datapath-windows: Append tunnel info to upcall for correct template

Formerly, there is no tunnel information appended in the upcall’s
packet data, which is expected by IPFIX in userspace to calculate
the template for exporting the sampled flow record of on egress
tunnel port.
To fix this, during performing OvsOutputUserspaceAction(), we
would check whether it is initiated by the sampling on egress
tunnel which would be indicated by the attribute as
OVS_USERSPACE_ATTR_EGRESS_TUN_PORT in the nested attribute
list. If so, we would append the tunKey in OvsForwardingContext
indexed by OVS_PACKET_ATTR_EGRESS_TUN_KEY to the upcall.
Besides, at this point, the source transport port and  source ip
address are not available in the structure, so we have to fill it in the
way how the packet would be capsulated during performing
OvsEncapGeneve(), which is following the
OvsOutputUserspaceAction() unfortunately.
I have tested the IPFIX functionality with the change, we could see the
template is correct and the expected tunnel information could be
packed in the IPFIX packet finally. The traffic for test is generated by
PING utility.

>From d727d051c9a44a4a93e5ee5f3da3ca9b125aad29 Mon Sep 17 00:00:00 2001
From: Amber Hu <qhu@vmware.com>
Date: Thu, 30 Jan 2020 18:01:32 -0800
Subject: [PATCH v3] datapath-windows: Append tunnel info to upcall for correct
 template

Signed-off-by: Amber Hu <qhu@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@ovn.org>
Signed-off-by: Alin Gabriel Serdean <aserdean@ovn.org>

1 files changed, 21 insertions, 3 deletions

diff --git a/datapath-windows/ovsext/Actions.c b/datapath-windows/ovsext/Actions.c
index 5c9b5c3a0..4a11cea5e 100644
--- a/datapath-windows/ovsext/Actions.c
+++ b/datapath-windows/ovsext/Actions.c
@@ -1815,10 +1815,12 @@ OvsOutputUserspaceAction(OvsForwardingContext *ovsFwdCtx,
 {
     NTSTATUS status = NDIS_STATUS_SUCCESS;
     PNL_ATTR userdataAttr;
-    PNL_ATTR queueAttr;
+    PNL_ATTR egrTunAttr = NULL;
     POVS_PACKET_QUEUE_ELEM elem;
     POVS_PACKET_HDR_INFO layers = &ovsFwdCtx->layers;
     BOOLEAN isRecv = FALSE;
+    OVS_FWD_INFO fwdInfo;
+    OvsIPv4TunnelKey tunKey;
 
     POVS_VPORT_ENTRY vport = OvsFindVportByPortNo(ovsFwdCtx->switchContext,
                                                   ovsFwdCtx->srcVportNo);
@@ -1830,13 +1832,29 @@ OvsOutputUserspaceAction(OvsForwardingContext *ovsFwdCtx,
         }
     }
 
-    queueAttr = NlAttrFindNested(attr, OVS_USERSPACE_ATTR_PID);
     userdataAttr = NlAttrFindNested(attr, OVS_USERSPACE_ATTR_USERDATA);
+    /* Indicate the packet is from egress-tunnel direction */
+    egrTunAttr = NlAttrFindNested(attr, OVS_USERSPACE_ATTR_EGRESS_TUN_PORT);
+
+    /* Fill tunnel key to export to usersspace to calculate the template id */
+    if (egrTunAttr) {
+        RtlZeroMemory(&tunKey,  sizeof tunKey);
+        RtlCopyMemory(&tunKey, &ovsFwdCtx->tunKey, sizeof tunKey);
+        if (!tunKey.src) {
+            status = OvsLookupIPFwdInfo(tunKey.src, tunKey.dst, &fwdInfo);
+            if (status == NDIS_STATUS_SUCCESS && tunKey.dst == fwdInfo.dstIpAddr) {
+                tunKey.src = fwdInfo.srcIpAddr;
+            }
+        }
+        tunKey.flow_hash = tunKey.flow_hash ? tunKey.flow_hash : MAXINT16;
+    }
 
     elem = OvsCreateQueueNlPacket(NlAttrData(userdataAttr),
                                   NlAttrGetSize(userdataAttr),
                                   OVS_PACKET_CMD_ACTION,
-                                  vport, key, ovsFwdCtx->curNbl,
+                                  vport, key,
+                                  egrTunAttr ? &(tunKey) : NULL,
+                                  ovsFwdCtx->curNbl,
                                   NET_BUFFER_LIST_FIRST_NB(ovsFwdCtx->curNbl),
                                   isRecv,
                                   layers);