X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=m4%2Ftuntap.m4;h=7da8e46a25d03d39a7a44377f3e71ee44319912f;hp=605ebef4a1645c1e784aef99d8d5dbaea738c659;hb=7fc068fe5421f7ec556b0b7db6f814e18b3326a4;hpb=c5c8e99afd3fae3868f20b5c7a4f8754498b39ad

diff --git a/m4/tuntap.m4 b/m4/tuntap.m4
index 605ebef4..7da8e46a 100644
--- a/m4/tuntap.m4
+++ b/m4/tuntap.m4
@@ -2,19 +2,36 @@ dnl Check to find out whether the running kernel has support for TUN/TAP
 
 AC_DEFUN(tinc_TUNTAP,
 [
+AC_ARG_WITH(kernel,
+  [  --with-kernel=dir       give the directory with kernel sources]
+  [                        (default: /usr/src/linux)],
+  kerneldir="$withval",
+  kerneldir="/usr/src/linux"
+)
+
 AC_CACHE_CHECK([for linux/if_tun.h], tinc_cv_linux_if_tun_h,
-[ AC_TRY_COMPILE([#include <linux/if_tun.h>],
-  [int a = IFF_TAP],
-  if_tun_h="linux/if_tun.h",
-  if_tun_h="no")
-   if test $if_tun_h = no; then
+[ 
+  AC_TRY_COMPILE([#include "$kerneldir/include/linux/if_tun.h"],
+    [int a = IFF_TAP;],
+    if_tun_h="\"$kerneldir/include/linux/if_tun.h\"",
+    [AC_TRY_COMPILE([#include <linux/if_tun.h>],
+      [int a = IFF_TAP;],
+      if_tun_h="<linux/if_tun.h>",
+      if_tun_h="no"
+    )]
+  )
+
+  if test $if_tun_h = no; then
     tinc_cv_linux_if_tun_h=none
   else
-    AC_DEFINE(HAVE_TUNTAP)
-    AC_DEFINE_UNQUOTED(LINUX_IF_TUN_H, "$if_tun_h")
-    AC_SUBST(LINUX_IF_TUN_H)
     tinc_cv_linux_if_tun_h=$if_tun_h
   fi
-  AC_SUBST(HAVE_TUNTAP)
 ])
+
+if test $tinc_cv_linux_if_tun_h != none; then
+  AC_DEFINE(HAVE_TUNTAP)
+  AC_DEFINE_UNQUOTED(LINUX_IF_TUN_H, $tinc_cv_linux_if_tun_h)
+  AC_SUBST(LINUX_IF_TUN_H)
+fi
+AC_SUBST(HAVE_TUNTAP)
 ])