linux-user: Add support for a group of btrfs ioctls used for snapshots
[qemu.git] / qapi / qobject-input-visitor.c
1 /*
2 * Input Visitor
3 *
4 * Copyright (C) 2012-2017 Red Hat, Inc.
5 * Copyright IBM, Corp. 2011
6 *
7 * Authors:
8 * Anthony Liguori <aliguori@us.ibm.com>
9 *
10 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
11 * See the COPYING.LIB file in the top-level directory.
12 *
13 */
14
15 #include "qemu/osdep.h"
16 #include <math.h>
17 #include "qapi/error.h"
18 #include "qapi/qobject-input-visitor.h"
19 #include "qapi/visitor-impl.h"
20 #include "qemu/queue.h"
21 #include "qapi/qmp/qjson.h"
22 #include "qapi/qmp/qbool.h"
23 #include "qapi/qmp/qdict.h"
24 #include "qapi/qmp/qerror.h"
25 #include "qapi/qmp/qlist.h"
26 #include "qapi/qmp/qnull.h"
27 #include "qapi/qmp/qnum.h"
28 #include "qapi/qmp/qstring.h"
29 #include "qemu/cutils.h"
30 #include "qemu/option.h"
31
32 typedef struct StackObject {
33 const char *name; /* Name of @obj in its parent, if any */
34 QObject *obj; /* QDict or QList being visited */
35 void *qapi; /* sanity check that caller uses same pointer */
36
37 GHashTable *h; /* If @obj is QDict: unvisited keys */
38 const QListEntry *entry; /* If @obj is QList: unvisited tail */
39 unsigned index; /* If @obj is QList: list index of @entry */
40
41 QSLIST_ENTRY(StackObject) node; /* parent */
42 } StackObject;
43
44 struct QObjectInputVisitor {
45 Visitor visitor;
46
47 /* Root of visit at visitor creation. */
48 QObject *root;
49 bool keyval; /* Assume @root made with keyval_parse() */
50
51 /* Stack of objects being visited (all entries will be either
52 * QDict or QList). */
53 QSLIST_HEAD(, StackObject) stack;
54
55 GString *errname; /* Accumulator for full_name() */
56 };
57
58 static QObjectInputVisitor *to_qiv(Visitor *v)
59 {
60 return container_of(v, QObjectInputVisitor, visitor);
61 }
62
63 /*
64 * Find the full name of something @qiv is currently visiting.
65 * @qiv is visiting something named @name in the stack of containers
66 * @qiv->stack.
67 * If @n is zero, return its full name.
68 * If @n is positive, return the full name of the @n-th container
69 * counting from the top. The stack of containers must have at least
70 * @n elements.
71 * The returned string is valid until the next full_name_nth(@v) or
72 * destruction of @v.
73 */
74 static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
75 int n)
76 {
77 StackObject *so;
78 char buf[32];
79
80 if (qiv->errname) {
81 g_string_truncate(qiv->errname, 0);
82 } else {
83 qiv->errname = g_string_new("");
84 }
85
86 QSLIST_FOREACH(so , &qiv->stack, node) {
87 if (n) {
88 n--;
89 } else if (qobject_type(so->obj) == QTYPE_QDICT) {
90 g_string_prepend(qiv->errname, name ?: "<anonymous>");
91 g_string_prepend_c(qiv->errname, '.');
92 } else {
93 snprintf(buf, sizeof(buf),
94 qiv->keyval ? ".%u" : "[%u]",
95 so->index);
96 g_string_prepend(qiv->errname, buf);
97 }
98 name = so->name;
99 }
100 assert(!n);
101
102 if (name) {
103 g_string_prepend(qiv->errname, name);
104 } else if (qiv->errname->str[0] == '.') {
105 g_string_erase(qiv->errname, 0, 1);
106 } else if (!qiv->errname->str[0]) {
107 return "<anonymous>";
108 }
109
110 return qiv->errname->str;
111 }
112
113 static const char *full_name(QObjectInputVisitor *qiv, const char *name)
114 {
115 return full_name_nth(qiv, name, 0);
116 }
117
118 static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
119 const char *name,
120 bool consume)
121 {
122 StackObject *tos;
123 QObject *qobj;
124 QObject *ret;
125
126 if (QSLIST_EMPTY(&qiv->stack)) {
127 /* Starting at root, name is ignored. */
128 assert(qiv->root);
129 return qiv->root;
130 }
131
132 /* We are in a container; find the next element. */
133 tos = QSLIST_FIRST(&qiv->stack);
134 qobj = tos->obj;
135 assert(qobj);
136
137 if (qobject_type(qobj) == QTYPE_QDICT) {
138 assert(name);
139 ret = qdict_get(qobject_to(QDict, qobj), name);
140 if (tos->h && consume && ret) {
141 bool removed = g_hash_table_remove(tos->h, name);
142 assert(removed);
143 }
144 } else {
145 assert(qobject_type(qobj) == QTYPE_QLIST);
146 assert(!name);
147 if (tos->entry) {
148 ret = qlist_entry_obj(tos->entry);
149 if (consume) {
150 tos->entry = qlist_next(tos->entry);
151 }
152 } else {
153 ret = NULL;
154 }
155 if (consume) {
156 tos->index++;
157 }
158 }
159
160 return ret;
161 }
162
163 static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
164 const char *name,
165 bool consume, Error **errp)
166 {
167 QObject *obj = qobject_input_try_get_object(qiv, name, consume);
168
169 if (!obj) {
170 error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
171 }
172 return obj;
173 }
174
175 static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv,
176 const char *name,
177 Error **errp)
178 {
179 QObject *qobj;
180 QString *qstr;
181
182 qobj = qobject_input_get_object(qiv, name, true, errp);
183 if (!qobj) {
184 return NULL;
185 }
186
187 qstr = qobject_to(QString, qobj);
188 if (!qstr) {
189 switch (qobject_type(qobj)) {
190 case QTYPE_QDICT:
191 case QTYPE_QLIST:
192 error_setg(errp, "Parameters '%s.*' are unexpected",
193 full_name(qiv, name));
194 return NULL;
195 default:
196 /* Non-string scalar (should this be an assertion?) */
197 error_setg(errp, "Internal error: parameter %s invalid",
198 full_name(qiv, name));
199 return NULL;
200 }
201 }
202
203 return qstring_get_str(qstr);
204 }
205
206 static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
207 const char *name,
208 QObject *obj, void *qapi)
209 {
210 GHashTable *h;
211 StackObject *tos = g_new0(StackObject, 1);
212 QDict *qdict = qobject_to(QDict, obj);
213 QList *qlist = qobject_to(QList, obj);
214 const QDictEntry *entry;
215
216 assert(obj);
217 tos->name = name;
218 tos->obj = obj;
219 tos->qapi = qapi;
220
221 if (qdict) {
222 h = g_hash_table_new(g_str_hash, g_str_equal);
223 for (entry = qdict_first(qdict);
224 entry;
225 entry = qdict_next(qdict, entry)) {
226 g_hash_table_insert(h, (void *)qdict_entry_key(entry), NULL);
227 }
228 tos->h = h;
229 } else {
230 assert(qlist);
231 tos->entry = qlist_first(qlist);
232 tos->index = -1;
233 }
234
235 QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
236 return tos->entry;
237 }
238
239
240 static bool qobject_input_check_struct(Visitor *v, Error **errp)
241 {
242 QObjectInputVisitor *qiv = to_qiv(v);
243 StackObject *tos = QSLIST_FIRST(&qiv->stack);
244 GHashTableIter iter;
245 const char *key;
246
247 assert(tos && !tos->entry);
248
249 g_hash_table_iter_init(&iter, tos->h);
250 if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
251 error_setg(errp, "Parameter '%s' is unexpected",
252 full_name(qiv, key));
253 return false;
254 }
255 return true;
256 }
257
258 static void qobject_input_stack_object_free(StackObject *tos)
259 {
260 if (tos->h) {
261 g_hash_table_unref(tos->h);
262 }
263
264 g_free(tos);
265 }
266
267 static void qobject_input_pop(Visitor *v, void **obj)
268 {
269 QObjectInputVisitor *qiv = to_qiv(v);
270 StackObject *tos = QSLIST_FIRST(&qiv->stack);
271
272 assert(tos && tos->qapi == obj);
273 QSLIST_REMOVE_HEAD(&qiv->stack, node);
274 qobject_input_stack_object_free(tos);
275 }
276
277 static bool qobject_input_start_struct(Visitor *v, const char *name, void **obj,
278 size_t size, Error **errp)
279 {
280 QObjectInputVisitor *qiv = to_qiv(v);
281 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
282
283 if (obj) {
284 *obj = NULL;
285 }
286 if (!qobj) {
287 return false;
288 }
289 if (qobject_type(qobj) != QTYPE_QDICT) {
290 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
291 full_name(qiv, name), "object");
292 return false;
293 }
294
295 qobject_input_push(qiv, name, qobj, obj);
296
297 if (obj) {
298 *obj = g_malloc0(size);
299 }
300 return true;
301 }
302
303 static void qobject_input_end_struct(Visitor *v, void **obj)
304 {
305 QObjectInputVisitor *qiv = to_qiv(v);
306 StackObject *tos = QSLIST_FIRST(&qiv->stack);
307
308 assert(qobject_type(tos->obj) == QTYPE_QDICT && tos->h);
309 qobject_input_pop(v, obj);
310 }
311
312
313 static bool qobject_input_start_list(Visitor *v, const char *name,
314 GenericList **list, size_t size,
315 Error **errp)
316 {
317 QObjectInputVisitor *qiv = to_qiv(v);
318 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
319 const QListEntry *entry;
320
321 if (list) {
322 *list = NULL;
323 }
324 if (!qobj) {
325 return false;
326 }
327 if (qobject_type(qobj) != QTYPE_QLIST) {
328 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
329 full_name(qiv, name), "array");
330 return false;
331 }
332
333 entry = qobject_input_push(qiv, name, qobj, list);
334 if (entry && list) {
335 *list = g_malloc0(size);
336 }
337 return true;
338 }
339
340 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
341 size_t size)
342 {
343 QObjectInputVisitor *qiv = to_qiv(v);
344 StackObject *tos = QSLIST_FIRST(&qiv->stack);
345
346 assert(tos && qobject_to(QList, tos->obj));
347
348 if (!tos->entry) {
349 return NULL;
350 }
351 tail->next = g_malloc0(size);
352 return tail->next;
353 }
354
355 static bool qobject_input_check_list(Visitor *v, Error **errp)
356 {
357 QObjectInputVisitor *qiv = to_qiv(v);
358 StackObject *tos = QSLIST_FIRST(&qiv->stack);
359
360 assert(tos && qobject_to(QList, tos->obj));
361
362 if (tos->entry) {
363 error_setg(errp, "Only %u list elements expected in %s",
364 tos->index + 1, full_name_nth(qiv, NULL, 1));
365 return false;
366 }
367 return true;
368 }
369
370 static void qobject_input_end_list(Visitor *v, void **obj)
371 {
372 QObjectInputVisitor *qiv = to_qiv(v);
373 StackObject *tos = QSLIST_FIRST(&qiv->stack);
374
375 assert(qobject_type(tos->obj) == QTYPE_QLIST && !tos->h);
376 qobject_input_pop(v, obj);
377 }
378
379 static bool qobject_input_start_alternate(Visitor *v, const char *name,
380 GenericAlternate **obj, size_t size,
381 Error **errp)
382 {
383 QObjectInputVisitor *qiv = to_qiv(v);
384 QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
385
386 if (!qobj) {
387 *obj = NULL;
388 return false;
389 }
390 *obj = g_malloc0(size);
391 (*obj)->type = qobject_type(qobj);
392 return true;
393 }
394
395 static bool qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
396 Error **errp)
397 {
398 QObjectInputVisitor *qiv = to_qiv(v);
399 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
400 QNum *qnum;
401
402 if (!qobj) {
403 return false;
404 }
405 qnum = qobject_to(QNum, qobj);
406 if (!qnum || !qnum_get_try_int(qnum, obj)) {
407 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
408 full_name(qiv, name), "integer");
409 return false;
410 }
411 return true;
412 }
413
414 static bool qobject_input_type_int64_keyval(Visitor *v, const char *name,
415 int64_t *obj, Error **errp)
416 {
417 QObjectInputVisitor *qiv = to_qiv(v);
418 const char *str = qobject_input_get_keyval(qiv, name, errp);
419
420 if (!str) {
421 return false;
422 }
423
424 if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
425 /* TODO report -ERANGE more nicely */
426 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
427 full_name(qiv, name), "integer");
428 return false;
429 }
430 return true;
431 }
432
433 static bool qobject_input_type_uint64(Visitor *v, const char *name,
434 uint64_t *obj, Error **errp)
435 {
436 QObjectInputVisitor *qiv = to_qiv(v);
437 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
438 QNum *qnum;
439 int64_t val;
440
441 if (!qobj) {
442 return false;
443 }
444 qnum = qobject_to(QNum, qobj);
445 if (!qnum) {
446 goto err;
447 }
448
449 if (qnum_get_try_uint(qnum, obj)) {
450 return true;
451 }
452
453 /* Need to accept negative values for backward compatibility */
454 if (qnum_get_try_int(qnum, &val)) {
455 *obj = val;
456 return true;
457 }
458
459 err:
460 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
461 full_name(qiv, name), "uint64");
462 return false;
463 }
464
465 static bool qobject_input_type_uint64_keyval(Visitor *v, const char *name,
466 uint64_t *obj, Error **errp)
467 {
468 QObjectInputVisitor *qiv = to_qiv(v);
469 const char *str = qobject_input_get_keyval(qiv, name, errp);
470
471 if (!str) {
472 return false;
473 }
474
475 if (qemu_strtou64(str, NULL, 0, obj) < 0) {
476 /* TODO report -ERANGE more nicely */
477 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
478 full_name(qiv, name), "integer");
479 return false;
480 }
481 return true;
482 }
483
484 static bool qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
485 Error **errp)
486 {
487 QObjectInputVisitor *qiv = to_qiv(v);
488 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
489 QBool *qbool;
490
491 if (!qobj) {
492 return false;
493 }
494 qbool = qobject_to(QBool, qobj);
495 if (!qbool) {
496 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
497 full_name(qiv, name), "boolean");
498 return false;
499 }
500
501 *obj = qbool_get_bool(qbool);
502 return true;
503 }
504
505 static bool qobject_input_type_bool_keyval(Visitor *v, const char *name,
506 bool *obj, Error **errp)
507 {
508 QObjectInputVisitor *qiv = to_qiv(v);
509 const char *str = qobject_input_get_keyval(qiv, name, errp);
510
511 if (!str) {
512 return false;
513 }
514
515 if (!strcmp(str, "on")) {
516 *obj = true;
517 } else if (!strcmp(str, "off")) {
518 *obj = false;
519 } else {
520 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
521 full_name(qiv, name), "'on' or 'off'");
522 return false;
523 }
524 return true;
525 }
526
527 static bool qobject_input_type_str(Visitor *v, const char *name, char **obj,
528 Error **errp)
529 {
530 QObjectInputVisitor *qiv = to_qiv(v);
531 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
532 QString *qstr;
533
534 *obj = NULL;
535 if (!qobj) {
536 return false;
537 }
538 qstr = qobject_to(QString, qobj);
539 if (!qstr) {
540 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
541 full_name(qiv, name), "string");
542 return false;
543 }
544
545 *obj = g_strdup(qstring_get_str(qstr));
546 return true;
547 }
548
549 static bool qobject_input_type_str_keyval(Visitor *v, const char *name,
550 char **obj, Error **errp)
551 {
552 QObjectInputVisitor *qiv = to_qiv(v);
553 const char *str = qobject_input_get_keyval(qiv, name, errp);
554
555 *obj = g_strdup(str);
556 return !!str;
557 }
558
559 static bool qobject_input_type_number(Visitor *v, const char *name, double *obj,
560 Error **errp)
561 {
562 QObjectInputVisitor *qiv = to_qiv(v);
563 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
564 QNum *qnum;
565
566 if (!qobj) {
567 return false;
568 }
569 qnum = qobject_to(QNum, qobj);
570 if (!qnum) {
571 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
572 full_name(qiv, name), "number");
573 return false;
574 }
575
576 *obj = qnum_get_double(qnum);
577 return true;
578 }
579
580 static bool qobject_input_type_number_keyval(Visitor *v, const char *name,
581 double *obj, Error **errp)
582 {
583 QObjectInputVisitor *qiv = to_qiv(v);
584 const char *str = qobject_input_get_keyval(qiv, name, errp);
585 double val;
586
587 if (!str) {
588 return false;
589 }
590
591 if (qemu_strtod_finite(str, NULL, &val)) {
592 /* TODO report -ERANGE more nicely */
593 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
594 full_name(qiv, name), "number");
595 return false;
596 }
597
598 *obj = val;
599 return true;
600 }
601
602 static bool qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
603 Error **errp)
604 {
605 QObjectInputVisitor *qiv = to_qiv(v);
606 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
607
608 *obj = NULL;
609 if (!qobj) {
610 return false;
611 }
612
613 *obj = qobject_ref(qobj);
614 return true;
615 }
616
617 static bool qobject_input_type_null(Visitor *v, const char *name,
618 QNull **obj, Error **errp)
619 {
620 QObjectInputVisitor *qiv = to_qiv(v);
621 QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
622
623 *obj = NULL;
624 if (!qobj) {
625 return false;
626 }
627
628 if (qobject_type(qobj) != QTYPE_QNULL) {
629 error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
630 full_name(qiv, name), "null");
631 return false;
632 }
633 *obj = qnull();
634 return true;
635 }
636
637 static bool qobject_input_type_size_keyval(Visitor *v, const char *name,
638 uint64_t *obj, Error **errp)
639 {
640 QObjectInputVisitor *qiv = to_qiv(v);
641 const char *str = qobject_input_get_keyval(qiv, name, errp);
642
643 if (!str) {
644 return false;
645 }
646
647 if (qemu_strtosz(str, NULL, obj) < 0) {
648 /* TODO report -ERANGE more nicely */
649 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
650 full_name(qiv, name), "size");
651 return false;
652 }
653 return true;
654 }
655
656 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
657 {
658 QObjectInputVisitor *qiv = to_qiv(v);
659 QObject *qobj = qobject_input_try_get_object(qiv, name, false);
660
661 if (!qobj) {
662 *present = false;
663 return;
664 }
665
666 *present = true;
667 }
668
669 static void qobject_input_free(Visitor *v)
670 {
671 QObjectInputVisitor *qiv = to_qiv(v);
672
673 while (!QSLIST_EMPTY(&qiv->stack)) {
674 StackObject *tos = QSLIST_FIRST(&qiv->stack);
675
676 QSLIST_REMOVE_HEAD(&qiv->stack, node);
677 qobject_input_stack_object_free(tos);
678 }
679
680 qobject_unref(qiv->root);
681 if (qiv->errname) {
682 g_string_free(qiv->errname, TRUE);
683 }
684 g_free(qiv);
685 }
686
687 static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
688 {
689 QObjectInputVisitor *v = g_malloc0(sizeof(*v));
690
691 assert(obj);
692
693 v->visitor.type = VISITOR_INPUT;
694 v->visitor.start_struct = qobject_input_start_struct;
695 v->visitor.check_struct = qobject_input_check_struct;
696 v->visitor.end_struct = qobject_input_end_struct;
697 v->visitor.start_list = qobject_input_start_list;
698 v->visitor.next_list = qobject_input_next_list;
699 v->visitor.check_list = qobject_input_check_list;
700 v->visitor.end_list = qobject_input_end_list;
701 v->visitor.start_alternate = qobject_input_start_alternate;
702 v->visitor.optional = qobject_input_optional;
703 v->visitor.free = qobject_input_free;
704
705 v->root = qobject_ref(obj);
706
707 return v;
708 }
709
710 Visitor *qobject_input_visitor_new(QObject *obj)
711 {
712 QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
713
714 v->visitor.type_int64 = qobject_input_type_int64;
715 v->visitor.type_uint64 = qobject_input_type_uint64;
716 v->visitor.type_bool = qobject_input_type_bool;
717 v->visitor.type_str = qobject_input_type_str;
718 v->visitor.type_number = qobject_input_type_number;
719 v->visitor.type_any = qobject_input_type_any;
720 v->visitor.type_null = qobject_input_type_null;
721
722 return &v->visitor;
723 }
724
725 Visitor *qobject_input_visitor_new_keyval(QObject *obj)
726 {
727 QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
728
729 v->visitor.type_int64 = qobject_input_type_int64_keyval;
730 v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
731 v->visitor.type_bool = qobject_input_type_bool_keyval;
732 v->visitor.type_str = qobject_input_type_str_keyval;
733 v->visitor.type_number = qobject_input_type_number_keyval;
734 v->visitor.type_any = qobject_input_type_any;
735 v->visitor.type_null = qobject_input_type_null;
736 v->visitor.type_size = qobject_input_type_size_keyval;
737 v->keyval = true;
738
739 return &v->visitor;
740 }
741
742 Visitor *qobject_input_visitor_new_str(const char *str,
743 const char *implied_key,
744 Error **errp)
745 {
746 bool is_json = str[0] == '{';
747 QObject *obj;
748 QDict *args;
749 Visitor *v;
750
751 if (is_json) {
752 obj = qobject_from_json(str, errp);
753 if (!obj) {
754 return NULL;
755 }
756 args = qobject_to(QDict, obj);
757 assert(args);
758 v = qobject_input_visitor_new(QOBJECT(args));
759 } else {
760 args = keyval_parse(str, implied_key, errp);
761 if (!args) {
762 return NULL;
763 }
764 v = qobject_input_visitor_new_keyval(QOBJECT(args));
765 }
766 qobject_unref(args);
767
768 return v;
769 }