--- /dev/null
+dnl Check to find the zlib headers/libraries
+
+AC_DEFUN(tinc_ZLIB,
+[
+ tinc_ac_save_CPPFLAGS="$CPPFLAGS"
+
+ AC_ARG_WITH(zlib-include,
+ [ --with-zlib-include=DIR zlib headers directory],
+ [zlib_include="$withval"
+ CFLAGS="$CFLAGS -I$withval"
+ CPPFLAGS="$CPPFLAGS -I$withval"]
+ )
+
+ AC_ARG_WITH(zlib-lib,
+ [ --with-zlib-lib=DIR zlib library directory],
+ [zlib_lib="$withval"
+ LIBS="$LIBS -L$withval"]
+ )
+
+ AC_CHECK_HEADERS(zlib.h,
+ [],
+ [AC_MSG_ERROR("zlib header files not found."); break]
+ )
+
+ CPPFLAGS="$tinc_ac_save_CPPFLAGS"
+
+ AC_CHECK_LIB(z, compress2,
+ [LIBS="$LIBS -lz"],
+ [AC_MSG_ERROR("zlib libraries not found.")]
+ )
+])