[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.
authorYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Wed, 14 Nov 2007 06:56:23 +0000 (15:56 +0900)
committerDavid S. Miller <davem@davemloft.net>
Mon, 28 Jan 2008 22:53:58 +0000 (14:53 -0800)
Policy table is implemented as an RCU linear list since we do not expect
large list nor frequent updates.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/if_addrlabel.h [new file with mode: 0644]
include/linux/rtnetlink.h
include/net/addrconf.h
net/ipv6/Makefile
net/ipv6/addrconf.c
net/ipv6/addrlabel.c [new file with mode: 0644]

diff --git a/include/linux/if_addrlabel.h b/include/linux/if_addrlabel.h
new file mode 100644 (file)
index 0000000..9fe79c9
--- /dev/null
@@ -0,0 +1,32 @@
+/*
+ * if_addrlabel.h - netlink interface for address labels
+ *
+ * Copyright (C)2007 USAGI/WIDE Project,  All Rights Reserved.
+ *
+ * Authors:
+ *     YOSHIFUJI Hideaki @ USAGI/WIDE <yoshfuji@linux-ipv6.org>
+ */
+
+#ifndef __LINUX_IF_ADDRLABEL_H
+#define __LINUX_IF_ADDRLABEL_H
+
+struct ifaddrlblmsg
+{
+       __u8            ifal_family;            /* Address family */
+       __u8            __ifal_reserved;        /* Reserved */
+       __u8            ifal_prefixlen;         /* Prefix length */
+       __u8            ifal_flags;             /* Flags */
+       __u32           ifal_index;             /* Link index */
+       __u32           ifal_seq;               /* sequence number */
+};
+
+enum
+{
+       IFAL_ADDRESS = 1,
+       IFAL_LABEL = 2,
+       __IFAL_MAX
+};
+
+#define IFAL_MAX       (__IFAL_MAX - 1)
+
+#endif
index 4e81836..e20dcc8 100644 (file)
@@ -100,6 +100,13 @@ enum {
        RTM_NEWNDUSEROPT = 68,
 #define RTM_NEWNDUSEROPT RTM_NEWNDUSEROPT
 
+       RTM_NEWADDRLABEL = 72,
+#define RTM_NEWADDRLABEL RTM_NEWADDRLABEL
+       RTM_DELADDRLABEL,
+#define RTM_NEWADDRLABEL RTM_NEWADDRLABEL
+       RTM_GETADDRLABEL,
+#define RTM_GETADDRLABEL RTM_GETADDRLABEL
+
        __RTM_MAX,
 #define RTM_MAX                (((__RTM_MAX + 3) & ~3) - 1)
 };
index 33b593e..bccc2fe 100644 (file)
@@ -84,6 +84,14 @@ extern void                  addrconf_leave_solict(struct inet6_dev *idev,
                                        struct in6_addr *addr);
 
 /*
+ *     IPv6 Address Label subsystem (addrlabel.c)
+ */
+extern int                     ipv6_addr_label_init(void);
+extern void                    ipv6_addr_label_rtnl_register(void);
+extern u32                     ipv6_addr_label(const struct in6_addr *addr,
+                                               int type, int ifindex);
+
+/*
  *     multicast prototypes (mcast.c)
  */
 extern int ipv6_sock_mc_join(struct sock *sk, int ifindex, 
index 87c23a7..5ffa980 100644 (file)
@@ -5,6 +5,7 @@
 obj-$(CONFIG_IPV6) += ipv6.o
 
 ipv6-objs :=   af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
+               addrlabel.o \
                route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
                raw.o protocol.o icmp.o mcast.o reassembly.o tcp_ipv6.o \
                exthdrs.o sysctl_net_ipv6.o datagram.o \
index e1e591b..a70cecf 100644 (file)
@@ -874,36 +874,6 @@ static inline int ipv6_saddr_preferred(int type)
        return 0;
 }
 
-/* static matching label */
-static inline int ipv6_addr_label(const struct in6_addr *addr, int type,
-                                 int ifindex)
-{
- /*
-  *    prefix (longest match)  label
-  *    -----------------------------
-  *    ::1/128                 0
-  *    ::/0                    1
-  *    2002::/16               2
-  *    ::/96                   3
-  *    ::ffff:0:0/96           4
-  *    fc00::/7                5
-  *    2001::/32               6
-  */
-       if (type & IPV6_ADDR_LOOPBACK)
-               return 0;
-       else if (type & IPV6_ADDR_COMPATv4)
-               return 3;
-       else if (type & IPV6_ADDR_MAPPED)
-               return 4;
-       else if (addr->s6_addr32[0] == htonl(0x20010000))
-               return 6;
-       else if (addr->s6_addr16[0] == htons(0x2002))
-               return 2;
-       else if ((addr->s6_addr[0] & 0xfe) == 0xfc)
-               return 5;
-       return 1;
-}
-
 int ipv6_dev_get_saddr(struct net_device *daddr_dev,
                       struct in6_addr *daddr, struct in6_addr *saddr)
 {
@@ -4189,7 +4159,13 @@ EXPORT_SYMBOL(unregister_inet6addr_notifier);
 
 int __init addrconf_init(void)
 {
-       int err = 0;
+       int err;
+
+       if ((err = ipv6_addr_label_init()) < 0) {
+               printk(KERN_CRIT "IPv6 Addrconf: cannot initialize default policy table: %d.\n",
+                       err);
+               return err;
+       }
 
        /* The addrconf netdev notifier requires that loopback_dev
         * has it's ipv6 private information allocated and setup
@@ -4240,6 +4216,8 @@ int __init addrconf_init(void)
        __rtnl_register(PF_INET6, RTM_GETMULTICAST, NULL, inet6_dump_ifmcaddr);
        __rtnl_register(PF_INET6, RTM_GETANYCAST, NULL, inet6_dump_ifacaddr);
 
+       ipv6_addr_label_rtnl_register();
+
 #ifdef CONFIG_SYSCTL
        addrconf_sysctl.sysctl_header =
                register_sysctl_table(addrconf_sysctl.addrconf_root_dir);
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
new file mode 100644 (file)
index 0000000..204d4d6
--- /dev/null
@@ -0,0 +1,551 @@
+/*
+ * IPv6 Address Label subsystem
+ * for the IPv6 "Default" Source Address Selection
+ *
+ * Copyright (C)2007 USAGI/WIDE Project
+ */
+/*
+ * Author:
+ *     YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/in6.h>
+#include <net/addrconf.h>
+#include <linux/if_addrlabel.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#if 0
+#define ADDRLABEL(x...) printk(x)
+#else
+#define ADDRLABEL(x...) do { ; } while(0)
+#endif
+
+/*
+ * Policy Table
+ */
+struct ip6addrlbl_entry
+{
+       struct in6_addr prefix;
+       int prefixlen;
+       int ifindex;
+       int addrtype;
+       u32 label;
+       struct hlist_node list;
+       atomic_t refcnt;
+       struct rcu_head rcu;
+};
+
+static struct ip6addrlbl_table
+{
+       struct hlist_head head;
+       spinlock_t lock;
+       u32 seq;
+} ip6addrlbl_table;
+
+/*
+ * Default policy table (RFC3484 + extensions)
+ *
+ * prefix              addr_type       label
+ * -------------------------------------------------------------------------
+ * ::1/128             LOOPBACK        0
+ * ::/0                        N/A             1
+ * 2002::/16           N/A             2
+ * ::/96               COMPATv4        3
+ * ::ffff:0:0/96       V4MAPPED        4
+ * fc00::/7            N/A             5               ULA (RFC 4193)
+ * 2001::/32           N/A             6               Teredo (RFC 4380)
+ *
+ * Note: 0xffffffff is used if we do not have any policies.
+ */
+
+#define IPV6_ADDR_LABEL_DEFAULT        0xffffffffUL
+
+static const __initdata struct ip6addrlbl_init_table
+{
+       const struct in6_addr *prefix;
+       int prefixlen;
+       u32 label;
+} ip6addrlbl_init_table[] = {
+       {       /* ::/0 */
+               .prefix = &in6addr_any,
+               .label = 1,
+       },{     /* fc00::/7 */
+               .prefix = &(struct in6_addr){{{ 0xfc }}},
+               .prefixlen = 7,
+               .label = 5,
+       },{     /* 2002::/16 */
+               .prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
+               .prefixlen = 16,
+               .label = 2,
+       },{     /* 2001::/32 */
+               .prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
+               .prefixlen = 32,
+               .label = 6,
+       },{     /* ::ffff:0:0 */
+               .prefix = &(struct in6_addr){{{ [10] = 0xff, [11] = 0xff }}},
+               .prefixlen = 96,
+               .label = 4,
+       },{     /* ::/96 */
+               .prefix = &in6addr_any,
+               .prefixlen = 96,
+               .label = 3,
+       },{     /* ::1/128 */
+               .prefix = &in6addr_loopback,
+               .prefixlen = 128,
+               .label = 0,
+       }
+};
+
+/* Object management */
+static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
+{
+       kfree(p);
+}
+
+static 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))
+               ip6addrlbl_free(p);
+}
+
+static void ip6addrlbl_free_rcu(struct rcu_head *h)
+{
+       ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
+}
+
+/* Find label */
+static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
+                             const struct in6_addr *addr,
+                             int addrtype, int ifindex)
+{
+       if (p->ifindex && p->ifindex != ifindex)
+               return 0;
+       if (p->addrtype && p->addrtype != addrtype)
+               return 0;
+       if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
+               return 0;
+       return 1;
+}
+
+static struct ip6addrlbl_entry *__ipv6_addr_label(const struct in6_addr *addr,
+                                                 int type, int ifindex)
+{
+       struct hlist_node *pos;
+       struct ip6addrlbl_entry *p;
+       hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
+               if (__ip6addrlbl_match(p, addr, type, ifindex))
+                       return p;
+       }
+       return NULL;
+}
+
+u32 ipv6_addr_label(const struct in6_addr *addr, int type, int ifindex)
+{
+       u32 label;
+       struct ip6addrlbl_entry *p;
+
+       type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
+
+       rcu_read_lock();
+       p = __ipv6_addr_label(addr, type, ifindex);
+       label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
+       rcu_read_unlock();
+
+       ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
+                       __FUNCTION__,
+                       NIP6(*addr), type, ifindex,
+                       label);
+
+       return label;
+}
+
+/* allocate one entry */
+struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
+                                         int prefixlen, int ifindex,
+                                         u32 label)
+{
+       struct ip6addrlbl_entry *newp;
+       int addrtype;
+
+       ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
+                       __FUNCTION__,
+                       NIP6(*prefix), prefixlen,
+                       ifindex,
+                       (unsigned int)label);
+
+       addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
+
+       switch (addrtype) {
+       case IPV6_ADDR_MAPPED:
+               if (prefixlen > 96)
+                       return ERR_PTR(-EINVAL);
+               if (prefixlen < 96)
+                       addrtype = 0;
+               break;
+       case IPV6_ADDR_COMPATv4:
+               if (prefixlen != 96)
+                       addrtype = 0;
+               break;
+       case IPV6_ADDR_LOOPBACK:
+               if (prefixlen != 128)
+                       addrtype = 0;
+               break;
+       }
+
+       newp = kmalloc(sizeof(*newp), GFP_KERNEL);
+       if (!newp)
+               return ERR_PTR(-ENOMEM);
+
+       ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
+       newp->prefixlen = prefixlen;
+       newp->ifindex = ifindex;
+       newp->addrtype = addrtype;
+       newp->label = label;
+       INIT_HLIST_NODE(&newp->list);
+       atomic_set(&newp->refcnt, 1);
+       return newp;
+}
+
+/* add a label */
+int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
+{
+       int ret = 0;
+
+       ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
+                       __FUNCTION__,
+                       newp, replace);
+
+       if (hlist_empty(&ip6addrlbl_table.head)) {
+               hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
+       } else {
+               struct hlist_node *pos, *n;
+               struct ip6addrlbl_entry *p = NULL;
+               hlist_for_each_entry_safe(p, pos, n,
+                                         &ip6addrlbl_table.head, list) {
+                       if (p->prefixlen == newp->prefixlen &&
+                           p->ifindex == newp->ifindex &&
+                           ipv6_addr_equal(&p->prefix, &newp->prefix)) {
+                               if (!replace) {
+                                       ret = -EEXIST;
+                                       goto out;
+                               }
+                               hlist_replace_rcu(&p->list, &newp->list);
+                               ip6addrlbl_put(p);
+                               call_rcu(&p->rcu, ip6addrlbl_free_rcu);
+                               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 */
+int ip6addrlbl_add(const struct in6_addr *prefix, int prefixlen,
+                      int ifindex, u32 label, int replace)
+{
+       struct ip6addrlbl_entry *newp;
+       int ret = 0;
+
+       ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
+                       __FUNCTION__,
+                       NIP6(*prefix), prefixlen,
+                       ifindex,
+                       (unsigned int)label,
+                       replace);
+
+       newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
+       if (IS_ERR(newp))
+               return PTR_ERR(newp);
+       spin_lock(&ip6addrlbl_table.lock);
+       ret = __ip6addrlbl_add(newp, replace);
+       spin_unlock(&ip6addrlbl_table.lock);
+       if (ret)
+               ip6addrlbl_free(newp);
+       return ret;
+}
+
+/* remove a label */
+int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
+                         int ifindex)
+{
+       struct ip6addrlbl_entry *p = NULL;
+       struct hlist_node *pos, *n;
+       int ret = -ESRCH;
+
+       ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
+                       __FUNCTION__,
+                       NIP6(*prefix), prefixlen,
+                       ifindex);
+
+       hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
+               if (p->prefixlen == prefixlen &&
+                   p->ifindex == ifindex &&
+                   ipv6_addr_equal(&p->prefix, prefix)) {
+                       hlist_del_rcu(&p->list);
+                       ip6addrlbl_put(p);
+                       call_rcu(&p->rcu, ip6addrlbl_free_rcu);
+                       ret = 0;
+                       break;
+               }
+       }
+       return ret;
+}
+
+int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
+                      int ifindex)
+{
+       struct in6_addr prefix_buf;
+       int ret;
+
+       ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
+                       __FUNCTION__,
+                       NIP6(*prefix), prefixlen,
+                       ifindex);
+
+       ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
+       spin_lock(&ip6addrlbl_table.lock);
+       ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
+       spin_unlock(&ip6addrlbl_table.lock);
+       return ret;
+}
+
+/* add default label */
+static __init int ip6addrlbl_init(void)
+{
+       int err = 0;
+       int i;
+
+       ADDRLABEL(KERN_DEBUG "%s()\n", __FUNCTION__);
+
+       for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
+               int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
+                                        ip6addrlbl_init_table[i].prefixlen,
+                                        0,
+                                        ip6addrlbl_init_table[i].label, 0);
+               /* XXX: should we free all rules when we catch an error? */
+               if (ret && (!err || err != -ENOMEM))
+                       err = ret;
+       }
+       return err;
+}
+
+int __init ipv6_addr_label_init(void)
+{
+       spin_lock_init(&ip6addrlbl_table.lock);
+
+       return ip6addrlbl_init();
+}
+
+static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
+       [IFAL_ADDRESS]          = { .len = sizeof(struct in6_addr), },
+       [IFAL_LABEL]            = { .len = sizeof(u32), },
+};
+
+static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
+                            void *arg)
+{
+       struct 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(&init_net, ifal->ifal_index))
+               return -EINVAL;
+
+       if (!tb[IFAL_ADDRESS])
+               return -EINVAL;
+
+       pfx = nla_data(tb[IFAL_ADDRESS]);
+       if (!pfx)
+               return -EINVAL;
+
+       if (!tb[IFAL_LABEL])
+               return -EINVAL;
+       label = nla_get_u32(tb[IFAL_LABEL]);
+       if (label == IPV6_ADDR_LABEL_DEFAULT)
+               return -EINVAL;
+
+       switch(nlh->nlmsg_type) {
+       case RTM_NEWADDRLABEL:
+               err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
+                                    ifal->ifal_index, label,
+                                    nlh->nlmsg_flags & NLM_F_REPLACE);
+               break;
+       case RTM_DELADDRLABEL:
+               err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
+                                    ifal->ifal_index);
+               break;
+       default:
+               err = -EOPNOTSUPP;
+       }
+       return err;
+}
+
+static inline void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
+                                    int prefixlen, int ifindex, u32 lseq)
+{
+       struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
+       ifal->ifal_family = AF_INET6;
+       ifal->ifal_prefixlen = prefixlen;
+       ifal->ifal_flags = 0;
+       ifal->ifal_index = ifindex;
+       ifal->ifal_seq = lseq;
+};
+
+static int ip6addrlbl_fill(struct sk_buff *skb,
+                          struct ip6addrlbl_entry *p,
+                          u32 lseq,
+                          u32 pid, u32 seq, int event,
+                          unsigned int flags)
+{
+       struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
+                                        sizeof(struct ifaddrlblmsg), flags);
+       if (!nlh)
+               return -EMSGSIZE;
+
+       ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
+
+       if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 ||
+           nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
+               nlmsg_cancel(skb, nlh);
+               return -EMSGSIZE;
+       }
+
+       return nlmsg_end(skb, nlh);
+}
+
+static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct 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) {
+                       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 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(&init_net, ifal->ifal_index))
+               return -EINVAL;
+
+       if (!tb[IFAL_ADDRESS])
+               return -EINVAL;
+
+       addr = nla_data(tb[IFAL_ADDRESS]);
+       if (!addr)
+               return -EINVAL;
+
+       rcu_read_lock();
+       p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
+       if (p && ip6addrlbl_hold(p))
+               p = NULL;
+       lseq = ip6addrlbl_table.seq;
+       rcu_read_unlock();
+
+       if (!p) {
+               err = -ESRCH;
+               goto out;
+       }
+
+       if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
+               ip6addrlbl_put(p);
+               return -ENOBUFS;
+       }
+
+       err = ip6addrlbl_fill(skb, p, lseq,
+                             NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+                             RTM_NEWADDRLABEL, 0);
+
+       ip6addrlbl_put(p);
+
+       if (err < 0) {
+               WARN_ON(err == -EMSGSIZE);
+               kfree_skb(skb);
+               goto out;
+       }
+
+       err = rtnl_unicast(skb, 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);
+}
+