Commit 69c7ff06 authored by Daniel Verkamp's avatar Daniel Verkamp Committed by Ben Walker
Browse files

json: allow decoding of non-standard comments 



Comments are not allowed in the JSON RFC, but some JSON libraries accept
JavaScript-style comments.

Add a flag that enables non-spec-compliant comment parsing.

Change-Id: I9dfb66bb46ecff1a22d8af5a9c50620686a4707c
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 0b8198ce

include/spdk/json.h

+7 −0
Original line number Diff line number Diff line
@@ -107,6 +107,13 @@ struct spdk_json_val { 
 */

#define SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE	0x000000001



/**

 * Allow parsing of comments.

 *

 * Comments are not allowed by the JSON RFC, so this is not enabled by default.

 */

#define SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS	0x000000002



/*

 * Parse JSON data.

 *

lib/json/json_parse.c

+54 −0
Original line number Diff line number Diff line
@@ -373,6 +373,50 @@ done: 
	}

}



static int

json_valid_comment(const uint8_t *start, const uint8_t *buf_end)

{

	const uint8_t *p = start;

	bool multiline;



	assert(buf_end > p);

	if (buf_end - p < 2) {

		return SPDK_JSON_PARSE_INCOMPLETE;

	}



	if (p[0] != '/') {

		return SPDK_JSON_PARSE_INVALID;

	}

	if (p[1] == '*') {

		multiline = true;

	} else if (p[1] == '/') {

		multiline = false;

	} else {

		return SPDK_JSON_PARSE_INVALID;

	}

	p += 2;



	if (multiline) {

		while (p != buf_end - 1) {

			if (p[0] == '*' && p[1] == '/') {

				/* Include the terminating star and slash in the comment */

				return p - start + 2;

			}

			p++;

		}

	} else {

		while (p != buf_end) {

			if (*p == '\r' || *p == '\n') {

				/* Do not include the line terminator in the comment */

				return p - start;

			}

			p++;

		}

	}



	return SPDK_JSON_PARSE_INCOMPLETE;

}



struct json_literal {

	enum spdk_json_val_type type;

	uint32_t len;
@@ -574,6 +618,16 @@ spdk_json_parse(void *json, size_t size, struct spdk_json_val *values, size_t nu 
			state = STATE_VALUE;

			break;



		case '/':

			if (!(flags & SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS)) {

				return SPDK_JSON_PARSE_INVALID;

			}

			rc = json_valid_comment(data, json_end);

			if (rc < 0) return rc;

			/* Skip over comment */

			data += rc;

			break;



		default:

			return SPDK_JSON_PARSE_INVALID;

		}

test/lib/json/parse/json_parse_ut.c

+68 −6
Original line number Diff line number Diff line
@@ -55,18 +55,24 @@ static int g_cur_val; 
 * Do two checks - first pass NULL for values to ensure the count is correct,

 *  then pass g_vals to get the actual values.

 */

#define PARSE_PASS(in, num_vals, trailing) \

#define PARSE_PASS_FLAGS(in, num_vals, trailing, flags) \

	BUF_SETUP(in); \

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, NULL, 0, &g_end, 0) == num_vals); \

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, NULL, 0, &g_end, flags) == num_vals); \

	memset(g_vals, 0, sizeof(g_vals)); \

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, g_vals, sizeof(g_vals), &g_end, SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE) == num_vals); \

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, g_vals, sizeof(g_vals), &g_end, flags | SPDK_JSON_PARSE_FLAG_DECODE_IN_PLACE) == num_vals); \

	CU_ASSERT(g_end == g_buf + sizeof(in) - sizeof(trailing)); \

	CU_ASSERT(memcmp(g_end, trailing, sizeof(trailing) - 1) == 0); \

	g_cur_val = 0



#define PARSE_FAIL(in, retval) \

#define PARSE_PASS(in, num_vals, trailing) \

	PARSE_PASS_FLAGS(in, num_vals, trailing, 0)



#define PARSE_FAIL_FLAGS(in, retval, flags) \

	BUF_SETUP(in); \

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, NULL, 0, &g_end, 0) == retval)

	CU_ASSERT(spdk_json_parse(g_buf, sizeof(in) - 1, NULL, 0, &g_end, flags) == retval)



#define PARSE_FAIL(in, retval) \

	PARSE_FAIL_FLAGS(in, retval, 0)



#define VAL_STRING_MATCH(str, var_type) \

	CU_ASSERT(g_vals[g_cur_val].type == var_type); \
@@ -797,6 +803,61 @@ test_parse_nesting(void) 
	PARSE_FAIL("{\"a\": [0, 1, 2]", SPDK_JSON_PARSE_INCOMPLETE);

}





static void

test_parse_comment(void)

{

	/* Comments are not allowed by the JSON RFC */

	PARSE_PASS("[0]", 3, "");

	PARSE_FAIL("/* test */[0]", SPDK_JSON_PARSE_INVALID);

	PARSE_FAIL("[/* test */0]", SPDK_JSON_PARSE_INVALID);

	PARSE_FAIL("[0/* test */]", SPDK_JSON_PARSE_INVALID);



	/*

	 * This is allowed since the parser stops once it reads a complete JSON object.

	 * The next parse call would fail (see tests above) when parsing the comment.

	 */

	PARSE_PASS("[0]/* test */", 3, "/* test */");



	/*

	 * Test with non-standard comments enabled.

	 */

	PARSE_PASS_FLAGS("/* test */[0]", 3, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_ARRAY_BEGIN(1);

	VAL_NUMBER("0");

	VAL_ARRAY_END();



	PARSE_PASS_FLAGS("[/* test */0]", 3, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_ARRAY_BEGIN(1);

	VAL_NUMBER("0");

	VAL_ARRAY_END();



	PARSE_PASS_FLAGS("[0/* test */]", 3, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_ARRAY_BEGIN(1);

	VAL_NUMBER("0");

	VAL_ARRAY_END();



	PARSE_FAIL_FLAGS("/* test */", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	PARSE_FAIL_FLAGS("[/* test */", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	PARSE_FAIL_FLAGS("[0/* test */", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);



	/*

	 * Single-line comments

	 */

	PARSE_PASS_FLAGS("// test\n0", 1, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_NUMBER("0");



	PARSE_PASS_FLAGS("// test\r\n0", 1, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_NUMBER("0");



	PARSE_PASS_FLAGS("// [0] test\n0", 1, "", SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	VAL_NUMBER("0");



	PARSE_FAIL_FLAGS("//", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	PARSE_FAIL_FLAGS("// test", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

	PARSE_FAIL_FLAGS("//\n", SPDK_JSON_PARSE_INCOMPLETE, SPDK_JSON_PARSE_FLAG_ALLOW_COMMENTS);

}



int main(int argc, char **argv)

{

	CU_pSuite	suite = NULL;
@@ -822,7 +883,8 @@ int main(int argc, char **argv) 
		CU_add_test(suite, "parse_number", test_parse_number) == NULL ||

		CU_add_test(suite, "parse_array", test_parse_array) == NULL ||

		CU_add_test(suite, "parse_object", test_parse_object) == NULL ||

		CU_add_test(suite, "parse_nesting", test_parse_nesting) == NULL) {

		CU_add_test(suite, "parse_nesting", test_parse_nesting) == NULL ||

		CU_add_test(suite, "parse_comment", test_parse_comment) == NULL) {

		CU_cleanup_registry();

		return CU_get_error();

	}