rpc: avoid name lookup when dispatching node device APIs

The node device APIs are a little unusual because we don't use a
"remote_nonnull_node_device" object on the wire, instead we just
have a "remote_string" for the device name. This meant dispatcher
code generation needed special cases. In doing so we mistakenly
used the virNodeDeviceLookupByName() API which gets dispatched
into the driver, instead of get_nonnull_node_device() which
directly populates a virNodeDevicePtr object.

This wasn't a problem with monolithic libvirtd, as the
virNodeDeviceLookupByName() API call was trivially satisfied
by the registered driver, albeit with an extra (undesirable)
authentication check. With the split daemons, the call to
virNodeDeviceLookupByName() fails in virtqemud, because the
node device driver obviously doesn't exist in that daemon.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

src/remote/remote_daemon_dispatch.c

@@ -95,6 +95,7 @@ static virNWFilterBindingPtr get_nonnull_nwfilter_binding(virConnectPtr conn, re
 static virDomainCheckpointPtr get_nonnull_domain_checkpoint(virDomainPtr dom, remote_nonnull_domain_checkpoint checkpoint);
 static virDomainSnapshotPtr get_nonnull_domain_snapshot(virDomainPtr dom, remote_nonnull_domain_snapshot snapshot);
 static virNodeDevicePtr get_nonnull_node_device(virConnectPtr conn, remote_nonnull_node_device dev);
+static virNodeDevicePtr get_nonnull_node_device_name(virConnectPtr conn, remote_nonnull_string name);
 static void make_nonnull_domain(remote_nonnull_domain *dom_dst, virDomainPtr dom_src);
 static void make_nonnull_network(remote_nonnull_network *net_dst, virNetworkPtr net_src);
 static void make_nonnull_network_port(remote_nonnull_network_port *port_dst, virNetworkPortPtr port_src);
@@ -7291,6 +7292,12 @@ get_nonnull_node_device(virConnectPtr conn, remote_nonnull_node_device dev)
     return virGetNodeDevice(conn, dev.name);
 }
 
+static virNodeDevicePtr
+get_nonnull_node_device_name(virConnectPtr conn, remote_nonnull_string name)
+{
+    return virGetNodeDevice(conn, name);
+}
+
 static void
 make_nonnull_domain(remote_nonnull_domain *dom_dst, virDomainPtr dom_src)
 {

src/rpc/gendispatch.pl

@@ -571,7 +571,7 @@ elsif ($mode eq "server") {
                 $has_node_device = 1;
                 push(@vars_list, "virNodeDevicePtr dev = NULL");
                 push(@getters_list,
-                     "    if (!(dev = virNodeDeviceLookupByName($conn_var, args->name)))\n" .
+                     "    if (!(dev = get_nonnull_node_device_name($conn_var, args->name)))\n" .
                      "        goto cleanup;\n");
                 push(@args_list, "dev");
                 push(@free_list,