VERBOSE
917 if (log_martians &&
918 peer->rate_tokens == 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 #endif
923 }
924 out_put_peer:
925 inet_putpeer(peer);
926 }
927
928 static int ip_error(struct sk_buff *skb)
929 {
930 struct rtable *rt = skb_rtable(skb);
931 struct net_device *dev = skb->dev;
932 struct in_device *in_dev;
933 struct inet_peer *peer;
934 unsigned long now;
935 struct net *net;
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 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
956 break;
957
958 case ENETUNREACH:
959 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
960 break;
961 }
962 goto out;
963 }
964
965 switch (rt->dst.error) {
966 case EINVAL:
967 default:
968 goto out;
969 case EHOSTUNREACH:
970 code = ICMP_HOST_UNREACH;
971 break;
972 case ENETUNREACH:
973 code = ICMP_NET_UNREACH;
974 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
975 break;
976 case EACCES:
977 code = ICMP_PKT_FILTERED;
978 break;
979 }
980
981 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
982 l3mdev_master_ifindex(skb->dev), 1);
983
984 send = true;
985 if (peer) {
986 now = jiffies;
987 peer->rate_tokens += now - peer->rate_last;
988 if (peer->rate_tokens > ip_rt_error_burst)
989 peer->rate_tokens = ip_rt_error_burst;
990 peer->rate_last = now;
991 if (peer->rate_tokens >= ip_rt_error_cost)
992 peer->rate_tokens -= ip_rt_error_cost;
993 else
994 send = false;
995 inet_putpeer(peer);
996 }
997 if (send)
998 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
999
1000 out: kfree_skb(skb);
1001 return 0;
1002 }
1003
1004 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
1005 {
1006 struct dst_entry *dst = &rt->dst;
1007 u32 old_mtu = ipv4_mtu(dst);
1008 struct fib_result res;
1009 bool lock = false;
1010
1011 if (ip_mtu_locked(dst))
1012 return;
1013
1014 if (old_mtu < mtu)
1015 return;
1016
1017 if (mtu < ip_rt_min_pmtu) {
1018 lock = true;
1019 mtu = min(old_mtu, ip_rt_min_pmtu);
1020 }
1021
1022 if (rt->rt_pmtu == mtu && !lock &&
1023 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
1024 return;
1025
1026 rcu_read_lock();
1027 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
1028 struct fib_nh *nh = &FIB_RES_NH(res);
1029
1030 update_or_create_fnhe(nh, fl4->daddr, 0, mtu, lock,
1031 jiffies + ip_rt_mtu_expires);
1032 }
1033 rcu_read_unlock();
1034 }
1035
1036 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1037 struct sk_buff *skb, u32 mtu)
1038 {
1039 struct rtable *rt = (struct rtable *) dst;
1040 struct flowi4 fl4;
1041
1042 ip_rt_build_flow_key(&fl4, sk, skb);
1043 __ip_rt_update_pmtu(rt, &fl4, mtu);
1044 }
1045
1046 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1047 int oif, u8 protocol)
1048 {
1049 const struct iphdr *iph = (const struct iphdr *) skb->data;
1050 struct flowi4 fl4;
1051 struct rtable *rt;
1052 u32 mark = IP4_REPLY_MARK(net, skb->mark);
1053
1054 __build_flow_key(net, &fl4, NULL, iph, oif,
1055 RT_TOS(iph->tos), protocol, mark, 0);
1056 rt = __ip_route_output_key(net, &fl4);
1057 if (!IS_ERR(rt)) {
1058 __ip_rt_update_pmtu(rt, &fl4, mtu);
1059 ip_rt_put(rt);
1060 }
1061 }
1062 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1063
1064 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1065 {
1066 const struct iphdr *iph = (const struct iphdr *) skb->data;
1067 struct flowi4 fl4;
1068 struct rtable *rt;
1069
1070 __build_flow_key(sock_net(sk), &fl4, sk, iph, 0, 0, 0, 0, 0);
1071
1072 if (!fl4.flowi4_mark)
1073 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1074
1075 rt = __ip_route_output_key(sock_net(sk), &fl4);
1076 if (!IS_ERR(rt)) {
1077 __ip_rt_update_pmtu(rt, &fl4, mtu);
1078 ip_rt_put(rt);
1079 }
1080 }
1081
1082 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1083 {
1084 const struct iphdr *iph = (const struct iphdr *) skb->data;
1085 struct flowi4 fl4;
1086 struct rtable *rt;
1087 struct dst_entry *odst = NULL;
1088 bool new = false;
1089 struct net *net = sock_net(sk);
1090
1091 bh_lock_sock(sk);
1092
1093 if (!ip_sk_accept_pmtu(sk))
1094 goto out;
1095
1096 odst = sk_dst_get(sk);
1097
1098 if (sock_owned_by_user(sk) || !odst) {
1099 __ipv4_sk_update_pmtu(skb, sk, mtu);
1100 goto out;
1101 }
1102
1103 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1104
1105 rt = (struct rtable *)odst;
1106 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1107 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1108 if (IS_ERR(rt))
1109 goto out;
1110
1111 new = true;
1112 }
1113
1114 __ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
1115
1116 if (!dst_check(&rt->dst, 0)) {
1117 if (new)
1118 dst_release(&rt->dst);
1119
1120 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1121 if (IS_ERR(rt))
1122 goto out;
1123
1124 new = true;
1125 }
1126
1127 if (new)
1128 sk_dst_set(sk, &rt->dst);
1129
1130 out:
1131 bh_unlock_sock(sk);
1132 dst_release(odst);
1133 }
1134 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1135
1136 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1137 int oif, u8 protocol)
1138 {
1139 const struct iphdr *iph = (const struct iphdr *) skb->data;
1140 struct flowi4 fl4;
1141 struct rtable *rt;
1142
1143 __build_flow_key(net, &fl4, NULL, iph, oif,
1144 RT_TOS(iph->tos), protocol, 0, 0);
1145 rt = __ip_route_output_key(net, &fl4);
1146 if (!IS_ERR(rt)) {
1147 __ip_do_redirect(rt, skb, &fl4, false);
1148 ip_rt_put(rt);
1149 }
1150 }
1151 EXPORT_SYMBOL_GPL(ipv4_redirect);
1152
1153 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1154 {
1155 const struct iphdr *iph = (const struct iphdr *) skb->data;
1156 struct flowi4 fl4;
1157 struct rtable *rt;
1158 struct net *net = sock_net(sk);
1159
1160 __build_flow_key(net, &fl4, sk, iph, 0, 0, 0, 0, 0);
1161 rt = __ip_route_output_key(net, &fl4);
1162 if (!IS_ERR(rt)) {
1163 __ip_do_redirect(rt, skb, &fl4, false);
1164 ip_rt_put(rt);
1165 }
1166 }
1167 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1168
1169 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1170 {
1171 struct rtable *rt = (struct rtable *) dst;
1172
1173 /* All IPV4 dsts are created with ->obsolete set to the value
1174 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1175 * into this function always.
1176 *
1177 * When a PMTU/redirect information update invalidates a route,
1178 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1179 * DST_OBSOLETE_DEAD by dst_free().
1180 */
1181 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1182 return NULL;
1183 return dst;
1184 }
1185
1186 static void ipv4_link_failure(struct sk_buff *skb)
1187 {
1188 struct rtable *rt;
1189
1190 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1191
1192 rt = skb_rtable(skb);
1193 if (rt)
1194 dst_set_expires(&rt->dst, 0);
1195 }
1196
1197 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1198 {
1199 pr_debug("%s: %pI4 -> %pI4, %s\n",
1200 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1201 skb->dev ? skb->dev->name : "?");
1202 kfree_skb(skb);
1203 WARN_ON(1);
1204 return 0;
1205 }
1206
1207 /*
1208 We do not cache source address of outgoing interface,
1209 because it is used only by IP RR, TS and SRR options,
1210 so that it out of fast path.
1211
1212 BTW remember: "addr" is allowed to be not aligned
1213 in IP options!
1214 */
1215
1216 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1217 {
1218 __be32 src;
1219
1220 if (rt_is_output_route(rt))
1221 src = ip_hdr(skb)->saddr;
1222 else {
1223 struct fib_result res;
1224 struct iphdr *iph = ip_hdr(skb);
1225 struct flowi4 fl4 = {
1226 .daddr = iph->daddr,
1227 .saddr = iph->saddr,
1228 .flowi4_tos = RT_TOS(iph->tos),
1229 .flowi4_oif = rt->dst.dev->ifindex,
1230 .flowi4_iif = skb->dev->ifindex,
1231 .flowi4_mark = skb->mark,
1232 };
1233
1234 rcu_read_lock();
1235 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1236 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1237 else
1238 src = inet_select_addr(rt->dst.dev,
1239 rt_nexthop(rt, iph->daddr),
1240 RT_SCOPE_UNIVERSE);
1241 rcu_read_unlock();
1242 }
1243 memcpy(addr, &src, 4);
1244 }
1245
1246 #ifdef CONFIG_IP_ROUTE_CLASSID
1247 static void set_class_tag(struct rtable *rt, u32 tag)
1248 {
1249 if (!(rt->dst.tclassid & 0xFFFF))
1250 rt->dst.tclassid |= tag & 0xFFFF;
1251 if (!(rt->dst.tclassid & 0xFFFF0000))
1252 rt->dst.tclassid |= tag & 0xFFFF0000;
1253 }
1254 #endif
1255
1256 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1257 {
1258 unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
1259 unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
1260 ip_rt_min_advmss);
1261
1262 return min(advmss, IPV4_MAX_PMTU - header_size);
1263 }
1264
1265 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1266 {
1267 const struct rtable *rt = (const struct rtable *) dst;
1268 unsigned int mtu = rt->rt_pmtu;
1269
1270 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1271 mtu = dst_metric_raw(dst, RTAX_MTU);
1272
1273 if (mtu)
1274 return mtu;
1275
1276 mtu = READ_ONCE(dst->dev->mtu);
1277
1278 if (unlikely(ip_mtu_locked(dst))) {
1279 if (rt->rt_uses_gateway && mtu > 576)
1280 mtu = 576;
1281 }
1282
1283 mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
1284
1285 return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
1286 }
1287
1288 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1289 {
1290 struct fnhe_hash_bucket *hash;
1291 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1292 u32 hval = fnhe_hashfun(daddr);
1293
1294 spin_lock_bh(&fnhe_lock);
1295
1296 hash = rcu_dereference_protected(nh->nh_exceptions,
1297 lockdep_is_held(&fnhe_lock));
1298 hash += hval;
1299
1300 fnhe_p = &hash->chain;
1301 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1302 while (fnhe) {
1303 if (fnhe->fnhe_daddr == daddr) {
1304 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1305 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1306 fnhe_flush_routes(fnhe);
1307 kfree_rcu(fnhe, rcu);
1308 break;
1309 }
1310 fnhe_p = &fnhe->fnhe_next;
1311 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1312 lockdep_is_held(&fnhe_lock));
1313 }
1314
1315 spin_unlock_bh(&fnhe_lock);
1316 }
1317
1318 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1319 {
1320 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1321 struct fib_nh_exception *fnhe;
1322 u32 hval;
1323
1324 if (!hash)
1325 return NULL;
1326
1327 hval = fnhe_hashfun(daddr);
1328
1329 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1330 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1331 if (fnhe->fnhe_daddr == daddr) {
1332 if (fnhe->fnhe_expires &&
1333 time_after(jiffies, fnhe->fnhe_expires)) {
1334 ip_del_fnhe(nh, daddr);
1335 break;
1336 }
1337 return fnhe;
1338 }
1339 }
1340 return NULL;
1341 }
1342
1343 /* MTU selection:
1344 * 1. mtu on route is locked - use it
1345 * 2. mtu from nexthop exception
1346 * 3. mtu from egress device
1347 */
1348
1349 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
1350 {
1351 struct fib_info *fi = res->fi;
1352 struct fib_nh *nh = &fi->fib_nh[res->nh_sel];
1353 struct net_device *dev = nh->nh_dev;
1354 u32 mtu = 0;
1355
1356 if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
1357 fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
1358 mtu = fi->fib_mtu;
1359
1360 if (likely(!mtu)) {
1361 struct fib_nh_exception *fnhe;
1362
1363 fnhe = find_exception(nh, daddr);
1364 if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
1365 mtu = fnhe->fnhe_pmtu;
1366 }
1367
1368 if (likely(!mtu))
1369 mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
1370
1371 return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu);
1372 }
1373
1374 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1375 __be32 daddr, const bool do_cache)
1376 {
1377 bool ret = false;
1378
1379 spin_lock_bh(&fnhe_lock);
1380
1381 if (daddr == fnhe->fnhe_daddr) {
1382 struct rtable __rcu **porig;
1383 struct rtable *orig;
1384 int genid = fnhe_genid(dev_net(rt->dst.dev));
1385
1386 if (rt_is_input_route(rt))
1387 porig = &fnhe->fnhe_rth_input;
1388 else
1389 porig = &fnhe->fnhe_rth_output;
1390 orig = rcu_dereference(*porig);
1391
1392 if (fnhe->fnhe_genid != genid) {
1393 fnhe->fnhe_genid = genid;
1394 fnhe->fnhe_gw = 0;
1395 fnhe->fnhe_pmtu = 0;
1396 fnhe->fnhe_expires = 0;
1397 fnhe->fnhe_mtu_locked = false;
1398 fnhe_flush_routes(fnhe);
1399 orig = NULL;
1400 }
1401 fill_route_from_fnhe(rt, fnhe);
1402 if (!rt->rt_gateway)
1403 rt->rt_gateway = daddr;
1404
1405 if (do_cache) {
1406 dst_hold(&rt->dst);
1407 rcu_assign_pointer(*porig, rt);
1408 if (orig) {
1409 dst_dev_put(&orig->dst);
1410 dst_release(&orig->dst);
1411 }
1412 ret = true;
1413 }
1414
1415 fnhe->fnhe_stamp = jiffies;
1416 }
1417 spin_unlock_bh(&fnhe_lock);
1418
1419 return ret;
1420 }
1421
1422 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1423 {
1424 struct rtable *orig, *prev, **p;
1425 bool ret = true;
1426
1427 if (rt_is_input_route(rt)) {
1428 p = (struct rtable **)&nh->nh_rth_input;
1429 } else {
1430 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1431 }
1432 orig = *p;
1433
1434 /* hold dst before doing cmpxchg() to avoid race condition
1435 * on this dst
1436 */
1437 dst_hold(&rt->dst);
1438 prev = cmpxchg(p, orig, rt);
1439 if (prev == orig) {
1440 if (orig) {
1441 dst_dev_put(&orig->dst);
1442 dst_release(&orig->dst);
1443 }
1444 } else {
1445 dst_release(&rt->dst);
1446 ret = false;
1447 }
1448
1449 return ret;
1450 }
1451
1452 struct uncached_list {
1453 spinlock_t lock;
1454 struct list_head head;
1455 };
1456
1457 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1458
1459 void rt_add_uncached_list(struct rtable *rt)
1460 {
1461 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1462
1463 rt->rt_uncached_list = ul;
1464
1465 spin_lock_bh(&ul->lock);
1466 list_add_tail(&rt->rt_uncached, &ul->head);
1467 spin_unlock_bh(&ul->lock);
1468 }
1469
1470 void rt_del_uncached_list(struct rtable *rt)
1471 {
1472 if (!list_empty(&rt->rt_uncached)) {
1473 struct uncached_list *ul = rt->rt_uncached_list;
1474
1475 spin_lock_bh(&ul->lock);
1476 list_del(&rt->rt_uncached);
1477 spin_unlock_bh(&ul->lock);
1478 }
1479 }
1480
1481 static void ipv4_dst_destroy(struct dst_entry *dst)
1482 {
1483 struct rtable *rt = (struct rtable *)dst;
1484
1485 ip_dst_metrics_put(dst);
1486 rt_del_uncached_list(rt);
1487 }
1488
1489 void rt_flush_dev(struct net_device *dev)
1490 {
1491 struct net *net = dev_net(dev);
1492 struct rtable *rt;
1493 int cpu;
1494
1495 for_each_possible_cpu(cpu) {
1496 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1497
1498 spin_lock_bh(&ul->lock);
1499 list_for_each_entry(rt, &ul->head, rt_uncached) {
1500 if (rt->dst.dev != dev)
1501 continue;
1502 rt->dst.dev = net->loopback_dev;
1503 dev_hold(rt->dst.dev);
1504 dev_put(dev);
1505 }
1506 spin_unlock_bh(&ul->lock);
1507 }
1508 }
1509
1510 static bool rt_cache_valid(const struct rtable *rt)
1511 {
1512 return rt &&
1513 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1514 !rt_is_expired(rt);
1515 }
1516
1517 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1518 const struct fib_result *res,
1519 struct fib_nh_exception *fnhe,
1520 struct fib_info *fi, u16 type, u32 itag,
1521 const bool do_cache)
1522 {
1523 bool cached = false;
1524
1525 if (fi) {
1526 struct fib_nh *nh = &FIB_RES_NH(*res);
1527
1528 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1529 rt->rt_gateway = nh->nh_gw;
1530 rt->rt_uses_gateway = 1;
1531 }
1532 ip_dst_init_metrics(&rt->dst, fi->fib_metrics);
1533
1534 #ifdef CONFIG_IP_ROUTE_CLASSID
1535 rt->dst.tclassid = nh->nh_tclassid;
1536 #endif
1537 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1538 if (unlikely(fnhe))
1539 cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
1540 else if (do_cache)
1541 cached = rt_cache_route(nh, rt);
1542 if (unlikely(!cached)) {
1543 /* Routes we intend to cache in nexthop exception or
1544 * FIB nexthop have the DST_NOCACHE bit clear.
1545 * However, if we are unsuccessful at storing this
1546 * route into the cache we really need to set it.
1547 */
1548 if (!rt->rt_gateway)
1549 rt->rt_gateway = daddr;
1550 rt_add_uncached_list(rt);
1551 }
1552 } else
1553 rt_add_uncached_list(rt);
1554
1555 #ifdef CONFIG_IP_ROUTE_CLASSID
1556 #ifdef CONFIG_IP_MULTIPLE_TABLES
1557 set_class_tag(rt, res->tclassid);
1558 #endif
1559 set_class_tag(rt, itag);
1560 #endif
1561 }
1562
1563 struct rtable *rt_dst_alloc(struct net_device *dev,
1564 unsigned int flags, u16 type,
1565 bool nopolicy, bool noxfrm, bool will_cache)
1566 {
1567 struct rtable *rt;
1568
1569 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1570 (will_cache ? 0 : DST_HOST) |
1571 (nopolicy ? DST_NOPOLICY : 0) |
1572 (noxfrm ? DST_NOXFRM : 0));
1573
1574 if (rt) {
1575 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1576 rt->rt_flags = flags;
1577 rt->rt_type = type;
1578 rt->rt_is_input = 0;
1579 rt->rt_iif = 0;
1580 rt->rt_pmtu = 0;
1581 rt->rt_mtu_locked = 0;
1582 rt->rt_gateway = 0;
1583 rt->rt_uses_gateway = 0;
1584 INIT_LIST_HEAD(&rt->rt_uncached);
1585
1586 rt->dst.output = ip_output;
1587 if (flags & RTCF_LOCAL)
1588 rt->dst.input = ip_local_deliver;
1589 }
1590
1591 return rt;
1592 }
1593 EXPORT_SYMBOL(rt_dst_alloc);
1594
1595 /* called in rcu_read_lock() section */
1596 int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1597 u8 tos, struct net_device *dev,
1598 struct in_device *in_dev, u32 *itag)
1599 {
1600 int err;
1601
1602 /* Primary sanity checks. */
1603 if (!in_dev)
1604 return -EINVAL;
1605
1606 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1607 skb->protocol != htons(ETH_P_IP))
1608 return -EINVAL;
1609
1610 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1611 return -EINVAL;
1612
1613 if (ipv4_is_zeronet(saddr)) {
1614 if (!ipv4_is_local_multicast(daddr) &&
1615 ip_hdr(skb)->protocol != IPPROTO_IGMP)
1616 return -EINVAL;
1617 } else {
1618 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1619 in_dev, itag);
1620 if (err < 0)
1621 return err;
1622 }
1623 return 0;
1624 }
1625
1626 /* called in rcu_read_lock() section */
1627 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1628 u8 tos, struct net_device *dev, int our)
1629 {
1630 struct in_device *in_dev = __in_dev_get_rcu(dev);
1631 unsigned int flags = RTCF_MULTICAST;
1632 struct rtable *rth;
1633 u32 itag = 0;
1634 int err;
1635
1636 err = ip_mc_validate_source(skb, daddr, saddr, tos, dev, in_dev, &itag);
1637 if (err)
1638 return err;
1639
1640 if (our)
1641 flags |= RTCF_LOCAL;
1642
1643 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1644 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1645 if (!rth)
1646 return -ENOBUFS;
1647
1648 #ifdef CONFIG_IP_ROUTE_CLASSID
1649 rth->dst.tclassid = itag;
1650 #endif
1651 rth->dst.output = ip_rt_bug;
1652 rth->rt_is_input= 1;
1653
1654 #ifdef CONFIG_IP_MROUTE
1655 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1656 rth->dst.input = ip_mr_input;
1657 #endif
1658 RT_CACHE_STAT_INC(in_slow_mc);
1659
1660 skb_dst_set(skb, &rth->dst);
1661 return 0;
1662 }
1663
1664
1665 static void ip_handle_martian_source(struct net_device *dev,
1666 struct in_device *in_dev,
1667 struct sk_buff *skb,
1668 __be32 daddr,
1669 __be32 saddr)
1670 {
1671 RT_CACHE_STAT_INC(in_martian_src);
1672 #ifdef CONFIG_IP_ROUTE_VERBOSE
1673 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1674 /*
1675 * RFC1812 recommendation, if source is martian,
1676 * the only hint is MAC header.
1677 */
1678 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1679 &daddr, &saddr, dev->name);
1680 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1681 print_hex_dump(KERN_WARNING, "ll header: ",
1682 DUMP_PREFIX_OFFSET, 16, 1,
1683 skb_mac_header(skb),
1684 dev->hard_header_len, false);
1685 }
1686 }
1687 #endif
1688 }
1689
1690 /* called in rcu_read_lock() section */
1691 static int __mkroute_input(struct sk_buff *skb,
1692 const struct fib_result *res,
1693 struct in_device *in_dev,
1694 __be32 daddr, __be32 saddr, u32 tos)
1695 {
1696 struct fib_nh_exception *fnhe;
1697 struct rtable *rth;
1698 int err;
1699 struct in_device *out_dev;
1700 bool do_cache;
1701 u32 itag = 0;
1702
1703 /* get a working reference to the output device */
1704 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1705 if (!out_dev) {
1706 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1707 return -EINVAL;
1708 }
1709
1710 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1711 in_dev->dev, in_dev, &itag);
1712 if (err < 0) {
1713 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1714 saddr);
1715
1716 goto cleanup;
1717 }
1718
1719 do_cache = res->fi && !itag;
1720 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1721 skb->protocol == htons(ETH_P_IP) &&
1722 (IN_DEV_SHARED_MEDIA(out_dev) ||
1723 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1724 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1725
1726 if (skb->protocol != htons(ETH_P_IP)) {
1727 /* Not IP (i.e. ARP). Do not create route, if it is
1728 * invalid for proxy arp. DNAT routes are always valid.
1729 *
1730 * Proxy arp feature have been extended to allow, ARP
1731 * replies back to the same interface, to support
1732 * Private VLAN switch technologies. See arp.c.
1733 */
1734 if (out_dev == in_dev &&
1735 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1736 err = -EINVAL;
1737 goto cleanup;
1738 }
1739 }
1740
1741 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1742 if (do_cache) {
1743 if (fnhe)
1744 rth = rcu_dereference(fnhe->fnhe_rth_input);
1745 else
1746 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1747 if (rt_cache_valid(rth)) {
1748 skb_dst_set_noref(skb, &rth->dst);
1749 goto out;
1750 }
1751 }
1752
1753 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1754 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1755 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1756 if (!rth) {
1757 err = -ENOBUFS;
1758 goto cleanup;
1759 }
1760
1761 rth->rt_is_input = 1;
1762 RT_CACHE_STAT_INC(in_slow_tot);
1763
1764 rth->dst.input = ip_forward;
1765
1766 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
1767 do_cache);
1768 lwtunnel_set_redirect(&rth->dst);
1769 skb_dst_set(skb, &rth->dst);
1770 out:
1771 err = 0;
1772 cleanup:
1773 return err;
1774 }
1775
1776 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1777 /* To make ICMP packets follow the right flow, the multipath hash is
1778 * calculated from the inner IP addresses.
1779 */
1780 static void ip_multipath_l3_keys(const struct sk_buff *skb,
1781 struct flow_keys *hash_keys)
1782 {
1783 const struct iphdr *outer_iph = ip_hdr(skb);
1784 const struct iphdr *key_iph = outer_iph;
1785 const struct iphdr *inner_iph;
1786 const struct icmphdr *icmph;
1787 struct iphdr _inner_iph;
1788 struct icmphdr _icmph;
1789
1790 if (likely(outer_iph->protocol != IPPROTO_ICMP))
1791 goto out;
1792
1793 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1794 goto out;
1795
1796 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1797 &_icmph);
1798 if (!icmph)
1799 goto out;
1800
1801 if (icmph->type != ICMP_DEST_UNREACH &&
1802 icmph->type != ICMP_REDIRECT &&
1803 icmph->type != ICMP_TIME_EXCEEDED &&
1804 icmph->type != ICMP_PARAMETERPROB)
1805 goto out;
1806
1807 inner_iph = skb_header_pointer(skb,
1808 outer_iph->ihl * 4 + sizeof(_icmph),
1809 sizeof(_inner_iph), &_inner_iph);
1810 if (!inner_iph)
1811 goto out;
1812
1813 key_iph = inner_iph;
1814 out:
1815 hash_keys->addrs.v4addrs.src = key_iph->saddr;
1816 hash_keys->addrs.v4addrs.dst = key_iph->daddr;
1817 }
1818
1819 /* if skb is set it will be used and fl4 can be NULL */
1820 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
1821 const struct sk_buff *skb, struct flow_keys *flkeys)
1822 {
1823 struct flow_keys hash_keys;
1824 u32 mhash;
1825
1826 switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
1827 case 0:
1828 memset(&hash_keys, 0, sizeof(hash_keys));
1829 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1830 if (skb) {
1831 ip_multipath_l3_keys(skb, &hash_keys);
1832 } else {
1833 hash_keys.addrs.v4addrs.src = fl4->saddr;
1834 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1835 }
1836 break;
1837 case 1:
1838 /* skb is currently provided only when forwarding */
1839 if (skb) {
1840 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
1841 struct flow_keys keys;
1842
1843 /* short-circuit if we already have L4 hash present */
1844 if (skb->l4_hash)
1845 return skb_get_hash_raw(skb) >> 1;
1846
1847 memset(&hash_keys, 0, sizeof(hash_keys));
1848
1849 if (!flkeys) {
1850 skb_flow_dissect_flow_keys(skb, &keys, flag);
1851 flkeys = &keys;
1852 }
1853
1854 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1855 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
1856 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
1857 hash_keys.ports.src = flkeys->ports.src;
1858 hash_keys.ports.dst = flkeys->ports.dst;
1859 hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
1860 } else {
1861 memset(&hash_keys, 0, sizeof(hash_keys));
1862 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1863 hash_keys.addrs.v4addrs.src = fl4->saddr;
1864 hash_keys.addrs.v4addrs.dst = fl4->daddr;
1865 hash_keys.ports.src = fl4->fl4_sport;
1866 hash_keys.ports.dst = fl4->fl4_dport;
1867 hash_keys.basic.ip_proto = fl4->flowi4_proto;
1868 }
1869 break;
1870 }
1871 mhash = flow_hash_from_keys(&hash_keys);
1872
1873 return mhash >> 1;
1874 }
1875 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1876
1877 static int ip_mkroute_input(struct sk_buff *skb,
1878 struct fib_result *res,
1879 struct in_device *in_dev,
1880 __be32 daddr, __be32 saddr, u32 tos,
1881 struct flow_keys *hkeys)
1882 {
1883 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1884 if (res->fi && res->fi->fib_nhs > 1) {
1885 int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
1886
1887 fib_select_multipath(res, h);
1888 }
1889 #endif
1890
1891 /* create a routing cache entry */
1892 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1893 }
1894
1895 /*
1896 * NOTE. We drop all the packets that has local source
1897 * addresses, because every properly looped back packet
1898 * must have correct destination already attached by output routine.
1899 *
1900 * Such approach solves two big problems:
1901 * 1. Not simplex devices are handled properly.
1902 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1903 * called with rcu_read_lock()
1904 */
1905
1906 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1907 u8 tos, struct net_device *dev,
1908 struct fib_result *res)
1909 {
1910 struct in_device *in_dev = __in_dev_get_rcu(dev);
1911 struct flow_keys *flkeys = NULL, _flkeys;
1912 struct net *net = dev_net(dev);
1913 struct ip_tunnel_info *tun_info;
1914 int err = -EINVAL;
1915 unsigned int flags = 0;
1916 u32 itag = 0;
1917 struct rtable *rth;
1918 struct flowi4 fl4;
1919 bool do_cache;
1920
1921 /* IP on this device is disabled. */
1922
1923 if (!in_dev)
1924 goto out;
1925
1926 /* Check for the most weird martians, which can be not detected
1927 by fib_lookup.
1928 */
1929
1930 tun_info = skb_tunnel_info(skb);
1931 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1932 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1933 else
1934 fl4.flowi4_tun_key.tun_id = 0;
1935 skb_dst_drop(skb);
1936
1937 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1938 goto martian_source;
1939
1940 res->fi = NULL;
1941 res->table = NULL;
1942 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1943 goto brd_input;
1944
1945 /* Accept zero addresses only to limited broadcast;
1946 * I even do not know to fix it or not. Waiting for complains :-)
1947 */
1948 if (ipv4_is_zeronet(saddr))
1949 goto martian_source;
1950
1951 if (ipv4_is_zeronet(daddr))
1952 goto martian_destination;
1953
1954 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1955 * and call it once if daddr or/and saddr are loopback addresses
1956 */
1957 if (ipv4_is_loopback(daddr)) {
1958 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1959 goto martian_destination;
1960 } else if (ipv4_is_loopback(saddr)) {
1961 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1962 goto martian_source;
1963 }
1964
1965 /*
1966 * Now we are ready to route packet.
1967 */
1968 fl4.flowi4_oif = 0;
1969 fl4.flowi4_iif = dev->ifindex;
1970 fl4.flowi4_mark = skb->mark;
1971 fl4.flowi4_tos = tos;
1972 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1973 fl4.flowi4_flags = 0;
1974 fl4.daddr = daddr;
1975 fl4.saddr = saddr;
1976 fl4.flowi4_uid = sock_net_uid(net, NULL);
1977
1978 if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) {
1979 flkeys = &_flkeys;
1980 } else {
1981 fl4.flowi4_proto = 0;
1982 fl4.fl4_sport = 0;
1983 fl4.fl4_dport = 0;
1984 }
1985
1986 err = fib_lookup(net, &fl4, res, 0);
1987 if (err != 0) {
1988 if (!IN_DEV_FORWARD(in_dev))
1989 err = -EHOSTUNREACH;
1990 goto no_route;
1991 }
1992
1993 if (res->type == RTN_BROADCAST) {
1994 if (IN_DEV_BFORWARD(in_dev))
1995 goto make_route;
1996 goto brd_input;
1997 }
1998
1999 if (res->type == RTN_LOCAL) {
2000 err = fib_validate_source(skb, saddr, daddr, tos,
2001 0, dev, in_dev, &itag);
2002 if (err < 0)
2003 goto martian_source;
2004 goto local_input;
2005 }
2006
2007 if (!IN_DEV_FORWARD(in_dev)) {
2008 err = -EHOSTUNREACH;
2009 goto no_route;
2010 }
2011 if (res->type != RTN_UNICAST)
2012 goto martian_destination;
2013
2014 make_route:
2015 err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
2016 out: return err;
2017
2018 brd_input:
2019 if (skb->protocol != htons(ETH_P_IP))
2020 goto e_inval;
2021
2022 if (!ipv4_is_zeronet(saddr)) {
2023 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
2024 in_dev, &itag);
2025 if (err < 0)
2026 goto martian_source;
2027 }
2028 flags |= RTCF_BROADCAST;
2029 res->type = RTN_BROADCAST;
2030 RT_CACHE_STAT_INC(in_brd);
2031
2032 local_input:
2033 do_cache = false;
2034 if (res->fi) {
2035 if (!itag) {
2036 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
2037 if (rt_cache_valid(rth)) {
2038 skb_dst_set_noref(skb, &rth->dst);
2039 err = 0;
2040 goto out;
2041 }
2042 do_cache = true;
2043 }
2044 }
2045
2046 rth = rt_dst_alloc(l3mdev_master_dev_rcu(dev) ? : net->loopback_dev,
2047 flags | RTCF_LOCAL, res->type,
2048 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
2049 if (!rth)
2050 goto e_nobufs;
2051
2052 rth->dst.output= ip_rt_bug;
2053 #ifdef CONFIG_IP_ROUTE_CLASSID
2054 rth->dst.tclassid = itag;
2055 #endif
2056 rth->rt_is_input = 1;
2057
2058 RT_CACHE_STAT_INC(in_slow_tot);
2059 if (res->type == RTN_UNREACHABLE) {
2060 rth->dst.input= ip_error;
2061 rth->dst.error= -err;
2062 rth->rt_flags &= ~RTCF_LOCAL;
2063 }
2064
2065 if (do_cache) {
2066 struct fib_nh *nh = &FIB_RES_NH(*res);
2067
2068 rth->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
2069 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
2070 WARN_ON(rth->dst.input == lwtunnel_input);
2071 rth->dst.lwtstate->orig_input = rth->dst.input;
2072 rth->dst.input = lwtunnel_input;
2073 }
2074
2075 if (unlikely(!rt_cache_route(nh, rth)))
2076 rt_add_uncached_list(rth);
2077 }
2078 skb_dst_set(skb, &rth->dst);
2079 err = 0;
2080 goto out;
2081
2082 no_route:
2083 RT_CACHE_STAT_INC(in_no_route);
2084 res->type = RTN_UNREACHABLE;
2085 res->fi = NULL;
2086 res->table = NULL;
2087 goto local_input;
2088
2089 /*
2090 * Do not cache martian addresses: they should be logged (RFC1812)
2091 */
2092 martian_destination:
2093 RT_CACHE_STAT_INC(in_martian_dst);
2094 #ifdef CONFIG_IP_ROUTE_VERBOSE
2095 if (IN_DEV_LOG_MARTIANS(in_dev))
2096 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
2097 &daddr, &saddr, dev->name);
2098 #endif
2099
2100 e_inval:
2101 err = -EINVAL;
2102 goto out;
2103
2104 e_nobufs:
2105 err = -ENOBUFS;
2106 goto out;
2107
2108 martian_source:
2109 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2110 goto out;
2111 }
2112
2113 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2114 u8 tos, struct net_device *dev)
2115 {
2116 struct fib_result res;
2117 int err;
2118
2119 tos &= IPTOS_RT_MASK;
2120 rcu_read_lock();
2121 err = ip_route_input_rcu(skb, daddr, saddr, tos, dev, &res);
2122 rcu_read_unlock();
2123
2124 return err;
2125 }
2126 EXPORT_SYMBOL(ip_route_input_noref);
2127
2128 /* called with rcu_read_lock held */
2129 int ip_route_input_rcu(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2130 u8 tos, struct net_device *dev, struct fib_result *res)
2131 {
2132 /* Multicast recognition logic is moved from route cache to here.
2133 The problem was that too many Ethernet cards have broken/missing
2134 hardware multicast filters :-( As result the host on multicasting
2135 network acquires a lot of useless route cache entries, sort of
2136 SDR messages from all the world. Now we try to get rid of them.
2137 Really, provided software IP multicast filter is organized
2138 reasonably (at least, hashed), it does not result in a slowdown
2139 comparing with route cache reject entries.
2140 Note, that multicast routers are not affected, because
2141 route cache entry is created eventually.
2142 */
2143 if (ipv4_is_multicast(daddr)) {
2144 struct in_device *in_dev = __in_dev_get_rcu(dev);
2145 int our = 0;
2146 int err = -EINVAL;
2147
2148 if (in_dev)
2149 our = ip_check_mc_rcu(in_dev, daddr, saddr,
2150 ip_hdr(skb)->protocol);
2151
2152 /* check l3 master if no match yet */
2153 if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
2154 struct in_device *l3_in_dev;
2155
2156 l3_in_dev = __in_dev_get_rcu(skb->dev);
2157 if (l3_in_dev)
2158 our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
2159 ip_hdr(skb)->protocol);
2160 }
2161
2162 if (our
2163 #ifdef CONFIG_IP_MROUTE
2164 ||
2165 (!ipv4_is_local_multicast(daddr) &&
2166 IN_DEV_MFORWARD(in_dev))
2167 #endif
2168 ) {
2169 err = ip_route_input_mc(skb, daddr, saddr,
2170 tos, dev, our);
2171 }
2172 return err;
2173 }
2174
2175 return ip_route_input_slow(skb, daddr, saddr, tos, dev, res);
2176 }
2177
2178 /* called with rcu_read_lock() */
2179 static struct rtable *__mkroute_output(const struct fib_result *res,
2180 const struct flowi4 *fl4, int orig_oif,
2181 struct net_device *dev_out,
2182 unsigned int flags)
2183 {
2184 struct fib_info *fi = res->fi;
2185 struct fib_nh_exception *fnhe;
2186 struct in_device *in_dev;
2187 u16 type = res->type;
2188 struct rtable *rth;
2189 bool do_cache;
2190
2191 in_dev = __in_dev_get_rcu(dev_out);
2192 if (!in_dev)
2193 return ERR_PTR(-EINVAL);
2194
2195 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2196 if (ipv4_is_loopback(fl4->saddr) &&
2197 !(dev_out->flags & IFF_LOOPBACK) &&
2198 !netif_is_l3_master(dev_out))
2199 return ERR_PTR(-EINVAL);
2200
2201 if (ipv4_is_lbcast(fl4->daddr))
2202 type = RTN_BROADCAST;
2203 else if (ipv4_is_multicast(fl4->daddr))
2204 type = RTN_MULTICAST;
2205 else if (ipv4_is_zeronet(fl4->daddr))
2206 return ERR_PTR(-EINVAL);
2207
2208 if (dev_out->flags & IFF_LOOPBACK)
2209 flags |= RTCF_LOCAL;
2210
2211 do_cache = true;
2212 if (type == RTN_BROADCAST) {
2213 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2214 fi = NULL;
2215 } else if (type == RTN_MULTICAST) {
2216 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2217 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2218 fl4->flowi4_proto))
2219 flags &= ~RTCF_LOCAL;
2220 else
2221 do_cache = false;
2222 /* If multicast route do not exist use
2223 * default one, but do not gateway in this case.
2224 * Yes, it is hack.
2225 */
2226 if (fi && res->prefixlen < 4)
2227 fi = NULL;
2228 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2229 (orig_oif != dev_out->ifindex)) {
2230 /* For local routes that require a particular output interface
2231 * we do not want to cache the result. Caching the result
2232 * causes incorrect behaviour when there are multiple source
2233 * addresses on the interface, the end result being that if the
2234 * intended recipient is waiting on that interface for the
2235 * packet he won't receive it because it will be delivered on
2236 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2237 * be set to the loopback interface as well.
2238 */
2239 do_cache = false;
2240 }
2241
2242 fnhe = NULL;
2243 do_cache &= fi != NULL;
2244 if (fi) {
2245 struct rtable __rcu **prth;
2246 struct fib_nh *nh = &FIB_RES_NH(*res);
2247
2248 fnhe = find_exception(nh, fl4->daddr);
2249 if (!do_cache)
2250 goto add;
2251 if (fnhe) {
2252 prth = &fnhe->fnhe_rth_output;
2253 } else {
2254 if (unlikely(fl4->flowi4_flags &
2255 FLOWI_FLAG_KNOWN_NH &&
2256 !(nh->nh_gw &&
2257 nh->nh_scope == RT_SCOPE_LINK))) {
2258 do_cache = false;
2259 goto add;
2260 }
2261 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2262 }
2263 rth = rcu_dereference(*prth);
2264 if (rt_cache_valid(rth) && dst_hold_safe(&rth->dst))
2265 return rth;
2266 }
2267
2268 add:
2269 rth = rt_dst_alloc(dev_out, flags, type,
2270 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2271 IN_DEV_CONF_GET(in_dev, NOXFRM),
2272 do_cache);
2273 if (!rth)
2274 return ERR_PTR(-ENOBUFS);
2275
2276 rth->rt_iif = orig_oif;
2277
2278 RT_CACHE_STAT_INC(out_slow_tot);
2279
2280 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2281 if (flags & RTCF_LOCAL &&
2282 !(dev_out->flags & IFF_LOOPBACK)) {
2283 rth->dst.output = ip_mc_output;
2284 RT_CACHE_STAT_INC(out_slow_mc);
2285 }
2286 #ifdef CONFIG_IP_MROUTE
2287 if (type == RTN_MULTICAST) {
2288 if (IN_DEV_MFORWARD(in_dev) &&
2289 !ipv4_is_local_multicast(fl4->daddr)) {
2290 rth->dst.input = ip_mr_input;
2291 rth->dst.output = ip_mc_output;
2292 }
2293 }
2294 #endif
2295 }
2296
2297 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
2298 lwtunnel_set_redirect(&rth->dst);
2299
2300 return rth;
2301 }
2302
2303 /*
2304 * Major route resolver routine.
2305 */
2306
2307 struct rtable *ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2308 const struct sk_buff *skb)
2309 {
2310 __u8 tos = RT_FL_TOS(fl4);
2311 struct fib_result res = {
2312 .type = RTN_UNSPEC,
2313 .fi = NULL,
2314 .table = NULL,
2315 .tclassid = 0,
2316 };
2317 struct rtable *rth;
2318
2319 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2320 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2321 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2322 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2323
2324 rcu_read_lock();
2325 rth = ip_route_output_key_hash_rcu(net, fl4, &res, skb);
2326 rcu_read_unlock();
2327
2328 return rth;
2329 }
2330 EXPORT_SYMBOL_GPL(ip_route_output_key_hash);
2331
2332 struct rtable *ip_route_output_key_hash_rcu(struct net *net, struct flowi4 *fl4,
2333 struct fib_result *res,
2334 const struct sk_buff *skb)
2335 {
2336 struct net_device *dev_out = NULL;
2337 int orig_oif = fl4->flowi4_oif;
2338 unsigned int flags = 0;
2339 struct rtable *rth;
2340 int err = -ENETUNREACH;
2341
2342 if (fl4->saddr) {
2343 rth = ERR_PTR(-EINVAL);
2344 if (ipv4_is_multicast(fl4->saddr) ||
2345 ipv4_is_lbcast(fl4->saddr) ||
2346 ipv4_is_zeronet(fl4->saddr))
2347 goto out;
2348
2349 /* I removed check for oif == dev_out->oif here.
2350 It was wrong for two reasons:
2351 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2352 is assigned to multiple interfaces.
2353 2. Moreover, we are allowed to send packets with saddr
2354 of another iface. --ANK
2355 */
2356
2357 if (fl4->flowi4_oif == 0 &&
2358 (ipv4_is_multicast(fl4->daddr) ||
2359 ipv4_is_lbcast(fl4->daddr))) {
2360 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2361 dev_out = __ip_dev_find(net, fl4->saddr, false);
2362 if (!dev_out)
2363 goto out;
2364
2365 /* Special hack: user can direct multicasts
2366 and limited broadcast via necessary interface
2367 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2368 This hack is not just for fun, it allows
2369 vic,vat and friends to work.
2370 They bind socket to loopback, set ttl to zero
2371 and expect that it will work.
2372 From the viewpoint of routing cache they are broken,
2373 because we are not allowed to build multicast path
2374 with loopback source addr (look, routing cache
2375 cannot know, that ttl is zero, so that packet
2376 will not leave this host and route is valid).
2377 Luckily, this hack is good workaround.
2378 */
2379
2380 fl4->flowi4_oif = dev_out->ifindex;
2381 goto make_route;
2382 }
2383
2384 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2385 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2386 if (!__ip_dev_find(net, fl4->saddr, false))
2387 goto out;
2388 }
2389 }
2390
2391
2392 if (fl4->flowi4_oif) {
2393 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2394 rth = ERR_PTR(-ENODEV);
2395 if (!dev_out)
2396 goto out;
2397
2398 /* RACE: Check return value of inet_select_addr instead. */
2399 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2400 rth = ERR_PTR(-ENETUNREACH);
2401 goto out;
2402 }
2403 if (ipv4_is_local_multicast(fl4->daddr) ||
2404 ipv4_is_lbcast(fl4->daddr) ||
2405 fl4->flowi4_proto == IPPROTO_IGMP) {
2406 if (!fl4->saddr)
2407 fl4->saddr = inet_select_addr(dev_out, 0,
2408 RT_SCOPE_LINK);
2409 goto make_route;
2410 }
2411 if (!fl4->saddr) {
2412 if (ipv4_is_multicast(fl4->daddr))
2413 fl4->saddr = inet_select_addr(dev_out, 0,
2414 fl4->flowi4_scope);
2415 else if (!fl4->daddr)
2416 fl4->saddr = inet_select_addr(dev_out, 0,
2417 RT_SCOPE_HOST);
2418 }
2419 }
2420
2421 if (!fl4->daddr) {
2422 fl4->daddr = fl4->saddr;
2423 if (!fl4->daddr)
2424 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2425 dev_out = net->loopback_dev;
2426 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2427 res->type = RTN_LOCAL;
2428 flags |= RTCF_LOCAL;
2429 goto make_route;
2430 }
2431
2432 err = fib_lookup(net, fl4, res, 0);
2433 if (err) {
2434 res->fi = NULL;
2435 res->table = NULL;
2436 if (fl4->flowi4_oif &&
2437 (ipv4_is_multicast(fl4->daddr) ||
2438 !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
2439 /* Apparently, routing tables are wrong. Assume,
2440 that the destination is on link.
2441
2442 WHY? DW.
2443 Because we are allowed to send to iface
2444 even if it has NO routes and NO assigned
2445 addresses. When oif is specified, routing
2446 tables are looked up with only one purpose:
2447 to catch if destination is gatewayed, rather than
2448 direct. Moreover, if MSG_DONTROUTE is set,
2449 we send packet, ignoring both routing tables
2450 and ifaddr state. --ANK
2451
2452
2453 We could make it even if oif is unknown,
2454 likely IPv6, but we do not.
2455 */
2456
2457 if (fl4->saddr == 0)
2458 fl4->saddr = inet_select_addr(dev_out, 0,
2459 RT_SCOPE_LINK);
2460 res->type = RTN_UNICAST;
2461 goto make_route;
2462 }
2463 rth = ERR_PTR(err);
2464 goto out;
2465 }
2466
2467 if (res->type == RTN_LOCAL) {
2468 if (!fl4->saddr) {
2469 if (res->fi->fib_prefsrc)
2470 fl4->saddr = res->fi->fib_prefsrc;
2471 else
2472 fl4->saddr = fl4->daddr;
2473 }
2474
2475 /* L3 master device is the loopback for that domain */
2476 dev_out = l3mdev_master_dev_rcu(FIB_RES_DEV(*res)) ? :
2477 net->loopback_dev;
2478
2479 /* make sure orig_oif points to fib result device even
2480 * though packet rx/tx happens over loopback or l3mdev
2481 */
2482 orig_oif = FIB_RES_OIF(*res);
2483
2484 fl4->flowi4_oif = dev_out->ifindex;
2485 flags |= RTCF_LOCAL;
2486 goto make_route;
2487 }
2488
2489 fib_select_path(net, res, fl4, skb);
2490
2491 dev_out = FIB_RES_DEV(*res);
2492 fl4->flowi4_oif = dev_out->ifindex;
2493
2494
2495 make_route:
2496 rth = __mkroute_output(res, fl4, orig_oif, dev_out, flags);
2497
2498 out:
2499 return rth;
2500 }
2501
2502 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2503 {
2504 return NULL;
2505 }
2506
2507 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2508 {
2509 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2510
2511 return mtu ? : dst->dev->mtu;
2512 }
2513
2514 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2515 struct sk_buff *skb, u32 mtu)
2516 {
2517 }
2518
2519 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2520 struct sk_buff *skb)
2521 {
2522 }
2523
2524 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2525 unsigned long old)
2526 {
2527 return NULL;
2528 }
2529
2530 static struct dst_ops ipv4_dst_blackhole_ops = {
2531 .family = AF_INET,
2532 .check = ipv4_blackhole_dst_check,
2533 .mtu = ipv4_blackhole_mtu,
2534 .default_advmss = ipv4_default_advmss,
2535 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2536 .redirect = ipv4_rt_blackhole_redirect,
2537 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2538 .neigh_lookup = ipv4_neigh_lookup,
2539 };
2540
2541 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2542 {
2543 struct rtable *ort = (struct rtable *) dst_orig;
2544 struct rtable *rt;
2545
2546 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
2547 if (rt) {
2548 struct dst_entry *new = &rt->dst;
2549
2550 new->__use = 1;
2551 new->input = dst_discard;
2552 new->output = dst_discard_out;
2553
2554 new->dev = net->loopback_dev;
2555 if (new->dev)
2556 dev_hold(new->dev);
2557
2558 rt->rt_is_input = ort->rt_is_input;
2559 rt->rt_iif = ort->rt_iif;
2560 rt->rt_pmtu = ort->rt_pmtu;
2561 rt->rt_mtu_locked = ort->rt_mtu_locked;
2562
2563 rt->rt_genid = rt_genid_ipv4(net);
2564 rt->rt_flags = ort->rt_flags;
2565 rt->rt_type = ort->rt_type;
2566 rt->rt_gateway = ort->rt_gateway;
2567 rt->rt_uses_gateway = ort->rt_uses_gateway;
2568
2569 INIT_LIST_HEAD(&rt->rt_uncached);
2570 }
2571
2572 dst_release(dst_orig);
2573
2574 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2575 }
2576
2577 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2578 const struct sock *sk)
2579 {
2580 struct rtable *rt = __ip_route_output_key(net, flp4);
2581
2582 if (IS_ERR(rt))
2583 return rt;
2584
2585 if (flp4->flowi4_proto)
2586 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2587 flowi4_to_flowi(flp4),
2588 sk, 0);
2589
2590 return rt;
2591 }
2592 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2593
2594 /* called with rcu_read_lock held */
2595 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2596 struct rtable *rt, u32 table_id, struct flowi4 *fl4,
2597 struct sk_buff *skb, u32 portid, u32 seq)
2598 {
2599 struct rtmsg *r;
2600 struct nlmsghdr *nlh;
2601 unsigned long expires = 0;
2602 u32 error;
2603 u32 metrics[RTAX_MAX];
2604
2605 nlh = nlmsg_put(skb, portid, seq, RTM_NEWROUTE, sizeof(*r), 0);
2606 if (!nlh)
2607 return -EMSGSIZE;
2608
2609 r = nlmsg_data(nlh);
2610 r->rtm_family = AF_INET;
2611 r->rtm_dst_len = 32;
2612 r->rtm_src_len = 0;
2613 r->rtm_tos = fl4->flowi4_tos;
2614 r->rtm_table = table_id < 256 ? table_id : RT_TABLE_COMPAT;
2615 if (nla_put_u32(skb, RTA_TABLE, table_id))
2616 goto nla_put_failure;
2617 r->rtm_type = rt->rt_type;
2618 r->rtm_scope = RT_SCOPE_UNIVERSE;
2619 r->rtm_protocol = RTPROT_UNSPEC;
2620 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2621 if (rt->rt_flags & RTCF_NOTIFY)
2622 r->rtm_flags |= RTM_F_NOTIFY;
2623 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2624 r->rtm_flags |= RTCF_DOREDIRECT;
2625
2626 if (nla_put_in_addr(skb, RTA_DST, dst))
2627 goto nla_put_failure;
2628 if (src) {
2629 r->rtm_src_len = 32;
2630 if (nla_put_in_addr(skb, RTA_SRC, src))
2631 goto nla_put_failure;
2632 }
2633 if (rt->dst.dev &&
2634 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2635 goto nla_put_failure;
2636 #ifdef CONFIG_IP_ROUTE_CLASSID
2637 if (rt->dst.tclassid &&
2638 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2639 goto nla_put_failure;
2640 #endif
2641 if (!rt_is_input_route(rt) &&
2642 fl4->saddr != src) {
2643 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2644 goto nla_put_failure;
2645 }
2646 if (rt->rt_uses_gateway &&
2647 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2648 goto nla_put_failure;
2649
2650 expires = rt->dst.expires;
2651 if (expires) {
2652 unsigned long now = jiffies;
2653
2654 if (time_before(now, expires))
2655 expires -= now;
2656 else
2657 expires = 0;
2658 }
2659
2660 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2661 if (rt->rt_pmtu && expires)
2662 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2663 if (rt->rt_mtu_locked && expires)
2664 metrics[RTAX_LOCK - 1] |= BIT(RTAX_MTU);
2665 if (rtnetlink_put_metrics(skb, metrics) < 0)
2666 goto nla_put_failure;
2667
2668 if (fl4->flowi4_mark &&
2669 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2670 goto nla_put_failure;
2671
2672 if (!uid_eq(fl4->flowi4_uid, INVALID_UID) &&
2673 nla_put_u32(skb, RTA_UID,
2674 from_kuid_munged(current_user_ns(), fl4->flowi4_uid)))
2675 goto nla_put_failure;
2676
2677 error = rt->dst.error;
2678
2679 if (rt_is_input_route(rt)) {
2680 #ifdef CONFIG_IP_MROUTE
2681 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2682 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2683 int err = ipmr_get_route(net, skb,
2684 fl4->saddr, fl4->daddr,
2685 r, portid);
2686
2687 if (err <= 0) {
2688 if (err == 0)
2689 return 0;
2690 goto nla_put_failure;
2691 }
2692 } else
2693 #endif
2694 if (nla_put_u32(skb, RTA_IIF, fl4->flowi4_iif))
2695 goto nla_put_failure;
2696 }
2697
2698 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2699 goto nla_put_failure;
2700
2701 nlmsg_end(skb, nlh);
2702 return 0;
2703
2704 nla_put_failure:
2705 nlmsg_cancel(skb, nlh);
2706 return -EMSGSIZE;
2707 }
2708
2709 static struct sk_buff *inet_rtm_getroute_build_skb(__be32 src, __be32 dst,
2710 u8 ip_proto, __be16 sport,
2711 __be16 dport)
2712 {
2713 struct sk_buff *skb;
2714 struct iphdr *iph;
2715
2716 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2717 if (!skb)
2718 return NULL;
2719
2720 /* Reserve room for dummy headers, this skb can pass
2721 * through good chunk of routing engine.
2722 */
2723 skb_reset_mac_header(skb);
2724 skb_reset_network_header(skb);
2725 skb->protocol = htons(ETH_P_IP);
2726 iph = skb_put(skb, sizeof(struct iphdr));
2727 iph->protocol = ip_proto;
2728 iph->saddr = src;
2729 iph->daddr = dst;
2730 iph->version = 0x4;
2731 iph->frag_off = 0;
2732 iph->ihl = 0x5;
2733 skb_set_transport_header(skb, skb->len);
2734
2735 switch (iph->protocol) {
2736 case IPPROTO_UDP: {
2737 struct udphdr *udph;
2738
2739 udph = skb_put_zero(skb, sizeof(struct udphdr));
2740 udph->source = sport;
2741 udph->dest = dport;
2742 udph->len = sizeof(struct udphdr);
2743 udph->check = 0;
2744 break;
2745 }
2746 case IPPROTO_TCP: {
2747 struct tcphdr *tcph;
2748
2749 tcph = skb_put_zero(skb, sizeof(struct tcphdr));
2750 tcph->source = sport;
2751 tcph->dest = dport;
2752 tcph->doff = sizeof(struct tcphdr) / 4;
2753 tcph->rst = 1;
2754 tcph->check = ~tcp_v4_check(sizeof(struct tcphdr),
2755 src, dst, 0);
2756 break;
2757 }
2758 case IPPROTO_ICMP: {
2759 struct icmphdr *icmph;
2760
2761 icmph = skb_put_zero(skb, sizeof(struct icmphdr));
2762 icmph->type = ICMP_ECHO;
2763 icmph->code = 0;
2764 }
2765 }
2766
2767 return skb;
2768 }
2769
2770 static int inet_rtm_valid_getroute_req(struct sk_buff *skb,
2771 const struct nlmsghdr *nlh,
2772 struct nlattr **tb,
2773 struct netlink_ext_ack *extack)
2774 {
2775 struct rtmsg *rtm;
2776 int i, err;
2777
2778 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2779 NL_SET_ERR_MSG(extack,
2780 "ipv4: Invalid header for route get request");
2781 return -EINVAL;
2782 }
2783
2784 if (!netlink_strict_get_check(skb))
2785 return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2786 rtm_ipv4_policy, extack);
2787
2788 rtm = nlmsg_data(nlh);
2789 if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2790 (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2791 rtm->rtm_table || rtm->rtm_protocol ||
2792 rtm->rtm_scope || rtm->rtm_type) {
2793 NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for route get request");
2794 return -EINVAL;
2795 }
2796
2797 if (rtm->rtm_flags & ~(RTM_F_NOTIFY |
2798 RTM_F_LOOKUP_TABLE |
2799 RTM_F_FIB_MATCH)) {
2800 NL_SET_ERR_MSG(extack, "ipv4: Unsupported rtm_flags for route get request");
2801 return -EINVAL;
2802 }
2803
2804 err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2805 rtm_ipv4_policy, extack);
2806 if (err)
2807 return err;
2808
2809 if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2810 (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2811 NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2812 return -EINVAL;
2813 }
2814
2815 for (i = 0; i <= RTA_MAX; i++) {
2816 if (!tb[i])
2817 continue;
2818
2819 switch (i) {
2820 case RTA_IIF:
2821 case RTA_OIF:
2822 case RTA_SRC:
2823 case RTA_DST:
2824 case RTA_IP_PROTO:
2825 case RTA_SPORT:
2826 case RTA_DPORT:
2827 case RTA_MARK:
2828 case RTA_UID:
2829 break;
2830 default:
2831 NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in route get request");
2832 return -EINVAL;
2833 }
2834 }
2835
2836 return 0;
2837 }
2838
2839 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2840 struct netlink_ext_ack *extack)
2841 {
2842 struct net *net = sock_net(in_skb->sk);
2843 struct nlattr *tb[RTA_MAX+1];
2844 u32 table_id = RT_TABLE_MAIN;
2845 __be16 sport = 0, dport = 0;
2846 struct fib_result res = {};
2847 u8 ip_proto = IPPROTO_UDP;
2848 struct rtable *rt = NULL;
2849 struct sk_buff *skb;
2850 struct rtmsg *rtm;
2851 struct flowi4 fl4 = {};
2852 __be32 dst = 0;
2853 __be32 src = 0;
2854 kuid_t uid;
2855 u32 iif;
2856 int err;
2857 int mark;
2858
2859 err = inet_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2860 if (err < 0)
2861 return err;
2862
2863 rtm = nlmsg_data(nlh);
2864 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2865 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2866 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2867 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2868 if (tb[RTA_UID])
2869 uid = make_kuid(current_user_ns(), nla_get_u32(tb[RTA_UID]));
2870 else
2871 uid = (iif ? INVALID_UID : current_uid());
2872
2873 if (tb[RTA_IP_PROTO]) {
2874 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
2875 &ip_proto, extack);
2876 if (err)
2877 return err;
2878 }
2879
2880 if (tb[RTA_SPORT])
2881 sport = nla_get_be16(tb[RTA_SPORT]);
2882
2883 if (tb[RTA_DPORT])
2884 dport = nla_get_be16(tb[RTA_DPORT]);
2885
2886 skb = inet_rtm_getroute_build_skb(src, dst, ip_proto, sport, dport);
2887 if (!skb)
2888 return -ENOBUFS;
2889
2890 fl4.daddr = dst;
2891 fl4.saddr = src;
2892 fl4.flowi4_tos = rtm->rtm_tos;
2893 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2894 fl4.flowi4_mark = mark;
2895 fl4.flowi4_uid = uid;
2896 if (sport)
2897 fl4.fl4_sport = sport;
2898 if (dport)
2899 fl4.fl4_dport = dport;
2900 fl4.flowi4_proto = ip_proto;
2901
2902 rcu_read_lock();
2903
2904 if (iif) {
2905 struct net_device *dev;
2906
2907 dev = dev_get_by_index_rcu(net, iif);
2908 if (!dev) {
2909 err = -ENODEV;
2910 goto errout_rcu;
2911 }
2912
2913 fl4.flowi4_iif = iif; /* for rt_fill_info */
2914 skb->dev = dev;
2915 skb->mark = mark;
2916 err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos,
2917 dev, &res);
2918
2919 rt = skb_rtable(skb);
2920 if (err == 0 && rt->dst.error)
2921 err = -rt->dst.error;
2922 } else {
2923 fl4.flowi4_iif = LOOPBACK_IFINDEX;
2924 skb->dev = net->loopback_dev;
2925 rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb);
2926 err = 0;
2927 if (IS_ERR(rt))
2928 err = PTR_ERR(rt);
2929 else
2930 skb_dst_set(skb, &rt->dst);
2931 }
2932
2933 if (err)
2934 goto errout_rcu;
2935
2936 if (rtm->rtm_flags & RTM_F_NOTIFY)
2937 rt->rt_flags |= RTCF_NOTIFY;
2938
2939 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2940 table_id = res.table ? res.table->tb_id : 0;
2941
2942 /* reset skb for netlink reply msg */
2943 skb_trim(skb, 0);
2944 skb_reset_network_header(skb);
2945 skb_reset_transport_header(skb);
2946 skb_reset_mac_header(skb);
2947
2948 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2949 if (!res.fi) {
2950 err = fib_props[res.type].error;
2951 if (!err)
2952 err = -EHOSTUNREACH;
2953 goto errout_rcu;
2954 }
2955 err = fib_dump_info(skb, NETLINK_CB(in_skb).portid,
2956 nlh->nlmsg_seq, RTM_NEWROUTE, table_id,
2957 rt->rt_type, res.prefix, res.prefixlen,
2958 fl4.flowi4_tos, res.fi, 0);
2959 } else {
2960 err = rt_fill_info(net, dst, src, rt, table_id, &fl4, skb,
2961 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq);
2962 }
2963 if (err < 0)
2964 goto errout_rcu;
2965
2966 rcu_read_unlock();
2967
2968 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2969
2970 errout_free:
2971 return err;
2972 errout_rcu:
2973 rcu_read_unlock();
2974 kfree_skb(skb);
2975 goto errout_free;
2976 }
2977
2978 void ip_rt_multicast_event(struct in_device *in_dev)
2979 {
2980 rt_cache_flush(dev_net(in_dev->dev));
2981 }
2982
2983 #ifdef CONFIG_SYSCTL
2984 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2985 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2986 static int ip_rt_gc_elasticity __read_mostly = 8;
2987 static int ip_min_valid_pmtu __read_mostly = IPV4_MIN_MTU;
2988
2989 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2990 void __user *buffer,
2991 size_t *lenp, loff_t *ppos)
2992 {
2993 struct net *net = (struct net *)__ctl->extra1;
2994
2995 if (write) {
2996 rt_cache_flush(net);
2997 fnhe_genid_bump(net);
2998 return 0;
2999 }
3000
3001 return -EINVAL;
3002 }
3003
3004 static struct ctl_table ipv4_route_table[] = {
3005 {
3006 .procname = "gc_thresh",
3007 .data = &ipv4_dst_ops.gc_thresh,
3008 .maxlen = sizeof(int),
3009 .mode = 0644,
3010 .proc_handler = proc_dointvec,
3011 },
3012 {
3013 .procname = "max_size",
3014 .data = &ip_rt_max_size,
3015 .maxlen = sizeof(int),
3016 .mode = 0644,
3017 .proc_handler = proc_dointvec,
3018 },
3019 {
3020 /* Deprecated. Use gc_min_interval_ms */
3021
3022 .procname = "gc_min_interval",
3023 .data = &ip_rt_gc_min_interval,
3024 .maxlen = sizeof(int),
3025 .mode = 0644,
3026 .proc_handler = proc_dointvec_jiffies,
3027 },
3028 {
3029 .procname = "gc_min_interval_ms",
3030 .data = &ip_rt_gc_min_interval,
3031 .maxlen = sizeof(int),
3032 .mode = 0644,
3033 .proc_handler = proc_dointvec_ms_jiffies,
3034 },
3035 {
3036 .procname = "gc_timeout",
3037 .data = &ip_rt_gc_timeout,
3038 .maxlen = sizeof(int),
3039 .mode = 0644,
3040 .proc_handler = proc_dointvec_jiffies,
3041 },
3042 {
3043 .procname = "gc_interval",
3044 .data = &ip_rt_gc_interval,
3045 .maxlen = sizeof(int),
3046 .mode = 0644,
3047 .proc_handler = proc_dointvec_jiffies,
3048 },
3049 {
3050 .procname = "redirect_load",
3051 .data = &ip_rt_redirect_load,
3052 .maxlen = sizeof(int),
3053 .mode = 0644,
3054 .proc_handler = proc_dointvec,
3055 },
3056 {
3057 .procname = "redirect_number",
3058 .data = &ip_rt_redirect_number,
3059 .maxlen = sizeof(int),
3060 .mode = 0644,
3061 .proc_handler = proc_dointvec,
3062 },
3063 {
3064 .procname = "redirect_silence",
3065 .data = &ip_rt_redirect_silence,
3066 .maxlen = sizeof(int),
3067 .mode = 0644,
3068 .proc_handler = proc_dointvec,
3069 },
3070 {
3071 .procname = "error_cost",
3072 .data = &ip_rt_error_cost,
3073 .maxlen = sizeof(int),
3074 .mode = 0644,
3075 .proc_handler = proc_dointvec,
3076 },
3077 {
3078 .procname = "error_burst",
3079 .data = &ip_rt_error_burst,
3080 .maxlen = sizeof(int),
3081 .mode = 0644,
3082 .proc_handler = proc_dointvec,
3083 },
3084 {
3085 .procname = "gc_elasticity",
3086 .data = &ip_rt_gc_elasticity,
3087 .maxlen = sizeof(int),
3088 .mode = 0644,
3089 .proc_handler = proc_dointvec,
3090 },
3091 {
3092 .procname = "mtu_expires",
3093 .data = &ip_rt_mtu_expires,
3094 .maxlen = sizeof(int),
3095 .mode = 0644,
3096 .proc_handler = proc_dointvec_jiffies,
3097 },
3098 {
3099 .procname = "min_pmtu",
3100 .data = &ip_rt_min_pmtu,
3101 .maxlen = sizeof(int),
3102 .mode = 0644,
3103 .proc_handler = proc_dointvec_minmax,
3104 .extra1 = &ip_min_valid_pmtu,
3105 },
3106 {
3107 .procname = "min_adv_mss",
3108 .data = &ip_rt_min_advmss,
3109 .maxlen = sizeof(int),
3110 .mode = 0644,
3111 .proc_handler = proc_dointvec,
3112 },
3113 { }
3114 };
3115
3116 static struct ctl_table ipv4_route_flush_table[] = {
3117 {
3118 .procname = "flush",
3119 .maxlen = sizeof(int),
3120 .mode = 0200,
3121 .proc_handler = ipv4_sysctl_rtcache_flush,
3122 },
3123 { },
3124 };
3125
3126 static __net_init int sysctl_route_net_init(struct net *net)
3127 {
3128 struct ctl_table *tbl;
3129
3130 tbl = ipv4_route_flush_table;
3131 if (!net_eq(net, &init_net)) {
3132 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3133 if (!tbl)
3134 goto err_dup;
3135
3136 /* Don't export sysctls to unprivileged users */
3137 if (net->user_ns != &init_user_ns)
3138 tbl[0].procname = NULL;
3139 }
3140 tbl[0].extra1 = net;
3141
3142 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
3143 if (!net->ipv4.route_hdr)
3144 goto err_reg;
3145 return 0;
3146
3147 err_reg:
3148 if (tbl != ipv4_route_flush_table)
3149 kfree(tbl);
3150 err_dup:
3151 return -ENOMEM;
3152 }
3153
3154 static __net_exit void sysctl_route_net_exit(struct net *net)
3155 {
3156 struct ctl_table *tbl;
3157
3158 tbl = net->ipv4.route_hdr->ctl_table_arg;
3159 unregister_net_sysctl_table(net->ipv4.route_hdr);
3160 BUG_ON(tbl == ipv4_route_flush_table);
3161 kfree(tbl);
3162 }
3163
3164 static __net_initdata struct pernet_operations sysctl_route_ops = {
3165 .init = sysctl_route_net_init,
3166 .exit = sysctl_route_net_exit,
3167 };
3168 #endif
3169
3170 static __net_init int rt_genid_init(struct net *net)
3171 {
3172 atomic_set(&net->ipv4.rt_genid, 0);
3173 atomic_set(&net->fnhe_genid, 0);
3174 atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
3175 return 0;
3176 }
3177
3178 static __net_initdata struct pernet_operations rt_genid_ops = {
3179 .init = rt_genid_init,
3180 };
3181
3182 static int __net_init ipv4_inetpeer_init(struct net *net)
3183 {
3184 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3185
3186 if (!bp)
3187 return -ENOMEM;
3188 inet_peer_base_init(bp);
3189 net->ipv4.peers = bp;
3190 return 0;
3191 }
3192
3193 static void __net_exit ipv4_inetpeer_exit(struct net *net)
3194 {
3195 struct inet_peer_base *bp = net->ipv4.peers;
3196
3197 net->ipv4.peers = NULL;
3198 inetpeer_invalidate_tree(bp);
3199 kfree(bp);
3200 }
3201
3202 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
3203 .init = ipv4_inetpeer_init,
3204 .exit = ipv4_inetpeer_exit,
3205 };
3206
3207 #ifdef CONFIG_IP_ROUTE_CLASSID
3208 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3209 #endif /* CONFIG_IP_ROUTE_CLASSID */
3210
3211 int __init ip_rt_init(void)
3212 {
3213 int cpu;
3214
3215 ip_idents = kmalloc_array(IP_IDENTS_SZ, sizeof(*ip_idents),
3216 GFP_KERNEL);
3217 if (!ip_idents)
3218 panic("IP: failed to allocate ip_idents\n");
3219
3220 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
3221
3222 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
3223 if (!ip_tstamps)
3224 panic("IP: failed to allocate ip_tstamps\n");
3225
3226 for_each_possible_cpu(cpu) {
3227 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
3228
3229 INIT_LIST_HEAD(&ul->head);
3230 spin_lock_init(&ul->lock);
3231 }
3232 #ifdef CONFIG_IP_ROUTE_CLASSID
3233 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3234 if (!ip_rt_acct)
3235 panic("IP: failed to allocate ip_rt_acct\n");
3236 #endif
3237
3238 ipv4_dst_ops.kmem_cachep =
3239 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3240 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3241
3242 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3243
3244 if (dst_entries_init(&ipv4_dst_ops) < 0)
3245 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3246
3247 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3248 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3249
3250 ipv4_dst_ops.gc_thresh = ~0;
3251 ip_rt_max_size = INT_MAX;
3252
3253 devinet_init();
3254 ip_fib_init();
3255
3256 if (ip_rt_proc_init())
3257 pr_err("Unable to create route proc files\n");
3258 #ifdef CONFIG_XFRM
3259 xfrm_init();
3260 xfrm4_init();
3261 #endif
3262 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL,
3263 RTNL_FLAG_DOIT_UNLOCKED);
3264
3265 #ifdef CONFIG_SYSCTL
3266 register_pernet_subsys(&sysctl_route_ops);
3267 #endif
3268 register_pernet_subsys(&rt_genid_ops);
3269 register_pernet_subsys(&ipv4_inetpeer_ops);
3270 return 0;
3271 }
3272
3273 #ifdef CONFIG_SYSCTL
3274 /*
3275 * We really need to sanitize the damn ipv4 init order, then all
3276 * this nonsense will go away.
3277 */
3278 void __init ip_static_sysctl_init(void)
3279 {
3280 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
3281 }
3282 #endif
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git