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| author | Mahesh Bandewar <maheshb@google.com> | 2011-05-04 15:30:11 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-05-08 15:59:12 -0700 |
| commit | eed2a12f1ed9aabf0676f4d0db34aad51976c5c6 (patch) | |
| tree | a86d3ff7c6a9840131d38af3dfc907c255bfbd99 /net/core/ethtool.c | |
| parent | 47a0200d535f08ac8f784a709c48995ca0b10288 (diff) | |
| download | blackbird-obmc-linux-eed2a12f1ed9aabf0676f4d0db34aad51976c5c6.tar.gz blackbird-obmc-linux-eed2a12f1ed9aabf0676f4d0db34aad51976c5c6.zip | |
net: Allow ethtool to set interface in loopback mode.
This patch enables ethtool to set the loopback mode on a given interface.
By configuring the interface in loopback mode in conjunction with a policy
route / rule, a userland application can stress the egress / ingress path
exposing the flows of the change in progress and potentially help developer(s)
understand the impact of those changes without even sending a packet out
on the network.
Following set of commands illustrates one such example -
a) ip -4 addr add 192.168.1.1/24 dev eth1
b) ip -4 rule add from all iif eth1 lookup 250
c) ip -4 route add local 0/0 dev lo proto kernel scope host table 250
d) arp -Ds 192.168.1.100 eth1
e) arp -Ds 192.168.1.200 eth1
f) sysctl -w net.ipv4.ip_nonlocal_bind=1
g) sysctl -w net.ipv4.conf.all.accept_local=1
# Assuming that the machine has 8 cores
h) taskset 000f netserver -L 192.168.1.200
i) taskset 00f0 netperf -t TCP_CRR -L 192.168.1.100 -H 192.168.1.200 -l 30
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/ethtool.c')
| -rw-r--r-- | net/core/ethtool.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 927819d92248..b6f405888538 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -362,7 +362,7 @@ static const char netdev_features_strings[ETHTOOL_DEV_FEATURE_WORDS * 32][ETH_GS /* NETIF_F_RXHASH */ "rx-hashing", /* NETIF_F_RXCSUM */ "rx-checksum", /* NETIF_F_NOCACHE_COPY */ "tx-nocache-copy" - "", + /* NETIF_F_LOOPBACK */ "loopback", }; static int __ethtool_get_sset_count(struct net_device *dev, int sset) |
