diff options
Diffstat (limited to 'usr/libexec/readonly-root')
| -rwxr-xr-x | usr/libexec/readonly-root | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/usr/libexec/readonly-root b/usr/libexec/readonly-root new file mode 100755 index 00000000..a3679580 --- /dev/null +++ b/usr/libexec/readonly-root @@ -0,0 +1,204 @@ +#!/bin/bash +# +# Set up readonly-root support. +# + +. /etc/init.d/functions + +# We need to initialize the $HOSTNAME variable by ourselves now: +# (It was previously done for RHEL-6 branch, but got lost in time.) +HOSTNAME="$(hostname)" + +# Check SELinux status +SELINUX_STATE= +if [ -e "/sys/fs/selinux/enforce" ] && [ "$(cat /proc/self/attr/current | tr -d '\000' )" != "kernel" ]; then + if [ -r "/sys/fs/selinux/enforce" ] ; then + SELINUX_STATE=$(cat "/sys/fs/selinux/enforce") + else + # assume enforcing if you can't read it + SELINUX_STATE=1 + fi +fi + +selinux_fixup() { + if [ -n "$SELINUX_STATE" ] && [ -e "$1" ]; then + restorecon -R "$1" + fi +} + +# Only read this once. +[ -z "${cmdline}" ] && cmdline=$(cat /proc/cmdline) + +READONLY= +if [ -f /etc/sysconfig/readonly-root ]; then + . /etc/sysconfig/readonly-root +fi +if strstr "$cmdline" readonlyroot ; then + READONLY=yes + [ -z "$RW_MOUNT" ] && RW_MOUNT=/var/lib/stateless/writable + [ -z "$STATE_MOUNT" ] && STATE_MOUNT=/var/lib/stateless/state +fi +if strstr "$cmdline" noreadonlyroot ; then + READONLY=no +fi + +MOUNTS=() +if [ "$READONLY" = "yes" -o "$TEMPORARY_STATE" = "yes" ]; then + + add_mount() { + mnt=${1%/} + MOUNTS=("${MOUNTS[@]}" "$mnt") + } + + cp_empty() { + if [ -e "$1" ]; then + echo "$1" | cpio -p -vd "$RW_MOUNT" &>/dev/null + add_mount $1 + fi + } + + cp_dirs() { + if [ -e "$1" ]; then + mkdir -p "$RW_MOUNT$1" + find "$1" -type d -print0 | cpio -p -0vd "$RW_MOUNT" &>/dev/null + add_mount $1 + fi + } + + cp_files() { + if [ -e "$1" ]; then + cp -a --parents "$1" "$RW_MOUNT" + add_mount $1 + fi + } + + # Common mount options for scratch space regardless of + # type of backing store + mountopts= + + # Scan partitions for local scratch storage + rw_mount_dev=$(blkid -t LABEL="$RW_LABEL" -l -o device) + + bindmountopts= + [ "$SLAVE_MOUNTS" = "yes" ] && bindmountopts="--make-slave" + + # First try to mount scratch storage from /etc/fstab, then any + # partition with the proper label. If either succeeds, be sure + # to wipe the scratch storage clean. If both fail, then mount + # scratch storage via tmpfs. + if mount $mountopts "$RW_MOUNT" > /dev/null 2>&1 ; then + rm -rf "$RW_MOUNT" > /dev/null 2>&1 + elif [ x$rw_mount_dev != x ] && mount $rw_mount_dev $mountopts "$RW_MOUNT" > /dev/null 2>&1; then + rm -rf "$RW_MOUNT" > /dev/null 2>&1 + else + mount -n -t tmpfs $RW_OPTIONS $mountopts none "$RW_MOUNT" + fi + + for file in /etc/rwtab /etc/rwtab.d/* /run/initramfs/rwtab ; do + is_ignored_file "$file" && continue + [ -f $file ] && while read type path ; do + case "$type" in + empty) + cp_empty $path + ;; + files) + cp_files $path + ;; + dirs) + cp_dirs $path + ;; + *) + ;; + esac + done < <(cat $file) + done + + for m in "${MOUNTS[@]}"; do + prefix=0 + for mount_point in "${MOUNTS[@]}"; do + [[ $m = $mount_point ]] && continue + if [[ $m =~ ^$mount_point/.* ]] ; then + prefix=1 + break + fi + done + [[ $prefix -eq 1 ]] && continue + + mount -n --bind $bindmountopts "$RW_MOUNT$m" "$m" + selinux_fixup "$m" + done + + # Use any state passed by initramfs + [ -d /run/initramfs/state ] && cp -a /run/initramfs/state/* $RW_MOUNT + + # In theory there should be no more than one network interface active + # this early in the boot process -- the one we're booting from. + # Use the network address to set the hostname of the client. This + # must be done even if we have local storage. + ipaddr= + if [ "$HOSTNAME" = "localhost" -o "$HOSTNAME" = "localhost.localdomain" ]; then + ipaddr=$(ip addr show to 0.0.0.0/0 scope global | awk '/[[:space:]]inet / { print gensub("/.*","","g",$2) }') + for ip in $ipaddr ; do + HOSTNAME= + eval $(ipcalc -h $ipaddr 2>/dev/null) + [ -n "$HOSTNAME" ] && { hostname ${HOSTNAME} ; break; } + done + fi + + # Clients with read-only root filesystems may be provided with a + # place where they can place minimal amounts of persistent + # state. SSH keys or puppet certificates for example. + # + # Ideally we'll use puppet to manage the state directory and to + # create the bind mounts. However, until that's all ready this + # is sufficient to build a working system. + + # First try to mount persistent data from /etc/fstab, then any + # partition with the proper label, then fallback to NFS + state_mount_dev=$(blkid -t LABEL="$STATE_LABEL" -l -o device) + if mount $mountopts $STATE_OPTIONS "$STATE_MOUNT" > /dev/null 2>&1 ; then + /bin/true + elif [ x$state_mount_dev != x ] && mount $state_mount_dev $mountopts "$STATE_MOUNT" > /dev/null 2>&1; then + /bin/true + elif [ ! -z "$CLIENTSTATE" ]; then + # No local storage was found. Make a final attempt to find + # state on an NFS server. + + mount -t nfs $CLIENTSTATE/$HOSTNAME $STATE_MOUNT -o rw,nolock + fi + + if [ -w "$STATE_MOUNT" ]; then + + mount_state() { + if [ -e "$1" ]; then + [ ! -e "$STATE_MOUNT$1" ] && cp -a --parents "$1" "$STATE_MOUNT" + mount -n --bind $bindmountopts "$STATE_MOUNT$1" "$1" + fi + } + + for file in /etc/statetab /etc/statetab.d/* ; do + is_ignored_file "$file" && continue + [ ! -f "$file" ] && continue + + if [ -f "$STATE_MOUNT/$file" ] ; then + mount -n --bind $bindmountopts "$STATE_MOUNT/$file" "$file" + fi + + for path in $(grep -v "^#" "$file" 2>/dev/null); do + mount_state "$path" + selinux_fixup "$path" + done + done + + if [ -f "$STATE_MOUNT/files" ] ; then + for path in $(grep -v "^#" "$STATE_MOUNT/files" 2>/dev/null); do + mount_state "$path" + selinux_fixup "$path" + done + fi + fi + + if mount | grep -q /var/lib/nfs/rpc_pipefs ; then + mount -t rpc_pipefs sunrpc /var/lib/nfs/rpc_pipefs + fi +fi |