[mirror_ubuntu-artful-kernel.git] / net / ipv6 / addrlabel.c

/*
 * IPv6 Address Label subsystem
 * for the IPv6 "Default" Source Address Selection
 *
 * Copyright (C)2007 USAGI/WIDE Project
 */
/*
 * Author:
 * 	YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/in6.h>
#include <net/addrconf.h>
#include <linux/if_addrlabel.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>

#if 0
#define ADDRLABEL(x...) printk(x)
#else
#define ADDRLABEL(x...) do { ; } while(0)
#endif

/*
 * Policy Table
 */
struct ip6addrlbl_entry
{
	struct in6_addr prefix;
	int prefixlen;
	int ifindex;
	int addrtype;
	u32 label;
	struct hlist_node list;
	atomic_t refcnt;
	struct rcu_head rcu;
};

static struct ip6addrlbl_table
{
	struct hlist_head head;
	spinlock_t lock;
	u32 seq;
} ip6addrlbl_table;

/*
 * Default policy table (RFC3484 + extensions)
 *
 * prefix		addr_type	label
 * -------------------------------------------------------------------------
 * ::1/128		LOOPBACK	0
 * ::/0			N/A		1
 * 2002::/16		N/A		2
 * ::/96		COMPATv4	3
 * ::ffff:0:0/96	V4MAPPED	4
 * fc00::/7		N/A		5		ULA (RFC 4193)
 * 2001::/32		N/A		6		Teredo (RFC 4380)
 * 2001:10::/28		N/A		7		ORCHID (RFC 4843)
 *
 * Note: 0xffffffff is used if we do not have any policies.
 */

#define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL

static const __initdata struct ip6addrlbl_init_table
{
	const struct in6_addr *prefix;
	int prefixlen;
	u32 label;
} ip6addrlbl_init_table[] = {
	{	/* ::/0 */
		.prefix = &in6addr_any,
		.label = 1,
	},{	/* fc00::/7 */
		.prefix = &(struct in6_addr){{{ 0xfc }}},
		.prefixlen = 7,
		.label = 5,
	},{	/* 2002::/16 */
		.prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
		.prefixlen = 16,
		.label = 2,
	},{	/* 2001::/32 */
		.prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
		.prefixlen = 32,
		.label = 6,
	},{	/* 2001:10::/28 */
		.prefix = &(struct in6_addr){{{ 0x20, 0x01, 0x00, 0x10 }}},
		.prefixlen = 28,
		.label = 7,
	},{	/* ::ffff:0:0 */
		.prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
		.prefixlen = 96,
		.label = 4,
	},{	/* ::/96 */
		.prefix = &in6addr_any,
		.prefixlen = 96,
		.label = 3,
	},{	/* ::1/128 */
		.prefix = &in6addr_loopback,
		.prefixlen = 128,
		.label = 0,
	}
};

/* Object management */
static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
{
	kfree(p);
}

static void ip6addrlbl_free_rcu(struct rcu_head *h)
{
	ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
}

static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
{
	return atomic_inc_not_zero(&p->refcnt);
}

static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
{
	if (atomic_dec_and_test(&p->refcnt))
		call_rcu(&p->rcu, ip6addrlbl_free_rcu);
}

/* Find label */
static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
			      const struct in6_addr *addr,
			      int addrtype, int ifindex)
{
	if (p->ifindex && p->ifindex != ifindex)
		return 0;
	if (p->addrtype && p->addrtype != addrtype)
		return 0;
	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
		return 0;
	return 1;
}

static struct ip6addrlbl_entry *__ipv6_addr_label(const struct in6_addr *addr,
						  int type, int ifindex)
{
	struct hlist_node *pos;
	struct ip6addrlbl_entry *p;
	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
		if (__ip6addrlbl_match(p, addr, type, ifindex))
			return p;
	}
	return NULL;
}

u32 ipv6_addr_label(const struct in6_addr *addr, int type, int ifindex)
{
	u32 label;
	struct ip6addrlbl_entry *p;

	type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;

	rcu_read_lock();
	p = __ipv6_addr_label(addr, type, ifindex);
	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
	rcu_read_unlock();

	ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
			__func__,
			NIP6(*addr), type, ifindex,
			label);

	return label;
}

/* allocate one entry */
static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
						 int prefixlen, int ifindex,
						 u32 label)
{
	struct ip6addrlbl_entry *newp;
	int addrtype;

	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
			__func__,
			NIP6(*prefix), prefixlen,
			ifindex,
			(unsigned int)label);

	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);

	switch (addrtype) {
	case IPV6_ADDR_MAPPED:
		if (prefixlen > 96)
			return ERR_PTR(-EINVAL);
		if (prefixlen < 96)
			addrtype = 0;
		break;
	case IPV6_ADDR_COMPATv4:
		if (prefixlen != 96)
			addrtype = 0;
		break;
	case IPV6_ADDR_LOOPBACK:
		if (prefixlen != 128)
			addrtype = 0;
		break;
	}

	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
	if (!newp)
		return ERR_PTR(-ENOMEM);

	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
	newp->prefixlen = prefixlen;
	newp->ifindex = ifindex;
	newp->addrtype = addrtype;
	newp->label = label;
	INIT_HLIST_NODE(&newp->list);
	atomic_set(&newp->refcnt, 1);
	return newp;
}

/* add a label */
static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
{
	int ret = 0;

	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
			__func__,
			newp, replace);

	if (hlist_empty(&ip6addrlbl_table.head)) {
		hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
	} else {
		struct hlist_node *pos, *n;
		struct ip6addrlbl_entry *p = NULL;
		hlist_for_each_entry_safe(p, pos, n,
					  &ip6addrlbl_table.head, list) {
			if (p->prefixlen == newp->prefixlen &&
			    p->ifindex == newp->ifindex &&
			    ipv6_addr_equal(&p->prefix, &newp->prefix)) {
				if (!replace) {
					ret = -EEXIST;
					goto out;
				}
				hlist_replace_rcu(&p->list, &newp->list);
				ip6addrlbl_put(p);
				goto out;
			} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
				   (p->prefixlen < newp->prefixlen)) {
				hlist_add_before_rcu(&newp->list, &p->list);
				goto out;
			}
		}
		hlist_add_after_rcu(&p->list, &newp->list);
	}
out:
	if (!ret)
		ip6addrlbl_table.seq++;
	return ret;
}

/* add a label */
static int ip6addrlbl_add(const struct in6_addr *prefix, int prefixlen,
			  int ifindex, u32 label, int replace)
{
	struct ip6addrlbl_entry *newp;
	int ret = 0;

	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
			__func__,
			NIP6(*prefix), prefixlen,
			ifindex,
			(unsigned int)label,
			replace);

	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
	if (IS_ERR(newp))
		return PTR_ERR(newp);
	spin_lock(&ip6addrlbl_table.lock);
	ret = __ip6addrlbl_add(newp, replace);
	spin_unlock(&ip6addrlbl_table.lock);
	if (ret)
		ip6addrlbl_free(newp);
	return ret;
}

/* remove a label */
static int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
			    int ifindex)
{
	struct ip6addrlbl_entry *p = NULL;
	struct hlist_node *pos, *n;
	int ret = -ESRCH;

	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
			__func__,
			NIP6(*prefix), prefixlen,
			ifindex);

	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
		if (p->prefixlen == prefixlen &&
		    p->ifindex == ifindex &&
		    ipv6_addr_equal(&p->prefix, prefix)) {
			hlist_del_rcu(&p->list);
			ip6addrlbl_put(p);
			ret = 0;
			break;
		}
	}
	return ret;
}

static int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
			  int ifindex)
{
	struct in6_addr prefix_buf;
	int ret;

	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
			__func__,
			NIP6(*prefix), prefixlen,
			ifindex);

	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
	spin_lock(&ip6addrlbl_table.lock);
	ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
	spin_unlock(&ip6addrlbl_table.lock);
	return ret;
}

/* add default label */
static __init int ip6addrlbl_init(void)
{
	int err = 0;
	int i;

	ADDRLABEL(KERN_DEBUG "%s()\n", __func__);

	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
		int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
					 ip6addrlbl_init_table[i].prefixlen,
					 0,
					 ip6addrlbl_init_table[i].label, 0);
		/* XXX: should we free all rules when we catch an error? */
		if (ret && (!err || err != -ENOMEM))
			err = ret;
	}
	return err;
}

int __init ipv6_addr_label_init(void)
{
	spin_lock_init(&ip6addrlbl_table.lock);

	return ip6addrlbl_init();
}

static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
	[IFAL_ADDRESS]		= { .len = sizeof(struct in6_addr), },
	[IFAL_LABEL]		= { .len = sizeof(u32), },
};

static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
			     void *arg)
{
	struct net *net = skb->sk->sk_net;
	struct ifaddrlblmsg *ifal;
	struct nlattr *tb[IFAL_MAX+1];
	struct in6_addr *pfx;
	u32 label;
	int err = 0;

	if (net != &init_net)
		return 0;

	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	if (err < 0)
		return err;

	ifal = nlmsg_data(nlh);

	if (ifal->ifal_family != AF_INET6 ||
	    ifal->ifal_prefixlen > 128)
		return -EINVAL;

	if (ifal->ifal_index &&
	    !__dev_get_by_index(&init_net, ifal->ifal_index))
		return -EINVAL;

	if (!tb[IFAL_ADDRESS])
		return -EINVAL;

	pfx = nla_data(tb[IFAL_ADDRESS]);
	if (!pfx)
		return -EINVAL;

	if (!tb[IFAL_LABEL])
		return -EINVAL;
	label = nla_get_u32(tb[IFAL_LABEL]);
	if (label == IPV6_ADDR_LABEL_DEFAULT)
		return -EINVAL;

	switch(nlh->nlmsg_type) {
	case RTM_NEWADDRLABEL:
		err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
				     ifal->ifal_index, label,
				     nlh->nlmsg_flags & NLM_F_REPLACE);
		break;
	case RTM_DELADDRLABEL:
		err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
				     ifal->ifal_index);
		break;
	default:
		err = -EOPNOTSUPP;
	}
	return err;
}

static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
				     int prefixlen, int ifindex, u32 lseq)
{
	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
	ifal->ifal_family = AF_INET6;
	ifal->ifal_prefixlen = prefixlen;
	ifal->ifal_flags = 0;
	ifal->ifal_index = ifindex;
	ifal->ifal_seq = lseq;
};

static int ip6addrlbl_fill(struct sk_buff *skb,
			   struct ip6addrlbl_entry *p,
			   u32 lseq,
			   u32 pid, u32 seq, int event,
			   unsigned int flags)
{
	struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
					 sizeof(struct ifaddrlblmsg), flags);
	if (!nlh)
		return -EMSGSIZE;

	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);

	if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 ||
	    nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
		nlmsg_cancel(skb, nlh);
		return -EMSGSIZE;
	}

	return nlmsg_end(skb, nlh);
}

static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net *net = skb->sk->sk_net;
	struct ip6addrlbl_entry *p;
	struct hlist_node *pos;
	int idx = 0, s_idx = cb->args[0];
	int err;

	if (net != &init_net)
		return 0;

	rcu_read_lock();
	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
		if (idx >= s_idx) {
			if ((err = ip6addrlbl_fill(skb, p,
						   ip6addrlbl_table.seq,
						   NETLINK_CB(cb->skb).pid,
						   cb->nlh->nlmsg_seq,
						   RTM_NEWADDRLABEL,
						   NLM_F_MULTI)) <= 0)
				break;
		}
		idx++;
	}
	rcu_read_unlock();
	cb->args[0] = idx;
	return skb->len;
}

static inline int ip6addrlbl_msgsize(void)
{
	return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
		+ nla_total_size(16)	/* IFAL_ADDRESS */
		+ nla_total_size(4)	/* IFAL_LABEL */
	);
}

static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
			  void *arg)
{
	struct net *net = in_skb->sk->sk_net;
	struct ifaddrlblmsg *ifal;
	struct nlattr *tb[IFAL_MAX+1];
	struct in6_addr *addr;
	u32 lseq;
	int err = 0;
	struct ip6addrlbl_entry *p;
	struct sk_buff *skb;

	if (net != &init_net)
		return 0;

	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	if (err < 0)
		return err;

	ifal = nlmsg_data(nlh);

	if (ifal->ifal_family != AF_INET6 ||
	    ifal->ifal_prefixlen != 128)
		return -EINVAL;

	if (ifal->ifal_index &&
	    !__dev_get_by_index(&init_net, ifal->ifal_index))
		return -EINVAL;

	if (!tb[IFAL_ADDRESS])
		return -EINVAL;

	addr = nla_data(tb[IFAL_ADDRESS]);
	if (!addr)
		return -EINVAL;

	rcu_read_lock();
	p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
	if (p && ip6addrlbl_hold(p))
		p = NULL;
	lseq = ip6addrlbl_table.seq;
	rcu_read_unlock();

	if (!p) {
		err = -ESRCH;
		goto out;
	}

	if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
		ip6addrlbl_put(p);
		return -ENOBUFS;
	}

	err = ip6addrlbl_fill(skb, p, lseq,
			      NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
			      RTM_NEWADDRLABEL, 0);

	ip6addrlbl_put(p);

	if (err < 0) {
		WARN_ON(err == -EMSGSIZE);
		kfree_skb(skb);
		goto out;
	}

	err = rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
out:
	return err;
}

void __init ipv6_addr_label_rtnl_register(void)
{
	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
}
Commit	Line	Data
2a8cc6c8 YH	1	/*
	2	* IPv6 Address Label subsystem
	3	* for the IPv6 "Default" Source Address Selection
	4	*
	5	* Copyright (C)2007 USAGI/WIDE Project
	6	*/
	7	/*
	8	* Author:
	9	* YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/list.h>
	14	#include <linux/rcupdate.h>
	15	#include <linux/in6.h>
	16	#include <net/addrconf.h>
	17	#include <linux/if_addrlabel.h>
	18	#include <linux/netlink.h>
	19	#include <linux/rtnetlink.h>
	20
	21	#if 0
	22	#define ADDRLABEL(x...) printk(x)
	23	#else
	24	#define ADDRLABEL(x...) do { ; } while(0)
	25	#endif
	26
	27	/*
	28	* Policy Table
	29	*/
	30	struct ip6addrlbl_entry
	31	{
	32	struct in6_addr prefix;
	33	int prefixlen;
	34	int ifindex;
	35	int addrtype;
	36	u32 label;
	37	struct hlist_node list;
	38	atomic_t refcnt;
	39	struct rcu_head rcu;
	40	};
	41
	42	static struct ip6addrlbl_table
	43	{
	44	struct hlist_head head;
	45	spinlock_t lock;
	46	u32 seq;
	47	} ip6addrlbl_table;
	48
	49	/*
	50	* Default policy table (RFC3484 + extensions)
	51	*
	52	* prefix addr_type label
	53	* -------------------------------------------------------------------------
	54	* ::1/128 LOOPBACK 0
	55	* ::/0 N/A 1
	56	* 2002::/16 N/A 2
	57	* ::/96 COMPATv4 3
	58	* ::ffff:0:0/96 V4MAPPED 4
	59	* fc00::/7 N/A 5 ULA (RFC 4193)
	60	* 2001::/32 N/A 6 Teredo (RFC 4380)
5fe47b8a	61	* 2001:10::/28 N/A 7 ORCHID (RFC 4843)
2a8cc6c8 YH	62	*
	63	* Note: 0xffffffff is used if we do not have any policies.
	64	*/
	65
	66	#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
	67
	68	static const __initdata struct ip6addrlbl_init_table
	69	{
	70	const struct in6_addr *prefix;
	71	int prefixlen;
	72	u32 label;
	73	} ip6addrlbl_init_table[] = {
	74	{ /* ::/0 */
	75	.prefix = &in6addr_any,
	76	.label = 1,
	77	},{ /* fc00::/7 */
	78	.prefix = &(struct in6_addr){{{ 0xfc }}},
	79	.prefixlen = 7,
	80	.label = 5,
	81	},{ /* 2002::/16 */
	82	.prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
	83	.prefixlen = 16,
	84	.label = 2,
	85	},{ /* 2001::/32 */
	86	.prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
	87	.prefixlen = 32,
	88	.label = 6,
5fe47b8a JMT	89	},{ /* 2001:10::/28 */
	90	.prefix = &(struct in6_addr){{{ 0x20, 0x01, 0x00, 0x10 }}},
	91	.prefixlen = 28,
	92	.label = 7,
2a8cc6c8 YH	93	},{ /* ::ffff:0:0 */
	94	.prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
	95	.prefixlen = 96,
	96	.label = 4,
	97	},{ /* ::/96 */
	98	.prefix = &in6addr_any,
	99	.prefixlen = 96,
	100	.label = 3,
	101	},{ /* ::1/128 */
	102	.prefix = &in6addr_loopback,
	103	.prefixlen = 128,
	104	.label = 0,
	105	}
	106	};
	107
	108	/* Object management */
	109	static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
	110	{
	111	kfree(p);
	112	}
	113
85040bcb YH	114	static void ip6addrlbl_free_rcu(struct rcu_head *h)
	115	{
	116	ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
	117	}
	118
2a8cc6c8 YH	119	static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
	120	{
	121	return atomic_inc_not_zero(&p->refcnt);
	122	}
	123
	124	static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
	125	{
	126	if (atomic_dec_and_test(&p->refcnt))
85040bcb	127	call_rcu(&p->rcu, ip6addrlbl_free_rcu);
2a8cc6c8 YH	128	}
	129
	130	/* Find label */
	131	static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
	132	const struct in6_addr *addr,
	133	int addrtype, int ifindex)
	134	{
	135	if (p->ifindex && p->ifindex != ifindex)
	136	return 0;
	137	if (p->addrtype && p->addrtype != addrtype)
	138	return 0;
	139	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
	140	return 0;
	141	return 1;
	142	}
	143
	144	static struct ip6addrlbl_entry __ipv6_addr_label(const struct in6_addr addr,
	145	int type, int ifindex)
	146	{
	147	struct hlist_node *pos;
	148	struct ip6addrlbl_entry *p;
	149	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
	150	if (__ip6addrlbl_match(p, addr, type, ifindex))
	151	return p;
	152	}
	153	return NULL;
	154	}
	155
	156	u32 ipv6_addr_label(const struct in6_addr *addr, int type, int ifindex)
	157	{
	158	u32 label;
	159	struct ip6addrlbl_entry *p;
	160
	161	type &= IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK;
	162
	163	rcu_read_lock();
	164	p = __ipv6_addr_label(addr, type, ifindex);
	165	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
	166	rcu_read_unlock();
	167
	168	ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
0dc47877	169	__func__,
2a8cc6c8 YH	170	NIP6(*addr), type, ifindex,
	171	label);
	172
	173	return label;
	174	}
	175
	176	/* allocate one entry */
40fee36e YH	177	static struct ip6addrlbl_entry ip6addrlbl_alloc(const struct in6_addr prefix,
	178	int prefixlen, int ifindex,
	179	u32 label)
2a8cc6c8 YH	180	{
	181	struct ip6addrlbl_entry *newp;
	182	int addrtype;
	183
	184	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
0dc47877	185	__func__,
2a8cc6c8 YH	186	NIP6(*prefix), prefixlen,
	187	ifindex,
	188	(unsigned int)label);
	189
	190	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK);
	191
	192	switch (addrtype) {
	193	case IPV6_ADDR_MAPPED:
	194	if (prefixlen > 96)
	195	return ERR_PTR(-EINVAL);
	196	if (prefixlen < 96)
	197	addrtype = 0;
	198	break;
	199	case IPV6_ADDR_COMPATv4:
	200	if (prefixlen != 96)
	201	addrtype = 0;
	202	break;
	203	case IPV6_ADDR_LOOPBACK:
	204	if (prefixlen != 128)
	205	addrtype = 0;
	206	break;
	207	}
	208
	209	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
	210	if (!newp)
	211	return ERR_PTR(-ENOMEM);
	212
	213	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
	214	newp->prefixlen = prefixlen;
	215	newp->ifindex = ifindex;
	216	newp->addrtype = addrtype;
	217	newp->label = label;
	218	INIT_HLIST_NODE(&newp->list);
	219	atomic_set(&newp->refcnt, 1);
	220	return newp;
	221	}
	222
	223	/* add a label */
40fee36e	224	static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
2a8cc6c8 YH	225	{
	226	int ret = 0;
	227
	228	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
0dc47877	229	__func__,
2a8cc6c8 YH	230	newp, replace);
	231
	232	if (hlist_empty(&ip6addrlbl_table.head)) {
	233	hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
	234	} else {
	235	struct hlist_node pos, n;
	236	struct ip6addrlbl_entry *p = NULL;
	237	hlist_for_each_entry_safe(p, pos, n,
	238	&ip6addrlbl_table.head, list) {
	239	if (p->prefixlen == newp->prefixlen &&
	240	p->ifindex == newp->ifindex &&
	241	ipv6_addr_equal(&p->prefix, &newp->prefix)) {
	242	if (!replace) {
	243	ret = -EEXIST;
	244	goto out;
	245	}
	246	hlist_replace_rcu(&p->list, &newp->list);
	247	ip6addrlbl_put(p);
2a8cc6c8 YH	248	goto out;
	249	} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) \|\|
	250	(p->prefixlen < newp->prefixlen)) {
	251	hlist_add_before_rcu(&newp->list, &p->list);
	252	goto out;
	253	}
	254	}
	255	hlist_add_after_rcu(&p->list, &newp->list);
	256	}
	257	out:
	258	if (!ret)
	259	ip6addrlbl_table.seq++;
	260	return ret;
	261	}
	262
	263	/* add a label */
40fee36e YH	264	static int ip6addrlbl_add(const struct in6_addr *prefix, int prefixlen,
40fee36e YH	265	int ifindex, u32 label, int replace)
2a8cc6c8 YH	266	{
	267	struct ip6addrlbl_entry *newp;
	268	int ret = 0;
	269
	270	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
0dc47877	271	__func__,
2a8cc6c8 YH	272	NIP6(*prefix), prefixlen,
	273	ifindex,
	274	(unsigned int)label,
	275	replace);
	276
	277	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
	278	if (IS_ERR(newp))
	279	return PTR_ERR(newp);
	280	spin_lock(&ip6addrlbl_table.lock);
	281	ret = __ip6addrlbl_add(newp, replace);
	282	spin_unlock(&ip6addrlbl_table.lock);
	283	if (ret)
	284	ip6addrlbl_free(newp);
	285	return ret;
	286	}
	287
	288	/* remove a label */
40fee36e YH	289	static int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
40fee36e YH	290	int ifindex)
2a8cc6c8 YH	291	{
	292	struct ip6addrlbl_entry *p = NULL;
	293	struct hlist_node pos, n;
	294	int ret = -ESRCH;
	295
	296	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
0dc47877	297	__func__,
2a8cc6c8 YH	298	NIP6(*prefix), prefixlen,
	299	ifindex);
	300
	301	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
	302	if (p->prefixlen == prefixlen &&
	303	p->ifindex == ifindex &&
	304	ipv6_addr_equal(&p->prefix, prefix)) {
	305	hlist_del_rcu(&p->list);
	306	ip6addrlbl_put(p);
2a8cc6c8 YH	307	ret = 0;
	308	break;
	309	}
	310	}
	311	return ret;
	312	}
	313
40fee36e YH	314	static int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
40fee36e YH	315	int ifindex)
2a8cc6c8 YH	316	{
	317	struct in6_addr prefix_buf;
	318	int ret;
	319
	320	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
0dc47877	321	__func__,
2a8cc6c8 YH	322	NIP6(*prefix), prefixlen,
	323	ifindex);
	324
	325	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
	326	spin_lock(&ip6addrlbl_table.lock);
	327	ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
	328	spin_unlock(&ip6addrlbl_table.lock);
	329	return ret;
	330	}
	331
	332	/* add default label */
	333	static __init int ip6addrlbl_init(void)
	334	{
	335	int err = 0;
	336	int i;
	337
0dc47877	338	ADDRLABEL(KERN_DEBUG "%s()\n", __func__);
2a8cc6c8 YH	339
	340	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
	341	int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
	342	ip6addrlbl_init_table[i].prefixlen,
	343	0,
	344	ip6addrlbl_init_table[i].label, 0);
	345	/* XXX: should we free all rules when we catch an error? */
	346	if (ret && (!err \|\| err != -ENOMEM))
	347	err = ret;
	348	}
	349	return err;
	350	}
	351
	352	int __init ipv6_addr_label_init(void)
	353	{
	354	spin_lock_init(&ip6addrlbl_table.lock);
	355
	356	return ip6addrlbl_init();
	357	}
	358
	359	static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
	360	[IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
	361	[IFAL_LABEL] = { .len = sizeof(u32), },
	362	};
	363
	364	static int ip6addrlbl_newdel(struct sk_buff skb, struct nlmsghdr nlh,
	365	void *arg)
	366	{
b854272b	367	struct net *net = skb->sk->sk_net;
2a8cc6c8 YH	368	struct ifaddrlblmsg *ifal;
	369	struct nlattr *tb[IFAL_MAX+1];
	370	struct in6_addr *pfx;
	371	u32 label;
	372	int err = 0;
	373
b854272b DL	374	if (net != &init_net)
	375	return 0;
	376
2a8cc6c8 YH	377	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	378	if (err < 0)
	379	return err;
	380
	381	ifal = nlmsg_data(nlh);
	382
	383	if (ifal->ifal_family != AF_INET6 \|\|
	384	ifal->ifal_prefixlen > 128)
	385	return -EINVAL;
	386
	387	if (ifal->ifal_index &&
	388	!__dev_get_by_index(&init_net, ifal->ifal_index))
	389	return -EINVAL;
	390
	391	if (!tb[IFAL_ADDRESS])
	392	return -EINVAL;
	393
	394	pfx = nla_data(tb[IFAL_ADDRESS]);
	395	if (!pfx)
	396	return -EINVAL;
	397
	398	if (!tb[IFAL_LABEL])
	399	return -EINVAL;
	400	label = nla_get_u32(tb[IFAL_LABEL]);
	401	if (label == IPV6_ADDR_LABEL_DEFAULT)
	402	return -EINVAL;
	403
	404	switch(nlh->nlmsg_type) {
	405	case RTM_NEWADDRLABEL:
	406	err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
	407	ifal->ifal_index, label,
	408	nlh->nlmsg_flags & NLM_F_REPLACE);
	409	break;
	410	case RTM_DELADDRLABEL:
	411	err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
	412	ifal->ifal_index);
	413	break;
	414	default:
	415	err = -EOPNOTSUPP;
	416	}
	417	return err;
	418	}
	419
	420	static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
	421	int prefixlen, int ifindex, u32 lseq)
	422	{
	423	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
	424	ifal->ifal_family = AF_INET6;
	425	ifal->ifal_prefixlen = prefixlen;
	426	ifal->ifal_flags = 0;
	427	ifal->ifal_index = ifindex;
	428	ifal->ifal_seq = lseq;
	429	};
	430
	431	static int ip6addrlbl_fill(struct sk_buff *skb,
	432	struct ip6addrlbl_entry *p,
	433	u32 lseq,
	434	u32 pid, u32 seq, int event,
	435	unsigned int flags)
	436	{
	437	struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
	438	sizeof(struct ifaddrlblmsg), flags);
	439	if (!nlh)
	440	return -EMSGSIZE;
441
442	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
443
444	if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 \|\|
445	nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
446	nlmsg_cancel(skb, nlh);
447	return -EMSGSIZE;
448	}
449
450	return nlmsg_end(skb, nlh);
451	}
452
453	static int ip6addrlbl_dump(struct sk_buff skb, struct netlink_callback cb)
454	{
b854272b	455	struct net *net = skb->sk->sk_net;
2a8cc6c8 YH	456	struct ip6addrlbl_entry *p;
	457	struct hlist_node *pos;
	458	int idx = 0, s_idx = cb->args[0];
	459	int err;
	460
b854272b DL	461	if (net != &init_net)
	462	return 0;
	463
2a8cc6c8 YH	464	rcu_read_lock();
	465	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
	466	if (idx >= s_idx) {
	467	if ((err = ip6addrlbl_fill(skb, p,
	468	ip6addrlbl_table.seq,
	469	NETLINK_CB(cb->skb).pid,
	470	cb->nlh->nlmsg_seq,
	471	RTM_NEWADDRLABEL,
	472	NLM_F_MULTI)) <= 0)
	473	break;
	474	}
	475	idx++;
	476	}
	477	rcu_read_unlock();
	478	cb->args[0] = idx;
	479	return skb->len;
	480	}
	481
	482	static inline int ip6addrlbl_msgsize(void)
	483	{
	484	return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
	485	+ nla_total_size(16) /* IFAL_ADDRESS */
	486	+ nla_total_size(4) /* IFAL_LABEL */
	487	);
	488	}
	489
	490	static int ip6addrlbl_get(struct sk_buff in_skb, struct nlmsghdr nlh,
	491	void *arg)
	492	{
b854272b	493	struct net *net = in_skb->sk->sk_net;
2a8cc6c8 YH	494	struct ifaddrlblmsg *ifal;
	495	struct nlattr *tb[IFAL_MAX+1];
	496	struct in6_addr *addr;
	497	u32 lseq;
	498	int err = 0;
	499	struct ip6addrlbl_entry *p;
	500	struct sk_buff *skb;
	501
b854272b DL	502	if (net != &init_net)
	503	return 0;
	504
2a8cc6c8 YH	505	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	506	if (err < 0)
	507	return err;
	508
	509	ifal = nlmsg_data(nlh);
	510
	511	if (ifal->ifal_family != AF_INET6 \|\|
	512	ifal->ifal_prefixlen != 128)
	513	return -EINVAL;
	514
	515	if (ifal->ifal_index &&
	516	!__dev_get_by_index(&init_net, ifal->ifal_index))
	517	return -EINVAL;
	518
	519	if (!tb[IFAL_ADDRESS])
	520	return -EINVAL;
	521
	522	addr = nla_data(tb[IFAL_ADDRESS]);
	523	if (!addr)
	524	return -EINVAL;
	525
	526	rcu_read_lock();
	527	p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
	528	if (p && ip6addrlbl_hold(p))
	529	p = NULL;
	530	lseq = ip6addrlbl_table.seq;
	531	rcu_read_unlock();
	532
	533	if (!p) {
	534	err = -ESRCH;
	535	goto out;
	536	}
	537
	538	if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
	539	ip6addrlbl_put(p);
	540	return -ENOBUFS;
	541	}
	542
	543	err = ip6addrlbl_fill(skb, p, lseq,
	544	NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
	545	RTM_NEWADDRLABEL, 0);
	546
	547	ip6addrlbl_put(p);
	548
	549	if (err < 0) {
	550	WARN_ON(err == -EMSGSIZE);
	551	kfree_skb(skb);
	552	goto out;
	553	}
	554
97c53cac	555	err = rtnl_unicast(skb, &init_net, NETLINK_CB(in_skb).pid);
2a8cc6c8 YH	556	out:
	557	return err;
	558	}
	559
	560	void __init ipv6_addr_label_rtnl_register(void)
	561	{
	562	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
	563	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
	564	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
	565	}
	566