[mirror_ubuntu-bionic-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
{
#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=" 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(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=" 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);
#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=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
			__func__,
			NIP6(*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=" 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 &&
		    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=" 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(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 <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	{
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
	189	ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
0dc47877	190	__func__,
2a8cc6c8 YH	191	NIP6(*addr), type, ifindex,
	192	label);
	193
	194	return label;
	195	}
	196
	197	/* allocate one entry */
3de23255 BT	198	static struct ip6addrlbl_entry ip6addrlbl_alloc(struct net net,
3de23255 BT	199	const struct in6_addr *prefix,
40fee36e YH	200	int prefixlen, int ifindex,
40fee36e YH	201	u32 label)
2a8cc6c8 YH	202	{
	203	struct ip6addrlbl_entry *newp;
	204	int addrtype;
	205
	206	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
0dc47877	207	__func__,
2a8cc6c8 YH	208	NIP6(*prefix), prefixlen,
	209	ifindex,
	210	(unsigned int)label);
	211
	212	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK);
	213
	214	switch (addrtype) {
	215	case IPV6_ADDR_MAPPED:
	216	if (prefixlen > 96)
	217	return ERR_PTR(-EINVAL);
	218	if (prefixlen < 96)
	219	addrtype = 0;
	220	break;
	221	case IPV6_ADDR_COMPATv4:
	222	if (prefixlen != 96)
	223	addrtype = 0;
	224	break;
	225	case IPV6_ADDR_LOOPBACK:
	226	if (prefixlen != 128)
	227	addrtype = 0;
	228	break;
	229	}
	230
	231	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
	232	if (!newp)
	233	return ERR_PTR(-ENOMEM);
	234
	235	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
	236	newp->prefixlen = prefixlen;
	237	newp->ifindex = ifindex;
	238	newp->addrtype = addrtype;
	239	newp->label = label;
	240	INIT_HLIST_NODE(&newp->list);
3de23255 BT	241	#ifdef CONFIG_NET_NS
	242	newp->lbl_net = hold_net(net);
	243	#endif
2a8cc6c8 YH	244	atomic_set(&newp->refcnt, 1);
	245	return newp;
	246	}
	247
	248	/* add a label */
40fee36e	249	static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
2a8cc6c8 YH	250	{
	251	int ret = 0;
	252
	253	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
0dc47877	254	__func__,
2a8cc6c8 YH	255	newp, replace);
	256
	257	if (hlist_empty(&ip6addrlbl_table.head)) {
	258	hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
	259	} else {
	260	struct hlist_node pos, n;
	261	struct ip6addrlbl_entry *p = NULL;
	262	hlist_for_each_entry_safe(p, pos, n,
	263	&ip6addrlbl_table.head, list) {
	264	if (p->prefixlen == newp->prefixlen &&
3de23255	265	net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
2a8cc6c8 YH	266	p->ifindex == newp->ifindex &&
	267	ipv6_addr_equal(&p->prefix, &newp->prefix)) {
	268	if (!replace) {
	269	ret = -EEXIST;
	270	goto out;
	271	}
	272	hlist_replace_rcu(&p->list, &newp->list);
	273	ip6addrlbl_put(p);
2a8cc6c8 YH	274	goto out;
	275	} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) \|\|
	276	(p->prefixlen < newp->prefixlen)) {
	277	hlist_add_before_rcu(&newp->list, &p->list);
	278	goto out;
	279	}
	280	}
	281	hlist_add_after_rcu(&p->list, &newp->list);
	282	}
	283	out:
	284	if (!ret)
	285	ip6addrlbl_table.seq++;
	286	return ret;
	287	}
	288
	289	/* add a label */
3de23255 BT	290	static int ip6addrlbl_add(struct net *net,
3de23255 BT	291	const struct in6_addr *prefix, int prefixlen,
40fee36e	292	int ifindex, u32 label, int replace)
2a8cc6c8 YH	293	{
	294	struct ip6addrlbl_entry *newp;
	295	int ret = 0;
	296
	297	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
0dc47877	298	__func__,
2a8cc6c8 YH	299	NIP6(*prefix), prefixlen,
	300	ifindex,
	301	(unsigned int)label,
	302	replace);
	303
3de23255	304	newp = ip6addrlbl_alloc(net, prefix, prefixlen, ifindex, label);
2a8cc6c8 YH	305	if (IS_ERR(newp))
	306	return PTR_ERR(newp);
	307	spin_lock(&ip6addrlbl_table.lock);
	308	ret = __ip6addrlbl_add(newp, replace);
	309	spin_unlock(&ip6addrlbl_table.lock);
	310	if (ret)
	311	ip6addrlbl_free(newp);
	312	return ret;
	313	}
	314
	315	/* remove a label */
3de23255 BT	316	static int __ip6addrlbl_del(struct net *net,
3de23255 BT	317	const struct in6_addr *prefix, int prefixlen,
40fee36e	318	int ifindex)
2a8cc6c8 YH	319	{
	320	struct ip6addrlbl_entry *p = NULL;
	321	struct hlist_node pos, n;
	322	int ret = -ESRCH;
	323
	324	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
0dc47877	325	__func__,
2a8cc6c8 YH	326	NIP6(*prefix), prefixlen,
	327	ifindex);
	328
	329	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
	330	if (p->prefixlen == prefixlen &&
3de23255	331	net_eq(ip6addrlbl_net(p), net) &&
2a8cc6c8 YH	332	p->ifindex == ifindex &&
	333	ipv6_addr_equal(&p->prefix, prefix)) {
	334	hlist_del_rcu(&p->list);
	335	ip6addrlbl_put(p);
2a8cc6c8 YH	336	ret = 0;
	337	break;
	338	}
	339	}
	340	return ret;
	341	}
	342
3de23255 BT	343	static int ip6addrlbl_del(struct net *net,
3de23255 BT	344	const struct in6_addr *prefix, int prefixlen,
40fee36e	345	int ifindex)
2a8cc6c8 YH	346	{
	347	struct in6_addr prefix_buf;
	348	int ret;
	349
	350	ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
0dc47877	351	__func__,
2a8cc6c8 YH	352	NIP6(*prefix), prefixlen,
	353	ifindex);
	354
	355	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
	356	spin_lock(&ip6addrlbl_table.lock);
3de23255	357	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
2a8cc6c8 YH	358	spin_unlock(&ip6addrlbl_table.lock);
	359	return ret;
	360	}
	361
	362	/* add default label */
3de23255	363	static int __net_init ip6addrlbl_net_init(struct net *net)
2a8cc6c8 YH	364	{
	365	int err = 0;
	366	int i;
	367
0dc47877	368	ADDRLABEL(KERN_DEBUG "%s()\n", __func__);
2a8cc6c8 YH	369
2a8cc6c8 YH	370	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
3de23255 BT	371	int ret = ip6addrlbl_add(net,
3de23255 BT	372	ip6addrlbl_init_table[i].prefix,
2a8cc6c8 YH	373	ip6addrlbl_init_table[i].prefixlen,
	374	0,
	375	ip6addrlbl_init_table[i].label, 0);
	376	/* XXX: should we free all rules when we catch an error? */
	377	if (ret && (!err \|\| err != -ENOMEM))
	378	err = ret;
	379	}
	380	return err;
	381	}
	382
3de23255 BT	383	static void __net_exit ip6addrlbl_net_exit(struct net *net)
	384	{
	385	struct ip6addrlbl_entry *p = NULL;
	386	struct hlist_node pos, n;
	387
	388	/* Remove all labels belonging to the exiting net */
	389	spin_lock(&ip6addrlbl_table.lock);
	390	hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
	391	if (net_eq(ip6addrlbl_net(p), net)) {
	392	hlist_del_rcu(&p->list);
	393	ip6addrlbl_put(p);
	394	}
	395	}
	396	spin_unlock(&ip6addrlbl_table.lock);
	397	}
	398
	399	static struct pernet_operations ipv6_addr_label_ops = {
	400	.init = ip6addrlbl_net_init,
	401	.exit = ip6addrlbl_net_exit,
	402	};
	403
2a8cc6c8 YH	404	int __init ipv6_addr_label_init(void)
	405	{
	406	spin_lock_init(&ip6addrlbl_table.lock);
	407
3de23255	408	return register_pernet_subsys(&ipv6_addr_label_ops);
2a8cc6c8 YH	409	}
	410
	411	static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
	412	[IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
	413	[IFAL_LABEL] = { .len = sizeof(u32), },
	414	};
	415
	416	static int ip6addrlbl_newdel(struct sk_buff skb, struct nlmsghdr nlh,
	417	void *arg)
	418	{
3b1e0a65	419	struct net *net = sock_net(skb->sk);
2a8cc6c8 YH	420	struct ifaddrlblmsg *ifal;
	421	struct nlattr *tb[IFAL_MAX+1];
	422	struct in6_addr *pfx;
	423	u32 label;
	424	int err = 0;
	425
	426	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	427	if (err < 0)
	428	return err;
	429
	430	ifal = nlmsg_data(nlh);
	431
	432	if (ifal->ifal_family != AF_INET6 \|\|
	433	ifal->ifal_prefixlen > 128)
	434	return -EINVAL;
	435
	436	if (ifal->ifal_index &&
3de23255	437	!__dev_get_by_index(net, ifal->ifal_index))
2a8cc6c8 YH	438	return -EINVAL;
	439
	440	if (!tb[IFAL_ADDRESS])
	441	return -EINVAL;
	442
	443	pfx = nla_data(tb[IFAL_ADDRESS]);
	444	if (!pfx)
	445	return -EINVAL;
	446
	447	if (!tb[IFAL_LABEL])
	448	return -EINVAL;
	449	label = nla_get_u32(tb[IFAL_LABEL]);
	450	if (label == IPV6_ADDR_LABEL_DEFAULT)
	451	return -EINVAL;
	452
	453	switch(nlh->nlmsg_type) {
	454	case RTM_NEWADDRLABEL:
3de23255	455	err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	456	ifal->ifal_index, label,
	457	nlh->nlmsg_flags & NLM_F_REPLACE);
	458	break;
	459	case RTM_DELADDRLABEL:
3de23255	460	err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	461	ifal->ifal_index);
	462	break;
	463	default:
	464	err = -EOPNOTSUPP;
	465	}
	466	return err;
	467	}
	468
	469	static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
	470	int prefixlen, int ifindex, u32 lseq)
	471	{
	472	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
	473	ifal->ifal_family = AF_INET6;
	474	ifal->ifal_prefixlen = prefixlen;
	475	ifal->ifal_flags = 0;
	476	ifal->ifal_index = ifindex;
	477	ifal->ifal_seq = lseq;
	478	};
	479
	480	static int ip6addrlbl_fill(struct sk_buff *skb,
	481	struct ip6addrlbl_entry *p,
	482	u32 lseq,
	483	u32 pid, u32 seq, int event,
	484	unsigned int flags)
	485	{
	486	struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
	487	sizeof(struct ifaddrlblmsg), flags);
	488	if (!nlh)
	489	return -EMSGSIZE;
	490
	491	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
	492
	493	if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 \|\|
	494	nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
	495	nlmsg_cancel(skb, nlh);
	496	return -EMSGSIZE;
	497	}
	498
	499	return nlmsg_end(skb, nlh);
	500	}
	501
	502	static int ip6addrlbl_dump(struct sk_buff skb, struct netlink_callback cb)
	503	{
3b1e0a65	504	struct net *net = sock_net(skb->sk);
2a8cc6c8 YH	505	struct ip6addrlbl_entry *p;
	506	struct hlist_node *pos;
	507	int idx = 0, s_idx = cb->args[0];
	508	int err;
	509
	510	rcu_read_lock();
	511	hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
3de23255 BT	512	if (idx >= s_idx &&
3de23255 BT	513	net_eq(ip6addrlbl_net(p), net)) {
2a8cc6c8 YH	514	if ((err = ip6addrlbl_fill(skb, p,
	515	ip6addrlbl_table.seq,
	516	NETLINK_CB(cb->skb).pid,
	517	cb->nlh->nlmsg_seq,
	518	RTM_NEWADDRLABEL,
	519	NLM_F_MULTI)) <= 0)
	520	break;
	521	}
	522	idx++;
	523	}
	524	rcu_read_unlock();
	525	cb->args[0] = idx;
	526	return skb->len;
	527	}
	528
	529	static inline int ip6addrlbl_msgsize(void)
	530	{
	531	return (NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
	532	+ nla_total_size(16) /* IFAL_ADDRESS */
	533	+ nla_total_size(4) /* IFAL_LABEL */
	534	);
	535	}
	536
	537	static int ip6addrlbl_get(struct sk_buff in_skb, struct nlmsghdr nlh,
	538	void *arg)
	539	{
3b1e0a65	540	struct net *net = sock_net(in_skb->sk);
2a8cc6c8 YH	541	struct ifaddrlblmsg *ifal;
	542	struct nlattr *tb[IFAL_MAX+1];
	543	struct in6_addr *addr;
	544	u32 lseq;
	545	int err = 0;
	546	struct ip6addrlbl_entry *p;
	547	struct sk_buff *skb;
	548
	549	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	550	if (err < 0)
	551	return err;
	552
	553	ifal = nlmsg_data(nlh);
	554
	555	if (ifal->ifal_family != AF_INET6 \|\|
	556	ifal->ifal_prefixlen != 128)
	557	return -EINVAL;
	558
	559	if (ifal->ifal_index &&
3de23255	560	!__dev_get_by_index(net, ifal->ifal_index))
2a8cc6c8 YH	561	return -EINVAL;
	562
	563	if (!tb[IFAL_ADDRESS])
	564	return -EINVAL;
	565
	566	addr = nla_data(tb[IFAL_ADDRESS]);
	567	if (!addr)
	568	return -EINVAL;
	569
	570	rcu_read_lock();
3de23255	571	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
2a8cc6c8 YH	572	if (p && ip6addrlbl_hold(p))
	573	p = NULL;
	574	lseq = ip6addrlbl_table.seq;
	575	rcu_read_unlock();
	576
	577	if (!p) {
	578	err = -ESRCH;
	579	goto out;
	580	}
	581
	582	if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
	583	ip6addrlbl_put(p);
	584	return -ENOBUFS;
	585	}
	586
	587	err = ip6addrlbl_fill(skb, p, lseq,
	588	NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
	589	RTM_NEWADDRLABEL, 0);
	590
	591	ip6addrlbl_put(p);
	592
	593	if (err < 0) {
	594	WARN_ON(err == -EMSGSIZE);
	595	kfree_skb(skb);
	596	goto out;
	597	}
	598
3de23255	599	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
2a8cc6c8 YH	600	out:
	601	return err;
	602	}
	603
	604	void __init ipv6_addr_label_rtnl_register(void)
	605	{
	606	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
	607	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
	608	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
	609	}
	610