dnl  OpenVPN -- An application to securely tunnel IP networks
 dnl             over a single UDP port, with support for SSL/TLS-based
 dnl             session authentication and key exchange,
 dnl             packet encryption, packet authentication, and
 dnl             packet compression.
 dnl

 dnl  Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net>

 dnl  Copyright (C) 2006-2012 Alon Bar-Lev <alon.barlev@gmail.com>

 dnl
 dnl  This program is free software; you can redistribute it and/or modify
 dnl  it under the terms of the GNU General Public License as published by
 dnl  the Free Software Foundation; either version 2 of the License, or
 dnl  (at your option) any later version.
 dnl
 dnl  This program is distributed in the hope that it will be useful,
 dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of
 dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 dnl  GNU General Public License for more details.
 dnl

 dnl  You should have received a copy of the GNU General Public License along
 dnl  with this program; if not, write to the Free Software Foundation, Inc.,
 dnl  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 
 dnl Process this file with autoconf to produce a configure script.
 

 AC_PREREQ(2.59)

 m4_include(version.m4)

 AC_INIT([PRODUCT_NAME], [PRODUCT_VERSION], [PRODUCT_BUGREPORT], [PRODUCT_TARNAME])
 m4_include(compat.m4)

 AC_DEFINE([OPENVPN_VERSION_RESOURCE], [PRODUCT_VERSION_RESOURCE], [Version in windows resource format])

 AC_SUBST([OPENVPN_VERSION_MAJOR], [PRODUCT_VERSION_MAJOR], [OpenVPN major version])
 AC_SUBST([OPENVPN_VERSION_MINOR], [PRODUCT_VERSION_MINOR], [OpenVPN minor version])
 AC_SUBST([OPENVPN_VERSION_PATCH], [PRODUCT_VERSION_PATCH], [OpenVPN patch level - may be a string or integer])

 AC_DEFINE([OPENVPN_VERSION_MAJOR], [PRODUCT_VERSION_MAJOR], [OpenVPN major version - integer])
 AC_DEFINE([OPENVPN_VERSION_MINOR], [PRODUCT_VERSION_MINOR], [OpenVPN minor version - integer])
 AC_DEFINE([OPENVPN_VERSION_PATCH], ["PRODUCT_VERSION_PATCH"], [OpenVPN patch level - may be a string or integer])

 AC_CONFIG_AUX_DIR([.])

 AC_CONFIG_HEADERS([config.h include/openvpn-plugin.h])

 AC_CONFIG_SRCDIR([src/openvpn/syshead.h])

 AC_CONFIG_MACRO_DIR([m4])

 
 dnl Initialize automake.  automake < 1.12 didn't have serial-tests and
 dnl gives an error if it sees this, but for automake >= 1.13
 dnl serial-tests is required so we have to include it.  Solution is to
 dnl test for the version of automake (by running an external command)
 dnl and provide it if necessary.  Note we have to do this entirely using
 dnl m4 macros since automake queries this macro by running
 dnl 'autoconf --trace ...'.
 m4_define([serial_tests], [
     m4_esyscmd([automake --version |
                 head -1 |
                 awk '{split ($NF,a,"."); if (a[1] == 1 && a[2] >= 12) { print "serial-tests" }}'
     ])
 ])
 AM_INIT_AUTOMAKE(foreign serial_tests) dnl NB: Do not [quote] this parameter.

 AC_CANONICAL_HOST
 AC_USE_SYSTEM_EXTENSIONS

 AC_ARG_ENABLE(
 	[lzo],

 	[AS_HELP_STRING([--disable-lzo], [disable LZO compression support @<:@default=yes@:>@])],

 	,

 	[enable_lzo="yes"]

 )
 

 AC_ARG_ENABLE(lz4,
 	[  --disable-lz4           Disable LZ4 compression support],
 	[enable_lz4="$enableval"],
 	[enable_lz4="yes"]
 )
 

 AC_ARG_ENABLE(comp-stub,
 	[  --enable-comp-stub      Don't compile compression support but still allow limited interoperability with compression-enabled peers],
 	[enable_comp_stub="$enableval"],
 	[enable_comp_stub="no"]

 )
 

 AC_ARG_ENABLE(

 	[ofb-cfb],

 	[AS_HELP_STRING([--disable-ofb-cfb], [disable support for OFB and CFB cipher modes @<:@default=yes@:>@])],

 	,
 	[enable_crypto_ofb_cfb="yes"]
 )
 
 AC_ARG_ENABLE(

 	[x509-alt-username],

 	[AS_HELP_STRING([--enable-x509-alt-username], [enable the --x509-username-field feature @<:@default=no@:>@])],

 	,
 	[enable_x509_alt_username="no"]

 )
 

 AC_ARG_ENABLE(
 	[server],

 	[AS_HELP_STRING([--disable-server], [disable server support only (but retain client support) @<:@default=yes@:>@])],

 	,
 	[enable_server="yes"]

 )
 

 AC_ARG_ENABLE(
 	[plugins],

 	[AS_HELP_STRING([--disable-plugins], [disable plug-in support @<:@default=yes@:>@])],

 	,
 	[enable_plugins="yes"]

 )
 

 AC_ARG_ENABLE(
 	[management],

 	[AS_HELP_STRING([--disable-management], [disable management server support @<:@default=yes@:>@])],

 	,
 	[enable_management="yes"]

 )
 

 AC_ARG_ENABLE(
 	[pkcs11],

 	[AS_HELP_STRING([--enable-pkcs11], [enable pkcs11 support @<:@default=no@:>@])],

 	,

 	[enable_pkcs11="no"]

 )
 

 AC_ARG_ENABLE(
 	[fragment],

 	[AS_HELP_STRING([--disable-fragment], [disable internal fragmentation support (--fragment) @<:@default=yes@:>@])],

 	,
 	[enable_fragment="yes"]

 )
 

 AC_ARG_ENABLE(
 	[multihome],

 	[AS_HELP_STRING([--disable-multihome], [disable multi-homed UDP server support (--multihome) @<:@default=yes@:>@])],

 	,
 	[enable_multihome="yes"]

 )
 

 AC_ARG_ENABLE(
 	[port-share],

 	[AS_HELP_STRING([--disable-port-share], [disable TCP server port-share support (--port-share) @<:@default=yes@:>@])],

 	,
 	[enable_port_share="yes"]

 )
 

 AC_ARG_ENABLE(
 	[debug],

 	[AS_HELP_STRING([--disable-debug], [disable debugging support (disable gremlin and verb 7+ messages) @<:@default=yes@:>@])],

 	,
 	[enable_debug="yes"]

 )
 

 AC_ARG_ENABLE(
 	[small],

 	[AS_HELP_STRING([--enable-small], [enable smaller executable size (disable OCC, usage message, and verb 4 parm list) @<:@default=no@:>@])],

 	,
 	[enable_small="no"]

 )
 

 AC_ARG_ENABLE(
 	[iproute2],

 	[AS_HELP_STRING([--enable-iproute2], [enable support for iproute2 @<:@default=no@:>@])],

 	,
 	[enable_iproute2="no"]

 )
 

 AC_ARG_ENABLE(
 	[def-auth],

 	[AS_HELP_STRING([--disable-def-auth], [disable deferred authentication @<:@default=yes@:>@])],

 	,
 	[enable_def_auth="yes"]

 )
 

 AC_ARG_ENABLE(
 	[pf],

 	[AS_HELP_STRING([--disable-pf], [disable internal packet filter @<:@default=yes@:>@])],

 	,
 	[enable_pf="yes"]

 )
 

 AC_ARG_ENABLE(

 	[plugin-auth-pam],

 	[AS_HELP_STRING([--disable-plugin-auth-pam], [disable auth-pam plugin @<:@default=platform specific@:>@])],

 	,

 	[
 		case "$host" in
 			*-*-openbsd*) enable_plugin_auth_pam="no";;
 			*-mingw*) enable_plugin_auth_pam="no";;
 			*) enable_plugin_auth_pam="yes";;
 		esac
 	]

 )
 
 AC_ARG_ENABLE(
 	[plugin-down-root],

 	[AS_HELP_STRING([--disable-plugin-down-root], [disable down-root plugin @<:@default=platform specific@:>@])],
 	,
 	[
 		case "$host" in
 			*-mingw*) enable_plugin_down_root="no";;
 			*) enable_plugin_down_root="yes";;
 		esac
 	]

 )
 
 AC_ARG_ENABLE(
 	[pam-dlopen],
 	[AS_HELP_STRING([--enable-pam-dlopen], [dlopen libpam @<:@default=no@:>@])],
 	,
 	[enable_pam_dlopen="no"]
 )
 
 AC_ARG_ENABLE(

 	[strict],

 	[AS_HELP_STRING([--enable-strict], [enable strict compiler warnings (debugging option) @<:@default=no@:>@])],

 	,
 	[enable_strict="no"]

 )
 

 AC_ARG_ENABLE(
 	[pedantic],

 	[AS_HELP_STRING([--enable-pedantic], [enable pedantic compiler warnings, will not generate a working executable (debugging option) @<:@default=no@:>@])],

 	,
 	[enable_pedantic="no"]

 )
 

 AC_ARG_ENABLE(

 	[werror],

 	[AS_HELP_STRING([--enable-werror], [promote compiler warnings to errors, will cause builds to fail if the compiler issues warnings (debugging option) @<:@default=no@:>@])],

 	,
 	[enable_werror="no"]
 )
 
 AC_ARG_ENABLE(

 	[strict-options],

 	[AS_HELP_STRING([--enable-strict-options], [enable strict options check between peers (debugging option) @<:@default=no@:>@])],

 	,
 	[enable_strict_options="no"]

 )
 

 AC_ARG_ENABLE(
 	[selinux],

 	[AS_HELP_STRING([--enable-selinux], [enable SELinux support @<:@default=no@:>@])],

 	,
 	[enable_selinux="no"]

 )
 

 AC_ARG_ENABLE(
 	[systemd],

 	[AS_HELP_STRING([--enable-systemd], [enable systemd suppport @<:@default=no@:>@])],

 	,
 	[enable_systemd="no"]

 )
 

 AC_ARG_ENABLE(
 	[async-push],

 	[AS_HELP_STRING([--enable-async-push], [enable async-push support for plugins providing deferred authentication @<:@default=no@:>@])],

 	,

 	[enable_async_push="no"]
 )
 

 AC_ARG_WITH(

 	[special-build],
 	[AS_HELP_STRING([--with-special-build=STRING], [specify special build string])],
 	[test -n "${withval}" && AC_DEFINE_UNQUOTED([CONFIGURE_SPECIAL_BUILD], ["${withval}"], [special build string])]
 )
 
 AC_ARG_WITH(

 	[mem-check],

 	[AS_HELP_STRING([--with-mem-check=TYPE], [build with debug memory checking, TYPE=no|dmalloc|valgrind|ssl @<:@default=no@:>@])],

 	[
 		case "${withval}" in
 			dmalloc|valgrind|ssl|no) ;;
 			*) AC_MSG_ERROR([bad value ${withval} for --mem-check]) ;;
 		esac
 	],
 	[with_mem_check="no"]

 )
 

 AC_ARG_WITH(

 	[crypto-library],

 	[AS_HELP_STRING([--with-crypto-library=library], [build with the given crypto library, TYPE=openssl|mbedtls @<:@default=openssl@:>@])],

 	[

 		case "${withval}" in
 			openssl|mbedtls) ;;

 			*) AC_MSG_ERROR([bad value ${withval} for --with-crypto-library]) ;;

 		esac
 	],

 	[with_crypto_library="openssl"]

 )
 

 AC_ARG_VAR([PLUGINDIR], [Path of plug-in directory @<:@default=LIBDIR/openvpn/plugins@:>@])
 if test -n "${PLUGINDIR}"; then
 	plugindir="${PLUGINDIR}"
 else
 	plugindir="\${libdir}/openvpn/plugins"
 fi

 AC_DEFINE_UNQUOTED([TARGET_ALIAS], ["${host}"], [A string representing our host])

 case "$host" in

 	*-*-linux*)
 		AC_DEFINE([TARGET_LINUX], [1], [Are we running on Linux?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["L"], [Target prefix])
 		;;
 	*-*-solaris*)
 		AC_DEFINE([TARGET_SOLARIS], [1], [Are we running on Solaris?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["S"], [Target prefix])

 		CPPFLAGS="$CPPFLAGS -D_XPG4_2"

 		;;
 	*-*-openbsd*)
 		AC_DEFINE([TARGET_OPENBSD], [1], [Are we running on OpenBSD?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["O"], [Target prefix])
 		;;
 	*-*-freebsd*)
 		AC_DEFINE([TARGET_FREEBSD], [1], [Are we running on FreeBSD?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["F"], [Target prefix])
 		;;
 	*-*-netbsd*)
 		AC_DEFINE([TARGET_NETBSD], [1], [Are we running NetBSD?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["N"], [Target prefix])
 		;;
 	*-*-darwin*)
 		AC_DEFINE([TARGET_DARWIN], [1], [Are we running on Mac OS X?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["M"], [Target prefix])

 		have_tap_header="yes"

 		dnl some Mac OS X tendering (we use vararg macros...)
 		CPPFLAGS="$CPPFLAGS -no-cpp-precomp"

 		ac_cv_type_struct_in_pktinfo=no

 		;;
 	*-mingw*)
 		AC_DEFINE([TARGET_WIN32], [1], [Are we running WIN32?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["W"], [Target prefix])

 		CPPFLAGS="${CPPFLAGS} -DWIN32_LEAN_AND_MEAN"

 		CPPFLAGS="${CPPFLAGS} -DNTDDI_VERSION=NTDDI_VISTA -D_WIN32_WINNT=_WIN32_WINNT_VISTA"

 		WIN32=yes
 		;;
 	*-*-dragonfly*)
 		AC_DEFINE([TARGET_DRAGONFLY], [1], [Are we running on DragonFlyBSD?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["D"], [Target prefix])
 		;;

 	*-aix*)
 		AC_DEFINE([TARGET_AIX], [1], [Are we running AIX?])
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["A"], [Target prefix])
 		ROUTE="/usr/sbin/route"
 		have_tap_header="yes"
 		ac_cv_header_net_if_h="no"	# exists, but breaks things
 		;;

 	*)
 		AC_DEFINE_UNQUOTED([TARGET_PREFIX], ["X"], [Target prefix])

 		have_tap_header="yes"

 		;;

 esac
 

 PKG_PROG_PKG_CONFIG
 AC_PROG_CPP

 AC_PROG_INSTALL

 AC_PROG_LN_S

 AC_PROG_SED

 AC_PROG_MAKE_SET

 AC_ARG_VAR([IFCONFIG], [full path to ipconfig utility])
 AC_ARG_VAR([ROUTE], [full path to route utility])
 AC_ARG_VAR([IPROUTE], [full path to ip utility])
 AC_ARG_VAR([NETSTAT], [path to netstat utility]) # tests
 AC_ARG_VAR([MAN2HTML], [path to man2html utility])

 AC_ARG_VAR([GIT], [path to git utility])

 AC_ARG_VAR([SYSTEMD_ASK_PASSWORD], [path to systemd-ask-password utility])

 AC_ARG_VAR([SYSTEMD_UNIT_DIR], [Path of systemd unit directory @<:@default=LIBDIR/systemd/system@:>@])

 AC_ARG_VAR([TMPFILES_DIR], [Path of tmpfiles directory @<:@default=LIBDIR/tmpfiles.d@:>@])

 AC_PATH_PROGS([IFCONFIG], [ifconfig],, [$PATH:/usr/local/sbin:/usr/sbin:/sbin])
 AC_PATH_PROGS([ROUTE], [route],, [$PATH:/usr/local/sbin:/usr/sbin:/sbin])
 AC_PATH_PROGS([IPROUTE], [ip],, [$PATH:/usr/local/sbin:/usr/sbin:/sbin])

 AC_PATH_PROGS([SYSTEMD_ASK_PASSWORD], [systemd-ask-password],, [$PATH:/usr/local/bin:/usr/bin:/bin])

 AC_CHECK_PROGS([NETSTAT], [netstat], [netstat], [$PATH:/usr/local/sbin:/usr/sbin:/sbin:/etc]) # tests
 AC_CHECK_PROGS([MAN2HTML], [man2html])

 AC_CHECK_PROGS([GIT], [git]) # optional

 AC_DEFINE_UNQUOTED([IFCONFIG_PATH], ["$IFCONFIG"], [Path to ifconfig tool])
 AC_DEFINE_UNQUOTED([IPROUTE_PATH], ["$IPROUTE"], [Path to iproute tool])
 AC_DEFINE_UNQUOTED([ROUTE_PATH], ["$ROUTE"], [Path to route tool])

 AC_DEFINE_UNQUOTED([SYSTEMD_ASK_PASSWORD_PATH], ["$SYSTEMD_ASK_PASSWORD"], [Path to systemd-ask-password tool])

 # Set -std=c99 unless user already specified a -std=
 case "${CFLAGS}" in
   *-std=*) ;;
   *)       CFLAGS="${CFLAGS} -std=c99" ;;
 esac
 

 #
 # Libtool
 #
 ifdef(
 	[LT_INIT],
 	[
 		LT_INIT([win32-dll])
 		LT_LANG([Windows Resource])
 	],
 	[
 		AC_LIBTOOL_WIN32_DLL
 		AC_LIBTOOL_RC
 		AC_PROG_LIBTOOL
 	]
 )
 

 AC_C_CONST
 AC_C_INLINE
 AC_C_VOLATILE
 AC_TYPE_OFF_T
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_TYPE_UID_T

 AC_TYPE_INT8_T
 AC_TYPE_INT16_T
 AC_TYPE_INT32_T
 AC_TYPE_INT64_T
 AC_TYPE_UINT8_T
 AC_TYPE_UINT16_T
 AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_SIGNAL

 AX_CPP_VARARG_MACRO_ISO
 AX_CPP_VARARG_MACRO_GCC

 AX_TYPE_SOCKLEN_T

 AX_EMPTY_ARRAY

 AC_CHECK_SIZEOF([unsigned int])
 AC_CHECK_SIZEOF([unsigned long])
 AC_CHECK_HEADERS([ \

 	stdio.h stdarg.h limits.h \

 	time.h errno.h fcntl.h io.h direct.h \
 	ctype.h sys/types.h sys/socket.h \

 	signal.h unistd.h dlfcn.h \

 	netinet/in.h netinet/in_systm.h \
 	netinet/tcp.h arpa/inet.h netdb.h \
 	windows.h winsock2.h ws2tcpip.h \

 	versionhelpers.h \

 ])

 AC_CHECK_HEADERS([ \

 	sys/time.h sys/ioctl.h sys/stat.h \

 	sys/mman.h sys/file.h sys/wait.h \

 	unistd.h signal.h libgen.h stropts.h \

 	syslog.h pwd.h grp.h \

 	sys/sockio.h sys/uio.h linux/sockios.h \

 	linux/types.h sys/poll.h sys/epoll.h err.h \
 ])

 SOCKET_INCLUDES="
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif

 #ifdef HAVE_NET_IF_H
 #include <net/if.h>
 #endif

 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
 #ifdef HAVE_WINDOWS_H
 #include <windows.h>
 #endif
 #ifdef HAVE_WINSOCK2_H
 #include <winsock2.h>
 #endif
 #ifdef HAVE_WS2TCPIP_H
 #include <ws2tcpip.h>
 #endif

 #ifdef HAVE_NETINET_IN_SYSTM_H
 #include <netinet/in_systm.h>
 #endif

 #ifdef HAVE_NETINET_IP_H
 #include <netinet/ip.h>
 #endif

 "

 AC_CHECK_HEADERS(

 	[net/if.h netinet/ip.h resolv.h sys/un.h net/if_utun.h sys/kern_control.h],

 	,
 	,

 	[[${SOCKET_INCLUDES}]]

 )
 
 AC_CHECK_TYPES(

 	[in_addr_t],

 	,
 	[AC_DEFINE([in_addr_t], [uint32_t], [Workaround missing in_addr_t])],
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPES(
 	[in_port_t],
 	,
 	[AC_DEFINE([in_port_t], [uint16_t], [Workaround missing in_port_t])],
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(
 	[struct iphdr],

 	[AC_DEFINE([HAVE_IPHDR], [1], [struct iphdr needed for IPv6 support])],

 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(
 	[struct sock_extended_err],

 	[AC_DEFINE([HAVE_SOCK_EXTENDED_ERR], [1], [struct sock_extended_err needed for extended socket error support])],

 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(
 	[struct msghdr],

 	[AC_DEFINE([HAVE_MSGHDR], [1], [struct msghdr needed for extended socket error support])],

 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(
 	[struct cmsghdr],

 	[AC_DEFINE([HAVE_CMSGHDR], [1], [struct cmsghdr needed for extended socket error support])],

 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(
 	[struct in_pktinfo],

 	[AC_DEFINE([HAVE_IN_PKTINFO], [1], [struct in_pktinfo needed for IP_PKTINFO support])],

 	,
 	[[${SOCKET_INCLUDES}]]
 )
 AC_CHECK_TYPE(

         [sa_family_t],
         [AC_DEFINE([HAVE_SA_FAMILY_T], [1], [sa_family_t, needed to hold AF_* info])],
         ,
         [[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_MEMBER(
 	[struct in_pktinfo.ipi_spec_dst],
 	[AC_DEFINE([HAVE_IPI_SPEC_DST], [1], [struct in_pktinfo.ipi_spec_dst needed for IP_PKTINFO support])],
 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_TYPE(

 	[struct sockaddr_in6],
 	,
 	[AC_MSG_ERROR([struct sockaddr_in6 not found, needed for ipv6 transport support.])],
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECK_DECLS(
 	[SO_MARK],
 	,
 	,
 	[[${SOCKET_INCLUDES}]]
 )

 AC_CHECKING([anonymous union support])
 AC_COMPILE_IFELSE(
 	[AC_LANG_PROGRAM(
 		[[
 			struct mystruct {
 			  union {
 			    int m1;
 			    char m2;
 			  };
 			};
 		]],
 		[[
 			struct mystruct s;
 			s.m1 = 1; s.m2 = 2;
 		]]
 	)],
 	[
 		AC_MSG_RESULT([yes])
 		AC_DEFINE([HAVE_ANONYMOUS_UNION_SUPPORT], [], [Compiler supports anonymous unions])
 	],
 	[AC_MSG_RESULT([no])]
 )

 saved_LDFLAGS="$LDFLAGS"
 LDFLAGS="$LDFLAGS -Wl,--wrap=exit"
 AC_MSG_CHECKING([linker supports --wrap])
 AC_LINK_IFELSE(
 	[AC_LANG_PROGRAM(
 		[[
 			void exit(int);
 			void __real_exit(int);
 			void __wrap_exit(int i) {
 				__real_exit(i);
 			}
 		]],
 		[[
 			exit(0);
 		]]
 	)],
 	[
 		AC_MSG_RESULT([yes])
 		have_ld_wrap_support=yes
 	],
 	[AC_MSG_RESULT([no])],
 )
 LDFLAGS="$saved_LDFLAGS"
 

 dnl We emulate signals in Windows
 AC_CHECK_DECLS(
 	[SIGHUP],

 	,

 	[AC_DEFINE([SIGHUP], [1], [SIGHUP replacement])],
 	[[
 		#ifdef HAVE_SIGNAL_H
 		#include <signal.h>
 		#endif
 	]]

 )

 AC_CHECK_DECLS(
 	[SIGINT],
 	,
 	[AC_DEFINE([SIGINT], [2], [SIGINT replacement])],
 	[[
 		#ifdef HAVE_SIGNAL_H
 		#include <signal.h>
 		#endif
 	]]
 )
 AC_CHECK_DECLS(
 	[SIGUSR1],
 	,
 	[AC_DEFINE([SIGUSR1], [10], [SIGUSR1 replacement])],
 	[[
 		#ifdef HAVE_SIGNAL_H
 		#include <signal.h>
 		#endif
 	]]
 )
 AC_CHECK_DECLS(
 	[SIGUSR2],
 	,
 	[AC_DEFINE([SIGUSR2], [12], [SIGUSR2 replacement])],
 	[[
 		#ifdef HAVE_SIGNAL_H
 		#include <signal.h>
 		#endif
 	]]
 )
 AC_CHECK_DECLS(
 	[SIGTERM],
 	,
 	[AC_DEFINE([SIGTERM], [15], [SIGTERM replacement])],
 	[[
 		#ifdef HAVE_SIGNAL_H
 		#include <signal.h>
 		#endif
 	]]
 )
 
 AC_FUNC_FORK
 

 AC_CHECK_FUNCS([ \
 	daemon chroot getpwnam setuid nice system getpid dup dup2 \

 	getpass syslog openlog mlockall getgrnam setgid \

 	setgroups stat flock readv writev time gettimeofday \

 	ctime memset vsnprintf strdup \

 	setsid chdir putenv getpeername unlink \
 	chsize ftruncate execve getpeereid umask basename dirname access \
 	epoll_create \
 ])

 
 AC_CHECK_LIB(
 	[dl],
 	[dlopen],
 	[DL_LIBS="-ldl"]
 )
 AC_SUBST([DL_LIBS])
 
 AC_CHECK_LIB(
 	[nsl],
 	[inet_ntoa],
 	[SOCKETS_LIBS="${SOCKETS_LIBS} -lnsl"]
 )
 AC_CHECK_LIB(
 	[socket],
 	[socket],
 	[SOCKETS_LIBS="${SOCKETS_LIBS} -lsocket"]
 )
 AC_CHECK_LIB(
 	[resolv],
 	[gethostbyname],
 	[SOCKETS_LIBS="${SOCKETS_LIBS} -lresolv"]
 )
 AC_SUBST([SOCKETS_LIBS])
 
 old_LIBS="${LIBS}"
 LIBS="${LIBS} ${SOCKETS_LIBS}"

 AC_CHECK_FUNCS([sendmsg recvmsg])

 # Windows use stdcall for winsock so we cannot auto detect these

 m4_define(
 	[SOCKET_FUNCS],
 [socket recv recvfrom send sendto listen dnl
 accept connect bind select gethostbyname inet_ntoa]dnl
 )
 m4_define(
 	[SOCKET_OPT_FUNCS],
 	[setsockopt getsockopt getsockname poll]dnl
 )

 if test "${WIN32}" = "yes"; then

 # normal autoconf function checking does not find inet_ntop/inet_pton
 # because they need to include the actual header file and link ws2_32.dll
 	LIBS="${LIBS} -lws2_32"
 	AC_MSG_CHECKING([for MinGW inet_ntop()/inet_pton()])
 	AC_LINK_IFELSE(
 		[AC_LANG_PROGRAM(
 			[[
 #include <ws2tcpip.h>
 			]],
 			[[
 int r = (int) inet_ntop (0, NULL, NULL, 0);
     r += inet_pton(AF_INET, NULL, NULL);
 return r;
 			]]
 		)],
 		[AC_MSG_RESULT([OK])
 		 AC_DEFINE([HAVE_INET_NTOP],[1],[MinGW inet_ntop])
 		 AC_DEFINE([HAVE_INET_PTON],[1],[MinGW inet_pton])
 		],
 		[AC_MSG_RESULT([not found])]
 	)

 	m4_foreach(
 		[F],
 		m4_split(SOCKET_FUNCS SOCKET_OPT_FUNCS),
 			m4_define([UF], [[m4_join([_], [HAVE], m4_toupper(F))]])
 			AC_DEFINE([UF], [1], [Win32 builtin])
 	)

 else

 	AC_CHECK_FUNCS([inet_ntop inet_pton])

 	AC_CHECK_FUNCS(
 		SOCKET_FUNCS,
 		,
 		[AC_MSG_ERROR([Required library function not found])]
 	)
 	AC_CHECK_FUNCS(SOCKET_OPT_FUNCS)
 fi

 LIBS="${old_LIBS}"

 # we assume res_init() always exist, but need to find out *where*...
 AC_SEARCH_LIBS(__res_init, resolv bind, ,
     AC_SEARCH_LIBS(res_9_init, resolv bind, ,
 	AC_SEARCH_LIBS(res_init, resolv bind, , )))
 

 AC_ARG_VAR([TAP_CFLAGS], [C compiler flags for tap])
 old_CFLAGS="${CFLAGS}"
 CFLAGS="${CFLAGS} ${TAP_CFLAGS}"
 AC_CHECK_HEADERS(
 	[ \
 		net/if_tun.h net/tun/if_tun.h \
 		linux/if_tun.h \
 		tap-windows.h \
 	],
 	[have_tap_header="yes"]
 )

 AC_CHECK_DECLS(
 	[TUNSETPERSIST],
 	[AC_DEFINE([ENABLE_FEATURE_TUN_PERSIST], [1], [We have persist tun capability])],
 	,
 	[[
 		#ifdef HAVE_LINUX_IF_TUN_H
 		#include <linux/if_tun.h>
 		#endif
 	]]
 )

 CFLAGS="${old_CFLAGS}"
 test "${have_tap_header}" = "yes" || AC_MSG_ERROR([no tap header could be found])
 

 AC_CHECK_LIB(
 	[selinux],
 	[setcon],
 	[SELINUX_LIBS="-lselinux"]
 )
 AC_SUBST([SELINUX_LIBS])
 

 AC_ARG_VAR([LIBPAM_CFLAGS], [C compiler flags for libpam])
 AC_ARG_VAR([LIBPAM_LIBS], [linker flags for libpam])
 if test -z "${LIBPAM_LIBS}"; then
 	AC_CHECK_LIB(
 		[pam],
 		[pam_start],
 		[LIBPAM_LIBS="-lpam"]
 	)
 fi
 

 case "${with_mem_check}" in
 	valgrind)

 		AC_CHECK_HEADERS(

 			[valgrind/memcheck.h],
 			[
 				CFLAGS="${CFLAGS} -g -fno-inline"
 				AC_DEFINE(
 					[USE_VALGRIND],
 					[1],
 					[Use valgrind memory debugging library]
 				)
 			],
 			[AC_MSG_ERROR([valgrind headers not found.])]
 		)
 		;;
 	dmalloc)

 		AC_CHECK_HEADERS(

 			[dmalloc.h],
 			[AC_CHECK_LIB(
 				[dmalloc],
 				[malloc],
 				[

 					LIBS="${LIBS} -ldmalloc"

 					AC_DEFINE(
 						[DMALLOC],
 						[1],
 						[Use dmalloc memory debugging library]
 					)
 				],
 				[AC_MSG_ERROR([dmalloc library not found.])]
 			)],
 			[AC_MSG_ERROR([dmalloc headers not found.])]
 		)
 		;;
 	ssl)
 		AC_CHECK_LIB(
 			[ssl],
 			[CRYPTO_mem_ctrl],
 			[
 				AC_DEFINE(
 					[CRYPTO_MDEBUG],
 					[1],
 					[Use memory debugging function in OpenSSL]
 				)
 				AC_MSG_NOTICE([NOTE: OpenSSL library must be compiled with CRYPTO_MDEBUG])
 			],
 			[AC_MSG_ERROR([Memory Debugging function in OpenSSL library not found.])]
 		)
 		;;
 esac

 PKG_CHECK_MODULES(

 	[PKCS11_HELPER],

 	[libpkcs11-helper-1 >= 1.11],

 	[have_pkcs11_helper="yes"],
 	[]
 )
 

 if test "${with_crypto_library}" = "openssl"; then

 	AC_ARG_VAR([OPENSSL_CFLAGS], [C compiler flags for OpenSSL])
 	AC_ARG_VAR([OPENSSL_LIBS], [linker flags for OpenSSL])
 
 	if test -z "${OPENSSL_CFLAGS}" -a -z "${OPENSSL_LIBS}"; then
 		# if the user did not explicitly specify flags, try to autodetect
 		PKG_CHECK_MODULES(
 			[OPENSSL],

 			[openssl >= 1.0.1],
 			[have_openssl="yes"],
 			[] # If this fails, we will do another test next

 		)
 		OPENSSL_LIBS=${OPENSSL_LIBS:--lssl -lcrypto}
 	fi

 
 	saved_CFLAGS="${CFLAGS}"
 	saved_LIBS="${LIBS}"

 	CFLAGS="${CFLAGS} ${OPENSSL_CFLAGS}"
 	LIBS="${LIBS} ${OPENSSL_LIBS}"
 

 	# If pkgconfig check failed or OPENSSL_CFLAGS/OPENSSL_LIBS env vars
 	# are used, check the version directly in the OpenSSL include file
 	if test "${have_openssl}" != "yes"; then
 		AC_MSG_CHECKING([additionally if OpenSSL is available and version >= 1.0.1])
 		AC_COMPILE_IFELSE(
 			[AC_LANG_PROGRAM(
 				[[
 #include <openssl/opensslv.h>
 				]],
 				[[
 /*	     Version encoding: MNNFFPPS - see opensslv.h for details */
 #if OPENSSL_VERSION_NUMBER < 0x10001000L
 #error OpenSSL too old
 #endif
 				]]
 			)],
 			[AC_MSG_RESULT([ok])],
 			[AC_MSG_ERROR([OpenSSL version too old])]
 		)
 	fi
 

 	AC_CHECK_FUNCS([SSL_CTX_new EVP_CIPHER_CTX_set_key_length],
 				   ,
 				   [AC_MSG_ERROR([openssl check failed])]
 	)
 

 	have_openssl_engine="yes"
 	AC_CHECK_FUNCS(
 		[ \
 			ENGINE_load_builtin_engines \
 			ENGINE_register_all_complete \
 			ENGINE_cleanup \
 		],
 		,
 		[have_openssl_engine="no"; break]
 	)

 	if test "${have_openssl_engine}" = "no"; then
 		AC_CHECK_DECL( [ENGINE_cleanup], [have_openssl_engine="yes"],,
 			[[
 				#include <openssl/engine.h>
 			]]
 		)
 	fi

 	if test "${have_openssl_engine}" = "yes"; then
 		AC_DEFINE([HAVE_OPENSSL_ENGINE], [1], [OpenSSL engine support available])
 	fi

 	have_crypto_aead_modes="yes"
 	AC_CHECK_FUNCS(
 		[EVP_aes_256_gcm],
 		,
 		[have_crypto_aead_modes="no"; break]
 	)
 

 	AC_CHECK_FUNCS(
 		[ \

 			HMAC_CTX_new \
 			HMAC_CTX_free \
 			HMAC_CTX_reset \

 			EVP_MD_CTX_new \
 			EVP_MD_CTX_free \
 			EVP_MD_CTX_reset \

 			OpenSSL_version \

 			SSL_CTX_get_default_passwd_cb \
 			SSL_CTX_get_default_passwd_cb_userdata \

 			SSL_CTX_set_security_level \

 			X509_get0_pubkey \

 			X509_STORE_get0_objects \

 			X509_OBJECT_free \
 			X509_OBJECT_get_type \

 			EVP_PKEY_id \
 			EVP_PKEY_get0_RSA \
 			EVP_PKEY_get0_DSA \

 			EVP_PKEY_get0_EC_KEY \

 			RSA_set_flags \
 			RSA_bits \
 			RSA_get0_key \
 			RSA_set0_key \

 			DSA_get0_pqg \
 			DSA_bits \

 			RSA_meth_new \
 			RSA_meth_free \
 			RSA_meth_set_pub_enc \
 			RSA_meth_set_pub_dec \
 			RSA_meth_set_priv_enc \
 			RSA_meth_set_priv_dec \
 			RSA_meth_set_init \
 			RSA_meth_set_finish \
 			RSA_meth_set0_app_data \

 			RSA_meth_get0_app_data \

 			EC_GROUP_order_bits

 		]

 	)
 

 	CFLAGS="${saved_CFLAGS}"
 	LIBS="${saved_LIBS}"
 

 	AC_DEFINE([ENABLE_CRYPTO_OPENSSL], [1], [Use OpenSSL library])
 	CRYPTO_CFLAGS="${OPENSSL_CFLAGS}"
 	CRYPTO_LIBS="${OPENSSL_LIBS}"

 elif test "${with_crypto_library}" = "mbedtls"; then

 	AC_ARG_VAR([MBEDTLS_CFLAGS], [C compiler flags for mbedtls])
 	AC_ARG_VAR([MBEDTLS_LIBS], [linker flags for mbedtls])

 	saved_CFLAGS="${CFLAGS}"
 	saved_LIBS="${LIBS}"
 

 	if test -z "${MBEDTLS_CFLAGS}" -a -z "${MBEDTLS_LIBS}"; then

 		# if the user did not explicitly specify flags, try to autodetect

 		LIBS="${LIBS} -lmbedtls -lmbedx509 -lmbedcrypto"

 		AC_CHECK_LIB(
 			[mbedtls],
 			[mbedtls_ssl_init],

 			[MBEDTLS_LIBS="-lmbedtls -lmbedx509 -lmbedcrypto"],

 			[AC_MSG_ERROR([Could not find mbed TLS.])],

 			[${PKCS11_HELPER_LIBS}]
 		)
 	fi

 	CFLAGS="${MBEDTLS_CFLAGS} ${PKCS11_HELPER_CFLAGS} ${CFLAGS}"
 	LIBS="${MBEDTLS_LIBS} ${PKCS11_HELPER_LIBS} ${LIBS}"

 	AC_MSG_CHECKING([mbedtls version])

 	AC_COMPILE_IFELSE(
 		[AC_LANG_PROGRAM(
 			[[

 #include <mbedtls/version.h>

 			]],
 			[[

 #if MBEDTLS_VERSION_NUMBER < 0x02000000 || MBEDTLS_VERSION_NUMBER >= 0x03000000

 #error invalid version

 #endif
 			]]
 		)],
 		[AC_MSG_RESULT([ok])],

 		[AC_MSG_ERROR([mbed TLS 2.y.z required])]

 	)

 	mbedtls_with_pkcs11="no"

 	AC_COMPILE_IFELSE(
 		[AC_LANG_PROGRAM(
 			[[

 #include <mbedtls/config.h>

 			]],
 			[[

 #ifndef MBEDTLS_PKCS11_C

 #error pkcs11 wrapper missing
 #endif
 			]]
 		)],

 		mbedtls_with_pkcs11="yes")

 	AC_MSG_CHECKING([mbedtls pkcs11 support])

 	if test "${enable_pkcs11}" = "yes"; then

 		if test "${mbedtls_with_pkcs11}" = "yes"; then

 			AC_MSG_RESULT([ok])
 		else

 			AC_MSG_ERROR([mbedtls has no pkcs11 wrapper compiled in])

 		fi
 	else

 		if test "${mbedtls_with_pkcs11}" != "yes"; then

 			AC_MSG_RESULT([ok])
 		else

 			AC_MSG_ERROR([mbed TLS compiled with PKCS11, while OpenVPN is not])

 		fi
 	fi

 
 	have_crypto_aead_modes="yes"
 	AC_CHECK_FUNCS(
 		[ \

 			mbedtls_cipher_write_tag \
 			mbedtls_cipher_check_tag \

 		],
 		,
 		[have_crypto_aead_modes="no"; break]
 	)
 

 	CFLAGS="${saved_CFLAGS}"
 	LIBS="${saved_LIBS}"

 	AC_DEFINE([ENABLE_CRYPTO_MBEDTLS], [1], [Use mbed TLS library])
 	CRYPTO_CFLAGS="${MBEDTLS_CFLAGS}"
 	CRYPTO_LIBS="${MBEDTLS_LIBS}"

 else

 	AC_MSG_ERROR([Invalid crypto library: ${with_crypto_library}])

 fi
 

 AC_ARG_VAR([LZO_CFLAGS], [C compiler flags for lzo])
 AC_ARG_VAR([LZO_LIBS], [linker flags for lzo])
 have_lzo="yes"
 if test -z "${LZO_LIBS}"; then
 	AC_CHECK_LIB(
 		[lzo2],
 		[lzo1x_1_15_compress],
 		[LZO_LIBS="-llzo2"],
 		[AC_CHECK_LIB(
 			[lzo],
 			[lzo1x_1_15_compress],
 			[LZO_LIBS="-llzo"],
 			[have_lzo="no"]
 		)]
 	)
 fi
 if test "${have_lzo}" = "yes"; then
 	saved_CFLAGS="${CFLAGS}"
 	CFLAGS="${CFLAGS} ${LZO_CFLAGS}"
 	AC_CHECK_HEADERS(
 		[lzo/lzoutil.h],
 		,
 		[AC_CHECK_HEADERS(
 			[lzoutil.h],
 			,
 			[AC_MSG_ERROR([lzoutil.h is missing])]
 		)]
 	)
 	AC_CHECK_HEADERS(
 		[lzo/lzo1x.h],
 		,
 		[AC_CHECK_HEADERS(
 			[lzo1x.h],
 			,
 			[AC_MSG_ERROR([lzo1x.h is missing])]
 		)]
 	)
 	CFLAGS="${saved_CFLAGS}"

 fi
 

 dnl

 dnl check for LZ4 library
 dnl
 
 AC_ARG_VAR([LZ4_CFLAGS], [C compiler flags for lz4])
 AC_ARG_VAR([LZ4_LIBS], [linker flags for lz4])
 if test "$enable_lz4" = "yes" && test "$enable_comp_stub" = "no"; then

     if test -z "${LZ4_CFLAGS}" -a -z "${LZ4_LIBS}"; then
 	# if the user did not explicitly specify flags, try to autodetect
 	PKG_CHECK_MODULES([LZ4],

 			  [liblz4 >= 1.7.1 liblz4 < 100],

 			  [have_lz4="yes"],

 			  [LZ4_LIBS="-llz4"] # If this fails, we will do another test next.
 					     # We also add set LZ4_LIBS otherwise the
 					     # linker will not know about the lz4 library

 	)
     fi
 
     saved_CFLAGS="${CFLAGS}"
     saved_LIBS="${LIBS}"
     CFLAGS="${CFLAGS} ${LZ4_CFLAGS}"
     LIBS="${LIBS} ${LZ4_LIBS}"
 
     # If pkgconfig check failed or LZ4_CFLAGS/LZ4_LIBS env vars
     # are used, check the version directly in the LZ4 include file
     if test "${have_lz4}" != "yes"; then
 	AC_CHECK_HEADERS([lz4.h],
 			 [have_lz4h="yes"],
 			 [])
 
 	if test "${have_lz4h}" = "yes" ; then
 	    AC_MSG_CHECKING([additionally if system LZ4 version >= 1.7.1])
 	    AC_COMPILE_IFELSE(
 		[AC_LANG_PROGRAM([[
 #include <lz4.h>
 				 ]],
 				 [[
 /* Version encoding: MMNNPP (Major miNor Patch) - see lz4.h for details */
 #if LZ4_VERSION_NUMBER < 10701L
 #error LZ4 is too old
 #endif
 				 ]]
 				)],
 		[
 		    AC_MSG_RESULT([ok])
 		    have_lz4="yes"
 		],
 		[AC_MSG_RESULT([system LZ4 library is too old])]
 	    )
 	fi
     fi

     # Double check we have a few needed functions
     if test "${have_lz4}" = "yes" ; then

 	AC_CHECK_LIB([lz4],

 		     [LZ4_compress_default],
 		     [],
 		     [have_lz4="no"])
 	AC_CHECK_LIB([lz4],
 		     [LZ4_decompress_safe],
 		     [],

 		     [have_lz4="no"])

     fi
 

     if test "${have_lz4}" != "yes" ; then

 	AC_MSG_RESULT([		usable LZ4 library or header not found, using version in src/compat/compat-lz4.*])

 	AC_DEFINE([NEED_COMPAT_LZ4], [1], [use copy of LZ4 source in compat/])
 	LZ4_LIBS=""

     fi
     OPTIONAL_LZ4_CFLAGS="${LZ4_CFLAGS}"
     OPTIONAL_LZ4_LIBS="${LZ4_LIBS}"

     AC_DEFINE(ENABLE_LZ4, [1], [Enable LZ4 compression library])

     CFLAGS="${saved_CFLAGS}"

     LIBS="${saved_LIBS}"

 fi
 
 

 dnl
 dnl Check for systemd
 dnl

 AM_CONDITIONAL([ENABLE_SYSTEMD], [test "${enable_systemd}" = "yes"])

 if test "$enable_systemd" = "yes" ; then
     PKG_CHECK_MODULES([libsystemd], [systemd libsystemd],
                       [],
                       [PKG_CHECK_MODULES([libsystemd], [libsystemd-daemon])]
                       )

 
     PKG_CHECK_EXISTS( [libsystemd > 216],
                      [AC_DEFINE([SYSTEMD_NEWER_THAN_216], [1],
                            [systemd is newer than v216])]
                     )
 

     AC_CHECK_HEADERS(systemd/sd-daemon.h,
        ,
        [
 	   AC_MSG_ERROR([systemd development headers not found.])
        ])
 
     saved_LIBS="${LIBS}"
     LIBS="${LIBS} ${libsystemd_LIBS}"
     AC_CHECK_FUNCS([sd_booted], [], [AC_MSG_ERROR([systemd library is missing sd_booted()])])
     OPTIONAL_SYSTEMD_LIBS="${libsystemd_LIBS}"
     AC_DEFINE(ENABLE_SYSTEMD, 1, [Enable systemd integration])
     LIBS="${saved_LIBS}"

 
     if test -n "${SYSTEMD_UNIT_DIR}"; then
         systemdunitdir="${SYSTEMD_UNIT_DIR}"
     else
         systemdunitdir="\${libdir}/systemd/system"
     fi

 
     if test -n "${TMPFILES_DIR}"; then
         tmpfilesdir="${TMPFILES_DIR}"
     else
         tmpfilesdir="\${libdir}/tmpfiles.d"
     fi

 fi

 AC_MSG_CHECKING([git checkout])
 GIT_CHECKOUT="no"
 if test -n "${GIT}" -a -d "${srcdir}/.git"; then
 	AC_DEFINE([HAVE_CONFIG_VERSION_H], [1], [extra version available in config-version.h])
 	GIT_CHECKOUT="yes"
 fi
 AC_MSG_RESULT([${GIT_CHECKOUT}])
 

 if test -n "${SP_PLATFORM_WINDOWS}"; then
 	AC_DEFINE_UNQUOTED([PATH_SEPARATOR], ['\\\\'], [Path separator]) #"
 	AC_DEFINE_UNQUOTED([PATH_SEPARATOR_STR], ["\\\\"], [Path separator]) #"
 else
 	AC_DEFINE_UNQUOTED([PATH_SEPARATOR], ['/'], [Path separator])
 	AC_DEFINE_UNQUOTED([PATH_SEPARATOR_STR], ["/"], [Path separator])
 fi
 
 dnl enable --x509-username-field feature if requested
 if test "${enable_x509_alt_username}" = "yes"; then

 	if test "${with_crypto_library}" = "mbedtls" ; then
 		AC_MSG_ERROR([mbed TLS does not support the --x509-username-field feature])

 	fi
 
 	AC_DEFINE([ENABLE_X509ALTUSERNAME], [1], [Enable --x509-username-field feature])
 fi
 
 test "${ac_cv_header_sys_uio_h}" = "yes" && AC_DEFINE([HAVE_IOVEC], [1], [struct iovec needed for IPv6 support])
 test "${enable_server}" = "no" && AC_DEFINE([ENABLE_CLIENT_ONLY], [1], [Enable client capability only])
 test "${enable_management}" = "yes" && AC_DEFINE([ENABLE_MANAGEMENT], [1], [Enable management server capability])
 test "${enable_multihome}" = "yes" && AC_DEFINE([ENABLE_MULTIHOME], [1], [Enable multi-homed UDP server capability])
 test "${enable_debug}" = "yes" && AC_DEFINE([ENABLE_DEBUG], [1], [Enable debugging support])
 test "${enable_small}" = "yes" && AC_DEFINE([ENABLE_SMALL], [1], [Enable smaller executable size])
 test "${enable_fragment}" = "yes" && AC_DEFINE([ENABLE_FRAGMENT], [1], [Enable internal fragmentation support])
 test "${enable_port_share}" = "yes" && AC_DEFINE([ENABLE_PORT_SHARE], [1], [Enable TCP Server port sharing])
 test "${enable_def_auth}" = "yes" && AC_DEFINE([ENABLE_DEF_AUTH], [1], [Enable deferred authentication])
 test "${enable_pf}" = "yes" && AC_DEFINE([ENABLE_PF], [1], [Enable internal packet filter])
 test "${enable_strict_options}" = "yes" && AC_DEFINE([ENABLE_STRICT_OPTIONS_CHECK], [1], [Enable strict options check between peers])

 test "${enable_crypto_ofb_cfb}" = "yes" && AC_DEFINE([ENABLE_OFB_CFB_MODE], [1], [Enable OFB and CFB cipher modes])
 test "${have_crypto_aead_modes}" = "yes" && AC_DEFINE([HAVE_AEAD_CIPHER_MODES], [1], [Use crypto library])
 OPTIONAL_CRYPTO_CFLAGS="${OPTIONAL_CRYPTO_CFLAGS} ${CRYPTO_CFLAGS}"
 OPTIONAL_CRYPTO_LIBS="${OPTIONAL_CRYPTO_LIBS} ${CRYPTO_LIBS}"

 if test "${enable_plugins}" = "yes"; then
 	OPTIONAL_DL_LIBS="${DL_LIBS}"

 	AC_DEFINE([ENABLE_PLUGIN], [1], [Enable plug-in support])

 else
 	enable_plugin_auth_pam="no"
 	enable_plugin_down_root="no"

 fi
 

 if test "${enable_iproute2}" = "yes"; then
 	test -z "${IPROUTE}" && AC_MSG_ERROR([ip utility is required but missing])
 	AC_DEFINE([ENABLE_IPROUTE], [1], [enable iproute2 support])
 else
 	if test "${WIN32}" != "yes"; then
 		test -z "${ROUTE}" && AC_MSG_ERROR([route utility is required but missing])
 		test -z "${IFCONFIG}" && AC_MSG_ERROR([ifconfig utility is required but missing])
 	fi
 fi

 if test "${enable_selinux}" = "yes"; then
 	test -z "${SELINUX_LIBS}" && AC_MSG_ERROR([libselinux required but missing])
 	OPTIONAL_SELINUX_LIBS="${SELINUX_LIBS}"
 	AC_DEFINE([ENABLE_SELINUX], [1], [SELinux support])
 fi
 

 if test "${enable_lzo}" = "yes"; then
 	test "${have_lzo}" != "yes" && AC_MSG_ERROR([lzo enabled but missing])
 	OPTIONAL_LZO_CFLAGS="${LZO_CFLAGS}"
 	OPTIONAL_LZO_LIBS="${LZO_LIBS}"
 	AC_DEFINE([ENABLE_LZO], [1], [Enable LZO compression library])
 fi

 if test "${enable_comp_stub}" = "yes"; then
 	test "${enable_lzo}" = "yes" && AC_MSG_ERROR([Cannot have both comp stub and lzo enabled (use --disable-lzo)])

 	test "${enable_lz4}" = "yes" && AC_MSG_ERROR([Cannot have both comp stub and LZ4 enabled (use --disable-lz4)])

 	AC_DEFINE([ENABLE_COMP_STUB], [1], [Enable compression stub capability])

 fi
 

 if test "${enable_pkcs11}" = "yes"; then
 	test "${have_pkcs11_helper}" != "yes" && AC_MSG_ERROR([PKCS11 enabled but libpkcs11-helper is missing])
 	OPTIONAL_PKCS11_HELPER_CFLAGS="${PKCS11_HELPER_CFLAGS}"
 	OPTIONAL_PKCS11_HELPER_LIBS="${PKCS11_HELPER_LIBS}"
 	AC_DEFINE([ENABLE_PKCS11], [1], [Enable PKCS11])

 	PKG_CHECK_MODULES(
 		[P11KIT],
 		[p11-kit-1],
 		[proxy_module="`$PKG_CONFIG --variable=proxy_module p11-kit-1`"
 		 AC_DEFINE_UNQUOTED([DEFAULT_PKCS11_MODULE], "${proxy_module}", [p11-kit proxy])],
 		[]
 	)

 fi
 

 AC_DEFUN([ACL_CHECK_ADD_COMPILE_FLAGS], [
     old_cflags="$CFLAGS"
     CFLAGS="$1 $CFLAGS"
     AC_MSG_CHECKING([whether the compiler acceppts $1])
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [AC_MSG_RESULT([yes])],
         [AC_MSG_RESULT([no]); CFLAGS="$old_cflags"])]

 )

 
 ACL_CHECK_ADD_COMPILE_FLAGS([-Wno-unused-function])
 ACL_CHECK_ADD_COMPILE_FLAGS([-Wno-unused-parameter])
 ACL_CHECK_ADD_COMPILE_FLAGS([-Wall])

 if test "${enable_pedantic}" = "yes"; then
 	enable_strict="yes"

 	CFLAGS="${CFLAGS} -pedantic"

 	AC_DEFINE([PEDANTIC], [1], [Enable pedantic mode])

 fi
 if test "${enable_strict}" = "yes"; then

 	CFLAGS="${CFLAGS} -Wsign-compare -Wuninitialized"

 fi

 if test "${enable_werror}" = "yes"; then
 	CFLAGS="${CFLAGS} -Werror"
 fi

 if test "${WIN32}" = "yes"; then
 	test -z "${MAN2HTML}" && AC_MSG_ERROR([man2html is required for win32])
 fi
 

 if test "${enable_plugin_auth_pam}" = "yes"; then
 	PLUGIN_AUTH_PAM_CFLAGS="${LIBPAM_CFLAGS}"
 	if test "${enable_pam_dlopen}" = "yes"; then
 		AC_DEFINE([USE_PAM_DLOPEN], [1], [dlopen libpam])
 		PLUGIN_AUTH_PAM_LIBS="${DL_LIBS}"
 	else
 		test -z "${LIBPAM_LIBS}" && AC_MSG_ERROR([libpam required but missing])
 		PLUGIN_AUTH_PAM_LIBS="${LIBPAM_LIBS}"
 	fi
 fi
 

 if test "${enable_async_push}" = "yes"; then
 	AC_CHECK_HEADERS(
 		[sys/inotify.h],
 		AC_DEFINE([ENABLE_ASYNC_PUSH], [1], [Enable async push]),
 		AC_MSG_ERROR([inotify.h not found.])
 	)
 fi
 

 CONFIGURE_DEFINES="`set | grep '^enable_.*=' ; set | grep '^with_.*='`"
 AC_DEFINE_UNQUOTED([CONFIGURE_DEFINES], ["`echo ${CONFIGURE_DEFINES}`"], [Configuration settings])
 

 TAP_WIN_COMPONENT_ID="PRODUCT_TAP_WIN_COMPONENT_ID"
 TAP_WIN_MIN_MAJOR="PRODUCT_TAP_WIN_MIN_MAJOR"
 TAP_WIN_MIN_MINOR="PRODUCT_TAP_WIN_MIN_MINOR"
 AC_DEFINE_UNQUOTED([TAP_WIN_COMPONENT_ID], ["${TAP_WIN_COMPONENT_ID}"], [The tap-windows id])
 AC_DEFINE_UNQUOTED([TAP_WIN_MIN_MAJOR], [${TAP_WIN_MIN_MAJOR}], [The tap-windows version number is required for OpenVPN])
 AC_DEFINE_UNQUOTED([TAP_WIN_MIN_MINOR], [${TAP_WIN_MIN_MINOR}], [The tap-windows version number is required for OpenVPN])
 AC_SUBST([TAP_WIN_COMPONENT_ID])
 AC_SUBST([TAP_WIN_MIN_MAJOR])
 AC_SUBST([TAP_WIN_MIN_MINOR])

 AC_SUBST([OPTIONAL_DL_LIBS])

 AC_SUBST([OPTIONAL_SELINUX_LIBS])

 AC_SUBST([OPTIONAL_CRYPTO_CFLAGS])
 AC_SUBST([OPTIONAL_CRYPTO_LIBS])

 AC_SUBST([OPTIONAL_LZO_CFLAGS])
 AC_SUBST([OPTIONAL_LZO_LIBS])

 AC_SUBST([OPTIONAL_LZ4_CFLAGS])
 AC_SUBST([OPTIONAL_LZ4_LIBS])

 AC_SUBST([OPTIONAL_SYSTEMD_LIBS])

 AC_SUBST([OPTIONAL_PKCS11_HELPER_CFLAGS])
 AC_SUBST([OPTIONAL_PKCS11_HELPER_LIBS])

 AC_SUBST([PLUGIN_AUTH_PAM_CFLAGS])
 AC_SUBST([PLUGIN_AUTH_PAM_LIBS])
 

 AM_CONDITIONAL([WIN32], [test "${WIN32}" = "yes"])

 AM_CONDITIONAL([GIT_CHECKOUT], [test "${GIT_CHECKOUT}" = "yes"])

 AM_CONDITIONAL([ENABLE_PLUGIN_AUTH_PAM], [test "${enable_plugin_auth_pam}" = "yes"])
 AM_CONDITIONAL([ENABLE_PLUGIN_DOWN_ROOT], [test "${enable_plugin_down_root}" = "yes"])

 AM_CONDITIONAL([HAVE_LD_WRAP_SUPPORT], [test "${have_ld_wrap_support}" = "yes"])

 sampledir="\$(docdir)/sample"

 AC_SUBST([plugindir])

 AC_SUBST([sampledir])
 

 AC_SUBST([systemdunitdir])

 AC_SUBST([tmpfilesdir])

 VENDOR_SRC_ROOT="\$(abs_top_srcdir)/vendor/"
 VENDOR_DIST_ROOT="\$(abs_top_builddir)/vendor/dist"
 VENDOR_BUILD_ROOT="\$(abs_top_builddir)/vendor/.build"
 AC_SUBST([VENDOR_SRC_ROOT])
 AC_SUBST([VENDOR_BUILD_ROOT])
 AC_SUBST([VENDOR_DIST_ROOT])
 
 TEST_LDFLAGS="-lcmocka -L\$(abs_top_builddir)/vendor/dist/lib -Wl,-rpath,\$(abs_top_builddir)/vendor/dist/lib"
 TEST_CFLAGS="-I\$(top_srcdir)/include -I\$(abs_top_builddir)/vendor/dist/include"
 
 AC_SUBST([TEST_LDFLAGS])
 AC_SUBST([TEST_CFLAGS])
 

 # Check if cmake is available and cmocka git submodule is initialized,
 # needed for unit testing
 AC_CHECK_PROGS([CMAKE], [cmake])
 if test -n "${CMAKE}"; then

    if test -f "${srcdir}/vendor/cmocka/CMakeLists.txt"; then

       AM_CONDITIONAL([CMOCKA_INITIALIZED], [true])
    else
       AM_CONDITIONAL([CMOCKA_INITIALIZED], [false])
       AC_MSG_RESULT([!! WARNING !! The cmoka git submodule has not been initialized or updated.  Unit testing cannot be performed.])
    fi
 else
    AC_MSG_RESULT([!! WARNING !! CMake is NOT available.  Unit testing cannot be performed.])
    AM_CONDITIONAL([CMOCKA_INITIALIZED], [false])
 fi
 
 

 AC_CONFIG_FILES([

 	version.sh

 	Makefile

 	build/Makefile

 	build/msvc/Makefile
 	build/msvc/msvc-generate/Makefile

 	distro/Makefile
 	distro/rpm/Makefile
 	distro/rpm/openvpn.spec

 	distro/systemd/Makefile

 	doc/Makefile
 	doc/doxygen/Makefile
 	doc/doxygen/openvpn.doxyfile

 	include/Makefile
 	src/Makefile

 	src/compat/Makefile

 	src/openvpn/Makefile
 	src/openvpnserv/Makefile

 	src/plugins/Makefile
 	src/plugins/auth-pam/Makefile
 	src/plugins/down-root/Makefile

 	tests/Makefile

         tests/unit_tests/Makefile
         tests/unit_tests/example_test/Makefile

         tests/unit_tests/openvpn/Makefile

         tests/unit_tests/plugins/Makefile
         tests/unit_tests/plugins/auth-pam/Makefile

         vendor/Makefile

 	sample/Makefile

 ])

 AC_CONFIG_FILES([tests/t_client.sh], [chmod +x tests/t_client.sh])

 AC_OUTPUT