block: add bdrv_find_backing_image
[qemu.git] / 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 scripts/check-qerror.sh to check.
44 */
45 static const QErrorStringTable qerror_table[] = {
46 {
47 .error_fmt = QERR_ADD_CLIENT_FAILED,
48 .desc = "Could not add client",
49 },
50 {
51 .error_fmt = QERR_BAD_BUS_FOR_DEVICE,
52 .desc = "Device '%(device)' can't go on a %(bad_bus_type) bus",
53 },
54 {
55 .error_fmt = QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
56 .desc = "Block format '%(format)' used by device '%(name)' does not support feature '%(feature)'",
57 },
58 {
59 .error_fmt = QERR_BUS_NO_HOTPLUG,
60 .desc = "Bus '%(bus)' does not support hotplugging",
61 },
62 {
63 .error_fmt = QERR_BUS_NOT_FOUND,
64 .desc = "Bus '%(bus)' not found",
65 },
66 {
67 .error_fmt = QERR_COMMAND_DISABLED,
68 .desc = "The command %(name) has been disabled for this instance",
69 },
70 {
71 .error_fmt = QERR_COMMAND_NOT_FOUND,
72 .desc = "The command %(name) has not been found",
73 },
74 {
75 .error_fmt = QERR_DEVICE_ENCRYPTED,
76 .desc = "Device '%(device)' is encrypted",
77 },
78 {
79 .error_fmt = QERR_DEVICE_FEATURE_BLOCKS_MIGRATION,
80 .desc = "Migration is disabled when using feature '%(feature)' in device '%(device)'",
81 },
82 {
83 .error_fmt = QERR_DEVICE_HAS_NO_MEDIUM,
84 .desc = "Device '%(device)' has no medium",
85 },
86 {
87 .error_fmt = QERR_DEVICE_INIT_FAILED,
88 .desc = "Device '%(device)' could not be initialized",
89 },
90 {
91 .error_fmt = QERR_DEVICE_IN_USE,
92 .desc = "Device '%(device)' is in use",
93 },
94 {
95 .error_fmt = QERR_DEVICE_IS_READ_ONLY,
96 .desc = "Device '%(device)' is read only",
97 },
98 {
99 .error_fmt = QERR_DEVICE_LOCKED,
100 .desc = "Device '%(device)' is locked",
101 },
102 {
103 .error_fmt = QERR_DEVICE_MULTIPLE_BUSSES,
104 .desc = "Device '%(device)' has multiple child busses",
105 },
106 {
107 .error_fmt = QERR_DEVICE_NO_BUS,
108 .desc = "Device '%(device)' has no child bus",
109 },
110 {
111 .error_fmt = QERR_DEVICE_NO_HOTPLUG,
112 .desc = "Device '%(device)' does not support hotplugging",
113 },
114 {
115 .error_fmt = QERR_DEVICE_NOT_ACTIVE,
116 .desc = "Device '%(device)' has not been activated",
117 },
118 {
119 .error_fmt = QERR_DEVICE_NOT_ENCRYPTED,
120 .desc = "Device '%(device)' is not encrypted",
121 },
122 {
123 .error_fmt = QERR_DEVICE_NOT_FOUND,
124 .desc = "Device '%(device)' not found",
125 },
126 {
127 .error_fmt = QERR_DEVICE_NOT_REMOVABLE,
128 .desc = "Device '%(device)' is not removable",
129 },
130 {
131 .error_fmt = QERR_DUPLICATE_ID,
132 .desc = "Duplicate ID '%(id)' for %(object)",
133 },
134 {
135 .error_fmt = QERR_FD_NOT_FOUND,
136 .desc = "File descriptor named '%(name)' not found",
137 },
138 {
139 .error_fmt = QERR_FD_NOT_SUPPLIED,
140 .desc = "No file descriptor supplied via SCM_RIGHTS",
141 },
142 {
143 .error_fmt = QERR_FEATURE_DISABLED,
144 .desc = "The feature '%(name)' is not enabled",
145 },
146 {
147 .error_fmt = QERR_INVALID_BLOCK_FORMAT,
148 .desc = "Invalid block format '%(name)'",
149 },
150 {
151 .error_fmt = QERR_INVALID_PARAMETER,
152 .desc = "Invalid parameter '%(name)'",
153 },
154 {
155 .error_fmt = QERR_INVALID_PARAMETER_COMBINATION,
156 .desc = "Invalid parameter combination",
157 },
158 {
159 .error_fmt = QERR_INVALID_PARAMETER_TYPE,
160 .desc = "Invalid parameter type, expected: %(expected)",
161 },
162 {
163 .error_fmt = QERR_INVALID_PARAMETER_VALUE,
164 .desc = "Parameter '%(name)' expects %(expected)",
165 },
166 {
167 .error_fmt = QERR_INVALID_PASSWORD,
168 .desc = "Password incorrect",
169 },
170 {
171 .error_fmt = QERR_IO_ERROR,
172 .desc = "An IO error has occurred",
173 },
174 {
175 .error_fmt = QERR_JSON_PARSE_ERROR,
176 .desc = "JSON parse error, %(message)",
177
178 },
179 {
180 .error_fmt = QERR_JSON_PARSING,
181 .desc = "Invalid JSON syntax",
182 },
183 {
184 .error_fmt = QERR_KVM_MISSING_CAP,
185 .desc = "Using KVM without %(capability), %(feature) unavailable",
186 },
187 {
188 .error_fmt = QERR_MIGRATION_EXPECTED,
189 .desc = "An incoming migration is expected before this command can be executed",
190 },
191 {
192 .error_fmt = QERR_MISSING_PARAMETER,
193 .desc = "Parameter '%(name)' is missing",
194 },
195 {
196 .error_fmt = QERR_NO_BUS_FOR_DEVICE,
197 .desc = "No '%(bus)' bus found for device '%(device)'",
198 },
199 {
200 .error_fmt = QERR_NOT_SUPPORTED,
201 .desc = "Not supported",
202 },
203 {
204 .error_fmt = QERR_OPEN_FILE_FAILED,
205 .desc = "Could not open '%(filename)'",
206 },
207 {
208 .error_fmt = QERR_PERMISSION_DENIED,
209 .desc = "Insufficient permission to perform this operation",
210 },
211 {
212 .error_fmt = QERR_PROPERTY_NOT_FOUND,
213 .desc = "Property '%(device).%(property)' not found",
214 },
215 {
216 .error_fmt = QERR_PROPERTY_VALUE_BAD,
217 .desc = "Property '%(device).%(property)' doesn't take value '%(value)'",
218 },
219 {
220 .error_fmt = QERR_PROPERTY_VALUE_IN_USE,
221 .desc = "Property '%(device).%(property)' can't take value '%(value)', it's in use",
222 },
223 {
224 .error_fmt = QERR_PROPERTY_VALUE_NOT_FOUND,
225 .desc = "Property '%(device).%(property)' can't find value '%(value)'",
226 },
227 {
228 .error_fmt = QERR_PROPERTY_VALUE_OUT_OF_RANGE,
229 .desc = "Property '%(device).%(property)' doesn't take "
230 "value %(value) (minimum: %(min), maximum: %(max)'",
231 },
232 {
233 .error_fmt = QERR_QGA_COMMAND_FAILED,
234 .desc = "Guest agent command failed, error was '%(message)'",
235 },
236 {
237 .error_fmt = QERR_QGA_LOGGING_FAILED,
238 .desc = "Guest agent failed to log non-optional log statement",
239 },
240 {
241 .error_fmt = QERR_QMP_BAD_INPUT_OBJECT,
242 .desc = "Expected '%(expected)' in QMP input",
243 },
244 {
245 .error_fmt = QERR_QMP_BAD_INPUT_OBJECT_MEMBER,
246 .desc = "QMP input object member '%(member)' expects '%(expected)'",
247 },
248 {
249 .error_fmt = QERR_QMP_EXTRA_MEMBER,
250 .desc = "QMP input object member '%(member)' is unexpected",
251 },
252 {
253 .error_fmt = QERR_RESET_REQUIRED,
254 .desc = "Resetting the Virtual Machine is required",
255 },
256 {
257 .error_fmt = QERR_SET_PASSWD_FAILED,
258 .desc = "Could not set password",
259 },
260 {
261 .error_fmt = QERR_TOO_MANY_FILES,
262 .desc = "Too many open files",
263 },
264 {
265 .error_fmt = QERR_UNDEFINED_ERROR,
266 .desc = "An undefined error has occurred",
267 },
268 {
269 .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
270 .desc = "'%(device)' uses a %(format) feature which is not "
271 "supported by this qemu version: %(feature)",
272 },
273 {
274 .error_fmt = QERR_UNSUPPORTED,
275 .desc = "this feature or command is not currently supported",
276 },
277 {
278 .error_fmt = QERR_VIRTFS_FEATURE_BLOCKS_MIGRATION,
279 .desc = "Migration is disabled when VirtFS export path '%(path)' "
280 "is mounted in the guest using mount_tag '%(tag)'",
281 },
282 {
283 .error_fmt = QERR_VNC_SERVER_FAILED,
284 .desc = "Could not start VNC server on %(target)",
285 },
286 {}
287 };
288
289 /**
290 * qerror_new(): Create a new QError
291 *
292 * Return strong reference.
293 */
294 QError *qerror_new(void)
295 {
296 QError *qerr;
297
298 qerr = g_malloc0(sizeof(*qerr));
299 QOBJECT_INIT(qerr, &qerror_type);
300
301 return qerr;
302 }
303
304 static void GCC_FMT_ATTR(2, 3) qerror_abort(const QError *qerr,
305 const char *fmt, ...)
306 {
307 va_list ap;
308
309 fprintf(stderr, "qerror: bad call in function '%s':\n", qerr->func);
310 fprintf(stderr, "qerror: -> ");
311
312 va_start(ap, fmt);
313 vfprintf(stderr, fmt, ap);
314 va_end(ap);
315
316 fprintf(stderr, "\nqerror: call at %s:%d\n", qerr->file, qerr->linenr);
317 abort();
318 }
319
320 static void GCC_FMT_ATTR(2, 0) qerror_set_data(QError *qerr,
321 const char *fmt, va_list *va)
322 {
323 QObject *obj;
324
325 obj = qobject_from_jsonv(fmt, va);
326 if (!obj) {
327 qerror_abort(qerr, "invalid format '%s'", fmt);
328 }
329 if (qobject_type(obj) != QTYPE_QDICT) {
330 qerror_abort(qerr, "error format is not a QDict '%s'", fmt);
331 }
332
333 qerr->error = qobject_to_qdict(obj);
334
335 obj = qdict_get(qerr->error, "class");
336 if (!obj) {
337 qerror_abort(qerr, "missing 'class' key in '%s'", fmt);
338 }
339 if (qobject_type(obj) != QTYPE_QSTRING) {
340 qerror_abort(qerr, "'class' key value should be a QString");
341 }
342
343 obj = qdict_get(qerr->error, "data");
344 if (!obj) {
345 qerror_abort(qerr, "missing 'data' key in '%s'", fmt);
346 }
347 if (qobject_type(obj) != QTYPE_QDICT) {
348 qerror_abort(qerr, "'data' key value should be a QDICT");
349 }
350 }
351
352 static void qerror_set_desc(QError *qerr, const char *fmt)
353 {
354 int i;
355
356 // FIXME: inefficient loop
357
358 for (i = 0; qerror_table[i].error_fmt; i++) {
359 if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
360 qerr->entry = &qerror_table[i];
361 return;
362 }
363 }
364
365 qerror_abort(qerr, "error format '%s' not found", fmt);
366 }
367
368 /**
369 * qerror_from_info(): Create a new QError from error information
370 *
371 * The information consists of:
372 *
373 * - file the file name of where the error occurred
374 * - linenr the line number of where the error occurred
375 * - func the function name of where the error occurred
376 * - fmt JSON printf-like dictionary, there must exist keys 'class' and
377 * 'data'
378 * - va va_list of all arguments specified by fmt
379 *
380 * Return strong reference.
381 */
382 QError *qerror_from_info(const char *file, int linenr, const char *func,
383 const char *fmt, va_list *va)
384 {
385 QError *qerr;
386
387 qerr = qerror_new();
388 loc_save(&qerr->loc);
389 qerr->linenr = linenr;
390 qerr->file = file;
391 qerr->func = func;
392
393 if (!fmt) {
394 qerror_abort(qerr, "QDict not specified");
395 }
396
397 qerror_set_data(qerr, fmt, va);
398 qerror_set_desc(qerr, fmt);
399
400 return qerr;
401 }
402
403 static void parse_error(const QErrorStringTable *entry, int c)
404 {
405 fprintf(stderr, "expected '%c' in '%s'", c, entry->desc);
406 abort();
407 }
408
409 static const char *append_field(QDict *error, QString *outstr,
410 const QErrorStringTable *entry,
411 const char *start)
412 {
413 QObject *obj;
414 QDict *qdict;
415 QString *key_qs;
416 const char *end, *key;
417
418 if (*start != '%')
419 parse_error(entry, '%');
420 start++;
421 if (*start != '(')
422 parse_error(entry, '(');
423 start++;
424
425 end = strchr(start, ')');
426 if (!end)
427 parse_error(entry, ')');
428
429 key_qs = qstring_from_substr(start, 0, end - start - 1);
430 key = qstring_get_str(key_qs);
431
432 qdict = qobject_to_qdict(qdict_get(error, "data"));
433 obj = qdict_get(qdict, key);
434 if (!obj) {
435 abort();
436 }
437
438 switch (qobject_type(obj)) {
439 case QTYPE_QSTRING:
440 qstring_append(outstr, qdict_get_str(qdict, key));
441 break;
442 case QTYPE_QINT:
443 qstring_append_int(outstr, qdict_get_int(qdict, key));
444 break;
445 default:
446 abort();
447 }
448
449 QDECREF(key_qs);
450 return ++end;
451 }
452
453 static QString *qerror_format_desc(QDict *error,
454 const QErrorStringTable *entry)
455 {
456 QString *qstring;
457 const char *p;
458
459 assert(entry != NULL);
460
461 qstring = qstring_new();
462
463 for (p = entry->desc; *p != '\0';) {
464 if (*p != '%') {
465 qstring_append_chr(qstring, *p++);
466 } else if (*(p + 1) == '%') {
467 qstring_append_chr(qstring, '%');
468 p += 2;
469 } else {
470 p = append_field(error, qstring, entry, p);
471 }
472 }
473
474 return qstring;
475 }
476
477 QString *qerror_format(const char *fmt, QDict *error)
478 {
479 const QErrorStringTable *entry = NULL;
480 int i;
481
482 for (i = 0; qerror_table[i].error_fmt; i++) {
483 if (strcmp(qerror_table[i].error_fmt, fmt) == 0) {
484 entry = &qerror_table[i];
485 break;
486 }
487 }
488
489 return qerror_format_desc(error, entry);
490 }
491
492 /**
493 * qerror_human(): Format QError data into human-readable string.
494 */
495 QString *qerror_human(const QError *qerror)
496 {
497 return qerror_format_desc(qerror->error, qerror->entry);
498 }
499
500 /**
501 * qerror_print(): Print QError data
502 *
503 * This function will print the member 'desc' of the specified QError object,
504 * it uses error_report() for this, so that the output is routed to the right
505 * place (ie. stderr or Monitor's device).
506 */
507 void qerror_print(QError *qerror)
508 {
509 QString *qstring = qerror_human(qerror);
510 loc_push_restore(&qerror->loc);
511 error_report("%s", qstring_get_str(qstring));
512 loc_pop(&qerror->loc);
513 QDECREF(qstring);
514 }
515
516 void qerror_report_internal(const char *file, int linenr, const char *func,
517 const char *fmt, ...)
518 {
519 va_list va;
520 QError *qerror;
521
522 va_start(va, fmt);
523 qerror = qerror_from_info(file, linenr, func, fmt, &va);
524 va_end(va);
525
526 if (monitor_cur_is_qmp()) {
527 monitor_set_error(cur_mon, qerror);
528 } else {
529 qerror_print(qerror);
530 QDECREF(qerror);
531 }
532 }
533
534 /* Evil... */
535 struct Error
536 {
537 QDict *obj;
538 const char *fmt;
539 char *msg;
540 };
541
542 void qerror_report_err(Error *err)
543 {
544 QError *qerr;
545 int i;
546
547 qerr = qerror_new();
548 loc_save(&qerr->loc);
549 QINCREF(err->obj);
550 qerr->error = err->obj;
551
552 for (i = 0; qerror_table[i].error_fmt; i++) {
553 if (strcmp(qerror_table[i].error_fmt, err->fmt) == 0) {
554 qerr->entry = &qerror_table[i];
555 break;
556 }
557 }
558
559 if (monitor_cur_is_qmp()) {
560 monitor_set_error(cur_mon, qerr);
561 } else {
562 qerror_print(qerr);
563 QDECREF(qerr);
564 }
565 }
566
567 /**
568 * qobject_to_qerror(): Convert a QObject into a QError
569 */
570 QError *qobject_to_qerror(const QObject *obj)
571 {
572 if (qobject_type(obj) != QTYPE_QERROR) {
573 return NULL;
574 }
575
576 return container_of(obj, QError, base);
577 }
578
579 /**
580 * qerror_destroy_obj(): Free all memory allocated by a QError
581 */
582 static void qerror_destroy_obj(QObject *obj)
583 {
584 QError *qerr;
585
586 assert(obj != NULL);
587 qerr = qobject_to_qerror(obj);
588
589 QDECREF(qerr->error);
590 g_free(qerr);
591 }