Bugfix 5240: Prevent re-installation of same version on running systems

Previously, it was possible in some cases to "add" a system image that
would over-write the running image.  This change fixes that by getting
the version string of the running system from the kernel command line
instead of the Vyatta version file.  This string represents the actual
directory name that holds the image, so is more reliable.

Also previously, an attempt to "add" a system image that had the same
version string as another image installed on the system (but was not
the running image) would always succeed.  This would completely
over-write that image.  Because of this destructive behavior, it
deserves a confirmation question.  This change prompts the user to see
if they really want to do that before proceeding.

1 files changed, 27 insertions, 5 deletions

diff --git a/scripts/install/install-image-existing b/scripts/install/install-image-existing
index 214fd2c8..b566c1e9 100755
--- a/scripts/install/install-image-existing
+++ b/scripts/install/install-image-existing
@@ -19,8 +19,14 @@ if [ `whoami` != 'root' ] ; then
   failure_exit 'This script must be run with root privileges.'
 fi
 
-CURVER=$(sed -n 's/^Version \+: \+\([^ ]\+\)$/\1/p' \
-           ${vyatta_sysconfdir}/version 2>/dev/null)
+# On image-installed systems, the image name can be found as the
+# directory under "/boot" on the path to the running kernel on the
+# boot line. On non-image-installed systems, this yelds the
+# name of the kernel image file.
+CURVER=`awk '{print $1}' /proc/cmdline`
+CURVER=${CURVER#BOOT_IMAGE=/boot/}
+CURVER=${CURVER%/vmlinuz*}
+
 if [ -z "$CURVER" ]; then
   failure_exit 'Cannot find current version.'
 fi
@@ -32,11 +38,11 @@ if [ -z "$NEWVER" ]; then
   failure_exit 'Cannot find new release version.'
 fi
 if [ "$CURVER" == "$NEWVER" ]; then
-  failure_exit "Cannot install the same release version \"$NEWVER\"."
+    echo "Image version $NEWVER is the same as the running system."
+    echo "Cannot install the same release version as the running system."
+    exit 1
 fi
 
-# start the install
-echo "Installing \"$NEWVER\" release."
 
 # this is the default if current install is union
 BOOT_DIR=/live/image/boot
@@ -47,6 +53,22 @@ elif [ "$CUR_INSTALL" != 'union' ]; then
   exit 1
 fi
 
+if [ -d $BOOT_DIR/$NEWVER ]; then
+    echo "Version $NEWVER is already installed on this system."
+    echo "Proceeding with this installation will delete this copy of"
+    echo "$NEWVER and replace it with a new copy."
+    echo -n "Do you want to replace it? (Yes/No) [No]: "
+    resp=$(get_response "No" "Yes No Y N")
+    if [ "$resp" != 'yes' ] && [ "$resp" != 'y' ]; then
+	echo "OK.  Will not replace $NEWVER"
+	echo "Exiting..."
+	exit 1
+    fi
+fi
+
+# start the install
+echo "Installing \"$NEWVER\" release."
+
 # create the new release directories
 REL_ROOT=$BOOT_DIR/$NEWVER
 RW_DIR="$REL_ROOT/live-rw"