gnu: Add libwebsockets.

* gnu/packages/libwebsockets.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

gnu-system.am

@@ -132,6 +132,7 @@ GNU_SYSTEM_MODULES =				\
   gnu/packages/libunistring.scm			\
   gnu/packages/libusb.scm			\
   gnu/packages/libunwind.scm			\
+  gnu/packages/libwebsockets.scm		\
   gnu/packages/lightning.scm			\
   gnu/packages/linux.scm			\
   gnu/packages/lout.scm				\

gnu/packages/libwebsockets.scm

@@ -0,0 +1,83 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2014 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix 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 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix 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.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages libwebsockets)
+  #:use-module (guix packages)
+  #:use-module (guix git-download)
+  #:use-module (guix build-system gnu)
+  #:use-module ((guix licenses)
+                #:select (lgpl2.1))
+  #:use-module (gnu packages autotools)
+  #:use-module ((gnu packages compression) #:select (zlib))
+  #:use-module (gnu packages perl)
+  #:use-module (gnu packages openssl))
+
+(define-public libwebsockets
+  (package
+    (name "libwebsockets")
+    (version "1.2")
+    (source (origin
+              ;; The project does not publish tarballs, so we have to take
+              ;; things from Git.
+              (method git-fetch)
+              (uri (git-reference
+                    (url "git://git.libwebsockets.org/libwebsockets")
+                    (commit (string-append "v" version
+                                           "-chrome26-firefox18"))))
+              (sha256
+               (base32
+                "1293hbz8qj4p27m1qjf8dn97r10xjyiwdpq491m87zi025s558cl"))
+              (file-name (string-append name "-" version))))
+
+    ;; The package has both CMake and GNU build systems, but the latter is
+    ;; apparently better supported (CMake-generated makefiles lack an
+    ;; 'install' target, for instance.)
+    (build-system gnu-build-system)
+
+    (arguments
+     '(#:phases (alist-replace
+                 'unpack
+                 ;; FIXME: Remove this when gnu-build-system handles that
+                 ;; case correctly.
+                 (lambda* (#:key source #:allow-other-keys)
+                   (mkdir "source")
+                   (chdir "source")
+                   (copy-recursively source ".")
+                   #t)
+
+                 (alist-cons-before
+                  'configure 'bootstrap
+                  (lambda _
+                    (chmod "libwebsockets-api-doc.html" #o666)
+                    (zero? (system* "./autogen.sh")))
+                  %standard-phases))))
+    (native-inputs `(("autoconf" ,autoconf)
+                     ("automake" ,automake)
+                     ("libtool" ,libtool "bin")
+                     ("perl" ,perl)))             ; to build the HTML doc
+    (inputs `(("zlib" ,zlib)
+              ("openssl" ,openssl)))
+    (synopsis "WebSockets library written in C")
+    (description
+     "libwebsockets is a library that allows C programs to establish client
+and server WebSockets connections---a protocol layered above HTTP that allows
+for efficient socket-like bidirectional reliable communication channels.")
+    (home-page "http://libwebsockets.org/")
+
+    ;; This is LGPLv2.1-only with extra exceptions specified in 'LICENSE'.
+    (license lgpl2.1)))