vsock_test: wait for the remote to close the connection

Before check if a send returns -EPIPE, we need to make sure the
connection is closed.
To do that, we use epoll API to wait EPOLLRDHUP or EPOLLHUP events
on the socket.
Reported-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/vsock/util.c

@@ -13,6 +13,8 @@
 #include <stdlib.h>
 #include <signal.h>
 #include <unistd.h>
+#include <assert.h>
+#include <sys/epoll.h>
 
 #include "timeout.h"
 #include "control.h"
@@ -44,6 +46,43 @@ unsigned int parse_cid(const char *str)
 	return n;
 }
 
+/* Wait for the remote to close the connection */
+void vsock_wait_remote_close(int fd)
+{
+	struct epoll_event ev;
+	int epollfd, nfds;
+
+	epollfd = epoll_create1(0);
+	if (epollfd == -1) {
+		perror("epoll_create1");
+		exit(EXIT_FAILURE);
+	}
+
+	ev.events = EPOLLRDHUP | EPOLLHUP;
+	ev.data.fd = fd;
+	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) == -1) {
+		perror("epoll_ctl");
+		exit(EXIT_FAILURE);
+	}
+
+	nfds = epoll_wait(epollfd, &ev, 1, TIMEOUT * 1000);
+	if (nfds == -1) {
+		perror("epoll_wait");
+		exit(EXIT_FAILURE);
+	}
+
+	if (nfds == 0) {
+		fprintf(stderr, "epoll_wait timed out\n");
+		exit(EXIT_FAILURE);
+	}
+
+	assert(nfds == 1);
+	assert(ev.events & (EPOLLRDHUP | EPOLLHUP));
+	assert(ev.data.fd == fd);
+
+	close(epollfd);
+}
+
 /* Connect to <cid, port> and return the file descriptor. */
 int vsock_stream_connect(unsigned int cid, unsigned int port)
 {

tools/testing/vsock/util.h

@@ -36,6 +36,7 @@ unsigned int parse_cid(const char *str);
 int vsock_stream_connect(unsigned int cid, unsigned int port);
 int vsock_stream_accept(unsigned int cid, unsigned int port,
 			struct sockaddr_vm *clientaddrp);
+void vsock_wait_remote_close(int fd);
 void send_byte(int fd, int expected_ret, int flags);
 void recv_byte(int fd, int expected_ret, int flags);
 void run_tests(const struct test_case *test_cases,

tools/testing/vsock/vsock_test.c

@@ -66,7 +66,6 @@ static void test_stream_client_close_client(const struct test_opts *opts)
 
 	send_byte(fd, 1, 0);
 	close(fd);
-	control_writeln("CLOSED");
 }
 
 static void test_stream_client_close_server(const struct test_opts *opts)
@@ -79,7 +78,10 @@ static void test_stream_client_close_server(const struct test_opts *opts)
 		exit(EXIT_FAILURE);
 	}
 
-	control_expectln("CLOSED");
+	/* Wait for the remote to close the connection, before check
+	 * -EPIPE error on send.
+	 */
+	vsock_wait_remote_close(fd);
 
 	send_byte(fd, -EPIPE, 0);
 	recv_byte(fd, 1, 0);
@@ -97,7 +99,10 @@ static void test_stream_server_close_client(const struct test_opts *opts)
 		exit(EXIT_FAILURE);
 	}
 
-	control_expectln("CLOSED");
+	/* Wait for the remote to close the connection, before check
+	 * -EPIPE error on send.
+	 */
+	vsock_wait_remote_close(fd);
 
 	send_byte(fd, -EPIPE, 0);
 	recv_byte(fd, 1, 0);
@@ -117,7 +122,6 @@ static void test_stream_server_close_server(const struct test_opts *opts)
 
 	send_byte(fd, 1, 0);
 	close(fd);
-	control_writeln("CLOSED");
 }
 
 /* With the standard socket sizes, VMCI is able to support about 100