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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" |
84a56f38 | 16 | #include "qapi/error.h" |
7b1b5d19 | 17 | #include "qapi/qmp/json-lexer.h" |
62815d85 | 18 | #include "qapi/qmp/json-parser.h" |
7b1b5d19 | 19 | #include "qapi/qmp/json-streamer.h" |
d7ff3acb | 20 | |
29c75ddd | 21 | #define MAX_TOKEN_SIZE (64ULL << 20) |
df649835 | 22 | #define MAX_TOKEN_COUNT (2ULL << 20) |
29c75ddd AL |
23 | #define MAX_NESTING (1ULL << 10) |
24 | ||
ba4dba54 EB |
25 | static void json_message_free_token(void *token, void *opaque) |
26 | { | |
27 | g_free(token); | |
28 | } | |
29 | ||
95385fe9 PB |
30 | static void json_message_free_tokens(JSONMessageParser *parser) |
31 | { | |
32 | if (parser->tokens) { | |
ba4dba54 | 33 | g_queue_foreach(parser->tokens, json_message_free_token, NULL); |
95385fe9 PB |
34 | g_queue_free(parser->tokens); |
35 | parser->tokens = NULL; | |
36 | } | |
37 | } | |
38 | ||
037f2440 MA |
39 | void json_message_process_token(JSONLexer *lexer, GString *input, |
40 | JSONTokenType type, int x, int y) | |
d7ff3acb AL |
41 | { |
42 | JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer); | |
ff281a27 | 43 | QObject *json = NULL; |
62815d85 | 44 | Error *err = NULL; |
9bada897 | 45 | JSONToken *token; |
d7ff3acb | 46 | |
c5461660 MA |
47 | switch (type) { |
48 | case JSON_LCURLY: | |
49 | parser->brace_count++; | |
50 | break; | |
51 | case JSON_RCURLY: | |
52 | parser->brace_count--; | |
53 | break; | |
54 | case JSON_LSQUARE: | |
55 | parser->bracket_count++; | |
56 | break; | |
57 | case JSON_RSQUARE: | |
58 | parser->bracket_count--; | |
59 | break; | |
269e57ae | 60 | case JSON_ERROR: |
84a56f38 | 61 | error_setg(&err, "JSON parse error, stray '%s'", input->str); |
269e57ae | 62 | goto out_emit; |
f9277915 MA |
63 | case JSON_END_OF_INPUT: |
64 | if (g_queue_is_empty(parser->tokens)) { | |
65 | return; | |
66 | } | |
67 | json = json_parser_parse(parser->tokens, parser->ap, &err); | |
68 | parser->tokens = NULL; | |
69 | goto out_emit; | |
c5461660 MA |
70 | default: |
71 | break; | |
d7ff3acb AL |
72 | } |
73 | ||
9bada897 PB |
74 | token = g_malloc(sizeof(JSONToken) + input->len + 1); |
75 | token->type = type; | |
76 | memcpy(token->str, input->str, input->len); | |
77 | token->str[input->len] = 0; | |
78 | token->x = x; | |
79 | token->y = y; | |
d7ff3acb | 80 | |
d2ca7c0b | 81 | parser->token_size += input->len; |
29c75ddd | 82 | |
9bada897 | 83 | g_queue_push_tail(parser->tokens, token); |
d7ff3acb | 84 | |
ff281a27 | 85 | if (parser->brace_count < 0 || |
55f8301f AL |
86 | parser->bracket_count < 0 || |
87 | (parser->brace_count == 0 && | |
88 | parser->bracket_count == 0)) { | |
ff281a27 MA |
89 | json = json_parser_parse(parser->tokens, parser->ap, &err); |
90 | parser->tokens = NULL; | |
5e2dafeb | 91 | goto out_emit; |
ff281a27 MA |
92 | } |
93 | ||
84a56f38 MA |
94 | /* |
95 | * Security consideration, we limit total memory allocated per object | |
96 | * and the maximum recursion depth that a message can force. | |
97 | */ | |
98 | if (parser->token_size > MAX_TOKEN_SIZE) { | |
99 | error_setg(&err, "JSON token size limit exceeded"); | |
100 | goto out_emit; | |
101 | } | |
102 | if (g_queue_get_length(parser->tokens) > MAX_TOKEN_COUNT) { | |
103 | error_setg(&err, "JSON token count limit exceeded"); | |
104 | goto out_emit; | |
105 | } | |
106 | if (parser->bracket_count + parser->brace_count > MAX_NESTING) { | |
107 | error_setg(&err, "JSON nesting depth limit exceeded"); | |
ff281a27 | 108 | goto out_emit; |
5e2dafeb MR |
109 | } |
110 | ||
111 | return; | |
112 | ||
5e2dafeb | 113 | out_emit: |
5e2dafeb MR |
114 | parser->brace_count = 0; |
115 | parser->bracket_count = 0; | |
ff281a27 | 116 | json_message_free_tokens(parser); |
95385fe9 | 117 | parser->tokens = g_queue_new(); |
5e2dafeb | 118 | parser->token_size = 0; |
62815d85 | 119 | parser->emit(parser->opaque, json, err); |
d7ff3acb AL |
120 | } |
121 | ||
122 | void json_message_parser_init(JSONMessageParser *parser, | |
62815d85 MA |
123 | void (*emit)(void *opaque, QObject *json, |
124 | Error *err), | |
125 | void *opaque, va_list *ap) | |
d7ff3acb | 126 | { |
62815d85 MA |
127 | parser->emit = emit; |
128 | parser->opaque = opaque; | |
129 | parser->ap = ap; | |
d7ff3acb AL |
130 | parser->brace_count = 0; |
131 | parser->bracket_count = 0; | |
95385fe9 | 132 | parser->tokens = g_queue_new(); |
29c75ddd | 133 | parser->token_size = 0; |
d7ff3acb | 134 | |
2cbd15aa | 135 | json_lexer_init(&parser->lexer, !!ap); |
d7ff3acb AL |
136 | } |
137 | ||
7c1e1d54 | 138 | void json_message_parser_feed(JSONMessageParser *parser, |
d7ff3acb AL |
139 | const char *buffer, size_t size) |
140 | { | |
7c1e1d54 | 141 | json_lexer_feed(&parser->lexer, buffer, size); |
d7ff3acb AL |
142 | } |
143 | ||
7c1e1d54 | 144 | void json_message_parser_flush(JSONMessageParser *parser) |
d7ff3acb | 145 | { |
7c1e1d54 | 146 | json_lexer_flush(&parser->lexer); |
f9277915 | 147 | assert(g_queue_is_empty(parser->tokens)); |
d7ff3acb AL |
148 | } |
149 | ||
150 | void json_message_parser_destroy(JSONMessageParser *parser) | |
151 | { | |
152 | json_lexer_destroy(&parser->lexer); | |
95385fe9 | 153 | json_message_free_tokens(parser); |
d7ff3acb | 154 | } |