usbip: dynamically allocate idev by nports found in sysfs

As the amount of available ports varies by the kernels build
configuration. To remove the limitation of the fixed 128 ports
we allocate the amount of idevs by using the number we get
from the kernel.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Acked-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/usb/usbip/libsrc/vhci_driver.c

@@ -135,11 +135,11 @@ static int refresh_imported_device_list(void)
 	return 0;
 }
 
-static int get_nports(void)
+static int get_nports(struct udev_device *hc_device)
 {
 	const char *attr_nports;
 
-	attr_nports = udev_device_get_sysattr_value(vhci_driver->hc_device, "nports");
+	attr_nports = udev_device_get_sysattr_value(hc_device, "nports");
 	if (!attr_nports) {
 		err("udev_device_get_sysattr_value nports failed");
 		return -1;
@@ -242,35 +242,41 @@ static int read_record(int rhport, char *host, unsigned long host_len,
 
 int usbip_vhci_driver_open(void)
 {
+	int nports;
+	struct udev_device *hc_device;
+
 	udev_context = udev_new();
 	if (!udev_context) {
 		err("udev_new failed");
 		return -1;
 	}
 
-	vhci_driver = calloc(1, sizeof(struct usbip_vhci_driver));
-
 	/* will be freed in usbip_driver_close() */
-	vhci_driver->hc_device =
+	hc_device =
 		udev_device_new_from_subsystem_sysname(udev_context,
 						       USBIP_VHCI_BUS_TYPE,
 						       USBIP_VHCI_DEVICE_NAME);
-	if (!vhci_driver->hc_device) {
+	if (!hc_device) {
 		err("udev_device_new_from_subsystem_sysname failed");
 		goto err;
 	}
 
-	vhci_driver->nports = get_nports();
-	dbg("available ports: %d", vhci_driver->nports);
-
-	if (vhci_driver->nports <= 0) {
+	nports = get_nports(hc_device);
+	if (nports <= 0) {
 		err("no available ports");
 		goto err;
-	} else if (vhci_driver->nports > MAXNPORT) {
-		err("port number exceeds %d", MAXNPORT);
+	}
+	dbg("available ports: %d", nports);
+
+	vhci_driver = calloc(1, sizeof(struct usbip_vhci_driver) +
+			nports * sizeof(struct usbip_imported_device));
+	if (!vhci_driver) {
+		err("vhci_driver allocation failed");
 		goto err;
 	}
 
+	vhci_driver->nports = nports;
+	vhci_driver->hc_device = hc_device;
 	vhci_driver->ncontrollers = get_ncontrollers();
 	dbg("available controllers: %d", vhci_driver->ncontrollers);
 
@@ -285,7 +291,7 @@ int usbip_vhci_driver_open(void)
 	return 0;
 
 err:
-	udev_device_unref(vhci_driver->hc_device);
+	udev_device_unref(hc_device);
 
 	if (vhci_driver)
 		free(vhci_driver);

tools/usb/usbip/libsrc/vhci_driver.h

@@ -13,7 +13,6 @@
 
 #define USBIP_VHCI_BUS_TYPE "platform"
 #define USBIP_VHCI_DEVICE_NAME "vhci_hcd.0"
-#define MAXNPORT 128
 
 enum hub_speed {
 	HUB_SPEED_HIGH = 0,
@@ -41,7 +40,7 @@ struct usbip_vhci_driver {
 
 	int ncontrollers;
 	int nports;
-	struct usbip_imported_device idev[MAXNPORT];
+	struct usbip_imported_device idev[];
 };