2 * JSON streaming support
4 * Copyright IBM, Corp. 2009
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
10 * See the COPYING.LIB file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qemu-common.h"
16 #include "qapi/qmp/json-lexer.h"
17 #include "qapi/qmp/json-streamer.h"
19 #define MAX_TOKEN_SIZE (64ULL << 20)
20 #define MAX_TOKEN_COUNT (2ULL << 20)
21 #define MAX_NESTING (1ULL << 10)
23 static void json_message_free_token(void *token
, void *opaque
)
28 static void json_message_free_tokens(JSONMessageParser
*parser
)
31 g_queue_foreach(parser
->tokens
, json_message_free_token
, NULL
);
32 g_queue_free(parser
->tokens
);
33 parser
->tokens
= NULL
;
37 static void json_message_process_token(JSONLexer
*lexer
, GString
*input
,
38 JSONTokenType type
, int x
, int y
)
40 JSONMessageParser
*parser
= container_of(lexer
, JSONMessageParser
, lexer
);
45 parser
->brace_count
++;
48 parser
->brace_count
--;
51 parser
->bracket_count
++;
54 parser
->bracket_count
--;
60 token
= g_malloc(sizeof(JSONToken
) + input
->len
+ 1);
62 memcpy(token
->str
, input
->str
, input
->len
);
63 token
->str
[input
->len
] = 0;
67 parser
->token_size
+= input
->len
;
69 g_queue_push_tail(parser
->tokens
, token
);
71 if (type
== JSON_ERROR
) {
73 } else if (parser
->brace_count
< 0 ||
74 parser
->bracket_count
< 0 ||
75 (parser
->brace_count
== 0 &&
76 parser
->bracket_count
== 0)) {
78 } else if (parser
->token_size
> MAX_TOKEN_SIZE
||
79 g_queue_get_length(parser
->tokens
) > MAX_TOKEN_COUNT
||
80 parser
->bracket_count
+ parser
->brace_count
> MAX_NESTING
) {
81 /* Security consideration, we limit total memory allocated per object
82 * and the maximum recursion depth that a message can force.
91 * Clear out token list and tell the parser to emit an error
92 * indication by passing it a NULL list
94 json_message_free_tokens(parser
);
96 /* send current list of tokens to parser and reset tokenizer */
97 parser
->brace_count
= 0;
98 parser
->bracket_count
= 0;
99 /* parser->emit takes ownership of parser->tokens. */
100 parser
->emit(parser
, parser
->tokens
);
101 parser
->tokens
= g_queue_new();
102 parser
->token_size
= 0;
105 void json_message_parser_init(JSONMessageParser
*parser
,
106 void (*func
)(JSONMessageParser
*, GQueue
*))
109 parser
->brace_count
= 0;
110 parser
->bracket_count
= 0;
111 parser
->tokens
= g_queue_new();
112 parser
->token_size
= 0;
114 json_lexer_init(&parser
->lexer
, json_message_process_token
);
117 int json_message_parser_feed(JSONMessageParser
*parser
,
118 const char *buffer
, size_t size
)
120 return json_lexer_feed(&parser
->lexer
, buffer
, size
);
123 int json_message_parser_flush(JSONMessageParser
*parser
)
125 return json_lexer_flush(&parser
->lexer
);
128 void json_message_parser_destroy(JSONMessageParser
*parser
)
130 json_lexer_destroy(&parser
->lexer
);
131 json_message_free_tokens(parser
);