diff -u postgresql-7.2b2/src/pl/plpython/error.expected postgresql-7.2b2-kbj/src/pl/plpython/error.expected
--- postgresql-7.2b2/src/pl/plpython/error.expected	Wed May  9 15:54:38 2001
+++ postgresql-7.2b2-kbj/src/pl/plpython/error.expected	Sun Nov 11 13:48:59 2001
@@ -1,5 +1,5 @@
 SELECT invalid_type_uncaught('rick');
-ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_uncaught_1175341' failed.
+ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_uncaught_112253' failed.
 plpy.SPIError: Cache lookup for type `test' failed.
 SELECT invalid_type_caught('rick');
 NOTICE:  ("Cache lookup for type `test' failed.",)
@@ -9,11 +9,32 @@
 (1 row)
 
 SELECT invalid_type_reraised('rick');
-ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_reraised_1175343' failed.
+ERROR:  plpython: Call of function `__plpython_procedure_invalid_type_reraised_112255' failed.
 plpy.Error: ("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_112260' 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_112261' failed.
+exceptions.IOError: can't open files in restricted mode
+SELECT getpid();
+ERROR:  plpython: Call of function `__plpython_procedure_getpid_112262' failed.
+exceptions.AttributeError: getpid
+SELECT uname();
+ERROR:  plpython: Call of function `__plpython_procedure_uname_112263' failed.
+exceptions.AttributeError: uname
+SELECT sys_exit();
+ERROR:  plpython: Call of function `__plpython_procedure_sys_exit_112264' failed.
+exceptions.AttributeError: exit
+SELECT sys_argv();
+    sys_argv    
+----------------
+ ['RESTRICTED']
 (1 row)
 
diff -u postgresql-7.2b2/src/pl/plpython/plpython.c postgresql-7.2b2-kbj/src/pl/plpython/plpython.c
--- postgresql-7.2b2/src/pl/plpython/plpython.c	Mon Nov  5 12:46:39 2001
+++ postgresql-7.2b2-kbj/src/pl/plpython/plpython.c	Thu Nov 15 09:27:20 2001
@@ -188,6 +188,10 @@
 static void PLy_init_safe_interp(void);
 static void PLy_init_plpy(void);
 
+/* Helper functions used during initialization */
+static int  populate_methods(PyObject *klass, PyMethodDef *methods);
+static PyObject *build_tuple(char* string_list[], int len);
+
 /* error handler.  collects the current Python exception, if any,
  * and appends it to the error and sends it to elog
  */
@@ -240,6 +244,10 @@
 static void PLy_output_tuple_funcs(PLyTypeInfo *, TupleDesc);
 static void PLy_input_tuple_funcs(PLyTypeInfo *, TupleDesc);
 
+/* RExec methods
+ */
+static PyObject *PLy_r_open(PyObject *self, PyObject* args);
+
 /* conversion functions
  */
 static PyObject *PLyDict_FromTuple(PLyTypeInfo *, HeapTuple, TupleDesc);
@@ -265,35 +273,60 @@
 static PyObject *PLy_interp_safe = NULL;
 static PyObject *PLy_interp_safe_globals = NULL;
 static PyObject *PLy_importable_modules = NULL;
+static PyObject *PLy_ok_posix_names = NULL;
+static PyObject *PLy_ok_sys_names = NULL;
 static PyObject *PLy_procedure_cache = NULL;
 
-char	   *PLy_importable_modules_list[] = {
+static char *PLy_importable_modules_list[] = {
 	"array",
 	"bisect",
+	"binascii",
 	"calendar",
 	"cmath",
+	"codecs",
 	"errno",
 	"marshal",
 	"math",
 	"md5",
 	"mpz",
 	"operator",
+	"pcre",
 	"pickle",
 	"random",
 	"re",
+	"regex",
+	"sre",
 	"sha",
 	"string",
 	"StringIO",
+	"struct",
 	"time",
 	"whrandom",
 	"zlib"
 };
 
+static char *PLy_ok_posix_names_list[] = {
+	/* None for now */
+};
+
+static char *PLy_ok_sys_names_list[] = {
+	"byteeorder",
+	"copyright",
+	"getdefaultencoding",
+	"getrefcount",
+	"hexrevision",
+	"maxint",
+	"maxunicode",
+	"platform",
+	"version",
+	"version_info"
+};
+
 /* Python exceptions
  */
-PyObject   *PLy_exc_error = NULL;
-PyObject   *PLy_exc_fatal = NULL;
-PyObject   *PLy_exc_spi_error = NULL;
+static PyObject   *PLy_exc_error = NULL;
+static PyObject   *PLy_exc_fatal = NULL;
+static PyObject   *PLy_exc_spi_error = NULL;
 
 /* some globals for the python module
  */
@@ -1150,12 +1183,6 @@
 	if ((proc->interp == NULL) || (PyErr_Occurred()))
 		PLy_elog(ERROR, "Unable to create rexec.RExec instance");
 
-	/*
-	 * tweak the list of permitted modules
-	 */
-	PyObject_SetAttrString(proc->interp, "ok_builtin_modules",
-						   PLy_importable_modules);
-
 	proc->reval = PyObject_GetAttrString(proc->interp, "r_eval");
 	if ((proc->reval == NULL) || (PyErr_Occurred()))
 		PLy_elog(ERROR, "Unable to get method `r_eval' from rexec.RExec");
@@ -1650,7 +1677,7 @@
 static PyObject *PLy_spi_execute_fetch_result(SPITupleTable *, int, int);
 
 
-PyTypeObject PLy_PlanType = {
+static PyTypeObject PLy_PlanType = {
 	PyObject_HEAD_INIT(NULL)
 	0,							/* ob_size */
 	"PLyPlan",					/* tp_name */
@@ -1679,13 +1706,13 @@
 	PLy_plan_doc,				/* tp_doc */
 };
 
-PyMethodDef PLy_plan_methods[] = {
+static PyMethodDef PLy_plan_methods[] = {
 	{"status", (PyCFunction) PLy_plan_status, METH_VARARGS, NULL},
 	{NULL, NULL, 0, NULL}
 };
 
 
-PySequenceMethods PLy_result_as_sequence = {
+static PySequenceMethods PLy_result_as_sequence = {
 	(inquiry) PLy_result_length,	/* sq_length */
 	(binaryfunc) 0,				/* sq_concat */
 	(intargfunc) 0,				/* sq_repeat */
@@ -1695,7 +1722,7 @@
 	(intintobjargproc) PLy_result_ass_slice,	/* sq_ass_slice */
 };
 
-PyTypeObject PLy_ResultType = {
+static PyTypeObject PLy_ResultType = {
 	PyObject_HEAD_INIT(NULL)
 	0,							/* ob_size */
 	"PLyResult",				/* tp_name */
@@ -1724,7 +1751,7 @@
 	PLy_result_doc,				/* tp_doc */
 };
 
-PyMethodDef PLy_result_methods[] = {
+static PyMethodDef PLy_result_methods[] = {
 	{"fetch", (PyCFunction) PLy_result_fetch, METH_VARARGS, NULL,},
 	{"nrows", (PyCFunction) PLy_result_nrows, METH_VARARGS, NULL},
 	{"status", (PyCFunction) PLy_result_status, METH_VARARGS, NULL},
@@ -1833,7 +1860,7 @@
 /* result object methods
  */
 
-static PyObject *
+PyObject *
 PLy_result_new(void)
 {
 	PLyResultObject *ob;
@@ -1853,7 +1880,7 @@
 	return (PyObject *) ob;
 }
 
-static void
+void
 PLy_result_dealloc(PyObject * arg)
 {
 	PLyResultObject *ob = (PLyResultObject *) arg;
@@ -1867,19 +1894,19 @@
 	PyMem_DEL(ob);
 }
 
-static PyObject *
+PyObject *
 PLy_result_getattr(PyObject * self, char *attr)
 {
 	return NULL;
 }
 
-static PyObject *
+PyObject *
 PLy_result_fetch(PyObject * self, PyObject * args)
 {
 	return NULL;
 }
 
-static PyObject *
+PyObject *
 PLy_result_nrows(PyObject * self, PyObject * args)
 {
 	PLyResultObject *ob = (PLyResultObject *) self;
@@ -1888,7 +1915,7 @@
 	return ob->nrows;
 }
 
-static PyObject *
+PyObject *
 PLy_result_status(PyObject * self, PyObject * args)
 {
 	PLyResultObject *ob = (PLyResultObject *) self;
@@ -2450,13 +2477,33 @@
 		elog(ERROR, "Unable to init plpy.");
 }
 
+/*
+ *  New RExec methods
+ */
+
+PyObject* 
+PLy_r_open(PyObject *self, PyObject* args)
+{
+	PyErr_SetString(PyExc_IOError, "can't open files in restricted mode");
+	return NULL;
+}
+
+
+static PyMethodDef PLy_r_exec_methods[] = {
+	{"r_open", (PyCFunction)PLy_r_open, METH_VARARGS, NULL},
+	{NULL, NULL, 0, NULL}
+};
+
+/*
+ *  Init new RExec
+ */
+
 void
 PLy_init_safe_interp(void)
 {
-	PyObject   *rmod;
+	PyObject   *rmod, *rexec, *rexec_dict;
 	char	   *rname = "rexec";
-	int			i,
-				imax;
+	int	    len;
 
 	enter();
 
@@ -2467,19 +2514,93 @@
 	PyDict_SetItemString(PLy_interp_globals, rname, rmod);
 	PLy_interp_safe = rmod;
 
-	imax = sizeof(PLy_importable_modules_list) / sizeof(char *);
-	PLy_importable_modules = PyTuple_New(imax);
-	for (i = 0; i < imax; i++)
-	{
-		PyObject   *m = PyString_FromString(PLy_importable_modules_list[i]);
+	len = sizeof(PLy_importable_modules_list) / sizeof(char *);
+	PLy_importable_modules = build_tuple(PLy_importable_modules_list, len);
 
-		PyTuple_SetItem(PLy_importable_modules, i, m);
-	}
+	len = sizeof(PLy_ok_posix_names_list) / sizeof(char *);
+	PLy_ok_posix_names = build_tuple(PLy_ok_posix_names_list, len);
+
+	len = sizeof(PLy_ok_sys_names_list) / sizeof(char *);
+	PLy_ok_sys_names = build_tuple(PLy_ok_sys_names_list, len);
 
 	PLy_interp_safe_globals = PyDict_New();
 	if (PLy_interp_safe_globals == NULL)
 		PLy_elog(ERROR, "Unable to create shared global dictionary.");
 
+	/*
+	 * get an rexec.RExec class
+	 */
+	rexec = PyDict_GetItemString(PyModule_GetDict(rmod), "RExec");
+
+	if (rexec == NULL || !PyClass_Check(rexec))
+		PLy_elog(ERROR, "Unable to get RExec object.");
+
+
+	rexec_dict = ((PyClassObject*)rexec)->cl_dict;
+
+	/*
+	 * tweak the list of permitted modules, posix and sys functions 
+	 */
+	PyDict_SetItemString(rexec_dict, "ok_builtin_modules", PLy_importable_modules);
+	PyDict_SetItemString(rexec_dict, "ok_posix_names",     PLy_ok_posix_names);
+	PyDict_SetItemString(rexec_dict, "ok_sys_names",       PLy_ok_sys_names);
+
+	/*
+	 * change the r_open behavior
+	 */
+	if( populate_methods(rexec, PLy_r_exec_methods) )
+		PLy_elog(ERROR, "Failed to update RExec methods.");
+}
+
+/* Helper function to build tuples from string lists */
+static
+PyObject *build_tuple(char* string_list[], int len)
+{
+	PyObject *tup = PyTuple_New(len);
+	int i;
+	for (i = 0; i < len; i++)
+	{
+		PyObject *m = PyString_FromString(string_list[i]);
+
+		PyTuple_SetItem(tup, i, m);
+	}
+	return tup;
+}
+
+/* Helper function for populating a class with method wrappers. */
+static int
+populate_methods(PyObject *klass, PyMethodDef *methods)
+{
+	if (!klass || !methods)
+		return 0;
+
+	for ( ; methods->ml_name; ++methods) {
+
+		/* get a wrapper for the built-in function */   
+		PyObject *func = PyCFunction_New(methods, NULL);
+		PyObject *meth;
+		int status;
+
+		if (!func)
+			return -1;
+
+		/* turn the function into an unbound method */  
+		if (!(meth = PyMethod_New(func, NULL, klass))) {
+			Py_DECREF(func);
+			return -1;
+		}
+
+		/* add method to dictionary */
+		status = PyDict_SetItemString( ((PyClassObject*)klass)->cl_dict, 
+						methods->ml_name, meth);
+		Py_DECREF(meth);
+		Py_DECREF(func);
+
+		/* stop now if an error occurred, otherwise do the next method */
+		if (status)
+			return status;
+	}
+	return 0;
 }
 
 
Only in postgresql-7.2b2-kbj/src/pl/plpython: plpython.c~
diff -u postgresql-7.2b2/src/pl/plpython/plpython_error.sql postgresql-7.2b2-kbj/src/pl/plpython/plpython_error.sql
--- postgresql-7.2b2/src/pl/plpython/plpython_error.sql	Wed May  9 15:54:38 2001
+++ postgresql-7.2b2-kbj/src/pl/plpython/plpython_error.sql	Sun Nov 11 13:48:27 2001
@@ -7,3 +7,11 @@
 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();
diff -u postgresql-7.2b2/src/pl/plpython/plpython_function.sql postgresql-7.2b2-kbj/src/pl/plpython/plpython_function.sql
--- postgresql-7.2b2/src/pl/plpython/plpython_function.sql	Wed May  9 15:54:38 2001
+++ postgresql-7.2b2-kbj/src/pl/plpython/plpython_function.sql	Sun Nov 11 13:47:08 2001
@@ -287,5 +287,36 @@
 '
 	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';