plpython security and error handling fixes, from

Kevin Jacobs and Brad McLean.

src/pl/plpython/error.expected

 SELECT invalid_type_uncaught('rick');
-ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_uncaught_1175341' failed.
+NOTICE:  plpython: in function __plpython_procedure_invalid_type_uncaught_49801:
 plpy.SPIError: Cache lookup for type `test' failed.
 SELECT invalid_type_caught('rick');
-NOTICE:  ("Cache lookup for type `test' failed.",)
- invalid_type_caught 
----------------------
- 
-(1 row)
-
+NOTICE:  plpython: in function __plpython_procedure_invalid_type_caught_49802:
+plpy.SPIError: Cache lookup for type `test' failed.
 SELECT invalid_type_reraised('rick');
-ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_reraised_1175343' failed.
-plpy.Error: ("Cache lookup for type `test' failed.",)
+NOTICE:  plpython: in function __plpython_procedure_invalid_type_reraised_49803:
+plpy.SPIError: Cache lookup for type `test' failed.
 SELECT valid_type('rick');
  valid_type 
 ------------
  
 (1 row)
 
+SELECT read_file('/etc/passwd');
+ERROR:  plpython: Call of function `__plpython_procedure_read_file_49809' failed.
+exceptions.IOError: can't open files in restricted mode
+SELECT write_file('/tmp/plpython','This is very bad');
+ERROR:  plpython: Call of function `__plpython_procedure_write_file_49810' failed.
+exceptions.IOError: can't open files in restricted mode
+SELECT getpid();
+ERROR:  plpython: Call of function `__plpython_procedure_getpid_49811' failed.
+exceptions.AttributeError: getpid
+SELECT uname();
+ERROR:  plpython: Call of function `__plpython_procedure_uname_49812' failed.
+exceptions.AttributeError: uname
+SELECT sys_exit();
+ERROR:  plpython: Call of function `__plpython_procedure_sys_exit_49813' failed.
+exceptions.AttributeError: exit
+SELECT sys_argv();
+    sys_argv    
+----------------
+ ['RESTRICTED']
+(1 row)
+

src/pl/plpython/plpython_error.sql

@@ -7,3 +7,11 @@ SELECT invalid_type_uncaught('rick');
 SELECT invalid_type_caught('rick');
 SELECT invalid_type_reraised('rick');
 SELECT valid_type('rick');
+
+-- Security sandbox tests
+SELECT read_file('/etc/passwd');
+SELECT write_file('/tmp/plpython','This is very bad');
+SELECT getpid();
+SELECT uname();
+SELECT sys_exit();
+SELECT sys_argv();

src/pl/plpython/plpython_function.sql

@@ -257,6 +257,12 @@ if len(rv):
 return None
 '
 	LANGUAGE 'plpython';
+/* Flat out syntax error
+*/
+CREATE FUNCTION sql_syntax_error() RETURNS text
+        AS
+'plpy.execute("syntax error")'
+        LANGUAGE 'plpython';
 
 /* check the handling of uncaught python exceptions
  */
@@ -287,5 +293,36 @@ return seq
 '
 	LANGUAGE 'plpython';
 
-
+CREATE OR REPLACE FUNCTION read_file(text) RETURNS text AS '
+  return open(args[0]).read()
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION write_file(text,text) RETURNS text AS '
+  open(args[0],"w").write(args[1])
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION getpid() RETURNS int4 AS '
+  import os
+  return os.getpid()
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION uname() RETURNS int4 AS '
+  import os
+  return os.uname()
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION sys_exit() RETURNS text AS '
+  import sys
+  return sys.exit()
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION sys_argv() RETURNS text AS '
+  import sys
+  return str(sys.argv)
+' LANGUAGE 'plpython';
+
+CREATE OR REPLACE FUNCTION sys_version() RETURNS text AS '
+  import sys
+  return str(sys.version)
+' LANGUAGE 'plpython';