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ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
[deliverable/linux.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 <asm/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 #include <linux/kmemleak.h>
112 #endif
113 #include <net/secure_seq.h>
114 #include <net/ip_tunnels.h>
115 #include <net/l3mdev.h>
116
117 #define RT_FL_TOS(oldflp4) \
118 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
119
120 #define RT_GC_TIMEOUT (300*HZ)
121
122 static int ip_rt_max_size;
123 static int ip_rt_redirect_number __read_mostly = 9;
124 static int ip_rt_redirect_load __read_mostly = HZ / 50;
125 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
126 static int ip_rt_error_cost __read_mostly = HZ;
127 static int ip_rt_error_burst __read_mostly = 5 * HZ;
128 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
129 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
130 static int ip_rt_min_advmss __read_mostly = 256;
131
132 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
133 /*
134 * Interface to generic destination cache.
135 */
136
137 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
138 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
139 static unsigned int ipv4_mtu(const struct dst_entry *dst);
140 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
141 static void ipv4_link_failure(struct sk_buff *skb);
142 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
143 struct sk_buff *skb, u32 mtu);
144 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk,
145 struct sk_buff *skb);
146 static void ipv4_dst_destroy(struct dst_entry *dst);
147
148 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
149 {
150 WARN_ON(1);
151 return NULL;
152 }
153
154 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
155 struct sk_buff *skb,
156 const void *daddr);
157
158 static struct dst_ops ipv4_dst_ops = {
159 .family = AF_INET,
160 .check = ipv4_dst_check,
161 .default_advmss = ipv4_default_advmss,
162 .mtu = ipv4_mtu,
163 .cow_metrics = ipv4_cow_metrics,
164 .destroy = ipv4_dst_destroy,
165 .negative_advice = ipv4_negative_advice,
166 .link_failure = ipv4_link_failure,
167 .update_pmtu = ip_rt_update_pmtu,
168 .redirect = ip_do_redirect,
169 .local_out = __ip_local_out,
170 .neigh_lookup = ipv4_neigh_lookup,
171 };
172
173 #define ECN_OR_COST(class) TC_PRIO_##class
174
175 const __u8 ip_tos2prio[16] = {
176 TC_PRIO_BESTEFFORT,
177 ECN_OR_COST(BESTEFFORT),
178 TC_PRIO_BESTEFFORT,
179 ECN_OR_COST(BESTEFFORT),
180 TC_PRIO_BULK,
181 ECN_OR_COST(BULK),
182 TC_PRIO_BULK,
183 ECN_OR_COST(BULK),
184 TC_PRIO_INTERACTIVE,
185 ECN_OR_COST(INTERACTIVE),
186 TC_PRIO_INTERACTIVE,
187 ECN_OR_COST(INTERACTIVE),
188 TC_PRIO_INTERACTIVE_BULK,
189 ECN_OR_COST(INTERACTIVE_BULK),
190 TC_PRIO_INTERACTIVE_BULK,
191 ECN_OR_COST(INTERACTIVE_BULK)
192 };
193 EXPORT_SYMBOL(ip_tos2prio);
194
195 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
196 #define RT_CACHE_STAT_INC(field) raw_cpu_inc(rt_cache_stat.field)
197
198 #ifdef CONFIG_PROC_FS
199 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
200 {
201 if (*pos)
202 return NULL;
203 return SEQ_START_TOKEN;
204 }
205
206 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
207 {
208 ++*pos;
209 return NULL;
210 }
211
212 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
213 {
214 }
215
216 static int rt_cache_seq_show(struct seq_file *seq, void *v)
217 {
218 if (v == SEQ_START_TOKEN)
219 seq_printf(seq, "%-127s\n",
220 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
221 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
222 "HHUptod\tSpecDst");
223 return 0;
224 }
225
226 static const struct seq_operations rt_cache_seq_ops = {
227 .start = rt_cache_seq_start,
228 .next = rt_cache_seq_next,
229 .stop = rt_cache_seq_stop,
230 .show = rt_cache_seq_show,
231 };
232
233 static int rt_cache_seq_open(struct inode *inode, struct file *file)
234 {
235 return seq_open(file, &rt_cache_seq_ops);
236 }
237
238 static const struct file_operations rt_cache_seq_fops = {
239 .owner = THIS_MODULE,
240 .open = rt_cache_seq_open,
241 .read = seq_read,
242 .llseek = seq_lseek,
243 .release = seq_release,
244 };
245
246
247 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
248 {
249 int cpu;
250
251 if (*pos == 0)
252 return SEQ_START_TOKEN;
253
254 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
255 if (!cpu_possible(cpu))
256 continue;
257 *pos = cpu+1;
258 return &per_cpu(rt_cache_stat, cpu);
259 }
260 return NULL;
261 }
262
263 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
264 {
265 int cpu;
266
267 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
268 if (!cpu_possible(cpu))
269 continue;
270 *pos = cpu+1;
271 return &per_cpu(rt_cache_stat, cpu);
272 }
273 return NULL;
274
275 }
276
277 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
278 {
279
280 }
281
282 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
283 {
284 struct rt_cache_stat *st = v;
285
286 if (v == SEQ_START_TOKEN) {
287 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
288 return 0;
289 }
290
291 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
292 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
293 dst_entries_get_slow(&ipv4_dst_ops),
294 0, /* st->in_hit */
295 st->in_slow_tot,
296 st->in_slow_mc,
297 st->in_no_route,
298 st->in_brd,
299 st->in_martian_dst,
300 st->in_martian_src,
301
302 0, /* st->out_hit */
303 st->out_slow_tot,
304 st->out_slow_mc,
305
306 0, /* st->gc_total */
307 0, /* st->gc_ignored */
308 0, /* st->gc_goal_miss */
309 0, /* st->gc_dst_overflow */
310 0, /* st->in_hlist_search */
311 0 /* st->out_hlist_search */
312 );
313 return 0;
314 }
315
316 static const struct seq_operations rt_cpu_seq_ops = {
317 .start = rt_cpu_seq_start,
318 .next = rt_cpu_seq_next,
319 .stop = rt_cpu_seq_stop,
320 .show = rt_cpu_seq_show,
321 };
322
323
324 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
325 {
326 return seq_open(file, &rt_cpu_seq_ops);
327 }
328
329 static const struct file_operations rt_cpu_seq_fops = {
330 .owner = THIS_MODULE,
331 .open = rt_cpu_seq_open,
332 .read = seq_read,
333 .llseek = seq_lseek,
334 .release = seq_release,
335 };
336
337 #ifdef CONFIG_IP_ROUTE_CLASSID
338 static int rt_acct_proc_show(struct seq_file *m, void *v)
339 {
340 struct ip_rt_acct *dst, *src;
341 unsigned int i, j;
342
343 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
344 if (!dst)
345 return -ENOMEM;
346
347 for_each_possible_cpu(i) {
348 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
349 for (j = 0; j < 256; j++) {
350 dst[j].o_bytes += src[j].o_bytes;
351 dst[j].o_packets += src[j].o_packets;
352 dst[j].i_bytes += src[j].i_bytes;
353 dst[j].i_packets += src[j].i_packets;
354 }
355 }
356
357 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
358 kfree(dst);
359 return 0;
360 }
361
362 static int rt_acct_proc_open(struct inode *inode, struct file *file)
363 {
364 return single_open(file, rt_acct_proc_show, NULL);
365 }
366
367 static const struct file_operations rt_acct_proc_fops = {
368 .owner = THIS_MODULE,
369 .open = rt_acct_proc_open,
370 .read = seq_read,
371 .llseek = seq_lseek,
372 .release = single_release,
373 };
374 #endif
375
376 static int __net_init ip_rt_do_proc_init(struct net *net)
377 {
378 struct proc_dir_entry *pde;
379
380 pde = proc_create("rt_cache", S_IRUGO, net->proc_net,
381 &rt_cache_seq_fops);
382 if (!pde)
383 goto err1;
384
385 pde = proc_create("rt_cache", S_IRUGO,
386 net->proc_net_stat, &rt_cpu_seq_fops);
387 if (!pde)
388 goto err2;
389
390 #ifdef CONFIG_IP_ROUTE_CLASSID
391 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
392 if (!pde)
393 goto err3;
394 #endif
395 return 0;
396
397 #ifdef CONFIG_IP_ROUTE_CLASSID
398 err3:
399 remove_proc_entry("rt_cache", net->proc_net_stat);
400 #endif
401 err2:
402 remove_proc_entry("rt_cache", net->proc_net);
403 err1:
404 return -ENOMEM;
405 }
406
407 static void __net_exit ip_rt_do_proc_exit(struct net *net)
408 {
409 remove_proc_entry("rt_cache", net->proc_net_stat);
410 remove_proc_entry("rt_cache", net->proc_net);
411 #ifdef CONFIG_IP_ROUTE_CLASSID
412 remove_proc_entry("rt_acct", net->proc_net);
413 #endif
414 }
415
416 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
417 .init = ip_rt_do_proc_init,
418 .exit = ip_rt_do_proc_exit,
419 };
420
421 static int __init ip_rt_proc_init(void)
422 {
423 return register_pernet_subsys(&ip_rt_proc_ops);
424 }
425
426 #else
427 static inline int ip_rt_proc_init(void)
428 {
429 return 0;
430 }
431 #endif /* CONFIG_PROC_FS */
432
433 static inline bool rt_is_expired(const struct rtable *rth)
434 {
435 return rth->rt_genid != rt_genid_ipv4(dev_net(rth->dst.dev));
436 }
437
438 void rt_cache_flush(struct net *net)
439 {
440 rt_genid_bump_ipv4(net);
441 }
442
443 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
444 struct sk_buff *skb,
445 const void *daddr)
446 {
447 struct net_device *dev = dst->dev;
448 const __be32 *pkey = daddr;
449 const struct rtable *rt;
450 struct neighbour *n;
451
452 rt = (const struct rtable *) dst;
453 if (rt->rt_gateway)
454 pkey = (const __be32 *) &rt->rt_gateway;
455 else if (skb)
456 pkey = &ip_hdr(skb)->daddr;
457
458 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
459 if (n)
460 return n;
461 return neigh_create(&arp_tbl, pkey, dev);
462 }
463
464 #define IP_IDENTS_SZ 2048u
465
466 static atomic_t *ip_idents __read_mostly;
467 static u32 *ip_tstamps __read_mostly;
468
469 /* In order to protect privacy, we add a perturbation to identifiers
470 * if one generator is seldom used. This makes hard for an attacker
471 * to infer how many packets were sent between two points in time.
472 */
473 u32 ip_idents_reserve(u32 hash, int segs)
474 {
475 u32 *p_tstamp = ip_tstamps + hash % IP_IDENTS_SZ;
476 atomic_t *p_id = ip_idents + hash % IP_IDENTS_SZ;
477 u32 old = ACCESS_ONCE(*p_tstamp);
478 u32 now = (u32)jiffies;
479 u32 new, delta = 0;
480
481 if (old != now && cmpxchg(p_tstamp, old, now) == old)
482 delta = prandom_u32_max(now - old);
483
484 /* Do not use atomic_add_return() as it makes UBSAN unhappy */
485 do {
486 old = (u32)atomic_read(p_id);
487 new = old + delta + segs;
488 } while (atomic_cmpxchg(p_id, old, new) != old);
489
490 return new - segs;
491 }
492 EXPORT_SYMBOL(ip_idents_reserve);
493
494 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs)
495 {
496 static u32 ip_idents_hashrnd __read_mostly;
497 u32 hash, id;
498
499 net_get_random_once(&ip_idents_hashrnd, sizeof(ip_idents_hashrnd));
500
501 hash = jhash_3words((__force u32)iph->daddr,
502 (__force u32)iph->saddr,
503 iph->protocol ^ net_hash_mix(net),
504 ip_idents_hashrnd);
505 id = ip_idents_reserve(hash, segs);
506 iph->id = htons(id);
507 }
508 EXPORT_SYMBOL(__ip_select_ident);
509
510 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
511 const struct iphdr *iph,
512 int oif, u8 tos,
513 u8 prot, u32 mark, int flow_flags)
514 {
515 if (sk) {
516 const struct inet_sock *inet = inet_sk(sk);
517
518 oif = sk->sk_bound_dev_if;
519 mark = sk->sk_mark;
520 tos = RT_CONN_FLAGS(sk);
521 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
522 }
523 flowi4_init_output(fl4, oif, mark, tos,
524 RT_SCOPE_UNIVERSE, prot,
525 flow_flags,
526 iph->daddr, iph->saddr, 0, 0);
527 }
528
529 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
530 const struct sock *sk)
531 {
532 const struct iphdr *iph = ip_hdr(skb);
533 int oif = skb->dev->ifindex;
534 u8 tos = RT_TOS(iph->tos);
535 u8 prot = iph->protocol;
536 u32 mark = skb->mark;
537
538 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
539 }
540
541 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
542 {
543 const struct inet_sock *inet = inet_sk(sk);
544 const struct ip_options_rcu *inet_opt;
545 __be32 daddr = inet->inet_daddr;
546
547 rcu_read_lock();
548 inet_opt = rcu_dereference(inet->inet_opt);
549 if (inet_opt && inet_opt->opt.srr)
550 daddr = inet_opt->opt.faddr;
551 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
552 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
553 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
554 inet_sk_flowi_flags(sk),
555 daddr, inet->inet_saddr, 0, 0);
556 rcu_read_unlock();
557 }
558
559 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
560 const struct sk_buff *skb)
561 {
562 if (skb)
563 build_skb_flow_key(fl4, skb, sk);
564 else
565 build_sk_flow_key(fl4, sk);
566 }
567
568 static inline void rt_free(struct rtable *rt)
569 {
570 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
571 }
572
573 static DEFINE_SPINLOCK(fnhe_lock);
574
575 static void fnhe_flush_routes(struct fib_nh_exception *fnhe)
576 {
577 struct rtable *rt;
578
579 rt = rcu_dereference(fnhe->fnhe_rth_input);
580 if (rt) {
581 RCU_INIT_POINTER(fnhe->fnhe_rth_input, NULL);
582 rt_free(rt);
583 }
584 rt = rcu_dereference(fnhe->fnhe_rth_output);
585 if (rt) {
586 RCU_INIT_POINTER(fnhe->fnhe_rth_output, NULL);
587 rt_free(rt);
588 }
589 }
590
591 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
592 {
593 struct fib_nh_exception *fnhe, *oldest;
594
595 oldest = rcu_dereference(hash->chain);
596 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
597 fnhe = rcu_dereference(fnhe->fnhe_next)) {
598 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
599 oldest = fnhe;
600 }
601 fnhe_flush_routes(oldest);
602 return oldest;
603 }
604
605 static inline u32 fnhe_hashfun(__be32 daddr)
606 {
607 static u32 fnhe_hashrnd __read_mostly;
608 u32 hval;
609
610 net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
611 hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
612 return hash_32(hval, FNHE_HASH_SHIFT);
613 }
614
615 static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)
616 {
617 rt->rt_pmtu = fnhe->fnhe_pmtu;
618 rt->dst.expires = fnhe->fnhe_expires;
619
620 if (fnhe->fnhe_gw) {
621 rt->rt_flags |= RTCF_REDIRECTED;
622 rt->rt_gateway = fnhe->fnhe_gw;
623 rt->rt_uses_gateway = 1;
624 }
625 }
626
627 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
628 u32 pmtu, unsigned long expires)
629 {
630 struct fnhe_hash_bucket *hash;
631 struct fib_nh_exception *fnhe;
632 struct rtable *rt;
633 unsigned int i;
634 int depth;
635 u32 hval = fnhe_hashfun(daddr);
636
637 spin_lock_bh(&fnhe_lock);
638
639 hash = rcu_dereference(nh->nh_exceptions);
640 if (!hash) {
641 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
642 if (!hash)
643 goto out_unlock;
644 rcu_assign_pointer(nh->nh_exceptions, hash);
645 }
646
647 hash += hval;
648
649 depth = 0;
650 for (fnhe = rcu_dereference(hash->chain); fnhe;
651 fnhe = rcu_dereference(fnhe->fnhe_next)) {
652 if (fnhe->fnhe_daddr == daddr)
653 break;
654 depth++;
655 }
656
657 if (fnhe) {
658 if (gw)
659 fnhe->fnhe_gw = gw;
660 if (pmtu) {
661 fnhe->fnhe_pmtu = pmtu;
662 fnhe->fnhe_expires = max(1UL, expires);
663 }
664 /* Update all cached dsts too */
665 rt = rcu_dereference(fnhe->fnhe_rth_input);
666 if (rt)
667 fill_route_from_fnhe(rt, fnhe);
668 rt = rcu_dereference(fnhe->fnhe_rth_output);
669 if (rt)
670 fill_route_from_fnhe(rt, fnhe);
671 } else {
672 if (depth > FNHE_RECLAIM_DEPTH)
673 fnhe = fnhe_oldest(hash);
674 else {
675 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
676 if (!fnhe)
677 goto out_unlock;
678
679 fnhe->fnhe_next = hash->chain;
680 rcu_assign_pointer(hash->chain, fnhe);
681 }
682 fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev));
683 fnhe->fnhe_daddr = daddr;
684 fnhe->fnhe_gw = gw;
685 fnhe->fnhe_pmtu = pmtu;
686 fnhe->fnhe_expires = expires;
687
688 /* Exception created; mark the cached routes for the nexthop
689 * stale, so anyone caching it rechecks if this exception
690 * applies to them.
691 */
692 rt = rcu_dereference(nh->nh_rth_input);
693 if (rt)
694 rt->dst.obsolete = DST_OBSOLETE_KILL;
695
696 for_each_possible_cpu(i) {
697 struct rtable __rcu **prt;
698 prt = per_cpu_ptr(nh->nh_pcpu_rth_output, i);
699 rt = rcu_dereference(*prt);
700 if (rt)
701 rt->dst.obsolete = DST_OBSOLETE_KILL;
702 }
703 }
704
705 fnhe->fnhe_stamp = jiffies;
706
707 out_unlock:
708 spin_unlock_bh(&fnhe_lock);
709 }
710
711 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
712 bool kill_route)
713 {
714 __be32 new_gw = icmp_hdr(skb)->un.gateway;
715 __be32 old_gw = ip_hdr(skb)->saddr;
716 struct net_device *dev = skb->dev;
717 struct in_device *in_dev;
718 struct fib_result res;
719 struct neighbour *n;
720 struct net *net;
721
722 switch (icmp_hdr(skb)->code & 7) {
723 case ICMP_REDIR_NET:
724 case ICMP_REDIR_NETTOS:
725 case ICMP_REDIR_HOST:
726 case ICMP_REDIR_HOSTTOS:
727 break;
728
729 default:
730 return;
731 }
732
733 if (rt->rt_gateway != old_gw)
734 return;
735
736 in_dev = __in_dev_get_rcu(dev);
737 if (!in_dev)
738 return;
739
740 net = dev_net(dev);
741 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
742 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
743 ipv4_is_zeronet(new_gw))
744 goto reject_redirect;
745
746 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
747 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
748 goto reject_redirect;
749 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
750 goto reject_redirect;
751 } else {
752 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
753 goto reject_redirect;
754 }
755
756 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
757 if (!IS_ERR(n)) {
758 if (!(n->nud_state & NUD_VALID)) {
759 neigh_event_send(n, NULL);
760 } else {
761 if (fib_lookup(net, fl4, &res, 0) == 0) {
762 struct fib_nh *nh = &FIB_RES_NH(res);
763
764 update_or_create_fnhe(nh, fl4->daddr, new_gw,
765 0, jiffies + ip_rt_gc_timeout);
766 }
767 if (kill_route)
768 rt->dst.obsolete = DST_OBSOLETE_KILL;
769 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
770 }
771 neigh_release(n);
772 }
773 return;
774
775 reject_redirect:
776 #ifdef CONFIG_IP_ROUTE_VERBOSE
777 if (IN_DEV_LOG_MARTIANS(in_dev)) {
778 const struct iphdr *iph = (const struct iphdr *) skb->data;
779 __be32 daddr = iph->daddr;
780 __be32 saddr = iph->saddr;
781
782 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
783 " Advised path = %pI4 -> %pI4\n",
784 &old_gw, dev->name, &new_gw,
785 &saddr, &daddr);
786 }
787 #endif
788 ;
789 }
790
791 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
792 {
793 struct rtable *rt;
794 struct flowi4 fl4;
795 const struct iphdr *iph = (const struct iphdr *) skb->data;
796 int oif = skb->dev->ifindex;
797 u8 tos = RT_TOS(iph->tos);
798 u8 prot = iph->protocol;
799 u32 mark = skb->mark;
800
801 rt = (struct rtable *) dst;
802
803 __build_flow_key(&fl4, sk, iph, oif, tos, prot, mark, 0);
804 __ip_do_redirect(rt, skb, &fl4, true);
805 }
806
807 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
808 {
809 struct rtable *rt = (struct rtable *)dst;
810 struct dst_entry *ret = dst;
811
812 if (rt) {
813 if (dst->obsolete > 0) {
814 ip_rt_put(rt);
815 ret = NULL;
816 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
817 rt->dst.expires) {
818 ip_rt_put(rt);
819 ret = NULL;
820 }
821 }
822 return ret;
823 }
824
825 /*
826 * Algorithm:
827 * 1. The first ip_rt_redirect_number redirects are sent
828 * with exponential backoff, then we stop sending them at all,
829 * assuming that the host ignores our redirects.
830 * 2. If we did not see packets requiring redirects
831 * during ip_rt_redirect_silence, we assume that the host
832 * forgot redirected route and start to send redirects again.
833 *
834 * This algorithm is much cheaper and more intelligent than dumb load limiting
835 * in icmp.c.
836 *
837 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
838 * and "frag. need" (breaks PMTU discovery) in icmp.c.
839 */
840
841 void ip_rt_send_redirect(struct sk_buff *skb)
842 {
843 struct rtable *rt = skb_rtable(skb);
844 struct in_device *in_dev;
845 struct inet_peer *peer;
846 struct net *net;
847 int log_martians;
848 int vif;
849
850 rcu_read_lock();
851 in_dev = __in_dev_get_rcu(rt->dst.dev);
852 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
853 rcu_read_unlock();
854 return;
855 }
856 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
857 vif = l3mdev_master_ifindex_rcu(rt->dst.dev);
858 rcu_read_unlock();
859
860 net = dev_net(rt->dst.dev);
861 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, vif, 1);
862 if (!peer) {
863 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST,
864 rt_nexthop(rt, ip_hdr(skb)->daddr));
865 return;
866 }
867
868 /* No redirected packets during ip_rt_redirect_silence;
869 * reset the algorithm.
870 */
871 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
872 peer->rate_tokens = 0;
873
874 /* Too many ignored redirects; do not send anything
875 * set dst.rate_last to the last seen redirected packet.
876 */
877 if (peer->rate_tokens >= ip_rt_redirect_number) {
878 peer->rate_last = jiffies;
879 goto out_put_peer;
880 }
881
882 /* Check for load limit; set rate_last to the latest sent
883 * redirect.
884 */
885 if (peer->rate_tokens == 0 ||
886 time_after(jiffies,
887 (peer->rate_last +
888 (ip_rt_redirect_load << peer->rate_tokens)))) {
889 __be32 gw = rt_nexthop(rt, ip_hdr(skb)->daddr);
890
891 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, gw);
892 peer->rate_last = jiffies;
893 ++peer->rate_tokens;
894 #ifdef CONFIG_IP_ROUTE_VERBOSE
895 if (log_martians &&
896 peer->rate_tokens == ip_rt_redirect_number)
897 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
898 &ip_hdr(skb)->saddr, inet_iif(skb),
899 &ip_hdr(skb)->daddr, &gw);
900 #endif
901 }
902 out_put_peer:
903 inet_putpeer(peer);
904 }
905
906 static int ip_error(struct sk_buff *skb)
907 {
908 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
909 struct rtable *rt = skb_rtable(skb);
910 struct inet_peer *peer;
911 unsigned long now;
912 struct net *net;
913 bool send;
914 int code;
915
916 /* IP on this device is disabled. */
917 if (!in_dev)
918 goto out;
919
920 net = dev_net(rt->dst.dev);
921 if (!IN_DEV_FORWARD(in_dev)) {
922 switch (rt->dst.error) {
923 case EHOSTUNREACH:
924 __IP_INC_STATS(net, IPSTATS_MIB_INADDRERRORS);
925 break;
926
927 case ENETUNREACH:
928 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
929 break;
930 }
931 goto out;
932 }
933
934 switch (rt->dst.error) {
935 case EINVAL:
936 default:
937 goto out;
938 case EHOSTUNREACH:
939 code = ICMP_HOST_UNREACH;
940 break;
941 case ENETUNREACH:
942 code = ICMP_NET_UNREACH;
943 __IP_INC_STATS(net, IPSTATS_MIB_INNOROUTES);
944 break;
945 case EACCES:
946 code = ICMP_PKT_FILTERED;
947 break;
948 }
949
950 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr,
951 l3mdev_master_ifindex(skb->dev), 1);
952
953 send = true;
954 if (peer) {
955 now = jiffies;
956 peer->rate_tokens += now - peer->rate_last;
957 if (peer->rate_tokens > ip_rt_error_burst)
958 peer->rate_tokens = ip_rt_error_burst;
959 peer->rate_last = now;
960 if (peer->rate_tokens >= ip_rt_error_cost)
961 peer->rate_tokens -= ip_rt_error_cost;
962 else
963 send = false;
964 inet_putpeer(peer);
965 }
966 if (send)
967 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
968
969 out: kfree_skb(skb);
970 return 0;
971 }
972
973 static void __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
974 {
975 struct dst_entry *dst = &rt->dst;
976 struct fib_result res;
977
978 if (dst_metric_locked(dst, RTAX_MTU))
979 return;
980
981 if (ipv4_mtu(dst) < mtu)
982 return;
983
984 if (mtu < ip_rt_min_pmtu)
985 mtu = ip_rt_min_pmtu;
986
987 if (rt->rt_pmtu == mtu &&
988 time_before(jiffies, dst->expires - ip_rt_mtu_expires / 2))
989 return;
990
991 rcu_read_lock();
992 if (fib_lookup(dev_net(dst->dev), fl4, &res, 0) == 0) {
993 struct fib_nh *nh = &FIB_RES_NH(res);
994
995 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
996 jiffies + ip_rt_mtu_expires);
997 }
998 rcu_read_unlock();
999 }
1000
1001 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1002 struct sk_buff *skb, u32 mtu)
1003 {
1004 struct rtable *rt = (struct rtable *) dst;
1005 struct flowi4 fl4;
1006
1007 ip_rt_build_flow_key(&fl4, sk, skb);
1008 __ip_rt_update_pmtu(rt, &fl4, mtu);
1009 }
1010
1011 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
1012 int oif, u32 mark, u8 protocol, int flow_flags)
1013 {
1014 const struct iphdr *iph = (const struct iphdr *) skb->data;
1015 struct flowi4 fl4;
1016 struct rtable *rt;
1017
1018 if (!mark)
1019 mark = IP4_REPLY_MARK(net, skb->mark);
1020
1021 __build_flow_key(&fl4, NULL, iph, oif,
1022 RT_TOS(iph->tos), protocol, mark, flow_flags);
1023 rt = __ip_route_output_key(net, &fl4);
1024 if (!IS_ERR(rt)) {
1025 __ip_rt_update_pmtu(rt, &fl4, mtu);
1026 ip_rt_put(rt);
1027 }
1028 }
1029 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
1030
1031 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1032 {
1033 const struct iphdr *iph = (const struct iphdr *) skb->data;
1034 struct flowi4 fl4;
1035 struct rtable *rt;
1036
1037 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1038
1039 if (!fl4.flowi4_mark)
1040 fl4.flowi4_mark = IP4_REPLY_MARK(sock_net(sk), skb->mark);
1041
1042 rt = __ip_route_output_key(sock_net(sk), &fl4);
1043 if (!IS_ERR(rt)) {
1044 __ip_rt_update_pmtu(rt, &fl4, mtu);
1045 ip_rt_put(rt);
1046 }
1047 }
1048
1049 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
1050 {
1051 const struct iphdr *iph = (const struct iphdr *) skb->data;
1052 struct flowi4 fl4;
1053 struct rtable *rt;
1054 struct dst_entry *odst = NULL;
1055 bool new = false;
1056
1057 bh_lock_sock(sk);
1058
1059 if (!ip_sk_accept_pmtu(sk))
1060 goto out;
1061
1062 odst = sk_dst_get(sk);
1063
1064 if (sock_owned_by_user(sk) || !odst) {
1065 __ipv4_sk_update_pmtu(skb, sk, mtu);
1066 goto out;
1067 }
1068
1069 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1070
1071 rt = (struct rtable *)odst;
1072 if (odst->obsolete && !odst->ops->check(odst, 0)) {
1073 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1074 if (IS_ERR(rt))
1075 goto out;
1076
1077 new = true;
1078 }
1079
1080 __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu);
1081
1082 if (!dst_check(&rt->dst, 0)) {
1083 if (new)
1084 dst_release(&rt->dst);
1085
1086 rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
1087 if (IS_ERR(rt))
1088 goto out;
1089
1090 new = true;
1091 }
1092
1093 if (new)
1094 sk_dst_set(sk, &rt->dst);
1095
1096 out:
1097 bh_unlock_sock(sk);
1098 dst_release(odst);
1099 }
1100 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
1101
1102 void ipv4_redirect(struct sk_buff *skb, struct net *net,
1103 int oif, u32 mark, u8 protocol, int flow_flags)
1104 {
1105 const struct iphdr *iph = (const struct iphdr *) skb->data;
1106 struct flowi4 fl4;
1107 struct rtable *rt;
1108
1109 __build_flow_key(&fl4, NULL, iph, oif,
1110 RT_TOS(iph->tos), protocol, mark, flow_flags);
1111 rt = __ip_route_output_key(net, &fl4);
1112 if (!IS_ERR(rt)) {
1113 __ip_do_redirect(rt, skb, &fl4, false);
1114 ip_rt_put(rt);
1115 }
1116 }
1117 EXPORT_SYMBOL_GPL(ipv4_redirect);
1118
1119 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
1120 {
1121 const struct iphdr *iph = (const struct iphdr *) skb->data;
1122 struct flowi4 fl4;
1123 struct rtable *rt;
1124
1125 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1126 rt = __ip_route_output_key(sock_net(sk), &fl4);
1127 if (!IS_ERR(rt)) {
1128 __ip_do_redirect(rt, skb, &fl4, false);
1129 ip_rt_put(rt);
1130 }
1131 }
1132 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1133
1134 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1135 {
1136 struct rtable *rt = (struct rtable *) dst;
1137
1138 /* All IPV4 dsts are created with ->obsolete set to the value
1139 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1140 * into this function always.
1141 *
1142 * When a PMTU/redirect information update invalidates a route,
1143 * this is indicated by setting obsolete to DST_OBSOLETE_KILL or
1144 * DST_OBSOLETE_DEAD by dst_free().
1145 */
1146 if (dst->obsolete != DST_OBSOLETE_FORCE_CHK || rt_is_expired(rt))
1147 return NULL;
1148 return dst;
1149 }
1150
1151 static void ipv4_link_failure(struct sk_buff *skb)
1152 {
1153 struct rtable *rt;
1154
1155 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1156
1157 rt = skb_rtable(skb);
1158 if (rt)
1159 dst_set_expires(&rt->dst, 0);
1160 }
1161
1162 static int ip_rt_bug(struct net *net, struct sock *sk, struct sk_buff *skb)
1163 {
1164 pr_debug("%s: %pI4 -> %pI4, %s\n",
1165 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1166 skb->dev ? skb->dev->name : "?");
1167 kfree_skb(skb);
1168 WARN_ON(1);
1169 return 0;
1170 }
1171
1172 /*
1173 We do not cache source address of outgoing interface,
1174 because it is used only by IP RR, TS and SRR options,
1175 so that it out of fast path.
1176
1177 BTW remember: "addr" is allowed to be not aligned
1178 in IP options!
1179 */
1180
1181 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1182 {
1183 __be32 src;
1184
1185 if (rt_is_output_route(rt))
1186 src = ip_hdr(skb)->saddr;
1187 else {
1188 struct fib_result res;
1189 struct flowi4 fl4;
1190 struct iphdr *iph;
1191
1192 iph = ip_hdr(skb);
1193
1194 memset(&fl4, 0, sizeof(fl4));
1195 fl4.daddr = iph->daddr;
1196 fl4.saddr = iph->saddr;
1197 fl4.flowi4_tos = RT_TOS(iph->tos);
1198 fl4.flowi4_oif = rt->dst.dev->ifindex;
1199 fl4.flowi4_iif = skb->dev->ifindex;
1200 fl4.flowi4_mark = skb->mark;
1201
1202 rcu_read_lock();
1203 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res, 0) == 0)
1204 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1205 else
1206 src = inet_select_addr(rt->dst.dev,
1207 rt_nexthop(rt, iph->daddr),
1208 RT_SCOPE_UNIVERSE);
1209 rcu_read_unlock();
1210 }
1211 memcpy(addr, &src, 4);
1212 }
1213
1214 #ifdef CONFIG_IP_ROUTE_CLASSID
1215 static void set_class_tag(struct rtable *rt, u32 tag)
1216 {
1217 if (!(rt->dst.tclassid & 0xFFFF))
1218 rt->dst.tclassid |= tag & 0xFFFF;
1219 if (!(rt->dst.tclassid & 0xFFFF0000))
1220 rt->dst.tclassid |= tag & 0xFFFF0000;
1221 }
1222 #endif
1223
1224 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1225 {
1226 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1227
1228 if (advmss == 0) {
1229 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1230 ip_rt_min_advmss);
1231 if (advmss > 65535 - 40)
1232 advmss = 65535 - 40;
1233 }
1234 return advmss;
1235 }
1236
1237 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1238 {
1239 const struct rtable *rt = (const struct rtable *) dst;
1240 unsigned int mtu = rt->rt_pmtu;
1241
1242 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1243 mtu = dst_metric_raw(dst, RTAX_MTU);
1244
1245 if (mtu)
1246 return mtu;
1247
1248 mtu = dst->dev->mtu;
1249
1250 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1251 if (rt->rt_uses_gateway && mtu > 576)
1252 mtu = 576;
1253 }
1254
1255 return min_t(unsigned int, mtu, IP_MAX_MTU);
1256 }
1257
1258 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1259 {
1260 struct fnhe_hash_bucket *hash = rcu_dereference(nh->nh_exceptions);
1261 struct fib_nh_exception *fnhe;
1262 u32 hval;
1263
1264 if (!hash)
1265 return NULL;
1266
1267 hval = fnhe_hashfun(daddr);
1268
1269 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1270 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1271 if (fnhe->fnhe_daddr == daddr)
1272 return fnhe;
1273 }
1274 return NULL;
1275 }
1276
1277 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1278 __be32 daddr)
1279 {
1280 bool ret = false;
1281
1282 spin_lock_bh(&fnhe_lock);
1283
1284 if (daddr == fnhe->fnhe_daddr) {
1285 struct rtable __rcu **porig;
1286 struct rtable *orig;
1287 int genid = fnhe_genid(dev_net(rt->dst.dev));
1288
1289 if (rt_is_input_route(rt))
1290 porig = &fnhe->fnhe_rth_input;
1291 else
1292 porig = &fnhe->fnhe_rth_output;
1293 orig = rcu_dereference(*porig);
1294
1295 if (fnhe->fnhe_genid != genid) {
1296 fnhe->fnhe_genid = genid;
1297 fnhe->fnhe_gw = 0;
1298 fnhe->fnhe_pmtu = 0;
1299 fnhe->fnhe_expires = 0;
1300 fnhe_flush_routes(fnhe);
1301 orig = NULL;
1302 }
1303 fill_route_from_fnhe(rt, fnhe);
1304 if (!rt->rt_gateway)
1305 rt->rt_gateway = daddr;
1306
1307 if (!(rt->dst.flags & DST_NOCACHE)) {
1308 rcu_assign_pointer(*porig, rt);
1309 if (orig)
1310 rt_free(orig);
1311 ret = true;
1312 }
1313
1314 fnhe->fnhe_stamp = jiffies;
1315 }
1316 spin_unlock_bh(&fnhe_lock);
1317
1318 return ret;
1319 }
1320
1321 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1322 {
1323 struct rtable *orig, *prev, **p;
1324 bool ret = true;
1325
1326 if (rt_is_input_route(rt)) {
1327 p = (struct rtable **)&nh->nh_rth_input;
1328 } else {
1329 p = (struct rtable **)raw_cpu_ptr(nh->nh_pcpu_rth_output);
1330 }
1331 orig = *p;
1332
1333 prev = cmpxchg(p, orig, rt);
1334 if (prev == orig) {
1335 if (orig)
1336 rt_free(orig);
1337 } else
1338 ret = false;
1339
1340 return ret;
1341 }
1342
1343 struct uncached_list {
1344 spinlock_t lock;
1345 struct list_head head;
1346 };
1347
1348 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
1349
1350 static void rt_add_uncached_list(struct rtable *rt)
1351 {
1352 struct uncached_list *ul = raw_cpu_ptr(&rt_uncached_list);
1353
1354 rt->rt_uncached_list = ul;
1355
1356 spin_lock_bh(&ul->lock);
1357 list_add_tail(&rt->rt_uncached, &ul->head);
1358 spin_unlock_bh(&ul->lock);
1359 }
1360
1361 static void ipv4_dst_destroy(struct dst_entry *dst)
1362 {
1363 struct rtable *rt = (struct rtable *) dst;
1364
1365 if (!list_empty(&rt->rt_uncached)) {
1366 struct uncached_list *ul = rt->rt_uncached_list;
1367
1368 spin_lock_bh(&ul->lock);
1369 list_del(&rt->rt_uncached);
1370 spin_unlock_bh(&ul->lock);
1371 }
1372 }
1373
1374 void rt_flush_dev(struct net_device *dev)
1375 {
1376 struct net *net = dev_net(dev);
1377 struct rtable *rt;
1378 int cpu;
1379
1380 for_each_possible_cpu(cpu) {
1381 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
1382
1383 spin_lock_bh(&ul->lock);
1384 list_for_each_entry(rt, &ul->head, rt_uncached) {
1385 if (rt->dst.dev != dev)
1386 continue;
1387 rt->dst.dev = net->loopback_dev;
1388 dev_hold(rt->dst.dev);
1389 dev_put(dev);
1390 }
1391 spin_unlock_bh(&ul->lock);
1392 }
1393 }
1394
1395 static bool rt_cache_valid(const struct rtable *rt)
1396 {
1397 return rt &&
1398 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1399 !rt_is_expired(rt);
1400 }
1401
1402 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1403 const struct fib_result *res,
1404 struct fib_nh_exception *fnhe,
1405 struct fib_info *fi, u16 type, u32 itag)
1406 {
1407 bool cached = false;
1408
1409 if (fi) {
1410 struct fib_nh *nh = &FIB_RES_NH(*res);
1411
1412 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) {
1413 rt->rt_gateway = nh->nh_gw;
1414 rt->rt_uses_gateway = 1;
1415 }
1416 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1417 #ifdef CONFIG_IP_ROUTE_CLASSID
1418 rt->dst.tclassid = nh->nh_tclassid;
1419 #endif
1420 rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
1421 if (unlikely(fnhe))
1422 cached = rt_bind_exception(rt, fnhe, daddr);
1423 else if (!(rt->dst.flags & DST_NOCACHE))
1424 cached = rt_cache_route(nh, rt);
1425 if (unlikely(!cached)) {
1426 /* Routes we intend to cache in nexthop exception or
1427 * FIB nexthop have the DST_NOCACHE bit clear.
1428 * However, if we are unsuccessful at storing this
1429 * route into the cache we really need to set it.
1430 */
1431 rt->dst.flags |= DST_NOCACHE;
1432 if (!rt->rt_gateway)
1433 rt->rt_gateway = daddr;
1434 rt_add_uncached_list(rt);
1435 }
1436 } else
1437 rt_add_uncached_list(rt);
1438
1439 #ifdef CONFIG_IP_ROUTE_CLASSID
1440 #ifdef CONFIG_IP_MULTIPLE_TABLES
1441 set_class_tag(rt, res->tclassid);
1442 #endif
1443 set_class_tag(rt, itag);
1444 #endif
1445 }
1446
1447 struct rtable *rt_dst_alloc(struct net_device *dev,
1448 unsigned int flags, u16 type,
1449 bool nopolicy, bool noxfrm, bool will_cache)
1450 {
1451 struct rtable *rt;
1452
1453 rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1454 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1455 (nopolicy ? DST_NOPOLICY : 0) |
1456 (noxfrm ? DST_NOXFRM : 0));
1457
1458 if (rt) {
1459 rt->rt_genid = rt_genid_ipv4(dev_net(dev));
1460 rt->rt_flags = flags;
1461 rt->rt_type = type;
1462 rt->rt_is_input = 0;
1463 rt->rt_iif = 0;
1464 rt->rt_pmtu = 0;
1465 rt->rt_gateway = 0;
1466 rt->rt_uses_gateway = 0;
1467 rt->rt_table_id = 0;
1468 INIT_LIST_HEAD(&rt->rt_uncached);
1469
1470 rt->dst.output = ip_output;
1471 if (flags & RTCF_LOCAL)
1472 rt->dst.input = ip_local_deliver;
1473 }
1474
1475 return rt;
1476 }
1477 EXPORT_SYMBOL(rt_dst_alloc);
1478
1479 /* called in rcu_read_lock() section */
1480 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1481 u8 tos, struct net_device *dev, int our)
1482 {
1483 struct rtable *rth;
1484 struct in_device *in_dev = __in_dev_get_rcu(dev);
1485 unsigned int flags = RTCF_MULTICAST;
1486 u32 itag = 0;
1487 int err;
1488
1489 /* Primary sanity checks. */
1490
1491 if (!in_dev)
1492 return -EINVAL;
1493
1494 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1495 skb->protocol != htons(ETH_P_IP))
1496 goto e_inval;
1497
1498 if (ipv4_is_loopback(saddr) && !IN_DEV_ROUTE_LOCALNET(in_dev))
1499 goto e_inval;
1500
1501 if (ipv4_is_zeronet(saddr)) {
1502 if (!ipv4_is_local_multicast(daddr))
1503 goto e_inval;
1504 } else {
1505 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1506 in_dev, &itag);
1507 if (err < 0)
1508 goto e_err;
1509 }
1510 if (our)
1511 flags |= RTCF_LOCAL;
1512
1513 rth = rt_dst_alloc(dev_net(dev)->loopback_dev, flags, RTN_MULTICAST,
1514 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1515 if (!rth)
1516 goto e_nobufs;
1517
1518 #ifdef CONFIG_IP_ROUTE_CLASSID
1519 rth->dst.tclassid = itag;
1520 #endif
1521 rth->dst.output = ip_rt_bug;
1522 rth->rt_is_input= 1;
1523
1524 #ifdef CONFIG_IP_MROUTE
1525 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1526 rth->dst.input = ip_mr_input;
1527 #endif
1528 RT_CACHE_STAT_INC(in_slow_mc);
1529
1530 skb_dst_set(skb, &rth->dst);
1531 return 0;
1532
1533 e_nobufs:
1534 return -ENOBUFS;
1535 e_inval:
1536 return -EINVAL;
1537 e_err:
1538 return err;
1539 }
1540
1541
1542 static void ip_handle_martian_source(struct net_device *dev,
1543 struct in_device *in_dev,
1544 struct sk_buff *skb,
1545 __be32 daddr,
1546 __be32 saddr)
1547 {
1548 RT_CACHE_STAT_INC(in_martian_src);
1549 #ifdef CONFIG_IP_ROUTE_VERBOSE
1550 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1551 /*
1552 * RFC1812 recommendation, if source is martian,
1553 * the only hint is MAC header.
1554 */
1555 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1556 &daddr, &saddr, dev->name);
1557 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1558 print_hex_dump(KERN_WARNING, "ll header: ",
1559 DUMP_PREFIX_OFFSET, 16, 1,
1560 skb_mac_header(skb),
1561 dev->hard_header_len, true);
1562 }
1563 }
1564 #endif
1565 }
1566
1567 static void ip_del_fnhe(struct fib_nh *nh, __be32 daddr)
1568 {
1569 struct fnhe_hash_bucket *hash;
1570 struct fib_nh_exception *fnhe, __rcu **fnhe_p;
1571 u32 hval = fnhe_hashfun(daddr);
1572
1573 spin_lock_bh(&fnhe_lock);
1574
1575 hash = rcu_dereference_protected(nh->nh_exceptions,
1576 lockdep_is_held(&fnhe_lock));
1577 hash += hval;
1578
1579 fnhe_p = &hash->chain;
1580 fnhe = rcu_dereference_protected(*fnhe_p, lockdep_is_held(&fnhe_lock));
1581 while (fnhe) {
1582 if (fnhe->fnhe_daddr == daddr) {
1583 rcu_assign_pointer(*fnhe_p, rcu_dereference_protected(
1584 fnhe->fnhe_next, lockdep_is_held(&fnhe_lock)));
1585 fnhe_flush_routes(fnhe);
1586 kfree_rcu(fnhe, rcu);
1587 break;
1588 }
1589 fnhe_p = &fnhe->fnhe_next;
1590 fnhe = rcu_dereference_protected(fnhe->fnhe_next,
1591 lockdep_is_held(&fnhe_lock));
1592 }
1593
1594 spin_unlock_bh(&fnhe_lock);
1595 }
1596
1597 /* called in rcu_read_lock() section */
1598 static int __mkroute_input(struct sk_buff *skb,
1599 const struct fib_result *res,
1600 struct in_device *in_dev,
1601 __be32 daddr, __be32 saddr, u32 tos)
1602 {
1603 struct fib_nh_exception *fnhe;
1604 struct rtable *rth;
1605 int err;
1606 struct in_device *out_dev;
1607 bool do_cache;
1608 u32 itag = 0;
1609
1610 /* get a working reference to the output device */
1611 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1612 if (!out_dev) {
1613 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1614 return -EINVAL;
1615 }
1616
1617 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1618 in_dev->dev, in_dev, &itag);
1619 if (err < 0) {
1620 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1621 saddr);
1622
1623 goto cleanup;
1624 }
1625
1626 do_cache = res->fi && !itag;
1627 if (out_dev == in_dev && err && IN_DEV_TX_REDIRECTS(out_dev) &&
1628 skb->protocol == htons(ETH_P_IP) &&
1629 (IN_DEV_SHARED_MEDIA(out_dev) ||
1630 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1631 IPCB(skb)->flags |= IPSKB_DOREDIRECT;
1632
1633 if (skb->protocol != htons(ETH_P_IP)) {
1634 /* Not IP (i.e. ARP). Do not create route, if it is
1635 * invalid for proxy arp. DNAT routes are always valid.
1636 *
1637 * Proxy arp feature have been extended to allow, ARP
1638 * replies back to the same interface, to support
1639 * Private VLAN switch technologies. See arp.c.
1640 */
1641 if (out_dev == in_dev &&
1642 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1643 err = -EINVAL;
1644 goto cleanup;
1645 }
1646 }
1647
1648 fnhe = find_exception(&FIB_RES_NH(*res), daddr);
1649 if (do_cache) {
1650 if (fnhe) {
1651 rth = rcu_dereference(fnhe->fnhe_rth_input);
1652 if (rth && rth->dst.expires &&
1653 time_after(jiffies, rth->dst.expires)) {
1654 ip_del_fnhe(&FIB_RES_NH(*res), daddr);
1655 fnhe = NULL;
1656 } else {
1657 goto rt_cache;
1658 }
1659 }
1660
1661 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1662
1663 rt_cache:
1664 if (rt_cache_valid(rth)) {
1665 skb_dst_set_noref(skb, &rth->dst);
1666 goto out;
1667 }
1668 }
1669
1670 rth = rt_dst_alloc(out_dev->dev, 0, res->type,
1671 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1672 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1673 if (!rth) {
1674 err = -ENOBUFS;
1675 goto cleanup;
1676 }
1677
1678 rth->rt_is_input = 1;
1679 if (res->table)
1680 rth->rt_table_id = res->table->tb_id;
1681 RT_CACHE_STAT_INC(in_slow_tot);
1682
1683 rth->dst.input = ip_forward;
1684
1685 rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
1686 if (lwtunnel_output_redirect(rth->dst.lwtstate)) {
1687 rth->dst.lwtstate->orig_output = rth->dst.output;
1688 rth->dst.output = lwtunnel_output;
1689 }
1690 if (lwtunnel_input_redirect(rth->dst.lwtstate)) {
1691 rth->dst.lwtstate->orig_input = rth->dst.input;
1692 rth->dst.input = lwtunnel_input;
1693 }
1694 skb_dst_set(skb, &rth->dst);
1695 out:
1696 err = 0;
1697 cleanup:
1698 return err;
1699 }
1700
1701 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1702
1703 /* To make ICMP packets follow the right flow, the multipath hash is
1704 * calculated from the inner IP addresses in reverse order.
1705 */
1706 static int ip_multipath_icmp_hash(struct sk_buff *skb)
1707 {
1708 const struct iphdr *outer_iph = ip_hdr(skb);
1709 struct icmphdr _icmph;
1710 const struct icmphdr *icmph;
1711 struct iphdr _inner_iph;
1712 const struct iphdr *inner_iph;
1713
1714 if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
1715 goto standard_hash;
1716
1717 icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
1718 &_icmph);
1719 if (!icmph)
1720 goto standard_hash;
1721
1722 if (icmph->type != ICMP_DEST_UNREACH &&
1723 icmph->type != ICMP_REDIRECT &&
1724 icmph->type != ICMP_TIME_EXCEEDED &&
1725 icmph->type != ICMP_PARAMETERPROB) {
1726 goto standard_hash;
1727 }
1728
1729 inner_iph = skb_header_pointer(skb,
1730 outer_iph->ihl * 4 + sizeof(_icmph),
1731 sizeof(_inner_iph), &_inner_iph);
1732 if (!inner_iph)
1733 goto standard_hash;
1734
1735 return fib_multipath_hash(inner_iph->daddr, inner_iph->saddr);
1736
1737 standard_hash:
1738 return fib_multipath_hash(outer_iph->saddr, outer_iph->daddr);
1739 }
1740
1741 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
1742
1743 static int ip_mkroute_input(struct sk_buff *skb,
1744 struct fib_result *res,
1745 const struct flowi4 *fl4,
1746 struct in_device *in_dev,
1747 __be32 daddr, __be32 saddr, u32 tos)
1748 {
1749 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1750 if (res->fi && res->fi->fib_nhs > 1) {
1751 int h;
1752
1753 if (unlikely(ip_hdr(skb)->protocol == IPPROTO_ICMP))
1754 h = ip_multipath_icmp_hash(skb);
1755 else
1756 h = fib_multipath_hash(saddr, daddr);
1757 fib_select_multipath(res, h);
1758 }
1759 #endif
1760
1761 /* create a routing cache entry */
1762 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1763 }
1764
1765 /*
1766 * NOTE. We drop all the packets that has local source
1767 * addresses, because every properly looped back packet
1768 * must have correct destination already attached by output routine.
1769 *
1770 * Such approach solves two big problems:
1771 * 1. Not simplex devices are handled properly.
1772 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1773 * called with rcu_read_lock()
1774 */
1775
1776 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1777 u8 tos, struct net_device *dev)
1778 {
1779 struct fib_result res;
1780 struct in_device *in_dev = __in_dev_get_rcu(dev);
1781 struct ip_tunnel_info *tun_info;
1782 struct flowi4 fl4;
1783 unsigned int flags = 0;
1784 u32 itag = 0;
1785 struct rtable *rth;
1786 int err = -EINVAL;
1787 struct net *net = dev_net(dev);
1788 bool do_cache;
1789
1790 /* IP on this device is disabled. */
1791
1792 if (!in_dev)
1793 goto out;
1794
1795 /* Check for the most weird martians, which can be not detected
1796 by fib_lookup.
1797 */
1798
1799 tun_info = skb_tunnel_info(skb);
1800 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
1801 fl4.flowi4_tun_key.tun_id = tun_info->key.tun_id;
1802 else
1803 fl4.flowi4_tun_key.tun_id = 0;
1804 skb_dst_drop(skb);
1805
1806 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1807 goto martian_source;
1808
1809 res.fi = NULL;
1810 res.table = NULL;
1811 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1812 goto brd_input;
1813
1814 /* Accept zero addresses only to limited broadcast;
1815 * I even do not know to fix it or not. Waiting for complains :-)
1816 */
1817 if (ipv4_is_zeronet(saddr))
1818 goto martian_source;
1819
1820 if (ipv4_is_zeronet(daddr))
1821 goto martian_destination;
1822
1823 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1824 * and call it once if daddr or/and saddr are loopback addresses
1825 */
1826 if (ipv4_is_loopback(daddr)) {
1827 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1828 goto martian_destination;
1829 } else if (ipv4_is_loopback(saddr)) {
1830 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1831 goto martian_source;
1832 }
1833
1834 /*
1835 * Now we are ready to route packet.
1836 */
1837 fl4.flowi4_oif = 0;
1838 fl4.flowi4_iif = l3mdev_fib_oif_rcu(dev);
1839 fl4.flowi4_mark = skb->mark;
1840 fl4.flowi4_tos = tos;
1841 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1842 fl4.flowi4_flags = 0;
1843 fl4.daddr = daddr;
1844 fl4.saddr = saddr;
1845 err = fib_lookup(net, &fl4, &res, 0);
1846 if (err != 0) {
1847 if (!IN_DEV_FORWARD(in_dev))
1848 err = -EHOSTUNREACH;
1849 goto no_route;
1850 }
1851
1852 if (res.type == RTN_BROADCAST)
1853 goto brd_input;
1854
1855 if (res.type == RTN_LOCAL) {
1856 err = fib_validate_source(skb, saddr, daddr, tos,
1857 0, dev, in_dev, &itag);
1858 if (err < 0)
1859 goto martian_source;
1860 goto local_input;
1861 }
1862
1863 if (!IN_DEV_FORWARD(in_dev)) {
1864 err = -EHOSTUNREACH;
1865 goto no_route;
1866 }
1867 if (res.type != RTN_UNICAST)
1868 goto martian_destination;
1869
1870 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1871 out: return err;
1872
1873 brd_input:
1874 if (skb->protocol != htons(ETH_P_IP))
1875 goto e_inval;
1876
1877 if (!ipv4_is_zeronet(saddr)) {
1878 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1879 in_dev, &itag);
1880 if (err < 0)
1881 goto martian_source;
1882 }
1883 flags |= RTCF_BROADCAST;
1884 res.type = RTN_BROADCAST;
1885 RT_CACHE_STAT_INC(in_brd);
1886
1887 local_input:
1888 do_cache = false;
1889 if (res.fi) {
1890 if (!itag) {
1891 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1892 if (rt_cache_valid(rth)) {
1893 skb_dst_set_noref(skb, &rth->dst);
1894 err = 0;
1895 goto out;
1896 }
1897 do_cache = true;
1898 }
1899 }
1900
1901 rth = rt_dst_alloc(net->loopback_dev, flags | RTCF_LOCAL, res.type,
1902 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1903 if (!rth)
1904 goto e_nobufs;
1905
1906 rth->dst.output= ip_rt_bug;
1907 #ifdef CONFIG_IP_ROUTE_CLASSID
1908 rth->dst.tclassid = itag;
1909 #endif
1910 rth->rt_is_input = 1;
1911 if (res.table)
1912 rth->rt_table_id = res.table->tb_id;
1913
1914 RT_CACHE_STAT_INC(in_slow_tot);
1915 if (res.type == RTN_UNREACHABLE) {
1916 rth->dst.input= ip_error;
1917 rth->dst.error= -err;
1918 rth->rt_flags &= ~RTCF_LOCAL;
1919 }
1920 if (do_cache) {
1921 if (unlikely(!rt_cache_route(&FIB_RES_NH(res), rth))) {
1922 rth->dst.flags |= DST_NOCACHE;
1923 rt_add_uncached_list(rth);
1924 }
1925 }
1926 skb_dst_set(skb, &rth->dst);
1927 err = 0;
1928 goto out;
1929
1930 no_route:
1931 RT_CACHE_STAT_INC(in_no_route);
1932 res.type = RTN_UNREACHABLE;
1933 res.fi = NULL;
1934 res.table = NULL;
1935 goto local_input;
1936
1937 /*
1938 * Do not cache martian addresses: they should be logged (RFC1812)
1939 */
1940 martian_destination:
1941 RT_CACHE_STAT_INC(in_martian_dst);
1942 #ifdef CONFIG_IP_ROUTE_VERBOSE
1943 if (IN_DEV_LOG_MARTIANS(in_dev))
1944 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1945 &daddr, &saddr, dev->name);
1946 #endif
1947
1948 e_inval:
1949 err = -EINVAL;
1950 goto out;
1951
1952 e_nobufs:
1953 err = -ENOBUFS;
1954 goto out;
1955
1956 martian_source:
1957 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1958 goto out;
1959 }
1960
1961 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1962 u8 tos, struct net_device *dev)
1963 {
1964 int res;
1965
1966 rcu_read_lock();
1967
1968 /* Multicast recognition logic is moved from route cache to here.
1969 The problem was that too many Ethernet cards have broken/missing
1970 hardware multicast filters :-( As result the host on multicasting
1971 network acquires a lot of useless route cache entries, sort of
1972 SDR messages from all the world. Now we try to get rid of them.
1973 Really, provided software IP multicast filter is organized
1974 reasonably (at least, hashed), it does not result in a slowdown
1975 comparing with route cache reject entries.
1976 Note, that multicast routers are not affected, because
1977 route cache entry is created eventually.
1978 */
1979 if (ipv4_is_multicast(daddr)) {
1980 struct in_device *in_dev = __in_dev_get_rcu(dev);
1981
1982 if (in_dev) {
1983 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1984 ip_hdr(skb)->protocol);
1985 if (our
1986 #ifdef CONFIG_IP_MROUTE
1987 ||
1988 (!ipv4_is_local_multicast(daddr) &&
1989 IN_DEV_MFORWARD(in_dev))
1990 #endif
1991 ) {
1992 int res = ip_route_input_mc(skb, daddr, saddr,
1993 tos, dev, our);
1994 rcu_read_unlock();
1995 return res;
1996 }
1997 }
1998 rcu_read_unlock();
1999 return -EINVAL;
2000 }
2001 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2002 rcu_read_unlock();
2003 return res;
2004 }
2005 EXPORT_SYMBOL(ip_route_input_noref);
2006
2007 /* called with rcu_read_lock() */
2008 static struct rtable *__mkroute_output(const struct fib_result *res,
2009 const struct flowi4 *fl4, int orig_oif,
2010 struct net_device *dev_out,
2011 unsigned int flags)
2012 {
2013 struct fib_info *fi = res->fi;
2014 struct fib_nh_exception *fnhe;
2015 struct in_device *in_dev;
2016 u16 type = res->type;
2017 struct rtable *rth;
2018 bool do_cache;
2019
2020 in_dev = __in_dev_get_rcu(dev_out);
2021 if (!in_dev)
2022 return ERR_PTR(-EINVAL);
2023
2024 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
2025 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2026 return ERR_PTR(-EINVAL);
2027
2028 if (ipv4_is_lbcast(fl4->daddr))
2029 type = RTN_BROADCAST;
2030 else if (ipv4_is_multicast(fl4->daddr))
2031 type = RTN_MULTICAST;
2032 else if (ipv4_is_zeronet(fl4->daddr))
2033 return ERR_PTR(-EINVAL);
2034
2035 if (dev_out->flags & IFF_LOOPBACK)
2036 flags |= RTCF_LOCAL;
2037
2038 do_cache = true;
2039 if (type == RTN_BROADCAST) {
2040 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2041 fi = NULL;
2042 } else if (type == RTN_MULTICAST) {
2043 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2044 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2045 fl4->flowi4_proto))
2046 flags &= ~RTCF_LOCAL;
2047 else
2048 do_cache = false;
2049 /* If multicast route do not exist use
2050 * default one, but do not gateway in this case.
2051 * Yes, it is hack.
2052 */
2053 if (fi && res->prefixlen < 4)
2054 fi = NULL;
2055 } else if ((type == RTN_LOCAL) && (orig_oif != 0) &&
2056 (orig_oif != dev_out->ifindex)) {
2057 /* For local routes that require a particular output interface
2058 * we do not want to cache the result. Caching the result
2059 * causes incorrect behaviour when there are multiple source
2060 * addresses on the interface, the end result being that if the
2061 * intended recipient is waiting on that interface for the
2062 * packet he won't receive it because it will be delivered on
2063 * the loopback interface and the IP_PKTINFO ipi_ifindex will
2064 * be set to the loopback interface as well.
2065 */
2066 fi = NULL;
2067 }
2068
2069 fnhe = NULL;
2070 do_cache &= fi != NULL;
2071 if (do_cache) {
2072 struct rtable __rcu **prth;
2073 struct fib_nh *nh = &FIB_RES_NH(*res);
2074
2075 fnhe = find_exception(nh, fl4->daddr);
2076 if (fnhe) {
2077 prth = &fnhe->fnhe_rth_output;
2078 rth = rcu_dereference(*prth);
2079 if (rth && rth->dst.expires &&
2080 time_after(jiffies, rth->dst.expires)) {
2081 ip_del_fnhe(nh, fl4->daddr);
2082 fnhe = NULL;
2083 } else {
2084 goto rt_cache;
2085 }
2086 }
2087
2088 if (unlikely(fl4->flowi4_flags &
2089 FLOWI_FLAG_KNOWN_NH &&
2090 !(nh->nh_gw &&
2091 nh->nh_scope == RT_SCOPE_LINK))) {
2092 do_cache = false;
2093 goto add;
2094 }
2095 prth = raw_cpu_ptr(nh->nh_pcpu_rth_output);
2096 rth = rcu_dereference(*prth);
2097
2098 rt_cache:
2099 if (rt_cache_valid(rth)) {
2100 dst_hold(&rth->dst);
2101 return rth;
2102 }
2103 }
2104
2105 add:
2106 rth = rt_dst_alloc(dev_out, flags, type,
2107 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2108 IN_DEV_CONF_GET(in_dev, NOXFRM),
2109 do_cache);
2110 if (!rth)
2111 return ERR_PTR(-ENOBUFS);
2112
2113 rth->rt_iif = orig_oif ? : 0;
2114 if (res->table)
2115 rth->rt_table_id = res->table->tb_id;
2116
2117 RT_CACHE_STAT_INC(out_slow_tot);
2118
2119 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2120 if (flags & RTCF_LOCAL &&
2121 !(dev_out->flags & IFF_LOOPBACK)) {
2122 rth->dst.output = ip_mc_output;
2123 RT_CACHE_STAT_INC(out_slow_mc);
2124 }
2125 #ifdef CONFIG_IP_MROUTE
2126 if (type == RTN_MULTICAST) {
2127 if (IN_DEV_MFORWARD(in_dev) &&
2128 !ipv4_is_local_multicast(fl4->daddr)) {
2129 rth->dst.input = ip_mr_input;
2130 rth->dst.output = ip_mc_output;
2131 }
2132 }
2133 #endif
2134 }
2135
2136 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
2137 if (lwtunnel_output_redirect(rth->dst.lwtstate))
2138 rth->dst.output = lwtunnel_output;
2139
2140 return rth;
2141 }
2142
2143 /*
2144 * Major route resolver routine.
2145 */
2146
2147 struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
2148 int mp_hash)
2149 {
2150 struct net_device *dev_out = NULL;
2151 __u8 tos = RT_FL_TOS(fl4);
2152 unsigned int flags = 0;
2153 struct fib_result res;
2154 struct rtable *rth;
2155 int master_idx;
2156 int orig_oif;
2157 int err = -ENETUNREACH;
2158
2159 res.tclassid = 0;
2160 res.fi = NULL;
2161 res.table = NULL;
2162
2163 orig_oif = fl4->flowi4_oif;
2164
2165 master_idx = l3mdev_master_ifindex_by_index(net, fl4->flowi4_oif);
2166 if (master_idx)
2167 fl4->flowi4_oif = master_idx;
2168 fl4->flowi4_iif = LOOPBACK_IFINDEX;
2169 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2170 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2171 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2172
2173 rcu_read_lock();
2174 if (fl4->saddr) {
2175 rth = ERR_PTR(-EINVAL);
2176 if (ipv4_is_multicast(fl4->saddr) ||
2177 ipv4_is_lbcast(fl4->saddr) ||
2178 ipv4_is_zeronet(fl4->saddr))
2179 goto out;
2180
2181 /* I removed check for oif == dev_out->oif here.
2182 It was wrong for two reasons:
2183 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2184 is assigned to multiple interfaces.
2185 2. Moreover, we are allowed to send packets with saddr
2186 of another iface. --ANK
2187 */
2188
2189 if (fl4->flowi4_oif == 0 &&
2190 (ipv4_is_multicast(fl4->daddr) ||
2191 ipv4_is_lbcast(fl4->daddr))) {
2192 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2193 dev_out = __ip_dev_find(net, fl4->saddr, false);
2194 if (!dev_out)
2195 goto out;
2196
2197 /* Special hack: user can direct multicasts
2198 and limited broadcast via necessary interface
2199 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2200 This hack is not just for fun, it allows
2201 vic,vat and friends to work.
2202 They bind socket to loopback, set ttl to zero
2203 and expect that it will work.
2204 From the viewpoint of routing cache they are broken,
2205 because we are not allowed to build multicast path
2206 with loopback source addr (look, routing cache
2207 cannot know, that ttl is zero, so that packet
2208 will not leave this host and route is valid).
2209 Luckily, this hack is good workaround.
2210 */
2211
2212 fl4->flowi4_oif = dev_out->ifindex;
2213 goto make_route;
2214 }
2215
2216 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2217 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2218 if (!__ip_dev_find(net, fl4->saddr, false))
2219 goto out;
2220 }
2221 }
2222
2223
2224 if (fl4->flowi4_oif) {
2225 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2226 rth = ERR_PTR(-ENODEV);
2227 if (!dev_out)
2228 goto out;
2229
2230 /* RACE: Check return value of inet_select_addr instead. */
2231 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2232 rth = ERR_PTR(-ENETUNREACH);
2233 goto out;
2234 }
2235 if (ipv4_is_local_multicast(fl4->daddr) ||
2236 ipv4_is_lbcast(fl4->daddr) ||
2237 fl4->flowi4_proto == IPPROTO_IGMP) {
2238 if (!fl4->saddr)
2239 fl4->saddr = inet_select_addr(dev_out, 0,
2240 RT_SCOPE_LINK);
2241 goto make_route;
2242 }
2243 if (!fl4->saddr) {
2244 if (ipv4_is_multicast(fl4->daddr))
2245 fl4->saddr = inet_select_addr(dev_out, 0,
2246 fl4->flowi4_scope);
2247 else if (!fl4->daddr)
2248 fl4->saddr = inet_select_addr(dev_out, 0,
2249 RT_SCOPE_HOST);
2250 }
2251
2252 rth = l3mdev_get_rtable(dev_out, fl4);
2253 if (rth)
2254 goto out;
2255 }
2256
2257 if (!fl4->daddr) {
2258 fl4->daddr = fl4->saddr;
2259 if (!fl4->daddr)
2260 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2261 dev_out = net->loopback_dev;
2262 fl4->flowi4_oif = LOOPBACK_IFINDEX;
2263 res.type = RTN_LOCAL;
2264 flags |= RTCF_LOCAL;
2265 goto make_route;
2266 }
2267
2268 err = fib_lookup(net, fl4, &res, 0);
2269 if (err) {
2270 res.fi = NULL;
2271 res.table = NULL;
2272 if (fl4->flowi4_oif &&
2273 !netif_index_is_l3_master(net, fl4->flowi4_oif)) {
2274 /* Apparently, routing tables are wrong. Assume,
2275 that the destination is on link.
2276
2277 WHY? DW.
2278 Because we are allowed to send to iface
2279 even if it has NO routes and NO assigned
2280 addresses. When oif is specified, routing
2281 tables are looked up with only one purpose:
2282 to catch if destination is gatewayed, rather than
2283 direct. Moreover, if MSG_DONTROUTE is set,
2284 we send packet, ignoring both routing tables
2285 and ifaddr state. --ANK
2286
2287
2288 We could make it even if oif is unknown,
2289 likely IPv6, but we do not.
2290 */
2291
2292 if (fl4->saddr == 0)
2293 fl4->saddr = inet_select_addr(dev_out, 0,
2294 RT_SCOPE_LINK);
2295 res.type = RTN_UNICAST;
2296 goto make_route;
2297 }
2298 rth = ERR_PTR(err);
2299 goto out;
2300 }
2301
2302 if (res.type == RTN_LOCAL) {
2303 if (!fl4->saddr) {
2304 if (res.fi->fib_prefsrc)
2305 fl4->saddr = res.fi->fib_prefsrc;
2306 else
2307 fl4->saddr = fl4->daddr;
2308 }
2309 dev_out = net->loopback_dev;
2310 fl4->flowi4_oif = dev_out->ifindex;
2311 flags |= RTCF_LOCAL;
2312 goto make_route;
2313 }
2314
2315 fib_select_path(net, &res, fl4, mp_hash);
2316
2317 dev_out = FIB_RES_DEV(res);
2318 fl4->flowi4_oif = dev_out->ifindex;
2319
2320
2321 make_route:
2322 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2323
2324 out:
2325 rcu_read_unlock();
2326 return rth;
2327 }
2328 EXPORT_SYMBOL_GPL(__ip_route_output_key_hash);
2329
2330 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2331 {
2332 return NULL;
2333 }
2334
2335 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2336 {
2337 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2338
2339 return mtu ? : dst->dev->mtu;
2340 }
2341
2342 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2343 struct sk_buff *skb, u32 mtu)
2344 {
2345 }
2346
2347 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2348 struct sk_buff *skb)
2349 {
2350 }
2351
2352 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2353 unsigned long old)
2354 {
2355 return NULL;
2356 }
2357
2358 static struct dst_ops ipv4_dst_blackhole_ops = {
2359 .family = AF_INET,
2360 .check = ipv4_blackhole_dst_check,
2361 .mtu = ipv4_blackhole_mtu,
2362 .default_advmss = ipv4_default_advmss,
2363 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2364 .redirect = ipv4_rt_blackhole_redirect,
2365 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2366 .neigh_lookup = ipv4_neigh_lookup,
2367 };
2368
2369 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2370 {
2371 struct rtable *ort = (struct rtable *) dst_orig;
2372 struct rtable *rt;
2373
2374 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2375 if (rt) {
2376 struct dst_entry *new = &rt->dst;
2377
2378 new->__use = 1;
2379 new->input = dst_discard;
2380 new->output = dst_discard_out;
2381
2382 new->dev = ort->dst.dev;
2383 if (new->dev)
2384 dev_hold(new->dev);
2385
2386 rt->rt_is_input = ort->rt_is_input;
2387 rt->rt_iif = ort->rt_iif;
2388 rt->rt_pmtu = ort->rt_pmtu;
2389
2390 rt->rt_genid = rt_genid_ipv4(net);
2391 rt->rt_flags = ort->rt_flags;
2392 rt->rt_type = ort->rt_type;
2393 rt->rt_gateway = ort->rt_gateway;
2394 rt->rt_uses_gateway = ort->rt_uses_gateway;
2395
2396 INIT_LIST_HEAD(&rt->rt_uncached);
2397 dst_free(new);
2398 }
2399
2400 dst_release(dst_orig);
2401
2402 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2403 }
2404
2405 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2406 const struct sock *sk)
2407 {
2408 struct rtable *rt = __ip_route_output_key(net, flp4);
2409
2410 if (IS_ERR(rt))
2411 return rt;
2412
2413 if (flp4->flowi4_proto)
2414 rt = (struct rtable *)xfrm_lookup_route(net, &rt->dst,
2415 flowi4_to_flowi(flp4),
2416 sk, 0);
2417
2418 return rt;
2419 }
2420 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2421
2422 static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id,
2423 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2424 u32 seq, int event, int nowait, unsigned int flags)
2425 {
2426 struct rtable *rt = skb_rtable(skb);
2427 struct rtmsg *r;
2428 struct nlmsghdr *nlh;
2429 unsigned long expires = 0;
2430 u32 error;
2431 u32 metrics[RTAX_MAX];
2432
2433 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2434 if (!nlh)
2435 return -EMSGSIZE;
2436
2437 r = nlmsg_data(nlh);
2438 r->rtm_family = AF_INET;
2439 r->rtm_dst_len = 32;
2440 r->rtm_src_len = 0;
2441 r->rtm_tos = fl4->flowi4_tos;
2442 r->rtm_table = table_id;
2443 if (nla_put_u32(skb, RTA_TABLE, table_id))
2444 goto nla_put_failure;
2445 r->rtm_type = rt->rt_type;
2446 r->rtm_scope = RT_SCOPE_UNIVERSE;
2447 r->rtm_protocol = RTPROT_UNSPEC;
2448 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2449 if (rt->rt_flags & RTCF_NOTIFY)
2450 r->rtm_flags |= RTM_F_NOTIFY;
2451 if (IPCB(skb)->flags & IPSKB_DOREDIRECT)
2452 r->rtm_flags |= RTCF_DOREDIRECT;
2453
2454 if (nla_put_in_addr(skb, RTA_DST, dst))
2455 goto nla_put_failure;
2456 if (src) {
2457 r->rtm_src_len = 32;
2458 if (nla_put_in_addr(skb, RTA_SRC, src))
2459 goto nla_put_failure;
2460 }
2461 if (rt->dst.dev &&
2462 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2463 goto nla_put_failure;
2464 #ifdef CONFIG_IP_ROUTE_CLASSID
2465 if (rt->dst.tclassid &&
2466 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2467 goto nla_put_failure;
2468 #endif
2469 if (!rt_is_input_route(rt) &&
2470 fl4->saddr != src) {
2471 if (nla_put_in_addr(skb, RTA_PREFSRC, fl4->saddr))
2472 goto nla_put_failure;
2473 }
2474 if (rt->rt_uses_gateway &&
2475 nla_put_in_addr(skb, RTA_GATEWAY, rt->rt_gateway))
2476 goto nla_put_failure;
2477
2478 expires = rt->dst.expires;
2479 if (expires) {
2480 unsigned long now = jiffies;
2481
2482 if (time_before(now, expires))
2483 expires -= now;
2484 else
2485 expires = 0;
2486 }
2487
2488 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2489 if (rt->rt_pmtu && expires)
2490 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2491 if (rtnetlink_put_metrics(skb, metrics) < 0)
2492 goto nla_put_failure;
2493
2494 if (fl4->flowi4_mark &&
2495 nla_put_u32(skb, RTA_MARK, fl4->flowi4_mark))
2496 goto nla_put_failure;
2497
2498 error = rt->dst.error;
2499
2500 if (rt_is_input_route(rt)) {
2501 #ifdef CONFIG_IP_MROUTE
2502 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
2503 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
2504 int err = ipmr_get_route(net, skb,
2505 fl4->saddr, fl4->daddr,
2506 r, nowait, portid);
2507
2508 if (err <= 0) {
2509 if (!nowait) {
2510 if (err == 0)
2511 return 0;
2512 goto nla_put_failure;
2513 } else {
2514 if (err == -EMSGSIZE)
2515 goto nla_put_failure;
2516 error = err;
2517 }
2518 }
2519 } else
2520 #endif
2521 if (nla_put_u32(skb, RTA_IIF, skb->dev->ifindex))
2522 goto nla_put_failure;
2523 }
2524
2525 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2526 goto nla_put_failure;
2527
2528 nlmsg_end(skb, nlh);
2529 return 0;
2530
2531 nla_put_failure:
2532 nlmsg_cancel(skb, nlh);
2533 return -EMSGSIZE;
2534 }
2535
2536 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2537 {
2538 struct net *net = sock_net(in_skb->sk);
2539 struct rtmsg *rtm;
2540 struct nlattr *tb[RTA_MAX+1];
2541 struct rtable *rt = NULL;
2542 struct flowi4 fl4;
2543 __be32 dst = 0;
2544 __be32 src = 0;
2545 u32 iif;
2546 int err;
2547 int mark;
2548 struct sk_buff *skb;
2549 u32 table_id = RT_TABLE_MAIN;
2550
2551 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2552 if (err < 0)
2553 goto errout;
2554
2555 rtm = nlmsg_data(nlh);
2556
2557 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2558 if (!skb) {
2559 err = -ENOBUFS;
2560 goto errout;
2561 }
2562
2563 /* Reserve room for dummy headers, this skb can pass
2564 through good chunk of routing engine.
2565 */
2566 skb_reset_mac_header(skb);
2567 skb_reset_network_header(skb);
2568
2569 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2570 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2571 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2572
2573 src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2574 dst = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2575 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2576 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2577
2578 memset(&fl4, 0, sizeof(fl4));
2579 fl4.daddr = dst;
2580 fl4.saddr = src;
2581 fl4.flowi4_tos = rtm->rtm_tos;
2582 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2583 fl4.flowi4_mark = mark;
2584
2585 if (netif_index_is_l3_master(net, fl4.flowi4_oif))
2586 fl4.flowi4_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF;
2587
2588 if (iif) {
2589 struct net_device *dev;
2590
2591 dev = __dev_get_by_index(net, iif);
2592 if (!dev) {
2593 err = -ENODEV;
2594 goto errout_free;
2595 }
2596
2597 skb->protocol = htons(ETH_P_IP);
2598 skb->dev = dev;
2599 skb->mark = mark;
2600 local_bh_disable();
2601 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2602 local_bh_enable();
2603
2604 rt = skb_rtable(skb);
2605 if (err == 0 && rt->dst.error)
2606 err = -rt->dst.error;
2607 } else {
2608 rt = ip_route_output_key(net, &fl4);
2609
2610 err = 0;
2611 if (IS_ERR(rt))
2612 err = PTR_ERR(rt);
2613 }
2614
2615 if (err)
2616 goto errout_free;
2617
2618 skb_dst_set(skb, &rt->dst);
2619 if (rtm->rtm_flags & RTM_F_NOTIFY)
2620 rt->rt_flags |= RTCF_NOTIFY;
2621
2622 if (rtm->rtm_flags & RTM_F_LOOKUP_TABLE)
2623 table_id = rt->rt_table_id;
2624
2625 err = rt_fill_info(net, dst, src, table_id, &fl4, skb,
2626 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2627 RTM_NEWROUTE, 0, 0);
2628 if (err < 0)
2629 goto errout_free;
2630
2631 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2632 errout:
2633 return err;
2634
2635 errout_free:
2636 kfree_skb(skb);
2637 goto errout;
2638 }
2639
2640 void ip_rt_multicast_event(struct in_device *in_dev)
2641 {
2642 rt_cache_flush(dev_net(in_dev->dev));
2643 }
2644
2645 #ifdef CONFIG_SYSCTL
2646 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
2647 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
2648 static int ip_rt_gc_elasticity __read_mostly = 8;
2649
2650 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
2651 void __user *buffer,
2652 size_t *lenp, loff_t *ppos)
2653 {
2654 struct net *net = (struct net *)__ctl->extra1;
2655
2656 if (write) {
2657 rt_cache_flush(net);
2658 fnhe_genid_bump(net);
2659 return 0;
2660 }
2661
2662 return -EINVAL;
2663 }
2664
2665 static struct ctl_table ipv4_route_table[] = {
2666 {
2667 .procname = "gc_thresh",
2668 .data = &ipv4_dst_ops.gc_thresh,
2669 .maxlen = sizeof(int),
2670 .mode = 0644,
2671 .proc_handler = proc_dointvec,
2672 },
2673 {
2674 .procname = "max_size",
2675 .data = &ip_rt_max_size,
2676 .maxlen = sizeof(int),
2677 .mode = 0644,
2678 .proc_handler = proc_dointvec,
2679 },
2680 {
2681 /* Deprecated. Use gc_min_interval_ms */
2682
2683 .procname = "gc_min_interval",
2684 .data = &ip_rt_gc_min_interval,
2685 .maxlen = sizeof(int),
2686 .mode = 0644,
2687 .proc_handler = proc_dointvec_jiffies,
2688 },
2689 {
2690 .procname = "gc_min_interval_ms",
2691 .data = &ip_rt_gc_min_interval,
2692 .maxlen = sizeof(int),
2693 .mode = 0644,
2694 .proc_handler = proc_dointvec_ms_jiffies,
2695 },
2696 {
2697 .procname = "gc_timeout",
2698 .data = &ip_rt_gc_timeout,
2699 .maxlen = sizeof(int),
2700 .mode = 0644,
2701 .proc_handler = proc_dointvec_jiffies,
2702 },
2703 {
2704 .procname = "gc_interval",
2705 .data = &ip_rt_gc_interval,
2706 .maxlen = sizeof(int),
2707 .mode = 0644,
2708 .proc_handler = proc_dointvec_jiffies,
2709 },
2710 {
2711 .procname = "redirect_load",
2712 .data = &ip_rt_redirect_load,
2713 .maxlen = sizeof(int),
2714 .mode = 0644,
2715 .proc_handler = proc_dointvec,
2716 },
2717 {
2718 .procname = "redirect_number",
2719 .data = &ip_rt_redirect_number,
2720 .maxlen = sizeof(int),
2721 .mode = 0644,
2722 .proc_handler = proc_dointvec,
2723 },
2724 {
2725 .procname = "redirect_silence",
2726 .data = &ip_rt_redirect_silence,
2727 .maxlen = sizeof(int),
2728 .mode = 0644,
2729 .proc_handler = proc_dointvec,
2730 },
2731 {
2732 .procname = "error_cost",
2733 .data = &ip_rt_error_cost,
2734 .maxlen = sizeof(int),
2735 .mode = 0644,
2736 .proc_handler = proc_dointvec,
2737 },
2738 {
2739 .procname = "error_burst",
2740 .data = &ip_rt_error_burst,
2741 .maxlen = sizeof(int),
2742 .mode = 0644,
2743 .proc_handler = proc_dointvec,
2744 },
2745 {
2746 .procname = "gc_elasticity",
2747 .data = &ip_rt_gc_elasticity,
2748 .maxlen = sizeof(int),
2749 .mode = 0644,
2750 .proc_handler = proc_dointvec,
2751 },
2752 {
2753 .procname = "mtu_expires",
2754 .data = &ip_rt_mtu_expires,
2755 .maxlen = sizeof(int),
2756 .mode = 0644,
2757 .proc_handler = proc_dointvec_jiffies,
2758 },
2759 {
2760 .procname = "min_pmtu",
2761 .data = &ip_rt_min_pmtu,
2762 .maxlen = sizeof(int),
2763 .mode = 0644,
2764 .proc_handler = proc_dointvec,
2765 },
2766 {
2767 .procname = "min_adv_mss",
2768 .data = &ip_rt_min_advmss,
2769 .maxlen = sizeof(int),
2770 .mode = 0644,
2771 .proc_handler = proc_dointvec,
2772 },
2773 { }
2774 };
2775
2776 static struct ctl_table ipv4_route_flush_table[] = {
2777 {
2778 .procname = "flush",
2779 .maxlen = sizeof(int),
2780 .mode = 0200,
2781 .proc_handler = ipv4_sysctl_rtcache_flush,
2782 },
2783 { },
2784 };
2785
2786 static __net_init int sysctl_route_net_init(struct net *net)
2787 {
2788 struct ctl_table *tbl;
2789
2790 tbl = ipv4_route_flush_table;
2791 if (!net_eq(net, &init_net)) {
2792 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2793 if (!tbl)
2794 goto err_dup;
2795
2796 /* Don't export sysctls to unprivileged users */
2797 if (net->user_ns != &init_user_ns)
2798 tbl[0].procname = NULL;
2799 }
2800 tbl[0].extra1 = net;
2801
2802 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2803 if (!net->ipv4.route_hdr)
2804 goto err_reg;
2805 return 0;
2806
2807 err_reg:
2808 if (tbl != ipv4_route_flush_table)
2809 kfree(tbl);
2810 err_dup:
2811 return -ENOMEM;
2812 }
2813
2814 static __net_exit void sysctl_route_net_exit(struct net *net)
2815 {
2816 struct ctl_table *tbl;
2817
2818 tbl = net->ipv4.route_hdr->ctl_table_arg;
2819 unregister_net_sysctl_table(net->ipv4.route_hdr);
2820 BUG_ON(tbl == ipv4_route_flush_table);
2821 kfree(tbl);
2822 }
2823
2824 static __net_initdata struct pernet_operations sysctl_route_ops = {
2825 .init = sysctl_route_net_init,
2826 .exit = sysctl_route_net_exit,
2827 };
2828 #endif
2829
2830 static __net_init int rt_genid_init(struct net *net)
2831 {
2832 atomic_set(&net->ipv4.rt_genid, 0);
2833 atomic_set(&net->fnhe_genid, 0);
2834 get_random_bytes(&net->ipv4.dev_addr_genid,
2835 sizeof(net->ipv4.dev_addr_genid));
2836 return 0;
2837 }
2838
2839 static __net_initdata struct pernet_operations rt_genid_ops = {
2840 .init = rt_genid_init,
2841 };
2842
2843 static int __net_init ipv4_inetpeer_init(struct net *net)
2844 {
2845 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2846
2847 if (!bp)
2848 return -ENOMEM;
2849 inet_peer_base_init(bp);
2850 net->ipv4.peers = bp;
2851 return 0;
2852 }
2853
2854 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2855 {
2856 struct inet_peer_base *bp = net->ipv4.peers;
2857
2858 net->ipv4.peers = NULL;
2859 inetpeer_invalidate_tree(bp);
2860 kfree(bp);
2861 }
2862
2863 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2864 .init = ipv4_inetpeer_init,
2865 .exit = ipv4_inetpeer_exit,
2866 };
2867
2868 #ifdef CONFIG_IP_ROUTE_CLASSID
2869 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2870 #endif /* CONFIG_IP_ROUTE_CLASSID */
2871
2872 int __init ip_rt_init(void)
2873 {
2874 int rc = 0;
2875 int cpu;
2876
2877 ip_idents = kmalloc(IP_IDENTS_SZ * sizeof(*ip_idents), GFP_KERNEL);
2878 if (!ip_idents)
2879 panic("IP: failed to allocate ip_idents\n");
2880
2881 prandom_bytes(ip_idents, IP_IDENTS_SZ * sizeof(*ip_idents));
2882
2883 ip_tstamps = kcalloc(IP_IDENTS_SZ, sizeof(*ip_tstamps), GFP_KERNEL);
2884 if (!ip_tstamps)
2885 panic("IP: failed to allocate ip_tstamps\n");
2886
2887 for_each_possible_cpu(cpu) {
2888 struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);
2889
2890 INIT_LIST_HEAD(&ul->head);
2891 spin_lock_init(&ul->lock);
2892 }
2893 #ifdef CONFIG_IP_ROUTE_CLASSID
2894 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2895 if (!ip_rt_acct)
2896 panic("IP: failed to allocate ip_rt_acct\n");
2897 #endif
2898
2899 ipv4_dst_ops.kmem_cachep =
2900 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2901 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2902
2903 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2904
2905 if (dst_entries_init(&ipv4_dst_ops) < 0)
2906 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2907
2908 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2909 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2910
2911 ipv4_dst_ops.gc_thresh = ~0;
2912 ip_rt_max_size = INT_MAX;
2913
2914 devinet_init();
2915 ip_fib_init();
2916
2917 if (ip_rt_proc_init())
2918 pr_err("Unable to create route proc files\n");
2919 #ifdef CONFIG_XFRM
2920 xfrm_init();
2921 xfrm4_init();
2922 #endif
2923 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2924
2925 #ifdef CONFIG_SYSCTL
2926 register_pernet_subsys(&sysctl_route_ops);
2927 #endif
2928 register_pernet_subsys(&rt_genid_ops);
2929 register_pernet_subsys(&ipv4_inetpeer_ops);
2930 return rc;
2931 }
2932
2933 #ifdef CONFIG_SYSCTL
2934 /*
2935 * We really need to sanitize the damn ipv4 init order, then all
2936 * this nonsense will go away.
2937 */
2938 void __init ip_static_sysctl_init(void)
2939 {
2940 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2941 }
2942 #endif
Linux kernel - Deliverables
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