xref: /linux/net/ipv6/route.c (revision 9d9659b6c0ebf7dde65ebada4c67980818245913)
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 #include <linux/capability.h>
28 #include <linux/errno.h>
29 #include <linux/types.h>
30 #include <linux/times.h>
31 #include <linux/socket.h>
32 #include <linux/sockios.h>
33 #include <linux/net.h>
34 #include <linux/route.h>
35 #include <linux/netdevice.h>
36 #include <linux/in6.h>
37 #include <linux/mroute6.h>
38 #include <linux/init.h>
39 #include <linux/if_arp.h>
40 #include <linux/proc_fs.h>
41 #include <linux/seq_file.h>
42 #include <linux/nsproxy.h>
43 #include <linux/slab.h>
44 #include <net/net_namespace.h>
45 #include <net/snmp.h>
46 #include <net/ipv6.h>
47 #include <net/ip6_fib.h>
48 #include <net/ip6_route.h>
49 #include <net/ndisc.h>
50 #include <net/addrconf.h>
51 #include <net/tcp.h>
52 #include <linux/rtnetlink.h>
53 #include <net/dst.h>
54 #include <net/xfrm.h>
55 #include <net/netevent.h>
56 #include <net/netlink.h>
57 
58 #include <asm/uaccess.h>
59 
60 #ifdef CONFIG_SYSCTL
61 #include <linux/sysctl.h>
62 #endif
63 
64 /* Set to 3 to get tracing. */
65 #define RT6_DEBUG 2
66 
67 #if RT6_DEBUG >= 3
68 #define RDBG(x) printk x
69 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
70 #else
71 #define RDBG(x)
72 #define RT6_TRACE(x...) do { ; } while (0)
73 #endif
74 
75 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
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_default_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, u32 mtu);
89 
90 #ifdef CONFIG_IPV6_ROUTE_INFO
91 static struct rt6_info *rt6_add_route_info(struct net *net,
92 					   struct in6_addr *prefix, int prefixlen,
93 					   struct in6_addr *gwaddr, int ifindex,
94 					   unsigned pref);
95 static struct rt6_info *rt6_get_route_info(struct net *net,
96 					   struct in6_addr *prefix, int prefixlen,
97 					   struct in6_addr *gwaddr, int ifindex);
98 #endif
99 
100 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
101 {
102 	struct rt6_info *rt = (struct rt6_info *) dst;
103 	struct inet_peer *peer;
104 	u32 *p = NULL;
105 
106 	if (!rt->rt6i_peer)
107 		rt6_bind_peer(rt, 1);
108 
109 	peer = rt->rt6i_peer;
110 	if (peer) {
111 		u32 *old_p = __DST_METRICS_PTR(old);
112 		unsigned long prev, new;
113 
114 		p = peer->metrics;
115 		if (inet_metrics_new(peer))
116 			memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
117 
118 		new = (unsigned long) p;
119 		prev = cmpxchg(&dst->_metrics, old, new);
120 
121 		if (prev != old) {
122 			p = __DST_METRICS_PTR(prev);
123 			if (prev & DST_METRICS_READ_ONLY)
124 				p = NULL;
125 		}
126 	}
127 	return p;
128 }
129 
130 static struct dst_ops ip6_dst_ops_template = {
131 	.family			=	AF_INET6,
132 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
133 	.gc			=	ip6_dst_gc,
134 	.gc_thresh		=	1024,
135 	.check			=	ip6_dst_check,
136 	.default_advmss		=	ip6_default_advmss,
137 	.default_mtu		=	ip6_default_mtu,
138 	.cow_metrics		=	ipv6_cow_metrics,
139 	.destroy		=	ip6_dst_destroy,
140 	.ifdown			=	ip6_dst_ifdown,
141 	.negative_advice	=	ip6_negative_advice,
142 	.link_failure		=	ip6_link_failure,
143 	.update_pmtu		=	ip6_rt_update_pmtu,
144 	.local_out		=	__ip6_local_out,
145 };
146 
147 static unsigned int ip6_blackhole_default_mtu(const struct dst_entry *dst)
148 {
149 	return 0;
150 }
151 
152 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
153 {
154 }
155 
156 static struct dst_ops ip6_dst_blackhole_ops = {
157 	.family			=	AF_INET6,
158 	.protocol		=	cpu_to_be16(ETH_P_IPV6),
159 	.destroy		=	ip6_dst_destroy,
160 	.check			=	ip6_dst_check,
161 	.default_mtu		=	ip6_blackhole_default_mtu,
162 	.default_advmss		=	ip6_default_advmss,
163 	.update_pmtu		=	ip6_rt_blackhole_update_pmtu,
164 };
165 
166 static const u32 ip6_template_metrics[RTAX_MAX] = {
167 	[RTAX_HOPLIMIT - 1] = 255,
168 };
169 
170 static struct rt6_info ip6_null_entry_template = {
171 	.dst = {
172 		.__refcnt	= ATOMIC_INIT(1),
173 		.__use		= 1,
174 		.obsolete	= -1,
175 		.error		= -ENETUNREACH,
176 		.input		= ip6_pkt_discard,
177 		.output		= ip6_pkt_discard_out,
178 	},
179 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
180 	.rt6i_protocol  = RTPROT_KERNEL,
181 	.rt6i_metric	= ~(u32) 0,
182 	.rt6i_ref	= ATOMIC_INIT(1),
183 };
184 
185 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
186 
187 static int ip6_pkt_prohibit(struct sk_buff *skb);
188 static int ip6_pkt_prohibit_out(struct sk_buff *skb);
189 
190 static struct rt6_info ip6_prohibit_entry_template = {
191 	.dst = {
192 		.__refcnt	= ATOMIC_INIT(1),
193 		.__use		= 1,
194 		.obsolete	= -1,
195 		.error		= -EACCES,
196 		.input		= ip6_pkt_prohibit,
197 		.output		= ip6_pkt_prohibit_out,
198 	},
199 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
200 	.rt6i_protocol  = RTPROT_KERNEL,
201 	.rt6i_metric	= ~(u32) 0,
202 	.rt6i_ref	= ATOMIC_INIT(1),
203 };
204 
205 static struct rt6_info ip6_blk_hole_entry_template = {
206 	.dst = {
207 		.__refcnt	= ATOMIC_INIT(1),
208 		.__use		= 1,
209 		.obsolete	= -1,
210 		.error		= -EINVAL,
211 		.input		= dst_discard,
212 		.output		= dst_discard,
213 	},
214 	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
215 	.rt6i_protocol  = RTPROT_KERNEL,
216 	.rt6i_metric	= ~(u32) 0,
217 	.rt6i_ref	= ATOMIC_INIT(1),
218 };
219 
220 #endif
221 
222 /* allocate dst with ip6_dst_ops */
223 static inline struct rt6_info *ip6_dst_alloc(struct dst_ops *ops)
224 {
225 	return (struct rt6_info *)dst_alloc(ops, 0);
226 }
227 
228 static void ip6_dst_destroy(struct dst_entry *dst)
229 {
230 	struct rt6_info *rt = (struct rt6_info *)dst;
231 	struct inet6_dev *idev = rt->rt6i_idev;
232 	struct inet_peer *peer = rt->rt6i_peer;
233 
234 	if (idev != NULL) {
235 		rt->rt6i_idev = NULL;
236 		in6_dev_put(idev);
237 	}
238 	if (peer) {
239 		rt->rt6i_peer = NULL;
240 		inet_putpeer(peer);
241 	}
242 }
243 
244 static atomic_t __rt6_peer_genid = ATOMIC_INIT(0);
245 
246 static u32 rt6_peer_genid(void)
247 {
248 	return atomic_read(&__rt6_peer_genid);
249 }
250 
251 void rt6_bind_peer(struct rt6_info *rt, int create)
252 {
253 	struct inet_peer *peer;
254 
255 	peer = inet_getpeer_v6(&rt->rt6i_dst.addr, create);
256 	if (peer && cmpxchg(&rt->rt6i_peer, NULL, peer) != NULL)
257 		inet_putpeer(peer);
258 	else
259 		rt->rt6i_peer_genid = rt6_peer_genid();
260 }
261 
262 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
263 			   int how)
264 {
265 	struct rt6_info *rt = (struct rt6_info *)dst;
266 	struct inet6_dev *idev = rt->rt6i_idev;
267 	struct net_device *loopback_dev =
268 		dev_net(dev)->loopback_dev;
269 
270 	if (dev != loopback_dev && idev != NULL && idev->dev == dev) {
271 		struct inet6_dev *loopback_idev =
272 			in6_dev_get(loopback_dev);
273 		if (loopback_idev != NULL) {
274 			rt->rt6i_idev = loopback_idev;
275 			in6_dev_put(idev);
276 		}
277 	}
278 }
279 
280 static __inline__ int rt6_check_expired(const struct rt6_info *rt)
281 {
282 	return (rt->rt6i_flags & RTF_EXPIRES) &&
283 		time_after(jiffies, rt->rt6i_expires);
284 }
285 
286 static inline int rt6_need_strict(struct in6_addr *daddr)
287 {
288 	return ipv6_addr_type(daddr) &
289 		(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
290 }
291 
292 /*
293  *	Route lookup. Any table->tb6_lock is implied.
294  */
295 
296 static inline struct rt6_info *rt6_device_match(struct net *net,
297 						    struct rt6_info *rt,
298 						    struct in6_addr *saddr,
299 						    int oif,
300 						    int flags)
301 {
302 	struct rt6_info *local = NULL;
303 	struct rt6_info *sprt;
304 
305 	if (!oif && ipv6_addr_any(saddr))
306 		goto out;
307 
308 	for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
309 		struct net_device *dev = sprt->rt6i_dev;
310 
311 		if (oif) {
312 			if (dev->ifindex == oif)
313 				return sprt;
314 			if (dev->flags & IFF_LOOPBACK) {
315 				if (sprt->rt6i_idev == NULL ||
316 				    sprt->rt6i_idev->dev->ifindex != oif) {
317 					if (flags & RT6_LOOKUP_F_IFACE && oif)
318 						continue;
319 					if (local && (!oif ||
320 						      local->rt6i_idev->dev->ifindex == oif))
321 						continue;
322 				}
323 				local = sprt;
324 			}
325 		} else {
326 			if (ipv6_chk_addr(net, saddr, dev,
327 					  flags & RT6_LOOKUP_F_IFACE))
328 				return sprt;
329 		}
330 	}
331 
332 	if (oif) {
333 		if (local)
334 			return local;
335 
336 		if (flags & RT6_LOOKUP_F_IFACE)
337 			return net->ipv6.ip6_null_entry;
338 	}
339 out:
340 	return rt;
341 }
342 
343 #ifdef CONFIG_IPV6_ROUTER_PREF
344 static void rt6_probe(struct rt6_info *rt)
345 {
346 	struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL;
347 	/*
348 	 * Okay, this does not seem to be appropriate
349 	 * for now, however, we need to check if it
350 	 * is really so; aka Router Reachability Probing.
351 	 *
352 	 * Router Reachability Probe MUST be rate-limited
353 	 * to no more than one per minute.
354 	 */
355 	if (!neigh || (neigh->nud_state & NUD_VALID))
356 		return;
357 	read_lock_bh(&neigh->lock);
358 	if (!(neigh->nud_state & NUD_VALID) &&
359 	    time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) {
360 		struct in6_addr mcaddr;
361 		struct in6_addr *target;
362 
363 		neigh->updated = jiffies;
364 		read_unlock_bh(&neigh->lock);
365 
366 		target = (struct in6_addr *)&neigh->primary_key;
367 		addrconf_addr_solict_mult(target, &mcaddr);
368 		ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL);
369 	} else
370 		read_unlock_bh(&neigh->lock);
371 }
372 #else
373 static inline void rt6_probe(struct rt6_info *rt)
374 {
375 }
376 #endif
377 
378 /*
379  * Default Router Selection (RFC 2461 6.3.6)
380  */
381 static inline int rt6_check_dev(struct rt6_info *rt, int oif)
382 {
383 	struct net_device *dev = rt->rt6i_dev;
384 	if (!oif || dev->ifindex == oif)
385 		return 2;
386 	if ((dev->flags & IFF_LOOPBACK) &&
387 	    rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif)
388 		return 1;
389 	return 0;
390 }
391 
392 static inline int rt6_check_neigh(struct rt6_info *rt)
393 {
394 	struct neighbour *neigh = rt->rt6i_nexthop;
395 	int m;
396 	if (rt->rt6i_flags & RTF_NONEXTHOP ||
397 	    !(rt->rt6i_flags & RTF_GATEWAY))
398 		m = 1;
399 	else if (neigh) {
400 		read_lock_bh(&neigh->lock);
401 		if (neigh->nud_state & NUD_VALID)
402 			m = 2;
403 #ifdef CONFIG_IPV6_ROUTER_PREF
404 		else if (neigh->nud_state & NUD_FAILED)
405 			m = 0;
406 #endif
407 		else
408 			m = 1;
409 		read_unlock_bh(&neigh->lock);
410 	} else
411 		m = 0;
412 	return m;
413 }
414 
415 static int rt6_score_route(struct rt6_info *rt, int oif,
416 			   int strict)
417 {
418 	int m, n;
419 
420 	m = rt6_check_dev(rt, oif);
421 	if (!m && (strict & RT6_LOOKUP_F_IFACE))
422 		return -1;
423 #ifdef CONFIG_IPV6_ROUTER_PREF
424 	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2;
425 #endif
426 	n = rt6_check_neigh(rt);
427 	if (!n && (strict & RT6_LOOKUP_F_REACHABLE))
428 		return -1;
429 	return m;
430 }
431 
432 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict,
433 				   int *mpri, struct rt6_info *match)
434 {
435 	int m;
436 
437 	if (rt6_check_expired(rt))
438 		goto out;
439 
440 	m = rt6_score_route(rt, oif, strict);
441 	if (m < 0)
442 		goto out;
443 
444 	if (m > *mpri) {
445 		if (strict & RT6_LOOKUP_F_REACHABLE)
446 			rt6_probe(match);
447 		*mpri = m;
448 		match = rt;
449 	} else if (strict & RT6_LOOKUP_F_REACHABLE) {
450 		rt6_probe(rt);
451 	}
452 
453 out:
454 	return match;
455 }
456 
457 static struct rt6_info *find_rr_leaf(struct fib6_node *fn,
458 				     struct rt6_info *rr_head,
459 				     u32 metric, int oif, int strict)
460 {
461 	struct rt6_info *rt, *match;
462 	int mpri = -1;
463 
464 	match = NULL;
465 	for (rt = rr_head; rt && rt->rt6i_metric == metric;
466 	     rt = rt->dst.rt6_next)
467 		match = find_match(rt, oif, strict, &mpri, match);
468 	for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;
469 	     rt = rt->dst.rt6_next)
470 		match = find_match(rt, oif, strict, &mpri, match);
471 
472 	return match;
473 }
474 
475 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict)
476 {
477 	struct rt6_info *match, *rt0;
478 	struct net *net;
479 
480 	RT6_TRACE("%s(fn->leaf=%p, oif=%d)\n",
481 		  __func__, fn->leaf, oif);
482 
483 	rt0 = fn->rr_ptr;
484 	if (!rt0)
485 		fn->rr_ptr = rt0 = fn->leaf;
486 
487 	match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict);
488 
489 	if (!match &&
490 	    (strict & RT6_LOOKUP_F_REACHABLE)) {
491 		struct rt6_info *next = rt0->dst.rt6_next;
492 
493 		/* no entries matched; do round-robin */
494 		if (!next || next->rt6i_metric != rt0->rt6i_metric)
495 			next = fn->leaf;
496 
497 		if (next != rt0)
498 			fn->rr_ptr = next;
499 	}
500 
501 	RT6_TRACE("%s() => %p\n",
502 		  __func__, match);
503 
504 	net = dev_net(rt0->rt6i_dev);
505 	return match ? match : net->ipv6.ip6_null_entry;
506 }
507 
508 #ifdef CONFIG_IPV6_ROUTE_INFO
509 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
510 		  struct in6_addr *gwaddr)
511 {
512 	struct net *net = dev_net(dev);
513 	struct route_info *rinfo = (struct route_info *) opt;
514 	struct in6_addr prefix_buf, *prefix;
515 	unsigned int pref;
516 	unsigned long lifetime;
517 	struct rt6_info *rt;
518 
519 	if (len < sizeof(struct route_info)) {
520 		return -EINVAL;
521 	}
522 
523 	/* Sanity check for prefix_len and length */
524 	if (rinfo->length > 3) {
525 		return -EINVAL;
526 	} else if (rinfo->prefix_len > 128) {
527 		return -EINVAL;
528 	} else if (rinfo->prefix_len > 64) {
529 		if (rinfo->length < 2) {
530 			return -EINVAL;
531 		}
532 	} else if (rinfo->prefix_len > 0) {
533 		if (rinfo->length < 1) {
534 			return -EINVAL;
535 		}
536 	}
537 
538 	pref = rinfo->route_pref;
539 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
540 		return -EINVAL;
541 
542 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
543 
544 	if (rinfo->length == 3)
545 		prefix = (struct in6_addr *)rinfo->prefix;
546 	else {
547 		/* this function is safe */
548 		ipv6_addr_prefix(&prefix_buf,
549 				 (struct in6_addr *)rinfo->prefix,
550 				 rinfo->prefix_len);
551 		prefix = &prefix_buf;
552 	}
553 
554 	rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, gwaddr,
555 				dev->ifindex);
556 
557 	if (rt && !lifetime) {
558 		ip6_del_rt(rt);
559 		rt = NULL;
560 	}
561 
562 	if (!rt && lifetime)
563 		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex,
564 					pref);
565 	else if (rt)
566 		rt->rt6i_flags = RTF_ROUTEINFO |
567 				 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
568 
569 	if (rt) {
570 		if (!addrconf_finite_timeout(lifetime)) {
571 			rt->rt6i_flags &= ~RTF_EXPIRES;
572 		} else {
573 			rt->rt6i_expires = jiffies + HZ * lifetime;
574 			rt->rt6i_flags |= RTF_EXPIRES;
575 		}
576 		dst_release(&rt->dst);
577 	}
578 	return 0;
579 }
580 #endif
581 
582 #define BACKTRACK(__net, saddr)			\
583 do { \
584 	if (rt == __net->ipv6.ip6_null_entry) {	\
585 		struct fib6_node *pn; \
586 		while (1) { \
587 			if (fn->fn_flags & RTN_TL_ROOT) \
588 				goto out; \
589 			pn = fn->parent; \
590 			if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \
591 				fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \
592 			else \
593 				fn = pn; \
594 			if (fn->fn_flags & RTN_RTINFO) \
595 				goto restart; \
596 		} \
597 	} \
598 } while(0)
599 
600 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
601 					     struct fib6_table *table,
602 					     struct flowi6 *fl6, int flags)
603 {
604 	struct fib6_node *fn;
605 	struct rt6_info *rt;
606 
607 	read_lock_bh(&table->tb6_lock);
608 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
609 restart:
610 	rt = fn->leaf;
611 	rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
612 	BACKTRACK(net, &fl6->saddr);
613 out:
614 	dst_use(&rt->dst, jiffies);
615 	read_unlock_bh(&table->tb6_lock);
616 	return rt;
617 
618 }
619 
620 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
621 			    const struct in6_addr *saddr, int oif, int strict)
622 {
623 	struct flowi6 fl6 = {
624 		.flowi6_oif = oif,
625 		.daddr = *daddr,
626 	};
627 	struct dst_entry *dst;
628 	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
629 
630 	if (saddr) {
631 		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
632 		flags |= RT6_LOOKUP_F_HAS_SADDR;
633 	}
634 
635 	dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
636 	if (dst->error == 0)
637 		return (struct rt6_info *) dst;
638 
639 	dst_release(dst);
640 
641 	return NULL;
642 }
643 
644 EXPORT_SYMBOL(rt6_lookup);
645 
646 /* ip6_ins_rt is called with FREE table->tb6_lock.
647    It takes new route entry, the addition fails by any reason the
648    route is freed. In any case, if caller does not hold it, it may
649    be destroyed.
650  */
651 
652 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info)
653 {
654 	int err;
655 	struct fib6_table *table;
656 
657 	table = rt->rt6i_table;
658 	write_lock_bh(&table->tb6_lock);
659 	err = fib6_add(&table->tb6_root, rt, info);
660 	write_unlock_bh(&table->tb6_lock);
661 
662 	return err;
663 }
664 
665 int ip6_ins_rt(struct rt6_info *rt)
666 {
667 	struct nl_info info = {
668 		.nl_net = dev_net(rt->rt6i_dev),
669 	};
670 	return __ip6_ins_rt(rt, &info);
671 }
672 
673 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, struct in6_addr *daddr,
674 				      struct in6_addr *saddr)
675 {
676 	struct rt6_info *rt;
677 
678 	/*
679 	 *	Clone the route.
680 	 */
681 
682 	rt = ip6_rt_copy(ort);
683 
684 	if (rt) {
685 		struct neighbour *neigh;
686 		int attempts = !in_softirq();
687 
688 		if (!(rt->rt6i_flags&RTF_GATEWAY)) {
689 			if (rt->rt6i_dst.plen != 128 &&
690 			    ipv6_addr_equal(&rt->rt6i_dst.addr, daddr))
691 				rt->rt6i_flags |= RTF_ANYCAST;
692 			ipv6_addr_copy(&rt->rt6i_gateway, daddr);
693 		}
694 
695 		ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
696 		rt->rt6i_dst.plen = 128;
697 		rt->rt6i_flags |= RTF_CACHE;
698 		rt->dst.flags |= DST_HOST;
699 
700 #ifdef CONFIG_IPV6_SUBTREES
701 		if (rt->rt6i_src.plen && saddr) {
702 			ipv6_addr_copy(&rt->rt6i_src.addr, saddr);
703 			rt->rt6i_src.plen = 128;
704 		}
705 #endif
706 
707 	retry:
708 		neigh = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
709 		if (IS_ERR(neigh)) {
710 			struct net *net = dev_net(rt->rt6i_dev);
711 			int saved_rt_min_interval =
712 				net->ipv6.sysctl.ip6_rt_gc_min_interval;
713 			int saved_rt_elasticity =
714 				net->ipv6.sysctl.ip6_rt_gc_elasticity;
715 
716 			if (attempts-- > 0) {
717 				net->ipv6.sysctl.ip6_rt_gc_elasticity = 1;
718 				net->ipv6.sysctl.ip6_rt_gc_min_interval = 0;
719 
720 				ip6_dst_gc(&net->ipv6.ip6_dst_ops);
721 
722 				net->ipv6.sysctl.ip6_rt_gc_elasticity =
723 					saved_rt_elasticity;
724 				net->ipv6.sysctl.ip6_rt_gc_min_interval =
725 					saved_rt_min_interval;
726 				goto retry;
727 			}
728 
729 			if (net_ratelimit())
730 				printk(KERN_WARNING
731 				       "ipv6: Neighbour table overflow.\n");
732 			dst_free(&rt->dst);
733 			return NULL;
734 		}
735 		rt->rt6i_nexthop = neigh;
736 
737 	}
738 
739 	return rt;
740 }
741 
742 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *daddr)
743 {
744 	struct rt6_info *rt = ip6_rt_copy(ort);
745 	if (rt) {
746 		ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);
747 		rt->rt6i_dst.plen = 128;
748 		rt->rt6i_flags |= RTF_CACHE;
749 		rt->dst.flags |= DST_HOST;
750 		rt->rt6i_nexthop = neigh_clone(ort->rt6i_nexthop);
751 	}
752 	return rt;
753 }
754 
755 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
756 				      struct flowi6 *fl6, int flags)
757 {
758 	struct fib6_node *fn;
759 	struct rt6_info *rt, *nrt;
760 	int strict = 0;
761 	int attempts = 3;
762 	int err;
763 	int reachable = net->ipv6.devconf_all->forwarding ? 0 : RT6_LOOKUP_F_REACHABLE;
764 
765 	strict |= flags & RT6_LOOKUP_F_IFACE;
766 
767 relookup:
768 	read_lock_bh(&table->tb6_lock);
769 
770 restart_2:
771 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
772 
773 restart:
774 	rt = rt6_select(fn, oif, strict | reachable);
775 
776 	BACKTRACK(net, &fl6->saddr);
777 	if (rt == net->ipv6.ip6_null_entry ||
778 	    rt->rt6i_flags & RTF_CACHE)
779 		goto out;
780 
781 	dst_hold(&rt->dst);
782 	read_unlock_bh(&table->tb6_lock);
783 
784 	if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
785 		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
786 	else if (!(rt->dst.flags & DST_HOST))
787 		nrt = rt6_alloc_clone(rt, &fl6->daddr);
788 	else
789 		goto out2;
790 
791 	dst_release(&rt->dst);
792 	rt = nrt ? : net->ipv6.ip6_null_entry;
793 
794 	dst_hold(&rt->dst);
795 	if (nrt) {
796 		err = ip6_ins_rt(nrt);
797 		if (!err)
798 			goto out2;
799 	}
800 
801 	if (--attempts <= 0)
802 		goto out2;
803 
804 	/*
805 	 * Race condition! In the gap, when table->tb6_lock was
806 	 * released someone could insert this route.  Relookup.
807 	 */
808 	dst_release(&rt->dst);
809 	goto relookup;
810 
811 out:
812 	if (reachable) {
813 		reachable = 0;
814 		goto restart_2;
815 	}
816 	dst_hold(&rt->dst);
817 	read_unlock_bh(&table->tb6_lock);
818 out2:
819 	rt->dst.lastuse = jiffies;
820 	rt->dst.__use++;
821 
822 	return rt;
823 }
824 
825 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
826 					    struct flowi6 *fl6, int flags)
827 {
828 	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
829 }
830 
831 void ip6_route_input(struct sk_buff *skb)
832 {
833 	struct ipv6hdr *iph = ipv6_hdr(skb);
834 	struct net *net = dev_net(skb->dev);
835 	int flags = RT6_LOOKUP_F_HAS_SADDR;
836 	struct flowi6 fl6 = {
837 		.flowi6_iif = skb->dev->ifindex,
838 		.daddr = iph->daddr,
839 		.saddr = iph->saddr,
840 		.flowlabel = (* (__be32 *) iph)&IPV6_FLOWINFO_MASK,
841 		.flowi6_mark = skb->mark,
842 		.flowi6_proto = iph->nexthdr,
843 	};
844 
845 	if (rt6_need_strict(&iph->daddr) && skb->dev->type != ARPHRD_PIMREG)
846 		flags |= RT6_LOOKUP_F_IFACE;
847 
848 	skb_dst_set(skb, fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_input));
849 }
850 
851 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
852 					     struct flowi6 *fl6, int flags)
853 {
854 	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
855 }
856 
857 struct dst_entry * ip6_route_output(struct net *net, struct sock *sk,
858 				    struct flowi6 *fl6)
859 {
860 	int flags = 0;
861 
862 	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
863 		flags |= RT6_LOOKUP_F_IFACE;
864 
865 	if (!ipv6_addr_any(&fl6->saddr))
866 		flags |= RT6_LOOKUP_F_HAS_SADDR;
867 	else if (sk)
868 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
869 
870 	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
871 }
872 
873 EXPORT_SYMBOL(ip6_route_output);
874 
875 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
876 {
877 	struct rt6_info *rt = dst_alloc(&ip6_dst_blackhole_ops, 1);
878 	struct rt6_info *ort = (struct rt6_info *) dst_orig;
879 	struct dst_entry *new = NULL;
880 
881 	if (rt) {
882 		new = &rt->dst;
883 
884 		new->__use = 1;
885 		new->input = dst_discard;
886 		new->output = dst_discard;
887 
888 		dst_copy_metrics(new, &ort->dst);
889 		new->dev = ort->dst.dev;
890 		if (new->dev)
891 			dev_hold(new->dev);
892 		rt->rt6i_idev = ort->rt6i_idev;
893 		if (rt->rt6i_idev)
894 			in6_dev_hold(rt->rt6i_idev);
895 		rt->rt6i_expires = 0;
896 
897 		ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
898 		rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
899 		rt->rt6i_metric = 0;
900 
901 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
902 #ifdef CONFIG_IPV6_SUBTREES
903 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
904 #endif
905 
906 		dst_free(new);
907 	}
908 
909 	dst_release(dst_orig);
910 	return new ? new : ERR_PTR(-ENOMEM);
911 }
912 
913 /*
914  *	Destination cache support functions
915  */
916 
917 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
918 {
919 	struct rt6_info *rt;
920 
921 	rt = (struct rt6_info *) dst;
922 
923 	if (rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie)) {
924 		if (rt->rt6i_peer_genid != rt6_peer_genid()) {
925 			if (!rt->rt6i_peer)
926 				rt6_bind_peer(rt, 0);
927 			rt->rt6i_peer_genid = rt6_peer_genid();
928 		}
929 		return dst;
930 	}
931 	return NULL;
932 }
933 
934 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
935 {
936 	struct rt6_info *rt = (struct rt6_info *) dst;
937 
938 	if (rt) {
939 		if (rt->rt6i_flags & RTF_CACHE) {
940 			if (rt6_check_expired(rt)) {
941 				ip6_del_rt(rt);
942 				dst = NULL;
943 			}
944 		} else {
945 			dst_release(dst);
946 			dst = NULL;
947 		}
948 	}
949 	return dst;
950 }
951 
952 static void ip6_link_failure(struct sk_buff *skb)
953 {
954 	struct rt6_info *rt;
955 
956 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
957 
958 	rt = (struct rt6_info *) skb_dst(skb);
959 	if (rt) {
960 		if (rt->rt6i_flags&RTF_CACHE) {
961 			dst_set_expires(&rt->dst, 0);
962 			rt->rt6i_flags |= RTF_EXPIRES;
963 		} else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
964 			rt->rt6i_node->fn_sernum = -1;
965 	}
966 }
967 
968 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
969 {
970 	struct rt6_info *rt6 = (struct rt6_info*)dst;
971 
972 	if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
973 		rt6->rt6i_flags |= RTF_MODIFIED;
974 		if (mtu < IPV6_MIN_MTU) {
975 			u32 features = dst_metric(dst, RTAX_FEATURES);
976 			mtu = IPV6_MIN_MTU;
977 			features |= RTAX_FEATURE_ALLFRAG;
978 			dst_metric_set(dst, RTAX_FEATURES, features);
979 		}
980 		dst_metric_set(dst, RTAX_MTU, mtu);
981 	}
982 }
983 
984 static unsigned int ip6_default_advmss(const struct dst_entry *dst)
985 {
986 	struct net_device *dev = dst->dev;
987 	unsigned int mtu = dst_mtu(dst);
988 	struct net *net = dev_net(dev);
989 
990 	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
991 
992 	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
993 		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
994 
995 	/*
996 	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
997 	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
998 	 * IPV6_MAXPLEN is also valid and means: "any MSS,
999 	 * rely only on pmtu discovery"
1000 	 */
1001 	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
1002 		mtu = IPV6_MAXPLEN;
1003 	return mtu;
1004 }
1005 
1006 static unsigned int ip6_default_mtu(const struct dst_entry *dst)
1007 {
1008 	unsigned int mtu = IPV6_MIN_MTU;
1009 	struct inet6_dev *idev;
1010 
1011 	rcu_read_lock();
1012 	idev = __in6_dev_get(dst->dev);
1013 	if (idev)
1014 		mtu = idev->cnf.mtu6;
1015 	rcu_read_unlock();
1016 
1017 	return mtu;
1018 }
1019 
1020 static struct dst_entry *icmp6_dst_gc_list;
1021 static DEFINE_SPINLOCK(icmp6_dst_lock);
1022 
1023 struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
1024 				  struct neighbour *neigh,
1025 				  const struct in6_addr *addr)
1026 {
1027 	struct rt6_info *rt;
1028 	struct inet6_dev *idev = in6_dev_get(dev);
1029 	struct net *net = dev_net(dev);
1030 
1031 	if (unlikely(idev == NULL))
1032 		return NULL;
1033 
1034 	rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
1035 	if (unlikely(rt == NULL)) {
1036 		in6_dev_put(idev);
1037 		goto out;
1038 	}
1039 
1040 	dev_hold(dev);
1041 	if (neigh)
1042 		neigh_hold(neigh);
1043 	else {
1044 		neigh = ndisc_get_neigh(dev, addr);
1045 		if (IS_ERR(neigh))
1046 			neigh = NULL;
1047 	}
1048 
1049 	rt->rt6i_dev	  = dev;
1050 	rt->rt6i_idev     = idev;
1051 	rt->rt6i_nexthop  = neigh;
1052 	atomic_set(&rt->dst.__refcnt, 1);
1053 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);
1054 	rt->dst.output  = ip6_output;
1055 
1056 #if 0	/* there's no chance to use these for ndisc */
1057 	rt->dst.flags   = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST
1058 				? DST_HOST
1059 				: 0;
1060 	ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
1061 	rt->rt6i_dst.plen = 128;
1062 #endif
1063 
1064 	spin_lock_bh(&icmp6_dst_lock);
1065 	rt->dst.next = icmp6_dst_gc_list;
1066 	icmp6_dst_gc_list = &rt->dst;
1067 	spin_unlock_bh(&icmp6_dst_lock);
1068 
1069 	fib6_force_start_gc(net);
1070 
1071 out:
1072 	return &rt->dst;
1073 }
1074 
1075 int icmp6_dst_gc(void)
1076 {
1077 	struct dst_entry *dst, **pprev;
1078 	int more = 0;
1079 
1080 	spin_lock_bh(&icmp6_dst_lock);
1081 	pprev = &icmp6_dst_gc_list;
1082 
1083 	while ((dst = *pprev) != NULL) {
1084 		if (!atomic_read(&dst->__refcnt)) {
1085 			*pprev = dst->next;
1086 			dst_free(dst);
1087 		} else {
1088 			pprev = &dst->next;
1089 			++more;
1090 		}
1091 	}
1092 
1093 	spin_unlock_bh(&icmp6_dst_lock);
1094 
1095 	return more;
1096 }
1097 
1098 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg),
1099 			    void *arg)
1100 {
1101 	struct dst_entry *dst, **pprev;
1102 
1103 	spin_lock_bh(&icmp6_dst_lock);
1104 	pprev = &icmp6_dst_gc_list;
1105 	while ((dst = *pprev) != NULL) {
1106 		struct rt6_info *rt = (struct rt6_info *) dst;
1107 		if (func(rt, arg)) {
1108 			*pprev = dst->next;
1109 			dst_free(dst);
1110 		} else {
1111 			pprev = &dst->next;
1112 		}
1113 	}
1114 	spin_unlock_bh(&icmp6_dst_lock);
1115 }
1116 
1117 static int ip6_dst_gc(struct dst_ops *ops)
1118 {
1119 	unsigned long now = jiffies;
1120 	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
1121 	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
1122 	int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size;
1123 	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
1124 	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
1125 	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
1126 	int entries;
1127 
1128 	entries = dst_entries_get_fast(ops);
1129 	if (time_after(rt_last_gc + rt_min_interval, now) &&
1130 	    entries <= rt_max_size)
1131 		goto out;
1132 
1133 	net->ipv6.ip6_rt_gc_expire++;
1134 	fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net);
1135 	net->ipv6.ip6_rt_last_gc = now;
1136 	entries = dst_entries_get_slow(ops);
1137 	if (entries < ops->gc_thresh)
1138 		net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1;
1139 out:
1140 	net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity;
1141 	return entries > rt_max_size;
1142 }
1143 
1144 /* Clean host part of a prefix. Not necessary in radix tree,
1145    but results in cleaner routing tables.
1146 
1147    Remove it only when all the things will work!
1148  */
1149 
1150 int ip6_dst_hoplimit(struct dst_entry *dst)
1151 {
1152 	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
1153 	if (hoplimit == 0) {
1154 		struct net_device *dev = dst->dev;
1155 		struct inet6_dev *idev;
1156 
1157 		rcu_read_lock();
1158 		idev = __in6_dev_get(dev);
1159 		if (idev)
1160 			hoplimit = idev->cnf.hop_limit;
1161 		else
1162 			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
1163 		rcu_read_unlock();
1164 	}
1165 	return hoplimit;
1166 }
1167 EXPORT_SYMBOL(ip6_dst_hoplimit);
1168 
1169 /*
1170  *
1171  */
1172 
1173 int ip6_route_add(struct fib6_config *cfg)
1174 {
1175 	int err;
1176 	struct net *net = cfg->fc_nlinfo.nl_net;
1177 	struct rt6_info *rt = NULL;
1178 	struct net_device *dev = NULL;
1179 	struct inet6_dev *idev = NULL;
1180 	struct fib6_table *table;
1181 	int addr_type;
1182 
1183 	if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128)
1184 		return -EINVAL;
1185 #ifndef CONFIG_IPV6_SUBTREES
1186 	if (cfg->fc_src_len)
1187 		return -EINVAL;
1188 #endif
1189 	if (cfg->fc_ifindex) {
1190 		err = -ENODEV;
1191 		dev = dev_get_by_index(net, cfg->fc_ifindex);
1192 		if (!dev)
1193 			goto out;
1194 		idev = in6_dev_get(dev);
1195 		if (!idev)
1196 			goto out;
1197 	}
1198 
1199 	if (cfg->fc_metric == 0)
1200 		cfg->fc_metric = IP6_RT_PRIO_USER;
1201 
1202 	table = fib6_new_table(net, cfg->fc_table);
1203 	if (table == NULL) {
1204 		err = -ENOBUFS;
1205 		goto out;
1206 	}
1207 
1208 	rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
1209 
1210 	if (rt == NULL) {
1211 		err = -ENOMEM;
1212 		goto out;
1213 	}
1214 
1215 	rt->dst.obsolete = -1;
1216 	rt->rt6i_expires = (cfg->fc_flags & RTF_EXPIRES) ?
1217 				jiffies + clock_t_to_jiffies(cfg->fc_expires) :
1218 				0;
1219 
1220 	if (cfg->fc_protocol == RTPROT_UNSPEC)
1221 		cfg->fc_protocol = RTPROT_BOOT;
1222 	rt->rt6i_protocol = cfg->fc_protocol;
1223 
1224 	addr_type = ipv6_addr_type(&cfg->fc_dst);
1225 
1226 	if (addr_type & IPV6_ADDR_MULTICAST)
1227 		rt->dst.input = ip6_mc_input;
1228 	else if (cfg->fc_flags & RTF_LOCAL)
1229 		rt->dst.input = ip6_input;
1230 	else
1231 		rt->dst.input = ip6_forward;
1232 
1233 	rt->dst.output = ip6_output;
1234 
1235 	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
1236 	rt->rt6i_dst.plen = cfg->fc_dst_len;
1237 	if (rt->rt6i_dst.plen == 128)
1238 	       rt->dst.flags = DST_HOST;
1239 
1240 #ifdef CONFIG_IPV6_SUBTREES
1241 	ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
1242 	rt->rt6i_src.plen = cfg->fc_src_len;
1243 #endif
1244 
1245 	rt->rt6i_metric = cfg->fc_metric;
1246 
1247 	/* We cannot add true routes via loopback here,
1248 	   they would result in kernel looping; promote them to reject routes
1249 	 */
1250 	if ((cfg->fc_flags & RTF_REJECT) ||
1251 	    (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK)
1252 					      && !(cfg->fc_flags&RTF_LOCAL))) {
1253 		/* hold loopback dev/idev if we haven't done so. */
1254 		if (dev != net->loopback_dev) {
1255 			if (dev) {
1256 				dev_put(dev);
1257 				in6_dev_put(idev);
1258 			}
1259 			dev = net->loopback_dev;
1260 			dev_hold(dev);
1261 			idev = in6_dev_get(dev);
1262 			if (!idev) {
1263 				err = -ENODEV;
1264 				goto out;
1265 			}
1266 		}
1267 		rt->dst.output = ip6_pkt_discard_out;
1268 		rt->dst.input = ip6_pkt_discard;
1269 		rt->dst.error = -ENETUNREACH;
1270 		rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
1271 		goto install_route;
1272 	}
1273 
1274 	if (cfg->fc_flags & RTF_GATEWAY) {
1275 		struct in6_addr *gw_addr;
1276 		int gwa_type;
1277 
1278 		gw_addr = &cfg->fc_gateway;
1279 		ipv6_addr_copy(&rt->rt6i_gateway, gw_addr);
1280 		gwa_type = ipv6_addr_type(gw_addr);
1281 
1282 		if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
1283 			struct rt6_info *grt;
1284 
1285 			/* IPv6 strictly inhibits using not link-local
1286 			   addresses as nexthop address.
1287 			   Otherwise, router will not able to send redirects.
1288 			   It is very good, but in some (rare!) circumstances
1289 			   (SIT, PtP, NBMA NOARP links) it is handy to allow
1290 			   some exceptions. --ANK
1291 			 */
1292 			err = -EINVAL;
1293 			if (!(gwa_type&IPV6_ADDR_UNICAST))
1294 				goto out;
1295 
1296 			grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
1297 
1298 			err = -EHOSTUNREACH;
1299 			if (grt == NULL)
1300 				goto out;
1301 			if (dev) {
1302 				if (dev != grt->rt6i_dev) {
1303 					dst_release(&grt->dst);
1304 					goto out;
1305 				}
1306 			} else {
1307 				dev = grt->rt6i_dev;
1308 				idev = grt->rt6i_idev;
1309 				dev_hold(dev);
1310 				in6_dev_hold(grt->rt6i_idev);
1311 			}
1312 			if (!(grt->rt6i_flags&RTF_GATEWAY))
1313 				err = 0;
1314 			dst_release(&grt->dst);
1315 
1316 			if (err)
1317 				goto out;
1318 		}
1319 		err = -EINVAL;
1320 		if (dev == NULL || (dev->flags&IFF_LOOPBACK))
1321 			goto out;
1322 	}
1323 
1324 	err = -ENODEV;
1325 	if (dev == NULL)
1326 		goto out;
1327 
1328 	if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) {
1329 		rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev);
1330 		if (IS_ERR(rt->rt6i_nexthop)) {
1331 			err = PTR_ERR(rt->rt6i_nexthop);
1332 			rt->rt6i_nexthop = NULL;
1333 			goto out;
1334 		}
1335 	}
1336 
1337 	rt->rt6i_flags = cfg->fc_flags;
1338 
1339 install_route:
1340 	if (cfg->fc_mx) {
1341 		struct nlattr *nla;
1342 		int remaining;
1343 
1344 		nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
1345 			int type = nla_type(nla);
1346 
1347 			if (type) {
1348 				if (type > RTAX_MAX) {
1349 					err = -EINVAL;
1350 					goto out;
1351 				}
1352 
1353 				dst_metric_set(&rt->dst, type, nla_get_u32(nla));
1354 			}
1355 		}
1356 	}
1357 
1358 	rt->dst.dev = dev;
1359 	rt->rt6i_idev = idev;
1360 	rt->rt6i_table = table;
1361 
1362 	cfg->fc_nlinfo.nl_net = dev_net(dev);
1363 
1364 	return __ip6_ins_rt(rt, &cfg->fc_nlinfo);
1365 
1366 out:
1367 	if (dev)
1368 		dev_put(dev);
1369 	if (idev)
1370 		in6_dev_put(idev);
1371 	if (rt)
1372 		dst_free(&rt->dst);
1373 	return err;
1374 }
1375 
1376 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info)
1377 {
1378 	int err;
1379 	struct fib6_table *table;
1380 	struct net *net = dev_net(rt->rt6i_dev);
1381 
1382 	if (rt == net->ipv6.ip6_null_entry)
1383 		return -ENOENT;
1384 
1385 	table = rt->rt6i_table;
1386 	write_lock_bh(&table->tb6_lock);
1387 
1388 	err = fib6_del(rt, info);
1389 	dst_release(&rt->dst);
1390 
1391 	write_unlock_bh(&table->tb6_lock);
1392 
1393 	return err;
1394 }
1395 
1396 int ip6_del_rt(struct rt6_info *rt)
1397 {
1398 	struct nl_info info = {
1399 		.nl_net = dev_net(rt->rt6i_dev),
1400 	};
1401 	return __ip6_del_rt(rt, &info);
1402 }
1403 
1404 static int ip6_route_del(struct fib6_config *cfg)
1405 {
1406 	struct fib6_table *table;
1407 	struct fib6_node *fn;
1408 	struct rt6_info *rt;
1409 	int err = -ESRCH;
1410 
1411 	table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
1412 	if (table == NULL)
1413 		return err;
1414 
1415 	read_lock_bh(&table->tb6_lock);
1416 
1417 	fn = fib6_locate(&table->tb6_root,
1418 			 &cfg->fc_dst, cfg->fc_dst_len,
1419 			 &cfg->fc_src, cfg->fc_src_len);
1420 
1421 	if (fn) {
1422 		for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1423 			if (cfg->fc_ifindex &&
1424 			    (rt->rt6i_dev == NULL ||
1425 			     rt->rt6i_dev->ifindex != cfg->fc_ifindex))
1426 				continue;
1427 			if (cfg->fc_flags & RTF_GATEWAY &&
1428 			    !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
1429 				continue;
1430 			if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric)
1431 				continue;
1432 			dst_hold(&rt->dst);
1433 			read_unlock_bh(&table->tb6_lock);
1434 
1435 			return __ip6_del_rt(rt, &cfg->fc_nlinfo);
1436 		}
1437 	}
1438 	read_unlock_bh(&table->tb6_lock);
1439 
1440 	return err;
1441 }
1442 
1443 /*
1444  *	Handle redirects
1445  */
1446 struct ip6rd_flowi {
1447 	struct flowi6 fl6;
1448 	struct in6_addr gateway;
1449 };
1450 
1451 static struct rt6_info *__ip6_route_redirect(struct net *net,
1452 					     struct fib6_table *table,
1453 					     struct flowi6 *fl6,
1454 					     int flags)
1455 {
1456 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
1457 	struct rt6_info *rt;
1458 	struct fib6_node *fn;
1459 
1460 	/*
1461 	 * Get the "current" route for this destination and
1462 	 * check if the redirect has come from approriate router.
1463 	 *
1464 	 * RFC 2461 specifies that redirects should only be
1465 	 * accepted if they come from the nexthop to the target.
1466 	 * Due to the way the routes are chosen, this notion
1467 	 * is a bit fuzzy and one might need to check all possible
1468 	 * routes.
1469 	 */
1470 
1471 	read_lock_bh(&table->tb6_lock);
1472 	fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
1473 restart:
1474 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1475 		/*
1476 		 * Current route is on-link; redirect is always invalid.
1477 		 *
1478 		 * Seems, previous statement is not true. It could
1479 		 * be node, which looks for us as on-link (f.e. proxy ndisc)
1480 		 * But then router serving it might decide, that we should
1481 		 * know truth 8)8) --ANK (980726).
1482 		 */
1483 		if (rt6_check_expired(rt))
1484 			continue;
1485 		if (!(rt->rt6i_flags & RTF_GATEWAY))
1486 			continue;
1487 		if (fl6->flowi6_oif != rt->rt6i_dev->ifindex)
1488 			continue;
1489 		if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway))
1490 			continue;
1491 		break;
1492 	}
1493 
1494 	if (!rt)
1495 		rt = net->ipv6.ip6_null_entry;
1496 	BACKTRACK(net, &fl6->saddr);
1497 out:
1498 	dst_hold(&rt->dst);
1499 
1500 	read_unlock_bh(&table->tb6_lock);
1501 
1502 	return rt;
1503 };
1504 
1505 static struct rt6_info *ip6_route_redirect(struct in6_addr *dest,
1506 					   struct in6_addr *src,
1507 					   struct in6_addr *gateway,
1508 					   struct net_device *dev)
1509 {
1510 	int flags = RT6_LOOKUP_F_HAS_SADDR;
1511 	struct net *net = dev_net(dev);
1512 	struct ip6rd_flowi rdfl = {
1513 		.fl6 = {
1514 			.flowi6_oif = dev->ifindex,
1515 			.daddr = *dest,
1516 			.saddr = *src,
1517 		},
1518 	};
1519 
1520 	ipv6_addr_copy(&rdfl.gateway, gateway);
1521 
1522 	if (rt6_need_strict(dest))
1523 		flags |= RT6_LOOKUP_F_IFACE;
1524 
1525 	return (struct rt6_info *)fib6_rule_lookup(net, &rdfl.fl6,
1526 						   flags, __ip6_route_redirect);
1527 }
1528 
1529 void rt6_redirect(struct in6_addr *dest, struct in6_addr *src,
1530 		  struct in6_addr *saddr,
1531 		  struct neighbour *neigh, u8 *lladdr, int on_link)
1532 {
1533 	struct rt6_info *rt, *nrt = NULL;
1534 	struct netevent_redirect netevent;
1535 	struct net *net = dev_net(neigh->dev);
1536 
1537 	rt = ip6_route_redirect(dest, src, saddr, neigh->dev);
1538 
1539 	if (rt == net->ipv6.ip6_null_entry) {
1540 		if (net_ratelimit())
1541 			printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop "
1542 			       "for redirect target\n");
1543 		goto out;
1544 	}
1545 
1546 	/*
1547 	 *	We have finally decided to accept it.
1548 	 */
1549 
1550 	neigh_update(neigh, lladdr, NUD_STALE,
1551 		     NEIGH_UPDATE_F_WEAK_OVERRIDE|
1552 		     NEIGH_UPDATE_F_OVERRIDE|
1553 		     (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
1554 				     NEIGH_UPDATE_F_ISROUTER))
1555 		     );
1556 
1557 	/*
1558 	 * Redirect received -> path was valid.
1559 	 * Look, redirects are sent only in response to data packets,
1560 	 * so that this nexthop apparently is reachable. --ANK
1561 	 */
1562 	dst_confirm(&rt->dst);
1563 
1564 	/* Duplicate redirect: silently ignore. */
1565 	if (neigh == rt->dst.neighbour)
1566 		goto out;
1567 
1568 	nrt = ip6_rt_copy(rt);
1569 	if (nrt == NULL)
1570 		goto out;
1571 
1572 	nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
1573 	if (on_link)
1574 		nrt->rt6i_flags &= ~RTF_GATEWAY;
1575 
1576 	ipv6_addr_copy(&nrt->rt6i_dst.addr, dest);
1577 	nrt->rt6i_dst.plen = 128;
1578 	nrt->dst.flags |= DST_HOST;
1579 
1580 	ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
1581 	nrt->rt6i_nexthop = neigh_clone(neigh);
1582 
1583 	if (ip6_ins_rt(nrt))
1584 		goto out;
1585 
1586 	netevent.old = &rt->dst;
1587 	netevent.new = &nrt->dst;
1588 	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
1589 
1590 	if (rt->rt6i_flags&RTF_CACHE) {
1591 		ip6_del_rt(rt);
1592 		return;
1593 	}
1594 
1595 out:
1596 	dst_release(&rt->dst);
1597 }
1598 
1599 /*
1600  *	Handle ICMP "packet too big" messages
1601  *	i.e. Path MTU discovery
1602  */
1603 
1604 static void rt6_do_pmtu_disc(struct in6_addr *daddr, struct in6_addr *saddr,
1605 			     struct net *net, u32 pmtu, int ifindex)
1606 {
1607 	struct rt6_info *rt, *nrt;
1608 	int allfrag = 0;
1609 again:
1610 	rt = rt6_lookup(net, daddr, saddr, ifindex, 0);
1611 	if (rt == NULL)
1612 		return;
1613 
1614 	if (rt6_check_expired(rt)) {
1615 		ip6_del_rt(rt);
1616 		goto again;
1617 	}
1618 
1619 	if (pmtu >= dst_mtu(&rt->dst))
1620 		goto out;
1621 
1622 	if (pmtu < IPV6_MIN_MTU) {
1623 		/*
1624 		 * According to RFC2460, PMTU is set to the IPv6 Minimum Link
1625 		 * MTU (1280) and a fragment header should always be included
1626 		 * after a node receiving Too Big message reporting PMTU is
1627 		 * less than the IPv6 Minimum Link MTU.
1628 		 */
1629 		pmtu = IPV6_MIN_MTU;
1630 		allfrag = 1;
1631 	}
1632 
1633 	/* New mtu received -> path was valid.
1634 	   They are sent only in response to data packets,
1635 	   so that this nexthop apparently is reachable. --ANK
1636 	 */
1637 	dst_confirm(&rt->dst);
1638 
1639 	/* Host route. If it is static, it would be better
1640 	   not to override it, but add new one, so that
1641 	   when cache entry will expire old pmtu
1642 	   would return automatically.
1643 	 */
1644 	if (rt->rt6i_flags & RTF_CACHE) {
1645 		dst_metric_set(&rt->dst, RTAX_MTU, pmtu);
1646 		if (allfrag) {
1647 			u32 features = dst_metric(&rt->dst, RTAX_FEATURES);
1648 			features |= RTAX_FEATURE_ALLFRAG;
1649 			dst_metric_set(&rt->dst, RTAX_FEATURES, features);
1650 		}
1651 		dst_set_expires(&rt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires);
1652 		rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES;
1653 		goto out;
1654 	}
1655 
1656 	/* Network route.
1657 	   Two cases are possible:
1658 	   1. It is connected route. Action: COW
1659 	   2. It is gatewayed route or NONEXTHOP route. Action: clone it.
1660 	 */
1661 	if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP))
1662 		nrt = rt6_alloc_cow(rt, daddr, saddr);
1663 	else
1664 		nrt = rt6_alloc_clone(rt, daddr);
1665 
1666 	if (nrt) {
1667 		dst_metric_set(&nrt->dst, RTAX_MTU, pmtu);
1668 		if (allfrag) {
1669 			u32 features = dst_metric(&nrt->dst, RTAX_FEATURES);
1670 			features |= RTAX_FEATURE_ALLFRAG;
1671 			dst_metric_set(&nrt->dst, RTAX_FEATURES, features);
1672 		}
1673 
1674 		/* According to RFC 1981, detecting PMTU increase shouldn't be
1675 		 * happened within 5 mins, the recommended timer is 10 mins.
1676 		 * Here this route expiration time is set to ip6_rt_mtu_expires
1677 		 * which is 10 mins. After 10 mins the decreased pmtu is expired
1678 		 * and detecting PMTU increase will be automatically happened.
1679 		 */
1680 		dst_set_expires(&nrt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires);
1681 		nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES;
1682 
1683 		ip6_ins_rt(nrt);
1684 	}
1685 out:
1686 	dst_release(&rt->dst);
1687 }
1688 
1689 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
1690 			struct net_device *dev, u32 pmtu)
1691 {
1692 	struct net *net = dev_net(dev);
1693 
1694 	/*
1695 	 * RFC 1981 states that a node "MUST reduce the size of the packets it
1696 	 * is sending along the path" that caused the Packet Too Big message.
1697 	 * Since it's not possible in the general case to determine which
1698 	 * interface was used to send the original packet, we update the MTU
1699 	 * on the interface that will be used to send future packets. We also
1700 	 * update the MTU on the interface that received the Packet Too Big in
1701 	 * case the original packet was forced out that interface with
1702 	 * SO_BINDTODEVICE or similar. This is the next best thing to the
1703 	 * correct behaviour, which would be to update the MTU on all
1704 	 * interfaces.
1705 	 */
1706 	rt6_do_pmtu_disc(daddr, saddr, net, pmtu, 0);
1707 	rt6_do_pmtu_disc(daddr, saddr, net, pmtu, dev->ifindex);
1708 }
1709 
1710 /*
1711  *	Misc support functions
1712  */
1713 
1714 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)
1715 {
1716 	struct net *net = dev_net(ort->rt6i_dev);
1717 	struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
1718 
1719 	if (rt) {
1720 		rt->dst.input = ort->dst.input;
1721 		rt->dst.output = ort->dst.output;
1722 
1723 		dst_copy_metrics(&rt->dst, &ort->dst);
1724 		rt->dst.error = ort->dst.error;
1725 		rt->dst.dev = ort->dst.dev;
1726 		if (rt->dst.dev)
1727 			dev_hold(rt->dst.dev);
1728 		rt->rt6i_idev = ort->rt6i_idev;
1729 		if (rt->rt6i_idev)
1730 			in6_dev_hold(rt->rt6i_idev);
1731 		rt->dst.lastuse = jiffies;
1732 		rt->rt6i_expires = 0;
1733 
1734 		ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway);
1735 		rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;
1736 		rt->rt6i_metric = 0;
1737 
1738 		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
1739 #ifdef CONFIG_IPV6_SUBTREES
1740 		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
1741 #endif
1742 		rt->rt6i_table = ort->rt6i_table;
1743 	}
1744 	return rt;
1745 }
1746 
1747 #ifdef CONFIG_IPV6_ROUTE_INFO
1748 static struct rt6_info *rt6_get_route_info(struct net *net,
1749 					   struct in6_addr *prefix, int prefixlen,
1750 					   struct in6_addr *gwaddr, int ifindex)
1751 {
1752 	struct fib6_node *fn;
1753 	struct rt6_info *rt = NULL;
1754 	struct fib6_table *table;
1755 
1756 	table = fib6_get_table(net, RT6_TABLE_INFO);
1757 	if (table == NULL)
1758 		return NULL;
1759 
1760 	write_lock_bh(&table->tb6_lock);
1761 	fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0);
1762 	if (!fn)
1763 		goto out;
1764 
1765 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
1766 		if (rt->rt6i_dev->ifindex != ifindex)
1767 			continue;
1768 		if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY))
1769 			continue;
1770 		if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr))
1771 			continue;
1772 		dst_hold(&rt->dst);
1773 		break;
1774 	}
1775 out:
1776 	write_unlock_bh(&table->tb6_lock);
1777 	return rt;
1778 }
1779 
1780 static struct rt6_info *rt6_add_route_info(struct net *net,
1781 					   struct in6_addr *prefix, int prefixlen,
1782 					   struct in6_addr *gwaddr, int ifindex,
1783 					   unsigned pref)
1784 {
1785 	struct fib6_config cfg = {
1786 		.fc_table	= RT6_TABLE_INFO,
1787 		.fc_metric	= IP6_RT_PRIO_USER,
1788 		.fc_ifindex	= ifindex,
1789 		.fc_dst_len	= prefixlen,
1790 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
1791 				  RTF_UP | RTF_PREF(pref),
1792 		.fc_nlinfo.pid = 0,
1793 		.fc_nlinfo.nlh = NULL,
1794 		.fc_nlinfo.nl_net = net,
1795 	};
1796 
1797 	ipv6_addr_copy(&cfg.fc_dst, prefix);
1798 	ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1799 
1800 	/* We should treat it as a default route if prefix length is 0. */
1801 	if (!prefixlen)
1802 		cfg.fc_flags |= RTF_DEFAULT;
1803 
1804 	ip6_route_add(&cfg);
1805 
1806 	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex);
1807 }
1808 #endif
1809 
1810 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev)
1811 {
1812 	struct rt6_info *rt;
1813 	struct fib6_table *table;
1814 
1815 	table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT);
1816 	if (table == NULL)
1817 		return NULL;
1818 
1819 	write_lock_bh(&table->tb6_lock);
1820 	for (rt = table->tb6_root.leaf; rt; rt=rt->dst.rt6_next) {
1821 		if (dev == rt->rt6i_dev &&
1822 		    ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
1823 		    ipv6_addr_equal(&rt->rt6i_gateway, addr))
1824 			break;
1825 	}
1826 	if (rt)
1827 		dst_hold(&rt->dst);
1828 	write_unlock_bh(&table->tb6_lock);
1829 	return rt;
1830 }
1831 
1832 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr,
1833 				     struct net_device *dev,
1834 				     unsigned int pref)
1835 {
1836 	struct fib6_config cfg = {
1837 		.fc_table	= RT6_TABLE_DFLT,
1838 		.fc_metric	= IP6_RT_PRIO_USER,
1839 		.fc_ifindex	= dev->ifindex,
1840 		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
1841 				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
1842 		.fc_nlinfo.pid = 0,
1843 		.fc_nlinfo.nlh = NULL,
1844 		.fc_nlinfo.nl_net = dev_net(dev),
1845 	};
1846 
1847 	ipv6_addr_copy(&cfg.fc_gateway, gwaddr);
1848 
1849 	ip6_route_add(&cfg);
1850 
1851 	return rt6_get_dflt_router(gwaddr, dev);
1852 }
1853 
1854 void rt6_purge_dflt_routers(struct net *net)
1855 {
1856 	struct rt6_info *rt;
1857 	struct fib6_table *table;
1858 
1859 	/* NOTE: Keep consistent with rt6_get_dflt_router */
1860 	table = fib6_get_table(net, RT6_TABLE_DFLT);
1861 	if (table == NULL)
1862 		return;
1863 
1864 restart:
1865 	read_lock_bh(&table->tb6_lock);
1866 	for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) {
1867 		if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) {
1868 			dst_hold(&rt->dst);
1869 			read_unlock_bh(&table->tb6_lock);
1870 			ip6_del_rt(rt);
1871 			goto restart;
1872 		}
1873 	}
1874 	read_unlock_bh(&table->tb6_lock);
1875 }
1876 
1877 static void rtmsg_to_fib6_config(struct net *net,
1878 				 struct in6_rtmsg *rtmsg,
1879 				 struct fib6_config *cfg)
1880 {
1881 	memset(cfg, 0, sizeof(*cfg));
1882 
1883 	cfg->fc_table = RT6_TABLE_MAIN;
1884 	cfg->fc_ifindex = rtmsg->rtmsg_ifindex;
1885 	cfg->fc_metric = rtmsg->rtmsg_metric;
1886 	cfg->fc_expires = rtmsg->rtmsg_info;
1887 	cfg->fc_dst_len = rtmsg->rtmsg_dst_len;
1888 	cfg->fc_src_len = rtmsg->rtmsg_src_len;
1889 	cfg->fc_flags = rtmsg->rtmsg_flags;
1890 
1891 	cfg->fc_nlinfo.nl_net = net;
1892 
1893 	ipv6_addr_copy(&cfg->fc_dst, &rtmsg->rtmsg_dst);
1894 	ipv6_addr_copy(&cfg->fc_src, &rtmsg->rtmsg_src);
1895 	ipv6_addr_copy(&cfg->fc_gateway, &rtmsg->rtmsg_gateway);
1896 }
1897 
1898 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
1899 {
1900 	struct fib6_config cfg;
1901 	struct in6_rtmsg rtmsg;
1902 	int err;
1903 
1904 	switch(cmd) {
1905 	case SIOCADDRT:		/* Add a route */
1906 	case SIOCDELRT:		/* Delete a route */
1907 		if (!capable(CAP_NET_ADMIN))
1908 			return -EPERM;
1909 		err = copy_from_user(&rtmsg, arg,
1910 				     sizeof(struct in6_rtmsg));
1911 		if (err)
1912 			return -EFAULT;
1913 
1914 		rtmsg_to_fib6_config(net, &rtmsg, &cfg);
1915 
1916 		rtnl_lock();
1917 		switch (cmd) {
1918 		case SIOCADDRT:
1919 			err = ip6_route_add(&cfg);
1920 			break;
1921 		case SIOCDELRT:
1922 			err = ip6_route_del(&cfg);
1923 			break;
1924 		default:
1925 			err = -EINVAL;
1926 		}
1927 		rtnl_unlock();
1928 
1929 		return err;
1930 	}
1931 
1932 	return -EINVAL;
1933 }
1934 
1935 /*
1936  *	Drop the packet on the floor
1937  */
1938 
1939 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
1940 {
1941 	int type;
1942 	struct dst_entry *dst = skb_dst(skb);
1943 	switch (ipstats_mib_noroutes) {
1944 	case IPSTATS_MIB_INNOROUTES:
1945 		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
1946 		if (type == IPV6_ADDR_ANY) {
1947 			IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
1948 				      IPSTATS_MIB_INADDRERRORS);
1949 			break;
1950 		}
1951 		/* FALLTHROUGH */
1952 	case IPSTATS_MIB_OUTNOROUTES:
1953 		IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
1954 			      ipstats_mib_noroutes);
1955 		break;
1956 	}
1957 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
1958 	kfree_skb(skb);
1959 	return 0;
1960 }
1961 
1962 static int ip6_pkt_discard(struct sk_buff *skb)
1963 {
1964 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
1965 }
1966 
1967 static int ip6_pkt_discard_out(struct sk_buff *skb)
1968 {
1969 	skb->dev = skb_dst(skb)->dev;
1970 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
1971 }
1972 
1973 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1974 
1975 static int ip6_pkt_prohibit(struct sk_buff *skb)
1976 {
1977 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
1978 }
1979 
1980 static int ip6_pkt_prohibit_out(struct sk_buff *skb)
1981 {
1982 	skb->dev = skb_dst(skb)->dev;
1983 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
1984 }
1985 
1986 #endif
1987 
1988 /*
1989  *	Allocate a dst for local (unicast / anycast) address.
1990  */
1991 
1992 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
1993 				    const struct in6_addr *addr,
1994 				    int anycast)
1995 {
1996 	struct net *net = dev_net(idev->dev);
1997 	struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops);
1998 	struct neighbour *neigh;
1999 
2000 	if (rt == NULL) {
2001 		if (net_ratelimit())
2002 			pr_warning("IPv6:  Maximum number of routes reached,"
2003 				   " consider increasing route/max_size.\n");
2004 		return ERR_PTR(-ENOMEM);
2005 	}
2006 
2007 	dev_hold(net->loopback_dev);
2008 	in6_dev_hold(idev);
2009 
2010 	rt->dst.flags = DST_HOST;
2011 	rt->dst.input = ip6_input;
2012 	rt->dst.output = ip6_output;
2013 	rt->rt6i_dev = net->loopback_dev;
2014 	rt->rt6i_idev = idev;
2015 	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, -1);
2016 	rt->dst.obsolete = -1;
2017 
2018 	rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP;
2019 	if (anycast)
2020 		rt->rt6i_flags |= RTF_ANYCAST;
2021 	else
2022 		rt->rt6i_flags |= RTF_LOCAL;
2023 	neigh = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway);
2024 	if (IS_ERR(neigh)) {
2025 		dst_free(&rt->dst);
2026 
2027 		return ERR_CAST(neigh);
2028 	}
2029 	rt->rt6i_nexthop = neigh;
2030 
2031 	ipv6_addr_copy(&rt->rt6i_dst.addr, addr);
2032 	rt->rt6i_dst.plen = 128;
2033 	rt->rt6i_table = fib6_get_table(net, RT6_TABLE_LOCAL);
2034 
2035 	atomic_set(&rt->dst.__refcnt, 1);
2036 
2037 	return rt;
2038 }
2039 
2040 struct arg_dev_net {
2041 	struct net_device *dev;
2042 	struct net *net;
2043 };
2044 
2045 static int fib6_ifdown(struct rt6_info *rt, void *arg)
2046 {
2047 	const struct arg_dev_net *adn = arg;
2048 	const struct net_device *dev = adn->dev;
2049 
2050 	if ((rt->rt6i_dev == dev || dev == NULL) &&
2051 	    rt != adn->net->ipv6.ip6_null_entry) {
2052 		RT6_TRACE("deleted by ifdown %p\n", rt);
2053 		return -1;
2054 	}
2055 	return 0;
2056 }
2057 
2058 void rt6_ifdown(struct net *net, struct net_device *dev)
2059 {
2060 	struct arg_dev_net adn = {
2061 		.dev = dev,
2062 		.net = net,
2063 	};
2064 
2065 	fib6_clean_all(net, fib6_ifdown, 0, &adn);
2066 	icmp6_clean_all(fib6_ifdown, &adn);
2067 }
2068 
2069 struct rt6_mtu_change_arg
2070 {
2071 	struct net_device *dev;
2072 	unsigned mtu;
2073 };
2074 
2075 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg)
2076 {
2077 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
2078 	struct inet6_dev *idev;
2079 
2080 	/* In IPv6 pmtu discovery is not optional,
2081 	   so that RTAX_MTU lock cannot disable it.
2082 	   We still use this lock to block changes
2083 	   caused by addrconf/ndisc.
2084 	*/
2085 
2086 	idev = __in6_dev_get(arg->dev);
2087 	if (idev == NULL)
2088 		return 0;
2089 
2090 	/* For administrative MTU increase, there is no way to discover
2091 	   IPv6 PMTU increase, so PMTU increase should be updated here.
2092 	   Since RFC 1981 doesn't include administrative MTU increase
2093 	   update PMTU increase is a MUST. (i.e. jumbo frame)
2094 	 */
2095 	/*
2096 	   If new MTU is less than route PMTU, this new MTU will be the
2097 	   lowest MTU in the path, update the route PMTU to reflect PMTU
2098 	   decreases; if new MTU is greater than route PMTU, and the
2099 	   old MTU is the lowest MTU in the path, update the route PMTU
2100 	   to reflect the increase. In this case if the other nodes' MTU
2101 	   also have the lowest MTU, TOO BIG MESSAGE will be lead to
2102 	   PMTU discouvery.
2103 	 */
2104 	if (rt->rt6i_dev == arg->dev &&
2105 	    !dst_metric_locked(&rt->dst, RTAX_MTU) &&
2106 	    (dst_mtu(&rt->dst) >= arg->mtu ||
2107 	     (dst_mtu(&rt->dst) < arg->mtu &&
2108 	      dst_mtu(&rt->dst) == idev->cnf.mtu6))) {
2109 		dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);
2110 	}
2111 	return 0;
2112 }
2113 
2114 void rt6_mtu_change(struct net_device *dev, unsigned mtu)
2115 {
2116 	struct rt6_mtu_change_arg arg = {
2117 		.dev = dev,
2118 		.mtu = mtu,
2119 	};
2120 
2121 	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, 0, &arg);
2122 }
2123 
2124 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
2125 	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
2126 	[RTA_OIF]               = { .type = NLA_U32 },
2127 	[RTA_IIF]		= { .type = NLA_U32 },
2128 	[RTA_PRIORITY]          = { .type = NLA_U32 },
2129 	[RTA_METRICS]           = { .type = NLA_NESTED },
2130 };
2131 
2132 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
2133 			      struct fib6_config *cfg)
2134 {
2135 	struct rtmsg *rtm;
2136 	struct nlattr *tb[RTA_MAX+1];
2137 	int err;
2138 
2139 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2140 	if (err < 0)
2141 		goto errout;
2142 
2143 	err = -EINVAL;
2144 	rtm = nlmsg_data(nlh);
2145 	memset(cfg, 0, sizeof(*cfg));
2146 
2147 	cfg->fc_table = rtm->rtm_table;
2148 	cfg->fc_dst_len = rtm->rtm_dst_len;
2149 	cfg->fc_src_len = rtm->rtm_src_len;
2150 	cfg->fc_flags = RTF_UP;
2151 	cfg->fc_protocol = rtm->rtm_protocol;
2152 
2153 	if (rtm->rtm_type == RTN_UNREACHABLE)
2154 		cfg->fc_flags |= RTF_REJECT;
2155 
2156 	if (rtm->rtm_type == RTN_LOCAL)
2157 		cfg->fc_flags |= RTF_LOCAL;
2158 
2159 	cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
2160 	cfg->fc_nlinfo.nlh = nlh;
2161 	cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
2162 
2163 	if (tb[RTA_GATEWAY]) {
2164 		nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16);
2165 		cfg->fc_flags |= RTF_GATEWAY;
2166 	}
2167 
2168 	if (tb[RTA_DST]) {
2169 		int plen = (rtm->rtm_dst_len + 7) >> 3;
2170 
2171 		if (nla_len(tb[RTA_DST]) < plen)
2172 			goto errout;
2173 
2174 		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
2175 	}
2176 
2177 	if (tb[RTA_SRC]) {
2178 		int plen = (rtm->rtm_src_len + 7) >> 3;
2179 
2180 		if (nla_len(tb[RTA_SRC]) < plen)
2181 			goto errout;
2182 
2183 		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
2184 	}
2185 
2186 	if (tb[RTA_OIF])
2187 		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
2188 
2189 	if (tb[RTA_PRIORITY])
2190 		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
2191 
2192 	if (tb[RTA_METRICS]) {
2193 		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
2194 		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
2195 	}
2196 
2197 	if (tb[RTA_TABLE])
2198 		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
2199 
2200 	err = 0;
2201 errout:
2202 	return err;
2203 }
2204 
2205 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2206 {
2207 	struct fib6_config cfg;
2208 	int err;
2209 
2210 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2211 	if (err < 0)
2212 		return err;
2213 
2214 	return ip6_route_del(&cfg);
2215 }
2216 
2217 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
2218 {
2219 	struct fib6_config cfg;
2220 	int err;
2221 
2222 	err = rtm_to_fib6_config(skb, nlh, &cfg);
2223 	if (err < 0)
2224 		return err;
2225 
2226 	return ip6_route_add(&cfg);
2227 }
2228 
2229 static inline size_t rt6_nlmsg_size(void)
2230 {
2231 	return NLMSG_ALIGN(sizeof(struct rtmsg))
2232 	       + nla_total_size(16) /* RTA_SRC */
2233 	       + nla_total_size(16) /* RTA_DST */
2234 	       + nla_total_size(16) /* RTA_GATEWAY */
2235 	       + nla_total_size(16) /* RTA_PREFSRC */
2236 	       + nla_total_size(4) /* RTA_TABLE */
2237 	       + nla_total_size(4) /* RTA_IIF */
2238 	       + nla_total_size(4) /* RTA_OIF */
2239 	       + nla_total_size(4) /* RTA_PRIORITY */
2240 	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
2241 	       + nla_total_size(sizeof(struct rta_cacheinfo));
2242 }
2243 
2244 static int rt6_fill_node(struct net *net,
2245 			 struct sk_buff *skb, struct rt6_info *rt,
2246 			 struct in6_addr *dst, struct in6_addr *src,
2247 			 int iif, int type, u32 pid, u32 seq,
2248 			 int prefix, int nowait, unsigned int flags)
2249 {
2250 	struct rtmsg *rtm;
2251 	struct nlmsghdr *nlh;
2252 	long expires;
2253 	u32 table;
2254 
2255 	if (prefix) {	/* user wants prefix routes only */
2256 		if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
2257 			/* success since this is not a prefix route */
2258 			return 1;
2259 		}
2260 	}
2261 
2262 	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags);
2263 	if (nlh == NULL)
2264 		return -EMSGSIZE;
2265 
2266 	rtm = nlmsg_data(nlh);
2267 	rtm->rtm_family = AF_INET6;
2268 	rtm->rtm_dst_len = rt->rt6i_dst.plen;
2269 	rtm->rtm_src_len = rt->rt6i_src.plen;
2270 	rtm->rtm_tos = 0;
2271 	if (rt->rt6i_table)
2272 		table = rt->rt6i_table->tb6_id;
2273 	else
2274 		table = RT6_TABLE_UNSPEC;
2275 	rtm->rtm_table = table;
2276 	NLA_PUT_U32(skb, RTA_TABLE, table);
2277 	if (rt->rt6i_flags&RTF_REJECT)
2278 		rtm->rtm_type = RTN_UNREACHABLE;
2279 	else if (rt->rt6i_flags&RTF_LOCAL)
2280 		rtm->rtm_type = RTN_LOCAL;
2281 	else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK))
2282 		rtm->rtm_type = RTN_LOCAL;
2283 	else
2284 		rtm->rtm_type = RTN_UNICAST;
2285 	rtm->rtm_flags = 0;
2286 	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2287 	rtm->rtm_protocol = rt->rt6i_protocol;
2288 	if (rt->rt6i_flags&RTF_DYNAMIC)
2289 		rtm->rtm_protocol = RTPROT_REDIRECT;
2290 	else if (rt->rt6i_flags & RTF_ADDRCONF)
2291 		rtm->rtm_protocol = RTPROT_KERNEL;
2292 	else if (rt->rt6i_flags&RTF_DEFAULT)
2293 		rtm->rtm_protocol = RTPROT_RA;
2294 
2295 	if (rt->rt6i_flags&RTF_CACHE)
2296 		rtm->rtm_flags |= RTM_F_CLONED;
2297 
2298 	if (dst) {
2299 		NLA_PUT(skb, RTA_DST, 16, dst);
2300 		rtm->rtm_dst_len = 128;
2301 	} else if (rtm->rtm_dst_len)
2302 		NLA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr);
2303 #ifdef CONFIG_IPV6_SUBTREES
2304 	if (src) {
2305 		NLA_PUT(skb, RTA_SRC, 16, src);
2306 		rtm->rtm_src_len = 128;
2307 	} else if (rtm->rtm_src_len)
2308 		NLA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr);
2309 #endif
2310 	if (iif) {
2311 #ifdef CONFIG_IPV6_MROUTE
2312 		if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) {
2313 			int err = ip6mr_get_route(net, skb, rtm, nowait);
2314 			if (err <= 0) {
2315 				if (!nowait) {
2316 					if (err == 0)
2317 						return 0;
2318 					goto nla_put_failure;
2319 				} else {
2320 					if (err == -EMSGSIZE)
2321 						goto nla_put_failure;
2322 				}
2323 			}
2324 		} else
2325 #endif
2326 			NLA_PUT_U32(skb, RTA_IIF, iif);
2327 	} else if (dst) {
2328 		struct inet6_dev *idev = ip6_dst_idev(&rt->dst);
2329 		struct in6_addr saddr_buf;
2330 		if (ipv6_dev_get_saddr(net, idev ? idev->dev : NULL,
2331 				       dst, 0, &saddr_buf) == 0)
2332 			NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
2333 	}
2334 
2335 	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
2336 		goto nla_put_failure;
2337 
2338 	if (rt->dst.neighbour)
2339 		NLA_PUT(skb, RTA_GATEWAY, 16, &rt->dst.neighbour->primary_key);
2340 
2341 	if (rt->dst.dev)
2342 		NLA_PUT_U32(skb, RTA_OIF, rt->rt6i_dev->ifindex);
2343 
2344 	NLA_PUT_U32(skb, RTA_PRIORITY, rt->rt6i_metric);
2345 
2346 	if (!(rt->rt6i_flags & RTF_EXPIRES))
2347 		expires = 0;
2348 	else if (rt->rt6i_expires - jiffies < INT_MAX)
2349 		expires = rt->rt6i_expires - jiffies;
2350 	else
2351 		expires = INT_MAX;
2352 
2353 	if (rtnl_put_cacheinfo(skb, &rt->dst, 0, 0, 0,
2354 			       expires, rt->dst.error) < 0)
2355 		goto nla_put_failure;
2356 
2357 	return nlmsg_end(skb, nlh);
2358 
2359 nla_put_failure:
2360 	nlmsg_cancel(skb, nlh);
2361 	return -EMSGSIZE;
2362 }
2363 
2364 int rt6_dump_route(struct rt6_info *rt, void *p_arg)
2365 {
2366 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
2367 	int prefix;
2368 
2369 	if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) {
2370 		struct rtmsg *rtm = nlmsg_data(arg->cb->nlh);
2371 		prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
2372 	} else
2373 		prefix = 0;
2374 
2375 	return rt6_fill_node(arg->net,
2376 		     arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
2377 		     NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
2378 		     prefix, 0, NLM_F_MULTI);
2379 }
2380 
2381 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
2382 {
2383 	struct net *net = sock_net(in_skb->sk);
2384 	struct nlattr *tb[RTA_MAX+1];
2385 	struct rt6_info *rt;
2386 	struct sk_buff *skb;
2387 	struct rtmsg *rtm;
2388 	struct flowi6 fl6;
2389 	int err, iif = 0;
2390 
2391 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
2392 	if (err < 0)
2393 		goto errout;
2394 
2395 	err = -EINVAL;
2396 	memset(&fl6, 0, sizeof(fl6));
2397 
2398 	if (tb[RTA_SRC]) {
2399 		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
2400 			goto errout;
2401 
2402 		ipv6_addr_copy(&fl6.saddr, nla_data(tb[RTA_SRC]));
2403 	}
2404 
2405 	if (tb[RTA_DST]) {
2406 		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
2407 			goto errout;
2408 
2409 		ipv6_addr_copy(&fl6.daddr, nla_data(tb[RTA_DST]));
2410 	}
2411 
2412 	if (tb[RTA_IIF])
2413 		iif = nla_get_u32(tb[RTA_IIF]);
2414 
2415 	if (tb[RTA_OIF])
2416 		fl6.flowi6_oif = nla_get_u32(tb[RTA_OIF]);
2417 
2418 	if (iif) {
2419 		struct net_device *dev;
2420 		dev = __dev_get_by_index(net, iif);
2421 		if (!dev) {
2422 			err = -ENODEV;
2423 			goto errout;
2424 		}
2425 	}
2426 
2427 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2428 	if (skb == NULL) {
2429 		err = -ENOBUFS;
2430 		goto errout;
2431 	}
2432 
2433 	/* Reserve room for dummy headers, this skb can pass
2434 	   through good chunk of routing engine.
2435 	 */
2436 	skb_reset_mac_header(skb);
2437 	skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
2438 
2439 	rt = (struct rt6_info*) ip6_route_output(net, NULL, &fl6);
2440 	skb_dst_set(skb, &rt->dst);
2441 
2442 	err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,
2443 			    RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
2444 			    nlh->nlmsg_seq, 0, 0, 0);
2445 	if (err < 0) {
2446 		kfree_skb(skb);
2447 		goto errout;
2448 	}
2449 
2450 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2451 errout:
2452 	return err;
2453 }
2454 
2455 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
2456 {
2457 	struct sk_buff *skb;
2458 	struct net *net = info->nl_net;
2459 	u32 seq;
2460 	int err;
2461 
2462 	err = -ENOBUFS;
2463 	seq = info->nlh != NULL ? info->nlh->nlmsg_seq : 0;
2464 
2465 	skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
2466 	if (skb == NULL)
2467 		goto errout;
2468 
2469 	err = rt6_fill_node(net, skb, rt, NULL, NULL, 0,
2470 				event, info->pid, seq, 0, 0, 0);
2471 	if (err < 0) {
2472 		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
2473 		WARN_ON(err == -EMSGSIZE);
2474 		kfree_skb(skb);
2475 		goto errout;
2476 	}
2477 	rtnl_notify(skb, net, info->pid, RTNLGRP_IPV6_ROUTE,
2478 		    info->nlh, gfp_any());
2479 	return;
2480 errout:
2481 	if (err < 0)
2482 		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
2483 }
2484 
2485 static int ip6_route_dev_notify(struct notifier_block *this,
2486 				unsigned long event, void *data)
2487 {
2488 	struct net_device *dev = (struct net_device *)data;
2489 	struct net *net = dev_net(dev);
2490 
2491 	if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) {
2492 		net->ipv6.ip6_null_entry->dst.dev = dev;
2493 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
2494 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2495 		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
2496 		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
2497 		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
2498 		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
2499 #endif
2500 	}
2501 
2502 	return NOTIFY_OK;
2503 }
2504 
2505 /*
2506  *	/proc
2507  */
2508 
2509 #ifdef CONFIG_PROC_FS
2510 
2511 struct rt6_proc_arg
2512 {
2513 	char *buffer;
2514 	int offset;
2515 	int length;
2516 	int skip;
2517 	int len;
2518 };
2519 
2520 static int rt6_info_route(struct rt6_info *rt, void *p_arg)
2521 {
2522 	struct seq_file *m = p_arg;
2523 
2524 	seq_printf(m, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
2525 
2526 #ifdef CONFIG_IPV6_SUBTREES
2527 	seq_printf(m, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
2528 #else
2529 	seq_puts(m, "00000000000000000000000000000000 00 ");
2530 #endif
2531 
2532 	if (rt->rt6i_nexthop) {
2533 		seq_printf(m, "%pi6", rt->rt6i_nexthop->primary_key);
2534 	} else {
2535 		seq_puts(m, "00000000000000000000000000000000");
2536 	}
2537 	seq_printf(m, " %08x %08x %08x %08x %8s\n",
2538 		   rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
2539 		   rt->dst.__use, rt->rt6i_flags,
2540 		   rt->rt6i_dev ? rt->rt6i_dev->name : "");
2541 	return 0;
2542 }
2543 
2544 static int ipv6_route_show(struct seq_file *m, void *v)
2545 {
2546 	struct net *net = (struct net *)m->private;
2547 	fib6_clean_all(net, rt6_info_route, 0, m);
2548 	return 0;
2549 }
2550 
2551 static int ipv6_route_open(struct inode *inode, struct file *file)
2552 {
2553 	return single_open_net(inode, file, ipv6_route_show);
2554 }
2555 
2556 static const struct file_operations ipv6_route_proc_fops = {
2557 	.owner		= THIS_MODULE,
2558 	.open		= ipv6_route_open,
2559 	.read		= seq_read,
2560 	.llseek		= seq_lseek,
2561 	.release	= single_release_net,
2562 };
2563 
2564 static int rt6_stats_seq_show(struct seq_file *seq, void *v)
2565 {
2566 	struct net *net = (struct net *)seq->private;
2567 	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
2568 		   net->ipv6.rt6_stats->fib_nodes,
2569 		   net->ipv6.rt6_stats->fib_route_nodes,
2570 		   net->ipv6.rt6_stats->fib_rt_alloc,
2571 		   net->ipv6.rt6_stats->fib_rt_entries,
2572 		   net->ipv6.rt6_stats->fib_rt_cache,
2573 		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
2574 		   net->ipv6.rt6_stats->fib_discarded_routes);
2575 
2576 	return 0;
2577 }
2578 
2579 static int rt6_stats_seq_open(struct inode *inode, struct file *file)
2580 {
2581 	return single_open_net(inode, file, rt6_stats_seq_show);
2582 }
2583 
2584 static const struct file_operations rt6_stats_seq_fops = {
2585 	.owner	 = THIS_MODULE,
2586 	.open	 = rt6_stats_seq_open,
2587 	.read	 = seq_read,
2588 	.llseek	 = seq_lseek,
2589 	.release = single_release_net,
2590 };
2591 #endif	/* CONFIG_PROC_FS */
2592 
2593 #ifdef CONFIG_SYSCTL
2594 
2595 static
2596 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write,
2597 			      void __user *buffer, size_t *lenp, loff_t *ppos)
2598 {
2599 	struct net *net;
2600 	int delay;
2601 	if (!write)
2602 		return -EINVAL;
2603 
2604 	net = (struct net *)ctl->extra1;
2605 	delay = net->ipv6.sysctl.flush_delay;
2606 	proc_dointvec(ctl, write, buffer, lenp, ppos);
2607 	fib6_run_gc(delay <= 0 ? ~0UL : (unsigned long)delay, net);
2608 	return 0;
2609 }
2610 
2611 ctl_table ipv6_route_table_template[] = {
2612 	{
2613 		.procname	=	"flush",
2614 		.data		=	&init_net.ipv6.sysctl.flush_delay,
2615 		.maxlen		=	sizeof(int),
2616 		.mode		=	0200,
2617 		.proc_handler	=	ipv6_sysctl_rtcache_flush
2618 	},
2619 	{
2620 		.procname	=	"gc_thresh",
2621 		.data		=	&ip6_dst_ops_template.gc_thresh,
2622 		.maxlen		=	sizeof(int),
2623 		.mode		=	0644,
2624 		.proc_handler	=	proc_dointvec,
2625 	},
2626 	{
2627 		.procname	=	"max_size",
2628 		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
2629 		.maxlen		=	sizeof(int),
2630 		.mode		=	0644,
2631 		.proc_handler	=	proc_dointvec,
2632 	},
2633 	{
2634 		.procname	=	"gc_min_interval",
2635 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2636 		.maxlen		=	sizeof(int),
2637 		.mode		=	0644,
2638 		.proc_handler	=	proc_dointvec_jiffies,
2639 	},
2640 	{
2641 		.procname	=	"gc_timeout",
2642 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
2643 		.maxlen		=	sizeof(int),
2644 		.mode		=	0644,
2645 		.proc_handler	=	proc_dointvec_jiffies,
2646 	},
2647 	{
2648 		.procname	=	"gc_interval",
2649 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
2650 		.maxlen		=	sizeof(int),
2651 		.mode		=	0644,
2652 		.proc_handler	=	proc_dointvec_jiffies,
2653 	},
2654 	{
2655 		.procname	=	"gc_elasticity",
2656 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
2657 		.maxlen		=	sizeof(int),
2658 		.mode		=	0644,
2659 		.proc_handler	=	proc_dointvec,
2660 	},
2661 	{
2662 		.procname	=	"mtu_expires",
2663 		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
2664 		.maxlen		=	sizeof(int),
2665 		.mode		=	0644,
2666 		.proc_handler	=	proc_dointvec_jiffies,
2667 	},
2668 	{
2669 		.procname	=	"min_adv_mss",
2670 		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
2671 		.maxlen		=	sizeof(int),
2672 		.mode		=	0644,
2673 		.proc_handler	=	proc_dointvec,
2674 	},
2675 	{
2676 		.procname	=	"gc_min_interval_ms",
2677 		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
2678 		.maxlen		=	sizeof(int),
2679 		.mode		=	0644,
2680 		.proc_handler	=	proc_dointvec_ms_jiffies,
2681 	},
2682 	{ }
2683 };
2684 
2685 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
2686 {
2687 	struct ctl_table *table;
2688 
2689 	table = kmemdup(ipv6_route_table_template,
2690 			sizeof(ipv6_route_table_template),
2691 			GFP_KERNEL);
2692 
2693 	if (table) {
2694 		table[0].data = &net->ipv6.sysctl.flush_delay;
2695 		table[0].extra1 = net;
2696 		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
2697 		table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
2698 		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2699 		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
2700 		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
2701 		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
2702 		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
2703 		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
2704 		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
2705 	}
2706 
2707 	return table;
2708 }
2709 #endif
2710 
2711 static int __net_init ip6_route_net_init(struct net *net)
2712 {
2713 	int ret = -ENOMEM;
2714 
2715 	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
2716 	       sizeof(net->ipv6.ip6_dst_ops));
2717 
2718 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
2719 		goto out_ip6_dst_ops;
2720 
2721 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
2722 					   sizeof(*net->ipv6.ip6_null_entry),
2723 					   GFP_KERNEL);
2724 	if (!net->ipv6.ip6_null_entry)
2725 		goto out_ip6_dst_entries;
2726 	net->ipv6.ip6_null_entry->dst.path =
2727 		(struct dst_entry *)net->ipv6.ip6_null_entry;
2728 	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
2729 	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
2730 			 ip6_template_metrics, true);
2731 
2732 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2733 	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
2734 					       sizeof(*net->ipv6.ip6_prohibit_entry),
2735 					       GFP_KERNEL);
2736 	if (!net->ipv6.ip6_prohibit_entry)
2737 		goto out_ip6_null_entry;
2738 	net->ipv6.ip6_prohibit_entry->dst.path =
2739 		(struct dst_entry *)net->ipv6.ip6_prohibit_entry;
2740 	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
2741 	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
2742 			 ip6_template_metrics, true);
2743 
2744 	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
2745 					       sizeof(*net->ipv6.ip6_blk_hole_entry),
2746 					       GFP_KERNEL);
2747 	if (!net->ipv6.ip6_blk_hole_entry)
2748 		goto out_ip6_prohibit_entry;
2749 	net->ipv6.ip6_blk_hole_entry->dst.path =
2750 		(struct dst_entry *)net->ipv6.ip6_blk_hole_entry;
2751 	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
2752 	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
2753 			 ip6_template_metrics, true);
2754 #endif
2755 
2756 	net->ipv6.sysctl.flush_delay = 0;
2757 	net->ipv6.sysctl.ip6_rt_max_size = 4096;
2758 	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
2759 	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
2760 	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
2761 	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
2762 	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
2763 	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
2764 
2765 #ifdef CONFIG_PROC_FS
2766 	proc_net_fops_create(net, "ipv6_route", 0, &ipv6_route_proc_fops);
2767 	proc_net_fops_create(net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops);
2768 #endif
2769 	net->ipv6.ip6_rt_gc_expire = 30*HZ;
2770 
2771 	ret = 0;
2772 out:
2773 	return ret;
2774 
2775 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2776 out_ip6_prohibit_entry:
2777 	kfree(net->ipv6.ip6_prohibit_entry);
2778 out_ip6_null_entry:
2779 	kfree(net->ipv6.ip6_null_entry);
2780 #endif
2781 out_ip6_dst_entries:
2782 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
2783 out_ip6_dst_ops:
2784 	goto out;
2785 }
2786 
2787 static void __net_exit ip6_route_net_exit(struct net *net)
2788 {
2789 #ifdef CONFIG_PROC_FS
2790 	proc_net_remove(net, "ipv6_route");
2791 	proc_net_remove(net, "rt6_stats");
2792 #endif
2793 	kfree(net->ipv6.ip6_null_entry);
2794 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2795 	kfree(net->ipv6.ip6_prohibit_entry);
2796 	kfree(net->ipv6.ip6_blk_hole_entry);
2797 #endif
2798 	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
2799 }
2800 
2801 static struct pernet_operations ip6_route_net_ops = {
2802 	.init = ip6_route_net_init,
2803 	.exit = ip6_route_net_exit,
2804 };
2805 
2806 static struct notifier_block ip6_route_dev_notifier = {
2807 	.notifier_call = ip6_route_dev_notify,
2808 	.priority = 0,
2809 };
2810 
2811 int __init ip6_route_init(void)
2812 {
2813 	int ret;
2814 
2815 	ret = -ENOMEM;
2816 	ip6_dst_ops_template.kmem_cachep =
2817 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
2818 				  SLAB_HWCACHE_ALIGN, NULL);
2819 	if (!ip6_dst_ops_template.kmem_cachep)
2820 		goto out;
2821 
2822 	ret = dst_entries_init(&ip6_dst_blackhole_ops);
2823 	if (ret)
2824 		goto out_kmem_cache;
2825 
2826 	ret = register_pernet_subsys(&ip6_route_net_ops);
2827 	if (ret)
2828 		goto out_dst_entries;
2829 
2830 	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
2831 
2832 	/* Registering of the loopback is done before this portion of code,
2833 	 * the loopback reference in rt6_info will not be taken, do it
2834 	 * manually for init_net */
2835 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
2836 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
2837   #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2838 	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
2839 	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
2840 	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
2841 	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
2842   #endif
2843 	ret = fib6_init();
2844 	if (ret)
2845 		goto out_register_subsys;
2846 
2847 	ret = xfrm6_init();
2848 	if (ret)
2849 		goto out_fib6_init;
2850 
2851 	ret = fib6_rules_init();
2852 	if (ret)
2853 		goto xfrm6_init;
2854 
2855 	ret = -ENOBUFS;
2856 	if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL) ||
2857 	    __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL) ||
2858 	    __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL))
2859 		goto fib6_rules_init;
2860 
2861 	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
2862 	if (ret)
2863 		goto fib6_rules_init;
2864 
2865 out:
2866 	return ret;
2867 
2868 fib6_rules_init:
2869 	fib6_rules_cleanup();
2870 xfrm6_init:
2871 	xfrm6_fini();
2872 out_fib6_init:
2873 	fib6_gc_cleanup();
2874 out_register_subsys:
2875 	unregister_pernet_subsys(&ip6_route_net_ops);
2876 out_dst_entries:
2877 	dst_entries_destroy(&ip6_dst_blackhole_ops);
2878 out_kmem_cache:
2879 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
2880 	goto out;
2881 }
2882 
2883 void ip6_route_cleanup(void)
2884 {
2885 	unregister_netdevice_notifier(&ip6_route_dev_notifier);
2886 	fib6_rules_cleanup();
2887 	xfrm6_fini();
2888 	fib6_gc_cleanup();
2889 	unregister_pernet_subsys(&ip6_route_net_ops);
2890 	dst_entries_destroy(&ip6_dst_blackhole_ops);
2891 	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
2892 }
2893