[mirror_ubuntu-focal-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 <linux/slab.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)
{
	return read_pnet(&lbl->lbl_net);
}

/*
 * Default policy table (RFC6724 + 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)
 * fec0::/10		N/A		11		Site-local
 *							(deprecated by RFC3879)
 * 3ffe::/16		N/A		12		6bone
 *
 * Note: 0xffffffff is used if we do not have any policies.
 * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
 */

#define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL

static const __net_initconst 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,
	},{	/* fec0::/10 */
		.prefix = &(struct in6_addr){{{ 0xfe, 0xc0 }}},
		.prefixlen = 10,
		.label = 11,
	},{	/* 2002::/16 */
		.prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
		.prefixlen = 16,
		.label = 2,
	},{	/* 3ffe::/16 */
		.prefix = &(struct in6_addr){{{ 0x3f, 0xfe }}},
		.prefixlen = 16,
		.label = 12,
	},{	/* 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 bool 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 bool __ip6addrlbl_match(struct net *net,
			       const struct ip6addrlbl_entry *p,
			       const struct in6_addr *addr,
			       int addrtype, int ifindex)
{
	if (!net_eq(ip6addrlbl_net(p), net))
		return false;
	if (p->ifindex && p->ifindex != ifindex)
		return false;
	if (p->addrtype && p->addrtype != addrtype)
		return false;
	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
		return false;
	return true;
}

static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
						  const struct in6_addr *addr,
						  int type, int ifindex)
{
	struct ip6addrlbl_entry *p;
	hlist_for_each_entry_rcu(p, &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 *n;
		struct ip6addrlbl_entry *p = NULL;
		hlist_for_each_entry_safe(p, 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 *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, 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 *n;

	/* Remove all labels belonging to the exiting net */
	spin_lock(&ip6addrlbl_table.lock);
	hlist_for_each_entry_safe(p, 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);
}

void ipv6_addr_label_cleanup(void)
{
	unregister_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 (!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:
		if (ifal->ifal_index &&
		    !__dev_get_by_index(net, ifal->ifal_index))
			return -EINVAL;

		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 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 portid, u32 seq, int event,
			   unsigned int flags)
{
	struct nlmsghdr *nlh = nlmsg_put(skb, portid, 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;
	int idx = 0, s_idx = cb->args[0];
	int err;

	rcu_read_lock();
	hlist_for_each_entry_rcu(p, &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).portid,
						   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).portid, 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).portid);
out:
	return err;
}

void __init ipv6_addr_label_rtnl_register(void)
{
	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel,
			NULL, NULL);
	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel,
			NULL, NULL);
	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get,
			ip6addrlbl_dump, NULL);
}
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>
5a0e3ad6	16	#include <linux/slab.h>
2a8cc6c8 YH	17	#include <net/addrconf.h>
	18	#include <linux/if_addrlabel.h>
	19	#include <linux/netlink.h>
	20	#include <linux/rtnetlink.h>
	21
	22	#if 0
	23	#define ADDRLABEL(x...) printk(x)
	24	#else
	25	#define ADDRLABEL(x...) do { ; } while(0)
	26	#endif
	27
	28	/*
	29	* Policy Table
	30	*/
	31	struct ip6addrlbl_entry
	32	{
3de23255 BT	33	#ifdef CONFIG_NET_NS
	34	struct net *lbl_net;
	35	#endif
2a8cc6c8 YH	36	struct in6_addr prefix;
	37	int prefixlen;
	38	int ifindex;
	39	int addrtype;
	40	u32 label;
	41	struct hlist_node list;
	42	atomic_t refcnt;
	43	struct rcu_head rcu;
	44	};
	45
	46	static struct ip6addrlbl_table
	47	{
	48	struct hlist_head head;
	49	spinlock_t lock;
	50	u32 seq;
	51	} ip6addrlbl_table;
	52
3de23255 BT	53	static inline
	54	struct net ip6addrlbl_net(const struct ip6addrlbl_entry lbl)
	55	{
c2d9ba9b	56	return read_pnet(&lbl->lbl_net);
3de23255 BT	57	}
3de23255 BT	58
2a8cc6c8	59	/*
417962a0	60	* Default policy table (RFC6724 + extensions)
2a8cc6c8 YH	61	*
	62	* prefix addr_type label
	63	* -------------------------------------------------------------------------
	64	* ::1/128 LOOPBACK 0
	65	* ::/0 N/A 1
	66	* 2002::/16 N/A 2
	67	* ::/96 COMPATv4 3
	68	* ::ffff:0:0/96 V4MAPPED 4
	69	* fc00::/7 N/A 5 ULA (RFC 4193)
	70	* 2001::/32 N/A 6 Teredo (RFC 4380)
5fe47b8a	71	* 2001:10::/28 N/A 7 ORCHID (RFC 4843)
417962a0 YH	72	* fec0::/10 N/A 11 Site-local
	73	* (deprecated by RFC3879)
	74	* 3ffe::/16 N/A 12 6bone
2a8cc6c8 YH	75	*
2a8cc6c8 YH	76	* Note: 0xffffffff is used if we do not have any policies.
417962a0	77	* Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
2a8cc6c8 YH	78	*/
	79
	80	#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
	81
04a6f82c	82	static const __net_initconst struct ip6addrlbl_init_table
2a8cc6c8 YH	83	{
	84	const struct in6_addr *prefix;
	85	int prefixlen;
	86	u32 label;
	87	} ip6addrlbl_init_table[] = {
	88	{ /* ::/0 */
	89	.prefix = &in6addr_any,
	90	.label = 1,
	91	},{ /* fc00::/7 */
	92	.prefix = &(struct in6_addr){{{ 0xfc }}},
	93	.prefixlen = 7,
	94	.label = 5,
417962a0 YH	95	},{ /* fec0::/10 */
	96	.prefix = &(struct in6_addr){{{ 0xfe, 0xc0 }}},
	97	.prefixlen = 10,
	98	.label = 11,
2a8cc6c8 YH	99	},{ /* 2002::/16 */
	100	.prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
	101	.prefixlen = 16,
	102	.label = 2,
417962a0 YH	103	},{ /* 3ffe::/16 */
	104	.prefix = &(struct in6_addr){{{ 0x3f, 0xfe }}},
	105	.prefixlen = 16,
	106	.label = 12,
2a8cc6c8 YH	107	},{ /* 2001::/32 */
	108	.prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
	109	.prefixlen = 32,
	110	.label = 6,
5fe47b8a JMT	111	},{ /* 2001:10::/28 */
	112	.prefix = &(struct in6_addr){{{ 0x20, 0x01, 0x00, 0x10 }}},
	113	.prefixlen = 28,
	114	.label = 7,
2a8cc6c8 YH	115	},{ /* ::ffff:0:0 */
	116	.prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
	117	.prefixlen = 96,
	118	.label = 4,
	119	},{ /* ::/96 */
	120	.prefix = &in6addr_any,
	121	.prefixlen = 96,
	122	.label = 3,
	123	},{ /* ::1/128 */
	124	.prefix = &in6addr_loopback,
	125	.prefixlen = 128,
	126	.label = 0,
	127	}
	128	};
	129
	130	/* Object management */
	131	static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
	132	{
3de23255 BT	133	#ifdef CONFIG_NET_NS
	134	release_net(p->lbl_net);
	135	#endif
2a8cc6c8 YH	136	kfree(p);
	137	}
	138
85040bcb YH	139	static void ip6addrlbl_free_rcu(struct rcu_head *h)
	140	{
	141	ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
	142	}
	143
a50feda5	144	static bool ip6addrlbl_hold(struct ip6addrlbl_entry *p)
2a8cc6c8 YH	145	{
	146	return atomic_inc_not_zero(&p->refcnt);
	147	}
	148
	149	static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
	150	{
	151	if (atomic_dec_and_test(&p->refcnt))
85040bcb	152	call_rcu(&p->rcu, ip6addrlbl_free_rcu);
2a8cc6c8 YH	153	}
	154
	155	/* Find label */
a50feda5 ED	156	static bool __ip6addrlbl_match(struct net *net,
	157	const struct ip6addrlbl_entry *p,
	158	const struct in6_addr *addr,
	159	int addrtype, int ifindex)
2a8cc6c8	160	{
3de23255	161	if (!net_eq(ip6addrlbl_net(p), net))
a50feda5	162	return false;
2a8cc6c8	163	if (p->ifindex && p->ifindex != ifindex)
a50feda5	164	return false;
2a8cc6c8	165	if (p->addrtype && p->addrtype != addrtype)
a50feda5	166	return false;
2a8cc6c8	167	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
a50feda5 ED	168	return false;
a50feda5 ED	169	return true;
2a8cc6c8 YH	170	}
2a8cc6c8 YH	171
3de23255 BT	172	static struct ip6addrlbl_entry __ipv6_addr_label(struct net net,
3de23255 BT	173	const struct in6_addr *addr,
2a8cc6c8 YH	174	int type, int ifindex)
2a8cc6c8 YH	175	{
2a8cc6c8	176	struct ip6addrlbl_entry *p;
b67bfe0d	177	hlist_for_each_entry_rcu(p, &ip6addrlbl_table.head, list) {
3de23255	178	if (__ip6addrlbl_match(net, p, addr, type, ifindex))
2a8cc6c8 YH	179	return p;
	180	}
	181	return NULL;
	182	}
	183
3de23255 BT	184	u32 ipv6_addr_label(struct net *net,
3de23255 BT	185	const struct in6_addr *addr, int type, int ifindex)
2a8cc6c8 YH	186	{
	187	u32 label;
	188	struct ip6addrlbl_entry *p;
	189
	190	type &= IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK;
	191
	192	rcu_read_lock();
3de23255	193	p = __ipv6_addr_label(net, addr, type, ifindex);
2a8cc6c8 YH	194	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
	195	rcu_read_unlock();
	196
5b095d98	197	ADDRLABEL(KERN_DEBUG "%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n",
0c6ce78a	198	__func__, addr, type, ifindex, label);
2a8cc6c8 YH	199
	200	return label;
	201	}
	202
	203	/* allocate one entry */
3de23255 BT	204	static struct ip6addrlbl_entry ip6addrlbl_alloc(struct net net,
3de23255 BT	205	const struct in6_addr *prefix,
40fee36e YH	206	int prefixlen, int ifindex,
40fee36e YH	207	u32 label)
2a8cc6c8 YH	208	{
	209	struct ip6addrlbl_entry *newp;
	210	int addrtype;
	211
5b095d98	212	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n",
0c6ce78a	213	__func__, prefix, prefixlen, ifindex, (unsigned int)label);
2a8cc6c8 YH	214
	215	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED \| IPV6_ADDR_COMPATv4 \| IPV6_ADDR_LOOPBACK);
	216
	217	switch (addrtype) {
	218	case IPV6_ADDR_MAPPED:
	219	if (prefixlen > 96)
	220	return ERR_PTR(-EINVAL);
	221	if (prefixlen < 96)
	222	addrtype = 0;
	223	break;
	224	case IPV6_ADDR_COMPATv4:
	225	if (prefixlen != 96)
	226	addrtype = 0;
	227	break;
	228	case IPV6_ADDR_LOOPBACK:
	229	if (prefixlen != 128)
	230	addrtype = 0;
	231	break;
	232	}
	233
	234	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
	235	if (!newp)
	236	return ERR_PTR(-ENOMEM);
	237
	238	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
	239	newp->prefixlen = prefixlen;
	240	newp->ifindex = ifindex;
	241	newp->addrtype = addrtype;
	242	newp->label = label;
	243	INIT_HLIST_NODE(&newp->list);
3de23255 BT	244	#ifdef CONFIG_NET_NS
	245	newp->lbl_net = hold_net(net);
	246	#endif
2a8cc6c8 YH	247	atomic_set(&newp->refcnt, 1);
	248	return newp;
	249	}
	250
	251	/* add a label */
40fee36e	252	static int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
2a8cc6c8 YH	253	{
	254	int ret = 0;
	255
	256	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
0dc47877	257	__func__,
2a8cc6c8 YH	258	newp, replace);
	259
	260	if (hlist_empty(&ip6addrlbl_table.head)) {
	261	hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
	262	} else {
b67bfe0d	263	struct hlist_node *n;
2a8cc6c8	264	struct ip6addrlbl_entry *p = NULL;
b67bfe0d	265	hlist_for_each_entry_safe(p, n,
2a8cc6c8 YH	266	&ip6addrlbl_table.head, list) {
2a8cc6c8 YH	267	if (p->prefixlen == newp->prefixlen &&
3de23255	268	net_eq(ip6addrlbl_net(p), ip6addrlbl_net(newp)) &&
2a8cc6c8 YH	269	p->ifindex == newp->ifindex &&
	270	ipv6_addr_equal(&p->prefix, &newp->prefix)) {
	271	if (!replace) {
	272	ret = -EEXIST;
	273	goto out;
	274	}
	275	hlist_replace_rcu(&p->list, &newp->list);
	276	ip6addrlbl_put(p);
2a8cc6c8 YH	277	goto out;
	278	} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) \|\|
	279	(p->prefixlen < newp->prefixlen)) {
	280	hlist_add_before_rcu(&newp->list, &p->list);
	281	goto out;
	282	}
	283	}
	284	hlist_add_after_rcu(&p->list, &newp->list);
	285	}
	286	out:
	287	if (!ret)
	288	ip6addrlbl_table.seq++;
	289	return ret;
	290	}
	291
	292	/* add a label */
3de23255 BT	293	static int ip6addrlbl_add(struct net *net,
3de23255 BT	294	const struct in6_addr *prefix, int prefixlen,
40fee36e	295	int ifindex, u32 label, int replace)
2a8cc6c8 YH	296	{
	297	struct ip6addrlbl_entry *newp;
	298	int ret = 0;
	299
5b095d98	300	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
0c6ce78a HH	301	__func__, prefix, prefixlen, ifindex, (unsigned int)label,
0c6ce78a HH	302	replace);
2a8cc6c8	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	{
2a8cc6c8 YH	320	struct ip6addrlbl_entry *p = NULL;
b67bfe0d	321	struct hlist_node *n;
2a8cc6c8 YH	322	int ret = -ESRCH;
2a8cc6c8 YH	323
5b095d98	324	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
0c6ce78a	325	__func__, prefix, prefixlen, ifindex);
2a8cc6c8	326
b67bfe0d	327	hlist_for_each_entry_safe(p, n, &ip6addrlbl_table.head, list) {
2a8cc6c8	328	if (p->prefixlen == prefixlen &&
3de23255	329	net_eq(ip6addrlbl_net(p), net) &&
2a8cc6c8 YH	330	p->ifindex == ifindex &&
	331	ipv6_addr_equal(&p->prefix, prefix)) {
	332	hlist_del_rcu(&p->list);
	333	ip6addrlbl_put(p);
2a8cc6c8 YH	334	ret = 0;
	335	break;
	336	}
	337	}
	338	return ret;
	339	}
	340
3de23255 BT	341	static int ip6addrlbl_del(struct net *net,
3de23255 BT	342	const struct in6_addr *prefix, int prefixlen,
40fee36e	343	int ifindex)
2a8cc6c8 YH	344	{
	345	struct in6_addr prefix_buf;
	346	int ret;
	347
5b095d98	348	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
0c6ce78a	349	__func__, prefix, prefixlen, ifindex);
2a8cc6c8 YH	350
	351	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
	352	spin_lock(&ip6addrlbl_table.lock);
3de23255	353	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
2a8cc6c8 YH	354	spin_unlock(&ip6addrlbl_table.lock);
	355	return ret;
	356	}
	357
	358	/* add default label */
3de23255	359	static int __net_init ip6addrlbl_net_init(struct net *net)
2a8cc6c8 YH	360	{
	361	int err = 0;
	362	int i;
	363
f3213831	364	ADDRLABEL(KERN_DEBUG "%s\n", __func__);
2a8cc6c8 YH	365
2a8cc6c8 YH	366	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
3de23255 BT	367	int ret = ip6addrlbl_add(net,
3de23255 BT	368	ip6addrlbl_init_table[i].prefix,
2a8cc6c8 YH	369	ip6addrlbl_init_table[i].prefixlen,
	370	0,
	371	ip6addrlbl_init_table[i].label, 0);
	372	/* XXX: should we free all rules when we catch an error? */
	373	if (ret && (!err \|\| err != -ENOMEM))
	374	err = ret;
	375	}
	376	return err;
	377	}
	378
3de23255 BT	379	static void __net_exit ip6addrlbl_net_exit(struct net *net)
	380	{
	381	struct ip6addrlbl_entry *p = NULL;
b67bfe0d	382	struct hlist_node *n;
3de23255 BT	383
	384	/* Remove all labels belonging to the exiting net */
	385	spin_lock(&ip6addrlbl_table.lock);
b67bfe0d	386	hlist_for_each_entry_safe(p, n, &ip6addrlbl_table.head, list) {
3de23255 BT	387	if (net_eq(ip6addrlbl_net(p), net)) {
	388	hlist_del_rcu(&p->list);
	389	ip6addrlbl_put(p);
	390	}
	391	}
	392	spin_unlock(&ip6addrlbl_table.lock);
	393	}
	394
	395	static struct pernet_operations ipv6_addr_label_ops = {
	396	.init = ip6addrlbl_net_init,
	397	.exit = ip6addrlbl_net_exit,
	398	};
	399
2a8cc6c8 YH	400	int __init ipv6_addr_label_init(void)
	401	{
	402	spin_lock_init(&ip6addrlbl_table.lock);
	403
3de23255	404	return register_pernet_subsys(&ipv6_addr_label_ops);
2a8cc6c8 YH	405	}
2a8cc6c8 YH	406
2cc6d2bf NH	407	void ipv6_addr_label_cleanup(void)
	408	{
	409	unregister_pernet_subsys(&ipv6_addr_label_ops);
	410	}
	411
2a8cc6c8 YH	412	static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
	413	[IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
	414	[IFAL_LABEL] = { .len = sizeof(u32), },
	415	};
	416
	417	static int ip6addrlbl_newdel(struct sk_buff skb, struct nlmsghdr nlh,
	418	void *arg)
	419	{
3b1e0a65	420	struct net *net = sock_net(skb->sk);
2a8cc6c8 YH	421	struct ifaddrlblmsg *ifal;
	422	struct nlattr *tb[IFAL_MAX+1];
	423	struct in6_addr *pfx;
	424	u32 label;
	425	int err = 0;
	426
	427	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	428	if (err < 0)
	429	return err;
	430
	431	ifal = nlmsg_data(nlh);
	432
	433	if (ifal->ifal_family != AF_INET6 \|\|
	434	ifal->ifal_prefixlen > 128)
	435	return -EINVAL;
	436
2a8cc6c8 YH	437	if (!tb[IFAL_ADDRESS])
	438	return -EINVAL;
	439
	440	pfx = nla_data(tb[IFAL_ADDRESS]);
	441	if (!pfx)
	442	return -EINVAL;
	443
	444	if (!tb[IFAL_LABEL])
	445	return -EINVAL;
	446	label = nla_get_u32(tb[IFAL_LABEL]);
	447	if (label == IPV6_ADDR_LABEL_DEFAULT)
	448	return -EINVAL;
	449
	450	switch(nlh->nlmsg_type) {
	451	case RTM_NEWADDRLABEL:
0771275b FW	452	if (ifal->ifal_index &&
	453	!__dev_get_by_index(net, ifal->ifal_index))
	454	return -EINVAL;
	455
3de23255	456	err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	457	ifal->ifal_index, label,
	458	nlh->nlmsg_flags & NLM_F_REPLACE);
	459	break;
	460	case RTM_DELADDRLABEL:
3de23255	461	err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
2a8cc6c8 YH	462	ifal->ifal_index);
	463	break;
	464	default:
	465	err = -EOPNOTSUPP;
	466	}
	467	return err;
	468	}
	469
a50feda5 ED	470	static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
a50feda5 ED	471	int prefixlen, int ifindex, u32 lseq)
2a8cc6c8 YH	472	{
	473	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
	474	ifal->ifal_family = AF_INET6;
	475	ifal->ifal_prefixlen = prefixlen;
	476	ifal->ifal_flags = 0;
	477	ifal->ifal_index = ifindex;
	478	ifal->ifal_seq = lseq;
	479	};
	480
	481	static int ip6addrlbl_fill(struct sk_buff *skb,
	482	struct ip6addrlbl_entry *p,
	483	u32 lseq,
15e47304	484	u32 portid, u32 seq, int event,
2a8cc6c8 YH	485	unsigned int flags)
2a8cc6c8 YH	486	{
15e47304	487	struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
2a8cc6c8 YH	488	sizeof(struct ifaddrlblmsg), flags);
	489	if (!nlh)
	490	return -EMSGSIZE;
	491
	492	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
	493
	494	if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 \|\|
	495	nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
	496	nlmsg_cancel(skb, nlh);
	497	return -EMSGSIZE;
	498	}
	499
	500	return nlmsg_end(skb, nlh);
	501	}
	502
	503	static int ip6addrlbl_dump(struct sk_buff skb, struct netlink_callback cb)
	504	{
3b1e0a65	505	struct net *net = sock_net(skb->sk);
2a8cc6c8	506	struct ip6addrlbl_entry *p;
2a8cc6c8 YH	507	int idx = 0, s_idx = cb->args[0];
	508	int err;
	509
	510	rcu_read_lock();
b67bfe0d	511	hlist_for_each_entry_rcu(p, &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,
2a8cc6c8 YH	515	ip6addrlbl_table.seq,
15e47304	516	NETLINK_CB(cb->skb).portid,
2a8cc6c8 YH	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	{
a02cec21	531	return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
2a8cc6c8	532	+ nla_total_size(16) /* IFAL_ADDRESS */
a02cec21	533	+ nla_total_size(4); /* IFAL_LABEL */
2a8cc6c8 YH	534	}
	535
	536	static int ip6addrlbl_get(struct sk_buff in_skb, struct nlmsghdr nlh,
	537	void *arg)
	538	{
3b1e0a65	539	struct net *net = sock_net(in_skb->sk);
2a8cc6c8 YH	540	struct ifaddrlblmsg *ifal;
	541	struct nlattr *tb[IFAL_MAX+1];
	542	struct in6_addr *addr;
	543	u32 lseq;
	544	int err = 0;
	545	struct ip6addrlbl_entry *p;
	546	struct sk_buff *skb;
	547
	548	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy);
	549	if (err < 0)
	550	return err;
	551
	552	ifal = nlmsg_data(nlh);
	553
	554	if (ifal->ifal_family != AF_INET6 \|\|
	555	ifal->ifal_prefixlen != 128)
	556	return -EINVAL;
	557
	558	if (ifal->ifal_index &&
3de23255	559	!__dev_get_by_index(net, ifal->ifal_index))
2a8cc6c8 YH	560	return -EINVAL;
	561
	562	if (!tb[IFAL_ADDRESS])
	563	return -EINVAL;
	564
	565	addr = nla_data(tb[IFAL_ADDRESS]);
	566	if (!addr)
	567	return -EINVAL;
	568
	569	rcu_read_lock();
3de23255	570	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
2a8cc6c8 YH	571	if (p && ip6addrlbl_hold(p))
	572	p = NULL;
	573	lseq = ip6addrlbl_table.seq;
	574	rcu_read_unlock();
	575
	576	if (!p) {
	577	err = -ESRCH;
	578	goto out;
	579	}
	580
	581	if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
	582	ip6addrlbl_put(p);
	583	return -ENOBUFS;
	584	}
	585
	586	err = ip6addrlbl_fill(skb, p, lseq,
15e47304	587	NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2a8cc6c8 YH	588	RTM_NEWADDRLABEL, 0);
	589
	590	ip6addrlbl_put(p);
	591
	592	if (err < 0) {
	593	WARN_ON(err == -EMSGSIZE);
	594	kfree_skb(skb);
	595	goto out;
	596	}
	597
15e47304	598	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2a8cc6c8 YH	599	out:
	600	return err;
	601	}
	602
	603	void __init ipv6_addr_label_rtnl_register(void)
	604	{
c7ac8679 GR	605	__rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel,
	606	NULL, NULL);
	607	__rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel,
	608	NULL, NULL);
	609	__rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get,
	610	ip6addrlbl_dump, NULL);
2a8cc6c8 YH	611	}
2a8cc6c8 YH	612