qerror.c

   1 /*
   2  * QError Module
   3  *
   4  * Copyright (C) 2009 Red Hat Inc.
   5  *
   6  * Authors:
   7  *  Luiz Capitulino <lcapitulino@redhat.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 #include "monitor.h"
  14 #include "qjson.h"
  15 #include "qerror.h"
  16 #include "qemu-common.h"
  17
  18 static void qerror_destroy_obj(QObject *obj);
  19
  20 static const QType qerror_type = {
  21     .code = QTYPE_QERROR,
  22     .destroy = qerror_destroy_obj,
  23 };
  24
  25 /**
  26  * The 'desc' parameter is a printf-like string, the format of the format
  27  * string is:
  28  *
  29  * %(KEY)
  30  *
  31  * Where KEY is a QDict key, which has to be passed to qerror_from_info().
  32  *
  33  * Example:
  34  *
  35  * "foo error on device: %(device) slot: %(slot_nr)"
  36  *
  37  * A single percent sign can be printed if followed by a second one,
  38  * for example:
  39  *
  40  * "running out of foo: %(foo)%%"
  41  *
  42  * Please keep the entries in alphabetical order.
  43  * Use "sed -n '/^static.*qerror_table\[\]/,/^};/s/QERR_/&/gp' qerror.c | sort -c"
  44  * to check.
  45  */
  46 static const QErrorStringTable qerror_table[] = {
  47     {
  48         .error_fmt = QERR_BAD_BUS_FOR_DEVICE,
  49         .desc      = "Device '%(device)' can't go on a %(bad_bus_type) bus",
  50     },
  51     {
  52         .error_fmt = QERR_BUS_NOT_FOUND,
  53         .desc      = "Bus '%(bus)' not found",
  54     },
  55     {
  56         .error_fmt = QERR_BUS_NO_HOTPLUG,
  57         .desc      = "Bus '%(bus)' does not support hotplugging",
  58     },
  59     {
  60         .error_fmt = QERR_COMMAND_NOT_FOUND,
  61         .desc      = "The command %(name) has not been found",
  62     },
  63     {
  64         .error_fmt = QERR_DEVICE_ENCRYPTED,
  65         .desc      = "Device '%(device)' is encrypted",
  66     },
  67     {
  68         .error_fmt = QERR_DEVICE_INIT_FAILED,
  69         .desc      = "Device '%(device)' could not be initialized",
  70     },
  71     {
  72         .error_fmt = QERR_DEVICE_IN_USE,
  73         .desc      = "Device '%(device)' is in use",
  74     },
  75     {
  76         .error_fmt = QERR_DEVICE_LOCKED,
  77         .desc      = "Device '%(device)' is locked",
  78     },
  79     {
  80         .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
  81         .desc      = "Device '%(device)' has multiple child busses",
  82     },
  83     {
  84         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
  85         .desc      = "Device '%(device)' has not been activated",
  86     },
  87     {
  88         .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
  89         .desc      = "Device '%(device)' is not encrypted",
  90     },
  91     {
  92         .error_fmt = QERR_DEVICE_NOT_FOUND,
  93         .desc      = "Device '%(device)' not found",
  94     },
  95     {
  96         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
  97         .desc      = "Device '%(device)' is not removable",
  98     },
  99     {
 100         .error_fmt = QERR_DEVICE_NO_BUS,
 101         .desc      = "Device '%(device)' has no child bus",
 102     },
 103     {
 104         .error_fmt = QERR_DUPLICATE_ID,
 105         .desc      = "Duplicate ID '%(id)' for %(object)",
 106     },
 107     {
 108         .error_fmt = QERR_FD_NOT_FOUND,
 109         .desc      = "File descriptor named '%(name)' not found",
 110     },
 111     {
 112         .error_fmt = QERR_FD_NOT_SUPPLIED,
 113         .desc      = "No file descriptor supplied via SCM_RIGHTS",
 114     },
 115     {
 116         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
 117         .desc      = "Invalid block format '%(name)'",
 118     },
 119     {
 120         .error_fmt = QERR_INVALID_PARAMETER,
 121         .desc      = "Invalid parameter '%(name)'",
 122     },
 123     {
 124         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 125         .desc      = "Invalid parameter type, expected: %(expected)",
 126     },
 127     {
 128         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
 129         .desc      = "Parameter '%(name)' expects %(expected)",
 130     },
 131     {
 132         .error_fmt = QERR_INVALID_PASSWORD,
 133         .desc      = "Password incorrect",
 134     },
 135     {
 136         .error_fmt = QERR_JSON_PARSING,
 137         .desc      = "Invalid JSON syntax",
 138     },
 139     {
 140         .error_fmt = QERR_KVM_MISSING_CAP,
 141         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 142     },
 143     {
 144         .error_fmt = QERR_MIGRATION_EXPECTED,
 145         .desc      = "An incoming migration is expected before this command can be executed",
 146     },
 147     {
 148         .error_fmt = QERR_MISSING_PARAMETER,
 149         .desc      = "Parameter '%(name)' is missing",
 150     },
 151     {
 152         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 153         .desc      = "No '%(bus)' bus found for device '%(device)'",
 154     },
 155     {
 156         .error_fmt = QERR_OPEN_FILE_FAILED,
 157         .desc      = "Could not open '%(filename)'",
 158     },
 159     {
 160         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 161         .desc      = "Property '%(device).%(property)' not found",
 162     },
 163     {
 164         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 165         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 166     },
 167     {
 168         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 169         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 170     },
 171     {
 172         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 173         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 174     },
 175     {
 176         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 177         .desc      = "Expected '%(expected)' in QMP input",
 178     },
 179     {
 180         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 181         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 182     },
 183     {
 184         .error_fmt = QERR_QMP_EXTRA_MEMBER,
 185         .desc      = "QMP input object member '%(member)' is unexpected",
 186     },
 187     {
 188         .error_fmt = QERR_SET_PASSWD_FAILED,
 189         .desc      = "Could not set password",
 190     },
 191     {
 192         .error_fmt = QERR_TOO_MANY_FILES,
 193         .desc      = "Too many open files",
 194     },
 195     {
 196         .error_fmt = QERR_UNDEFINED_ERROR,
 197         .desc      = "An undefined error has ocurred",
 198     },
 199     {
 200         .error_fmt = QERR_VNC_SERVER_FAILED,
 201         .desc      = "Could not start VNC server on %(target)",
 202     },
 203     {}
 204 };
 205
 206 /**
 207  * qerror_new(): Create a new QError
 208  *
 209  * Return strong reference.
 210  */
 211 QError *qerror_new(void)
 212 {
 213     QError *qerr;
 214
 215     qerr = qemu_mallocz(sizeof(*qerr));
 216     QOBJECT_INIT(qerr, &qerror_type);
 217
 218     return qerr;
 219 }
 220
 221 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
 222                                             const char *fmt, ...)
 223 {
 224     va_list ap;
 225
 226     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 227     fprintf(stderr, "qerror: -> ");
 228
 229     va_start(ap, fmt);
 230     vfprintf(stderr, fmt, ap);
 231     va_end(ap);
 232
 233     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 234     abort();
 235 }
 236
 237 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
 238                                                const char *fmt, va_list *va)
 239 {
 240     QObject *obj;
 241
 242     obj = qobject_from_jsonv(fmt, va);
 243     if (!obj) {
 244         qerror_abort(qerr, "invalid format '%s'", fmt);
 245     }
 246     if (qobject_type(obj) != QTYPE_QDICT) {
 247         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 248     }
 249
 250     qerr->error = qobject_to_qdict(obj);
 251
 252     obj = qdict_get(qerr->error, "class");
 253     if (!obj) {
 254         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 255     }
 256     if (qobject_type(obj) != QTYPE_QSTRING) {
 257         qerror_abort(qerr, "'class' key value should be a QString");
 258     }
 259
 260     obj = qdict_get(qerr->error, "data");
 261     if (!obj) {
 262         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 263     }
 264     if (qobject_type(obj) != QTYPE_QDICT) {
 265         qerror_abort(qerr, "'data' key value should be a QDICT");
 266     }
 267 }
 268
 269 static void qerror_set_desc(QError *qerr, const char *fmt)
 270 {
 271     int i;
 272
 273     // FIXME: inefficient loop
 274
 275     for (i = 0; qerror_table[i].error_fmt; i++) {
 276         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 277             qerr->entry = &qerror_table[i];
 278             return;
 279         }
 280     }
 281
 282     qerror_abort(qerr, "error format '%s' not found", fmt);
 283 }
 284
 285 /**
 286  * qerror_from_info(): Create a new QError from error information
 287  *
 288  * The information consists of:
 289  *
 290  * - file   the file name of where the error occurred
 291  * - linenr the line number of where the error occurred
 292  * - func   the function name of where the error occurred
 293  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 294  *          'data'
 295  * - va     va_list of all arguments specified by fmt
 296  *
 297  * Return strong reference.
 298  */
 299 QError *qerror_from_info(const char *file, int linenr, const char *func,
 300                          const char *fmt, va_list *va)
 301 {
 302     QError *qerr;
 303
 304     qerr = qerror_new();
 305     loc_save(&qerr->loc);
 306     qerr->linenr = linenr;
 307     qerr->file = file;
 308     qerr->func = func;
 309
 310     if (!fmt) {
 311         qerror_abort(qerr, "QDict not specified");
 312     }
 313
 314     qerror_set_data(qerr, fmt, va);
 315     qerror_set_desc(qerr, fmt);
 316
 317     return qerr;
 318 }
 319
 320 static void parse_error(const QError *qerror, int c)
 321 {
 322     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
 323 }
 324
 325 static const char *append_field(QString *outstr, const QError *qerror,
 326                                 const char *start)
 327 {
 328     QObject *obj;
 329     QDict *qdict;
 330     QString *key_qs;
 331     const char *end, *key;
 332
 333     if (*start != '%')
 334         parse_error(qerror, '%');
 335     start++;
 336     if (*start != '(')
 337         parse_error(qerror, '(');
 338     start++;
 339
 340     end = strchr(start, ')');
 341     if (!end)
 342         parse_error(qerror, ')');
 343
 344     key_qs = qstring_from_substr(start, 0, end - start - 1);
 345     key = qstring_get_str(key_qs);
 346
 347     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
 348     obj = qdict_get(qdict, key);
 349     if (!obj) {
 350         qerror_abort(qerror, "key '%s' not found in QDict", key);
 351     }
 352
 353     switch (qobject_type(obj)) {
 354         case QTYPE_QSTRING:
 355             qstring_append(outstr, qdict_get_str(qdict, key));
 356             break;
 357         case QTYPE_QINT:
 358             qstring_append_int(outstr, qdict_get_int(qdict, key));
 359             break;
 360         default:
 361             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
 362     }
 363
 364     QDECREF(key_qs);
 365     return ++end;
 366 }
 367
 368 /**
 369  * qerror_human(): Format QError data into human-readable string.
 370  *
 371  * Formats according to member 'desc' of the specified QError object.
 372  */
 373 QString *qerror_human(const QError *qerror)
 374 {
 375     const char *p;
 376     QString *qstring;
 377
 378     assert(qerror->entry != NULL);
 379
 380     qstring = qstring_new();
 381
 382     for (p = qerror->entry->desc; *p != '\0';) {
 383         if (*p != '%') {
 384             qstring_append_chr(qstring, *p++);
 385         } else if (*(p + 1) == '%') {
 386             qstring_append_chr(qstring, '%');
 387             p += 2;
 388         } else {
 389             p = append_field(qstring, qerror, p);
 390         }
 391     }
 392
 393     return qstring;
 394 }
 395
 396 /**
 397  * qerror_print(): Print QError data
 398  *
 399  * This function will print the member 'desc' of the specified QError object,
 400  * it uses error_report() for this, so that the output is routed to the right
 401  * place (ie. stderr or Monitor's device).
 402  */
 403 void qerror_print(QError *qerror)
 404 {
 405     QString *qstring = qerror_human(qerror);
 406     loc_push_restore(&qerror->loc);
 407     error_report("%s", qstring_get_str(qstring));
 408     loc_pop(&qerror->loc);
 409     QDECREF(qstring);
 410 }
 411
 412 void qerror_report_internal(const char *file, int linenr, const char *func,
 413                             const char *fmt, ...)
 414 {
 415     va_list va;
 416     QError *qerror;
 417
 418     va_start(va, fmt);
 419     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 420     va_end(va);
 421
 422     if (monitor_cur_is_qmp()) {
 423         monitor_set_error(cur_mon, qerror);
 424     } else {
 425         qerror_print(qerror);
 426         QDECREF(qerror);
 427     }
 428 }
 429
 430 /**
 431  * qobject_to_qerror(): Convert a QObject into a QError
 432  */
 433 QError *qobject_to_qerror(const QObject *obj)
 434 {
 435     if (qobject_type(obj) != QTYPE_QERROR) {
 436         return NULL;
 437     }
 438
 439     return container_of(obj, QError, base);
 440 }
 441
 442 /**
 443  * qerror_destroy_obj(): Free all memory allocated by a QError
 444  */
 445 static void qerror_destroy_obj(QObject *obj)
 446 {
 447     QError *qerr;
 448
 449     assert(obj != NULL);
 450     qerr = qobject_to_qerror(obj);
 451
 452     QDECREF(qerr->error);
 453     qemu_free(qerr);
 454 }