#!/bin/bash
#
# Systemd rule generator for ibft interfaces
#
# Copyright (c) 2022 Hannes Reinecke, SUSE Labs
# This script is licensed under the GPL.
#
# When booted with 'ip=ibft' dracut will rename the
# interface to 'ibft*'. After systemd has started
# it'll try to rename the interface yet again with
# a persistent name.
# But as the ibft interface is already renamed _and_
# in use, the second renaming will fail and udev
# will complain.
# So add a dummy rule which signals udev the correct name
#
# Interface renaming happes at 80-net-setup-link.rules,
# so we need to hook in before that.
#
IBFT_RULE_DIR=/run/udev/rules.d
IBFT_RULES=${IBFT_RULE_DIR}/79-ibft.rules

# ensure we have a rules directory and no rules file
if [ -d ${IBFT_RULE_DIR} ] ; then
    rm -f ${IBFT_RULES} 2> /dev/null
else
    mkdir -p ${IBFT_RULE_DIR}
fi

# create an iBFT udev rule for each iBFT NIC found
for d in /sys/firmware/ibft/ethernet* ; do
    [ -d "$d" ] || break
    num="${d##*/ethernet}"
    read mac < $d/mac
    printf 'SUBSYSTEM=="net", KERNEL=="ibft*", ACTION=="add", DRIVERS=="?*", ATTR{address}=="%s", ATTR{type}=="1", NAME="ibft%s"\n' "$mac" "$num" >> $IBFT_RULES
done