65e3bee395b0135050aa5b2b9aec64978de7f163
[ipfire-2.x.git] / html / cgi-bin / ddns.cgi
1 #!/usr/bin/perl
2 ###############################################################################
3 #                                                                             #
4 # IPFire.org - A linux based firewall                                         #
5 # Copyright (C) 2007-2014  IPFire Team  <info@ipfire.org>                     #
6 #                                                                             #
7 # This program is free software: you can redistribute it and/or modify        #
8 # it under the terms of the GNU General Public License as published by        #
9 # the Free Software Foundation, either version 3 of the License, or           #
10 # (at your option) any later version.                                         #
11 #                                                                             #
12 # This program is distributed in the hope that it will be useful,             #
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
15 # GNU General Public License for more details.                                #
16 #                                                                             #
17 # You should have received a copy of the GNU General Public License           #
18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
19 #                                                                             #
20 ###############################################################################
21
22 use strict;
23
24 # enable only the following on debugging purpose
25 #use warnings;
26 #use CGI::Carp 'fatalsToBrowser';
27
28 require '/var/ipfire/general-functions.pl';
29 require "${General::swroot}/lang.pl";
30 require "${General::swroot}/header.pl";
31
32 #workaround to suppress a warning when a variable is used only once
33 my @dummy = ( ${Header::table2colour}, ${Header::colouryellow} );
34 undef (@dummy);
35
36 my %color = ();
37 my %mainsettings = ();
38 &General::readhash("${General::swroot}/main/settings", \%mainsettings);
39 &General::readhash("/srv/web/ipfire/html/themes/".$mainsettings{'THEME'}."/include/colors.txt", \%color);
40
41 # Config file for basic configuration.
42 my $settingsfile = "${General::swroot}/ddns/settings";
43
44 # Config file to store the configured ddns providers.
45 my $datafile = "${General::swroot}/ddns/config";
46
47 # Dynamic ddns programm call.
48 my @ddnsprog = ("/usr/bin/ddns", "--config",
49                 "/var/ipfire/ddns/ddns.conf",
50                 "update-all");
51
52 my %settings=();
53 my $errormessage = '';
54
55 # DDNS General settings.
56 $settings{'BEHINDROUTER'} = 'RED_IP';
57
58 # Account settings.
59 $settings{'HOSTNAME'} = '';
60 $settings{'DOMAIN'} = '';
61 $settings{'LOGIN'} = '';
62 $settings{'PASSWORD'} = '';
63 $settings{'ENABLED'} = '';
64 $settings{'PROXY'} = '';
65 $settings{'SERVICE'} = '';
66
67 $settings{'ACTION'} = '';
68
69 # Get supported ddns providers.
70 my @providers = &GetProviders();
71
72 # Hook to regenerate the configuration files, if cgi got called from command line.
73 if ($ENV{"REMOTE_ADDR"} eq "") {
74         &GenerateDDNSConfigFile();
75         exit(0);
76 }
77
78 &Header::showhttpheaders();
79
80 #Get GUI values
81 &Header::getcgihash(\%settings);
82
83 # Read configuration file.
84 open(FILE, "$datafile") or die "Unable to open $datafile.";
85 my @current = <FILE>;
86 close (FILE);
87
88 #
89 # Save General Settings.
90 #
91 if ($settings{'ACTION'} eq $Lang::tr{'save'}) {
92
93         # Open /var/ipfire/ddns/settings for writing.
94         open(FILE, ">$settingsfile") or die "Unable to open $settingsfile.";
95
96         # Lock file for writing.
97         flock FILE, 2;
98
99         # Check if BEHINDROUTER has been configured.
100         if ($settings{'BEHINDROUTER'} ne '') {
101                 print FILE "BEHINDROUTER=$settings{'BEHINDROUTER'}\n";
102         }
103
104         # Close file after writing.
105         close(FILE);
106
107         # Unset given CGI parmas.
108         undef %settings;
109
110         # Update ddns config file.
111         &GenerateDDNSConfigFile();
112 }
113
114 #
115 # Toggle enable/disable field.  Field is in second position
116 #
117 if ($settings{'ACTION'} eq $Lang::tr{'toggle enable disable'}) {
118
119         # Open /var/ipfire/ddns/config for writing.
120         open(FILE, ">$datafile") or die "Unable to open $datafile.";
121
122         # Lock file for writing.
123         flock FILE, 2;
124
125         my @temp;
126         my $id = 0;
127
128         # Read file line by line.
129         foreach my $line (@current) {
130
131                 # Remove newlines.
132                 chomp($line);
133
134                 if ($settings{'ID'} eq $id) {
135
136                         # Splitt lines (splitting element is a single ",") and save values into temp array.
137                         @temp = split(/\,/,$line);
138
139                         # Check if we want to toggle ENABLED or WILDCARDS.
140                         if ($settings{'ENABLED'} ne '') {
141
142                                 # Update ENABLED.
143                                 print FILE "$temp[0],$temp[1],$temp[2],$temp[3],$temp[4],$temp[5],$temp[6],$settings{'ENABLED'}\n";
144                         }
145                 } else {
146
147                         # Print unmodified line.
148                         print FILE "$line\n";
149                 }
150
151                 # Increase $id.
152                 $id++;
153         }
154
155         # Close file after writing.
156         close(FILE);
157
158         # Unset given CGI params.
159         undef %settings;
160
161         # Write out logging notice.
162         &General::log($Lang::tr{'ddns hostname modified'});
163
164         # Update ddns config file.
165         &GenerateDDNSConfigFile();
166 }
167
168 #
169 # Add new accounts, or edit existing ones.
170 #
171 if (($settings{'ACTION'} eq $Lang::tr{'add'}) || ($settings{'ACTION'} eq $Lang::tr{'update'})) {
172
173         # Check if a hostname has been given.
174         if ($settings{'HOSTNAME'} eq '') {
175                 $errormessage = $Lang::tr{'hostname not set'};
176         }
177
178         # Check if a valid domainname has been provided.
179         if (!&General::validdomainname($settings{'HOSTNAME'})) {
180                 $errormessage = $Lang::tr{'invalid domain name'};
181         }
182
183         # Check if a username has been sent.
184         if ($settings{'LOGIN'} eq '') {
185                 $errormessage = $Lang::tr{'username not set'};
186         }
187
188         # Check if a password has been typed in.
189         # freedns.afraid.org does not require this field.
190         if (($settings{'PASSWORD'} eq '') && ($settings{'SERVICE'} ne 'freedns.afraid.org') && ($settings{'SERVICE'} ne 'regfish.com')) {
191                 $errormessage = $Lang::tr{'password not set'};
192         }
193
194         # Go furter if there was no error.
195         if ( ! $errormessage) {
196
197                 # Splitt hostname field into 2 parts for storrage.
198                 my($hostname, $domain) = split(/\./, $settings{'HOSTNAME'}, 2);
199
200                 # Handle adding new accounts.
201                 if ($settings{'ACTION'} eq $Lang::tr{'add'}) {
202
203                         # Open /var/ipfire/ddns/config for writing.
204                         open(FILE, ">>$datafile") or die "Unable to open $datafile.";
205
206                         # Lock file for writing.
207                         flock FILE, 2;
208
209                         # Add account data to the file.
210                         print FILE "$settings{'SERVICE'},$hostname,$domain,$settings{'PROXY'},$settings{'WILDCARDS'},$settings{'LOGIN'},$settings{'PASSWORD'},$settings{'ENABLED'}\n";
211
212                         # Close file after writing.
213                         close(FILE);
214
215                         # Write out notice to logfile.
216                         &General::log($Lang::tr{'ddns hostname added'});
217
218                         # Update ddns config file.
219
220                 # Handle account edditing.
221                 } elsif ($settings{'ACTION'} eq $Lang::tr{'update'}) {
222
223                         # Open /var/ipfire/ddns/config for writing.
224                         open(FILE, ">$datafile") or die "Unable to open $datafile.";
225
226                         # Lock file for writing.
227                         flock FILE, 2;
228
229                         my $id = 0;
230
231                         # Read file line by line.
232                         foreach my $line (@current) {
233
234                                 if ($settings{'ID'} eq $id) {
235                                         print FILE "$settings{'SERVICE'},$hostname,$domain,$settings{'PROXY'},$settings{'WILDCARDS'},$settings{'LOGIN'},$settings{'PASSWORD'},$settings{'ENABLED'}\n";
236                                 } else {
237                                         print FILE "$line";
238                                 }
239
240                                 # Increase $id.
241                                 $id++;
242                         }
243
244                         # Close file after writing.
245                         close(FILE);
246
247                         # Write out notice to logfile.
248                         &General::log($Lang::tr{'ddns hostname modified'});
249                 }
250
251                 # Unset given CGI params.
252                 undef %settings;
253
254                 # Update ddns config file.
255                 &GenerateDDNSConfigFile();
256         }
257 }
258
259 #
260 # Remove existing accounts.
261 #
262 if ($settings{'ACTION'} eq $Lang::tr{'remove'}) {
263
264         # Open /var/ipfire/ddns/config for writing.
265         open(FILE, ">$datafile") or die "Unable to open $datafile.";
266
267         # Lock file for writing.
268         flock FILE, 2;
269
270         my $id = 0;
271
272         # Read file line by line.
273         foreach my $line (@current) {
274
275                 # Write back every line, except the one we want to drop
276                 # (identified by the ID)
277                 unless ($settings{'ID'} eq $id) {
278                         print FILE "$line";
279                 }
280
281                 # Increase id.
282                 $id++;
283         }
284
285         # Close file after writing.
286         close(FILE);
287
288         # Unset given CGI params.
289         undef %settings;
290
291         # Write out notice to logfile.
292         &General::log($Lang::tr{'ddns hostname removed'});
293
294         # Update ddns config file.
295         &GenerateDDNSConfigFile();
296 }
297
298 #
299 # Read items for editing.
300 #
301 if ($settings{'ACTION'} eq $Lang::tr{'edit'}) {
302
303         my $id = 0;
304         my @temp;
305
306         # Read file line by line.
307         foreach my $line (@current) {
308
309                 if ($settings{'ID'} eq $id) {
310
311                         # Remove newlines.
312                         chomp($line);
313
314                         # Splitt lines (splitting element is a single ",") and save values into temp array.
315                         @temp = split(/\,/,$line);
316
317                         $settings{'SERVICE'} = $temp[0];
318                         $settings{'HOSTNAME'} = "$temp[1].$temp[2]";
319                         $settings{'PROXY'} = $temp[3];
320                         $settings{'WILDCARDS'} = $temp[4];
321                         $settings{'LOGIN'} = $temp[5];
322                         $settings{'PASSWORD'} = $temp[6];
323                         $settings{'ENABLED'} = $temp[7];
324                 }
325         # Increase $id.
326         $id++;
327
328         }
329 }
330
331 #
332 # Handle forced updates.
333 #
334 if ($settings{'ACTION'} eq $Lang::tr{'instant update'}) {
335     system(@ddnsprog) == 0 or die "@ddnsprog failed: $?\n";
336 }
337
338 #
339 # Set default values.
340 #
341 if (! $settings{'ACTION'}) {
342         $settings{'SERVICE'} = 'dyndns.org';
343         $settings{'ENABLED'} = 'on';
344 }
345
346 &Header::openpage($Lang::tr{'dynamic dns'}, 1, '');
347 &Header::openbigbox('100%', 'left', '', $errormessage);
348
349 # Read file for general ddns settings.
350 &General::readhash($settingsfile, \%settings);
351
352 my %checked =();
353 $checked{'BEHINDROUTER'}{'RED_IP'} = '';
354 $checked{'BEHINDROUTER'}{'FETCH_IP'} = '';
355 $checked{'BEHINDROUTER'}{$settings{'BEHINDROUTER'}} = "checked='checked'";
356
357 $checked{'ENABLED'}{'on'} = ($settings{'ENABLED'} eq '' ) ? '' : "checked='checked'";
358
359 # Show box for errormessages..
360 if ($errormessage) {
361     &Header::openbox('100%', 'left', $Lang::tr{'error messages'});
362     print "<font class='base'>$errormessage&nbsp;</font>";
363     &Header::closebox();
364 }
365
366 &Header::openbox('100%', 'left', $Lang::tr{'settings'});
367
368 ##
369 # Section for general ddns setup.
370 print <<END
371 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
372 <table width='100%'>
373         <tr>
374                 <td class='base'>$Lang::tr{'dyn dns source choice'}</td>
375         </tr>
376         <tr>
377                 <td class='base'><input type='radio' name='BEHINDROUTER' value='RED_IP' $checked{'BEHINDROUTER'}{'RED_IP'} />
378                 $Lang::tr{'use ipfire red ip'}</td>
379         </tr>
380         <tr>
381                 <td class='base'><input type='radio' name='BEHINDROUTER' value='FETCH_IP' $checked{'BEHINDROUTER'}{'FETCH_IP'} />
382                 $Lang::tr{'fetch ip from'}</td>
383         </tr>
384 </table>
385 <br />
386 <hr />
387
388 <table width='100%'>
389         <tr>
390                 <td align='right' valign='top' class='base'><input type='submit' name='ACTION' value='$Lang::tr{'save'}' /></td>
391         </tr>
392 </table>
393 </form>
394 END
395 ;
396
397 &Header::closebox();
398
399 ##
400 # Section to add or edit an existing entry.
401
402 # Default is add.
403 my $buttontext = $Lang::tr{'add'};
404
405 # Change buttontext and headline if we edit an account.
406 if ($settings{'ACTION'} eq $Lang::tr{'edit'}) {
407
408         # Rename button and print headline for updating.
409         $buttontext = $Lang::tr{'update'};
410         &Header::openbox('100%', 'left', $Lang::tr{'edit an existing host'});
411 } else {
412
413         # Otherwise use default button text and show headline for adding a new account.
414         &Header::openbox('100%', 'left', $Lang::tr{'add a host'});
415 }
416
417 print <<END
418
419 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
420 <input type='hidden' name='ID' value='$settings{'ID'}' />
421 <table width='100%'>
422         <tr>
423                 <td width='25%' class='base'>$Lang::tr{'service'}:</td>
424                 <td width='25%'>
425 END
426 ;
427                 # Generate dropdown menu for service selection.
428                 print"<select size='1' name='SERVICE'>\n";
429
430                 my $selected;
431
432                 # Loop to print the providerlist.
433                 foreach my $provider (@providers) {
434
435                         # Check if the current provider needs to be selected.
436                         if ($provider eq $settings{'SERVICE'}) {
437                                 $selected = 'selected';
438                         } else {
439                                 $selected = "";
440                         }
441
442                         # Print out the HTML option field.
443                         print "<option value=\"$provider\" $selected>$provider</option>\n";
444                 }
445
446                 print"</select></td>\n";
447 print <<END
448                 <td width='20%' class='base'>$Lang::tr{'hostname'}:</td>
449                 <td width='30%'><input type='text' name='HOSTNAME' value='$settings{'HOSTNAME'}' /></td>
450         </tr>
451
452         <tr>
453                 <td class='base'>$Lang::tr{'enabled'}</td>
454                 <td><input type='checkbox' name='ENABLED' value='on' $checked{'ENABLED'}{'on'} /></td>
455                 <td class='base'>$Lang::tr{'username'}</td>
456                 <td><input type='text' name='LOGIN' value='$settings{'LOGIN'}' /></td>
457         </tr>
458
459         <tr>
460                 <td class='base'></td>
461                 <td></td>
462                 <td class='base'>$Lang::tr{'password'}</td>
463                 <td><input type='password' name='PASSWORD' value='$settings{'PASSWORD'}' /></td>
464         </tr>
465 </table>
466 <br>
467 <hr>
468
469 <table width='100%'>
470 <tr>
471     <td width='30%' align='right' class='base'>
472         <input type='hidden' name='ACTION' value='$buttontext'>
473         <input type='submit' name='SUBMIT' value='$buttontext'></td>
474 </tr>
475 </table>
476 </form>
477 END
478 ;
479 &Header::closebox();
480
481 ##
482 # Third section, display all created ddns hosts.
483 # Re-open file to get changes.
484 open(FILE, $datafile) or die "Unable to open $datafile.";
485 @current = <FILE>;
486 close(FILE);
487
488 # Get IP address of the red interface.
489 my $ip = &General::GetDyndnsRedIP();
490 my $id = 0;
491 my $toggle_enabled;
492
493 if (@current) {
494         &Header::openbox('100%', 'left', $Lang::tr{'current hosts'});
495
496         print <<END;
497 <table width='100%' class='tbl'>
498         <tr>
499                 <th width='30%' align='center' class='boldbase'><b>$Lang::tr{'service'}</b></th>
500                 <th width='50%' align='center' class='boldbase'><b>$Lang::tr{'hostname'}</b></th>
501                 <th width='20%' colspan='3' class='boldbase' align='center'><b>$Lang::tr{'action'}</b></th>
502         </tr>
503 END
504
505         foreach my $line (@current) {
506                 # Remove newlines.
507                 chomp(@current);
508                 my @temp = split(/\,/,$line);
509
510                 # Handle hostname details. Only connect the values with a dott if both are available.
511                 my $hostname="";
512
513                 if (($temp[1]) && ($temp[2])) {
514                         $hostname="$temp[1].$temp[2]";
515                 } else {
516                         $hostname="$temp[1]";
517                 }
518
519                 # Generate value for enable/disable checkbox.
520                 my $sync = '';
521                 my $gif = '';
522                 my $gdesc = '';
523
524                 if ($temp[7] eq "on") {
525                         $gif = 'on.gif';
526                         $gdesc = $Lang::tr{'click to disable'};
527
528                         # Check if the given hostname is a FQDN before doing a nslookup.
529                         if (&General::validfqdn($hostname)) {
530                                 $sync = (&General::DyndnsServiceSync ($ip,$temp[1], $temp[2]) ? "<font color='green'>": "<font color='red'>") ;
531                         }
532
533                         $toggle_enabled = 'off';
534                 } else {
535                         $sync = "<font color='blue'>";
536                         $gif = 'off.gif';
537                         $gdesc = $Lang::tr{'click to enable'};
538                         $toggle_enabled = 'on';
539                 }
540
541                 # Background color.
542                 my $col="";
543
544                 if ($settings{'ID'} eq $id) {
545                         $col="bgcolor='${Header::colouryellow}'";
546                 } elsif (!($temp[0] ~~ @providers)) {
547                         $col="bgcolor='#FF4D4D'";
548                 } elsif ($id % 2) {
549                         $col="bgcolor='$color{'color20'}'";
550                 } else {
551                         $col="bgcolor='$color{'color22'}'";
552                 }
553
554                 # The following HTML Code still is part of the loop.
555                 print <<END;
556 <tr>
557         <td align='center' $col><a href='http://$temp[0]'>$temp[0]</a></td>
558         <td align='center' $col>$sync$temp[1].$sync$temp[2]</td>
559
560         <td align='center' $col><form method='post' action='$ENV{'SCRIPT_NAME'}'>
561                 <input type='hidden' name='ID' value='$id'>
562                 <input type='hidden' name='ENABLED' value='$toggle_enabled'>
563                 <input type='hidden' name='ACTION' value='$Lang::tr{'toggle enable disable'}' />
564                 <input type='image' name='$Lang::tr{'toggle enable disable'}' src='/images/$gif' alt='$gdesc' title='$gdesc' />
565         </form></td>
566
567         <td align='center' $col><form method='post' action='$ENV{'SCRIPT_NAME'}'>
568                 <input type='hidden' name='ID' value='$id'>
569                 <input type='hidden' name='ACTION' value='$Lang::tr{'edit'}' />
570                 <input type='image' name='$Lang::tr{'edit'}' src='/images/edit.gif' alt='$Lang::tr{'edit'}' title='$Lang::tr{'edit'}' />
571         </form></td>
572
573         <td align='center' $col><form method='post' action='$ENV{'SCRIPT_NAME'}'>
574                 <input type='hidden' name='ID' value='$id'>
575                 <input type='hidden' name='ACTION' value='$Lang::tr{'remove'}' />
576                 <input type='image' name='$Lang::tr{'remove'}' src='/images/delete.gif' alt='$Lang::tr{'remove'}' title='$Lang::tr{'remove'}' />
577         </form></td>
578 </tr>
579 END
580                 $id++;
581         }
582
583         print <<END;
584 </table>
585 <table width='100%'>
586         <tr>
587                 <td class='boldbase'>&nbsp;<b>$Lang::tr{'legend'}:&nbsp;</b></td>
588                 <td><img src='/images/on.gif' alt='$Lang::tr{'click to disable'}' /></td>
589                 <td class='base'>$Lang::tr{'click to disable'}</td>
590                 <td>&nbsp;&nbsp;</td>
591                 <td><img src='/images/off.gif' alt='$Lang::tr{'click to enable'}' /></td>
592                 <td class='base'>$Lang::tr{'click to enable'}</td>
593                 <td>&nbsp;&nbsp;</td>
594                 <td><img src='/images/edit.gif' alt='$Lang::tr{'edit'}' /></td>
595                 <td class='base'>$Lang::tr{'edit'}</td>
596                 <td>&nbsp;&nbsp;</td>
597                 <td><img src='/images/delete.gif' alt='$Lang::tr{'remove'}' /></td>
598                 <td class='base'>$Lang::tr{'remove'}</td>
599                 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
600                         <td align='right' width='30%'><input type='submit' name='ACTION' value='$Lang::tr{'instant update'}' /></td>
601                 </form>
602         </tr>
603 </table>
604 END
605
606         &Header::closebox();
607 }
608
609 &Header::closebigbox();
610 &Header::closepage();
611
612 # Function to generate the required configuration file for the DDNS tool.
613 sub GenerateDDNSConfigFile {
614         # Open datafile file
615         open(SETTINGS, "<$datafile") or die "Could not open $datafile.";
616
617         open(FILE, ">${General::swroot}/ddns/ddns.conf");
618
619         # Global configuration options.
620         print FILE "[config]\n";
621
622         # Check if we guess our IP address by an extranal server.
623         if ($settings{'BEHINDROUTER'} eq "FETCH_IP") {
624                 print FILE "guess_external_ip = true\n";
625         } else {
626                 print FILE "guess_external_ip = false\n";
627         }
628
629         # Use an upstream proxy and generate proxy url.
630         my %proxysettings;
631         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
632         if ($proxysettings{'UPSTREAM_PROXY'}) {
633                 my $proxy_string = "http://";
634
635                 if ($proxysettings{'UPSTREAM_USER'} && $proxysettings{'UPSTREAM_PASSWORD'}) {
636                         $proxy_string .= "$proxysettings{'UPSTREAM_USER'}:$proxysettings{'UPSTREAM_PASSWORD'}@";
637                 }
638
639                 $proxy_string .= $proxysettings{'UPSTREAM_PROXY'};
640
641                 print FILE "proxy = $proxy_string\n";
642         }
643
644         print FILE "\n";
645
646         while (<SETTINGS>) {
647                 my $line = $_;
648
649                 # Generate array based on the line content (seperator is a single or multiple space's)
650                 my @settings = split(/,/, $line);
651                 my ($provider, $hostname, $domain, $proxy, $wildcards, $username, $password, $enabled) = @settings;
652
653                 # Skip entries if they are not (longer) supported.
654                 next unless ($provider ~~ @providers);
655
656                 # Skip disabled entries.
657                 next if ($enabled eq "off");
658
659                 print FILE "[$hostname.$domain]\n";
660                 print FILE "provider = $provider\n";
661
662                 my $use_token = 0;
663
664                 # Handle token based auth for various providers.
665                 if ($provider ~~ ["dns.lightningwirelabs.com", "entrydns.net", "regfish.com"] && $username eq "token") {
666                         $use_token = 1;
667
668                 # Handle token auth for freedns.afraid.org and regfish.com.
669                 } elsif ($provider ~~ ["freedns.afraid.org", "regfish.com"] && $password eq "") {
670                         $use_token = 1;
671                         $password = $username;
672
673                 # Handle keys for nsupdate
674                 } elsif (($provider eq "nsupdate") && $username && $password) {
675                         print FILE "key = $username\n";
676                         print FILE "secret = $password\n";
677
678                         $username = "";
679                         $password = "";
680
681                 # Handle keys for nsupdate.info
682                 } elsif (($provider eq "nsupdate.info") && $password) {
683                         print FILE "secret = $password\n";
684
685                         $username = "";
686                         $password = "";
687                 }
688
689                 # Write auth details.
690                 if ($use_token) {
691                         print FILE "token = $password\n";
692                 } elsif ($username && $password) {
693                         print FILE "username = $username\n";
694                         print FILE "password = $password\n";
695                 }
696
697                 # These providers need to be set to only use IPv4.
698                 if ($provider ~~ ["freedns.afraid.org", "nsupdate.info", "opendns.com", "variomedia.de", "zoneedit.com"]) {
699                         print FILE "proto = ipv4\n";
700                 }
701
702                 print FILE "\n";
703         }
704
705         close(SETTINGS);
706         close(FILE);
707 }
708
709 # Function which generates an array (@providers) which contains the supported providers.
710 sub GetProviders {
711         # Get supported providers.
712         open(PROVIDERS, "/usr/bin/ddns list-providers |");
713
714         # Create new array to store the providers.
715         my @providers = ();
716
717         while (<PROVIDERS>) {
718                 my $provider = $_;
719
720                 # Remove following newlines.
721                 chomp($provider);
722
723                 # Add provider to the array.
724                 push(@providers, $provider);
725         }
726
727         close(PROVIDERS);
728
729         # Return our array.
730         return @providers;
731 }