linux/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
Or Gerlitz 335a64a5a9 IPoIB: Allow setting policy to ignore multicast groups
The kernel IB stack allows (through the RDMA CM) userspace
applications to join and use multicast groups from the IPoIB MGID
range.  This allows multicast traffic to be handled directly from
userspace QPs, without going through the kernel stack, which gives
better performance for some applications.

However, to fully interoperate with IP multicast, such userspace
applications need to participate in IGMP reports and queries, or else
routers may not forward the multicast traffic to the system where the
application is running.  The simplest way to do this is to share the
kernel IGMP implementation by using the IP_ADD_MEMBERSHIP option to
join multicast groups that are being handled directly in userspace.

However, in such cases, the actual multicast traffic should not also
be handled by the IPoIB interface, because that would burn resources
handling multicast packets that will just be discarded in the kernel.

To handle this, this patch adds lookup on the database used for IB
multicast group reference counting when IPoIB is joining multicast
groups, and if a multicast group is already handled by user space,
then the IPoIB kernel driver ignores the group.  This is controlled by
a per-interface policy flag.  When the flag is set, IPoIB will not
join and attach its QP to a multicast group which already has an entry
in the database; when the flag is cleared, IPoIB will behave as before
this change.

For each IPoIB interface, the /sys/class/net/$intf/umcast attribute
controls the policy flag.  The default value is off/0.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-10-10 13:02:30 -07:00

175 lines
4.4 KiB
C

/*
* Copyright (c) 2004 Topspin Communications. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* $Id: ipoib_vlan.c 1349 2004-12-16 21:09:43Z roland $
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#include "ipoib.h"
static ssize_t show_parent(struct device *d, struct device_attribute *attr,
char *buf)
{
struct net_device *dev = to_net_dev(d);
struct ipoib_dev_priv *priv = netdev_priv(dev);
return sprintf(buf, "%s\n", priv->parent->name);
}
static DEVICE_ATTR(parent, S_IRUGO, show_parent, NULL);
int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv;
char intf_name[IFNAMSIZ];
int result;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = netdev_priv(pdev);
mutex_lock(&ppriv->vlan_mutex);
/*
* First ensure this isn't a duplicate. We check the parent device and
* then all of the child interfaces to make sure the Pkey doesn't match.
*/
if (ppriv->pkey == pkey) {
result = -ENOTUNIQ;
goto err;
}
list_for_each_entry(priv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey) {
result = -ENOTUNIQ;
goto err;
}
}
snprintf(intf_name, sizeof intf_name, "%s.%04x",
ppriv->dev->name, pkey);
priv = ipoib_intf_alloc(intf_name);
if (!priv) {
result = -ENOMEM;
goto err;
}
set_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags);
priv->pkey = pkey;
memcpy(priv->dev->dev_addr, ppriv->dev->dev_addr, INFINIBAND_ALEN);
priv->dev->broadcast[8] = pkey >> 8;
priv->dev->broadcast[9] = pkey & 0xff;
result = ipoib_dev_init(priv->dev, ppriv->ca, ppriv->port);
if (result < 0) {
ipoib_warn(ppriv, "failed to initialize subinterface: "
"device %s, port %d",
ppriv->ca->name, ppriv->port);
goto device_init_failed;
}
result = register_netdev(priv->dev);
if (result) {
ipoib_warn(priv, "failed to initialize; error %i", result);
goto register_failed;
}
priv->parent = ppriv->dev;
ipoib_create_debug_files(priv->dev);
if (ipoib_cm_add_mode_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_pkey_attr(priv->dev))
goto sysfs_failed;
if (ipoib_add_umcast_attr(priv->dev))
goto sysfs_failed;
if (device_create_file(&priv->dev->dev, &dev_attr_parent))
goto sysfs_failed;
list_add_tail(&priv->list, &ppriv->child_intfs);
mutex_unlock(&ppriv->vlan_mutex);
return 0;
sysfs_failed:
ipoib_delete_debug_files(priv->dev);
unregister_netdev(priv->dev);
register_failed:
ipoib_dev_cleanup(priv->dev);
device_init_failed:
free_netdev(priv->dev);
err:
mutex_unlock(&ppriv->vlan_mutex);
return result;
}
int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
{
struct ipoib_dev_priv *ppriv, *priv, *tpriv;
int ret = -ENOENT;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
ppriv = netdev_priv(pdev);
mutex_lock(&ppriv->vlan_mutex);
list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
if (priv->pkey == pkey) {
unregister_netdev(priv->dev);
ipoib_dev_cleanup(priv->dev);
list_del(&priv->list);
free_netdev(priv->dev);
ret = 0;
break;
}
}
mutex_unlock(&ppriv->vlan_mutex);
return ret;
}