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-rw-r--r--qobject/json-streamer.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
new file mode 100644
index 0000000000..1b2f9b1d10
--- /dev/null
+++ b/qobject/json-streamer.c
@@ -0,0 +1,122 @@
+/*
+ * JSON streaming support
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qapi/qmp/qlist.h"
+#include "qapi/qmp/qint.h"
+#include "qapi/qmp/qdict.h"
+#include "qemu-common.h"
+#include "qapi/qmp/json-lexer.h"
+#include "qapi/qmp/json-streamer.h"
+
+#define MAX_TOKEN_SIZE (64ULL << 20)
+#define MAX_NESTING (1ULL << 10)
+
+static void json_message_process_token(JSONLexer *lexer, QString *token, JSONTokenType type, int x, int y)
+{
+ JSONMessageParser *parser = container_of(lexer, JSONMessageParser, lexer);
+ QDict *dict;
+
+ if (type == JSON_OPERATOR) {
+ switch (qstring_get_str(token)[0]) {
+ case '{':
+ parser->brace_count++;
+ break;
+ case '}':
+ parser->brace_count--;
+ break;
+ case '[':
+ parser->bracket_count++;
+ break;
+ case ']':
+ parser->bracket_count--;
+ break;
+ default:
+ break;
+ }
+ }
+
+ dict = qdict_new();
+ qdict_put(dict, "type", qint_from_int(type));
+ QINCREF(token);
+ qdict_put(dict, "token", token);
+ qdict_put(dict, "x", qint_from_int(x));
+ qdict_put(dict, "y", qint_from_int(y));
+
+ parser->token_size += token->length;
+
+ qlist_append(parser->tokens, dict);
+
+ if (type == JSON_ERROR) {
+ goto out_emit_bad;
+ } else if (parser->brace_count < 0 ||
+ parser->bracket_count < 0 ||
+ (parser->brace_count == 0 &&
+ parser->bracket_count == 0)) {
+ goto out_emit;
+ } else if (parser->token_size > MAX_TOKEN_SIZE ||
+ parser->bracket_count > MAX_NESTING ||
+ parser->brace_count > MAX_NESTING) {
+ /* Security consideration, we limit total memory allocated per object
+ * and the maximum recursion depth that a message can force.
+ */
+ goto out_emit;
+ }
+
+ return;
+
+out_emit_bad:
+ /* clear out token list and tell the parser to emit and error
+ * indication by passing it a NULL list
+ */
+ QDECREF(parser->tokens);
+ parser->tokens = NULL;
+out_emit:
+ /* send current list of tokens to parser and reset tokenizer */
+ parser->brace_count = 0;
+ parser->bracket_count = 0;
+ parser->emit(parser, parser->tokens);
+ if (parser->tokens) {
+ QDECREF(parser->tokens);
+ }
+ parser->tokens = qlist_new();
+ parser->token_size = 0;
+}
+
+void json_message_parser_init(JSONMessageParser *parser,
+ void (*func)(JSONMessageParser *, QList *))
+{
+ parser->emit = func;
+ parser->brace_count = 0;
+ parser->bracket_count = 0;
+ parser->tokens = qlist_new();
+ parser->token_size = 0;
+
+ json_lexer_init(&parser->lexer, json_message_process_token);
+}
+
+int json_message_parser_feed(JSONMessageParser *parser,
+ const char *buffer, size_t size)
+{
+ return json_lexer_feed(&parser->lexer, buffer, size);
+}
+
+int json_message_parser_flush(JSONMessageParser *parser)
+{
+ return json_lexer_flush(&parser->lexer);
+}
+
+void json_message_parser_destroy(JSONMessageParser *parser)
+{
+ json_lexer_destroy(&parser->lexer);
+ QDECREF(parser->tokens);
+}