xref: /qemu/qapi/qobject-input-visitor.c (revision 6c02258e143700314ebf268dae47eb23db17d1cf)
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 "qapi/error.h"
17 #include "qapi/qobject-input-visitor.h"
18 #include "qapi/visitor-impl.h"
19 #include "qemu/queue.h"
20 #include "qemu-common.h"
21 #include "qapi/qmp/qjson.h"
22 #include "qapi/qmp/types.h"
23 #include "qapi/qmp/qerror.h"
24 #include "qemu/cutils.h"
25 #include "qemu/option.h"
26 
27 typedef struct StackObject {
28     const char *name;            /* Name of @obj in its parent, if any */
29     QObject *obj;                /* QDict or QList being visited */
30     void *qapi; /* sanity check that caller uses same pointer */
31 
32     GHashTable *h;              /* If @obj is QDict: unvisited keys */
33     const QListEntry *entry;    /* If @obj is QList: unvisited tail */
34     unsigned index;             /* If @obj is QList: list index of @entry */
35 
36     QSLIST_ENTRY(StackObject) node; /* parent */
37 } StackObject;
38 
39 struct QObjectInputVisitor {
40     Visitor visitor;
41 
42     /* Root of visit at visitor creation. */
43     QObject *root;
44     bool keyval;                /* Assume @root made with keyval_parse() */
45 
46     /* Stack of objects being visited (all entries will be either
47      * QDict or QList). */
48     QSLIST_HEAD(, StackObject) stack;
49 
50     GString *errname;           /* Accumulator for full_name() */
51 };
52 
53 static QObjectInputVisitor *to_qiv(Visitor *v)
54 {
55     return container_of(v, QObjectInputVisitor, visitor);
56 }
57 
58 /*
59  * Find the full name of something @qiv is currently visiting.
60  * @qiv is visiting something named @name in the stack of containers
61  * @qiv->stack.
62  * If @n is zero, return its full name.
63  * If @n is positive, return the full name of the @n-th container
64  * counting from the top.  The stack of containers must have at least
65  * @n elements.
66  * The returned string is valid until the next full_name_nth(@v) or
67  * destruction of @v.
68  */
69 static const char *full_name_nth(QObjectInputVisitor *qiv, const char *name,
70                                  int n)
71 {
72     StackObject *so;
73     char buf[32];
74 
75     if (qiv->errname) {
76         g_string_truncate(qiv->errname, 0);
77     } else {
78         qiv->errname = g_string_new("");
79     }
80 
81     QSLIST_FOREACH(so , &qiv->stack, node) {
82         if (n) {
83             n--;
84         } else if (qobject_type(so->obj) == QTYPE_QDICT) {
85             g_string_prepend(qiv->errname, name ?: "<anonymous>");
86             g_string_prepend_c(qiv->errname, '.');
87         } else {
88             snprintf(buf, sizeof(buf),
89                      qiv->keyval ? ".%u" : "[%u]",
90                      so->index);
91             g_string_prepend(qiv->errname, buf);
92         }
93         name = so->name;
94     }
95     assert(!n);
96 
97     if (name) {
98         g_string_prepend(qiv->errname, name);
99     } else if (qiv->errname->str[0] == '.') {
100         g_string_erase(qiv->errname, 0, 1);
101     } else if (!qiv->errname->str[0]) {
102         return "<anonymous>";
103     }
104 
105     return qiv->errname->str;
106 }
107 
108 static const char *full_name(QObjectInputVisitor *qiv, const char *name)
109 {
110     return full_name_nth(qiv, name, 0);
111 }
112 
113 static QObject *qobject_input_try_get_object(QObjectInputVisitor *qiv,
114                                              const char *name,
115                                              bool consume)
116 {
117     StackObject *tos;
118     QObject *qobj;
119     QObject *ret;
120 
121     if (QSLIST_EMPTY(&qiv->stack)) {
122         /* Starting at root, name is ignored. */
123         assert(qiv->root);
124         return qiv->root;
125     }
126 
127     /* We are in a container; find the next element. */
128     tos = QSLIST_FIRST(&qiv->stack);
129     qobj = tos->obj;
130     assert(qobj);
131 
132     if (qobject_type(qobj) == QTYPE_QDICT) {
133         assert(name);
134         ret = qdict_get(qobject_to_qdict(qobj), name);
135         if (tos->h && consume && ret) {
136             bool removed = g_hash_table_remove(tos->h, name);
137             assert(removed);
138         }
139     } else {
140         assert(qobject_type(qobj) == QTYPE_QLIST);
141         assert(!name);
142         if (tos->entry) {
143             ret = qlist_entry_obj(tos->entry);
144             if (consume) {
145                 tos->entry = qlist_next(tos->entry);
146             }
147         } else {
148             ret = NULL;
149         }
150         if (consume) {
151             tos->index++;
152         }
153     }
154 
155     return ret;
156 }
157 
158 static QObject *qobject_input_get_object(QObjectInputVisitor *qiv,
159                                          const char *name,
160                                          bool consume, Error **errp)
161 {
162     QObject *obj = qobject_input_try_get_object(qiv, name, consume);
163 
164     if (!obj) {
165         error_setg(errp, QERR_MISSING_PARAMETER, full_name(qiv, name));
166     }
167     return obj;
168 }
169 
170 static const char *qobject_input_get_keyval(QObjectInputVisitor *qiv,
171                                             const char *name,
172                                             Error **errp)
173 {
174     QObject *qobj;
175     QString *qstr;
176 
177     qobj = qobject_input_get_object(qiv, name, true, errp);
178     if (!qobj) {
179         return NULL;
180     }
181 
182     qstr = qobject_to_qstring(qobj);
183     if (!qstr) {
184         switch (qobject_type(qobj)) {
185         case QTYPE_QDICT:
186         case QTYPE_QLIST:
187             error_setg(errp, "Parameters '%s.*' are unexpected",
188                        full_name(qiv, name));
189             return NULL;
190         default:
191             /* Non-string scalar (should this be an assertion?) */
192             error_setg(errp, "Internal error: parameter %s invalid",
193                        full_name(qiv, name));
194             return NULL;
195         }
196     }
197 
198     return qstring_get_str(qstr);
199 }
200 
201 static void qdict_add_key(const char *key, QObject *obj, void *opaque)
202 {
203     GHashTable *h = opaque;
204     g_hash_table_insert(h, (gpointer) key, NULL);
205 }
206 
207 static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
208                                             const char *name,
209                                             QObject *obj, void *qapi)
210 {
211     GHashTable *h;
212     StackObject *tos = g_new0(StackObject, 1);
213 
214     assert(obj);
215     tos->name = name;
216     tos->obj = obj;
217     tos->qapi = qapi;
218 
219     if (qobject_type(obj) == QTYPE_QDICT) {
220         h = g_hash_table_new(g_str_hash, g_str_equal);
221         qdict_iter(qobject_to_qdict(obj), qdict_add_key, h);
222         tos->h = h;
223     } else {
224         assert(qobject_type(obj) == QTYPE_QLIST);
225         tos->entry = qlist_first(qobject_to_qlist(obj));
226         tos->index = -1;
227     }
228 
229     QSLIST_INSERT_HEAD(&qiv->stack, tos, node);
230     return tos->entry;
231 }
232 
233 
234 static void qobject_input_check_struct(Visitor *v, Error **errp)
235 {
236     QObjectInputVisitor *qiv = to_qiv(v);
237     StackObject *tos = QSLIST_FIRST(&qiv->stack);
238     GHashTableIter iter;
239     const char *key;
240 
241     assert(tos && !tos->entry);
242 
243     g_hash_table_iter_init(&iter, tos->h);
244     if (g_hash_table_iter_next(&iter, (void **)&key, NULL)) {
245         error_setg(errp, "Parameter '%s' is unexpected",
246                    full_name(qiv, key));
247     }
248 }
249 
250 static void qobject_input_stack_object_free(StackObject *tos)
251 {
252     if (tos->h) {
253         g_hash_table_unref(tos->h);
254     }
255 
256     g_free(tos);
257 }
258 
259 static void qobject_input_pop(Visitor *v, void **obj)
260 {
261     QObjectInputVisitor *qiv = to_qiv(v);
262     StackObject *tos = QSLIST_FIRST(&qiv->stack);
263 
264     assert(tos && tos->qapi == obj);
265     QSLIST_REMOVE_HEAD(&qiv->stack, node);
266     qobject_input_stack_object_free(tos);
267 }
268 
269 static void qobject_input_start_struct(Visitor *v, const char *name, void **obj,
270                                        size_t size, Error **errp)
271 {
272     QObjectInputVisitor *qiv = to_qiv(v);
273     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
274 
275     if (obj) {
276         *obj = NULL;
277     }
278     if (!qobj) {
279         return;
280     }
281     if (qobject_type(qobj) != QTYPE_QDICT) {
282         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
283                    full_name(qiv, name), "object");
284         return;
285     }
286 
287     qobject_input_push(qiv, name, qobj, obj);
288 
289     if (obj) {
290         *obj = g_malloc0(size);
291     }
292 }
293 
294 
295 static void qobject_input_start_list(Visitor *v, const char *name,
296                                      GenericList **list, size_t size,
297                                      Error **errp)
298 {
299     QObjectInputVisitor *qiv = to_qiv(v);
300     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
301     const QListEntry *entry;
302 
303     if (list) {
304         *list = NULL;
305     }
306     if (!qobj) {
307         return;
308     }
309     if (qobject_type(qobj) != QTYPE_QLIST) {
310         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
311                    full_name(qiv, name), "array");
312         return;
313     }
314 
315     entry = qobject_input_push(qiv, name, qobj, list);
316     if (entry && list) {
317         *list = g_malloc0(size);
318     }
319 }
320 
321 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
322                                             size_t size)
323 {
324     QObjectInputVisitor *qiv = to_qiv(v);
325     StackObject *tos = QSLIST_FIRST(&qiv->stack);
326 
327     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
328 
329     if (!tos->entry) {
330         return NULL;
331     }
332     tail->next = g_malloc0(size);
333     return tail->next;
334 }
335 
336 static void qobject_input_check_list(Visitor *v, Error **errp)
337 {
338     QObjectInputVisitor *qiv = to_qiv(v);
339     StackObject *tos = QSLIST_FIRST(&qiv->stack);
340 
341     assert(tos && tos->obj && qobject_type(tos->obj) == QTYPE_QLIST);
342 
343     if (tos->entry) {
344         error_setg(errp, "Only %u list elements expected in %s",
345                    tos->index + 1, full_name_nth(qiv, NULL, 1));
346     }
347 }
348 
349 
350 static void qobject_input_start_alternate(Visitor *v, const char *name,
351                                           GenericAlternate **obj, size_t size,
352                                           bool promote_int, Error **errp)
353 {
354     QObjectInputVisitor *qiv = to_qiv(v);
355     QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
356 
357     if (!qobj) {
358         *obj = NULL;
359         return;
360     }
361     *obj = g_malloc0(size);
362     (*obj)->type = qobject_type(qobj);
363     if (promote_int && (*obj)->type == QTYPE_QINT) {
364         (*obj)->type = QTYPE_QFLOAT;
365     }
366 }
367 
368 static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
369                                      Error **errp)
370 {
371     QObjectInputVisitor *qiv = to_qiv(v);
372     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
373     QInt *qint;
374 
375     if (!qobj) {
376         return;
377     }
378     qint = qobject_to_qint(qobj);
379     if (!qint) {
380         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
381                    full_name(qiv, name), "integer");
382         return;
383     }
384 
385     *obj = qint_get_int(qint);
386 }
387 
388 
389 static void qobject_input_type_int64_keyval(Visitor *v, const char *name,
390                                             int64_t *obj, Error **errp)
391 {
392     QObjectInputVisitor *qiv = to_qiv(v);
393     const char *str = qobject_input_get_keyval(qiv, name, errp);
394 
395     if (!str) {
396         return;
397     }
398 
399     if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
400         /* TODO report -ERANGE more nicely */
401         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
402                    full_name(qiv, name), "integer");
403     }
404 }
405 
406 static void qobject_input_type_uint64(Visitor *v, const char *name,
407                                       uint64_t *obj, Error **errp)
408 {
409     /* FIXME: qobject_to_qint mishandles values over INT64_MAX */
410     QObjectInputVisitor *qiv = to_qiv(v);
411     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
412     QInt *qint;
413 
414     if (!qobj) {
415         return;
416     }
417     qint = qobject_to_qint(qobj);
418     if (!qint) {
419         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
420                    full_name(qiv, name), "integer");
421         return;
422     }
423 
424     *obj = qint_get_int(qint);
425 }
426 
427 static void qobject_input_type_uint64_keyval(Visitor *v, const char *name,
428                                              uint64_t *obj, Error **errp)
429 {
430     QObjectInputVisitor *qiv = to_qiv(v);
431     const char *str = qobject_input_get_keyval(qiv, name, errp);
432 
433     if (!str) {
434         return;
435     }
436 
437     if (qemu_strtou64(str, NULL, 0, obj) < 0) {
438         /* TODO report -ERANGE more nicely */
439         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
440                    full_name(qiv, name), "integer");
441     }
442 }
443 
444 static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
445                                     Error **errp)
446 {
447     QObjectInputVisitor *qiv = to_qiv(v);
448     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
449     QBool *qbool;
450 
451     if (!qobj) {
452         return;
453     }
454     qbool = qobject_to_qbool(qobj);
455     if (!qbool) {
456         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
457                    full_name(qiv, name), "boolean");
458         return;
459     }
460 
461     *obj = qbool_get_bool(qbool);
462 }
463 
464 static void qobject_input_type_bool_keyval(Visitor *v, const char *name,
465                                            bool *obj, Error **errp)
466 {
467     QObjectInputVisitor *qiv = to_qiv(v);
468     const char *str = qobject_input_get_keyval(qiv, name, errp);
469 
470     if (!str) {
471         return;
472     }
473 
474     if (!strcmp(str, "on")) {
475         *obj = true;
476     } else if (!strcmp(str, "off")) {
477         *obj = false;
478     } else {
479         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
480                    full_name(qiv, name), "'on' or 'off'");
481     }
482 }
483 
484 static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
485                                    Error **errp)
486 {
487     QObjectInputVisitor *qiv = to_qiv(v);
488     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
489     QString *qstr;
490 
491     *obj = NULL;
492     if (!qobj) {
493         return;
494     }
495     qstr = qobject_to_qstring(qobj);
496     if (!qstr) {
497         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
498                    full_name(qiv, name), "string");
499         return;
500     }
501 
502     *obj = g_strdup(qstring_get_str(qstr));
503 }
504 
505 static void qobject_input_type_str_keyval(Visitor *v, const char *name,
506                                           char **obj, Error **errp)
507 {
508     QObjectInputVisitor *qiv = to_qiv(v);
509     const char *str = qobject_input_get_keyval(qiv, name, errp);
510 
511     *obj = g_strdup(str);
512 }
513 
514 static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
515                                       Error **errp)
516 {
517     QObjectInputVisitor *qiv = to_qiv(v);
518     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
519     QInt *qint;
520     QFloat *qfloat;
521 
522     if (!qobj) {
523         return;
524     }
525     qint = qobject_to_qint(qobj);
526     if (qint) {
527         *obj = qint_get_int(qobject_to_qint(qobj));
528         return;
529     }
530 
531     qfloat = qobject_to_qfloat(qobj);
532     if (qfloat) {
533         *obj = qfloat_get_double(qobject_to_qfloat(qobj));
534         return;
535     }
536 
537     error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
538                full_name(qiv, name), "number");
539 }
540 
541 static void qobject_input_type_number_keyval(Visitor *v, const char *name,
542                                              double *obj, Error **errp)
543 {
544     QObjectInputVisitor *qiv = to_qiv(v);
545     const char *str = qobject_input_get_keyval(qiv, name, errp);
546     char *endp;
547 
548     if (!str) {
549         return;
550     }
551 
552     errno = 0;
553     *obj = strtod(str, &endp);
554     if (errno || endp == str || *endp) {
555         /* TODO report -ERANGE more nicely */
556         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
557                    full_name(qiv, name), "number");
558     }
559 }
560 
561 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
562                                    Error **errp)
563 {
564     QObjectInputVisitor *qiv = to_qiv(v);
565     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
566 
567     *obj = NULL;
568     if (!qobj) {
569         return;
570     }
571 
572     qobject_incref(qobj);
573     *obj = qobj;
574 }
575 
576 static void qobject_input_type_null(Visitor *v, const char *name, Error **errp)
577 {
578     QObjectInputVisitor *qiv = to_qiv(v);
579     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
580 
581     if (!qobj) {
582         return;
583     }
584 
585     if (qobject_type(qobj) != QTYPE_QNULL) {
586         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
587                    full_name(qiv, name), "null");
588     }
589 }
590 
591 static void qobject_input_type_size_keyval(Visitor *v, const char *name,
592                                            uint64_t *obj, Error **errp)
593 {
594     QObjectInputVisitor *qiv = to_qiv(v);
595     const char *str = qobject_input_get_keyval(qiv, name, errp);
596 
597     if (!str) {
598         return;
599     }
600 
601     if (qemu_strtosz(str, NULL, obj) < 0) {
602         /* TODO report -ERANGE more nicely */
603         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
604                    full_name(qiv, name), "size");
605     }
606 }
607 
608 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
609 {
610     QObjectInputVisitor *qiv = to_qiv(v);
611     QObject *qobj = qobject_input_try_get_object(qiv, name, false);
612 
613     if (!qobj) {
614         *present = false;
615         return;
616     }
617 
618     *present = true;
619 }
620 
621 static void qobject_input_free(Visitor *v)
622 {
623     QObjectInputVisitor *qiv = to_qiv(v);
624 
625     while (!QSLIST_EMPTY(&qiv->stack)) {
626         StackObject *tos = QSLIST_FIRST(&qiv->stack);
627 
628         QSLIST_REMOVE_HEAD(&qiv->stack, node);
629         qobject_input_stack_object_free(tos);
630     }
631 
632     qobject_decref(qiv->root);
633     if (qiv->errname) {
634         g_string_free(qiv->errname, TRUE);
635     }
636     g_free(qiv);
637 }
638 
639 static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
640 {
641     QObjectInputVisitor *v = g_malloc0(sizeof(*v));
642 
643     assert(obj);
644 
645     v->visitor.type = VISITOR_INPUT;
646     v->visitor.start_struct = qobject_input_start_struct;
647     v->visitor.check_struct = qobject_input_check_struct;
648     v->visitor.end_struct = qobject_input_pop;
649     v->visitor.start_list = qobject_input_start_list;
650     v->visitor.next_list = qobject_input_next_list;
651     v->visitor.check_list = qobject_input_check_list;
652     v->visitor.end_list = qobject_input_pop;
653     v->visitor.start_alternate = qobject_input_start_alternate;
654     v->visitor.optional = qobject_input_optional;
655     v->visitor.free = qobject_input_free;
656 
657     v->root = obj;
658     qobject_incref(obj);
659 
660     return v;
661 }
662 
663 Visitor *qobject_input_visitor_new(QObject *obj)
664 {
665     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
666 
667     v->visitor.type_int64 = qobject_input_type_int64;
668     v->visitor.type_uint64 = qobject_input_type_uint64;
669     v->visitor.type_bool = qobject_input_type_bool;
670     v->visitor.type_str = qobject_input_type_str;
671     v->visitor.type_number = qobject_input_type_number;
672     v->visitor.type_any = qobject_input_type_any;
673     v->visitor.type_null = qobject_input_type_null;
674 
675     return &v->visitor;
676 }
677 
678 Visitor *qobject_input_visitor_new_keyval(QObject *obj)
679 {
680     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
681 
682     v->visitor.type_int64 = qobject_input_type_int64_keyval;
683     v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
684     v->visitor.type_bool = qobject_input_type_bool_keyval;
685     v->visitor.type_str = qobject_input_type_str_keyval;
686     v->visitor.type_number = qobject_input_type_number_keyval;
687     v->visitor.type_any = qobject_input_type_any;
688     v->visitor.type_null = qobject_input_type_null;
689     v->visitor.type_size = qobject_input_type_size_keyval;
690     v->keyval = true;
691 
692     return &v->visitor;
693 }
694 
695 Visitor *qobject_input_visitor_new_str(const char *str,
696                                        const char *implied_key,
697                                        Error **errp)
698 {
699     bool is_json = str[0] == '{';
700     QObject *obj;
701     QDict *args;
702     Visitor *v;
703 
704     if (is_json) {
705         obj = qobject_from_json(str, errp);
706         if (!obj) {
707             /* Work around qobject_from_json() lossage TODO fix that */
708             if (errp && !*errp) {
709                 error_setg(errp, "JSON parse error");
710                 return NULL;
711             }
712             return NULL;
713         }
714         args = qobject_to_qdict(obj);
715         assert(args);
716         v = qobject_input_visitor_new(QOBJECT(args));
717     } else {
718         args = keyval_parse(str, implied_key, errp);
719         if (!args) {
720             return NULL;
721         }
722         v = qobject_input_visitor_new_keyval(QOBJECT(args));
723     }
724     QDECREF(args);
725 
726     return v;
727 }
728