datapath-windows: Refactor sofware offloads and mss

The purpose of this patch is to refactor the software offloads found in
the VXLAN and GRE code and also to refactor how the maximmum segment
size for a given NBL is obtained.

This patch introduces two functions OvsApplySWChecksumOnNB and OVSGetTcpMSS.

OVSGetTcpMSS - will return the mss found in a given NBL.

OvsApplySWChecksumOnNB - will compute and set software offloads for a given
                         NBL.

Signed-off-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Acked-by: Sorin Vinturis <svinturis at cloudbasesolutions.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 8 insertions, 77 deletions

diff --git a/datapath-windows/ovsext/Gre.c b/datapath-windows/ovsext/Gre.c
index 5abd4a43e..cb4159379 100644
--- a/datapath-windows/ovsext/Gre.c
+++ b/datapath-windows/ovsext/Gre.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015 Cloudbase Solutions Srl
+ * Copyright (c) 2015, 2016 Cloudbase Solutions Srl
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,11 +17,12 @@
 #include "precomp.h"
 
 #include "Atomic.h"
-#include "Checksum.h"
+#include "Debug.h"
 #include "Flow.h"
 #include "Gre.h"
 #include "IpHelper.h"
 #include "NetProto.h"
+#include "Offload.h"
 #include "PacketIO.h"
 #include "PacketParser.h"
 #include "Switch.h"
@@ -33,7 +34,6 @@
 #undef OVS_DBG_MOD
 #endif
 #define OVS_DBG_MOD OVS_DBG_GRE
-#include "Debug.h"
 
 static NDIS_STATUS
 OvsDoEncapGre(POVS_VPORT_ENTRY vport, PNET_BUFFER_LIST curNbl,
@@ -147,21 +147,8 @@ OvsDoEncapGre(POVS_VPORT_ENTRY vport,
     packetLength = NET_BUFFER_DATA_LENGTH(curNb);
 
     if (layers->isTcp) {
-        NDIS_TCP_LARGE_SEND_OFFLOAD_NET_BUFFER_LIST_INFO tsoInfo;
-
-        tsoInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
-                                             TcpLargeSendNetBufferListInfo);
-        switch (tsoInfo.Transmit.Type) {
-            case NDIS_TCP_LARGE_SEND_OFFLOAD_V1_TYPE:
-                mss = tsoInfo.LsoV1Transmit.MSS;
-                break;
-            case NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE:
-                mss = tsoInfo.LsoV2Transmit.MSS;
-                break;
-            default:
-                OVS_LOG_ERROR("Unknown LSO transmit type:%d",
-                              tsoInfo.Transmit.Type);
-        }
+        mss = OVSGetTcpMSS(curNbl);
+
         OVS_LOG_TRACE("MSS %u packet len %u", mss,
                       packetLength);
         if (mss) {
@@ -188,71 +175,15 @@ OvsDoEncapGre(POVS_VPORT_ENTRY vport,
             OVS_LOG_ERROR("Unable to copy NBL");
             return NDIS_STATUS_FAILURE;
         }
-        /*
-         * To this point we do not have GRE hardware offloading.
-         * Apply defined checksums
-         */
-        curNb = NET_BUFFER_LIST_FIRST_NB(*newNbl);
-        curMdl = NET_BUFFER_CURRENT_MDL(curNb);
-        bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl,
-                                                           LowPagePriority);
-        if (!bufferStart) {
-            status = NDIS_STATUS_RESOURCES;
-            goto ret_error;
-        }
 
         NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
         csumInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
                                               TcpIpChecksumNetBufferListInfo);
 
-        bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
-
-        if (layers->isIPv4) {
-            IPHdr *ip = (IPHdr *)(bufferStart + layers->l3Offset);
-
-            if (csumInfo.Transmit.IpHeaderChecksum) {
-                ip->check = 0;
-                ip->check = IPChecksum((UINT8 *)ip, 4 * ip->ihl, 0);
-            }
-
-            if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
-                UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
-                TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
-                tcp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
-                                              IPPROTO_TCP, csumLength);
-                tcp->check = CalculateChecksumNB(curNb, csumLength,
-                                                 (UINT32)(layers->l4Offset));
-            } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
-                UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
-                UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
-                udp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
-                                              IPPROTO_UDP, csumLength);
-                udp->check = CalculateChecksumNB(curNb, csumLength,
-                                                 (UINT32)(layers->l4Offset));
-            }
-        } else if (layers->isIPv6) {
-            IPv6Hdr *ip = (IPv6Hdr *)(bufferStart + layers->l3Offset);
-
-            if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
-                UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
-                TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
-                tcp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
-                                                (UINT32 *) &ip->daddr,
-                                                IPPROTO_TCP, csumLength);
-                tcp->check = CalculateChecksumNB(curNb, csumLength,
-                                                 (UINT32)(layers->l4Offset));
-            } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
-                UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
-                UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
-                udp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
-                                                (UINT32 *) &ip->daddr,
-                                                IPPROTO_UDP, csumLength);
-                udp->check = CalculateChecksumNB(curNb, csumLength,
-                                                 (UINT32)(layers->l4Offset));
-            }
+        status = OvsApplySWChecksumOnNB(layers, *newNbl, &csumInfo);
+        if (status != NDIS_STATUS_SUCCESS) {
+            goto ret_error;
         }
-        /* Clear out TcpIpChecksumNetBufferListInfo flag */
-        NET_BUFFER_LIST_INFO(*newNbl, TcpIpChecksumNetBufferListInfo) = 0;
     }
 
     curNbl = *newNbl;