datapath-windows: Add new NlFillOvsMsgForNfGenMsg method in Netlink.c

Create a new method to create and fill OvsMessage with NfGenMsg. This will
be used for sending Netfilter based Netlink messages.

Signed-off-by: Sairam Venugopal <vsairam@vmware.com>
Acked-by: Paul-Daniel Boca <pboca@cloudbasesolutions.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>

Author: Sairam Venugopal

datapath-windows/ovsext/Netlink/Netlink.c

@@ -71,6 +71,45 @@ NlFillOvsMsg(PNL_BUFFER nlBuf, UINT16 nlmsgType,
     return writeOk;
 }
 
+/*
+ * ---------------------------------------------------------------------------
+ * Prepare netlink message headers. This API adds
+ * NL_MSG_HDR + GENL_HDR + OVS_HDR to the tail of input NLBuf.
+ * Attributes should be added by caller.
+ * ---------------------------------------------------------------------------
+ */
+BOOLEAN
+NlFillOvsMsgForNfGenMsg(PNL_BUFFER nlBuf, UINT16 nlmsgType,
+                        UINT16 nlmsgFlags, UINT32 nlmsgSeq,
+                        UINT32 nlmsgPid, UINT8 nfgenFamily,
+                        UINT8 nfGenVersion, UINT32 dpNo)
+{
+    BOOLEAN writeOk;
+    OVS_MESSAGE msgOut;
+    UINT32 offset = NlBufSize(nlBuf);
+
+    /* To keep compiler happy for release build. */
+    UNREFERENCED_PARAMETER(offset);
+    ASSERT(NlBufAt(nlBuf, offset, 0) != 0);
+
+    msgOut.nlMsg.nlmsgType = nlmsgType;
+    msgOut.nlMsg.nlmsgFlags = nlmsgFlags;
+    msgOut.nlMsg.nlmsgSeq = nlmsgSeq;
+    msgOut.nlMsg.nlmsgPid = nlmsgPid;
+    msgOut.nlMsg.nlmsgLen = sizeof(struct _OVS_MESSAGE);
+
+    msgOut.nfGenMsg.nfgenFamily = nfgenFamily;
+    msgOut.nfGenMsg.version = nfGenVersion;
+    msgOut.nfGenMsg.resId = 0;
+
+    msgOut.ovsHdr.dp_ifindex = dpNo;
+
+    writeOk = NlMsgPutTail(nlBuf, (PCHAR)(&msgOut),
+                           sizeof (struct _OVS_MESSAGE));
+
+    return writeOk;
+}
+
 /*
  * ---------------------------------------------------------------------------
  * Prepare NL_MSG_HDR only. This API appends a NL_MSG_HDR to the tail of

datapath-windows/ovsext/Netlink/Netlink.h

@@ -95,6 +95,10 @@ BOOLEAN NlFillOvsMsg(PNL_BUFFER nlBuf,
                      UINT16 nlmsgType, UINT16 nlmsgFlags,
                      UINT32 nlmsgSeq, UINT32 nlmsgPid,
                      UINT8 genlCmd, UINT8 genlVer, UINT32 dpNo);
+BOOLEAN NlFillOvsMsgForNfGenMsg(PNL_BUFFER nlBuf, UINT16 nlmsgType,
+                                UINT16 nlmsgFlags, UINT32 nlmsgSeq,
+                                UINT32 nlmsgPid, UINT8 nfgenFamily,
+                                UINT8 nfGenVersion, UINT32 dpNo);
 BOOLEAN NlFillNlHdr(PNL_BUFFER nlBuf,
                     UINT16 nlmsgType, UINT16 nlmsgFlags,
                     UINT32 nlmsgSeq, UINT32 nlmsgPid);