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 scripts/check-qerror.sh to check.
  44  */
  45 static const QErrorStringTable qerror_table[] = {
  46     {
  47         .error_fmt = QERR_ADD_CLIENT_FAILED,
  48         .desc      = "Could not add client",
  49     },
  50     {
  51         .error_fmt = QERR_AMBIGUOUS_PATH,
  52         .desc      = "Path '%(path)' does not uniquely identify a %(object)"
  53     },
  54     {
  55         .error_fmt = QERR_BAD_BUS_FOR_DEVICE,
  56         .desc      = "Device '%(device)' can't go on a %(bad_bus_type) bus",
  57     },
  58     {
  59         .error_fmt = QERR_BASE_NOT_FOUND,
  60         .desc      = "Base '%(base)' not found",
  61     },
  62     {
  63         .error_fmt = QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
  64         .desc      = "Block format '%(format)' used by device '%(name)' does not support feature '%(feature)'",
  65     },
  66     {
  67         .error_fmt = QERR_BUS_NO_HOTPLUG,
  68         .desc      = "Bus '%(bus)' does not support hotplugging",
  69     },
  70     {
  71         .error_fmt = QERR_BUS_NOT_FOUND,
  72         .desc      = "Bus '%(bus)' not found",
  73     },
  74     {
  75         .error_fmt = QERR_COMMAND_DISABLED,
  76         .desc      = "The command %(name) has been disabled for this instance",
  77     },
  78     {
  79         .error_fmt = QERR_COMMAND_NOT_FOUND,
  80         .desc      = "The command %(name) has not been found",
  81     },
  82     {
  83         .error_fmt = QERR_DEVICE_ENCRYPTED,
  84         .desc      = "Device '%(device)' is encrypted",
  85     },
  86     {
  87         .error_fmt = QERR_DEVICE_FEATURE_BLOCKS_MIGRATION,
  88         .desc      = "Migration is disabled when using feature '%(feature)' in device '%(device)'",
  89     },
  90     {
  91         .error_fmt = QERR_DEVICE_HAS_NO_MEDIUM,
  92         .desc      = "Device '%(device)' has no medium",
  93     },
  94     {
  95         .error_fmt = QERR_DEVICE_INIT_FAILED,
  96         .desc      = "Device '%(device)' could not be initialized",
  97     },
  98     {
  99         .error_fmt = QERR_DEVICE_IN_USE,
 100         .desc      = "Device '%(device)' is in use",
 101     },
 102     {
 103         .error_fmt = QERR_DEVICE_IS_READ_ONLY,
 104         .desc      = "Device '%(device)' is read only",
 105     },
 106     {
 107         .error_fmt = QERR_DEVICE_LOCKED,
 108         .desc      = "Device '%(device)' is locked",
 109     },
 110     {
 111         .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
 112         .desc      = "Device '%(device)' has multiple child busses",
 113     },
 114     {
 115         .error_fmt = QERR_DEVICE_NO_BUS,
 116         .desc      = "Device '%(device)' has no child bus",
 117     },
 118     {
 119         .error_fmt = QERR_DEVICE_NO_HOTPLUG,
 120         .desc      = "Device '%(device)' does not support hotplugging",
 121     },
 122     {
 123         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
 124         .desc      = "Device '%(device)' has not been activated",
 125     },
 126     {
 127         .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
 128         .desc      = "Device '%(device)' is not encrypted",
 129     },
 130     {
 131         .error_fmt = QERR_DEVICE_NOT_FOUND,
 132         .desc      = "Device '%(device)' not found",
 133     },
 134     {
 135         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
 136         .desc      = "Device '%(device)' is not removable",
 137     },
 138     {
 139         .error_fmt = QERR_DUPLICATE_ID,
 140         .desc      = "Duplicate ID '%(id)' for %(object)",
 141     },
 142     {
 143         .error_fmt = QERR_FD_NOT_FOUND,
 144         .desc      = "File descriptor named '%(name)' not found",
 145     },
 146     {
 147         .error_fmt = QERR_FD_NOT_SUPPLIED,
 148         .desc      = "No file descriptor supplied via SCM_RIGHTS",
 149     },
 150     {
 151         .error_fmt = QERR_FEATURE_DISABLED,
 152         .desc      = "The feature '%(name)' is not enabled",
 153     },
 154     {
 155         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
 156         .desc      = "Invalid block format '%(name)'",
 157     },
 158     {
 159         .error_fmt = QERR_INVALID_PARAMETER,
 160         .desc      = "Invalid parameter '%(name)'",
 161     },
 162     {
 163         .error_fmt = QERR_INVALID_PARAMETER_COMBINATION,
 164         .desc      = "Invalid parameter combination",
 165     },
 166     {
 167         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 168         .desc      = "Invalid parameter type for '%(name)', expected: %(expected)",
 169     },
 170     {
 171         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
 172         .desc      = "Parameter '%(name)' expects %(expected)",
 173     },
 174     {
 175         .error_fmt = QERR_INVALID_PASSWORD,
 176         .desc      = "Password incorrect",
 177     },
 178     {
 179         .error_fmt = QERR_IO_ERROR,
 180         .desc      = "An IO error has occurred",
 181     },
 182     {
 183         .error_fmt = QERR_JSON_PARSE_ERROR,
 184         .desc      = "JSON parse error, %(message)",
 185
 186     },
 187     {
 188         .error_fmt = QERR_JSON_PARSING,
 189         .desc      = "Invalid JSON syntax",
 190     },
 191     {
 192         .error_fmt = QERR_KVM_MISSING_CAP,
 193         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 194     },
 195     {
 196         .error_fmt = QERR_MIGRATION_EXPECTED,
 197         .desc      = "An incoming migration is expected before this command can be executed",
 198     },
 199     {
 200         .error_fmt = QERR_MISSING_PARAMETER,
 201         .desc      = "Parameter '%(name)' is missing",
 202     },
 203     {
 204         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 205         .desc      = "No '%(bus)' bus found for device '%(device)'",
 206     },
 207     {
 208         .error_fmt = QERR_NOT_SUPPORTED,
 209         .desc      = "Not supported",
 210     },
 211     {
 212         .error_fmt = QERR_OPEN_FILE_FAILED,
 213         .desc      = "Could not open '%(filename)'",
 214     },
 215     {
 216         .error_fmt = QERR_PERMISSION_DENIED,
 217         .desc      = "Insufficient permission to perform this operation",
 218     },
 219     {
 220         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 221         .desc      = "Property '%(device).%(property)' not found",
 222     },
 223     {
 224         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 225         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 226     },
 227     {
 228         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 229         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 230     },
 231     {
 232         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 233         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 234     },
 235     {
 236         .error_fmt = QERR_PROPERTY_VALUE_OUT_OF_RANGE,
 237         .desc      = "Property '%(device).%(property)' doesn't take "
 238                      "value %(value) (minimum: %(min), maximum: %(max)'",
 239     },
 240     {
 241         .error_fmt = QERR_QGA_COMMAND_FAILED,
 242         .desc      = "Guest agent command failed, error was '%(message)'",
 243     },
 244     {
 245         .error_fmt = QERR_QGA_LOGGING_FAILED,
 246         .desc      = "Guest agent failed to log non-optional log statement",
 247     },
 248     {
 249         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 250         .desc      = "Expected '%(expected)' in QMP input",
 251     },
 252     {
 253         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 254         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 255     },
 256     {
 257         .error_fmt = QERR_QMP_EXTRA_MEMBER,
 258         .desc      = "QMP input object member '%(member)' is unexpected",
 259     },
 260     {
 261         .error_fmt = QERR_RESET_REQUIRED,
 262         .desc      = "Resetting the Virtual Machine is required",
 263     },
 264     {
 265         .error_fmt = QERR_SET_PASSWD_FAILED,
 266         .desc      = "Could not set password",
 267     },
 268     {
 269         .error_fmt = QERR_TOO_MANY_FILES,
 270         .desc      = "Too many open files",
 271     },
 272     {
 273         .error_fmt = QERR_UNDEFINED_ERROR,
 274         .desc      = "An undefined error has occurred",
 275     },
 276     {
 277         .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
 278         .desc      = "'%(device)' uses a %(format) feature which is not "
 279                      "supported by this qemu version: %(feature)",
 280     },
 281     {
 282         .error_fmt = QERR_UNSUPPORTED,
 283         .desc      = "this feature or command is not currently supported",
 284     },
 285     {
 286         .error_fmt = QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
 287         .desc      = "Migration is disabled when VirtFS export path '%(path)' "
 288                      "is mounted in the guest using mount_tag '%(tag)'",
 289     },
 290     {
 291         .error_fmt = QERR_VNC_SERVER_FAILED,
 292         .desc      = "Could not start VNC server on %(target)",
 293     },
 294     {}
 295 };
 296
 297 /**
 298  * qerror_new(): Create a new QError
 299  *
 300  * Return strong reference.
 301  */
 302 QError *qerror_new(void)
 303 {
 304     QError *qerr;
 305
 306     qerr = g_malloc0(sizeof(*qerr));
 307     QOBJECT_INIT(qerr, &qerror_type);
 308
 309     return qerr;
 310 }
 311
 312 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
 313                                             const char *fmt, ...)
 314 {
 315     va_list ap;
 316
 317     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 318     fprintf(stderr, "qerror: -> ");
 319
 320     va_start(ap, fmt);
 321     vfprintf(stderr, fmt, ap);
 322     va_end(ap);
 323
 324     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 325     abort();
 326 }
 327
 328 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
 329                                                const char *fmt, va_list *va)
 330 {
 331     QObject *obj;
 332
 333     obj = qobject_from_jsonv(fmt, va);
 334     if (!obj) {
 335         qerror_abort(qerr, "invalid format '%s'", fmt);
 336     }
 337     if (qobject_type(obj) != QTYPE_QDICT) {
 338         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 339     }
 340
 341     qerr->error = qobject_to_qdict(obj);
 342
 343     obj = qdict_get(qerr->error, "class");
 344     if (!obj) {
 345         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 346     }
 347     if (qobject_type(obj) != QTYPE_QSTRING) {
 348         qerror_abort(qerr, "'class' key value should be a QString");
 349     }
 350
 351     obj = qdict_get(qerr->error, "data");
 352     if (!obj) {
 353         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 354     }
 355     if (qobject_type(obj) != QTYPE_QDICT) {
 356         qerror_abort(qerr, "'data' key value should be a QDICT");
 357     }
 358 }
 359
 360 static void qerror_set_desc(QError *qerr, const char *fmt)
 361 {
 362     int i;
 363
 364     // FIXME: inefficient loop
 365
 366     for (i = 0; qerror_table[i].error_fmt; i++) {
 367         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 368             qerr->entry = &qerror_table[i];
 369             return;
 370         }
 371     }
 372
 373     qerror_abort(qerr, "error format '%s' not found", fmt);
 374 }
 375
 376 /**
 377  * qerror_from_info(): Create a new QError from error information
 378  *
 379  * The information consists of:
 380  *
 381  * - file   the file name of where the error occurred
 382  * - linenr the line number of where the error occurred
 383  * - func   the function name of where the error occurred
 384  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 385  *          'data'
 386  * - va     va_list of all arguments specified by fmt
 387  *
 388  * Return strong reference.
 389  */
 390 QError *qerror_from_info(const char *file, int linenr, const char *func,
 391                          const char *fmt, va_list *va)
 392 {
 393     QError *qerr;
 394
 395     qerr = qerror_new();
 396     loc_save(&qerr->loc);
 397     qerr->linenr = linenr;
 398     qerr->file = file;
 399     qerr->func = func;
 400
 401     if (!fmt) {
 402         qerror_abort(qerr, "QDict not specified");
 403     }
 404
 405     qerror_set_data(qerr, fmt, va);
 406     qerror_set_desc(qerr, fmt);
 407
 408     return qerr;
 409 }
 410
 411 static void parse_error(const QErrorStringTable *entry, int c)
 412 {
 413     fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
 414     abort();
 415 }
 416
 417 static const char *append_field(QDict *error, QString *outstr,
 418                                 const QErrorStringTable *entry,
 419                                 const char *start)
 420 {
 421     QObject *obj;
 422     QDict *qdict;
 423     QString *key_qs;
 424     const char *end, *key;
 425
 426     if (*start != '%')
 427         parse_error(entry, '%');
 428     start++;
 429     if (*start != '(')
 430         parse_error(entry, '(');
 431     start++;
 432
 433     end = strchr(start, ')');
 434     if (!end)
 435         parse_error(entry, ')');
 436
 437     key_qs = qstring_from_substr(start, 0, end - start - 1);
 438     key = qstring_get_str(key_qs);
 439
 440     qdict = qobject_to_qdict(qdict_get(error, "data"));
 441     obj = qdict_get(qdict, key);
 442     if (!obj) {
 443         abort();
 444     }
 445
 446     switch (qobject_type(obj)) {
 447         case QTYPE_QSTRING:
 448             qstring_append(outstr, qdict_get_str(qdict, key));
 449             break;
 450         case QTYPE_QINT:
 451             qstring_append_int(outstr, qdict_get_int(qdict, key));
 452             break;
 453         default:
 454             abort();
 455     }
 456
 457     QDECREF(key_qs);
 458     return ++end;
 459 }
 460
 461 static QString *qerror_format_desc(QDict *error,
 462                                    const QErrorStringTable *entry)
 463 {
 464     QString *qstring;
 465     const char *p;
 466
 467     assert(entry != NULL);
 468
 469     qstring = qstring_new();
 470
 471     for (p = entry->desc; *p != '\0';) {
 472         if (*p != '%') {
 473             qstring_append_chr(qstring, *p++);
 474         } else if (*(p + 1) == '%') {
 475             qstring_append_chr(qstring, '%');
 476             p += 2;
 477         } else {
 478             p = append_field(error, qstring, entry, p);
 479         }
 480     }
 481
 482     return qstring;
 483 }
 484
 485 QString *qerror_format(const char *fmt, QDict *error)
 486 {
 487     const QErrorStringTable *entry = NULL;
 488     int i;
 489
 490     for (i = 0; qerror_table[i].error_fmt; i++) {
 491         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 492             entry = &qerror_table[i];
 493             break;
 494         }
 495     }
 496
 497     return qerror_format_desc(error, entry);
 498 }
 499
 500 /**
 501  * qerror_human(): Format QError data into human-readable string.
 502  */
 503 QString *qerror_human(const QError *qerror)
 504 {
 505     return qerror_format_desc(qerror->error, qerror->entry);
 506 }
 507
 508 /**
 509  * qerror_print(): Print QError data
 510  *
 511  * This function will print the member 'desc' of the specified QError object,
 512  * it uses error_report() for this, so that the output is routed to the right
 513  * place (ie. stderr or Monitor's device).
 514  */
 515 void qerror_print(QError *qerror)
 516 {
 517     QString *qstring = qerror_human(qerror);
 518     loc_push_restore(&qerror->loc);
 519     error_report("%s", qstring_get_str(qstring));
 520     loc_pop(&qerror->loc);
 521     QDECREF(qstring);
 522 }
 523
 524 void qerror_report_internal(const char *file, int linenr, const char *func,
 525                             const char *fmt, ...)
 526 {
 527     va_list va;
 528     QError *qerror;
 529
 530     va_start(va, fmt);
 531     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 532     va_end(va);
 533
 534     if (monitor_cur_is_qmp()) {
 535         monitor_set_error(cur_mon, qerror);
 536     } else {
 537         qerror_print(qerror);
 538         QDECREF(qerror);
 539     }
 540 }
 541
 542 /* Evil... */
 543 struct Error
 544 {
 545     QDict *obj;
 546     const char *fmt;
 547     char *msg;
 548 };
 549
 550 void qerror_report_err(Error *err)
 551 {
 552     QError *qerr;
 553     int i;
 554
 555     qerr = qerror_new();
 556     loc_save(&qerr->loc);
 557     QINCREF(err->obj);
 558     qerr->error = err->obj;
 559
 560     for (i = 0; qerror_table[i].error_fmt; i++) {
 561         if (strcmp(qerror_table[i].error_fmt, err->fmt) == 0) {
 562             qerr->entry = &qerror_table[i];
 563             break;
 564         }
 565     }
 566
 567     if (monitor_cur_is_qmp()) {
 568         monitor_set_error(cur_mon, qerr);
 569     } else {
 570         qerror_print(qerr);
 571         QDECREF(qerr);
 572     }
 573 }
 574
 575 void assert_no_error(Error *err)
 576 {
 577     if (err) {
 578         qerror_report_err(err);
 579         abort();
 580     }
 581 }
 582
 583 /**
 584  * qobject_to_qerror(): Convert a QObject into a QError
 585  */
 586 QError *qobject_to_qerror(const QObject *obj)
 587 {
 588     if (qobject_type(obj) != QTYPE_QERROR) {
 589         return NULL;
 590     }
 591
 592     return container_of(obj, QError, base);
 593 }
 594
 595 /**
 596  * qerror_destroy_obj(): Free all memory allocated by a QError
 597  */
 598 static void qerror_destroy_obj(QObject *obj)
 599 {
 600     QError *qerr;
 601
 602     assert(obj != NULL);
 603     qerr = qobject_to_qerror(obj);
 604
 605     QDECREF(qerr->error);
 606     g_free(qerr);
 607 }