gnu: services: Add pcscd service.

* gnu/services/security-token.scm: New file.
* gnu/tests/security-token.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Register new files.
* doc/guix.texi (Miscellaneous Services): Document the service.

doc/guix.texi

@@ -20331,6 +20331,37 @@ An association list specifies kernel parameters and their values.
 @end table
 @end deftp
 
+@cindex pcscd
+@subsubheading PC/SC Smart Card Daemon Service
+
+The @code{(gnu services security-token)} module provides the following service
+to run @command{pcscd}, the PC/SC Smart Card Daemon.  @command{pcscd} is the
+daemon program for pcsc-lite and the MuscleCard framework. It is a resource
+manager that coordinates communications with smart card readers, smart cards
+and cryptographic tokens that are connected to the system.
+
+@defvr {Scheme Variable} pcscd-service-type
+Service type for the @command{pcscd} service.  Its value must be a
+@code{pcscd-configuration} object.  To run pcscd in the default
+configuration, instantiate it as:
+
+@example
+(service pcscd-service-type)
+@end example
+@end defvr
+
+@deftp {Data Type} pcscd-configuration
+The data type representing the configuration of @command{pcscd}.
+
+@table @asis
+@item @code{pcsc-lite} (default: @code{pcsc-lite})
+The pcsc-lite package that provides pcscd.
+@item @code{usb-drivers} (default: @code{(list ccid)})
+List of packages that provide USB drivers to pcscd. Drivers are expected to be
+under @file{pcsc/drivers} in the store directory of the package.
+@end table
+@end deftp
+
 @cindex lirc
 @subsubheading Lirc Service
 

gnu/local.mk

@@ -486,6 +486,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/services/monitoring.scm			\
   %D%/services/networking.scm			\
   %D%/services/nfs.scm			\
+  %D%/services/security-token.scm		\
   %D%/services/shepherd.scm			\
   %D%/services/sound.scm			\
   %D%/services/herd.scm				\
@@ -540,6 +541,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/tests/messaging.scm			\
   %D%/tests/networking.scm			\
   %D%/tests/rsync.scm				\
+  %D%/tests/security-token.scm			\
   %D%/tests/ssh.scm				\
   %D%/tests/version-control.scm			\
   %D%/tests/virtualization.scm			\

gnu/services/security-token.scm

@@ -0,0 +1,84 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Arun Isaac <arunisaac@systemreboot.net>
+;;;
+;;; 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 services security-token)
+  #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu packages admin)
+  #:use-module (gnu packages security-token)
+  #:use-module (gnu system shadow)
+  #:use-module (guix gexp)
+  #:use-module (guix modules)
+  #:use-module (guix records)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-26)
+  #:export (pcscd-configuration
+            pcscd-configuration?
+            pcscd-configuration-pcsc-lite
+            pcscd-configuration-usb-drivers
+            pcscd-service-type))
+
+;;;
+;;; PC/SC Smart Card Daemon
+;;;
+
+(define-record-type* <pcscd-configuration>
+  pcscd-configuration make-pcscd-configuration pcscd-configuration?
+  (pcsc-lite pcscd-configuration-pcsc-lite
+             (default pcsc-lite))
+  (usb-drivers pcscd-configuration-usb-drivers
+               (default (list ccid))))
+
+(define pcscd-shepherd-service
+  (match-lambda
+    (($ <pcscd-configuration> pcsc-lite)
+     (with-imported-modules (source-module-closure
+                             '((gnu build shepherd)))
+       (shepherd-service
+        (documentation "PC/SC Smart Card Daemon")
+        (provision '(pcscd))
+        (requirement '(syslogd))
+        (modules '((gnu build shepherd)))
+        (start #~(lambda _
+                   (invoke #$(file-append pcsc-lite "/sbin/pcscd"))
+                   (call-with-input-file "/var/run/pcscd/pcscd.pid" read)))
+        (stop #~(make-kill-destructor)))))))
+
+(define pcscd-activation
+  (match-lambda
+    (($ <pcscd-configuration> pcsc-lite usb-drivers)
+     #~(begin
+         (use-modules (guix build utils))
+         (mkdir-p "/var/lib")
+         (symlink #$(directory-union
+                     "pcsc"
+                     (map (cut file-append <> "/pcsc")
+                          usb-drivers))
+                  "/var/lib/pcsc")))))
+
+(define pcscd-service-type
+  (service-type
+   (name 'pcscd)
+   (description
+    "Run @command{pcscd}, the PC/SC smart card daemon.")
+   (extensions
+    (list (service-extension shepherd-root-service-type
+                             (compose list pcscd-shepherd-service))
+          (service-extension activation-service-type
+                             pcscd-activation)))
+   (default-value (pcscd-configuration))))

gnu/tests/security-token.scm

@@ -0,0 +1,71 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2018 Arun Isaac <arunisaac@systemreboot.net>
+;;;
+;;; 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 tests security-token)
+  #:use-module (gnu tests)
+  #:use-module (gnu system vm)
+  #:use-module (gnu services)
+  #:use-module (gnu services security-token)
+  #:use-module (guix gexp)
+  #:export (%test-pcscd))
+
+(define %pcscd-os
+  (simple-operating-system
+   (service pcscd-service-type)))
+
+(define* (run-pcscd-test)
+  "Run tests of 'pcscd-service-type'."
+  (define os
+    (marionette-operating-system
+     %pcscd-os
+     #:imported-modules '((gnu services herd))
+     #:requirements '(pcscd)))
+
+  (define test
+    (with-imported-modules '((gnu build marionette))
+      #~(begin
+          (use-modules (srfi srfi-64)
+                       (gnu build marionette))
+          (define marionette
+            (make-marionette (list #$(virtual-machine os))))
+
+          (mkdir #$output)
+          (chdir #$output)
+
+          (test-begin "pcscd")
+
+          (test-assert "pcscd is alive"
+            (marionette-eval
+             '(begin
+                (use-modules (gnu services herd))
+                (live-service-running
+                 (find (lambda (live)
+                         (memq 'pcscd (live-service-provision live)))
+                       (current-services))))
+             marionette))
+
+          (test-end)
+          (exit (= (test-runner-fail-count (test-runner-current)) 0)))))
+
+  (gexp->derivation "pcscd" test))
+
+(define %test-pcscd
+  (system-test
+   (name "pcscd")
+   (description "Test a running pcscd daemon.")
+   (value (run-pcscd-test))))