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