unix_bind(): take BSD and abstract address cases into new helpers

unix_bind_bsd() and unix_bind_abstract() respectively.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/unix/af_unix.c

@@ -1014,63 +1014,29 @@ static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
 	return err;
 }
 
-static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+static int unix_bind_bsd(struct sock *sk, struct unix_address *addr)
 {
-	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
 	struct unix_sock *u = unix_sk(sk);
-	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
-	char *sun_path = sunaddr->sun_path;
-	int err;
-	unsigned int hash;
-	struct unix_address *addr;
-
-	err = -EINVAL;
-	if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
-	    sunaddr->sun_family != AF_UNIX)
-		goto out;
-
-	if (addr_len == sizeof(short)) {
-		err = unix_autobind(sock);
-		goto out;
-	}
-
-	err = unix_mkname(sunaddr, addr_len, &hash);
-	if (err < 0)
-		goto out;
-	addr_len = err;
-	err = -ENOMEM;
-	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
-	if (!addr)
-		goto out;
-
-	memcpy(addr->name, sunaddr, addr_len);
-	addr->len = addr_len;
-	addr->hash = hash ^ sk->sk_type;
-	refcount_set(&addr->refcnt, 1);
-
-	if (sun_path[0]) {
 	struct path path = { };
 	umode_t mode = S_IFSOCK |
-		       (SOCK_INODE(sock)->i_mode & ~current_umask());
-		err = unix_mknod(sun_path, mode, &path);
-		if (err) {
-			if (err == -EEXIST)
-				err = -EADDRINUSE;
-			goto out_addr;
-		}
+	       (SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask());
+	unsigned int hash;
+	int err;
+
+	err = unix_mknod(addr->name->sun_path, mode, &path);
+	if (err)
+		return err;
 
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err) {
 		path_put(&path);
-			goto out_addr;
+		return err;
 	}
 
-		err = -EINVAL;
 	if (u->addr) {
 		mutex_unlock(&u->bindlock);
 		path_put(&path);
-			goto out_addr;
+		return -EINVAL;
 	}
 
 	addr->hash = UNIX_HASH_SIZE;
@@ -1080,38 +1046,73 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	__unix_set_addr(sk, addr, hash);
 	spin_unlock(&unix_table_lock);
 	mutex_unlock(&u->bindlock);
-		addr = NULL;
-		err = 0;
-	} else {
+	return 0;
+}
+
+static int unix_bind_abstract(struct sock *sk, unsigned hash,
+			      struct unix_address *addr)
+{
+	struct unix_sock *u = unix_sk(sk);
+	int err;
+
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
-			goto out_addr;
+		return err;
 
-		err = -EINVAL;
 	if (u->addr) {
 		mutex_unlock(&u->bindlock);
-			goto out_addr;
+		return -EINVAL;
 	}
 
 	spin_lock(&unix_table_lock);
-		err = -EADDRINUSE;
-		if (__unix_find_socket_byname(net, sunaddr, addr_len,
+	if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
 				      sk->sk_type, hash)) {
 		spin_unlock(&unix_table_lock);
 		mutex_unlock(&u->bindlock);
-			goto out_addr;
+		return -EADDRINUSE;
 	}
 	__unix_set_addr(sk, addr, addr->hash);
 	spin_unlock(&unix_table_lock);
 	mutex_unlock(&u->bindlock);
-		addr = NULL;
-		err = 0;
-	}
-out_addr:
-	if (addr)
-		unix_release_addr(addr);
-out:
+	return 0;
+}
+
+static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
+	char *sun_path = sunaddr->sun_path;
+	int err;
+	unsigned int hash;
+	struct unix_address *addr;
+
+	if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
+	    sunaddr->sun_family != AF_UNIX)
+		return -EINVAL;
+
+	if (addr_len == sizeof(short))
+		return unix_autobind(sock);
+
+	err = unix_mkname(sunaddr, addr_len, &hash);
+	if (err < 0)
 		return err;
+	addr_len = err;
+	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
+
+	memcpy(addr->name, sunaddr, addr_len);
+	addr->len = addr_len;
+	addr->hash = hash ^ sk->sk_type;
+	refcount_set(&addr->refcnt, 1);
+
+	if (sun_path[0])
+		err = unix_bind_bsd(sk, addr);
+	else
+		err = unix_bind_abstract(sk, hash, addr);
+	if (err)
+		unix_release_addr(addr);
+	return err == -EEXIST ? -EADDRINUSE : err;
 }
 
 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)