X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/151e9bb8f89da9dcf731681e4d645cc94d1b6a3e..ab6f1b0d12478b8fe266e3dacc3de7121df29066:/svc/tripe-ifup.in

diff --git a/svc/tripe-ifup.in b/svc/tripe-ifup.in
index 80a315b7..63b5b2d6 100644
--- a/svc/tripe-ifup.in
+++ b/svc/tripe-ifup.in
@@ -46,11 +46,16 @@ fi
 peer=$1 ifname=$2 family=$3; shift 3
 
 ## Parse the address family.
+case "$family" in
+  INET) ipsz=20 ;;
+  INET6) ipsz=40 ;;
+  *) echo >&2 "$0: unknown address family $family"; exit 1 ;;
+esac
 case "$family,$#" in
-  INET,1) addr=$1 port=4070 ;;
-  INET,2) addr=$1 port=$2 ;;
-  INET,*) echo >&2 "$0: bad INET address"; exit 1 ;;
-  *)      echo >&2 "$0: unknown address family $family"; exit 1 ;;
+  INET,1 | INET6,1) addr=$1 port=4070 ;;
+  INET,2 | INET6,2) addr=$1 port=$2 ;;
+  INET,* | INET6,*) echo >&2 "$0: bad $family address"; exit 1 ;;
+  *) echo >&2 "$0: unknown address family $family"; exit 1 ;;
 esac
 
 ###--------------------------------------------------------------------------
@@ -134,7 +139,7 @@ case $haveaddr4,$haveaddr6 in
 	mtu=$P_MTU;;
       *)
 	pathmtu=$(pathmtu "$addr")
-	mtu=$(expr "$pathmtu" - 29 - $A_BULK_OVERHEAD)
+	mtu=$(( $pathmtu - $ipsz - 9 - $A_BULK_OVERHEAD ))
 	;;
     esac
     try ip link set dev "$ifname" up mtu "$mtu"