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/qmp/types.h"
  16 #include "qapi/qmp/dispatch.h"
  17 #include "qapi/qmp/json-parser.h"
  18 #include "qapi-types.h"
  19 #include "qapi/qmp/qerror.h"
  20
  21 static QDict *qmp_dispatch_check_obj(const QObject *request, Error **errp)
  22 {
  23     const QDictEntry *ent;
  24     const char *arg_name;
  25     const QObject *arg_obj;
  26     bool has_exec_key = false;
  27     QDict *dict = NULL;
  28
  29     if (qobject_type(request) != QTYPE_QDICT) {
  30         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT,
  31                    "request is not a dictionary");
  32         return NULL;
  33     }
  34
  35     dict = qobject_to_qdict(request);
  36
  37     for (ent = qdict_first(dict); ent;
  38          ent = qdict_next(dict, ent)) {
  39         arg_name = qdict_entry_key(ent);
  40         arg_obj = qdict_entry_value(ent);
  41
  42         if (!strcmp(arg_name, "execute")) {
  43             if (qobject_type(arg_obj) != QTYPE_QSTRING) {
  44                 error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT_MEMBER, "execute",
  45                            "string");
  46                 return NULL;
  47             }
  48             has_exec_key = true;
  49         } else if (strcmp(arg_name, "arguments")) {
  50             error_setg(errp, QERR_QMP_EXTRA_MEMBER, arg_name);
  51             return NULL;
  52         }
  53     }
  54
  55     if (!has_exec_key) {
  56         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT, "execute");
  57         return NULL;
  58     }
  59
  60     return dict;
  61 }
  62
  63 static QObject *do_qmp_dispatch(QObject *request, Error **errp)
  64 {
  65     Error *local_err = NULL;
  66     const char *command;
  67     QDict *args, *dict;
  68     QmpCommand *cmd;
  69     QObject *ret = NULL;
  70
  71     dict = qmp_dispatch_check_obj(request, errp);
  72     if (!dict) {
  73         return NULL;
  74     }
  75
  76     command = qdict_get_str(dict, "execute");
  77     cmd = qmp_find_command(command);
  78     if (cmd == NULL) {
  79         error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
  80                   "The command %s has not been found", command);
  81         return NULL;
  82     }
  83     if (!cmd->enabled) {
  84         error_setg(errp, "The command %s has been disabled for this instance",
  85                    command);
  86         return NULL;
  87     }
  88
  89     if (!qdict_haskey(dict, "arguments")) {
  90         args = qdict_new();
  91     } else {
  92         args = qdict_get_qdict(dict, "arguments");
  93         QINCREF(args);
  94     }
  95
  96     switch (cmd->type) {
  97     case QCT_NORMAL:
  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         break;
 107     }
 108
 109     QDECREF(args);
 110
 111     return ret;
 112 }
 113
 114 QObject *qmp_build_error_object(Error *err)
 115 {
 116     return qobject_from_jsonf("{ 'class': %s, 'desc': %s }",
 117                               QapiErrorClass_lookup[error_get_class(err)],
 118                               error_get_pretty(err));
 119 }
 120
 121 QObject *qmp_dispatch(QObject *request)
 122 {
 123     Error *err = NULL;
 124     QObject *ret;
 125     QDict *rsp;
 126
 127     ret = do_qmp_dispatch(request, &err);
 128
 129     rsp = qdict_new();
 130     if (err) {
 131         qdict_put_obj(rsp, "error", qmp_build_error_object(err));
 132         error_free(err);
 133     } else if (ret) {
 134         qdict_put_obj(rsp, "return", ret);
 135     } else {
 136         QDECREF(rsp);
 137         return NULL;
 138     }
 139
 140     return QOBJECT(rsp);
 141 }