'\" t
.\"     Title: SECURITY LABEL
.\"    Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\"      Date: 2016
.\"    Manual: PostgreSQL 9.5.2 Documentation
.\"    Source: PostgreSQL 9.5.2
.\"  Language: English
.\"
.TH "SECURITY LABEL" "5sql" "2016" "PostgreSQL 9.5.2" "PostgreSQL 9.5.2 Documentation"
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.nh
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.SH "NAME"
SECURITY_LABEL \- define or change a security label applied to an object
.SH "SYNOPSIS"
.sp
.nf
SECURITY LABEL [ FOR \fIprovider\fR ] ON
{
  TABLE \fIobject_name\fR |
  COLUMN \fItable_name\fR\&.\fIcolumn_name\fR |
  AGGREGATE \fIaggregate_name\fR ( \fIaggregate_signature\fR ) |
  DATABASE \fIobject_name\fR |
  DOMAIN \fIobject_name\fR |
  EVENT TRIGGER \fIobject_name\fR |
  FOREIGN TABLE \fIobject_name\fR
  FUNCTION \fIfunction_name\fR ( [ [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [, \&.\&.\&.] ] ) |
  LARGE OBJECT \fIlarge_object_oid\fR |
  MATERIALIZED VIEW \fIobject_name\fR |
  [ PROCEDURAL ] LANGUAGE \fIobject_name\fR |
  ROLE \fIobject_name\fR |
  SCHEMA \fIobject_name\fR |
  SEQUENCE \fIobject_name\fR |
  TABLESPACE \fIobject_name\fR |
  TYPE \fIobject_name\fR |
  VIEW \fIobject_name\fR
} IS \(aq\fIlabel\fR\(aq

where \fIaggregate_signature\fR is:

* |
[ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [ , \&.\&.\&. ] |
[ [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [ , \&.\&.\&. ] ] ORDER BY [ \fIargmode\fR ] [ \fIargname\fR ] \fIargtype\fR [ , \&.\&.\&. ]
.fi
.SH "DESCRIPTION"
.PP

\fBSECURITY LABEL\fR
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
\fBregister_label_provider\fR\&.
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.PP

\fBregister_label_provider\fR
is not an SQL function; it can only be called from C code loaded into the backend\&.
.sp .5v
.RE
.PP
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
SE\-Linux\&. Such systems make all access control decisions based on object labels, rather than traditional discretionary access control (DAC) concepts such as users and groups\&.
.SH "PARAMETERS"
.PP
\fIobject_name\fR
.br
\fItable_name\&.column_name\fR
.br
\fIaggregate_name\fR
.br
\fIfunction_name\fR
.RS 4
The name of the object to be labeled\&. Names of tables, aggregates, domains, foreign tables, functions, sequences, types, and views can be schema\-qualified\&.
.RE
.PP
\fIprovider\fR
.RS 4
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\&.
.RE
.PP
\fIargmode\fR
.RS 4
The mode of a function or aggregate argument:
IN,
OUT,
INOUT, or
VARIADIC\&. If omitted, the default is
IN\&. Note that
\fBSECURITY LABEL\fR
does not actually pay any attention to
OUT
arguments, since only the input arguments are needed to determine the function\(aqs identity\&. So it is sufficient to list the
IN,
INOUT, and
VARIADIC
arguments\&.
.RE
.PP
\fIargname\fR
.RS 4
The name of a function or aggregate argument\&. Note that
\fBSECURITY LABEL\fR
does not actually pay any attention to argument names, since only the argument data types are needed to determine the function\(aqs identity\&.
.RE
.PP
\fIargtype\fR
.RS 4
The data type of a function or aggregate argument\&.
.RE
.PP
\fIlarge_object_oid\fR
.RS 4
The OID of the large object\&.
.RE
.PP
PROCEDURAL
.RS 4
This is a noise word\&.
.RE
.PP
\fIlabel\fR
.RS 4
The new security label, written as a string literal; or
NULL
to drop the security label\&.
.RE
.SH "EXAMPLES"
.PP
The following example shows how the security label of a table might be changed\&.
.sp
.if n \{\
.RS 4
.\}
.nf
SECURITY LABEL FOR selinux ON TABLE mytable IS \(aqsystem_u:object_r:sepgsql_table_t:s0\(aq;
.fi
.if n \{\
.RE
.\}
.SH "COMPATIBILITY"
.PP
There is no
\fBSECURITY LABEL\fR
command in the SQL standard\&.
.SH "SEE ALSO"
sepgsql, src/test/modules/dummy_seclabel