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_LOCKED,
  73         .desc      = "Device '%(device)' is locked",
  74     },
  75     {
  76         .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
  77         .desc      = "Device '%(device)' has multiple child busses",
  78     },
  79     {
  80         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
  81         .desc      = "Device '%(device)' has not been activated by the guest",
  82     },
  83     {
  84         .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
  85         .desc      = "Device '%(device)' is not encrypted",
  86     },
  87     {
  88         .error_fmt = QERR_DEVICE_NOT_FOUND,
  89         .desc      = "Device '%(device)' not found",
  90     },
  91     {
  92         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
  93         .desc      = "Device '%(device)' is not removable",
  94     },
  95     {
  96         .error_fmt = QERR_DEVICE_NO_BUS,
  97         .desc      = "Device '%(device)' has no child bus",
  98     },
  99     {
 100         .error_fmt = QERR_FD_NOT_FOUND,
 101         .desc      = "File descriptor named '%(name)' not found",
 102     },
 103     {
 104         .error_fmt = QERR_FD_NOT_SUPPLIED,
 105         .desc      = "No file descriptor supplied via SCM_RIGHTS",
 106     },
 107     {
 108         .error_fmt = QERR_INVALID_BLOCK_FORMAT,
 109         .desc      = "Invalid block format '%(name)'",
 110     },
 111     {
 112         .error_fmt = QERR_INVALID_PARAMETER,
 113         .desc      = "Invalid parameter '%(name)'",
 114     },
 115     {
 116         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
 117         .desc      = "Invalid parameter type, expected: %(expected)",
 118     },
 119     {
 120         .error_fmt = QERR_INVALID_PASSWORD,
 121         .desc      = "Password incorrect",
 122     },
 123     {
 124         .error_fmt = QERR_JSON_PARSING,
 125         .desc      = "Invalid JSON syntax",
 126     },
 127     {
 128         .error_fmt = QERR_KVM_MISSING_CAP,
 129         .desc      = "Using KVM without %(capability), %(feature) unavailable",
 130     },
 131     {
 132         .error_fmt = QERR_MISSING_PARAMETER,
 133         .desc      = "Parameter '%(name)' is missing",
 134     },
 135     {
 136         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
 137         .desc      = "No '%(bus)' bus found for device '%(device)'",
 138     },
 139     {
 140         .error_fmt = QERR_OPEN_FILE_FAILED,
 141         .desc      = "Could not open '%(filename)'",
 142     },
 143     {
 144         .error_fmt = QERR_PROPERTY_NOT_FOUND,
 145         .desc      = "Property '%(device).%(property)' not found",
 146     },
 147     {
 148         .error_fmt = QERR_PROPERTY_VALUE_BAD,
 149         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
 150     },
 151     {
 152         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
 153         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
 154     },
 155     {
 156         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
 157         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
 158     },
 159     {
 160         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
 161         .desc      = "Bad QMP input object",
 162     },
 163     {
 164         .error_fmt = QERR_SET_PASSWD_FAILED,
 165         .desc      = "Could not set password",
 166     },
 167     {
 168         .error_fmt = QERR_TOO_MANY_FILES,
 169         .desc      = "Too many open files",
 170     },
 171     {
 172         .error_fmt = QERR_UNDEFINED_ERROR,
 173         .desc      = "An undefined error has ocurred",
 174     },
 175     {
 176         .error_fmt = QERR_VNC_SERVER_FAILED,
 177         .desc      = "Could not start VNC server on %(target)",
 178     },
 179     {}
 180 };
 181
 182 /**
 183  * qerror_new(): Create a new QError
 184  *
 185  * Return strong reference.
 186  */
 187 QError *qerror_new(void)
 188 {
 189     QError *qerr;
 190
 191     qerr = qemu_mallocz(sizeof(*qerr));
 192     QOBJECT_INIT(qerr, &qerror_type);
 193
 194     return qerr;
 195 }
 196
 197 static void qerror_abort(const QError *qerr, const char *fmt, ...)
 198 {
 199     va_list ap;
 200
 201     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
 202     fprintf(stderr, "qerror: -> ");
 203
 204     va_start(ap, fmt);
 205     vfprintf(stderr, fmt, ap);
 206     va_end(ap);
 207
 208     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
 209     abort();
 210 }
 211
 212 static void qerror_set_data(QError *qerr, const char *fmt, va_list *va)
 213 {
 214     QObject *obj;
 215
 216     obj = qobject_from_jsonv(fmt, va);
 217     if (!obj) {
 218         qerror_abort(qerr, "invalid format '%s'", fmt);
 219     }
 220     if (qobject_type(obj) != QTYPE_QDICT) {
 221         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
 222     }
 223
 224     qerr->error = qobject_to_qdict(obj);
 225
 226     obj = qdict_get(qerr->error, "class");
 227     if (!obj) {
 228         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
 229     }
 230     if (qobject_type(obj) != QTYPE_QSTRING) {
 231         qerror_abort(qerr, "'class' key value should be a QString");
 232     }
 233
 234     obj = qdict_get(qerr->error, "data");
 235     if (!obj) {
 236         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
 237     }
 238     if (qobject_type(obj) != QTYPE_QDICT) {
 239         qerror_abort(qerr, "'data' key value should be a QDICT");
 240     }
 241 }
 242
 243 static void qerror_set_desc(QError *qerr, const char *fmt)
 244 {
 245     int i;
 246
 247     // FIXME: inefficient loop
 248
 249     for (i = 0; qerror_table[i].error_fmt; i++) {
 250         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
 251             qerr->entry = &qerror_table[i];
 252             return;
 253         }
 254     }
 255
 256     qerror_abort(qerr, "error format '%s' not found", fmt);
 257 }
 258
 259 /**
 260  * qerror_from_info(): Create a new QError from error information
 261  *
 262  * The information consists of:
 263  *
 264  * - file   the file name of where the error occurred
 265  * - linenr the line number of where the error occurred
 266  * - func   the function name of where the error occurred
 267  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
 268  *          'data'
 269  * - va     va_list of all arguments specified by fmt
 270  *
 271  * Return strong reference.
 272  */
 273 QError *qerror_from_info(const char *file, int linenr, const char *func,
 274                          const char *fmt, va_list *va)
 275 {
 276     QError *qerr;
 277
 278     qerr = qerror_new();
 279     loc_save(&qerr->loc);
 280     qerr->linenr = linenr;
 281     qerr->file = file;
 282     qerr->func = func;
 283
 284     if (!fmt) {
 285         qerror_abort(qerr, "QDict not specified");
 286     }
 287
 288     qerror_set_data(qerr, fmt, va);
 289     qerror_set_desc(qerr, fmt);
 290
 291     return qerr;
 292 }
 293
 294 static void parse_error(const QError *qerror, int c)
 295 {
 296     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
 297 }
 298
 299 static const char *append_field(QString *outstr, const QError *qerror,
 300                                 const char *start)
 301 {
 302     QObject *obj;
 303     QDict *qdict;
 304     QString *key_qs;
 305     const char *end, *key;
 306
 307     if (*start != '%')
 308         parse_error(qerror, '%');
 309     start++;
 310     if (*start != '(')
 311         parse_error(qerror, '(');
 312     start++;
 313
 314     end = strchr(start, ')');
 315     if (!end)
 316         parse_error(qerror, ')');
 317
 318     key_qs = qstring_from_substr(start, 0, end - start - 1);
 319     key = qstring_get_str(key_qs);
 320
 321     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
 322     obj = qdict_get(qdict, key);
 323     if (!obj) {
 324         qerror_abort(qerror, "key '%s' not found in QDict", key);
 325     }
 326
 327     switch (qobject_type(obj)) {
 328         case QTYPE_QSTRING:
 329             qstring_append(outstr, qdict_get_str(qdict, key));
 330             break;
 331         case QTYPE_QINT:
 332             qstring_append_int(outstr, qdict_get_int(qdict, key));
 333             break;
 334         default:
 335             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
 336     }
 337
 338     QDECREF(key_qs);
 339     return ++end;
 340 }
 341
 342 /**
 343  * qerror_human(): Format QError data into human-readable string.
 344  *
 345  * Formats according to member 'desc' of the specified QError object.
 346  */
 347 QString *qerror_human(const QError *qerror)
 348 {
 349     const char *p;
 350     QString *qstring;
 351
 352     assert(qerror->entry != NULL);
 353
 354     qstring = qstring_new();
 355
 356     for (p = qerror->entry->desc; *p != '\0';) {
 357         if (*p != '%') {
 358             qstring_append_chr(qstring, *p++);
 359         } else if (*(p + 1) == '%') {
 360             qstring_append_chr(qstring, '%');
 361             p += 2;
 362         } else {
 363             p = append_field(qstring, qerror, p);
 364         }
 365     }
 366
 367     return qstring;
 368 }
 369
 370 /**
 371  * qerror_print(): Print QError data
 372  *
 373  * This function will print the member 'desc' of the specified QError object,
 374  * it uses error_report() for this, so that the output is routed to the right
 375  * place (ie. stderr or Monitor's device).
 376  */
 377 void qerror_print(QError *qerror)
 378 {
 379     QString *qstring = qerror_human(qerror);
 380     loc_push_restore(&qerror->loc);
 381     error_report("%s", qstring_get_str(qstring));
 382     loc_pop(&qerror->loc);
 383     QDECREF(qstring);
 384 }
 385
 386 void qerror_report_internal(const char *file, int linenr, const char *func,
 387                             const char *fmt, ...)
 388 {
 389     va_list va;
 390     QError *qerror;
 391
 392     va_start(va, fmt);
 393     qerror = qerror_from_info(file, linenr, func, fmt, &va);
 394     va_end(va);
 395
 396     if (monitor_cur_is_qmp()) {
 397         monitor_set_error(cur_mon, qerror);
 398     } else {
 399         qerror_print(qerror);
 400         QDECREF(qerror);
 401     }
 402 }
 403
 404 /**
 405  * qobject_to_qerror(): Convert a QObject into a QError
 406  */
 407 QError *qobject_to_qerror(const QObject *obj)
 408 {
 409     if (qobject_type(obj) != QTYPE_QERROR) {
 410         return NULL;
 411     }
 412
 413     return container_of(obj, QError, base);
 414 }
 415
 416 /**
 417  * qerror_destroy_obj(): Free all memory allocated by a QError
 418  */
 419 static void qerror_destroy_obj(QObject *obj)
 420 {
 421     QError *qerr;
 422
 423     assert(obj != NULL);
 424     qerr = qobject_to_qerror(obj);
 425
 426     QDECREF(qerr->error);
 427     qemu_free(qerr);
 428 }