#!/usr/bin/perl -w

require 5.004;

use strict;

print "Enter port the server should listen on [42800]: ";

my $port = <stdin>; chop $port;

$port = 42800 unless $port =~ /^\d+$/;

print "\nUser name or UID to run as [nobody]: ";

my $user = <stdin>; chop $user; $user = 'nobody' if $user eq '';

my ($login, $pass, $uid, $gid);

unless ($user =~ /^\d+$/) {

    ($login, $pass, $uid, $gid) = getpwnam ($user) or

	die "User '$user' not in passwd file.";

}

my $g_default = (defined $gid) ? $gid : 'nogroup';

print "Group name or GID to run as [$g_default]: ";

my $group = <stdin>; chop $group; $group = $g_default if $group eq '';

unless ($group =~ /^\d+$/) {

    $gid = getgrnam ($group) or

	die "Group '$group' not in group file.";

}

print "\nEnter list of hosts which should be authorized to";

print "\nconnect to the server (terminate with a blank line):\n\n";

print "SECURITY WARNING:\n";

print "  Enabling access for a particular hosts means the ALL USERS on this host will\n";

print "  be allowed to connect to the server !\n\n";

print "  If you want security, let this table empty and use the 'xauth' method instead.\n";

print "  Look at the manpage of gnuserv (1) as shipped with GNU Emacs for more details\n";

print "  about security. The server uses the same security mechanisms like gnuserv from\n";

print "  XEmacs 20.3\n\n";

my @hosts = ();

my @host_addrs = ();

my @host_names = ();

while (1) {

    print "Host: ";

    my $host = <stdin>; chop $host; 

    last if $host eq '';

    my ($name,$aliases,$addrtype,$length,@addrs) = gethostbyname ($host) or

	die "gethostbyname (): Can't resolve '$host'";

    my ($a,$b,$c,$d) = unpack('C4',$addrs[0]);

    push @hosts, sprintf ("0x%02X%02X%02X%02X", $d, $c, $b, $a);

    push @host_addrs, sprintf ("%d.%d.%d.%d", $a, $b, $c, $d);

    push @host_names, $name;

};

print "\n";

print "This is your config:\n";

print "====================\n\n"; 

printf qq[%-30s: %d\n\n], 'Port', $port;

printf qq[%-30s: %d\n], 'UID', $uid;

printf qq[%-30s: %d\n\n], 'GID', $gid;

foreach (0..$#hosts) {

    printf qq[%-30s (%s - %s)\n], $host_names[$_], $hosts[$_], $host_addrs [$_];

}

print "\n";

print "Accept? (yes/no) ";

my $accept = <stdin>; chop $accept;

exit unless $accept eq 'yes';

print "\n";

open CONFIG, "> server_config.h" or

    die "open (server_config.h): $!";

select CONFIG;

printf qq[\#define SERVER_PORT\t\t%d\n\n], $port;

printf qq[\#define SERVER_UID\t\t%d\n], $uid;

printf qq[\#define SERVER_GID\t\t%d\n\n], $gid;

printf qq[\#define HOST_TABLE_ENTRIES\t%d\n\n], $#hosts + 1;

foreach (@host_names) {

    $_ = qq["$_"];

}

printf qq[const char *permitted_host_names [HOST_TABLE_ENTRIES] = \n];

printf qq[{ %s };\n\n], join (', ', @host_names);

printf qq[unsigned long permitted_hosts [HOST_TABLE_ENTRIES];\n];

close CONFIG;

select STDOUT;

print "Your config has successfully been written to 'server_config.h'.\n";