KVM: Update headers (except HIOR mess)
[qemu.git] / json-streamer.c
1 /*
2 * JSON streaming support
3 *
4 * Copyright IBM, Corp. 2009
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
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.
11 *
12 */
13
14 #include "qlist.h"
15 #include "qint.h"
16 #include "qdict.h"
17 #include "qemu-common.h"
18 #include "json-lexer.h"
19 #include "json-streamer.h"
20
21 #define MAX_TOKEN_SIZE (64ULL << 20)
22 #define MAX_NESTING (1ULL << 10)
23
24 static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y)
25 {
26 JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
27 QDict *dict;
28
29 if (type == JSON_OPERATOR) {
30 switch (qstring_get_str(token)[0]) {
31 case '{':
32 parser->brace_count++;
33 break;
34 case '}':
35 parser->brace_count--;
36 break;
37 case '[':
38 parser->bracket_count++;
39 break;
40 case ']':
41 parser->bracket_count--;
42 break;
43 default:
44 break;
45 }
46 }
47
48 dict = qdict_new();
49 qdict_put(dict, "type", qint_from_int(type));
50 QINCREF(token);
51 qdict_put(dict, "token", token);
52 qdict_put(dict, "x", qint_from_int(x));
53 qdict_put(dict, "y", qint_from_int(y));
54
55 parser->token_size += token->length;
56
57 qlist_append(parser->tokens, dict);
58
59 if (type == JSON_ERROR) {
60 goto out_emit_bad;
61 } else if (parser->brace_count < 0 ||
62 parser->bracket_count < 0 ||
63 (parser->brace_count == 0 &&
64 parser->bracket_count == 0)) {
65 goto out_emit;
66 } else if (parser->token_size > MAX_TOKEN_SIZE ||
67 parser->bracket_count > MAX_NESTING ||
68 parser->brace_count > MAX_NESTING) {
69 /* Security consideration, we limit total memory allocated per object
70 * and the maximum recursion depth that a message can force.
71 */
72 goto out_emit;
73 }
74
75 return;
76
77 out_emit_bad:
78 /* clear out token list and tell the parser to emit and error
79 * indication by passing it a NULL list
80 */
81 QDECREF(parser->tokens);
82 parser->tokens = NULL;
83 out_emit:
84 /* send current list of tokens to parser and reset tokenizer */
85 parser->brace_count = 0;
86 parser->bracket_count = 0;
87 parser->emit(parser, parser->tokens);
88 if (parser->tokens) {
89 QDECREF(parser->tokens);
90 }
91 parser->tokens = qlist_new();
92 parser->token_size = 0;
93 }
94
95 void json_message_parser_init(JSONMessageParser *parser,
96 void (*func)(JSONMessageParser *, QList *))
97 {
98 parser->emit = func;
99 parser->brace_count = 0;
100 parser->bracket_count = 0;
101 parser->tokens = qlist_new();
102 parser->token_size = 0;
103
104 json_lexer_init(&parser->lexer, json_message_process_token);
105 }
106
107 int json_message_parser_feed(JSONMessageParser *parser,
108 const char *buffer, size_t size)
109 {
110 return json_lexer_feed(&parser->lexer, buffer, size);
111 }
112
113 int json_message_parser_flush(JSONMessageParser *parser)
114 {
115 return json_lexer_flush(&parser->lexer);
116 }
117
118 void json_message_parser_destroy(JSONMessageParser *parser)
119 {
120 json_lexer_destroy(&parser->lexer);
121 QDECREF(parser->tokens);
122 }