illiliti
81 lines
2.8 KiB
Markdown
81 lines
2.8 KiB
Markdown
# libudev-zero
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Drop-in replacement for `libudev` that intended to work with any device manager
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## Why?
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Because `udev` sucks, it is bloated and overengineered. `udev` is just
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like `systemd`, it locks you into using non-portable crap that you can't
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avoid because multiple programs depend on it. Look, even FreeBSD was forced
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to rewrite[0] this crappy library because `libinput` hard-depends on `udev`.
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Without `libinput` you can't use `wayland` and many other cool stuff.
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Michael Forney (author of `cproc`, `samurai`, Oasis Linux, ...) decided to
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fork[1] `libinput` and remove the hard dependency on `udev`. Is this a
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solution? Yes. Is this a complete solution? No. This fork has a lot of
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disadvantages like requiring patching applications to use `libinput_netlink`
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instead of the `libinput_udev` API in order to use the automatic detection of
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input devices and hotplugging. Static configuration is also required for
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anything other than input devices (e.g drm devices). Moreover hotplugging is
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vulnerable to race conditions when `libinput` handles the `uevent` faster than
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the device manager which can lead to file permission issues. `libudev-zero`
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prevents these race conditions by design.
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Thankfully `udev` has stable API and hopefully no changes will be made to it
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the future. On this basis I decided to create this clean-room implementation
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of `libudev` which can be used with any or without a device manager.
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[0] https://github.com/FreeBSDDesktop/libudev-devd
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[1] https://github.com/oasislinux/libinput
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## What Works
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* [x] xorg-server
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* [ ] dosfstools - need to implement udev_enumerate_add_match_parent()
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* [x] libinput
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* [x] usbutils
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* [x] wlroots
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* [x] weston
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* [x] libusb
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* [x] kwin
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* [ ] ???
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## Dependencies
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* C99 compiler (build time)
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* POSIX make (build time)
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* POSIX & XSI libc
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* inotify & eventfd
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* Linux >= 2.6.39
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## Installation
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```sh
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make
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make PREFIX=/usr install
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```
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## Hotplugging
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Note that hotplugging support is fully optional. You can skip
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this step if you don't have a need for the hotplugging capability.
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In order to use hotplugging, you need to configure device manager to send
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`uevent` messages to `UDEV_MONITOR_DIR`. `UDEV_MONITOR_DIR` is arbitrary
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shared directory used by `libudev-zero` to receive `uevent` messages. By
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default, `UDEV_MONITOR_DIR` points to `/tmp/.libudev-zero`. You can change
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that directory at compile time by passing `-DUDEV_MONITOR_DIR=<dir>` to
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`CFLAGS` or at runtime by setting `UDEV_MONITOR_DIR` environment variable.
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Keep in mind that already processed `uevent` messages wouldn't be automatically
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purged. You can set `UDEV_MONITOR_DIR` to directory on tmpfs to purge them on
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reboot/shutdown.
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Refer to [contrib](contrib) for usage examples and configs.
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## Donate
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You can send a donation to `BTC: 1BwrcsgtWZeLVvNeEQSg4A28a3yrGN3FpK`
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Thank you very much!
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