Initial import of qemu-2.4.1HEADmaster

1 files changed, 373 insertions, 0 deletions

diff --git a/qobject/json-lexer.c b/qobject/json-lexer.c
new file mode 100644
index 00000000..b19623e2
--- /dev/null
+++ b/qobject/json-lexer.c
@@ -0,0 +1,373 @@
+/*
+ * 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);
+}