| Message ID | 1507582067-36718-2-git-send-email-u9012063@gmail.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | ip_gre: a bunch of fixes for mtu | expand |
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index c105a315b1a3..286065c35959 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -947,8 +947,8 @@ static void __gre_tunnel_init(struct net_device *dev) t_hlen = tunnel->hlen + sizeof(struct iphdr); - dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; - dev->mtu = ETH_DATA_LEN - t_hlen - 4; + dev->needed_headroom = LL_MAX_HEADER + t_hlen; + dev->mtu = ETH_DATA_LEN - t_hlen; dev->features |= GRE_FEATURES; dev->hw_features |= GRE_FEATURES;
The ip_gre_calc_hlen() already counts gre's base header len (4-byte) plus optional header's len, so tunnel->hlen has the entire gre headeri + options len. Thus, remove the -4 and +4 when calculating the needed_headroom and mtu. Fixes: 4565e9919cda ("gre: Setup and TX path for gre/UDP foo-over-udp encapsulation") Signed-off-by: William Tu <u9012063@gmail.com> Cc: Tom Herbert <tom@quantonium.net> --- net/ipv4/ip_gre.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)