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Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Evolve keventd from a power_supply-only monitor into a full device
manager capable of replacing mdev/mdevd on embedded systems. This
is the first step towards Finit v5.0 where keventd absorbs devmon.
New capabilities:
- Parse all uevent actions (add, remove, change, bind, unbind)
- Create and remove /dev nodes with subsystem-aware permissions
- Create persistent symlinks in /dev/disk/by-{id,path} and
/dev/input/by-{id,path}, tracked for cleanup on device removal
- Load firmware from /lib/firmware/ via the sysfs loading protocol
- Spawn modprobe for MODALIAS events (async, non-blocking)
- Coldplug support via -c flag (walks /sys/devices to replay events)
- Set dev/* conditions for Finit's service dependency system
The original power_supply monitoring and sys/pwr/ac condition are
preserved.
New files: keventd.h (structures/API), uevent.c (all device logic).
The receive buffer is increased to 8K with a 1MB socket buffer to
reduce event loss during coldplug bursts.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Rewrite doc/keventd.md from a 14-line stub into comprehensive documentation covering all features of the new unified keventd: device node creation, persistent symlinks, firmware loading, module loading, coldplug, conditions, and command-line usage. Update doc/conditions.md to list keventd as the primary provider of dev/* and sys/pwr/* conditions, with devmon as fallback when an external device manager is used instead. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
After keventd processes a uevent (creating device nodes, loading modules, etc.), rebroadcast the original event to netlink group 0x4 so that libudev-zero consumers -- graphical applications, Wayland/X11 compositors, libinput, and anything else using libudev to monitor device hotplug -- can receive device events. Rebroadcast is enabled by default. Use -g to override the target netlink group mask, or -G to disable rebroadcast entirely. Bit 0 (kernel group) is always masked out to prevent feedback loops. Ref: #451 (comment) See: https://github.com/illiliti/libudev-zero Suggested-by: Aaron Andersen <aaron@fosslib.net> Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
This is a backwards compatible mode for users upgrading and not noticing that keventd is now build by default. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Transform keventd from a power-supply monitor + basic hotplug handler into
a full udev-compatible device manager.
Rules engine (rules.c):
- Full .rules file parser covering all udev key types: ACTION, KERNEL,
SUBSYSTEM, DEVPATH, ENV, ATTR, SYSCTL, TAG, RESULT, PROGRAM, TEST,
parent-chain KERNELS/SUBSYSTEMS/ATTRS/DRIVERS, and more
- Pattern matching: plain string, fnmatch glob, and pipe-separated alternatives
- Operators: ==, !=, =, +=, -=, :=
- Assignments: NAME=, MODE=, OWNER=, GROUP=, SYMLINK+=, ENV{k}=, TAG+=, RUN+=
- IMPORT{program|file|builtin|parent|cmdline|db}=
- PROGRAM= with stdout capture for subsequent RESULT== matching
- GOTO=/LABEL= flow control
- Loads *.rules from /lib/udev/rules.d, /run/udev/rules.d, /etc/udev/rules.d
and an optional extra directory (-r DIR); reloads on SIGHUP
Builtin framework (builtin.c):
- kmod: load module by MODALIAS or explicit alias
- hwdb: match device against *.hwdb text files in udev hwdb dirs; builds
correct lookup key per subsystem — evdev:input:b*v*p*e* for input,
usb:v*p* for USB, raw modalias for PCI/platform
- path_id: build stable ID_PATH / ID_PATH_TAG from sysfs topology (PCI, USB,
ATA, NVMe, platform, ACPI, virtio)
- usb_id: read idVendor/idProduct/bcdDevice/serial from sysfs; look up
ID_VENDOR_FROM_DATABASE and ID_MODEL_FROM_DATABASE from usb.ids
(hwdata package) when available; silent fallback when absent
- input_id: classify input devices (keyboard, mouse, joystick, touchscreen,
touchpad) from evdev capability bitmasks in sysfs
- net_id: generate predictable names — MAC-based enx<mac> and PCI-slot-based
enp<bus>s<dev>[f<func>]
- blkid: probe filesystem type, UUID, and label via libblkid; sets ID_FS_*
and ID_PART_TABLE_* properties
Network interface renaming (uevent.c):
- netdev_add() renames interfaces via SIOCSIFNAME when a NAME= rule matched,
then sets the Finit dev/ condition on the final name; and any setup using
persistent interface naming via udev rules
Device node and symlink improvements (uevent.c):
- NAME=, MODE=, OWNER=, GROUP= overrides from matched rules applied at
mknod/chown time, falling back to the built-in permission table
- SYMLINK+= links from rules applied alongside built-in by-id/by-path links
Device property database (udevdb.c):
- Persist per-device E:/S:/I: records to /run/udev/data/ on ADD/CHANGE,
delete on REMOVE; IMPORT{db}= restores saved properties into event env
Build:
- libblkid (util-linux) is now required for keventd
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Add 27 stock rules installed to /lib/udev/rules.d/. Rules invoking /lib/udev/<helper> fall back to keventd builtins (path_id, usb_id, blkid, hwdb, kmod, net_id, input_id) when the helper binary is absent; user-supplied helpers in /lib/udev/ still take precedence. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
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The changes to Finit's
keventdon this branch, in conjunction with libudev-zero, should prove to be a good-enough replacement for many systems.We might adopted libudev-zero to the project in case that's needed, but hopefully we can bring it some new fresh blood instead 🧛
Important
This branch is still an active work in progress, and it may even be dropped and its feature set be moved to the
nextbranch, which is the canonical branch for all Finit 5 work.