xref: /linux/net/ipv6/route.c (revision d458cdf712e0c671e8e819abb16ecd6e44f9daec)
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 = -2,
70 	RT6_NUD_FAIL_SOFT = -1,
71 	RT6_NUD_SUCCEED = 1
72 };
73 
74 static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
75 				    const struct in6_addr *dest);
76 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
77 static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
78 static unsigned int	 ip6_mtu(const struct dst_entry *dst);
79 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
80 static void		ip6_dst_destroy(struct dst_entry *);
81 static void		ip6_dst_ifdown(struct dst_entry *,
82 				       struct net_device *dev, int how);
83 static int		 ip6_dst_gc(struct dst_ops *ops);
84 
85 static int		ip6_pkt_discard(struct sk_buff *skb);
86 static int		ip6_pkt_discard_out(struct sk_buff *skb);
87 static void		ip6_link_failure(struct sk_buff *skb);
88 static void		ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
89 					   struct sk_buff *skb, u32 mtu);
90 static void		rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
91 					struct sk_buff *skb);
92 static int rt6_score_route(struct rt6_info *rt, int oif, int strict);
93 
94 #ifdef CONFIG_IPV6_ROUTE_INFO
95 static struct rt6_info *rt6_add_route_info(struct net *net,
96 					   const struct in6_addr *prefix, int prefixlen,
97 					   const struct in6_addr *gwaddr, int ifindex,
98 					   unsigned int pref);
99 static struct rt6_info *rt6_get_route_info(struct net *net,
100 					   const struct in6_addr *prefix, int prefixlen,
101 					   const struct in6_addr *gwaddr, int ifindex);
102 #endif
103 
104 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
105 {
106 	struct rt6_info *rt = (struct rt6_info *) dst;
107 	struct inet_peer *peer;
108 	u32 *p = NULL;
109 
110 	if (!(rt->dst.flags & DST_HOST))
111 		return NULL;
112 
113 	peer = rt6_get_peer_create(rt);
114 	if (peer) {
115 		u32 *old_p = __DST_METRICS_PTR(old);
116 		unsigned long prev, new;
117 
118 		p = peer->metrics;
119 		if (inet_metrics_new(peer))
120 			memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
121 
122 		new = (unsigned long) p;
123 		prev = cmpxchg(&dst->_metrics, old, new);
124 
125 		if (prev != old) {
126 			p = __DST_METRICS_PTR(prev);
127 			if (prev & DST_METRICS_READ_ONLY)
128 				p = NULL;
129 		}
130 	}
131 	return p;
132 }
133 
134 static inline const void *choose_neigh_daddr(struct rt6_info *rt,
135 					     struct sk_buff *skb,
136 					     const void *daddr)
137 {
138 	struct in6_addr *p = &rt->rt6i_gateway;
139 
140 	if (!ipv6_addr_any(p))
141 		return (const void *) p;
142 	else if (skb)
143 		return &ipv6_hdr(skb)->daddr;
144 	return daddr;
145 }
146 
147 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst,
148 					  struct sk_buff *skb,
149 					  const void *daddr)
150 {
151 	struct rt6_info *rt = (struct rt6_info *) dst;
152 	struct neighbour *n;
153 
154 	daddr = choose_neigh_daddr(rt, skb, daddr);
155 	n = __ipv6_neigh_lookup(dst->dev, daddr);
156 	if (n)
157 		return n;
158 	return neigh_create(&nd_tbl, daddr, dst->dev);
159 }
160 
161 static struct dst_ops ip6_dst_ops_template = {
162 	.family			=	AF_INET6,
163 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
164 	.gc			=	ip6_dst_gc,
165 	.gc_thresh		=	1024,
166 	.check			=	ip6_dst_check,
167 	.default_advmss		=	ip6_default_advmss,
168 	.mtu			=	ip6_mtu,
169 	.cow_metrics		=	ipv6_cow_metrics,
170 	.destroy		=	ip6_dst_destroy,
171 	.ifdown			=	ip6_dst_ifdown,
172 	.negative_advice	=	ip6_negative_advice,
173 	.link_failure		=	ip6_link_failure,
174 	.update_pmtu		=	ip6_rt_update_pmtu,
175 	.redirect		=	rt6_do_redirect,
176 	.local_out		=	__ip6_local_out,
177 	.neigh_lookup		=	ip6_neigh_lookup,
178 };
179 
180 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst)
181 {
182 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
183 
184 	return mtu ? : dst->dev->mtu;
185 }
186 
187 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
188 					 struct sk_buff *skb, u32 mtu)
189 {
190 }
191 
192 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
193 				      struct sk_buff *skb)
194 {
195 }
196 
197 static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst,
198 					 unsigned long old)
199 {
200 	return NULL;
201 }
202 
203 static struct dst_ops ip6_dst_blackhole_ops = {
204 	.family			=	AF_INET6,
205 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
206 	.destroy		=	ip6_dst_destroy,
207 	.check			=	ip6_dst_check,
208 	.mtu			=	ip6_blackhole_mtu,
209 	.default_advmss		=	ip6_default_advmss,
210 	.update_pmtu		=	ip6_rt_blackhole_update_pmtu,
211 	.redirect		=	ip6_rt_blackhole_redirect,
212 	.cow_metrics		=	ip6_rt_blackhole_cow_metrics,
213 	.neigh_lookup		=	ip6_neigh_lookup,
214 };
215 
216 static const u32 ip6_template_metrics[RTAX_MAX] = {
217 	[RTAX_HOPLIMIT - 1] = 0,
218 };
219 
220 static const struct rt6_info ip6_null_entry_template = {
221 	.dst = {
222 		.__refcnt	= ATOMIC_INIT(1),
223 		.__use		= 1,
224 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
225 		.error		= -ENETUNREACH,
226 		.input		= ip6_pkt_discard,
227 		.output		= ip6_pkt_discard_out,
228 	},
229 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
230 	.rt6i_protocol  = RTPROT_KERNEL,
231 	.rt6i_metric	= ~(u32) 0,
232 	.rt6i_ref	= ATOMIC_INIT(1),
233 };
234 
235 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
236 
237 static int ip6_pkt_prohibit(struct sk_buff *skb);
238 static int ip6_pkt_prohibit_out(struct sk_buff *skb);
239 
240 static const struct rt6_info ip6_prohibit_entry_template = {
241 	.dst = {
242 		.__refcnt	= ATOMIC_INIT(1),
243 		.__use		= 1,
244 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
245 		.error		= -EACCES,
246 		.input		= ip6_pkt_prohibit,
247 		.output		= ip6_pkt_prohibit_out,
248 	},
249 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
250 	.rt6i_protocol  = RTPROT_KERNEL,
251 	.rt6i_metric	= ~(u32) 0,
252 	.rt6i_ref	= ATOMIC_INIT(1),
253 };
254 
255 static const struct rt6_info ip6_blk_hole_entry_template = {
256 	.dst = {
257 		.__refcnt	= ATOMIC_INIT(1),
258 		.__use		= 1,
259 		.obsolete	= DST_OBSOLETE_FORCE_CHK,
260 		.error		= -EINVAL,
261 		.input		= dst_discard,
262 		.output		= dst_discard,
263 	},
264 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
265 	.rt6i_protocol  = RTPROT_KERNEL,
266 	.rt6i_metric	= ~(u32) 0,
267 	.rt6i_ref	= ATOMIC_INIT(1),
268 };
269 
270 #endif
271 
272 /* allocate dst with ip6_dst_ops */
273 static inline struct rt6_info *ip6_dst_alloc(struct net *net,
274 					     struct net_device *dev,
275 					     int flags,
276 					     struct fib6_table *table)
277 {
278 	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
279 					0, DST_OBSOLETE_FORCE_CHK, flags);
280 
281 	if (rt) {
282 		struct dst_entry *dst = &rt->dst;
283 
284 		memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
285 		rt6_init_peer(rt, table ? &table->tb6_peers : net->ipv6.peers);
286 		rt->rt6i_genid = rt_genid_ipv6(net);
287 		INIT_LIST_HEAD(&rt->rt6i_siblings);
288 	}
289 	return rt;
290 }
291 
292 static void ip6_dst_destroy(struct dst_entry *dst)
293 {
294 	struct rt6_info *rt = (struct rt6_info *)dst;
295 	struct inet6_dev *idev = rt->rt6i_idev;
296 	struct dst_entry *from = dst->from;
297 
298 	if (!(rt->dst.flags & DST_HOST))
299 		dst_destroy_metrics_generic(dst);
300 
301 	if (idev) {
302 		rt->rt6i_idev = NULL;
303 		in6_dev_put(idev);
304 	}
305 
306 	dst->from = NULL;
307 	dst_release(from);
308 
309 	if (rt6_has_peer(rt)) {
310 		struct inet_peer *peer = rt6_peer_ptr(rt);
311 		inet_putpeer(peer);
312 	}
313 }
314 
315 void rt6_bind_peer(struct rt6_info *rt, int create)
316 {
317 	struct inet_peer_base *base;
318 	struct inet_peer *peer;
319 
320 	base = inetpeer_base_ptr(rt->_rt6i_peer);
321 	if (!base)
322 		return;
323 
324 	peer = inet_getpeer_v6(base, &rt->rt6i_dst.addr, create);
325 	if (peer) {
326 		if (!rt6_set_peer(rt, peer))
327 			inet_putpeer(peer);
328 	}
329 }
330 
331 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
332 			   int how)
333 {
334 	struct rt6_info *rt = (struct rt6_info *)dst;
335 	struct inet6_dev *idev = rt->rt6i_idev;
336 	struct net_device *loopback_dev =
337 		dev_net(dev)->loopback_dev;
338 
339 	if (dev != loopback_dev) {
340 		if (idev && idev->dev == dev) {
341 			struct inet6_dev *loopback_idev =
342 				in6_dev_get(loopback_dev);
343 			if (loopback_idev) {
344 				rt->rt6i_idev = loopback_idev;
345 				in6_dev_put(idev);
346 			}
347 		}
348 	}
349 }
350 
351 static bool rt6_check_expired(const struct rt6_info *rt)
352 {
353 	if (rt->rt6i_flags & RTF_EXPIRES) {
354 		if (time_after(jiffies, rt->dst.expires))
355 			return true;
356 	} else if (rt->dst.from) {
357 		return rt6_check_expired((struct rt6_info *) rt->dst.from);
358 	}
359 	return false;
360 }
361 
362 static bool rt6_need_strict(const struct in6_addr *daddr)
363 {
364 	return ipv6_addr_type(daddr) &
365 		(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
366 }
367 
368 /* Multipath route selection:
369  *   Hash based function using packet header and flowlabel.
370  * Adapted from fib_info_hashfn()
371  */
372 static int rt6_info_hash_nhsfn(unsigned int candidate_count,
373 			       const struct flowi6 *fl6)
374 {
375 	unsigned int val = fl6->flowi6_proto;
376 
377 	val ^= ipv6_addr_hash(&fl6->daddr);
378 	val ^= ipv6_addr_hash(&fl6->saddr);
379 
380 	/* Work only if this not encapsulated */
381 	switch (fl6->flowi6_proto) {
382 	case IPPROTO_UDP:
383 	case IPPROTO_TCP:
384 	case IPPROTO_SCTP:
385 		val ^= (__force u16)fl6->fl6_sport;
386 		val ^= (__force u16)fl6->fl6_dport;
387 		break;
388 
389 	case IPPROTO_ICMPV6:
390 		val ^= (__force u16)fl6->fl6_icmp_type;
391 		val ^= (__force u16)fl6->fl6_icmp_code;
392 		break;
393 	}
394 	/* RFC6438 recommands to use flowlabel */
395 	val ^= (__force u32)fl6->flowlabel;
396 
397 	/* Perhaps, we need to tune, this function? */
398 	val = val ^ (val >> 7) ^ (val >> 12);
399 	return val % candidate_count;
400 }
401 
402 static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
403 					     struct flowi6 *fl6, int oif,
404 					     int strict)
405 {
406 	struct rt6_info *sibling, *next_sibling;
407 	int route_choosen;
408 
409 	route_choosen = rt6_info_hash_nhsfn(match->rt6i_nsiblings + 1, fl6);
410 	/* Don't change the route, if route_choosen == 0
411 	 * (siblings does not include ourself)
412 	 */
413 	if (route_choosen)
414 		list_for_each_entry_safe(sibling, next_sibling,
415 				&match->rt6i_siblings, rt6i_siblings) {
416 			route_choosen--;
417 			if (route_choosen == 0) {
418 				if (rt6_score_route(sibling, oif, strict) < 0)
419 					break;
420 				match = sibling;
421 				break;
422 			}
423 		}
424 	return match;
425 }
426 
427 /*
428  *	Route lookup. Any table->tb6_lock is implied.
429  */
430 
431 static inline struct rt6_info *rt6_device_match(struct net *net,
432 						    struct rt6_info *rt,
433 						    const struct in6_addr *saddr,
434 						    int oif,
435 						    int flags)
436 {
437 	struct rt6_info *local = NULL;
438 	struct rt6_info *sprt;
439 
440 	if (!oif && ipv6_addr_any(saddr))
441 		goto out;
442 
443 	for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
444 		struct net_device *dev = sprt->dst.dev;
445 
446 		if (oif) {
447 			if (dev->ifindex == oif)
448 				return sprt;
449 			if (dev->flags & IFF_LOOPBACK) {
450 				if (!sprt->rt6i_idev ||
451 				    sprt->rt6i_idev->dev->ifindex != oif) {
452 					if (flags & RT6_LOOKUP_F_IFACE && oif)
453 						continue;
454 					if (local && (!oif ||
455 						      local->rt6i_idev->dev->ifindex == oif))
456 						continue;
457 				}
458 				local = sprt;
459 			}
460 		} else {
461 			if (ipv6_chk_addr(net, saddr, dev,
462 					  flags & RT6_LOOKUP_F_IFACE))
463 				return sprt;
464 		}
465 	}
466 
467 	if (oif) {
468 		if (local)
469 			return local;
470 
471 		if (flags & RT6_LOOKUP_F_IFACE)
472 			return net->ipv6.ip6_null_entry;
473 	}
474 out:
475 	return rt;
476 }
477 
478 #ifdef CONFIG_IPV6_ROUTER_PREF
479 static void rt6_probe(struct rt6_info *rt)
480 {
481 	struct neighbour *neigh;
482 	/*
483 	 * Okay, this does not seem to be appropriate
484 	 * for now, however, we need to check if it
485 	 * is really so; aka Router Reachability Probing.
486 	 *
487 	 * Router Reachability Probe MUST be rate-limited
488 	 * to no more than one per minute.
489 	 */
490 	if (!rt || !(rt->rt6i_flags & RTF_GATEWAY))
491 		return;
492 	rcu_read_lock_bh();
493 	neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
494 	if (neigh) {
495 		write_lock(&neigh->lock);
496 		if (neigh->nud_state & NUD_VALID)
497 			goto out;
498 	}
499 
500 	if (!neigh ||
501 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
502 		struct in6_addr mcaddr;
503 		struct in6_addr *target;
504 
505 		if (neigh) {
506 			neigh->updated = jiffies;
507 			write_unlock(&neigh->lock);
508 		}
509 
510 		target = (struct in6_addr *)&rt->rt6i_gateway;
511 		addrconf_addr_solict_mult(target, &mcaddr);
512 		ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL);
513 	} else {
514 out:
515 		write_unlock(&neigh->lock);
516 	}
517 	rcu_read_unlock_bh();
518 }
519 #else
520 static inline void rt6_probe(struct rt6_info *rt)
521 {
522 }
523 #endif
524 
525 /*
526  * Default Router Selection (RFC 2461 6.3.6)
527  */
528 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
529 {
530 	struct net_device *dev = rt->dst.dev;
531 	if (!oif || dev->ifindex == oif)
532 		return 2;
533 	if ((dev->flags & IFF_LOOPBACK) &&
534 	    rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
535 		return 1;
536 	return 0;
537 }
538 
539 static inline enum rt6_nud_state rt6_check_neigh(struct rt6_info *rt)
540 {
541 	struct neighbour *neigh;
542 	enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
543 
544 	if (rt->rt6i_flags & RTF_NONEXTHOP ||
545 	    !(rt->rt6i_flags & RTF_GATEWAY))
546 		return RT6_NUD_SUCCEED;
547 
548 	rcu_read_lock_bh();
549 	neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
550 	if (neigh) {
551 		read_lock(&neigh->lock);
552 		if (neigh->nud_state & NUD_VALID)
553 			ret = RT6_NUD_SUCCEED;
554 #ifdef CONFIG_IPV6_ROUTER_PREF
555 		else if (!(neigh->nud_state & NUD_FAILED))
556 			ret = RT6_NUD_SUCCEED;
557 #endif
558 		read_unlock(&neigh->lock);
559 	} else {
560 		ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
561 		      RT6_NUD_SUCCEED : RT6_NUD_FAIL_SOFT;
562 	}
563 	rcu_read_unlock_bh();
564 
565 	return ret;
566 }
567 
568 static int rt6_score_route(struct rt6_info *rt, int oif,
569 			   int strict)
570 {
571 	int m;
572 
573 	m = rt6_check_dev(rt, oif);
574 	if (!m && (strict & RT6_LOOKUP_F_IFACE))
575 		return RT6_NUD_FAIL_HARD;
576 #ifdef CONFIG_IPV6_ROUTER_PREF
577 	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
578 #endif
579 	if (strict & RT6_LOOKUP_F_REACHABLE) {
580 		int n = rt6_check_neigh(rt);
581 		if (n < 0)
582 			return n;
583 	}
584 	return m;
585 }
586 
587 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
588 				   int *mpri, struct rt6_info *match,
589 				   bool *do_rr)
590 {
591 	int m;
592 	bool match_do_rr = false;
593 
594 	if (rt6_check_expired(rt))
595 		goto out;
596 
597 	m = rt6_score_route(rt, oif, strict);
598 	if (m == RT6_NUD_FAIL_SOFT && !IS_ENABLED(CONFIG_IPV6_ROUTER_PREF)) {
599 		match_do_rr = true;
600 		m = 0; /* lowest valid score */
601 	} else if (m < 0) {
602 		goto out;
603 	}
604 
605 	if (strict & RT6_LOOKUP_F_REACHABLE)
606 		rt6_probe(rt);
607 
608 	if (m > *mpri) {
609 		*do_rr = match_do_rr;
610 		*mpri = m;
611 		match = rt;
612 	}
613 out:
614 	return match;
615 }
616 
617 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
618 				     struct rt6_info *rr_head,
619 				     u32 metric, int oif, int strict,
620 				     bool *do_rr)
621 {
622 	struct rt6_info *rt, *match;
623 	int mpri = -1;
624 
625 	match = NULL;
626 	for (rt = rr_head; rt && rt->rt6i_metric == metric;
627 	     rt = rt->dst.rt6_next)
628 		match = find_match(rt, oif, strict, &mpri, match, do_rr);
629 	for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;
630 	     rt = rt->dst.rt6_next)
631 		match = find_match(rt, oif, strict, &mpri, match, do_rr);
632 
633 	return match;
634 }
635 
636 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
637 {
638 	struct rt6_info *match, *rt0;
639 	struct net *net;
640 	bool do_rr = false;
641 
642 	rt0 = fn->rr_ptr;
643 	if (!rt0)
644 		fn->rr_ptr = rt0 = fn->leaf;
645 
646 	match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict,
647 			     &do_rr);
648 
649 	if (do_rr) {
650 		struct rt6_info *next = rt0->dst.rt6_next;
651 
652 		/* no entries matched; do round-robin */
653 		if (!next || next->rt6i_metric != rt0->rt6i_metric)
654 			next = fn->leaf;
655 
656 		if (next != rt0)
657 			fn->rr_ptr = next;
658 	}
659 
660 	net = dev_net(rt0->dst.dev);
661 	return match ? match : net->ipv6.ip6_null_entry;
662 }
663 
664 #ifdef CONFIG_IPV6_ROUTE_INFO
665 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
666 		  const struct in6_addr *gwaddr)
667 {
668 	struct net *net = dev_net(dev);
669 	struct route_info *rinfo = (struct route_info *) opt;
670 	struct in6_addr prefix_buf, *prefix;
671 	unsigned int pref;
672 	unsigned long lifetime;
673 	struct rt6_info *rt;
674 
675 	if (len < sizeof(struct route_info)) {
676 		return -EINVAL;
677 	}
678 
679 	/* Sanity check for prefix_len and length */
680 	if (rinfo->length > 3) {
681 		return -EINVAL;
682 	} else if (rinfo->prefix_len > 128) {
683 		return -EINVAL;
684 	} else if (rinfo->prefix_len > 64) {
685 		if (rinfo->length < 2) {
686 			return -EINVAL;
687 		}
688 	} else if (rinfo->prefix_len > 0) {
689 		if (rinfo->length < 1) {
690 			return -EINVAL;
691 		}
692 	}
693 
694 	pref = rinfo->route_pref;
695 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
696 		return -EINVAL;
697 
698 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
699 
700 	if (rinfo->length == 3)
701 		prefix = (struct in6_addr *)rinfo->prefix;
702 	else {
703 		/* this function is safe */
704 		ipv6_addr_prefix(&prefix_buf,
705 				 (struct in6_addr *)rinfo->prefix,
706 				 rinfo->prefix_len);
707 		prefix = &prefix_buf;
708 	}
709 
710 	rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, gwaddr,
711 				dev->ifindex);
712 
713 	if (rt && !lifetime) {
714 		ip6_del_rt(rt);
715 		rt = NULL;
716 	}
717 
718 	if (!rt && lifetime)
719 		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
720 					pref);
721 	else if (rt)
722 		rt->rt6i_flags = RTF_ROUTEINFO |
723 				 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
724 
725 	if (rt) {
726 		if (!addrconf_finite_timeout(lifetime))
727 			rt6_clean_expires(rt);
728 		else
729 			rt6_set_expires(rt, jiffies + HZ * lifetime);
730 
731 		ip6_rt_put(rt);
732 	}
733 	return 0;
734 }
735 #endif
736 
737 #define BACKTRACK(__net, saddr)			\
738 do { \
739 	if (rt == __net->ipv6.ip6_null_entry) {	\
740 		struct fib6_node *pn; \
741 		while (1) { \
742 			if (fn->fn_flags & RTN_TL_ROOT) \
743 				goto out; \
744 			pn = fn->parent; \
745 			if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \
746 				fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \
747 			else \
748 				fn = pn; \
749 			if (fn->fn_flags & RTN_RTINFO) \
750 				goto restart; \
751 		} \
752 	} \
753 } while (0)
754 
755 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
756 					     struct fib6_table *table,
757 					     struct flowi6 *fl6, int flags)
758 {
759 	struct fib6_node *fn;
760 	struct rt6_info *rt;
761 
762 	read_lock_bh(&table->tb6_lock);
763 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
764 restart:
765 	rt = fn->leaf;
766 	rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
767 	if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
768 		rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
769 	BACKTRACK(net, &fl6->saddr);
770 out:
771 	dst_use(&rt->dst, jiffies);
772 	read_unlock_bh(&table->tb6_lock);
773 	return rt;
774 
775 }
776 
777 struct dst_entry * ip6_route_lookup(struct net *net, struct flowi6 *fl6,
778 				    int flags)
779 {
780 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
781 }
782 EXPORT_SYMBOL_GPL(ip6_route_lookup);
783 
784 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
785 			    const struct in6_addr *saddr, int oif, int strict)
786 {
787 	struct flowi6 fl6 = {
788 		.flowi6_oif = oif,
789 		.daddr = *daddr,
790 	};
791 	struct dst_entry *dst;
792 	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
793 
794 	if (saddr) {
795 		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
796 		flags |= RT6_LOOKUP_F_HAS_SADDR;
797 	}
798 
799 	dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
800 	if (dst->error == 0)
801 		return (struct rt6_info *) dst;
802 
803 	dst_release(dst);
804 
805 	return NULL;
806 }
807 
808 EXPORT_SYMBOL(rt6_lookup);
809 
810 /* ip6_ins_rt is called with FREE table->tb6_lock.
811    It takes new route entry, the addition fails by any reason the
812    route is freed. In any case, if caller does not hold it, it may
813    be destroyed.
814  */
815 
816 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info)
817 {
818 	int err;
819 	struct fib6_table *table;
820 
821 	table = rt->rt6i_table;
822 	write_lock_bh(&table->tb6_lock);
823 	err = fib6_add(&table->tb6_root, rt, info);
824 	write_unlock_bh(&table->tb6_lock);
825 
826 	return err;
827 }
828 
829 int ip6_ins_rt(struct rt6_info *rt)
830 {
831 	struct nl_info info = {
832 		.nl_net = dev_net(rt->dst.dev),
833 	};
834 	return __ip6_ins_rt(rt, &info);
835 }
836 
837 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort,
838 				      const struct in6_addr *daddr,
839 				      const struct in6_addr *saddr)
840 {
841 	struct rt6_info *rt;
842 
843 	/*
844 	 *	Clone the route.
845 	 */
846 
847 	rt = ip6_rt_copy(ort, daddr);
848 
849 	if (rt) {
850 		if (!(rt->rt6i_flags & RTF_GATEWAY)) {
851 			if (ort->rt6i_dst.plen != 128 &&
852 			    ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
853 				rt->rt6i_flags |= RTF_ANYCAST;
854 			rt->rt6i_gateway = *daddr;
855 		}
856 
857 		rt->rt6i_flags |= RTF_CACHE;
858 
859 #ifdef CONFIG_IPV6_SUBTREES
860 		if (rt->rt6i_src.plen && saddr) {
861 			rt->rt6i_src.addr = *saddr;
862 			rt->rt6i_src.plen = 128;
863 		}
864 #endif
865 	}
866 
867 	return rt;
868 }
869 
870 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort,
871 					const struct in6_addr *daddr)
872 {
873 	struct rt6_info *rt = ip6_rt_copy(ort, daddr);
874 
875 	if (rt)
876 		rt->rt6i_flags |= RTF_CACHE;
877 	return rt;
878 }
879 
880 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
881 				      struct flowi6 *fl6, int flags)
882 {
883 	struct fib6_node *fn;
884 	struct rt6_info *rt, *nrt;
885 	int strict = 0;
886 	int attempts = 3;
887 	int err;
888 	int reachable = net->ipv6.devconf_all->forwarding ? 0 : RT6_LOOKUP_F_REACHABLE;
889 
890 	strict |= flags & RT6_LOOKUP_F_IFACE;
891 
892 relookup:
893 	read_lock_bh(&table->tb6_lock);
894 
895 restart_2:
896 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
897 
898 restart:
899 	rt = rt6_select(fn, oif, strict | reachable);
900 	if (rt->rt6i_nsiblings)
901 		rt = rt6_multipath_select(rt, fl6, oif, strict | reachable);
902 	BACKTRACK(net, &fl6->saddr);
903 	if (rt == net->ipv6.ip6_null_entry ||
904 	    rt->rt6i_flags & RTF_CACHE)
905 		goto out;
906 
907 	dst_hold(&rt->dst);
908 	read_unlock_bh(&table->tb6_lock);
909 
910 	if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)))
911 		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
912 	else if (!(rt->dst.flags & DST_HOST))
913 		nrt = rt6_alloc_clone(rt, &fl6->daddr);
914 	else
915 		goto out2;
916 
917 	ip6_rt_put(rt);
918 	rt = nrt ? : net->ipv6.ip6_null_entry;
919 
920 	dst_hold(&rt->dst);
921 	if (nrt) {
922 		err = ip6_ins_rt(nrt);
923 		if (!err)
924 			goto out2;
925 	}
926 
927 	if (--attempts <= 0)
928 		goto out2;
929 
930 	/*
931 	 * Race condition! In the gap, when table->tb6_lock was
932 	 * released someone could insert this route.  Relookup.
933 	 */
934 	ip6_rt_put(rt);
935 	goto relookup;
936 
937 out:
938 	if (reachable) {
939 		reachable = 0;
940 		goto restart_2;
941 	}
942 	dst_hold(&rt->dst);
943 	read_unlock_bh(&table->tb6_lock);
944 out2:
945 	rt->dst.lastuse = jiffies;
946 	rt->dst.__use++;
947 
948 	return rt;
949 }
950 
951 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
952 					    struct flowi6 *fl6, int flags)
953 {
954 	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
955 }
956 
957 static struct dst_entry *ip6_route_input_lookup(struct net *net,
958 						struct net_device *dev,
959 						struct flowi6 *fl6, int flags)
960 {
961 	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
962 		flags |= RT6_LOOKUP_F_IFACE;
963 
964 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
965 }
966 
967 void ip6_route_input(struct sk_buff *skb)
968 {
969 	const struct ipv6hdr *iph = ipv6_hdr(skb);
970 	struct net *net = dev_net(skb->dev);
971 	int flags = RT6_LOOKUP_F_HAS_SADDR;
972 	struct flowi6 fl6 = {
973 		.flowi6_iif = skb->dev->ifindex,
974 		.daddr = iph->daddr,
975 		.saddr = iph->saddr,
976 		.flowlabel = ip6_flowinfo(iph),
977 		.flowi6_mark = skb->mark,
978 		.flowi6_proto = iph->nexthdr,
979 	};
980 
981 	skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
982 }
983 
984 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
985 					     struct flowi6 *fl6, int flags)
986 {
987 	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
988 }
989 
990 struct dst_entry * ip6_route_output(struct net *net, const struct sock *sk,
991 				    struct flowi6 *fl6)
992 {
993 	int flags = 0;
994 
995 	fl6->flowi6_iif = LOOPBACK_IFINDEX;
996 
997 	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
998 		flags |= RT6_LOOKUP_F_IFACE;
999 
1000 	if (!ipv6_addr_any(&fl6->saddr))
1001 		flags |= RT6_LOOKUP_F_HAS_SADDR;
1002 	else if (sk)
1003 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
1004 
1005 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
1006 }
1007 
1008 EXPORT_SYMBOL(ip6_route_output);
1009 
1010 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
1011 {
1012 	struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
1013 	struct dst_entry *new = NULL;
1014 
1015 	rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0);
1016 	if (rt) {
1017 		new = &rt->dst;
1018 
1019 		memset(new + 1, 0, sizeof(*rt) - sizeof(*new));
1020 		rt6_init_peer(rt, net->ipv6.peers);
1021 
1022 		new->__use = 1;
1023 		new->input = dst_discard;
1024 		new->output = dst_discard;
1025 
1026 		if (dst_metrics_read_only(&ort->dst))
1027 			new->_metrics = ort->dst._metrics;
1028 		else
1029 			dst_copy_metrics(new, &ort->dst);
1030 		rt->rt6i_idev = ort->rt6i_idev;
1031 		if (rt->rt6i_idev)
1032 			in6_dev_hold(rt->rt6i_idev);
1033 
1034 		rt->rt6i_gateway = ort->rt6i_gateway;
1035 		rt->rt6i_flags = ort->rt6i_flags;
1036 		rt->rt6i_metric = 0;
1037 
1038 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1039 #ifdef CONFIG_IPV6_SUBTREES
1040 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1041 #endif
1042 
1043 		dst_free(new);
1044 	}
1045 
1046 	dst_release(dst_orig);
1047 	return new ? new : ERR_PTR(-ENOMEM);
1048 }
1049 
1050 /*
1051  *	Destination cache support functions
1052  */
1053 
1054 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
1055 {
1056 	struct rt6_info *rt;
1057 
1058 	rt = (struct rt6_info *) dst;
1059 
1060 	/* All IPV6 dsts are created with ->obsolete set to the value
1061 	 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
1062 	 * into this function always.
1063 	 */
1064 	if (rt->rt6i_genid != rt_genid_ipv6(dev_net(rt->dst.dev)))
1065 		return NULL;
1066 
1067 	if (rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie))
1068 		return dst;
1069 
1070 	return NULL;
1071 }
1072 
1073 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
1074 {
1075 	struct rt6_info *rt = (struct rt6_info *) dst;
1076 
1077 	if (rt) {
1078 		if (rt->rt6i_flags & RTF_CACHE) {
1079 			if (rt6_check_expired(rt)) {
1080 				ip6_del_rt(rt);
1081 				dst = NULL;
1082 			}
1083 		} else {
1084 			dst_release(dst);
1085 			dst = NULL;
1086 		}
1087 	}
1088 	return dst;
1089 }
1090 
1091 static void ip6_link_failure(struct sk_buff *skb)
1092 {
1093 	struct rt6_info *rt;
1094 
1095 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
1096 
1097 	rt = (struct rt6_info *) skb_dst(skb);
1098 	if (rt) {
1099 		if (rt->rt6i_flags & RTF_CACHE) {
1100 			dst_hold(&rt->dst);
1101 			if (ip6_del_rt(rt))
1102 				dst_free(&rt->dst);
1103 		} else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
1104 			rt->rt6i_node->fn_sernum = -1;
1105 		}
1106 	}
1107 }
1108 
1109 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
1110 			       struct sk_buff *skb, u32 mtu)
1111 {
1112 	struct rt6_info *rt6 = (struct rt6_info*)dst;
1113 
1114 	dst_confirm(dst);
1115 	if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
1116 		struct net *net = dev_net(dst->dev);
1117 
1118 		rt6->rt6i_flags |= RTF_MODIFIED;
1119 		if (mtu < IPV6_MIN_MTU) {
1120 			u32 features = dst_metric(dst, RTAX_FEATURES);
1121 			mtu = IPV6_MIN_MTU;
1122 			features |= RTAX_FEATURE_ALLFRAG;
1123 			dst_metric_set(dst, RTAX_FEATURES, features);
1124 		}
1125 		dst_metric_set(dst, RTAX_MTU, mtu);
1126 		rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires);
1127 	}
1128 }
1129 
1130 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
1131 		     int oif, u32 mark)
1132 {
1133 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1134 	struct dst_entry *dst;
1135 	struct flowi6 fl6;
1136 
1137 	memset(&fl6, 0, sizeof(fl6));
1138 	fl6.flowi6_oif = oif;
1139 	fl6.flowi6_mark = mark;
1140 	fl6.daddr = iph->daddr;
1141 	fl6.saddr = iph->saddr;
1142 	fl6.flowlabel = ip6_flowinfo(iph);
1143 
1144 	dst = ip6_route_output(net, NULL, &fl6);
1145 	if (!dst->error)
1146 		ip6_rt_update_pmtu(dst, NULL, skb, ntohl(mtu));
1147 	dst_release(dst);
1148 }
1149 EXPORT_SYMBOL_GPL(ip6_update_pmtu);
1150 
1151 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
1152 {
1153 	ip6_update_pmtu(skb, sock_net(sk), mtu,
1154 			sk->sk_bound_dev_if, sk->sk_mark);
1155 }
1156 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
1157 
1158 /* Handle redirects */
1159 struct ip6rd_flowi {
1160 	struct flowi6 fl6;
1161 	struct in6_addr gateway;
1162 };
1163 
1164 static struct rt6_info *__ip6_route_redirect(struct net *net,
1165 					     struct fib6_table *table,
1166 					     struct flowi6 *fl6,
1167 					     int flags)
1168 {
1169 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
1170 	struct rt6_info *rt;
1171 	struct fib6_node *fn;
1172 
1173 	/* Get the "current" route for this destination and
1174 	 * check if the redirect has come from approriate router.
1175 	 *
1176 	 * RFC 4861 specifies that redirects should only be
1177 	 * accepted if they come from the nexthop to the target.
1178 	 * Due to the way the routes are chosen, this notion
1179 	 * is a bit fuzzy and one might need to check all possible
1180 	 * routes.
1181 	 */
1182 
1183 	read_lock_bh(&table->tb6_lock);
1184 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1185 restart:
1186 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1187 		if (rt6_check_expired(rt))
1188 			continue;
1189 		if (rt->dst.error)
1190 			break;
1191 		if (!(rt->rt6i_flags & RTF_GATEWAY))
1192 			continue;
1193 		if (fl6->flowi6_oif != rt->dst.dev->ifindex)
1194 			continue;
1195 		if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1196 			continue;
1197 		break;
1198 	}
1199 
1200 	if (!rt)
1201 		rt = net->ipv6.ip6_null_entry;
1202 	else if (rt->dst.error) {
1203 		rt = net->ipv6.ip6_null_entry;
1204 		goto out;
1205 	}
1206 	BACKTRACK(net, &fl6->saddr);
1207 out:
1208 	dst_hold(&rt->dst);
1209 
1210 	read_unlock_bh(&table->tb6_lock);
1211 
1212 	return rt;
1213 };
1214 
1215 static struct dst_entry *ip6_route_redirect(struct net *net,
1216 					const struct flowi6 *fl6,
1217 					const struct in6_addr *gateway)
1218 {
1219 	int flags = RT6_LOOKUP_F_HAS_SADDR;
1220 	struct ip6rd_flowi rdfl;
1221 
1222 	rdfl.fl6 = *fl6;
1223 	rdfl.gateway = *gateway;
1224 
1225 	return fib6_rule_lookup(net, &rdfl.fl6,
1226 				flags, __ip6_route_redirect);
1227 }
1228 
1229 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark)
1230 {
1231 	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
1232 	struct dst_entry *dst;
1233 	struct flowi6 fl6;
1234 
1235 	memset(&fl6, 0, sizeof(fl6));
1236 	fl6.flowi6_oif = oif;
1237 	fl6.flowi6_mark = mark;
1238 	fl6.daddr = iph->daddr;
1239 	fl6.saddr = iph->saddr;
1240 	fl6.flowlabel = ip6_flowinfo(iph);
1241 
1242 	dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr);
1243 	rt6_do_redirect(dst, NULL, skb);
1244 	dst_release(dst);
1245 }
1246 EXPORT_SYMBOL_GPL(ip6_redirect);
1247 
1248 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif,
1249 			    u32 mark)
1250 {
1251 	const struct ipv6hdr *iph = ipv6_hdr(skb);
1252 	const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
1253 	struct dst_entry *dst;
1254 	struct flowi6 fl6;
1255 
1256 	memset(&fl6, 0, sizeof(fl6));
1257 	fl6.flowi6_oif = oif;
1258 	fl6.flowi6_mark = mark;
1259 	fl6.daddr = msg->dest;
1260 	fl6.saddr = iph->daddr;
1261 
1262 	dst = ip6_route_redirect(net, &fl6, &iph->saddr);
1263 	rt6_do_redirect(dst, NULL, skb);
1264 	dst_release(dst);
1265 }
1266 
1267 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
1268 {
1269 	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark);
1270 }
1271 EXPORT_SYMBOL_GPL(ip6_sk_redirect);
1272 
1273 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
1274 {
1275 	struct net_device *dev = dst->dev;
1276 	unsigned int mtu = dst_mtu(dst);
1277 	struct net *net = dev_net(dev);
1278 
1279 	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
1280 
1281 	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
1282 		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
1283 
1284 	/*
1285 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
1286 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
1287 	 * IPV6_MAXPLEN is also valid and means: "any MSS,
1288 	 * rely only on pmtu discovery"
1289 	 */
1290 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
1291 		mtu = IPV6_MAXPLEN;
1292 	return mtu;
1293 }
1294 
1295 static unsigned int ip6_mtu(const struct dst_entry *dst)
1296 {
1297 	struct inet6_dev *idev;
1298 	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1299 
1300 	if (mtu)
1301 		return mtu;
1302 
1303 	mtu = IPV6_MIN_MTU;
1304 
1305 	rcu_read_lock();
1306 	idev = __in6_dev_get(dst->dev);
1307 	if (idev)
1308 		mtu = idev->cnf.mtu6;
1309 	rcu_read_unlock();
1310 
1311 	return mtu;
1312 }
1313 
1314 static struct dst_entry *icmp6_dst_gc_list;
1315 static DEFINE_SPINLOCK(icmp6_dst_lock);
1316 
1317 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
1318 				  struct flowi6 *fl6)
1319 {
1320 	struct dst_entry *dst;
1321 	struct rt6_info *rt;
1322 	struct inet6_dev *idev = in6_dev_get(dev);
1323 	struct net *net = dev_net(dev);
1324 
1325 	if (unlikely(!idev))
1326 		return ERR_PTR(-ENODEV);
1327 
1328 	rt = ip6_dst_alloc(net, dev, 0, NULL);
1329 	if (unlikely(!rt)) {
1330 		in6_dev_put(idev);
1331 		dst = ERR_PTR(-ENOMEM);
1332 		goto out;
1333 	}
1334 
1335 	rt->dst.flags |= DST_HOST;
1336 	rt->dst.output  = ip6_output;
1337 	atomic_set(&rt->dst.__refcnt, 1);
1338 	rt->rt6i_dst.addr = fl6->daddr;
1339 	rt->rt6i_dst.plen = 128;
1340 	rt->rt6i_idev     = idev;
1341 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
1342 
1343 	spin_lock_bh(&icmp6_dst_lock);
1344 	rt->dst.next = icmp6_dst_gc_list;
1345 	icmp6_dst_gc_list = &rt->dst;
1346 	spin_unlock_bh(&icmp6_dst_lock);
1347 
1348 	fib6_force_start_gc(net);
1349 
1350 	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
1351 
1352 out:
1353 	return dst;
1354 }
1355 
1356 int icmp6_dst_gc(void)
1357 {
1358 	struct dst_entry *dst, **pprev;
1359 	int more = 0;
1360 
1361 	spin_lock_bh(&icmp6_dst_lock);
1362 	pprev = &icmp6_dst_gc_list;
1363 
1364 	while ((dst = *pprev) != NULL) {
1365 		if (!atomic_read(&dst->__refcnt)) {
1366 			*pprev = dst->next;
1367 			dst_free(dst);
1368 		} else {
1369 			pprev = &dst->next;
1370 			++more;
1371 		}
1372 	}
1373 
1374 	spin_unlock_bh(&icmp6_dst_lock);
1375 
1376 	return more;
1377 }
1378 
1379 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg),
1380 			    void *arg)
1381 {
1382 	struct dst_entry *dst, **pprev;
1383 
1384 	spin_lock_bh(&icmp6_dst_lock);
1385 	pprev = &icmp6_dst_gc_list;
1386 	while ((dst = *pprev) != NULL) {
1387 		struct rt6_info *rt = (struct rt6_info *) dst;
1388 		if (func(rt, arg)) {
1389 			*pprev = dst->next;
1390 			dst_free(dst);
1391 		} else {
1392 			pprev = &dst->next;
1393 		}
1394 	}
1395 	spin_unlock_bh(&icmp6_dst_lock);
1396 }
1397 
1398 static int ip6_dst_gc(struct dst_ops *ops)
1399 {
1400 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
1401 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
1402 	int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
1403 	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
1404 	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
1405 	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
1406 	int entries;
1407 
1408 	entries = dst_entries_get_fast(ops);
1409 	if (time_after(rt_last_gc + rt_min_interval, jiffies) &&
1410 	    entries <= rt_max_size)
1411 		goto out;
1412 
1413 	net->ipv6.ip6_rt_gc_expire++;
1414 	fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, entries > rt_max_size);
1415 	entries = dst_entries_get_slow(ops);
1416 	if (entries < ops->gc_thresh)
1417 		net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
1418 out:
1419 	net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
1420 	return entries > rt_max_size;
1421 }
1422 
1423 /*
1424  *
1425  */
1426 
1427 int ip6_route_add(struct fib6_config *cfg)
1428 {
1429 	int err;
1430 	struct net *net = cfg->fc_nlinfo.nl_net;
1431 	struct rt6_info *rt = NULL;
1432 	struct net_device *dev = NULL;
1433 	struct inet6_dev *idev = NULL;
1434 	struct fib6_table *table;
1435 	int addr_type;
1436 
1437 	if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1438 		return -EINVAL;
1439 #ifndef CONFIG_IPV6_SUBTREES
1440 	if (cfg->fc_src_len)
1441 		return -EINVAL;
1442 #endif
1443 	if (cfg->fc_ifindex) {
1444 		err = -ENODEV;
1445 		dev = dev_get_by_index(net, cfg->fc_ifindex);
1446 		if (!dev)
1447 			goto out;
1448 		idev = in6_dev_get(dev);
1449 		if (!idev)
1450 			goto out;
1451 	}
1452 
1453 	if (cfg->fc_metric == 0)
1454 		cfg->fc_metric = IP6_RT_PRIO_USER;
1455 
1456 	err = -ENOBUFS;
1457 	if (cfg->fc_nlinfo.nlh &&
1458 	    !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
1459 		table = fib6_get_table(net, cfg->fc_table);
1460 		if (!table) {
1461 			pr_warn("NLM_F_CREATE should be specified when creating new route\n");
1462 			table = fib6_new_table(net, cfg->fc_table);
1463 		}
1464 	} else {
1465 		table = fib6_new_table(net, cfg->fc_table);
1466 	}
1467 
1468 	if (!table)
1469 		goto out;
1470 
1471 	rt = ip6_dst_alloc(net, NULL, DST_NOCOUNT, table);
1472 
1473 	if (!rt) {
1474 		err = -ENOMEM;
1475 		goto out;
1476 	}
1477 
1478 	if (cfg->fc_flags & RTF_EXPIRES)
1479 		rt6_set_expires(rt, jiffies +
1480 				clock_t_to_jiffies(cfg->fc_expires));
1481 	else
1482 		rt6_clean_expires(rt);
1483 
1484 	if (cfg->fc_protocol == RTPROT_UNSPEC)
1485 		cfg->fc_protocol = RTPROT_BOOT;
1486 	rt->rt6i_protocol = cfg->fc_protocol;
1487 
1488 	addr_type = ipv6_addr_type(&cfg->fc_dst);
1489 
1490 	if (addr_type & IPV6_ADDR_MULTICAST)
1491 		rt->dst.input = ip6_mc_input;
1492 	else if (cfg->fc_flags & RTF_LOCAL)
1493 		rt->dst.input = ip6_input;
1494 	else
1495 		rt->dst.input = ip6_forward;
1496 
1497 	rt->dst.output = ip6_output;
1498 
1499 	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1500 	rt->rt6i_dst.plen = cfg->fc_dst_len;
1501 	if (rt->rt6i_dst.plen == 128)
1502 	       rt->dst.flags |= DST_HOST;
1503 
1504 	if (!(rt->dst.flags & DST_HOST) && cfg->fc_mx) {
1505 		u32 *metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL);
1506 		if (!metrics) {
1507 			err = -ENOMEM;
1508 			goto out;
1509 		}
1510 		dst_init_metrics(&rt->dst, metrics, 0);
1511 	}
1512 #ifdef CONFIG_IPV6_SUBTREES
1513 	ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1514 	rt->rt6i_src.plen = cfg->fc_src_len;
1515 #endif
1516 
1517 	rt->rt6i_metric = cfg->fc_metric;
1518 
1519 	/* We cannot add true routes via loopback here,
1520 	   they would result in kernel looping; promote them to reject routes
1521 	 */
1522 	if ((cfg->fc_flags & RTF_REJECT) ||
1523 	    (dev && (dev->flags & IFF_LOOPBACK) &&
1524 	     !(addr_type & IPV6_ADDR_LOOPBACK) &&
1525 	     !(cfg->fc_flags & RTF_LOCAL))) {
1526 		/* hold loopback dev/idev if we haven't done so. */
1527 		if (dev != net->loopback_dev) {
1528 			if (dev) {
1529 				dev_put(dev);
1530 				in6_dev_put(idev);
1531 			}
1532 			dev = net->loopback_dev;
1533 			dev_hold(dev);
1534 			idev = in6_dev_get(dev);
1535 			if (!idev) {
1536 				err = -ENODEV;
1537 				goto out;
1538 			}
1539 		}
1540 		rt->dst.output = ip6_pkt_discard_out;
1541 		rt->dst.input = ip6_pkt_discard;
1542 		rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1543 		switch (cfg->fc_type) {
1544 		case RTN_BLACKHOLE:
1545 			rt->dst.error = -EINVAL;
1546 			break;
1547 		case RTN_PROHIBIT:
1548 			rt->dst.error = -EACCES;
1549 			break;
1550 		case RTN_THROW:
1551 			rt->dst.error = -EAGAIN;
1552 			break;
1553 		default:
1554 			rt->dst.error = -ENETUNREACH;
1555 			break;
1556 		}
1557 		goto install_route;
1558 	}
1559 
1560 	if (cfg->fc_flags & RTF_GATEWAY) {
1561 		const struct in6_addr *gw_addr;
1562 		int gwa_type;
1563 
1564 		gw_addr = &cfg->fc_gateway;
1565 		rt->rt6i_gateway = *gw_addr;
1566 		gwa_type = ipv6_addr_type(gw_addr);
1567 
1568 		if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1569 			struct rt6_info *grt;
1570 
1571 			/* IPv6 strictly inhibits using not link-local
1572 			   addresses as nexthop address.
1573 			   Otherwise, router will not able to send redirects.
1574 			   It is very good, but in some (rare!) circumstances
1575 			   (SIT, PtP, NBMA NOARP links) it is handy to allow
1576 			   some exceptions. --ANK
1577 			 */
1578 			err = -EINVAL;
1579 			if (!(gwa_type & IPV6_ADDR_UNICAST))
1580 				goto out;
1581 
1582 			grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
1583 
1584 			err = -EHOSTUNREACH;
1585 			if (!grt)
1586 				goto out;
1587 			if (dev) {
1588 				if (dev != grt->dst.dev) {
1589 					ip6_rt_put(grt);
1590 					goto out;
1591 				}
1592 			} else {
1593 				dev = grt->dst.dev;
1594 				idev = grt->rt6i_idev;
1595 				dev_hold(dev);
1596 				in6_dev_hold(grt->rt6i_idev);
1597 			}
1598 			if (!(grt->rt6i_flags & RTF_GATEWAY))
1599 				err = 0;
1600 			ip6_rt_put(grt);
1601 
1602 			if (err)
1603 				goto out;
1604 		}
1605 		err = -EINVAL;
1606 		if (!dev || (dev->flags & IFF_LOOPBACK))
1607 			goto out;
1608 	}
1609 
1610 	err = -ENODEV;
1611 	if (!dev)
1612 		goto out;
1613 
1614 	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
1615 		if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
1616 			err = -EINVAL;
1617 			goto out;
1618 		}
1619 		rt->rt6i_prefsrc.addr = cfg->fc_prefsrc;
1620 		rt->rt6i_prefsrc.plen = 128;
1621 	} else
1622 		rt->rt6i_prefsrc.plen = 0;
1623 
1624 	rt->rt6i_flags = cfg->fc_flags;
1625 
1626 install_route:
1627 	if (cfg->fc_mx) {
1628 		struct nlattr *nla;
1629 		int remaining;
1630 
1631 		nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
1632 			int type = nla_type(nla);
1633 
1634 			if (type) {
1635 				if (type > RTAX_MAX) {
1636 					err = -EINVAL;
1637 					goto out;
1638 				}
1639 
1640 				dst_metric_set(&rt->dst, type, nla_get_u32(nla));
1641 			}
1642 		}
1643 	}
1644 
1645 	rt->dst.dev = dev;
1646 	rt->rt6i_idev = idev;
1647 	rt->rt6i_table = table;
1648 
1649 	cfg->fc_nlinfo.nl_net = dev_net(dev);
1650 
1651 	return __ip6_ins_rt(rt, &cfg->fc_nlinfo);
1652 
1653 out:
1654 	if (dev)
1655 		dev_put(dev);
1656 	if (idev)
1657 		in6_dev_put(idev);
1658 	if (rt)
1659 		dst_free(&rt->dst);
1660 	return err;
1661 }
1662 
1663 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
1664 {
1665 	int err;
1666 	struct fib6_table *table;
1667 	struct net *net = dev_net(rt->dst.dev);
1668 
1669 	if (rt == net->ipv6.ip6_null_entry) {
1670 		err = -ENOENT;
1671 		goto out;
1672 	}
1673 
1674 	table = rt->rt6i_table;
1675 	write_lock_bh(&table->tb6_lock);
1676 	err = fib6_del(rt, info);
1677 	write_unlock_bh(&table->tb6_lock);
1678 
1679 out:
1680 	ip6_rt_put(rt);
1681 	return err;
1682 }
1683 
1684 int ip6_del_rt(struct rt6_info *rt)
1685 {
1686 	struct nl_info info = {
1687 		.nl_net = dev_net(rt->dst.dev),
1688 	};
1689 	return __ip6_del_rt(rt, &info);
1690 }
1691 
1692 static int ip6_route_del(struct fib6_config *cfg)
1693 {
1694 	struct fib6_table *table;
1695 	struct fib6_node *fn;
1696 	struct rt6_info *rt;
1697 	int err = -ESRCH;
1698 
1699 	table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
1700 	if (!table)
1701 		return err;
1702 
1703 	read_lock_bh(&table->tb6_lock);
1704 
1705 	fn = fib6_locate(&table->tb6_root,
1706 			 &cfg->fc_dst, cfg->fc_dst_len,
1707 			 &cfg->fc_src, cfg->fc_src_len);
1708 
1709 	if (fn) {
1710 		for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1711 			if (cfg->fc_ifindex &&
1712 			    (!rt->dst.dev ||
1713 			     rt->dst.dev->ifindex != cfg->fc_ifindex))
1714 				continue;
1715 			if (cfg->fc_flags & RTF_GATEWAY &&
1716 			    !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
1717 				continue;
1718 			if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
1719 				continue;
1720 			dst_hold(&rt->dst);
1721 			read_unlock_bh(&table->tb6_lock);
1722 
1723 			return __ip6_del_rt(rt, &cfg->fc_nlinfo);
1724 		}
1725 	}
1726 	read_unlock_bh(&table->tb6_lock);
1727 
1728 	return err;
1729 }
1730 
1731 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
1732 {
1733 	struct net *net = dev_net(skb->dev);
1734 	struct netevent_redirect netevent;
1735 	struct rt6_info *rt, *nrt = NULL;
1736 	struct ndisc_options ndopts;
1737 	struct inet6_dev *in6_dev;
1738 	struct neighbour *neigh;
1739 	struct rd_msg *msg;
1740 	int optlen, on_link;
1741 	u8 *lladdr;
1742 
1743 	optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
1744 	optlen -= sizeof(*msg);
1745 
1746 	if (optlen < 0) {
1747 		net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
1748 		return;
1749 	}
1750 
1751 	msg = (struct rd_msg *)icmp6_hdr(skb);
1752 
1753 	if (ipv6_addr_is_multicast(&msg->dest)) {
1754 		net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
1755 		return;
1756 	}
1757 
1758 	on_link = 0;
1759 	if (ipv6_addr_equal(&msg->dest, &msg->target)) {
1760 		on_link = 1;
1761 	} else if (ipv6_addr_type(&msg->target) !=
1762 		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
1763 		net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
1764 		return;
1765 	}
1766 
1767 	in6_dev = __in6_dev_get(skb->dev);
1768 	if (!in6_dev)
1769 		return;
1770 	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
1771 		return;
1772 
1773 	/* RFC2461 8.1:
1774 	 *	The IP source address of the Redirect MUST be the same as the current
1775 	 *	first-hop router for the specified ICMP Destination Address.
1776 	 */
1777 
1778 	if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) {
1779 		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
1780 		return;
1781 	}
1782 
1783 	lladdr = NULL;
1784 	if (ndopts.nd_opts_tgt_lladdr) {
1785 		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
1786 					     skb->dev);
1787 		if (!lladdr) {
1788 			net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
1789 			return;
1790 		}
1791 	}
1792 
1793 	rt = (struct rt6_info *) dst;
1794 	if (rt == net->ipv6.ip6_null_entry) {
1795 		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
1796 		return;
1797 	}
1798 
1799 	/* Redirect received -> path was valid.
1800 	 * Look, redirects are sent only in response to data packets,
1801 	 * so that this nexthop apparently is reachable. --ANK
1802 	 */
1803 	dst_confirm(&rt->dst);
1804 
1805 	neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
1806 	if (!neigh)
1807 		return;
1808 
1809 	/*
1810 	 *	We have finally decided to accept it.
1811 	 */
1812 
1813 	neigh_update(neigh, lladdr, NUD_STALE,
1814 		     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1815 		     NEIGH_UPDATE_F_OVERRIDE|
1816 		     (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1817 				     NEIGH_UPDATE_F_ISROUTER))
1818 		     );
1819 
1820 	nrt = ip6_rt_copy(rt, &msg->dest);
1821 	if (!nrt)
1822 		goto out;
1823 
1824 	nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1825 	if (on_link)
1826 		nrt->rt6i_flags &= ~RTF_GATEWAY;
1827 
1828 	nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
1829 
1830 	if (ip6_ins_rt(nrt))
1831 		goto out;
1832 
1833 	netevent.old = &rt->dst;
1834 	netevent.new = &nrt->dst;
1835 	netevent.daddr = &msg->dest;
1836 	netevent.neigh = neigh;
1837 	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1838 
1839 	if (rt->rt6i_flags & RTF_CACHE) {
1840 		rt = (struct rt6_info *) dst_clone(&rt->dst);
1841 		ip6_del_rt(rt);
1842 	}
1843 
1844 out:
1845 	neigh_release(neigh);
1846 }
1847 
1848 /*
1849  *	Misc support functions
1850  */
1851 
1852 static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
1853 				    const struct in6_addr *dest)
1854 {
1855 	struct net *net = dev_net(ort->dst.dev);
1856 	struct rt6_info *rt = ip6_dst_alloc(net, ort->dst.dev, 0,
1857 					    ort->rt6i_table);
1858 
1859 	if (rt) {
1860 		rt->dst.input = ort->dst.input;
1861 		rt->dst.output = ort->dst.output;
1862 		rt->dst.flags |= DST_HOST;
1863 
1864 		rt->rt6i_dst.addr = *dest;
1865 		rt->rt6i_dst.plen = 128;
1866 		dst_copy_metrics(&rt->dst, &ort->dst);
1867 		rt->dst.error = ort->dst.error;
1868 		rt->rt6i_idev = ort->rt6i_idev;
1869 		if (rt->rt6i_idev)
1870 			in6_dev_hold(rt->rt6i_idev);
1871 		rt->dst.lastuse = jiffies;
1872 
1873 		rt->rt6i_gateway = ort->rt6i_gateway;
1874 		rt->rt6i_flags = ort->rt6i_flags;
1875 		if ((ort->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ==
1876 		    (RTF_DEFAULT | RTF_ADDRCONF))
1877 			rt6_set_from(rt, ort);
1878 		rt->rt6i_metric = 0;
1879 
1880 #ifdef CONFIG_IPV6_SUBTREES
1881 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1882 #endif
1883 		memcpy(&rt->rt6i_prefsrc, &ort->rt6i_prefsrc, sizeof(struct rt6key));
1884 		rt->rt6i_table = ort->rt6i_table;
1885 	}
1886 	return rt;
1887 }
1888 
1889 #ifdef CONFIG_IPV6_ROUTE_INFO
1890 static struct rt6_info *rt6_get_route_info(struct net *net,
1891 					   const struct in6_addr *prefix, int prefixlen,
1892 					   const struct in6_addr *gwaddr, int ifindex)
1893 {
1894 	struct fib6_node *fn;
1895 	struct rt6_info *rt = NULL;
1896 	struct fib6_table *table;
1897 
1898 	table = fib6_get_table(net, RT6_TABLE_INFO);
1899 	if (!table)
1900 		return NULL;
1901 
1902 	read_lock_bh(&table->tb6_lock);
1903 	fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0);
1904 	if (!fn)
1905 		goto out;
1906 
1907 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1908 		if (rt->dst.dev->ifindex != ifindex)
1909 			continue;
1910 		if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1911 			continue;
1912 		if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1913 			continue;
1914 		dst_hold(&rt->dst);
1915 		break;
1916 	}
1917 out:
1918 	read_unlock_bh(&table->tb6_lock);
1919 	return rt;
1920 }
1921 
1922 static struct rt6_info *rt6_add_route_info(struct net *net,
1923 					   const struct in6_addr *prefix, int prefixlen,
1924 					   const struct in6_addr *gwaddr, int ifindex,
1925 					   unsigned int pref)
1926 {
1927 	struct fib6_config cfg = {
1928 		.fc_table	= RT6_TABLE_INFO,
1929 		.fc_metric	= IP6_RT_PRIO_USER,
1930 		.fc_ifindex	= ifindex,
1931 		.fc_dst_len	= prefixlen,
1932 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
1933 				  RTF_UP | RTF_PREF(pref),
1934 		.fc_nlinfo.portid = 0,
1935 		.fc_nlinfo.nlh = NULL,
1936 		.fc_nlinfo.nl_net = net,
1937 	};
1938 
1939 	cfg.fc_dst = *prefix;
1940 	cfg.fc_gateway = *gwaddr;
1941 
1942 	/* We should treat it as a default route if prefix length is 0. */
1943 	if (!prefixlen)
1944 		cfg.fc_flags |= RTF_DEFAULT;
1945 
1946 	ip6_route_add(&cfg);
1947 
1948 	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex);
1949 }
1950 #endif
1951 
1952 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev)
1953 {
1954 	struct rt6_info *rt;
1955 	struct fib6_table *table;
1956 
1957 	table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT);
1958 	if (!table)
1959 		return NULL;
1960 
1961 	read_lock_bh(&table->tb6_lock);
1962 	for (rt = table->tb6_root.leaf; rt; rt=rt->dst.rt6_next) {
1963 		if (dev == rt->dst.dev &&
1964 		    ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1965 		    ipv6_addr_equal(&rt->rt6i_gateway, addr))
1966 			break;
1967 	}
1968 	if (rt)
1969 		dst_hold(&rt->dst);
1970 	read_unlock_bh(&table->tb6_lock);
1971 	return rt;
1972 }
1973 
1974 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr,
1975 				     struct net_device *dev,
1976 				     unsigned int pref)
1977 {
1978 	struct fib6_config cfg = {
1979 		.fc_table	= RT6_TABLE_DFLT,
1980 		.fc_metric	= IP6_RT_PRIO_USER,
1981 		.fc_ifindex	= dev->ifindex,
1982 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
1983 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
1984 		.fc_nlinfo.portid = 0,
1985 		.fc_nlinfo.nlh = NULL,
1986 		.fc_nlinfo.nl_net = dev_net(dev),
1987 	};
1988 
1989 	cfg.fc_gateway = *gwaddr;
1990 
1991 	ip6_route_add(&cfg);
1992 
1993 	return rt6_get_dflt_router(gwaddr, dev);
1994 }
1995 
1996 void rt6_purge_dflt_routers(struct net *net)
1997 {
1998 	struct rt6_info *rt;
1999 	struct fib6_table *table;
2000 
2001 	/* NOTE: Keep consistent with rt6_get_dflt_router */
2002 	table = fib6_get_table(net, RT6_TABLE_DFLT);
2003 	if (!table)
2004 		return;
2005 
2006 restart:
2007 	read_lock_bh(&table->tb6_lock);
2008 	for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
2009 		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
2010 		    (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) {
2011 			dst_hold(&rt->dst);
2012 			read_unlock_bh(&table->tb6_lock);
2013 			ip6_del_rt(rt);
2014 			goto restart;
2015 		}
2016 	}
2017 	read_unlock_bh(&table->tb6_lock);
2018 }
2019 
2020 static void rtmsg_to_fib6_config(struct net *net,
2021 				 struct in6_rtmsg *rtmsg,
2022 				 struct fib6_config *cfg)
2023 {
2024 	memset(cfg, 0, sizeof(*cfg));
2025 
2026 	cfg->fc_table = RT6_TABLE_MAIN;
2027 	cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
2028 	cfg->fc_metric = rtmsg->rtmsg_metric;
2029 	cfg->fc_expires = rtmsg->rtmsg_info;
2030 	cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
2031 	cfg->fc_src_len = rtmsg->rtmsg_src_len;
2032 	cfg->fc_flags = rtmsg->rtmsg_flags;
2033 
2034 	cfg->fc_nlinfo.nl_net = net;
2035 
2036 	cfg->fc_dst = rtmsg->rtmsg_dst;
2037 	cfg->fc_src = rtmsg->rtmsg_src;
2038 	cfg->fc_gateway = rtmsg->rtmsg_gateway;
2039 }
2040 
2041 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
2042 {
2043 	struct fib6_config cfg;
2044 	struct in6_rtmsg rtmsg;
2045 	int err;
2046 
2047 	switch(cmd) {
2048 	case SIOCADDRT:		/* Add a route */
2049 	case SIOCDELRT:		/* Delete a route */
2050 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
2051 			return -EPERM;
2052 		err = copy_from_user(&rtmsg, arg,
2053 				     sizeof(struct in6_rtmsg));
2054 		if (err)
2055 			return -EFAULT;
2056 
2057 		rtmsg_to_fib6_config(net, &rtmsg, &cfg);
2058 
2059 		rtnl_lock();
2060 		switch (cmd) {
2061 		case SIOCADDRT:
2062 			err = ip6_route_add(&cfg);
2063 			break;
2064 		case SIOCDELRT:
2065 			err = ip6_route_del(&cfg);
2066 			break;
2067 		default:
2068 			err = -EINVAL;
2069 		}
2070 		rtnl_unlock();
2071 
2072 		return err;
2073 	}
2074 
2075 	return -EINVAL;
2076 }
2077 
2078 /*
2079  *	Drop the packet on the floor
2080  */
2081 
2082 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
2083 {
2084 	int type;
2085 	struct dst_entry *dst = skb_dst(skb);
2086 	switch (ipstats_mib_noroutes) {
2087 	case IPSTATS_MIB_INNOROUTES:
2088 		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
2089 		if (type == IPV6_ADDR_ANY) {
2090 			IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2091 				      IPSTATS_MIB_INADDRERRORS);
2092 			break;
2093 		}
2094 		/* FALLTHROUGH */
2095 	case IPSTATS_MIB_OUTNOROUTES:
2096 		IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
2097 			      ipstats_mib_noroutes);
2098 		break;
2099 	}
2100 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
2101 	kfree_skb(skb);
2102 	return 0;
2103 }
2104 
2105 static int ip6_pkt_discard(struct sk_buff *skb)
2106 {
2107 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
2108 }
2109 
2110 static int ip6_pkt_discard_out(struct sk_buff *skb)
2111 {
2112 	skb->dev = skb_dst(skb)->dev;
2113 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
2114 }
2115 
2116 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2117 
2118 static int ip6_pkt_prohibit(struct sk_buff *skb)
2119 {
2120 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
2121 }
2122 
2123 static int ip6_pkt_prohibit_out(struct sk_buff *skb)
2124 {
2125 	skb->dev = skb_dst(skb)->dev;
2126 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
2127 }
2128 
2129 #endif
2130 
2131 /*
2132  *	Allocate a dst for local (unicast / anycast) address.
2133  */
2134 
2135 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
2136 				    const struct in6_addr *addr,
2137 				    bool anycast)
2138 {
2139 	struct net *net = dev_net(idev->dev);
2140 	struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev, 0, NULL);
2141 
2142 	if (!rt) {
2143 		net_warn_ratelimited("Maximum number of routes reached, consider increasing route/max_size\n");
2144 		return ERR_PTR(-ENOMEM);
2145 	}
2146 
2147 	in6_dev_hold(idev);
2148 
2149 	rt->dst.flags |= DST_HOST;
2150 	rt->dst.input = ip6_input;
2151 	rt->dst.output = ip6_output;
2152 	rt->rt6i_idev = idev;
2153 
2154 	rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
2155 	if (anycast)
2156 		rt->rt6i_flags |= RTF_ANYCAST;
2157 	else
2158 		rt->rt6i_flags |= RTF_LOCAL;
2159 
2160 	rt->rt6i_dst.addr = *addr;
2161 	rt->rt6i_dst.plen = 128;
2162 	rt->rt6i_table = fib6_get_table(net, RT6_TABLE_LOCAL);
2163 
2164 	atomic_set(&rt->dst.__refcnt, 1);
2165 
2166 	return rt;
2167 }
2168 
2169 int ip6_route_get_saddr(struct net *net,
2170 			struct rt6_info *rt,
2171 			const struct in6_addr *daddr,
2172 			unsigned int prefs,
2173 			struct in6_addr *saddr)
2174 {
2175 	struct inet6_dev *idev = ip6_dst_idev((struct dst_entry*)rt);
2176 	int err = 0;
2177 	if (rt->rt6i_prefsrc.plen)
2178 		*saddr = rt->rt6i_prefsrc.addr;
2179 	else
2180 		err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
2181 					 daddr, prefs, saddr);
2182 	return err;
2183 }
2184 
2185 /* remove deleted ip from prefsrc entries */
2186 struct arg_dev_net_ip {
2187 	struct net_device *dev;
2188 	struct net *net;
2189 	struct in6_addr *addr;
2190 };
2191 
2192 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg)
2193 {
2194 	struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
2195 	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
2196 	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
2197 
2198 	if (((void *)rt->dst.dev == dev || !dev) &&
2199 	    rt != net->ipv6.ip6_null_entry &&
2200 	    ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) {
2201 		/* remove prefsrc entry */
2202 		rt->rt6i_prefsrc.plen = 0;
2203 	}
2204 	return 0;
2205 }
2206 
2207 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
2208 {
2209 	struct net *net = dev_net(ifp->idev->dev);
2210 	struct arg_dev_net_ip adni = {
2211 		.dev = ifp->idev->dev,
2212 		.net = net,
2213 		.addr = &ifp->addr,
2214 	};
2215 	fib6_clean_all(net, fib6_remove_prefsrc, 0, &adni);
2216 }
2217 
2218 struct arg_dev_net {
2219 	struct net_device *dev;
2220 	struct net *net;
2221 };
2222 
2223 static int fib6_ifdown(struct rt6_info *rt, void *arg)
2224 {
2225 	const struct arg_dev_net *adn = arg;
2226 	const struct net_device *dev = adn->dev;
2227 
2228 	if ((rt->dst.dev == dev || !dev) &&
2229 	    rt != adn->net->ipv6.ip6_null_entry)
2230 		return -1;
2231 
2232 	return 0;
2233 }
2234 
2235 void rt6_ifdown(struct net *net, struct net_device *dev)
2236 {
2237 	struct arg_dev_net adn = {
2238 		.dev = dev,
2239 		.net = net,
2240 	};
2241 
2242 	fib6_clean_all(net, fib6_ifdown, 0, &adn);
2243 	icmp6_clean_all(fib6_ifdown, &adn);
2244 }
2245 
2246 struct rt6_mtu_change_arg {
2247 	struct net_device *dev;
2248 	unsigned int mtu;
2249 };
2250 
2251 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
2252 {
2253 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
2254 	struct inet6_dev *idev;
2255 
2256 	/* In IPv6 pmtu discovery is not optional,
2257 	   so that RTAX_MTU lock cannot disable it.
2258 	   We still use this lock to block changes
2259 	   caused by addrconf/ndisc.
2260 	*/
2261 
2262 	idev = __in6_dev_get(arg->dev);
2263 	if (!idev)
2264 		return 0;
2265 
2266 	/* For administrative MTU increase, there is no way to discover
2267 	   IPv6 PMTU increase, so PMTU increase should be updated here.
2268 	   Since RFC 1981 doesn't include administrative MTU increase
2269 	   update PMTU increase is a MUST. (i.e. jumbo frame)
2270 	 */
2271 	/*
2272 	   If new MTU is less than route PMTU, this new MTU will be the
2273 	   lowest MTU in the path, update the route PMTU to reflect PMTU
2274 	   decreases; if new MTU is greater than route PMTU, and the
2275 	   old MTU is the lowest MTU in the path, update the route PMTU
2276 	   to reflect the increase. In this case if the other nodes' MTU
2277 	   also have the lowest MTU, TOO BIG MESSAGE will be lead to
2278 	   PMTU discouvery.
2279 	 */
2280 	if (rt->dst.dev == arg->dev &&
2281 	    !dst_metric_locked(&rt->dst, RTAX_MTU) &&
2282 	    (dst_mtu(&rt->dst) >= arg->mtu ||
2283 	     (dst_mtu(&rt->dst) < arg->mtu &&
2284 	      dst_mtu(&rt->dst) == idev->cnf.mtu6))) {
2285 		dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
2286 	}
2287 	return 0;
2288 }
2289 
2290 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
2291 {
2292 	struct rt6_mtu_change_arg arg = {
2293 		.dev = dev,
2294 		.mtu = mtu,
2295 	};
2296 
2297 	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, 0, &arg);
2298 }
2299 
2300 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
2301 	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
2302 	[RTA_OIF]               = { .type = NLA_U32 },
2303 	[RTA_IIF]		= { .type = NLA_U32 },
2304 	[RTA_PRIORITY]          = { .type = NLA_U32 },
2305 	[RTA_METRICS]           = { .type = NLA_NESTED },
2306 	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
2307 };
2308 
2309 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
2310 			      struct fib6_config *cfg)
2311 {
2312 	struct rtmsg *rtm;
2313 	struct nlattr *tb[RTA_MAX+1];
2314 	int err;
2315 
2316 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2317 	if (err < 0)
2318 		goto errout;
2319 
2320 	err = -EINVAL;
2321 	rtm = nlmsg_data(nlh);
2322 	memset(cfg, 0, sizeof(*cfg));
2323 
2324 	cfg->fc_table = rtm->rtm_table;
2325 	cfg->fc_dst_len = rtm->rtm_dst_len;
2326 	cfg->fc_src_len = rtm->rtm_src_len;
2327 	cfg->fc_flags = RTF_UP;
2328 	cfg->fc_protocol = rtm->rtm_protocol;
2329 	cfg->fc_type = rtm->rtm_type;
2330 
2331 	if (rtm->rtm_type == RTN_UNREACHABLE ||
2332 	    rtm->rtm_type == RTN_BLACKHOLE ||
2333 	    rtm->rtm_type == RTN_PROHIBIT ||
2334 	    rtm->rtm_type == RTN_THROW)
2335 		cfg->fc_flags |= RTF_REJECT;
2336 
2337 	if (rtm->rtm_type == RTN_LOCAL)
2338 		cfg->fc_flags |= RTF_LOCAL;
2339 
2340 	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;
2341 	cfg->fc_nlinfo.nlh = nlh;
2342 	cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
2343 
2344 	if (tb[RTA_GATEWAY]) {
2345 		nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16);
2346 		cfg->fc_flags |= RTF_GATEWAY;
2347 	}
2348 
2349 	if (tb[RTA_DST]) {
2350 		int plen = (rtm->rtm_dst_len + 7) >> 3;
2351 
2352 		if (nla_len(tb[RTA_DST]) < plen)
2353 			goto errout;
2354 
2355 		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
2356 	}
2357 
2358 	if (tb[RTA_SRC]) {
2359 		int plen = (rtm->rtm_src_len + 7) >> 3;
2360 
2361 		if (nla_len(tb[RTA_SRC]) < plen)
2362 			goto errout;
2363 
2364 		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
2365 	}
2366 
2367 	if (tb[RTA_PREFSRC])
2368 		nla_memcpy(&cfg->fc_prefsrc, tb[RTA_PREFSRC], 16);
2369 
2370 	if (tb[RTA_OIF])
2371 		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
2372 
2373 	if (tb[RTA_PRIORITY])
2374 		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
2375 
2376 	if (tb[RTA_METRICS]) {
2377 		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2378 		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2379 	}
2380 
2381 	if (tb[RTA_TABLE])
2382 		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2383 
2384 	if (tb[RTA_MULTIPATH]) {
2385 		cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
2386 		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
2387 	}
2388 
2389 	err = 0;
2390 errout:
2391 	return err;
2392 }
2393 
2394 static int ip6_route_multipath(struct fib6_config *cfg, int add)
2395 {
2396 	struct fib6_config r_cfg;
2397 	struct rtnexthop *rtnh;
2398 	int remaining;
2399 	int attrlen;
2400 	int err = 0, last_err = 0;
2401 
2402 beginning:
2403 	rtnh = (struct rtnexthop *)cfg->fc_mp;
2404 	remaining = cfg->fc_mp_len;
2405 
2406 	/* Parse a Multipath Entry */
2407 	while (rtnh_ok(rtnh, remaining)) {
2408 		memcpy(&r_cfg, cfg, sizeof(*cfg));
2409 		if (rtnh->rtnh_ifindex)
2410 			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
2411 
2412 		attrlen = rtnh_attrlen(rtnh);
2413 		if (attrlen > 0) {
2414 			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
2415 
2416 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
2417 			if (nla) {
2418 				nla_memcpy(&r_cfg.fc_gateway, nla, 16);
2419 				r_cfg.fc_flags |= RTF_GATEWAY;
2420 			}
2421 		}
2422 		err = add ? ip6_route_add(&r_cfg) : ip6_route_del(&r_cfg);
2423 		if (err) {
2424 			last_err = err;
2425 			/* If we are trying to remove a route, do not stop the
2426 			 * loop when ip6_route_del() fails (because next hop is
2427 			 * already gone), we should try to remove all next hops.
2428 			 */
2429 			if (add) {
2430 				/* If add fails, we should try to delete all
2431 				 * next hops that have been already added.
2432 				 */
2433 				add = 0;
2434 				goto beginning;
2435 			}
2436 		}
2437 		/* Because each route is added like a single route we remove
2438 		 * this flag after the first nexthop (if there is a collision,
2439 		 * we have already fail to add the first nexthop:
2440 		 * fib6_add_rt2node() has reject it).
2441 		 */
2442 		cfg->fc_nlinfo.nlh->nlmsg_flags &= ~NLM_F_EXCL;
2443 		rtnh = rtnh_next(rtnh, &remaining);
2444 	}
2445 
2446 	return last_err;
2447 }
2448 
2449 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh)
2450 {
2451 	struct fib6_config cfg;
2452 	int err;
2453 
2454 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2455 	if (err < 0)
2456 		return err;
2457 
2458 	if (cfg.fc_mp)
2459 		return ip6_route_multipath(&cfg, 0);
2460 	else
2461 		return ip6_route_del(&cfg);
2462 }
2463 
2464 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh)
2465 {
2466 	struct fib6_config cfg;
2467 	int err;
2468 
2469 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2470 	if (err < 0)
2471 		return err;
2472 
2473 	if (cfg.fc_mp)
2474 		return ip6_route_multipath(&cfg, 1);
2475 	else
2476 		return ip6_route_add(&cfg);
2477 }
2478 
2479 static inline size_t rt6_nlmsg_size(void)
2480 {
2481 	return NLMSG_ALIGN(sizeof(struct rtmsg))
2482 	       + nla_total_size(16) /* RTA_SRC */
2483 	       + nla_total_size(16) /* RTA_DST */
2484 	       + nla_total_size(16) /* RTA_GATEWAY */
2485 	       + nla_total_size(16) /* RTA_PREFSRC */
2486 	       + nla_total_size(4) /* RTA_TABLE */
2487 	       + nla_total_size(4) /* RTA_IIF */
2488 	       + nla_total_size(4) /* RTA_OIF */
2489 	       + nla_total_size(4) /* RTA_PRIORITY */
2490 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2491 	       + nla_total_size(sizeof(struct rta_cacheinfo));
2492 }
2493 
2494 static int rt6_fill_node(struct net *net,
2495 			 struct sk_buff *skb, struct rt6_info *rt,
2496 			 struct in6_addr *dst, struct in6_addr *src,
2497 			 int iif, int type, u32 portid, u32 seq,
2498 			 int prefix, int nowait, unsigned int flags)
2499 {
2500 	struct rtmsg *rtm;
2501 	struct nlmsghdr *nlh;
2502 	long expires;
2503 	u32 table;
2504 
2505 	if (prefix) {	/* user wants prefix routes only */
2506 		if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2507 			/* success since this is not a prefix route */
2508 			return 1;
2509 		}
2510 	}
2511 
2512 	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
2513 	if (!nlh)
2514 		return -EMSGSIZE;
2515 
2516 	rtm = nlmsg_data(nlh);
2517 	rtm->rtm_family = AF_INET6;
2518 	rtm->rtm_dst_len = rt->rt6i_dst.plen;
2519 	rtm->rtm_src_len = rt->rt6i_src.plen;
2520 	rtm->rtm_tos = 0;
2521 	if (rt->rt6i_table)
2522 		table = rt->rt6i_table->tb6_id;
2523 	else
2524 		table = RT6_TABLE_UNSPEC;
2525 	rtm->rtm_table = table;
2526 	if (nla_put_u32(skb, RTA_TABLE, table))
2527 		goto nla_put_failure;
2528 	if (rt->rt6i_flags & RTF_REJECT) {
2529 		switch (rt->dst.error) {
2530 		case -EINVAL:
2531 			rtm->rtm_type = RTN_BLACKHOLE;
2532 			break;
2533 		case -EACCES:
2534 			rtm->rtm_type = RTN_PROHIBIT;
2535 			break;
2536 		case -EAGAIN:
2537 			rtm->rtm_type = RTN_THROW;
2538 			break;
2539 		default:
2540 			rtm->rtm_type = RTN_UNREACHABLE;
2541 			break;
2542 		}
2543 	}
2544 	else if (rt->rt6i_flags & RTF_LOCAL)
2545 		rtm->rtm_type = RTN_LOCAL;
2546 	else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK))
2547 		rtm->rtm_type = RTN_LOCAL;
2548 	else
2549 		rtm->rtm_type = RTN_UNICAST;
2550 	rtm->rtm_flags = 0;
2551 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2552 	rtm->rtm_protocol = rt->rt6i_protocol;
2553 	if (rt->rt6i_flags & RTF_DYNAMIC)
2554 		rtm->rtm_protocol = RTPROT_REDIRECT;
2555 	else if (rt->rt6i_flags & RTF_ADDRCONF) {
2556 		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO))
2557 			rtm->rtm_protocol = RTPROT_RA;
2558 		else
2559 			rtm->rtm_protocol = RTPROT_KERNEL;
2560 	}
2561 
2562 	if (rt->rt6i_flags & RTF_CACHE)
2563 		rtm->rtm_flags |= RTM_F_CLONED;
2564 
2565 	if (dst) {
2566 		if (nla_put(skb, RTA_DST, 16, dst))
2567 			goto nla_put_failure;
2568 		rtm->rtm_dst_len = 128;
2569 	} else if (rtm->rtm_dst_len)
2570 		if (nla_put(skb, RTA_DST, 16, &rt->rt6i_dst.addr))
2571 			goto nla_put_failure;
2572 #ifdef CONFIG_IPV6_SUBTREES
2573 	if (src) {
2574 		if (nla_put(skb, RTA_SRC, 16, src))
2575 			goto nla_put_failure;
2576 		rtm->rtm_src_len = 128;
2577 	} else if (rtm->rtm_src_len &&
2578 		   nla_put(skb, RTA_SRC, 16, &rt->rt6i_src.addr))
2579 		goto nla_put_failure;
2580 #endif
2581 	if (iif) {
2582 #ifdef CONFIG_IPV6_MROUTE
2583 		if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) {
2584 			int err = ip6mr_get_route(net, skb, rtm, nowait);
2585 			if (err <= 0) {
2586 				if (!nowait) {
2587 					if (err == 0)
2588 						return 0;
2589 					goto nla_put_failure;
2590 				} else {
2591 					if (err == -EMSGSIZE)
2592 						goto nla_put_failure;
2593 				}
2594 			}
2595 		} else
2596 #endif
2597 			if (nla_put_u32(skb, RTA_IIF, iif))
2598 				goto nla_put_failure;
2599 	} else if (dst) {
2600 		struct in6_addr saddr_buf;
2601 		if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0 &&
2602 		    nla_put(skb, RTA_PREFSRC, 16, &saddr_buf))
2603 			goto nla_put_failure;
2604 	}
2605 
2606 	if (rt->rt6i_prefsrc.plen) {
2607 		struct in6_addr saddr_buf;
2608 		saddr_buf = rt->rt6i_prefsrc.addr;
2609 		if (nla_put(skb, RTA_PREFSRC, 16, &saddr_buf))
2610 			goto nla_put_failure;
2611 	}
2612 
2613 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2614 		goto nla_put_failure;
2615 
2616 	if (rt->rt6i_flags & RTF_GATEWAY) {
2617 		if (nla_put(skb, RTA_GATEWAY, 16, &rt->rt6i_gateway) < 0)
2618 			goto nla_put_failure;
2619 	}
2620 
2621 	if (rt->dst.dev &&
2622 	    nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
2623 		goto nla_put_failure;
2624 	if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))
2625 		goto nla_put_failure;
2626 
2627 	expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;
2628 
2629 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
2630 		goto nla_put_failure;
2631 
2632 	return nlmsg_end(skb, nlh);
2633 
2634 nla_put_failure:
2635 	nlmsg_cancel(skb, nlh);
2636 	return -EMSGSIZE;
2637 }
2638 
2639 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
2640 {
2641 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
2642 	int prefix;
2643 
2644 	if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
2645 		struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
2646 		prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
2647 	} else
2648 		prefix = 0;
2649 
2650 	return rt6_fill_node(arg->net,
2651 		     arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
2652 		     NETLINK_CB(arg->cb->skb).portid, arg->cb->nlh->nlmsg_seq,
2653 		     prefix, 0, NLM_F_MULTI);
2654 }
2655 
2656 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh)
2657 {
2658 	struct net *net = sock_net(in_skb->sk);
2659 	struct nlattr *tb[RTA_MAX+1];
2660 	struct rt6_info *rt;
2661 	struct sk_buff *skb;
2662 	struct rtmsg *rtm;
2663 	struct flowi6 fl6;
2664 	int err, iif = 0, oif = 0;
2665 
2666 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2667 	if (err < 0)
2668 		goto errout;
2669 
2670 	err = -EINVAL;
2671 	memset(&fl6, 0, sizeof(fl6));
2672 
2673 	if (tb[RTA_SRC]) {
2674 		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
2675 			goto errout;
2676 
2677 		fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
2678 	}
2679 
2680 	if (tb[RTA_DST]) {
2681 		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
2682 			goto errout;
2683 
2684 		fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
2685 	}
2686 
2687 	if (tb[RTA_IIF])
2688 		iif = nla_get_u32(tb[RTA_IIF]);
2689 
2690 	if (tb[RTA_OIF])
2691 		oif = nla_get_u32(tb[RTA_OIF]);
2692 
2693 	if (iif) {
2694 		struct net_device *dev;
2695 		int flags = 0;
2696 
2697 		dev = __dev_get_by_index(net, iif);
2698 		if (!dev) {
2699 			err = -ENODEV;
2700 			goto errout;
2701 		}
2702 
2703 		fl6.flowi6_iif = iif;
2704 
2705 		if (!ipv6_addr_any(&fl6.saddr))
2706 			flags |= RT6_LOOKUP_F_HAS_SADDR;
2707 
2708 		rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6,
2709 							       flags);
2710 	} else {
2711 		fl6.flowi6_oif = oif;
2712 
2713 		rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
2714 	}
2715 
2716 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2717 	if (!skb) {
2718 		ip6_rt_put(rt);
2719 		err = -ENOBUFS;
2720 		goto errout;
2721 	}
2722 
2723 	/* Reserve room for dummy headers, this skb can pass
2724 	   through good chunk of routing engine.
2725 	 */
2726 	skb_reset_mac_header(skb);
2727 	skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
2728 
2729 	skb_dst_set(skb, &rt->dst);
2730 
2731 	err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,
2732 			    RTM_NEWROUTE, NETLINK_CB(in_skb).portid,
2733 			    nlh->nlmsg_seq, 0, 0, 0);
2734 	if (err < 0) {
2735 		kfree_skb(skb);
2736 		goto errout;
2737 	}
2738 
2739 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2740 errout:
2741 	return err;
2742 }
2743 
2744 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
2745 {
2746 	struct sk_buff *skb;
2747 	struct net *net = info->nl_net;
2748 	u32 seq;
2749 	int err;
2750 
2751 	err = -ENOBUFS;
2752 	seq = info->nlh ? info->nlh->nlmsg_seq : 0;
2753 
2754 	skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
2755 	if (!skb)
2756 		goto errout;
2757 
2758 	err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
2759 				event, info->portid, seq, 0, 0, 0);
2760 	if (err < 0) {
2761 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
2762 		WARN_ON(err == -EMSGSIZE);
2763 		kfree_skb(skb);
2764 		goto errout;
2765 	}
2766 	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
2767 		    info->nlh, gfp_any());
2768 	return;
2769 errout:
2770 	if (err < 0)
2771 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
2772 }
2773 
2774 static int ip6_route_dev_notify(struct notifier_block *this,
2775 				unsigned long event, void *ptr)
2776 {
2777 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
2778 	struct net *net = dev_net(dev);
2779 
2780 	if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
2781 		net->ipv6.ip6_null_entry->dst.dev = dev;
2782 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
2783 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2784 		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
2785 		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
2786 		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
2787 		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
2788 #endif
2789 	}
2790 
2791 	return NOTIFY_OK;
2792 }
2793 
2794 /*
2795  *	/proc
2796  */
2797 
2798 #ifdef CONFIG_PROC_FS
2799 
2800 static const struct file_operations ipv6_route_proc_fops = {
2801 	.owner		= THIS_MODULE,
2802 	.open		= ipv6_route_open,
2803 	.read		= seq_read,
2804 	.llseek		= seq_lseek,
2805 	.release	= seq_release_net,
2806 };
2807 
2808 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2809 {
2810 	struct net *net = (struct net *)seq->private;
2811 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2812 		   net->ipv6.rt6_stats->fib_nodes,
2813 		   net->ipv6.rt6_stats->fib_route_nodes,
2814 		   net->ipv6.rt6_stats->fib_rt_alloc,
2815 		   net->ipv6.rt6_stats->fib_rt_entries,
2816 		   net->ipv6.rt6_stats->fib_rt_cache,
2817 		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
2818 		   net->ipv6.rt6_stats->fib_discarded_routes);
2819 
2820 	return 0;
2821 }
2822 
2823 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2824 {
2825 	return single_open_net(inode, file, rt6_stats_seq_show);
2826 }
2827 
2828 static const struct file_operations rt6_stats_seq_fops = {
2829 	.owner	 = THIS_MODULE,
2830 	.open	 = rt6_stats_seq_open,
2831 	.read	 = seq_read,
2832 	.llseek	 = seq_lseek,
2833 	.release = single_release_net,
2834 };
2835 #endif	/* CONFIG_PROC_FS */
2836 
2837 #ifdef CONFIG_SYSCTL
2838 
2839 static
2840 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
2841 			      void __user *buffer, size_t *lenp, loff_t *ppos)
2842 {
2843 	struct net *net;
2844 	int delay;
2845 	if (!write)
2846 		return -EINVAL;
2847 
2848 	net = (struct net *)ctl->extra1;
2849 	delay = net->ipv6.sysctl.flush_delay;
2850 	proc_dointvec(ctl, write, buffer, lenp, ppos);
2851 	fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
2852 	return 0;
2853 }
2854 
2855 struct ctl_table ipv6_route_table_template[] = {
2856 	{
2857 		.procname	=	"flush",
2858 		.data		=	&init_net.ipv6.sysctl.flush_delay,
2859 		.maxlen		=	sizeof(int),
2860 		.mode		=	0200,
2861 		.proc_handler	=	ipv6_sysctl_rtcache_flush
2862 	},
2863 	{
2864 		.procname	=	"gc_thresh",
2865 		.data		=	&ip6_dst_ops_template.gc_thresh,
2866 		.maxlen		=	sizeof(int),
2867 		.mode		=	0644,
2868 		.proc_handler	=	proc_dointvec,
2869 	},
2870 	{
2871 		.procname	=	"max_size",
2872 		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
2873 		.maxlen		=	sizeof(int),
2874 		.mode		=	0644,
2875 		.proc_handler	=	proc_dointvec,
2876 	},
2877 	{
2878 		.procname	=	"gc_min_interval",
2879 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2880 		.maxlen		=	sizeof(int),
2881 		.mode		=	0644,
2882 		.proc_handler	=	proc_dointvec_jiffies,
2883 	},
2884 	{
2885 		.procname	=	"gc_timeout",
2886 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
2887 		.maxlen		=	sizeof(int),
2888 		.mode		=	0644,
2889 		.proc_handler	=	proc_dointvec_jiffies,
2890 	},
2891 	{
2892 		.procname	=	"gc_interval",
2893 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
2894 		.maxlen		=	sizeof(int),
2895 		.mode		=	0644,
2896 		.proc_handler	=	proc_dointvec_jiffies,
2897 	},
2898 	{
2899 		.procname	=	"gc_elasticity",
2900 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
2901 		.maxlen		=	sizeof(int),
2902 		.mode		=	0644,
2903 		.proc_handler	=	proc_dointvec,
2904 	},
2905 	{
2906 		.procname	=	"mtu_expires",
2907 		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
2908 		.maxlen		=	sizeof(int),
2909 		.mode		=	0644,
2910 		.proc_handler	=	proc_dointvec_jiffies,
2911 	},
2912 	{
2913 		.procname	=	"min_adv_mss",
2914 		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
2915 		.maxlen		=	sizeof(int),
2916 		.mode		=	0644,
2917 		.proc_handler	=	proc_dointvec,
2918 	},
2919 	{
2920 		.procname	=	"gc_min_interval_ms",
2921 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2922 		.maxlen		=	sizeof(int),
2923 		.mode		=	0644,
2924 		.proc_handler	=	proc_dointvec_ms_jiffies,
2925 	},
2926 	{ }
2927 };
2928 
2929 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
2930 {
2931 	struct ctl_table *table;
2932 
2933 	table = kmemdup(ipv6_route_table_template,
2934 			sizeof(ipv6_route_table_template),
2935 			GFP_KERNEL);
2936 
2937 	if (table) {
2938 		table[0].data = &net->ipv6.sysctl.flush_delay;
2939 		table[0].extra1 = net;
2940 		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
2941 		table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
2942 		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2943 		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
2944 		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
2945 		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
2946 		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
2947 		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
2948 		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2949 
2950 		/* Don't export sysctls to unprivileged users */
2951 		if (net->user_ns != &init_user_ns)
2952 			table[0].procname = NULL;
2953 	}
2954 
2955 	return table;
2956 }
2957 #endif
2958 
2959 static int __net_init ip6_route_net_init(struct net *net)
2960 {
2961 	int ret = -ENOMEM;
2962 
2963 	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
2964 	       sizeof(net->ipv6.ip6_dst_ops));
2965 
2966 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
2967 		goto out_ip6_dst_ops;
2968 
2969 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
2970 					   sizeof(*net->ipv6.ip6_null_entry),
2971 					   GFP_KERNEL);
2972 	if (!net->ipv6.ip6_null_entry)
2973 		goto out_ip6_dst_entries;
2974 	net->ipv6.ip6_null_entry->dst.path =
2975 		(struct dst_entry *)net->ipv6.ip6_null_entry;
2976 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
2977 	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
2978 			 ip6_template_metrics, true);
2979 
2980 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2981 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
2982 					       sizeof(*net->ipv6.ip6_prohibit_entry),
2983 					       GFP_KERNEL);
2984 	if (!net->ipv6.ip6_prohibit_entry)
2985 		goto out_ip6_null_entry;
2986 	net->ipv6.ip6_prohibit_entry->dst.path =
2987 		(struct dst_entry *)net->ipv6.ip6_prohibit_entry;
2988 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
2989 	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
2990 			 ip6_template_metrics, true);
2991 
2992 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
2993 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
2994 					       GFP_KERNEL);
2995 	if (!net->ipv6.ip6_blk_hole_entry)
2996 		goto out_ip6_prohibit_entry;
2997 	net->ipv6.ip6_blk_hole_entry->dst.path =
2998 		(struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
2999 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
3000 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
3001 			 ip6_template_metrics, true);
3002 #endif
3003 
3004 	net->ipv6.sysctl.flush_delay = 0;
3005 	net->ipv6.sysctl.ip6_rt_max_size = 4096;
3006 	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
3007 	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
3008 	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
3009 	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
3010 	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
3011 	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
3012 
3013 	net->ipv6.ip6_rt_gc_expire = 30*HZ;
3014 
3015 	ret = 0;
3016 out:
3017 	return ret;
3018 
3019 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3020 out_ip6_prohibit_entry:
3021 	kfree(net->ipv6.ip6_prohibit_entry);
3022 out_ip6_null_entry:
3023 	kfree(net->ipv6.ip6_null_entry);
3024 #endif
3025 out_ip6_dst_entries:
3026 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3027 out_ip6_dst_ops:
3028 	goto out;
3029 }
3030 
3031 static void __net_exit ip6_route_net_exit(struct net *net)
3032 {
3033 	kfree(net->ipv6.ip6_null_entry);
3034 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3035 	kfree(net->ipv6.ip6_prohibit_entry);
3036 	kfree(net->ipv6.ip6_blk_hole_entry);
3037 #endif
3038 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
3039 }
3040 
3041 static int __net_init ip6_route_net_init_late(struct net *net)
3042 {
3043 #ifdef CONFIG_PROC_FS
3044 	proc_create("ipv6_route", 0, net->proc_net, &ipv6_route_proc_fops);
3045 	proc_create("rt6_stats", S_IRUGO, net->proc_net, &rt6_stats_seq_fops);
3046 #endif
3047 	return 0;
3048 }
3049 
3050 static void __net_exit ip6_route_net_exit_late(struct net *net)
3051 {
3052 #ifdef CONFIG_PROC_FS
3053 	remove_proc_entry("ipv6_route", net->proc_net);
3054 	remove_proc_entry("rt6_stats", net->proc_net);
3055 #endif
3056 }
3057 
3058 static struct pernet_operations ip6_route_net_ops = {
3059 	.init = ip6_route_net_init,
3060 	.exit = ip6_route_net_exit,
3061 };
3062 
3063 static int __net_init ipv6_inetpeer_init(struct net *net)
3064 {
3065 	struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
3066 
3067 	if (!bp)
3068 		return -ENOMEM;
3069 	inet_peer_base_init(bp);
3070 	net->ipv6.peers = bp;
3071 	return 0;
3072 }
3073 
3074 static void __net_exit ipv6_inetpeer_exit(struct net *net)
3075 {
3076 	struct inet_peer_base *bp = net->ipv6.peers;
3077 
3078 	net->ipv6.peers = NULL;
3079 	inetpeer_invalidate_tree(bp);
3080 	kfree(bp);
3081 }
3082 
3083 static struct pernet_operations ipv6_inetpeer_ops = {
3084 	.init	=	ipv6_inetpeer_init,
3085 	.exit	=	ipv6_inetpeer_exit,
3086 };
3087 
3088 static struct pernet_operations ip6_route_net_late_ops = {
3089 	.init = ip6_route_net_init_late,
3090 	.exit = ip6_route_net_exit_late,
3091 };
3092 
3093 static struct notifier_block ip6_route_dev_notifier = {
3094 	.notifier_call = ip6_route_dev_notify,
3095 	.priority = 0,
3096 };
3097 
3098 int __init ip6_route_init(void)
3099 {
3100 	int ret;
3101 
3102 	ret = -ENOMEM;
3103 	ip6_dst_ops_template.kmem_cachep =
3104 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
3105 				  SLAB_HWCACHE_ALIGN, NULL);
3106 	if (!ip6_dst_ops_template.kmem_cachep)
3107 		goto out;
3108 
3109 	ret = dst_entries_init(&ip6_dst_blackhole_ops);
3110 	if (ret)
3111 		goto out_kmem_cache;
3112 
3113 	ret = register_pernet_subsys(&ipv6_inetpeer_ops);
3114 	if (ret)
3115 		goto out_dst_entries;
3116 
3117 	ret = register_pernet_subsys(&ip6_route_net_ops);
3118 	if (ret)
3119 		goto out_register_inetpeer;
3120 
3121 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
3122 
3123 	/* Registering of the loopback is done before this portion of code,
3124 	 * the loopback reference in rt6_info will not be taken, do it
3125 	 * manually for init_net */
3126 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
3127 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3128   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
3129 	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
3130 	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3131 	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
3132 	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
3133   #endif
3134 	ret = fib6_init();
3135 	if (ret)
3136 		goto out_register_subsys;
3137 
3138 	ret = xfrm6_init();
3139 	if (ret)
3140 		goto out_fib6_init;
3141 
3142 	ret = fib6_rules_init();
3143 	if (ret)
3144 		goto xfrm6_init;
3145 
3146 	ret = register_pernet_subsys(&ip6_route_net_late_ops);
3147 	if (ret)
3148 		goto fib6_rules_init;
3149 
3150 	ret = -ENOBUFS;
3151 	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) ||
3152 	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) ||
3153 	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL))
3154 		goto out_register_late_subsys;
3155 
3156 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
3157 	if (ret)
3158 		goto out_register_late_subsys;
3159 
3160 out:
3161 	return ret;
3162 
3163 out_register_late_subsys:
3164 	unregister_pernet_subsys(&ip6_route_net_late_ops);
3165 fib6_rules_init:
3166 	fib6_rules_cleanup();
3167 xfrm6_init:
3168 	xfrm6_fini();
3169 out_fib6_init:
3170 	fib6_gc_cleanup();
3171 out_register_subsys:
3172 	unregister_pernet_subsys(&ip6_route_net_ops);
3173 out_register_inetpeer:
3174 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
3175 out_dst_entries:
3176 	dst_entries_destroy(&ip6_dst_blackhole_ops);
3177 out_kmem_cache:
3178 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3179 	goto out;
3180 }
3181 
3182 void ip6_route_cleanup(void)
3183 {
3184 	unregister_netdevice_notifier(&ip6_route_dev_notifier);
3185 	unregister_pernet_subsys(&ip6_route_net_late_ops);
3186 	fib6_rules_cleanup();
3187 	xfrm6_fini();
3188 	fib6_gc_cleanup();
3189 	unregister_pernet_subsys(&ipv6_inetpeer_ops);
3190 	unregister_pernet_subsys(&ip6_route_net_ops);
3191 	dst_entries_destroy(&ip6_dst_blackhole_ops);
3192 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
3193 }
3194