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json: Fix streamer not to ignore trailing unterminated structures

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json_message_process_token() accumulates tokens until it got the
sequence of tokens that comprise a single JSON value (it counts curly
braces and square brackets to decide).  It feeds those token sequences
to json_parser_parse().  If a non-empty sequence of tokens remains at
the end of the parse, it's silently ignored.  check-qjson.c cases
unterminated_array(), unterminated_array_comma(), unterminated_dict(),
unterminated_dict_comma() demonstrate this bug.

Fix as follows.  Introduce a JSON_END_OF_INPUT token.  When the
streamer receives it, it feeds the accumulated tokens to
json_parser_parse().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180823164025.12553-46-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2018-08-23 18:40:12 +02:00
parent e06d008ac8
commit f9277915ee
4 changed files with 15 additions and 4 deletions
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1
include/qapi/qmp/json-lexer.h
View File

@ -30,6 +30,7 @@ typedef enum json_token_type {
JSON_INTERP,
JSON_SKIP,
JSON_ERROR,
JSON_END_OF_INPUT,
} JSONTokenType;
typedef struct JSONLexer {

2
qobject/json-lexer.c
View File

@ -347,6 +347,8 @@ void json_lexer_flush(JSONLexer *lexer)
if (lexer->state != lexer->start_state) {
json_lexer_feed_char(lexer, 0, true);
}
json_message_process_token(lexer, lexer->token, JSON_END_OF_INPUT,
lexer->x, lexer->y);
}
void json_lexer_destroy(JSONLexer *lexer)

8
qobject/json-streamer.c
View File

@ -60,6 +60,13 @@ void json_message_process_token(JSONLexer *lexer, GString *input,
case JSON_ERROR:
error_setg(&err, "JSON parse error, stray '%s'", input->str);
goto out_emit;
case JSON_END_OF_INPUT:
if (g_queue_is_empty(parser->tokens)) {
return;
}
json = json_parser_parse(parser->tokens, parser->ap, &err);
parser->tokens = NULL;
goto out_emit;
default:
break;
}
@ -137,6 +144,7 @@ void json_message_parser_feed(JSONMessageParser *parser,
void json_message_parser_flush(JSONMessageParser *parser)
{
json_lexer_flush(&parser->lexer);
assert(g_queue_is_empty(parser->tokens));
}
void json_message_parser_destroy(JSONMessageParser *parser)

8
tests/check-qjson.c
View File

@ -1360,7 +1360,7 @@ static void unterminated_array(void)
{
Error *err = NULL;
QObject *obj = qobject_from_json("[32", &err);
g_assert(!err); /* BUG */
error_free_or_abort(&err);
g_assert(obj == NULL);
}
@ -1368,7 +1368,7 @@ static void unterminated_array_comma(void)
{
Error *err = NULL;
QObject *obj = qobject_from_json("[32,", &err);
g_assert(!err); /* BUG */
error_free_or_abort(&err);
g_assert(obj == NULL);
}
@ -1384,7 +1384,7 @@ static void unterminated_dict(void)
{
Error *err = NULL;
QObject *obj = qobject_from_json("{'abc':32", &err);
g_assert(!err); /* BUG */
error_free_or_abort(&err);
g_assert(obj == NULL);
}
@ -1392,7 +1392,7 @@ static void unterminated_dict_comma(void)
{
Error *err = NULL;
QObject *obj = qobject_from_json("{'abc':32,", &err);
g_assert(!err); /* BUG */
error_free_or_abort(&err);
g_assert(obj == NULL);
}