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