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ip6_gre: fix device features for ioctl setup 

When ip6gre is created using ioctl, its features, such as
scatter-gather, GSO and tx-checksumming will be turned off:

  # ip -f inet6 tunnel add gre6 mode ip6gre remote fd00::1
  # ethtool -k gre6 (truncated output)
    tx-checksumming: off
    scatter-gather: off
    tcp-segmentation-offload: off
    generic-segmentation-offload: off [requested on]

But when netlink is used, they will be enabled:
  # ip link add gre6 type ip6gre remote fd00::1
  # ethtool -k gre6 (truncated output)
    tx-checksumming: on
    scatter-gather: on
    tcp-segmentation-offload: on
    generic-segmentation-offload: on

This results in a loss of performance when gre6 is created via ioctl.
The issue was found with LTP/gre tests.

Fix it by moving the setup of device features to a separate function
and invoke it with ndo_init callback because both netlink and ioctl
will eventually call it via register_netdevice():

   register_netdevice()
       - ndo_init() callback -> ip6gre_tunnel_init() or ip6gre_tap_init()
           - ip6gre_tunnel_init_common()
                - ip6gre_tnl_init_features()

The moved code also contains two minor style fixes:
  * removed needless tab from GRE6_FEATURES on NETIF_F_HIGHDMA line.
  * fixed the issue reported by checkpatch: "Unnecessary parentheses around
    'nt->encap.type == TUNNEL_ENCAP_NONE'"

Fixes: ac4eb009e4 ("ip6gre: Add support for basic offloads offloads excluding GSO")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexey Kodanev 2017-12-20 19:36:03 +03:00 committed by David S. Miller
parent 74ee0e8c1b
commit e5a9336adb
1 changed files with 32 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
net/ipv6/ip6_gre.c
View File

@ -1014,6 +1014,36 @@ static void ip6gre_tunnel_setup(struct net_device *dev)
eth_random_addr(dev->perm_addr);
}
#define GRE6_FEATURES (NETIF_F_SG | \
NETIF_F_FRAGLIST | \
NETIF_F_HIGHDMA | \
NETIF_F_HW_CSUM)
static void ip6gre_tnl_init_features(struct net_device *dev)
{
struct ip6_tnl *nt = netdev_priv(dev);
dev->features |= GRE6_FEATURES;
dev->hw_features |= GRE6_FEATURES;
if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
/* TCP offload with GRE SEQ is not supported, nor
* can we support 2 levels of outer headers requiring
* an update.
*/
if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
nt->encap.type == TUNNEL_ENCAP_NONE) {
dev->features |= NETIF_F_GSO_SOFTWARE;
dev->hw_features |= NETIF_F_GSO_SOFTWARE;
}
/* Can use a lockless transmit, unless we generate
* output sequences
*/
dev->features |= NETIF_F_LLTX;
}
}
static int ip6gre_tunnel_init_common(struct net_device *dev)
{
struct ip6_tnl *tunnel;
@ -1048,6 +1078,8 @@ static int ip6gre_tunnel_init_common(struct net_device *dev)
if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu -= 8;
ip6gre_tnl_init_features(dev);
return 0;
}
@ -1298,11 +1330,6 @@ static const struct net_device_ops ip6gre_tap_netdev_ops = {
.ndo_get_iflink = ip6_tnl_get_iflink,
};
#define GRE6_FEATURES (NETIF_F_SG | \
NETIF_F_FRAGLIST | \
NETIF_F_HIGHDMA | \
NETIF_F_HW_CSUM)
static void ip6gre_tap_setup(struct net_device *dev)
{
@ -1383,26 +1410,6 @@ static int ip6gre_newlink(struct net *src_net, struct net_device *dev,
nt->net = dev_net(dev);
ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
dev->features |= GRE6_FEATURES;
dev->hw_features |= GRE6_FEATURES;
if (!(nt->parms.o_flags & TUNNEL_SEQ)) {
/* TCP offload with GRE SEQ is not supported, nor
* can we support 2 levels of outer headers requiring
* an update.
*/
if (!(nt->parms.o_flags & TUNNEL_CSUM) ||
(nt->encap.type == TUNNEL_ENCAP_NONE)) {
dev->features |= NETIF_F_GSO_SOFTWARE;
dev->hw_features |= NETIF_F_GSO_SOFTWARE;
}
/* Can use a lockless transmit, unless we generate
* output sequences
*/
dev->features |= NETIF_F_LLTX;
}
err = register_netdevice(dev);
if (err)
goto out;