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-types.h"
  20 #include "qapi/qmp/qerror.h"
  21
  22 static 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     if (qobject_type(request) != QTYPE_QDICT) {
  31         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT,
  32                    "request is not a dictionary");
  33         return NULL;
  34     }
  35
  36     dict = qobject_to_qdict(request);
  37
  38     for (ent = qdict_first(dict); ent;
  39          ent = qdict_next(dict, ent)) {
  40         arg_name = qdict_entry_key(ent);
  41         arg_obj = qdict_entry_value(ent);
  42
  43         if (!strcmp(arg_name, "execute")) {
  44             if (qobject_type(arg_obj) != QTYPE_QSTRING) {
  45                 error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT_MEMBER, "execute",
  46                            "string");
  47                 return NULL;
  48             }
  49             has_exec_key = true;
  50         } else if (strcmp(arg_name, "arguments")) {
  51             error_setg(errp, QERR_QMP_EXTRA_MEMBER, arg_name);
  52             return NULL;
  53         }
  54     }
  55
  56     if (!has_exec_key) {
  57         error_setg(errp, QERR_QMP_BAD_INPUT_OBJECT, "execute");
  58         return NULL;
  59     }
  60
  61     return dict;
  62 }
  63
  64 static QObject *do_qmp_dispatch(QObject *request, Error **errp)
  65 {
  66     Error *local_err = NULL;
  67     const char *command;
  68     QDict *args, *dict;
  69     QmpCommand *cmd;
  70     QObject *ret = NULL;
  71
  72     dict = qmp_dispatch_check_obj(request, errp);
  73     if (!dict) {
  74         return NULL;
  75     }
  76
  77     command = qdict_get_str(dict, "execute");
  78     cmd = qmp_find_command(command);
  79     if (cmd == NULL) {
  80         error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
  81                   "The command %s has not been found", command);
  82         return NULL;
  83     }
  84     if (!cmd->enabled) {
  85         error_setg(errp, "The command %s has been disabled for this instance",
  86                    command);
  87         return NULL;
  88     }
  89
  90     if (!qdict_haskey(dict, "arguments")) {
  91         args = qdict_new();
  92     } else {
  93         args = qdict_get_qdict(dict, "arguments");
  94         QINCREF(args);
  95     }
  96
  97     switch (cmd->type) {
  98     case QCT_NORMAL:
  99         cmd->fn(args, &ret, &local_err);
 100         if (local_err) {
 101             error_propagate(errp, local_err);
 102         } else if (cmd->options & QCO_NO_SUCCESS_RESP) {
 103             g_assert(!ret);
 104         } else if (!ret) {
 105             ret = QOBJECT(qdict_new());
 106         }
 107         break;
 108     }
 109
 110     QDECREF(args);
 111
 112     return ret;
 113 }
 114
 115 QObject *qmp_build_error_object(Error *err)
 116 {
 117     return qobject_from_jsonf("{ 'class': %s, 'desc': %s }",
 118                               QapiErrorClass_lookup[error_get_class(err)],
 119                               error_get_pretty(err));
 120 }
 121
 122 QObject *qmp_dispatch(QObject *request)
 123 {
 124     Error *err = NULL;
 125     QObject *ret;
 126     QDict *rsp;
 127
 128     ret = do_qmp_dispatch(request, &err);
 129
 130     rsp = qdict_new();
 131     if (err) {
 132         qdict_put_obj(rsp, "error", qmp_build_error_object(err));
 133         error_free(err);
 134     } else if (ret) {
 135         qdict_put_obj(rsp, "return", ret);
 136     } else {
 137         QDECREF(rsp);
 138         return NULL;
 139     }
 140
 141     return QOBJECT(rsp);
 142 }