Merge remote-tracking branch 'remotes/huth-gitlab/tags/pull-request-2020-08-05' into...
[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/qjson.h"
18 #include "qapi/qmp/qbool.h"
19 #include "qapi/qmp/qdict.h"
20 #include "qapi/qmp/qlist.h"
21 #include "qapi/qmp/qnum.h"
22 #include "qapi/qmp/qstring.h"
23 #include "qemu/unicode.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(const QObject *obj, QString *str, int pretty, int indent);
153
154 static void json_pretty_newline(QString *str, bool pretty, int indent)
155 {
156 int i;
157
158 if (pretty) {
159 qstring_append(str, "\n");
160 for (i = 0; i < indent; i++) {
161 qstring_append(str, " ");
162 }
163 }
164 }
165
166 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
167 {
168 switch (qobject_type(obj)) {
169 case QTYPE_QNULL:
170 qstring_append(str, "null");
171 break;
172 case QTYPE_QNUM: {
173 QNum *val = qobject_to(QNum, obj);
174 char *buffer = qnum_to_string(val);
175 qstring_append(str, buffer);
176 g_free(buffer);
177 break;
178 }
179 case QTYPE_QSTRING: {
180 QString *val = qobject_to(QString, obj);
181 const char *ptr;
182 int cp;
183 char buf[16];
184 char *end;
185
186 ptr = qstring_get_str(val);
187 qstring_append(str, "\"");
188
189 for (; *ptr; ptr = end) {
190 cp = mod_utf8_codepoint(ptr, 6, &end);
191 switch (cp) {
192 case '\"':
193 qstring_append(str, "\\\"");
194 break;
195 case '\\':
196 qstring_append(str, "\\\\");
197 break;
198 case '\b':
199 qstring_append(str, "\\b");
200 break;
201 case '\f':
202 qstring_append(str, "\\f");
203 break;
204 case '\n':
205 qstring_append(str, "\\n");
206 break;
207 case '\r':
208 qstring_append(str, "\\r");
209 break;
210 case '\t':
211 qstring_append(str, "\\t");
212 break;
213 default:
214 if (cp < 0) {
215 cp = 0xFFFD; /* replacement character */
216 }
217 if (cp > 0xFFFF) {
218 /* beyond BMP; need a surrogate pair */
219 snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
220 0xD800 + ((cp - 0x10000) >> 10),
221 0xDC00 + ((cp - 0x10000) & 0x3FF));
222 } else if (cp < 0x20 || cp >= 0x7F) {
223 snprintf(buf, sizeof(buf), "\\u%04X", cp);
224 } else {
225 buf[0] = cp;
226 buf[1] = 0;
227 }
228 qstring_append(str, buf);
229 }
230 };
231
232 qstring_append(str, "\"");
233 break;
234 }
235 case QTYPE_QDICT: {
236 QDict *val = qobject_to(QDict, obj);
237 const char *comma = pretty ? "," : ", ";
238 const char *sep = "";
239 const QDictEntry *entry;
240 QString *qkey;
241
242 qstring_append(str, "{");
243
244 for (entry = qdict_first(val);
245 entry;
246 entry = qdict_next(val, entry)) {
247 qstring_append(str, sep);
248 json_pretty_newline(str, pretty, indent + 1);
249
250 qkey = qstring_from_str(qdict_entry_key(entry));
251 to_json(QOBJECT(qkey), str, pretty, indent + 1);
252 qobject_unref(qkey);
253
254 qstring_append(str, ": ");
255 to_json(qdict_entry_value(entry), str, pretty, indent + 1);
256 sep = comma;
257 }
258
259 json_pretty_newline(str, pretty, indent);
260 qstring_append(str, "}");
261 break;
262 }
263 case QTYPE_QLIST: {
264 QList *val = qobject_to(QList, obj);
265 const char *comma = pretty ? "," : ", ";
266 const char *sep = "";
267 QListEntry *entry;
268
269 qstring_append(str, "[");
270
271 QLIST_FOREACH_ENTRY(val, entry) {
272 qstring_append(str, sep);
273 json_pretty_newline(str, pretty, indent + 1);
274 to_json(qlist_entry_obj(entry), str, pretty, indent + 1);
275 sep = comma;
276 }
277
278 json_pretty_newline(str, pretty, indent);
279 qstring_append(str, "]");
280 break;
281 }
282 case QTYPE_QBOOL: {
283 QBool *val = qobject_to(QBool, obj);
284
285 if (qbool_get_bool(val)) {
286 qstring_append(str, "true");
287 } else {
288 qstring_append(str, "false");
289 }
290 break;
291 }
292 default:
293 abort();
294 }
295 }
296
297 QString *qobject_to_json(const QObject *obj)
298 {
299 QString *str = qstring_new();
300
301 to_json(obj, str, 0, 0);
302
303 return str;
304 }
305
306 QString *qobject_to_json_pretty(const QObject *obj)
307 {
308 QString *str = qstring_new();
309
310 to_json(obj, str, 1, 0);
311
312 return str;
313 }