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_JSON_PARSE_ERROR,
 145         .desc      = "JSON parse error, %(message)",
 146
 147     },
 148     {
 149         .error_fmt = QERR_KVM_MISSING_CAP,
 150         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 151     },
 152     {
 153         .error_fmt = QERR_MIGRATION_EXPECTED,
 154         .desc      = "An incoming migration is expected before this command can be executed",
 155     },
 156     {
 157         .error_fmt = QERR_MISSING_PARAMETER,
 158         .desc      = "Parameter '%(name)' is missing",
 159     },
 160     {
 161         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 162         .desc      = "No '%(bus)' bus found for device '%(device)'",
 163     },
 164     {
 165         .error_fmt = QERR_OPEN_FILE_FAILED,
 166         .desc      = "Could not open '%(filename)'",
 167     },
 168     {
 169         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 170         .desc      = "Property '%(device).%(property)' not found",
 171     },
 172     {
 173         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 174         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 175     },
 176     {
 177         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 178         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 179     },
 180     {
 181         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 182         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 183     },
 184     {
 185         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 186         .desc      = "Expected '%(expected)' in QMP input",
 187     },
 188     {
 189         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 190         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 191     },
 192     {
 193         .error_fmt = QERR_QMP_EXTRA_MEMBER,
 194         .desc      = "QMP input object member '%(member)' is unexpected",
 195     },
 196     {
 197         .error_fmt = QERR_SET_PASSWD_FAILED,
 198         .desc      = "Could not set password",
 199     },
 200     {
 201         .error_fmt = QERR_TOO_MANY_FILES,
 202         .desc      = "Too many open files",
 203     },
 204     {
 205         .error_fmt = QERR_UNDEFINED_ERROR,
 206         .desc      = "An undefined error has ocurred",
 207     },
 208     {
 209         .error_fmt = QERR_UNSUPPORTED,
 210         .desc      = "this feature or command is not currently supported",
 211     },
 212     {
 213         .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
 214         .desc      = "'%(device)' uses a %(format) feature which is not "
 215                      "supported by this qemu version: %(feature)",
 216     },
 217     {
 218         .error_fmt = QERR_VNC_SERVER_FAILED,
 219         .desc      = "Could not start VNC server on %(target)",
 220     },
 221     {}
 222 };
 223
 224 /**
 225  * qerror_new(): Create a new QError
 226  *
 227  * Return strong reference.
 228  */
 229 QError *qerror_new(void)
 230 {
 231     QError *qerr;
 232
 233     qerr = qemu_mallocz(sizeof(*qerr));
 234     QOBJECT_INIT(qerr, &qerror_type);
 235
 236     return qerr;
 237 }
 238
 239 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
 240                                             const char *fmt, ...)
 241 {
 242     va_list ap;
 243
 244     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 245     fprintf(stderr, "qerror: -> ");
 246
 247     va_start(ap, fmt);
 248     vfprintf(stderr, fmt, ap);
 249     va_end(ap);
 250
 251     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 252     abort();
 253 }
 254
 255 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
 256                                                const char *fmt, va_list *va)
 257 {
 258     QObject *obj;
 259
 260     obj = qobject_from_jsonv(fmt, va);
 261     if (!obj) {
 262         qerror_abort(qerr, "invalid format '%s'", fmt);
 263     }
 264     if (qobject_type(obj) != QTYPE_QDICT) {
 265         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 266     }
 267
 268     qerr->error = qobject_to_qdict(obj);
 269
 270     obj = qdict_get(qerr->error, "class");
 271     if (!obj) {
 272         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 273     }
 274     if (qobject_type(obj) != QTYPE_QSTRING) {
 275         qerror_abort(qerr, "'class' key value should be a QString");
 276     }
 277
 278     obj = qdict_get(qerr->error, "data");
 279     if (!obj) {
 280         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 281     }
 282     if (qobject_type(obj) != QTYPE_QDICT) {
 283         qerror_abort(qerr, "'data' key value should be a QDICT");
 284     }
 285 }
 286
 287 static void qerror_set_desc(QError *qerr, const char *fmt)
 288 {
 289     int i;
 290
 291     // FIXME: inefficient loop
 292
 293     for (i = 0; qerror_table[i].error_fmt; i++) {
 294         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 295             qerr->entry = &qerror_table[i];
 296             return;
 297         }
 298     }
 299
 300     qerror_abort(qerr, "error format '%s' not found", fmt);
 301 }
 302
 303 /**
 304  * qerror_from_info(): Create a new QError from error information
 305  *
 306  * The information consists of:
 307  *
 308  * - file   the file name of where the error occurred
 309  * - linenr the line number of where the error occurred
 310  * - func   the function name of where the error occurred
 311  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 312  *          'data'
 313  * - va     va_list of all arguments specified by fmt
 314  *
 315  * Return strong reference.
 316  */
 317 QError *qerror_from_info(const char *file, int linenr, const char *func,
 318                          const char *fmt, va_list *va)
 319 {
 320     QError *qerr;
 321
 322     qerr = qerror_new();
 323     loc_save(&qerr->loc);
 324     qerr->linenr = linenr;
 325     qerr->file = file;
 326     qerr->func = func;
 327
 328     if (!fmt) {
 329         qerror_abort(qerr, "QDict not specified");
 330     }
 331
 332     qerror_set_data(qerr, fmt, va);
 333     qerror_set_desc(qerr, fmt);
 334
 335     return qerr;
 336 }
 337
 338 static void parse_error(const QErrorStringTable *entry, int c)
 339 {
 340     fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
 341     abort();
 342 }
 343
 344 static const char *append_field(QDict *error, QString *outstr,
 345                                 const QErrorStringTable *entry,
 346                                 const char *start)
 347 {
 348     QObject *obj;
 349     QDict *qdict;
 350     QString *key_qs;
 351     const char *end, *key;
 352
 353     if (*start != '%')
 354         parse_error(entry, '%');
 355     start++;
 356     if (*start != '(')
 357         parse_error(entry, '(');
 358     start++;
 359
 360     end = strchr(start, ')');
 361     if (!end)
 362         parse_error(entry, ')');
 363
 364     key_qs = qstring_from_substr(start, 0, end - start - 1);
 365     key = qstring_get_str(key_qs);
 366
 367     qdict = qobject_to_qdict(qdict_get(error, "data"));
 368     obj = qdict_get(qdict, key);
 369     if (!obj) {
 370         abort();
 371     }
 372
 373     switch (qobject_type(obj)) {
 374         case QTYPE_QSTRING:
 375             qstring_append(outstr, qdict_get_str(qdict, key));
 376             break;
 377         case QTYPE_QINT:
 378             qstring_append_int(outstr, qdict_get_int(qdict, key));
 379             break;
 380         default:
 381             abort();
 382     }
 383
 384     QDECREF(key_qs);
 385     return ++end;
 386 }
 387
 388 static QString *qerror_format_desc(QDict *error,
 389                                    const QErrorStringTable *entry)
 390 {
 391     QString *qstring;
 392     const char *p;
 393
 394     assert(entry != NULL);
 395
 396     qstring = qstring_new();
 397
 398     for (p = entry->desc; *p != '\0';) {
 399         if (*p != '%') {
 400             qstring_append_chr(qstring, *p++);
 401         } else if (*(p + 1) == '%') {
 402             qstring_append_chr(qstring, '%');
 403             p += 2;
 404         } else {
 405             p = append_field(error, qstring, entry, p);
 406         }
 407     }
 408
 409     return qstring;
 410 }
 411
 412 QString *qerror_format(const char *fmt, QDict *error)
 413 {
 414     const QErrorStringTable *entry = NULL;
 415     int i;
 416
 417     for (i = 0; qerror_table[i].error_fmt; i++) {
 418         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 419             entry = &qerror_table[i];
 420             break;
 421         }
 422     }
 423
 424     return qerror_format_desc(error, entry);
 425 }
 426
 427 /**
 428  * qerror_human(): Format QError data into human-readable string.
 429  */
 430 QString *qerror_human(const QError *qerror)
 431 {
 432     return qerror_format_desc(qerror->error, qerror->entry);
 433 }
 434
 435 /**
 436  * qerror_print(): Print QError data
 437  *
 438  * This function will print the member 'desc' of the specified QError object,
 439  * it uses error_report() for this, so that the output is routed to the right
 440  * place (ie. stderr or Monitor's device).
 441  */
 442 void qerror_print(QError *qerror)
 443 {
 444     QString *qstring = qerror_human(qerror);
 445     loc_push_restore(&qerror->loc);
 446     error_report("%s", qstring_get_str(qstring));
 447     loc_pop(&qerror->loc);
 448     QDECREF(qstring);
 449 }
 450
 451 void qerror_report_internal(const char *file, int linenr, const char *func,
 452                             const char *fmt, ...)
 453 {
 454     va_list va;
 455     QError *qerror;
 456
 457     va_start(va, fmt);
 458     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 459     va_end(va);
 460
 461     if (monitor_cur_is_qmp()) {
 462         monitor_set_error(cur_mon, qerror);
 463     } else {
 464         qerror_print(qerror);
 465         QDECREF(qerror);
 466     }
 467 }
 468
 469 /**
 470  * qobject_to_qerror(): Convert a QObject into a QError
 471  */
 472 QError *qobject_to_qerror(const QObject *obj)
 473 {
 474     if (qobject_type(obj) != QTYPE_QERROR) {
 475         return NULL;
 476     }
 477
 478     return container_of(obj, QError, base);
 479 }
 480
 481 /**
 482  * qerror_destroy_obj(): Free all memory allocated by a QError
 483  */
 484 static void qerror_destroy_obj(QObject *obj)
 485 {
 486     QError *qerr;
 487
 488     assert(obj != NULL);
 489     qerr = qobject_to_qerror(obj);
 490
 491     QDECREF(qerr->error);
 492     qemu_free(qerr);
 493 }