From 36eabda3d094dae30a74350c6289c163349b744d Mon Sep 17 00:00:00 2001 From: Ben Greear Date: Sat, 11 Feb 2012 15:39:14 +0000 Subject: [PATCH] net: Support RXFCS feature flag. When set on hardware that supports the feature, this causes the Ethernet FCS to be appended to the end of the skb. Useful for sniffing packets. Signed-off-by: Ben Greear Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- Documentation/networking/netdev-features.txt | 6 ++++++ include/linux/netdev_features.h | 2 ++ net/core/ethtool.c | 1 + 3 files changed, 9 insertions(+) diff --git a/Documentation/networking/netdev-features.txt b/Documentation/networking/netdev-features.txt index 4b1c0dcef84c..7d2781230d30 100644 --- a/Documentation/networking/netdev-features.txt +++ b/Documentation/networking/netdev-features.txt @@ -152,3 +152,9 @@ NETIF_F_VLAN_CHALLENGED should be set for devices which can't cope with VLAN headers. Some drivers set this because the cards can't handle the bigger MTU. [FIXME: Those cases could be fixed in VLAN code by allowing only reduced-MTU VLANs. This may be not useful, though.] + +* rx-fcs + +This requests that the NIC append the Ethernet Frame Checksum (FCS) +to the end of the skb data. This allows sniffers and other tools to +read the CRC recorded by the NIC on receipt of the packet. diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index 77f5202977ce..d1331865f830 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -54,6 +54,7 @@ enum { 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 */ /* * Add your fresh new feature above and remember to update @@ -98,6 +99,7 @@ enum { #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) /* Features valid for ethtool to change */ /* = all defined minus driver/device-class-related */ diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 3f79db1b612a..080161924a0d 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -73,6 +73,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] [NETIF_F_RXCSUM_BIT] = "rx-checksum", [NETIF_F_NOCACHE_COPY_BIT] = "tx-nocache-copy", [NETIF_F_LOOPBACK_BIT] = "loopback", + [NETIF_F_RXFCS_BIT] = "rx-fcs", }; static int ethtool_get_features(struct net_device *dev, void __user *useraddr) -- 2.20.1