xref: /linux/net/ipv6/addrlabel.c (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IPv6 Address Label subsystem
4  * for the IPv6 "Default" Source Address Selection
5  *
6  * Copyright (C)2007 USAGI/WIDE Project
7  */
8 /*
9  * Author:
10  *	YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/rcupdate.h>
16 #include <linux/in6.h>
17 #include <linux/slab.h>
18 #include <net/addrconf.h>
19 #include <linux/if_addrlabel.h>
20 #include <linux/netlink.h>
21 #include <linux/rtnetlink.h>
22 
23 /*
24  * Policy Table
25  */
26 struct ip6addrlbl_entry {
27 	struct in6_addr prefix;
28 	int prefixlen;
29 	int ifindex;
30 	int addrtype;
31 	u32 label;
32 	struct hlist_node list;
33 	struct rcu_head rcu;
34 };
35 
36 /*
37  * Default policy table (RFC6724 + extensions)
38  *
39  * prefix		addr_type	label
40  * -------------------------------------------------------------------------
41  * ::1/128		LOOPBACK	0
42  * ::/0			N/A		1
43  * 2002::/16		N/A		2
44  * ::/96		COMPATv4	3
45  * ::ffff:0:0/96	V4MAPPED	4
46  * fc00::/7		N/A		5		ULA (RFC 4193)
47  * 2001::/32		N/A		6		Teredo (RFC 4380)
48  * 2001:10::/28		N/A		7		ORCHID (RFC 4843)
49  * fec0::/10		N/A		11		Site-local
50  *							(deprecated by RFC3879)
51  * 3ffe::/16		N/A		12		6bone
52  *
53  * Note: 0xffffffff is used if we do not have any policies.
54  * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
55  */
56 
57 #define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL
58 
59 static const __net_initconst struct ip6addrlbl_init_table
60 {
61 	const struct in6_addr *prefix;
62 	int prefixlen;
63 	u32 label;
64 } ip6addrlbl_init_table[] = {
65 	{	/* ::/0 */
66 		.prefix = &in6addr_any,
67 		.label = 1,
68 	}, {	/* fc00::/7 */
69 		.prefix = &(struct in6_addr){ { { 0xfc } } } ,
70 		.prefixlen = 7,
71 		.label = 5,
72 	}, {	/* fec0::/10 */
73 		.prefix = &(struct in6_addr){ { { 0xfe, 0xc0 } } },
74 		.prefixlen = 10,
75 		.label = 11,
76 	}, {	/* 2002::/16 */
77 		.prefix = &(struct in6_addr){ { { 0x20, 0x02 } } },
78 		.prefixlen = 16,
79 		.label = 2,
80 	}, {	/* 3ffe::/16 */
81 		.prefix = &(struct in6_addr){ { { 0x3f, 0xfe } } },
82 		.prefixlen = 16,
83 		.label = 12,
84 	}, {	/* 2001::/32 */
85 		.prefix = &(struct in6_addr){ { { 0x20, 0x01 } } },
86 		.prefixlen = 32,
87 		.label = 6,
88 	}, {	/* 2001:10::/28 */
89 		.prefix = &(struct in6_addr){ { { 0x20, 0x01, 0x00, 0x10 } } },
90 		.prefixlen = 28,
91 		.label = 7,
92 	}, {	/* ::ffff:0:0 */
93 		.prefix = &(struct in6_addr){ { { [10] = 0xff, [11] = 0xff } } },
94 		.prefixlen = 96,
95 		.label = 4,
96 	}, {	/* ::/96 */
97 		.prefix = &in6addr_any,
98 		.prefixlen = 96,
99 		.label = 3,
100 	}, {	/* ::1/128 */
101 		.prefix = &in6addr_loopback,
102 		.prefixlen = 128,
103 		.label = 0,
104 	}
105 };
106 
107 /* Find label */
__ip6addrlbl_match(const struct ip6addrlbl_entry * p,const struct in6_addr * addr,int addrtype,int ifindex)108 static bool __ip6addrlbl_match(const struct ip6addrlbl_entry *p,
109 			       const struct in6_addr *addr,
110 			       int addrtype, int ifindex)
111 {
112 	if (p->ifindex && p->ifindex != ifindex)
113 		return false;
114 	if (p->addrtype && p->addrtype != addrtype)
115 		return false;
116 	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
117 		return false;
118 	return true;
119 }
120 
__ipv6_addr_label(struct net * net,const struct in6_addr * addr,int type,int ifindex)121 static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
122 						  const struct in6_addr *addr,
123 						  int type, int ifindex)
124 {
125 	struct ip6addrlbl_entry *p;
126 
127 	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
128 		if (__ip6addrlbl_match(p, addr, type, ifindex))
129 			return p;
130 	}
131 	return NULL;
132 }
133 
ipv6_addr_label(struct net * net,const struct in6_addr * addr,int type,int ifindex)134 u32 ipv6_addr_label(struct net *net,
135 		    const struct in6_addr *addr, int type, int ifindex)
136 {
137 	u32 label;
138 	struct ip6addrlbl_entry *p;
139 
140 	type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
141 
142 	rcu_read_lock();
143 	p = __ipv6_addr_label(net, addr, type, ifindex);
144 	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
145 	rcu_read_unlock();
146 
147 	net_dbg_ratelimited("%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n", __func__, addr, type,
148 			    ifindex, label);
149 
150 	return label;
151 }
152 
153 /* allocate one entry */
ip6addrlbl_alloc(const struct in6_addr * prefix,int prefixlen,int ifindex,u32 label)154 static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
155 						 int prefixlen, int ifindex,
156 						 u32 label)
157 {
158 	struct ip6addrlbl_entry *newp;
159 	int addrtype;
160 
161 	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n", __func__,
162 			    prefix, prefixlen, ifindex, (unsigned int)label);
163 
164 	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
165 
166 	switch (addrtype) {
167 	case IPV6_ADDR_MAPPED:
168 		if (prefixlen > 96)
169 			return ERR_PTR(-EINVAL);
170 		if (prefixlen < 96)
171 			addrtype = 0;
172 		break;
173 	case IPV6_ADDR_COMPATv4:
174 		if (prefixlen != 96)
175 			addrtype = 0;
176 		break;
177 	case IPV6_ADDR_LOOPBACK:
178 		if (prefixlen != 128)
179 			addrtype = 0;
180 		break;
181 	}
182 
183 	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
184 	if (!newp)
185 		return ERR_PTR(-ENOMEM);
186 
187 	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
188 	newp->prefixlen = prefixlen;
189 	newp->ifindex = ifindex;
190 	newp->addrtype = addrtype;
191 	newp->label = label;
192 	INIT_HLIST_NODE(&newp->list);
193 	return newp;
194 }
195 
196 /* add a label */
__ip6addrlbl_add(struct net * net,struct ip6addrlbl_entry * newp,int replace)197 static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp,
198 			    int replace)
199 {
200 	struct ip6addrlbl_entry *last = NULL, *p = NULL;
201 	struct hlist_node *n;
202 	int ret = 0;
203 
204 	net_dbg_ratelimited("%s(newp=%p, replace=%d)\n", __func__, newp, replace);
205 
206 	hlist_for_each_entry_safe(p, n,	&net->ipv6.ip6addrlbl_table.head, list) {
207 		if (p->prefixlen == newp->prefixlen &&
208 		    p->ifindex == newp->ifindex &&
209 		    ipv6_addr_equal(&p->prefix, &newp->prefix)) {
210 			if (!replace) {
211 				ret = -EEXIST;
212 				goto out;
213 			}
214 			hlist_replace_rcu(&p->list, &newp->list);
215 			kfree_rcu(p, rcu);
216 			goto out;
217 		} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
218 			   (p->prefixlen < newp->prefixlen)) {
219 			hlist_add_before_rcu(&newp->list, &p->list);
220 			goto out;
221 		}
222 		last = p;
223 	}
224 	if (last)
225 		hlist_add_behind_rcu(&newp->list, &last->list);
226 	else
227 		hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head);
228 out:
229 	if (!ret)
230 		WRITE_ONCE(net->ipv6.ip6addrlbl_table.seq,
231 			   net->ipv6.ip6addrlbl_table.seq + 1);
232 	return ret;
233 }
234 
235 /* add a label */
ip6addrlbl_add(struct net * net,const struct in6_addr * prefix,int prefixlen,int ifindex,u32 label,int replace)236 static int ip6addrlbl_add(struct net *net,
237 			  const struct in6_addr *prefix, int prefixlen,
238 			  int ifindex, u32 label, int replace)
239 {
240 	struct ip6addrlbl_entry *newp;
241 	int ret = 0;
242 
243 	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
244 			    __func__, prefix, prefixlen, ifindex, (unsigned int)label, replace);
245 
246 	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
247 	if (IS_ERR(newp))
248 		return PTR_ERR(newp);
249 	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
250 	ret = __ip6addrlbl_add(net, newp, replace);
251 	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
252 	if (ret)
253 		kfree(newp);
254 	return ret;
255 }
256 
257 /* remove a label */
__ip6addrlbl_del(struct net * net,const struct in6_addr * prefix,int prefixlen,int ifindex)258 static int __ip6addrlbl_del(struct net *net,
259 			    const struct in6_addr *prefix, int prefixlen,
260 			    int ifindex)
261 {
262 	struct ip6addrlbl_entry *p = NULL;
263 	struct hlist_node *n;
264 	int ret = -ESRCH;
265 
266 	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
267 			    prefixlen, ifindex);
268 
269 	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
270 		if (p->prefixlen == prefixlen &&
271 		    p->ifindex == ifindex &&
272 		    ipv6_addr_equal(&p->prefix, prefix)) {
273 			hlist_del_rcu(&p->list);
274 			kfree_rcu(p, rcu);
275 			ret = 0;
276 			break;
277 		}
278 	}
279 	return ret;
280 }
281 
ip6addrlbl_del(struct net * net,const struct in6_addr * prefix,int prefixlen,int ifindex)282 static int ip6addrlbl_del(struct net *net,
283 			  const struct in6_addr *prefix, int prefixlen,
284 			  int ifindex)
285 {
286 	struct in6_addr prefix_buf;
287 	int ret;
288 
289 	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
290 			    prefixlen, ifindex);
291 
292 	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
293 	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
294 	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
295 	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
296 	return ret;
297 }
298 
299 /* add default label */
ip6addrlbl_net_init(struct net * net)300 static int __net_init ip6addrlbl_net_init(struct net *net)
301 {
302 	struct ip6addrlbl_entry *p = NULL;
303 	struct hlist_node *n;
304 	int err;
305 	int i;
306 
307 	spin_lock_init(&net->ipv6.ip6addrlbl_table.lock);
308 	INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);
309 
310 	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
311 		err = ip6addrlbl_add(net,
312 				     ip6addrlbl_init_table[i].prefix,
313 				     ip6addrlbl_init_table[i].prefixlen,
314 				     0,
315 				     ip6addrlbl_init_table[i].label, 0);
316 		if (err)
317 			goto err_ip6addrlbl_add;
318 	}
319 	return 0;
320 
321 err_ip6addrlbl_add:
322 	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
323 		hlist_del_rcu(&p->list);
324 		kfree_rcu(p, rcu);
325 	}
326 	return err;
327 }
328 
ip6addrlbl_net_exit(struct net * net)329 static void __net_exit ip6addrlbl_net_exit(struct net *net)
330 {
331 	struct ip6addrlbl_entry *p = NULL;
332 	struct hlist_node *n;
333 
334 	/* Remove all labels belonging to the exiting net */
335 	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
336 	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
337 		hlist_del_rcu(&p->list);
338 		kfree_rcu(p, rcu);
339 	}
340 	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
341 }
342 
343 static struct pernet_operations ipv6_addr_label_ops = {
344 	.init = ip6addrlbl_net_init,
345 	.exit = ip6addrlbl_net_exit,
346 };
347 
ipv6_addr_label_init(void)348 int __init ipv6_addr_label_init(void)
349 {
350 	return register_pernet_subsys(&ipv6_addr_label_ops);
351 }
352 
ipv6_addr_label_cleanup(void)353 void ipv6_addr_label_cleanup(void)
354 {
355 	unregister_pernet_subsys(&ipv6_addr_label_ops);
356 }
357 
358 static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
359 	[IFAL_ADDRESS]		= { .len = sizeof(struct in6_addr), },
360 	[IFAL_LABEL]		= { .len = sizeof(u32), },
361 };
362 
addrlbl_ifindex_exists(struct net * net,int ifindex)363 static bool addrlbl_ifindex_exists(struct net *net, int ifindex)
364 {
365 
366 	struct net_device *dev;
367 
368 	rcu_read_lock();
369 	dev = dev_get_by_index_rcu(net, ifindex);
370 	rcu_read_unlock();
371 
372 	return dev != NULL;
373 }
374 
ip6addrlbl_newdel(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)375 static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
376 			     struct netlink_ext_ack *extack)
377 {
378 	struct net *net = sock_net(skb->sk);
379 	struct ifaddrlblmsg *ifal;
380 	struct nlattr *tb[IFAL_MAX+1];
381 	struct in6_addr *pfx;
382 	u32 label;
383 	int err = 0;
384 
385 	err = nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb, IFAL_MAX,
386 				     ifal_policy, extack);
387 	if (err < 0)
388 		return err;
389 
390 	ifal = nlmsg_data(nlh);
391 
392 	if (ifal->ifal_family != AF_INET6 ||
393 	    ifal->ifal_prefixlen > 128)
394 		return -EINVAL;
395 
396 	if (!tb[IFAL_ADDRESS])
397 		return -EINVAL;
398 	pfx = nla_data(tb[IFAL_ADDRESS]);
399 
400 	if (!tb[IFAL_LABEL])
401 		return -EINVAL;
402 	label = nla_get_u32(tb[IFAL_LABEL]);
403 	if (label == IPV6_ADDR_LABEL_DEFAULT)
404 		return -EINVAL;
405 
406 	switch (nlh->nlmsg_type) {
407 	case RTM_NEWADDRLABEL:
408 		if (ifal->ifal_index &&
409 		    !addrlbl_ifindex_exists(net, ifal->ifal_index))
410 			return -EINVAL;
411 
412 		err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
413 				     ifal->ifal_index, label,
414 				     nlh->nlmsg_flags & NLM_F_REPLACE);
415 		break;
416 	case RTM_DELADDRLABEL:
417 		err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
418 				     ifal->ifal_index);
419 		break;
420 	default:
421 		err = -EOPNOTSUPP;
422 	}
423 	return err;
424 }
425 
ip6addrlbl_putmsg(struct nlmsghdr * nlh,int prefixlen,int ifindex,u32 lseq)426 static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
427 			      int prefixlen, int ifindex, u32 lseq)
428 {
429 	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
430 	ifal->ifal_family = AF_INET6;
431 	ifal->__ifal_reserved = 0;
432 	ifal->ifal_prefixlen = prefixlen;
433 	ifal->ifal_flags = 0;
434 	ifal->ifal_index = ifindex;
435 	ifal->ifal_seq = lseq;
436 };
437 
ip6addrlbl_fill(struct sk_buff * skb,const struct ip6addrlbl_entry * p,u32 lseq,u32 portid,u32 seq,int event,unsigned int flags)438 static int ip6addrlbl_fill(struct sk_buff *skb,
439 			   const struct ip6addrlbl_entry *p,
440 			   u32 lseq,
441 			   u32 portid, u32 seq, int event,
442 			   unsigned int flags)
443 {
444 	struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
445 					 sizeof(struct ifaddrlblmsg), flags);
446 	if (!nlh)
447 		return -EMSGSIZE;
448 
449 	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
450 
451 	if (nla_put_in6_addr(skb, IFAL_ADDRESS, &p->prefix) < 0 ||
452 	    nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
453 		nlmsg_cancel(skb, nlh);
454 		return -EMSGSIZE;
455 	}
456 
457 	nlmsg_end(skb, nlh);
458 	return 0;
459 }
460 
ip6addrlbl_valid_dump_req(const struct nlmsghdr * nlh,struct netlink_ext_ack * extack)461 static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh,
462 				     struct netlink_ext_ack *extack)
463 {
464 	struct ifaddrlblmsg *ifal;
465 
466 	ifal = nlmsg_payload(nlh, sizeof(*ifal));
467 	if (!ifal) {
468 		NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request");
469 		return -EINVAL;
470 	}
471 
472 	if (ifal->__ifal_reserved || ifal->ifal_prefixlen ||
473 	    ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) {
474 		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request");
475 		return -EINVAL;
476 	}
477 
478 	if (nlmsg_attrlen(nlh, sizeof(*ifal))) {
479 		NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump request");
480 		return -EINVAL;
481 	}
482 
483 	return 0;
484 }
485 
ip6addrlbl_dump(struct sk_buff * skb,struct netlink_callback * cb)486 static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
487 {
488 	const struct nlmsghdr *nlh = cb->nlh;
489 	struct net *net = sock_net(skb->sk);
490 	struct ip6addrlbl_entry *p;
491 	int idx = 0, s_idx = cb->args[0];
492 	int err = 0;
493 	u32 lseq;
494 
495 	if (cb->strict_check) {
496 		err = ip6addrlbl_valid_dump_req(nlh, cb->extack);
497 		if (err < 0)
498 			return err;
499 	}
500 
501 	rcu_read_lock();
502 	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
503 	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
504 		if (idx >= s_idx) {
505 			err = ip6addrlbl_fill(skb, p,
506 					      lseq,
507 					      NETLINK_CB(cb->skb).portid,
508 					      nlh->nlmsg_seq,
509 					      RTM_NEWADDRLABEL,
510 					      NLM_F_MULTI);
511 			if (err < 0)
512 				break;
513 		}
514 		idx++;
515 	}
516 	rcu_read_unlock();
517 	cb->args[0] = idx;
518 	return err;
519 }
520 
ip6addrlbl_msgsize(void)521 static inline int ip6addrlbl_msgsize(void)
522 {
523 	return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
524 		+ nla_total_size(16)	/* IFAL_ADDRESS */
525 		+ nla_total_size(4);	/* IFAL_LABEL */
526 }
527 
ip6addrlbl_valid_get_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)528 static int ip6addrlbl_valid_get_req(struct sk_buff *skb,
529 				    const struct nlmsghdr *nlh,
530 				    struct nlattr **tb,
531 				    struct netlink_ext_ack *extack)
532 {
533 	struct ifaddrlblmsg *ifal;
534 	int i, err;
535 
536 	ifal = nlmsg_payload(nlh, sizeof(*ifal));
537 	if (!ifal) {
538 		NL_SET_ERR_MSG_MOD(extack, "Invalid header for addrlabel get request");
539 		return -EINVAL;
540 	}
541 
542 	if (!netlink_strict_get_check(skb))
543 		return nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb,
544 					      IFAL_MAX, ifal_policy, extack);
545 
546 	if (ifal->__ifal_reserved || ifal->ifal_flags || ifal->ifal_seq) {
547 		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for addrlabel get request");
548 		return -EINVAL;
549 	}
550 
551 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifal), tb, IFAL_MAX,
552 					    ifal_policy, extack);
553 	if (err)
554 		return err;
555 
556 	for (i = 0; i <= IFAL_MAX; i++) {
557 		if (!tb[i])
558 			continue;
559 
560 		switch (i) {
561 		case IFAL_ADDRESS:
562 			break;
563 		default:
564 			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in addrlabel get request");
565 			return -EINVAL;
566 		}
567 	}
568 
569 	return 0;
570 }
571 
ip6addrlbl_get(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)572 static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
573 			  struct netlink_ext_ack *extack)
574 {
575 	struct net *net = sock_net(in_skb->sk);
576 	struct ifaddrlblmsg *ifal;
577 	struct nlattr *tb[IFAL_MAX+1];
578 	struct in6_addr *addr;
579 	u32 lseq;
580 	int err = 0;
581 	struct ip6addrlbl_entry *p;
582 	struct sk_buff *skb;
583 
584 	err = ip6addrlbl_valid_get_req(in_skb, nlh, tb, extack);
585 	if (err < 0)
586 		return err;
587 
588 	ifal = nlmsg_data(nlh);
589 
590 	if (ifal->ifal_family != AF_INET6 ||
591 	    ifal->ifal_prefixlen != 128)
592 		return -EINVAL;
593 
594 	if (ifal->ifal_index &&
595 	    !addrlbl_ifindex_exists(net, ifal->ifal_index))
596 		return -EINVAL;
597 
598 	if (!tb[IFAL_ADDRESS])
599 		return -EINVAL;
600 	addr = nla_data(tb[IFAL_ADDRESS]);
601 
602 	skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
603 	if (!skb)
604 		return -ENOBUFS;
605 
606 	err = -ESRCH;
607 
608 	rcu_read_lock();
609 	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
610 	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
611 	if (p)
612 		err = ip6addrlbl_fill(skb, p, lseq,
613 				      NETLINK_CB(in_skb).portid,
614 				      nlh->nlmsg_seq,
615 				      RTM_NEWADDRLABEL, 0);
616 	rcu_read_unlock();
617 
618 	if (err < 0) {
619 		WARN_ON(err == -EMSGSIZE);
620 		kfree_skb(skb);
621 	} else {
622 		err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
623 	}
624 	return err;
625 }
626 
627 static const struct rtnl_msg_handler ipv6_adddr_label_rtnl_msg_handlers[] __initconst_or_module = {
628 	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_NEWADDRLABEL,
629 	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
630 	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_DELADDRLABEL,
631 	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
632 	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_GETADDRLABEL,
633 	 .doit = ip6addrlbl_get, .dumpit = ip6addrlbl_dump,
634 	 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
635 };
636 
ipv6_addr_label_rtnl_register(void)637 int __init ipv6_addr_label_rtnl_register(void)
638 {
639 	return rtnl_register_many(ipv6_adddr_label_rtnl_msg_handlers);
640 }
641