ssht

   1 #!/usr/bin/env bash
   2
   3 #=======================================================================
   4 # ssht
   5 # File ID: 307e8876-e099-11e0-94c2-ef2688b28a12
   6 #
   7 # Create/terminate SSH tunnel or set up VNC connection.
   8 #
   9 # Author: Øyvind A. Holm <sunny@sunbase.org>
  10 # License: GNU General Public License version 2 or later.
  11 #=======================================================================
  12
  13 progname=ssht
  14 VERSION=0.2.2
  15
  16 ARGS="$(getopt -o "\
  17 c\
  18 h\
  19 k\
  20 l\
  21 q\
  22 t\
  23 V:\
  24 v\
  25 " -l "\
  26 connect,\
  27 help,\
  28 kill,\
  29 list,\
  30 quiet,\
  31 tunnel,\
  32 vnc:,\
  33 verbose,\
  34 version,\
  35 " -n "$progname" -- "$@")"
  36 test "$?" = "0" || exit 1
  37 eval set -- "$ARGS"
  38
  39 opt_connect=0
  40 opt_help=0
  41 opt_kill=0
  42 opt_list=0
  43 opt_quiet=0
  44 opt_tunnel=0
  45 opt_vnc=''
  46 opt_verbose=0
  47 while :; do
  48     case "$1" in
  49         -c|--connect) opt_connect=1; shift ;;
  50         -h|--help) opt_help=1; shift ;;
  51         -k|--kill) opt_kill=1; shift ;;
  52         -l|--list) opt_list=1; shift ;;
  53         -q|--quiet) opt_quiet=$(($opt_quiet + 1)); shift ;;
  54         -t|--tunnel) opt_tunnel=1; shift ;;
  55         -V|--vnc) opt_vnc=$2; shift 2 ;;
  56         -v|--verbose) opt_verbose=$(($opt_verbose + 1)); shift ;;
  57         --version) echo $progname $VERSION; exit 0 ;;
  58         --) shift; break ;;
  59         *) echo $progname: Internal error >&2; exit 1 ;;
  60     esac
  61 done
  62 opt_verbose=$(($opt_verbose - $opt_quiet))
  63
  64 rcfile="$HOME/.sshtrc"
  65
  66 if test "$opt_help" = "1"; then
  67     test $opt_verbose -gt 0 && { echo; echo $progname $VERSION; }
  68     cat <<END
  69
  70 Create/terminate SSH tunnel or set up VNC connection.
  71
  72 Usage: $progname [options]
  73
  74 Options:
  75
  76   -c, --connect
  77     Connect to SSH tunnel from outside.
  78   -h, --help
  79     Show this help.
  80   -k, --kill
  81     Kill SSH tunnel.
  82   -l, --list
  83     List PID of active tunnel.
  84   -q, --quiet
  85     Be more quiet. Can be repeated to increase silence.
  86   -t, --tunnel
  87     Create SSH tunnel if none exist yet.
  88   -v, --verbose
  89     Increase level of verbosity. Can be repeated.
  90   -V DISPLAY [QUALITY], --vnc DISPLAY [QUALITY]
  91     Connect via VNC to display DISPLAY. QUALITY can be 0 (worst, but
  92     great compression) to 9 (best quality). If QUALITY is not specified,
  93     top quality and no compression is used.
  94   --version
  95     Print version information.
  96
  97 The file "$rcfile"
  98 is a regular shell script used for setting constants:
  99
 100   SSHT_PORT
 101     Port number for SSH tunnel. Choose something random above 1024,
 102     preferably not listed in /etc/services .
 103   SSHT_HOST
 104     SSH username and host on the format USER@HOST .
 105   SSHT_USERNAME
 106     SSH username used with -c/--connect option.
 107   SSHT_CMD
 108     Command to set up the SSH tunnel. If not defined, a default value is
 109     used.
 110
 111 END
 112     exit 0
 113 fi
 114
 115 msg() {
 116     echo "$progname: $*" >&2
 117 }
 118
 119 test -e "$rcfile" && . "$rcfile"
 120
 121 if test -z "$SSHT_PORT"; then
 122     msg SSHT_PORT environment variable is not defined
 123     exit 1
 124 fi
 125 if test -z "$SSHT_HOST"; then
 126     msg SSHT_HOST environment variable is not defined
 127     exit 1
 128 fi
 129 if test -z "$SSHT_CMD"; then
 130     SSHT_CMD="ssh -A -Y -q -N -R $SSHT_PORT:localhost:22 $SSHT_HOST"
 131 fi
 132
 133 unset SSHT_PID
 134 SSHT_PID=$(pgrep -f -x "$SSHT_CMD")
 135
 136 if test "$opt_connect" = "1"; then
 137     if test -z "$SSHT_USERNAME"; then
 138         msg SSHT_USERNAME environment variable is not defined
 139         exit 1
 140     fi
 141     sess -t c_ssht.c -- ssh -A -Y -p $SSHT_PORT -l $SSHT_USERNAME localhost
 142 elif test "$opt_kill" = "1"; then
 143     test -n "$SSHT_PID" || { msg No tunnel found; exit 1; }
 144     kill $SSHT_PID
 145 elif test "$opt_list" = "1"; then
 146     test -n "$SSHT_PID" && echo $SSHT_PID
 147 elif test "$opt_tunnel" = "1"; then
 148     test -n "$SSHT_PID" && {
 149         msg Tunnel already active at PID $SSHT_PID
 150         exit 1
 151     }
 152     # FIXME: Create some standardised version of this
 153     ps x | grep "bash -c while :; do date; sleep 2; done" |
 154         grep -v "grep " | awk '{print $1}' | xargs -r kill
 155     sess -t c_ssht.t -- $SSHT_CMD &
 156 elif test -n "$opt_vnc"; then
 157     msg Running pkill...
 158     pkill -9 -f "ssh -L 590$opt_vnc:localhost:590$opt_vnc"
 159     msg Creating ssh tunnel...
 160     sess -d ssh_tunnel -- \
 161         ssh -L 590$opt_vnc:localhost:590$opt_vnc -C -N -f $SSHT_HOST
 162     quality_str=
 163     if test -n "$1"; then
 164         quality_str="-quality $1"
 165         msg Starting xtightvncviewer with quality $1...
 166         sess -- xtightvncviewer -encodings tight -depth 16 -compresslevel 9 \
 167                 -nocursorshape $quality_str localhost:$opt_vnc
 168     else
 169         msg Starting xtightvncviewer with top quality...
 170         sess -- xtightvncviewer -encodings tight -truecolour -nojpeg \
 171                 -nocursorshape localhost:$opt_vnc
 172     fi
 173     msg Destroying ssh tunnel...
 174     pkill -9 -f "ssh -L 590$opt_vnc:localhost:590$opt_vnc"
 175 else
 176     msg No option specified
 177     exit 1
 178 fi