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_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
  53         .desc      = "Block format '%(format)' used by device '%(name)' does not support feature '%(feature)'",
  54     },
  55     {
  56         .error_fmt = QERR_BUS_NOT_FOUND,
  57         .desc      = "Bus '%(bus)' not found",
  58     },
  59     {
  60         .error_fmt = QERR_BUS_NO_HOTPLUG,
  61         .desc      = "Bus '%(bus)' does not support hotplugging",
  62     },
  63     {
  64         .error_fmt = QERR_COMMAND_NOT_FOUND,
  65         .desc      = "The command %(name) has not been found",
  66     },
  67     {
  68         .error_fmt = QERR_DEVICE_ENCRYPTED,
  69         .desc      = "Device '%(device)' is encrypted",
  70     },
  71     {
  72         .error_fmt = QERR_DEVICE_INIT_FAILED,
  73         .desc      = "Device '%(device)' could not be initialized",
  74     },
  75     {
  76         .error_fmt = QERR_DEVICE_IN_USE,
  77         .desc      = "Device '%(device)' is in use",
  78     },
  79     {
  80         .error_fmt = QERR_DEVICE_FEATURE_BLOCKS_MIGRATION,
  81         .desc      = "Migration is disabled when using feature '%(feature)' in device '%(device)'",
  82     },
  83     {
  84         .error_fmt = QERR_DEVICE_LOCKED,
  85         .desc      = "Device '%(device)' is locked",
  86     },
  87     {
  88         .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
  89         .desc      = "Device '%(device)' has multiple child busses",
  90     },
  91     {
  92         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
  93         .desc      = "Device '%(device)' has not been activated",
  94     },
  95     {
  96         .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
  97         .desc      = "Device '%(device)' is not encrypted",
  98     },
  99     {
 100         .error_fmt = QERR_DEVICE_NOT_FOUND,
 101         .desc      = "Device '%(device)' not found",
 102     },
 103     {
 104         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
 105         .desc      = "Device '%(device)' is not removable",
 106     },
 107     {
 108         .error_fmt = QERR_DEVICE_NO_BUS,
 109         .desc      = "Device '%(device)' has no child bus",
 110     },
 111     {
 112         .error_fmt = QERR_DEVICE_NO_HOTPLUG,
 113         .desc      = "Device '%(device)' does not support hotplugging",
 114     },
 115     {
 116         .error_fmt = QERR_DUPLICATE_ID,
 117         .desc      = "Duplicate ID '%(id)' for %(object)",
 118     },
 119     {
 120         .error_fmt = QERR_FD_NOT_FOUND,
 121         .desc      = "File descriptor named '%(name)' not found",
 122     },
 123     {
 124         .error_fmt = QERR_FD_NOT_SUPPLIED,
 125         .desc      = "No file descriptor supplied via SCM_RIGHTS",
 126     },
 127     {
 128         .error_fmt = QERR_FEATURE_DISABLED,
 129         .desc      = "The feature '%(name)' is not enabled",
 130     },
 131     {
 132         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
 133         .desc      = "Invalid block format '%(name)'",
 134     },
 135     {
 136         .error_fmt = QERR_INVALID_PARAMETER,
 137         .desc      = "Invalid parameter '%(name)'",
 138     },
 139     {
 140         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 141         .desc      = "Invalid parameter type, expected: %(expected)",
 142     },
 143     {
 144         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
 145         .desc      = "Parameter '%(name)' expects %(expected)",
 146     },
 147     {
 148         .error_fmt = QERR_INVALID_PASSWORD,
 149         .desc      = "Password incorrect",
 150     },
 151     {
 152         .error_fmt = QERR_JSON_PARSING,
 153         .desc      = "Invalid JSON syntax",
 154     },
 155     {
 156         .error_fmt = QERR_JSON_PARSE_ERROR,
 157         .desc      = "JSON parse error, %(message)",
 158
 159     },
 160     {
 161         .error_fmt = QERR_KVM_MISSING_CAP,
 162         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 163     },
 164     {
 165         .error_fmt = QERR_MIGRATION_EXPECTED,
 166         .desc      = "An incoming migration is expected before this command can be executed",
 167     },
 168     {
 169         .error_fmt = QERR_MISSING_PARAMETER,
 170         .desc      = "Parameter '%(name)' is missing",
 171     },
 172     {
 173         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 174         .desc      = "No '%(bus)' bus found for device '%(device)'",
 175     },
 176     {
 177         .error_fmt = QERR_OPEN_FILE_FAILED,
 178         .desc      = "Could not open '%(filename)'",
 179     },
 180     {
 181         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 182         .desc      = "Property '%(device).%(property)' not found",
 183     },
 184     {
 185         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 186         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 187     },
 188     {
 189         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 190         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 191     },
 192     {
 193         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 194         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 195     },
 196     {
 197         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 198         .desc      = "Expected '%(expected)' in QMP input",
 199     },
 200     {
 201         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 202         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 203     },
 204     {
 205         .error_fmt = QERR_QMP_EXTRA_MEMBER,
 206         .desc      = "QMP input object member '%(member)' is unexpected",
 207     },
 208     {
 209         .error_fmt = QERR_RESET_REQUIRED,
 210         .desc      = "Resetting the Virtual Machine is required",
 211     },
 212     {
 213         .error_fmt = QERR_SET_PASSWD_FAILED,
 214         .desc      = "Could not set password",
 215     },
 216     {
 217         .error_fmt = QERR_ADD_CLIENT_FAILED,
 218         .desc      = "Could not add client",
 219     },
 220     {
 221         .error_fmt = QERR_TOO_MANY_FILES,
 222         .desc      = "Too many open files",
 223     },
 224     {
 225         .error_fmt = QERR_UNDEFINED_ERROR,
 226         .desc      = "An undefined error has occurred",
 227     },
 228     {
 229         .error_fmt = QERR_UNSUPPORTED,
 230         .desc      = "this feature or command is not currently supported",
 231     },
 232     {
 233         .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
 234         .desc      = "'%(device)' uses a %(format) feature which is not "
 235                      "supported by this qemu version: %(feature)",
 236     },
 237     {
 238         .error_fmt = QERR_VNC_SERVER_FAILED,
 239         .desc      = "Could not start VNC server on %(target)",
 240     },
 241     {
 242         .error_fmt = QERR_QGA_LOGGING_FAILED,
 243         .desc      = "Guest agent failed to log non-optional log statement",
 244     },
 245     {
 246         .error_fmt = QERR_QGA_COMMAND_FAILED,
 247         .desc      = "Guest agent command failed, error was '%(message)'",
 248     },
 249     {}
 250 };
 251
 252 /**
 253  * qerror_new(): Create a new QError
 254  *
 255  * Return strong reference.
 256  */
 257 QError *qerror_new(void)
 258 {
 259     QError *qerr;
 260
 261     qerr = g_malloc0(sizeof(*qerr));
 262     QOBJECT_INIT(qerr, &qerror_type);
 263
 264     return qerr;
 265 }
 266
 267 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
 268                                             const char *fmt, ...)
 269 {
 270     va_list ap;
 271
 272     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 273     fprintf(stderr, "qerror: -> ");
 274
 275     va_start(ap, fmt);
 276     vfprintf(stderr, fmt, ap);
 277     va_end(ap);
 278
 279     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 280     abort();
 281 }
 282
 283 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
 284                                                const char *fmt, va_list *va)
 285 {
 286     QObject *obj;
 287
 288     obj = qobject_from_jsonv(fmt, va);
 289     if (!obj) {
 290         qerror_abort(qerr, "invalid format '%s'", fmt);
 291     }
 292     if (qobject_type(obj) != QTYPE_QDICT) {
 293         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 294     }
 295
 296     qerr->error = qobject_to_qdict(obj);
 297
 298     obj = qdict_get(qerr->error, "class");
 299     if (!obj) {
 300         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 301     }
 302     if (qobject_type(obj) != QTYPE_QSTRING) {
 303         qerror_abort(qerr, "'class' key value should be a QString");
 304     }
 305
 306     obj = qdict_get(qerr->error, "data");
 307     if (!obj) {
 308         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 309     }
 310     if (qobject_type(obj) != QTYPE_QDICT) {
 311         qerror_abort(qerr, "'data' key value should be a QDICT");
 312     }
 313 }
 314
 315 static void qerror_set_desc(QError *qerr, const char *fmt)
 316 {
 317     int i;
 318
 319     // FIXME: inefficient loop
 320
 321     for (i = 0; qerror_table[i].error_fmt; i++) {
 322         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 323             qerr->entry = &qerror_table[i];
 324             return;
 325         }
 326     }
 327
 328     qerror_abort(qerr, "error format '%s' not found", fmt);
 329 }
 330
 331 /**
 332  * qerror_from_info(): Create a new QError from error information
 333  *
 334  * The information consists of:
 335  *
 336  * - file   the file name of where the error occurred
 337  * - linenr the line number of where the error occurred
 338  * - func   the function name of where the error occurred
 339  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 340  *          'data'
 341  * - va     va_list of all arguments specified by fmt
 342  *
 343  * Return strong reference.
 344  */
 345 QError *qerror_from_info(const char *file, int linenr, const char *func,
 346                          const char *fmt, va_list *va)
 347 {
 348     QError *qerr;
 349
 350     qerr = qerror_new();
 351     loc_save(&qerr->loc);
 352     qerr->linenr = linenr;
 353     qerr->file = file;
 354     qerr->func = func;
 355
 356     if (!fmt) {
 357         qerror_abort(qerr, "QDict not specified");
 358     }
 359
 360     qerror_set_data(qerr, fmt, va);
 361     qerror_set_desc(qerr, fmt);
 362
 363     return qerr;
 364 }
 365
 366 static void parse_error(const QErrorStringTable *entry, int c)
 367 {
 368     fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
 369     abort();
 370 }
 371
 372 static const char *append_field(QDict *error, QString *outstr,
 373                                 const QErrorStringTable *entry,
 374                                 const char *start)
 375 {
 376     QObject *obj;
 377     QDict *qdict;
 378     QString *key_qs;
 379     const char *end, *key;
 380
 381     if (*start != '%')
 382         parse_error(entry, '%');
 383     start++;
 384     if (*start != '(')
 385         parse_error(entry, '(');
 386     start++;
 387
 388     end = strchr(start, ')');
 389     if (!end)
 390         parse_error(entry, ')');
 391
 392     key_qs = qstring_from_substr(start, 0, end - start - 1);
 393     key = qstring_get_str(key_qs);
 394
 395     qdict = qobject_to_qdict(qdict_get(error, "data"));
 396     obj = qdict_get(qdict, key);
 397     if (!obj) {
 398         abort();
 399     }
 400
 401     switch (qobject_type(obj)) {
 402         case QTYPE_QSTRING:
 403             qstring_append(outstr, qdict_get_str(qdict, key));
 404             break;
 405         case QTYPE_QINT:
 406             qstring_append_int(outstr, qdict_get_int(qdict, key));
 407             break;
 408         default:
 409             abort();
 410     }
 411
 412     QDECREF(key_qs);
 413     return ++end;
 414 }
 415
 416 static QString *qerror_format_desc(QDict *error,
 417                                    const QErrorStringTable *entry)
 418 {
 419     QString *qstring;
 420     const char *p;
 421
 422     assert(entry != NULL);
 423
 424     qstring = qstring_new();
 425
 426     for (p = entry->desc; *p != '\0';) {
 427         if (*p != '%') {
 428             qstring_append_chr(qstring, *p++);
 429         } else if (*(p + 1) == '%') {
 430             qstring_append_chr(qstring, '%');
 431             p += 2;
 432         } else {
 433             p = append_field(error, qstring, entry, p);
 434         }
 435     }
 436
 437     return qstring;
 438 }
 439
 440 QString *qerror_format(const char *fmt, QDict *error)
 441 {
 442     const QErrorStringTable *entry = NULL;
 443     int i;
 444
 445     for (i = 0; qerror_table[i].error_fmt; i++) {
 446         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 447             entry = &qerror_table[i];
 448             break;
 449         }
 450     }
 451
 452     return qerror_format_desc(error, entry);
 453 }
 454
 455 /**
 456  * qerror_human(): Format QError data into human-readable string.
 457  */
 458 QString *qerror_human(const QError *qerror)
 459 {
 460     return qerror_format_desc(qerror->error, qerror->entry);
 461 }
 462
 463 /**
 464  * qerror_print(): Print QError data
 465  *
 466  * This function will print the member 'desc' of the specified QError object,
 467  * it uses error_report() for this, so that the output is routed to the right
 468  * place (ie. stderr or Monitor's device).
 469  */
 470 void qerror_print(QError *qerror)
 471 {
 472     QString *qstring = qerror_human(qerror);
 473     loc_push_restore(&qerror->loc);
 474     error_report("%s", qstring_get_str(qstring));
 475     loc_pop(&qerror->loc);
 476     QDECREF(qstring);
 477 }
 478
 479 void qerror_report_internal(const char *file, int linenr, const char *func,
 480                             const char *fmt, ...)
 481 {
 482     va_list va;
 483     QError *qerror;
 484
 485     va_start(va, fmt);
 486     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 487     va_end(va);
 488
 489     if (monitor_cur_is_qmp()) {
 490         monitor_set_error(cur_mon, qerror);
 491     } else {
 492         qerror_print(qerror);
 493         QDECREF(qerror);
 494     }
 495 }
 496
 497 /* Evil... */
 498 struct Error
 499 {
 500     QDict *obj;
 501     const char *fmt;
 502     char *msg;
 503 };
 504
 505 void qerror_report_err(Error *err)
 506 {
 507     QError *qerr;
 508     int i;
 509
 510     qerr = qerror_new();
 511     loc_save(&qerr->loc);
 512     QINCREF(err->obj);
 513     qerr->error = err->obj;
 514
 515     for (i = 0; qerror_table[i].error_fmt; i++) {
 516         if (strcmp(qerror_table[i].error_fmt, err->fmt) == 0) {
 517             qerr->entry = &qerror_table[i];
 518             break;
 519         }
 520     }
 521
 522     if (monitor_cur_is_qmp()) {
 523         monitor_set_error(cur_mon, qerr);
 524     } else {
 525         qerror_print(qerr);
 526         QDECREF(qerr);
 527     }
 528 }
 529
 530 /**
 531  * qobject_to_qerror(): Convert a QObject into a QError
 532  */
 533 QError *qobject_to_qerror(const QObject *obj)
 534 {
 535     if (qobject_type(obj) != QTYPE_QERROR) {
 536         return NULL;
 537     }
 538
 539     return container_of(obj, QError, base);
 540 }
 541
 542 /**
 543  * qerror_destroy_obj(): Free all memory allocated by a QError
 544  */
 545 static void qerror_destroy_obj(QObject *obj)
 546 {
 547     QError *qerr;
 548
 549     assert(obj != NULL);
 550     qerr = qobject_to_qerror(obj);
 551
 552     QDECREF(qerr->error);
 553     g_free(qerr);
 554 }