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 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      = "Expected '%(expected)' in QMP input",
 174     },
 175     {
 176         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
 177         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
 178     },
 179     {
 180         .error_fmt = QERR_SET_PASSWD_FAILED,
 181         .desc      = "Could not set password",
 182     },
 183     {
 184         .error_fmt = QERR_TOO_MANY_FILES,
 185         .desc      = "Too many open files",
 186     },
 187     {
 188         .error_fmt = QERR_UNDEFINED_ERROR,
 189         .desc      = "An undefined error has ocurred",
 190     },
 191     {
 192         .error_fmt = QERR_VNC_SERVER_FAILED,
 193         .desc      = "Could not start VNC server on %(target)",
 194     },
 195     {}
 196 };
 197
 198 /**
 199  * qerror_new(): Create a new QError
 200  *
 201  * Return strong reference.
 202  */
 203 QError *qerror_new(void)
 204 {
 205     QError *qerr;
 206
 207     qerr = qemu_mallocz(sizeof(*qerr));
 208     QOBJECT_INIT(qerr, &qerror_type);
 209
 210     return qerr;
 211 }
 212
 213 static void qerror_abort(const QError *qerr, const char *fmt, ...)
 214 {
 215     va_list ap;
 216
 217     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 218     fprintf(stderr, "qerror: -> ");
 219
 220     va_start(ap, fmt);
 221     vfprintf(stderr, fmt, ap);
 222     va_end(ap);
 223
 224     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 225     abort();
 226 }
 227
 228 static void qerror_set_data(QError *qerr, const char *fmt, va_list *va)
 229 {
 230     QObject *obj;
 231
 232     obj = qobject_from_jsonv(fmt, va);
 233     if (!obj) {
 234         qerror_abort(qerr, "invalid format '%s'", fmt);
 235     }
 236     if (qobject_type(obj) != QTYPE_QDICT) {
 237         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 238     }
 239
 240     qerr->error = qobject_to_qdict(obj);
 241
 242     obj = qdict_get(qerr->error, "class");
 243     if (!obj) {
 244         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 245     }
 246     if (qobject_type(obj) != QTYPE_QSTRING) {
 247         qerror_abort(qerr, "'class' key value should be a QString");
 248     }
 249
 250     obj = qdict_get(qerr->error, "data");
 251     if (!obj) {
 252         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 253     }
 254     if (qobject_type(obj) != QTYPE_QDICT) {
 255         qerror_abort(qerr, "'data' key value should be a QDICT");
 256     }
 257 }
 258
 259 static void qerror_set_desc(QError *qerr, const char *fmt)
 260 {
 261     int i;
 262
 263     // FIXME: inefficient loop
 264
 265     for (i = 0; qerror_table[i].error_fmt; i++) {
 266         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 267             qerr->entry = &qerror_table[i];
 268             return;
 269         }
 270     }
 271
 272     qerror_abort(qerr, "error format '%s' not found", fmt);
 273 }
 274
 275 /**
 276  * qerror_from_info(): Create a new QError from error information
 277  *
 278  * The information consists of:
 279  *
 280  * - file   the file name of where the error occurred
 281  * - linenr the line number of where the error occurred
 282  * - func   the function name of where the error occurred
 283  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 284  *          'data'
 285  * - va     va_list of all arguments specified by fmt
 286  *
 287  * Return strong reference.
 288  */
 289 QError *qerror_from_info(const char *file, int linenr, const char *func,
 290                          const char *fmt, va_list *va)
 291 {
 292     QError *qerr;
 293
 294     qerr = qerror_new();
 295     loc_save(&qerr->loc);
 296     qerr->linenr = linenr;
 297     qerr->file = file;
 298     qerr->func = func;
 299
 300     if (!fmt) {
 301         qerror_abort(qerr, "QDict not specified");
 302     }
 303
 304     qerror_set_data(qerr, fmt, va);
 305     qerror_set_desc(qerr, fmt);
 306
 307     return qerr;
 308 }
 309
 310 static void parse_error(const QError *qerror, int c)
 311 {
 312     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
 313 }
 314
 315 static const char *append_field(QString *outstr, const QError *qerror,
 316                                 const char *start)
 317 {
 318     QObject *obj;
 319     QDict *qdict;
 320     QString *key_qs;
 321     const char *end, *key;
 322
 323     if (*start != '%')
 324         parse_error(qerror, '%');
 325     start++;
 326     if (*start != '(')
 327         parse_error(qerror, '(');
 328     start++;
 329
 330     end = strchr(start, ')');
 331     if (!end)
 332         parse_error(qerror, ')');
 333
 334     key_qs = qstring_from_substr(start, 0, end - start - 1);
 335     key = qstring_get_str(key_qs);
 336
 337     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
 338     obj = qdict_get(qdict, key);
 339     if (!obj) {
 340         qerror_abort(qerror, "key '%s' not found in QDict", key);
 341     }
 342
 343     switch (qobject_type(obj)) {
 344         case QTYPE_QSTRING:
 345             qstring_append(outstr, qdict_get_str(qdict, key));
 346             break;
 347         case QTYPE_QINT:
 348             qstring_append_int(outstr, qdict_get_int(qdict, key));
 349             break;
 350         default:
 351             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
 352     }
 353
 354     QDECREF(key_qs);
 355     return ++end;
 356 }
 357
 358 /**
 359  * qerror_human(): Format QError data into human-readable string.
 360  *
 361  * Formats according to member 'desc' of the specified QError object.
 362  */
 363 QString *qerror_human(const QError *qerror)
 364 {
 365     const char *p;
 366     QString *qstring;
 367
 368     assert(qerror->entry != NULL);
 369
 370     qstring = qstring_new();
 371
 372     for (p = qerror->entry->desc; *p != '\0';) {
 373         if (*p != '%') {
 374             qstring_append_chr(qstring, *p++);
 375         } else if (*(p + 1) == '%') {
 376             qstring_append_chr(qstring, '%');
 377             p += 2;
 378         } else {
 379             p = append_field(qstring, qerror, p);
 380         }
 381     }
 382
 383     return qstring;
 384 }
 385
 386 /**
 387  * qerror_print(): Print QError data
 388  *
 389  * This function will print the member 'desc' of the specified QError object,
 390  * it uses error_report() for this, so that the output is routed to the right
 391  * place (ie. stderr or Monitor's device).
 392  */
 393 void qerror_print(QError *qerror)
 394 {
 395     QString *qstring = qerror_human(qerror);
 396     loc_push_restore(&qerror->loc);
 397     error_report("%s", qstring_get_str(qstring));
 398     loc_pop(&qerror->loc);
 399     QDECREF(qstring);
 400 }
 401
 402 void qerror_report_internal(const char *file, int linenr, const char *func,
 403                             const char *fmt, ...)
 404 {
 405     va_list va;
 406     QError *qerror;
 407
 408     va_start(va, fmt);
 409     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 410     va_end(va);
 411
 412     if (monitor_cur_is_qmp()) {
 413         monitor_set_error(cur_mon, qerror);
 414     } else {
 415         qerror_print(qerror);
 416         QDECREF(qerror);
 417     }
 418 }
 419
 420 /**
 421  * qobject_to_qerror(): Convert a QObject into a QError
 422  */
 423 QError *qobject_to_qerror(const QObject *obj)
 424 {
 425     if (qobject_type(obj) != QTYPE_QERROR) {
 426         return NULL;
 427     }
 428
 429     return container_of(obj, QError, base);
 430 }
 431
 432 /**
 433  * qerror_destroy_obj(): Free all memory allocated by a QError
 434  */
 435 static void qerror_destroy_obj(QObject *obj)
 436 {
 437     QError *qerr;
 438
 439     assert(obj != NULL);
 440     qerr = qobject_to_qerror(obj);
 441
 442     QDECREF(qerr->error);
 443     qemu_free(qerr);
 444 }