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Commit | Line | Data |
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d7ff3acb AL |
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 | ||
f2ad72b3 | 14 | #include "qemu/osdep.h" |
d7ff3acb | 15 | #include "qemu-common.h" |
7b1b5d19 | 16 | #include "qapi/qmp/json-lexer.h" |
62815d85 | 17 | #include "qapi/qmp/json-parser.h" |
7b1b5d19 | 18 | #include "qapi/qmp/json-streamer.h" |
d7ff3acb | 19 | |
29c75ddd | 20 | #define MAX_TOKEN_SIZE (64ULL << 20) |
df649835 | 21 | #define MAX_TOKEN_COUNT (2ULL << 20) |
29c75ddd AL |
22 | #define MAX_NESTING (1ULL << 10) |
23 | ||
ba4dba54 EB |
24 | static void json_message_free_token(void *token, void *opaque) |
25 | { | |
26 | g_free(token); | |
27 | } | |
28 | ||
95385fe9 PB |
29 | static void json_message_free_tokens(JSONMessageParser *parser) |
30 | { | |
31 | if (parser->tokens) { | |
ba4dba54 | 32 | g_queue_foreach(parser->tokens, json_message_free_token, NULL); |
95385fe9 PB |
33 | g_queue_free(parser->tokens); |
34 | parser->tokens = NULL; | |
35 | } | |
36 | } | |
37 | ||
037f2440 MA |
38 | void json_message_process_token(JSONLexer *lexer, GString *input, |
39 | JSONTokenType type, int x, int y) | |
d7ff3acb AL |
40 | { |
41 | JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer); | |
ff281a27 | 42 | QObject *json = NULL; |
62815d85 | 43 | Error *err = NULL; |
9bada897 | 44 | JSONToken *token; |
d7ff3acb | 45 | |
c5461660 MA |
46 | switch (type) { |
47 | case JSON_LCURLY: | |
48 | parser->brace_count++; | |
49 | break; | |
50 | case JSON_RCURLY: | |
51 | parser->brace_count--; | |
52 | break; | |
53 | case JSON_LSQUARE: | |
54 | parser->bracket_count++; | |
55 | break; | |
56 | case JSON_RSQUARE: | |
57 | parser->bracket_count--; | |
58 | break; | |
269e57ae MA |
59 | case JSON_ERROR: |
60 | goto out_emit; | |
c5461660 MA |
61 | default: |
62 | break; | |
d7ff3acb AL |
63 | } |
64 | ||
9bada897 PB |
65 | token = g_malloc(sizeof(JSONToken) + input->len + 1); |
66 | token->type = type; | |
67 | memcpy(token->str, input->str, input->len); | |
68 | token->str[input->len] = 0; | |
69 | token->x = x; | |
70 | token->y = y; | |
d7ff3acb | 71 | |
d2ca7c0b | 72 | parser->token_size += input->len; |
29c75ddd | 73 | |
9bada897 | 74 | g_queue_push_tail(parser->tokens, token); |
d7ff3acb | 75 | |
ff281a27 | 76 | if (parser->brace_count < 0 || |
55f8301f AL |
77 | parser->bracket_count < 0 || |
78 | (parser->brace_count == 0 && | |
79 | parser->bracket_count == 0)) { | |
ff281a27 MA |
80 | json = json_parser_parse(parser->tokens, parser->ap, &err); |
81 | parser->tokens = NULL; | |
5e2dafeb | 82 | goto out_emit; |
ff281a27 MA |
83 | } |
84 | ||
85 | if (parser->token_size > MAX_TOKEN_SIZE || | |
df649835 | 86 | g_queue_get_length(parser->tokens) > MAX_TOKEN_COUNT || |
4f2d31fb | 87 | parser->bracket_count + parser->brace_count > MAX_NESTING) { |
29c75ddd AL |
88 | /* Security consideration, we limit total memory allocated per object |
89 | * and the maximum recursion depth that a message can force. | |
90 | */ | |
ff281a27 | 91 | goto out_emit; |
5e2dafeb MR |
92 | } |
93 | ||
94 | return; | |
95 | ||
5e2dafeb | 96 | out_emit: |
5e2dafeb MR |
97 | parser->brace_count = 0; |
98 | parser->bracket_count = 0; | |
ff281a27 | 99 | json_message_free_tokens(parser); |
95385fe9 | 100 | parser->tokens = g_queue_new(); |
5e2dafeb | 101 | parser->token_size = 0; |
62815d85 | 102 | parser->emit(parser->opaque, json, err); |
d7ff3acb AL |
103 | } |
104 | ||
105 | void json_message_parser_init(JSONMessageParser *parser, | |
62815d85 MA |
106 | void (*emit)(void *opaque, QObject *json, |
107 | Error *err), | |
108 | void *opaque, va_list *ap) | |
d7ff3acb | 109 | { |
62815d85 MA |
110 | parser->emit = emit; |
111 | parser->opaque = opaque; | |
112 | parser->ap = ap; | |
d7ff3acb AL |
113 | parser->brace_count = 0; |
114 | parser->bracket_count = 0; | |
95385fe9 | 115 | parser->tokens = g_queue_new(); |
29c75ddd | 116 | parser->token_size = 0; |
d7ff3acb | 117 | |
2cbd15aa | 118 | json_lexer_init(&parser->lexer, !!ap); |
d7ff3acb AL |
119 | } |
120 | ||
7c1e1d54 | 121 | void json_message_parser_feed(JSONMessageParser *parser, |
d7ff3acb AL |
122 | const char *buffer, size_t size) |
123 | { | |
7c1e1d54 | 124 | json_lexer_feed(&parser->lexer, buffer, size); |
d7ff3acb AL |
125 | } |
126 | ||
7c1e1d54 | 127 | void json_message_parser_flush(JSONMessageParser *parser) |
d7ff3acb | 128 | { |
7c1e1d54 | 129 | json_lexer_flush(&parser->lexer); |
d7ff3acb AL |
130 | } |
131 | ||
132 | void json_message_parser_destroy(JSONMessageParser *parser) | |
133 | { | |
134 | json_lexer_destroy(&parser->lexer); | |
95385fe9 | 135 | json_message_free_tokens(parser); |
d7ff3acb | 136 | } |