stap-serverd

   1 #!/bin/bash
   2
   3 # Compile server manager for systemtap
   4 #
   5 # Copyright (C) 2008 Red Hat Inc.
   6 #
   7 # This file is part of systemtap, and is free software.  You can
   8 # redistribute it and/or modify it under the terms of the GNU General
   9 # Public License (GPL); either version 2, or (at your option) any
  10 # later version.
  11
  12 # This script publishes its presence on the network and then listens for
  13 # incoming connections. When a connection is detected, the stap-server script
  14 # is run to handle the request.
  15
  16 # Catch ctrl-c
  17 trap 'handle_sigint' SIGINT
  18
  19 #-----------------------------------------------------------------------------
  20 # Helper functions.
  21 #-----------------------------------------------------------------------------
  22 # function: initialization PORT
  23 function initialization {
  24     # Default settings.
  25     tmpdir_prefix_serverd=stap.serverd
  26     avahi_type=_stap._tcp
  27     port=$1
  28     test "X$port" = "X" && port=65000
  29 }
  30
  31 # function: advertise_presence
  32 #
  33 # Advertise the availability of the server on the network.
  34 function advertise_presence {
  35     # Build up a string representing our server's properties.
  36     # TODO: this needs fleshing out.
  37
  38     local sysinfo=`uname -r`
  39     local txt="$sysinfo"
  40
  41     # Call avahi-publish-service to advertise our presence.
  42     avahi-publish-service "Systemtap Compile Server on `uname -n`" \
  43         $avahi_type $port $txt > /dev/null 2>&1 &
  44
  45     echo "Systemtap Compile Server on `uname -n` listening on port $port"
  46 }
  47
  48 # function: listen
  49 #
  50 # Listen for and handle requests to the server.
  51 function listen {
  52     # Work in a temporary directory
  53     tmpdir=`mktemp -dt $tmpdir_prefix_serverd.XXXXXX` || \
  54         fatal "ERROR: cannot create temporary directory " $tmpdir
  55     cd $tmpdir
  56
  57     # Create a fifo for communicating with the server
  58     local fifo_name=$tmpdir_prefix_serverd.fifo
  59     mknod $fifo_name p || \
  60         fatal "ERROR: cannot create temporary fifo " $tmpdir/$fifo_name
  61
  62     # Loop forever accepting requests
  63     while true
  64     do
  65         nc -l $port < $fifo_name | stap-server $((port + 1)) > $fifo_name 2>&1
  66     done
  67 }
  68
  69 # function: fatal [ MESSAGE ]
  70 #
  71 # Fatal error
  72 # Prints its arguments to stderr and exits
  73 function fatal {
  74     echo "$@" >&2
  75     exit 1
  76 }
  77
  78 # function: handle_sigint
  79 #
  80 # Terminate gracefully when SIGINT is received.
  81 function handle_sigint {
  82     echo "$0: received SIGINT. Exiting."
  83     cd `dirname $tmpdir`
  84     rm -fr $tmpdir
  85     exit
  86 }
  87
  88 #-----------------------------------------------------------------------------
  89 # Beginning of main line execution.
  90 #-----------------------------------------------------------------------------
  91 initialization "$@"
  92 advertise_presence
  93 listen