From bfd84c8f3e3c7cc0e129cad276e74eb9aea41c37 Mon Sep 17 00:00:00 2001
From: Nicola Fontana <ntd@entidi.it>
Date: Mon, 13 Dec 2021 09:56:32 +0000
Subject: [PATCH] Add UPDOWN_INTERFACES option to ethercat.conf

---
 script/ethercat.conf  | 17 +++++++++++++----
 script/ethercatctl.in | 28 +++++++++++++++++++++-------
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/script/ethercat.conf b/script/ethercat.conf
index 0125fb78..689be68e 100644
--- a/script/ethercat.conf
+++ b/script/ethercat.conf
@@ -61,10 +61,6 @@ MASTER0_DEVICE=""
 # Note: The e100, e1000, e1000e, r8169, ccat, igb and igc drivers are not built by
 # default. Enable them with the --enable-<driver> configure switches.
 #
-# Attention: When using the generic driver, the corresponding Ethernet device
-# has to be activated (with OS methods, for example 'ip link set ethX up'),
-# before the master is started, otherwise all frames will time out.
-#
 DEVICE_MODULES=""
 
 # If you have any issues about network interfaces not being configured
@@ -72,6 +68,19 @@ DEVICE_MODULES=""
 # Have a look at the service file, you'll find some details there.
 #
 
+#
+# List of interfaces to bring up and down automatically.
+#
+# Specify a space-separated list of interface names (such as eth0 or
+# enp0s1) that shall be brought up on `ethercatctl start` and down on
+# `ethercatctl stop`.
+#
+# When using the generic driver, the corresponding Ethernet device has to be
+# activated before the master is started, otherwise all frames will time out.
+# This the perfect use-case for `UPDOWN_INTERFACES`.
+#
+UPDOWN_INTERFACES=""
+
 #
 # Flags for loading kernel modules.
 #
diff --git a/script/ethercatctl.in b/script/ethercatctl.in
index 8c938a05..763147ac 100755
--- a/script/ethercatctl.in
+++ b/script/ethercatctl.in
@@ -47,18 +47,22 @@ fi
 
 #------------------------------------------------------------------------------
 
+is_mac_address() {
+    local x='[0-9a-fA-F]'
+    echo "$1" | grep -qE "^($x$x:){5}$x$x\$" -
+}
+
+#------------------------------------------------------------------------------
+
 parse_mac_address() {
     local DEVICENAMETOMAC
-    if [ -z "${1}" ]; then
-        MAC=""
-    elif echo ${1} | grep -qE '^([0-9a-fA-F]{2}:){5}[0-9a-fA-F]{2}$'; then
-        MAC=${1}
+    if [ -z "${1}" ] || is_mac_address "${1}"; then
+        MAC="${1}"
     else
         DEVICENAMETOMAC=$("${IP}" address show dev "${1}" |
             awk '/link\/ether/ { print $2; }')
-        if echo "${DEVICENAMETOMAC}" |
-            grep -qE '^([0-9a-fA-F]{2}:){5}[0-9a-fA-F]{2}$'; then
-            MAC=${DEVICENAMETOMAC}
+        if is_mac_address "${DEVICENAMETOMAC}"; then
+            MAC="${DEVICENAMETOMAC}"
         else
             echo Invalid MAC address or interface name \""${1}"\" \
                 in ${ETHERCAT_CONFIG}
@@ -72,6 +76,11 @@ parse_mac_address() {
 case "${1}" in
 
 start)
+    # bring up all updown interfaces before anything else
+    for interface in $UPDOWN_INTERFACES; do
+        $IP link set dev $interface up
+    done
+
     # construct DEVICES and BACKUPS from configuration variables
     DEVICES=""
     BACKUPS=""
@@ -167,6 +176,11 @@ stop)
         ${MODPROBE} ${MODPROBE_FLAGS} "${MODULE}"
     done
 
+    # bring down all updown interfaces
+    for interface in $UPDOWN_INTERFACES; do
+        $IP link set dev $interface down
+    done
+
     exit 0
     ;;