Prior to this commit, the isc-dhcp implementation was the only DHCP
implementation supported by dhcp-client-shepherd-service. This is
problematic as the ISC implementation has reached end-of-life in
2022(!). As a first step to migrate away from isc-dhcp, this commit
adds support for dhcpcd to dhcp-client-shepherd-service. Currently,
it has to be enabled explicitly via the package field of the
dhcp-client-configuration. In the future, it is intended to become
the default to migrate away from isc-dhcp.
While at it, also remove isc-dhcp from %base-packages as it is no
longer necessarily needed and it will be pulled in by the DHCP
client service if required.
* gnu/services/networking.scm (dhcp-client-shepherd-service): Add
support for the dhcpcd client implementation.
* gnu/services/networking.scm (dhcp-client-account-service): New
procedure.
* gnu/services/networking.scm (dhcp-client-service-type): Add optional
account-service-type extensions (needed for dhcpcd).
* gnu/system.scm (%base-packages-networking): Remove isc-dhcp from
%base-packages (will be pulled in by dhcp-client-shepherd-service).
Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
---
Changes since v1:
* Remove isc-dhcp from %base-packages
gnu/services/networking.scm | 84 ++++++++++++++++++++++++++-----------
gnu/system.scm | 2 +-
2 files changed, 61 insertions(+), 25 deletions(-)
Toggle diff (132 lines)
diff --git a/gnu/services/networking.scm b/gnu/services/networking.scm
index 495d049728..3621e2bda2 100644
--- a/gnu/services/networking.scm
+++ b/gnu/services/networking.scm
@@ -316,25 +316,21 @@ (define-record-type* <dhcp-client-configuration>
(define dhcp-client-shepherd-service
(match-lambda
((? dhcp-client-configuration? config)
- (let ((package (dhcp-client-configuration-package config))
- (requirement (dhcp-client-configuration-shepherd-requirement config))
- (provision (dhcp-client-configuration-shepherd-provision config))
- (interfaces (dhcp-client-configuration-interfaces config))
- (pid-file "/var/run/dhclient.pid"))
+ (let* ((package (dhcp-client-configuration-package config))
+ (client-name (package-name package))
+ (requirement (dhcp-client-configuration-shepherd-requirement config))
+ (provision (dhcp-client-configuration-shepherd-provision config))
+ (interfaces (dhcp-client-configuration-interfaces config)))
(list (shepherd-service
(documentation "Set up networking via DHCP.")
(requirement `(user-processes udev ,@requirement))
(provision provision)
- ;; XXX: Running with '-nw' ("no wait") avoids blocking for a minute when
- ;; networking is unavailable, but also means that the interface is not up
- ;; yet when 'start' completes. To wait for the interface to be ready, one
- ;; should instead monitor udev events.
(start #~(lambda _
- (define dhclient
- (string-append #$package "/sbin/dhclient"))
+ (use-modules (ice-9 popen)
+ (ice-9 rdelim))
- ;; When invoked without any arguments, 'dhclient' discovers all
+ ;; When invoked without any arguments, the client discovers all
;; non-loopback interfaces *that are up*. However, the relevant
;; interfaces are typically down at this point. Thus we perform
;; our own interface discovery here.
@@ -355,17 +351,40 @@ (define dhcp-client-shepherd-service
(_
#~'#$interfaces))))
- (false-if-exception (delete-file #$pid-file))
- (let ((pid (fork+exec-command
- ;; By default dhclient uses a
- ;; pre-standardization implementation of
- ;; DDNS, which is incompatable with
- ;; non-ISC DHCP servers; thus, pass '-I'.
- ;; <https://kb.isc.org/docs/aa-01091>.
- (cons* dhclient "-nw" "-I"
- "-pf" #$pid-file ifaces))))
- (and (zero? (cdr (waitpid pid)))
- (read-pid-file #$pid-file)))))
+ ;; Returns the execution configuration for the DHCP client
+ ;; selected by the package field of dhcp-client-configuration.
+ ;; The configuration is a pair of pidfile and execution command
+ ;; where the latter is a list.
+ (define exec-config
+ (case (string->symbol #$client-name)
+ ((isc-dhcp)
+ (let ((pid-file "/var/run/dhclient.pid"))
+ (cons
+ (cons* (string-append #$package "/sbin/dhclient")
+ "-nw" "-I" "-pf" pid-file ifaces)
+ pid-file)))
+ ((dhcpcd)
+ ;; For dhcpcd, the utilized pid-file depends on the
+ ;; command-line arguments. If multiple interfaces are
+ ;; given, a different pid-file is returned. Hence, we
+ ;; consult dhcpcd itself to determine the pid-file.
+ (let* ((cmd (string-append #$package "/sbin/dhcpcd"))
+ (arg (cons* cmd "-b" ifaces)))
+ (cons arg
+ (let* ((pipe (string-join (append arg '("-P")) " "))
+ (port (open-input-pipe pipe))
+ (path (read-line port)))
+ (close-pipe port)
+ path))))
+ (else
+ (error (G_ "unknown 'package' value in dhcp-client-configuration")))))
+
+ (let ((pid-file (cdr exec-config))
+ (exec-cmd (car exec-config)))
+ (false-if-exception (delete-file pid-file))
+ (let ((pid (fork+exec-command exec-cmd)))
+ (and (zero? (cdr (waitpid pid)))
+ (read-pid-file pid-file))))))
(stop #~(make-kill-destructor))))))
(package
(warning (G_ "'dhcp-client' service now expects a \
@@ -377,10 +396,27 @@ (define dhcp-client-shepherd-service
(dhcp-client-configuration
(package package))))))
+(define (dhcp-client-account-service config)
+ (let ((package (dhcp-client-configuration-package config)))
+ ;; Contrary to other DHCP clients (e.g. dhclient), dhcpcd supports
+ ;; privilege separation. Hence, we need to create an account here.
+ (if (string=? "dhcpcd" (package-name package))
+ (list (user-group (name "dhcpcd") (system? #t))
+ (user-account
+ (name "dhcpcd")
+ (group "dhcpcd")
+ (system? #t)
+ (comment "dhcpcd daemon user")
+ (home-directory "/var/empty")
+ (shell "/run/current-system/profile/sbin/nologin")))
+ '())))
+
(define dhcp-client-service-type
(service-type (name 'dhcp-client)
(extensions
- (list (service-extension shepherd-root-service-type
+ (list (service-extension account-service-type
+ dhcp-client-account-service)
+ (service-extension shepherd-root-service-type
dhcp-client-shepherd-service)))
(default-value (dhcp-client-configuration))
(description "Run @command{dhcp}, a Dynamic Host Configuration
diff --git a/gnu/system.scm b/gnu/system.scm
index 3cd64a5c9f..a7676ec90e 100644
--- a/gnu/system.scm
+++ b/gnu/system.scm
@@ -917,7 +917,7 @@ (define %base-packages-interactive
(define %base-packages-networking
;; Default set of networking packages.
- (list inetutils isc-dhcp
+ (list inetutils
iproute
wget
;; wireless-tools is deprecated in favor of iw, but it's still what
