From patchwork Fri Nov 9 23:35:24 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: vxlan: Fix error that was resulting in VXLAN MTU size being 10 bytes too large From: Alexander Duyck X-Patchwork-Id: 198161 Message-Id: <20121109233354.17208.36271.stgit@gitlad.jf.intel.com> To: netdev@vger.kernel.org Cc: davem@davemloft.net, shemminger@vyatta.com Date: Fri, 09 Nov 2012 15:35:24 -0800 This change fixes an issue I found where VXLAN frames were fragmented when they were up to the VXLAN MTU size. I root caused the issue to the fact that the headroom was 4 + 20 + 8 + 8. This math doesn't appear to be correct because we are not inserting a VLAN header, but instead a 2nd Ethernet header. As such the math for the overhead should be 20 + 8 + 8 + 14 to account for the extra headers that are inserted for VXLAN. Signed-off-by: Alexander Duyck --- drivers/net/vxlan.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 410ebc8..0b75c19 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -51,8 +51,8 @@ #define VXLAN_N_VID (1u << 24) #define VXLAN_VID_MASK (VXLAN_N_VID - 1) -/* VLAN + IP header + UDP + VXLAN */ -#define VXLAN_HEADROOM (4 + 20 + 8 + 8) +/* IP header + UDP + VXLAN + Ethernet header */ +#define VXLAN_HEADROOM (20 + 8 + 8 + 14) #define VXLAN_FLAGS 0x08000000 /* struct vxlanhdr.vx_flags required value. */