Updated version 0.7 from 'upstream/0.7'

with Debian dir f7472d5bcc10740151744430428b01f92443ba16

4 files changed, 94 insertions, 83 deletions

diff --git a/ChangeLog b/ChangeLog
index e425583..606324f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,8 @@
-nat-traverse -- Use of UDP to traverse NAT gateways
+nat-traverse -- NAT gateway traversal utility
+
+2017-10-28
+    * v0.7: Fixed a minor syntactical issue which caused a warning on modern
+            Perl and relicensed under GPL version 3 or later.
 
 2012-12-24
     * v0.6: Fixed the port forwarding example in the documentation,
diff --git a/README b/README
index fcc7084..25d0f76 100644
--- a/README
+++ b/README
@@ -1,5 +1,5 @@
 NAME
-    nat-traverse - Use of UDP to traverse NAT gateways
+    nat-traverse - NAT gateway traversal utility
 
 SYNOPSIS
     To create a simple text-only tunnel, use the commands
@@ -11,7 +11,7 @@ SYNOPSIS
     on "right". See "EXAMPLES" for more.
 
 VERSION
-    This document describes nat-traverse v0.5.
+    This document describes nat-traverse v0.7.
 
 DESCRIPTION
     nat-traverse establishes connections between nodes which are behind NAT
@@ -137,8 +137,8 @@ EXAMPLES
     above.
 
   Setup of a VPN with OpenVPN
-    You can use <OpenVPN> over nat-traverse if you want to have a *secure*
-    VPN.
+    You can use OpenVPN <https://openvpn.net/> over nat-traverse if you want
+    to have a *secure* VPN.
 
     Using OpenVPN over nat-traverse requires only one change to OpenVPN's
     configuration file, presuming that you don't want to use OpenVPN's
@@ -189,26 +189,30 @@ LIMITATIONS
     port numbers are (in general) not predictable.
 
 SEE ALSO
-    <RFC 1631 at http://www.ietf.org/rfc/rfc1631.txt>
+    RFC 1631 at https://www.ietf.org/rfc/rfc1631.txt
+    <https://www.ietf.org/rfc/rfc1631.txt>
         The IP Network Address Translator (NAT). K. Egevang, P. Francis. May
         1994. (Obsoleted by RFC3022) (Status: INFORMATIONAL)
 
-    <RFC 3022 at http://www.ietf.org/rfc/rfc3022.txt>
+    RFC 3022 at https://www.ietf.org/rfc/rfc3022.txt
+    <https://www.ietf.org/rfc/rfc3022.txt>
         Traditional IP Network Address Translator (Traditional NAT). P.
         Srisuresh, K. Egevang. January 2001. (Obsoletes RFC1631) (Status:
         INFORMATIONAL)
 
-    <RFC 1661 at http://www.ietf.org/rfc/rfc1661.txt>
+    RFC 1661 at https://www.ietf.org/rfc/rfc1661.txt
+    <https://www.ietf.org/rfc/rfc1661.txt>
         The Point-to-Point Protocol (PPP). W. Simpson, Ed.. July 1994.
         (Obsoletes RFC1548) (Updated by RFC2153) (Also STD0051) (Status:
         STANDARD)
 
-    <http://ppp.samba.org/>
+    <https://ppp.samba.org/>
         Website of Paul's PPP Package (open source implementation of the
         Point-to-Point Protocol (PPP) on Linux and Solaris)
 
-    <German talk about nat-traverse at
-    http://linide.sourceforge.net/nat-traverse/nat-traverse-talk.pdf>
+    German talk about nat-traverse at
+    https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf
+    <https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf>
         Dieser Vortrag zeigt, wie man einen Tunnel zwischen zwei Computern,
         die beide hinter NAT-Gateways sitzen, hinbekommt. Dazu wird ein
         neues Programm vorgestellt, welches sowohl einfache Tastendrücke an
@@ -217,15 +221,16 @@ SEE ALSO
         VPN schnell aufgebaut.
 
 AUTHOR
-    Copyright (C) 2005, 2012 Ingo Blechschmidt, <iblech@web.de>.
+    Copyright (C) 2005, 2012, 2017 Ingo Blechschmidt,
+    <iblech@speicherleck.de>.
 
-    You may want to visit nat-traverse's Freecode project page,
-    <http://freecode.com/projects/nat-traverse/>.
+    The source code repository is hosted at
+    <https://gitlab.com/iblech/nat-traverse>.
 
 LICENSE
     This program 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
+    Free Software Foundation; either version 3 of the License, or (at your
     option) any later version.
 
     This program is distributed in the hope that it will be useful, but
diff --git a/nat-traverse b/nat-traverse
index e829154..c5ab5d1 100755
--- a/nat-traverse
+++ b/nat-traverse
@@ -1,21 +1,20 @@
-#!/usr/bin/perl
-# nat-traverse -- Use of UDP to traverse NAT gateways
-# Copyright (C) 2005, 2012 Ingo Blechschmidt <iblech@web.de>
+#!/usr/bin/env perl
+# nat-traverse -- NAT gateway traversal utility
+# Copyright (C) 2005, 2012, 2017 Ingo Blechschmidt <iblech@speicherleck.de>
 #
 # This program 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
+# as published by the Free Software Foundation; either version 3
 # of the License, or (at your option) any later version.
 #
 # This program 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
+# 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 this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
-# USA.
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
 use warnings;
 use strict;
@@ -38,7 +37,7 @@ GetOptions(
   "timeout=i"          => \(my $TIMEOUT = 10),
   "quit-after-connect" => \my $QUIT_AFTER_CONNECT,
   "cmd=s"              => \my $CMD,
-  "version"            => sub { print "nat-traverse 0.6\n"; exit },
+  "version"            => sub { print "nat-traverse 0.7\n"; exit },
   "help"               => \&usage,
 ) or usage();
 usage() unless @ARGV == 1;
@@ -86,7 +85,7 @@ syswrite $sock, ACK_MAGIC;
 debug " done.\n";
 
 # Waiting for ACK packet so we see the connection is established.
-debug "Waiting for ACK (timeout: $TIMEOUT\Es)... ";
+debug "Waiting for ACK (timeout: ${TIMEOUT}s)... ";
 {
   local $SIG{ALRM} = sub { die " timeout.\n" };
   alarm $TIMEOUT;
@@ -155,7 +154,7 @@ if(defined $CMD) {
 
 # Display usage info.
 sub usage { print STDERR <<'USAGE'; exit }
-nat-traverse v0.6 -- Use of UDP to traverse NAT gateways
+nat-traverse v0.7 -- NAT gateway traversal utility
 
 Usage:
   user@left  $ nat-traverse [options] port1:natgw-of-right:port2
@@ -181,13 +180,13 @@ Available options:
   --help                This help.
 
 Options may be abbreviated to uniqueness.
-Run "perldoc nat-traverse" for more information.
+Run "man nat-traverse" for more information.
 USAGE
 
 
 =head1 NAME
 
-nat-traverse - Use of UDP to traverse NAT gateways
+nat-traverse - NAT gateway traversal utility
 
 =head1 SYNOPSIS
 
@@ -201,7 +200,7 @@ C<right>. See L</EXAMPLES> for more.
 
 =head1 VERSION
 
-This document describes nat-traverse v0.6.
+This document describes nat-traverse v0.7.
 
 =head1 DESCRIPTION
 
@@ -345,7 +344,7 @@ reliable streams, use PPP on top of nat-traverse, as described above.
 
 =head2 Setup of a VPN with OpenVPN
 
-You can use L<OpenVPN|http://openvpn.net/> over nat-traverse if you want to
+You can use L<OpenVPN|https://openvpn.net/> over nat-traverse if you want to
 have a I<secure> VPN.
 
 Using OpenVPN over nat-traverse requires only one change to OpenVPN's
@@ -402,30 +401,30 @@ are (in general) not predictable.
 =over
 
 =item L<RFC 1631 at
-http://www.ietf.org/rfc/rfc1631.txt|http://www.ietf.org/rfc/rfc1631.txt>
+https://www.ietf.org/rfc/rfc1631.txt|https://www.ietf.org/rfc/rfc1631.txt>
 
 The IP Network Address Translator (NAT). K. Egevang, P. Francis.  May 1994.
 (Obsoleted by RFC3022) (Status: INFORMATIONAL)
 
 =item L<RFC 3022 at
-http://www.ietf.org/rfc/rfc3022.txt|http://www.ietf.org/rfc/rfc3022.txt>
+https://www.ietf.org/rfc/rfc3022.txt|https://www.ietf.org/rfc/rfc3022.txt>
 
 Traditional IP Network Address Translator (Traditional NAT). P.  Srisuresh,
 K. Egevang. January 2001.  (Obsoletes RFC1631) (Status: INFORMATIONAL)
 
 =item L<RFC 1661 at
-http://www.ietf.org/rfc/rfc1661.txt|http://www.ietf.org/rfc/rfc1661.txt>
+https://www.ietf.org/rfc/rfc1661.txt|https://www.ietf.org/rfc/rfc1661.txt>
 
 The Point-to-Point Protocol (PPP). W. Simpson, Ed.. July 1994.  (Obsoletes
 RFC1548) (Updated by RFC2153) (Also STD0051) (Status: STANDARD)
 
-=item L<http://ppp.samba.org/>
+=item L<https://ppp.samba.org/>
 
 Website of Paul's PPP Package (open source implementation of the
 Point-to-Point Protocol (PPP) on Linux and Solaris)
 
 =item L<German talk about nat-traverse at
-http://linide.sourceforge.net/nat-traverse/nat-traverse-talk.pdf|http://linide.sourceforge.net/nat-traverse/nat-traverse-talk.pdf>
+https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf|https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf>
 
 Dieser Vortrag zeigt, wie man einen Tunnel zwischen zwei Computern, die
 beide hinter NAT-Gateways sitzen, hinbekommt. Dazu wird ein neues Programm
@@ -437,22 +436,21 @@ starten kann. Damit ist ein einfaches VPN schnell aufgebaut.
 
 =head1 AUTHOR
 
-Copyright (C) 2005, 2012 Ingo Blechschmidt, E<lt>iblech@web.deE<gt>.
+Copyright (C) 2005, 2012, 2017 Ingo Blechschmidt, E<lt>iblech@speicherleck.deE<gt>.
 
-You may want to visit nat-traverse's Freecode project page,
-L<http://freecode.com/projects/nat-traverse/>.
+The source code repository is hosted at L<https://gitlab.com/iblech/nat-traverse>.
 
 =head1 LICENSE
 
 This program 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
+Foundation; either version 3 of the License, or (at your option) any later
 version.
 
 This program 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.
+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
 this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
-Street, Fifth Floor, Boston, MA  02110-1301, USA.
+Street, Fifth Floor, Boston, MA 02110-1301, USA.
diff --git a/nat-traverse.1 b/nat-traverse.1
index 76700c8..2ccdb7c 100644
--- a/nat-traverse.1
+++ b/nat-traverse.1
@@ -1,4 +1,4 @@
-.\" Automatically generated by Pod::Man 2.22 (Pod::Simple 3.14)
+.\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32)
 .\"
 .\" Standard preamble:
 .\" ========================================================================
@@ -38,26 +38,31 @@
 .    ds PI \(*p
 .    ds L" ``
 .    ds R" ''
+.    ds C`
+.    ds C'
 'br\}
 .\"
 .\" Escape single quotes in literal strings from groff's Unicode transform.
 .ie \n(.g .ds Aq \(aq
 .el       .ds Aq '
 .\"
-.\" If the F register is turned on, we'll generate index entries on stderr for
+.\" If the F register is >0, we'll generate index entries on stderr for
 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
 .\" entries marked with X<> in POD.  Of course, you'll have to process the
 .\" output yourself in some meaningful fashion.
-.ie \nF \{\
-.    de IX
-.    tm Index:\\$1\t\\n%\t"\\$2"
+.\"
+.\" Avoid warning from groff about undefined register 'F'.
+.de IX
 ..
-.    nr % 0
-.    rr F
-.\}
-.el \{\
+.if !\nF .nr F 0
+.if \nF>0 \{\
 .    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
 ..
+.    if !\nF==2 \{\
+.        nr % 0
+.        nr F 2
+.    \}
 .\}
 .\"
 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
@@ -123,14 +128,14 @@
 .rm #[ #] #H #V #F C
 .\" ========================================================================
 .\"
-.IX Title "NAT-TRAVERSE-0.6 1"
-.TH NAT-TRAVERSE-0.6 1 "2012-12-24" "perl v5.10.1" "User Contributed Perl Documentation"
+.IX Title "NAT-TRAVERSE 1"
+.TH NAT-TRAVERSE 1 "2017-10-28" "perl v5.24.2" "User Contributed Perl Documentation"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
 .nh
 .SH "NAME"
-nat\-traverse \- Use of UDP to traverse NAT gateways
+nat\-traverse \- NAT gateway traversal utility
 .SH "SYNOPSIS"
 .IX Header "SYNOPSIS"
 To create a simple text-only tunnel, use the commands
@@ -141,27 +146,27 @@ To create a simple text-only tunnel, use the commands
 .Ve
 .PP
 where \f(CW40000\fR is an unused \s-1UDP\s0 port on \f(CW\*(C`left\*(C'\fR and \f(CW40001\fR is an unused port on
-\&\f(CW\*(C`right\*(C'\fR. See \*(L"\s-1EXAMPLES\s0\*(R" for more.
+\&\f(CW\*(C`right\*(C'\fR. See \*(L"\s-1EXAMPLES\*(R"\s0 for more.
 .SH "VERSION"
 .IX Header "VERSION"
-This document describes nat-traverse v0.5.
+This document describes nat-traverse v0.7.
 .SH "DESCRIPTION"
 .IX Header "DESCRIPTION"
 nat-traverse establishes connections between nodes which are behind \s-1NAT\s0
 gateways, i.e. hosts which do \fInot\fR have public \s-1IP\s0 addresses. Additionally,
 you can setup a small \s-1VPN\s0 by using pppd on top of nat-traverse (see
-\&\*(L"\s-1EXAMPLES\s0\*(R").  nat-traverse does \fInot\fR need an external server on the
+\&\*(L"\s-1EXAMPLES\*(R"\s0).  nat-traverse does \fInot\fR need an external server on the
 Internet, and it isn't necessary to reconfigure the involved \s-1NAT\s0 gateways,
 either. \fInat-traverse works out-of-the-box.\fR
 .PP
-See \*(L"\s-1TECHNIQUE\s0\*(R" for how this is achieved.
+See \*(L"\s-1TECHNIQUE\*(R"\s0 for how this is achieved.
 .PP
 Limitation: nat-traverse does not work with gateways which change the port
 numbers. This is a fundamental problem of nat-traverse's design, as the changed
 port numbers are (in general) not predictable.
 .SH "OPTIONS"
 .IX Header "OPTIONS"
-.ie n .IP """\f(CIlocal_port\f(CW:\f(CIpeer\f(CW:\f(CIremote_port\f(CW"" (required)" 4
+.ie n .IP """\fIlocal_port\fP:\fIpeer\fP:\fIremote_port\fP"" (required)" 4
 .el .IP "\f(CW\f(CIlocal_port\f(CW:\f(CIpeer\f(CW:\f(CIremote_port\f(CW\fR (required)" 4
 .IX Item "local_port:peer:remote_port (required)"
 Sets the local port to use and the remote address to connect to.
@@ -169,7 +174,7 @@ Sets the local port to use and the remote address to connect to.
 Note that you have to give the \s-1IP\s0 address or hostname of the \fI\s-1NAT\s0 gateway\fR of
 the host you want to connect to, as the target host doesn't have a public \s-1IP\s0
 address.
-.ie n .IP """\-\-cmd=""\f(CIpppd...\f(CW""""" 4
+.ie n .IP """\-\-cmd=""\fIpppd...\fP""""" 4
 .el .IP "\f(CW\-\-cmd=``\f(CIpppd...\f(CW''\fR" 4
 .IX Item "--cmd=""pppd..."""
 Runs the specified command after establishing the connection.
@@ -179,12 +184,12 @@ everything the command writes to \s-1STDOUT\s0 will be forwarded to the peer.
 .Sp
 If no command is specified, nat-traverse will relay input from \s-1STDIN\s0 to the peer
 and vice versa, i.e. nat-traverse degrades to netcat.
-.ie n .IP """\-\-window=\f(CI10\f(CW""" 4
+.ie n .IP """\-\-window=\fI10\fP""" 4
 .el .IP "\f(CW\-\-window=\f(CI10\f(CW\fR" 4
 .IX Item "--window=10"
 Sets the number of initial garbage packets to send. The default, 10, should
 work with most firewalls.
-.ie n .IP """\-\-timeout=\f(CI10\f(CW""" 4
+.ie n .IP """\-\-timeout=\fI10\fP""" 4
 .el .IP "\f(CW\-\-timeout=\f(CI10\f(CW\fR" 4
 .IX Item "--timeout=10"
 Sets the maximum number of seconds to wait for an acknowledgement by the peer.
@@ -225,7 +230,7 @@ either relay \s-1STDIN/STDOUT\s0 to the socket or execute a program.
 .IX Header "EXAMPLES"
 .SS "Setup of a small \s-1VPN\s0 with \s-1PPP\s0"
 .IX Subsection "Setup of a small VPN with PPP"
-It's easy to setup a \s-1VPN\s0 (Virtual Private Network) by using the Point-to-Point
+It's easy to setup a \s-1VPN \s0(Virtual Private Network) by using the Point-to-Point
 Protocol Daemon, \f(CW\*(C`pppd\*(C'\fR:
 .PP
 .Vb 7
@@ -245,7 +250,7 @@ establish reliable \s-1TCP\s0 connections over the tunnel, even though the tunne
 \&\s-1UDP\s0!  Furthermore, you could even add IPv6 addresses to \f(CW\*(C`ppp0\*(C'\fR by running \f(CW\*(C`ip
 \&\-6 addr add...\*(C'\fR!
 .PP
-Note though that although this \s-1VPN\s0 \fIis\fR arguably a private network, it is \fInot\fR
+Note though that although this \s-1VPN \s0\fIis\fR arguably a private network, it is \fInot\fR
 secured in any way. You may want to use \s-1SSH\s0 to encrypt the connection.
 .SS "Port Forwarding with netcat"
 .IX Subsection "Port Forwarding with netcat"
@@ -274,8 +279,8 @@ data is transported via \s-1UDP\s0; so this is only a toy example. If you want
 reliable streams, use \s-1PPP\s0 on top of nat-traverse, as described above.
 .SS "Setup of a \s-1VPN\s0 with OpenVPN"
 .IX Subsection "Setup of a VPN with OpenVPN"
-You can use <OpenVPN> over nat-traverse if you want to
-have a \fIsecure\fR \s-1VPN\s0.
+You can use OpenVPN <https://openvpn.net/> over nat-traverse if you want to
+have a \fIsecure\fR \s-1VPN.\s0
 .PP
 Using OpenVPN over nat-traverse requires only one change to OpenVPN's
 configuration file, presuming that you don't want to use OpenVPN's multi-client
@@ -330,46 +335,45 @@ is a fundamental problem of nat-traverse's design, as the changed port numbers
 are (in general) not predictable.
 .SH "SEE ALSO"
 .IX Header "SEE ALSO"
-.IP "<\s-1RFC\s0 1631 at http://www.ietf.org/rfc/rfc1631.txt>" 4
-.IX Item "<RFC 1631 at http://www.ietf.org/rfc/rfc1631.txt>"
+.IP "\s-1RFC 1631\s0 at https://www.ietf.org/rfc/rfc1631.txt <https://www.ietf.org/rfc/rfc1631.txt>" 4
+.IX Item "RFC 1631 at https://www.ietf.org/rfc/rfc1631.txt <https://www.ietf.org/rfc/rfc1631.txt>"
 The \s-1IP\s0 Network Address Translator (\s-1NAT\s0). K. Egevang, P. Francis.  May 1994.
 (Obsoleted by \s-1RFC3022\s0) (Status: \s-1INFORMATIONAL\s0)
-.IP "<\s-1RFC\s0 3022 at http://www.ietf.org/rfc/rfc3022.txt>" 4
-.IX Item "<RFC 3022 at http://www.ietf.org/rfc/rfc3022.txt>"
+.IP "\s-1RFC 3022\s0 at https://www.ietf.org/rfc/rfc3022.txt <https://www.ietf.org/rfc/rfc3022.txt>" 4
+.IX Item "RFC 3022 at https://www.ietf.org/rfc/rfc3022.txt <https://www.ietf.org/rfc/rfc3022.txt>"
 Traditional \s-1IP\s0 Network Address Translator (Traditional \s-1NAT\s0). P.  Srisuresh,
 K. Egevang. January 2001.  (Obsoletes \s-1RFC1631\s0) (Status: \s-1INFORMATIONAL\s0)
-.IP "<\s-1RFC\s0 1661 at http://www.ietf.org/rfc/rfc1661.txt>" 4
-.IX Item "<RFC 1661 at http://www.ietf.org/rfc/rfc1661.txt>"
+.IP "\s-1RFC 1661\s0 at https://www.ietf.org/rfc/rfc1661.txt <https://www.ietf.org/rfc/rfc1661.txt>" 4
+.IX Item "RFC 1661 at https://www.ietf.org/rfc/rfc1661.txt <https://www.ietf.org/rfc/rfc1661.txt>"
 The Point-to-Point Protocol (\s-1PPP\s0). W. Simpson, Ed.. July 1994.  (Obsoletes
 \&\s-1RFC1548\s0) (Updated by \s-1RFC2153\s0) (Also \s-1STD0051\s0) (Status: \s-1STANDARD\s0)
-.IP "<http://ppp.samba.org/>" 4
-.IX Item "<http://ppp.samba.org/>"
+.IP "<https://ppp.samba.org/>" 4
+.IX Item "<https://ppp.samba.org/>"
 Website of Paul's \s-1PPP\s0 Package (open source implementation of the
 Point-to-Point Protocol (\s-1PPP\s0) on Linux and Solaris)
-.IP "<German talk about nat-traverse at http://linide.sourceforge.net/nat\-traverse/nat\-traverse\-talk.pdf>" 4
-.IX Item "<German talk about nat-traverse at http://linide.sourceforge.net/nat-traverse/nat-traverse-talk.pdf>"
+.IP "German talk about nat-traverse at https://www.speicherleck.de/iblech/nat\-traverse/nat\-traverse\-talk.pdf <https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf>" 4
+.IX Item "German talk about nat-traverse at https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf <https://www.speicherleck.de/iblech/nat-traverse/nat-traverse-talk.pdf>"
 Dieser Vortrag zeigt, wie man einen Tunnel zwischen zwei Computern, die
 beide hinter NAT-Gateways sitzen, hinbekommt. Dazu wird ein neues Programm
-vorgestellt, welches sowohl einfache TastendrA\*~Xcke an die Gegenseite
+vorgestellt, welches sowohl einfache Tastendru\*:cke an die Gegenseite
 weiterleiten, als auch beliebige Programme mit Verbindungen zur Gegenseite
 starten kann. Damit ist ein einfaches \s-1VPN\s0 schnell aufgebaut.
 .SH "AUTHOR"
 .IX Header "AUTHOR"
-Copyright (C) 2005, 2012 Ingo Blechschmidt, <iblech@web.de>.
+Copyright (C) 2005, 2012, 2017 Ingo Blechschmidt, <iblech@speicherleck.de>.
 .PP
-You may want to visit nat-traverse's Freecode project page,
-<http://freecode.com/projects/nat\-traverse/>.
+The source code repository is hosted at <https://gitlab.com/iblech/nat\-traverse>.
 .SH "LICENSE"
 .IX Header "LICENSE"
 This program is free software; you can redistribute it and/or modify it under
 the terms of the \s-1GNU\s0 General Public License as published by the Free Software
-Foundation; either version 2 of the License, or (at your option) any later
+Foundation; either version 3 of the License, or (at your option) any later
 version.
 .PP
-This program is distributed in the hope that it will be useful, but \s-1WITHOUT\s0 \s-1ANY\s0
-\&\s-1WARRANTY\s0; without even the implied warranty of \s-1MERCHANTABILITY\s0 or \s-1FITNESS\s0 \s-1FOR\s0 A
-\&\s-1PARTICULAR\s0 \s-1PURPOSE\s0.  See the \s-1GNU\s0 General Public License for more details.
+This program is distributed in the hope that it will be useful, but \s-1WITHOUT ANY
+WARRANTY\s0; without even the implied warranty of \s-1MERCHANTABILITY\s0 or \s-1FITNESS FOR A
+PARTICULAR PURPOSE.\s0 See the \s-1GNU\s0 General Public License for more details.
 .PP
 You should have received a copy of the \s-1GNU\s0 General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
-Street, Fifth Floor, Boston, \s-1MA\s0  02110\-1301, \s-1USA\s0.
+Street, Fifth Floor, Boston, \s-1MA 02110\-1301, USA.\s0