gdipc.pl

动态域名解决方案。类似windows下的花生壳。代码用perl编写

  close(CONFIG);
  chmod 0600, $configfile;

  # initialise cache file
  open(CACHE, ">$cachefile") or
    die "Could not create cache file $cachefile: $!\n";
  print CACHE "0.0.0.0;0\n";
  close(CACHE);
  chmod 0600, $cachefile;
}

# check address and connect to server to send update
sub sendlogin {
  my $username = shift;
  my $password = shift;
  my $domain = shift;
  my $serverip = shift;
  my $serveraction = shift;
  my $cachefile = shift;
  my $mintime = shift;
  my $maxtime = shift;

  # trust $serverip
  if ($serverip =~ /(.*)/) {
    $serverip = $1;
  }

  # last three arguments passed?
  my $cacheip   = '0.0.0.0';
  my $cachetime = '0';
  if (! $cachefile) {
    $mintime = 0;
    $maxtime = 0;
  } else {

    # trust $cachefile
    if ($cachefile =~ /(.*)/) {
      $cachefile = $1;
    }

    print "Cache file name: $cachefile\n";

    # read cache
    if (open(CACHE, "$cachefile")) {
      my $line = <CACHE>;
      if ($line) {
        chomp($line);
        ($cacheip, $cachetime) = split(/;/,$line);
      }
      close(CACHE);
    }
  }

  # requesting offline, but already offline?
  if (!$opt_i and $serveraction eq '1' and $cacheip eq '0.0.0.0') {
    print "No update done for $username.$domain - already offline\n";
    return;
  }

  # use query command to get address?
  callquery()
    if $serveraction eq '0' and $opt_q and !$queryaddress;

  # current time
  my $timenow = time;

  # update wanted but not needed?
  if (($serveraction eq '0' or $serveraction eq '2') and
      $cacheip ne '0.0.0.0') {

    # maximum time not exceeded?
    if ($timenow < ($cachetime + $maxtime)) {

      # address still valid?
      if (checkaddress($cacheip)) {
        print "No update done for $username.$domain - $cacheip still valid\n";
        return;
      }

      # not enough time gone by?
      if ($timenow < ($cachetime + $mintime)) {
        print "No update from $cacheip done for $username.$domain - too soon\n";
        return;
      }
    }
  }

  # get server type, address, port and URL
  my $srvtype = 'd';
  my ($serverhost, $serverport, $url);
  if ($serverip =~ /^http:\/\/(.*?)(\/.*)$/) {
    # web server
    $srvtype = 'w';
    $serverip = $1;
    $url = $2;
    ($serverhost, $serverport) = split(/:/, $serverip . ':80');
  } else {
    # direct TCP connection
    ($serverhost, $serverport) = split(/:/, $serverip . ':3495');
  }

  # start the update
  print "Attempting update at $serverhost ...\n";
  my $inet_addr = gethostbyname($serverhost);
  if (!$inet_addr) {
    print "Could not do DNS lookup for $serverhost\n";
    return;
  }
  my $paddr = sockaddr_in($serverport, $inet_addr);

  # connect to server
  socket(SERVER, PF_INET, SOCK_STREAM, getprotobyname('tcp'));
  if (!connect(SERVER, $paddr)) {
    print "Could not connect to $serverhost:$serverport\n";
    return;
  }

  # set autoflush on
  select(SERVER);
  $| = 1;
  select(STDOUT);

  # retrieve the salt (et al)
  my $salt;
  my $gentime;
  my $checkval;

  # HTTP headers
  my $httphdrs = "HTTP/1.0\r
User-Agent: GnuDIP/2.3.5\r
Pragma: no-cache\r
Host: $serverhost:$serverport\r
\r
";

  # direct TCP connection
  if ($srvtype eq 'd') {
    $salt = <SERVER>;
    $salt = '' if ! defined $salt;
    chomp($salt);

  # web server
  } else {
    #print "GET $url $httphdrs";
    print SERVER "GET $url $httphdrs";
    my %resp = ();
    while (my $line = <SERVER>) {
      $line = '' if ! defined $line;
      chomp($line);
      #print "$line\n";
      if ($line =~ /^<meta name=\"(.*)\" content=\"(.*)\">$/) {
        $resp{$1} = $2;
      }
    }
    close SERVER;
    $salt     = $resp{'salt'};
    $gentime  = $resp{'time'};
    $checkval = $resp{'sign'};

    # reconnect
    socket(SERVER, PF_INET, SOCK_STREAM, getprotobyname('tcp'));
    if (!connect(SERVER, $paddr)) {
      print "Could not reconnect to $serverhost:$serverport\n";
      return;
    }
    select(SERVER);
    $| = 1;
    select(STDOUT);
  }

  # got a salt?
  if (!$salt) {
    print "Server did not send salt for $username.$domain\n";
    close SERVER;
    return;
  }

  # get our IP address
  my $ip;

  # have address from query?
  if ($queryaddress) {
    $ip = $queryaddress;

  # get IP address of our end of connection
  } else {
    my $client_addr = getsockname(SERVER);
    if (!$client_addr) {
      print "Could not get our IP address for $username.$domain\n";
      close(SERVER);
      return;
    }
    my ($port, $packed_ip) = sockaddr_in($client_addr);
    $ip = inet_ntoa($packed_ip);
  }

  # salt and digest password
  $password = md5_hex("$password.$salt");

  # send update to server and retrieve response
  my $response   = '';
  my $receivedip = '';

  # direct TCP connection
  if ($srvtype eq 'd') {
    my $updmsg = "$username:$password:$domain:$serveraction";
    $updmsg   .= ":$ip" if $serveraction eq '0';
    print SERVER "$updmsg\n";
    $response = <SERVER>;
    close SERVER;
    $response = '' if ! defined $response;
    chomp($response);
    if ($response =~ /^(.*):(.*)$/) {
      $response   = $1;
      $ip         = $2;
      $receivedip = 1;
    }

  # web server
  } else {
    my $updmsg =
      "salt=$salt&time=$gentime&sign=$checkval&user=$username&" .
      "pass=$password&domn=$domain&reqc=$serveraction";
    $updmsg .= "&addr=$ip" if $serveraction eq '0';
    #print "GET $url?$updmsg $httphdrs";
    print SERVER "GET $url?$updmsg $httphdrs";
    my %resp = ();
    while (my $line = <SERVER>) {
      $line = '' if ! defined $line;
      chomp($line);
      #print "$line\n";
      if ($line =~ /^<meta name=\"(.*)\" content=\"(.*)\">$/) {
        $resp{$1} = $2;
      }
    }
    close SERVER;
    $response = $resp{'retc'} if defined $resp{'retc'};
    if (defined $resp{'addr'}) {
      $ip          = $resp{'addr'};
      $receivedip = 1;
    }
  }

  # got a response?
  if ($response eq '') {
    print "Server did not respond to login attempt for $username.$domain\n";
    return;
  }

  # check response
  if ($response eq '0') {
    if ($serveraction eq '2' and !$receivedip) {
      print "Server did not send IP address for $username.$domain\n";
    } else {
      if ($cachefile) {
        if (!open(CACHE, ">$cachefile")) {
          print "Could not write cache file $cachefile: $!\n";
        } else {
          print CACHE "$ip;$timenow\n";
          close(CACHE);
          # address changed?
          $addrchange = 1 if $cacheip ne $ip;
          # good address (was not tested if past max time))
          $chkaddr{$ip} = 1;
        }
        print "Update to address $ip from $cacheip successful for $username.$domain\n";
      } else {
        print "Update to address $ip successful for $username.$domain\n";
      }
    }
  } elsif ($response eq '1') {
    print "Invalid login attempt for $username.$domain\n";
  } elsif ($response eq '2') {
    if ($cachefile) {
      if (!open(CACHE, ">$cachefile")) {
        print "Could not write cache file $cachefile: $!\n";
      } else {
        print CACHE "0.0.0.0;$timenow\n";
        close(CACHE);
        # address changed?
        $addrchange = 1 if $cacheip ne '0.0.0.0';
      }
    }
    print "Offline request successful for $username.$domain\n";
  } else {
    print "Server sent invalid response to login attempt for $username.$domain\n";
  }
}

# check whether an address is valid
# - uses address from query command if available and compares it
#   to the cached address, otherwise:
# - sends random data to the cached address
# - if it receives it back the address is good
sub checkaddress {

  # get parameter
  my $testip = shift;
  return '' if ! defined $testip;

  # trust $testip
  if ($testip =~ /(.*)/) {
    $testip = $1;
  }

  # already checked this address?
  return $chkaddr{$testip} if defined $chkaddr{$testip};

  # assume bad address
  $chkaddr{$testip} = '';

  # have address from query?
  if ($queryaddress) {

    # address the same?
    if ($testip ne $queryaddress) {
      print "Address returned by \"-q\" does not match cached address\n";
      return '';
    }

    # good address
    $chkaddr{$testip} = 1;
    return 1;
  }

  # generate a test value
  my $testdata = randomsalt();

  # print a trace to STDERR?
  my $trace = '';
  #$trace = 1;

  # bind socket for receive
  socket(RECEIVE, PF_INET, SOCK_DGRAM, getprotobyname('udp'))
    || die "socket for RECEIVE failed in checkaddress: $!\n";
  setsockopt(RECEIVE, SOL_SOCKET, SO_REUSEADDR, pack("l", 1))
    || die "setsockopt failed in checkaddress: $!\n";
  bind(RECEIVE, sockaddr_in($recvport, INADDR_ANY))
    || die "bind failed in checkaddress: $!\n";

  # random port being used to receive? (no gateway?)
  ($sendport) = sockaddr_in(getsockname(RECEIVE)) if $recvport eq 0;

  # send packet
  socket(SEND, PF_INET, SOCK_DGRAM, getprotobyname('udp'))
    || die "socket for SEND failed in checkaddress: $!\n";
  if (! send(SEND, $testdata, 0, sockaddr_in($sendport, inet_aton($testip)))) {
    close SEND;
    close RECEIVE;
    # not a good address
    print "Address validation failed for $testip - send failed: $!\n";
    return '';
  }
  print STDERR "sent data: $testdata\n" if $trace;
  close SEND;

  # wait for packet, with a timeout
  my $sin = '';
  vec($sin, fileno(RECEIVE), 1) = 1;
  if (! select($sin, undef, undef, $opt_w)) {
    print STDERR "select failed\n" if $trace;
    close RECEIVE;
    # not a good address
    print "Address validation failed for $testip - UDP packet timed out\n";
    return '';
  }

  # receive it
  print STDERR "select succeeded\n" if $trace;
  recv(RECEIVE, my $check, 20, 0)
    || die "receive failed in checkaddress: $!\n";
  close RECEIVE;
  print STDERR "received data: $check\n" if $trace;

  # data matches?
  if ($check ne $testdata) {
    print "Address validation failed for $testip - data not matched\n";
    return '';
  }

  # good address
  $chkaddr{$testip} = 1;
  return 1;
}

# call query command to get address
sub callquery {

  # flush before command
  select(STDERR);
  $| = 1;
  select(STDOUT);
  $| = 1;

  # call the command
  $queryaddress = `$opt_q`;
  my $retcode = $?;
  $retcode = $retcode >> 8;

  # command succeeded?
  if (! defined $queryaddress) {
    print "Query command failed - no ouput retrieved\n";
    exit 1;
  } elsif ($retcode != 0) {
    print "Query command returned non-zero status: $retcode\n";
    exit 1;
  }
  chomp($queryaddress);
  if (!$queryaddress) {
    print "Query command returned empty address\n";
    exit 1;
  }

  print "Query command returned address $queryaddress\n";
}

# make 10 character random string
sub randomsalt {
  my @chars = ( 'A' .. 'Z', 'a' .. 'z', 0 .. 9);
  my $str = '';
  for (my $charcount = 0; $charcount < 10; $charcount++) {
    $str .= $chars[ rand @chars ];
  }
  return $str;
}