net: netlink_getname, packet_getname -- use DECLARE_SOCKADDR guard

Use guard DECLARE_SOCKADDR in a few more places which allow
us to catch if the structure copied back is too big.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netlink/af_netlink.c

@@ -708,7 +708,7 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr,
 {
 	struct sock *sk = sock->sk;
 	struct netlink_sock *nlk = nlk_sk(sk);
-	struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
+	DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
 
 	nladdr->nl_family = AF_NETLINK;
 	nladdr->nl_pad = 0;

net/packet/af_packet.c

@@ -1537,7 +1537,7 @@ static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
 	struct net_device *dev;
 	struct sock *sk = sock->sk;
 	struct packet_sock *po = pkt_sk(sk);
-	struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
+	DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
 
 	if (peer)
 		return -EOPNOTSUPP;

net/unix/af_unix.c

@@ -1259,7 +1259,7 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_
 {
 	struct sock *sk = sock->sk;
 	struct unix_sock *u;
-	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
+	DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, uaddr);
 	int err = 0;
 
 	if (peer) {