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/json-parser.h" 18 #include "qapi/qmp/qdict.h" 19 #include "qapi/qmp/qjson.h" 20 #include "qapi/qmp/qbool.h" 21 #include "sysemu/sysemu.h" 22 23 static QDict *qmp_dispatch_check_obj(const QObject *request, bool allow_oob, 24 Error **errp) 25 { 26 const char *exec_key = NULL; 27 const QDictEntry *ent; 28 const char *arg_name; 29 const QObject *arg_obj; 30 QDict *dict; 31 32 dict = qobject_to(QDict, request); 33 if (!dict) { 34 error_setg(errp, "QMP input must be a JSON object"); 35 return NULL; 36 } 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 || (!strcmp(arg_name, "exec-oob") && allow_oob)) { 45 if (qobject_type(arg_obj) != QTYPE_QSTRING) { 46 error_setg(errp, "QMP input member '%s' must be a string", 47 arg_name); 48 return NULL; 49 } 50 if (exec_key) { 51 error_setg(errp, "QMP input member '%s' clashes with '%s'", 52 arg_name, exec_key); 53 return NULL; 54 } 55 exec_key = arg_name; 56 } else if (!strcmp(arg_name, "arguments")) { 57 if (qobject_type(arg_obj) != QTYPE_QDICT) { 58 error_setg(errp, 59 "QMP input member 'arguments' must be an object"); 60 return NULL; 61 } 62 } else { 63 error_setg(errp, "QMP input member '%s' is unexpected", 64 arg_name); 65 return NULL; 66 } 67 } 68 69 if (!exec_key) { 70 error_setg(errp, "QMP input lacks member 'execute'"); 71 return NULL; 72 } 73 74 return dict; 75 } 76 77 static QObject *do_qmp_dispatch(QmpCommandList *cmds, QObject *request, 78 bool allow_oob, Error **errp) 79 { 80 Error *local_err = NULL; 81 bool oob; 82 const char *command; 83 QDict *args, *dict; 84 QmpCommand *cmd; 85 QObject *ret = NULL; 86 87 dict = qmp_dispatch_check_obj(request, allow_oob, errp); 88 if (!dict) { 89 return NULL; 90 } 91 92 command = qdict_get_try_str(dict, "execute"); 93 oob = false; 94 if (!command) { 95 assert(allow_oob); 96 command = qdict_get_str(dict, "exec-oob"); 97 oob = true; 98 } 99 cmd = qmp_find_command(cmds, command); 100 if (cmd == NULL) { 101 error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, 102 "The command %s has not been found", command); 103 return NULL; 104 } 105 if (!cmd->enabled) { 106 error_setg(errp, "The command %s has been disabled for this instance", 107 command); 108 return NULL; 109 } 110 if (oob && !(cmd->options & QCO_ALLOW_OOB)) { 111 error_setg(errp, "The command %s does not support OOB", 112 command); 113 return false; 114 } 115 116 if (runstate_check(RUN_STATE_PRECONFIG) && 117 !(cmd->options & QCO_ALLOW_PRECONFIG)) { 118 error_setg(errp, "The command '%s' isn't permitted in '%s' state", 119 cmd->name, RunState_str(RUN_STATE_PRECONFIG)); 120 return NULL; 121 } 122 123 if (!qdict_haskey(dict, "arguments")) { 124 args = qdict_new(); 125 } else { 126 args = qdict_get_qdict(dict, "arguments"); 127 qobject_ref(args); 128 } 129 130 cmd->fn(args, &ret, &local_err); 131 if (local_err) { 132 error_propagate(errp, local_err); 133 } else if (cmd->options & QCO_NO_SUCCESS_RESP) { 134 g_assert(!ret); 135 } else if (!ret) { 136 /* TODO turn into assertion */ 137 ret = QOBJECT(qdict_new()); 138 } 139 140 qobject_unref(args); 141 142 return ret; 143 } 144 145 QDict *qmp_error_response(Error *err) 146 { 147 QDict *rsp; 148 149 rsp = qdict_from_jsonf_nofail("{ 'error': { 'class': %s, 'desc': %s } }", 150 QapiErrorClass_str(error_get_class(err)), 151 error_get_pretty(err)); 152 error_free(err); 153 return rsp; 154 } 155 156 /* 157 * Does @qdict look like a command to be run out-of-band? 158 */ 159 bool qmp_is_oob(QDict *dict) 160 { 161 return qdict_haskey(dict, "exec-oob") 162 && !qdict_haskey(dict, "execute"); 163 } 164 165 QDict *qmp_dispatch(QmpCommandList *cmds, QObject *request, 166 bool allow_oob) 167 { 168 Error *err = NULL; 169 QObject *ret; 170 QDict *rsp; 171 172 ret = do_qmp_dispatch(cmds, request, allow_oob, &err); 173 174 if (err) { 175 rsp = qmp_error_response(err); 176 } else if (ret) { 177 rsp = qdict_new(); 178 qdict_put_obj(rsp, "return", ret); 179 } else { 180 /* Can only happen for commands with QCO_NO_SUCCESS_RESP */ 181 rsp = NULL; 182 } 183 184 return rsp; 185 } 186