feature/dialog: feature provides a wrapper around dialogs

This feature provides a wrapper around dialogs such as password prompts.
Work with dialogs becomes more challenging when plymouth is used. Other
utilities can also be used to display the dialog.

Signed-off-by: Alexey Gladkov <[email protected]>

Author: legionus

features/dialog/README.md

@@ -0,0 +1,5 @@
+# Feature: dialog
+
+This feature provides a wrapper around dialogs such as password prompts. Work
+with dialogs becomes more challenging when using bootsplash/plymouth. Other
+utilities can also be used to display the dialog.

features/dialog/config.mk

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+DIALOG_DATADIR ?= $(FEATURESDIR)/dialog/data

features/dialog/data/bin/dialog-sh-functions

@@ -0,0 +1,115 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+if [ -z "${__dialog_sh_functions-}" ]; then
+__dialog_sh_functions=1
+
+__dialog_plymouth_is_running=
+
+# shellcheck disable=SC2120
+dialog_plymouth_is_running()
+{
+	local recheck="${1-}"
+
+	if [ -n "$recheck" ] || [ -z "${__dialog_plymouth_is_running-}" ]; then
+		type -P plymouth >/dev/null && plymouth --ping 2>/dev/null &&
+			__dialog_plymouth_is_running=1 ||
+			__dialog_plymouth_is_running=0
+	fi
+
+	[ "$__dialog_plymouth_is_running" = 1 ]
+}
+
+__ask_pass_directly()
+{
+	local prompt tries cmd rc
+
+	prompt="$1"; shift
+	tries="$1"; shift
+	cmd="$1"; shift
+
+	! dialog_plymouth_is_running ||
+		plymouth hide-splash 2>/dev/null
+
+	rc=2
+
+	while [ "$rc" != 0 ] && [ "$tries" != 0 ]; do
+		"$cmd"
+		rc="$?"
+		tries=$(($tries - 1))
+	done
+
+	! dialog_plymouth_is_running ||
+		plymouth show-splash 2>/dev/null
+
+	return $rc
+}
+
+__ask_pass_with_unl0kr()
+{
+	local prompt tries cmd rc
+
+	prompt="$1"; shift
+	tries="$1"; shift
+	cmd="$1"; shift
+
+	! dialog_plymouth_is_running ||
+		plymouth hide-splash 2>/dev/null
+
+	rc=2
+
+	while [ "$rc" != 0 ] && [ "$tries" != 0 ]; do
+		unl0kr 2>/dev/null | "$cmd"
+		rc="$?"
+		tries=$(($tries - 1))
+	done
+
+	! dialog_plymouth_is_running ||
+		plymouth show-splash 2>/dev/null
+
+	return $rc
+}
+
+__ask_pass_with_plymouth()
+{
+	local prompt tries cmd
+
+	prompt="$1"; shift
+	tries="$1"; shift
+	cmd="$1"; shift
+
+	plymouth ask-for-password \
+		--prompt "$prompt" \
+		--number-of-tries="$tries" \
+		--command="$cmd"
+}
+
+dialog_ask_pass()
+{
+	local rc tries ask tempfile
+
+	prompt="$1"; shift
+	tries="$1"; shift
+
+	ask=__ask_pass_directly
+
+	! dialog_plymouth_is_running || ask=__ask_pass_with_plymouth
+	! type -P unl0kr >/dev/null  || ask=__ask_pass_with_unl0kr
+
+	tempfile="/.initrd/dialog-ask-pass-$$.$BASHPID"
+	{
+		printf '#!/bin/bash\n'
+		printf 'exec '
+		printf ' %q' "$@"
+	} > "$tempfile"
+	chmod +x "$tempfile"
+
+	rc=0
+	"$ask" "$prompt" "$tries" "$tempfile" || rc="$?"
+
+	rm -f -- "$tempfile"
+
+	return $rc
+}
+
+fi # __dialog_sh_functions

features/dialog/rules.mk

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+PUT_FEATURE_DIRS += $(DIALOG_DATADIR)

features/luks/config.mk

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
-$(call feature-requires,depmod-image devmapper modules-crypto-user-api system-glibc)
+$(call feature-requires,depmod-image devmapper modules-crypto-user-api system-glibc dialog)
 
 CRYPTSETUP_BIN		?= cryptsetup
 LUKS_DATADIR		?= $(FEATURESDIR)/luks/data

features/luks/data/lib/uevent/handlers/085-luks

@@ -8,6 +8,7 @@
 
 . uevent-sh-functions
 . initrd-sh-functions
+. dialog-sh-functions
 . crypttab-sh-functions
 
 PROG="${QUEUE:--}: session=${SESSION:-0}: $PROG"
@@ -48,28 +49,6 @@ match_dev_in_array() {
 	return 1
 }
 
-luks_unl0kr_ask_pass() {
-	[ "$#" = 2 ] || return 1
-
-	local cmd tries rc
-
-	rc=2
-	cmd="$1"; shift
-	tries="$1"; shift
-
-	plymouth hide-splash 2>/dev/null
-
-	while [ "$rc" != 0 ] && [ "$tries" != 0 ]; do
-		unl0kr 2>/dev/null | $cmd
-		rc=$?
-		tries=$(($tries - 1))
-	done
-
-	plymouth show-splash 2>/dev/null
-
-	return $rc
-}
-
 read_pkcs11_key() {
 	local keyid="$1" tries=${luks_tries:-3}
 
@@ -104,25 +83,10 @@ read_pkcs11_key() {
 	type="data"
 	output_file="$path"
 	flags="-l -r"
-	if plymouth --ping 2>/dev/null; then
-		if type -P unl0kr >/dev/null; then
-			luks_unl0kr_ask_pass pkcs11-tool-wrapper $tries
-			rc=$?
-		else
-			add_new_line="true"\
-			plymouth ask-for-password \
-				--prompt "Please enter passphrase for smart card:" \
-				--number-of-tries=$tries \
-				--command="pkcs11-tool-wrapper"
-			rc=$?
-		fi
-	else
-		rc=1
-                while [ "$rc" != "0" ]; do
-			pkcs11-tool-wrapper
-			rc="$?"
-                done
-	fi
+
+	dialog_ask_pass "Please enter passphrase for smart card:" "$tries" \
+		"pkcs11-tool-wrapper"
+	rc="$?"
 
 	return "$rc"
 }
@@ -194,40 +158,6 @@ findkey() {
 	return 2
 }
 
-cryptsetup_ask_pass() {
-	local rc=0 tries=${luks_tries:-3}
-
-	{
-		printf 'exec cryptsetup'
-		printf ' %q' "$@"
-	} > /.initrd/cryptsetup-ask-pass
-
-	if plymouth --ping 2>/dev/null; then
-		if type -P unl0kr >/dev/null; then
-			luks_unl0kr_ask_pass "bash /.initrd/cryptsetup-ask-pass" $tries
-			rc=$?
-		else
-			plymouth ask-for-password \
-				--prompt "Please enter passphrase for $LUKS_ROOT:" \
-				--number-of-tries=$tries \
-				--command="bash /.initrd/cryptsetup-ask-pass"
-			rc="$?"
-		fi
-	else
-		rc=2
-		# WARNING: Wait decrypt forever!
-		while [ "$rc" = 2 ] && [ "$tries" -ne 0 ]; do
-			bash /.initrd/cryptsetup-ask-pass
-			rc="$?"
-			tries=$(( $tries - 1 ))
-		done
-	fi
-
-	rm -f -- /.initrd/cryptsetup-ask-pass
-
-	return $rc
-}
-
 in_list() {
 	local a n="$1"
 	for a; do
@@ -427,7 +357,9 @@ handler() {
 		fi
 		if [ "$rc" -ne 0 ]; then
 			message "Trying to ask the user for a password."
-			cryptsetup_ask_pass "$@"
+			dialog_ask_pass \
+				"Please enter passphrase for $LUKS_ROOT:" "$luks_tries" \
+				"cryptsetup" "$@"
 			rc="$?"
 		fi
 	fi