guest agent: add RPC blacklist command-line option

This adds a command-line option, -b/--blacklist, that accepts a
comma-seperated list of RPCs to disable, or prints a list of
available RPCs if passed "?".

In consequence this also adds general blacklisting and RPC listing
facilities to the new QMP dispatch/registry facilities, should the
QMP monitor ever have a need for such a thing.

Ideally, to avoid support/compatability issues in the future,
blacklisting guest agent functionality will be the exceptional
case, but we add the functionality here to handle guest administrators
with specific requirements.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 558469325c..43f640a95e 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -79,6 +79,10 @@ static QObject *do_qmp_dispatch(QObject *request, Error **errp)
         error_set(errp, QERR_COMMAND_NOT_FOUND, command);
         return NULL;
     }
+    if (!cmd->enabled) {
+        error_set(errp, QERR_COMMAND_DISABLED, command);
+        return NULL;
+    }
 
     if (!qdict_haskey(dict, "arguments")) {
         args = qdict_new();