run two tunnels, which is probably wrong (leads to timeouts on local host)

pulseaudio-tcp

@@ -94,6 +94,70 @@ do_setup() {
 		fi
 	done
 
+	inbound=${inbound:-true}
+
+	while true ; do
+		if "$inbound" ; then
+			prompt="Y/n"
+		else
+			prompt="y/N"
+		fi
+
+		read -r -p "Enable inbound audio ($prompt): " inbound_in
+
+		case "$inbound_in" in
+			"")
+				if test -n "$inbound" ; then
+					inbound_in=$inbound
+					break 2
+				fi
+			;;
+			y|Y)
+				inbound_in=true
+				break 2
+			;;
+			n|N)
+				inbound_in=false
+				break 2
+			;;
+			*)
+				echo "ERROR: Please type \"y\" or \"n\"." >&2
+			;;
+		esac
+	done
+
+	outbound=${outbound:-true}
+
+	while true ; do
+		if "$outbound" ; then
+			prompt="Y/n"
+		else
+			prompt="y/N"
+		fi
+
+		read -r -p "Enable outbound audio ($prompt): " outbound_in
+
+		case "$outbound_in" in
+			"")
+				if test -n "$outbound" ; then
+					outbound_in=$outbound
+					break 2
+				fi
+			;;
+			y|Y)
+				outbound_in=true
+				break 2
+			;;
+			n|N)
+				outbound_in=false
+				break 2
+			;;
+			*)
+				echo "ERROR: Please type \"y\" or \"n\"." >&2
+			;;
+		esac
+	done
+
 	cat > "$config" << EOF
 # Configuration file for pulseaudio-tcp
 # Generated on $(LC_ALL=C date) by $USER using $0
@@ -103,29 +167,54 @@ remote_ip="$remote_ip_in"
 
 # Username on remote host
 remote_user="$remote_user_in"
+
+# Enable inbound audio from $remote_user @$remote_ip?
+inbound=$inbound_in
+
+# Enable outbound audio to $remote_user @$remote_ip?
+outbound=$outbound_in
 EOF
 }
 
 # Check if SSH port forwarding is running
 check_pa_ssh() {
+	if ! "$outbound" && ! "$inbound" ; then
+		return 0
+	else
 		for pid in $(pidof ssh) ; do
-		grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline && return 0
+			if grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline ; then
+				if "$outbound" ; then
+					grep -Fq -e -L /proc/"$pid"/cmdline || {
+						echo "ERROR: No SSH port forwarding to remote server for outbound audio established." >&2
+						return 1 ;
+					}
+				fi
+
+				if "$inbound" ; then
+					grep -Fq -e -L /proc/"$pid"/cmdline || {
+						echo "ERROR: No SSH port forwarding from remote server for inbound audio established." >&2
+						return 1 ;
+					}
+				fi
+			fi
 		done
 
+		echo "ERROR: No SSH port forwarding established." >&2
 		return 1
+	fi
 }
 
 # Perform status operation
 do_status() {
 	rv=0
 
-	if ! _ssh pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
+	if ! check_pa_ssh ; then
-		echo "ERROR: PulseAudio module \"module-native-protocol-tcp\" is not loaded on remote_ip=$remote_ip." >&2
 		rv=1
 	fi
 
-	if ! check_pa_ssh ; then
+	if "$outbound" ; then
-		echo "ERROR: SSH port forwarding to remote_ip=$remote_ip is not running." >&2
+		if ! _ssh pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
+			echo "ERROR: PulseAudio module \"module-native-protocol-tcp\" is not loaded on remote_ip=$remote_ip." >&2
 			rv=1
 		fi
 
@@ -138,6 +227,19 @@ do_status() {
 			echo "ERROR: \"tunnel-sink.tcp:127.0.0.1\" is not the default PulseAudio sink." >&2
 			rv=1
 		fi
+	fi
+
+	if "$inbound" ; then
+		if ! pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
+			echo "ERROR: PulseAudio module \"module-native-protocol-tcp\" is not loaded." >&2
+			rv=1
+		fi
+
+		if ! _ssh pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
+			echo "ERROR: PulseAudio module \"module-tunnel-sink\" is not loaded on remote_ip=$remote_ip." >&2
+			rv=1
+		fi
+	fi
 
 	if test "$rv" -eq 0 ; then
 		echo "INFO: All checks passed; pulseaudio-tcp status is okay." >&2
@@ -158,7 +260,7 @@ sync_pa_cookie() {
 }
 
 # Enable PulseAudio TCP tunnel server on remote host
-enable_pa_tunnel_server() {
+enable_remote_pa_tunnel_server() {
 	if _ssh pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
 		echo "INFO: PulseAudio module \"module-native-protocol-tcp\" already loaded on remote_ip=$remote_ip." >&2
 		return 0
@@ -171,13 +273,33 @@ enable_pa_tunnel_server() {
 	fi
 }
 
+# Enable PulseAudio TCP tunnel server on local host
+enable_local_pa_tunnel_server() {
+	if pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
+		echo "INFO: PulseAudio module \"module-native-protocol-tcp\" already loaded." >&2
+		return 0
+	elif pactl load-module module-native-protocol-tcp listen=127.0.0.1 auth-ip-acl=127.0.0.1 ; then
+		echo "INFO: Loaded PulseAudio module \"module-native-protocol-tcp\"." >&2
+		return 0
+	else
+		echo "ERROR: Unable to load PulseAudio module \"module-native-protocol-tcp\"." >&2
+		return 1
+	fi
+}
+
 # Establish SSH port forwarding to PulseAudio TCP server on remote host
 establish_ssh_portforward() {
+	if "$outbound" && ! "$inbound" ; then
 		_ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713
+	elif "$inbound" && ! "$outbound" ; then
+		_ssh -fNT -R 127.0.0.1:4713:127.0.0.1:4713
+	elif "$outbound" && "$inbound" ; then
+		_ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713 -R 127.0.0.1:4713:127.0.0.1:4713
+	fi
 }
 
 # Enable tunnel sink on local host
-enable_pa_tunnel_sink() {
+enable_local_pa_tunnel_sink() {
 	if pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
 		echo "INFO: PulseAudio module \"module-tunnel-sink\" already loaded." >&2
 		return 0
@@ -190,8 +312,22 @@ enable_pa_tunnel_sink() {
 	fi
 }
 
+# Enable tunnel sink on remote host
+enable_remote_pa_tunnel_sink() {
+	if _ssh pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
+		echo "INFO: PulseAudio module \"module-tunnel-sink\" already loaded on remote_ip=$remote_ip." >&2
+		return 0
+	elif _ssh pactl load-module module-tunnel-sink server=tcp:127.0.0.1 ; then
+		echo "INFO: Loaded PulseAudio module \"module-tunnel-sink\" on remote_ip=$remote_ip." >&2
+		return 0
+	else
+		echo "ERROR: Unable to load PulseAudio module \"module-tunnel-sink\" on remote_ip=$remote_ip." >&2
+		return 1
+	fi
+}
+
 # Set tunnel sink as default sink on local host
-set_pa_tunnel_sink_as_default() {
+set_local_pa_tunnel_sink_as_default() {
 	if pactl set-default-sink tunnel-sink.tcp:127.0.0.1 ; then
 		echo "INFO: Set \"tunnel-sink.tcp:127.0.0.1\" as default PulseAudio sink." >&2
 		return 0
@@ -204,16 +340,48 @@ set_pa_tunnel_sink_as_default() {
 # Perform start operation
 do_start() {
 	sync_pa_cookie || return 1
-	enable_pa_tunnel_server || return 1
 	establish_ssh_portforward || return 1
-	enable_pa_tunnel_sink || return 1
+
-	set_pa_tunnel_sink_as_default || return 1
+	if "$outbound" ; then
+		enable_remote_pa_tunnel_server || return 1
+		enable_local_pa_tunnel_sink || return 1
+		set_local_pa_tunnel_sink_as_default || return 1
+	fi
+
+	if "$inbound" ; then
+		enable_local_pa_tunnel_server || return 1
+		enable_remote_pa_tunnel_sink || return 1
+	fi
 
 	return 0
 }
 
+# Remove PulseAudio TCP tunnel sink on remote host
+remove_remote_pa_tunnel_sink() {
+	if ! _ssh pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
+		echo "INFO: PulseAudio module \"module-tunnel-sink\" is not loaded on remote_ip=$remote_ip." >&2
+		return 0
+	elif ! _ssh pactl list sinks | grep -Fq "tunnel-sink.tcp:127.0.0.1" ; then
+		echo "INFO: No PulseAudio tunnel sink to 127.0.0.1 exists on remote_ip=$remote_ip." >&2
+		return 0
+	else
+		owner_module=$(
+			_ssh pactl --format json list sinks 2>/dev/null | \
+				jq '.[] | select(.name=="tunnel-sink.tcp:127.0.0.1") | .owner_module' -r
+		)
+
+		if ! _ssh pactl unload-module "$owner_module" ; then
+			echo "ERROR: Could not unload owner module $owner_module of PulseAudio sink \"tunnel-sink.tcp:127.0.0.1\" on remote_ip=$remote_ip." >&2
+			return 1
+		else
+			echo "INFO: Unloaded owner module $owner_module of PulseAudio sink \"tunnel-sink.tcp:127.0.0.1\" on remote_ip=$remote_ip." >&2
+			return 0
+		fi
+	fi
+}
+
 # Remove PulseAudio TCP tunnel sink on local host
-remove_pa_tunnel_sink() {
+remove_local_pa_tunnel_sink() {
 	if ! pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
 		echo "INFO: PulseAudio module \"module-tunnel-sink\" is not loaded." >&2
 		return 0
@@ -236,17 +404,22 @@ remove_pa_tunnel_sink() {
 	fi
 }
 
-# Terminate SSH portforwarding session
+# Stop PulseAudio TCP tunnel server on local host.
-terminate_ssh_portforward() {
+disable_local_pa_tunnel_server() {
-	for pid in $(pidof ssh) ; do
+	if ! pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
-		if grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline ; then
+		echo "INFO: PulseAudio module \"module-native-protocol-tcp\" not loaded." >&2
-			kill -TERM "$pid"
+		return 0
+	elif ! pactl unload-module module-native-protocol-tcp ; then
+		echo "ERROR: Could not unload PulseAudio module \"module-native-protocol-tcp\"." >&2
+		return 1
+	else
+		echo "INFO: Unloaded PulseAudio module \"module-native-protocol-tcp\"." >&2
+		return 0
 	fi
-	done
 }
 
 # Stop PulseAudio TCP tunnel server on remote host.
-disable_pa_tunnel_server() {
+disable_remote_pa_tunnel_server() {
 	if ! _ssh pactl list modules | grep -Fq "Name: module-native-protocol-tcp" ; then
 		echo "INFO: PulseAudio module \"module-native-protocol-tcp\" not loaded on remote_ip=$remote_ip." >&2
 		return 0
@@ -259,11 +432,28 @@ disable_pa_tunnel_server() {
 	fi
 }
 
+# Terminate SSH portforwarding session
+terminate_ssh_portforward() {
+	for pid in $(pidof ssh) ; do
+		if grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline ; then
+			kill -TERM "$pid"
+		fi
+	done
+}
+
 # Perform stop operation
 do_stop() {
-	remove_pa_tunnel_sink || return 1
+	if "$outbound" ; then
+		remove_local_pa_tunnel_sink || return 1
+		disable_remote_pa_tunnel_server || return 1
+	fi
+
+	if "$inbound" ; then
+		remove_remote_pa_tunnel_sink || return 1
+		disable_local_pa_tunnel_server || return 1
+	fi
+
 	terminate_ssh_portforward || return 1
-	disable_pa_tunnel_server || return 1
 
 	return 0
 }
@@ -316,7 +506,7 @@ else
 		""|-h|--help)
 			cat << EOF
 Setup and run encrypted connection to remote PulseAudio/Pipewire server
-Usage: $0 setup|start|stop|status
+Usage: $0 restart|setup|start|status|stop
 EOF
 			rv=0
 		;;
@@ -332,12 +522,17 @@ EOF
 			do_stop
 			rv=$?
 		;;
+		restart)
+			do_stop
+			do_start
+			rv=$?
+		;;
 		status)
 			do_status
 			rv=$?
 		;;
 		*)
-			echo "ERROR: Usage: $0 setup|start|stop|status" >&2
+			echo "ERROR: Usage: $0 restart|setup|start|status|stop" >&2
 			rv=1
 		;;
 	esac