update documentation to bidirectional operation

README.md

@@ -1,4 +1,4 @@
-# pulseaudio-tcp - Redirect PulseAudio to Remote Computer
+# pulseaudio-tcp - Redirect PulseAudio to and from Remote Computer
 
 ## Requirements
 
@@ -12,7 +12,10 @@
 ### Installation on Client Playback Host
 
 * pulseaudio-tcp should be installed on a computer running PulseAudio or Pipewire with PulseAudio compatibility.
-* The computer pulseaudio-tcp is installed on ("local host") should use use a remote computer that has speakers attached ("remote host") for playback.
+* The computer pulseaudio-tcp is installed on ("local host") should use use a remote computer ("remote host") for playback.
+  - This is refered to as "outbound" audio.
+* The local host should receive audio from the remote host for recording.
+  - This is refered to as "inbound" audio.
 * The IP address and username of the remote host should be known.
 
 ### SSH to User Session on Remote Host
@@ -33,7 +36,7 @@ sudo make install
 
 ## Usage
 
-### Configuration
+### Setup Procedure
 
 As regular user on local host:
 
@@ -41,19 +44,37 @@ As regular user on local host:
 pulseadio-tcp setup
 ```
 
-### Start service
+The following questions will be asked:
+
+* IP address of remote host.
+* Name of user on remote host running PulseAudio/Pipewire.
+* Enable inbound audio.
+* Enable outbound audio.
+
+### Configuration File
+
+The setup procedure writes a configuration file `$HOME/.config/pulseaudio-tcp/config.inc.sh`:
+
+```
+remote_ip="192.168.1.166"
+remote_user="remoteuser"
+inbound=true
+outbound=true
+```
+
+### Starting the Service
 
 ```shell
 pulseadio-tcp start
 ```
 
-### Stop service
+### Stopping the Service
 
 ```shell
 pulseadio-tcp stop
 ```
 
-### Check if service is running
+### Checking if the Service is running
 
 ```shell
 pulseadio-tcp status

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 $0
@@ -103,15 +167,27 @@ remote_ip="$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() {
 	for pid in $(pidof ssh) ; do
-		grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline && return 0
+		if grep -Fq $USER-pulseaudio /proc/"$pid"/cmdline ; then
+			grep -Fq -e -L /proc/"$pid"/cmdline || {
+				echo "ERROR: No SSH port forwarding to remote server is established." >&2
+				return 1 ;
+			}
+		fi
 	done
 
+	echo "ERROR: No SSH is established." >&2
 	return 1
 }
 
@@ -119,24 +195,32 @@ check_pa_ssh() {
 do_status() {
 	rv=0
 
+	if ! check_pa_ssh ; then
+		rv=1
+	fi
+
 	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
 
-	if ! check_pa_ssh ; then
-		echo "ERROR: SSH port forwarding to remote_ip=$remote_ip is not running." >&2
-		rv=1
+	if "$outbound" ; then
+		if ! pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
+			echo "ERROR: PulseAudio module \"module-tunnel-sink\" is not loaded." >&2
+			rv=1
+		fi
+
+		if ! pactl get-default-sink | grep -Fq "tunnel-sink.tcp:127.0.0.1" ; then
+			echo "ERROR: \"tunnel-sink.tcp:127.0.0.1\" is not the default PulseAudio sink." >&2
+			rv=1
+		fi
 	fi
 
-	if ! pactl list modules | grep -Fq "Name: module-tunnel-sink" ; then
-		echo "ERROR: PulseAudio module \"module-tunnel-sink\" is not loaded." >&2
-		rv=1
-	fi
-
-	if ! pactl get-default-sink | grep -Fq "tunnel-sink.tcp:127.0.0.1" ; then
-		echo "ERROR: \"tunnel-sink.tcp:127.0.0.1\" is not the default PulseAudio sink." >&2
-		rv=1
+	if "$inbound" ; then
+		if ! pactl list modules | grep -Fq "Name: module-tunnel-source" ; then
+			echo "ERROR: PulseAudio module \"module-tunnel-source\" is not loaded." >&2
+			rv=1
+		fi
 	fi
 
 	if test "$rv" -eq 0 ; then
@@ -157,8 +241,13 @@ sync_pa_cookie() {
 	fi
 }
 
+# Establish SSH port forwarding to PulseAudio TCP server on remote host
+establish_ssh_portforward() {
+	_ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713
+}
+
 # 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 +260,8 @@ enable_pa_tunnel_server() {
 	fi
 }
 
-# Establish SSH port forwarding to PulseAudio TCP server on remote host
-establish_ssh_portforward() {
-	_ssh -fNT -L 127.0.0.1:4713:127.0.0.1:4713
-}
-
 # 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 +274,22 @@ enable_pa_tunnel_sink() {
 	fi
 }
 
+# Enable tunnel source on local host
+enable_local_pa_tunnel_source() {
+	if pactl list modules | grep -Fq "Name: module-tunnel-source" ; then
+		echo "INFO: PulseAudio module \"module-tunnel-source\" already loaded." >&2
+		return 0
+	elif pactl load-module module-tunnel-source server=tcp:127.0.0.1 ; then
+		echo "INFO: Loaded PulseAudio module \"module-tunnel-source\"." >&2
+		return 0
+	else
+		echo "ERROR: Unable to load PulseAudio module \"module-tunnel-source\"." >&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 +302,23 @@ 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
+	enable_remote_pa_tunnel_server || return 1
+
+	if "$outbound" ; then
+		enable_local_pa_tunnel_sink || return 1
+		set_local_pa_tunnel_sink_as_default || return 1
+	fi
+
+	if "$inbound" ; then
+		enable_local_pa_tunnel_source || return 1
+	fi
 
 	return 0
 }
 
 # 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 +341,32 @@ remove_pa_tunnel_sink() {
 	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 "$pid"
+# Remove PulseAudio TCP tunnel source on local host
+remove_local_pa_tunnel_source() {
+	if ! pactl list modules | grep -Fq "Name: module-tunnel-source" ; then
+		echo "INFO: PulseAudio module \"module-tunnel-source\" is not loaded." >&2
+		return 0
+	elif ! pactl list sources | grep -Fq "tunnel-source.tcp:127.0.0.1" ; then
+		echo "INFO: No PulseAudio tunnel source from 127.0.0.1 exists." >&2
+		return 0
+	else
+		owner_module=$(
+			pactl --format json list sources 2>/dev/null | \
+				jq '.[] | select(.name=="tunnel-source.tcp:127.0.0.1") | .owner_module' -r
+		)
+
+		if ! pactl unload-module "$owner_module" ; then
+			echo "ERROR: Could not unload owner module $owner_module of PulseAudio source \"tunnel-source.tcp:127.0.0.1\"." >&2
+			return 1
+		else
+			echo "INFO: Unloaded owner module $owner_module of PulseAudio source \"tunnel-source.tcp:127.0.0.1\"." >&2
+			return 0
 		fi
-	done
+	fi
 }
 
 # 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 +379,27 @@ 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
+	fi
+
+	if "$inbound" ; then
+		remove_local_pa_tunnel_source || return 1
+	fi
+
+	disable_remote_pa_tunnel_server || return 1
 	terminate_ssh_portforward || return 1
-	disable_pa_tunnel_server || return 1
 
 	return 0
 }
@@ -316,7 +452,7 @@ else
 		""|-h|--help)
 			cat << EOF
 Setup and run encrypted connection to remote PulseAudio/Pipewire server
-Usage: $0 setup|start|stop|status
+Usage: $0 restart|setup|start|status|stop
 EOF
 			rv=0
 		;;
@@ -332,12 +468,17 @@ EOF
 			do_stop
 			rv=$?
 		;;
+		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