<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/alter_role.sgml,v 1.16 2010/04/03 07:22:57 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/alter_role.sgml,v 1.17 2010/04/21 20:54:19 tgl Exp $
PostgreSQL documentation
-->
ALTER ROLE <replaceable class="PARAMETER">name</replaceable> [ [ WITH ] <replaceable class="PARAMETER">option</replaceable> [ ... ] ]
<phrase>where <replaceable class="PARAMETER">option</replaceable> can be:</phrase>
-
+
SUPERUSER | NOSUPERUSER
| CREATEDB | NOCREATEDB
| CREATEROLE | NOCREATEROLE
| LOGIN | NOLOGIN
| CONNECTION LIMIT <replaceable class="PARAMETER">connlimit</replaceable>
| [ ENCRYPTED | UNENCRYPTED ] PASSWORD '<replaceable class="PARAMETER">password</replaceable>'
- | VALID UNTIL '<replaceable class="PARAMETER">timestamp</replaceable>'
+ | VALID UNTIL '<replaceable class="PARAMETER">timestamp</replaceable>'
ALTER ROLE <replaceable class="PARAMETER">name</replaceable> RENAME TO <replaceable>new_name</replaceable>
<para>
The first variant of this command listed in the synopsis can change
- many of the role attributes that can be specified in
+ many of the role attributes that can be specified in
<xref linkend="sql-createrole">.
(All the possible attributes are covered,
except that there are no options for adding or removing memberships; use
password is <literal>MD5</>-encrypted.
</para>
- <para>
- The remaining variants change a role's session default for a configuration variable
- for all databases or, when the <literal>IN DATABASE</literal> clause is specified,
- for the named database. Whenever the role subsequently
+ <para>
+ The remaining variants change a role's session default for a configuration
+ variable, either for all databases or, when the <literal>IN
+ DATABASE</literal> clause is specified, only for sessions in
+ the named database. Whenever the role subsequently
starts a new session, the specified value becomes the session
default, overriding whatever setting is present in
<filename>postgresql.conf</> or has been received from the postgres
- command line. This only happens at login time, so configuration
- settings associated with a role to which you've <xref
- linkend="sql-set-role"> will be ignored. Settings set to
- a role directly are overridden by any database specific settings attached to a role.
+ command line. This only happens at login time; executing
+ <xref linkend="sql-set-role"> or
+ <xref linkend="sql-set-session-authorization"> does not cause new
+ configuration values to be set.
+ Settings set for all databases are overridden by database-specific settings
+ attached to a role.
Superusers can change anyone's session defaults. Roles having
<literal>CREATEROLE</> privilege can change defaults for non-superuser
- roles. Certain variables cannot be set this way, or can only be
+ roles. Ordinary roles can only set defaults for themselves.
+ Certain configuration variables cannot be set this way, or can only be
set if a superuser issues the command.
</para>
</refsect1>
<literal>RESET ALL</literal> to clear all role-specific settings.
<literal>SET FROM CURRENT</> saves the session's current value of
the parameter as the role-specific value.
- If used in conjunction with <literal>IN DATABASE</literal>, the configuration
+ If <literal>IN DATABASE</literal> is specified, the configuration
parameter is set or removed for the given role and database only.
</para>
<para>
- Role-specific variable setting take effect only at login;
- <xref linkend="sql-set-role">
- does not process role-specific variable settings.
+ Role-specific variable settings take effect only at login;
+ <xref linkend="sql-set-role"> and
+ <xref linkend="sql-set-session-authorization">
+ do not process role-specific variable settings.
</para>
<para>
in cleartext, and it might also be logged in the client's command
history or the server log. <xref linkend="app-psql">
contains a command
- <command>\password</command> that can be used to safely change a
- role's password.
+ <command>\password</command> that can be used to change a
+ role's password without exposing the cleartext password.
</para>
<para>
</para>
<para>
- Give a role a non-default, database-specific setting of the
- <xref linkend="guc-client-min-messages"> parameter:
+ Give a role a non-default, database-specific setting of the
+ <xref linkend="guc-client-min-messages"> parameter:
<programlisting>
ALTER ROLE fred IN DATABASE devel SET client_min_messages = DEBUG;
<refsect1>
<title>Compatibility</title>
-
+
<para>
The <command>ALTER ROLE</command> statement is a
<productname>PostgreSQL</productname> extension.
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.549 2010/04/20 11:15:06 rhaas Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.550 2010/04/21 20:54:19 tgl Exp $
*
*--------------------------------------------------------------------
*/
static void ShowAllGUCConfig(DestReceiver *dest);
static char *_ShowOption(struct config_generic * record, bool use_units);
static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
+static bool validate_option_array_item(const char *name, const char *value,
+ bool skipIfNoPermissions);
/*
if (args == NIL)
return NULL;
- /* Else get flags for the variable */
- record = find_option(name, true, ERROR);
- if (record == NULL)
- ereport(ERROR,
- (errcode(ERRCODE_UNDEFINED_OBJECT),
- errmsg("unrecognized configuration parameter \"%s\"", name)));
-
- flags = record->flags;
+ /*
+ * Get flags for the variable; if it's not known, use default flags.
+ * (Caller might throw error later, but not our business to do so here.)
+ */
+ record = find_option(name, false, WARNING);
+ if (record)
+ flags = record->flags;
+ else
+ flags = 0;
/* Complain if list input and non-list variable */
if ((flags & GUC_LIST_INPUT) == 0 &&
else
phcontext = PGC_SIGHUP;
break;
+
case PGC_S_DATABASE:
case PGC_S_USER:
case PGC_S_DATABASE_USER:
+ /*
+ * The existing value came from an ALTER ROLE/DATABASE SET command.
+ * We can assume that at the time the command was issued, we
+ * checked that the issuing user was superuser if the variable
+ * requires superuser privileges to set. So it's safe to
+ * use SUSET context here.
+ */
+ phcontext = PGC_SUSET;
+ break;
+
case PGC_S_CLIENT:
case PGC_S_SESSION:
default:
+ /*
+ * We must assume that the value came from an untrusted user,
+ * even if the current_user is a superuser.
+ */
phcontext = PGC_USERSET;
break;
}
ArrayType *
GUCArrayAdd(ArrayType *array, const char *name, const char *value)
{
- const char *varname;
+ struct config_generic *record;
Datum datum;
char *newval;
ArrayType *a;
Assert(name);
Assert(value);
- /* test if the option is valid */
- set_config_option(name, value,
- superuser() ? PGC_SUSET : PGC_USERSET,
- PGC_S_TEST, GUC_ACTION_SET, false);
+ /* test if the option is valid and we're allowed to set it */
+ (void) validate_option_array_item(name, value, false);
- /* convert name to canonical spelling, so we can use plain strcmp */
- (void) GetConfigOptionByName(name, &varname);
- name = varname;
+ /* normalize name (converts obsolete GUC names to modern spellings) */
+ record = find_option(name, false, WARNING);
+ if (record)
+ name = record->name;
+ /* build new item for array */
newval = palloc(strlen(name) + 1 + strlen(value) + 1);
sprintf(newval, "%s=%s", name, value);
datum = CStringGetTextDatum(newval);
if (isnull)
continue;
current = TextDatumGetCString(d);
+
+ /* check for match up through and including '=' */
if (strncmp(current, newval, strlen(name) + 1) == 0)
{
index = i;
ArrayType *
GUCArrayDelete(ArrayType *array, const char *name)
{
- const char *varname;
+ struct config_generic *record;
ArrayType *newarray;
int i;
int index;
Assert(name);
- /* test if the option is valid */
- set_config_option(name, NULL,
- superuser() ? PGC_SUSET : PGC_USERSET,
- PGC_S_TEST, GUC_ACTION_SET, false);
+ /* test if the option is valid and we're allowed to set it */
+ (void) validate_option_array_item(name, NULL, false);
- /* convert name to canonical spelling, so we can use plain strcmp */
- (void) GetConfigOptionByName(name, &varname);
- name = varname;
+ /* normalize name (converts obsolete GUC names to modern spellings) */
+ record = find_option(name, false, WARNING);
+ if (record)
+ name = record->name;
/* if array is currently null, then surely nothing to delete */
if (!array)
&& val[strlen(name)] == '=')
continue;
-
/* else add it to the output array */
if (newarray)
- {
newarray = array_set(newarray, 1, &index,
d,
false,
-1 /* TEXT's typlen */ ,
false /* TEXT's typbyval */ ,
'i' /* TEXT's typalign */ );
- }
else
newarray = construct_array(&d, 1,
TEXTOID,
return newarray;
}
+
/*
* Given a GUC array, delete all settings from it that our permission
* level allows: if superuser, delete them all; if regular user, only
if (!array)
return NULL;
- /* if we're superuser, we can delete everything */
+ /* if we're superuser, we can delete everything, so just do it */
if (superuser())
return NULL;
char *val;
char *eqsgn;
bool isnull;
- struct config_generic *gconf;
d = array_ref(array, 1, &i,
-1 /* varlenarray */ ,
false /* TEXT's typbyval */ ,
'i' /* TEXT's typalign */ ,
&isnull);
-
if (isnull)
continue;
val = TextDatumGetCString(d);
eqsgn = strchr(val, '=');
*eqsgn = '\0';
- gconf = find_option(val, false, WARNING);
- if (!gconf)
- continue;
-
- /* note: superuser-ness was already checked above */
- /* skip entry if OK to delete */
- if (gconf->context == PGC_USERSET)
+ /* skip if we have permission to delete it */
+ if (validate_option_array_item(val, NULL, true))
continue;
- /* XXX do we need to worry about database owner? */
-
/* else add it to the output array */
if (newarray)
- {
newarray = array_set(newarray, 1, &index,
d,
false,
-1 /* TEXT's typlen */ ,
false /* TEXT's typbyval */ ,
'i' /* TEXT's typalign */ );
- }
else
newarray = construct_array(&d, 1,
TEXTOID,
return newarray;
}
+/*
+ * Validate a proposed option setting for GUCArrayAdd/Delete/Reset.
+ *
+ * name is the option name. value is the proposed value for the Add case,
+ * or NULL for the Delete/Reset cases. If skipIfNoPermissions is true, it's
+ * not an error to have no permissions to set the option.
+ *
+ * Returns TRUE if OK, FALSE if skipIfNoPermissions is true and user does not
+ * have permission to change this option (all other error cases result in an
+ * error being thrown).
+ */
+static bool
+validate_option_array_item(const char *name, const char *value,
+ bool skipIfNoPermissions)
+
+{
+ struct config_generic *gconf;
+
+ /*
+ * There are three cases to consider:
+ *
+ * name is a known GUC variable. Check the value normally, check
+ * permissions normally (ie, allow if variable is USERSET, or if it's
+ * SUSET and user is superuser).
+ *
+ * name is not known, but exists or can be created as a placeholder
+ * (implying it has a prefix listed in custom_variable_classes).
+ * We allow this case if you're a superuser, otherwise not. Superusers
+ * are assumed to know what they're doing. We can't allow it for other
+ * users, because when the placeholder is resolved it might turn out to
+ * be a SUSET variable; define_custom_variable assumes we checked that.
+ *
+ * name is not known and can't be created as a placeholder. Throw error,
+ * unless skipIfNoPermissions is true, in which case return FALSE.
+ * (It's tempting to allow this case to superusers, if the name is
+ * qualified but not listed in custom_variable_classes. That would
+ * ease restoring of dumps containing ALTER ROLE/DATABASE SET. However,
+ * it's not clear that this usage justifies such a loss of error checking.
+ * You can always fix custom_variable_classes before you restore.)
+ */
+ gconf = find_option(name, true, WARNING);
+ if (!gconf)
+ {
+ /* not known, failed to make a placeholder */
+ if (skipIfNoPermissions)
+ return false;
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("unrecognized configuration parameter \"%s\"", name)));
+ }
+
+ if (gconf->flags & GUC_CUSTOM_PLACEHOLDER)
+ {
+ /*
+ * We cannot do any meaningful check on the value, so only permissions
+ * are useful to check.
+ */
+ if (superuser())
+ return true;
+ if (skipIfNoPermissions)
+ return false;
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("permission denied to set parameter \"%s\"", name)));
+ }
+
+ /* manual permissions check so we can avoid an error being thrown */
+ if (gconf->context == PGC_USERSET)
+ /* ok */ ;
+ else if (gconf->context == PGC_SUSET && superuser())
+ /* ok */ ;
+ else if (skipIfNoPermissions)
+ return false;
+ /* if a permissions error should be thrown, let set_config_option do it */
+
+ /* test for permissions and valid option value */
+ set_config_option(name, value,
+ superuser() ? PGC_SUSET : PGC_USERSET,
+ PGC_S_TEST, GUC_ACTION_SET, false);
+
+ return true;
+}
+
/*
* assign_hook and show_hook subroutines
projects / postgresql / commitdiff