From mboxrd@z Thu Jan 1 00:00:00 1970 X-GM-THRID: 6634399131619033088 X-Received: by 2002:a17:906:6899:: with SMTP id n25-v6mr3749253ejr.11.1544705187324; Thu, 13 Dec 2018 04:46:27 -0800 (PST) X-BeenThere: isar-users@googlegroups.com Received: by 2002:a50:b1e2:: with SMTP id n31ls658280edd.3.gmail; Thu, 13 Dec 2018 04:46:26 -0800 (PST) X-Google-Smtp-Source: AFSGD/VF6FgLEV7sd9QJPTLi4+Y5UfmlptEo58lz9QwyWpmaDVVdKTk574Pk9BM0uEIkE2oe6R9/ X-Received: by 2002:a50:86d3:: with SMTP id 19mr4584373edu.5.1544705186779; Thu, 13 Dec 2018 04:46:26 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544705186; cv=none; d=google.com; s=arc-20160816; b=VpXNlghvIKUiOkVJasesLxnOWY2QSkD+lAI3p9E7aeuEVBG6gl0QrLAn2h0N9fupFL XOaG5yp9Z09WRCtJ25lvzm6hIRWFrSZVt6puOjFLH6FQQs+hMlGQ7T6OSeFe6DOKP7DW MnBuTKLg5SgQgkYUxUjq86JmV7ewuFIRQvpA6bcBc5BF7HEnNSz7w+0lUZcWR6LrEXZ1 xilXFZIpzVyMo7A0PCapihpM6iVvWdHlnyZcMXXNu7nOZJb1jrQmIYgsPFc2QrFEpfOy WbwqUECo+/wUDIAbeKv++9NitR1sQGJStk76pub2QvorUb/8758CWGHOz+MgaeL5tDY4 Nsow== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date; bh=hWFrh9ew5jHWN6wK0Eyl38lE7X0BR4v9DqZLO5sWabo=; b=SR+0QnHHL5rKLqIopejUua0XVjZvV3kW9dfXnW9loLhSQyIF50iyPhYcyUT0hJuVFK Rp6E9ZX56GUDeWPaWM7VxBF33x1qFx0E5bjONWY8p6MJYUiARCT6sNlp7htlrTDvX9WP B4hy15IKm5a8pCsUBlTr+jU6OKj12V1kJfeiXD3YEgSsOQ25clUfZi03jsmOdeur6Br+ L89iI/PWu/p9XmCl/t/07CTKWQjJ/aCWbvMampmIulrSW7bdeH8ODmnb9mnhz5sErXdg P6kCOGQ1BOPu/GwbPFfAdtm9ugIw5JtF+AzHSIJ9k8rpPcINCbG+vvhh3AuNB+nQrLXZ cTPA== ARC-Authentication-Results: i=1; gmr-mx.google.com; spf=pass (google.com: domain of henning.schild@siemens.com designates 192.35.17.28 as permitted sender) smtp.mailfrom=henning.schild@siemens.com Return-Path: Received: from goliath.siemens.de (goliath.siemens.de. [192.35.17.28]) by gmr-mx.google.com with ESMTPS id h28si103484edh.4.2018.12.13.04.46.26 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 13 Dec 2018 04:46:26 -0800 (PST) Received-SPF: pass (google.com: domain of henning.schild@siemens.com designates 192.35.17.28 as permitted sender) client-ip=192.35.17.28; Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of henning.schild@siemens.com designates 192.35.17.28 as permitted sender) smtp.mailfrom=henning.schild@siemens.com Received: from mail1.sbs.de (mail1.sbs.de [192.129.41.35]) by goliath.siemens.de (8.15.2/8.15.2) with ESMTPS id wBDCkPVv014392 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 13 Dec 2018 13:46:25 +0100 Received: from md1za8fc.ad001.siemens.net ([139.25.69.236]) by mail1.sbs.de (8.15.2/8.15.2) with ESMTP id wBDCkPGT025204; Thu, 13 Dec 2018 13:46:25 +0100 Date: Thu, 13 Dec 2018 13:46:25 +0100 From: Henning Schild To: Harald Seiler Cc: Subject: Re: [PATCH] sshd-regen-keys: Fix sshd deadlock on boot Message-ID: <20181213134625.4a811e3b@md1za8fc.ad001.siemens.net> In-Reply-To: <1544691418.2560.7.camel@denx.de> References: <1544691418.2560.7.camel@denx.de> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TUID: PkjTBX2lysH9 Am Thu, 13 Dec 2018 09:56:58 +0100 schrieb Harald Seiler : > Currently, when sshd-regen-keys runs dpkg-reconfigure, this > will lead to a call to `systemctl restart ssh`. This call blocks > forever because of course the sshd-regen-keys unit, which is a > dependency of sshd, hasn't finished at this point and can't do so > because it is waiting as well. > > To circumvent this deadlock, this commit changes sshd-regen-keys' > behavior so sshd is first disabled and only reenabled after the > job is done. > > Signed-off-by: Harald Seiler > --- > .../sshd-regen-keys/files/sshd-regen-keys.service | 2 +- > .../sshd-regen-keys/files/sshd-regen-keys.sh | 19 > +++++++++++++++++++ .../sshd-regen-keys/sshd-regen-keys_0.1.bb > | 7 +++++-- 3 files changed, 25 insertions(+), 3 deletions(-) > create mode 100644 > meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.sh > > diff --git > a/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.service > b/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.service > index 3b8231f..a05e1a9 100644 --- > a/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.service > +++ > b/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.service > @@ -10,7 +10,7 @@ ConditionPathIsReadWrite=/etc Type=oneshot > RemainAfterExit=yes Environment=DEBIAN_FRONTEND=noninteractive > -ExecStart=/bin/sh -c "rm -v /etc/ssh/ssh_host_*_key*; > dpkg-reconfigure openssh-server" > +ExecStart=/usr/sbin/sshd-regen-keys.sh ExecStartPost=-/bin/systemctl > disable sshd-regen-keys.service StandardOutput=syslog > StandardError=syslog diff --git > a/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.sh > b/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.sh new > file mode 100644 index 0000000..294e8fa --- /dev/null > +++ b/meta/recipes-support/sshd-regen-keys/files/sshd-regen-keys.sh > @@ -0,0 +1,19 @@ > +#!/usr/bin/env sh > + > +echo -n "SSH server is " > +if systemctl is-enabled ssh; then > + SSHD_ENABLED="true" > + systemctl disable --no-reload ssh > +fi > + > +echo "Removing keys ..." > +rm -v /etc/ssh/ssh_host_*_key* > + > +echo "Regenerating keys ..." > +dpkg-reconfigure openssh-server > + > +if test -n $SSHD_ENABLED; then > + echo "Reenabling ssh server ..." > + systemctl enable --no-reload ssh > + systemctl start --no-block ssh Do we need the start? Is that not in fact taking us into the same issue? ... i guess that is the "--no-block". Henning > +fi > diff --git > a/meta/recipes-support/sshd-regen-keys/sshd-regen-keys_0.1.bb > b/meta/recipes-support/sshd-regen-keys/sshd-regen-keys_0.1.bb index > 02e9e25..6f12414 100644 --- > a/meta/recipes-support/sshd-regen-keys/sshd-regen-keys_0.1.bb +++ > b/meta/recipes-support/sshd-regen-keys/sshd-regen-keys_0.1.bb @@ -6,9 > +6,12 @@ MAINTAINER = "isar-users " > DEBIAN_DEPENDS = "openssh-server, systemd" SRC_URI = "file://postinst > \ > - file://sshd-regen-keys.service" > + file://sshd-regen-keys.service \ > + file://sshd-regen-keys.sh" > > +do_install[cleandirs] = "${D}/lib/systemd/system \ > + ${D}/usr/sbin" > do_install() { > - install -v -d -m 755 "${D}/lib/systemd/system" > install -v -m 644 "${WORKDIR}/sshd-regen-keys.service" > "${D}/lib/systemd/system/sshd-regen-keys.service" > + install -v -m 755 "${WORKDIR}/sshd-regen-keys.sh" > "${D}/usr/sbin/sshd-regen-keys.sh" }