qapi/qmp-dispatch.c

   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/types.h"
  17 #include "qapi/qmp/dispatch.h"
  18 #include "qapi/qmp/json-parser.h"
  19 #include "qapi/qmp/qjson.h"
  20 #include "qapi-types.h"
  21 #include "qapi/qmp/qerror.h"
  22
  23 static QDict *qmp_dispatch_check_obj(const QObject *request, Error **errp)
  24 {
  25     const QDictEntry *ent;
  26     const char *arg_name;
  27     const QObject *arg_obj;
  28     bool has_exec_key = false;
  29     QDict *dict = NULL;
  30
  31     if (qobject_type(request) != QTYPE_QDICT) {
  32         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT,
  33                    "request is not a dictionary");
  34         return NULL;
  35     }
  36
  37     dict = qobject_to_qdict(request);
  38
  39     for (ent = qdict_first(dict); ent;
  40          ent = qdict_next(dict, ent)) {
  41         arg_name = qdict_entry_key(ent);
  42         arg_obj = qdict_entry_value(ent);
  43
  44         if (!strcmp(arg_name, "execute")) {
  45             if (qobject_type(arg_obj) != QTYPE_QSTRING) {
  46                 error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT_MEMBER, "execute",
  47                            "string");
  48                 return NULL;
  49             }
  50             has_exec_key = true;
  51         } else if (strcmp(arg_name, "arguments")) {
  52             error_setg(errp, QERR_QMP_EXTRA_MEMBER, arg_name);
  53             return NULL;
  54         }
  55     }
  56
  57     if (!has_exec_key) {
  58         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT, "execute");
  59         return NULL;
  60     }
  61
  62     return dict;
  63 }
  64
  65 static QObject *do_qmp_dispatch(QObject *request, Error **errp)
  66 {
  67     Error *local_err = NULL;
  68     const char *command;
  69     QDict *args, *dict;
  70     QmpCommand *cmd;
  71     QObject *ret = NULL;
  72
  73     dict = qmp_dispatch_check_obj(request, errp);
  74     if (!dict) {
  75         return NULL;
  76     }
  77
  78     command = qdict_get_str(dict, "execute");
  79     cmd = qmp_find_command(command);
  80     if (cmd == NULL) {
  81         error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
  82                   "The command %s has not been found", command);
  83         return NULL;
  84     }
  85     if (!cmd->enabled) {
  86         error_setg(errp, "The command %s has been disabled for this instance",
  87                    command);
  88         return NULL;
  89     }
  90
  91     if (!qdict_haskey(dict, "arguments")) {
  92         args = qdict_new();
  93     } else {
  94         args = qdict_get_qdict(dict, "arguments");
  95         QINCREF(args);
  96     }
  97
  98     cmd->fn(args, &ret, &local_err);
  99     if (local_err) {
 100         error_propagate(errp, local_err);
 101     } else if (cmd->options & QCO_NO_SUCCESS_RESP) {
 102         g_assert(!ret);
 103     } else if (!ret) {
 104         ret = QOBJECT(qdict_new());
 105     }
 106
 107     QDECREF(args);
 108
 109     return ret;
 110 }
 111
 112 QObject *qmp_build_error_object(Error *err)
 113 {
 114     return qobject_from_jsonf("{ 'class': %s, 'desc': %s }",
 115                               QapiErrorClass_lookup[error_get_class(err)],
 116                               error_get_pretty(err));
 117 }
 118
 119 QObject *qmp_dispatch(QObject *request)
 120 {
 121     Error *err = NULL;
 122     QObject *ret;
 123     QDict *rsp;
 124
 125     ret = do_qmp_dispatch(request, &err);
 126
 127     rsp = qdict_new();
 128     if (err) {
 129         qdict_put_obj(rsp, "error", qmp_build_error_object(err));
 130         error_free(err);
 131     } else if (ret) {
 132         qdict_put_obj(rsp, "return", ret);
 133     } else {
 134         QDECREF(rsp);
 135         return NULL;
 136     }
 137
 138     return QOBJECT(rsp);
 139 }