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