datapath-windows: Implement locking in conntrack NAT.

This patch primarily replaces existing ndis RWlock based implementaion
for NAT in conntrack with a spinlock based implementation inside NAT,
module along with some conntrack optimization.

- The 'ovsNatTable' and 'ovsUnNatTable' tables are shared
  between cleanup threads and packet processing thread.
  In order to protect these two tables use a spinlock.
  Also introduce counters to track number of nat entries.
- Introduce a new function OvsGetTcpHeader() to retrieve TCP header
  and payload length, to optimize for TCP traffic.
- Optimize conntrack look up.
- Remove 'bucketlockRef' member from conntrack entry structure.

Testing:
Verified loading/unloading the driver with driver verified enabled.
Ran TCP/UDP and ICMP traffic.

Signed-off-by: Anand Kumar <kumaranand@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@ovn.org>
Signed-off-by: Alin Gabriel Serdean <aserdean@ovn.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/datapath-windows/ovsext/Conntrack-ftp.c b/datapath-windows/ovsext/Conntrack-ftp.c
index 6830dfafa..ce09a6528 100644
--- a/datapath-windows/ovsext/Conntrack-ftp.c
+++ b/datapath-windows/ovsext/Conntrack-ftp.c
@@ -129,14 +129,14 @@ OvsCtHandleFtp(PNET_BUFFER_LIST curNbl,
     char temp[256] = { 0 };
     char ftpMsg[256] = { 0 };
 
+    UINT32 len;
     TCPHdr tcpStorage;
     const TCPHdr *tcp;
-    tcp = OvsGetTcp(curNbl, layers->l4Offset, &tcpStorage);
+    tcp = OvsGetTcpHeader(curNbl, layers, &tcpStorage, &len);
     if (!tcp) {
         return NDIS_STATUS_INVALID_PACKET;
     }
 
-    UINT32 len = OvsGetTcpPayloadLength(curNbl);
     if (len > sizeof(temp)) {
         /* We only care up to 256 */
         len = sizeof(temp);