Only fetch and upgrade if a new snapshot is available.

Based on a diff by Marco Bonetti (sid77 AT slackware.it).

discussed with deraadt@, OK kn

2 files changed, 22 insertions, 11 deletions

diff --git a/usr.sbin/sysupgrade/sysupgrade.8 b/usr.sbin/sysupgrade/sysupgrade.8
index 88c8a43b034..27d3d3143c3 100644
--- a/usr.sbin/sysupgrade/sysupgrade.8
+++ b/usr.sbin/sysupgrade/sysupgrade.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: sysupgrade.8,v 1.2 2019/04/26 05:54:49 jmc Exp $
+.\"	$OpenBSD: sysupgrade.8,v 1.3 2019/05/03 13:04:40 florian Exp $
 .\"
 .\" Copyright (c) 2019 Florian Obser <florian@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: April 26 2019 $
+.Dd $Mdocdate: May 3 2019 $
 .Dt SYSUPGRADE 8
 .Os
 .Sh NAME
@@ -23,12 +23,13 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl c
+.Op Fl f
 .Op Ar installurl
 .Sh DESCRIPTION
 .Nm
 is a utility to upgrade
 .Ox
-to the next release or a new snapshot.
+to the next release or a new snapshot if available.
 .Pp
 .Nm
 downloads the necessary files to
@@ -52,6 +53,10 @@ The default is to find out if the system is running a release or a snapshot.
 In case of release
 .Nm
 downloads the next release.
+.It Fl f
+force an already applied upgrade.
+The default is to upgrade to latest snapshot only if available.
+This option has no effect on releases.
 .El
 .Sh FILES
 .Bl -tag -width "/home/_sysupgrade" -compact
diff --git a/usr.sbin/sysupgrade/sysupgrade.sh b/usr.sbin/sysupgrade/sysupgrade.sh
index e532d7f94d1..7225b0d840f 100644
--- a/usr.sbin/sysupgrade/sysupgrade.sh
+++ b/usr.sbin/sysupgrade/sysupgrade.sh
@@ -1,6 +1,6 @@
 #!/bin/ksh
 #
-# $OpenBSD: sysupgrade.sh,v 1.8 2019/04/29 22:27:39 ian Exp $
+# $OpenBSD: sysupgrade.sh,v 1.9 2019/05/03 13:04:40 florian Exp $
 #
 # Copyright (c) 1997-2015 Todd Miller, Theo de Raadt, Ken Westerback
 # Copyright (c) 2015 Robert Peichaer <rpe@openbsd.org>
@@ -33,7 +33,7 @@ ug_err()
 
 usage()
 {
-	ug_err "usage: ${0##*/} [-c] [installurl]"
+	ug_err "usage: ${0##*/} [-cf] [installurl]"
 }
 
 unpriv()
@@ -63,12 +63,14 @@ rmel() {
 }
 
 CURRENT=false
-
-while getopts c arg; do
-        case ${arg} in
-        c)      CURRENT=true;;
-        *)      usage;;
-        esac
+FORCE=false
+
+while getopts cf arg; do
+	case ${arg} in
+	c)	CURRENT=true;;
+	f)	FORCE=true;;
+	*)	usage;;
+	esac
 done
 
 set -A _KERNV -- $(sysctl -n kern.version |
@@ -112,6 +114,10 @@ cd ${SETSDIR}
 
 unpriv -f SHA256.sig ftp -Vmo SHA256.sig ${URL}SHA256.sig
 
+if cmp -s /var/db/installed.SHA256.sig SHA256.sig && ! $FORCE; then
+	ug_err "Already on latest snapshot."
+fi
+
 _KEY=openbsd-${_KERNV[0]%.*}${_KERNV[0]#*.}-base.pub
 _NEXTKEY=openbsd-${NEXT_VERSION%.*}${NEXT_VERSION#*.}-base.pub