[Buildroot] [PATCH 4/4] package/openssh: add sd socket-activated ssh daemon services

[Norbert Lange]

Am So., 7. Juni 2020 um 21:32 Uhr schrieb Jérémy ROSEN <jeremy.rosen at smile.fr>:
>
>
>
> Le dim. 7 juin 2020 à 21:11, Norbert Lange <nolange79 at gmail.com> a écrit :
>>
>> Am So., 7. Juni 2020 um 13:07 Uhr schrieb Jérémy ROSEN <jeremy.rosen at smile.fr>:
>> >
>> >
>> >
>> > Le sam. 6 juin 2020 à 00:59, Norbert Lange <nolange79 at gmail.com> a écrit :
>> >>
>> >> Signed-off-by: Norbert Lange <nolange79 at gmail.com>
>> >> ---
>> >>  package/openssh/openssh.mk               |  6 +++---
>> >>  package/openssh/sshd-host-keygen.service |  2 +-
>> >>  package/openssh/sshd.socket              | 11 +++++++++++
>> >>  package/openssh/sshd at .service            | 10 ++++++++++
>> >>  4 files changed, 25 insertions(+), 4 deletions(-)
>> >>  create mode 100644 package/openssh/sshd.socket
>> >>  create mode 100644 package/openssh/sshd at .service
>> >>
>> >> diff --git a/package/openssh/openssh.mk b/package/openssh/openssh.mk
>> >> index 6b3ee1f5f4..1f2638e9c9 100644
>> >> --- a/package/openssh/openssh.mk
>> >> +++ b/package/openssh/openssh.mk
>> >> @@ -114,9 +114,9 @@ endef
>> >>  OPENSSH_POST_INSTALL_TARGET_HOOKS += OPENSSH_INSTALL_SERVER_PROGRAMS
>> >>
>> >>  define OPENSSH_INSTALL_INIT_SYSTEMD
>> >> -       mkdir $(TARGET_DIR)/usr/lib/systemd/system
>> >> -       $(INSTALL) -m 644 package/openssh/sshd*.service \
>> >> -               $(TARGET_DIR)/usr/lib/systemd/system/
>> >> +       mkdir -p $(TARGET_DIR)/usr/lib/systemd/system
>> >> +       $(INSTALL) -m 644 package/openssh/sshd*.service package/openssh/sshd.socket \
>> >> +               $(TARGET_DIR)/usr/lib/systemd/system/.
>> >>         $(OPENSSH_INSTALL_SYSTEMD_SYSUSERS)
>> >>  endef
>> >>
>> >> diff --git a/package/openssh/sshd-host-keygen.service b/package/openssh/sshd-host-keygen.service
>> >> index 058e671c44..ffde622b01 100644
>> >> --- a/package/openssh/sshd-host-keygen.service
>> >> +++ b/package/openssh/sshd-host-keygen.service
>> >> @@ -17,4 +17,4 @@ Type=oneshot
>> >>  RemainAfterExit=yes
>> >>
>> >>  [Install]
>> >> -WantedBy=sshd.service
>> >> +WantedBy=sshd.service sshd.socket
>> >> diff --git a/package/openssh/sshd.socket b/package/openssh/sshd.socket
>> >> new file mode 100644
>> >> index 0000000000..bbae9ed7aa
>> >> --- /dev/null
>> >> +++ b/package/openssh/sshd.socket
>> >> @@ -0,0 +1,11 @@
>> >> +[Unit]
>> >> +Description=OpenBSD Secure Shell server socket
>> >> +Before=sshd.service
>> >> +Conflicts=sshd.service
>> >
>> > No, that would stop the socket when the service is started, and you don't want that.
>> > If you do that, only one connection would be accepted before the socket is stoped
>> > and since you have accept=yes no further connections would be accepted
>>
>> there is the singular sshd service
>> and the sshd.socket which spawns sshd@ instance services.
>> Those are mutually exclusive (because of the "Conflicts"), the
>> "Before" line just ensures that the sshd.socket wins out by default.
>>
>
> aah right, I messed up sshd.service and sshd at .service in my head.
> my bad.
>
> I personally think we shouldn't install both methods.
> either choose a distro-wide decision or provide a config option
>
> Anyway, I see what you are doing now, and that should work, AFAICT.
>
> I still think that it's cool that openssh supports all those startup methods,
> but I'm not convinced we need to support all of them in BR.

sshd is better for throughput/efficiency if you have alot connections,

the socket option saves memory if you rarely have connections (and is
actually a simpler service file).

I would support both, but let users pick.

Norbert