SECURITY LABEL

SECURITY LABEL

7

SQL - Language Statements

SECURITY LABEL

define or change a security label applied to an object

SECURITY LABEL \[ FOR

provider

\] ON { TABLE

object\_name

\| COLUMN

table\_name

.

column\_name

\| AGGREGATE

aggregate\_name

(

aggregate\_signature

) \| DATABASE

object\_name

\| DOMAIN

object\_name

\| EVENT TRIGGER

object\_name

\| FOREIGN TABLE

object\_name

FUNCTION

function\_name

\[ ( \[ \[

argmode

\] \[

argname

\]

argtype

\[, \...\] \] ) \] \| LARGE OBJECT

large\_object\_oid

\| MATERIALIZED VIEW

object\_name

\| \[ PROCEDURAL \] LANGUAGE

object\_name

\| PROCEDURE

procedure\_name

\[ ( \[ \[

argmode

\] \[

argname

\]

argtype

\[, \...\] \] ) \] \| PUBLICATION

object\_name

\| ROLE

object\_name

\| ROUTINE

routine\_name

\[ ( \[ \[

argmode

\] \[

argname

\]

argtype

\[, \...\] \] ) \] \| SCHEMA

object\_name

\| SEQUENCE

object\_name

\| SUBSCRIPTION

object\_name

\| TABLESPACE

object\_name

\| TYPE

object\_name

\| VIEW

object\_name

} IS \'

label

\'

where

aggregate\_signature

is:

\* \| \[

argmode

\] \[

argname

\]

argtype

\[ , \... \] \| \[ \[

argmode

\] \[

argname

\]

argtype

\[ , \... \] \] ORDER BY \[

argmode

\] \[

argname

\]

argtype

\[ , \... \]

Description
===========

`SECURITY LABEL` applies a security label to a database object. An
arbitrary number of security labels, one per label provider, can be
associated with a given database object. Label providers are loadable
modules which register themselves by using the function
`register_label_provider`.

> **Note**
>
> `register_label_provider` is not an SQL function; it can only be
> called from C code loaded into the backend.

The label provider determines whether a given label is valid and whether
it is permissible to assign that label to a given object. The meaning of
a given label is likewise at the discretion of the label provider.
PostgreSQL places no restrictions on whether or how a label provider
must interpret security labels; it merely provides a mechanism for
storing them. In practice, this facility is intended to allow
integration with label-based mandatory access control (MAC) systems such
as SELinux. Such systems make all access control decisions based on
object labels, rather than traditional discretionary access control
(DAC) concepts such as users and groups.

Parameters
==========

object\_name; table\_name.column\_name; aggregate\_name; function\_name; procedure\_name; routine\_name

:   The name of the object to be labeled. Names of objects that reside
    in schemas (tables, functions, etc.) can be schema-qualified.

provider

:   The name of the provider with which this label is to be associated.
    The named provider must be loaded and must consent to the proposed
    labeling operation. If exactly one provider is loaded, the provider
    name may be omitted for brevity.

argmode

:   The mode of a function, procedure, or aggregate argument: `IN`,
    `OUT`, `INOUT`, or `VARIADIC`. If omitted, the default is `IN`. Note
    that `SECURITY LABEL` does not actually pay any attention to `OUT`
    arguments, since only the input arguments are needed to determine
    the function\'s identity. So it is sufficient to list the `IN`,
    `INOUT`, and `VARIADIC` arguments.

argname

:   The name of a function, procedure, or aggregate argument. Note that
    `SECURITY LABEL` does not actually pay any attention to argument
    names, since only the argument data types are needed to determine
    the function\'s identity.

argtype

:   The data type of a function, procedure, or aggregate argument.

large\_object\_oid

:   The OID of the large object.

`PROCEDURAL`

:   This is a noise word.

label

:   The new security label, written as a string literal; or `NULL` to
    drop the security label.

Examples
========

The following example shows how the security label of a table might be
changed.

    SECURITY LABEL FOR selinux ON TABLE mytable IS 'system_u:object_r:sepgsql_table_t:s0';

Compatibility
=============

There is no `SECURITY LABEL` command in the SQL standard.

See Also
========

src/test/modules/dummy\_seclabel
