Copy input in json_parse_buffer

The ovis_json.h file included a #define that would collide with flex/bison parsers attempting to use this library. The input buffer is copied because the scanner modifies the contents, and requires two terminating '\0'.
ovis-hpc · Jul 20, 2020 · a16bb54 · a16bb54
1 parent af58d0a
commit a16bb54
Show file tree

Hide file tree

Showing 3 changed files with 25 additions and 16 deletions.
diff --git a/lib/src/ovis_json/ovis_json.h b/lib/src/ovis_json/ovis_json.h
@@ -164,5 +164,4 @@ extern jbuf_t jbuf_append_str(jbuf_t jb, const char *fmt, ...);
 extern jbuf_t jbuf_append_va(jbuf_t jb, const char *fmt, va_list ap);
 extern void jbuf_free(jbuf_t jb);
 
-#define YYSTYPE json_entity_t
 #endif
diff --git a/lib/src/ovis_json/ovis_json_lexer.l b/lib/src/ovis_json/ovis_json_lexer.l
@@ -5,6 +5,8 @@
 #include <ovis_json.h>
 #include "ovis_json_parser.h"
 
+#define YYSTYPE json_entity_t
+
 struct yyguts_t;
 void update_yylloc(YYLTYPE *, struct yyguts_t *);
 void init_yylloc(YYLTYPE *, struct yyguts_t *);
@@ -125,3 +127,23 @@ void init_yylloc(YYLTYPE *yyl, struct yyguts_t *yyg)
 	yyl->first_column = yyl->last_column = 0;
 	yylineno = 0;
 }
+
+int json_parse_buffer(json_parser_t p, char *buf, size_t buf_len, json_entity_t *pentity)
+{
+	int rc;
+	*pentity = NULL;
+	char *nbuf = malloc(buf_len + 2);
+	if (!nbuf)
+		return ENOMEM;
+	memcpy(nbuf, buf, buf_len);
+	nbuf[buf_len] = YY_END_OF_BUFFER_CHAR;
+	nbuf[buf_len+1] = YY_END_OF_BUFFER_CHAR;
+	if (NULL == yy_scan_buffer(buf, buf_len + 2, p->scanner)) {
+		rc = EINVAL;
+		goto out;
+	}
+	rc = yyparse(p, nbuf, buf_len + 2, pentity);
+out:
+	free(nbuf);
+	return rc;
+}
diff --git a/lib/src/ovis_json/ovis_json_parser.y b/lib/src/ovis_json/ovis_json_parser.y
@@ -5,7 +5,9 @@
 #include <string.h>
 #include <errno.h>
 #include "ovis_json.h"
+
 #define YYLTYPE struct json_loc_s
+#define YYSTYPE json_entity_t
 
 void yyerror(YYLTYPE *yylloc, json_parser_t parser, char *input, size_t input_len,
 	     json_entity_t *pentity, const char *str)
@@ -127,7 +129,7 @@ item_list: /* empty */ { $$ = new_list_val(); }
     ;
 
 %%
-#include <assert.h>
+
 json_parser_t json_parser_new(size_t user_data) {
 	json_parser_t p = calloc(1, sizeof *p + user_data);
 	if (p)
@@ -141,17 +143,3 @@ void json_parser_free(json_parser_t parser)
 	free(parser);
 }
 
-int json_parse_buffer(json_parser_t p, char *buf, size_t buf_len, json_entity_t *pentity)
-{
-	int rc;
-	*pentity = NULL;
-	/* NB: Force two 0x00 on the end of the buffer for the scanner. If
-	 * the user didn't allocate enough memory, this could corrupt
-	 * memory */
-	buf[buf_len] = 0x00;
-	buf[buf_len+1] = 0x00;
-	assert(NULL != yy_scan_buffer(buf, buf_len+2, p->scanner));
-	rc = yyparse(p, buf, buf_len, pentity);
-	return rc;
-}
-