configure: add a check for ETHERTYPE_IPV6

ETHERTYPE_IPV6 defined in net/ethernet.h is pretty recent. If absent,
we hard-code the value into CFLAGS. This patch requires regeneration
of configure.

diff --git a/configure.in b/configure.in
index f4da333..96af8ef 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -44,6 +44,8 @@ dnl [do we really need this ?] AC_CHECK_HEADERS(linux/netlink.h linux/rtnetlink.
 AC_CHECK_HEADERS(openssl/ssl.h openssl/md5.h openssl/err.h,,AC_MSG_ERROR([
   !!! OpenSSL is not properly installed on your system. !!!
   !!! Can not include OpenSSL headers files.            !!!]))
+AC_CHECK_DECL([ETHERTYPE_IPV6],[],[CFLAGS="$CFLAGS -DETHERTYPE_IPV6=0x86dd"],
+  [[@%:@include <net/ethernet.h>]])
 
 dnl ----[ Checks for libraries ]----
 AC_CHECK_LIB(crypto, MD5_Init,,AC_MSG_ERROR([OpenSSL libraries are required]))