[ovs-dev] [PATCH] datapath-windows: Add support for handling DEI bit of VLAN header

[Anand Kumar]

The Drop eligible indicator(DEI) is 1 bit wide and it is part of
Tag control information (TCI) in VLAN header, which indicates that
the frame can be dropped during congestion.

Signed-off-by: Anand Kumar <kumaranand at vmware.com>
---
 datapath-windows/ovsext/Actions.c |  1 +
 datapath-windows/ovsext/User.c    | 19 +++++++++++++------
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/datapath-windows/ovsext/Actions.c b/datapath-windows/ovsext/Actions.c
index 9bbc787..6922f05 100644
--- a/datapath-windows/ovsext/Actions.c
+++ b/datapath-windows/ovsext/Actions.c
@@ -2023,6 +2023,7 @@ OvsDoExecuteActions(POVS_SWITCH_CONTEXT switchContext,
                  vlan = (struct ovs_action_push_vlan *)NlAttrGet((const PNL_ATTR)a);
                  vlanTag->TagHeader.VlanId = ntohs(vlan->vlan_tci) & 0xfff;
                  vlanTag->TagHeader.UserPriority = ntohs(vlan->vlan_tci) >> 13;
+                 vlanTag->TagHeader.CanonicalFormatId = (ntohs(vlan->vlan_tci) >> 12) & 0x1;
 
                  NET_BUFFER_LIST_INFO(ovsFwdCtx.curNbl,
                                       Ieee8021QNetBufferListInfo) = vlanTagValue;
diff --git a/datapath-windows/ovsext/User.c b/datapath-windows/ovsext/User.c
index 4693a8b..509472f 100644
--- a/datapath-windows/ovsext/User.c
+++ b/datapath-windows/ovsext/User.c
@@ -1000,11 +1000,12 @@ OvsCreateQueueNlPacket(PVOID userData,
                        POVS_PACKET_HDR_INFO hdrInfo)
 {
 #define VLAN_TAG_SIZE 4
-    UINT32 allocLen, dataLen, extraLen;
+    UINT32 allocLen, dataLen, extraLen = 0;
     POVS_PACKET_QUEUE_ELEM elem;
     UINT8 *src, *dst;
     NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
-    NDIS_NET_BUFFER_LIST_8021Q_INFO vlanInfo;
+    PNDIS_NET_BUFFER_LIST_8021Q_INFO vlanInfo = NULL;
+    PVOID vlanTag;
     OvsIPv4TunnelKey *tunnelKey = (OvsIPv4TunnelKey *)&key->tunKey;
     UINT32 pid;
     UINT32 nlMsgSize;
@@ -1037,8 +1038,13 @@ OvsCreateQueueNlPacket(PVOID userData,
         return NULL;
     }
 
-    vlanInfo.Value = NET_BUFFER_LIST_INFO(nbl, Ieee8021QNetBufferListInfo);
-    extraLen = vlanInfo.TagHeader.VlanId ? VLAN_TAG_SIZE : 0;
+    vlanTag = NET_BUFFER_LIST_INFO(nbl, Ieee8021QNetBufferListInfo);
+    if (vlanTag) {
+        vlanInfo = (PNDIS_NET_BUFFER_LIST_8021Q_INFO)(PVOID *)&vlanTag;
+        if (vlanInfo->Value) {
+            extraLen = VLAN_TAG_SIZE;
+        }
+    }
 
     dataLen = NET_BUFFER_DATA_LENGTH(nb);
 
@@ -1148,8 +1154,9 @@ OvsCreateQueueNlPacket(PVOID userData,
         ((UINT32 *)dst)[2] = ((UINT32 *)src)[2];
         dst += 12;
         ((UINT16 *)dst)[0] = htons(0x8100);
-        ((UINT16 *)dst)[1] = htons(vlanInfo.TagHeader.VlanId |
-            (vlanInfo.TagHeader.UserPriority << 13));
+        ((UINT16 *)dst)[1] = htons(vlanInfo->TagHeader.VlanId |
+            (vlanInfo->TagHeader.CanonicalFormatId << 12) |
+            (vlanInfo->TagHeader.UserPriority << 13));
         elem->hdrInfo.l3Offset += VLAN_TAG_SIZE;
         elem->hdrInfo.l4Offset += VLAN_TAG_SIZE;
         ovsUserStats.vlanInsert++;
-- 
2.9.3.windows.1