Squashed commit of the following:

commit 025f56212d
Author: Andreas Granig <andreas@granig.com>
Date:   Tue Oct 4 14:23:01 2022 +0200

    Document the mqtt-tls-alpn option

commit e6cc320d19
Author: Andreas Granig <andreas@granig.com>
Date:   Mon Oct 3 21:41:14 2022 +0200

    Add TLS ALPN option to be set when connecting MQTT

    This is required to be set to "mqtt" for instance when connecting
    to the AWS IoT Core data endpoint at port 443 to indicate we're
    sending MQTT, because in that case websocket and mqtt shares the same
    port for whatever reason.

Change-Id: I6a391e815411b178187ef42aa009e45853d1c388

daemon/main.c

@@ -559,6 +559,7 @@ static void options(int *argc, char ***argv) {
 #ifdef HAVE_MQTT
 		{ "mqtt-host",0,0,	G_OPTION_ARG_STRING,	&rtpe_config.mqtt_host,	"Mosquitto broker host or address",	"HOST|IP"},
 		{ "mqtt-port",0,0,	G_OPTION_ARG_INT,	&rtpe_config.mqtt_port,	"Mosquitto broker port number",		"INT"},
+		{ "mqtt-tls-alpn",0,0,	G_OPTION_ARG_STRING,	&rtpe_config.mqtt_tls_alpn,	"Mosquitto broker TLS ALPN",	"STRING"},
 		{ "mqtt-id",0,0,	G_OPTION_ARG_STRING,	&rtpe_config.mqtt_id,	"Mosquitto client ID",			"STRING"},
 		{ "mqtt-keepalive",0,0,	G_OPTION_ARG_INT,	&rtpe_config.mqtt_keepalive,"Seconds between mosquitto keepalives","INT"},
 		{ "mqtt-user",0,0,	G_OPTION_ARG_STRING,	&rtpe_config.mqtt_user,	"Username for mosquitto auth",		"USERNAME"},

daemon/mqtt.c

@@ -61,6 +61,14 @@ static int mqtt_connect(void) {
 		}
 	}
 
+    if (rtpe_config.mqtt_tls_alpn) {
+		int ret = mosquitto_string_option(mosq, MOSQ_OPT_TLS_ALPN, rtpe_config.mqtt_tls_alpn);
+		if (ret != MOSQ_ERR_SUCCESS) {
+			ilog(LOG_ERR, "Failed to set mosquitto TLS ALPN options: %s", mosquitto_strerror(errno));
+			return -1;
+		}
+    }
+
 	ret = mosquitto_connect(mosq, rtpe_config.mqtt_host, rtpe_config.mqtt_port,
 			rtpe_config.mqtt_keepalive);
 	if (ret != MOSQ_ERR_SUCCESS) {

daemon/rtpengine.pod

@@ -995,11 +995,14 @@ to enable authentication.
 
 =item B<--mqtt-keyfile=>I<FILE>
 
+=item B<--mqtt-tls-alpn=>I<STRING>
+
 Enable TLS to connect to Mosquitto broker, optionally with client certificate
 authentication. At least B<cafile> or B<capath> must be given to enable TLS. To
 enable client certificate authentication, both B<certfile> and B<keyfile> must
 be set. All files must be in PEM format. Password-proteted files are not
-supported.
+supported. The B<tls-alpn> can be set (e.g. mqtt) if a service like AWS IoT
+Core shares the same TLS port for two different network protocols.
 
 =item B<--mqtt-publish-qos=>B<0>|B<1>|B<2>
 

etc/rtpengine.conf

@@ -118,6 +118,7 @@ recording-method = proc
 
 # mqtt-host = localhost
 # mqtt-port = 1883
+# mqtt-tls-alpn = mqtt
 # mqtt-id =
 # mqtt-user = foo
 # mqtt-pass = bar

include/main.h

@@ -135,6 +135,7 @@ struct rtpengine_config {
 	int			poller_per_thread;
 	char			*mqtt_host;
 	int			mqtt_port;
+	char			*mqtt_tls_alpn;
 	char			*mqtt_id;
 	int			mqtt_keepalive;
 	char			*mqtt_user;