xref: /openbmc/linux/net/ipv6/route.c (revision 93d90ad7)
1 /*
2  *	Linux INET6 implementation
3  *	FIB front-end.
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  *
8  *	This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  */
13 
14 /*	Changes:
15  *
16  *	YOSHIFUJI Hideaki @USAGI
17  *		reworked default router selection.
18  *		- respect outgoing interface
19  *		- select from (probably) reachable routers (i.e.
20  *		routers in REACHABLE, STALE, DELAY or PROBE states).
21  *		- always select the same router if it is (probably)
22  *		reachable.  otherwise, round-robin the list.
23  *	Ville Nuorvala
24  *		Fixed routing subtrees.
25  */
26 
27 #define pr_fmt(fmt) "IPv6: " fmt
28 
29 #include <linux/capability.h>
30 #include <linux/errno.h>
31 #include <linux/export.h>
32 #include <linux/types.h>
33 #include <linux/times.h>
34 #include <linux/socket.h>
35 #include <linux/sockios.h>
36 #include <linux/net.h>
37 #include <linux/route.h>
38 #include <linux/netdevice.h>
39 #include <linux/in6.h>
40 #include <linux/mroute6.h>
41 #include <linux/init.h>
42 #include <linux/if_arp.h>
43 #include <linux/proc_fs.h>
44 #include <linux/seq_file.h>
45 #include <linux/nsproxy.h>
46 #include <linux/slab.h>
47 #include <net/net_namespace.h>
48 #include <net/snmp.h>
49 #include <net/ipv6.h>
50 #include <net/ip6_fib.h>
51 #include <net/ip6_route.h>
52 #include <net/ndisc.h>
53 #include <net/addrconf.h>
54 #include <net/tcp.h>
55 #include <linux/rtnetlink.h>
56 #include <net/dst.h>
57 #include <net/xfrm.h>
58 #include <net/netevent.h>
59 #include <net/netlink.h>
60 #include <net/nexthop.h>
61 
62 #include <asm/uaccess.h>
63 
64 #ifdef CONFIG_SYSCTL
65 #include <linux/sysctl.h>
66 #endif
67 
68 enum rt6_nud_state {
69 	RT6_NUD_FAIL_HARD = -3,
70 	RT6_NUD_FAIL_PROBE = -2,
71 	RT6_NUD_FAIL_DO_RR = -1,
72 	RT6_NUD_SUCCEED = 1
73 };
74 
75 static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
76 				    const struct in6_addr *dest);
77 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
78 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
79 static unsigned int	 ip6_mtu(const struct dst_entry *dst);
80 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
81 static void		ip6_dst_destroy(struct dst_entry *);
82 static void		ip6_dst_ifdown(struct dst_entry *,
83 				       struct net_device *dev, int how);
84 static int		 ip6_dst_gc(struct dst_ops *ops);
85 
86 static int		ip6_pkt_discard(struct sk_buff *skb);
87 static int		ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb);
88 static int		ip6_pkt_prohibit(struct sk_buff *skb);
89 static int		ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb);
90 static void		ip6_link_failure(struct sk_buff *skb);
91 static void		ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
92 					   struct sk_buff *skb, u32 mtu);
93 static void		rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
94 					struct sk_buff *skb);
95 static int rt6_score_route(struct rt6_info *rt, int oif, int strict);
96 
97 #ifdef CONFIG_IPV6_ROUTE_INFO
98 static struct rt6_info *rt6_add_route_info(struct net *net,
99 					   const struct in6_addr *prefix, int prefixlen,
100 					   const struct in6_addr *gwaddr, int ifindex,
101 					   unsigned int pref);
102 static struct rt6_info *rt6_get_route_info(struct net *net,
103 					   const struct in6_addr *prefix, int prefixlen,
104 					   const struct in6_addr *gwaddr, int ifindex);
105 #endif
106 
107 static void rt6_bind_peer(struct rt6_info *rt, int create)
108 {
109 	struct inet_peer_base *base;
110 	struct inet_peer *peer;
111 
112 	base = inetpeer_base_ptr(rt->_rt6i_peer);
113 	if (!base)
114 		return;
115 
116 	peer = inet_getpeer_v6(base, &rt->rt6i_dst.addr, create);
117 	if (peer) {
118 		if (!rt6_set_peer(rt, peer))
119 			inet_putpeer(peer);
120 	}
121 }
122 
123 static struct inet_peer *__rt6_get_peer(struct rt6_info *rt, int create)
124 {
125 	if (rt6_has_peer(rt))
126 		return rt6_peer_ptr(rt);
127 
128 	rt6_bind_peer(rt, create);
129 	return (rt6_has_peer(rt) ? rt6_peer_ptr(rt) : NULL);
130 }
131 
132 static struct inet_peer *rt6_get_peer_create(struct rt6_info *rt)
133 {
134 	return __rt6_get_peer(rt, 1);
135 }
136 
137 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
138 {
139 	struct rt6_info *rt = (struct rt6_info *) dst;
140 	struct inet_peer *peer;
141 	u32 *p = NULL;
142 
143 	if (!(rt->dst.flags & DST_HOST))
144 		return NULL;
145 
146 	peer = rt6_get_peer_create(rt);
147 	if (peer) {
148 		u32 *old_p = __DST_METRICS_PTR(old);
149 		unsigned long prev, new;
150 
151 		p = peer->metrics;
152 		if (inet_metrics_new(peer) ||
153 		    (old & DST_METRICS_FORCE_OVERWRITE))
154 			memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
155 
156 		new = (unsigned long) p;
157 		prev = cmpxchg(&dst->_metrics, old, new);
158 
159 		if (prev != old) {
160 			p = __DST_METRICS_PTR(prev);
161 			if (prev & DST_METRICS_READ_ONLY)
162 				p = NULL;
163 		}
164 	}
165 	return p;
166 }
167 
168 static inline const void *choose_neigh_daddr(struct rt6_info *rt,
169 					     struct sk_buff *skb,
170 					     const void *daddr)
171 {
172 	struct in6_addr *p = &rt->rt6i_gateway;
173 
174 	if (!ipv6_addr_any(p))
175 		return (const void *) p;
176 	else if (skb)
177 		return &ipv6_hdr(skb)->daddr;
178 	return daddr;
179 }
180 
181 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst,
182 					  struct sk_buff *skb,
183 					  const void *daddr)
184 {
185 	struct rt6_info *rt = (struct rt6_info *) dst;
186 	struct neighbour *n;
187 
188 	daddr = choose_neigh_daddr(rt, skb, daddr);
189 	n = __ipv6_neigh_lookup(dst->dev, daddr);
190 	if (n)
191 		return n;
192 	return neigh_create(&nd_tbl, daddr, dst->dev);
193 }
194 
195 static struct dst_ops ip6_dst_ops_template = {
196 	.family			=	AF_INET6,
197 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
198 	.gc			=	ip6_dst_gc,
199 	.gc_thresh		=	1024,
200 	.check			=	ip6_dst_check,
201 	.default_advmss		=	ip6_default_advmss,
202 	.mtu			=	ip6_mtu,
203 	.cow_metrics		=	ipv6_cow_metrics,
204 	.destroy		=	ip6_dst_destroy,
205 	.ifdown			=	ip6_dst_ifdown,
206 	.negative_advice	=	ip6_negative_advice,
207 	.link_failure		=	ip6_link_failure,
208 	.update_pmtu		=	ip6_rt_update_pmtu,
209 	.redirect		=	rt6_do_redirect,
210 	.local_out		=	__ip6_local_out,
211 	.neigh_lookup		=	ip6_neigh_lookup,
212 };
213 
214 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
215 {
216 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
217 
218 	return mtu ? : dst->dev->mtu;
219 }
220 
221 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
222 					 struct sk_buff *skb, u32 mtu)
223 {
224 }
225 
226 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
227 				      struct sk_buff *skb)
228 {
229 }
230 
231 static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst,
232 					 unsigned long old)
233 {
234 	return NULL;
235 }
236 
237 static struct dst_ops ip6_dst_blackhole_ops = {
238 	.family			=	AF_INET6,
239 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
240 	.destroy		=	ip6_dst_destroy,
241 	.check			=	ip6_dst_check,
242 	.mtu			=	ip6_blackhole_mtu,
243 	.default_advmss		=	ip6_default_advmss,
244 	.update_pmtu		=	ip6_rt_blackhole_update_pmtu,
245 	.redirect		=	ip6_rt_blackhole_redirect,
246 	.cow_metrics		=	ip6_rt_blackhole_cow_metrics,
247 	.neigh_lookup		=	ip6_neigh_lookup,
248 };
249 
250 static const u32 ip6_template_metrics[RTAX_MAX] = {
251 	[RTAX_HOPLIMIT - 1] = 0,
252 };
253 
254 static const struct rt6_info ip6_null_entry_template = {
255 	.dst = {
256 		.__refcnt	= ATOMIC_INIT(1),
257 		.__use		= 1,
258 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
259 		.error		= -ENETUNREACH,
260 		.input		= ip6_pkt_discard,
261 		.output		= ip6_pkt_discard_out,
262 	},
263 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
264 	.rt6i_protocol  = RTPROT_KERNEL,
265 	.rt6i_metric	= ~(u32) 0,
266 	.rt6i_ref	= ATOMIC_INIT(1),
267 };
268 
269 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
270 
271 static const struct rt6_info ip6_prohibit_entry_template = {
272 	.dst = {
273 		.__refcnt	= ATOMIC_INIT(1),
274 		.__use		= 1,
275 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
276 		.error		= -EACCES,
277 		.input		= ip6_pkt_prohibit,
278 		.output		= ip6_pkt_prohibit_out,
279 	},
280 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
281 	.rt6i_protocol  = RTPROT_KERNEL,
282 	.rt6i_metric	= ~(u32) 0,
283 	.rt6i_ref	= ATOMIC_INIT(1),
284 };
285 
286 static const struct rt6_info ip6_blk_hole_entry_template = {
287 	.dst = {
288 		.__refcnt	= ATOMIC_INIT(1),
289 		.__use		= 1,
290 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
291 		.error		= -EINVAL,
292 		.input		= dst_discard,
293 		.output		= dst_discard_sk,
294 	},
295 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
296 	.rt6i_protocol  = RTPROT_KERNEL,
297 	.rt6i_metric	= ~(u32) 0,
298 	.rt6i_ref	= ATOMIC_INIT(1),
299 };
300 
301 #endif
302 
303 /* allocate dst with ip6_dst_ops */
304 static inline struct rt6_info *ip6_dst_alloc(struct net *net,
305 					     struct net_device *dev,
306 					     int flags,
307 					     struct fib6_table *table)
308 {
309 	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
310 					0, DST_OBSOLETE_FORCE_CHK, flags);
311 
312 	if (rt) {
313 		struct dst_entry *dst = &rt->dst;
314 
315 		memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
316 		rt6_init_peer(rt, table ? &table->tb6_peers : net->ipv6.peers);
317 		INIT_LIST_HEAD(&rt->rt6i_siblings);
318 	}
319 	return rt;
320 }
321 
322 static void ip6_dst_destroy(struct dst_entry *dst)
323 {
324 	struct rt6_info *rt = (struct rt6_info *)dst;
325 	struct inet6_dev *idev = rt->rt6i_idev;
326 	struct dst_entry *from = dst->from;
327 
328 	if (!(rt->dst.flags & DST_HOST))
329 		dst_destroy_metrics_generic(dst);
330 
331 	if (idev) {
332 		rt->rt6i_idev = NULL;
333 		in6_dev_put(idev);
334 	}
335 
336 	dst->from = NULL;
337 	dst_release(from);
338 
339 	if (rt6_has_peer(rt)) {
340 		struct inet_peer *peer = rt6_peer_ptr(rt);
341 		inet_putpeer(peer);
342 	}
343 }
344 
345 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
346 			   int how)
347 {
348 	struct rt6_info *rt = (struct rt6_info *)dst;
349 	struct inet6_dev *idev = rt->rt6i_idev;
350 	struct net_device *loopback_dev =
351 		dev_net(dev)->loopback_dev;
352 
353 	if (dev != loopback_dev) {
354 		if (idev && idev->dev == dev) {
355 			struct inet6_dev *loopback_idev =
356 				in6_dev_get(loopback_dev);
357 			if (loopback_idev) {
358 				rt->rt6i_idev = loopback_idev;
359 				in6_dev_put(idev);
360 			}
361 		}
362 	}
363 }
364 
365 static bool rt6_check_expired(const struct rt6_info *rt)
366 {
367 	if (rt->rt6i_flags & RTF_EXPIRES) {
368 		if (time_after(jiffies, rt->dst.expires))
369 			return true;
370 	} else if (rt->dst.from) {
371 		return rt6_check_expired((struct rt6_info *) rt->dst.from);
372 	}
373 	return false;
374 }
375 
376 /* Multipath route selection:
377  *   Hash based function using packet header and flowlabel.
378  * Adapted from fib_info_hashfn()
379  */
380 static int rt6_info_hash_nhsfn(unsigned int candidate_count,
381 			       const struct flowi6 *fl6)
382 {
383 	unsigned int val = fl6->flowi6_proto;
384 
385 	val ^= ipv6_addr_hash(&fl6->daddr);
386 	val ^= ipv6_addr_hash(&fl6->saddr);
387 
388 	/* Work only if this not encapsulated */
389 	switch (fl6->flowi6_proto) {
390 	case IPPROTO_UDP:
391 	case IPPROTO_TCP:
392 	case IPPROTO_SCTP:
393 		val ^= (__force u16)fl6->fl6_sport;
394 		val ^= (__force u16)fl6->fl6_dport;
395 		break;
396 
397 	case IPPROTO_ICMPV6:
398 		val ^= (__force u16)fl6->fl6_icmp_type;
399 		val ^= (__force u16)fl6->fl6_icmp_code;
400 		break;
401 	}
402 	/* RFC6438 recommands to use flowlabel */
403 	val ^= (__force u32)fl6->flowlabel;
404 
405 	/* Perhaps, we need to tune, this function? */
406 	val = val ^ (val >> 7) ^ (val >> 12);
407 	return val % candidate_count;
408 }
409 
410 static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
411 					     struct flowi6 *fl6, int oif,
412 					     int strict)
413 {
414 	struct rt6_info *sibling, *next_sibling;
415 	int route_choosen;
416 
417 	route_choosen = rt6_info_hash_nhsfn(match->rt6i_nsiblings + 1, fl6);
418 	/* Don't change the route, if route_choosen == 0
419 	 * (siblings does not include ourself)
420 	 */
421 	if (route_choosen)
422 		list_for_each_entry_safe(sibling, next_sibling,
423 				&match->rt6i_siblings, rt6i_siblings) {
424 			route_choosen--;
425 			if (route_choosen == 0) {
426 				if (rt6_score_route(sibling, oif, strict) < 0)
427 					break;
428 				match = sibling;
429 				break;
430 			}
431 		}
432 	return match;
433 }
434 
435 /*
436  *	Route lookup. Any table->tb6_lock is implied.
437  */
438 
439 static inline struct rt6_info *rt6_device_match(struct net *net,
440 						    struct rt6_info *rt,
441 						    const struct in6_addr *saddr,
442 						    int oif,
443 						    int flags)
444 {
445 	struct rt6_info *local = NULL;
446 	struct rt6_info *sprt;
447 
448 	if (!oif && ipv6_addr_any(saddr))
449 		goto out;
450 
451 	for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
452 		struct net_device *dev = sprt->dst.dev;
453 
454 		if (oif) {
455 			if (dev->ifindex == oif)
456 				return sprt;
457 			if (dev->flags & IFF_LOOPBACK) {
458 				if (!sprt->rt6i_idev ||
459 				    sprt->rt6i_idev->dev->ifindex != oif) {
460 					if (flags & RT6_LOOKUP_F_IFACE && oif)
461 						continue;
462 					if (local && (!oif ||
463 						      local->rt6i_idev->dev->ifindex == oif))
464 						continue;
465 				}
466 				local = sprt;
467 			}
468 		} else {
469 			if (ipv6_chk_addr(net, saddr, dev,
470 					  flags & RT6_LOOKUP_F_IFACE))
471 				return sprt;
472 		}
473 	}
474 
475 	if (oif) {
476 		if (local)
477 			return local;
478 
479 		if (flags & RT6_LOOKUP_F_IFACE)
480 			return net->ipv6.ip6_null_entry;
481 	}
482 out:
483 	return rt;
484 }
485 
486 #ifdef CONFIG_IPV6_ROUTER_PREF
487 struct __rt6_probe_work {
488 	struct work_struct work;
489 	struct in6_addr target;
490 	struct net_device *dev;
491 };
492 
493 static void rt6_probe_deferred(struct work_struct *w)
494 {
495 	struct in6_addr mcaddr;
496 	struct __rt6_probe_work *work =
497 		container_of(w, struct __rt6_probe_work, work);
498 
499 	addrconf_addr_solict_mult(&work->target, &mcaddr);
500 	ndisc_send_ns(work->dev, NULL, &work->target, &mcaddr, NULL);
501 	dev_put(work->dev);
502 	kfree(w);
503 }
504 
505 static void rt6_probe(struct rt6_info *rt)
506 {
507 	struct neighbour *neigh;
508 	/*
509 	 * Okay, this does not seem to be appropriate
510 	 * for now, however, we need to check if it
511 	 * is really so; aka Router Reachability Probing.
512 	 *
513 	 * Router Reachability Probe MUST be rate-limited
514 	 * to no more than one per minute.
515 	 */
516 	if (!rt || !(rt->rt6i_flags & RTF_GATEWAY))
517 		return;
518 	rcu_read_lock_bh();
519 	neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
520 	if (neigh) {
521 		write_lock(&neigh->lock);
522 		if (neigh->nud_state & NUD_VALID)
523 			goto out;
524 	}
525 
526 	if (!neigh ||
527 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
528 		struct __rt6_probe_work *work;
529 
530 		work = kmalloc(sizeof(*work), GFP_ATOMIC);
531 
532 		if (neigh && work)
533 			__neigh_set_probe_once(neigh);
534 
535 		if (neigh)
536 			write_unlock(&neigh->lock);
537 
538 		if (work) {
539 			INIT_WORK(&work->work, rt6_probe_deferred);
540 			work->target = rt->rt6i_gateway;
541 			dev_hold(rt->dst.dev);
542 			work->dev = rt->dst.dev;
543 			schedule_work(&work->work);
544 		}
545 	} else {
546 out:
547 		write_unlock(&neigh->lock);
548 	}
549 	rcu_read_unlock_bh();
550 }
551 #else
552 static inline void rt6_probe(struct rt6_info *rt)
553 {
554 }
555 #endif
556 
557 /*
558  * Default Router Selection (RFC 2461 6.3.6)
559  */
560 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
561 {
562 	struct net_device *dev = rt->dst.dev;
563 	if (!oif || dev->ifindex == oif)
564 		return 2;
565 	if ((dev->flags & IFF_LOOPBACK) &&
566 	    rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
567 		return 1;
568 	return 0;
569 }
570 
571 static inline enum rt6_nud_state rt6_check_neigh(struct rt6_info *rt)
572 {
573 	struct neighbour *neigh;
574 	enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
575 
576 	if (rt->rt6i_flags & RTF_NONEXTHOP ||
577 	    !(rt->rt6i_flags & RTF_GATEWAY))
578 		return RT6_NUD_SUCCEED;
579 
580 	rcu_read_lock_bh();
581 	neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
582 	if (neigh) {
583 		read_lock(&neigh->lock);
584 		if (neigh->nud_state & NUD_VALID)
585 			ret = RT6_NUD_SUCCEED;
586 #ifdef CONFIG_IPV6_ROUTER_PREF
587 		else if (!(neigh->nud_state & NUD_FAILED))
588 			ret = RT6_NUD_SUCCEED;
589 		else
590 			ret = RT6_NUD_FAIL_PROBE;
591 #endif
592 		read_unlock(&neigh->lock);
593 	} else {
594 		ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
595 		      RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
596 	}
597 	rcu_read_unlock_bh();
598 
599 	return ret;
600 }
601 
602 static int rt6_score_route(struct rt6_info *rt, int oif,
603 			   int strict)
604 {
605 	int m;
606 
607 	m = rt6_check_dev(rt, oif);
608 	if (!m && (strict & RT6_LOOKUP_F_IFACE))
609 		return RT6_NUD_FAIL_HARD;
610 #ifdef CONFIG_IPV6_ROUTER_PREF
611 	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
612 #endif
613 	if (strict & RT6_LOOKUP_F_REACHABLE) {
614 		int n = rt6_check_neigh(rt);
615 		if (n < 0)
616 			return n;
617 	}
618 	return m;
619 }
620 
621 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
622 				   int *mpri, struct rt6_info *match,
623 				   bool *do_rr)
624 {
625 	int m;
626 	bool match_do_rr = false;
627 
628 	if (rt6_check_expired(rt))
629 		goto out;
630 
631 	m = rt6_score_route(rt, oif, strict);
632 	if (m == RT6_NUD_FAIL_DO_RR) {
633 		match_do_rr = true;
634 		m = 0; /* lowest valid score */
635 	} else if (m == RT6_NUD_FAIL_HARD) {
636 		goto out;
637 	}
638 
639 	if (strict & RT6_LOOKUP_F_REACHABLE)
640 		rt6_probe(rt);
641 
642 	/* note that m can be RT6_NUD_FAIL_PROBE at this point */
643 	if (m > *mpri) {
644 		*do_rr = match_do_rr;
645 		*mpri = m;
646 		match = rt;
647 	}
648 out:
649 	return match;
650 }
651 
652 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
653 				     struct rt6_info *rr_head,
654 				     u32 metric, int oif, int strict,
655 				     bool *do_rr)
656 {
657 	struct rt6_info *rt, *match;
658 	int mpri = -1;
659 
660 	match = NULL;
661 	for (rt = rr_head; rt && rt->rt6i_metric == metric;
662 	     rt = rt->dst.rt6_next)
663 		match = find_match(rt, oif, strict, &mpri, match, do_rr);
664 	for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;
665 	     rt = rt->dst.rt6_next)
666 		match = find_match(rt, oif, strict, &mpri, match, do_rr);
667 
668 	return match;
669 }
670 
671 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
672 {
673 	struct rt6_info *match, *rt0;
674 	struct net *net;
675 	bool do_rr = false;
676 
677 	rt0 = fn->rr_ptr;
678 	if (!rt0)
679 		fn->rr_ptr = rt0 = fn->leaf;
680 
681 	match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict,
682 			     &do_rr);
683 
684 	if (do_rr) {
685 		struct rt6_info *next = rt0->dst.rt6_next;
686 
687 		/* no entries matched; do round-robin */
688 		if (!next || next->rt6i_metric != rt0->rt6i_metric)
689 			next = fn->leaf;
690 
691 		if (next != rt0)
692 			fn->rr_ptr = next;
693 	}
694 
695 	net = dev_net(rt0->dst.dev);
696 	return match ? match : net->ipv6.ip6_null_entry;
697 }
698 
699 #ifdef CONFIG_IPV6_ROUTE_INFO
700 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
701 		  const struct in6_addr *gwaddr)
702 {
703 	struct net *net = dev_net(dev);
704 	struct route_info *rinfo = (struct route_info *) opt;
705 	struct in6_addr prefix_buf, *prefix;
706 	unsigned int pref;
707 	unsigned long lifetime;
708 	struct rt6_info *rt;
709 
710 	if (len < sizeof(struct route_info)) {
711 		return -EINVAL;
712 	}
713 
714 	/* Sanity check for prefix_len and length */
715 	if (rinfo->length > 3) {
716 		return -EINVAL;
717 	} else if (rinfo->prefix_len > 128) {
718 		return -EINVAL;
719 	} else if (rinfo->prefix_len > 64) {
720 		if (rinfo->length < 2) {
721 			return -EINVAL;
722 		}
723 	} else if (rinfo->prefix_len > 0) {
724 		if (rinfo->length < 1) {
725 			return -EINVAL;
726 		}
727 	}
728 
729 	pref = rinfo->route_pref;
730 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
731 		return -EINVAL;
732 
733 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
734 
735 	if (rinfo->length == 3)
736 		prefix = (struct in6_addr *)rinfo->prefix;
737 	else {
738 		/* this function is safe */
739 		ipv6_addr_prefix(&prefix_buf,
740 				 (struct in6_addr *)rinfo->prefix,
741 				 rinfo->prefix_len);
742 		prefix = &prefix_buf;
743 	}
744 
745 	if (rinfo->prefix_len == 0)
746 		rt = rt6_get_dflt_router(gwaddr, dev);
747 	else
748 		rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
749 					gwaddr, dev->ifindex);
750 
751 	if (rt && !lifetime) {
752 		ip6_del_rt(rt);
753 		rt = NULL;
754 	}
755 
756 	if (!rt && lifetime)
757 		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
758 					pref);
759 	else if (rt)
760 		rt->rt6i_flags = RTF_ROUTEINFO |
761 				 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
762 
763 	if (rt) {
764 		if (!addrconf_finite_timeout(lifetime))
765 			rt6_clean_expires(rt);
766 		else
767 			rt6_set_expires(rt, jiffies + HZ * lifetime);
768 
769 		ip6_rt_put(rt);
770 	}
771 	return 0;
772 }
773 #endif
774 
775 static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
776 					struct in6_addr *saddr)
777 {
778 	struct fib6_node *pn;
779 	while (1) {
780 		if (fn->fn_flags & RTN_TL_ROOT)
781 			return NULL;
782 		pn = fn->parent;
783 		if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn)
784 			fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr);
785 		else
786 			fn = pn;
787 		if (fn->fn_flags & RTN_RTINFO)
788 			return fn;
789 	}
790 }
791 
792 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
793 					     struct fib6_table *table,
794 					     struct flowi6 *fl6, int flags)
795 {
796 	struct fib6_node *fn;
797 	struct rt6_info *rt;
798 
799 	read_lock_bh(&table->tb6_lock);
800 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
801 restart:
802 	rt = fn->leaf;
803 	rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
804 	if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
805 		rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
806 	if (rt == net->ipv6.ip6_null_entry) {
807 		fn = fib6_backtrack(fn, &fl6->saddr);
808 		if (fn)
809 			goto restart;
810 	}
811 	dst_use(&rt->dst, jiffies);
812 	read_unlock_bh(&table->tb6_lock);
813 	return rt;
814 
815 }
816 
817 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
818 				    int flags)
819 {
820 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
821 }
822 EXPORT_SYMBOL_GPL(ip6_route_lookup);
823 
824 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
825 			    const struct in6_addr *saddr, int oif, int strict)
826 {
827 	struct flowi6 fl6 = {
828 		.flowi6_oif = oif,
829 		.daddr = *daddr,
830 	};
831 	struct dst_entry *dst;
832 	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
833 
834 	if (saddr) {
835 		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
836 		flags |= RT6_LOOKUP_F_HAS_SADDR;
837 	}
838 
839 	dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
840 	if (dst->error == 0)
841 		return (struct rt6_info *) dst;
842 
843 	dst_release(dst);
844 
845 	return NULL;
846 }
847 EXPORT_SYMBOL(rt6_lookup);
848 
849 /* ip6_ins_rt is called with FREE table->tb6_lock.
850    It takes new route entry, the addition fails by any reason the
851    route is freed. In any case, if caller does not hold it, it may
852    be destroyed.
853  */
854 
855 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info,
856 			struct nlattr *mx, int mx_len)
857 {
858 	int err;
859 	struct fib6_table *table;
860 
861 	table = rt->rt6i_table;
862 	write_lock_bh(&table->tb6_lock);
863 	err = fib6_add(&table->tb6_root, rt, info, mx, mx_len);
864 	write_unlock_bh(&table->tb6_lock);
865 
866 	return err;
867 }
868 
869 int ip6_ins_rt(struct rt6_info *rt)
870 {
871 	struct nl_info info = {
872 		.nl_net = dev_net(rt->dst.dev),
873 	};
874 	return __ip6_ins_rt(rt, &info, NULL, 0);
875 }
876 
877 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort,
878 				      const struct in6_addr *daddr,
879 				      const struct in6_addr *saddr)
880 {
881 	struct rt6_info *rt;
882 
883 	/*
884 	 *	Clone the route.
885 	 */
886 
887 	rt = ip6_rt_copy(ort, daddr);
888 
889 	if (rt) {
890 		if (ort->rt6i_dst.plen != 128 &&
891 		    ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
892 			rt->rt6i_flags |= RTF_ANYCAST;
893 
894 		rt->rt6i_flags |= RTF_CACHE;
895 
896 #ifdef CONFIG_IPV6_SUBTREES
897 		if (rt->rt6i_src.plen && saddr) {
898 			rt->rt6i_src.addr = *saddr;
899 			rt->rt6i_src.plen = 128;
900 		}
901 #endif
902 	}
903 
904 	return rt;
905 }
906 
907 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort,
908 					const struct in6_addr *daddr)
909 {
910 	struct rt6_info *rt = ip6_rt_copy(ort, daddr);
911 
912 	if (rt)
913 		rt->rt6i_flags |= RTF_CACHE;
914 	return rt;
915 }
916 
917 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
918 				      struct flowi6 *fl6, int flags)
919 {
920 	struct fib6_node *fn, *saved_fn;
921 	struct rt6_info *rt, *nrt;
922 	int strict = 0;
923 	int attempts = 3;
924 	int err;
925 
926 	strict |= flags & RT6_LOOKUP_F_IFACE;
927 	if (net->ipv6.devconf_all->forwarding == 0)
928 		strict |= RT6_LOOKUP_F_REACHABLE;
929 
930 redo_fib6_lookup_lock:
931 	read_lock_bh(&table->tb6_lock);
932 
933 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
934 	saved_fn = fn;
935 
936 redo_rt6_select:
937 	rt = rt6_select(fn, oif, strict);
938 	if (rt->rt6i_nsiblings)
939 		rt = rt6_multipath_select(rt, fl6, oif, strict);
940 	if (rt == net->ipv6.ip6_null_entry) {
941 		fn = fib6_backtrack(fn, &fl6->saddr);
942 		if (fn)
943 			goto redo_rt6_select;
944 		else if (strict & RT6_LOOKUP_F_REACHABLE) {
945 			/* also consider unreachable route */
946 			strict &= ~RT6_LOOKUP_F_REACHABLE;
947 			fn = saved_fn;
948 			goto redo_rt6_select;
949 		} else {
950 			dst_hold(&rt->dst);
951 			read_unlock_bh(&table->tb6_lock);
952 			goto out2;
953 		}
954 	}
955 
956 	dst_hold(&rt->dst);
957 	read_unlock_bh(&table->tb6_lock);
958 
959 	if (rt->rt6i_flags & RTF_CACHE)
960 		goto out2;
961 
962 	if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)))
963 		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
964 	else if (!(rt->dst.flags & DST_HOST))
965 		nrt = rt6_alloc_clone(rt, &fl6->daddr);
966 	else
967 		goto out2;
968 
969 	ip6_rt_put(rt);
970 	rt = nrt ? : net->ipv6.ip6_null_entry;
971 
972 	dst_hold(&rt->dst);
973 	if (nrt) {
974 		err = ip6_ins_rt(nrt);
975 		if (!err)
976 			goto out2;
977 	}
978 
979 	if (--attempts <= 0)
980 		goto out2;
981 
982 	/*
983 	 * Race condition! In the gap, when table->tb6_lock was
984 	 * released someone could insert this route.  Relookup.
985 	 */
986 	ip6_rt_put(rt);
987 	goto redo_fib6_lookup_lock;
988 
989 out2:
990 	rt->dst.lastuse = jiffies;
991 	rt->dst.__use++;
992 
993 	return rt;
994 }
995 
996 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
997 					    struct flowi6 *fl6, int flags)
998 {
999 	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
1000 }
1001 
1002 static struct dst_entry *ip6_route_input_lookup(struct net *net,
1003 						struct net_device *dev,
1004 						struct flowi6 *fl6, int flags)
1005 {
1006 	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
1007 		flags |= RT6_LOOKUP_F_IFACE;
1008 
1009 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
1010 }
1011 
1012 void ip6_route_input(struct sk_buff *skb)
1013 {
1014 	const struct ipv6hdr *iph = ipv6_hdr(skb);
1015 	struct net *net = dev_net(skb->dev);
1016 	int flags = RT6_LOOKUP_F_HAS_SADDR;
1017 	struct flowi6 fl6 = {
1018 		.flowi6_iif = skb->dev->ifindex,
1019 		.daddr = iph->daddr,
1020 		.saddr = iph->saddr,
1021 		.flowlabel = ip6_flowinfo(iph),
1022 		.flowi6_mark = skb->mark,
1023 		.flowi6_proto = iph->nexthdr,
1024 	};
1025 
1026 	skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
1027 }
1028 
1029 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
1030 					     struct flowi6 *fl6, int flags)
1031 {
1032 	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
1033 }
1034 
1035 struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk,
1036 				    struct flowi6 *fl6)
1037 {
1038 	int flags = 0;
1039 
1040 	fl6->flowi6_iif = LOOPBACK_IFINDEX;
1041 
1042 	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
1043 		flags |= RT6_LOOKUP_F_IFACE;
1044 
1045 	if (!ipv6_addr_any(&fl6->saddr))
1046 		flags |= RT6_LOOKUP_F_HAS_SADDR;
1047 	else if (sk)
1048 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
1049 
1050 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
1051 }
1052 EXPORT_SYMBOL(ip6_route_output);
1053 
1054 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
1055 {
1056 	struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
1057 	struct dst_entry *new = NULL;
1058 
1059 	rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0);
1060 	if (rt) {
1061 		new = &rt->dst;
1062 
1063 		memset(new + 1, 0, sizeof(*rt) - sizeof(*new));
1064 		rt6_init_peer(rt, net->ipv6.peers);
1065 
1066 		new->__use = 1;
1067 		new->input = dst_discard;
1068 		new->output = dst_discard_sk;
1069 
1070 		if (dst_metrics_read_only(&ort->dst))
1071 			new->_metrics = ort->dst._metrics;
1072 		else
1073 			dst_copy_metrics(new, &ort->dst);
1074 		rt->rt6i_idev = ort->rt6i_idev;
1075 		if (rt->rt6i_idev)
1076 			in6_dev_hold(rt->rt6i_idev);
1077 
1078 		rt->rt6i_gateway = ort->rt6i_gateway;
1079 		rt->rt6i_flags = ort->rt6i_flags;
1080 		rt->rt6i_metric = 0;
1081 
1082 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1083 #ifdef CONFIG_IPV6_SUBTREES
1084 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1085 #endif
1086 
1087 		dst_free(new);
1088 	}
1089 
1090 	dst_release(dst_orig);
1091 	return new ? new : ERR_PTR(-ENOMEM);
1092 }
1093 
1094 /*
1095  *	Destination cache support functions
1096  */
1097 
1098 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
1099 {
1100 	struct rt6_info *rt;
1101 
1102 	rt = (struct rt6_info *) dst;
1103 
1104 	/* All IPV6 dsts are created with ->obsolete set to the value
1105 	 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1106 	 * into this function always.
1107 	 */
1108 	if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie))
1109 		return NULL;
1110 
1111 	if (rt6_check_expired(rt))
1112 		return NULL;
1113 
1114 	return dst;
1115 }
1116 
1117 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
1118 {
1119 	struct rt6_info *rt = (struct rt6_info *) dst;
1120 
1121 	if (rt) {
1122 		if (rt->rt6i_flags & RTF_CACHE) {
1123 			if (rt6_check_expired(rt)) {
1124 				ip6_del_rt(rt);
1125 				dst = NULL;
1126 			}
1127 		} else {
1128 			dst_release(dst);
1129 			dst = NULL;
1130 		}
1131 	}
1132 	return dst;
1133 }
1134 
1135 static void ip6_link_failure(struct sk_buff *skb)
1136 {
1137 	struct rt6_info *rt;
1138 
1139 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
1140 
1141 	rt = (struct rt6_info *) skb_dst(skb);
1142 	if (rt) {
1143 		if (rt->rt6i_flags & RTF_CACHE) {
1144 			dst_hold(&rt->dst);
1145 			if (ip6_del_rt(rt))
1146 				dst_free(&rt->dst);
1147 		} else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
1148 			rt->rt6i_node->fn_sernum = -1;
1149 		}
1150 	}
1151 }
1152 
1153 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1154 			       struct sk_buff *skb, u32 mtu)
1155 {
1156 	struct rt6_info *rt6 = (struct rt6_info *)dst;
1157 
1158 	dst_confirm(dst);
1159 	if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
1160 		struct net *net = dev_net(dst->dev);
1161 
1162 		rt6->rt6i_flags |= RTF_MODIFIED;
1163 		if (mtu < IPV6_MIN_MTU)
1164 			mtu = IPV6_MIN_MTU;
1165 
1166 		dst_metric_set(dst, RTAX_MTU, mtu);
1167 		rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires);
1168 	}
1169 }
1170 
1171 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
1172 		     int oif, u32 mark)
1173 {
1174 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1175 	struct dst_entry *dst;
1176 	struct flowi6 fl6;
1177 
1178 	memset(&fl6, 0, sizeof(fl6));
1179 	fl6.flowi6_oif = oif;
1180 	fl6.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark);
1181 	fl6.daddr = iph->daddr;
1182 	fl6.saddr = iph->saddr;
1183 	fl6.flowlabel = ip6_flowinfo(iph);
1184 
1185 	dst = ip6_route_output(net, NULL, &fl6);
1186 	if (!dst->error)
1187 		ip6_rt_update_pmtu(dst, NULL, skb, ntohl(mtu));
1188 	dst_release(dst);
1189 }
1190 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
1191 
1192 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
1193 {
1194 	ip6_update_pmtu(skb, sock_net(sk), mtu,
1195 			sk->sk_bound_dev_if, sk->sk_mark);
1196 }
1197 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
1198 
1199 /* Handle redirects */
1200 struct ip6rd_flowi {
1201 	struct flowi6 fl6;
1202 	struct in6_addr gateway;
1203 };
1204 
1205 static struct rt6_info *__ip6_route_redirect(struct net *net,
1206 					     struct fib6_table *table,
1207 					     struct flowi6 *fl6,
1208 					     int flags)
1209 {
1210 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
1211 	struct rt6_info *rt;
1212 	struct fib6_node *fn;
1213 
1214 	/* Get the "current" route for this destination and
1215 	 * check if the redirect has come from approriate router.
1216 	 *
1217 	 * RFC 4861 specifies that redirects should only be
1218 	 * accepted if they come from the nexthop to the target.
1219 	 * Due to the way the routes are chosen, this notion
1220 	 * is a bit fuzzy and one might need to check all possible
1221 	 * routes.
1222 	 */
1223 
1224 	read_lock_bh(&table->tb6_lock);
1225 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1226 restart:
1227 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1228 		if (rt6_check_expired(rt))
1229 			continue;
1230 		if (rt->dst.error)
1231 			break;
1232 		if (!(rt->rt6i_flags & RTF_GATEWAY))
1233 			continue;
1234 		if (fl6->flowi6_oif != rt->dst.dev->ifindex)
1235 			continue;
1236 		if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1237 			continue;
1238 		break;
1239 	}
1240 
1241 	if (!rt)
1242 		rt = net->ipv6.ip6_null_entry;
1243 	else if (rt->dst.error) {
1244 		rt = net->ipv6.ip6_null_entry;
1245 	} else if (rt == net->ipv6.ip6_null_entry) {
1246 		fn = fib6_backtrack(fn, &fl6->saddr);
1247 		if (fn)
1248 			goto restart;
1249 	}
1250 
1251 	dst_hold(&rt->dst);
1252 
1253 	read_unlock_bh(&table->tb6_lock);
1254 
1255 	return rt;
1256 };
1257 
1258 static struct dst_entry *ip6_route_redirect(struct net *net,
1259 					const struct flowi6 *fl6,
1260 					const struct in6_addr *gateway)
1261 {
1262 	int flags = RT6_LOOKUP_F_HAS_SADDR;
1263 	struct ip6rd_flowi rdfl;
1264 
1265 	rdfl.fl6 = *fl6;
1266 	rdfl.gateway = *gateway;
1267 
1268 	return fib6_rule_lookup(net, &rdfl.fl6,
1269 				flags, __ip6_route_redirect);
1270 }
1271 
1272 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
1273 {
1274 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1275 	struct dst_entry *dst;
1276 	struct flowi6 fl6;
1277 
1278 	memset(&fl6, 0, sizeof(fl6));
1279 	fl6.flowi6_iif = LOOPBACK_IFINDEX;
1280 	fl6.flowi6_oif = oif;
1281 	fl6.flowi6_mark = mark;
1282 	fl6.daddr = iph->daddr;
1283 	fl6.saddr = iph->saddr;
1284 	fl6.flowlabel = ip6_flowinfo(iph);
1285 
1286 	dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr);
1287 	rt6_do_redirect(dst, NULL, skb);
1288 	dst_release(dst);
1289 }
1290 EXPORT_SYMBOL_GPL(ip6_redirect);
1291 
1292 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
1293 			    u32 mark)
1294 {
1295 	const struct ipv6hdr *iph = ipv6_hdr(skb);
1296 	const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
1297 	struct dst_entry *dst;
1298 	struct flowi6 fl6;
1299 
1300 	memset(&fl6, 0, sizeof(fl6));
1301 	fl6.flowi6_iif = LOOPBACK_IFINDEX;
1302 	fl6.flowi6_oif = oif;
1303 	fl6.flowi6_mark = mark;
1304 	fl6.daddr = msg->dest;
1305 	fl6.saddr = iph->daddr;
1306 
1307 	dst = ip6_route_redirect(net, &fl6, &iph->saddr);
1308 	rt6_do_redirect(dst, NULL, skb);
1309 	dst_release(dst);
1310 }
1311 
1312 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
1313 {
1314 	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);
1315 }
1316 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
1317 
1318 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
1319 {
1320 	struct net_device *dev = dst->dev;
1321 	unsigned int mtu = dst_mtu(dst);
1322 	struct net *net = dev_net(dev);
1323 
1324 	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
1325 
1326 	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
1327 		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
1328 
1329 	/*
1330 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
1331 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
1332 	 * IPV6_MAXPLEN is also valid and means: "any MSS,
1333 	 * rely only on pmtu discovery"
1334 	 */
1335 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
1336 		mtu = IPV6_MAXPLEN;
1337 	return mtu;
1338 }
1339 
1340 static unsigned int ip6_mtu(const struct dst_entry *dst)
1341 {
1342 	struct inet6_dev *idev;
1343 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1344 
1345 	if (mtu)
1346 		goto out;
1347 
1348 	mtu = IPV6_MIN_MTU;
1349 
1350 	rcu_read_lock();
1351 	idev = __in6_dev_get(dst->dev);
1352 	if (idev)
1353 		mtu = idev->cnf.mtu6;
1354 	rcu_read_unlock();
1355 
1356 out:
1357 	return min_t(unsigned int, mtu, IP6_MAX_MTU);
1358 }
1359 
1360 static struct dst_entry *icmp6_dst_gc_list;
1361 static DEFINE_SPINLOCK(icmp6_dst_lock);
1362 
1363 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
1364 				  struct flowi6 *fl6)
1365 {
1366 	struct dst_entry *dst;
1367 	struct rt6_info *rt;
1368 	struct inet6_dev *idev = in6_dev_get(dev);
1369 	struct net *net = dev_net(dev);
1370 
1371 	if (unlikely(!idev))
1372 		return ERR_PTR(-ENODEV);
1373 
1374 	rt = ip6_dst_alloc(net, dev, 0, NULL);
1375 	if (unlikely(!rt)) {
1376 		in6_dev_put(idev);
1377 		dst = ERR_PTR(-ENOMEM);
1378 		goto out;
1379 	}
1380 
1381 	rt->dst.flags |= DST_HOST;
1382 	rt->dst.output  = ip6_output;
1383 	atomic_set(&rt->dst.__refcnt, 1);
1384 	rt->rt6i_gateway  = fl6->daddr;
1385 	rt->rt6i_dst.addr = fl6->daddr;
1386 	rt->rt6i_dst.plen = 128;
1387 	rt->rt6i_idev     = idev;
1388 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
1389 
1390 	spin_lock_bh(&icmp6_dst_lock);
1391 	rt->dst.next = icmp6_dst_gc_list;
1392 	icmp6_dst_gc_list = &rt->dst;
1393 	spin_unlock_bh(&icmp6_dst_lock);
1394 
1395 	fib6_force_start_gc(net);
1396 
1397 	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
1398 
1399 out:
1400 	return dst;
1401 }
1402 
1403 int icmp6_dst_gc(void)
1404 {
1405 	struct dst_entry *dst, **pprev;
1406 	int more = 0;
1407 
1408 	spin_lock_bh(&icmp6_dst_lock);
1409 	pprev = &icmp6_dst_gc_list;
1410 
1411 	while ((dst = *pprev) != NULL) {
1412 		if (!atomic_read(&dst->__refcnt)) {
1413 			*pprev = dst->next;
1414 			dst_free(dst);
1415 		} else {
1416 			pprev = &dst->next;
1417 			++more;
1418 		}
1419 	}
1420 
1421 	spin_unlock_bh(&icmp6_dst_lock);
1422 
1423 	return more;
1424 }
1425 
1426 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg),
1427 			    void *arg)
1428 {
1429 	struct dst_entry *dst, **pprev;
1430 
1431 	spin_lock_bh(&icmp6_dst_lock);
1432 	pprev = &icmp6_dst_gc_list;
1433 	while ((dst = *pprev) != NULL) {
1434 		struct rt6_info *rt = (struct rt6_info *) dst;
1435 		if (func(rt, arg)) {
1436 			*pprev = dst->next;
1437 			dst_free(dst);
1438 		} else {
1439 			pprev = &dst->next;
1440 		}
1441 	}
1442 	spin_unlock_bh(&icmp6_dst_lock);
1443 }
1444 
1445 static int ip6_dst_gc(struct dst_ops *ops)
1446 {
1447 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
1448 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
1449 	int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
1450 	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
1451 	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
1452 	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
1453 	int entries;
1454 
1455 	entries = dst_entries_get_fast(ops);
1456 	if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
1457 	    entries <= rt_max_size)
1458 		goto out;
1459 
1460 	net->ipv6.ip6_rt_gc_expire++;
1461 	fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true);
1462 	entries = dst_entries_get_slow(ops);
1463 	if (entries < ops->gc_thresh)
1464 		net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
1465 out:
1466 	net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
1467 	return entries > rt_max_size;
1468 }
1469 
1470 /*
1471  *
1472  */
1473 
1474 int ip6_route_add(struct fib6_config *cfg)
1475 {
1476 	int err;
1477 	struct net *net = cfg->fc_nlinfo.nl_net;
1478 	struct rt6_info *rt = NULL;
1479 	struct net_device *dev = NULL;
1480 	struct inet6_dev *idev = NULL;
1481 	struct fib6_table *table;
1482 	int addr_type;
1483 
1484 	if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1485 		return -EINVAL;
1486 #ifndef CONFIG_IPV6_SUBTREES
1487 	if (cfg->fc_src_len)
1488 		return -EINVAL;
1489 #endif
1490 	if (cfg->fc_ifindex) {
1491 		err = -ENODEV;
1492 		dev = dev_get_by_index(net, cfg->fc_ifindex);
1493 		if (!dev)
1494 			goto out;
1495 		idev = in6_dev_get(dev);
1496 		if (!idev)
1497 			goto out;
1498 	}
1499 
1500 	if (cfg->fc_metric == 0)
1501 		cfg->fc_metric = IP6_RT_PRIO_USER;
1502 
1503 	err = -ENOBUFS;
1504 	if (cfg->fc_nlinfo.nlh &&
1505 	    !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
1506 		table = fib6_get_table(net, cfg->fc_table);
1507 		if (!table) {
1508 			pr_warn("NLM_F_CREATE should be specified when creating new route\n");
1509 			table = fib6_new_table(net, cfg->fc_table);
1510 		}
1511 	} else {
1512 		table = fib6_new_table(net, cfg->fc_table);
1513 	}
1514 
1515 	if (!table)
1516 		goto out;
1517 
1518 	rt = ip6_dst_alloc(net, NULL, (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT, table);
1519 
1520 	if (!rt) {
1521 		err = -ENOMEM;
1522 		goto out;
1523 	}
1524 
1525 	if (cfg->fc_flags & RTF_EXPIRES)
1526 		rt6_set_expires(rt, jiffies +
1527 				clock_t_to_jiffies(cfg->fc_expires));
1528 	else
1529 		rt6_clean_expires(rt);
1530 
1531 	if (cfg->fc_protocol == RTPROT_UNSPEC)
1532 		cfg->fc_protocol = RTPROT_BOOT;
1533 	rt->rt6i_protocol = cfg->fc_protocol;
1534 
1535 	addr_type = ipv6_addr_type(&cfg->fc_dst);
1536 
1537 	if (addr_type & IPV6_ADDR_MULTICAST)
1538 		rt->dst.input = ip6_mc_input;
1539 	else if (cfg->fc_flags & RTF_LOCAL)
1540 		rt->dst.input = ip6_input;
1541 	else
1542 		rt->dst.input = ip6_forward;
1543 
1544 	rt->dst.output = ip6_output;
1545 
1546 	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1547 	rt->rt6i_dst.plen = cfg->fc_dst_len;
1548 	if (rt->rt6i_dst.plen == 128) {
1549 		rt->dst.flags |= DST_HOST;
1550 		dst_metrics_set_force_overwrite(&rt->dst);
1551 	}
1552 
1553 #ifdef CONFIG_IPV6_SUBTREES
1554 	ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1555 	rt->rt6i_src.plen = cfg->fc_src_len;
1556 #endif
1557 
1558 	rt->rt6i_metric = cfg->fc_metric;
1559 
1560 	/* We cannot add true routes via loopback here,
1561 	   they would result in kernel looping; promote them to reject routes
1562 	 */
1563 	if ((cfg->fc_flags & RTF_REJECT) ||
1564 	    (dev && (dev->flags & IFF_LOOPBACK) &&
1565 	     !(addr_type & IPV6_ADDR_LOOPBACK) &&
1566 	     !(cfg->fc_flags & RTF_LOCAL))) {
1567 		/* hold loopback dev/idev if we haven't done so. */
1568 		if (dev != net->loopback_dev) {
1569 			if (dev) {
1570 				dev_put(dev);
1571 				in6_dev_put(idev);
1572 			}
1573 			dev = net->loopback_dev;
1574 			dev_hold(dev);
1575 			idev = in6_dev_get(dev);
1576 			if (!idev) {
1577 				err = -ENODEV;
1578 				goto out;
1579 			}
1580 		}
1581 		rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1582 		switch (cfg->fc_type) {
1583 		case RTN_BLACKHOLE:
1584 			rt->dst.error = -EINVAL;
1585 			rt->dst.output = dst_discard_sk;
1586 			rt->dst.input = dst_discard;
1587 			break;
1588 		case RTN_PROHIBIT:
1589 			rt->dst.error = -EACCES;
1590 			rt->dst.output = ip6_pkt_prohibit_out;
1591 			rt->dst.input = ip6_pkt_prohibit;
1592 			break;
1593 		case RTN_THROW:
1594 		default:
1595 			rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN
1596 					: -ENETUNREACH;
1597 			rt->dst.output = ip6_pkt_discard_out;
1598 			rt->dst.input = ip6_pkt_discard;
1599 			break;
1600 		}
1601 		goto install_route;
1602 	}
1603 
1604 	if (cfg->fc_flags & RTF_GATEWAY) {
1605 		const struct in6_addr *gw_addr;
1606 		int gwa_type;
1607 
1608 		gw_addr = &cfg->fc_gateway;
1609 		rt->rt6i_gateway = *gw_addr;
1610 		gwa_type = ipv6_addr_type(gw_addr);
1611 
1612 		if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1613 			struct rt6_info *grt;
1614 
1615 			/* IPv6 strictly inhibits using not link-local
1616 			   addresses as nexthop address.
1617 			   Otherwise, router will not able to send redirects.
1618 			   It is very good, but in some (rare!) circumstances
1619 			   (SIT, PtP, NBMA NOARP links) it is handy to allow
1620 			   some exceptions. --ANK
1621 			 */
1622 			err = -EINVAL;
1623 			if (!(gwa_type & IPV6_ADDR_UNICAST))
1624 				goto out;
1625 
1626 			grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
1627 
1628 			err = -EHOSTUNREACH;
1629 			if (!grt)
1630 				goto out;
1631 			if (dev) {
1632 				if (dev != grt->dst.dev) {
1633 					ip6_rt_put(grt);
1634 					goto out;
1635 				}
1636 			} else {
1637 				dev = grt->dst.dev;
1638 				idev = grt->rt6i_idev;
1639 				dev_hold(dev);
1640 				in6_dev_hold(grt->rt6i_idev);
1641 			}
1642 			if (!(grt->rt6i_flags & RTF_GATEWAY))
1643 				err = 0;
1644 			ip6_rt_put(grt);
1645 
1646 			if (err)
1647 				goto out;
1648 		}
1649 		err = -EINVAL;
1650 		if (!dev || (dev->flags & IFF_LOOPBACK))
1651 			goto out;
1652 	}
1653 
1654 	err = -ENODEV;
1655 	if (!dev)
1656 		goto out;
1657 
1658 	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
1659 		if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
1660 			err = -EINVAL;
1661 			goto out;
1662 		}
1663 		rt->rt6i_prefsrc.addr = cfg->fc_prefsrc;
1664 		rt->rt6i_prefsrc.plen = 128;
1665 	} else
1666 		rt->rt6i_prefsrc.plen = 0;
1667 
1668 	rt->rt6i_flags = cfg->fc_flags;
1669 
1670 install_route:
1671 	rt->dst.dev = dev;
1672 	rt->rt6i_idev = idev;
1673 	rt->rt6i_table = table;
1674 
1675 	cfg->fc_nlinfo.nl_net = dev_net(dev);
1676 
1677 	return __ip6_ins_rt(rt, &cfg->fc_nlinfo, cfg->fc_mx, cfg->fc_mx_len);
1678 
1679 out:
1680 	if (dev)
1681 		dev_put(dev);
1682 	if (idev)
1683 		in6_dev_put(idev);
1684 	if (rt)
1685 		dst_free(&rt->dst);
1686 	return err;
1687 }
1688 
1689 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
1690 {
1691 	int err;
1692 	struct fib6_table *table;
1693 	struct net *net = dev_net(rt->dst.dev);
1694 
1695 	if (rt == net->ipv6.ip6_null_entry) {
1696 		err = -ENOENT;
1697 		goto out;
1698 	}
1699 
1700 	table = rt->rt6i_table;
1701 	write_lock_bh(&table->tb6_lock);
1702 	err = fib6_del(rt, info);
1703 	write_unlock_bh(&table->tb6_lock);
1704 
1705 out:
1706 	ip6_rt_put(rt);
1707 	return err;
1708 }
1709 
1710 int ip6_del_rt(struct rt6_info *rt)
1711 {
1712 	struct nl_info info = {
1713 		.nl_net = dev_net(rt->dst.dev),
1714 	};
1715 	return __ip6_del_rt(rt, &info);
1716 }
1717 
1718 static int ip6_route_del(struct fib6_config *cfg)
1719 {
1720 	struct fib6_table *table;
1721 	struct fib6_node *fn;
1722 	struct rt6_info *rt;
1723 	int err = -ESRCH;
1724 
1725 	table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
1726 	if (!table)
1727 		return err;
1728 
1729 	read_lock_bh(&table->tb6_lock);
1730 
1731 	fn = fib6_locate(&table->tb6_root,
1732 			 &cfg->fc_dst, cfg->fc_dst_len,
1733 			 &cfg->fc_src, cfg->fc_src_len);
1734 
1735 	if (fn) {
1736 		for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1737 			if (cfg->fc_ifindex &&
1738 			    (!rt->dst.dev ||
1739 			     rt->dst.dev->ifindex != cfg->fc_ifindex))
1740 				continue;
1741 			if (cfg->fc_flags & RTF_GATEWAY &&
1742 			    !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
1743 				continue;
1744 			if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
1745 				continue;
1746 			dst_hold(&rt->dst);
1747 			read_unlock_bh(&table->tb6_lock);
1748 
1749 			return __ip6_del_rt(rt, &cfg->fc_nlinfo);
1750 		}
1751 	}
1752 	read_unlock_bh(&table->tb6_lock);
1753 
1754 	return err;
1755 }
1756 
1757 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
1758 {
1759 	struct net *net = dev_net(skb->dev);
1760 	struct netevent_redirect netevent;
1761 	struct rt6_info *rt, *nrt = NULL;
1762 	struct ndisc_options ndopts;
1763 	struct inet6_dev *in6_dev;
1764 	struct neighbour *neigh;
1765 	struct rd_msg *msg;
1766 	int optlen, on_link;
1767 	u8 *lladdr;
1768 
1769 	optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
1770 	optlen -= sizeof(*msg);
1771 
1772 	if (optlen < 0) {
1773 		net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
1774 		return;
1775 	}
1776 
1777 	msg = (struct rd_msg *)icmp6_hdr(skb);
1778 
1779 	if (ipv6_addr_is_multicast(&msg->dest)) {
1780 		net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
1781 		return;
1782 	}
1783 
1784 	on_link = 0;
1785 	if (ipv6_addr_equal(&msg->dest, &msg->target)) {
1786 		on_link = 1;
1787 	} else if (ipv6_addr_type(&msg->target) !=
1788 		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1789 		net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
1790 		return;
1791 	}
1792 
1793 	in6_dev = __in6_dev_get(skb->dev);
1794 	if (!in6_dev)
1795 		return;
1796 	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
1797 		return;
1798 
1799 	/* RFC2461 8.1:
1800 	 *	The IP source address of the Redirect MUST be the same as the current
1801 	 *	first-hop router for the specified ICMP Destination Address.
1802 	 */
1803 
1804 	if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) {
1805 		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
1806 		return;
1807 	}
1808 
1809 	lladdr = NULL;
1810 	if (ndopts.nd_opts_tgt_lladdr) {
1811 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1812 					     skb->dev);
1813 		if (!lladdr) {
1814 			net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
1815 			return;
1816 		}
1817 	}
1818 
1819 	rt = (struct rt6_info *) dst;
1820 	if (rt == net->ipv6.ip6_null_entry) {
1821 		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
1822 		return;
1823 	}
1824 
1825 	/* Redirect received -> path was valid.
1826 	 * Look, redirects are sent only in response to data packets,
1827 	 * so that this nexthop apparently is reachable. --ANK
1828 	 */
1829 	dst_confirm(&rt->dst);
1830 
1831 	neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
1832 	if (!neigh)
1833 		return;
1834 
1835 	/*
1836 	 *	We have finally decided to accept it.
1837 	 */
1838 
1839 	neigh_update(neigh, lladdr, NUD_STALE,
1840 		     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1841 		     NEIGH_UPDATE_F_OVERRIDE|
1842 		     (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1843 				     NEIGH_UPDATE_F_ISROUTER))
1844 		     );
1845 
1846 	nrt = ip6_rt_copy(rt, &msg->dest);
1847 	if (!nrt)
1848 		goto out;
1849 
1850 	nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1851 	if (on_link)
1852 		nrt->rt6i_flags &= ~RTF_GATEWAY;
1853 
1854 	nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
1855 
1856 	if (ip6_ins_rt(nrt))
1857 		goto out;
1858 
1859 	netevent.old = &rt->dst;
1860 	netevent.new = &nrt->dst;
1861 	netevent.daddr = &msg->dest;
1862 	netevent.neigh = neigh;
1863 	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1864 
1865 	if (rt->rt6i_flags & RTF_CACHE) {
1866 		rt = (struct rt6_info *) dst_clone(&rt->dst);
1867 		ip6_del_rt(rt);
1868 	}
1869 
1870 out:
1871 	neigh_release(neigh);
1872 }
1873 
1874 /*
1875  *	Misc support functions
1876  */
1877 
1878 static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
1879 				    const struct in6_addr *dest)
1880 {
1881 	struct net *net = dev_net(ort->dst.dev);
1882 	struct rt6_info *rt = ip6_dst_alloc(net, ort->dst.dev, 0,
1883 					    ort->rt6i_table);
1884 
1885 	if (rt) {
1886 		rt->dst.input = ort->dst.input;
1887 		rt->dst.output = ort->dst.output;
1888 		rt->dst.flags |= DST_HOST;
1889 
1890 		rt->rt6i_dst.addr = *dest;
1891 		rt->rt6i_dst.plen = 128;
1892 		dst_copy_metrics(&rt->dst, &ort->dst);
1893 		rt->dst.error = ort->dst.error;
1894 		rt->rt6i_idev = ort->rt6i_idev;
1895 		if (rt->rt6i_idev)
1896 			in6_dev_hold(rt->rt6i_idev);
1897 		rt->dst.lastuse = jiffies;
1898 
1899 		if (ort->rt6i_flags & RTF_GATEWAY)
1900 			rt->rt6i_gateway = ort->rt6i_gateway;
1901 		else
1902 			rt->rt6i_gateway = *dest;
1903 		rt->rt6i_flags = ort->rt6i_flags;
1904 		rt6_set_from(rt, ort);
1905 		rt->rt6i_metric = 0;
1906 
1907 #ifdef CONFIG_IPV6_SUBTREES
1908 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1909 #endif
1910 		memcpy(&rt->rt6i_prefsrc, &ort->rt6i_prefsrc, sizeof(struct rt6key));
1911 		rt->rt6i_table = ort->rt6i_table;
1912 	}
1913 	return rt;
1914 }
1915 
1916 #ifdef CONFIG_IPV6_ROUTE_INFO
1917 static struct rt6_info *rt6_get_route_info(struct net *net,
1918 					   const struct in6_addr *prefix, int prefixlen,
1919 					   const struct in6_addr *gwaddr, int ifindex)
1920 {
1921 	struct fib6_node *fn;
1922 	struct rt6_info *rt = NULL;
1923 	struct fib6_table *table;
1924 
1925 	table = fib6_get_table(net, RT6_TABLE_INFO);
1926 	if (!table)
1927 		return NULL;
1928 
1929 	read_lock_bh(&table->tb6_lock);
1930 	fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0);
1931 	if (!fn)
1932 		goto out;
1933 
1934 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1935 		if (rt->dst.dev->ifindex != ifindex)
1936 			continue;
1937 		if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1938 			continue;
1939 		if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1940 			continue;
1941 		dst_hold(&rt->dst);
1942 		break;
1943 	}
1944 out:
1945 	read_unlock_bh(&table->tb6_lock);
1946 	return rt;
1947 }
1948 
1949 static struct rt6_info *rt6_add_route_info(struct net *net,
1950 					   const struct in6_addr *prefix, int prefixlen,
1951 					   const struct in6_addr *gwaddr, int ifindex,
1952 					   unsigned int pref)
1953 {
1954 	struct fib6_config cfg = {
1955 		.fc_table	= RT6_TABLE_INFO,
1956 		.fc_metric	= IP6_RT_PRIO_USER,
1957 		.fc_ifindex	= ifindex,
1958 		.fc_dst_len	= prefixlen,
1959 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
1960 				  RTF_UP | RTF_PREF(pref),
1961 		.fc_nlinfo.portid = 0,
1962 		.fc_nlinfo.nlh = NULL,
1963 		.fc_nlinfo.nl_net = net,
1964 	};
1965 
1966 	cfg.fc_dst = *prefix;
1967 	cfg.fc_gateway = *gwaddr;
1968 
1969 	/* We should treat it as a default route if prefix length is 0. */
1970 	if (!prefixlen)
1971 		cfg.fc_flags |= RTF_DEFAULT;
1972 
1973 	ip6_route_add(&cfg);
1974 
1975 	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex);
1976 }
1977 #endif
1978 
1979 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev)
1980 {
1981 	struct rt6_info *rt;
1982 	struct fib6_table *table;
1983 
1984 	table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT);
1985 	if (!table)
1986 		return NULL;
1987 
1988 	read_lock_bh(&table->tb6_lock);
1989 	for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
1990 		if (dev == rt->dst.dev &&
1991 		    ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1992 		    ipv6_addr_equal(&rt->rt6i_gateway, addr))
1993 			break;
1994 	}
1995 	if (rt)
1996 		dst_hold(&rt->dst);
1997 	read_unlock_bh(&table->tb6_lock);
1998 	return rt;
1999 }
2000 
2001 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
2002 				     struct net_device *dev,
2003 				     unsigned int pref)
2004 {
2005 	struct fib6_config cfg = {
2006 		.fc_table	= RT6_TABLE_DFLT,
2007 		.fc_metric	= IP6_RT_PRIO_USER,
2008 		.fc_ifindex	= dev->ifindex,
2009 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
2010 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
2011 		.fc_nlinfo.portid = 0,
2012 		.fc_nlinfo.nlh = NULL,
2013 		.fc_nlinfo.nl_net = dev_net(dev),
2014 	};
2015 
2016 	cfg.fc_gateway = *gwaddr;
2017 
2018 	ip6_route_add(&cfg);
2019 
2020 	return rt6_get_dflt_router(gwaddr, dev);
2021 }
2022 
2023 void rt6_purge_dflt_routers(struct net *net)
2024 {
2025 	struct rt6_info *rt;
2026 	struct fib6_table *table;
2027 
2028 	/* NOTE: Keep consistent with rt6_get_dflt_router */
2029 	table = fib6_get_table(net, RT6_TABLE_DFLT);
2030 	if (!table)
2031 		return;
2032 
2033 restart:
2034 	read_lock_bh(&table->tb6_lock);
2035 	for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2036 		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
2037 		    (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
2038 			dst_hold(&rt->dst);
2039 			read_unlock_bh(&table->tb6_lock);
2040 			ip6_del_rt(rt);
2041 			goto restart;
2042 		}
2043 	}
2044 	read_unlock_bh(&table->tb6_lock);
2045 }
2046 
2047 static void rtmsg_to_fib6_config(struct net *net,
2048 				 struct in6_rtmsg *rtmsg,
2049 				 struct fib6_config *cfg)
2050 {
2051 	memset(cfg, 0, sizeof(*cfg));
2052 
2053 	cfg->fc_table = RT6_TABLE_MAIN;
2054 	cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
2055 	cfg->fc_metric = rtmsg->rtmsg_metric;
2056 	cfg->fc_expires = rtmsg->rtmsg_info;
2057 	cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
2058 	cfg->fc_src_len = rtmsg->rtmsg_src_len;
2059 	cfg->fc_flags = rtmsg->rtmsg_flags;
2060 
2061 	cfg->fc_nlinfo.nl_net = net;
2062 
2063 	cfg->fc_dst = rtmsg->rtmsg_dst;
2064 	cfg->fc_src = rtmsg->rtmsg_src;
2065 	cfg->fc_gateway = rtmsg->rtmsg_gateway;
2066 }
2067 
2068 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
2069 {
2070 	struct fib6_config cfg;
2071 	struct in6_rtmsg rtmsg;
2072 	int err;
2073 
2074 	switch (cmd) {
2075 	case SIOCADDRT:		/* Add a route */
2076 	case SIOCDELRT:		/* Delete a route */
2077 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2078 			return -EPERM;
2079 		err = copy_from_user(&rtmsg, arg,
2080 				     sizeof(struct in6_rtmsg));
2081 		if (err)
2082 			return -EFAULT;
2083 
2084 		rtmsg_to_fib6_config(net, &rtmsg, &cfg);
2085 
2086 		rtnl_lock();
2087 		switch (cmd) {
2088 		case SIOCADDRT:
2089 			err = ip6_route_add(&cfg);
2090 			break;
2091 		case SIOCDELRT:
2092 			err = ip6_route_del(&cfg);
2093 			break;
2094 		default:
2095 			err = -EINVAL;
2096 		}
2097 		rtnl_unlock();
2098 
2099 		return err;
2100 	}
2101 
2102 	return -EINVAL;
2103 }
2104 
2105 /*
2106  *	Drop the packet on the floor
2107  */
2108 
2109 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
2110 {
2111 	int type;
2112 	struct dst_entry *dst = skb_dst(skb);
2113 	switch (ipstats_mib_noroutes) {
2114 	case IPSTATS_MIB_INNOROUTES:
2115 		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
2116 		if (type == IPV6_ADDR_ANY) {
2117 			IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2118 				      IPSTATS_MIB_INADDRERRORS);
2119 			break;
2120 		}
2121 		/* FALLTHROUGH */
2122 	case IPSTATS_MIB_OUTNOROUTES:
2123 		IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2124 			      ipstats_mib_noroutes);
2125 		break;
2126 	}
2127 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
2128 	kfree_skb(skb);
2129 	return 0;
2130 }
2131 
2132 static int ip6_pkt_discard(struct sk_buff *skb)
2133 {
2134 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
2135 }
2136 
2137 static int ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb)
2138 {
2139 	skb->dev = skb_dst(skb)->dev;
2140 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
2141 }
2142 
2143 static int ip6_pkt_prohibit(struct sk_buff *skb)
2144 {
2145 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
2146 }
2147 
2148 static int ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb)
2149 {
2150 	skb->dev = skb_dst(skb)->dev;
2151 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
2152 }
2153 
2154 /*
2155  *	Allocate a dst for local (unicast / anycast) address.
2156  */
2157 
2158 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
2159 				    const struct in6_addr *addr,
2160 				    bool anycast)
2161 {
2162 	struct net *net = dev_net(idev->dev);
2163 	struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev,
2164 					    DST_NOCOUNT, NULL);
2165 	if (!rt)
2166 		return ERR_PTR(-ENOMEM);
2167 
2168 	in6_dev_hold(idev);
2169 
2170 	rt->dst.flags |= DST_HOST;
2171 	rt->dst.input = ip6_input;
2172 	rt->dst.output = ip6_output;
2173 	rt->rt6i_idev = idev;
2174 
2175 	rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
2176 	if (anycast)
2177 		rt->rt6i_flags |= RTF_ANYCAST;
2178 	else
2179 		rt->rt6i_flags |= RTF_LOCAL;
2180 
2181 	rt->rt6i_gateway  = *addr;
2182 	rt->rt6i_dst.addr = *addr;
2183 	rt->rt6i_dst.plen = 128;
2184 	rt->rt6i_table = fib6_get_table(net, RT6_TABLE_LOCAL);
2185 
2186 	atomic_set(&rt->dst.__refcnt, 1);
2187 
2188 	return rt;
2189 }
2190 
2191 int ip6_route_get_saddr(struct net *net,
2192 			struct rt6_info *rt,
2193 			const struct in6_addr *daddr,
2194 			unsigned int prefs,
2195 			struct in6_addr *saddr)
2196 {
2197 	struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt);
2198 	int err = 0;
2199 	if (rt->rt6i_prefsrc.plen)
2200 		*saddr = rt->rt6i_prefsrc.addr;
2201 	else
2202 		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
2203 					 daddr, prefs, saddr);
2204 	return err;
2205 }
2206 
2207 /* remove deleted ip from prefsrc entries */
2208 struct arg_dev_net_ip {
2209 	struct net_device *dev;
2210 	struct net *net;
2211 	struct in6_addr *addr;
2212 };
2213 
2214 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg)
2215 {
2216 	struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
2217 	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
2218 	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
2219 
2220 	if (((void *)rt->dst.dev == dev || !dev) &&
2221 	    rt != net->ipv6.ip6_null_entry &&
2222 	    ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {
2223 		/* remove prefsrc entry */
2224 		rt->rt6i_prefsrc.plen = 0;
2225 	}
2226 	return 0;
2227 }
2228 
2229 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
2230 {
2231 	struct net *net = dev_net(ifp->idev->dev);
2232 	struct arg_dev_net_ip adni = {
2233 		.dev = ifp->idev->dev,
2234 		.net = net,
2235 		.addr = &ifp->addr,
2236 	};
2237 	fib6_clean_all(net, fib6_remove_prefsrc, &adni);
2238 }
2239 
2240 #define RTF_RA_ROUTER		(RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY)
2241 #define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)
2242 
2243 /* Remove routers and update dst entries when gateway turn into host. */
2244 static int fib6_clean_tohost(struct rt6_info *rt, void *arg)
2245 {
2246 	struct in6_addr *gateway = (struct in6_addr *)arg;
2247 
2248 	if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) ||
2249 	     ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) &&
2250 	     ipv6_addr_equal(gateway, &rt->rt6i_gateway)) {
2251 		return -1;
2252 	}
2253 	return 0;
2254 }
2255 
2256 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
2257 {
2258 	fib6_clean_all(net, fib6_clean_tohost, gateway);
2259 }
2260 
2261 struct arg_dev_net {
2262 	struct net_device *dev;
2263 	struct net *net;
2264 };
2265 
2266 static int fib6_ifdown(struct rt6_info *rt, void *arg)
2267 {
2268 	const struct arg_dev_net *adn = arg;
2269 	const struct net_device *dev = adn->dev;
2270 
2271 	if ((rt->dst.dev == dev || !dev) &&
2272 	    rt != adn->net->ipv6.ip6_null_entry)
2273 		return -1;
2274 
2275 	return 0;
2276 }
2277 
2278 void rt6_ifdown(struct net *net, struct net_device *dev)
2279 {
2280 	struct arg_dev_net adn = {
2281 		.dev = dev,
2282 		.net = net,
2283 	};
2284 
2285 	fib6_clean_all(net, fib6_ifdown, &adn);
2286 	icmp6_clean_all(fib6_ifdown, &adn);
2287 }
2288 
2289 struct rt6_mtu_change_arg {
2290 	struct net_device *dev;
2291 	unsigned int mtu;
2292 };
2293 
2294 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
2295 {
2296 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
2297 	struct inet6_dev *idev;
2298 
2299 	/* In IPv6 pmtu discovery is not optional,
2300 	   so that RTAX_MTU lock cannot disable it.
2301 	   We still use this lock to block changes
2302 	   caused by addrconf/ndisc.
2303 	*/
2304 
2305 	idev = __in6_dev_get(arg->dev);
2306 	if (!idev)
2307 		return 0;
2308 
2309 	/* For administrative MTU increase, there is no way to discover
2310 	   IPv6 PMTU increase, so PMTU increase should be updated here.
2311 	   Since RFC 1981 doesn't include administrative MTU increase
2312 	   update PMTU increase is a MUST. (i.e. jumbo frame)
2313 	 */
2314 	/*
2315 	   If new MTU is less than route PMTU, this new MTU will be the
2316 	   lowest MTU in the path, update the route PMTU to reflect PMTU
2317 	   decreases; if new MTU is greater than route PMTU, and the
2318 	   old MTU is the lowest MTU in the path, update the route PMTU
2319 	   to reflect the increase. In this case if the other nodes' MTU
2320 	   also have the lowest MTU, TOO BIG MESSAGE will be lead to
2321 	   PMTU discouvery.
2322 	 */
2323 	if (rt->dst.dev == arg->dev &&
2324 	    !dst_metric_locked(&rt->dst, RTAX_MTU) &&
2325 	    (dst_mtu(&rt->dst) >= arg->mtu ||
2326 	     (dst_mtu(&rt->dst) < arg->mtu &&
2327 	      dst_mtu(&rt->dst) == idev->cnf.mtu6))) {
2328 		dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
2329 	}
2330 	return 0;
2331 }
2332 
2333 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
2334 {
2335 	struct rt6_mtu_change_arg arg = {
2336 		.dev = dev,
2337 		.mtu = mtu,
2338 	};
2339 
2340 	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
2341 }
2342 
2343 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
2344 	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
2345 	[RTA_OIF]               = { .type = NLA_U32 },
2346 	[RTA_IIF]		= { .type = NLA_U32 },
2347 	[RTA_PRIORITY]          = { .type = NLA_U32 },
2348 	[RTA_METRICS]           = { .type = NLA_NESTED },
2349 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
2350 };
2351 
2352 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
2353 			      struct fib6_config *cfg)
2354 {
2355 	struct rtmsg *rtm;
2356 	struct nlattr *tb[RTA_MAX+1];
2357 	int err;
2358 
2359 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2360 	if (err < 0)
2361 		goto errout;
2362 
2363 	err = -EINVAL;
2364 	rtm = nlmsg_data(nlh);
2365 	memset(cfg, 0, sizeof(*cfg));
2366 
2367 	cfg->fc_table = rtm->rtm_table;
2368 	cfg->fc_dst_len = rtm->rtm_dst_len;
2369 	cfg->fc_src_len = rtm->rtm_src_len;
2370 	cfg->fc_flags = RTF_UP;
2371 	cfg->fc_protocol = rtm->rtm_protocol;
2372 	cfg->fc_type = rtm->rtm_type;
2373 
2374 	if (rtm->rtm_type == RTN_UNREACHABLE ||
2375 	    rtm->rtm_type == RTN_BLACKHOLE ||
2376 	    rtm->rtm_type == RTN_PROHIBIT ||
2377 	    rtm->rtm_type == RTN_THROW)
2378 		cfg->fc_flags |= RTF_REJECT;
2379 
2380 	if (rtm->rtm_type == RTN_LOCAL)
2381 		cfg->fc_flags |= RTF_LOCAL;
2382 
2383 	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
2384 	cfg->fc_nlinfo.nlh = nlh;
2385 	cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
2386 
2387 	if (tb[RTA_GATEWAY]) {
2388 		nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16);
2389 		cfg->fc_flags |= RTF_GATEWAY;
2390 	}
2391 
2392 	if (tb[RTA_DST]) {
2393 		int plen = (rtm->rtm_dst_len + 7) >> 3;
2394 
2395 		if (nla_len(tb[RTA_DST]) < plen)
2396 			goto errout;
2397 
2398 		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
2399 	}
2400 
2401 	if (tb[RTA_SRC]) {
2402 		int plen = (rtm->rtm_src_len + 7) >> 3;
2403 
2404 		if (nla_len(tb[RTA_SRC]) < plen)
2405 			goto errout;
2406 
2407 		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
2408 	}
2409 
2410 	if (tb[RTA_PREFSRC])
2411 		nla_memcpy(&cfg->fc_prefsrc, tb[RTA_PREFSRC], 16);
2412 
2413 	if (tb[RTA_OIF])
2414 		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
2415 
2416 	if (tb[RTA_PRIORITY])
2417 		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
2418 
2419 	if (tb[RTA_METRICS]) {
2420 		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2421 		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2422 	}
2423 
2424 	if (tb[RTA_TABLE])
2425 		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2426 
2427 	if (tb[RTA_MULTIPATH]) {
2428 		cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
2429 		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
2430 	}
2431 
2432 	err = 0;
2433 errout:
2434 	return err;
2435 }
2436 
2437 static int ip6_route_multipath(struct fib6_config *cfg, int add)
2438 {
2439 	struct fib6_config r_cfg;
2440 	struct rtnexthop *rtnh;
2441 	int remaining;
2442 	int attrlen;
2443 	int err = 0, last_err = 0;
2444 
2445 beginning:
2446 	rtnh = (struct rtnexthop *)cfg->fc_mp;
2447 	remaining = cfg->fc_mp_len;
2448 
2449 	/* Parse a Multipath Entry */
2450 	while (rtnh_ok(rtnh, remaining)) {
2451 		memcpy(&r_cfg, cfg, sizeof(*cfg));
2452 		if (rtnh->rtnh_ifindex)
2453 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
2454 
2455 		attrlen = rtnh_attrlen(rtnh);
2456 		if (attrlen > 0) {
2457 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
2458 
2459 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
2460 			if (nla) {
2461 				nla_memcpy(&r_cfg.fc_gateway, nla, 16);
2462 				r_cfg.fc_flags |= RTF_GATEWAY;
2463 			}
2464 		}
2465 		err = add ? ip6_route_add(&r_cfg) : ip6_route_del(&r_cfg);
2466 		if (err) {
2467 			last_err = err;
2468 			/* If we are trying to remove a route, do not stop the
2469 			 * loop when ip6_route_del() fails (because next hop is
2470 			 * already gone), we should try to remove all next hops.
2471 			 */
2472 			if (add) {
2473 				/* If add fails, we should try to delete all
2474 				 * next hops that have been already added.
2475 				 */
2476 				add = 0;
2477 				goto beginning;
2478 			}
2479 		}
2480 		/* Because each route is added like a single route we remove
2481 		 * this flag after the first nexthop (if there is a collision,
2482 		 * we have already fail to add the first nexthop:
2483 		 * fib6_add_rt2node() has reject it).
2484 		 */
2485 		cfg->fc_nlinfo.nlh->nlmsg_flags &= ~NLM_F_EXCL;
2486 		rtnh = rtnh_next(rtnh, &remaining);
2487 	}
2488 
2489 	return last_err;
2490 }
2491 
2492 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
2493 {
2494 	struct fib6_config cfg;
2495 	int err;
2496 
2497 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2498 	if (err < 0)
2499 		return err;
2500 
2501 	if (cfg.fc_mp)
2502 		return ip6_route_multipath(&cfg, 0);
2503 	else
2504 		return ip6_route_del(&cfg);
2505 }
2506 
2507 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
2508 {
2509 	struct fib6_config cfg;
2510 	int err;
2511 
2512 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2513 	if (err < 0)
2514 		return err;
2515 
2516 	if (cfg.fc_mp)
2517 		return ip6_route_multipath(&cfg, 1);
2518 	else
2519 		return ip6_route_add(&cfg);
2520 }
2521 
2522 static inline size_t rt6_nlmsg_size(void)
2523 {
2524 	return NLMSG_ALIGN(sizeof(struct rtmsg))
2525 	       + nla_total_size(16) /* RTA_SRC */
2526 	       + nla_total_size(16) /* RTA_DST */
2527 	       + nla_total_size(16) /* RTA_GATEWAY */
2528 	       + nla_total_size(16) /* RTA_PREFSRC */
2529 	       + nla_total_size(4) /* RTA_TABLE */
2530 	       + nla_total_size(4) /* RTA_IIF */
2531 	       + nla_total_size(4) /* RTA_OIF */
2532 	       + nla_total_size(4) /* RTA_PRIORITY */
2533 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2534 	       + nla_total_size(sizeof(struct rta_cacheinfo));
2535 }
2536 
2537 static int rt6_fill_node(struct net *net,
2538 			 struct sk_buff *skb, struct rt6_info *rt,
2539 			 struct in6_addr *dst, struct in6_addr *src,
2540 			 int iif, int type, u32 portid, u32 seq,
2541 			 int prefix, int nowait, unsigned int flags)
2542 {
2543 	struct rtmsg *rtm;
2544 	struct nlmsghdr *nlh;
2545 	long expires;
2546 	u32 table;
2547 
2548 	if (prefix) {	/* user wants prefix routes only */
2549 		if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2550 			/* success since this is not a prefix route */
2551 			return 1;
2552 		}
2553 	}
2554 
2555 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
2556 	if (!nlh)
2557 		return -EMSGSIZE;
2558 
2559 	rtm = nlmsg_data(nlh);
2560 	rtm->rtm_family = AF_INET6;
2561 	rtm->rtm_dst_len = rt->rt6i_dst.plen;
2562 	rtm->rtm_src_len = rt->rt6i_src.plen;
2563 	rtm->rtm_tos = 0;
2564 	if (rt->rt6i_table)
2565 		table = rt->rt6i_table->tb6_id;
2566 	else
2567 		table = RT6_TABLE_UNSPEC;
2568 	rtm->rtm_table = table;
2569 	if (nla_put_u32(skb, RTA_TABLE, table))
2570 		goto nla_put_failure;
2571 	if (rt->rt6i_flags & RTF_REJECT) {
2572 		switch (rt->dst.error) {
2573 		case -EINVAL:
2574 			rtm->rtm_type = RTN_BLACKHOLE;
2575 			break;
2576 		case -EACCES:
2577 			rtm->rtm_type = RTN_PROHIBIT;
2578 			break;
2579 		case -EAGAIN:
2580 			rtm->rtm_type = RTN_THROW;
2581 			break;
2582 		default:
2583 			rtm->rtm_type = RTN_UNREACHABLE;
2584 			break;
2585 		}
2586 	}
2587 	else if (rt->rt6i_flags & RTF_LOCAL)
2588 		rtm->rtm_type = RTN_LOCAL;
2589 	else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK))
2590 		rtm->rtm_type = RTN_LOCAL;
2591 	else
2592 		rtm->rtm_type = RTN_UNICAST;
2593 	rtm->rtm_flags = 0;
2594 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2595 	rtm->rtm_protocol = rt->rt6i_protocol;
2596 	if (rt->rt6i_flags & RTF_DYNAMIC)
2597 		rtm->rtm_protocol = RTPROT_REDIRECT;
2598 	else if (rt->rt6i_flags & RTF_ADDRCONF) {
2599 		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO))
2600 			rtm->rtm_protocol = RTPROT_RA;
2601 		else
2602 			rtm->rtm_protocol = RTPROT_KERNEL;
2603 	}
2604 
2605 	if (rt->rt6i_flags & RTF_CACHE)
2606 		rtm->rtm_flags |= RTM_F_CLONED;
2607 
2608 	if (dst) {
2609 		if (nla_put(skb, RTA_DST, 16, dst))
2610 			goto nla_put_failure;
2611 		rtm->rtm_dst_len = 128;
2612 	} else if (rtm->rtm_dst_len)
2613 		if (nla_put(skb, RTA_DST, 16, &rt->rt6i_dst.addr))
2614 			goto nla_put_failure;
2615 #ifdef CONFIG_IPV6_SUBTREES
2616 	if (src) {
2617 		if (nla_put(skb, RTA_SRC, 16, src))
2618 			goto nla_put_failure;
2619 		rtm->rtm_src_len = 128;
2620 	} else if (rtm->rtm_src_len &&
2621 		   nla_put(skb, RTA_SRC, 16, &rt->rt6i_src.addr))
2622 		goto nla_put_failure;
2623 #endif
2624 	if (iif) {
2625 #ifdef CONFIG_IPV6_MROUTE
2626 		if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) {
2627 			int err = ip6mr_get_route(net, skb, rtm, nowait);
2628 			if (err <= 0) {
2629 				if (!nowait) {
2630 					if (err == 0)
2631 						return 0;
2632 					goto nla_put_failure;
2633 				} else {
2634 					if (err == -EMSGSIZE)
2635 						goto nla_put_failure;
2636 				}
2637 			}
2638 		} else
2639 #endif
2640 			if (nla_put_u32(skb, RTA_IIF, iif))
2641 				goto nla_put_failure;
2642 	} else if (dst) {
2643 		struct in6_addr saddr_buf;
2644 		if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0 &&
2645 		    nla_put(skb, RTA_PREFSRC, 16, &saddr_buf))
2646 			goto nla_put_failure;
2647 	}
2648 
2649 	if (rt->rt6i_prefsrc.plen) {
2650 		struct in6_addr saddr_buf;
2651 		saddr_buf = rt->rt6i_prefsrc.addr;
2652 		if (nla_put(skb, RTA_PREFSRC, 16, &saddr_buf))
2653 			goto nla_put_failure;
2654 	}
2655 
2656 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2657 		goto nla_put_failure;
2658 
2659 	if (rt->rt6i_flags & RTF_GATEWAY) {
2660 		if (nla_put(skb, RTA_GATEWAY, 16, &rt->rt6i_gateway) < 0)
2661 			goto nla_put_failure;
2662 	}
2663 
2664 	if (rt->dst.dev &&
2665 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2666 		goto nla_put_failure;
2667 	if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))
2668 		goto nla_put_failure;
2669 
2670 	expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;
2671 
2672 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
2673 		goto nla_put_failure;
2674 
2675 	return nlmsg_end(skb, nlh);
2676 
2677 nla_put_failure:
2678 	nlmsg_cancel(skb, nlh);
2679 	return -EMSGSIZE;
2680 }
2681 
2682 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
2683 {
2684 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
2685 	int prefix;
2686 
2687 	if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
2688 		struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
2689 		prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
2690 	} else
2691 		prefix = 0;
2692 
2693 	return rt6_fill_node(arg->net,
2694 		     arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
2695 		     NETLINK_CB(arg->cb->skb).portid, arg->cb->nlh->nlmsg_seq,
2696 		     prefix, 0, NLM_F_MULTI);
2697 }
2698 
2699 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
2700 {
2701 	struct net *net = sock_net(in_skb->sk);
2702 	struct nlattr *tb[RTA_MAX+1];
2703 	struct rt6_info *rt;
2704 	struct sk_buff *skb;
2705 	struct rtmsg *rtm;
2706 	struct flowi6 fl6;
2707 	int err, iif = 0, oif = 0;
2708 
2709 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2710 	if (err < 0)
2711 		goto errout;
2712 
2713 	err = -EINVAL;
2714 	memset(&fl6, 0, sizeof(fl6));
2715 
2716 	if (tb[RTA_SRC]) {
2717 		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
2718 			goto errout;
2719 
2720 		fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
2721 	}
2722 
2723 	if (tb[RTA_DST]) {
2724 		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
2725 			goto errout;
2726 
2727 		fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
2728 	}
2729 
2730 	if (tb[RTA_IIF])
2731 		iif = nla_get_u32(tb[RTA_IIF]);
2732 
2733 	if (tb[RTA_OIF])
2734 		oif = nla_get_u32(tb[RTA_OIF]);
2735 
2736 	if (tb[RTA_MARK])
2737 		fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
2738 
2739 	if (iif) {
2740 		struct net_device *dev;
2741 		int flags = 0;
2742 
2743 		dev = __dev_get_by_index(net, iif);
2744 		if (!dev) {
2745 			err = -ENODEV;
2746 			goto errout;
2747 		}
2748 
2749 		fl6.flowi6_iif = iif;
2750 
2751 		if (!ipv6_addr_any(&fl6.saddr))
2752 			flags |= RT6_LOOKUP_F_HAS_SADDR;
2753 
2754 		rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6,
2755 							       flags);
2756 	} else {
2757 		fl6.flowi6_oif = oif;
2758 
2759 		rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
2760 	}
2761 
2762 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2763 	if (!skb) {
2764 		ip6_rt_put(rt);
2765 		err = -ENOBUFS;
2766 		goto errout;
2767 	}
2768 
2769 	/* Reserve room for dummy headers, this skb can pass
2770 	   through good chunk of routing engine.
2771 	 */
2772 	skb_reset_mac_header(skb);
2773 	skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
2774 
2775 	skb_dst_set(skb, &rt->dst);
2776 
2777 	err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,
2778 			    RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
2779 			    nlh->nlmsg_seq, 0, 0, 0);
2780 	if (err < 0) {
2781 		kfree_skb(skb);
2782 		goto errout;
2783 	}
2784 
2785 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2786 errout:
2787 	return err;
2788 }
2789 
2790 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
2791 {
2792 	struct sk_buff *skb;
2793 	struct net *net = info->nl_net;
2794 	u32 seq;
2795 	int err;
2796 
2797 	err = -ENOBUFS;
2798 	seq = info->nlh ? info->nlh->nlmsg_seq : 0;
2799 
2800 	skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
2801 	if (!skb)
2802 		goto errout;
2803 
2804 	err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
2805 				event, info->portid, seq, 0, 0, 0);
2806 	if (err < 0) {
2807 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
2808 		WARN_ON(err == -EMSGSIZE);
2809 		kfree_skb(skb);
2810 		goto errout;
2811 	}
2812 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
2813 		    info->nlh, gfp_any());
2814 	return;
2815 errout:
2816 	if (err < 0)
2817 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
2818 }
2819 
2820 static int ip6_route_dev_notify(struct notifier_block *this,
2821 				unsigned long event, void *ptr)
2822 {
2823 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2824 	struct net *net = dev_net(dev);
2825 
2826 	if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
2827 		net->ipv6.ip6_null_entry->dst.dev = dev;
2828 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
2829 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2830 		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
2831 		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
2832 		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
2833 		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
2834 #endif
2835 	}
2836 
2837 	return NOTIFY_OK;
2838 }
2839 
2840 /*
2841  *	/proc
2842  */
2843 
2844 #ifdef CONFIG_PROC_FS
2845 
2846 static const struct file_operations ipv6_route_proc_fops = {
2847 	.owner		= THIS_MODULE,
2848 	.open		= ipv6_route_open,
2849 	.read		= seq_read,
2850 	.llseek		= seq_lseek,
2851 	.release	= seq_release_net,
2852 };
2853 
2854 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2855 {
2856 	struct net *net = (struct net *)seq->private;
2857 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2858 		   net->ipv6.rt6_stats->fib_nodes,
2859 		   net->ipv6.rt6_stats->fib_route_nodes,
2860 		   net->ipv6.rt6_stats->fib_rt_alloc,
2861 		   net->ipv6.rt6_stats->fib_rt_entries,
2862 		   net->ipv6.rt6_stats->fib_rt_cache,
2863 		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
2864 		   net->ipv6.rt6_stats->fib_discarded_routes);
2865 
2866 	return 0;
2867 }
2868 
2869 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2870 {
2871 	return single_open_net(inode, file, rt6_stats_seq_show);
2872 }
2873 
2874 static const struct file_operations rt6_stats_seq_fops = {
2875 	.owner	 = THIS_MODULE,
2876 	.open	 = rt6_stats_seq_open,
2877 	.read	 = seq_read,
2878 	.llseek	 = seq_lseek,
2879 	.release = single_release_net,
2880 };
2881 #endif	/* CONFIG_PROC_FS */
2882 
2883 #ifdef CONFIG_SYSCTL
2884 
2885 static
2886 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
2887 			      void __user *buffer, size_t *lenp, loff_t *ppos)
2888 {
2889 	struct net *net;
2890 	int delay;
2891 	if (!write)
2892 		return -EINVAL;
2893 
2894 	net = (struct net *)ctl->extra1;
2895 	delay = net->ipv6.sysctl.flush_delay;
2896 	proc_dointvec(ctl, write, buffer, lenp, ppos);
2897 	fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
2898 	return 0;
2899 }
2900 
2901 struct ctl_table ipv6_route_table_template[] = {
2902 	{
2903 		.procname	=	"flush",
2904 		.data		=	&init_net.ipv6.sysctl.flush_delay,
2905 		.maxlen		=	sizeof(int),
2906 		.mode		=	0200,
2907 		.proc_handler	=	ipv6_sysctl_rtcache_flush
2908 	},
2909 	{
2910 		.procname	=	"gc_thresh",
2911 		.data		=	&ip6_dst_ops_template.gc_thresh,
2912 		.maxlen		=	sizeof(int),
2913 		.mode		=	0644,
2914 		.proc_handler	=	proc_dointvec,
2915 	},
2916 	{
2917 		.procname	=	"max_size",
2918 		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
2919 		.maxlen		=	sizeof(int),
2920 		.mode		=	0644,
2921 		.proc_handler	=	proc_dointvec,
2922 	},
2923 	{
2924 		.procname	=	"gc_min_interval",
2925 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2926 		.maxlen		=	sizeof(int),
2927 		.mode		=	0644,
2928 		.proc_handler	=	proc_dointvec_jiffies,
2929 	},
2930 	{
2931 		.procname	=	"gc_timeout",
2932 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
2933 		.maxlen		=	sizeof(int),
2934 		.mode		=	0644,
2935 		.proc_handler	=	proc_dointvec_jiffies,
2936 	},
2937 	{
2938 		.procname	=	"gc_interval",
2939 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
2940 		.maxlen		=	sizeof(int),
2941 		.mode		=	0644,
2942 		.proc_handler	=	proc_dointvec_jiffies,
2943 	},
2944 	{
2945 		.procname	=	"gc_elasticity",
2946 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
2947 		.maxlen		=	sizeof(int),
2948 		.mode		=	0644,
2949 		.proc_handler	=	proc_dointvec,
2950 	},
2951 	{
2952 		.procname	=	"mtu_expires",
2953 		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
2954 		.maxlen		=	sizeof(int),
2955 		.mode		=	0644,
2956 		.proc_handler	=	proc_dointvec_jiffies,
2957 	},
2958 	{
2959 		.procname	=	"min_adv_mss",
2960 		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
2961 		.maxlen		=	sizeof(int),
2962 		.mode		=	0644,
2963 		.proc_handler	=	proc_dointvec,
2964 	},
2965 	{
2966 		.procname	=	"gc_min_interval_ms",
2967 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2968 		.maxlen		=	sizeof(int),
2969 		.mode		=	0644,
2970 		.proc_handler	=	proc_dointvec_ms_jiffies,
2971 	},
2972 	{ }
2973 };
2974 
2975 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
2976 {
2977 	struct ctl_table *table;
2978 
2979 	table = kmemdup(ipv6_route_table_template,
2980 			sizeof(ipv6_route_table_template),
2981 			GFP_KERNEL);
2982 
2983 	if (table) {
2984 		table[0].data = &net->ipv6.sysctl.flush_delay;
2985 		table[0].extra1 = net;
2986 		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
2987 		table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
2988 		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2989 		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
2990 		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
2991 		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
2992 		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
2993 		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
2994 		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2995 
2996 		/* Don't export sysctls to unprivileged users */
2997 		if (net->user_ns != &init_user_ns)
2998 			table[0].procname = NULL;
2999 	}
3000 
3001 	return table;
3002 }
3003 #endif
3004 
3005 static int __net_init ip6_route_net_init(struct net *net)
3006 {
3007 	int ret = -ENOMEM;
3008 
3009 	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
3010 	       sizeof(net->ipv6.ip6_dst_ops));
3011 
3012 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
3013 		goto out_ip6_dst_ops;
3014 
3015 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
3016 					   sizeof(*net->ipv6.ip6_null_entry),
3017 					   GFP_KERNEL);
3018 	if (!net->ipv6.ip6_null_entry)
3019 		goto out_ip6_dst_entries;
3020 	net->ipv6.ip6_null_entry->dst.path =
3021 		(struct dst_entry *)net->ipv6.ip6_null_entry;
3022 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3023 	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
3024 			 ip6_template_metrics, true);
3025 
3026 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3027 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
3028 					       sizeof(*net->ipv6.ip6_prohibit_entry),
3029 					       GFP_KERNEL);
3030 	if (!net->ipv6.ip6_prohibit_entry)
3031 		goto out_ip6_null_entry;
3032 	net->ipv6.ip6_prohibit_entry->dst.path =
3033 		(struct dst_entry *)net->ipv6.ip6_prohibit_entry;
3034 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3035 	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
3036 			 ip6_template_metrics, true);
3037 
3038 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
3039 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
3040 					       GFP_KERNEL);
3041 	if (!net->ipv6.ip6_blk_hole_entry)
3042 		goto out_ip6_prohibit_entry;
3043 	net->ipv6.ip6_blk_hole_entry->dst.path =
3044 		(struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
3045 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3046 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
3047 			 ip6_template_metrics, true);
3048 #endif
3049 
3050 	net->ipv6.sysctl.flush_delay = 0;
3051 	net->ipv6.sysctl.ip6_rt_max_size = 4096;
3052 	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
3053 	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
3054 	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
3055 	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
3056 	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
3057 	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
3058 
3059 	net->ipv6.ip6_rt_gc_expire = 30*HZ;
3060 
3061 	ret = 0;
3062 out:
3063 	return ret;
3064 
3065 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3066 out_ip6_prohibit_entry:
3067 	kfree(net->ipv6.ip6_prohibit_entry);
3068 out_ip6_null_entry:
3069 	kfree(net->ipv6.ip6_null_entry);
3070 #endif
3071 out_ip6_dst_entries:
3072 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3073 out_ip6_dst_ops:
3074 	goto out;
3075 }
3076 
3077 static void __net_exit ip6_route_net_exit(struct net *net)
3078 {
3079 	kfree(net->ipv6.ip6_null_entry);
3080 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3081 	kfree(net->ipv6.ip6_prohibit_entry);
3082 	kfree(net->ipv6.ip6_blk_hole_entry);
3083 #endif
3084 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3085 }
3086 
3087 static int __net_init ip6_route_net_init_late(struct net *net)
3088 {
3089 #ifdef CONFIG_PROC_FS
3090 	proc_create("ipv6_route", 0, net->proc_net, &ipv6_route_proc_fops);
3091 	proc_create("rt6_stats", S_IRUGO, net->proc_net, &rt6_stats_seq_fops);
3092 #endif
3093 	return 0;
3094 }
3095 
3096 static void __net_exit ip6_route_net_exit_late(struct net *net)
3097 {
3098 #ifdef CONFIG_PROC_FS
3099 	remove_proc_entry("ipv6_route", net->proc_net);
3100 	remove_proc_entry("rt6_stats", net->proc_net);
3101 #endif
3102 }
3103 
3104 static struct pernet_operations ip6_route_net_ops = {
3105 	.init = ip6_route_net_init,
3106 	.exit = ip6_route_net_exit,
3107 };
3108 
3109 static int __net_init ipv6_inetpeer_init(struct net *net)
3110 {
3111 	struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3112 
3113 	if (!bp)
3114 		return -ENOMEM;
3115 	inet_peer_base_init(bp);
3116 	net->ipv6.peers = bp;
3117 	return 0;
3118 }
3119 
3120 static void __net_exit ipv6_inetpeer_exit(struct net *net)
3121 {
3122 	struct inet_peer_base *bp = net->ipv6.peers;
3123 
3124 	net->ipv6.peers = NULL;
3125 	inetpeer_invalidate_tree(bp);
3126 	kfree(bp);
3127 }
3128 
3129 static struct pernet_operations ipv6_inetpeer_ops = {
3130 	.init	=	ipv6_inetpeer_init,
3131 	.exit	=	ipv6_inetpeer_exit,
3132 };
3133 
3134 static struct pernet_operations ip6_route_net_late_ops = {
3135 	.init = ip6_route_net_init_late,
3136 	.exit = ip6_route_net_exit_late,
3137 };
3138 
3139 static struct notifier_block ip6_route_dev_notifier = {
3140 	.notifier_call = ip6_route_dev_notify,
3141 	.priority = 0,
3142 };
3143 
3144 int __init ip6_route_init(void)
3145 {
3146 	int ret;
3147 
3148 	ret = -ENOMEM;
3149 	ip6_dst_ops_template.kmem_cachep =
3150 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
3151 				  SLAB_HWCACHE_ALIGN, NULL);
3152 	if (!ip6_dst_ops_template.kmem_cachep)
3153 		goto out;
3154 
3155 	ret = dst_entries_init(&ip6_dst_blackhole_ops);
3156 	if (ret)
3157 		goto out_kmem_cache;
3158 
3159 	ret = register_pernet_subsys(&ipv6_inetpeer_ops);
3160 	if (ret)
3161 		goto out_dst_entries;
3162 
3163 	ret = register_pernet_subsys(&ip6_route_net_ops);
3164 	if (ret)
3165 		goto out_register_inetpeer;
3166 
3167 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
3168 
3169 	/* Registering of the loopback is done before this portion of code,
3170 	 * the loopback reference in rt6_info will not be taken, do it
3171 	 * manually for init_net */
3172 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
3173 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3174   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3175 	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
3176 	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3177 	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
3178 	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3179   #endif
3180 	ret = fib6_init();
3181 	if (ret)
3182 		goto out_register_subsys;
3183 
3184 	ret = xfrm6_init();
3185 	if (ret)
3186 		goto out_fib6_init;
3187 
3188 	ret = fib6_rules_init();
3189 	if (ret)
3190 		goto xfrm6_init;
3191 
3192 	ret = register_pernet_subsys(&ip6_route_net_late_ops);
3193 	if (ret)
3194 		goto fib6_rules_init;
3195 
3196 	ret = -ENOBUFS;
3197 	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||
3198 	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
3199 	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))
3200 		goto out_register_late_subsys;
3201 
3202 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
3203 	if (ret)
3204 		goto out_register_late_subsys;
3205 
3206 out:
3207 	return ret;
3208 
3209 out_register_late_subsys:
3210 	unregister_pernet_subsys(&ip6_route_net_late_ops);
3211 fib6_rules_init:
3212 	fib6_rules_cleanup();
3213 xfrm6_init:
3214 	xfrm6_fini();
3215 out_fib6_init:
3216 	fib6_gc_cleanup();
3217 out_register_subsys:
3218 	unregister_pernet_subsys(&ip6_route_net_ops);
3219 out_register_inetpeer:
3220 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
3221 out_dst_entries:
3222 	dst_entries_destroy(&ip6_dst_blackhole_ops);
3223 out_kmem_cache:
3224 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3225 	goto out;
3226 }
3227 
3228 void ip6_route_cleanup(void)
3229 {
3230 	unregister_netdevice_notifier(&ip6_route_dev_notifier);
3231 	unregister_pernet_subsys(&ip6_route_net_late_ops);
3232 	fib6_rules_cleanup();
3233 	xfrm6_fini();
3234 	fib6_gc_cleanup();
3235 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
3236 	unregister_pernet_subsys(&ip6_route_net_ops);
3237 	dst_entries_destroy(&ip6_dst_blackhole_ops);
3238 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3239 }
3240