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_INVALID_BLOCK_FORMAT,
 121         .desc      = "Invalid block format '%(name)'",
 122     },
 123     {
 124         .error_fmt = QERR_INVALID_PARAMETER,
 125         .desc      = "Invalid parameter '%(name)'",
 126     },
 127     {
 128         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 129         .desc      = "Invalid parameter type, expected: %(expected)",
 130     },
 131     {
 132         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
 133         .desc      = "Parameter '%(name)' expects %(expected)",
 134     },
 135     {
 136         .error_fmt = QERR_INVALID_PASSWORD,
 137         .desc      = "Password incorrect",
 138     },
 139     {
 140         .error_fmt = QERR_JSON_PARSING,
 141         .desc      = "Invalid JSON syntax",
 142     },
 143     {
 144         .error_fmt = QERR_KVM_MISSING_CAP,
 145         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 146     },
 147     {
 148         .error_fmt = QERR_MIGRATION_EXPECTED,
 149         .desc      = "An incoming migration is expected before this command can be executed",
 150     },
 151     {
 152         .error_fmt = QERR_MISSING_PARAMETER,
 153         .desc      = "Parameter '%(name)' is missing",
 154     },
 155     {
 156         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 157         .desc      = "No '%(bus)' bus found for device '%(device)'",
 158     },
 159     {
 160         .error_fmt = QERR_OPEN_FILE_FAILED,
 161         .desc      = "Could not open '%(filename)'",
 162     },
 163     {
 164         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 165         .desc      = "Property '%(device).%(property)' not found",
 166     },
 167     {
 168         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 169         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 170     },
 171     {
 172         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 173         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 174     },
 175     {
 176         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 177         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 178     },
 179     {
 180         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 181         .desc      = "Expected '%(expected)' in QMP input",
 182     },
 183     {
 184         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 185         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 186     },
 187     {
 188         .error_fmt = QERR_QMP_EXTRA_MEMBER,
 189         .desc      = "QMP input object member '%(member)' is unexpected",
 190     },
 191     {
 192         .error_fmt = QERR_SET_PASSWD_FAILED,
 193         .desc      = "Could not set password",
 194     },
 195     {
 196         .error_fmt = QERR_TOO_MANY_FILES,
 197         .desc      = "Too many open files",
 198     },
 199     {
 200         .error_fmt = QERR_UNDEFINED_ERROR,
 201         .desc      = "An undefined error has ocurred",
 202     },
 203     {
 204         .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
 205         .desc      = "'%(device)' uses a %(format) feature which is not "
 206                      "supported by this qemu version: %(feature)",
 207     },
 208     {
 209         .error_fmt = QERR_VNC_SERVER_FAILED,
 210         .desc      = "Could not start VNC server on %(target)",
 211     },
 212     {}
 213 };
 214
 215 /**
 216  * qerror_new(): Create a new QError
 217  *
 218  * Return strong reference.
 219  */
 220 QError *qerror_new(void)
 221 {
 222     QError *qerr;
 223
 224     qerr = qemu_mallocz(sizeof(*qerr));
 225     QOBJECT_INIT(qerr, &qerror_type);
 226
 227     return qerr;
 228 }
 229
 230 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
 231                                             const char *fmt, ...)
 232 {
 233     va_list ap;
 234
 235     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 236     fprintf(stderr, "qerror: -> ");
 237
 238     va_start(ap, fmt);
 239     vfprintf(stderr, fmt, ap);
 240     va_end(ap);
 241
 242     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 243     abort();
 244 }
 245
 246 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
 247                                                const char *fmt, va_list *va)
 248 {
 249     QObject *obj;
 250
 251     obj = qobject_from_jsonv(fmt, va);
 252     if (!obj) {
 253         qerror_abort(qerr, "invalid format '%s'", fmt);
 254     }
 255     if (qobject_type(obj) != QTYPE_QDICT) {
 256         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 257     }
 258
 259     qerr->error = qobject_to_qdict(obj);
 260
 261     obj = qdict_get(qerr->error, "class");
 262     if (!obj) {
 263         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 264     }
 265     if (qobject_type(obj) != QTYPE_QSTRING) {
 266         qerror_abort(qerr, "'class' key value should be a QString");
 267     }
 268
 269     obj = qdict_get(qerr->error, "data");
 270     if (!obj) {
 271         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 272     }
 273     if (qobject_type(obj) != QTYPE_QDICT) {
 274         qerror_abort(qerr, "'data' key value should be a QDICT");
 275     }
 276 }
 277
 278 static void qerror_set_desc(QError *qerr, const char *fmt)
 279 {
 280     int i;
 281
 282     // FIXME: inefficient loop
 283
 284     for (i = 0; qerror_table[i].error_fmt; i++) {
 285         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 286             qerr->entry = &qerror_table[i];
 287             return;
 288         }
 289     }
 290
 291     qerror_abort(qerr, "error format '%s' not found", fmt);
 292 }
 293
 294 /**
 295  * qerror_from_info(): Create a new QError from error information
 296  *
 297  * The information consists of:
 298  *
 299  * - file   the file name of where the error occurred
 300  * - linenr the line number of where the error occurred
 301  * - func   the function name of where the error occurred
 302  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 303  *          'data'
 304  * - va     va_list of all arguments specified by fmt
 305  *
 306  * Return strong reference.
 307  */
 308 QError *qerror_from_info(const char *file, int linenr, const char *func,
 309                          const char *fmt, va_list *va)
 310 {
 311     QError *qerr;
 312
 313     qerr = qerror_new();
 314     loc_save(&qerr->loc);
 315     qerr->linenr = linenr;
 316     qerr->file = file;
 317     qerr->func = func;
 318
 319     if (!fmt) {
 320         qerror_abort(qerr, "QDict not specified");
 321     }
 322
 323     qerror_set_data(qerr, fmt, va);
 324     qerror_set_desc(qerr, fmt);
 325
 326     return qerr;
 327 }
 328
 329 static void parse_error(const QErrorStringTable *entry, int c)
 330 {
 331     fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
 332     abort();
 333 }
 334
 335 static const char *append_field(QDict *error, QString *outstr,
 336                                 const QErrorStringTable *entry,
 337                                 const char *start)
 338 {
 339     QObject *obj;
 340     QDict *qdict;
 341     QString *key_qs;
 342     const char *end, *key;
 343
 344     if (*start != '%')
 345         parse_error(entry, '%');
 346     start++;
 347     if (*start != '(')
 348         parse_error(entry, '(');
 349     start++;
 350
 351     end = strchr(start, ')');
 352     if (!end)
 353         parse_error(entry, ')');
 354
 355     key_qs = qstring_from_substr(start, 0, end - start - 1);
 356     key = qstring_get_str(key_qs);
 357
 358     qdict = qobject_to_qdict(qdict_get(error, "data"));
 359     obj = qdict_get(qdict, key);
 360     if (!obj) {
 361         abort();
 362     }
 363
 364     switch (qobject_type(obj)) {
 365         case QTYPE_QSTRING:
 366             qstring_append(outstr, qdict_get_str(qdict, key));
 367             break;
 368         case QTYPE_QINT:
 369             qstring_append_int(outstr, qdict_get_int(qdict, key));
 370             break;
 371         default:
 372             abort();
 373     }
 374
 375     QDECREF(key_qs);
 376     return ++end;
 377 }
 378
 379 static QString *qerror_format_desc(QDict *error,
 380                                    const QErrorStringTable *entry)
 381 {
 382     QString *qstring;
 383     const char *p;
 384
 385     assert(entry != NULL);
 386
 387     qstring = qstring_new();
 388
 389     for (p = entry->desc; *p != '\0';) {
 390         if (*p != '%') {
 391             qstring_append_chr(qstring, *p++);
 392         } else if (*(p + 1) == '%') {
 393             qstring_append_chr(qstring, '%');
 394             p += 2;
 395         } else {
 396             p = append_field(error, qstring, entry, p);
 397         }
 398     }
 399
 400     return qstring;
 401 }
 402
 403 QString *qerror_format(const char *fmt, QDict *error)
 404 {
 405     const QErrorStringTable *entry = NULL;
 406     int i;
 407
 408     for (i = 0; qerror_table[i].error_fmt; i++) {
 409         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 410             entry = &qerror_table[i];
 411             break;
 412         }
 413     }
 414
 415     return qerror_format_desc(error, entry);
 416 }
 417
 418 /**
 419  * qerror_human(): Format QError data into human-readable string.
 420  */
 421 QString *qerror_human(const QError *qerror)
 422 {
 423     return qerror_format_desc(qerror->error, qerror->entry);
 424 }
 425
 426 /**
 427  * qerror_print(): Print QError data
 428  *
 429  * This function will print the member 'desc' of the specified QError object,
 430  * it uses error_report() for this, so that the output is routed to the right
 431  * place (ie. stderr or Monitor's device).
 432  */
 433 void qerror_print(QError *qerror)
 434 {
 435     QString *qstring = qerror_human(qerror);
 436     loc_push_restore(&qerror->loc);
 437     error_report("%s", qstring_get_str(qstring));
 438     loc_pop(&qerror->loc);
 439     QDECREF(qstring);
 440 }
 441
 442 void qerror_report_internal(const char *file, int linenr, const char *func,
 443                             const char *fmt, ...)
 444 {
 445     va_list va;
 446     QError *qerror;
 447
 448     va_start(va, fmt);
 449     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 450     va_end(va);
 451
 452     if (monitor_cur_is_qmp()) {
 453         monitor_set_error(cur_mon, qerror);
 454     } else {
 455         qerror_print(qerror);
 456         QDECREF(qerror);
 457     }
 458 }
 459
 460 /**
 461  * qobject_to_qerror(): Convert a QObject into a QError
 462  */
 463 QError *qobject_to_qerror(const QObject *obj)
 464 {
 465     if (qobject_type(obj) != QTYPE_QERROR) {
 466         return NULL;
 467     }
 468
 469     return container_of(obj, QError, base);
 470 }
 471
 472 /**
 473  * qerror_destroy_obj(): Free all memory allocated by a QError
 474  */
 475 static void qerror_destroy_obj(QObject *obj)
 476 {
 477     QError *qerr;
 478
 479     assert(obj != NULL);
 480     qerr = qobject_to_qerror(obj);
 481
 482     QDECREF(qerr->error);
 483     qemu_free(qerr);
 484 }