xref: /qemu/qapi/qobject-input-visitor.c (revision 7b1cd1c6) 
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 void 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     }
254 }
255 
256 static void qobject_input_stack_object_free(StackObject *tos)
257 {
258     if (tos->h) {
259         g_hash_table_unref(tos->h);
260     }
261 
262     g_free(tos);
263 }
264 
265 static void qobject_input_pop(Visitor *v, void **obj)
266 {
267     QObjectInputVisitor *qiv = to_qiv(v);
268     StackObject *tos = QSLIST_FIRST(&qiv->stack);
269 
270     assert(tos && tos->qapi == obj);
271     QSLIST_REMOVE_HEAD(&qiv->stack, node);
272     qobject_input_stack_object_free(tos);
273 }
274 
275 static void qobject_input_start_struct(Visitor *v, const char *name, void **obj,
276                                        size_t size, Error **errp)
277 {
278     QObjectInputVisitor *qiv = to_qiv(v);
279     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
280 
281     if (obj) {
282         *obj = NULL;
283     }
284     if (!qobj) {
285         return;
286     }
287     if (qobject_type(qobj) != QTYPE_QDICT) {
288         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
289                    full_name(qiv, name), "object");
290         return;
291     }
292 
293     qobject_input_push(qiv, name, qobj, obj);
294 
295     if (obj) {
296         *obj = g_malloc0(size);
297     }
298 }
299 
300 static void qobject_input_end_struct(Visitor *v, void **obj)
301 {
302     QObjectInputVisitor *qiv = to_qiv(v);
303     StackObject *tos = QSLIST_FIRST(&qiv->stack);
304 
305     assert(qobject_type(tos->obj) == QTYPE_QDICT && tos->h);
306     qobject_input_pop(v, obj);
307 }
308 
309 
310 static void qobject_input_start_list(Visitor *v, const char *name,
311                                      GenericList **list, size_t size,
312                                      Error **errp)
313 {
314     QObjectInputVisitor *qiv = to_qiv(v);
315     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
316     const QListEntry *entry;
317 
318     if (list) {
319         *list = NULL;
320     }
321     if (!qobj) {
322         return;
323     }
324     if (qobject_type(qobj) != QTYPE_QLIST) {
325         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
326                    full_name(qiv, name), "array");
327         return;
328     }
329 
330     entry = qobject_input_push(qiv, name, qobj, list);
331     if (entry && list) {
332         *list = g_malloc0(size);
333     }
334 }
335 
336 static GenericList *qobject_input_next_list(Visitor *v, GenericList *tail,
337                                             size_t size)
338 {
339     QObjectInputVisitor *qiv = to_qiv(v);
340     StackObject *tos = QSLIST_FIRST(&qiv->stack);
341 
342     assert(tos && qobject_to(QList, tos->obj));
343 
344     if (!tos->entry) {
345         return NULL;
346     }
347     tail->next = g_malloc0(size);
348     return tail->next;
349 }
350 
351 static void qobject_input_check_list(Visitor *v, Error **errp)
352 {
353     QObjectInputVisitor *qiv = to_qiv(v);
354     StackObject *tos = QSLIST_FIRST(&qiv->stack);
355 
356     assert(tos && qobject_to(QList, tos->obj));
357 
358     if (tos->entry) {
359         error_setg(errp, "Only %u list elements expected in %s",
360                    tos->index + 1, full_name_nth(qiv, NULL, 1));
361     }
362 }
363 
364 static void qobject_input_end_list(Visitor *v, void **obj)
365 {
366     QObjectInputVisitor *qiv = to_qiv(v);
367     StackObject *tos = QSLIST_FIRST(&qiv->stack);
368 
369     assert(qobject_type(tos->obj) == QTYPE_QLIST && !tos->h);
370     qobject_input_pop(v, obj);
371 }
372 
373 static void qobject_input_start_alternate(Visitor *v, const char *name,
374                                           GenericAlternate **obj, size_t size,
375                                           Error **errp)
376 {
377     QObjectInputVisitor *qiv = to_qiv(v);
378     QObject *qobj = qobject_input_get_object(qiv, name, false, errp);
379 
380     if (!qobj) {
381         *obj = NULL;
382         return;
383     }
384     *obj = g_malloc0(size);
385     (*obj)->type = qobject_type(qobj);
386 }
387 
388 static void qobject_input_type_int64(Visitor *v, const char *name, int64_t *obj,
389                                      Error **errp)
390 {
391     QObjectInputVisitor *qiv = to_qiv(v);
392     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
393     QNum *qnum;
394 
395     if (!qobj) {
396         return;
397     }
398     qnum = qobject_to(QNum, qobj);
399     if (!qnum || !qnum_get_try_int(qnum, obj)) {
400         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
401                    full_name(qiv, name), "integer");
402     }
403 }
404 
405 static void qobject_input_type_int64_keyval(Visitor *v, const char *name,
406                                             int64_t *obj, Error **errp)
407 {
408     QObjectInputVisitor *qiv = to_qiv(v);
409     const char *str = qobject_input_get_keyval(qiv, name, errp);
410 
411     if (!str) {
412         return;
413     }
414 
415     if (qemu_strtoi64(str, NULL, 0, obj) < 0) {
416         /* TODO report -ERANGE more nicely */
417         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
418                    full_name(qiv, name), "integer");
419     }
420 }
421 
422 static void qobject_input_type_uint64(Visitor *v, const char *name,
423                                       uint64_t *obj, Error **errp)
424 {
425     QObjectInputVisitor *qiv = to_qiv(v);
426     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
427     QNum *qnum;
428     int64_t val;
429 
430     if (!qobj) {
431         return;
432     }
433     qnum = qobject_to(QNum, qobj);
434     if (!qnum) {
435         goto err;
436     }
437 
438     if (qnum_get_try_uint(qnum, obj)) {
439         return;
440     }
441 
442     /* Need to accept negative values for backward compatibility */
443     if (qnum_get_try_int(qnum, &val)) {
444         *obj = val;
445         return;
446     }
447 
448 err:
449     error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
450                full_name(qiv, name), "uint64");
451 }
452 
453 static void qobject_input_type_uint64_keyval(Visitor *v, const char *name,
454                                              uint64_t *obj, Error **errp)
455 {
456     QObjectInputVisitor *qiv = to_qiv(v);
457     const char *str = qobject_input_get_keyval(qiv, name, errp);
458 
459     if (!str) {
460         return;
461     }
462 
463     if (qemu_strtou64(str, NULL, 0, obj) < 0) {
464         /* TODO report -ERANGE more nicely */
465         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
466                    full_name(qiv, name), "integer");
467     }
468 }
469 
470 static void qobject_input_type_bool(Visitor *v, const char *name, bool *obj,
471                                     Error **errp)
472 {
473     QObjectInputVisitor *qiv = to_qiv(v);
474     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
475     QBool *qbool;
476 
477     if (!qobj) {
478         return;
479     }
480     qbool = qobject_to(QBool, qobj);
481     if (!qbool) {
482         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
483                    full_name(qiv, name), "boolean");
484         return;
485     }
486 
487     *obj = qbool_get_bool(qbool);
488 }
489 
490 static void qobject_input_type_bool_keyval(Visitor *v, const char *name,
491                                            bool *obj, Error **errp)
492 {
493     QObjectInputVisitor *qiv = to_qiv(v);
494     const char *str = qobject_input_get_keyval(qiv, name, errp);
495 
496     if (!str) {
497         return;
498     }
499 
500     if (!strcmp(str, "on")) {
501         *obj = true;
502     } else if (!strcmp(str, "off")) {
503         *obj = false;
504     } else {
505         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
506                    full_name(qiv, name), "'on' or 'off'");
507     }
508 }
509 
510 static void qobject_input_type_str(Visitor *v, const char *name, char **obj,
511                                    Error **errp)
512 {
513     QObjectInputVisitor *qiv = to_qiv(v);
514     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
515     QString *qstr;
516 
517     *obj = NULL;
518     if (!qobj) {
519         return;
520     }
521     qstr = qobject_to(QString, qobj);
522     if (!qstr) {
523         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
524                    full_name(qiv, name), "string");
525         return;
526     }
527 
528     *obj = g_strdup(qstring_get_str(qstr));
529 }
530 
531 static void qobject_input_type_str_keyval(Visitor *v, const char *name,
532                                           char **obj, Error **errp)
533 {
534     QObjectInputVisitor *qiv = to_qiv(v);
535     const char *str = qobject_input_get_keyval(qiv, name, errp);
536 
537     *obj = g_strdup(str);
538 }
539 
540 static void qobject_input_type_number(Visitor *v, const char *name, double *obj,
541                                       Error **errp)
542 {
543     QObjectInputVisitor *qiv = to_qiv(v);
544     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
545     QNum *qnum;
546 
547     if (!qobj) {
548         return;
549     }
550     qnum = qobject_to(QNum, qobj);
551     if (!qnum) {
552         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
553                    full_name(qiv, name), "number");
554         return;
555     }
556 
557     *obj = qnum_get_double(qnum);
558 }
559 
560 static void qobject_input_type_number_keyval(Visitor *v, const char *name,
561                                              double *obj, Error **errp)
562 {
563     QObjectInputVisitor *qiv = to_qiv(v);
564     const char *str = qobject_input_get_keyval(qiv, name, errp);
565     double val;
566 
567     if (!str) {
568         return;
569     }
570 
571     if (qemu_strtod_finite(str, NULL, &val)) {
572         /* TODO report -ERANGE more nicely */
573         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
574                    full_name(qiv, name), "number");
575         return;
576     }
577 
578     *obj = val;
579 }
580 
581 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,
582                                    Error **errp)
583 {
584     QObjectInputVisitor *qiv = to_qiv(v);
585     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
586 
587     *obj = NULL;
588     if (!qobj) {
589         return;
590     }
591 
592     *obj = qobject_ref(qobj);
593 }
594 
595 static void qobject_input_type_null(Visitor *v, const char *name,
596                                     QNull **obj, Error **errp)
597 {
598     QObjectInputVisitor *qiv = to_qiv(v);
599     QObject *qobj = qobject_input_get_object(qiv, name, true, errp);
600 
601     *obj = NULL;
602     if (!qobj) {
603         return;
604     }
605 
606     if (qobject_type(qobj) != QTYPE_QNULL) {
607         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
608                    full_name(qiv, name), "null");
609         return;
610     }
611     *obj = qnull();
612 }
613 
614 static void qobject_input_type_size_keyval(Visitor *v, const char *name,
615                                            uint64_t *obj, Error **errp)
616 {
617     QObjectInputVisitor *qiv = to_qiv(v);
618     const char *str = qobject_input_get_keyval(qiv, name, errp);
619 
620     if (!str) {
621         return;
622     }
623 
624     if (qemu_strtosz(str, NULL, obj) < 0) {
625         /* TODO report -ERANGE more nicely */
626         error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
627                    full_name(qiv, name), "size");
628     }
629 }
630 
631 static void qobject_input_optional(Visitor *v, const char *name, bool *present)
632 {
633     QObjectInputVisitor *qiv = to_qiv(v);
634     QObject *qobj = qobject_input_try_get_object(qiv, name, false);
635 
636     if (!qobj) {
637         *present = false;
638         return;
639     }
640 
641     *present = true;
642 }
643 
644 static void qobject_input_free(Visitor *v)
645 {
646     QObjectInputVisitor *qiv = to_qiv(v);
647 
648     while (!QSLIST_EMPTY(&qiv->stack)) {
649         StackObject *tos = QSLIST_FIRST(&qiv->stack);
650 
651         QSLIST_REMOVE_HEAD(&qiv->stack, node);
652         qobject_input_stack_object_free(tos);
653     }
654 
655     qobject_unref(qiv->root);
656     if (qiv->errname) {
657         g_string_free(qiv->errname, TRUE);
658     }
659     g_free(qiv);
660 }
661 
662 static QObjectInputVisitor *qobject_input_visitor_base_new(QObject *obj)
663 {
664     QObjectInputVisitor *v = g_malloc0(sizeof(*v));
665 
666     assert(obj);
667 
668     v->visitor.type = VISITOR_INPUT;
669     v->visitor.start_struct = qobject_input_start_struct;
670     v->visitor.check_struct = qobject_input_check_struct;
671     v->visitor.end_struct = qobject_input_end_struct;
672     v->visitor.start_list = qobject_input_start_list;
673     v->visitor.next_list = qobject_input_next_list;
674     v->visitor.check_list = qobject_input_check_list;
675     v->visitor.end_list = qobject_input_end_list;
676     v->visitor.start_alternate = qobject_input_start_alternate;
677     v->visitor.optional = qobject_input_optional;
678     v->visitor.free = qobject_input_free;
679 
680     v->root = qobject_ref(obj);
681 
682     return v;
683 }
684 
685 Visitor *qobject_input_visitor_new(QObject *obj)
686 {
687     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
688 
689     v->visitor.type_int64 = qobject_input_type_int64;
690     v->visitor.type_uint64 = qobject_input_type_uint64;
691     v->visitor.type_bool = qobject_input_type_bool;
692     v->visitor.type_str = qobject_input_type_str;
693     v->visitor.type_number = qobject_input_type_number;
694     v->visitor.type_any = qobject_input_type_any;
695     v->visitor.type_null = qobject_input_type_null;
696 
697     return &v->visitor;
698 }
699 
700 Visitor *qobject_input_visitor_new_keyval(QObject *obj)
701 {
702     QObjectInputVisitor *v = qobject_input_visitor_base_new(obj);
703 
704     v->visitor.type_int64 = qobject_input_type_int64_keyval;
705     v->visitor.type_uint64 = qobject_input_type_uint64_keyval;
706     v->visitor.type_bool = qobject_input_type_bool_keyval;
707     v->visitor.type_str = qobject_input_type_str_keyval;
708     v->visitor.type_number = qobject_input_type_number_keyval;
709     v->visitor.type_any = qobject_input_type_any;
710     v->visitor.type_null = qobject_input_type_null;
711     v->visitor.type_size = qobject_input_type_size_keyval;
712     v->keyval = true;
713 
714     return &v->visitor;
715 }
716 
717 Visitor *qobject_input_visitor_new_str(const char *str,
718                                        const char *implied_key,
719                                        Error **errp)
720 {
721     bool is_json = str[0] == '{';
722     QObject *obj;
723     QDict *args;
724     Visitor *v;
725 
726     if (is_json) {
727         obj = qobject_from_json(str, errp);
728         if (!obj) {
729             return NULL;
730         }
731         args = qobject_to(QDict, obj);
732         assert(args);
733         v = qobject_input_visitor_new(QOBJECT(args));
734     } else {
735         args = keyval_parse(str, implied_key, errp);
736         if (!args) {
737             return NULL;
738         }
739         v = qobject_input_visitor_new_keyval(QOBJECT(args));
740     }
741     qobject_unref(args);
742 
743     return v;
744 }
745