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/dispatch.h" 17 #include "qapi/qmp/qdict.h" 18 #include "qapi/qmp/qjson.h" 19 #include "sysemu/runstate.h" 20 #include "qapi/qmp/qbool.h" 21 22 static QDict *qmp_dispatch_check_obj(const QObject *request, bool allow_oob, 23 Error **errp) 24 { 25 const char *exec_key = NULL; 26 const QDictEntry *ent; 27 const char *arg_name; 28 const QObject *arg_obj; 29 QDict *dict; 30 31 dict = qobject_to(QDict, request); 32 if (!dict) { 33 error_setg(errp, "QMP input must be a JSON object"); 34 return NULL; 35 } 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 || (!strcmp(arg_name, "exec-oob") && allow_oob)) { 44 if (qobject_type(arg_obj) != QTYPE_QSTRING) { 45 error_setg(errp, "QMP input member '%s' must be a string", 46 arg_name); 47 return NULL; 48 } 49 if (exec_key) { 50 error_setg(errp, "QMP input member '%s' clashes with '%s'", 51 arg_name, exec_key); 52 return NULL; 53 } 54 exec_key = arg_name; 55 } else if (!strcmp(arg_name, "arguments")) { 56 if (qobject_type(arg_obj) != QTYPE_QDICT) { 57 error_setg(errp, 58 "QMP input member 'arguments' must be an object"); 59 return NULL; 60 } 61 } else if (!strcmp(arg_name, "id")) { 62 continue; 63 } else { 64 error_setg(errp, "QMP input member '%s' is unexpected", 65 arg_name); 66 return NULL; 67 } 68 } 69 70 if (!exec_key) { 71 error_setg(errp, "QMP input lacks member 'execute'"); 72 return NULL; 73 } 74 75 return dict; 76 } 77 78 static QObject *do_qmp_dispatch(QmpCommandList *cmds, QObject *request, 79 bool allow_oob, Error **errp) 80 { 81 Error *local_err = NULL; 82 bool oob; 83 const char *command; 84 QDict *args, *dict; 85 QmpCommand *cmd; 86 QObject *ret = NULL; 87 88 dict = qmp_dispatch_check_obj(request, allow_oob, errp); 89 if (!dict) { 90 return NULL; 91 } 92 93 command = qdict_get_try_str(dict, "execute"); 94 oob = false; 95 if (!command) { 96 assert(allow_oob); 97 command = qdict_get_str(dict, "exec-oob"); 98 oob = true; 99 } 100 cmd = qmp_find_command(cmds, command); 101 if (cmd == NULL) { 102 error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, 103 "The command %s has not been found", command); 104 return NULL; 105 } 106 if (!cmd->enabled) { 107 error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, 108 "The command %s has been disabled for this instance", 109 command); 110 return NULL; 111 } 112 if (oob && !(cmd->options & QCO_ALLOW_OOB)) { 113 error_setg(errp, "The command %s does not support OOB", 114 command); 115 return NULL; 116 } 117 118 if (runstate_check(RUN_STATE_PRECONFIG) && 119 !(cmd->options & QCO_ALLOW_PRECONFIG)) { 120 error_setg(errp, "The command '%s' isn't permitted in '%s' state", 121 cmd->name, RunState_str(RUN_STATE_PRECONFIG)); 122 return NULL; 123 } 124 125 if (!qdict_haskey(dict, "arguments")) { 126 args = qdict_new(); 127 } else { 128 args = qdict_get_qdict(dict, "arguments"); 129 qobject_ref(args); 130 } 131 132 cmd->fn(args, &ret, &local_err); 133 if (local_err) { 134 error_propagate(errp, local_err); 135 } else if (cmd->options & QCO_NO_SUCCESS_RESP) { 136 g_assert(!ret); 137 } else if (!ret) { 138 /* TODO turn into assertion */ 139 ret = QOBJECT(qdict_new()); 140 } 141 142 qobject_unref(args); 143 144 return ret; 145 } 146 147 QDict *qmp_error_response(Error *err) 148 { 149 QDict *rsp; 150 151 rsp = qdict_from_jsonf_nofail("{ 'error': { 'class': %s, 'desc': %s } }", 152 QapiErrorClass_str(error_get_class(err)), 153 error_get_pretty(err)); 154 error_free(err); 155 return rsp; 156 } 157 158 /* 159 * Does @qdict look like a command to be run out-of-band? 160 */ 161 bool qmp_is_oob(const QDict *dict) 162 { 163 return qdict_haskey(dict, "exec-oob") 164 && !qdict_haskey(dict, "execute"); 165 } 166 167 QDict *qmp_dispatch(QmpCommandList *cmds, QObject *request, 168 bool allow_oob) 169 { 170 Error *err = NULL; 171 QDict *dict = qobject_to(QDict, request); 172 QObject *ret, *id = dict ? qdict_get(dict, "id") : NULL; 173 QDict *rsp; 174 175 ret = do_qmp_dispatch(cmds, request, allow_oob, &err); 176 if (err) { 177 rsp = qmp_error_response(err); 178 } else if (ret) { 179 rsp = qdict_new(); 180 qdict_put_obj(rsp, "return", ret); 181 } else { 182 /* Can only happen for commands with QCO_NO_SUCCESS_RESP */ 183 rsp = NULL; 184 } 185 186 if (rsp && id) { 187 qdict_put_obj(rsp, "id", qobject_ref(id)); 188 } 189 190 return rsp; 191 } 192