aboutsummaryrefslogtreecommitdiff
path: root/qapi/qmp-dispatch.c
blob: c30c7ff9e17ef428b12e59fcbd8e489094024761 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
 * Core Definitions for QAPI/QMP Dispatch
 *
 * Copyright IBM, Corp. 2011
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 * See the COPYING.LIB file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qapi/qmp/dispatch.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qjson.h"
#include "sysemu/runstate.h"
#include "qapi/qmp/qbool.h"

static QDict *qmp_dispatch_check_obj(QDict *dict, bool allow_oob,
                                     Error **errp)
{
    const char *exec_key = NULL;
    const QDictEntry *ent;
    const char *arg_name;
    const QObject *arg_obj;

    for (ent = qdict_first(dict); ent;
         ent = qdict_next(dict, ent)) {
        arg_name = qdict_entry_key(ent);
        arg_obj = qdict_entry_value(ent);

        if (!strcmp(arg_name, "execute")
            || (!strcmp(arg_name, "exec-oob") && allow_oob)) {
            if (qobject_type(arg_obj) != QTYPE_QSTRING) {
                error_setg(errp, "QMP input member '%s' must be a string",
                           arg_name);
                return NULL;
            }
            if (exec_key) {
                error_setg(errp, "QMP input member '%s' clashes with '%s'",
                           arg_name, exec_key);
                return NULL;
            }
            exec_key = arg_name;
        } else if (!strcmp(arg_name, "arguments")) {
            if (qobject_type(arg_obj) != QTYPE_QDICT) {
                error_setg(errp,
                           "QMP input member 'arguments' must be an object");
                return NULL;
            }
        } else if (!strcmp(arg_name, "id")) {
            continue;
        } else {
            error_setg(errp, "QMP input member '%s' is unexpected",
                       arg_name);
            return NULL;
        }
    }

    if (!exec_key) {
        error_setg(errp, "QMP input lacks member 'execute'");
        return NULL;
    }

    return dict;
}

QDict *qmp_error_response(Error *err)
{
    QDict *rsp;

    rsp = qdict_from_jsonf_nofail("{ 'error': { 'class': %s, 'desc': %s } }",
                                  QapiErrorClass_str(error_get_class(err)),
                                  error_get_pretty(err));
    error_free(err);
    return rsp;
}

/*
 * Does @qdict look like a command to be run out-of-band?
 */
bool qmp_is_oob(const QDict *dict)
{
    return qdict_haskey(dict, "exec-oob")
        && !qdict_haskey(dict, "execute");
}

QDict *qmp_dispatch(const QmpCommandList *cmds, QObject *request,
                    bool allow_oob)
{
    Error *err = NULL;
    bool oob;
    const char *command;
    QDict *args;
    const QmpCommand *cmd;
    QDict *dict;
    QObject *id;
    QObject *ret = NULL;
    QDict *rsp = NULL;

    dict = qobject_to(QDict, request);
    if (!dict) {
        id = NULL;
        error_setg(&err, "QMP input must be a JSON object");
        goto out;
    }

    id = qdict_get(dict, "id");

    if (!qmp_dispatch_check_obj(dict, allow_oob, &err)) {
        goto out;
    }

    command = qdict_get_try_str(dict, "execute");
    oob = false;
    if (!command) {
        assert(allow_oob);
        command = qdict_get_str(dict, "exec-oob");
        oob = true;
    }
    cmd = qmp_find_command(cmds, command);
    if (cmd == NULL) {
        error_set(&err, ERROR_CLASS_COMMAND_NOT_FOUND,
                  "The command %s has not been found", command);
        goto out;
    }
    if (!cmd->enabled) {
        error_set(&err, ERROR_CLASS_COMMAND_NOT_FOUND,
                  "The command %s has been disabled for this instance",
                  command);
        goto out;
    }
    if (oob && !(cmd->options & QCO_ALLOW_OOB)) {
        error_setg(&err, "The command %s does not support OOB",
                   command);
        goto out;
    }

    if (runstate_check(RUN_STATE_PRECONFIG) &&
        !(cmd->options & QCO_ALLOW_PRECONFIG)) {
        error_setg(&err, "The command '%s' isn't permitted in '%s' state",
                   cmd->name, RunState_str(RUN_STATE_PRECONFIG));
        goto out;
    }

    if (!qdict_haskey(dict, "arguments")) {
        args = qdict_new();
    } else {
        args = qdict_get_qdict(dict, "arguments");
        qobject_ref(args);
    }
    cmd->fn(args, &ret, &err);
    qobject_unref(args);
    if (err) {
        goto out;
    }

    if (cmd->options & QCO_NO_SUCCESS_RESP) {
        g_assert(!ret);
        return NULL;
    } else if (!ret) {
        /*
         * When the command's schema has no 'returns', cmd->fn()
         * leaves @ret null.  The QMP spec calls for an empty object
         * then; supply it.
         */
        ret = QOBJECT(qdict_new());
    }

    rsp = qdict_new();
    qdict_put_obj(rsp, "return", ret);

out:
    if (err) {
        assert(!rsp);
        rsp = qmp_error_response(err);
    }

    assert(rsp);

    if (id) {
        qdict_put_obj(rsp, "id", qobject_ref(id));
    }

    return rsp;
}