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_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_QMP_EXTRA_MEMBER,
 181         .desc      = "QMP input object member '%(member)' is unexpected",
 182     },
 183     {
 184         .error_fmt = QERR_SET_PASSWD_FAILED,
 185         .desc      = "Could not set password",
 186     },
 187     {
 188         .error_fmt = QERR_TOO_MANY_FILES,
 189         .desc      = "Too many open files",
 190     },
 191     {
 192         .error_fmt = QERR_UNDEFINED_ERROR,
 193         .desc      = "An undefined error has ocurred",
 194     },
 195     {
 196         .error_fmt = QERR_VNC_SERVER_FAILED,
 197         .desc      = "Could not start VNC server on %(target)",
 198     },
 199     {}
 200 };
 201
 202 /**
 203  * qerror_new(): Create a new QError
 204  *
 205  * Return strong reference.
 206  */
 207 QError *qerror_new(void)
 208 {
 209     QError *qerr;
 210
 211     qerr = qemu_mallocz(sizeof(*qerr));
 212     QOBJECT_INIT(qerr, &qerror_type);
 213
 214     return qerr;
 215 }
 216
 217 static void qerror_abort(const QError *qerr, const char *fmt, ...)
 218 {
 219     va_list ap;
 220
 221     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 222     fprintf(stderr, "qerror: -> ");
 223
 224     va_start(ap, fmt);
 225     vfprintf(stderr, fmt, ap);
 226     va_end(ap);
 227
 228     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 229     abort();
 230 }
 231
 232 static void qerror_set_data(QError *qerr, const char *fmt, va_list *va)
 233 {
 234     QObject *obj;
 235
 236     obj = qobject_from_jsonv(fmt, va);
 237     if (!obj) {
 238         qerror_abort(qerr, "invalid format '%s'", fmt);
 239     }
 240     if (qobject_type(obj) != QTYPE_QDICT) {
 241         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 242     }
 243
 244     qerr->error = qobject_to_qdict(obj);
 245
 246     obj = qdict_get(qerr->error, "class");
 247     if (!obj) {
 248         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 249     }
 250     if (qobject_type(obj) != QTYPE_QSTRING) {
 251         qerror_abort(qerr, "'class' key value should be a QString");
 252     }
 253
 254     obj = qdict_get(qerr->error, "data");
 255     if (!obj) {
 256         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 257     }
 258     if (qobject_type(obj) != QTYPE_QDICT) {
 259         qerror_abort(qerr, "'data' key value should be a QDICT");
 260     }
 261 }
 262
 263 static void qerror_set_desc(QError *qerr, const char *fmt)
 264 {
 265     int i;
 266
 267     // FIXME: inefficient loop
 268
 269     for (i = 0; qerror_table[i].error_fmt; i++) {
 270         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 271             qerr->entry = &qerror_table[i];
 272             return;
 273         }
 274     }
 275
 276     qerror_abort(qerr, "error format '%s' not found", fmt);
 277 }
 278
 279 /**
 280  * qerror_from_info(): Create a new QError from error information
 281  *
 282  * The information consists of:
 283  *
 284  * - file   the file name of where the error occurred
 285  * - linenr the line number of where the error occurred
 286  * - func   the function name of where the error occurred
 287  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 288  *          'data'
 289  * - va     va_list of all arguments specified by fmt
 290  *
 291  * Return strong reference.
 292  */
 293 QError *qerror_from_info(const char *file, int linenr, const char *func,
 294                          const char *fmt, va_list *va)
 295 {
 296     QError *qerr;
 297
 298     qerr = qerror_new();
 299     loc_save(&qerr->loc);
 300     qerr->linenr = linenr;
 301     qerr->file = file;
 302     qerr->func = func;
 303
 304     if (!fmt) {
 305         qerror_abort(qerr, "QDict not specified");
 306     }
 307
 308     qerror_set_data(qerr, fmt, va);
 309     qerror_set_desc(qerr, fmt);
 310
 311     return qerr;
 312 }
 313
 314 static void parse_error(const QError *qerror, int c)
 315 {
 316     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
 317 }
 318
 319 static const char *append_field(QString *outstr, const QError *qerror,
 320                                 const char *start)
 321 {
 322     QObject *obj;
 323     QDict *qdict;
 324     QString *key_qs;
 325     const char *end, *key;
 326
 327     if (*start != '%')
 328         parse_error(qerror, '%');
 329     start++;
 330     if (*start != '(')
 331         parse_error(qerror, '(');
 332     start++;
 333
 334     end = strchr(start, ')');
 335     if (!end)
 336         parse_error(qerror, ')');
 337
 338     key_qs = qstring_from_substr(start, 0, end - start - 1);
 339     key = qstring_get_str(key_qs);
 340
 341     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
 342     obj = qdict_get(qdict, key);
 343     if (!obj) {
 344         qerror_abort(qerror, "key '%s' not found in QDict", key);
 345     }
 346
 347     switch (qobject_type(obj)) {
 348         case QTYPE_QSTRING:
 349             qstring_append(outstr, qdict_get_str(qdict, key));
 350             break;
 351         case QTYPE_QINT:
 352             qstring_append_int(outstr, qdict_get_int(qdict, key));
 353             break;
 354         default:
 355             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
 356     }
 357
 358     QDECREF(key_qs);
 359     return ++end;
 360 }
 361
 362 /**
 363  * qerror_human(): Format QError data into human-readable string.
 364  *
 365  * Formats according to member 'desc' of the specified QError object.
 366  */
 367 QString *qerror_human(const QError *qerror)
 368 {
 369     const char *p;
 370     QString *qstring;
 371
 372     assert(qerror->entry != NULL);
 373
 374     qstring = qstring_new();
 375
 376     for (p = qerror->entry->desc; *p != '\0';) {
 377         if (*p != '%') {
 378             qstring_append_chr(qstring, *p++);
 379         } else if (*(p + 1) == '%') {
 380             qstring_append_chr(qstring, '%');
 381             p += 2;
 382         } else {
 383             p = append_field(qstring, qerror, p);
 384         }
 385     }
 386
 387     return qstring;
 388 }
 389
 390 /**
 391  * qerror_print(): Print QError data
 392  *
 393  * This function will print the member 'desc' of the specified QError object,
 394  * it uses error_report() for this, so that the output is routed to the right
 395  * place (ie. stderr or Monitor's device).
 396  */
 397 void qerror_print(QError *qerror)
 398 {
 399     QString *qstring = qerror_human(qerror);
 400     loc_push_restore(&qerror->loc);
 401     error_report("%s", qstring_get_str(qstring));
 402     loc_pop(&qerror->loc);
 403     QDECREF(qstring);
 404 }
 405
 406 void qerror_report_internal(const char *file, int linenr, const char *func,
 407                             const char *fmt, ...)
 408 {
 409     va_list va;
 410     QError *qerror;
 411
 412     va_start(va, fmt);
 413     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 414     va_end(va);
 415
 416     if (monitor_cur_is_qmp()) {
 417         monitor_set_error(cur_mon, qerror);
 418     } else {
 419         qerror_print(qerror);
 420         QDECREF(qerror);
 421     }
 422 }
 423
 424 /**
 425  * qobject_to_qerror(): Convert a QObject into a QError
 426  */
 427 QError *qobject_to_qerror(const QObject *obj)
 428 {
 429     if (qobject_type(obj) != QTYPE_QERROR) {
 430         return NULL;
 431     }
 432
 433     return container_of(obj, QError, base);
 434 }
 435
 436 /**
 437  * qerror_destroy_obj(): Free all memory allocated by a QError
 438  */
 439 static void qerror_destroy_obj(QObject *obj)
 440 {
 441     QError *qerr;
 442
 443     assert(obj != NULL);
 444     qerr = qobject_to_qerror(obj);
 445
 446     QDECREF(qerr->error);
 447     qemu_free(qerr);
 448 }