test/vsock: refactor vsock_accept

This is a preliminary patch to introduce SOCK_STREAM bind connect test.
vsock_accept() is split into vsock_listen() and vsock_accept().

Co-developed-by: Luigi Leonardi <luigi.leonardi@outlook.com>
Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com>
Signed-off-by: Filippo Storniolo <f.storniolo95@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: fstorniolo

tools/testing/vsock/util.c

@@ -136,11 +136,8 @@ int vsock_seqpacket_connect(unsigned int cid, unsigned int port)
 	return vsock_connect(cid, port, SOCK_SEQPACKET);
 }
 
-/* Listen on <cid, port> and return the first incoming connection.  The remote
- * address is stored to clientaddrp.  clientaddrp may be NULL.
- */
-static int vsock_accept(unsigned int cid, unsigned int port,
-			struct sockaddr_vm *clientaddrp, int type)
+/* Listen on <cid, port> and return the file descriptor. */
+static int vsock_listen(unsigned int cid, unsigned int port, int type)
 {
 	union {
 		struct sockaddr sa;
@@ -152,14 +149,7 @@ static int vsock_accept(unsigned int cid, unsigned int port,
 			.svm_cid = cid,
 		},
 	};
-	union {
-		struct sockaddr sa;
-		struct sockaddr_vm svm;
-	} clientaddr;
-	socklen_t clientaddr_len = sizeof(clientaddr.svm);
 	int fd;
-	int client_fd;
-	int old_errno;
 
 	fd = socket(AF_VSOCK, type, 0);
 	if (fd < 0) {
@@ -177,6 +167,24 @@ static int vsock_accept(unsigned int cid, unsigned int port,
 		exit(EXIT_FAILURE);
 	}
 
+	return fd;
+}
+
+/* Listen on <cid, port> and return the first incoming connection.  The remote
+ * address is stored to clientaddrp.  clientaddrp may be NULL.
+ */
+static int vsock_accept(unsigned int cid, unsigned int port,
+			struct sockaddr_vm *clientaddrp, int type)
+{
+	union {
+		struct sockaddr sa;
+		struct sockaddr_vm svm;
+	} clientaddr;
+	socklen_t clientaddr_len = sizeof(clientaddr.svm);
+	int fd, client_fd, old_errno;
+
+	fd = vsock_listen(cid, port, type);
+
 	control_writeln("LISTENING");
 
 	timeout_begin(TIMEOUT);