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