diff options
| 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 | |
| parent | 47a0200d535f08ac8f784a709c48995ca0b10288 (diff) | |
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>
| -rw-r--r-- | drivers/net/loopback.c | 3 | ||||
| -rw-r--r-- | include/linux/netdevice.h | 3 | ||||
| -rw-r--r-- | net/core/ethtool.c | 2 |
3 files changed, 5 insertions, 3 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 = ð_header_ops; dev->netdev_ops = &loopback_ops; diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d5de66af46f9..e7244ed1f9a8 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1067,6 +1067,7 @@ struct net_device { #define NETIF_F_RXHASH (1 << 28) /* Receive hashing offload */ #define NETIF_F_RXCSUM (1 << 29) /* Receive checksumming offload */ #define NETIF_F_NOCACHE_COPY (1 << 30) /* Use no-cache copyfromuser */ +#define NETIF_F_LOOPBACK (1 << 31) /* Enable loopback */ /* Segmentation offload features */ #define NETIF_F_GSO_SHIFT 16 @@ -1082,7 +1083,7 @@ struct net_device { /* = all defined minus driver/device-class-related */ #define NETIF_F_NEVER_CHANGE (NETIF_F_VLAN_CHALLENGED | \ NETIF_F_LLTX | NETIF_F_NETNS_LOCAL) -#define NETIF_F_ETHTOOL_BITS (0x7f3fffff & ~NETIF_F_NEVER_CHANGE) +#define NETIF_F_ETHTOOL_BITS (0xff3fffff & ~NETIF_F_NEVER_CHANGE) /* List of features with software fallbacks. */ #define NETIF_F_GSO_SOFTWARE (NETIF_F_TSO | NETIF_F_TSO_ECN | \ 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) |