Implement zleep as a ffoo module

mkit/config.ini

@@ -55,3 +55,4 @@
 
 [files:share]
     src/ffoo/saturnin_www.sh                = ffoo/saturnin_www.sh
+    src/ffoo/saturnin_zleep.sh              = ffoo/saturnin_zleep.sh

src/ffoo/saturnin_zleep.sh

@@ -0,0 +1,83 @@
+#!/bin/bash
+
+ffoo import pretty
+ffoo import recon
+
+__zleep_user_part() {
+    saturnin iam undocking
+    slock &
+}
+
+__zleep_try_umount() {
+    local mp=$1
+    mountpoint -q $mp || return 0
+    umount        $mp || return 1
+    mount | grep  $mp && return 1
+    return 0
+}
+
+__zleep_try_umount_all() {
+    local mp
+    for mp in $(saturnin conf -p iam.mounting.point);
+    do
+        __zleep_try_umount $mp || return 1
+    done
+    return 0
+}
+
+__zleep_sudo_part() {
+    wait_until -d 5 -t 30 __zleep_try_umount_all || die "unable to unmount drives"
+    pm-suspend
+}
+
+__zleep_sudo_part_started() {
+    # i.e. password prompt went ok
+    test -e $ZLEEP_ON_ROOT
+    rv=$?
+    debug -v rv
+    return $rv
+}
+
+__zleep_user_part_done() {
+    ! test -e $ZLEEP_ON_USER
+    rv=$?
+    debug -v rv
+    return $rv
+}
+
+zleep() {
+    #
+    # Put the host on sleep
+    #
+    # We need to
+    #
+    #  1. authenticate
+    #  2. start user's part in the background -- mainly slock
+    #  3. start root's part -- put system on sleep (unmount, suspend)
+    #
+    # This is solved by forking with sudo, and waiting for user part to indicate
+    # it has finished.  That way, we can ensure that suspend happens *after* the
+    # screen has been locked, and at the same time we leave authentication part
+    # on sudo.
+    #
+    if test -z "$ZLEEP_ON_USER";    ## we are parent (running as normal user)
+    then
+        ZLEEP_ON_USER=$(mktemp)
+        ZLEEP_ON_ROOT=$(mktemp -u)
+        debug -v ZLEEP_ON_USER ZLEEP_ON_ROOT
+        sudo \
+            ZLEEP_ON_ROOT=$ZLEEP_ON_ROOT \
+            ZLEEP_ON_USER=$ZLEEP_ON_USER \
+            saturnin iam zleeping &
+        wait_until -t 60 __zleep_sudo_part_started    # i.e. password prompt done
+        __zleep_user_part
+        rm -f $ZLEEP_ON_USER
+    else                            ## we are child (running as root)
+        touch $ZLEEP_ON_ROOT
+        test $(id -u) -eq 0         || die "must be root"
+        wait_until __zleep_user_part_done   || die "timeout waiting for parent"
+        __zleep_sudo_part
+        rm -f $ZLEEP_ON_ROOT
+        return $?
+    fi
+}