Create default roles

This creates an initial set of default roles which administrators may
use to grant access to, historically, superuser-only functions.  Using
these roles instead of granting superuser access reduces the number of
superuser roles required for a system.  Documention for each of the
default roles has been added to user-manag.sgml.

Bump catversion to 201604082, as we had a commit that bumped it to
201604081 and another that set it back to 201604071...

Reviews by José Luis Tallón and Robert Haas

5 files changed, 20 insertions, 5 deletions

diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index ebc7bb388a7..a44fa38173a 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -21,6 +21,7 @@
 #include <unistd.h>
 
 #include "access/sysattr.h"
+#include "catalog/pg_authid.h"
 #include "catalog/catalog.h"
 #include "catalog/pg_tablespace.h"
 #include "catalog/pg_type.h"
@@ -244,7 +245,8 @@ pg_signal_backend(int pid, int sig)
 		return SIGNAL_BACKEND_NOSUPERUSER;
 
 	/* Users can signal backends they have role membership in. */
-	if (!has_privs_of_role(GetUserId(), proc->roleId))
+	if (!has_privs_of_role(GetUserId(), proc->roleId) &&
+		!has_privs_of_role(GetUserId(), DEFAULT_ROLE_SIGNAL_BACKENDID))
 		return SIGNAL_BACKEND_NOPERMISSION;
 
 	/*
@@ -290,7 +292,7 @@ pg_cancel_backend(PG_FUNCTION_ARGS)
 	if (r == SIGNAL_BACKEND_NOPERMISSION)
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be a member of the role whose query is being canceled"))));
+				 (errmsg("must be a member of the role whose query is being canceled or member of pg_signal_backend"))));
 
 	PG_RETURN_BOOL(r == SIGNAL_BACKEND_SUCCESS);
 }
@@ -314,7 +316,7 @@ pg_terminate_backend(PG_FUNCTION_ARGS)
 	if (r == SIGNAL_BACKEND_NOPERMISSION)
 		ereport(ERROR,
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-				 (errmsg("must be a member of the role whose process is being terminated"))));
+				 (errmsg("must be a member of the role whose process is being terminated or member of pg_signal_backend"))));
 
 	PG_RETURN_BOOL(r == SIGNAL_BACKEND_SUCCESS);
 }
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 6d254ba133c..5b7053da067 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201604071
+#define CATALOG_VERSION_NO	201604082
 
 #endif
diff --git a/src/include/catalog/pg_authid.h b/src/include/catalog/pg_authid.h
index c1630833b81..533081def6e 100644
--- a/src/include/catalog/pg_authid.h
+++ b/src/include/catalog/pg_authid.h
@@ -93,10 +93,16 @@ typedef FormData_pg_authid *Form_pg_authid;
  *
  * The uppercase quantities will be replaced at initdb time with
  * user choices.
+ *
+ * If adding new default roles or changing the OIDs below, be sure to add or
+ * update the #defines which follow as appropriate.
  * ----------------
  */
 DATA(insert OID = 10 ( "POSTGRES" t t t t t t t -1 _null_ _null_));
+DATA(insert OID = 4200 ( "pg_signal_backend" f t f f f f f -1 _null_ _null_));
+
+#define BOOTSTRAP_SUPERUSERID			10
 
-#define BOOTSTRAP_SUPERUSERID 10
+#define DEFAULT_ROLE_SIGNAL_BACKENDID	4200
 
 #endif   /* PG_AUTHID_H */
diff --git a/src/test/regress/expected/rolenames.out b/src/test/regress/expected/rolenames.out
index 01b3b90ec14..15a97abe195 100644
--- a/src/test/regress/expected/rolenames.out
+++ b/src/test/regress/expected/rolenames.out
@@ -824,6 +824,11 @@ ERROR:  role "pg_abcdef" is reserved
 DETAIL:  Cannot GRANT roles to a reserved role.
 SET ROLE pg_testrole; -- error
 ERROR:  invalid value for parameter "role": "pg_testrole"
+SET ROLE pg_signal_backend; --error
+ERROR:  invalid value for parameter "role": "pg_signal_backend"
+CREATE SCHEMA test_schema AUTHORIZATION pg_signal_backend; --error
+ERROR:  role "pg_signal_backend" is reserved
+DETAIL:  Cannot specify reserved role as owner.
 UPDATE pg_proc SET proacl = null WHERE proname LIKE 'testagg_';
 SELECT proname, proacl FROM pg_proc WHERE proname LIKE 'testagg_';
  proname  | proacl 
diff --git a/src/test/regress/sql/rolenames.sql b/src/test/regress/sql/rolenames.sql
index 1e0e9af8da1..b58a16359b2 100644
--- a/src/test/regress/sql/rolenames.sql
+++ b/src/test/regress/sql/rolenames.sql
@@ -385,6 +385,8 @@ GRANT testrol0 TO pg_abc; -- error
 GRANT pg_abc TO pg_abcdef; -- error
 
 SET ROLE pg_testrole; -- error
+SET ROLE pg_signal_backend; --error
+CREATE SCHEMA test_schema AUTHORIZATION pg_signal_backend; --error
 
 UPDATE pg_proc SET proacl = null WHERE proname LIKE 'testagg_';
 SELECT proname, proacl FROM pg_proc WHERE proname LIKE 'testagg_';