tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy GLIB has recently started to officially support the gcc cleanup attribute in its public API, hence let's do the same for our APIs. With this patch we'll define an xyz_unrefp() call for each public xyz_unref() call, to make it easy to use inside a __attribute__((cleanup())) expression. Then, all code is ported over to make use of this. The new calls are also documented in the man pages, with examples how to use them (well, I only added docs where the _unref() call itself already had docs, and the examples, only cover sd_bus_unrefp() and sd_event_unrefp()). This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we tend to call our destructors these days. Note that this defines no public macro that wraps gcc's attribute and makes it easier to use. While I think it's our duty in the library to make our stuff easy to use, I figure it's not our duty to make gcc's own features easy to use on its own. Most likely, client code which wants to make use of this should define its own: #define _cleanup_(function) __attribute__((cleanup(function))) Or similar, to make the gcc feature easier to use. Making this logic public has the benefit that we can remove three header files whose only purpose was to define these functions internally. See #2008.

util-lib: split out allocation calls into alloc-util.[ch]

util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.

bus-util: support details in CheckAuthorization calls Extra details for an action can be supplied when calling polkit's CheckAuthorization method. Details are a list of key/value string pairs. Custom policy can use these details when making authorization decisions.

everywhere: actually make use of DUAL_TIMESTAMP_NULL macro Let's use it as initializer where appropriate.

sd-bus: drop bus parameter from message callback prototype This should simplify the prototype a bit. The bus parameter is redundant in most cases, and in the few where it matters it can be derived from the message via sd_bus_message_get_bus().

logind: open up most bus calls for unpriviliged processes, using PolicyKit Also, allow clients to alter their own objects without any further priviliges. i.e. this allows clients to kill and lock their own sessions without involving PK.

bus: use EUID over UID and fix unix-creds Whenever a process performs an action on an object, the kernel uses the EUID of the process to do permission checks and to apply on any newly created objects. The UID of a process is only used if someone *ELSE* acts on the process. That is, the UID of a process defines who owns the process, the EUID defines what privileges are used by this process when performing an action. Process limits, on the other hand, are always applied to the real UID, not the effective UID. This is, because a process has a user object linked, which always corresponds to its UID. A process never has a user object linked for its EUID. Thus, accounting (and limits) is always done on the real UID. This commit fixes all sd-bus users to use the EUID when performing privilege checks and alike. Furthermore, it fixes unix-creds to be parsed as EUID, not UID (as the kernel always takes the EUID on UDS). Anyone using UID (eg., to do user-accounting) has to fall back to the EUID as UDS does not transmit the UID.

logind: hide 'self' links if not available If the caller does not run in a session/seat or has no tracked user, hide the /org/freedesktop/login1/.../self links in introspection data. Otherwise, "busctl tree org.freedesktop.login1" tries to query those nodes even though it cant.

logind: when a bus call is done on a session, user or seat, optionally determine them from the caller credentials More specifically, if an operation is requested on a session with an empty name, the caller's session is used. If an operation is requested on a seat with an empty name, the seat of the caller's session is used. Finally, if an operation on the user with UID -1 is requested, the user of the client's session is used (and not the UID of the client!).

logind: include "self" object links in dbus introspection Makes "busctl introspect" a lot more fun.

logind: remove spurious include of <sys/capability.h> They do not use any functions from libcap directly. The CAP_* constants in use through these files come from "missing.h" which will import <linux/capability.h> and complement it with CAP_* constants not defined by the current kernel headers. The "missing.h" header is imported through "util.h" which gets imported in "logind.h". Tested that "systemd-logind" builds cleanly and works after this change.

sd-bus: move common errors src/shared/bus-errors.h → src/libsystemd/sd-bus/bus-common-errors.h Stuff in src/shared/ should not use stuff from src/libsystemd/ really.

logind: fix typo

sd-bus: introduce sd_bus_slot objects encapsulating callbacks or vtables attached to a bus connection This makes callback behaviour more like sd-event or sd-resolve, and creates proper object for unregistering callbacks. Taking the refernce to the slot is optional. If not taken life time of the slot will be bound to the underlying bus object (or in the case of an async call until the reply has been recieved).

bus: replace sd_bus_label_{escape,unescape}() by new sd_bus_path_{encode,decode}() The new calls work similarly, but enforce a that a common, fixed bus path prefix is used. This follows discussions with Simon McVittie on IRC that it should be a good idea to make sure that people don't use the escaping applied here too wildly as anything other than the last label of a bus path.

logind: add a debug message in case the session already exists If the session already exists then the only way to log it is to set the debug option of pam_systemd. There are no debug messages in the login service that permits to log if the session already exists. So just add it, and while we are it add the "uid" field to the debug message that indicates that the session was created.

Introduce strv_consume which takes ownership This mirrors set_consume and makes the common use a bit nicer.

logind: always kill session when termination is requested KillUserProcesses=yes/no should be ignored when termination is explicitly requested.

man: introduce new "Desktop" property for sessions This is initialized from XDG_SESSION_DESKTOP and is useful for GNOME to recognize its own sessions. It's supposed to be set to a short string identifying the session, such as "kde" or "gnome".

logind: wait for the user service to finish startup before completing login attempt

bus: decorate the various object vtables with SD_BUS_VTABLE_PROPERTY_CONST where appropriate

bus: introduce "trusted" bus concept and encode access control in object vtables Introduces a new concept of "trusted" vs. "untrusted" busses. For the latter libsystemd-bus will automatically do per-method access control, for the former all access is automatically granted. Per-method access control is encoded in the vtables: by default all methods are only accessible to privileged clients. If the SD_BUS_VTABLE_UNPRIVILEGED flag is set for a method it is accessible to unprivileged clients too. By default whether a client is privileged is determined via checking for its CAP_SYS_ADMIN capability, but this can be altered via the SD_BUS_VTABLE_CAPABILITY() macro that can be ORed into the flags field of the method. Writable properties are also subject to SD_BUS_VTABLE_UNPRIVILEGED and SD_BUS_VTABLE_CAPABILITY() for controlling write access to them. Note however that read access is unrestricted, as PropertiesChanged messages might send out the values anyway as an unrestricted broadcast. By default the system bus is set to "untrusted" and the user bus is "trusted" since per-method access control on the latter is unnecessary. On dbus1 busses we check the UID of the caller rather than the configured capability since the capability cannot be determined without race. On kdbus the capability is checked if possible from the attached meta-data of a message and otherwise queried from the sending peer. This also decorates the vtables of the various daemons we ship with these flags.

bus: add new sd_bus_creds object to encapsulate process credentials This way we can unify handling of credentials that are attached to messages, or can be queried for bus name owners or connection peers. This also adds the ability to extend incomplete credential information with data from /proc, Also, provide a convenience call that will automatically determine the most appropriate credential object for an incoming message, by using the the attached information if possible, the sending name information if available and otherwise the peer's credentials.

pam_systemd: do not set XDG_RUNTIME_DIR if the session's original user is not the same as the newly logged in one It's better not to set any XDG_RUNTIME_DIR at all rather than one of a different user. So let's do this. This changes the bus call parameters of CreateSession(), but that is explicitly an internal API hence should be fine. Note however, that a logind restart (the way the RPM postinst scriptlets do it) is necessary to make things work again.

bus: also add error parameter to object find and enumerator callbacks Just in order to bring things inline with the method and property callbacks.

bus: rework message handlers to always take an error argument Message handler callbacks can be simplified drastically if the dispatcher automatically replies to method calls if errors are returned. Thus: add an sd_bus_error argument to all message handlers. When we dispatch a message handler and it returns negative or a set sd_bus_error we send this as message error back to the client. This means errors returned by handlers by default are given back to clients instead of rippling all the way up to the event loop, which is desirable to make things robust. As a side-effect we can now easily turn the SELinux checks into normal function calls, since the method call dispatcher will generate the right error replies automatically now. Also, make sure we always pass the error structure to all property and method handlers as last argument to follow the usual style of passing variables for return values as last argument.

bus: let's simplify things by getting rid of unnecessary bus parameters

bus: add API calls to escape string components of objects paths

core: convert PID 1 to libsystemd-bus This patch converts PID 1 to libsystemd-bus and thus drops the dependency on libdbus. The only remaining code using libdbus is a test case that validates our bus marshalling against libdbus' marshalling, and this dependency can be turned off. This patch also adds a couple of things to libsystem-bus, that are necessary to make the port work: - Synthesizing of "Disconnected" messages when bus connections are severed. - Support for attaching multiple vtables for the same interface on the same path. This patch also fixes the SetDefaultTarget() and GetDefaultTarget() bus calls which used an inappropriate signature. As a side effect we will now generate PropertiesChanged messages which carry property contents, rather than just invalidation information.

logind: create the session fifo before saving the session file If the session fifo is not created the session state written to the session file is "closing". This caused the lock screen in gnome-shell to go into a loop trying to find the active session. The problem was introduced in the sd-bus port in cc3773810855956bad92337cee8fa193584ab62e Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=71525

pam_systemd: dup the fd received from logind Otherwise sd_bus_message cleanup would close it.

logind: add virtual object paths that always can be used to refer to the callers session, user, seat or machine object This way clients can skip invoking GetSessionByPID() for their own PID or a similar call to access these objects.

logind: port logind to libsystemd-bus

logind: fix bus introspection data for TakeControl()

logind: fix build for ARM with sizeof(dev_t) > sizeof(void*) Unfortunately on ARM-32 systems dev_t can be 64bit and thus we cannot store it easily in void* keys for hashtables. Fix that by passing a pointer to the dev_t variable instead.

logind: introduce session-devices A session-device is a device that is bound to a seat and used by a session-controller to run the session. This currently includes DRM, fbdev and evdev devices. A session-device can be created via RequestDevice() on the dbus API of the session. You can drop it via ReleaseDevice() again. Once the session is destroyed or you drop control of the session, all session-devices are automatically destroyed. Session devices follow the session "active" state. A device can be active/running or inactive/paused. Whenever a session is not the active session, no session-device of it can be active. That is, if a session is not in foreground, all session-devices are paused. Whenever a session becomes active, all devices are resumed/activated by logind. If it fails, a device may stay paused. With every session-device you request, you also get a file-descriptor back. logind keeps a copy of this fd and uses kernel specific calls to pause/resume the file-descriptors. For example, a DRM fd is muted by logind as long as a given session is not active. Hence, the fd of the application is also muted. Once the session gets active, logind unmutes the fd and the application will get DRM access again. This, however, requires kernel support. DRM devices provide DRM-Master for synchronization, evdev devices have EVIOCREVOKE (pending on linux-input-ML). fbdev devices do not provide such synchronization methods (and never will). Note that for evdev devices, we call EVIOCREVOKE once a session gets inactive. However, this cannot be undone (the fd is still valid but mostly unusable). So we reopen a new fd once the session is activated and send it together with the ResumeDevice() signal. With this infrastructure in place, compositors can now run without CAP_SYS_ADMIN (that is, without being root). They use RequestControl() to acquire a session and listen for devices via udev_monitor. For every device they want to open, they call RequestDevice() on logind. This returns a fd which they can use now. They no longer have to open the devices themselves or call any privileged ioctls. This is all done by logind. Session-switches are still bound to VTs. Hence, compositors will get notified via the usual VT mechanisms and can cleanup their state. Once the VT switch is acknowledged as usual, logind will get notified via sysfs and pause the old-session's devices and resume the devices of the new session. To allow using this infrastructure with systems without VTs, we provide notification signals. logind sends PauseDevice("force") dbus signals to the current session controller for every device that it pauses. And it sends ResumeDevice signals for every device that it resumes. For seats with VTs this is sent _after_ the VT switch is acknowledged. Because the compositor already acknowledged that it cleaned-up all devices. However, for seats without VTs, this is used to notify the active compositor that the session is about to be deactivated. That is, logind sends PauseDevice("force") for each active device and then performs the session-switch. The session-switch changes the "Active" property of the session which can be monitored by the compositor. The new session is activated and the ResumeDevice events are sent. For seats without VTs, this is a forced session-switch. As this is not backwards-compatible (xserver actually crashes, weston drops the related devices, ..) we also provide an acknowledged session-switch. Note that this is never used for sessions with VTs. You use the acknowledged VT-switch on these seats. An acknowledged session switch sends PauseDevice("pause") instead of PauseDevice("force") to the active session. It schedules a short timeout and waits for the session to acknowledge each of them with PauseDeviceComplete(). Once all are acknowledged, or the session ran out of time, a PauseDevice("force") is sent for all remaining active devices and the session switch is performed. Note that this is only partially implemented, yet, as we don't allow multi-session without VTs, yet. A follow up commit will hook it up and implemented the acknowledgements+timeout. The implementation is quite simple. We use major/minor exclusively to identify devices on the bus. On RequestDevice() we retrieve the udev_device from the major/minor and search for an existing "Device" object. If no exists, we create it. This guarantees us that we are notified whenever the device changes seats or is removed. We create a new SessionDevice object and link it to the related Session and Device. Session->devices is a hashtable to lookup SessionDevice objects via major/minor. Device->session_devices is a linked list so we can release all linked session-devices once a device vanishes. Now we only have to hook this up in seat_set_active() so we correctly change device states during session-switches. As mentioned earlier, these are forced state-changes as VTs are currently used exclusively for multi-session implementations. Everything else are hooks to release all session-devices once the controller changes or a session is closed or removed.

logind: add session controllers A session usually has only a single compositor or other application that controls graphics and input devices on it. To avoid multiple applications from hijacking each other's devices or even using the devices in parallel, we add session controllers. A session controller is an application that manages a session. Specific API calls may be limited to controllers to avoid others from getting unprivileged access to restricted resources. A session becomes a controller by calling the RequestControl() dbus API call. It can drop it via ReleaseControl(). logind tracks bus-names to release the controller once an application closes the bus. We use the new bus-name tracking to do that. Note that during ReleaseControl() we need to check whether some other session also tracks the name before we remove it from the bus-name tracking list. Currently, we only allow one controller at a time. However, the public API does not enforce this restriction. So if it makes sense, we can allow multiple controllers in parallel later. Or we can add a "scope" parameter, which allows a different controller for graphics-devices, sound-devices and whatever you want. Note that currently you get -EBUSY if there is already a controller. You can force the RequestControl() call (root-only) to drop the current controller and recover the session during an emergency. To recover a seat, this is not needed, though. You can simply create a new session or force-activate it. To become a session controller, a dbus caller must either be root or the same user as the user of the session. This allows us to run a session compositor as user and we no longer need any CAP_SYS_ADMIN.

logind: update the session state file before we send out the CreateSession() reply https://bugs.freedesktop.org/show_bug.cgi?id=67273

logind: update state file after generating the session fifo, not before https://bugs.freedesktop.org/show_bug.cgi?id=67273

machined: correct how some properties are exported on the bus

logind: port over to use scopes+slices for all cgroup stuff In order to prepare things for the single-writer cgroup scheme, let's make logind use systemd's own primitives for cgroup management. Every login user now gets his own private slice unit, in which his sessions live in a scope unit each. Also, add user@$UID.service to the same slice, and implicitly start it on first login.

logind: add infrastructure to keep track of machines, and move to slices - This changes all logind cgroup objects to use slice objects rather than fixed croup locations. - logind can now collect minimal information about running VMs/containers. As fixed cgroup locations can no longer be used we need an entity that keeps track of machine cgroups in whatever slice they might be located. Since logind already keeps track of users, sessions and seats this is a trivial addition. - nspawn will now register with logind and pass various bits of metadata along. A new option "--slice=" has been added to place the container in a specific slice. - loginctl gained commands to list, introspect and terminate machines. - user.slice and machine.slice will now be pulled in by logind.service, since only logind.service requires this slice.

move _cleanup_ attribute in front of the type http://lists.freedesktop.org/archives/systemd-devel/2013-April/010510.html

logind: exploit previous cleanups and simplify returns

logind: Make more use of cleanup macros

Use bus_maybe_send_reply() where applicable This is a followup to: commit 1a37b9b9043ef83e9900e460a9a1fccced3acf89 It will fix denial messages from dbus-daemon between gdm and systemd-logind on logging into GNOME due to this. See the previous commit for more details.

logind: unify all session lock loop

logind: expose missing signals in Session bus objects

login: check return value of session_get_idle_hint

logind: introduce a state for session, being one of online, active, closing online = logged in active = logged in and session is in the fg closing = nominally logged out but some left-over processes still around Related to: https://bugzilla.gnome.org/show_bug.cgi?id=677556

systemctl: show main and control PID explicitly in cgroup-show In some cases the main/control PID of a service can be outside of the services cgroups (for example, if logind readjusts the processes' cgroup). In order to clarify this for the user show the main/control PID in the cgroup tree nonetheless, but mark them specially.

relicense to LGPLv2.1 (with exceptions) We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.

login: track login class (i.e. one of "user", "greeter", "lock-screen") for each session This introduces the new PAM environment variable XDG_SESSION_CLASS. If not set, defaults to "user". This is useful for apps that want to distuingish real user logins from "fake" ones which just exist to show a gdm login screen or a lock screen.

logind: Terminate bus_login_session_user_properties Fixes segfault in systemd-logind, triggered by: systemd-loginctl show-session $XDG_SESSION_ID. Bug introduced by d200735e13c52dcfe36c0e066f9f6c2fbfb85a9c, so only systemd v39 is affected.

dbus: more efficient implementation of properties The way the various properties[] arrays are initialized is inefficient: - only the .data members change at runtime, yet the whole arrays of properties with all the fields are constructed on the stack one by one by the code. - there's duplication, eg. the properties of "org.freedesktop.systemd1.Unit" are repeated in several unit types. Fix it by moving the information about properties into static const sections. Instead of storing the .data directly in the property, store a constant offset from a run-time base. The small arrays of struct BusBoundProperties bind together the constant information with the right runtime information (the base pointer). On my system the code shrinks by 60 KB, data increases by 10 KB.

logind: send out Lock signal when locking

logind: move logind into its own subdirectory