qerror.c

   1 /*
   2  * QError: QEMU Error data-type.
   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 by the guest",
  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_DUPLICATE_ID,
 105         .desc      = "Duplicate ID '%(id)' for %(object)",
 106     },
 107     {
 108         .error_fmt = QERR_FD_NOT_FOUND,
 109         .desc      = "File descriptor named '%(name)' not found",
 110     },
 111     {
 112         .error_fmt = QERR_FD_NOT_SUPPLIED,
 113         .desc      = "No file descriptor supplied via SCM_RIGHTS",
 114     },
 115     {
 116         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
 117         .desc      = "Invalid block format '%(name)'",
 118     },
 119     {
 120         .error_fmt = QERR_INVALID_PARAMETER,
 121         .desc      = "Invalid parameter '%(name)'",
 122     },
 123     {
 124         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 125         .desc      = "Invalid parameter type, expected: %(expected)",
 126     },
 127     {
 128         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
 129         .desc      = "Parameter '%(name)' expects %(expected)",
 130     },
 131     {
 132         .error_fmt = QERR_INVALID_PASSWORD,
 133         .desc      = "Password incorrect",
 134     },
 135     {
 136         .error_fmt = QERR_JSON_PARSING,
 137         .desc      = "Invalid JSON syntax",
 138     },
 139     {
 140         .error_fmt = QERR_KVM_MISSING_CAP,
 141         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 142     },
 143     {
 144         .error_fmt = QERR_MISSING_PARAMETER,
 145         .desc      = "Parameter '%(name)' is missing",
 146     },
 147     {
 148         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 149         .desc      = "No '%(bus)' bus found for device '%(device)'",
 150     },
 151     {
 152         .error_fmt = QERR_OPEN_FILE_FAILED,
 153         .desc      = "Could not open '%(filename)'",
 154     },
 155     {
 156         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 157         .desc      = "Property '%(device).%(property)' not found",
 158     },
 159     {
 160         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 161         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 162     },
 163     {
 164         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 165         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 166     },
 167     {
 168         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 169         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 170     },
 171     {
 172         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 173         .desc      = "Bad QMP input object",
 174     },
 175     {
 176         .error_fmt = QERR_SET_PASSWD_FAILED,
 177         .desc      = "Could not set password",
 178     },
 179     {
 180         .error_fmt = QERR_TOO_MANY_FILES,
 181         .desc      = "Too many open files",
 182     },
 183     {
 184         .error_fmt = QERR_UNDEFINED_ERROR,
 185         .desc      = "An undefined error has ocurred",
 186     },
 187     {
 188         .error_fmt = QERR_VNC_SERVER_FAILED,
 189         .desc      = "Could not start VNC server on %(target)",
 190     },
 191     {}
 192 };
 193
 194 /**
 195  * qerror_new(): Create a new QError
 196  *
 197  * Return strong reference.
 198  */
 199 QError *qerror_new(void)
 200 {
 201     QError *qerr;
 202
 203     qerr = qemu_mallocz(sizeof(*qerr));
 204     QOBJECT_INIT(qerr, &qerror_type);
 205
 206     return qerr;
 207 }
 208
 209 static void qerror_abort(const QError *qerr, const char *fmt, ...)
 210 {
 211     va_list ap;
 212
 213     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 214     fprintf(stderr, "qerror: -> ");
 215
 216     va_start(ap, fmt);
 217     vfprintf(stderr, fmt, ap);
 218     va_end(ap);
 219
 220     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 221     abort();
 222 }
 223
 224 static void qerror_set_data(QError *qerr, const char *fmt, va_list *va)
 225 {
 226     QObject *obj;
 227
 228     obj = qobject_from_jsonv(fmt, va);
 229     if (!obj) {
 230         qerror_abort(qerr, "invalid format '%s'", fmt);
 231     }
 232     if (qobject_type(obj) != QTYPE_QDICT) {
 233         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 234     }
 235
 236     qerr->error = qobject_to_qdict(obj);
 237
 238     obj = qdict_get(qerr->error, "class");
 239     if (!obj) {
 240         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 241     }
 242     if (qobject_type(obj) != QTYPE_QSTRING) {
 243         qerror_abort(qerr, "'class' key value should be a QString");
 244     }
 245
 246     obj = qdict_get(qerr->error, "data");
 247     if (!obj) {
 248         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 249     }
 250     if (qobject_type(obj) != QTYPE_QDICT) {
 251         qerror_abort(qerr, "'data' key value should be a QDICT");
 252     }
 253 }
 254
 255 static void qerror_set_desc(QError *qerr, const char *fmt)
 256 {
 257     int i;
 258
 259     // FIXME: inefficient loop
 260
 261     for (i = 0; qerror_table[i].error_fmt; i++) {
 262         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 263             qerr->entry = &qerror_table[i];
 264             return;
 265         }
 266     }
 267
 268     qerror_abort(qerr, "error format '%s' not found", fmt);
 269 }
 270
 271 /**
 272  * qerror_from_info(): Create a new QError from error information
 273  *
 274  * The information consists of:
 275  *
 276  * - file   the file name of where the error occurred
 277  * - linenr the line number of where the error occurred
 278  * - func   the function name of where the error occurred
 279  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 280  *          'data'
 281  * - va     va_list of all arguments specified by fmt
 282  *
 283  * Return strong reference.
 284  */
 285 QError *qerror_from_info(const char *file, int linenr, const char *func,
 286                          const char *fmt, va_list *va)
 287 {
 288     QError *qerr;
 289
 290     qerr = qerror_new();
 291     loc_save(&qerr->loc);
 292     qerr->linenr = linenr;
 293     qerr->file = file;
 294     qerr->func = func;
 295
 296     if (!fmt) {
 297         qerror_abort(qerr, "QDict not specified");
 298     }
 299
 300     qerror_set_data(qerr, fmt, va);
 301     qerror_set_desc(qerr, fmt);
 302
 303     return qerr;
 304 }
 305
 306 static void parse_error(const QError *qerror, int c)
 307 {
 308     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
 309 }
 310
 311 static const char *append_field(QString *outstr, const QError *qerror,
 312                                 const char *start)
 313 {
 314     QObject *obj;
 315     QDict *qdict;
 316     QString *key_qs;
 317     const char *end, *key;
 318
 319     if (*start != '%')
 320         parse_error(qerror, '%');
 321     start++;
 322     if (*start != '(')
 323         parse_error(qerror, '(');
 324     start++;
 325
 326     end = strchr(start, ')');
 327     if (!end)
 328         parse_error(qerror, ')');
 329
 330     key_qs = qstring_from_substr(start, 0, end - start - 1);
 331     key = qstring_get_str(key_qs);
 332
 333     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
 334     obj = qdict_get(qdict, key);
 335     if (!obj) {
 336         qerror_abort(qerror, "key '%s' not found in QDict", key);
 337     }
 338
 339     switch (qobject_type(obj)) {
 340         case QTYPE_QSTRING:
 341             qstring_append(outstr, qdict_get_str(qdict, key));
 342             break;
 343         case QTYPE_QINT:
 344             qstring_append_int(outstr, qdict_get_int(qdict, key));
 345             break;
 346         default:
 347             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
 348     }
 349
 350     QDECREF(key_qs);
 351     return ++end;
 352 }
 353
 354 /**
 355  * qerror_human(): Format QError data into human-readable string.
 356  *
 357  * Formats according to member 'desc' of the specified QError object.
 358  */
 359 QString *qerror_human(const QError *qerror)
 360 {
 361     const char *p;
 362     QString *qstring;
 363
 364     assert(qerror->entry != NULL);
 365
 366     qstring = qstring_new();
 367
 368     for (p = qerror->entry->desc; *p != '\0';) {
 369         if (*p != '%') {
 370             qstring_append_chr(qstring, *p++);
 371         } else if (*(p + 1) == '%') {
 372             qstring_append_chr(qstring, '%');
 373             p += 2;
 374         } else {
 375             p = append_field(qstring, qerror, p);
 376         }
 377     }
 378
 379     return qstring;
 380 }
 381
 382 /**
 383  * qerror_print(): Print QError data
 384  *
 385  * This function will print the member 'desc' of the specified QError object,
 386  * it uses error_report() for this, so that the output is routed to the right
 387  * place (ie. stderr or Monitor's device).
 388  */
 389 void qerror_print(QError *qerror)
 390 {
 391     QString *qstring = qerror_human(qerror);
 392     loc_push_restore(&qerror->loc);
 393     error_report("%s", qstring_get_str(qstring));
 394     loc_pop(&qerror->loc);
 395     QDECREF(qstring);
 396 }
 397
 398 void qerror_report_internal(const char *file, int linenr, const char *func,
 399                             const char *fmt, ...)
 400 {
 401     va_list va;
 402     QError *qerror;
 403
 404     va_start(va, fmt);
 405     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 406     va_end(va);
 407
 408     if (monitor_cur_is_qmp()) {
 409         monitor_set_error(cur_mon, qerror);
 410     } else {
 411         qerror_print(qerror);
 412         QDECREF(qerror);
 413     }
 414 }
 415
 416 /**
 417  * qobject_to_qerror(): Convert a QObject into a QError
 418  */
 419 QError *qobject_to_qerror(const QObject *obj)
 420 {
 421     if (qobject_type(obj) != QTYPE_QERROR) {
 422         return NULL;
 423     }
 424
 425     return container_of(obj, QError, base);
 426 }
 427
 428 /**
 429  * qerror_destroy_obj(): Free all memory allocated by a QError
 430  */
 431 static void qerror_destroy_obj(QObject *obj)
 432 {
 433     QError *qerr;
 434
 435     assert(obj != NULL);
 436     qerr = qobject_to_qerror(obj);
 437
 438     QDECREF(qerr->error);
 439     qemu_free(qerr);
 440 }