qobject/qjson.c

   1 /*
   2  * QObject JSON integration
   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
  14 #include "qemu/osdep.h"
  15 #include "qapi/error.h"
  16 #include "qapi/qmp/json-lexer.h"
  17 #include "qapi/qmp/json-parser.h"
  18 #include "qapi/qmp/json-streamer.h"
  19 #include "qapi/qmp/qjson.h"
  20 #include "qapi/qmp/qbool.h"
  21 #include "qapi/qmp/qdict.h"
  22 #include "qapi/qmp/qlist.h"
  23 #include "qapi/qmp/qnum.h"
  24 #include "qapi/qmp/qstring.h"
  25 #include "qemu/unicode.h"
  26
  27 typedef struct JSONParsingState
  28 {
  29     JSONMessageParser parser;
  30     va_list *ap;
  31     QObject *result;
  32     Error *err;
  33 } JSONParsingState;
  34
  35 static void parse_json(JSONMessageParser *parser, GQueue *tokens)
  36 {
  37     JSONParsingState *s = container_of(parser, JSONParsingState, parser);
  38
  39     s->result = json_parser_parse_err(tokens, s->ap, &s->err);
  40 }
  41
  42 QObject *qobject_from_jsonv(const char *string, va_list *ap, Error **errp)
  43 {
  44     JSONParsingState state = {};
  45
  46     state.ap = ap;
  47
  48     json_message_parser_init(&state.parser, parse_json);
  49     json_message_parser_feed(&state.parser, string, strlen(string));
  50     json_message_parser_flush(&state.parser);
  51     json_message_parser_destroy(&state.parser);
  52
  53     error_propagate(errp, state.err);
  54     return state.result;
  55 }
  56
  57 QObject *qobject_from_json(const char *string, Error **errp)
  58 {
  59     return qobject_from_jsonv(string, NULL, errp);
  60 }
  61
  62 /*
  63  * IMPORTANT: This function aborts on error, thus it must not
  64  * be used with untrusted arguments.
  65  */
  66 QObject *qobject_from_jsonf(const char *string, ...)
  67 {
  68     QObject *obj;
  69     va_list ap;
  70
  71     va_start(ap, string);
  72     obj = qobject_from_jsonv(string, &ap, &error_abort);
  73     va_end(ap);
  74
  75     assert(obj != NULL);
  76     return obj;
  77 }
  78
  79 /*
  80  * Parse @string as JSON object with %-escapes interpolated.
  81  * Abort on error.  Do not use with untrusted @string.
  82  * Return the resulting QDict.  It is never null.
  83  */
  84 QDict *qdict_from_jsonf_nofail(const char *string, ...)
  85 {
  86     QDict *obj;
  87     va_list ap;
  88
  89     va_start(ap, string);
  90     obj = qobject_to(QDict, qobject_from_jsonv(string, &ap, &error_abort));
  91     va_end(ap);
  92
  93     assert(obj);
  94     return obj;
  95 }
  96
  97 typedef struct ToJsonIterState
  98 {
  99     int indent;
 100     int pretty;
 101     int count;
 102     QString *str;
 103 } ToJsonIterState;
 104
 105 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
 106
 107 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
 108 {
 109     ToJsonIterState *s = opaque;
 110     QString *qkey;
 111     int j;
 112
 113     if (s->count) {
 114         qstring_append(s->str, s->pretty ? "," : ", ");
 115     }
 116
 117     if (s->pretty) {
 118         qstring_append(s->str, "\n");
 119         for (j = 0 ; j < s->indent ; j++)
 120             qstring_append(s->str, "    ");
 121     }
 122
 123     qkey = qstring_from_str(key);
 124     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
 125     QDECREF(qkey);
 126
 127     qstring_append(s->str, ": ");
 128     to_json(obj, s->str, s->pretty, s->indent);
 129     s->count++;
 130 }
 131
 132 static void to_json_list_iter(QObject *obj, void *opaque)
 133 {
 134     ToJsonIterState *s = opaque;
 135     int j;
 136
 137     if (s->count) {
 138         qstring_append(s->str, s->pretty ? "," : ", ");
 139     }
 140
 141     if (s->pretty) {
 142         qstring_append(s->str, "\n");
 143         for (j = 0 ; j < s->indent ; j++)
 144             qstring_append(s->str, "    ");
 145     }
 146
 147     to_json(obj, s->str, s->pretty, s->indent);
 148     s->count++;
 149 }
 150
 151 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
 152 {
 153     switch (qobject_type(obj)) {
 154     case QTYPE_QNULL:
 155         qstring_append(str, "null");
 156         break;
 157     case QTYPE_QNUM: {
 158         QNum *val = qobject_to(QNum, obj);
 159         char *buffer = qnum_to_string(val);
 160         qstring_append(str, buffer);
 161         g_free(buffer);
 162         break;
 163     }
 164     case QTYPE_QSTRING: {
 165         QString *val = qobject_to(QString, obj);
 166         const char *ptr;
 167         int cp;
 168         char buf[16];
 169         char *end;
 170
 171         ptr = qstring_get_str(val);
 172         qstring_append(str, "\"");
 173
 174         for (; *ptr; ptr = end) {
 175             cp = mod_utf8_codepoint(ptr, 6, &end);
 176             switch (cp) {
 177             case '\"':
 178                 qstring_append(str, "\\\"");
 179                 break;
 180             case '\\':
 181                 qstring_append(str, "\\\\");
 182                 break;
 183             case '\b':
 184                 qstring_append(str, "\\b");
 185                 break;
 186             case '\f':
 187                 qstring_append(str, "\\f");
 188                 break;
 189             case '\n':
 190                 qstring_append(str, "\\n");
 191                 break;
 192             case '\r':
 193                 qstring_append(str, "\\r");
 194                 break;
 195             case '\t':
 196                 qstring_append(str, "\\t");
 197                 break;
 198             default:
 199                 if (cp < 0) {
 200                     cp = 0xFFFD; /* replacement character */
 201                 }
 202                 if (cp > 0xFFFF) {
 203                     /* beyond BMP; need a surrogate pair */
 204                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
 205                              0xD800 + ((cp - 0x10000) >> 10),
 206                              0xDC00 + ((cp - 0x10000) & 0x3FF));
 207                 } else if (cp < 0x20 || cp >= 0x7F) {
 208                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
 209                 } else {
 210                     buf[0] = cp;
 211                     buf[1] = 0;
 212                 }
 213                 qstring_append(str, buf);
 214             }
 215         };
 216
 217         qstring_append(str, "\"");
 218         break;
 219     }
 220     case QTYPE_QDICT: {
 221         ToJsonIterState s;
 222         QDict *val = qobject_to(QDict, obj);
 223
 224         s.count = 0;
 225         s.str = str;
 226         s.indent = indent + 1;
 227         s.pretty = pretty;
 228         qstring_append(str, "{");
 229         qdict_iter(val, to_json_dict_iter, &s);
 230         if (pretty) {
 231             int j;
 232             qstring_append(str, "\n");
 233             for (j = 0 ; j < indent ; j++)
 234                 qstring_append(str, "    ");
 235         }
 236         qstring_append(str, "}");
 237         break;
 238     }
 239     case QTYPE_QLIST: {
 240         ToJsonIterState s;
 241         QList *val = qobject_to(QList, obj);
 242
 243         s.count = 0;
 244         s.str = str;
 245         s.indent = indent + 1;
 246         s.pretty = pretty;
 247         qstring_append(str, "[");
 248         qlist_iter(val, (void *)to_json_list_iter, &s);
 249         if (pretty) {
 250             int j;
 251             qstring_append(str, "\n");
 252             for (j = 0 ; j < indent ; j++)
 253                 qstring_append(str, "    ");
 254         }
 255         qstring_append(str, "]");
 256         break;
 257     }
 258     case QTYPE_QBOOL: {
 259         QBool *val = qobject_to(QBool, obj);
 260
 261         if (qbool_get_bool(val)) {
 262             qstring_append(str, "true");
 263         } else {
 264             qstring_append(str, "false");
 265         }
 266         break;
 267     }
 268     default:
 269         abort();
 270     }
 271 }
 272
 273 QString *qobject_to_json(const QObject *obj)
 274 {
 275     QString *str = qstring_new();
 276
 277     to_json(obj, str, 0, 0);
 278
 279     return str;
 280 }
 281
 282 QString *qobject_to_json_pretty(const QObject *obj)
 283 {
 284     QString *str = qstring_new();
 285
 286     to_json(obj, str, 1, 0);
 287
 288     return str;
 289 }