examples/msr/msrserv.pl
branchstable-1.0
changeset 1619 0d4119024f55
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/msr/msrserv.pl	Mon May 29 09:08:56 2006 +0000
@@ -0,0 +1,267 @@
+#!/usr/bin/perl -w
+
+#------------------------------------------------------------------------------
+#
+#  Copyright (C) 2006  Ingenieurgemeinschaft IgH
+#
+#  This file is part of the IgH EtherCAT Master.
+#
+#  The IgH EtherCAT Master is free software; you can redistribute it
+#  and/or modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2 of the
+#  License, or (at your option) any later version.
+#
+#  The IgH EtherCAT Master is distributed in the hope that it will be
+#  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with the IgH EtherCAT Master; if not, write to the Free Software
+#  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#  The right to use EtherCAT Technology is granted and comes free of
+#  charge under condition of compatibility of product made by
+#  Licensee. People intending to distribute/sell products based on the
+#  code, have to sign an agreement to guarantee that products using
+#  software based on IgH EtherCAT master stay compatible with the actual
+#  EtherCAT specification (which are released themselves as an open
+#  standard) as the (only) precondition to have the right to use EtherCAT
+#  Technology, IP and trade marks.
+#
+#------------------------------------------------------------------------------
+#
+#  Multithreaded Server
+#  according to the example from "Programming Perl"
+#  this code is improved according to the example from
+#  perldoc perlipc, so now safely being usable under Perl 5.8
+#  (see note (*))
+#
+#  works with read/write on a device-file
+#
+#------------------------------------------------------------------------------
+
+require 5.002;
+use strict;
+BEGIN { $ENV{PATH} = '/opt/msr/bin:/usr/bin:/bin' }
+use Socket;
+use Carp;
+use FileHandle;
+use Getopt::Std;
+
+use Sys::Syslog qw(:DEFAULT setlogsock);
+
+use vars qw (
+	     $self $pid $dolog $port $dev %opts $selfbase
+	     $len $offset $stream $written $read $log $blksize
+	     $instdir
+	     $authfile %authhosts
+	     );
+
+
+# Do logging to local syslogd by unix-domain socket instead of inetd
+setlogsock("unix");
+
+# Prototypes and some little Tools
+sub spawn;
+sub logmsg {
+  my ($level, $debug, @text) = @_;
+  syslog("daemon|$level", @text) if $debug > $dolog;
+#  print STDERR "daemon|$level", @text, "\n" if $dolog;
+}
+sub out {
+  my $waitpid = wait;
+  logmsg("notice", 2, "$waitpid exited");
+  unlink "$selfbase.pid";
+  exit 0;
+}
+
+sub help {
+  print "\n  usage: $0 [-l og] [-h elp] [-p port] [-d device]\n";
+  exit;
+}
+
+# Process Options
+%opts = (
+	 "l" => 1,
+	 "h" => 0,
+	 "p" => 2345,
+	 "d" => "/dev/msr"
+	 );
+
+getopts("lhp:d:", \%opts);
+
+help if $opts{"h"};
+
+( $self =  $0 ) =~ s+.*/++ ;
+( $selfbase = $self ) =~ s/\..*//;
+$log = "$selfbase.log";
+$dolog = $opts{"l"};
+$port = $opts{"p"};
+$dev = $opts{"d"};
+$blksize = 1024; # try to write as much bytes
+$instdir = "/opt/msr";
+$authfile = "$instdir/etc/hosts.auth";
+
+# Start logging
+openlog($self, 'pid');
+
+# Flush Output, dont buffer
+$| = 1;
+
+# first fork and run in background
+if ($pid = fork) {
+#  open LOG, ">$log" if $dolog;
+#  close LOG;
+  logmsg("notice", 2, "forked process: $pid\n");
+  exit 0;
+}
+
+# Server tells about startup success
+open (PID, ">/$instdir/var/run/$selfbase.pid");
+print PID "$$\n";
+close PID;
+
+# Cleanup on exit (due to kill -TERM signal)
+$SIG{TERM} = \&out;
+
+# We use streams
+my $proto = getprotobyname('tcp');
+
+# Open Server socket
+socket(Server, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
+setsockopt(Server, SOL_SOCKET, SO_REUSEADDR, pack("l", 1))
+  or die "setsocketopt: $!";
+bind (Server, sockaddr_in($port, INADDR_ANY))
+  or die "bind: $!";
+listen (Server, SOMAXCONN)
+  or die "listen: $!";
+
+%authhosts = ();
+# get authorized hosts
+open (AUTH, $authfile)
+  or logmsg ("notice", 2, "Could not read allowed hosts file: $authfile");
+while (<AUTH>) {
+    chomp;
+    my $host = lc $_;
+     if ($host =~ /^[\d\w]/) {
+	 $authhosts{$_} = 1;
+	 logmsg ("notice", 2, "Authorized host: >$host<");
+     }
+}
+close (AUTH);
+
+# tell about open server socket
+logmsg ("notice", 2, "Server started at port $port");
+
+my $waitedpid = 0;
+my $paddr;
+
+# wait for children to return, thus avoiding zombies
+# improvement (*)
+use POSIX ":sys_wait_h";
+sub REAPER {
+  my $child;
+  while (($waitedpid = waitpid(-1,WNOHANG)) > 0) {
+    logmsg ("notice", 2, "reaped $waitedpid", ($? ? " with exit $?" : ""));
+  }
+  $SIG{CHLD} = \&REAPER;  # loathe sysV
+}
+
+# also all sub-processes should wait for their children
+$SIG{CHLD} = \&REAPER;
+
+# start a new server for every incoming request
+# improvement (*) -- loop forever
+
+while ( 1 ) {
+  for ( $waitedpid = 0;
+	($paddr = accept(Client,Server)) || $waitedpid;
+	$waitedpid = 0, close Client ) {
+    next if $waitedpid and not $paddr;
+    my ($port, $iaddr) = sockaddr_in($paddr);
+    my $name = lc gethostbyaddr($iaddr, AF_INET);
+    my $ipaddr = inet_ntoa($iaddr);
+    my $n = 0;
+
+# tell about the requesting client
+    logmsg ("info", 2, "Connection from >$ipaddr< ($name) at port $port");
+
+    spawn sub {
+      my ($head, $hlen, $pos, $pegel, $typ, $siz, $nch, $nrec, $dat, $i, $j, $n, $llen); 
+      my ($watchpegel, $shmpegel);
+      my ($rin, $rout, $in, $line, $data_requested, $oversample);
+      my (@channels);
+
+#   to use stdio on writing to Client
+      Client->autoflush();
+
+#   Open Device
+      sysopen (DEV, "$dev", O_RDWR | O_NONBLOCK, 0666) or die("can't open $dev");
+
+#   Bitmask to check for input on stdin
+      $rin = "";
+      vec($rin, fileno(Client), 1) = 1;
+
+#   check for authorized hosts
+      my $access = 'deny';
+      $access = 'allow' if $authhosts{$ipaddr};
+      $line = "<remote_host host=\"$ipaddr\" access=\"$access\">\n";
+      logmsg ("info", 2, $line);
+      $len = length $line;
+      $offset = 0;
+      while ($len) {
+	$written = syswrite (DEV, $line, $len, $offset);
+	$len -= $written;
+	$offset += $written;
+      }
+
+      while ( 1 ) {
+	$in = select ($rout=$rin, undef, undef, 0.0); # poll client
+#     look for any Input from Client
+	if ($in) {
+#       exit on EOF
+	  $len = sysread (Client, $line, $blksize) or exit;
+	  logmsg("info", 0, "got $len bytes: \"$line\"");
+	  $offset = 0;
+#       copy request to device
+	  while ($len) {
+	    $written = syswrite (DEV, $line, $len, $offset);
+	    $len -= $written;
+	    $offset += $written;
+	  }
+	}
+#     look for some output from device
+	if ($len = sysread DEV, $stream, $blksize) {
+	  print Client $stream;
+	} else {
+	  select undef, undef, undef, 0.1; # calm down if nothing on device
+	}
+      }
+    };
+    logmsg("info", 2, "spawned\n");
+  }
+  logmsg("info", 2, "server loop\n");
+}
+
+sub spawn {
+  my $coderef = shift;
+
+  unless (@_ == 0 && $coderef && ref($coderef) eq 'CODE') {
+    confess "usage: spawn CODEREF";
+  }
+  my $pid;
+  if (!defined($pid = fork)) {
+    logmsg ("notice", 2, "fork failed: $!");
+    return;
+  } elsif ($pid) {
+    logmsg ("notice", 2, "Request $pid");
+    return; # Parent
+  }
+
+# do not use fdup as in the original example
+# open (STDIN, "<&Client") or die "Can't dup client to stdin";
+# open (STDOUT, ">&Client") or die "Can't dup client to stdout";
+# STDOUT->autoflush();
+  exit &$coderef();
+}