使用 udev 规则在没有 sudo 的情况下调用 libusb [英] libusb calls without sudo using udev-rules

问题描述

仅在 Kubuntu 16.04 64 位上测试.我有一个应用程序，其来源不在我的控制之下.它使用了一些 libusb 调用，这些调用以例如:

Tested on Kubuntu 16.04 64 bit only. I have an application which source is not under my control. It uses some libusb calls which ends up in e.g.:

libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/001/031: Permission denied
libusb: error [_get_usbfs_fd] libusb requires write access to USB device nodes.                                   

以 root 身份运行上述应用程序时，它按预期工作.当我更改相关文件的权限时:

When running the above mentioned application as root, it works as expected. When I change the permissions of the regarding file like:

sudo chmod a+w /dev/bus/usb/001/031

然后应用程序将使用标准用户权限(直到我断开/重新连接我的 USB 设备).

then the application will work with standard user rights (until I disconnect / reconnect my usb device).

现在我正在寻找一种方法，例如每次插入特定USB设备时自动执行chmod a+w.是否可以通过编写特定的 udev 规则来实现?

Now I'm looking for a way, to e.g. automatically execute the chmod a+w each time when the specific usb device is plugged in. Might this be possible by writing a specific udev rule?

也许 libusb 调用的其他解决方案没有 root 权限?

Maybe other solutions the libusb calls without root rights?

解决方案:根据 David Grayson 的回答，我现在在我的规则文件中添加了带有 SUBSYSTEM=="usb" 的附加行.我的规则文件现在最终看起来像这样:

Solution: Based upon David Grayson's answer, I'd now added an additional line with SUBSYSTEM=="usb" to my rule file. My rules file now finally looks like this:

SUBSYSTEM=="tty", ATTRS{idVendor}=="1234", ATTRS{idProduct}=="5678", MODE="0666"
SUBSYSTEM=="usb", ATTRS{idVendor}=="1234", ATTRS{idProduct}=="5678", MODE="0666"

推荐答案

我建议你在 /etc/udev/rules.d 中添加一个名为 usb.rules 的新文件代码>.它应该有以下内容:

I suggest that you add a new file in /etc/udev/rules.d named usb.rules. It should have the following contents:

SUBSYSTEM=="usb", MODE="0666"

这将使所有用户都可以读写所有 USB 设备.

This will make all USB devices readable and writable by all users.

您还可以使用 Ignacio 的回答中提到的 idVendor 和 idProduct 属性将其缩小到特定的 USB 设备.

You could also narrow it down to specific USB devices using idVendor and idProduct attributes mentioned in Ignacio's answer.

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