Annotation of qemu/qerror.c, revision 1.1.1.3

1.1       root        1: /*
1.1.1.2   root        2:  * QError Module
1.1       root        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:  */
1.1.1.2   root       12: 
                     13: #include "monitor.h"
1.1       root       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)%%"
1.1.1.2   root       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.
1.1       root       45:  */
                     46: static const QErrorStringTable qerror_table[] = {
                     47:     {
1.1.1.2   root       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:     {
1.1       root       60:         .error_fmt = QERR_COMMAND_NOT_FOUND,
                     61:         .desc      = "The command %(name) has not been found",
                     62:     },
                     63:     {
                     64:         .error_fmt = QERR_DEVICE_ENCRYPTED,
1.1.1.2   root       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",
1.1       root       74:     },
                     75:     {
                     76:         .error_fmt = QERR_DEVICE_LOCKED,
1.1.1.2   root       77:         .desc      = "Device '%(device)' is locked",
                     78:     },
                     79:     {
                     80:         .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
                     81:         .desc      = "Device '%(device)' has multiple child busses",
1.1       root       82:     },
                     83:     {
                     84:         .error_fmt = QERR_DEVICE_NOT_ACTIVE,
1.1.1.2   root       85:         .desc      = "Device '%(device)' has not been activated",
                     86:     },
                     87:     {
                     88:         .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
                     89:         .desc      = "Device '%(device)' is not encrypted",
1.1       root       90:     },
                     91:     {
                     92:         .error_fmt = QERR_DEVICE_NOT_FOUND,
1.1.1.2   root       93:         .desc      = "Device '%(device)' not found",
1.1       root       94:     },
                     95:     {
                     96:         .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
1.1.1.2   root       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:     {
1.1.1.3 ! root      104:         .error_fmt = QERR_DEVICE_NO_HOTPLUG,
        !           105:         .desc      = "Device '%(device)' does not support hotplugging",
        !           106:     },
        !           107:     {
1.1.1.2   root      108:         .error_fmt = QERR_DUPLICATE_ID,
                    109:         .desc      = "Duplicate ID '%(id)' for %(object)",
1.1       root      110:     },
                    111:     {
                    112:         .error_fmt = QERR_FD_NOT_FOUND,
1.1.1.2   root      113:         .desc      = "File descriptor named '%(name)' not found",
1.1       root      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,
1.1.1.2   root      121:         .desc      = "Invalid block format '%(name)'",
1.1       root      122:     },
                    123:     {
                    124:         .error_fmt = QERR_INVALID_PARAMETER,
1.1.1.2   root      125:         .desc      = "Invalid parameter '%(name)'",
1.1       root      126:     },
                    127:     {
                    128:         .error_fmt = QERR_INVALID_PARAMETER_TYPE,
                    129:         .desc      = "Invalid parameter type, expected: %(expected)",
                    130:     },
                    131:     {
1.1.1.2   root      132:         .error_fmt = QERR_INVALID_PARAMETER_VALUE,
                    133:         .desc      = "Parameter '%(name)' expects %(expected)",
                    134:     },
                    135:     {
1.1       root      136:         .error_fmt = QERR_INVALID_PASSWORD,
1.1.1.2   root      137:         .desc      = "Password incorrect",
1.1       root      138:     },
                    139:     {
                    140:         .error_fmt = QERR_JSON_PARSING,
                    141:         .desc      = "Invalid JSON syntax",
                    142:     },
                    143:     {
                    144:         .error_fmt = QERR_KVM_MISSING_CAP,
                    145:         .desc      = "Using KVM without %(capability), %(feature) unavailable",
                    146:     },
                    147:     {
1.1.1.2   root      148:         .error_fmt = QERR_MIGRATION_EXPECTED,
                    149:         .desc      = "An incoming migration is expected before this command can be executed",
                    150:     },
                    151:     {
1.1       root      152:         .error_fmt = QERR_MISSING_PARAMETER,
1.1.1.2   root      153:         .desc      = "Parameter '%(name)' is missing",
                    154:     },
                    155:     {
                    156:         .error_fmt = QERR_NO_BUS_FOR_DEVICE,
                    157:         .desc      = "No '%(bus)' bus found for device '%(device)'",
                    158:     },
                    159:     {
                    160:         .error_fmt = QERR_OPEN_FILE_FAILED,
                    161:         .desc      = "Could not open '%(filename)'",
                    162:     },
                    163:     {
                    164:         .error_fmt = QERR_PROPERTY_NOT_FOUND,
                    165:         .desc      = "Property '%(device).%(property)' not found",
                    166:     },
                    167:     {
                    168:         .error_fmt = QERR_PROPERTY_VALUE_BAD,
                    169:         .desc      = "Property '%(device).%(property)' doesn't take value '%(value)'",
                    170:     },
                    171:     {
                    172:         .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
                    173:         .desc      = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
                    174:     },
                    175:     {
                    176:         .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
                    177:         .desc      = "Property '%(device).%(property)' can't find value '%(value)'",
1.1       root      178:     },
                    179:     {
                    180:         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
1.1.1.2   root      181:         .desc      = "Expected '%(expected)' in QMP input",
                    182:     },
                    183:     {
                    184:         .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
                    185:         .desc      = "QMP input object member '%(member)' expects '%(expected)'",
                    186:     },
                    187:     {
                    188:         .error_fmt = QERR_QMP_EXTRA_MEMBER,
                    189:         .desc      = "QMP input object member '%(member)' is unexpected",
1.1       root      190:     },
                    191:     {
                    192:         .error_fmt = QERR_SET_PASSWD_FAILED,
                    193:         .desc      = "Could not set password",
                    194:     },
                    195:     {
                    196:         .error_fmt = QERR_TOO_MANY_FILES,
                    197:         .desc      = "Too many open files",
                    198:     },
                    199:     {
                    200:         .error_fmt = QERR_UNDEFINED_ERROR,
                    201:         .desc      = "An undefined error has ocurred",
                    202:     },
                    203:     {
1.1.1.3 ! root      204:         .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
        !           205:         .desc      = "'%(device)' uses a %(format) feature which is not "
        !           206:                      "supported by this qemu version: %(feature)",
        !           207:     },
        !           208:     {
1.1       root      209:         .error_fmt = QERR_VNC_SERVER_FAILED,
                    210:         .desc      = "Could not start VNC server on %(target)",
                    211:     },
                    212:     {}
                    213: };
                    214: 
                    215: /**
                    216:  * qerror_new(): Create a new QError
                    217:  *
                    218:  * Return strong reference.
                    219:  */
                    220: QError *qerror_new(void)
                    221: {
                    222:     QError *qerr;
                    223: 
                    224:     qerr = qemu_mallocz(sizeof(*qerr));
                    225:     QOBJECT_INIT(qerr, &qerror_type);
                    226: 
                    227:     return qerr;
                    228: }
                    229: 
1.1.1.3 ! root      230: static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
        !           231:                                             const char *fmt, ...)
1.1       root      232: {
                    233:     va_list ap;
                    234: 
                    235:     fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
                    236:     fprintf(stderr, "qerror: -> ");
                    237: 
                    238:     va_start(ap, fmt);
                    239:     vfprintf(stderr, fmt, ap);
                    240:     va_end(ap);
                    241: 
                    242:     fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
                    243:     abort();
                    244: }
                    245: 
1.1.1.3 ! root      246: static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
        !           247:                                                const char *fmt, va_list *va)
1.1       root      248: {
                    249:     QObject *obj;
                    250: 
                    251:     obj = qobject_from_jsonv(fmt, va);
                    252:     if (!obj) {
                    253:         qerror_abort(qerr, "invalid format '%s'", fmt);
                    254:     }
                    255:     if (qobject_type(obj) != QTYPE_QDICT) {
                    256:         qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
                    257:     }
                    258: 
                    259:     qerr->error = qobject_to_qdict(obj);
                    260: 
                    261:     obj = qdict_get(qerr->error, "class");
                    262:     if (!obj) {
                    263:         qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
                    264:     }
                    265:     if (qobject_type(obj) != QTYPE_QSTRING) {
                    266:         qerror_abort(qerr, "'class' key value should be a QString");
                    267:     }
                    268:     
                    269:     obj = qdict_get(qerr->error, "data");
                    270:     if (!obj) {
                    271:         qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
                    272:     }
                    273:     if (qobject_type(obj) != QTYPE_QDICT) {
                    274:         qerror_abort(qerr, "'data' key value should be a QDICT");
                    275:     }
                    276: }
                    277: 
                    278: static void qerror_set_desc(QError *qerr, const char *fmt)
                    279: {
                    280:     int i;
                    281: 
                    282:     // FIXME: inefficient loop
                    283: 
                    284:     for (i = 0; qerror_table[i].error_fmt; i++) {
                    285:         if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
                    286:             qerr->entry = &qerror_table[i];
                    287:             return;
                    288:         }
                    289:     }
                    290: 
                    291:     qerror_abort(qerr, "error format '%s' not found", fmt);
                    292: }
                    293: 
                    294: /**
                    295:  * qerror_from_info(): Create a new QError from error information
                    296:  *
                    297:  * The information consists of:
                    298:  *
                    299:  * - file   the file name of where the error occurred
                    300:  * - linenr the line number of where the error occurred
                    301:  * - func   the function name of where the error occurred
                    302:  * - fmt    JSON printf-like dictionary, there must exist keys 'class' and
                    303:  *          'data'
                    304:  * - va     va_list of all arguments specified by fmt
                    305:  *
                    306:  * Return strong reference.
                    307:  */
                    308: QError *qerror_from_info(const char *file, int linenr, const char *func,
                    309:                          const char *fmt, va_list *va)
                    310: {
                    311:     QError *qerr;
                    312: 
                    313:     qerr = qerror_new();
1.1.1.2   root      314:     loc_save(&qerr->loc);
1.1       root      315:     qerr->linenr = linenr;
                    316:     qerr->file = file;
                    317:     qerr->func = func;
                    318: 
                    319:     if (!fmt) {
                    320:         qerror_abort(qerr, "QDict not specified");
                    321:     }
                    322: 
                    323:     qerror_set_data(qerr, fmt, va);
                    324:     qerror_set_desc(qerr, fmt);
                    325: 
                    326:     return qerr;
                    327: }
                    328: 
                    329: static void parse_error(const QError *qerror, int c)
                    330: {
                    331:     qerror_abort(qerror, "expected '%c' in '%s'", c, qerror->entry->desc);
                    332: }
                    333: 
                    334: static const char *append_field(QString *outstr, const QError *qerror,
                    335:                                 const char *start)
                    336: {
                    337:     QObject *obj;
                    338:     QDict *qdict;
                    339:     QString *key_qs;
                    340:     const char *end, *key;
                    341: 
                    342:     if (*start != '%')
                    343:         parse_error(qerror, '%');
                    344:     start++;
                    345:     if (*start != '(')
                    346:         parse_error(qerror, '(');
                    347:     start++;
                    348: 
                    349:     end = strchr(start, ')');
                    350:     if (!end)
                    351:         parse_error(qerror, ')');
                    352: 
                    353:     key_qs = qstring_from_substr(start, 0, end - start - 1);
                    354:     key = qstring_get_str(key_qs);
                    355: 
                    356:     qdict = qobject_to_qdict(qdict_get(qerror->error, "data"));
                    357:     obj = qdict_get(qdict, key);
                    358:     if (!obj) {
                    359:         qerror_abort(qerror, "key '%s' not found in QDict", key);
                    360:     }
                    361: 
                    362:     switch (qobject_type(obj)) {
                    363:         case QTYPE_QSTRING:
                    364:             qstring_append(outstr, qdict_get_str(qdict, key));
                    365:             break;
                    366:         case QTYPE_QINT:
                    367:             qstring_append_int(outstr, qdict_get_int(qdict, key));
                    368:             break;
                    369:         default:
                    370:             qerror_abort(qerror, "invalid type '%c'", qobject_type(obj));
                    371:     }
                    372: 
                    373:     QDECREF(key_qs);
                    374:     return ++end;
                    375: }
                    376: 
                    377: /**
                    378:  * qerror_human(): Format QError data into human-readable string.
                    379:  *
                    380:  * Formats according to member 'desc' of the specified QError object.
                    381:  */
                    382: QString *qerror_human(const QError *qerror)
                    383: {
                    384:     const char *p;
                    385:     QString *qstring;
                    386: 
                    387:     assert(qerror->entry != NULL);
                    388: 
                    389:     qstring = qstring_new();
                    390: 
                    391:     for (p = qerror->entry->desc; *p != '\0';) {
                    392:         if (*p != '%') {
                    393:             qstring_append_chr(qstring, *p++);
                    394:         } else if (*(p + 1) == '%') {
                    395:             qstring_append_chr(qstring, '%');
                    396:             p += 2;
                    397:         } else {
                    398:             p = append_field(qstring, qerror, p);
                    399:         }
                    400:     }
                    401: 
                    402:     return qstring;
                    403: }
                    404: 
                    405: /**
                    406:  * qerror_print(): Print QError data
                    407:  *
                    408:  * This function will print the member 'desc' of the specified QError object,
1.1.1.2   root      409:  * it uses error_report() for this, so that the output is routed to the right
1.1       root      410:  * place (ie. stderr or Monitor's device).
                    411:  */
1.1.1.2   root      412: void qerror_print(QError *qerror)
1.1       root      413: {
                    414:     QString *qstring = qerror_human(qerror);
1.1.1.2   root      415:     loc_push_restore(&qerror->loc);
                    416:     error_report("%s", qstring_get_str(qstring));
                    417:     loc_pop(&qerror->loc);
1.1       root      418:     QDECREF(qstring);
                    419: }
                    420: 
1.1.1.2   root      421: void qerror_report_internal(const char *file, int linenr, const char *func,
                    422:                             const char *fmt, ...)
                    423: {
                    424:     va_list va;
                    425:     QError *qerror;
                    426: 
                    427:     va_start(va, fmt);
                    428:     qerror = qerror_from_info(file, linenr, func, fmt, &va);
                    429:     va_end(va);
                    430: 
                    431:     if (monitor_cur_is_qmp()) {
                    432:         monitor_set_error(cur_mon, qerror);
                    433:     } else {
                    434:         qerror_print(qerror);
                    435:         QDECREF(qerror);
                    436:     }
                    437: }
                    438: 
1.1       root      439: /**
                    440:  * qobject_to_qerror(): Convert a QObject into a QError
                    441:  */
                    442: QError *qobject_to_qerror(const QObject *obj)
                    443: {
                    444:     if (qobject_type(obj) != QTYPE_QERROR) {
                    445:         return NULL;
                    446:     }
                    447: 
                    448:     return container_of(obj, QError, base);
                    449: }
                    450: 
                    451: /**
                    452:  * qerror_destroy_obj(): Free all memory allocated by a QError
                    453:  */
                    454: static void qerror_destroy_obj(QObject *obj)
                    455: {
                    456:     QError *qerr;
                    457: 
                    458:     assert(obj != NULL);
                    459:     qerr = qobject_to_qerror(obj);
                    460: 
                    461:     QDECREF(qerr->error);
                    462:     qemu_free(qerr);
                    463: }

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