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-parser.h"
18 #include "qapi/qmp/json-streamer.h"
20 #define MAX_TOKEN_SIZE (64ULL << 20)
21 #define MAX_TOKEN_COUNT (2ULL << 20)
22 #define MAX_NESTING (1ULL << 10)
24 static void json_message_free_token(void *token
, void *opaque
)
29 static void json_message_free_tokens(JSONMessageParser
*parser
)
32 g_queue_foreach(parser
->tokens
, json_message_free_token
, NULL
);
33 g_queue_free(parser
->tokens
);
34 parser
->tokens
= NULL
;
38 void json_message_process_token(JSONLexer
*lexer
, GString
*input
,
39 JSONTokenType type
, int x
, int y
)
41 JSONMessageParser
*parser
= container_of(lexer
, JSONMessageParser
, lexer
);
48 parser
->brace_count
++;
51 parser
->brace_count
--;
54 parser
->bracket_count
++;
57 parser
->bracket_count
--;
63 token
= g_malloc(sizeof(JSONToken
) + input
->len
+ 1);
65 memcpy(token
->str
, input
->str
, input
->len
);
66 token
->str
[input
->len
] = 0;
70 parser
->token_size
+= input
->len
;
72 g_queue_push_tail(parser
->tokens
, token
);
74 if (type
== JSON_ERROR
) {
78 if (parser
->brace_count
< 0 ||
79 parser
->bracket_count
< 0 ||
80 (parser
->brace_count
== 0 &&
81 parser
->bracket_count
== 0)) {
82 json
= json_parser_parse(parser
->tokens
, parser
->ap
, &err
);
83 parser
->tokens
= NULL
;
87 if (parser
->token_size
> MAX_TOKEN_SIZE
||
88 g_queue_get_length(parser
->tokens
) > MAX_TOKEN_COUNT
||
89 parser
->bracket_count
+ parser
->brace_count
> MAX_NESTING
) {
90 /* Security consideration, we limit total memory allocated per object
91 * and the maximum recursion depth that a message can force.
99 parser
->brace_count
= 0;
100 parser
->bracket_count
= 0;
101 json_message_free_tokens(parser
);
102 parser
->tokens
= g_queue_new();
103 parser
->token_size
= 0;
104 parser
->emit(parser
->opaque
, json
, err
);
107 void json_message_parser_init(JSONMessageParser
*parser
,
108 void (*emit
)(void *opaque
, QObject
*json
,
110 void *opaque
, va_list *ap
)
113 parser
->opaque
= opaque
;
115 parser
->brace_count
= 0;
116 parser
->bracket_count
= 0;
117 parser
->tokens
= g_queue_new();
118 parser
->token_size
= 0;
120 json_lexer_init(&parser
->lexer
);
123 void json_message_parser_feed(JSONMessageParser
*parser
,
124 const char *buffer
, size_t size
)
126 json_lexer_feed(&parser
->lexer
, buffer
, size
);
129 void json_message_parser_flush(JSONMessageParser
*parser
)
131 json_lexer_flush(&parser
->lexer
);
134 void json_message_parser_destroy(JSONMessageParser
*parser
)
136 json_lexer_destroy(&parser
->lexer
);
137 json_message_free_tokens(parser
);