The rules directories were read one after the other, each sorted on
its own. udev instead sorts all files from all directories together
and lets a file mask one of the same name in a lower priority
directory. The difference broke both standard override idioms
without a sound: copying a rules file to /etc/udev/rules.d/ to edit
it left the original running too, and symlinking a name to /dev/null
disabled nothing.
Collect everything with glob(), drop entries shadowed by a later
directory, and sort the survivors by filename, same as udev and the
tmpfiles.d handling in Finit itself. The -r directory sits above
/etc/ so a test ruleset can override anything shipped.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Three copies of read-first-line-from-a-file (sysfs_read_file, a
static sysfs_read, fgetline), two condition emitters symlinking the
same reconf marker (cond_emit, sys_cond), two seqnum-stable loops,
and five hand-rolled logit() prototypes, none with a printf
attribute, so no format string was ever checked.
Keep one of each: cond_emit() is exported and mkpaths its parents,
which also retires init_dev_condition_dir() and the sys/ directory
priming loop; logit() moves to keventd.h with the format attribute;
the stability test becomes seqnum_stable(), shared by the coldplug
gate and settle; kev_now_ms() serves dbus.c too. rule_ctx_free()
and kev_seq_baseline() had one caller each in their own files, now
static.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The udev parity gaps that were blocked on IPC -- settle, trigger,
info, queue introspection, runtime rule reload -- become bus methods.
keventd serves its own socket the way Finit serves /run/finit/bus:
brokerless, libink, one socket per daemon, no forwarding between the
two.
Settle(u) -> b parked until the queue drains or the timeout
passes; true when settled
Trigger(s, s) replay events, action + subsystem glob
Info(s) -> a{ss} /run/udev/data properties for a devpath
RulesReload() -> u re-read rules dirs, returns rule count
QueueEmpty (b), SeqnumProcessed (t) properties
DeviceProcessed (ss) signal after each fully handled event
The queue state is the highest kernel seqnum keventd has handled,
baselined at startup, against /sys/kernel/uevent_seqnum. keventd -S
now asks the running daemon first and falls back to seqnum polling.
In passive mode Trigger and RulesReload refuse. Adds
link_call_connection() for the park bookkeeping.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
udevdb_read_parent() contained the general capability, keyed from
sysfs when no uevent is in hand. Split it out as
udevdb_read_devpath() for the D-Bus Info method; parent lookup
becomes a wrapper.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
coldplug_trigger(action, subsystem-glob) replays events for a subset
of devices, the D-Bus Trigger method needs both knobs; coldplug() is
now the ("add", NULL) case. nftw() has no user cookie, so the
parameters ride in file statics.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
When started with -c (the default when keventd is the device manager),
gate the pidfile on the kernel's uevent_seqnum having been stable for
200ms. Up to now ready signaling with the pidfile was done right after
coldplug() triggered the kernel to re-emit events, but before uev_run()
had drained any of them, so <pid/keventd> really only meant "listening
on netlink".
With the gate, services that depend on <pid/keventd> can now assume /dev
is populated and persistent symlinks are live.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Stop-gap "settle" equivalent of udevadm settle for migration scenarios.
Polls /sys/kernel/uevent_seqnum every 50ms and exits zero when the
sequence number has been stable for 200ms (or non-zero after -t SECONDS
timeout, default 30s).
This is racy by design -- a slow probe firing after we return still
races -- so the doc steers users toward dev/, class/, and bind/
conditions for any service they control. Settle is for legacy boot
scripts and init transitions where condition wiring isn't feasible.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
dev/<X> only fires when a device gets a /dev node, which leaves a lot of
embedded-relevant hardware uncoverable: DSA switch cores, IIO sensors,
LEDs, backlight, PHYs, regulators -- all live purely under sysfs.
Two new condition namespaces:
class/<subsystem>/<sysname> asserted on every sysfs class device add
(e.g. <class/leds/blue>)
driver/<name> asserted while the driver is bound to at
least one device (e.g. <driver/mt7530>)
A driver can bind to several devices, so driver/ conditions are
refcounted: asserted on first bind, cleared when the last device is
unbound.
dev_cond() is generalized into a static cond_emit(prefix, rel, set) so
class_cond() and driver_cond() share the same mkpath + symlink/erase
code. The name avoids colliding with src/cond.h's public cond_path()
helper (unrelated function that returns a condition's filesystem path).
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
When a rule references an absolute helper path (e.g. /lib/udev/fido_id,
/lib/udev/scsi_id) that the system does not ship and we have no matching
builtin either, return 1 from try_builtin_fallback() so the caller does
not fork /bin/sh on a binary that's known to be missing. Previously
each such uevent left a zombie 127 child for keventd's sigchld_cb to
reap -- harmless but noisy and wasteful at coldplug.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
modprobe_load() and run_program() used to temporarily restore the
default SIGCHLD handler around fork+waitpid because the main loop set
SIGCHLD=SIG_IGN. With the libuev conversion, sigchld_cb in keventd.c
handles reaping via signalfd -- and signalfd does not interfere with
synchronous waitpid(pid, ...) -- so the dance is dead code.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Replace the raw poll() + global running/reload_rules flag dance with
libuev. All four signals (SIGUSR1, SIGTERM, SIGHUP, SIGCHLD) are now
handled via uev_signal_init() -- libuev uses signalfd internally so the
handlers run in normal main-loop context, not async signal context.
The SIGCHLD handler waitpid(-1, WNOHANG) reaps any subprocess (modprobe
loads, rule RUN+= helpers) instead of the old SIG_IGN auto-reap trick.
Synchronous waitpid() in modprobe_load() and run_program() still works
because signalfd queues the signal -- it only reaches sigchld_cb on the
next main-loop iteration.
The netlink receive loop becomes uevent_cb() registered via uev_io_init(),
with the receive buffer passed via the watcher's arg slot (avoids
file-static state). ENOBUFS and EINTR/EAGAIN are still tolerated, any
other recv() error still panic()s.
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>
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>
Joachim Wiberg