Currently applications for devices which only are accessed from userspace
can use claim / release interface to make sure they don't get in each others
way. The same however does not work for applications which first need to detach
a "native" / in kernel driver, as this detach will not only detach native
drivers but also the usbfs driver, thus stealing the device from another
userspace / libusb app.
This patch fixes libusb_detach_kernel_driver to only detach "real" kernel
drivers and not the special usbfs driver used for userspace access to
USB devices. If the usbfs driver is found LIBUSB_ERROR_BUSY will be
returned.
Signed-off-by: Hans de Goede <hdego...@redhat.com>
---
libusb/core.c | 1 +
libusb/os/linux_usbfs.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/libusb/core.c b/libusb/core.c
index eccc216..18f56ca 100644
--- a/libusb/core.c
+++ b/libusb/core.c
@@ -1546,6 +1546,7 @@ int API_EXPORTED
libusb_detach_kernel_driver(libusb_device_handle *dev,
* \returns 0 on success
* \returns LIBUSB_ERROR_NOT_FOUND if no kernel driver was active
* \returns LIBUSB_ERROR_INVALID_PARAM if the interface does not exist
+ * \returns LIBUSB_ERROR_BUSY if the interface is in use by another libusb app
* \returns LIBUSB_ERROR_NO_DEVICE if the device has been disconnected
* \returns LIBUSB_ERROR_NOT_SUPPORTED on platforms where the functionality
* is not available
diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
index dad7536..72fd2b4 100644
--- a/libusb/os/linux_usbfs.c
+++ b/libusb/os/linux_usbfs.c
@@ -1522,12 +1522,18 @@ static int op_detach_kernel_driver(struct
libusb_device_handle *handle,
{
int fd = _device_handle_priv(handle)->fd;
struct usbfs_ioctl command;
+ struct usbfs_getdriver getdrv;
int r;
command.ifno = interface;
command.ioctl_code = IOCTL_USBFS_DISCONNECT;
command.data = NULL;
+ getdrv.interface = interface;
+ r = ioctl(fd, IOCTL_USBFS_GETDRIVER, &getdrv);
+ if (r == 0 && strcmp(getdrv.driver, "usbfs") == 0)
+ return LIBUSB_ERROR_BUSY;
+
r = ioctl(fd, IOCTL_USBFS_IOCTL, &command);
if (r) {
if (errno == ENODATA)
--
1.7.10.4
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
libusbx-devel mailing list
libusbx-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/libusbx-devel
