The attached patch, which incorporates the previous one sent and

currently unapplied regarding spi_internal.c, makes some additional
fixes relating to return types, and also contains the fix for
preventing  the use of insecure versions of Safe.pm.

There is one remaing return case that does not appear to work, namely
return of a composite directly in a select, i.e. if  foo returns some
composite type, 'select * from foo()' works but 'select foo()' doesn't.
We will either fix that or document it as a limitation.

The function plperl_func_handler is a mess - I will try to get it
cleaned up (and split up) in a subsequent patch, time permitting.

Also, reiterating previous advice - this changes slightly the API for
spi_exec_query - the returned object has either 2 or 3 members: 'status'
(string) and 'proceesed' (int,- number of rows) and, if rows are
returned, 'rows' (array of tuple hashes).

Andrew Dunstan

Author: bmomjian

src/pl/plperl/plperl.c

@@ -33,7 +33,7 @@
  *	  ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.45 2004/07/01 20:50:22 joe Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plperl/plperl.c,v 1.46 2004/07/12 14:31:04 momjian Exp $
  *
  **********************************************************************/
 
@@ -80,6 +80,7 @@ typedef struct plperl_proc_desc
 	CommandId	fn_cmin;
 	bool		lanpltrusted;
 	bool		fn_retistuple;	/* true, if function returns tuple */
+	bool		fn_retisset;		/*true, if function returns set*/
 	Oid			ret_oid;		/* Oid of returning type */
 	FmgrInfo	result_in_func;
 	Oid			result_typioparam;
@@ -95,11 +96,13 @@ typedef struct plperl_proc_desc
  * Global data
  **********************************************************************/
 static int	plperl_firstcall = 1;
+static bool plperl_safe_init_done = false;
 static PerlInterpreter *plperl_interp = NULL;
 static HV  *plperl_proc_hash = NULL;
-AV		   *g_row_keys = NULL;
-AV		   *g_column_keys = NULL;
-int			g_attr_num = 0;
+static AV		   *g_row_keys = NULL;
+static AV		   *g_column_keys = NULL;
+static SV		   *srf_perlret=NULL; /*keep returned value*/
+static int			g_attr_num = 0;
 
 /**********************************************************************
  * Forward declarations
@@ -215,11 +218,7 @@ plperl_init_interp(void)
 		 * no commas between the next lines please. They are supposed to be
 		 * one string
 		 */
-		"require Safe; SPI::bootstrap(); use vars qw(%_SHARED);"
-		"use vars qw($PLContainer); $PLContainer = new Safe('PLPerl');"
-		"$PLContainer->permit_only(':default');$PLContainer->permit(':base_math');"
-		"$PLContainer->share(qw[&elog &spi_exec_query &DEBUG &LOG &INFO &NOTICE &WARNING &ERROR %SHARED ]);"
-		"sub ::mksafefunc { return $PLContainer->reval(qq[sub { $_[0] $_[1]}]); }"
+		"SPI::bootstrap(); use vars qw(%_SHARED);"
 		"sub ::mkunsafefunc {return eval(qq[ sub { $_[0] $_[1] } ]); }"
 	};
 
@@ -238,6 +237,41 @@ plperl_init_interp(void)
 
 }
 
+
+static void
+plperl_safe_init(void)
+{
+	static char *safe_module  =
+		"require Safe; $Safe::VERSION";
+
+	static char * safe_ok =
+		"use vars qw($PLContainer); $PLContainer = new Safe('PLPerl');"
+		"$PLContainer->permit_only(':default');$PLContainer->permit(':base_math');"
+		"$PLContainer->share(qw[&elog &spi_exec_query &DEBUG &LOG &INFO &NOTICE &WARNING &ERROR %SHARED ]);"
+		"sub ::mksafefunc { return $PLContainer->reval(qq[sub { $_[0] $_[1]}]); }"
+		;
+
+	static char * safe_bad = 
+		"use vars qw($PLContainer); $PLContainer = new Safe('PLPerl');"
+		"$PLContainer->permit_only(':default');$PLContainer->permit(':base_math');"
+		"$PLContainer->share(qw[&elog &DEBUG &LOG &INFO &NOTICE &WARNING &ERROR %SHARED ]);"
+		"sub ::mksafefunc { return $PLContainer->reval(qq[sub { "
+		"elog(ERROR,'trusted perl functions disabled - please upgrade perl Safe module to at least 2.09');}]); }"
+		;
+
+	SV * res;
+
+	float safe_version;
+
+	res = eval_pv(safe_module,FALSE); /* TRUE = croak if failure */
+
+	safe_version = SvNV(res);
+
+	eval_pv((safe_version < 2.09 ? safe_bad : safe_ok),FALSE);
+
+	plperl_safe_init_done = true;
+}
+
 /**********************************************************************
  * turn a tuple into a hash expression and add it to a list
  **********************************************************************/
@@ -596,6 +630,9 @@ plperl_create_sub(char *s, bool trusted)
 	SV		   *subref;
 	int			count;
 
+	if(trusted && !plperl_safe_init_done)
+		plperl_safe_init();
+
 	ENTER;
 	SAVETMPS;
 	PUSHMARK(SP);
@@ -839,15 +876,22 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 	/* Find or compile the function */
 	prodesc = compile_plperl_function(fcinfo->flinfo->fn_oid, false);
 	/************************************************************
-	 * Call the Perl function
+	 * Call the Perl function if not returning set
 	 ************************************************************/
+	 if (!prodesc->fn_retisset)
 	perlret = plperl_call_perl_func(prodesc, fcinfo);
-	if (prodesc->fn_retistuple && SRF_IS_FIRSTCALL())
+	 else 
 	{
-
+		if (SRF_IS_FIRSTCALL()) /*call function only once*/
+			srf_perlret = plperl_call_perl_func(prodesc, fcinfo);
+		perlret = srf_perlret;
+	 }
+
+	 if (prodesc->fn_retisset && SRF_IS_FIRSTCALL())
+	 {
+		 if (prodesc->fn_retistuple) g_column_keys = newAV();
 		if (SvTYPE(perlret) != SVt_RV)
-			elog(ERROR, "plperl: this function must return a reference");
-		g_column_keys = newAV();
+			 elog(ERROR, "plperl: set-returning function must return reference");
 	}
 
 	/************************************************************
@@ -882,14 +926,15 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 		char	  **values = NULL;
 		ReturnSetInfo  *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 
-		if (!rsinfo)
+		if (prodesc->fn_retisset && !rsinfo)
 			ereport(ERROR,
 					(errcode(ERRCODE_SYNTAX_ERROR),
 					errmsg("returning a composite type is not allowed in this context"),
 					errhint("This function is intended for use in the FROM clause.")));
 
 		if (SvTYPE(perlret) != SVt_RV)
-			elog(ERROR, "plperl: this function must return a reference");
+			elog(ERROR, "plperl: composite-returning function must return a reference");
+
 
 		isset = plperl_is_set(perlret);
 
@@ -997,6 +1042,53 @@ plperl_func_handler(PG_FUNCTION_ARGS)
 			SRF_RETURN_DONE(funcctx);
 		}
 	}
+	else if (prodesc->fn_retisset)
+	{
+		FuncCallContext	*funcctx;
+		
+		if (SRF_IS_FIRSTCALL())
+		{
+			MemoryContext oldcontext;
+			int i;
+
+			funcctx = SRF_FIRSTCALL_INIT();
+			oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+			if(SvTYPE(SvRV(perlret))!=SVt_PVAV) elog(ERROR, "plperl: set-returning function must return reference to array");
+				else funcctx->max_calls =  av_len((AV*)SvRV(perlret))+1;
+		}
+		
+		funcctx = SRF_PERCALL_SETUP();
+		
+		if (funcctx->call_cntr < funcctx->max_calls)
+		{
+			Datum		result;
+			AV* 		array;
+			SV** 		svp;
+			int 			i;
+
+			array = (AV*)SvRV(perlret);
+			svp = av_fetch(array, funcctx->call_cntr, FALSE);
+
+			if (SvTYPE(*svp) != SVt_NULL)
+				result = FunctionCall3(&prodesc->result_in_func,
+								   PointerGetDatum(SvPV(*svp, PL_na)),
+								   ObjectIdGetDatum(prodesc->result_typioparam),
+								   Int32GetDatum(-1));
+			else
+			{
+				fcinfo->isnull = true;
+				result = (Datum) 0;
+			}
+			SRF_RETURN_NEXT(funcctx, result);
+			fcinfo->isnull = false;
+		} 
+		else
+		{
+			if (perlret) SvREFCNT_dec(perlret);
+			SRF_RETURN_DONE(funcctx);
+		}
+	 }
 	else if (! fcinfo->isnull)
 	{
 		retval = FunctionCall3(&prodesc->result_in_func,
@@ -1249,6 +1341,8 @@ compile_plperl_function(Oid fn_oid, bool is_trigger)
 				}
 			}
 
+			prodesc->fn_retisset = procStruct->proretset; /*true, if function returns set*/
+
 			if (typeStruct->typtype == 'c' || procStruct->prorettype == RECORDOID)
 			{
 				prodesc->fn_retistuple = true;

src/pl/plperl/spi_internal.c

@@ -82,42 +82,48 @@ plperl_hash_from_tuple(HeapTuple tuple, TupleDesc tupdesc)
 		* Get the attributes value
 		************************************************************/
 		attdata = SPI_getvalue(tuple, tupdesc, i+1);
+		if(attdata)
 		hv_store(array, attname, strlen(attname), newSVpv(attdata,0), 0);
+		else
+			hv_store(array, attname, strlen(attname), newSVpv("undef",0), 0);
 	}
 	return array;
 }
 
 static HV*
-plperl_spi_execute_fetch_result(SPITupleTable *tuptable, int rows, int status)
+plperl_spi_execute_fetch_result(SPITupleTable *tuptable, int processed, int status)
 {
 
 	HV *result;
+	 AV *rows;
 	int i;
 
 	result = newHV();
+	rows = newAV();
 
 	if (status == SPI_OK_UTILITY)
 	{
 		hv_store(result, "status", strlen("status"), newSVpv("SPI_OK_UTILITY",0), 0);
-		hv_store(result, "rows", strlen("rows"), newSViv(rows), 0);
+		hv_store(result, "processed", strlen("processed"), newSViv(processed), 0);
 	}
 	else if (status != SPI_OK_SELECT)
 	{
 		hv_store(result, "status", strlen("status"), newSVpv((char*)plperl_spi_status_string(status),0), 0);
-		hv_store(result, "rows", strlen("rows"), newSViv(rows), 0);
+		hv_store(result, "processed", strlen("processed"), newSViv(processed), 0);
 	}
 	else
 	{
-		if (rows)
+		hv_store(result, "status", strlen("status"), newSVpv((char*)plperl_spi_status_string(status),0), 0);
+		hv_store(result, "processed", strlen("processed"), newSViv(processed), 0);
+		if (processed)
 		{
-			char* key=palloc(sizeof(int));
 			HV *row;
-			for (i = 0; i < rows; i++)
+			for (i = 0; i < processed; i++)
 			{
 				row = plperl_hash_from_tuple(tuptable->vals[i], tuptable->tupdesc);
-				sprintf(key, "%i", i);
-				hv_store(result, key, strlen(key), newRV_noinc((SV*)row), 0);
+				 av_store(rows, i, newRV_noinc((SV*)row));
 			}
+			hv_store(result, "rows", strlen("rows"), newRV_noinc((SV*)rows), 0);
 			SPI_freetuptable(tuptable);
 		}
 	}

src/pl/plperl/spi_internal.h

@@ -1,6 +1,7 @@
 #include "EXTERN.h"
 #include "perl.h"
 #include "XSUB.h"
+#include "ppport.h"
 
 int			spi_DEBUG(void);