Right now, if you're already in a session and call CreateSession, we
return information about the current session of yours. This is highy
confusing and a nasty hack. Avoid that, and instead return a commonly
known error, so the caller can detect that.
This has the side-effect, that we no longer override XDG_VTNR and XDG_SEAT
in pam_systemd, if you're already in a session. But this sounds like the
right thing to do, anyway.
Old gdm and lightdm start the user-session during login before they
destroy the greeter-session. Therefore, the user-session will take over
the VT from the greeter. We recently prevented this by never allowing
multiple sessions on the same VT. Fix this now, by explicitly allowing
this if the owning session is a GREETER.
Note that gdm no longer behaves like this. Instead, due to wayland, they
always use a different VT for each session. All other login-managers are
highly encouraged to destroy the greeter-session _before_ starting the
user-session. We now work around this, but this will probably not last
forever (and will already have nasty side-effects on the greeter-session).
- Make sure that the IPv6PrivacyExtensions=yes results in
prefer-temporary, not prefer-public.
- Introduce special enum value "kernel" to leave setting unset, similar
how we have it for the IP forwarding settings.
- Bring the enum values in sync with the the strings we parse for them,
to the level this makes sense (specifically, rename "disabled" to
"no", and "prefer-temporary" to "yes").
- Make sure we really set the value to to "no" by default, the way it is
already documented in the man page.
- Fix whitespace error.
- Make sure link_ipv6_privacy_extensions() actually returns the correct
enum type, rather than implicitly casting it to "bool".
- properly size formatting buffer for ipv6 sysctl value
- Don't complain if /proc/sys isn't writable
- Document that the enum follows the kernel's own values (0 = off, 1 =
prefer-public, 2 = prefer-temporary)
- Drop redundant negating of error code passed to log_syntax()
- Manpage fixes
This fixes a number of issues from PR #417
