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authorMahesh Bandewar <maheshb@google.com>2011-05-04 15:30:11 +0000
committerDavid S. Miller <davem@davemloft.net>2011-05-08 15:59:12 -0700
commiteed2a12f1ed9aabf0676f4d0db34aad51976c5c6 (patch)
treea86d3ff7c6a9840131d38af3dfc907c255bfbd99 /drivers/net/loopback.c
parent47a0200d535f08ac8f784a709c48995ca0b10288 (diff)
downloadlinux-eed2a12f1ed9aabf0676f4d0db34aad51976c5c6.tar.bz2
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 'drivers/net/loopback.c')
-rw-r--r--drivers/net/loopback.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index d70fb76edb77..4ce9e5f2c069 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -174,7 +174,8 @@ static void loopback_setup(struct net_device *dev)
| NETIF_F_HIGHDMA
| NETIF_F_LLTX
| NETIF_F_NETNS_LOCAL
- | NETIF_F_VLAN_CHALLENGED;
+ | NETIF_F_VLAN_CHALLENGED
+ | NETIF_F_LOOPBACK;
dev->ethtool_ops = &loopback_ethtool_ops;
dev->header_ops = &eth_header_ops;
dev->netdev_ops = &loopback_ops;