From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roopa Prabhu Subject: [net-next-2.6 PATCH 0/8 RFC v2] macvlan: MAC Address filtering support for passthru mode Date: Tue, 18 Oct 2011 23:25:54 -0700 Message-ID: <20111019062543.7242.3969.stgit@savbu-pc100.cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: sri@us.ibm.com, dragos.tatulea@gmail.com, arnd@arndb.de, kvm@vger.kernel.org, mst@redhat.com, davem@davemloft.net, mchan@broadcom.com, dwang2@cisco.com, shemminger@vyatta.com, eric.dumazet@gmail.com, kaber@trash.net, benve@cisco.com To: netdev@vger.kernel.org Return-path: Sender: kvm-owner@vger.kernel.org List-Id: netdev.vger.kernel.org v1 version of this RFC patch was posted at http://www.spinics.net/lists/netdev/msg174245.html Today macvtap used in virtualized environment does not have support to propagate MAC, VLAN and interface flags from guest to lowerdev. Which means to be able to register additional VLANs, unicast and multicast addresses or change pkt filter flags in the guest, the lowerdev has to be put in promisocous mode. Today the only macvlan mode that supports this is the PASSTHRU mode and it puts the lower dev in promiscous mode. PASSTHRU mode was added primarily for the SRIOV usecase. In PASSTHRU mode there is a 1-1 mapping between macvtap and physical NIC or VF. There are two problems with putting the lowerdev in promiscous mode (ie SRIOV VF's): - Some SRIOV cards dont support promiscous mode today (Thread on Intel driver indicates that http://lists.openwall.net/netdev/2011/09/27/6) - For the SRIOV NICs that support it, Putting the lowerdev in promiscous mode leads to additional traffic being sent up to the guest virtio-net to filter result in extra overheads. Both the above problems can be solved by offloading filtering to the lowerdev hw. ie lowerdev does not need to be in promiscous mode as long as the guest filters are passed down to the lowerdev. This patch basically adds the infrastructure to set and get MAC and VLAN filters on an interface via rtnetlink. And adds support in macvlan and macvtap to allow set and get filter operations. Earlier version of this patch provided the TUNSETTXFILTER macvtap interface for setting address filtering. In response to feedback, This version introduces a netlink interface for the same. Response to some of the questions raised during v1: - Netlink interface: This patch provides the following netlink interface to set mac and vlan filters : [IFLA_RX_FILTER] = { [IFLA_ADDR_FILTER] = { [IFLA_ADDR_FILTER_FLAGS] [IFLA_ADDR_FILTER_UC_LIST] = { [IFLA_ADDR_LIST_ENTRY] } [IFLA_ADDR_FILTER_MC_LIST] = { [IFLA_ADDR_LIST_ENTRY] } } [IFLA_VLAN_FILTER] = { [IFLA_VLAN_BITMAP] } } Note: The IFLA_VLAN_FILTER is a nested attribute and contains only IFLA_VLAN_BITMAP today. The idea is that the IFLA_VLAN_FILTER can be extended tomorrow to use a vlan list option if some implementations prefer a list instead. And it provides the following rtnl_link_ops to set/get MAC/VLAN filters: int (*set_rx_addr_filter)(struct net_device *dev, struct nlattr *tb[]); int (*set_rx_vlan_filter)(struct net_device *dev, struct nlattr *tb[]); size_t (*get_rx_addr_filter_size)(const struct net_device *dev); size_t (*get_rx_vlan_filter_size)(const struct net_device *dev); int (*fill_rx_addr_filter)(struct sk_buff *skb, const struct net_device *dev); int (*fill_rx_vlan_filter)(struct sk_buff *skb, const struct net_device *dev); Note: The choice of rtnl_link_ops was because I saw the use case for this in virtual devices that need to do filtering in sw like macvlan and tun. Hw devices usually have filtering in hw with netdev->uc and mc lists to indicate active filters. But I can move from rtnl_link_ops to netdev_ops if that is the preferred way to go and if there is a need to support this interface on all kinds of interfaces. Please suggest. - Protection against address spoofing: - This patch adds filtering support only for macvtap PASSTHRU Mode. PASSTHRU mode is used mainly with SRIOV VF's. And SRIOV VF's come with anti mac/vlan spoofing support. (Recently added IFLA_VF_SPOOFCHK). In 802.1Qbh case the port profile has a knob to enable/disable anti spoof check. Lowerdevice drivers also enforce limits on the number of address registrations allowed. - Support for multiqueue devices: Enable filtering on individual queues (?): AFAIK, there is no netdev interface to install per queue hw filters for a multi queue interface. And also I dont know of any hw that provides an interface to set hw filters on a per queue basis. A multi queue device appears as a single lowerdev (ie netdev) and uses the same uc and mc lists to setup unicast and multicast hw filters. So i dont see a huge problem with this patch coming in the way for multi queue devices. - Support for non-PASSTHRU mode: I started implementing this. But there are a couple of problems. - The lowerdev may not be a SRIOV VF and may not have anti spoof capability - Today, in non-PASSTHRU cases macvlan_handle_frame assumes that every macvlan device on top of the lowerdev has a single unique mac. And the macvlans are hashed on that single mac address. To support filtering for non-PASSTHRU mode in addition to this patch the following needs to be done: - non-passthru mode with a single macvlan over a lower dev can be treated as PASSTHRU case - For non-PASSTHRU mode with multiple macvlans over a single lower dev: - Multiple unicast mac's now need to be hashed to the same macvlan device. The macvlan hash needs to change for lookup based on any one of the multiple unicast addresses a macvlan is interested in - We need to consider vlans during the lookup too - So the macvlan device hash needs to hash on both mac and vlan - But the support for filtering in non-PASSTHRU mode can be built on this patch This patch series implements the following 01/8 rtnetlink: Netlink interface for setting MAC and VLAN filters 02/8 rtnetlink: Add rtnl link operations for MAC address and VLAN filtering 03/8 rtnetlink: Add support to set MAC/VLAN filters 04/8 rtnetlink: Add support to get MAC/VLAN filters 05/8 macvlan: Add support to set MAC/VLAN filter rtnl link operations 06/8 macvlan: Add support to get MAC/VLAN filter rtnl link operations 07/8 macvtap: Add support to set MAC/VLAN filter rtnl link operations 08/8 macvtap: Add support to get MAC/VLAN filter rtnl link operations Please comment. Thanks. Signed-off-by: Roopa Prabhu Signed-off-by: Christian Benvenuti Signed-off-by: David Wang