session: Handle signals

1 files changed, 45 insertions, 0 deletions

diff --git a/lib/session.sh b/lib/session.sh
index a2d18e3..fec6aec 100644
--- a/lib/session.sh
+++ b/lib/session.sh
@@ -33,6 +33,7 @@ session_arch=
 session_plat=
 session_mountdir=
 session_atexit=
+session_sigs=
 
 session_begin()
 {
@@ -54,6 +55,8 @@ session_begin()
 		error 2 "$(get_msg 'install_running')"
 	fi
 
+	session_set_sigs
+
 	if ! mutex_lock_timeout "${session_root}/prokit/sessions.lock" 5; then
 		error 2 "$(get_msg 'cant_lock_sessions')"
 	fi
@@ -87,6 +90,8 @@ session_begin()
 
 session_end()
 {
+	session_unset_sigs
+
 	# Unregister the session.
 	profile_bind_umount "${session_arch}" "${session_plat}" \
 		"${session_mountdir}" \
@@ -173,3 +178,43 @@ session_umount()
 			sed -n '1!G;h;$p')
 		EOF
 }
+
+session_set_sigs()
+{
+	local i=
+	local sig=
+
+	# We need the signal *number* in the signal handler.  The only portable
+	# and easy way to get the number of a named signal is to search for it
+	# as in the following loop hack.
+	i=0
+	session_sigs=''
+	while [ ${i} -lt 127 ]; do
+		i=$(($i + 1))
+		sig="$(kill -l ${i} 2>/dev/null)" || continue
+		case "${sig}" in
+			'HUP' | 'INT' | 'QUIT' | 'ABRT' | 'ALRM' | 'TERM')
+				session_sigs="${session_sigs} ${i}"
+				trap "session_handle_sig ${i}" ${i}
+				;;
+		esac
+	done
+}
+
+session_unset_sigs()
+{
+	trap - ${session_sigs}
+}
+
+session_handle_sig()
+{
+	local sig="${1}"
+
+	session_end
+
+	if [ "x${exit_status:+set}" = 'xset' ]; then
+		exit ${exit_status}
+	else
+		exit $((128 + $sig))
+	fi
+}