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linux-next/include/linux/netdev_features.h
Simon Horman 0d89d2035f MPLS: Add limited GSO support
In the case where a non-MPLS packet is received and an MPLS stack is
added it may well be the case that the original skb is GSO but the
NIC used for transmit does not support GSO of MPLS packets.

The aim of this code is to provide GSO in software for MPLS packets
whose skbs are GSO.

SKB Usage:

When an implementation adds an MPLS stack to a non-MPLS packet it should do
the following to skb metadata:

* Set skb->inner_protocol to the old non-MPLS ethertype of the packet.
  skb->inner_protocol is added by this patch.

* Set skb->protocol to the new MPLS ethertype of the packet.

* Set skb->network_header to correspond to the
  end of the L3 header, including the MPLS label stack.

I have posted a patch, "[PATCH v3.29] datapath: Add basic MPLS support to
kernel" which adds MPLS support to the kernel datapath of Open vSwtich.
That patch sets the above requirements in datapath/actions.c:push_mpls()
and was used to exercise this code.  The datapath patch is against the Open
vSwtich tree but it is intended that it be added to the Open vSwtich code
present in the mainline Linux kernel at some point.

Features:

I believe that the approach that I have taken is at least partially
consistent with the handling of other protocols.  Jesse, I understand that
you have some ideas here.  I am more than happy to change my implementation.

This patch adds dev->mpls_features which may be used by devices
to advertise features supported for MPLS packets.

A new NETIF_F_MPLS_GSO feature is added for devices which support
hardware MPLS GSO offload.  Currently no devices support this
and MPLS GSO always falls back to software.

Alternate Implementation:

One possible alternate implementation is to teach netif_skb_features()
and skb_network_protocol() about MPLS, in a similar way to their
understanding of VLANs. I believe this would avoid the need
for net/mpls/mpls_gso.c and in particular the calls to
__skb_push() and __skb_push() in mpls_gso_segment().

I have decided on the implementation in this patch as it should
not introduce any overhead in the case where mpls_gso is not compiled
into the kernel or inserted as a module.

MPLS GSO suggested by Jesse Gross.
Based in part on "v4 GRE: Add TCP segmentation offload for GRE"
by Pravin B Shelar.

Cc: Jesse Gross <jesse@nicira.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-27 22:50:59 -07:00

161 lines
6.4 KiB
C

/*
* Network device features.
*
*
* 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.
*/
#ifndef _LINUX_NETDEV_FEATURES_H
#define _LINUX_NETDEV_FEATURES_H
#include <linux/types.h>
typedef u64 netdev_features_t;
enum {
NETIF_F_SG_BIT, /* Scatter/gather IO. */
NETIF_F_IP_CSUM_BIT, /* Can checksum TCP/UDP over IPv4. */
__UNUSED_NETIF_F_1,
NETIF_F_HW_CSUM_BIT, /* Can checksum all the packets. */
NETIF_F_IPV6_CSUM_BIT, /* Can checksum TCP/UDP over IPV6 */
NETIF_F_HIGHDMA_BIT, /* Can DMA to high memory. */
NETIF_F_FRAGLIST_BIT, /* Scatter/gather IO. */
NETIF_F_HW_VLAN_CTAG_TX_BIT, /* Transmit VLAN CTAG HW acceleration */
NETIF_F_HW_VLAN_CTAG_RX_BIT, /* Receive VLAN CTAG HW acceleration */
NETIF_F_HW_VLAN_CTAG_FILTER_BIT,/* Receive filtering on VLAN CTAGs */
NETIF_F_VLAN_CHALLENGED_BIT, /* Device cannot handle VLAN packets */
NETIF_F_GSO_BIT, /* Enable software GSO. */
NETIF_F_LLTX_BIT, /* LockLess TX - deprecated. Please */
/* do not use LLTX in new drivers */
NETIF_F_NETNS_LOCAL_BIT, /* Does not change network namespaces */
NETIF_F_GRO_BIT, /* Generic receive offload */
NETIF_F_LRO_BIT, /* large receive offload */
/**/NETIF_F_GSO_SHIFT, /* keep the order of SKB_GSO_* bits */
NETIF_F_TSO_BIT /* ... TCPv4 segmentation */
= NETIF_F_GSO_SHIFT,
NETIF_F_UFO_BIT, /* ... UDPv4 fragmentation */
NETIF_F_GSO_ROBUST_BIT, /* ... ->SKB_GSO_DODGY */
NETIF_F_TSO_ECN_BIT, /* ... TCP ECN support */
NETIF_F_TSO6_BIT, /* ... TCPv6 segmentation */
NETIF_F_FSO_BIT, /* ... FCoE segmentation */
NETIF_F_GSO_GRE_BIT, /* ... GRE with TSO */
NETIF_F_GSO_UDP_TUNNEL_BIT, /* ... UDP TUNNEL with TSO */
NETIF_F_GSO_MPLS_BIT, /* ... MPLS segmentation */
/**/NETIF_F_GSO_LAST = /* last bit, see GSO_MASK */
NETIF_F_GSO_MPLS_BIT,
NETIF_F_FCOE_CRC_BIT, /* FCoE CRC32 */
NETIF_F_SCTP_CSUM_BIT, /* SCTP checksum offload */
NETIF_F_FCOE_MTU_BIT, /* Supports max FCoE MTU, 2158 bytes*/
NETIF_F_NTUPLE_BIT, /* N-tuple filters supported */
NETIF_F_RXHASH_BIT, /* Receive hashing offload */
NETIF_F_RXCSUM_BIT, /* Receive checksumming offload */
NETIF_F_NOCACHE_COPY_BIT, /* Use no-cache copyfromuser */
NETIF_F_LOOPBACK_BIT, /* Enable loopback */
NETIF_F_RXFCS_BIT, /* Append FCS to skb pkt data */
NETIF_F_RXALL_BIT, /* Receive errored frames too */
NETIF_F_HW_VLAN_STAG_TX_BIT, /* Transmit VLAN STAG HW acceleration */
NETIF_F_HW_VLAN_STAG_RX_BIT, /* Receive VLAN STAG HW acceleration */
NETIF_F_HW_VLAN_STAG_FILTER_BIT,/* Receive filtering on VLAN STAGs */
/*
* Add your fresh new feature above and remember to update
* netdev_features_strings[] in net/core/ethtool.c and maybe
* some feature mask #defines below. Please also describe it
* in Documentation/networking/netdev-features.txt.
*/
/**/NETDEV_FEATURE_COUNT
};
/* copy'n'paste compression ;) */
#define __NETIF_F_BIT(bit) ((netdev_features_t)1 << (bit))
#define __NETIF_F(name) __NETIF_F_BIT(NETIF_F_##name##_BIT)
#define NETIF_F_FCOE_CRC __NETIF_F(FCOE_CRC)
#define NETIF_F_FCOE_MTU __NETIF_F(FCOE_MTU)
#define NETIF_F_FRAGLIST __NETIF_F(FRAGLIST)
#define NETIF_F_FSO __NETIF_F(FSO)
#define NETIF_F_GRO __NETIF_F(GRO)
#define NETIF_F_GSO __NETIF_F(GSO)
#define NETIF_F_GSO_ROBUST __NETIF_F(GSO_ROBUST)
#define NETIF_F_HIGHDMA __NETIF_F(HIGHDMA)
#define NETIF_F_HW_CSUM __NETIF_F(HW_CSUM)
#define NETIF_F_HW_VLAN_CTAG_FILTER __NETIF_F(HW_VLAN_CTAG_FILTER)
#define NETIF_F_HW_VLAN_CTAG_RX __NETIF_F(HW_VLAN_CTAG_RX)
#define NETIF_F_HW_VLAN_CTAG_TX __NETIF_F(HW_VLAN_CTAG_TX)
#define NETIF_F_IP_CSUM __NETIF_F(IP_CSUM)
#define NETIF_F_IPV6_CSUM __NETIF_F(IPV6_CSUM)
#define NETIF_F_LLTX __NETIF_F(LLTX)
#define NETIF_F_LOOPBACK __NETIF_F(LOOPBACK)
#define NETIF_F_LRO __NETIF_F(LRO)
#define NETIF_F_NETNS_LOCAL __NETIF_F(NETNS_LOCAL)
#define NETIF_F_NOCACHE_COPY __NETIF_F(NOCACHE_COPY)
#define NETIF_F_NTUPLE __NETIF_F(NTUPLE)
#define NETIF_F_RXCSUM __NETIF_F(RXCSUM)
#define NETIF_F_RXHASH __NETIF_F(RXHASH)
#define NETIF_F_SCTP_CSUM __NETIF_F(SCTP_CSUM)
#define NETIF_F_SG __NETIF_F(SG)
#define NETIF_F_TSO6 __NETIF_F(TSO6)
#define NETIF_F_TSO_ECN __NETIF_F(TSO_ECN)
#define NETIF_F_TSO __NETIF_F(TSO)
#define NETIF_F_UFO __NETIF_F(UFO)
#define NETIF_F_VLAN_CHALLENGED __NETIF_F(VLAN_CHALLENGED)
#define NETIF_F_RXFCS __NETIF_F(RXFCS)
#define NETIF_F_RXALL __NETIF_F(RXALL)
#define NETIF_F_GSO_GRE __NETIF_F(GSO_GRE)
#define NETIF_F_GSO_UDP_TUNNEL __NETIF_F(GSO_UDP_TUNNEL)
#define NETIF_F_GSO_MPLS __NETIF_F(GSO_MPLS)
#define NETIF_F_HW_VLAN_STAG_FILTER __NETIF_F(HW_VLAN_STAG_FILTER)
#define NETIF_F_HW_VLAN_STAG_RX __NETIF_F(HW_VLAN_STAG_RX)
#define NETIF_F_HW_VLAN_STAG_TX __NETIF_F(HW_VLAN_STAG_TX)
/* Features valid for ethtool to change */
/* = all defined minus driver/device-class-related */
#define NETIF_F_NEVER_CHANGE (NETIF_F_VLAN_CHALLENGED | \
NETIF_F_LLTX | NETIF_F_NETNS_LOCAL)
/* remember that ((t)1 << t_BITS) is undefined in C99 */
#define NETIF_F_ETHTOOL_BITS ((__NETIF_F_BIT(NETDEV_FEATURE_COUNT - 1) | \
(__NETIF_F_BIT(NETDEV_FEATURE_COUNT - 1) - 1)) & \
~NETIF_F_NEVER_CHANGE)
/* Segmentation offload feature mask */
#define NETIF_F_GSO_MASK (__NETIF_F_BIT(NETIF_F_GSO_LAST + 1) - \
__NETIF_F_BIT(NETIF_F_GSO_SHIFT))
/* List of features with software fallbacks. */
#define NETIF_F_GSO_SOFTWARE (NETIF_F_TSO | NETIF_F_TSO_ECN | \
NETIF_F_TSO6 | NETIF_F_UFO)
#define NETIF_F_GEN_CSUM NETIF_F_HW_CSUM
#define NETIF_F_V4_CSUM (NETIF_F_GEN_CSUM | NETIF_F_IP_CSUM)
#define NETIF_F_V6_CSUM (NETIF_F_GEN_CSUM | NETIF_F_IPV6_CSUM)
#define NETIF_F_ALL_CSUM (NETIF_F_V4_CSUM | NETIF_F_V6_CSUM)
#define NETIF_F_ALL_TSO (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_TSO_ECN)
#define NETIF_F_ALL_FCOE (NETIF_F_FCOE_CRC | NETIF_F_FCOE_MTU | \
NETIF_F_FSO)
/*
* If one device supports one of these features, then enable them
* for all in netdev_increment_features.
*/
#define NETIF_F_ONE_FOR_ALL (NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ROBUST | \
NETIF_F_SG | NETIF_F_HIGHDMA | \
NETIF_F_FRAGLIST | NETIF_F_VLAN_CHALLENGED)
/*
* If one device doesn't support one of these features, then disable it
* for all in netdev_increment_features.
*/
#define NETIF_F_ALL_FOR_ALL (NETIF_F_NOCACHE_COPY | NETIF_F_FSO)
/* changeable features with no special hardware requirements */
#define NETIF_F_SOFT_FEATURES (NETIF_F_GSO | NETIF_F_GRO)
#endif /* _LINUX_NETDEV_FEATURES_H */