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netlink: Rename pid to portid to avoid confusion
[GitHub/mt8127/android_kernel_alcatel_ttab.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 <net/dst.h>
93 #include <net/net_namespace.h>
94 #include <net/protocol.h>
95 #include <net/ip.h>
96 #include <net/route.h>
97 #include <net/inetpeer.h>
98 #include <net/sock.h>
99 #include <net/ip_fib.h>
100 #include <net/arp.h>
101 #include <net/tcp.h>
102 #include <net/icmp.h>
103 #include <net/xfrm.h>
104 #include <net/netevent.h>
105 #include <net/rtnetlink.h>
106 #ifdef CONFIG_SYSCTL
107 #include <linux/sysctl.h>
108 #include <linux/kmemleak.h>
109 #endif
110 #include <net/secure_seq.h>
111
112 #define RT_FL_TOS(oldflp4) \
113 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
114
115 #define IP_MAX_MTU 0xFFF0
116
117 #define RT_GC_TIMEOUT (300*HZ)
118
119 static int ip_rt_max_size;
120 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
121 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
122 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
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_gc_elasticity __read_mostly = 8;
129 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
130 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
131 static int ip_rt_min_advmss __read_mostly = 256;
132
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 void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
149 int how)
150 {
151 }
152
153 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
154 {
155 WARN_ON(1);
156 return NULL;
157 }
158
159 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
160 struct sk_buff *skb,
161 const void *daddr);
162
163 static struct dst_ops ipv4_dst_ops = {
164 .family = AF_INET,
165 .protocol = cpu_to_be16(ETH_P_IP),
166 .check = ipv4_dst_check,
167 .default_advmss = ipv4_default_advmss,
168 .mtu = ipv4_mtu,
169 .cow_metrics = ipv4_cow_metrics,
170 .destroy = ipv4_dst_destroy,
171 .ifdown = ipv4_dst_ifdown,
172 .negative_advice = ipv4_negative_advice,
173 .link_failure = ipv4_link_failure,
174 .update_pmtu = ip_rt_update_pmtu,
175 .redirect = ip_do_redirect,
176 .local_out = __ip_local_out,
177 .neigh_lookup = ipv4_neigh_lookup,
178 };
179
180 #define ECN_OR_COST(class) TC_PRIO_##class
181
182 const __u8 ip_tos2prio[16] = {
183 TC_PRIO_BESTEFFORT,
184 ECN_OR_COST(BESTEFFORT),
185 TC_PRIO_BESTEFFORT,
186 ECN_OR_COST(BESTEFFORT),
187 TC_PRIO_BULK,
188 ECN_OR_COST(BULK),
189 TC_PRIO_BULK,
190 ECN_OR_COST(BULK),
191 TC_PRIO_INTERACTIVE,
192 ECN_OR_COST(INTERACTIVE),
193 TC_PRIO_INTERACTIVE,
194 ECN_OR_COST(INTERACTIVE),
195 TC_PRIO_INTERACTIVE_BULK,
196 ECN_OR_COST(INTERACTIVE_BULK),
197 TC_PRIO_INTERACTIVE_BULK,
198 ECN_OR_COST(INTERACTIVE_BULK)
199 };
200 EXPORT_SYMBOL(ip_tos2prio);
201
202 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
203 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
204
205 static inline int rt_genid(struct net *net)
206 {
207 return atomic_read(&net->ipv4.rt_genid);
208 }
209
210 #ifdef CONFIG_PROC_FS
211 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
212 {
213 if (*pos)
214 return NULL;
215 return SEQ_START_TOKEN;
216 }
217
218 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
219 {
220 ++*pos;
221 return NULL;
222 }
223
224 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
225 {
226 }
227
228 static int rt_cache_seq_show(struct seq_file *seq, void *v)
229 {
230 if (v == SEQ_START_TOKEN)
231 seq_printf(seq, "%-127s\n",
232 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
233 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
234 "HHUptod\tSpecDst");
235 return 0;
236 }
237
238 static const struct seq_operations rt_cache_seq_ops = {
239 .start = rt_cache_seq_start,
240 .next = rt_cache_seq_next,
241 .stop = rt_cache_seq_stop,
242 .show = rt_cache_seq_show,
243 };
244
245 static int rt_cache_seq_open(struct inode *inode, struct file *file)
246 {
247 return seq_open(file, &rt_cache_seq_ops);
248 }
249
250 static const struct file_operations rt_cache_seq_fops = {
251 .owner = THIS_MODULE,
252 .open = rt_cache_seq_open,
253 .read = seq_read,
254 .llseek = seq_lseek,
255 .release = seq_release,
256 };
257
258
259 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
260 {
261 int cpu;
262
263 if (*pos == 0)
264 return SEQ_START_TOKEN;
265
266 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
267 if (!cpu_possible(cpu))
268 continue;
269 *pos = cpu+1;
270 return &per_cpu(rt_cache_stat, cpu);
271 }
272 return NULL;
273 }
274
275 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
276 {
277 int cpu;
278
279 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
280 if (!cpu_possible(cpu))
281 continue;
282 *pos = cpu+1;
283 return &per_cpu(rt_cache_stat, cpu);
284 }
285 return NULL;
286
287 }
288
289 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
290 {
291
292 }
293
294 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
295 {
296 struct rt_cache_stat *st = v;
297
298 if (v == SEQ_START_TOKEN) {
299 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");
300 return 0;
301 }
302
303 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
304 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
305 dst_entries_get_slow(&ipv4_dst_ops),
306 st->in_hit,
307 st->in_slow_tot,
308 st->in_slow_mc,
309 st->in_no_route,
310 st->in_brd,
311 st->in_martian_dst,
312 st->in_martian_src,
313
314 st->out_hit,
315 st->out_slow_tot,
316 st->out_slow_mc,
317
318 st->gc_total,
319 st->gc_ignored,
320 st->gc_goal_miss,
321 st->gc_dst_overflow,
322 st->in_hlist_search,
323 st->out_hlist_search
324 );
325 return 0;
326 }
327
328 static const struct seq_operations rt_cpu_seq_ops = {
329 .start = rt_cpu_seq_start,
330 .next = rt_cpu_seq_next,
331 .stop = rt_cpu_seq_stop,
332 .show = rt_cpu_seq_show,
333 };
334
335
336 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
337 {
338 return seq_open(file, &rt_cpu_seq_ops);
339 }
340
341 static const struct file_operations rt_cpu_seq_fops = {
342 .owner = THIS_MODULE,
343 .open = rt_cpu_seq_open,
344 .read = seq_read,
345 .llseek = seq_lseek,
346 .release = seq_release,
347 };
348
349 #ifdef CONFIG_IP_ROUTE_CLASSID
350 static int rt_acct_proc_show(struct seq_file *m, void *v)
351 {
352 struct ip_rt_acct *dst, *src;
353 unsigned int i, j;
354
355 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
356 if (!dst)
357 return -ENOMEM;
358
359 for_each_possible_cpu(i) {
360 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
361 for (j = 0; j < 256; j++) {
362 dst[j].o_bytes += src[j].o_bytes;
363 dst[j].o_packets += src[j].o_packets;
364 dst[j].i_bytes += src[j].i_bytes;
365 dst[j].i_packets += src[j].i_packets;
366 }
367 }
368
369 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
370 kfree(dst);
371 return 0;
372 }
373
374 static int rt_acct_proc_open(struct inode *inode, struct file *file)
375 {
376 return single_open(file, rt_acct_proc_show, NULL);
377 }
378
379 static const struct file_operations rt_acct_proc_fops = {
380 .owner = THIS_MODULE,
381 .open = rt_acct_proc_open,
382 .read = seq_read,
383 .llseek = seq_lseek,
384 .release = single_release,
385 };
386 #endif
387
388 static int __net_init ip_rt_do_proc_init(struct net *net)
389 {
390 struct proc_dir_entry *pde;
391
392 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
393 &rt_cache_seq_fops);
394 if (!pde)
395 goto err1;
396
397 pde = proc_create("rt_cache", S_IRUGO,
398 net->proc_net_stat, &rt_cpu_seq_fops);
399 if (!pde)
400 goto err2;
401
402 #ifdef CONFIG_IP_ROUTE_CLASSID
403 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
404 if (!pde)
405 goto err3;
406 #endif
407 return 0;
408
409 #ifdef CONFIG_IP_ROUTE_CLASSID
410 err3:
411 remove_proc_entry("rt_cache", net->proc_net_stat);
412 #endif
413 err2:
414 remove_proc_entry("rt_cache", net->proc_net);
415 err1:
416 return -ENOMEM;
417 }
418
419 static void __net_exit ip_rt_do_proc_exit(struct net *net)
420 {
421 remove_proc_entry("rt_cache", net->proc_net_stat);
422 remove_proc_entry("rt_cache", net->proc_net);
423 #ifdef CONFIG_IP_ROUTE_CLASSID
424 remove_proc_entry("rt_acct", net->proc_net);
425 #endif
426 }
427
428 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
429 .init = ip_rt_do_proc_init,
430 .exit = ip_rt_do_proc_exit,
431 };
432
433 static int __init ip_rt_proc_init(void)
434 {
435 return register_pernet_subsys(&ip_rt_proc_ops);
436 }
437
438 #else
439 static inline int ip_rt_proc_init(void)
440 {
441 return 0;
442 }
443 #endif /* CONFIG_PROC_FS */
444
445 static inline bool rt_is_expired(const struct rtable *rth)
446 {
447 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
448 }
449
450 void rt_cache_flush(struct net *net)
451 {
452 atomic_inc(&net->ipv4.rt_genid);
453 }
454
455 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
456 struct sk_buff *skb,
457 const void *daddr)
458 {
459 struct net_device *dev = dst->dev;
460 const __be32 *pkey = daddr;
461 const struct rtable *rt;
462 struct neighbour *n;
463
464 rt = (const struct rtable *) dst;
465 if (rt->rt_gateway)
466 pkey = (const __be32 *) &rt->rt_gateway;
467 else if (skb)
468 pkey = &ip_hdr(skb)->daddr;
469
470 n = __ipv4_neigh_lookup(dev, *(__force u32 *)pkey);
471 if (n)
472 return n;
473 return neigh_create(&arp_tbl, pkey, dev);
474 }
475
476 /*
477 * Peer allocation may fail only in serious out-of-memory conditions. However
478 * we still can generate some output.
479 * Random ID selection looks a bit dangerous because we have no chances to
480 * select ID being unique in a reasonable period of time.
481 * But broken packet identifier may be better than no packet at all.
482 */
483 static void ip_select_fb_ident(struct iphdr *iph)
484 {
485 static DEFINE_SPINLOCK(ip_fb_id_lock);
486 static u32 ip_fallback_id;
487 u32 salt;
488
489 spin_lock_bh(&ip_fb_id_lock);
490 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
491 iph->id = htons(salt & 0xFFFF);
492 ip_fallback_id = salt;
493 spin_unlock_bh(&ip_fb_id_lock);
494 }
495
496 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
497 {
498 struct net *net = dev_net(dst->dev);
499 struct inet_peer *peer;
500
501 peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
502 if (peer) {
503 iph->id = htons(inet_getid(peer, more));
504 inet_putpeer(peer);
505 return;
506 }
507
508 ip_select_fb_ident(iph);
509 }
510 EXPORT_SYMBOL(__ip_select_ident);
511
512 static void __build_flow_key(struct flowi4 *fl4, const struct sock *sk,
513 const struct iphdr *iph,
514 int oif, u8 tos,
515 u8 prot, u32 mark, int flow_flags)
516 {
517 if (sk) {
518 const struct inet_sock *inet = inet_sk(sk);
519
520 oif = sk->sk_bound_dev_if;
521 mark = sk->sk_mark;
522 tos = RT_CONN_FLAGS(sk);
523 prot = inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol;
524 }
525 flowi4_init_output(fl4, oif, mark, tos,
526 RT_SCOPE_UNIVERSE, prot,
527 flow_flags,
528 iph->daddr, iph->saddr, 0, 0);
529 }
530
531 static void build_skb_flow_key(struct flowi4 *fl4, const struct sk_buff *skb,
532 const struct sock *sk)
533 {
534 const struct iphdr *iph = ip_hdr(skb);
535 int oif = skb->dev->ifindex;
536 u8 tos = RT_TOS(iph->tos);
537 u8 prot = iph->protocol;
538 u32 mark = skb->mark;
539
540 __build_flow_key(fl4, sk, iph, oif, tos, prot, mark, 0);
541 }
542
543 static void build_sk_flow_key(struct flowi4 *fl4, const struct sock *sk)
544 {
545 const struct inet_sock *inet = inet_sk(sk);
546 const struct ip_options_rcu *inet_opt;
547 __be32 daddr = inet->inet_daddr;
548
549 rcu_read_lock();
550 inet_opt = rcu_dereference(inet->inet_opt);
551 if (inet_opt && inet_opt->opt.srr)
552 daddr = inet_opt->opt.faddr;
553 flowi4_init_output(fl4, sk->sk_bound_dev_if, sk->sk_mark,
554 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
555 inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,
556 inet_sk_flowi_flags(sk),
557 daddr, inet->inet_saddr, 0, 0);
558 rcu_read_unlock();
559 }
560
561 static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk,
562 const struct sk_buff *skb)
563 {
564 if (skb)
565 build_skb_flow_key(fl4, skb, sk);
566 else
567 build_sk_flow_key(fl4, sk);
568 }
569
570 static inline void rt_free(struct rtable *rt)
571 {
572 call_rcu(&rt->dst.rcu_head, dst_rcu_free);
573 }
574
575 static DEFINE_SPINLOCK(fnhe_lock);
576
577 static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
578 {
579 struct fib_nh_exception *fnhe, *oldest;
580 struct rtable *orig;
581
582 oldest = rcu_dereference(hash->chain);
583 for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe;
584 fnhe = rcu_dereference(fnhe->fnhe_next)) {
585 if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp))
586 oldest = fnhe;
587 }
588 orig = rcu_dereference(oldest->fnhe_rth);
589 if (orig) {
590 RCU_INIT_POINTER(oldest->fnhe_rth, NULL);
591 rt_free(orig);
592 }
593 return oldest;
594 }
595
596 static inline u32 fnhe_hashfun(__be32 daddr)
597 {
598 u32 hval;
599
600 hval = (__force u32) daddr;
601 hval ^= (hval >> 11) ^ (hval >> 22);
602
603 return hval & (FNHE_HASH_SIZE - 1);
604 }
605
606 static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
607 u32 pmtu, unsigned long expires)
608 {
609 struct fnhe_hash_bucket *hash;
610 struct fib_nh_exception *fnhe;
611 int depth;
612 u32 hval = fnhe_hashfun(daddr);
613
614 spin_lock_bh(&fnhe_lock);
615
616 hash = nh->nh_exceptions;
617 if (!hash) {
618 hash = kzalloc(FNHE_HASH_SIZE * sizeof(*hash), GFP_ATOMIC);
619 if (!hash)
620 goto out_unlock;
621 nh->nh_exceptions = hash;
622 }
623
624 hash += hval;
625
626 depth = 0;
627 for (fnhe = rcu_dereference(hash->chain); fnhe;
628 fnhe = rcu_dereference(fnhe->fnhe_next)) {
629 if (fnhe->fnhe_daddr == daddr)
630 break;
631 depth++;
632 }
633
634 if (fnhe) {
635 if (gw)
636 fnhe->fnhe_gw = gw;
637 if (pmtu) {
638 fnhe->fnhe_pmtu = pmtu;
639 fnhe->fnhe_expires = expires;
640 }
641 } else {
642 if (depth > FNHE_RECLAIM_DEPTH)
643 fnhe = fnhe_oldest(hash);
644 else {
645 fnhe = kzalloc(sizeof(*fnhe), GFP_ATOMIC);
646 if (!fnhe)
647 goto out_unlock;
648
649 fnhe->fnhe_next = hash->chain;
650 rcu_assign_pointer(hash->chain, fnhe);
651 }
652 fnhe->fnhe_daddr = daddr;
653 fnhe->fnhe_gw = gw;
654 fnhe->fnhe_pmtu = pmtu;
655 fnhe->fnhe_expires = expires;
656 }
657
658 fnhe->fnhe_stamp = jiffies;
659
660 out_unlock:
661 spin_unlock_bh(&fnhe_lock);
662 return;
663 }
664
665 static void __ip_do_redirect(struct rtable *rt, struct sk_buff *skb, struct flowi4 *fl4,
666 bool kill_route)
667 {
668 __be32 new_gw = icmp_hdr(skb)->un.gateway;
669 __be32 old_gw = ip_hdr(skb)->saddr;
670 struct net_device *dev = skb->dev;
671 struct in_device *in_dev;
672 struct fib_result res;
673 struct neighbour *n;
674 struct net *net;
675
676 switch (icmp_hdr(skb)->code & 7) {
677 case ICMP_REDIR_NET:
678 case ICMP_REDIR_NETTOS:
679 case ICMP_REDIR_HOST:
680 case ICMP_REDIR_HOSTTOS:
681 break;
682
683 default:
684 return;
685 }
686
687 if (rt->rt_gateway != old_gw)
688 return;
689
690 in_dev = __in_dev_get_rcu(dev);
691 if (!in_dev)
692 return;
693
694 net = dev_net(dev);
695 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
696 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
697 ipv4_is_zeronet(new_gw))
698 goto reject_redirect;
699
700 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
701 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
702 goto reject_redirect;
703 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
704 goto reject_redirect;
705 } else {
706 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
707 goto reject_redirect;
708 }
709
710 n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
711 if (n) {
712 if (!(n->nud_state & NUD_VALID)) {
713 neigh_event_send(n, NULL);
714 } else {
715 if (fib_lookup(net, fl4, &res) == 0) {
716 struct fib_nh *nh = &FIB_RES_NH(res);
717
718 update_or_create_fnhe(nh, fl4->daddr, new_gw,
719 0, 0);
720 }
721 if (kill_route)
722 rt->dst.obsolete = DST_OBSOLETE_KILL;
723 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
724 }
725 neigh_release(n);
726 }
727 return;
728
729 reject_redirect:
730 #ifdef CONFIG_IP_ROUTE_VERBOSE
731 if (IN_DEV_LOG_MARTIANS(in_dev)) {
732 const struct iphdr *iph = (const struct iphdr *) skb->data;
733 __be32 daddr = iph->daddr;
734 __be32 saddr = iph->saddr;
735
736 net_info_ratelimited("Redirect from %pI4 on %s about %pI4 ignored\n"
737 " Advised path = %pI4 -> %pI4\n",
738 &old_gw, dev->name, &new_gw,
739 &saddr, &daddr);
740 }
741 #endif
742 ;
743 }
744
745 static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
746 {
747 struct rtable *rt;
748 struct flowi4 fl4;
749
750 rt = (struct rtable *) dst;
751
752 ip_rt_build_flow_key(&fl4, sk, skb);
753 __ip_do_redirect(rt, skb, &fl4, true);
754 }
755
756 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
757 {
758 struct rtable *rt = (struct rtable *)dst;
759 struct dst_entry *ret = dst;
760
761 if (rt) {
762 if (dst->obsolete > 0) {
763 ip_rt_put(rt);
764 ret = NULL;
765 } else if ((rt->rt_flags & RTCF_REDIRECTED) ||
766 rt->dst.expires) {
767 ip_rt_put(rt);
768 ret = NULL;
769 }
770 }
771 return ret;
772 }
773
774 /*
775 * Algorithm:
776 * 1. The first ip_rt_redirect_number redirects are sent
777 * with exponential backoff, then we stop sending them at all,
778 * assuming that the host ignores our redirects.
779 * 2. If we did not see packets requiring redirects
780 * during ip_rt_redirect_silence, we assume that the host
781 * forgot redirected route and start to send redirects again.
782 *
783 * This algorithm is much cheaper and more intelligent than dumb load limiting
784 * in icmp.c.
785 *
786 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
787 * and "frag. need" (breaks PMTU discovery) in icmp.c.
788 */
789
790 void ip_rt_send_redirect(struct sk_buff *skb)
791 {
792 struct rtable *rt = skb_rtable(skb);
793 struct in_device *in_dev;
794 struct inet_peer *peer;
795 struct net *net;
796 int log_martians;
797
798 rcu_read_lock();
799 in_dev = __in_dev_get_rcu(rt->dst.dev);
800 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
801 rcu_read_unlock();
802 return;
803 }
804 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
805 rcu_read_unlock();
806
807 net = dev_net(rt->dst.dev);
808 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
809 if (!peer) {
810 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
811 return;
812 }
813
814 /* No redirected packets during ip_rt_redirect_silence;
815 * reset the algorithm.
816 */
817 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
818 peer->rate_tokens = 0;
819
820 /* Too many ignored redirects; do not send anything
821 * set dst.rate_last to the last seen redirected packet.
822 */
823 if (peer->rate_tokens >= ip_rt_redirect_number) {
824 peer->rate_last = jiffies;
825 goto out_put_peer;
826 }
827
828 /* Check for load limit; set rate_last to the latest sent
829 * redirect.
830 */
831 if (peer->rate_tokens == 0 ||
832 time_after(jiffies,
833 (peer->rate_last +
834 (ip_rt_redirect_load << peer->rate_tokens)))) {
835 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
836 peer->rate_last = jiffies;
837 ++peer->rate_tokens;
838 #ifdef CONFIG_IP_ROUTE_VERBOSE
839 if (log_martians &&
840 peer->rate_tokens == ip_rt_redirect_number)
841 net_warn_ratelimited("host %pI4/if%d ignores redirects for %pI4 to %pI4\n",
842 &ip_hdr(skb)->saddr, inet_iif(skb),
843 &ip_hdr(skb)->daddr, &rt->rt_gateway);
844 #endif
845 }
846 out_put_peer:
847 inet_putpeer(peer);
848 }
849
850 static int ip_error(struct sk_buff *skb)
851 {
852 struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
853 struct rtable *rt = skb_rtable(skb);
854 struct inet_peer *peer;
855 unsigned long now;
856 struct net *net;
857 bool send;
858 int code;
859
860 net = dev_net(rt->dst.dev);
861 if (!IN_DEV_FORWARD(in_dev)) {
862 switch (rt->dst.error) {
863 case EHOSTUNREACH:
864 IP_INC_STATS_BH(net, IPSTATS_MIB_INADDRERRORS);
865 break;
866
867 case ENETUNREACH:
868 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
869 break;
870 }
871 goto out;
872 }
873
874 switch (rt->dst.error) {
875 case EINVAL:
876 default:
877 goto out;
878 case EHOSTUNREACH:
879 code = ICMP_HOST_UNREACH;
880 break;
881 case ENETUNREACH:
882 code = ICMP_NET_UNREACH;
883 IP_INC_STATS_BH(net, IPSTATS_MIB_INNOROUTES);
884 break;
885 case EACCES:
886 code = ICMP_PKT_FILTERED;
887 break;
888 }
889
890 peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
891
892 send = true;
893 if (peer) {
894 now = jiffies;
895 peer->rate_tokens += now - peer->rate_last;
896 if (peer->rate_tokens > ip_rt_error_burst)
897 peer->rate_tokens = ip_rt_error_burst;
898 peer->rate_last = now;
899 if (peer->rate_tokens >= ip_rt_error_cost)
900 peer->rate_tokens -= ip_rt_error_cost;
901 else
902 send = false;
903 inet_putpeer(peer);
904 }
905 if (send)
906 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
907
908 out: kfree_skb(skb);
909 return 0;
910 }
911
912 static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu)
913 {
914 struct fib_result res;
915
916 if (mtu < ip_rt_min_pmtu)
917 mtu = ip_rt_min_pmtu;
918
919 rcu_read_lock();
920 if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) {
921 struct fib_nh *nh = &FIB_RES_NH(res);
922
923 update_or_create_fnhe(nh, fl4->daddr, 0, mtu,
924 jiffies + ip_rt_mtu_expires);
925 }
926 rcu_read_unlock();
927 return mtu;
928 }
929
930 static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
931 struct sk_buff *skb, u32 mtu)
932 {
933 struct rtable *rt = (struct rtable *) dst;
934 struct flowi4 fl4;
935
936 ip_rt_build_flow_key(&fl4, sk, skb);
937 mtu = __ip_rt_update_pmtu(rt, &fl4, mtu);
938
939 if (!rt->rt_pmtu) {
940 dst->obsolete = DST_OBSOLETE_KILL;
941 } else {
942 rt->rt_pmtu = mtu;
943 rt->dst.expires = max(1UL, jiffies + ip_rt_mtu_expires);
944 }
945 }
946
947 void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
948 int oif, u32 mark, u8 protocol, int flow_flags)
949 {
950 const struct iphdr *iph = (const struct iphdr *) skb->data;
951 struct flowi4 fl4;
952 struct rtable *rt;
953
954 __build_flow_key(&fl4, NULL, iph, oif,
955 RT_TOS(iph->tos), protocol, mark, flow_flags);
956 rt = __ip_route_output_key(net, &fl4);
957 if (!IS_ERR(rt)) {
958 __ip_rt_update_pmtu(rt, &fl4, mtu);
959 ip_rt_put(rt);
960 }
961 }
962 EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
963
964 void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
965 {
966 const struct iphdr *iph = (const struct iphdr *) skb->data;
967 struct flowi4 fl4;
968 struct rtable *rt;
969
970 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
971 rt = __ip_route_output_key(sock_net(sk), &fl4);
972 if (!IS_ERR(rt)) {
973 __ip_rt_update_pmtu(rt, &fl4, mtu);
974 ip_rt_put(rt);
975 }
976 }
977 EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);
978
979 void ipv4_redirect(struct sk_buff *skb, struct net *net,
980 int oif, u32 mark, u8 protocol, int flow_flags)
981 {
982 const struct iphdr *iph = (const struct iphdr *) skb->data;
983 struct flowi4 fl4;
984 struct rtable *rt;
985
986 __build_flow_key(&fl4, NULL, iph, oif,
987 RT_TOS(iph->tos), protocol, mark, flow_flags);
988 rt = __ip_route_output_key(net, &fl4);
989 if (!IS_ERR(rt)) {
990 __ip_do_redirect(rt, skb, &fl4, false);
991 ip_rt_put(rt);
992 }
993 }
994 EXPORT_SYMBOL_GPL(ipv4_redirect);
995
996 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
997 {
998 const struct iphdr *iph = (const struct iphdr *) skb->data;
999 struct flowi4 fl4;
1000 struct rtable *rt;
1001
1002 __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0);
1003 rt = __ip_route_output_key(sock_net(sk), &fl4);
1004 if (!IS_ERR(rt)) {
1005 __ip_do_redirect(rt, skb, &fl4, false);
1006 ip_rt_put(rt);
1007 }
1008 }
1009 EXPORT_SYMBOL_GPL(ipv4_sk_redirect);
1010
1011 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1012 {
1013 struct rtable *rt = (struct rtable *) dst;
1014
1015 /* All IPV4 dsts are created with ->obsolete set to the value
1016 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1017 * into this function always.
1018 *
1019 * When a PMTU/redirect information update invalidates a
1020 * route, this is indicated by setting obsolete to
1021 * DST_OBSOLETE_KILL.
1022 */
1023 if (dst->obsolete == DST_OBSOLETE_KILL || rt_is_expired(rt))
1024 return NULL;
1025 return dst;
1026 }
1027
1028 static void ipv4_link_failure(struct sk_buff *skb)
1029 {
1030 struct rtable *rt;
1031
1032 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1033
1034 rt = skb_rtable(skb);
1035 if (rt)
1036 dst_set_expires(&rt->dst, 0);
1037 }
1038
1039 static int ip_rt_bug(struct sk_buff *skb)
1040 {
1041 pr_debug("%s: %pI4 -> %pI4, %s\n",
1042 __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1043 skb->dev ? skb->dev->name : "?");
1044 kfree_skb(skb);
1045 WARN_ON(1);
1046 return 0;
1047 }
1048
1049 /*
1050 We do not cache source address of outgoing interface,
1051 because it is used only by IP RR, TS and SRR options,
1052 so that it out of fast path.
1053
1054 BTW remember: "addr" is allowed to be not aligned
1055 in IP options!
1056 */
1057
1058 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1059 {
1060 __be32 src;
1061
1062 if (rt_is_output_route(rt))
1063 src = ip_hdr(skb)->saddr;
1064 else {
1065 struct fib_result res;
1066 struct flowi4 fl4;
1067 struct iphdr *iph;
1068
1069 iph = ip_hdr(skb);
1070
1071 memset(&fl4, 0, sizeof(fl4));
1072 fl4.daddr = iph->daddr;
1073 fl4.saddr = iph->saddr;
1074 fl4.flowi4_tos = RT_TOS(iph->tos);
1075 fl4.flowi4_oif = rt->dst.dev->ifindex;
1076 fl4.flowi4_iif = skb->dev->ifindex;
1077 fl4.flowi4_mark = skb->mark;
1078
1079 rcu_read_lock();
1080 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1081 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1082 else
1083 src = inet_select_addr(rt->dst.dev,
1084 rt_nexthop(rt, iph->daddr),
1085 RT_SCOPE_UNIVERSE);
1086 rcu_read_unlock();
1087 }
1088 memcpy(addr, &src, 4);
1089 }
1090
1091 #ifdef CONFIG_IP_ROUTE_CLASSID
1092 static void set_class_tag(struct rtable *rt, u32 tag)
1093 {
1094 if (!(rt->dst.tclassid & 0xFFFF))
1095 rt->dst.tclassid |= tag & 0xFFFF;
1096 if (!(rt->dst.tclassid & 0xFFFF0000))
1097 rt->dst.tclassid |= tag & 0xFFFF0000;
1098 }
1099 #endif
1100
1101 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1102 {
1103 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1104
1105 if (advmss == 0) {
1106 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1107 ip_rt_min_advmss);
1108 if (advmss > 65535 - 40)
1109 advmss = 65535 - 40;
1110 }
1111 return advmss;
1112 }
1113
1114 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1115 {
1116 const struct rtable *rt = (const struct rtable *) dst;
1117 unsigned int mtu = rt->rt_pmtu;
1118
1119 if (!mtu || time_after_eq(jiffies, rt->dst.expires))
1120 mtu = dst_metric_raw(dst, RTAX_MTU);
1121
1122 if (mtu && rt_is_output_route(rt))
1123 return mtu;
1124
1125 mtu = dst->dev->mtu;
1126
1127 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1128 if (rt->rt_gateway && mtu > 576)
1129 mtu = 576;
1130 }
1131
1132 if (mtu > IP_MAX_MTU)
1133 mtu = IP_MAX_MTU;
1134
1135 return mtu;
1136 }
1137
1138 static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
1139 {
1140 struct fnhe_hash_bucket *hash = nh->nh_exceptions;
1141 struct fib_nh_exception *fnhe;
1142 u32 hval;
1143
1144 if (!hash)
1145 return NULL;
1146
1147 hval = fnhe_hashfun(daddr);
1148
1149 for (fnhe = rcu_dereference(hash[hval].chain); fnhe;
1150 fnhe = rcu_dereference(fnhe->fnhe_next)) {
1151 if (fnhe->fnhe_daddr == daddr)
1152 return fnhe;
1153 }
1154 return NULL;
1155 }
1156
1157 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
1158 __be32 daddr)
1159 {
1160 bool ret = false;
1161
1162 spin_lock_bh(&fnhe_lock);
1163
1164 if (daddr == fnhe->fnhe_daddr) {
1165 struct rtable *orig;
1166
1167 if (fnhe->fnhe_pmtu) {
1168 unsigned long expires = fnhe->fnhe_expires;
1169 unsigned long diff = expires - jiffies;
1170
1171 if (time_before(jiffies, expires)) {
1172 rt->rt_pmtu = fnhe->fnhe_pmtu;
1173 dst_set_expires(&rt->dst, diff);
1174 }
1175 }
1176 if (fnhe->fnhe_gw) {
1177 rt->rt_flags |= RTCF_REDIRECTED;
1178 rt->rt_gateway = fnhe->fnhe_gw;
1179 }
1180
1181 orig = rcu_dereference(fnhe->fnhe_rth);
1182 rcu_assign_pointer(fnhe->fnhe_rth, rt);
1183 if (orig)
1184 rt_free(orig);
1185
1186 fnhe->fnhe_stamp = jiffies;
1187 ret = true;
1188 } else {
1189 /* Routes we intend to cache in nexthop exception have
1190 * the DST_NOCACHE bit clear. However, if we are
1191 * unsuccessful at storing this route into the cache
1192 * we really need to set it.
1193 */
1194 rt->dst.flags |= DST_NOCACHE;
1195 }
1196 spin_unlock_bh(&fnhe_lock);
1197
1198 return ret;
1199 }
1200
1201 static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt)
1202 {
1203 struct rtable *orig, *prev, **p;
1204 bool ret = true;
1205
1206 if (rt_is_input_route(rt)) {
1207 p = (struct rtable **)&nh->nh_rth_input;
1208 } else {
1209 if (!nh->nh_pcpu_rth_output)
1210 goto nocache;
1211 p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output);
1212 }
1213 orig = *p;
1214
1215 prev = cmpxchg(p, orig, rt);
1216 if (prev == orig) {
1217 if (orig)
1218 rt_free(orig);
1219 } else {
1220 /* Routes we intend to cache in the FIB nexthop have
1221 * the DST_NOCACHE bit clear. However, if we are
1222 * unsuccessful at storing this route into the cache
1223 * we really need to set it.
1224 */
1225 nocache:
1226 rt->dst.flags |= DST_NOCACHE;
1227 ret = false;
1228 }
1229
1230 return ret;
1231 }
1232
1233 static DEFINE_SPINLOCK(rt_uncached_lock);
1234 static LIST_HEAD(rt_uncached_list);
1235
1236 static void rt_add_uncached_list(struct rtable *rt)
1237 {
1238 spin_lock_bh(&rt_uncached_lock);
1239 list_add_tail(&rt->rt_uncached, &rt_uncached_list);
1240 spin_unlock_bh(&rt_uncached_lock);
1241 }
1242
1243 static void ipv4_dst_destroy(struct dst_entry *dst)
1244 {
1245 struct rtable *rt = (struct rtable *) dst;
1246
1247 if (!list_empty(&rt->rt_uncached)) {
1248 spin_lock_bh(&rt_uncached_lock);
1249 list_del(&rt->rt_uncached);
1250 spin_unlock_bh(&rt_uncached_lock);
1251 }
1252 }
1253
1254 void rt_flush_dev(struct net_device *dev)
1255 {
1256 if (!list_empty(&rt_uncached_list)) {
1257 struct net *net = dev_net(dev);
1258 struct rtable *rt;
1259
1260 spin_lock_bh(&rt_uncached_lock);
1261 list_for_each_entry(rt, &rt_uncached_list, rt_uncached) {
1262 if (rt->dst.dev != dev)
1263 continue;
1264 rt->dst.dev = net->loopback_dev;
1265 dev_hold(rt->dst.dev);
1266 dev_put(dev);
1267 }
1268 spin_unlock_bh(&rt_uncached_lock);
1269 }
1270 }
1271
1272 static bool rt_cache_valid(const struct rtable *rt)
1273 {
1274 return rt &&
1275 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
1276 !rt_is_expired(rt);
1277 }
1278
1279 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
1280 const struct fib_result *res,
1281 struct fib_nh_exception *fnhe,
1282 struct fib_info *fi, u16 type, u32 itag)
1283 {
1284 bool cached = false;
1285
1286 if (fi) {
1287 struct fib_nh *nh = &FIB_RES_NH(*res);
1288
1289 if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK)
1290 rt->rt_gateway = nh->nh_gw;
1291 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1292 #ifdef CONFIG_IP_ROUTE_CLASSID
1293 rt->dst.tclassid = nh->nh_tclassid;
1294 #endif
1295 if (unlikely(fnhe))
1296 cached = rt_bind_exception(rt, fnhe, daddr);
1297 else if (!(rt->dst.flags & DST_NOCACHE))
1298 cached = rt_cache_route(nh, rt);
1299 }
1300 if (unlikely(!cached))
1301 rt_add_uncached_list(rt);
1302
1303 #ifdef CONFIG_IP_ROUTE_CLASSID
1304 #ifdef CONFIG_IP_MULTIPLE_TABLES
1305 set_class_tag(rt, res->tclassid);
1306 #endif
1307 set_class_tag(rt, itag);
1308 #endif
1309 }
1310
1311 static struct rtable *rt_dst_alloc(struct net_device *dev,
1312 bool nopolicy, bool noxfrm, bool will_cache)
1313 {
1314 return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
1315 (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
1316 (nopolicy ? DST_NOPOLICY : 0) |
1317 (noxfrm ? DST_NOXFRM : 0));
1318 }
1319
1320 /* called in rcu_read_lock() section */
1321 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1322 u8 tos, struct net_device *dev, int our)
1323 {
1324 struct rtable *rth;
1325 struct in_device *in_dev = __in_dev_get_rcu(dev);
1326 u32 itag = 0;
1327 int err;
1328
1329 /* Primary sanity checks. */
1330
1331 if (in_dev == NULL)
1332 return -EINVAL;
1333
1334 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
1335 skb->protocol != htons(ETH_P_IP))
1336 goto e_inval;
1337
1338 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1339 if (ipv4_is_loopback(saddr))
1340 goto e_inval;
1341
1342 if (ipv4_is_zeronet(saddr)) {
1343 if (!ipv4_is_local_multicast(daddr))
1344 goto e_inval;
1345 } else {
1346 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1347 in_dev, &itag);
1348 if (err < 0)
1349 goto e_err;
1350 }
1351 rth = rt_dst_alloc(dev_net(dev)->loopback_dev,
1352 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, false);
1353 if (!rth)
1354 goto e_nobufs;
1355
1356 #ifdef CONFIG_IP_ROUTE_CLASSID
1357 rth->dst.tclassid = itag;
1358 #endif
1359 rth->dst.output = ip_rt_bug;
1360
1361 rth->rt_genid = rt_genid(dev_net(dev));
1362 rth->rt_flags = RTCF_MULTICAST;
1363 rth->rt_type = RTN_MULTICAST;
1364 rth->rt_is_input= 1;
1365 rth->rt_iif = 0;
1366 rth->rt_pmtu = 0;
1367 rth->rt_gateway = 0;
1368 INIT_LIST_HEAD(&rth->rt_uncached);
1369 if (our) {
1370 rth->dst.input= ip_local_deliver;
1371 rth->rt_flags |= RTCF_LOCAL;
1372 }
1373
1374 #ifdef CONFIG_IP_MROUTE
1375 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
1376 rth->dst.input = ip_mr_input;
1377 #endif
1378 RT_CACHE_STAT_INC(in_slow_mc);
1379
1380 skb_dst_set(skb, &rth->dst);
1381 return 0;
1382
1383 e_nobufs:
1384 return -ENOBUFS;
1385 e_inval:
1386 return -EINVAL;
1387 e_err:
1388 return err;
1389 }
1390
1391
1392 static void ip_handle_martian_source(struct net_device *dev,
1393 struct in_device *in_dev,
1394 struct sk_buff *skb,
1395 __be32 daddr,
1396 __be32 saddr)
1397 {
1398 RT_CACHE_STAT_INC(in_martian_src);
1399 #ifdef CONFIG_IP_ROUTE_VERBOSE
1400 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
1401 /*
1402 * RFC1812 recommendation, if source is martian,
1403 * the only hint is MAC header.
1404 */
1405 pr_warn("martian source %pI4 from %pI4, on dev %s\n",
1406 &daddr, &saddr, dev->name);
1407 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
1408 print_hex_dump(KERN_WARNING, "ll header: ",
1409 DUMP_PREFIX_OFFSET, 16, 1,
1410 skb_mac_header(skb),
1411 dev->hard_header_len, true);
1412 }
1413 }
1414 #endif
1415 }
1416
1417 /* called in rcu_read_lock() section */
1418 static int __mkroute_input(struct sk_buff *skb,
1419 const struct fib_result *res,
1420 struct in_device *in_dev,
1421 __be32 daddr, __be32 saddr, u32 tos)
1422 {
1423 struct rtable *rth;
1424 int err;
1425 struct in_device *out_dev;
1426 unsigned int flags = 0;
1427 bool do_cache;
1428 u32 itag;
1429
1430 /* get a working reference to the output device */
1431 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
1432 if (out_dev == NULL) {
1433 net_crit_ratelimited("Bug in ip_route_input_slow(). Please report.\n");
1434 return -EINVAL;
1435 }
1436
1437
1438 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
1439 in_dev->dev, in_dev, &itag);
1440 if (err < 0) {
1441 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
1442 saddr);
1443
1444 goto cleanup;
1445 }
1446
1447 if (out_dev == in_dev && err &&
1448 (IN_DEV_SHARED_MEDIA(out_dev) ||
1449 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
1450 flags |= RTCF_DOREDIRECT;
1451
1452 if (skb->protocol != htons(ETH_P_IP)) {
1453 /* Not IP (i.e. ARP). Do not create route, if it is
1454 * invalid for proxy arp. DNAT routes are always valid.
1455 *
1456 * Proxy arp feature have been extended to allow, ARP
1457 * replies back to the same interface, to support
1458 * Private VLAN switch technologies. See arp.c.
1459 */
1460 if (out_dev == in_dev &&
1461 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
1462 err = -EINVAL;
1463 goto cleanup;
1464 }
1465 }
1466
1467 do_cache = false;
1468 if (res->fi) {
1469 if (!itag) {
1470 rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input);
1471 if (rt_cache_valid(rth)) {
1472 skb_dst_set_noref(skb, &rth->dst);
1473 goto out;
1474 }
1475 do_cache = true;
1476 }
1477 }
1478
1479 rth = rt_dst_alloc(out_dev->dev,
1480 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1481 IN_DEV_CONF_GET(out_dev, NOXFRM), do_cache);
1482 if (!rth) {
1483 err = -ENOBUFS;
1484 goto cleanup;
1485 }
1486
1487 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
1488 rth->rt_flags = flags;
1489 rth->rt_type = res->type;
1490 rth->rt_is_input = 1;
1491 rth->rt_iif = 0;
1492 rth->rt_pmtu = 0;
1493 rth->rt_gateway = 0;
1494 INIT_LIST_HEAD(&rth->rt_uncached);
1495
1496 rth->dst.input = ip_forward;
1497 rth->dst.output = ip_output;
1498
1499 rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag);
1500 skb_dst_set(skb, &rth->dst);
1501 out:
1502 err = 0;
1503 cleanup:
1504 return err;
1505 }
1506
1507 static int ip_mkroute_input(struct sk_buff *skb,
1508 struct fib_result *res,
1509 const struct flowi4 *fl4,
1510 struct in_device *in_dev,
1511 __be32 daddr, __be32 saddr, u32 tos)
1512 {
1513 #ifdef CONFIG_IP_ROUTE_MULTIPATH
1514 if (res->fi && res->fi->fib_nhs > 1)
1515 fib_select_multipath(res);
1516 #endif
1517
1518 /* create a routing cache entry */
1519 return __mkroute_input(skb, res, in_dev, daddr, saddr, tos);
1520 }
1521
1522 /*
1523 * NOTE. We drop all the packets that has local source
1524 * addresses, because every properly looped back packet
1525 * must have correct destination already attached by output routine.
1526 *
1527 * Such approach solves two big problems:
1528 * 1. Not simplex devices are handled properly.
1529 * 2. IP spoofing attempts are filtered with 100% of guarantee.
1530 * called with rcu_read_lock()
1531 */
1532
1533 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1534 u8 tos, struct net_device *dev)
1535 {
1536 struct fib_result res;
1537 struct in_device *in_dev = __in_dev_get_rcu(dev);
1538 struct flowi4 fl4;
1539 unsigned int flags = 0;
1540 u32 itag = 0;
1541 struct rtable *rth;
1542 int err = -EINVAL;
1543 struct net *net = dev_net(dev);
1544 bool do_cache;
1545
1546 /* IP on this device is disabled. */
1547
1548 if (!in_dev)
1549 goto out;
1550
1551 /* Check for the most weird martians, which can be not detected
1552 by fib_lookup.
1553 */
1554
1555 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr))
1556 goto martian_source;
1557
1558 res.fi = NULL;
1559 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
1560 goto brd_input;
1561
1562 /* Accept zero addresses only to limited broadcast;
1563 * I even do not know to fix it or not. Waiting for complains :-)
1564 */
1565 if (ipv4_is_zeronet(saddr))
1566 goto martian_source;
1567
1568 if (ipv4_is_zeronet(daddr))
1569 goto martian_destination;
1570
1571 /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(),
1572 * and call it once if daddr or/and saddr are loopback addresses
1573 */
1574 if (ipv4_is_loopback(daddr)) {
1575 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1576 goto martian_destination;
1577 } else if (ipv4_is_loopback(saddr)) {
1578 if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net))
1579 goto martian_source;
1580 }
1581
1582 /*
1583 * Now we are ready to route packet.
1584 */
1585 fl4.flowi4_oif = 0;
1586 fl4.flowi4_iif = dev->ifindex;
1587 fl4.flowi4_mark = skb->mark;
1588 fl4.flowi4_tos = tos;
1589 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
1590 fl4.daddr = daddr;
1591 fl4.saddr = saddr;
1592 err = fib_lookup(net, &fl4, &res);
1593 if (err != 0)
1594 goto no_route;
1595
1596 RT_CACHE_STAT_INC(in_slow_tot);
1597
1598 if (res.type == RTN_BROADCAST)
1599 goto brd_input;
1600
1601 if (res.type == RTN_LOCAL) {
1602 err = fib_validate_source(skb, saddr, daddr, tos,
1603 LOOPBACK_IFINDEX,
1604 dev, in_dev, &itag);
1605 if (err < 0)
1606 goto martian_source_keep_err;
1607 goto local_input;
1608 }
1609
1610 if (!IN_DEV_FORWARD(in_dev))
1611 goto no_route;
1612 if (res.type != RTN_UNICAST)
1613 goto martian_destination;
1614
1615 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
1616 out: return err;
1617
1618 brd_input:
1619 if (skb->protocol != htons(ETH_P_IP))
1620 goto e_inval;
1621
1622 if (!ipv4_is_zeronet(saddr)) {
1623 err = fib_validate_source(skb, saddr, 0, tos, 0, dev,
1624 in_dev, &itag);
1625 if (err < 0)
1626 goto martian_source_keep_err;
1627 }
1628 flags |= RTCF_BROADCAST;
1629 res.type = RTN_BROADCAST;
1630 RT_CACHE_STAT_INC(in_brd);
1631
1632 local_input:
1633 do_cache = false;
1634 if (res.fi) {
1635 if (!itag) {
1636 rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input);
1637 if (rt_cache_valid(rth)) {
1638 skb_dst_set_noref(skb, &rth->dst);
1639 err = 0;
1640 goto out;
1641 }
1642 do_cache = true;
1643 }
1644 }
1645
1646 rth = rt_dst_alloc(net->loopback_dev,
1647 IN_DEV_CONF_GET(in_dev, NOPOLICY), false, do_cache);
1648 if (!rth)
1649 goto e_nobufs;
1650
1651 rth->dst.input= ip_local_deliver;
1652 rth->dst.output= ip_rt_bug;
1653 #ifdef CONFIG_IP_ROUTE_CLASSID
1654 rth->dst.tclassid = itag;
1655 #endif
1656
1657 rth->rt_genid = rt_genid(net);
1658 rth->rt_flags = flags|RTCF_LOCAL;
1659 rth->rt_type = res.type;
1660 rth->rt_is_input = 1;
1661 rth->rt_iif = 0;
1662 rth->rt_pmtu = 0;
1663 rth->rt_gateway = 0;
1664 INIT_LIST_HEAD(&rth->rt_uncached);
1665 if (res.type == RTN_UNREACHABLE) {
1666 rth->dst.input= ip_error;
1667 rth->dst.error= -err;
1668 rth->rt_flags &= ~RTCF_LOCAL;
1669 }
1670 if (do_cache)
1671 rt_cache_route(&FIB_RES_NH(res), rth);
1672 skb_dst_set(skb, &rth->dst);
1673 err = 0;
1674 goto out;
1675
1676 no_route:
1677 RT_CACHE_STAT_INC(in_no_route);
1678 res.type = RTN_UNREACHABLE;
1679 if (err == -ESRCH)
1680 err = -ENETUNREACH;
1681 goto local_input;
1682
1683 /*
1684 * Do not cache martian addresses: they should be logged (RFC1812)
1685 */
1686 martian_destination:
1687 RT_CACHE_STAT_INC(in_martian_dst);
1688 #ifdef CONFIG_IP_ROUTE_VERBOSE
1689 if (IN_DEV_LOG_MARTIANS(in_dev))
1690 net_warn_ratelimited("martian destination %pI4 from %pI4, dev %s\n",
1691 &daddr, &saddr, dev->name);
1692 #endif
1693
1694 e_inval:
1695 err = -EINVAL;
1696 goto out;
1697
1698 e_nobufs:
1699 err = -ENOBUFS;
1700 goto out;
1701
1702 martian_source:
1703 err = -EINVAL;
1704 martian_source_keep_err:
1705 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
1706 goto out;
1707 }
1708
1709 int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
1710 u8 tos, struct net_device *dev)
1711 {
1712 int res;
1713
1714 rcu_read_lock();
1715
1716 /* Multicast recognition logic is moved from route cache to here.
1717 The problem was that too many Ethernet cards have broken/missing
1718 hardware multicast filters :-( As result the host on multicasting
1719 network acquires a lot of useless route cache entries, sort of
1720 SDR messages from all the world. Now we try to get rid of them.
1721 Really, provided software IP multicast filter is organized
1722 reasonably (at least, hashed), it does not result in a slowdown
1723 comparing with route cache reject entries.
1724 Note, that multicast routers are not affected, because
1725 route cache entry is created eventually.
1726 */
1727 if (ipv4_is_multicast(daddr)) {
1728 struct in_device *in_dev = __in_dev_get_rcu(dev);
1729
1730 if (in_dev) {
1731 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
1732 ip_hdr(skb)->protocol);
1733 if (our
1734 #ifdef CONFIG_IP_MROUTE
1735 ||
1736 (!ipv4_is_local_multicast(daddr) &&
1737 IN_DEV_MFORWARD(in_dev))
1738 #endif
1739 ) {
1740 int res = ip_route_input_mc(skb, daddr, saddr,
1741 tos, dev, our);
1742 rcu_read_unlock();
1743 return res;
1744 }
1745 }
1746 rcu_read_unlock();
1747 return -EINVAL;
1748 }
1749 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
1750 rcu_read_unlock();
1751 return res;
1752 }
1753 EXPORT_SYMBOL(ip_route_input_noref);
1754
1755 /* called with rcu_read_lock() */
1756 static struct rtable *__mkroute_output(const struct fib_result *res,
1757 const struct flowi4 *fl4, int orig_oif,
1758 struct net_device *dev_out,
1759 unsigned int flags)
1760 {
1761 struct fib_info *fi = res->fi;
1762 struct fib_nh_exception *fnhe;
1763 struct in_device *in_dev;
1764 u16 type = res->type;
1765 struct rtable *rth;
1766
1767 in_dev = __in_dev_get_rcu(dev_out);
1768 if (!in_dev)
1769 return ERR_PTR(-EINVAL);
1770
1771 if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev)))
1772 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
1773 return ERR_PTR(-EINVAL);
1774
1775 if (ipv4_is_lbcast(fl4->daddr))
1776 type = RTN_BROADCAST;
1777 else if (ipv4_is_multicast(fl4->daddr))
1778 type = RTN_MULTICAST;
1779 else if (ipv4_is_zeronet(fl4->daddr))
1780 return ERR_PTR(-EINVAL);
1781
1782 if (dev_out->flags & IFF_LOOPBACK)
1783 flags |= RTCF_LOCAL;
1784
1785 if (type == RTN_BROADCAST) {
1786 flags |= RTCF_BROADCAST | RTCF_LOCAL;
1787 fi = NULL;
1788 } else if (type == RTN_MULTICAST) {
1789 flags |= RTCF_MULTICAST | RTCF_LOCAL;
1790 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
1791 fl4->flowi4_proto))
1792 flags &= ~RTCF_LOCAL;
1793 /* If multicast route do not exist use
1794 * default one, but do not gateway in this case.
1795 * Yes, it is hack.
1796 */
1797 if (fi && res->prefixlen < 4)
1798 fi = NULL;
1799 }
1800
1801 fnhe = NULL;
1802 if (fi) {
1803 struct rtable __rcu **prth;
1804
1805 fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr);
1806 if (fnhe)
1807 prth = &fnhe->fnhe_rth;
1808 else
1809 prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output);
1810 rth = rcu_dereference(*prth);
1811 if (rt_cache_valid(rth)) {
1812 dst_hold(&rth->dst);
1813 return rth;
1814 }
1815 }
1816 rth = rt_dst_alloc(dev_out,
1817 IN_DEV_CONF_GET(in_dev, NOPOLICY),
1818 IN_DEV_CONF_GET(in_dev, NOXFRM),
1819 fi);
1820 if (!rth)
1821 return ERR_PTR(-ENOBUFS);
1822
1823 rth->dst.output = ip_output;
1824
1825 rth->rt_genid = rt_genid(dev_net(dev_out));
1826 rth->rt_flags = flags;
1827 rth->rt_type = type;
1828 rth->rt_is_input = 0;
1829 rth->rt_iif = orig_oif ? : 0;
1830 rth->rt_pmtu = 0;
1831 rth->rt_gateway = 0;
1832 INIT_LIST_HEAD(&rth->rt_uncached);
1833
1834 RT_CACHE_STAT_INC(out_slow_tot);
1835
1836 if (flags & RTCF_LOCAL)
1837 rth->dst.input = ip_local_deliver;
1838 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1839 if (flags & RTCF_LOCAL &&
1840 !(dev_out->flags & IFF_LOOPBACK)) {
1841 rth->dst.output = ip_mc_output;
1842 RT_CACHE_STAT_INC(out_slow_mc);
1843 }
1844 #ifdef CONFIG_IP_MROUTE
1845 if (type == RTN_MULTICAST) {
1846 if (IN_DEV_MFORWARD(in_dev) &&
1847 !ipv4_is_local_multicast(fl4->daddr)) {
1848 rth->dst.input = ip_mr_input;
1849 rth->dst.output = ip_mc_output;
1850 }
1851 }
1852 #endif
1853 }
1854
1855 rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
1856
1857 return rth;
1858 }
1859
1860 /*
1861 * Major route resolver routine.
1862 */
1863
1864 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
1865 {
1866 struct net_device *dev_out = NULL;
1867 __u8 tos = RT_FL_TOS(fl4);
1868 unsigned int flags = 0;
1869 struct fib_result res;
1870 struct rtable *rth;
1871 int orig_oif;
1872
1873 res.tclassid = 0;
1874 res.fi = NULL;
1875 res.table = NULL;
1876
1877 orig_oif = fl4->flowi4_oif;
1878
1879 fl4->flowi4_iif = LOOPBACK_IFINDEX;
1880 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
1881 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
1882 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
1883
1884 rcu_read_lock();
1885 if (fl4->saddr) {
1886 rth = ERR_PTR(-EINVAL);
1887 if (ipv4_is_multicast(fl4->saddr) ||
1888 ipv4_is_lbcast(fl4->saddr) ||
1889 ipv4_is_zeronet(fl4->saddr))
1890 goto out;
1891
1892 /* I removed check for oif == dev_out->oif here.
1893 It was wrong for two reasons:
1894 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
1895 is assigned to multiple interfaces.
1896 2. Moreover, we are allowed to send packets with saddr
1897 of another iface. --ANK
1898 */
1899
1900 if (fl4->flowi4_oif == 0 &&
1901 (ipv4_is_multicast(fl4->daddr) ||
1902 ipv4_is_lbcast(fl4->daddr))) {
1903 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1904 dev_out = __ip_dev_find(net, fl4->saddr, false);
1905 if (dev_out == NULL)
1906 goto out;
1907
1908 /* Special hack: user can direct multicasts
1909 and limited broadcast via necessary interface
1910 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
1911 This hack is not just for fun, it allows
1912 vic,vat and friends to work.
1913 They bind socket to loopback, set ttl to zero
1914 and expect that it will work.
1915 From the viewpoint of routing cache they are broken,
1916 because we are not allowed to build multicast path
1917 with loopback source addr (look, routing cache
1918 cannot know, that ttl is zero, so that packet
1919 will not leave this host and route is valid).
1920 Luckily, this hack is good workaround.
1921 */
1922
1923 fl4->flowi4_oif = dev_out->ifindex;
1924 goto make_route;
1925 }
1926
1927 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
1928 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
1929 if (!__ip_dev_find(net, fl4->saddr, false))
1930 goto out;
1931 }
1932 }
1933
1934
1935 if (fl4->flowi4_oif) {
1936 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
1937 rth = ERR_PTR(-ENODEV);
1938 if (dev_out == NULL)
1939 goto out;
1940
1941 /* RACE: Check return value of inet_select_addr instead. */
1942 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
1943 rth = ERR_PTR(-ENETUNREACH);
1944 goto out;
1945 }
1946 if (ipv4_is_local_multicast(fl4->daddr) ||
1947 ipv4_is_lbcast(fl4->daddr)) {
1948 if (!fl4->saddr)
1949 fl4->saddr = inet_select_addr(dev_out, 0,
1950 RT_SCOPE_LINK);
1951 goto make_route;
1952 }
1953 if (fl4->saddr) {
1954 if (ipv4_is_multicast(fl4->daddr))
1955 fl4->saddr = inet_select_addr(dev_out, 0,
1956 fl4->flowi4_scope);
1957 else if (!fl4->daddr)
1958 fl4->saddr = inet_select_addr(dev_out, 0,
1959 RT_SCOPE_HOST);
1960 }
1961 }
1962
1963 if (!fl4->daddr) {
1964 fl4->daddr = fl4->saddr;
1965 if (!fl4->daddr)
1966 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
1967 dev_out = net->loopback_dev;
1968 fl4->flowi4_oif = LOOPBACK_IFINDEX;
1969 res.type = RTN_LOCAL;
1970 flags |= RTCF_LOCAL;
1971 goto make_route;
1972 }
1973
1974 if (fib_lookup(net, fl4, &res)) {
1975 res.fi = NULL;
1976 res.table = NULL;
1977 if (fl4->flowi4_oif) {
1978 /* Apparently, routing tables are wrong. Assume,
1979 that the destination is on link.
1980
1981 WHY? DW.
1982 Because we are allowed to send to iface
1983 even if it has NO routes and NO assigned
1984 addresses. When oif is specified, routing
1985 tables are looked up with only one purpose:
1986 to catch if destination is gatewayed, rather than
1987 direct. Moreover, if MSG_DONTROUTE is set,
1988 we send packet, ignoring both routing tables
1989 and ifaddr state. --ANK
1990
1991
1992 We could make it even if oif is unknown,
1993 likely IPv6, but we do not.
1994 */
1995
1996 if (fl4->saddr == 0)
1997 fl4->saddr = inet_select_addr(dev_out, 0,
1998 RT_SCOPE_LINK);
1999 res.type = RTN_UNICAST;
2000 goto make_route;
2001 }
2002 rth = ERR_PTR(-ENETUNREACH);
2003 goto out;
2004 }
2005
2006 if (res.type == RTN_LOCAL) {
2007 if (!fl4->saddr) {
2008 if (res.fi->fib_prefsrc)
2009 fl4->saddr = res.fi->fib_prefsrc;
2010 else
2011 fl4->saddr = fl4->daddr;
2012 }
2013 dev_out = net->loopback_dev;
2014 fl4->flowi4_oif = dev_out->ifindex;
2015 flags |= RTCF_LOCAL;
2016 goto make_route;
2017 }
2018
2019 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2020 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2021 fib_select_multipath(&res);
2022 else
2023 #endif
2024 if (!res.prefixlen &&
2025 res.table->tb_num_default > 1 &&
2026 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2027 fib_select_default(&res);
2028
2029 if (!fl4->saddr)
2030 fl4->saddr = FIB_RES_PREFSRC(net, res);
2031
2032 dev_out = FIB_RES_DEV(res);
2033 fl4->flowi4_oif = dev_out->ifindex;
2034
2035
2036 make_route:
2037 rth = __mkroute_output(&res, fl4, orig_oif, dev_out, flags);
2038
2039 out:
2040 rcu_read_unlock();
2041 return rth;
2042 }
2043 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2044
2045 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2046 {
2047 return NULL;
2048 }
2049
2050 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2051 {
2052 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2053
2054 return mtu ? : dst->dev->mtu;
2055 }
2056
2057 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
2058 struct sk_buff *skb, u32 mtu)
2059 {
2060 }
2061
2062 static void ipv4_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
2063 struct sk_buff *skb)
2064 {
2065 }
2066
2067 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2068 unsigned long old)
2069 {
2070 return NULL;
2071 }
2072
2073 static struct dst_ops ipv4_dst_blackhole_ops = {
2074 .family = AF_INET,
2075 .protocol = cpu_to_be16(ETH_P_IP),
2076 .check = ipv4_blackhole_dst_check,
2077 .mtu = ipv4_blackhole_mtu,
2078 .default_advmss = ipv4_default_advmss,
2079 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2080 .redirect = ipv4_rt_blackhole_redirect,
2081 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2082 .neigh_lookup = ipv4_neigh_lookup,
2083 };
2084
2085 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2086 {
2087 struct rtable *ort = (struct rtable *) dst_orig;
2088 struct rtable *rt;
2089
2090 rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
2091 if (rt) {
2092 struct dst_entry *new = &rt->dst;
2093
2094 new->__use = 1;
2095 new->input = dst_discard;
2096 new->output = dst_discard;
2097
2098 new->dev = ort->dst.dev;
2099 if (new->dev)
2100 dev_hold(new->dev);
2101
2102 rt->rt_is_input = ort->rt_is_input;
2103 rt->rt_iif = ort->rt_iif;
2104 rt->rt_pmtu = ort->rt_pmtu;
2105
2106 rt->rt_genid = rt_genid(net);
2107 rt->rt_flags = ort->rt_flags;
2108 rt->rt_type = ort->rt_type;
2109 rt->rt_gateway = ort->rt_gateway;
2110
2111 INIT_LIST_HEAD(&rt->rt_uncached);
2112
2113 dst_free(new);
2114 }
2115
2116 dst_release(dst_orig);
2117
2118 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2119 }
2120
2121 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2122 struct sock *sk)
2123 {
2124 struct rtable *rt = __ip_route_output_key(net, flp4);
2125
2126 if (IS_ERR(rt))
2127 return rt;
2128
2129 if (flp4->flowi4_proto)
2130 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2131 flowi4_to_flowi(flp4),
2132 sk, 0);
2133
2134 return rt;
2135 }
2136 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2137
2138 static int rt_fill_info(struct net *net, __be32 dst, __be32 src,
2139 struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
2140 u32 seq, int event, int nowait, unsigned int flags)
2141 {
2142 struct rtable *rt = skb_rtable(skb);
2143 struct rtmsg *r;
2144 struct nlmsghdr *nlh;
2145 unsigned long expires = 0;
2146 u32 error;
2147 u32 metrics[RTAX_MAX];
2148
2149 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
2150 if (nlh == NULL)
2151 return -EMSGSIZE;
2152
2153 r = nlmsg_data(nlh);
2154 r->rtm_family = AF_INET;
2155 r->rtm_dst_len = 32;
2156 r->rtm_src_len = 0;
2157 r->rtm_tos = fl4->flowi4_tos;
2158 r->rtm_table = RT_TABLE_MAIN;
2159 if (nla_put_u32(skb, RTA_TABLE, RT_TABLE_MAIN))
2160 goto nla_put_failure;
2161 r->rtm_type = rt->rt_type;
2162 r->rtm_scope = RT_SCOPE_UNIVERSE;
2163 r->rtm_protocol = RTPROT_UNSPEC;
2164 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2165 if (rt->rt_flags & RTCF_NOTIFY)
2166 r->rtm_flags |= RTM_F_NOTIFY;
2167
2168 if (nla_put_be32(skb, RTA_DST, dst))
2169 goto nla_put_failure;
2170 if (src) {
2171 r->rtm_src_len = 32;
2172 if (nla_put_be32(skb, RTA_SRC, src))
2173 goto nla_put_failure;
2174 }
2175 if (rt->dst.dev &&
2176 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2177 goto nla_put_failure;
2178 #ifdef CONFIG_IP_ROUTE_CLASSID
2179 if (rt->dst.tclassid &&
2180 nla_put_u32(skb, RTA_FLOW, rt->dst.tclassid))
2181 goto nla_put_failure;
2182 #endif
2183 if (!rt_is_input_route(rt) &&
2184 fl4->saddr != src) {
2185 if (nla_put_be32(skb, RTA_PREFSRC, fl4->saddr))
2186 goto nla_put_failure;
2187 }
2188 if (rt->rt_gateway &&
2189 nla_put_be32(skb, RTA_GATEWAY, rt->rt_gateway))
2190 goto nla_put_failure;
2191
2192 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));
2193 if (rt->rt_pmtu)
2194 metrics[RTAX_MTU - 1] = rt->rt_pmtu;
2195 if (rtnetlink_put_metrics(skb, metrics) < 0)
2196 goto nla_put_failure;
2197
2198 if (fl4->flowi4_mark &&
2199 nla_put_be32(skb, RTA_MARK, fl4->flowi4_mark))
2200 goto nla_put_failure;
2201
2202 error = rt->dst.error;
2203 expires = rt->dst.expires;
2204 if (expires) {
2205 if (time_before(jiffies, expires))
2206 expires -= jiffies;
2207 else
2208 expires = 0;
2209 }
2210
2211 if (rt_is_input_route(rt)) {
2212 if (nla_put_u32(skb, RTA_IIF, rt->rt_iif))
2213 goto nla_put_failure;
2214 }
2215
2216 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, error) < 0)
2217 goto nla_put_failure;
2218
2219 return nlmsg_end(skb, nlh);
2220
2221 nla_put_failure:
2222 nlmsg_cancel(skb, nlh);
2223 return -EMSGSIZE;
2224 }
2225
2226 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
2227 {
2228 struct net *net = sock_net(in_skb->sk);
2229 struct rtmsg *rtm;
2230 struct nlattr *tb[RTA_MAX+1];
2231 struct rtable *rt = NULL;
2232 struct flowi4 fl4;
2233 __be32 dst = 0;
2234 __be32 src = 0;
2235 u32 iif;
2236 int err;
2237 int mark;
2238 struct sk_buff *skb;
2239
2240 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
2241 if (err < 0)
2242 goto errout;
2243
2244 rtm = nlmsg_data(nlh);
2245
2246 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2247 if (skb == NULL) {
2248 err = -ENOBUFS;
2249 goto errout;
2250 }
2251
2252 /* Reserve room for dummy headers, this skb can pass
2253 through good chunk of routing engine.
2254 */
2255 skb_reset_mac_header(skb);
2256 skb_reset_network_header(skb);
2257
2258 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
2259 ip_hdr(skb)->protocol = IPPROTO_ICMP;
2260 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
2261
2262 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
2263 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
2264 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
2265 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
2266
2267 memset(&fl4, 0, sizeof(fl4));
2268 fl4.daddr = dst;
2269 fl4.saddr = src;
2270 fl4.flowi4_tos = rtm->rtm_tos;
2271 fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
2272 fl4.flowi4_mark = mark;
2273
2274 if (iif) {
2275 struct net_device *dev;
2276
2277 dev = __dev_get_by_index(net, iif);
2278 if (dev == NULL) {
2279 err = -ENODEV;
2280 goto errout_free;
2281 }
2282
2283 skb->protocol = htons(ETH_P_IP);
2284 skb->dev = dev;
2285 skb->mark = mark;
2286 local_bh_disable();
2287 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
2288 local_bh_enable();
2289
2290 rt = skb_rtable(skb);
2291 if (err == 0 && rt->dst.error)
2292 err = -rt->dst.error;
2293 } else {
2294 rt = ip_route_output_key(net, &fl4);
2295
2296 err = 0;
2297 if (IS_ERR(rt))
2298 err = PTR_ERR(rt);
2299 }
2300
2301 if (err)
2302 goto errout_free;
2303
2304 skb_dst_set(skb, &rt->dst);
2305 if (rtm->rtm_flags & RTM_F_NOTIFY)
2306 rt->rt_flags |= RTCF_NOTIFY;
2307
2308 err = rt_fill_info(net, dst, src, &fl4, skb,
2309 NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2310 RTM_NEWROUTE, 0, 0);
2311 if (err <= 0)
2312 goto errout_free;
2313
2314 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2315 errout:
2316 return err;
2317
2318 errout_free:
2319 kfree_skb(skb);
2320 goto errout;
2321 }
2322
2323 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
2324 {
2325 return skb->len;
2326 }
2327
2328 void ip_rt_multicast_event(struct in_device *in_dev)
2329 {
2330 rt_cache_flush(dev_net(in_dev->dev));
2331 }
2332
2333 #ifdef CONFIG_SYSCTL
2334 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
2335 void __user *buffer,
2336 size_t *lenp, loff_t *ppos)
2337 {
2338 if (write) {
2339 rt_cache_flush((struct net *)__ctl->extra1);
2340 return 0;
2341 }
2342
2343 return -EINVAL;
2344 }
2345
2346 static ctl_table ipv4_route_table[] = {
2347 {
2348 .procname = "gc_thresh",
2349 .data = &ipv4_dst_ops.gc_thresh,
2350 .maxlen = sizeof(int),
2351 .mode = 0644,
2352 .proc_handler = proc_dointvec,
2353 },
2354 {
2355 .procname = "max_size",
2356 .data = &ip_rt_max_size,
2357 .maxlen = sizeof(int),
2358 .mode = 0644,
2359 .proc_handler = proc_dointvec,
2360 },
2361 {
2362 /* Deprecated. Use gc_min_interval_ms */
2363
2364 .procname = "gc_min_interval",
2365 .data = &ip_rt_gc_min_interval,
2366 .maxlen = sizeof(int),
2367 .mode = 0644,
2368 .proc_handler = proc_dointvec_jiffies,
2369 },
2370 {
2371 .procname = "gc_min_interval_ms",
2372 .data = &ip_rt_gc_min_interval,
2373 .maxlen = sizeof(int),
2374 .mode = 0644,
2375 .proc_handler = proc_dointvec_ms_jiffies,
2376 },
2377 {
2378 .procname = "gc_timeout",
2379 .data = &ip_rt_gc_timeout,
2380 .maxlen = sizeof(int),
2381 .mode = 0644,
2382 .proc_handler = proc_dointvec_jiffies,
2383 },
2384 {
2385 .procname = "gc_interval",
2386 .data = &ip_rt_gc_interval,
2387 .maxlen = sizeof(int),
2388 .mode = 0644,
2389 .proc_handler = proc_dointvec_jiffies,
2390 },
2391 {
2392 .procname = "redirect_load",
2393 .data = &ip_rt_redirect_load,
2394 .maxlen = sizeof(int),
2395 .mode = 0644,
2396 .proc_handler = proc_dointvec,
2397 },
2398 {
2399 .procname = "redirect_number",
2400 .data = &ip_rt_redirect_number,
2401 .maxlen = sizeof(int),
2402 .mode = 0644,
2403 .proc_handler = proc_dointvec,
2404 },
2405 {
2406 .procname = "redirect_silence",
2407 .data = &ip_rt_redirect_silence,
2408 .maxlen = sizeof(int),
2409 .mode = 0644,
2410 .proc_handler = proc_dointvec,
2411 },
2412 {
2413 .procname = "error_cost",
2414 .data = &ip_rt_error_cost,
2415 .maxlen = sizeof(int),
2416 .mode = 0644,
2417 .proc_handler = proc_dointvec,
2418 },
2419 {
2420 .procname = "error_burst",
2421 .data = &ip_rt_error_burst,
2422 .maxlen = sizeof(int),
2423 .mode = 0644,
2424 .proc_handler = proc_dointvec,
2425 },
2426 {
2427 .procname = "gc_elasticity",
2428 .data = &ip_rt_gc_elasticity,
2429 .maxlen = sizeof(int),
2430 .mode = 0644,
2431 .proc_handler = proc_dointvec,
2432 },
2433 {
2434 .procname = "mtu_expires",
2435 .data = &ip_rt_mtu_expires,
2436 .maxlen = sizeof(int),
2437 .mode = 0644,
2438 .proc_handler = proc_dointvec_jiffies,
2439 },
2440 {
2441 .procname = "min_pmtu",
2442 .data = &ip_rt_min_pmtu,
2443 .maxlen = sizeof(int),
2444 .mode = 0644,
2445 .proc_handler = proc_dointvec,
2446 },
2447 {
2448 .procname = "min_adv_mss",
2449 .data = &ip_rt_min_advmss,
2450 .maxlen = sizeof(int),
2451 .mode = 0644,
2452 .proc_handler = proc_dointvec,
2453 },
2454 { }
2455 };
2456
2457 static struct ctl_table ipv4_route_flush_table[] = {
2458 {
2459 .procname = "flush",
2460 .maxlen = sizeof(int),
2461 .mode = 0200,
2462 .proc_handler = ipv4_sysctl_rtcache_flush,
2463 },
2464 { },
2465 };
2466
2467 static __net_init int sysctl_route_net_init(struct net *net)
2468 {
2469 struct ctl_table *tbl;
2470
2471 tbl = ipv4_route_flush_table;
2472 if (!net_eq(net, &init_net)) {
2473 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
2474 if (tbl == NULL)
2475 goto err_dup;
2476 }
2477 tbl[0].extra1 = net;
2478
2479 net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
2480 if (net->ipv4.route_hdr == NULL)
2481 goto err_reg;
2482 return 0;
2483
2484 err_reg:
2485 if (tbl != ipv4_route_flush_table)
2486 kfree(tbl);
2487 err_dup:
2488 return -ENOMEM;
2489 }
2490
2491 static __net_exit void sysctl_route_net_exit(struct net *net)
2492 {
2493 struct ctl_table *tbl;
2494
2495 tbl = net->ipv4.route_hdr->ctl_table_arg;
2496 unregister_net_sysctl_table(net->ipv4.route_hdr);
2497 BUG_ON(tbl == ipv4_route_flush_table);
2498 kfree(tbl);
2499 }
2500
2501 static __net_initdata struct pernet_operations sysctl_route_ops = {
2502 .init = sysctl_route_net_init,
2503 .exit = sysctl_route_net_exit,
2504 };
2505 #endif
2506
2507 static __net_init int rt_genid_init(struct net *net)
2508 {
2509 atomic_set(&net->ipv4.rt_genid, 0);
2510 get_random_bytes(&net->ipv4.dev_addr_genid,
2511 sizeof(net->ipv4.dev_addr_genid));
2512 return 0;
2513 }
2514
2515 static __net_initdata struct pernet_operations rt_genid_ops = {
2516 .init = rt_genid_init,
2517 };
2518
2519 static int __net_init ipv4_inetpeer_init(struct net *net)
2520 {
2521 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
2522
2523 if (!bp)
2524 return -ENOMEM;
2525 inet_peer_base_init(bp);
2526 net->ipv4.peers = bp;
2527 return 0;
2528 }
2529
2530 static void __net_exit ipv4_inetpeer_exit(struct net *net)
2531 {
2532 struct inet_peer_base *bp = net->ipv4.peers;
2533
2534 net->ipv4.peers = NULL;
2535 inetpeer_invalidate_tree(bp);
2536 kfree(bp);
2537 }
2538
2539 static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
2540 .init = ipv4_inetpeer_init,
2541 .exit = ipv4_inetpeer_exit,
2542 };
2543
2544 #ifdef CONFIG_IP_ROUTE_CLASSID
2545 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
2546 #endif /* CONFIG_IP_ROUTE_CLASSID */
2547
2548 int __init ip_rt_init(void)
2549 {
2550 int rc = 0;
2551
2552 #ifdef CONFIG_IP_ROUTE_CLASSID
2553 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
2554 if (!ip_rt_acct)
2555 panic("IP: failed to allocate ip_rt_acct\n");
2556 #endif
2557
2558 ipv4_dst_ops.kmem_cachep =
2559 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
2560 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
2561
2562 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
2563
2564 if (dst_entries_init(&ipv4_dst_ops) < 0)
2565 panic("IP: failed to allocate ipv4_dst_ops counter\n");
2566
2567 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
2568 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
2569
2570 ipv4_dst_ops.gc_thresh = ~0;
2571 ip_rt_max_size = INT_MAX;
2572
2573 devinet_init();
2574 ip_fib_init();
2575
2576 if (ip_rt_proc_init())
2577 pr_err("Unable to create route proc files\n");
2578 #ifdef CONFIG_XFRM
2579 xfrm_init();
2580 xfrm4_init(ip_rt_max_size);
2581 #endif
2582 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
2583
2584 #ifdef CONFIG_SYSCTL
2585 register_pernet_subsys(&sysctl_route_ops);
2586 #endif
2587 register_pernet_subsys(&rt_genid_ops);
2588 register_pernet_subsys(&ipv4_inetpeer_ops);
2589 return rc;
2590 }
2591
2592 #ifdef CONFIG_SYSCTL
2593 /*
2594 * We really need to sanitize the damn ipv4 init order, then all
2595 * this nonsense will go away.
2596 */
2597 void __init ip_static_sysctl_init(void)
2598 {
2599 register_net_sysctl(&init_net, "net/ipv4/route", ipv4_route_table);
2600 }
2601 #endif
kernel source for telekom puls (alcatel/mediatek)