datapath-windows: Transactional error support in Flow commands.

In this patch we added the code to handle transactional errors
in flow commands.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Validate ETHERTYPE and ETHERNET attribute.

During vswitchd boot up kernel is receiving FLOW_ADD commands
without ETHERTYPE attribute. Added additional check for the same
in this patch. During the same phase kernel is also receiving
packet_execute with no ETHERNET attribute.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Reply for Flow Flush.

Added changes to send a reply for FLOW_FUSH case. This is needed
as with nithin's transaction reply changes we'll need reply for each
command.

This patch also contains minor fixes for sending replies in
success case as well.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Remove setting of replyLen to zero.

This was one of the review comment which i forgot to address in
FLOW_DUMP checkin. We do not need to explicitly set replyLen to zero
 as caller would have already set it.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Remove invalid assertion.

Assert(rc) would always hit for a valid case, hence
replaced it with error code based check.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Tested-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
datapath-windows: Fix assertion in Netlink.c

NlBufAt should be called with valid boundary limits (within head and tail).
Incorrect argument to NlBufAt was leading to assert hit, fixed the same.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Tested-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>