1 #!/usr/bin/perl -w |
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2 |
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3 #------------------------------------------------------------------------------ |
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4 # |
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5 # Copyright (C) 2006 Ingenieurgemeinschaft IgH |
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6 # |
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7 # This file is part of the IgH EtherCAT Master. |
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8 # |
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9 # The IgH EtherCAT Master is free software; you can redistribute it |
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10 # and/or modify it under the terms of the GNU General Public License |
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11 # as published by the Free Software Foundation; version 2 of the License. |
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12 # |
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13 # The IgH EtherCAT Master is distributed in the hope that it will be |
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14 # useful, but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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16 # GNU General Public License for more details. |
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17 # |
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18 # You should have received a copy of the GNU General Public License |
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19 # along with the IgH EtherCAT Master; if not, write to the Free Software |
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20 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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21 # |
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22 #------------------------------------------------------------------------------ |
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23 # |
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24 # Multithreaded Server |
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25 # according to the example from "Programming Perl" |
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26 # this code is improved according to the example from |
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27 # perldoc perlipc, so now safely being usable under Perl 5.8 |
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28 # (see note (*)) |
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29 # |
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30 # works with read/write on a device-file |
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31 # |
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32 #------------------------------------------------------------------------------ |
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33 |
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34 require 5.002; |
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35 use strict; |
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36 BEGIN { $ENV{PATH} = '/opt/msr/bin:/usr/bin:/bin' } |
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37 use Socket; |
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38 use Carp; |
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39 use FileHandle; |
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40 use Getopt::Std; |
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41 |
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42 use Sys::Syslog qw(:DEFAULT setlogsock); |
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43 |
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44 use vars qw ( |
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45 $self $pid $dolog $port $dev %opts $selfbase |
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46 $len $offset $stream $written $read $log $blksize |
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47 $instdir |
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48 $authfile %authhosts |
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49 ); |
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50 |
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51 |
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52 # Do logging to local syslogd by unix-domain socket instead of inetd |
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53 setlogsock("unix"); |
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54 |
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55 # Prototypes and some little Tools |
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56 sub spawn; |
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57 sub logmsg { |
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58 my ($level, $debug, @text) = @_; |
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59 syslog("daemon|$level", @text) if $debug > $dolog; |
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60 # print STDERR "daemon|$level", @text, "\n" if $dolog; |
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61 } |
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62 sub out { |
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63 my $waitpid = wait; |
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64 logmsg("notice", 2, "$waitpid exited"); |
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65 unlink "$selfbase.pid"; |
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66 exit 0; |
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67 } |
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68 |
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69 sub help { |
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70 print "\n usage: $0 [-l og] [-h elp] [-p port] [-d device]\n"; |
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71 exit; |
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72 } |
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73 |
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74 # Process Options |
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75 %opts = ( |
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76 "l" => 1, |
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77 "h" => 0, |
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78 "p" => 2345, |
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79 "d" => "/dev/msr" |
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80 ); |
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81 |
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82 getopts("lhp:d:", \%opts); |
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83 |
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84 help if $opts{"h"}; |
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85 |
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86 ( $self = $0 ) =~ s+.*/++ ; |
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87 ( $selfbase = $self ) =~ s/\..*//; |
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88 $log = "$selfbase.log"; |
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89 $dolog = $opts{"l"}; |
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90 $port = $opts{"p"}; |
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91 $dev = $opts{"d"}; |
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92 $blksize = 1024; # try to write as much bytes |
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93 $instdir = "/opt/msr"; |
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94 $authfile = "$instdir/etc/hosts.auth"; |
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95 |
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96 # Start logging |
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97 openlog($self, 'pid'); |
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98 |
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99 # Flush Output, dont buffer |
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100 $| = 1; |
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101 |
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102 # first fork and run in background |
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103 if ($pid = fork) { |
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104 # open LOG, ">$log" if $dolog; |
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105 # close LOG; |
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106 logmsg("notice", 2, "forked process: $pid\n"); |
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107 exit 0; |
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108 } |
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109 |
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110 # Server tells about startup success |
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111 open (PID, ">/$instdir/var/run/$selfbase.pid"); |
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112 print PID "$$\n"; |
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113 close PID; |
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114 |
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115 # Cleanup on exit (due to kill -TERM signal) |
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116 $SIG{TERM} = \&out; |
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117 |
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118 # We use streams |
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119 my $proto = getprotobyname('tcp'); |
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120 |
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121 # Open Server socket |
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122 socket(Server, PF_INET, SOCK_STREAM, $proto) or die "socket: $!"; |
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123 setsockopt(Server, SOL_SOCKET, SO_REUSEADDR, pack("l", 1)) |
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124 or die "setsocketopt: $!"; |
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125 bind (Server, sockaddr_in($port, INADDR_ANY)) |
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126 or die "bind: $!"; |
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127 listen (Server, SOMAXCONN) |
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128 or die "listen: $!"; |
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129 |
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130 %authhosts = (); |
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131 # get authorized hosts |
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132 open (AUTH, $authfile) |
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133 or logmsg ("notice", 2, "Could not read allowed hosts file: $authfile"); |
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134 while (<AUTH>) { |
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135 chomp; |
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136 my $host = lc $_; |
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137 if ($host =~ /^[\d\w]/) { |
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138 $authhosts{$_} = 1; |
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139 logmsg ("notice", 2, "Authorized host: >$host<"); |
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140 } |
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141 } |
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142 close (AUTH); |
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143 |
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144 # tell about open server socket |
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145 logmsg ("notice", 2, "Server started at port $port"); |
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146 |
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147 my $waitedpid = 0; |
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148 my $paddr; |
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149 |
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150 # wait for children to return, thus avoiding zombies |
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151 # improvement (*) |
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152 use POSIX ":sys_wait_h"; |
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153 sub REAPER { |
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154 my $child; |
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155 while (($waitedpid = waitpid(-1,WNOHANG)) > 0) { |
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156 logmsg ("notice", 2, "reaped $waitedpid", ($? ? " with exit $?" : "")); |
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157 } |
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158 $SIG{CHLD} = \&REAPER; # loathe sysV |
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159 } |
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160 |
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161 # also all sub-processes should wait for their children |
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162 $SIG{CHLD} = \&REAPER; |
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163 |
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164 # start a new server for every incoming request |
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165 # improvement (*) -- loop forever |
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166 |
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167 while ( 1 ) { |
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168 for ( $waitedpid = 0; |
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169 ($paddr = accept(Client,Server)) || $waitedpid; |
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170 $waitedpid = 0, close Client ) { |
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171 next if $waitedpid and not $paddr; |
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172 my ($port, $iaddr) = sockaddr_in($paddr); |
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173 my $name = lc gethostbyaddr($iaddr, AF_INET); |
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174 my $ipaddr = inet_ntoa($iaddr); |
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175 my $n = 0; |
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176 |
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177 # tell about the requesting client |
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178 logmsg ("info", 2, "Connection from >$ipaddr< ($name) at port $port"); |
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179 |
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180 spawn sub { |
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181 my ($head, $hlen, $pos, $pegel, $typ, $siz, $nch, $nrec, $dat, $i, $j, $n, $llen); |
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182 my ($watchpegel, $shmpegel); |
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183 my ($rin, $rout, $in, $line, $data_requested, $oversample); |
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184 my (@channels); |
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185 |
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186 # to use stdio on writing to Client |
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187 Client->autoflush(); |
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188 |
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189 # Open Device |
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190 sysopen (DEV, "$dev", O_RDWR | O_NONBLOCK, 0666) or die("can't open $dev"); |
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191 |
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192 # Bitmask to check for input on stdin |
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193 $rin = ""; |
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194 vec($rin, fileno(Client), 1) = 1; |
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195 |
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196 # check for authorized hosts |
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197 my $access = 'deny'; |
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198 $access = 'allow' if $authhosts{$ipaddr}; |
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199 $line = "<remote_host host=\"$ipaddr\" access=\"$access\">\n"; |
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200 logmsg ("info", 2, $line); |
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201 $len = length $line; |
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202 $offset = 0; |
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203 while ($len) { |
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204 $written = syswrite (DEV, $line, $len, $offset); |
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205 $len -= $written; |
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206 $offset += $written; |
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207 } |
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208 |
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209 while ( 1 ) { |
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210 $in = select ($rout=$rin, undef, undef, 0.0); # poll client |
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211 # look for any Input from Client |
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212 if ($in) { |
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213 # exit on EOF |
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214 $len = sysread (Client, $line, $blksize) or exit; |
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215 logmsg("info", 0, "got $len bytes: \"$line\""); |
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216 $offset = 0; |
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217 # copy request to device |
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218 while ($len) { |
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219 $written = syswrite (DEV, $line, $len, $offset); |
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220 $len -= $written; |
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221 $offset += $written; |
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222 } |
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223 } |
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224 # look for some output from device |
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225 if ($len = sysread DEV, $stream, $blksize) { |
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226 print Client $stream; |
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227 } else { |
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228 select undef, undef, undef, 0.1; # calm down if nothing on device |
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229 } |
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230 } |
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231 }; |
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232 logmsg("info", 2, "spawned\n"); |
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233 } |
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234 logmsg("info", 2, "server loop\n"); |
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235 } |
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236 |
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237 sub spawn { |
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238 my $coderef = shift; |
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239 |
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240 unless (@_ == 0 && $coderef && ref($coderef) eq 'CODE') { |
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241 confess "usage: spawn CODEREF"; |
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242 } |
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243 my $pid; |
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244 if (!defined($pid = fork)) { |
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245 logmsg ("notice", 2, "fork failed: $!"); |
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246 return; |
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247 } elsif ($pid) { |
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248 logmsg ("notice", 2, "Request $pid"); |
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249 return; # Parent |
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250 } |
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251 |
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252 # do not use fdup as in the original example |
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253 # open (STDIN, "<&Client") or die "Can't dup client to stdin"; |
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254 # open (STDOUT, ">&Client") or die "Can't dup client to stdout"; |
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255 # STDOUT->autoflush(); |
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256 exit &$coderef(); |
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257 } |
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