/* * 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); }