xref: /openbmc/qemu/qapi/qmp-dispatch.c (revision 89854803)
1 /*
2  * Core Definitions for QAPI/QMP Dispatch
3  *
4  * Copyright IBM, Corp. 2011
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/dispatch.h"
17 #include "qapi/qmp/json-parser.h"
18 #include "qapi/qmp/qdict.h"
19 #include "qapi/qmp/qjson.h"
20 #include "qapi/qmp/qbool.h"
21 
22 QDict *qmp_dispatch_check_obj(const QObject *request, Error **errp)
23 {
24     const QDictEntry *ent;
25     const char *arg_name;
26     const QObject *arg_obj;
27     bool has_exec_key = false;
28     QDict *dict = NULL;
29 
30     dict = qobject_to(QDict, request);
31     if (!dict) {
32         error_setg(errp, "QMP input must be a JSON object");
33         return NULL;
34     }
35 
36     for (ent = qdict_first(dict); ent;
37          ent = qdict_next(dict, ent)) {
38         arg_name = qdict_entry_key(ent);
39         arg_obj = qdict_entry_value(ent);
40 
41         if (!strcmp(arg_name, "execute")) {
42             if (qobject_type(arg_obj) != QTYPE_QSTRING) {
43                 error_setg(errp,
44                            "QMP input member 'execute' must be a string");
45                 return NULL;
46             }
47             has_exec_key = true;
48         } else if (!strcmp(arg_name, "arguments")) {
49             if (qobject_type(arg_obj) != QTYPE_QDICT) {
50                 error_setg(errp,
51                            "QMP input member 'arguments' must be an object");
52                 return NULL;
53             }
54         } else if (!strcmp(arg_name, "id")) {
55             continue;
56         } else if (!strcmp(arg_name, "control")) {
57             if (qobject_type(arg_obj) != QTYPE_QDICT) {
58                 error_setg(errp,
59                            "QMP input member 'control' must be a dict");
60                 return NULL;
61             }
62         } else {
63             error_setg(errp, "QMP input member '%s' is unexpected",
64                        arg_name);
65             return NULL;
66         }
67     }
68 
69     if (!has_exec_key) {
70         error_setg(errp, "QMP input lacks member 'execute'");
71         return NULL;
72     }
73 
74     return dict;
75 }
76 
77 static QObject *do_qmp_dispatch(QmpCommandList *cmds, QObject *request,
78                                 Error **errp)
79 {
80     Error *local_err = NULL;
81     const char *command;
82     QDict *args, *dict;
83     QmpCommand *cmd;
84     QObject *ret = NULL;
85 
86     dict = qmp_dispatch_check_obj(request, errp);
87     if (!dict) {
88         return NULL;
89     }
90 
91     command = qdict_get_str(dict, "execute");
92     cmd = qmp_find_command(cmds, command);
93     if (cmd == NULL) {
94         error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
95                   "The command %s has not been found", command);
96         return NULL;
97     }
98     if (!cmd->enabled) {
99         error_setg(errp, "The command %s has been disabled for this instance",
100                    command);
101         return NULL;
102     }
103 
104     if (!qdict_haskey(dict, "arguments")) {
105         args = qdict_new();
106     } else {
107         args = qdict_get_qdict(dict, "arguments");
108         qobject_ref(args);
109     }
110 
111     cmd->fn(args, &ret, &local_err);
112     if (local_err) {
113         error_propagate(errp, local_err);
114     } else if (cmd->options & QCO_NO_SUCCESS_RESP) {
115         g_assert(!ret);
116     } else if (!ret) {
117         ret = QOBJECT(qdict_new());
118     }
119 
120     qobject_unref(args);
121 
122     return ret;
123 }
124 
125 QObject *qmp_build_error_object(Error *err)
126 {
127     return qobject_from_jsonf("{ 'class': %s, 'desc': %s }",
128                               QapiErrorClass_str(error_get_class(err)),
129                               error_get_pretty(err));
130 }
131 
132 /*
133  * Detect whether a request should be run out-of-band, by quickly
134  * peeking at whether we have: { "control": { "run-oob": true } }. By
135  * default commands are run in-band.
136  */
137 bool qmp_is_oob(QDict *dict)
138 {
139     QBool *bool_obj;
140 
141     dict = qdict_get_qdict(dict, "control");
142     if (!dict) {
143         return false;
144     }
145 
146     bool_obj = qobject_to(QBool, qdict_get(dict, "run-oob"));
147     if (!bool_obj) {
148         return false;
149     }
150 
151     return qbool_get_bool(bool_obj);
152 }
153 
154 QObject *qmp_dispatch(QmpCommandList *cmds, QObject *request)
155 {
156     Error *err = NULL;
157     QObject *ret;
158     QDict *rsp;
159 
160     ret = do_qmp_dispatch(cmds, request, &err);
161 
162     rsp = qdict_new();
163     if (err) {
164         qdict_put_obj(rsp, "error", qmp_build_error_object(err));
165         error_free(err);
166     } else if (ret) {
167         qdict_put_obj(rsp, "return", ret);
168     } else {
169         qobject_unref(rsp);
170         return NULL;
171     }
172 
173     return QOBJECT(rsp);
174 }
175