[linux.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 <[email protected]>
 */

#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
{
#ifdef CONFIG_NET_NS
	struct net *lbl_net;
#endif
	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;

static inline
struct net *ip6addrlbl_net(const struct ip6addrlbl_entry *lbl)
{
#ifdef CONFIG_NET_NS
	return lbl->lbl_net;
#else
	return &init_net;
#endif
}

/*
 * 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 __net_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)
{
#ifdef CONFIG_NET_NS
	release_net(p->lbl_net);
#endif
	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 net *net,
			      struct ip6addrlbl_entry *p,
			      const struct in6_addr *addr,
			      int addrtype, int ifindex)
{
	if (!net_eq(ip6addrlbl_net(p), net))
		return 0;
	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(struct net *net,
						  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(net, p, addr, type, ifindex))
			return p;
	}
	return NULL;
}

u32 ipv6_addr_label(struct net *net,
		    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(net, addr, type, ifindex);
	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
	rcu_read_unlock();

	ADDRLABEL(KERN_DEBUG "%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n",
		  __func__, addr, type, ifindex, label);

	return label;
}

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

	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n",
		  __func__, 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);
#ifdef CONFIG_NET_NS
	newp->lbl_net = hold_net(net);
#endif
	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 &&
			    net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
			    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(struct net *net,
			  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=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
		  __func__, prefix, prefixlen, ifindex, (unsigned int)label,
		  replace);

	newp = ip6addrlbl_alloc(net, 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(struct net *net,
			    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=%pI6, prefixlen=%d, ifindex=%d)\n",
		  __func__, prefix, prefixlen, ifindex);

	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
		if (p->prefixlen == prefixlen &&
		    net_eq(ip6addrlbl_net(p), net) &&
		    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(struct net *net,
			  const struct in6_addr *prefix, int prefixlen,
			  int ifindex)
{
	struct in6_addr prefix_buf;
	int ret;

	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
		  __func__, prefix, prefixlen, ifindex);

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

/* add default label */
static int __net_init ip6addrlbl_net_init(struct net *net)
{
	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(net,
					 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;
}

static void __net_exit ip6addrlbl_net_exit(struct net *net)
{
	struct ip6addrlbl_entry *p = NULL;
	struct hlist_node *pos, *n;

	/* Remove all labels belonging to the exiting net */
	spin_lock(&ip6addrlbl_table.lock);
	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
		if (net_eq(ip6addrlbl_net(p), net)) {
			hlist_del_rcu(&p->list);
			ip6addrlbl_put(p);
		}
	}
	spin_unlock(&ip6addrlbl_table.lock);
}

static struct pernet_operations ipv6_addr_label_ops = {
	.init = ip6addrlbl_net_init,
	.exit = ip6addrlbl_net_exit,
};

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

	return register_pernet_subsys(&ipv6_addr_label_ops);
}

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 = sock_net(skb->sk);
	struct ifaddrlblmsg *ifal;
	struct nlattr *tb[IFAL_MAX+1];
	struct in6_addr *pfx;
	u32 label;
	int err = 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(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(net, pfx, ifal->ifal_prefixlen,
				     ifal->ifal_index, label,
				     nlh->nlmsg_flags & NLM_F_REPLACE);
		break;
	case RTM_DELADDRLABEL:
		err = ip6addrlbl_del(net, 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 = sock_net(skb->sk);
	struct ip6addrlbl_entry *p;
	struct hlist_node *pos;
	int idx = 0, s_idx = cb->args[0];
	int err;

	rcu_read_lock();
	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
		if (idx >= s_idx &&
		    net_eq(ip6addrlbl_net(p), net)) {
			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 = sock_net(in_skb->sk);
	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;

	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(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(net, 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, 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 <[email protected]>
	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	{
3de23255 BT	32	#ifdef CONFIG_NET_NS
	33	struct net *lbl_net;
	34	#endif
2a8cc6c8 YH	35	struct in6_addr prefix;
	36	int prefixlen;
	37	int ifindex;
	38	int addrtype;
	39	u32 label;
	40	struct hlist_node list;
	41	atomic_t refcnt;
	42	struct rcu_head rcu;
	43	};
	44
	45	static struct ip6addrlbl_table
	46	{
	47	struct hlist_head head;
	48	spinlock_t lock;
	49	u32 seq;
	50	} ip6addrlbl_table;
	51
3de23255 BT	52	static inline
	53	struct net ip6addrlbl_net(const struct ip6addrlbl_entry lbl)
	54	{
	55	#ifdef CONFIG_NET_NS
	56	return lbl->lbl_net;
	57	#else
	58	return &init_net;
	59	#endif
	60	}
	61
2a8cc6c8 YH	62	/*
	63	* Default policy table (RFC3484 + extensions)
	64	*
	65	* prefix addr_type label
	66	* -------------------------------------------------------------------------
	67	* ::1/128 LOOPBACK 0
	68	* ::/0 N/A 1
	69	* 2002::/16 N/A 2
	70	* ::/96 COMPATv4 3
	71	* ::ffff:0:0/96 V4MAPPED 4
	72	* fc00::/7 N/A 5 ULA (RFC 4193)
	73	* 2001::/32 N/A 6 Teredo (RFC 4380)
5fe47b8a	74	* 2001:10::/28 N/A 7 ORCHID (RFC 4843)
2a8cc6c8 YH	75	*
	76	* Note: 0xffffffff is used if we do not have any policies.
	77	*/
	78
	79	#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
	80
3de23255	81	static const __net_initdata struct ip6addrlbl_init_table
2a8cc6c8 YH	82	{
	83	const struct in6_addr *prefix;
	84	int prefixlen;
	85	u32 label;
	86	} ip6addrlbl_init_table[] = {
	87	{ /* ::/0 */
	88	.prefix = &in6addr_any,
	89	.label = 1,
	90	},{ /* fc00::/7 */
	91	.prefix = &(struct in6_addr){{{ 0xfc }}},
	92	.prefixlen = 7,
	93	.label = 5,
	94	},{ /* 2002::/16 */
	95	.prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
	96	.prefixlen = 16,
	97	.label = 2,
	98	},{ /* 2001::/32 */
	99	.prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
	100	.prefixlen = 32,
	101	.label = 6,
5fe47b8a JMT	102	},{ /* 2001:10::/28 */
	103	.prefix = &(struct in6_addr){{{ 0x20, 0x01, 0x00, 0x10 }}},
	104	.prefixlen = 28,
	105	.label = 7,
2a8cc6c8 YH	106	},{ /* ::ffff:0:0 */
	107	.prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
	108	.prefixlen = 96,
	109	.label = 4,
	110	},{ /* ::/96 */
	111	.prefix = &in6addr_any,
	112	.prefixlen = 96,
	113	.label = 3,
	114	},{ /* ::1/128 */
	115	.prefix = &in6addr_loopback,
	116	.prefixlen = 128,
	117	.label = 0,
	118	}
	119	};
	120
	121	/* Object management */
	122	static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
	123	{
3de23255 BT	124	#ifdef CONFIG_NET_NS
	125	release_net(p->lbl_net);
	126	#endif
2a8cc6c8 YH	127	kfree(p);
	128	}
	129
85040bcb YH	130	static void ip6addrlbl_free_rcu(struct rcu_head *h)
	131	{
	132	ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
	133	}
	134
2a8cc6c8 YH	135	static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
	136	{
	137	return atomic_inc_not_zero(&p->refcnt);
	138	}
	139
	140	static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
	141	{
	142	if (atomic_dec_and_test(&p->refcnt))
85040bcb	143	call_rcu(&p->rcu, ip6addrlbl_free_rcu);
2a8cc6c8 YH	144	}
	145
	146	/* Find label */
3de23255 BT	147	static int __ip6addrlbl_match(struct net *net,
3de23255 BT	148	struct ip6addrlbl_entry *p,
2a8cc6c8 YH	149	const struct in6_addr *addr,
	150	int addrtype, int ifindex)
	151	{
3de23255 BT	152	if (!net_eq(ip6addrlbl_net(p), net))
3de23255 BT	153	return 0;
2a8cc6c8 YH	154	if (p->ifindex && p->ifindex != ifindex)
	155	return 0;
	156	if (p->addrtype && p->addrtype != addrtype)
	157	return 0;
	158	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
	159	return 0;
	160	return 1;
	161	}
	162
3de23255 BT	163	static struct ip6addrlbl_entry __ipv6_addr_label(struct net net,
3de23255 BT	164	const struct in6_addr *addr,
2a8cc6c8 YH	165	int type, int ifindex)
	166	{
	167	struct hlist_node *pos;
	168	struct ip6addrlbl_entry *p;
	169	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
3de23255	170	if (__ip6addrlbl_match(net, p, addr, type, ifindex))
2a8cc6c8 YH	171	return p;
	172	}
	173	return NULL;
	174	}
	175
3de23255 BT	176	u32 ipv6_addr_label(struct net *net,
3de23255 BT	177	const struct in6_addr *addr, int type, int ifindex)
2a8cc6c8 YH	178	{
	179	u32 label;
	180	struct ip6addrlbl_entry *p;
	181
	182	type &= IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK;
	183
	184	rcu_read_lock();
3de23255	185	p = __ipv6_addr_label(net, addr, type, ifindex);
2a8cc6c8 YH	186	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
	187	rcu_read_unlock();
	188
5b095d98	189	ADDRLABEL(KERN_DEBUG "%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n",
0c6ce78a	190	__func__, addr, type, ifindex, label);
2a8cc6c8 YH	191
	192	return label;
	193	}
	194
	195	/* allocate one entry */
3de23255 BT	196	static struct ip6addrlbl_entry ip6addrlbl_alloc(struct net net,
3de23255 BT	197	const struct in6_addr *prefix,
40fee36e YH	198	int prefixlen, int ifindex,
40fee36e YH	199	u32 label)
2a8cc6c8 YH	200	{
	201	struct ip6addrlbl_entry *newp;
	202	int addrtype;
	203
5b095d98	204	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n",
0c6ce78a	205	__func__, prefix, prefixlen, ifindex, (unsigned int)label);
2a8cc6c8 YH	206
	207	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK);
	208
	209	switch (addrtype) {
	210	case IPV6_ADDR_MAPPED:
	211	if (prefixlen > 96)
	212	return ERR_PTR(-EINVAL);
	213	if (prefixlen < 96)
	214	addrtype = 0;
	215	break;
	216	case IPV6_ADDR_COMPATv4:
	217	if (prefixlen != 96)
	218	addrtype = 0;
	219	break;
	220	case IPV6_ADDR_LOOPBACK:
	221	if (prefixlen != 128)
	222	addrtype = 0;
	223	break;
	224	}
	225
	226	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
	227	if (!newp)
	228	return ERR_PTR(-ENOMEM);
	229
	230	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
	231	newp->prefixlen = prefixlen;
	232	newp->ifindex = ifindex;
	233	newp->addrtype = addrtype;
	234	newp->label = label;
	235	INIT_HLIST_NODE(&newp->list);
3de23255 BT	236	#ifdef CONFIG_NET_NS
	237	newp->lbl_net = hold_net(net);
	238	#endif
2a8cc6c8 YH	239	atomic_set(&newp->refcnt, 1);
	240	return newp;
	241	}
	242
	243	/* add a label */
40fee36e	244	static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
2a8cc6c8 YH	245	{
	246	int ret = 0;
	247
	248	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
0dc47877	249	__func__,
2a8cc6c8 YH	250	newp, replace);
	251
	252	if (hlist_empty(&ip6addrlbl_table.head)) {
	253	hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
	254	} else {
	255	struct hlist_node pos, n;
	256	struct ip6addrlbl_entry *p = NULL;
	257	hlist_for_each_entry_safe(p, pos, n,
	258	&ip6addrlbl_table.head, list) {
	259	if (p->prefixlen == newp->prefixlen &&
3de23255	260	net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
2a8cc6c8 YH	261	p->ifindex == newp->ifindex &&
	262	ipv6_addr_equal(&p->prefix, &newp->prefix)) {
	263	if (!replace) {
	264	ret = -EEXIST;
	265	goto out;
	266	}
	267	hlist_replace_rcu(&p->list, &newp->list);
	268	ip6addrlbl_put(p);
2a8cc6c8 YH	269	goto out;
	270	} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) \|\|
	271	(p->prefixlen < newp->prefixlen)) {
	272	hlist_add_before_rcu(&newp->list, &p->list);
	273	goto out;
	274	}
	275	}
	276	hlist_add_after_rcu(&p->list, &newp->list);
	277	}
	278	out:
	279	if (!ret)
	280	ip6addrlbl_table.seq++;
	281	return ret;
	282	}
	283
	284	/* add a label */
3de23255 BT	285	static int ip6addrlbl_add(struct net *net,
3de23255 BT	286	const struct in6_addr *prefix, int prefixlen,
40fee36e	287	int ifindex, u32 label, int replace)
2a8cc6c8 YH	288	{
	289	struct ip6addrlbl_entry *newp;
	290	int ret = 0;
	291
5b095d98	292	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
0c6ce78a HH	293	__func__, prefix, prefixlen, ifindex, (unsigned int)label,
0c6ce78a HH	294	replace);
2a8cc6c8	295
3de23255	296	newp = ip6addrlbl_alloc(net, prefix, prefixlen, ifindex, label);
2a8cc6c8 YH	297	if (IS_ERR(newp))
	298	return PTR_ERR(newp);
	299	spin_lock(&ip6addrlbl_table.lock);
	300	ret = __ip6addrlbl_add(newp, replace);
	301	spin_unlock(&ip6addrlbl_table.lock);
	302	if (ret)
	303	ip6addrlbl_free(newp);
	304	return ret;
	305	}
	306
	307	/* remove a label */
3de23255 BT	308	static int __ip6addrlbl_del(struct net *net,
3de23255 BT	309	const struct in6_addr *prefix, int prefixlen,
40fee36e	310	int ifindex)
2a8cc6c8 YH	311	{
	312	struct ip6addrlbl_entry *p = NULL;
	313	struct hlist_node pos, n;
	314	int ret = -ESRCH;
	315
5b095d98	316	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
0c6ce78a	317	__func__, prefix, prefixlen, ifindex);
2a8cc6c8 YH	318
	319	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
	320	if (p->prefixlen == prefixlen &&
3de23255	321	net_eq(ip6addrlbl_net(p), net) &&
2a8cc6c8 YH	322	p->ifindex == ifindex &&
	323	ipv6_addr_equal(&p->prefix, prefix)) {
	324	hlist_del_rcu(&p->list);
	325	ip6addrlbl_put(p);
2a8cc6c8 YH	326	ret = 0;
	327	break;
	328	}
	329	}
	330	return ret;
	331	}
	332
3de23255 BT	333	static int ip6addrlbl_del(struct net *net,
3de23255 BT	334	const struct in6_addr *prefix, int prefixlen,
40fee36e	335	int ifindex)
2a8cc6c8 YH	336	{
	337	struct in6_addr prefix_buf;
	338	int ret;
	339
5b095d98	340	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
0c6ce78a	341	__func__, prefix, prefixlen, ifindex);
2a8cc6c8 YH	342
	343	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
	344	spin_lock(&ip6addrlbl_table.lock);
3de23255	345	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
2a8cc6c8 YH	346	spin_unlock(&ip6addrlbl_table.lock);
	347	return ret;
	348	}
	349
	350	/* add default label */
3de23255	351	static int __net_init ip6addrlbl_net_init(struct net *net)
2a8cc6c8 YH	352	{
	353	int err = 0;
	354	int i;
	355
0dc47877	356	ADDRLABEL(KERN_DEBUG "%s()\n", __func__);
2a8cc6c8 YH	357
2a8cc6c8 YH	358	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
3de23255 BT	359	int ret = ip6addrlbl_add(net,
3de23255 BT	360	ip6addrlbl_init_table[i].prefix,
2a8cc6c8 YH	361	ip6addrlbl_init_table[i].prefixlen,
	362	0,
	363	ip6addrlbl_init_table[i].label, 0);
	364	/* XXX: should we free all rules when we catch an error? */
	365	if (ret && (!err \|\| err != -ENOMEM))
	366	err = ret;
	367	}
	368	return err;
	369	}
	370
3de23255 BT	371	static void __net_exit ip6addrlbl_net_exit(struct net *net)
	372	{
	373	struct ip6addrlbl_entry *p = NULL;
	374	struct hlist_node pos, n;
	375
	376	/* Remove all labels belonging to the exiting net */
	377	spin_lock(&ip6addrlbl_table.lock);
	378	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
	379	if (net_eq(ip6addrlbl_net(p), net)) {
	380	hlist_del_rcu(&p->list);
	381	ip6addrlbl_put(p);
	382	}
	383	}
	384	spin_unlock(&ip6addrlbl_table.lock);
	385	}
	386
	387	static struct pernet_operations ipv6_addr_label_ops = {
	388	.init = ip6addrlbl_net_init,
	389	.exit = ip6addrlbl_net_exit,
	390	};
	391
2a8cc6c8 YH	392	int __init ipv6_addr_label_init(void)
	393	{
	394	spin_lock_init(&ip6addrlbl_table.lock);
	395
3de23255	396	return register_pernet_subsys(&ipv6_addr_label_ops);
2a8cc6c8 YH	397	}
	398
	399	static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
	400	[IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
	401	[IFAL_LABEL] = { .len = sizeof(u32), },
	402	};
	403
	404	static int ip6addrlbl_newdel(struct sk_buff skb, struct nlmsghdr nlh,
	405	void *arg)
	406	{
3b1e0a65	407	struct net *net = sock_net(skb->sk);
2a8cc6c8 YH	408	struct ifaddrlblmsg *ifal;
	409	struct nlattr *tb[IFAL_MAX+1];
	410	struct in6_addr *pfx;
	411	u32 label;
	412	int err = 0;
	413
	414	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	415	if (err < 0)
	416	return err;
	417
	418	ifal = nlmsg_data(nlh);
	419
	420	if (ifal->ifal_family != AF_INET6 \|\|
	421	ifal->ifal_prefixlen > 128)
	422	return -EINVAL;
	423
	424	if (ifal->ifal_index &&
3de23255	425	!__dev_get_by_index(net, ifal->ifal_index))
2a8cc6c8 YH	426	return -EINVAL;
	427
	428	if (!tb[IFAL_ADDRESS])
	429	return -EINVAL;
	430
	431	pfx = nla_data(tb[IFAL_ADDRESS]);
	432	if (!pfx)
	433	return -EINVAL;
	434
	435	if (!tb[IFAL_LABEL])
	436	return -EINVAL;
	437	label = nla_get_u32(tb[IFAL_LABEL]);
	438	if (label == IPV6_ADDR_LABEL_DEFAULT)
	439	return -EINVAL;
	440
	441	switch(nlh->nlmsg_type) {
	442	case RTM_NEWADDRLABEL:
3de23255	443	err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	444	ifal->ifal_index, label,
	445	nlh->nlmsg_flags & NLM_F_REPLACE);
	446	break;
	447	case RTM_DELADDRLABEL:
3de23255	448	err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	449	ifal->ifal_index);
	450	break;
	451	default:
	452	err = -EOPNOTSUPP;
	453	}
	454	return err;
	455	}
	456
	457	static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
	458	int prefixlen, int ifindex, u32 lseq)
	459	{
	460	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
	461	ifal->ifal_family = AF_INET6;
	462	ifal->ifal_prefixlen = prefixlen;
	463	ifal->ifal_flags = 0;
	464	ifal->ifal_index = ifindex;
	465	ifal->ifal_seq = lseq;
	466	};
	467
	468	static int ip6addrlbl_fill(struct sk_buff *skb,
	469	struct ip6addrlbl_entry *p,
	470	u32 lseq,
	471	u32 pid, u32 seq, int event,
	472	unsigned int flags)
	473	{
	474	struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
	475	sizeof(struct ifaddrlblmsg), flags);
	476	if (!nlh)
	477	return -EMSGSIZE;
	478
	479	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
	480
	481	if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 \|\|
	482	nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
	483	nlmsg_cancel(skb, nlh);
	484	return -EMSGSIZE;
	485	}
	486
	487	return nlmsg_end(skb, nlh);
	488	}
	489
	490	static int ip6addrlbl_dump(struct sk_buff skb, struct netlink_callback cb)
	491	{
3b1e0a65	492	struct net *net = sock_net(skb->sk);
2a8cc6c8 YH	493	struct ip6addrlbl_entry *p;
	494	struct hlist_node *pos;
	495	int idx = 0, s_idx = cb->args[0];
	496	int err;
	497
	498	rcu_read_lock();
	499	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
3de23255 BT	500	if (idx >= s_idx &&
3de23255 BT	501	net_eq(ip6addrlbl_net(p), net)) {
2a8cc6c8 YH	502	if ((err = ip6addrlbl_fill(skb, p,
	503	ip6addrlbl_table.seq,
	504	NETLINK_CB(cb->skb).pid,
	505	cb->nlh->nlmsg_seq,
	506	RTM_NEWADDRLABEL,
	507	NLM_F_MULTI)) <= 0)
	508	break;
	509	}
	510	idx++;
	511	}
	512	rcu_read_unlock();
	513	cb->args[0] = idx;
	514	return skb->len;
	515	}
	516
	517	static inline int ip6addrlbl_msgsize(void)
	518	{
	519	return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
	520	+ nla_total_size(16) /* IFAL_ADDRESS */
	521	+ nla_total_size(4) /* IFAL_LABEL */
	522	);
	523	}
	524
	525	static int ip6addrlbl_get(struct sk_buff in_skb, struct nlmsghdr nlh,
	526	void *arg)
	527	{
3b1e0a65	528	struct net *net = sock_net(in_skb->sk);
2a8cc6c8 YH	529	struct ifaddrlblmsg *ifal;
	530	struct nlattr *tb[IFAL_MAX+1];
	531	struct in6_addr *addr;
	532	u32 lseq;
	533	int err = 0;
	534	struct ip6addrlbl_entry *p;
	535	struct sk_buff *skb;
	536
	537	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	538	if (err < 0)
	539	return err;
	540
	541	ifal = nlmsg_data(nlh);
	542
	543	if (ifal->ifal_family != AF_INET6 \|\|
	544	ifal->ifal_prefixlen != 128)
	545	return -EINVAL;
	546
	547	if (ifal->ifal_index &&
3de23255	548	!__dev_get_by_index(net, ifal->ifal_index))
2a8cc6c8 YH	549	return -EINVAL;
	550
	551	if (!tb[IFAL_ADDRESS])
	552	return -EINVAL;
	553
	554	addr = nla_data(tb[IFAL_ADDRESS]);
	555	if (!addr)
	556	return -EINVAL;
	557
	558	rcu_read_lock();
3de23255	559	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
2a8cc6c8 YH	560	if (p && ip6addrlbl_hold(p))
	561	p = NULL;
	562	lseq = ip6addrlbl_table.seq;
	563	rcu_read_unlock();
	564
	565	if (!p) {
	566	err = -ESRCH;
	567	goto out;
	568	}
	569
	570	if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
	571	ip6addrlbl_put(p);
	572	return -ENOBUFS;
	573	}
	574
	575	err = ip6addrlbl_fill(skb, p, lseq,
	576	NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
	577	RTM_NEWADDRLABEL, 0);
	578
	579	ip6addrlbl_put(p);
	580
	581	if (err < 0) {
	582	WARN_ON(err == -EMSGSIZE);
	583	kfree_skb(skb);
	584	goto out;
	585	}
	586
3de23255	587	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2a8cc6c8 YH	588	out:
	589	return err;
	590	}
	591
	592	void __init ipv6_addr_label_rtnl_register(void)
	593	{
	594	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
	595	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
	596	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
	597	}
	598