--- /dev/null
+/*
+ * JSON lexer
+ *
+ * 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/qstring.h"
+#include "qapi/qmp/qlist.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qint.h"
+#include "qemu-common.h"
+#include "qapi/qmp/json-lexer.h"
+
+#define MAX_TOKEN_SIZE (64ULL << 20)
+
+/*
+ * \"([^\\\"]|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*\"
+ * '([^\\']|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*'
+ * 0|([1-9][0-9]*(.[0-9]+)?([eE]([-+])?[0-9]+))
+ * [{}\[\],:]
+ * [a-z]+
+ *
+ */
+
+enum json_lexer_state {
+ IN_ERROR = 0,
+ IN_DQ_UCODE3,
+ IN_DQ_UCODE2,
+ IN_DQ_UCODE1,
+ IN_DQ_UCODE0,
+ IN_DQ_STRING_ESCAPE,
+ IN_DQ_STRING,
+ IN_SQ_UCODE3,
+ IN_SQ_UCODE2,
+ IN_SQ_UCODE1,
+ IN_SQ_UCODE0,
+ IN_SQ_STRING_ESCAPE,
+ IN_SQ_STRING,
+ IN_ZERO,
+ IN_DIGITS,
+ IN_DIGIT,
+ IN_EXP_E,
+ IN_MANTISSA,
+ IN_MANTISSA_DIGITS,
+ IN_NONZERO_NUMBER,
+ IN_NEG_NONZERO_NUMBER,
+ IN_KEYWORD,
+ IN_ESCAPE,
+ IN_ESCAPE_L,
+ IN_ESCAPE_LL,
+ IN_ESCAPE_I,
+ IN_ESCAPE_I6,
+ IN_ESCAPE_I64,
+ IN_WHITESPACE,
+ IN_START,
+};
+
+#define TERMINAL(state) [0 ... 0x7F] = (state)
+
+/* Return whether TERMINAL is a terminal state and the transition to it
+ from OLD_STATE required lookahead. This happens whenever the table
+ below uses the TERMINAL macro. */
+#define TERMINAL_NEEDED_LOOKAHEAD(old_state, terminal) \
+ (json_lexer[(old_state)][0] == (terminal))
+
+static const uint8_t json_lexer[][256] = {
+ /* double quote string */
+ [IN_DQ_UCODE3] = {
+ ['0' ... '9'] = IN_DQ_STRING,
+ ['a' ... 'f'] = IN_DQ_STRING,
+ ['A' ... 'F'] = IN_DQ_STRING,
+ },
+ [IN_DQ_UCODE2] = {
+ ['0' ... '9'] = IN_DQ_UCODE3,
+ ['a' ... 'f'] = IN_DQ_UCODE3,
+ ['A' ... 'F'] = IN_DQ_UCODE3,
+ },
+ [IN_DQ_UCODE1] = {
+ ['0' ... '9'] = IN_DQ_UCODE2,
+ ['a' ... 'f'] = IN_DQ_UCODE2,
+ ['A' ... 'F'] = IN_DQ_UCODE2,
+ },
+ [IN_DQ_UCODE0] = {
+ ['0' ... '9'] = IN_DQ_UCODE1,
+ ['a' ... 'f'] = IN_DQ_UCODE1,
+ ['A' ... 'F'] = IN_DQ_UCODE1,
+ },
+ [IN_DQ_STRING_ESCAPE] = {
+ ['b'] = IN_DQ_STRING,
+ ['f'] = IN_DQ_STRING,
+ ['n'] = IN_DQ_STRING,
+ ['r'] = IN_DQ_STRING,
+ ['t'] = IN_DQ_STRING,
+ ['/'] = IN_DQ_STRING,
+ ['\\'] = IN_DQ_STRING,
+ ['\''] = IN_DQ_STRING,
+ ['\"'] = IN_DQ_STRING,
+ ['u'] = IN_DQ_UCODE0,
+ },
+ [IN_DQ_STRING] = {
+ [1 ... 0xBF] = IN_DQ_STRING,
+ [0xC2 ... 0xF4] = IN_DQ_STRING,
+ ['\\'] = IN_DQ_STRING_ESCAPE,
+ ['"'] = JSON_STRING,
+ },
+
+ /* single quote string */
+ [IN_SQ_UCODE3] = {
+ ['0' ... '9'] = IN_SQ_STRING,
+ ['a' ... 'f'] = IN_SQ_STRING,
+ ['A' ... 'F'] = IN_SQ_STRING,
+ },
+ [IN_SQ_UCODE2] = {
+ ['0' ... '9'] = IN_SQ_UCODE3,
+ ['a' ... 'f'] = IN_SQ_UCODE3,
+ ['A' ... 'F'] = IN_SQ_UCODE3,
+ },
+ [IN_SQ_UCODE1] = {
+ ['0' ... '9'] = IN_SQ_UCODE2,
+ ['a' ... 'f'] = IN_SQ_UCODE2,
+ ['A' ... 'F'] = IN_SQ_UCODE2,
+ },
+ [IN_SQ_UCODE0] = {
+ ['0' ... '9'] = IN_SQ_UCODE1,
+ ['a' ... 'f'] = IN_SQ_UCODE1,
+ ['A' ... 'F'] = IN_SQ_UCODE1,
+ },
+ [IN_SQ_STRING_ESCAPE] = {
+ ['b'] = IN_SQ_STRING,
+ ['f'] = IN_SQ_STRING,
+ ['n'] = IN_SQ_STRING,
+ ['r'] = IN_SQ_STRING,
+ ['t'] = IN_SQ_STRING,
+ ['/'] = IN_SQ_STRING,
+ ['\\'] = IN_SQ_STRING,
+ ['\''] = IN_SQ_STRING,
+ ['\"'] = IN_SQ_STRING,
+ ['u'] = IN_SQ_UCODE0,
+ },
+ [IN_SQ_STRING] = {
+ [1 ... 0xBF] = IN_SQ_STRING,
+ [0xC2 ... 0xF4] = IN_SQ_STRING,
+ ['\\'] = IN_SQ_STRING_ESCAPE,
+ ['\''] = JSON_STRING,
+ },
+
+ /* Zero */
+ [IN_ZERO] = {
+ TERMINAL(JSON_INTEGER),
+ ['0' ... '9'] = IN_ERROR,
+ ['.'] = IN_MANTISSA,
+ },
+
+ /* Float */
+ [IN_DIGITS] = {
+ TERMINAL(JSON_FLOAT),
+ ['0' ... '9'] = IN_DIGITS,
+ },
+
+ [IN_DIGIT] = {
+ ['0' ... '9'] = IN_DIGITS,
+ },
+
+ [IN_EXP_E] = {
+ ['-'] = IN_DIGIT,
+ ['+'] = IN_DIGIT,
+ ['0' ... '9'] = IN_DIGITS,
+ },
+
+ [IN_MANTISSA_DIGITS] = {
+ TERMINAL(JSON_FLOAT),
+ ['0' ... '9'] = IN_MANTISSA_DIGITS,
+ ['e'] = IN_EXP_E,
+ ['E'] = IN_EXP_E,
+ },
+
+ [IN_MANTISSA] = {
+ ['0' ... '9'] = IN_MANTISSA_DIGITS,
+ },
+
+ /* Number */
+ [IN_NONZERO_NUMBER] = {
+ TERMINAL(JSON_INTEGER),
+ ['0' ... '9'] = IN_NONZERO_NUMBER,
+ ['e'] = IN_EXP_E,
+ ['E'] = IN_EXP_E,
+ ['.'] = IN_MANTISSA,
+ },
+
+ [IN_NEG_NONZERO_NUMBER] = {
+ ['0'] = IN_ZERO,
+ ['1' ... '9'] = IN_NONZERO_NUMBER,
+ },
+
+ /* keywords */
+ [IN_KEYWORD] = {
+ TERMINAL(JSON_KEYWORD),
+ ['a' ... 'z'] = IN_KEYWORD,
+ },
+
+ /* whitespace */
+ [IN_WHITESPACE] = {
+ TERMINAL(JSON_SKIP),
+ [' '] = IN_WHITESPACE,
+ ['\t'] = IN_WHITESPACE,
+ ['\r'] = IN_WHITESPACE,
+ ['\n'] = IN_WHITESPACE,
+ },
+
+ /* escape */
+ [IN_ESCAPE_LL] = {
+ ['d'] = JSON_ESCAPE,
+ },
+
+ [IN_ESCAPE_L] = {
+ ['d'] = JSON_ESCAPE,
+ ['l'] = IN_ESCAPE_LL,
+ },
+
+ [IN_ESCAPE_I64] = {
+ ['d'] = JSON_ESCAPE,
+ },
+
+ [IN_ESCAPE_I6] = {
+ ['4'] = IN_ESCAPE_I64,
+ },
+
+ [IN_ESCAPE_I] = {
+ ['6'] = IN_ESCAPE_I6,
+ },
+
+ [IN_ESCAPE] = {
+ ['d'] = JSON_ESCAPE,
+ ['i'] = JSON_ESCAPE,
+ ['p'] = JSON_ESCAPE,
+ ['s'] = JSON_ESCAPE,
+ ['f'] = JSON_ESCAPE,
+ ['l'] = IN_ESCAPE_L,
+ ['I'] = IN_ESCAPE_I,
+ },
+
+ /* top level rule */
+ [IN_START] = {
+ ['"'] = IN_DQ_STRING,
+ ['\''] = IN_SQ_STRING,
+ ['0'] = IN_ZERO,
+ ['1' ... '9'] = IN_NONZERO_NUMBER,
+ ['-'] = IN_NEG_NONZERO_NUMBER,
+ ['{'] = JSON_OPERATOR,
+ ['}'] = JSON_OPERATOR,
+ ['['] = JSON_OPERATOR,
+ [']'] = JSON_OPERATOR,
+ [','] = JSON_OPERATOR,
+ [':'] = JSON_OPERATOR,
+ ['a' ... 'z'] = IN_KEYWORD,
+ ['%'] = IN_ESCAPE,
+ [' '] = IN_WHITESPACE,
+ ['\t'] = IN_WHITESPACE,
+ ['\r'] = IN_WHITESPACE,
+ ['\n'] = IN_WHITESPACE,
+ },
+};
+
+void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func)
+{
+ lexer->emit = func;
+ lexer->state = IN_START;
+ lexer->token = qstring_new();
+ lexer->x = lexer->y = 0;
+}
+
+static int json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
+{
+ int char_consumed, new_state;
+
+ lexer->x++;
+ if (ch == '\n') {
+ lexer->x = 0;
+ lexer->y++;
+ }
+
+ do {
+ new_state = json_lexer[lexer->state][(uint8_t)ch];
+ char_consumed = !TERMINAL_NEEDED_LOOKAHEAD(lexer->state, new_state);
+ if (char_consumed) {
+ qstring_append_chr(lexer->token, ch);
+ }
+
+ switch (new_state) {
+ case JSON_OPERATOR:
+ case JSON_ESCAPE:
+ case JSON_INTEGER:
+ case JSON_FLOAT:
+ case JSON_KEYWORD:
+ case JSON_STRING:
+ lexer->emit(lexer, lexer->token, new_state, lexer->x, lexer->y);
+ /* fall through */
+ case JSON_SKIP:
+ QDECREF(lexer->token);
+ lexer->token = qstring_new();
+ new_state = IN_START;
+ break;
+ case IN_ERROR:
+ /* XXX: To avoid having previous bad input leaving the parser in an
+ * unresponsive state where we consume unpredictable amounts of
+ * subsequent "good" input, percolate this error state up to the
+ * tokenizer/parser by forcing a NULL object to be emitted, then
+ * reset state.
+ *
+ * Also note that this handling is required for reliable channel
+ * negotiation between QMP and the guest agent, since chr(0xFF)
+ * is placed at the beginning of certain events to ensure proper
+ * delivery when the channel is in an unknown state. chr(0xFF) is
+ * never a valid ASCII/UTF-8 sequence, so this should reliably
+ * induce an error/flush state.
+ */
+ lexer->emit(lexer, lexer->token, JSON_ERROR, lexer->x, lexer->y);
+ QDECREF(lexer->token);
+ lexer->token = qstring_new();
+ new_state = IN_START;
+ lexer->state = new_state;
+ return 0;
+ default:
+ break;
+ }
+ lexer->state = new_state;
+ } while (!char_consumed && !flush);
+
+ /* Do not let a single token grow to an arbitrarily large size,
+ * this is a security consideration.
+ */
+ if (lexer->token->length > MAX_TOKEN_SIZE) {
+ lexer->emit(lexer, lexer->token, lexer->state, lexer->x, lexer->y);
+ QDECREF(lexer->token);
+ lexer->token = qstring_new();
+ lexer->state = IN_START;
+ }
+
+ return 0;
+}
+
+int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size)
+{
+ size_t i;
+
+ for (i = 0; i < size; i++) {
+ int err;
+
+ err = json_lexer_feed_char(lexer, buffer[i], false);
+ if (err < 0) {
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+int json_lexer_flush(JSONLexer *lexer)
+{
+ return lexer->state == IN_START ? 0 : json_lexer_feed_char(lexer, 0, true);
+}
+
+void json_lexer_destroy(JSONLexer *lexer)
+{
+ QDECREF(lexer->token);
+}
Code Review / kvmfornfv.git / blobdiff