PolkitUnixProcess: polkit Reference Manual

## PolkitUnixProcess PolkitUnixProcess — Unix processs |

## Functions

PolkitSubject * | polkit_unix_process_new ()
PolkitSubject * | polkit_unix_process_new_full ()
PolkitSubject * | polkit_unix_process_new_for_owner ()
void | polkit_unix_process_set_pid ()
gint | polkit_unix_process_get_pid ()
void | polkit_unix_process_set_start_time ()
guint64 | polkit_unix_process_get_start_time ()
void | polkit_unix_process_set_uid ()
gint | polkit_unix_process_get_uid ()
gint | polkit_unix_process_get_owner ()

## Properties

guint64 | cgroupid | Read
guint | ctty | Read
GArray * | gids | Read / Write / Construct
int | pid | Read / Write / Construct
int | pidfd | Read / Write / Construct
gboolean | pidfd-is-safe | Read
int | ppidfd | Read
guint64 | start-time | Read / Write / Construct
int | uid | Read / Write / Construct

## Types and Values

| PolkitUnixProcess

## Object Hierarchy

        GObject
        ╰── PolkitUnixProcess

## Implemented Interfaces

PolkitUnixProcess implements PolkitSubject.

## Description

An object for representing a UNIX process. In order to be reliable and race-free, this requires support for PID File Descriptors in the kernel, dbus-daemon/broker and systemd. With this functionality, we can reliably track processes without risking PID reuse and race conditions, and compare them.

NOTE: If PID FDs are not available, this object will fall back to using PIDs, and this designed is now known broken; a mechanism to exploit a delay in start time in the Linux kernel was identified. Avoid calling `polkit_subject_equal()` to compare two processes.

To uniquely identify processes, both the process id and the start time of the process (a monotonic increasing value representing the time since the kernel was started) is used.

NOTE: This object stores, and provides access to, the real UID of the process. That value can change over time (with set*uid*(2) and exec*(2)). Checks whether an operation is allowed need to take care to use the UID value as of the time when the operation was made (or, following the `open()` privilege check model, when the connection making the operation possible was initiated). That is usually done by initializing this with `polkit_unix_process_new_for_owner()` with trusted data.

## Functions

### polkit_unix_process_new ()

    PolkitSubject *
    polkit_unix_process_new (gint pid);

`polkit_unix_process_new` is deprecated and should not be used in newly-written code.

Creates a new PolkitUnixProcess for `pid` .

The uid and start time of the process will be looked up in using e.g. the `/proc` filesystem depending on the platform in use.

#### Parameters

pid | The process id. |

#### Returns

A PolkitSubject. Free with `g_object_unref()`.

[transfer full]

### polkit_unix_process_new_full ()

    PolkitSubject *
    polkit_unix_process_new_full (gint pid,
                                  guint64 start_time);

`polkit_unix_process_new_full` is deprecated and should not be used in newly-written code.

Creates a new PolkitUnixProcess object for `pid` and `start_time` .

The uid of the process will be looked up in using e.g. the `/proc` filesystem depending on the platform in use.

#### Parameters

pid | The process id. |
start_time | The start time for `pid` . |

#### Returns

A PolkitSubject. Free with `g_object_unref()`.

[transfer full]

### polkit_unix_process_new_for_owner ()

    PolkitSubject *
    polkit_unix_process_new_for_owner (gint pid,
                                       guint64 start_time,
                                       gint uid);

Creates a new PolkitUnixProcess object for `pid` , `start_time` and `uid` .

#### Parameters

pid | The process id. |
start_time | The start time for `pid` or 0 to look it up in e.g. `/proc`. |
uid | The (real, not effective) uid of the owner of `pid` or -1 to look it up in e.g. `/proc`. |

#### Returns

A PolkitSubject. Free with `g_object_unref()`.

[transfer full]

### polkit_unix_process_set_pid ()

    void
    polkit_unix_process_set_pid (PolkitUnixProcess *process,
                                 gint pid);

Sets `pid` for `process` .

#### Parameters

process | A PolkitUnixProcess. |
pid | A process id. |

### polkit_unix_process_get_pid ()

    gint
    polkit_unix_process_get_pid (PolkitUnixProcess *process);

Gets the process id for `process` .

#### Parameters

process | A PolkitUnixProcess. |

#### Returns

The process id for `process` .

### polkit_unix_process_set_start_time ()

    void
    polkit_unix_process_set_start_time (PolkitUnixProcess *process,
                                        guint64 start_time);

Set the start time of `process` .

#### Parameters

process | A PolkitUnixProcess. |
start_time | The start time for `pid` . |

### polkit_unix_process_get_start_time ()

    guint64
    polkit_unix_process_get_start_time (PolkitUnixProcess *process);

Gets the start time of `process` .

#### Parameters

process | A PolkitUnixProcess. |

#### Returns

The start time of `process` .

### polkit_unix_process_set_uid ()

    void
    polkit_unix_process_set_uid (PolkitUnixProcess *process,
                                 gint uid);

Sets the (real, not effective) user id for `process` .

#### Parameters

process | A PolkitUnixProcess. |
uid | The user id to set for `process` or -1 to unset it. |

### polkit_unix_process_get_uid ()

    gint
    polkit_unix_process_get_uid (PolkitUnixProcess *process);

Gets the user id for `process` . Note that this is the real user-id, not the effective user-id.

NOTE: The UID may change over time, so the returned value may not match the current state of the underlying process; or the UID may have been set by `polkit_unix_process_new_for_owner()` or `polkit_unix_process_set_uid()`, in which case it may not correspond to the actual UID of the referenced process at all (at any point in time).

#### Parameters

process | A PolkitUnixProcess. |

#### Returns

The user id for `process` or -1 if unknown.

### polkit_unix_process_get_owner ()

    gint
    polkit_unix_process_get_owner (PolkitUnixProcess *process,
                                   GError **error);

`polkit_unix_process_get_owner` is deprecated and should not be used in newly-written code.

(deprecated)

#### Parameters

process | A PolkitUnixProcess. |
error | Return location for error. |

## Types and Values

### PolkitUnixProcess

    typedef struct _PolkitUnixProcess PolkitUnixProcess;

The PolkitUnixProcess struct should not be accessed directly.

## Property Details

### The `“cgroupid”` property

      “cgroupid”                 guint64

The start time of the process.

Owner: PolkitUnixProcess

Flags: Read

Default value: 0

### The `“ctty”` property

      “ctty”                     guint

The UNIX process controlling TTY.

Owner: PolkitUnixProcess

Flags: Read

Allowed values: <= G_MAXINT

Default value: 0

### The `“gids”` property

      “gids”                     GArray *

The UNIX group ids of the process.

Owner: PolkitUnixProcess

Flags: Read / Write / Construct

### The `“pid”` property

      “pid”                      int

The UNIX process id.

Owner: PolkitUnixProcess

Flags: Read / Write / Construct

Allowed values: >= 0

Default value: 0

### The `“pidfd”` property

      “pidfd”                    int

The UNIX process id file descriptor.

Owner: PolkitUnixProcess

Flags: Read / Write / Construct

Allowed values: >= -1

Default value: -1

### The `“pidfd-is-safe”` property

      “pidfd-is-safe”            gboolean

Whether the UNIX process ID file descriptor is safe.

Owner: PolkitUnixProcess

Flags: Read

Default value: FALSE

### The `“ppidfd”` property

      “ppidfd”                   int

The UNIX process' parent id file descriptor.

Owner: PolkitUnixProcess

Flags: Read

Allowed values: >= -1

Default value: -1

### The `“start-time”` property

      “start-time”               guint64

The start time of the process.

Owner: PolkitUnixProcess

Flags: Read / Write / Construct

Default value: 0

### The `“uid”` property

      “uid”                      int

The UNIX user id of the process or -1 if unknown.

Note that this is the real user-id, not the effective user-id.

Owner: PolkitUnixProcess

Flags: Read / Write / Construct

Default value: -1