Make device close cleaner.

src/bsd/device.c

@@ -197,9 +197,11 @@ static void close_device(void) {
 		default:
 			close(device_fd);
 	}
+	device_fd = -1;
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/cygwin/device.c

@@ -215,12 +215,13 @@ static bool setup_device(void) {
 static void close_device(void) {
 	close(sp[0]);
 	close(sp[1]);
-	CloseHandle(device_handle);
+	CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 
 	kill(reader_pid, SIGKILL);
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/linux/device.c

@@ -110,10 +110,12 @@ static bool setup_device(void) {
 
 static void close_device(void) {
 	close(device_fd);
+	device_fd = -1;
 
-	free(type);
-	free(device);
-	free(iface);
+	free(type); type = NULL;
+	free(device); device = NULL;
+	free(iface); iface = NULL;
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/mingw/device.c

@@ -213,10 +213,11 @@ static bool setup_device(void) {
 }
 
 static void close_device(void) {
-	CloseHandle(device_handle);
+	CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/multicast_device.c

@@ -148,13 +148,15 @@ error:
 }
 
 static void close_device(void) {
-	close(device_fd);
+	close(device_fd); device_fd = -1;
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
 
-	if(ai)
-		freeaddrinfo(ai);
+	if(ai) {
+		freeaddrinfo(ai); ai = NULL;
+	}
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/raw_socket_device.c

@@ -83,10 +83,11 @@ static bool setup_device(void) {
 }
 
 static void close_device(void) {
-	close(device_fd);
+	close(device_fd); device_fd = -1;
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/solaris/device.c

@@ -287,11 +287,11 @@ static void close_device(void) {
 		}
 	}
 
-	close(ip_fd);
-	close(device_fd);
+	close(ip_fd); ip_fd = -1;
+	close(device_fd); device_fd = -1;
 
-	free(device);
-	free(iface);
+	free(device); device = NULL;
+	free(iface); iface = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/uml_device.c

@@ -156,22 +156,29 @@ static bool setup_device(void) {
 }
 
 void close_device(void) {
-	if(listen_fd >= 0)
-		close(listen_fd);
+	if(listen_fd >= 0) {
+		close(listen_fd); listen_fd = -1;
+	}
 
-	if(request_fd >= 0)
-		close(request_fd);
+	if(request_fd >= 0) {
+		close(request_fd); request_fd = -1;
+	}
 
-	if(data_fd >= 0)
-		close(data_fd);
+	if(data_fd >= 0) {
+		close(data_fd); data_fd = -1;
+	}
 
-	if(write_fd >= 0)
-		close(write_fd);
+	if(write_fd >= 0) {
+		close(write_fd); write_fd = -1;
+	}
 
 	unlink(device);
 
-	free(device);
-	if(iface) free(iface);
+	free(device); device = NULL;
+	if(iface) {
+		free(iface); iface = NULL;
+	}
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {

src/vde_device.c

@@ -82,15 +82,18 @@ static bool setup_device(void) {
 }
 
 static void close_device(void) {
-	if(conn)
-		plug.vde_close(conn);
+	if(conn) {
+		plug.vde_close(conn); conn = NULL;
+	}
 
 	if(plug.dl_handle)
 		libvdeplug_dynclose(plug);
 
-	free(device);
+	free(device); device = NULL;
 
-	free(iface);
+	free(iface); iface = NULL;
+
+	device_info = NULL;
 }
 
 static bool read_packet(vpn_packet_t *packet) {