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