diff options
Diffstat (limited to 'libusb/os/linux_usbfs.c')
| -rw-r--r-- | libusb/os/linux_usbfs.c | 67 |
1 files changed, 52 insertions, 15 deletions
diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c index 4c0fb41..e69578c 100644 --- a/libusb/os/linux_usbfs.c +++ b/libusb/os/linux_usbfs.c @@ -249,6 +249,9 @@ static int usbfs_get_active_config_descriptor(struct libusb_device *dev, unsigned char *buffer, size_t len) { struct linux_device_priv *priv = __device_priv(dev); + if (!priv->config_descriptor) + return LIBUSB_ERROR_NOT_FOUND; /* device is unconfigured */ + /* retrieve cached copy */ memcpy(buffer, priv->config_descriptor, len); return 0; @@ -280,6 +283,9 @@ static int sysfs_get_active_config_descriptor(struct libusb_device *dev, if (r < 0) { usbi_err("read failed, ret=%d errno=%d", fd, errno); return LIBUSB_ERROR_IO; + } else if (r == 0) { + usbi_dbg("device is unconfigured"); + return LIBUSB_ERROR_NOT_FOUND; } else if (r < len) { usbi_err("short read %d/%d", r, len); return LIBUSB_ERROR_IO; @@ -416,7 +422,7 @@ static int cache_active_config(struct libusb_device *dev, int fd, } /* read the bConfigurationValue for a device */ -static int sysfs_get_active_config(struct libusb_device *dev) +static int sysfs_get_active_config(struct libusb_device *dev, int *config) { char *endptr; char tmp[4] = {0, 0, 0, 0}; @@ -435,8 +441,9 @@ static int sysfs_get_active_config(struct libusb_device *dev) r, errno); return LIBUSB_ERROR_IO; } else if (r == 0) { - usbi_err("short bConfigurationValue read"); - return LIBUSB_ERROR_IO; + usbi_err("device unconfigured"); + *config = -1; + return 0; } if (tmp[sizeof(tmp) - 1] != 0) { @@ -453,7 +460,8 @@ static int sysfs_get_active_config(struct libusb_device *dev) return LIBUSB_ERROR_IO; } - return (int) num; + *config = (int) num; + return 0; } /* send a control message to retrieve active configuration */ @@ -489,6 +497,7 @@ static int initialize_device(struct libusb_device *dev, uint8_t busnum, char path[PATH_MAX + 1]; int fd; int active_config = 0; + int device_configured = 1; ssize_t r; dev->bus_number = busnum; @@ -507,9 +516,11 @@ static int initialize_device(struct libusb_device *dev, uint8_t busnum, priv->config_descriptor = NULL; if (sysfs_can_relate_devices) { - active_config = sysfs_get_active_config(dev); - if (active_config < 0) - return active_config; + int tmp = sysfs_get_active_config(dev, &active_config); + if (tmp < 0) + return tmp; + if (active_config == -1) + device_configured = 0; } __get_usbfs_path(dev, path); @@ -539,6 +550,14 @@ static int initialize_device(struct libusb_device *dev, uint8_t busnum, if (active_config < 0) { close(fd); return active_config; + } else if (active_config == 0) { + /* some buggy devices have a configuration 0, but we're + * reaching into the corner of a corner case here, so let's + * not support buggy devices in these circumstances. + * stick to the specs: a configuration value of 0 means + * unconfigured. */ + usbi_dbg("assuming unconfigured device"); + device_configured = 0; } } } @@ -562,13 +581,20 @@ static int initialize_device(struct libusb_device *dev, uint8_t busnum, return LIBUSB_ERROR_IO; } - r = cache_active_config(dev, fd, active_config); - close(fd); - if (r < 0) { - free(dev_buf); - return r; + /* bit of a hack: set num_configurations now because cache_active_config() + * calls usbi_get_config_index_by_value() which uses it */ + dev->num_configurations = dev_buf[DEVICE_DESC_LENGTH - 1]; + + if (device_configured) { + r = cache_active_config(dev, fd, active_config); + if (r < 0) { + close(fd); + free(dev_buf); + return r; + } } + close(fd); priv->dev_descriptor = dev_buf; return 0; } @@ -745,6 +771,8 @@ static int sysfs_scan_device(struct discovered_devs **_discdevs, return LIBUSB_ERROR_IO; } + sysfs_can_relate_devices = 1; + r = fscanf(fd, "%d", &busnum); fclose(fd); if (r != 1) { @@ -859,6 +887,7 @@ static void op_close(struct libusb_device_handle *dev_handle) static int op_set_configuration(struct libusb_device_handle *handle, int config) { + struct linux_device_priv *priv = __device_priv(handle->dev); int fd = __device_handle_priv(handle)->fd; int r = ioctl(fd, IOCTL_USBFS_SETCONFIG, &config); if (r) { @@ -873,9 +902,17 @@ static int op_set_configuration(struct libusb_device_handle *handle, int config) if (!sysfs_has_descriptors) { /* update our cached active config descriptor */ - r = cache_active_config(handle->dev, fd, config); - if (r < 0) - usbi_warn("failed to update cached config descriptor, error %d", r); + if (config == -1) { + if (priv->config_descriptor) { + free(priv->config_descriptor); + priv->config_descriptor = NULL; + } + } else { + r = cache_active_config(handle->dev, fd, config); + if (r < 0) + usbi_warn("failed to update cached config descriptor, " + "error %d", r); + } } return 0; |