iankelling.org Git - distro-setup/blob - vpn-static-ip

   1 #!/bin/bash
   2 # I, Ian Kelling, follow the GNU license recommendations at
   3 # https://www.gnu.org/licenses/license-recommendations.en.html. They
   4 # recommend that small programs, < 300 lines, be licensed under the
   5 # Apache License 2.0. This file contains or is part of one or more small
   6 # programs. If a small program grows beyond 300 lines, I plan to switch
   7 # its license to GPL.
   8
   9 # Copyright 2024 Ian Kelling
  10
  11 # Licensed under the Apache License, Version 2.0 (the "License");
  12 # you may not use this file except in compliance with the License.
  13 # You may obtain a copy of the License at
  14
  15 #     http://www.apache.org/licenses/LICENSE-2.0
  16
  17 # Unless required by applicable law or agreed to in writing, software
  18 # distributed under the License is distributed on an "AS IS" BASIS,
  19 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  20 # See the License for the specific language governing permissions and
  21 # limitations under the License.
  22
  23 if ! test "$BASH_VERSION"; then echo "error: shell is not bash" >&2; exit 1; fi
  24 shopt -s inherit_errexit 2>/dev/null ||: # ignore fail in bash < 4.4
  25 set -eE -o pipefail
  26 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?. PIPESTATUS: ${PIPESTATUS[*]}" >&2' ERR
  27
  28 [[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
  29
  30 conf=$1
  31
  32 # We block dns lookups from going outside the vpn network namespace,
  33 # there might be some other workaround, but just resolving to static ips
  34 # is a simple fix.
  35
  36 main() {
  37   while read -r host port; do
  38     while read -r ip; do
  39       echo $ip | grep -E '[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*' &>/dev/null || continue
  40       printf "remote %s %s\n" "$ip" "$port" >>$conf
  41       ret=0
  42     done < <(timeout -s 9 1 dig +short $host ||:)
  43   done < <(sed -rn 's/^ *# *remote //p' $conf)
  44
  45 }
  46
  47
  48 sed --follow-symlinks -i '/^ *remote /d' $conf
  49 ret=1
  50 main
  51 # give it one retry if it failed initially
  52 if (( ret )); then
  53   sleep 2
  54   main
  55 fi
  56
  57 if ((ret)); then
  58   echo "vpn-static-ip: error: failed to set any ips" >&2
  59   exit 1
  60 fi