Disallow "=" in names of reloptions and foreign-data options.

tglsfdc · tglsfdc · commit d4046125dd7d · 2025-06-02T15:22:44.000-04:00
We store values for these options as array elements with the syntax "name=value", hence a name containing "=" confuses matters when it's time to read the array back in. Since validation of the options is often done (long) after this conversion to array format, that leads to confusing and off-point error messages. We can improve matters by rejecting names containing "=" up-front. (Probably a better design would have involved pairs of array elements, but it's too late now --- and anyway, there's no evident use-case for option names like this. We already reject such names in some other contexts such as GUCs.) Reported-by: Chapman Flack <jcflack@acm.org> Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Chapman Flack <jcflack@acm.org> Discussion: https://postgr.es/m/6830EB30.8090904@acm.org Backpatch-through: 13
diff --git a/contrib/file_fdw/expected/file_fdw.out b/contrib/file_fdw/expected/file_fdw.out
@@ -48,6 +48,10 @@ SET ROLE regress_file_fdw_superuser;
 CREATE USER MAPPING FOR regress_file_fdw_superuser SERVER file_server;
 CREATE USER MAPPING FOR regress_no_priv_user SERVER file_server;
 -- validator tests
+CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (foo 'bar');  -- ERROR
+ERROR:  invalid option "foo"
+CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS ("a=b" 'true');  -- ERROR
+ERROR:  invalid option name "a=b": must not contain "="
 CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (format 'xml');  -- ERROR
 ERROR:  COPY format "xml" not recognized
 CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (format 'text', quote ':');          -- ERROR
diff --git a/contrib/file_fdw/sql/file_fdw.sql b/contrib/file_fdw/sql/file_fdw.sql
@@ -55,6 +55,8 @@ CREATE USER MAPPING FOR regress_file_fdw_superuser SERVER file_server;
 CREATE USER MAPPING FOR regress_no_priv_user SERVER file_server;
 
 -- validator tests
+CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (foo 'bar');  -- ERROR
+CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS ("a=b" 'true');  -- ERROR
 CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (format 'xml');  -- ERROR
 CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (format 'text', quote ':');          -- ERROR
 CREATE FOREIGN TABLE tbl () SERVER file_server OPTIONS (format 'text', escape ':');         -- ERROR
diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
@@ -1232,8 +1232,9 @@ transformRelOptions(Datum oldOptions, List *defList, const char *namspace,
 		}
 		else
 		{
-			text	   *t;
+			const char *name;
 			const char *value;
+			text	   *t;
 			Size		len;
 
 			/*
@@ -1280,19 +1281,27 @@ transformRelOptions(Datum oldOptions, List *defList, const char *namspace,
 			 * have just "name", assume "name=true" is meant.  Note: the
 			 * namespace is not output.
 			 */
+			name = def->defname;
 			if (def->arg != NULL)
 				value = defGetString(def);
 			else
 				value = "true";
 
+			/* Insist that name not contain "=", else "a=b=c" is ambiguous */
+			if (strchr(name, '=') != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("invalid option name \"%s\": must not contain \"=\"",
+								name)));
+
 			/*
 			 * This is not a great place for this test, but there's no other
 			 * convenient place to filter the option out. As WITH (oids =
 			 * false) will be removed someday, this seems like an acceptable
 			 * amount of ugly.
 			 */
 			if (acceptOidsOff && def->defnamespace == NULL &&
-				strcmp(def->defname, "oids") == 0)
+				strcmp(name, "oids") == 0)
 			{
 				if (defGetBoolean(def))
 					ereport(ERROR,
@@ -1302,11 +1311,11 @@ transformRelOptions(Datum oldOptions, List *defList, const char *namspace,
 				continue;
 			}
 
-			len = VARHDRSZ + strlen(def->defname) + 1 + strlen(value);
+			len = VARHDRSZ + strlen(name) + 1 + strlen(value);
 			/* +1 leaves room for sprintf's trailing null */
 			t = (text *) palloc(len + 1);
 			SET_VARSIZE(t, len);
-			sprintf(VARDATA(t), "%s=%s", def->defname, value);
+			sprintf(VARDATA(t), "%s=%s", name, value);
 
 			astate = accumArrayResult(astate, PointerGetDatum(t),
 									  false, TEXTOID,
diff --git a/src/backend/commands/foreigncmds.c b/src/backend/commands/foreigncmds.c
@@ -71,15 +71,26 @@ optionListToArray(List *options)
 	foreach(cell, options)
 	{
 		DefElem    *def = lfirst(cell);
+		const char *name;
 		const char *value;
 		Size		len;
 		text	   *t;
 
+		name = def->defname;
 		value = defGetString(def);
-		len = VARHDRSZ + strlen(def->defname) + 1 + strlen(value);
+
+		/* Insist that name not contain "=", else "a=b=c" is ambiguous */
+		if (strchr(name, '=') != NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("invalid option name \"%s\": must not contain \"=\"",
+							name)));
+
+		len = VARHDRSZ + strlen(name) + 1 + strlen(value);
+		/* +1 leaves room for sprintf's trailing null */
 		t = palloc(len + 1);
 		SET_VARSIZE(t, len);
-		sprintf(VARDATA(t), "%s=%s", def->defname, value);
+		sprintf(VARDATA(t), "%s=%s", name, value);
 
 		astate = accumArrayResult(astate, PointerGetDatum(t),
 								  false, TEXTOID,
