Merge remote-tracking branch 'remotes/cohuck-gitlab/tags/s390x-20210121' into staging
[qemu.git] / qobject / qjson.c
1 /*
2 * QObject JSON integration
3 *
4 * Copyright IBM, Corp. 2009
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.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
14 #include "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qapi/qmp/json-parser.h"
17 #include "qapi/qmp/json-writer.h"
18 #include "qapi/qmp/qjson.h"
19 #include "qapi/qmp/qbool.h"
20 #include "qapi/qmp/qdict.h"
21 #include "qapi/qmp/qlist.h"
22 #include "qapi/qmp/qnum.h"
23 #include "qapi/qmp/qstring.h"
24
25 typedef struct JSONParsingState
26 {
27 JSONMessageParser parser;
28 QObject *result;
29 Error *err;
30 } JSONParsingState;
31
32 static void consume_json(void *opaque, QObject *json, Error *err)
33 {
34 JSONParsingState *s = opaque;
35
36 assert(!json != !err);
37 assert(!s->result || !s->err);
38
39 if (s->result) {
40 qobject_unref(s->result);
41 s->result = NULL;
42 error_setg(&s->err, "Expecting at most one JSON value");
43 }
44 if (s->err) {
45 qobject_unref(json);
46 error_free(err);
47 return;
48 }
49 s->result = json;
50 s->err = err;
51 }
52
53 /*
54 * Parse @string as JSON value.
55 * If @ap is non-null, interpolate %-escapes.
56 * Takes ownership of %p arguments.
57 * On success, return the JSON value.
58 * On failure, store an error through @errp and return NULL.
59 * Ownership of %p arguments becomes indeterminate then. To avoid
60 * leaks, callers passing %p must terminate on error, e.g. by passing
61 * &error_abort.
62 */
63 static QObject *qobject_from_jsonv(const char *string, va_list *ap,
64 Error **errp)
65 {
66 JSONParsingState state = {};
67
68 json_message_parser_init(&state.parser, consume_json, &state, ap);
69 json_message_parser_feed(&state.parser, string, strlen(string));
70 json_message_parser_flush(&state.parser);
71 json_message_parser_destroy(&state.parser);
72
73 if (!state.result && !state.err) {
74 error_setg(&state.err, "Expecting a JSON value");
75 }
76
77 error_propagate(errp, state.err);
78 return state.result;
79 }
80
81 QObject *qobject_from_json(const char *string, Error **errp)
82 {
83 return qobject_from_jsonv(string, NULL, errp);
84 }
85
86 /*
87 * Parse @string as JSON value with %-escapes interpolated.
88 * Abort on error. Do not use with untrusted @string.
89 * Return the resulting QObject. It is never null.
90 */
91 QObject *qobject_from_vjsonf_nofail(const char *string, va_list ap)
92 {
93 va_list ap_copy;
94 QObject *obj;
95
96 /* va_copy() is needed when va_list is an array type */
97 va_copy(ap_copy, ap);
98 obj = qobject_from_jsonv(string, &ap_copy, &error_abort);
99 va_end(ap_copy);
100
101 assert(obj);
102 return obj;
103 }
104
105 /*
106 * Parse @string as JSON value with %-escapes interpolated.
107 * Abort on error. Do not use with untrusted @string.
108 * Return the resulting QObject. It is never null.
109 */
110 QObject *qobject_from_jsonf_nofail(const char *string, ...)
111 {
112 QObject *obj;
113 va_list ap;
114
115 va_start(ap, string);
116 obj = qobject_from_vjsonf_nofail(string, ap);
117 va_end(ap);
118
119 return obj;
120 }
121
122 /*
123 * Parse @string as JSON object with %-escapes interpolated.
124 * Abort on error. Do not use with untrusted @string.
125 * Return the resulting QDict. It is never null.
126 */
127 QDict *qdict_from_vjsonf_nofail(const char *string, va_list ap)
128 {
129 QDict *qdict;
130
131 qdict = qobject_to(QDict, qobject_from_vjsonf_nofail(string, ap));
132 assert(qdict);
133 return qdict;
134 }
135
136 /*
137 * Parse @string as JSON object with %-escapes interpolated.
138 * Abort on error. Do not use with untrusted @string.
139 * Return the resulting QDict. It is never null.
140 */
141 QDict *qdict_from_jsonf_nofail(const char *string, ...)
142 {
143 QDict *qdict;
144 va_list ap;
145
146 va_start(ap, string);
147 qdict = qdict_from_vjsonf_nofail(string, ap);
148 va_end(ap);
149 return qdict;
150 }
151
152 static void to_json(JSONWriter *writer, const char *name,
153 const QObject *obj)
154 {
155 switch (qobject_type(obj)) {
156 case QTYPE_QNULL:
157 json_writer_null(writer, name);
158 break;
159 case QTYPE_QNUM: {
160 QNum *val = qobject_to(QNum, obj);
161
162 switch (val->kind) {
163 case QNUM_I64:
164 json_writer_int64(writer, name, val->u.i64);
165 break;
166 case QNUM_U64:
167 json_writer_uint64(writer, name, val->u.u64);
168 break;
169 case QNUM_DOUBLE:
170 json_writer_double(writer, name, val->u.dbl);
171 break;
172 default:
173 abort();
174 }
175 break;
176 }
177 case QTYPE_QSTRING: {
178 QString *val = qobject_to(QString, obj);
179
180 json_writer_str(writer, name, qstring_get_str(val));
181 break;
182 }
183 case QTYPE_QDICT: {
184 QDict *val = qobject_to(QDict, obj);
185 const QDictEntry *entry;
186
187 json_writer_start_object(writer, name);
188
189 for (entry = qdict_first(val);
190 entry;
191 entry = qdict_next(val, entry)) {
192 to_json(writer, qdict_entry_key(entry), qdict_entry_value(entry));
193 }
194
195 json_writer_end_object(writer);
196 break;
197 }
198 case QTYPE_QLIST: {
199 QList *val = qobject_to(QList, obj);
200 QListEntry *entry;
201
202 json_writer_start_array(writer, name);
203
204 QLIST_FOREACH_ENTRY(val, entry) {
205 to_json(writer, NULL, qlist_entry_obj(entry));
206 }
207
208 json_writer_end_array(writer);
209 break;
210 }
211 case QTYPE_QBOOL: {
212 QBool *val = qobject_to(QBool, obj);
213
214 json_writer_bool(writer, name, qbool_get_bool(val));
215 break;
216 }
217 default:
218 abort();
219 }
220 }
221
222 GString *qobject_to_json_pretty(const QObject *obj, bool pretty)
223 {
224 JSONWriter *writer = json_writer_new(pretty);
225
226 to_json(writer, NULL, obj);
227 return json_writer_get_and_free(writer);
228 }
229
230 GString *qobject_to_json(const QObject *obj)
231 {
232 return qobject_to_json_pretty(obj, false);
233 }