diff --git a/meta/classes/useradd_base.bbclass b/meta/classes/useradd_base.bbclass
new file mode 100644
index 0000000..802f3a1
--- /dev/null
+++ b/meta/classes/useradd_base.bbclass
@@ -0,0 +1,230 @@
+# This bbclass provides basic functionality for user/group settings.
+# This bbclass is intended to be inherited by useradd.bbclass and
+# extrausers.bbclass.
+
+# The following functions basically have similar logic.
+# *) Perform necessary checks before invoking the actual command
+# *) Invoke the actual command, make retries if necessary
+# *) Error out if an error occurs.
+
+# Note that before invoking these functions, make sure the global variable
+# PSEUDO is set up correctly.
+
+perform_groupadd () {
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing groupadd with [$opts] and $retries times of retry"
+	local groupname=`echo "$opts" | awk '{ print $NF }'`
+	local group_exists="`grep "^$groupname:" $rootdir/etc/group || true`"
+	if test "x$group_exists" = "x"; then
+		local count=0
+		while true; do
+			eval $PSEUDO groupadd $opts || true
+			group_exists="`grep "^$groupname:" $rootdir/etc/group || true`"
+			if test "x$group_exists" = "x"; then
+				bbwarn "${PN}: groupadd command did not succeed. Retrying..."
+			else
+				break
+			fi
+			count=`expr $count + 1`
+			if test $count = $retries; then
+				bbfatal "${PN}: Tried running groupadd command $retries times without success, giving up"
+			fi
+                        sleep $count
+		done
+	else
+		bbnote "${PN}: group $groupname already exists, not re-creating it"
+	fi
+}
+
+perform_useradd () {
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing useradd with [$opts] and $retries times of retry"
+	local username=`echo "$opts" | awk '{ print $NF }'`
+	local user_exists="`grep "^$username:" $rootdir/etc/passwd || true`"
+	if test "x$user_exists" = "x"; then
+	       local count=0
+	       while true; do
+		       eval $PSEUDO useradd $opts || true
+		       user_exists="`grep "^$username:" $rootdir/etc/passwd || true`"
+		       if test "x$user_exists" = "x"; then
+			       bbwarn "${PN}: useradd command did not succeed. Retrying..."
+		       else
+			       break
+		       fi
+		       count=`expr $count + 1`
+		       if test $count = $retries; then
+				bbfatal "${PN}: Tried running useradd command $retries times without success, giving up"
+		       fi
+		       sleep $count
+	       done
+	else
+		bbnote "${PN}: user $username already exists, not re-creating it"
+	fi
+}
+
+perform_groupmems () {
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing groupmems with [$opts] and $retries times of retry"
+	local groupname=`echo "$opts" | awk '{ for (i = 1; i < NF; i++) if ($i == "-g" || $i == "--group") print $(i+1) }'`
+	local username=`echo "$opts" | awk '{ for (i = 1; i < NF; i++) if ($i == "-a" || $i == "--add") print $(i+1) }'`
+	bbnote "${PN}: Running groupmems command with group $groupname and user $username"
+	# groupmems fails if /etc/gshadow does not exist
+	local gshadow=""
+	if [ -f $rootdir${sysconfdir}/gshadow ]; then
+		gshadow="yes"
+	else
+		gshadow="no"
+		touch $rootdir${sysconfdir}/gshadow
+	fi
+	local mem_exists="`grep "^$groupname:[^:]*:[^:]*:\([^,]*,\)*$username\(,[^,]*\)*" $rootdir/etc/group || true`"
+	if test "x$mem_exists" = "x"; then
+		local count=0
+		while true; do
+			eval $PSEUDO groupmems $opts || true
+			mem_exists="`grep "^$groupname:[^:]*:[^:]*:\([^,]*,\)*$username\(,[^,]*\)*" $rootdir/etc/group || true`"
+			if test "x$mem_exists" = "x"; then
+				bbwarn "${PN}: groupmems command did not succeed. Retrying..."
+			else
+				break
+			fi
+			count=`expr $count + 1`
+			if test $count = $retries; then
+				if test "x$gshadow" = "xno"; then
+					rm -f $rootdir${sysconfdir}/gshadow
+					rm -f $rootdir${sysconfdir}/gshadow-
+				fi
+				bbfatal "${PN}: Tried running groupmems command $retries times without success, giving up"
+			fi
+			sleep $count
+		done
+	else
+		bbwarn "${PN}: group $groupname already contains $username, not re-adding it"
+	fi
+	if test "x$gshadow" = "xno"; then
+		rm -f $rootdir${sysconfdir}/gshadow
+		rm -f $rootdir${sysconfdir}/gshadow-
+	fi
+}
+
+perform_groupdel () {
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing groupdel with [$opts] and $retries times of retry"
+	local groupname=`echo "$opts" | awk '{ print $NF }'`
+	local group_exists="`grep "^$groupname:" $rootdir/etc/group || true`"
+	if test "x$group_exists" != "x"; then
+		local count=0
+		while true; do
+			eval $PSEUDO groupdel $opts || true
+			group_exists="`grep "^$groupname:" $rootdir/etc/group || true`"
+			if test "x$group_exists" != "x"; then
+				bbwarn "${PN}: groupdel command did not succeed. Retrying..."
+			else
+				break
+			fi
+			count=`expr $count + 1`
+			if test $count = $retries; then
+				bbfatal "${PN}: Tried running groupdel command $retries times without success, giving up"
+			fi
+			sleep $count
+		done
+	else
+		bbwarn "${PN}: group $groupname doesn't exist, not removing it"
+	fi
+}
+
+perform_userdel () {
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing userdel with [$opts] and $retries times of retry"
+	local username=`echo "$opts" | awk '{ print $NF }'`
+	local user_exists="`grep "^$username:" $rootdir/etc/passwd || true`"
+	if test "x$user_exists" != "x"; then
+	       local count=0
+	       while true; do
+		       eval $PSEUDO userdel $opts || true
+		       user_exists="`grep "^$username:" $rootdir/etc/passwd || true`"
+		       if test "x$user_exists" != "x"; then
+			       bbwarn "${PN}: userdel command did not succeed. Retrying..."
+		       else
+			       break
+		       fi
+		       count=`expr $count + 1`
+		       if test $count = $retries; then
+				bbfatal "${PN}: Tried running userdel command $retries times without success, giving up"
+		       fi
+		       sleep $count
+	       done
+	else
+		bbwarn "${PN}: user $username doesn't exist, not removing it"
+	fi
+}
+
+perform_groupmod () {
+	# Other than the return value of groupmod, there's no simple way to judge whether the command
+	# succeeds, so we disable -e option temporarily
+	set +e
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing groupmod with [$opts] and $retries times of retry"
+	local groupname=`echo "$opts" | awk '{ print $NF }'`
+	local group_exists="`grep "^$groupname:" $rootdir/etc/group || true`"
+	if test "x$group_exists" != "x"; then
+		local count=0
+		while true; do
+			eval $PSEUDO groupmod $opts
+			if test $? != 0; then
+				bbwarn "${PN}: groupmod command did not succeed. Retrying..."
+			else
+				break
+			fi
+			count=`expr $count + 1`
+			if test $count = $retries; then
+				bbfatal "${PN}: Tried running groupmod command $retries times without success, giving up"
+			fi
+			sleep $count
+		done
+	else
+		bbwarn "${PN}: group $groupname doesn't exist, unable to modify it"
+	fi
+	set -e
+}
+
+perform_usermod () {
+	# Same reason with groupmod, temporarily disable -e option
+	set +e
+	local rootdir="$1"
+	local opts="$2"
+	local retries="$3"
+	bbnote "${PN}: Performing usermod with [$opts] and $retries times of retry"
+	local username=`echo "$opts" | awk '{ print $NF }'`
+	local user_exists="`grep "^$username:" $rootdir/etc/passwd || true`"
+	if test "x$user_exists" != "x"; then
+	       local count=0
+	       while true; do
+		       eval $PSEUDO usermod $opts
+		       if test $? != 0; then
+			       bbwarn "${PN}: usermod command did not succeed. Retrying..."
+		       else
+			       break
+		       fi
+		       count=`expr $count + 1`
+		       if test $count = $retries; then
+				bbfatal "${PN}: Tried running usermod command $retries times without success, giving up"
+		       fi
+		       sleep $count
+	       done
+	else
+		bbwarn "${PN}: user $username doesn't exist, unable to modify it"
+	fi
+	set -e
+}