Apply a PAM session to run/task/sysv/services Finit starts, pam_limits
above all, so a service running as a given user picks up that user's
limits the way a login does.
Add a new `pam` setting for the new block format (only), like the
per-service directories, naming a file in /etc/pam.d:
service weston {
user = "weston"
pam = "weston-autologin"
command = "/usr/bin/weston --continue-without-input"
}
pam_close_session() has to be called by a process still holding the
handle, and the handle does not survive exec(). Hence the keeper: it
holds the handle, drops to the service's credentials, and waits for a
parent-death signal before closing the session. Same shape as
systemd's (sd-pam), for the same reason, and one per fork, so the
script hooks open and close their own.
The keeper closes the descriptors it inherited from Finit and only
those. Closing everything would also take out what pam_open_session()
opened for itself, a keyring fd or a lock file, and leave the modules
to close a session with those pulled out from under them. Closing
nothing, as (sd-pam) does, would leave it holding the write end of the
notify pipe for the service's whole lifetime and starve notify = "s6"
services of their ready signal. So the fds open before pam_start()
are snapshotted and exactly those are closed, while the ones PAM opens
after are marked close-on-exec so the daemon does not inherit them
either.
A refused value, a denied account stack, an uninstalled pam.d file,
and a build without PAM support all keep the service from starting
rather than running it with the stacks skipped: one that quietly loses
pam_limits and its private /tmp, with nothing said. Capabilities a
module like pam_cap.so granted are merged into the IAB Finit applies
instead of being replaced by it, which only helps a service that also
sets capabilities, the other arm being a plain setuid() with nothing
left to restore once permitted is empty.
The test sysroot gains pam_permit.so, pam_deny.so and pam_limits.so,
which ldd cannot see, libpam dlopen()s them, and the test skips when
the host has none to stage. The negative cases pin the exit status
rather than only asserting crashed, which serv reports for any early
exit, so a bad command or an unwritable pidfile cannot pass for a
rejected session.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The line-based format has had the flag since v4.4 (issue #286), where
it prepends -p to the built-in getty, which turns it into login -p and
passes the environment on. The block format was written from the three
documented tty variants and the flags listed in the tty documentation,
and passenv was in neither, so it was left out. Converting a tty line
that used it therefore lost it, with nothing said.
It only reaches the built-in getty. An external getty is handed its
arguments through command, so there is nowhere to put a -p, and the
setting is refused with a warning rather than quietly ignored.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The migration guide told anyone holding the repeated-stanza idiom for a
per-platform service to split the variants across files or stay on the
line-based format, because a block title is an identity and the
variants have to share one barrier. provides is the answer, so the
guide converts that shape now instead of routing around it, and the
header of 10-hotplug.conf.in no longer points at the workaround.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The migration guide covered a stanza at a time, which is the wrong
shape for the two idioms that repeated a whole stanza. One of them,
several candidate binaries for one service, is now a command list.
The other, one service gated differently per platform, has no block
equivalent: those blocks share an identity because they share the
barrier condition downstream services wait for, so they cannot be
given separate titles. For that one the guide says to split the
variants across files, or leave that file in the line-based format,
which Finit still reads.
The udevd example in services.md taught the merge-broken form, and
system/10-hotplug.conf.in pointed readers at it for their syslogd.
Also lists libConfuse among the build dependencies. It has been
mandatory since the new .conf format landed, and build.md still said
two libraries. And corrects the note on variable expansion: it is
${VAR} that libconfuse expands when the file is read, with
${VAR:-default} supported. A plain $VAR reaches the service, which is
what makes `command = "syslogd -F $SYSLOGD_ARGS"` work with envfile.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
The new-format reference describes the block format on its own terms,
which is the wrong lookup direction for someone holding a legacy
one-liner. Aaron migrated Finix OS from the PR description, proving
the need for a token-in, key-out mapping in the user guide.
One table per part of a stanza, worked conversions for the shapes
that changed structurally -- cgroup selection and the three tty
variants -- and the dropped tokens listed with their replacements.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Joachim Wiberg