diff --git a/configure.ac b/configure.ac
index afdaec34..c5ce5776 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,464 +1,467 @@
 #
 # Copyright (C) 2010-2018 Red Hat, Inc.  All rights reserved.
 #
 # Authors: Fabio M. Di Nitto <fabbione@kronosnet.org>
 #          Federico Simoncelli <fsimon@kronosnet.org>
 #
 # This software licensed under GPL-2.0+, LGPL-2.0+
 #
 
 #                                               -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 #
 
 AC_PREREQ([2.63])
 AC_INIT([kronosnet],
 	m4_esyscmd([build-aux/git-version-gen .tarball-version]),
 	[devel@lists.kronosnet.org])
 # Don't let AC_PROC_CC (invoked by AC_USE_SYSTEM_EXTENSIONS) replace
 # undefined CFLAGS with -g -O2, overriding our special OPT_CFLAGS.
 : ${CFLAGS=""}
 AC_USE_SYSTEM_EXTENSIONS
 AM_INIT_AUTOMAKE([1.13 dist-bzip2 dist-xz color-tests -Wno-portability subdir-objects])
 
 LT_PREREQ([2.2.6])
 # --enable-new-dtags: Use RUNPATH instead of RPATH.
 # It is necessary to have this done before libtool does linker detection.
 # See also: https://github.com/kronosnet/kronosnet/issues/107
+# --as-needed: Modern systems have builtin ceil() making -lm superfluous but
+# AC_SEARCH_LIBS can't detect this because it tests with a false prototype
 AX_CHECK_LINK_FLAG([-Wl,--enable-new-dtags],[AM_LDFLAGS=-Wl,--enable-new-dtags])
+AX_CHECK_LINK_FLAG([-Wl,--as-needed],[AM_LDFLAGS="$AM_LDFLAGS -Wl,--as-needed"])
 AC_SUBST([AM_LDFLAGS])
 saved_LDFLAGS="$LDFLAGS"
 LDFLAGS="$AM_LDFLAGS $LDFLAGS"
 LT_INIT
 LDFLAGS="$saved_LDFLAGS"
 
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_SRCDIR([kronosnetd/main.c])
 AC_CONFIG_HEADERS([config.h])
 
 AC_CANONICAL_HOST
 AC_PROG_LIBTOOL
 
 AC_LANG([C])
 
 systemddir=${prefix}/lib/systemd/system
 
 if test "$prefix" = "NONE"; then
 	prefix="/usr"
 	if test "$localstatedir" = "\${prefix}/var"; then
 		localstatedir="/var"
 	fi
 	if test "$sysconfdir" = "\${prefix}/etc"; then
 		sysconfdir="/etc"
 	fi
 	if test "$systemddir" = "NONE/lib/systemd/system"; then
 		systemddir=/lib/systemd/system
 	fi
 	if test "$libdir" = "\${exec_prefix}/lib"; then
 		if test -e /usr/lib64; then
 			libdir="/usr/lib64"
 		else
 			libdir="/usr/lib"
 		fi
 	fi
 fi
 
 AC_PROG_AWK
 AC_PROG_GREP
 AC_PROG_SED
 AC_PROG_CPP
 AC_PROG_CC
 AC_PROG_CC_C99
 if test "x$ac_cv_prog_cc_c99" = "xno"; then
 	AC_MSG_ERROR(["C99 support is required"])
 fi
 AC_PROG_LN_S
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
 PKG_PROG_PKG_CONFIG
 AC_CHECK_PROGS([DOXYGEN], [doxygen])
 
 AC_CHECK_PROGS([VALGRIND_EXEC], [valgrind])
 AM_CONDITIONAL([HAS_VALGRIND], [test x$VALGRIND_EXEC != "x"])
 
 # KNET_OPTION_DEFINES(stem,type,detection code)
 # stem: enters name of option, Automake conditional and preprocessor define
 # type: compress or crypto, determines where the default comes from
 AC_DEFUN([KNET_OPTION_DEFINES],[
 AC_ARG_ENABLE([$2-$1],[AS_HELP_STRING([--disable-$2-$1],[disable libknet $1 support])],,
 	[enable_$2_$1="$enable_$2_all"])
 AM_CONDITIONAL([BUILD_]m4_toupper([$2_$1]),[test "x$enable_$2_$1" = xyes])
 if test "x$enable_$2_$1" = xyes; then
 	$3
 fi
 AC_DEFINE_UNQUOTED([WITH_]m4_toupper([$2_$1]), [`test "x$enable_$2_$1" != xyes; echo $?`], $1 $2 [built in])
 ])
 
 AC_ARG_ENABLE([libknet-sctp],
 	[AS_HELP_STRING([--disable-libknet-sctp],[disable libknet SCTP support])],,
 	[ enable_libknet_sctp="yes" ])
 AM_CONDITIONAL([BUILDSCTP], [test x$enable_libknet_sctp = xyes])
 
 AC_ARG_ENABLE([crypto-all],
 	[AS_HELP_STRING([--disable-crypto-all],[disable libknet all crypto modules support])],,
 	[ enable_crypto_all="yes" ])
 
 KNET_OPTION_DEFINES([nss],[crypto],[PKG_CHECK_MODULES([nss], [nss])])
 KNET_OPTION_DEFINES([openssl],[crypto],[
 	PKG_CHECK_MODULES([openssl],[libcrypto < 1.1],
 			  [AC_DEFINE_UNQUOTED([BUILDCRYPTOOPENSSL10], [1], [openssl 1.0 crypto])],
 			  [PKG_CHECK_MODULES([openssl],[libcrypto >= 1.1],
 					     [AC_DEFINE_UNQUOTED([BUILDCRYPTOOPENSSL11], [1], [openssl 1.1 crypto])])])
 ])
 
 AC_ARG_ENABLE([compress-all],
 	[AS_HELP_STRING([--disable-compress-all],[disable libknet all compress modules support])],,
 	[ enable_compress_all="yes" ])
 
 KNET_OPTION_DEFINES([zlib],[compress],[PKG_CHECK_MODULES([zlib], [zlib])])
 KNET_OPTION_DEFINES([lz4],[compress],[PKG_CHECK_MODULES([liblz4], [liblz4])])
 KNET_OPTION_DEFINES([lzo2],[compress],[
 	PKG_CHECK_MODULES([lzo2], [lzo2],
 		[# work around broken pkg-config file in v2.10
 		 AC_SUBST([lzo2_CFLAGS],[`echo $lzo2_CFLAGS | sed 's,/lzo *, ,'`])],
 		[AC_CHECK_HEADERS([lzo/lzo1x.h],
 			[AC_CHECK_LIB([lzo2], [lzo1x_decompress_safe],
 				[AC_SUBST([lzo2_LIBS], [-llzo2])])],
 				[AC_MSG_ERROR(["missing required lzo/lzo1x.h header"])])])
 ])
 KNET_OPTION_DEFINES([lzma],[compress],[PKG_CHECK_MODULES([liblzma], [liblzma])])
 KNET_OPTION_DEFINES([bzip2],[compress],[
 	PKG_CHECK_MODULES([bzip2], [bzip2],,
 		[AC_CHECK_HEADERS([bzlib.h],
 			[AC_CHECK_LIB([bz2], [BZ2_bzBuffToBuffCompress],
 				[AC_SUBST([bzip2_LIBS], [-lbz2])])],
 				[AC_MSG_ERROR(["missing required bzlib.h"])])])
 ])
 
 AC_ARG_ENABLE([poc],
 	[AS_HELP_STRING([--enable-poc],[enable building poc code])],,
 	[ enable_poc="no" ])
 AM_CONDITIONAL([BUILD_POC], [test x$enable_poc = xyes])
 
 AC_ARG_ENABLE([kronosnetd],
 	[AS_HELP_STRING([--enable-kronosnetd],[Kronosnetd support])],,
 	[ enable_kronosnetd="no" ])
 AM_CONDITIONAL([BUILD_KRONOSNETD], [test x$enable_kronosnetd = xyes])
 
 AC_ARG_ENABLE([runautogen],
 	[AS_HELP_STRING([--enable-runautogen],[run autogen.sh])],,
 	[ enable_runautogen="no" ])
 AM_CONDITIONAL([BUILD_RUNAUTOGEN], [test x$enable_runautogen = xyes])
 
 override_rpm_debuginfo_option="yes"
 AC_ARG_ENABLE([rpm-debuginfo],
 	[AS_HELP_STRING([--enable-rpm-debuginfo],[build debuginfo packages])],,
 	[ enable_rpm_debuginfo="no", override_rpm_debuginfo_option="no" ])
 AM_CONDITIONAL([BUILD_RPM_DEBUGINFO], [test x$enable_rpm_debuginfo = xyes])
 AM_CONDITIONAL([OVERRIDE_RPM_DEBUGINFO], [test x$override_rpm_debuginfo_option = xyes])
 
 AC_ARG_ENABLE([libtap],
 	[AS_HELP_STRING([--enable-libtap],[libtap support])],,
 	[ enable_libtap="no" ])
 
 if test "x$enable_kronosnetd" = xyes; then
 	enable_libtap=yes
 fi
 AM_CONDITIONAL([BUILD_LIBTAP], [test x$enable_libtap = xyes])
 
 ## local helper functions
 # this function checks if CC support options passed as
 # args. Global CPPFLAGS are ignored during this test.
 cc_supports_flag() {
 	saveCPPFLAGS="$CPPFLAGS"
 	CPPFLAGS="$@"
 	if echo $CC | grep -q clang; then
 		CPPFLAGS="-Werror $CPPFLAGS"
 	fi
 	AC_MSG_CHECKING([whether $CC supports "$@"])
 	AC_PREPROC_IFELSE([AC_LANG_PROGRAM([])],
 			  [RC=0; AC_MSG_RESULT([yes])],
 			  [RC=1; AC_MSG_RESULT([no])])
 	CPPFLAGS="$saveCPPFLAGS"
 	return $RC
 }
 
 # Checks for C features
 AC_C_INLINE
 
 # Checks for libraries.
 AX_PTHREAD(,[AC_MSG_ERROR([POSIX threads support is required])])
 AC_CHECK_LIB([m], [ceil], [AC_SUBST([m_LIBS], [-lm])], [AC_MSG_ERROR([kronosnet requires m library])])
 saved_LIBS="$LIBS"
 LIBS=
 AC_SEARCH_LIBS([clock_gettime], [rt], , [AC_MSG_ERROR([clock_gettime not found])])
 AC_SUBST([rt_LIBS], [$LIBS])
 LIBS=
 AC_SEARCH_LIBS([dlopen], [dl dld], , [AC_MSG_ERROR([dlopen not found])])
 AC_SUBST([dl_LIBS], [$LIBS])
 LIBS="$saved_LIBS"
 
 # OS detection
 
 AC_MSG_CHECKING([for os in ${host_os}])
 case "$host_os" in
 	*linux*)
 		AC_DEFINE_UNQUOTED([KNET_LINUX], [1], [Compiling for Linux platform])
 		AC_MSG_RESULT([Linux])
 		;;
 	*bsd*)
 		AC_DEFINE_UNQUOTED([KNET_BSD], [1], [Compiling for BSD platform])
 		AC_MSG_RESULT([BSD])
 		if test "x$enable_libtap" = xyes; then
 			AC_MSG_ERROR([libtap is not currently supported on BSD platforms])
 		fi
 		;;
 	*)
 		AC_MSG_ERROR([Unsupported OS? hmmmm])
 		;;
 esac
 
 # Checks for header files.
 AC_CHECK_HEADERS([fcntl.h])
 AC_CHECK_HEADERS([stdlib.h])
 AC_CHECK_HEADERS([string.h])
 AC_CHECK_HEADERS([strings.h])
 AC_CHECK_HEADERS([sys/ioctl.h])
 AC_CHECK_HEADERS([syslog.h])
 AC_CHECK_HEADERS([unistd.h])
 AC_CHECK_HEADERS([netinet/in.h])
 AC_CHECK_HEADERS([sys/socket.h])
 AC_CHECK_HEADERS([arpa/inet.h])
 AC_CHECK_HEADERS([netdb.h])
 AC_CHECK_HEADERS([limits.h])
 AC_CHECK_HEADERS([stdint.h])
 AC_CHECK_HEADERS([sys/epoll.h])
 
 if test "x$enable_libknet_sctp" = xyes; then
 	AC_CHECK_HEADERS([netinet/sctp.h],, [AC_MSG_ERROR(["missing required SCTP headers"])])
 fi
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_INLINE
 AC_TYPE_SIZE_T
 AC_TYPE_PID_T
 AC_TYPE_SSIZE_T
 AC_TYPE_UINT8_T
 AC_TYPE_UINT16_T
 AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_INT32_T
 
 # Checks for library functions.
 AC_FUNC_ALLOCA
 AC_FUNC_FORK
 AC_FUNC_MALLOC
 AC_FUNC_REALLOC
 AC_CHECK_FUNCS([kevent])
 # if neither sys/epoll.h nor kevent are present, we should fail.
 
 if test "x$ac_cv_header_sys_epoll_h" = xno && test "x$ac_cv_func_kevent" = xno; then
 	AC_MSG_ERROR([Both epoll and kevent unavailable on this OS])
 fi
 
 if test "x$ac_cv_header_sys_epoll_h" = xyes && test "x$ac_cv_func_kevent" = xyes; then
 	AC_MSG_ERROR([Both epoll and kevent available on this OS, please contact the maintainers to fix the code])
 fi
 
 # required by doxyman to build man pages dynamically
 PKG_CHECK_MODULES([libqb], [libqb])
 PKG_CHECK_MODULES([libxml], [libxml-2.0])
 
 # checks (for kronosnetd)
 if test "x$enable_kronosnetd" = xyes; then
 	AC_CHECK_HEADERS([security/pam_appl.h],
 			 [AC_CHECK_LIB([pam], [pam_start],
 				       [AC_SUBST([pam_LIBS], [-lpam])],
 				       [AC_MSG_ERROR([Unable to find LinuxPAM devel files])])])
 
 	AC_CHECK_HEADERS([security/pam_misc.h],
 			 [AC_CHECK_LIB([pam_misc], [misc_conv],
 				       [AC_SUBST([pam_misc_LIBS], [-lpam_misc])],
 				       [AC_MSG_ERROR([Unable to find LinuxPAM MISC devel files])])])
 
 	AC_CHECK_LIB([qb], [qb_log_thread_priority_set],
 		     [have_qb_log_thread_priority_set="yes"],
 		     [have_qb_log_thread_priority_set="no"])
 	if test "x${have_qb_log_thread_priority_set}" = xyes; then
 		AC_DEFINE_UNQUOTED([HAVE_QB_LOG_THREAD_PRIORITY_SET], [1], [have qb_log_thread_priority_set])
 	fi
 fi
 
 # local options
 AC_ARG_ENABLE([debug],
 	[AS_HELP_STRING([--enable-debug],[enable debug build])])
 
 AC_ARG_WITH([initdefaultdir],
 	[AS_HELP_STRING([--with-initdefaultdir=DIR],[path to /etc/sysconfig or /etc/default dir])],
 	[ INITDEFAULTDIR="$withval" ],
 	[ INITDEFAULTDIR="$sysconfdir/default" ])
 
 AC_ARG_WITH([initddir],
 	[AS_HELP_STRING([--with-initddir=DIR],[path to init script directory])],
 	[ INITDDIR="$withval" ],
 	[ INITDDIR="$sysconfdir/init.d" ])
 
 AC_ARG_WITH([systemddir],
 	[AS_HELP_STRING([--with-systemddir=DIR],[path to systemd unit files directory])],
 	[ SYSTEMDDIR="$withval" ],
 	[ SYSTEMDDIR="$systemddir" ])
 
 AC_ARG_WITH([syslogfacility],
 	[AS_HELP_STRING([--with-syslogfacility=FACILITY],[default syslog facility])],
 	[ SYSLOGFACILITY="$withval" ],
 	[ SYSLOGFACILITY="LOG_DAEMON" ])
 
 AC_ARG_WITH([sysloglevel],
 	[AS_HELP_STRING([--with-sysloglevel=LEVEL],[default syslog level])],
 	[ SYSLOGLEVEL="$withval" ],
 	[ SYSLOGLEVEL="LOG_INFO" ])
 
 AC_ARG_WITH([defaultadmgroup],
 	[AS_HELP_STRING([--with-defaultadmgroup=GROUP],
 		[define PAM group. Users part of this group will be allowed to configure
 		 kronosnet. Others will only receive read-only rights.])],
 	[ DEFAULTADMGROUP="$withval" ],
 	[ DEFAULTADMGROUP="kronosnetadm" ])
 
 ## random vars
 LOGDIR=${localstatedir}/log/
 RUNDIR=${localstatedir}/run/
 DEFAULT_CONFIG_DIR=${sysconfdir}/kronosnet
 
 ## do subst
 
 AC_SUBST([DEFAULT_CONFIG_DIR])
 AC_SUBST([INITDEFAULTDIR])
 AC_SUBST([INITDDIR])
 AC_SUBST([SYSTEMDDIR])
 AC_SUBST([LOGDIR])
 AC_SUBST([DEFAULTADMGROUP])
 
 AC_DEFINE_UNQUOTED([DEFAULT_CONFIG_DIR],
 		   ["$(eval echo ${DEFAULT_CONFIG_DIR})"],
 		   [Default config directory])
 
 AC_DEFINE_UNQUOTED([DEFAULT_CONFIG_FILE],
 		   ["$(eval echo ${DEFAULT_CONFIG_DIR}/kronosnetd.conf)"],
 		   [Default config file])
 
 AC_DEFINE_UNQUOTED([LOGDIR],
 		   ["$(eval echo ${LOGDIR})"],
 		   [Default logging directory])
 
 AC_DEFINE_UNQUOTED([DEFAULT_LOG_FILE],
 		   ["$(eval echo ${LOGDIR}/kronosnetd.log)"],
 		   [Default log file])
 
 AC_DEFINE_UNQUOTED([RUNDIR],
 		   ["$(eval echo ${RUNDIR})"],
 		   [Default run directory])
 
 AC_DEFINE_UNQUOTED([SYSLOGFACILITY],
 		   [$(eval echo ${SYSLOGFACILITY})],
 		   [Default syslog facility])
 
 AC_DEFINE_UNQUOTED([SYSLOGLEVEL],
 		   [$(eval echo ${SYSLOGLEVEL})],
 		   [Default syslog level])
 
 AC_DEFINE_UNQUOTED([DEFAULTADMGROUP],
 		   ["$(eval echo ${DEFAULTADMGROUP})"],
 		   [Default admin group])
 
 # debug build stuff
 if test "x${enable_debug}" = xyes; then
 	AC_DEFINE_UNQUOTED([DEBUG], [1], [Compiling Debugging code])
 	OPT_CFLAGS="-O0"
 else
 	OPT_CFLAGS="-O3"
 fi
 
 # gdb flags
 if test "x${GCC}" = xyes; then
 	GDB_FLAGS="-ggdb3"
 else
 	GDB_FLAGS="-g"
 fi
 
 # extra warnings
 EXTRA_WARNINGS=""
 
 WARNLIST="
 	all
 	extra
 	unused
 	shadow
 	missing-prototypes
 	missing-declarations
 	suggest-attribute=noreturn
 	suggest-attribute=format
 	strict-prototypes
 	declaration-after-statement
 	pointer-arith
 	write-strings
 	cast-align
 	bad-function-cast
 	missing-format-attribute
 	float-equal
 	format=2
 	format-signedness
 	format-security
 	format-nonliteral
 	no-long-long
 	unsigned-char
 	gnu89-inline
 	no-strict-aliasing
 	error
 	address
 	cpp
 	overflow
 	parentheses
 	sequence-point
 	switch
 	shift-overflow=2
 	overlength-strings
 	retundent-decls
 	init-self
 	uninitialized
 	unused-but-set-variable
 	unused-function
 	unused-result
 	unused-value
 	unused-variable
 	unknown-pragmas
 	no-unused-parameter
 	"
 
 for j in $WARNLIST; do
 	if cc_supports_flag -W$j; then
 		EXTRA_WARNINGS="$EXTRA_WARNINGS -W$j";
 	fi
 done
 
 AC_SUBST([AM_CFLAGS],["$OPT_CFLAGS $GDB_FLAGS $EXTRA_WARNINGS"])
 
 AC_CONFIG_FILES([
 		Makefile
 		init/Makefile
 		libtap/Makefile
 		libtap/libtap.pc
 		kronosnetd/Makefile
 		kronosnetd/kronosnetd.logrotate
 		libknet/Makefile
 		libknet/libknet.pc
 		libknet/tests/Makefile
 		libknet/man/Doxyfile
 		libknet/man/Makefile
 		build-aux/Makefile
 		poc-code/Makefile
 		poc-code/iov-hash/Makefile
 		poc-code/access-list/Makefile
 		])
 
 AC_OUTPUT