restart-network

#!/bin/bash

# SPDX-FileCopyrightText: 2015 - 2024 sudorook <daemon@nullcodon.com>
#
# SPDX-License-Identifier: GPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <https://www.gnu.org/licenses/>.

set -euo pipefail

ROOT="$(dirname "${0}")"

source "${ROOT}"/globals

#
# Consider removing this. MAC address randomization is built into
# NetworkManager now, so use of macchanger is not needed. Set
# <iface>.cloned-mac-address=random in /etc/NetworkManager/NetworkManager.conf,
# and this whole script can be replaced entirely by:
#
#   $ sudo systemctl restart NetworkManager.service
#
# Otherwise, to keep this script, implement the following fixes:
#  - Parse the results of `ip link show` to figure out the interface names for
#    the 'all' option.
#  - Use getopt to parse command line options.
#  - Print a message upon use describing the NetworkManager MAC address option.
#  - Actually check that the MAC address of the interface(s) are actually
#    changed.
#
#   --A
#

! check_command macchanger && exit 3

function print_interfaces {
  ip link show | grep "^[0-9]" | grep -v "virbr\|tun\|lo" |
    cut -d ":" -f2 | sed -e 's/^\s\(.*\)$/  \1/g'
}

if [ "${#}" -ne 1 ]; then
  show_error "Error. Specify the network interface to restart."
  print_interfaces
  exit 1
fi

iface="${1}"

if [ "${iface}" = "all" ]; then
  sudo bash -c "\
    systemctl stop NetworkManager.service && \
    ip link set dev wlp3s0 down && \
    ip link set dev enp0s25 down && \
    macchanger -e wlp3s0 && \
    macchanger -e enp0s25 && \
    ip link set dev wlp3s0 up && \
    ip link set dev enp0s25 up && \
    systemctl start NetworkManager.service"
  exit 0
fi

if test "$(ip link show | grep -c "${iface}")" -ne 0; then
  sudo bash -c "\
    systemctl stop NetworkManager.service && \
    ip link set dev ${iface} down && \
    macchanger -e ${iface} && \
    ip link set dev ${iface} up && \
    systemctl start NetworkManager.service"
  exit 0
else
  show_error "Interface ${iface@Q} doesn't exist. Pick from:"
  print_interfaces
  exit 1
fi