@@ -292,7 +292,8 @@ modparam("topos", "event_mode", 2)

 		<title><varname>contact_host</varname> (str)</title>

 		<para>

 			You may need to control the host part of the Contact header added

-			by topos.

+			by topos. If the contact_host_avp parameter is set, this value is

+			ignored.

 			For example when using TLS with TOPOS the remote UAS must be able to open

 			a new TLS socket to the contact header.

@@ -433,6 +434,33 @@ modparam("topos", "b_contact_avp", "$avp(tps-bct)")

 ...

 modparam("topos", "rr_update", 1)

 ...

+</programlisting>

+		</example>

+	</section>

+	<section id="topos.p.contact_host_avp">

+		<title><varname>contact_host_avp</varname> (str)</title>

+		<para>

+			You may need to control the host part of the Contact header added

+			by topos. This parameter allows to take the value from an AVP

+			during run-time. If this parameter is set, the contact_host

+			parameter is ignored.

+

+			For example when using TLS with TOPOS the remote UAS must be able to open

+			a new TLS socket to the contact header.

+			In this case, the contact header must contain a domain name with a trusted CA

+			signed certitificate.

+		</para>

+		<para>

+		<emphasis>

+			Default value is empty, not set.

+		</emphasis>

+		</para>

+		<example>

+		<title>Set <varname>contact_host_avp</varname> parameter</title>

+		<programlisting format="linespecific">

+...

+modparam("topos", "contact_host_avp", "$avp(contact_host)")

+...

 </programlisting>

 		</example>

 	</section>

@@ -96,6 +96,8 @@ static int _tps_eventrt_sending = -1;

 static str _tps_eventrt_sending_name = str_init("topos:msg-sending");

 str _tps_contact_host = str_init("");

 int _tps_contact_mode = 0;

+str _tps_contact_host_avp = str_init("");

+pv_spec_t _tps_contact_host_avp_spec;

 str _tps_cparam_name = str_init("tps");

 str _tps_acontact_avp;

 str _tps_bcontact_avp;

@@ -142,7 +144,8 @@ static param_export_t params[]={

 	{"cparam_name",		PARAM_STR, &_tps_cparam_name},

 	{"a_contact_avp",	PARAM_STR, &_tps_acontact_avp},

 	{"b_contact_avp",	PARAM_STR, &_tps_bcontact_avp},

-	{"rr_update",       PARAM_INT, &_tps_rr_update},

+	{"contact_host_avp",    PARAM_STR, &_tps_contact_host_avp},

+	{"rr_update",		PARAM_INT, &_tps_rr_update},

 	{0,0,0}

 };

@@ -235,6 +238,15 @@ static int mod_init(void)

 		}

 	}

+	if(_tps_contact_host_avp.len > 0 && _tps_contact_host_avp.s != NULL) {

+		if(pv_parse_spec(&_tps_contact_host_avp, &_tps_contact_host_avp_spec) == 0

+				|| _tps_contact_host_avp_spec.type != PVT_AVP) {

+			LM_ERR("malformed or non AVP %.*s AVP definition\n",

+			_tps_contact_host_avp.len, _tps_contact_host_avp.s);

+			return -1;

+		}

+	}

+

 	sr_event_register_cb(SREV_NET_DATA_IN,  tps_msg_received);

 	sr_event_register_cb(SREV_NET_DATA_OUT, tps_msg_sent);

@@ -61,6 +61,8 @@ extern str _tps_acontact_avp;

 extern str _tps_bcontact_avp;

 extern pv_spec_t _tps_acontact_spec;

 extern pv_spec_t _tps_bcontact_spec;

+extern str _tps_contact_host_avp;

+extern pv_spec_t _tps_contact_host_avp_spec;

 #define TPS_STORAGE_LOCK_SIZE	1<<9

 static gen_lock_set_t *_tps_storage_lock_set = NULL;

@@ -343,12 +345,23 @@ int tps_storage_fill_contact(sip_msg_t *msg, tps_data_t *td, str *uuid, int dir,

 			td->cp++;

 		}

-		if (_tps_contact_host.len) { // using configured hostname in the contact header

-			memcpy(td->cp, _tps_contact_host.s, _tps_contact_host.len);

-			td->cp += _tps_contact_host.len;

+		// contact_host AVP takes preference

+		if (_tps_contact_host_avp.len) {

+			if ((pv_get_spec_value(msg, &_tps_contact_host_avp_spec, &pv_val) != 0) &&

+					(pv_val.flags & PV_VAL_STR) && (pv_val.rs.len <= 0)) {

+				LM_ERR("could not evaluate contact_host AVP\n");

+				return -1;

+			}

+			memcpy(td->cp, pv_val.rs.s, pv_val.rs.len);

+			td->cp += pv_val.rs.len;

 		} else {

-			memcpy(td->cp, puri.host.s, puri.host.len);

-			td->cp += puri.host.len;

+			if (_tps_contact_host.len) { // using configured hostname in the contact header

+				memcpy(td->cp, _tps_contact_host.s, _tps_contact_host.len);

+				td->cp += _tps_contact_host.len;

+			} else {

+				memcpy(td->cp, puri.host.s, puri.host.len);

+				td->cp += puri.host.len;

+			}

 		}

 		if(puri.port.len>0) {

 			*td->cp = ':';