From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42460) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cjmOG-0007um-Na for qemu-devel@nongnu.org; Fri, 03 Mar 2017 07:33:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cjmOD-0007zC-Rn for qemu-devel@nongnu.org; Fri, 03 Mar 2017 07:32:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48112) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cjmOD-0007yC-Je for qemu-devel@nongnu.org; Fri, 03 Mar 2017 07:32:53 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C1D1A2DC342 for ; Fri, 3 Mar 2017 12:32:53 +0000 (UTC) From: Markus Armbruster Date: Fri, 3 Mar 2017 13:32:27 +0100 Message-Id: <1488544368-30622-8-git-send-email-armbru@redhat.com> In-Reply-To: <1488544368-30622-1-git-send-email-armbru@redhat.com> References: <1488544368-30622-1-git-send-email-armbru@redhat.com> Subject: [Qemu-devel] [PATCH v4 07/28] qmp: Clean up how we enforce capability negotiation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org To enforce capability negotiation before normal operation, handle_qmp_command() inspects every command before it's handed off to qmp_dispatch(). This is a bit of a layering violation, and results in duplicated code. Before capability negotiation (!cur_mon->in_command_mode), we fail commands other than "qmp_capabilities". This is what enforces capability negotiation. Afterwards, we fail command "qmp_capabilities". Clean this up as follows. The obvious place to fail a command is the command itself, so move the "afterwards" check to qmp_qmp_capabilities(). We do the "before" check in every other command, but that would be bothersome. Instead, start with an alternate list of commant that contains only "qmp_capabilities". Switch to the full list in qmp_qmp_capabilities(). Additionally, replace the generic human-readable error message for CommandNotFound by one that reminds the user to run qmp_capabilities. Without that, we'd regress commit 2d5a834. Signed-off-by: Markus Armbruster --- monitor.c | 76 +++++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 42 insertions(+), 34 deletions(-) diff --git a/monitor.c b/monitor.c index c7f7602..b540096 100644 --- a/monitor.c +++ b/monitor.c @@ -165,7 +165,7 @@ typedef struct { * When command qmp_capabilities succeeds, we go into command * mode. */ - bool in_command_mode; /* are we in command mode? */ + QmpCommandList *commands; } MonitorQMP; /* @@ -221,7 +221,7 @@ static int mon_refcount; static mon_cmd_t mon_cmds[]; static mon_cmd_t info_cmds[]; -QmpCommandList qmp_commands; +QmpCommandList qmp_commands, qmp_cap_negotiation_commands; Monitor *cur_mon; @@ -416,7 +416,8 @@ static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict) trace_monitor_protocol_event_emit(event, qdict); QLIST_FOREACH(mon, &mon_list, entry) { - if (monitor_is_qmp(mon) && mon->qmp.in_command_mode) { + if (monitor_is_qmp(mon) + && mon->qmp.commands != &qmp_cap_negotiation_commands) { monitor_json_emitter(mon, QOBJECT(qdict)); } } @@ -565,11 +566,6 @@ static void monitor_qapi_event_init(void) qmp_event_set_func_emit(monitor_qapi_event_queue); } -void qmp_qmp_capabilities(Error **errp) -{ - cur_mon->qmp.in_command_mode = true; -} - static void handle_hmp_command(Monitor *mon, const char *cmdline); static void monitor_data_init(Monitor *mon) @@ -921,7 +917,7 @@ CommandInfoList *qmp_query_commands(Error **errp) { CommandInfoList *list = NULL; - qmp_for_each_command(&qmp_commands, query_commands_cb, &list); + qmp_for_each_command(cur_mon->qmp.commands, query_commands_cb, &list); return list; } @@ -1001,6 +997,13 @@ static void qmp_unregister_commands_hack(void) void monitor_init_qmp_commands(void) { + /* + * Two command lists: + * - qmp_commands contains all QMP commands + * - qmp_cap_negotiation_commands contains just + * "qmp_capabilities", to enforce capability negotiation + */ + qmp_init_marshal(&qmp_commands); qmp_register_command(&qmp_commands, "query-qmp-schema", @@ -1012,6 +1015,22 @@ void monitor_init_qmp_commands(void) QCO_NO_OPTIONS); qmp_unregister_commands_hack(); + + QTAILQ_INIT(&qmp_cap_negotiation_commands); + qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities", + qmp_marshal_qmp_capabilities, QCO_NO_OPTIONS); +} + +void qmp_qmp_capabilities(Error **errp) +{ + if (cur_mon->qmp.commands == &qmp_commands) { + error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, + "Capabilities negotiation is already complete, command " + "ignored"); + return; + } + + cur_mon->qmp.commands = &qmp_commands; } /* set the current CPU defined by the user */ @@ -3681,26 +3700,6 @@ static int monitor_can_read(void *opaque) return (mon->suspend_cnt == 0) ? 1 : 0; } -static bool invalid_qmp_mode(const Monitor *mon, const char *cmd, - Error **errp) -{ - bool is_cap = g_str_equal(cmd, "qmp_capabilities"); - - if (is_cap && mon->qmp.in_command_mode) { - error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, - "Capabilities negotiation is already complete, command " - "'%s' ignored", cmd); - return true; - } - if (!is_cap && !mon->qmp.in_command_mode) { - error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND, - "Expecting capabilities negotiation with " - "'qmp_capabilities' before command '%s'", cmd); - return true; - } - return false; -} - /* * Input object checking rules * @@ -3786,11 +3785,20 @@ static void handle_qmp_command(JSONMessageParser *parser, GQueue *tokens) cmd_name = qdict_get_str(qdict, "execute"); trace_handle_qmp_command(mon, cmd_name); - if (invalid_qmp_mode(mon, cmd_name, &err)) { - goto err_out; - } + rsp = qmp_dispatch(cur_mon->qmp.commands, req); - rsp = qmp_dispatch(&qmp_commands, req); + qdict = qdict_get_qdict(qobject_to_qdict(rsp), "error"); + if (qdict) { + if (mon->qmp.commands == &qmp_cap_negotiation_commands + && !g_strcmp0(qdict_get_try_str(qdict, "class"), + QapiErrorClass_lookup[ERROR_CLASS_COMMAND_NOT_FOUND])) { + /* Provide a more useful error message */ + qdict_del(qdict, "desc"); + qdict_put(qdict, "desc", + qstring_from_str("Expecting capabilities negotiation" + " with 'qmp_capabilities'")); + } + } err_out: if (err) { @@ -3888,7 +3896,7 @@ static void monitor_qmp_event(void *opaque, int event) switch (event) { case CHR_EVENT_OPENED: - mon->qmp.in_command_mode = false; + mon->qmp.commands = &qmp_cap_negotiation_commands; data = get_qmp_greeting(); monitor_json_emitter(mon, data); qobject_decref(data); -- 2.7.4