xref: /openbmc/qemu/qobject/qjson.c (revision 56c4bfb3) 
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 "qapi/qmp/json-lexer.h"
15 #include "qapi/qmp/json-parser.h"
16 #include "qapi/qmp/json-streamer.h"
17 #include "qapi/qmp/qjson.h"
18 #include "qapi/qmp/qint.h"
19 #include "qapi/qmp/qlist.h"
20 #include "qapi/qmp/qbool.h"
21 #include "qapi/qmp/qfloat.h"
22 #include "qapi/qmp/qdict.h"
23 
24 typedef struct JSONParsingState
25 {
26     JSONMessageParser parser;
27     va_list *ap;
28     QObject *result;
29 } JSONParsingState;
30 
31 static void parse_json(JSONMessageParser *parser, QList *tokens)
32 {
33     JSONParsingState *s = container_of(parser, JSONParsingState, parser);
34     s->result = json_parser_parse(tokens, s->ap);
35 }
36 
37 QObject *qobject_from_jsonv(const char *string, va_list *ap)
38 {
39     JSONParsingState state = {};
40 
41     state.ap = ap;
42 
43     json_message_parser_init(&state.parser, parse_json);
44     json_message_parser_feed(&state.parser, string, strlen(string));
45     json_message_parser_flush(&state.parser);
46     json_message_parser_destroy(&state.parser);
47 
48     return state.result;
49 }
50 
51 QObject *qobject_from_json(const char *string)
52 {
53     return qobject_from_jsonv(string, NULL);
54 }
55 
56 /*
57  * IMPORTANT: This function aborts on error, thus it must not
58  * be used with untrusted arguments.
59  */
60 QObject *qobject_from_jsonf(const char *string, ...)
61 {
62     QObject *obj;
63     va_list ap;
64 
65     va_start(ap, string);
66     obj = qobject_from_jsonv(string, &ap);
67     va_end(ap);
68 
69     assert(obj != NULL);
70     return obj;
71 }
72 
73 typedef struct ToJsonIterState
74 {
75     int indent;
76     int pretty;
77     int count;
78     QString *str;
79 } ToJsonIterState;
80 
81 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
82 
83 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
84 {
85     ToJsonIterState *s = opaque;
86     QString *qkey;
87     int j;
88 
89     if (s->count)
90         qstring_append(s->str, ", ");
91 
92     if (s->pretty) {
93         qstring_append(s->str, "\n");
94         for (j = 0 ; j < s->indent ; j++)
95             qstring_append(s->str, "    ");
96     }
97 
98     qkey = qstring_from_str(key);
99     to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
100     QDECREF(qkey);
101 
102     qstring_append(s->str, ": ");
103     to_json(obj, s->str, s->pretty, s->indent);
104     s->count++;
105 }
106 
107 static void to_json_list_iter(QObject *obj, void *opaque)
108 {
109     ToJsonIterState *s = opaque;
110     int j;
111 
112     if (s->count)
113         qstring_append(s->str, ", ");
114 
115     if (s->pretty) {
116         qstring_append(s->str, "\n");
117         for (j = 0 ; j < s->indent ; j++)
118             qstring_append(s->str, "    ");
119     }
120 
121     to_json(obj, s->str, s->pretty, s->indent);
122     s->count++;
123 }
124 
125 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
126 {
127     switch (qobject_type(obj)) {
128     case QTYPE_QINT: {
129         QInt *val = qobject_to_qint(obj);
130         char buffer[1024];
131 
132         snprintf(buffer, sizeof(buffer), "%" PRId64, qint_get_int(val));
133         qstring_append(str, buffer);
134         break;
135     }
136     case QTYPE_QSTRING: {
137         QString *val = qobject_to_qstring(obj);
138         const char *ptr;
139         int cp;
140         char buf[16];
141         char *end;
142 
143         ptr = qstring_get_str(val);
144         qstring_append(str, "\"");
145 
146         for (; *ptr; ptr = end) {
147             cp = mod_utf8_codepoint(ptr, 6, &end);
148             switch (cp) {
149             case '\"':
150                 qstring_append(str, "\\\"");
151                 break;
152             case '\\':
153                 qstring_append(str, "\\\\");
154                 break;
155             case '\b':
156                 qstring_append(str, "\\b");
157                 break;
158             case '\f':
159                 qstring_append(str, "\\f");
160                 break;
161             case '\n':
162                 qstring_append(str, "\\n");
163                 break;
164             case '\r':
165                 qstring_append(str, "\\r");
166                 break;
167             case '\t':
168                 qstring_append(str, "\\t");
169                 break;
170             default:
171                 if (cp < 0) {
172                     cp = 0xFFFD; /* replacement character */
173                 }
174                 if (cp > 0xFFFF) {
175                     /* beyond BMP; need a surrogate pair */
176                     snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
177                              0xD800 + ((cp - 0x10000) >> 10),
178                              0xDC00 + ((cp - 0x10000) & 0x3FF));
179                 } else if (cp < 0x20 || cp >= 0x7F) {
180                     snprintf(buf, sizeof(buf), "\\u%04X", cp);
181                 } else {
182                     buf[0] = cp;
183                     buf[1] = 0;
184                 }
185                 qstring_append(str, buf);
186             }
187         };
188 
189         qstring_append(str, "\"");
190         break;
191     }
192     case QTYPE_QDICT: {
193         ToJsonIterState s;
194         QDict *val = qobject_to_qdict(obj);
195 
196         s.count = 0;
197         s.str = str;
198         s.indent = indent + 1;
199         s.pretty = pretty;
200         qstring_append(str, "{");
201         qdict_iter(val, to_json_dict_iter, &s);
202         if (pretty) {
203             int j;
204             qstring_append(str, "\n");
205             for (j = 0 ; j < indent ; j++)
206                 qstring_append(str, "    ");
207         }
208         qstring_append(str, "}");
209         break;
210     }
211     case QTYPE_QLIST: {
212         ToJsonIterState s;
213         QList *val = qobject_to_qlist(obj);
214 
215         s.count = 0;
216         s.str = str;
217         s.indent = indent + 1;
218         s.pretty = pretty;
219         qstring_append(str, "[");
220         qlist_iter(val, (void *)to_json_list_iter, &s);
221         if (pretty) {
222             int j;
223             qstring_append(str, "\n");
224             for (j = 0 ; j < indent ; j++)
225                 qstring_append(str, "    ");
226         }
227         qstring_append(str, "]");
228         break;
229     }
230     case QTYPE_QFLOAT: {
231         QFloat *val = qobject_to_qfloat(obj);
232         char buffer[1024];
233         int len;
234 
235         len = snprintf(buffer, sizeof(buffer), "%f", qfloat_get_double(val));
236         while (len > 0 && buffer[len - 1] == '0') {
237             len--;
238         }
239 
240         if (len && buffer[len - 1] == '.') {
241             buffer[len - 1] = 0;
242         } else {
243             buffer[len] = 0;
244         }
245 
246         qstring_append(str, buffer);
247         break;
248     }
249     case QTYPE_QBOOL: {
250         QBool *val = qobject_to_qbool(obj);
251 
252         if (qbool_get_int(val)) {
253             qstring_append(str, "true");
254         } else {
255             qstring_append(str, "false");
256         }
257         break;
258     }
259     case QTYPE_QERROR:
260         /* XXX: should QError be emitted? */
261     case QTYPE_NONE:
262         break;
263     case QTYPE_MAX:
264         abort();
265     }
266 }
267 
268 QString *qobject_to_json(const QObject *obj)
269 {
270     QString *str = qstring_new();
271 
272     to_json(obj, str, 0, 0);
273 
274     return str;
275 }
276 
277 QString *qobject_to_json_pretty(const QObject *obj)
278 {
279     QString *str = qstring_new();
280 
281     to_json(obj, str, 1, 0);
282 
283     return str;
284 }
285