infiniband-diags: Add build_dr_path_to_lid in new libdr

Add build_dr_path_to_lid() in a new static library (libdr) that is
linked into all diags under src/. It follows switch Linear Forwarding
Tables via live SMP queries to build a direct route (DR) path to a
destination LID, with optional per-hop dumping and vport-LID resolution.

This is needed for XDR: SMP via LID is not guaranteed to work in XDR
fabrics, so utilities must be able to build and walk a direct route to
reach a destination LID.

Signed-off-by: Asaf Mazor <amazor@nvidia.com>

Author: mazorasaf

infiniband-diags/CMakeLists.txt

@@ -1,5 +1,6 @@
 publish_internal_headers(""
   ibdiag_common.h
+  ibdiag_dr.h
   ibdiag_sa.h
   )
 
@@ -10,6 +11,7 @@ install(FILES
 
 add_library(ibdiags_tools STATIC
   ibdiag_common.c
+  ibdiag_dr.c
   ibdiag_sa.c
   )