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-objects.h"
  15 #include "qapi/qmp-core.h"
  16 #include "json-parser.h"
  17 #include "qapi-types.h"
  18 #include "error.h"
  19 #include "error_int.h"
  20 #include "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_set(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_set(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_set(errp, QERR_QMP_EXTRA_MEMBER, arg_name);
  52             return NULL;
  53         }
  54     }
  55
  56     if (!has_exec_key) {
  57         error_set(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     const char *command;
  67     QDict *args, *dict;
  68     QmpCommand *cmd;
  69     QObject *ret = NULL;
  70
  71
  72     dict = qmp_dispatch_check_obj(request, errp);
  73     if (!dict || error_is_set(errp)) {
  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, QERR_COMMAND_NOT_FOUND, command);
  81         return NULL;
  82     }
  83     if (!cmd->enabled) {
  84         error_set(errp, QERR_COMMAND_DISABLED, command);
  85         return NULL;
  86     }
  87
  88     if (!qdict_haskey(dict, "arguments")) {
  89         args = qdict_new();
  90     } else {
  91         args = qdict_get_qdict(dict, "arguments");
  92         QINCREF(args);
  93     }
  94
  95     switch (cmd->type) {
  96     case QCT_NORMAL:
  97         cmd->fn(args, &ret, errp);
  98         if (!error_is_set(errp)) {
  99             if (cmd->options & QCO_NO_SUCCESS_RESP) {
 100                 g_assert(!ret);
 101             } else if (!ret) {
 102                 ret = QOBJECT(qdict_new());
 103             }
 104         }
 105         break;
 106     }
 107
 108     QDECREF(args);
 109
 110     return ret;
 111 }
 112
 113 QObject *qmp_build_error_object(Error *errp)
 114 {
 115     return qobject_from_jsonf("{ 'class': %s, 'desc': %s }",
 116                               ErrorClass_lookup[error_get_class(errp)],
 117                               error_get_pretty(errp));
 118 }
 119
 120 QObject *qmp_dispatch(QObject *request)
 121 {
 122     Error *err = NULL;
 123     QObject *ret;
 124     QDict *rsp;
 125
 126     ret = do_qmp_dispatch(request, &err);
 127
 128     rsp = qdict_new();
 129     if (err) {
 130         qdict_put_obj(rsp, "error", qmp_build_error_object(err));
 131         error_free(err);
 132     } else if (ret) {
 133         qdict_put_obj(rsp, "return", ret);
 134     } else {
 135         QDECREF(rsp);
 136         return NULL;
 137     }
 138
 139     return QOBJECT(rsp);
 140 }