#!/bin/sh # Copyright (c) 2020 Ariadne Conill # # Permission to use, copy, modify, and/or distribute this software for any # purpose with or without fee is hereby granted, provided that the above # copyright notice and this permission notice appear in all copies. # # This software is provided 'as is' and without any warranty, express or # implied. In no event shall the authors be liable for any damages arising # from the use of this software. # # Manage wifi connections using wpa_supplicant. # # Vocabulary: # wifi-ssid - The SSID name to connect to. # wifi-psk - The pre-shared key to use. # wifi-config - A path to a wpa_supplicant config file, for special configs. # # If wifi-config is not set, wifi-ssid and wifi-psk are required, and a config # will be generated as /run/wpa_supplicant.$IFACE.conf. # # The wpa_supplicant PID is stored in /run/wpa_supplicant.$IFACE.pid. die() { printf "ERROR: %s\n" "$1" >&2 exit 1 } [ -z "$IFACE" ] && die "IFACE not set" [ -z "$PHASE" ] && die "PHASE not set" PIDFILE="/run/wpa_supplicant.$IFACE.pid" # Do not allow mixing wifi-config-path and wifi-ssid/wifi-psk. [ -n "$IF_WIFI_CONFIG_PATH" -a -n "$IF_WIFI_SSID" ] && die "wifi-config-path cannot be used with wifi-ssid" [ -n "$IF_WIFI_CONFIG_PATH" -a -n "$IF_WIFI_PSK" ] && die "wifi-config-path cannot be used with wifi-psk" # Set IF_WIFI_CONFIG_PATH to the default path if not already set. [ -z "$IF_WIFI_CONFIG_PATH" ] && IF_WIFI_CONFIG_PATH="/run/wpa_supplicant.$IFACE.conf" # Supplicant options. WPA_SUPPLICANT_OPTS="-qq -B -i$IFACE -c$IF_WIFI_CONFIG_PATH -P$PIDFILE" # Given $IF_WIFI_SSID and $IF_WIFI_PSK, generate a config file at $IF_WIFI_CONFIG_PATH. generate_config() { [ -z "$IF_WIFI_SSID" ] && die "wifi-ssid not set" [ -z "$IF_WIFI_PSK" ] && die "wifi-psk not set" # We use a pipeline here to avoid leaking PSK into the process name. (echo $IF_WIFI_PSK | /sbin/wpa_passphrase $IF_WIFI_SSID) >$IF_WIFI_CONFIG_PATH [ ! -e "$IF_WIFI_CONFIG_PATH" ] && die "failed to write temporary config: $IF_WIFI_CONFIG_PATH" } # Start a supplicant process for $IFACE. start() { # If there is no config file located at $IF_WIFI_CONFIG_PATH, generate one. [ ! -e "$IF_WIFI_CONFIG_PATH" ] && generate_config /sbin/wpa_supplicant $WPA_SUPPLICANT_OPTS } # Stop the supplicant process for $IFACE. stop() { kill -9 $(cat $PIDFILE) 2>/dev/null rm $PIDFILE } [ -z "$VERBOSE" ] || set -x case "$PHASE" in pre-up) start ;; post-down) stop ;; esac