test: use random port in range for socket tests

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/test/shutdown.c b/test/shutdown.c
index 5f4e9cc..5aa1371 100644
--- a/test/shutdown.c
+++ b/test/shutdown.c
@@ -32,6 +32,8 @@
 	if (argc > 1)
 		return 0;
 
+	srand(getpid());
+
 	recv_s0 = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
 
 	ret = setsockopt(recv_s0, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val));
@@ -40,7 +42,7 @@
 	assert(ret != -1);
 
 	addr.sin_family = AF_INET;
-	addr.sin_port = 0x1235;
+	addr.sin_port = (rand() % 61440) + 4096;
 	addr.sin_addr.s_addr = 0x0100007fU;
 
 	ret = bind(recv_s0, (struct sockaddr*)&addr, sizeof(addr));
diff --git a/test/socket-rw-eagain.c b/test/socket-rw-eagain.c
index e08f984..b6406d8 100644
--- a/test/socket-rw-eagain.c
+++ b/test/socket-rw-eagain.c
@@ -28,6 +28,8 @@
 	if (argc > 1)
 		return 0;
 
+	srand(getpid());
+
 	recv_s0 = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
 
 	ret = setsockopt(recv_s0, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val));
@@ -36,7 +38,7 @@
 	assert(ret != -1);
 
 	addr.sin_family = AF_INET;
-	addr.sin_port = 0x1235;
+	addr.sin_port = (rand() % 61440) + 4096;
 	addr.sin_addr.s_addr = 0x0100007fU;
 
 	ret = bind(recv_s0, (struct sockaddr*)&addr, sizeof(addr));
diff --git a/test/socket-rw.c b/test/socket-rw.c
index 77fae59..47ae25c 100644
--- a/test/socket-rw.c
+++ b/test/socket-rw.c
@@ -30,6 +30,8 @@
 	if (argc > 1)
 		return 0;
 
+	srand(getpid());
+
 	recv_s0 = socket(AF_INET, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
 
 	ret = setsockopt(recv_s0, SOL_SOCKET, SO_REUSEPORT, &val, sizeof(val));
@@ -38,7 +40,7 @@
 	assert(ret != -1);
 
 	addr.sin_family = AF_INET;
-	addr.sin_port = 0x1235;
+	addr.sin_port = (rand() % 61440) + 4096;
 	addr.sin_addr.s_addr = 0x0100007fU;
 
 	ret = bind(recv_s0, (struct sockaddr*)&addr, sizeof(addr));