Added starting DTLS MTU to info returned by Janus API

dtls-bio.c

@@ -25,6 +25,9 @@ void janus_dtls_bio_agent_set_mtu(int start_mtu) {
 	mtu = start_mtu;
 	JANUS_LOG(LOG_VERB, "Setting starting MTU in the DTLS BIO writer: %d\n", mtu);
 }
+int janus_dtls_bio_agent_get_mtu(void) {
+	return mtu;
+}
 
 /* BIO implementation */
 static int janus_dtls_bio_agent_write(BIO *h, const char *buf, int num);

dtls-bio.h

@@ -27,9 +27,12 @@ BIO *BIO_janus_dtls_agent_new(void *dtls);
  * you know for sure the MTU in the network Janus is deployed in is
  * smaller than that, it makes sense to configure an according value to
  * start from
- * @param start_mtu The MTU to start from (1472 by default)
+ * @param start_mtu The MTU to start from (1200 by default)
  */
 void janus_dtls_bio_agent_set_mtu(int start_mtu);
+/*! \brief Return which MTU was configured for the BIO agent writer
+ * @returns The MTU the stack will start from for each session */
+int janus_dtls_bio_agent_get_mtu(void);
 
 #if defined(LIBRESSL_VERSION_NUMBER)
 #define JANUS_USE_OPENSSL_PRE_1_1_API (1)

janus.c

@@ -353,6 +353,7 @@ static json_t *janus_info(const char *transaction) {
 	json_object_set_new(info, "twcc-period", json_integer(janus_get_twcc_period()));
 	if(janus_get_dscp() > 0)
 		json_object_set_new(info, "dscp", json_integer(janus_get_dscp()));
+	json_object_set_new(info, "dtls-mtu", json_integer(janus_dtls_bio_agent_get_mtu()));
 	if(janus_ice_get_stun_server() != NULL) {
 		char server[255];
 		g_snprintf(server, 255, "%s:%"SCNu16, janus_ice_get_stun_server(), janus_ice_get_stun_port());