gnu/packages/vpn.scm

   1 ;;; GNU Guix --- Functional package management for GNU
   2 ;;; Copyright © 2013 Andreas Enge <andreas@enge.fr>
   3 ;;; Copyright © 2013, 2016, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
   4 ;;; Copyright © 2014 Eric Bavier <bavier@member.fsf.org>
   5 ;;; Copyright © 2015 Jeff Mickey <j@codemac.net>
   6 ;;; Copyright © 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
   7 ;;; Copyright © 2016, 2017, 2018, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
   8 ;;; Copyright © 2017 Julien Lepiller <julien@lepiller.eu>
   9 ;;; Copyright © 2018 Pierre Langlois <pierre.langlois@gmx.com>
  10 ;;; Copyright © 2018 Meiyo Peng <meiyo.peng@gmail.com>
  11 ;;; Copyright © 2019 Leo Famulari <leo@famulari.name>
  12 ;;; Copyright © 2019 Rutger Helling <rhelling@mykolab.com>
  13 ;;;
  14 ;;; This file is part of GNU Guix.
  15 ;;;
  16 ;;; GNU Guix is free software; you can redistribute it and/or modify it
  17 ;;; under the terms of the GNU General Public License as published by
  18 ;;; the Free Software Foundation; either version 3 of the License, or (at
  19 ;;; your option) any later version.
  20 ;;;
  21 ;;; GNU Guix is distributed in the hope that it will be useful, but
  22 ;;; WITHOUT ANY WARRANTY; without even the implied warranty of
  23 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 ;;; GNU General Public License for more details.
  25 ;;;
  26 ;;; You should have received a copy of the GNU General Public License
  27 ;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
  28
  29 (define-module (gnu packages vpn)
  30   #:use-module ((guix licenses) #:prefix license:)
  31   #:use-module (guix packages)
  32   #:use-module (guix download)
  33   #:use-module (guix git-download)
  34   #:use-module (guix build-system cmake)
  35   #:use-module (guix build-system gnu)
  36   #:use-module (guix build-system python)
  37   #:use-module (gnu packages)
  38   #:use-module (gnu packages admin)
  39   #:use-module (gnu packages base)
  40   #:use-module (gnu packages check)
  41   #:use-module (gnu packages autotools)
  42   #:use-module (gnu packages compression)
  43   #:use-module (gnu packages gettext)
  44   #:use-module (gnu packages gnupg)
  45   #:use-module (gnu packages libevent)
  46   #:use-module (gnu packages linux)
  47   #:use-module (gnu packages nss)
  48   #:use-module (gnu packages perl)
  49   #:use-module (gnu packages pkg-config)
  50   #:use-module (gnu packages python)
  51   #:use-module (gnu packages python-xyz)
  52   #:use-module (gnu packages tls)
  53   #:use-module (gnu packages xml))
  54
  55 (define-public gvpe
  56   (package
  57     (name "gvpe")
  58     (version "3.1")
  59     (source (origin
  60               (method url-fetch)
  61               (uri (string-append "mirror://gnu/gvpe/gvpe-"
  62                                   version ".tar.gz"))
  63               (sha256
  64                (base32
  65                 "1cz8n75ksl0l908zc5l3rnfm1hv7130s2w8710799fr5sxrdbszi"))))
  66     (build-system gnu-build-system)
  67     (home-page "http://software.schmorp.de/pkg/gvpe.html")
  68     (native-inputs `(("pkg-config" ,pkg-config)))
  69     (inputs `(("openssl" ,openssl)
  70               ("zlib" ,zlib)))
  71     (synopsis "Secure VPN among multiple nodes over an untrusted network")
  72     (description
  73      "The GNU Virtual Private Ethernet creates a virtual network
  74 with multiple nodes using a variety of transport protocols.  It works
  75 by creating encrypted host-to-host tunnels between multiple
  76 endpoints.")
  77     (license license:gpl3+)))
  78
  79 (define-public vpnc
  80   (package
  81    (name "vpnc")
  82    (version "0.5.3")
  83    (source (origin
  84             (method url-fetch)
  85             (uri (string-append "https://www.unix-ag.uni-kl.de/~massar/vpnc/vpnc-"
  86                                 version ".tar.gz"))
  87             (sha256 (base32
  88                      "1128860lis89g1s21hqxvap2nq426c9j4bvgghncc1zj0ays7kj6"))))
  89    (build-system gnu-build-system)
  90    (inputs `(("libgcrypt" ,libgcrypt)
  91              ("perl" ,perl)
  92              ("vpnc-scripts" ,vpnc-scripts)))
  93    (arguments
  94     `(#:tests? #f ; there is no check target
  95       #:phases
  96       (modify-phases %standard-phases
  97         (add-after 'unpack 'use-store-paths
  98           (lambda* (#:key inputs outputs #:allow-other-keys)
  99             (let ((out          (assoc-ref outputs "out"))
 100                   (vpnc-scripts (assoc-ref inputs  "vpnc-scripts")))
 101               (substitute* "config.c"
 102                 (("/etc/vpnc/vpnc-script")
 103                  (string-append vpnc-scripts "/etc/vpnc/vpnc-script")))
 104               (substitute* "Makefile"
 105                 (("ETCDIR=.*")
 106                  (string-append "ETCDIR=" out "/etc/vpnc\n"))
 107                 (("PREFIX=.*")
 108                  (string-append "PREFIX=" out "\n")))
 109               #t)))
 110         (delete 'configure))))          ; no configure script
 111    (synopsis "Client for Cisco VPN concentrators")
 112    (description
 113     "vpnc is a VPN client compatible with Cisco's EasyVPN equipment.
 114 It supports IPSec (ESP) with Mode Configuration and Xauth.  It supports only
 115 shared-secret IPSec authentication with Xauth, AES (256, 192, 128), 3DES,
 116 1DES, MD5, SHA1, DH1/2/5 and IP tunneling.  It runs entirely in userspace.
 117 Only \"Universal TUN/TAP device driver support\" is needed in the kernel.")
 118    (license license:gpl2+) ; some file are bsd-2, see COPYING
 119    (home-page "http://www.unix-ag.uni-kl.de/~massar/vpnc/")))
 120
 121 (define-public vpnc-scripts
 122   (let ((commit "1000e0f6dd7d6bff163169a46359211c1fc3a6d2"))
 123     (package
 124       (name "vpnc-scripts")
 125       (version (string-append "20190116." (string-take commit 7)))
 126       (source (origin
 127                 (method git-fetch)
 128                 (uri
 129                  (git-reference
 130                   (url "git://git.infradead.org/users/dwmw2/vpnc-scripts.git")
 131                   (commit commit)))
 132                 (file-name (git-file-name name version))
 133                 (sha256
 134                  (base32
 135                   "1g41yarz2bl0f73kbjqnywr485ghanbp7nmspklfb0n07yp0z6ak"))))
 136       (build-system gnu-build-system)
 137       (inputs `(("coreutils" ,coreutils)
 138                 ("grep" ,grep)
 139                 ("iproute2" ,iproute)    ; for ‘ip’
 140                 ("net-tools" ,net-tools) ; for ‘ifconfig’, ‘route’
 141                 ("sed" ,sed)
 142                 ("which" ,which)))
 143       (arguments
 144        `(#:phases
 145          (modify-phases %standard-phases
 146            (add-after 'unpack 'use-relative-paths
 147              ;; Patch the scripts to work with and use relative paths.
 148              (lambda* _
 149                (for-each (lambda (script)
 150                            (substitute* script
 151                              (("^PATH=.*") "")
 152                              (("(/usr|)/s?bin/") "")
 153                              (("\\[ +-x +([^]]+) +\\]" _ command)
 154                               (string-append "command -v >/dev/null 2>&1 "
 155                                              command))))
 156                          (find-files "." "^vpnc-script"))
 157                #t))
 158            (delete 'configure)          ; no configure script
 159            (replace 'build
 160              (lambda _
 161                (invoke "gcc" "-o" "netunshare" "netunshare.c")))
 162            (replace 'install
 163              ;; There is no Makefile; manually install the relevant files.
 164              (lambda* (#:key outputs #:allow-other-keys)
 165                (let* ((out (assoc-ref outputs "out"))
 166                       (etc (string-append out "/etc/vpnc")))
 167                  (for-each (lambda (file)
 168                              (install-file file etc))
 169                            (append (find-files "." "^vpnc-script")
 170                                    (list "netunshare"
 171                                          "xinetd.netns.conf")))
 172                  #t)))
 173            (add-after 'install 'wrap-scripts
 174              ;; Wrap scripts with paths to their common hard dependencies.
 175              ;; Optional dependencies will need to be installed by the user.
 176              (lambda* (#:key inputs outputs #:allow-other-keys)
 177                (let ((out (assoc-ref outputs "out")))
 178                  (for-each
 179                   (lambda (script)
 180                     (wrap-program script
 181                       `("PATH" ":" prefix
 182                         ,(map (lambda (name)
 183                                 (let ((input (assoc-ref inputs name)))
 184                                   (string-append input "/bin:"
 185                                                  input "/sbin")))
 186                               (list "coreutils"
 187                                     "grep"
 188                                     "iproute2"
 189                                     "net-tools"
 190                                     "sed"
 191                                     "which")))))
 192                   (find-files (string-append out "/etc/vpnc/vpnc-script")
 193                               "^vpnc-script"))
 194                  #t))))
 195          #:tests? #f))                  ; no tests
 196       (home-page "http://git.infradead.org/users/dwmw2/vpnc-scripts.git")
 197       (synopsis "Network configuration scripts for Cisco VPN clients")
 198       (description
 199        "This set of scripts configures routing and name services when invoked
 200 by the VPNC or OpenConnect Cisco @dfn{Virtual Private Network} (VPN) clients.
 201
 202 The default @command{vpnc-script} automatically configures most common
 203 connections, and provides hooks for performing custom actions at various stages
 204 of the connection or disconnection process.
 205
 206 Alternative scripts are provided for more complicated set-ups, or to serve as an
 207 example for writing your own.  For example, @command{vpnc-script-sshd} contains
 208 the entire VPN in a network namespace accessible only through SSH.")
 209       (license license:gpl2+))))
 210
 211 (define-public ocproxy
 212   (package
 213     (name "ocproxy")
 214     (version "1.60")
 215     (source (origin
 216               (method url-fetch)
 217               (uri (string-append
 218                     "https://github.com/cernekee/ocproxy/archive/v"
 219                     version ".tar.gz"))
 220               (file-name (string-append name "-" version ".tar.gz"))
 221               (sha256
 222                (base32
 223                 "1b4rg3xq5jnrp2l14sw0msan8kqhdxmsd7gpw9lkiwvxy13pcdm7"))))
 224     (build-system gnu-build-system)
 225     (native-inputs
 226      `(("autoconf" ,autoconf)
 227        ("automake" ,automake)))
 228     (inputs
 229      `(("libevent" ,libevent)))
 230     (arguments
 231      '(#:phases
 232        (modify-phases %standard-phases
 233          (add-after 'unpack 'autogen
 234            (lambda _ (invoke "sh" "autogen.sh"))))))
 235     (home-page "https://github.com/cernekee/ocproxy")
 236     (synopsis "OpenConnect proxy")
 237     (description
 238      "User-level @dfn{SOCKS} and port forwarding proxy for OpenConnect based
 239 on LwIP.  When using ocproxy, OpenConnect only handles network activity that
 240 the user specifically asks to proxy, so the @dfn{VPN} interface no longer
 241 \"hijacks\" all network traffic on the host.")
 242     (license license:bsd-3)))
 243
 244 (define-public openconnect
 245   (package
 246    (name "openconnect")
 247    (version "8.03")
 248    (source (origin
 249             (method url-fetch)
 250             (uri (string-append "ftp://ftp.infradead.org/pub/openconnect/"
 251                                 "openconnect-" version ".tar.gz"))
 252             (sha256 (base32
 253                      "1wlypi68kqqg2mdck8wvf6aanhrmf9i7z6lngyxvcrp23jdzz34h"))))
 254    (build-system gnu-build-system)
 255    (inputs
 256     `(("libxml2" ,libxml2)
 257       ("gnutls" ,gnutls)
 258       ("vpnc-scripts" ,vpnc-scripts)
 259       ("zlib" ,zlib)))
 260    (native-inputs
 261     `(("gettext" ,gettext-minimal)
 262       ("pkg-config" ,pkg-config)))
 263    (arguments
 264     `(#:configure-flags
 265       `(,(string-append "--with-vpnc-script="
 266                         (assoc-ref %build-inputs "vpnc-scripts")
 267                         "/etc/vpnc/vpnc-script"))))
 268    (synopsis "Client for Cisco VPN")
 269    (description
 270     "OpenConnect is a client for Cisco's AnyConnect SSL VPN, which is
 271 supported by the ASA5500 Series, by IOS 12.4(9)T or later on Cisco SR500,
 272 870, 880, 1800, 2800, 3800, 7200 Series and Cisco 7301 Routers,
 273 and probably others.")
 274    (license license:lgpl2.1)
 275    (home-page "https://www.infradead.org/openconnect/")))
 276
 277 (define-public openvpn
 278   (package
 279     (name "openvpn")
 280     (version "2.4.7")
 281     (source (origin
 282               (method url-fetch)
 283               (uri (string-append
 284                     "https://swupdate.openvpn.org/community/releases/openvpn-"
 285                     version ".tar.xz"))
 286               (sha256
 287                (base32
 288                 "0j7na936isk9j8nsdrrbw7wmy09inmjqvsb8mw8az7k61xbm6bx4"))))
 289     (build-system gnu-build-system)
 290     (arguments
 291      '(#:configure-flags '("--enable-iproute2=yes")))
 292     (native-inputs
 293      `(("iproute2" ,iproute)))
 294     (inputs
 295      `(("lz4" ,lz4)
 296        ("lzo" ,lzo)
 297        ("openssl" ,openssl)
 298        ("linux-pam" ,linux-pam)))
 299     (home-page "https://openvpn.net/")
 300     (synopsis "Virtual private network daemon")
 301     (description
 302      "OpenVPN implements virtual private network (@dfn{VPN}) techniques
 303 for creating secure point-to-point or site-to-site connections in routed or
 304 bridged configurations and remote access facilities.  It uses a custom
 305 security protocol that utilizes SSL/TLS for key exchange.  It is capable of
 306 traversing network address translators (@dfn{NAT}s) and firewalls.")
 307     (license license:gpl2)))
 308
 309 (define-public tinc
 310   (package
 311     (name "tinc")
 312     (version "1.0.35")
 313     (source (origin
 314               (method url-fetch)
 315               (uri (string-append "https://tinc-vpn.org/packages/"
 316                                   name "-" version ".tar.gz"))
 317               (sha256
 318                (base32
 319                 "0pl92sdwrkiwgll78x0ww06hfljd07mkwm62g8x17qn3gha3pj0q"))))
 320     (build-system gnu-build-system)
 321     (arguments
 322      '(#:configure-flags
 323        '("--sysconfdir=/etc"
 324          "--localstatedir=/var")))
 325     (inputs `(("zlib" ,zlib)
 326               ("lzo" ,lzo)
 327               ("openssl" ,openssl)))
 328     (home-page "https://tinc-vpn.org")
 329     (synopsis "Virtual Private Network (VPN) daemon")
 330     (description
 331      "Tinc is a VPN that uses tunnelling and encryption to create a secure
 332 private network between hosts on the internet.")
 333     (license license:gpl2+)))
 334
 335 (define-public sshuttle
 336   (package
 337     (name "sshuttle")
 338     (version "0.78.5")
 339     (source
 340      (origin
 341        (method url-fetch)
 342        (uri (pypi-uri name version))
 343        (sha256
 344         (base32
 345          "0vp13xwrhx4m6zgsyzvai84lkq9mzkaw47j58dk0ll95kaymk2x8"))))
 346     (build-system python-build-system)
 347     (arguments
 348      `(#:phases
 349        (modify-phases %standard-phases
 350          (add-after 'unpack 'patch-FHS-file-names
 351            (lambda _
 352              (substitute* "sshuttle/client.py"
 353                (("/usr/bin/env") (which "env")))
 354              (substitute* "sshuttle/ssh.py"
 355                (("/bin/sh") "sh"))
 356              #t)))))
 357     (native-inputs
 358      `(("python-setuptools-scm" ,python-setuptools-scm)
 359        ;; For tests only.
 360        ("python-flake8", python-flake8)
 361        ("python-mock" ,python-mock)
 362        ("python-pytest-cov" ,python-pytest-cov)
 363        ("python-pytest-runner" ,python-pytest-runner)))
 364     (home-page "https://github.com/sshuttle/sshuttle")
 365     (synopsis "VPN that transparently forwards connections over SSH")
 366     (description "sshuttle creates an encrypted virtual private network (VPN)
 367 connection to any remote server to which you have secure shell (SSH) access.
 368 The only requirement is a suitable version of Python on the server;
 369 administrative privileges are required only on the client.  Unlike most VPNs,
 370 sshuttle forwards entire sessions, not packets, using kernel transparent
 371 proxying.  This makes it faster and more reliable than SSH's own tunneling and
 372 port forwarding features.  It can forward both TCP and UDP traffic, including
 373 DNS domain name queries.")
 374     (license license:lgpl2.0))) ; incorrectly identified as GPL in ‘setup.py’
 375
 376 (define-public sshoot
 377   (package
 378     (name "sshoot")
 379     (version "1.2.6")
 380     (source
 381      (origin
 382        (method url-fetch)
 383        (uri (pypi-uri name version))
 384        (sha256
 385         (base32
 386          "1ccgh0hjyxrwkgy3hnxz3hgbjbs0lmfs25d5l5jam0xbpcpj63h0"))))
 387     (build-system python-build-system)
 388     (arguments
 389      '(#:phases
 390        (modify-phases %standard-phases
 391          (add-after 'unpack 'patch-paths
 392            (lambda _
 393              (substitute* "sshoot/tests/test_manager.py"
 394                (("/bin/sh") (which "sh")))
 395              #t)))))
 396     (inputs
 397      `(("python-argcomplete" ,python-argcomplete)
 398        ("python-prettytable" ,python-prettytable)
 399        ("python-pyyaml" ,python-pyyaml)))
 400     ;; For tests only.
 401     (native-inputs
 402      `(("python-fixtures" ,python-fixtures)
 403        ("python-pbr" ,python-pbr)
 404        ("python-testtools" ,python-testtools)))
 405     (home-page "https://github.com/albertodonato/sshoot")
 406     (synopsis "sshuttle VPN session manager")
 407     (description "sshoot provides a command-line interface to manage multiple
 408 @command{sshuttle} virtual private networks.  It supports flexible profiles
 409 with configuration options for most of @command{sshuttle}’s features.")
 410     (license license:gpl3+)))
 411
 412 (define-public badvpn
 413   (package
 414     (name "badvpn")
 415     (version "1.999.130")
 416     (source
 417      (origin
 418        (method git-fetch)
 419        (uri (git-reference
 420              (url "https://github.com/ambrop72/badvpn.git")
 421              (commit version)))
 422        (file-name (git-file-name name version))
 423        (sha256
 424         (base32 "0rm67xhi7bh3yph1vh07imv5y1pwyldvw3wa5bz471g8mnkc7d3c"))))
 425     (build-system cmake-build-system)
 426     (arguments
 427      '(#:tests? #f))                    ; no tests
 428     (inputs
 429      `(("nspr" ,nspr)
 430        ("nss" ,nss)
 431        ("openssl" ,openssl)))
 432     (native-inputs
 433      `(("pkg-config" ,pkg-config)))
 434     (home-page "https://github.com/ambrop72/badvpn")
 435     (synopsis "Peer-to-peer virtual private network (VPN)")
 436     (description "@code{BadVPN} is a collection of virtual private
 437 network (VPN) tools.  It includes:
 438
 439 @enumerate
 440 @item NCD programming language.\n
 441 NCD (Network Configuration Daemon) is a daemon and programming/scripting
 442 language for configuration of network interfaces and other aspects of the
 443 operating system.
 444 @item Tun2socks network-layer proxifier.\n
 445 The tun2socks program socksifes TCP connections at the network layer.  It
 446 implements a TUN device which accepts all incoming TCP connections (regardless
 447 of destination IP), and forwards the connections through a SOCKS server.
 448 @item Peer-to-peer VPN.\n
 449 The peer-to-peer VPN implements a Layer 2 (Ethernet) network between the peers
 450 (VPN nodes).
 451 @end enumerate")
 452     ;; This project contains a bundled lwIP. lwIP is also released under the
 453     ;; 3-clause BSD license.
 454     (license license:bsd-3)))
 455
 456 (define-public wireguard
 457   (package
 458     (name "wireguard")
 459     (version "0.0.20190601")
 460     (source (origin
 461               (method url-fetch)
 462               (uri (string-append "https://git.zx2c4.com/WireGuard/snapshot/"
 463                                   "WireGuard-" version ".tar.xz"))
 464               (sha256
 465                (base32
 466                 "0s2mys78whsr0yw045a132iqx6nfy3c6hppiskbln5x04hc4ca3m"))))
 467     (build-system gnu-build-system)
 468     (outputs '("out" ; The WireGuard userspace tools
 469                "kernel-patch")) ; A patch to build Linux with WireGuard support
 470     (arguments
 471      `(#:tests? #f ; No tests available.
 472        #:make-flags
 473        (list "CC=gcc"
 474              "WITH_BASHCOMPLETION=yes"
 475              ;; Build and install the helper script wg-quick(8).
 476              "WITH_WGQUICK=yes"
 477              (string-append "PREFIX=" (assoc-ref %outputs "out"))
 478              (string-append "SYSCONFDIR=" (assoc-ref %outputs "out") "/etc"))
 479        #:modules ((guix build gnu-build-system)
 480                   (guix build utils)
 481                   (ice-9 popen)
 482                   (ice-9 textual-ports))
 483        #:phases
 484        (modify-phases %standard-phases
 485          ;; There is no ./configure script.
 486          (delete 'configure)
 487          ;; Until WireGuard is added to the upstream Linux kernel, it is
 488          ;; distributed as a kernel patch generated by this script.
 489          (add-after 'patch-source-shebangs 'make-patch
 490            (lambda* (#:key outputs #:allow-other-keys)
 491              (let* ((output (string-append (assoc-ref outputs "kernel-patch")
 492                                            "/wireguard.patch"))
 493                     (patch-builder "./contrib/kernel-tree/create-patch.sh")
 494                     (port (open-input-pipe patch-builder))
 495                     (str (get-string-all port)))
 496                (close-pipe port)
 497                (mkdir-p (dirname output))
 498                (call-with-output-file output
 499                  (lambda (port)
 500                    (format port "~a" str))))
 501                #t))
 502          (add-after 'make-patch 'chdir
 503            (lambda _
 504              (chdir "src/tools")
 505              #t))
 506          ;; Otherwise the 'install-license-file' phase installs nothing.
 507          ;; <https://bugs.gnu.org/34703>
 508          (add-after 'install 'reset-cwd
 509            (lambda _
 510              (chdir "../..")
 511              #t)))))
 512     (inputs
 513      `(("libmnl" ,libmnl)))
 514     (home-page "https://www.wireguard.com/")
 515     (synopsis "Tools for configuring WireGuard")
 516     (description "This package provides the userspace tools for setting and
 517 retrieving configuration of WireGuard network tunnel interfaces, and a patch
 518 that can be applied to a Linux kernel source tree in order to build it with
 519 WireGuard support.")
 520     (license license:gpl2)))
 521
 522 (define-public xl2tpd
 523   (package
 524     (name "xl2tpd")
 525     (version "1.3.14")
 526     (source (origin
 527               (method git-fetch)
 528               (uri (git-reference
 529                     (url "https://github.com/xelerance/xl2tpd")
 530                     (commit (string-append "v" version))))
 531               (file-name (git-file-name name version))
 532               (sha256
 533                (base32
 534                 "1c2ahxz2zmmxwmk951d2qhijgz67zhwa1hn0r59fgz0y14w22myi"))))
 535     (build-system gnu-build-system)
 536     (arguments
 537      `(#:make-flags (list (string-append "DESTDIR=" %output)
 538                           "CC=gcc")
 539        #:phases (modify-phases %standard-phases
 540                   (delete 'configure))  ; no configure script
 541        #:tests? #f))                    ; no tests provided
 542     (inputs `(("libpcap" ,libpcap)))
 543     (home-page "https://www.xelerance.com/software/xl2tpd/")
 544     (synopsis "Layer 2 Tunnelling Protocol Daemon (RFC 2661)")
 545     (description
 546      "xl2tpd is an implementation of the Layer 2 Tunnelling Protocol (RFC 2661).
 547 L2TP allows you to tunnel PPP over UDP.")
 548     (license license:gpl2)))