cmake: simplified FindLibNL

cmake/FindLibNL.cmake

@@ -1,38 +1,17 @@
-message("Searching for Linux netlink library")
-
-if (LibNL_FIND_REQUIRED)
-	message("  (required)")
-else (LibNL_FIND_REQUIRED)
-	message("  (not required)")
-endif (LibNL_FIND_REQUIRED)
-
-find_path(LibNL_INCLUDE_DIR netlink/netlink.h
-	/usr/include
-	/usr/include/libnl3
-	/usr/local/include
-	/usr/local/include/libnl3
+find_path(LibNL_INCLUDE_DIR
+  NAMES netlink/netlink.h
+  PATH_SUFFIXES include/libnl3 libnl3
 )
 
-find_library(LibNL_LIBRARY NAMES nl nl-3)
-find_library(LibNL_ROUTE_LIBRARY NAMES nl-route nl-route-3)
-find_library(LibNL_NETFILTER_LIBRARY NAMES nl-nf nl-nf-3)
-find_library(LibNL_GENL_LIBRARY NAMES nl-genl nl-genl-3)
+find_library(LibNL_LIBRARY        NAMES nl-3 nl)
+find_library(LibNL_ROUTE_LIBRARY  NAMES nl-route-3 nl-route)
+find_library(LibNL_NETFILTER_LIBRARY NAMES nl-nf-3 nl-nf)
+find_library(LibNL_GENL_LIBRARY   NAMES nl-genl-3 nl-genl)
 
-if (LibNL_INCLUDE_DIR AND LibNL_LIBRARY)
-	set(LibNL_FOUND TRUE)
-endif (LibNL_INCLUDE_DIR AND LibNL_LIBRARY)
-
-if (LibNL_FOUND)
-	if (NOT LibNL_FIND_QUIETLY)
-	set(LibNL_LIBRARIES ${LibNL_LIBRARY} ${LibNL_ROUTE_LIBRARY} ${LibNL_NETFILTER_LIBRARY} ${LibNL_GENL_LIBRARY})
-        message("Found netlink libraries:  ${LibNL_LIBRARIES}")
-        message("Found netlink includes: ${LibNL_INCLUDE_DIR}")
-		endif (NOT LibNL_FIND_QUIETLY)
-ELSE (LibNL_FOUND)
-	if (LibNL_FIND_REQUIRED)
-		message("Netlink version 3 development packages cannot be found.")
-		message("In Debian/Ubuntu, they may be called:")
-		message("libnl-3-dev libnl-genl-3dev libnl-nf-3-dev libnl-route-3-dev")
-		message(FATAL_ERROR "Could not find netlink library.")
-	endif (LibNL_FIND_REQUIRED)
-endif (LibNL_FOUND)
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(LibNL DEFAULT_MSG
+  LibNL_INCLUDE_DIR
+  LibNL_LIBRARY
+  LibNL_ROUTE_LIBRARY
+  LibNL_GENL_LIBRARY
+)