+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"$HAVE_NETLINK" = xyes ])
+
+#
+# Check for net/route.h
+#
+AC_CHECK_HEADER(net/route.h,
+HAVE_PF_ROUTE=yes
+AC_DEFINE([HAVE_PF_ROUTE],[],[Support for PF_ROUTE])
+, [], [
+#include <sys/types.h>
+#include <sys/socket.h>
+])
+
+AM_CONDITIONAL(HAVE_PF_ROUTE, [ test x"$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"$HAVE_SYS_FILIO_H" = xyes ])
+
+#
+# Check for sys/sysctl.h; not present on Solaris
+#
+AC_CHECK_HEADER(sys/sysctl.h,
+HAVE_SYS_SYSCTL=yes
+AC_DEFINE([HAVE_SYS_SYSCTL_H],[],[Support for sys/sysctl.h])
+, [], [
+#include <sys/types.h>
+#include <sys/socket.h>
+])
+
+AM_CONDITIONAL(HAVE_SYS_SYSCTL_H, [ test x"$HAVE_SYS_SYSCTL_H" = xyes ])
+
+#
+# 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)
+ ])
+])
+