+ACX_PTHREAD(,AC_MSG_ERROR([Missing POSIX Threads support]))
+
+#
+# Check for netlink.h
+#
+AC_CHECK_HEADER(linux/netlink.h,
+HAVE_NETLINK=yes
+AC_DEFINE([HAVE_NETLINK],[],[Support for Linux netlink])
+, [], [
+#include <sys/socket.h>
+#include <asm/types.h>
+])
+
+AM_CONDITIONAL(HAVE_NETLINK, [ test x"$HAVE_NETLINK" = xyes ])
+
+if test "x$HAVE_NETLINK" = "xyes" ; then
+ # Test whether rtnetlink.h can be included when compiled with -std=c99
+ # some distributions (e.g. archlinux) have broken headers that dont
+ # define __u64 with -std=c99
+ AC_MSG_CHECKING([checking whether rtnetlink.h can be included with -std=c99])
+ AC_TRY_COMPILE([#include <linux/rtnetlink.h>], [],
+ [AC_MSG_RESULT([yes])], [AC_MSG_ERROR([no])])
+fi
+
+#
+# Check for net/route.h
+#
+AC_CHECK_HEADER(net/route.h,
+HAVE_PF_ROUTE=yes
+AC_DEFINE([HAVE_PF_ROUTE],[],[Support for PF_ROUTE])
+, [], [
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if_dl.h>
+])
+
+AM_CONDITIONAL(HAVE_PF_ROUTE, [ test x"$HAVE_PF_ROUTE" = xyes ])
+
+#
+# Check for sys/filio.h; needed for FIONREAD on Solaris
+#
+AC_CHECK_HEADER(sys/filio.h,
+HAVE_SYS_FILIO_H=yes
+AC_DEFINE([HAVE_SYS_FILIO_H],[],[Support for sys/filio.h])
+, [], [
+])
+
+AM_CONDITIONAL(HAVE_SYS_FILIO_H, [ test x"$HAVE_SYS_FILIO_H" = xyes ])
+
+#
+# Check for sys/sysctl.h; not present on Solaris
+#
+AC_CHECK_HEADER(sys/sysctl.h,
+HAVE_SYS_SYSCTL=yes
+AC_DEFINE([HAVE_SYS_SYSCTL_H],[],[Support for sys/sysctl.h])
+, [], [
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/param.h>
+])
+
+AM_CONDITIONAL(HAVE_SYS_SYSCTL_H, [ test x"$HAVE_SYS_SYSCTL_H" = xyes ])
+
+#
+# Check for lifconf struct; only present on Solaris
+#
+AC_MSG_CHECKING(for struct lifconf)
+AC_CACHE_VAL(catta_cv_has_struct_lifconf,
+[AC_TRY_COMPILE(
+[#include <sys/socket.h>
+#include <net/if.h>
+],[sizeof (struct lifconf);],
+catta_cv_has_struct_lifconf=yes,catta_cv_has_struct_lifconf=no)])
+AC_MSG_RESULT($catta_cv_has_struct_lifconf)
+if test $catta_cv_has_struct_lifconf = yes; then
+ AC_DEFINE(HAVE_STRUCT_LIFCONF,1,[Define if there is a struct lifconf.])
+fi
+
+#
+# Check for struct ip_mreqn
+#
+AC_MSG_CHECKING(for struct ip_mreqn)
+AC_TRY_COMPILE([#include <netinet/in.h>], [
+ struct ip_mreqn mreq;
+ mreq.imr_address.s_addr = 0;
+], [
+ # Yes, we have it...
+ AC_MSG_RESULT(yes)
+ AC_DEFINE([HAVE_STRUCT_IP_MREQN],[],[Support for struct ip_mreqn])
+], [
+ # We'll just have to try and use struct ip_mreq
+ AC_MSG_RESULT(no)
+ AC_MSG_CHECKING(for struct ip_mreq)
+ AC_TRY_COMPILE([#include <netinet/in.h>], [
+ struct ip_mreq mreq;
+ mreq.imr_interface.s_addr = 0;
+ ], [
+ # Yes, we have it...
+ AC_MSG_RESULT(yes)
+ AC_DEFINE([HAVE_STRUCT_IP_MREQ],[],[Support for struct ip_mreq])
+ ], [
+ # No multicast support
+ AC_MSG_RESULT(no)
+ ])
+])
+
+test_gcc_flag() {
+ AC_LANG_CONFTEST([AC_LANG_SOURCE([[int main() {}]])])
+ $CC -c conftest.c $CFLAGS $@ > /dev/null 2> /dev/null
+ ret=$?
+ rm -f conftest.o
+ return $ret
+}
+
+# If using GCC specify some additional parameters
+if test "x$GCC" = "xyes" ; then
+
+ DESIRED_FLAGS="-Wall -W -Wextra -pedantic -pipe -Wformat -Wold-style-definition -Wdeclaration-after-statement -Wfloat-equal -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wmissing-noreturn -Wshadow -Wendif-labels -Wpointer-arith -Wbad-function-cast -Wcast-qual -Wcast-align -Wwrite-strings -fdiagnostics-show-option -Wno-cast-qual -fno-strict-aliasing"
+
+ for flag in $DESIRED_FLAGS ; do
+ AC_MSG_CHECKING([whether $CC accepts $flag])
+ if test_gcc_flag $flag ; then
+ CFLAGS="$CFLAGS $flag"
+ AC_MSG_RESULT([yes])
+ else
+ AC_MSG_RESULT([no])
+ fi
+ done
+fi
+