datapath: Hardcode vport multicast group ID on older kernels.

Older kernels do not advertise the multicast groups of families
when requested by userspace.  As a workaround, this patch hardcodes
the multicast group ID of the ovs_vport family on these kernels.
Userspace will be able to fall back to this hardcoded value if the
standard mechanism is unavailable.

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/linux/compat/genetlink.inc b/datapath/linux/compat/genetlink.inc
index d381e4f..9e7d90d 100644 (file)
--- a/datapath/linux/compat/genetlink.inc
+++ b/datapath/linux/compat/genetlink.inc
@@ -6,6 +6,9 @@
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
 #include <linux/mutex.h>
 
+#include "openvswitch/datapath-compat.h"
+#include "openvswitch/datapath-protocol.h"
+
 static DEFINE_MUTEX(mc_group_mutex);
 
 int genl_register_mc_group(struct genl_family *family,
@@ -13,9 +16,15 @@ int genl_register_mc_group(struct genl_family *family,
 {
        static int next_group = GENL_FIRST_MCGROUP;
 
+       grp->family = family;
+
+       if (!strcmp(grp->name, OVS_VPORT_MCGROUP)) {
+               grp->id = OVS_VPORT_MCGROUP_FALLBACK_ID;
+               return 0;
+       }
+
        mutex_lock(&mc_group_mutex);
        grp->id = next_group;
-       grp->family = family;
 
        if (++next_group > GENL_LAST_MCGROUP)
                next_group = GENL_FIRST_MCGROUP;

diff --git a/include/openvswitch/automake.mk b/include/openvswitch/automake.mk
index b7c6723..24a6826 100644 (file)
--- a/include/openvswitch/automake.mk
+++ b/include/openvswitch/automake.mk
@@ -1,5 +1,6 @@
 noinst_HEADERS += \
        include/openvswitch/brcompat-netlink.h \
+       include/openvswitch/datapath-compat.h \
        include/openvswitch/datapath-protocol.h \
        include/openvswitch/tunnel.h \
        include/openvswitch/types.h

diff --git a/include/openvswitch/datapath-compat.h b/include/openvswitch/datapath-compat.h
new file mode 100644 (file)
index 0000000..cf0e519
--- /dev/null
+++ b/include/openvswitch/datapath-compat.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2011 Nicira Networks.
+ *
+ * This file is offered under your choice of two licenses: Apache 2.0 or GNU
+ * GPL 2.0 or later.  The permission statements for each of these licenses is
+ * given below.  You may license your modifications to this file under either
+ * of these licenses or both.  If you wish to license your modifications under
+ * only one of these licenses, delete the permission text for the other
+ * license.
+ *
+ * ----------------------------------------------------------------------
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ----------------------------------------------------------------------
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ * ----------------------------------------------------------------------
+ */
+
+#ifndef OPENVSWITCH_DATAPATH_COMPAT_H
+#define OPENVSWITCH_DATAPATH_COMPAT_H 1
+
+#define OVS_VPORT_MCGROUP_FALLBACK_ID 33
+
+#endif /* openvswitch/datapath-compat.h */