mirror of
https://github.com/troglobit/finit.git
synced 2026-10-02 05:52:48 +07:00
Joachim Wiberg
3231ade38a
A pass over the whole branch before merge, mostly in libink since that is the new code and the part exposed to the wire. Grouped here rather than scattered so the review is easy to read in one place. libink parser and dispatch: - Bound reader lengths so a 32-bit size_t can't wrap a wire length past the guard and read out of bounds. Reachable pre-auth on any bus, so it matters on the 32-bit targets Finit runs on. - Drop a peer when a reply send fails instead of limping on with a half-written frame; a built-in whose send failed used to fall through and put a second frame on the wire. initctl: - Copy a D-Bus error name out of the reply before closing the client; the reply points into memory the close frees. Both error paths now share one helper so this can't creep back. Authorization: - Take the caller's groups from the kernel (SO_PEERCRED plus SO_PEERGROUPS) rather than getpwuid()/getgrouplist(), which go through NSS and can block PID 1 on a slow LDAP or SSSD backend. The check is now a lookup against the group resolved once at init, with no NSS and no 256 KiB array on the stack. A caller reaching us through a broker carries no group set, so system-bus privileged methods are root-only; the local bus keeps group support. See libink/README.md for the note on lifting that. Shutdown: - Call dbus_exit() from the shutdown path so the server, its peers, and the socket are let go cleanly. The teardown existed but nobody called it. Tests, CI, docs: - A fuzz target for the message parser, run as a quick sweep in the suite and properly under libFuzzer in CI, with the corpus carried between runs. The -as-uid tests drop groups the way a login does so SO_PEERGROUPS sees the right set, and widen the test socket to reach the per-method check behind the 0660 gate. Bring the GitHub actions up to versions that run on Node 24, and tidy a few small things a /simplify pass turned up. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Introduction
{ align=right width=40% }
Reverse engineered from the EeePC fastinit
"gaps filled with frog DNA …"
— Claudio Matsuoka
Finit is a process starter and supervisor designed to run as PID 1 on Linux systems. It consists of a set of plugins and can be set up using configuration files. Plugins start at hook points and can run various set up tasks and/or install event handlers that later provide runtime services, e.g., PID file monitoring, or conditions.
Features
- Runlevels, defined per service
- One-shot tasks, services (daemons), or SysV init start/stop scripts
- Runparts and
/etc/rc.localsupport - Process supervision similar to systemd
- Fine-grained privilege control:
- Linux capabilities for minimal required privileges
- Supplementary groups for multi-group resource access
- Sourcing environment files
- Conditions for network/process/custom dependencies
- Readiness notification; PID files (native) for synchronizing system startup, support for systemd sd_notify(), or s6 style too
- Limited support for tmpfiles.d(5) (no aging, attributes, or subvolumes)
- Pre/Post script actions
- Rudimentary templating support
- Tooling to enable/disable services
- Automatic reload of modified configuration files (optional)
- Built-in getty
- Built-in watchdog, with support for hand-over to watchdogd
- Built-in support for Debian/BusyBox
/etc/network/interfaces - Cgroups v2, both configuration and monitoring in
initctl top - Plugin support for customization
- Proper rescue mode with bundled
suloginfor protected maintenance shell - Switch root support for initramfs-to-real-root transitions
- Integration with watchdogd for full system supervision
- Logging to kernel ring buffer before
syslogdhas started, see the recommended sysklogd project for complete logging integration and how to log to the kernel ring buffer from scripts usinglogger
For a more thorough overview, see the Features section.
Tip
See SysV Init Compatibility for help to quickly get going with an existing SysV or BusyBox init setup.
Origin
This project is based on the original finit by Claudio Matsuoka which was reverse engineered from syscalls of the EeePC fastinit.
Finit is developed and maintained by Joachim Wiberg at GitHub. Please file bug reports, clone it, or send pull requests for bug fixes and proposed extensions.