#!/bin/sh
band=5
ssid=$(serial)_TestWifi
crypto=WPA2_PSK_AES
channel=auto
# use $WIFI_PSK from the environment if given.
# You shouldn't pass passwords as command-line options because they show up
# in 'ps' even to users other than you.
psk=${WIFI_PSK-1234567890}

. /etc/utils.sh


log() {
  echo "$@" >&2
}


die() {
  log "Fatal:" "$@"
  exit 99
}


bin=$(basename "$0")
USAGE="
Usage: $bin set [options...]
 -b <band>        Wifi band to use (5 GHz or 2.4 GHz, default=$band)
 -c <channel>     Channel to use (default=$channel)
 -s <ssid>        SSID to use (default=$ssid)
 -e <encryption>  Encryption type to use (WPA_PSK_AES,
                    WPA2_PSK_AES, WPA_PSK_TKIP, WPA2_PSK_TKIP,
                    WEP, or NONE) (default=$crypto)
"
usage() {
  echo "$USAGE"
  exit 1
}


WL() {
  log "wl" "$@"
  wl "$@" || die "wl $*: failed"
}


IWCONFIG() {
  log "iwconfig" "$@"
  iwconfig "$@" || die "iwconfig $*: failed"
}


# Only 'set' command exists right now, but use it for extensibility later
cmd=$1
if [ "$cmd" != "set" ]; then
  usage
fi
shift


while getopts "b:s:e:c:" opt
do
  case $opt in
    b) band=$OPTARG ;;
    c) channel=$OPTARG ;;
    s) ssid=$OPTARG ;;
    e) crypto=$OPTARG ;;
    *) usage ;;
  esac
done

if runnable wl; then
  log "Configuring broadcom wifi."
  WL radio on
  WL down
  WL ssid ""
  [ "$channel" = "auto" ] || band=auto
  case $band in
    5)    WL band a ;;
    2.4)  WL band b ;;
    auto) WL band auto ;;
    *) die "invalid band '$band'" ;;
  esac
  WL ap 0
  WL up
  if [ "$channel" = "auto" ]; then
    # We can only run autochannel when ap=0, but setting ap=1 later will
    # wipe the value.  So we have to capture the autochannel setting, then
    # set it later.  'wl autochannel 2' is thus useless.
    WL autochannel 1
    sleep 3  # enough time to scan all the 2.4 or 5 GHz channels at 100ms each
    channel=$(WL autochannel | ( read chan junk; echo "$chan"; ))
  fi
  WL ap 1
  WL chanspec "$channel"
  WL auth 0
  WL infra 1
  case $crypto in
    *_AES)  WL wsec 4 ;;
    *_TKIP) WL wsec 2 ;;
    WEP)    WL wsec 1 ;;
    NONE)   WL wsec 0 ;;
    *) die "invalid crypto '$crypto'" ;;
  esac
  WL sup_wpa 1
  case $crypto in
    WPA_*)    WL wpa_auth 4 ;;
    WPA2_*)   WL wpa_auth 128 ;;
    WEP|NONE) WL wpa_auth 0 ;;
    *) die "invalid crypto '$crypto'" ;;
  esac
  WL up
  case $crypto in
    *_PSK_*)
      # WPA keys must be added *before* setting the SSID
      WL set_pmk "$psk"
      WL ssid "$ssid"
      ;;
    WEP)
      # WEP keys must be added *after* setting the SSID
      WL ssid "$ssid"
      WL addwep 0 "$psk"
      ;;
    NONE)
      WL ssid "$ssid"
      ;;
    *)
      die "invalid crypto '$crypto'"
      ;;
  esac
elif runnable iwconfig; then
  log "Configuring atheros wifi."
  ifc=$(
    ifcname=
    iwlist channel 2>/dev/null |
    while read word channum colon freq junk; do
      case $word in
        Channel)
          startswith "$freq" "$band" || continue
          if [ "$channel" = "auto" ] ||
             [ "$channum" = "$channel" -o "$channum" = "0$channel" ]; then
            echo "$ifcname"
            break
          fi
          ;;
        *)
          ifcname=$word
          ;;
      esac
    done
  )
  [ -n "$ifc" ] || die "no wifi interface for band='$band' channel='$channel'"
  log "Using wifi interface: '$ifc'"
  IWC() {
    IWCONFIG "$ifc" "$@"
  }
  for mode in 11ACVHT80 11ACVHT40 11NGHT40 11ACVHT20 11NGHT20; do
    if iwpriv "$ifc" mode "$mode" 2>/dev/null; then
      log "Mode for $ifc is $mode"
      break
    fi
  done
  IWC essid ""
  IWC mode master
  IWC channel "$channel"  # may be "auto"
  case $crypto in
    WPA_*) auth_algs=1; wpa=1 ;;
    WPA2_*) auth_algs=1; wpa=2 ;;
    WEP) auth_algs=3; wpa=0 ;;
    NONE) auth_algs=1; wpa=0 ;;
    *) die "invalid crypto protocol in '$crypto'" ;;
  esac
  case $crypto in
    *_AES) wpa_pairwise=CCMP ;;
    *_TKIP) wpa_pairwise=TKIP ;;
    WEP|NONE) wpa_pairwise=CCMP ;;
    *) die "invalid crypto alg in '$crypto'" ;;
  esac
  atomic /tmp/hostapd.conf.${band}g "
interface=$ifc
ssid=$ssid
auth_algs=$auth_algs
wpa=$wpa
wpa_passphrase=$psk
wpa_key_mgmt=WPA-PSK
wpa_pairwise=$wpa_pairwise
"
  case $crypto in
    WPA2_*|WPA_*|WEP|NONE)
      pidfile=/tmp/hostapd.pid.${band}g
      babysit 60 startpid /tmp/hostapd.pid.${band}g \
          hostapd -dK /tmp/hostapd.conf.${band}g \
          2>&1 | logos hostapd-${band}g &
      ;;
    *)
      die "invalid crypto '$crypto'"
      ;;
  esac
  IWC essid -- "$ssid"
else
  die "No wifi runtime found."
fi