unified_client

#!/bin/sh

if [ -x "$(command -v id 2> /dev/null)" ]; then
  USERID="$(id -u 2> /dev/null)"
fi

if [ -z "${USERID}" ] && [ -n "${UID}" ]; then
  USERID=${UID}
fi

if [ -n "${USERID}" ] &&  [ "${USERID}" != "0" ]; then
  printf "Run it as root\n" ; exit 1;
elif [ -z "${USERID}" ] && [ -z "${UID}" ]; then
  printf "Unable to detect if running as root\n"
fi

if [ -z "${3}" ]; then
  printf "Usage: %s <interface> <connection time in seconds> <wpa_supplicant.conf> [wpa_supplicant.conf]\n" "${0}"
  exit 1
fi

interface="${1}"
shift
connection_timeout="${1}"
shift
conf_files="${*}"

#wait for interface
printf "Waiting for %s...\n" "${interface}"
while true; do
  if ip addr show "${interface}" > /dev/null 2>&1; then
    break
  fi
  sleep 1
done
printf "We have %s, continuing...\n" "${interface}"

politekill() {
  for i in "${@}"; do
    pkill -TERM -f "${i}"
  done
  sleep 1
  for i in "${@}"; do
    pkill -9 -f "${1}"
  done
}

control_c() {
  politekill "${arping_cmdline}" "${dhcp_cmdline}" "${wpa_supplicant_cmdline}"
  ip addr flush dev "${interface}"
  exit
}

trap control_c INT
trap control_c TERM
trap control_c EXIT

#todo: detect arping more correctly, including debian/raspbian arping
if [ -x /usr/bin/arping ]; then
	which_arping="/usr/bin/arping -c 5 -w 5 -I"
elif [ -x /usr/sbin/arping ]; then
	which_arping="/usr/sbin/arping -c 5 -W 1 -i -v"
elif [ -x /bin/arping ]; then
	which_arping="/bin/arping -c 5 -w 5 -I"
fi

while true;
do
  #this loop includes between 10 and 50 seconds of sleep for each config file in "conf_files"
  #so each AP will have a client connected for 30ish seconds at least once every number of conf_files minutes (absent deauth floods)
  for conffile in ${conf_files}; do
    if [ ! -e "config/${conffile}" ]; then
      printf "config/%s specified at the command line is not present, failing.\n" "${conffile}"
      exit 1
    fi
    if [ ! -r "config/${conffile}" ]; then
      printf "config/%s specified at the command line is not readable, failing.\n" "${conffile}"
      exit 1
    fi
    ssid=$(sed -n -e 's/^[[:space:]]*//g' -e 's/"//g' -e '/^ssid=/s/ssid=//p' "config/${conffile}" | head -n1)
    #set each command as a variable so it is always identical in the code
    dhcp_cmdline="dhcpcd --waitip=4 --hostname=${ssid} --noipv4ll --ipv4only ${interface} --request=0.0.0.0"
    wpa_supplicant_cmdline="wpa_supplicant -Dnl80211 -i ${interface} -c config/${conffile}"
    arping_cmdline="${which_arping} ${interface}"

    #kill everything and ensure it's dead
    politekill "${wpa_supplicant_cmdline}" "${dhcp_cmdline}" "${arping_cmdline}"

    #start new wpa_supplicant and wait up to 12 seconds for a connection
    printf "Attempting to connect %s to SSID: %s for %ss using config %s...\n" "${interface}" "${ssid}" "${connection_timeout}" "${conffile}"
    ${wpa_supplicant_cmdline} &
    for i in $(seq 12); do
      if iw "${interface}" link | grep -q '^Connected'; then
        break
      fi
      sleep 1
    done

    #start new dhcp client and wait up to 28 seconds for success
    ${dhcp_cmdline} &
    for i in $(seq 28); do
      if [ -n "$(ip route show dev "${interface}" | awk '/default/ {print $3}')" ]; then
        break
      fi
      sleep 1
    done

    #register connection attempt
    touch "/run/rfctf_status/${ssid}_attempt"

    if [ -n "$(ip route show dev "${interface}" | awk '/default/ {print $3}')" ]; then
      printf "We have an ip address\n"
      start_time=$(date '+%s')
      while [ "${start_time}" -gt $(( $(date '+%s') - connection_timeout )) ]; do
        #we should be checking arping success but the exit codes are weird
        ${arping_cmdline} "$(ip route show dev "${interface}" | awk '/default/ {print $3}')"
        #register connection success
        #since we are not 100% sure we are connected, let's include the ip address for now
        ip addr show dev "${interface}" 2>&1 | awk '/inet / {print $2}' > "/run/rfctf_status/${ssid}_active"
        if [ -x "helpers/${conffile%.*}" ]; then
          timeout 10 "helpers/${conffile%.*}"
        fi
      done
    else
      printf "We never got an ip address, recycling.\n"
    fi

    #disconnect and cleanup
    politekill "${wpa_supplicant_cmdline}" "${dhcp_cmdline}" "${arping_cmdline}"
    sleep 1
    ip addr flush dev "${interface}"
  done
done