The size of the listen_port for sesman cannot exceed
XRDP_SOCKETS_MAXPATH. We should use this value rather than
an arbitrary value of 256.
(cherry picked from commit dd1dc7c630)
The top level socket directory is now called XRDP_SOCKET_ROOT_PATH.
Below that are user-specific directories referred to with the
XRDP_SOCKET_PATH macro - this name is hard-coded into xorgxrdp and
the audio modules as an environment variable.
XRDP_SOCKET_PATH now looks like $XRDP_SOCKET_ROOT_PATH/<uid>
XRDP_SOCKET_PATH is only writeable by the user, and readable by the user
and the xrdp process.
Improve the built-in access checks for sesman/sesexec:-
- Group existence is checked for at login-time rather than program
start time
- The name of the group is now included in the message
Also, check for UID == 0 when checking for root, rather than just
checking the name (which might be an alias)
This allows Linux's no_new_privs restriction to be disabled when starting
the X server, which may be desirable if xrdp is running inside a kernel
confinement framework such as AppArmor or SELinux.
Rename g_file_open() to g_file_open_rw(), and add a new g_file_open_ro()
call that wraps the common g_file_open_ex(file, 1, 0, 0, 0) idiom. This
will make the file access mode more explicit in the code.
Change all calls to g_file_open() to the _ro() or _rw() variant as
appropriate, and replace g_file_open_ex(file, 1, 0, 0, 0) with the _ro()
call.
Lastly, add tests for the two new calls to test_os_calls.c (code
courteously provided by matt335672).
Now that authentication/authorization and session creation are
happening in the same process, there is no need for a separate call
to finish an auth session. This change prevents the upper software
layers from needing to track whether auth_start_session() has been
called or not.
When allocating a display number, we should be aware that
IANA only allow TCP displays up to :63. This PR adds that restriction in
to sesman.ini as a default, to prevent us allocating unavailable TCP
ports.
By default TCP ports are not enabled for X servers, but users can easily
change this if they wish to access X displays directly over the network.
This restriction is in addition to the MaxSessions limit already present
in sesman.ini
By setting the new config value 'AllowAlternateShell' to 'no' it is now
possible to prevent the use of an alternate shell, which can be set by
the connecting user.
The default remains unchanged and any shell is allowed if the config
value is not specified. It can also be set explicitly to 'yes' to achieve
the same outcome.
Fixes: #850
matt335672