[PATCH 17/18] staging: usbip: userspace: don't throw error when trying to read configuration specific attributes

Valentina Manea
2014-03-08T12:54:36Z

When a device has just been bound to usbip-host but the client hasn't
set a configuration on it, certain attributes will not exist. Don't
treat this as an error.

Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
---
drivers/staging/usbip/userspace/libsrc/usbip_common.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/usbip/userspace/libsrc/usbip_common.c b/drivers/staging/usbip/userspace/libsrc/usbip_common.c
index 998c11c..238bf5b 100644
--- a/drivers/staging/usbip/userspace/libsrc/usbip_common.c
+++ b/drivers/staging/usbip/userspace/libsrc/usbip_common.c
@@ -127,10 +127,23 @@ int read_attr_value(struct udev_device *dev, const char *name,
goto err;
}

+ /* The client chooses the device configuration
+ * when attaching it so right after being bound
+ * to usbip-host on the server the device will
+ * have no configuration.
+ * Therefore, attributes such as bConfigurationValue
+ * and bNumInterfaces will not exist and sscanf will
+ * fail. Check for these cases and don't treat them
+ * as errors.
+ */
+
ret = sscanf(attr, format, &num);
if (ret < 1) {
- err("sscanf failed");
- goto err;
+ if (strcmp(name, "bConfigurationValue") &&
+ strcmp(name, "bNumInterfaces")) {
+ err("sscanf failed for attribute %s", name);
+ goto err;
+ }
}

err:
--
1.8.1.2