Add rtpp_bind_local support for the offer/answer/engage.

When this AVP is set, its value would be provided to the rtpproxy
with "l" modifier, allowing proper address to be selected for the
session.

Author: sobomax

modules/rtpproxy/README

@@ -604,6 +604,11 @@ if (is_method("INVITE") && has_totag()) {
    returns the resulted body in it. If not used, the message's
    body is used, and the outgoing body is changed.
 
+   If $avp(rtpp_bind_local) is set to a string, its value is
+   appended as l<value> to the RTPProxy U/L command (for example,
+   "[1:2:3]" for IPv6). This applies to both rtpproxy_offer() and
+   rtpproxy_answer().
+
    This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
    FAILURE_ROUTE, BRANCH_ROUTE.
 

modules/rtpproxy/doc/rtpproxy_admin.xml

@@ -740,6 +740,13 @@ if (is_method("INVITE") && has_totag()) {
 					and returns the resulted body in it. If not used, the message's
 					body is used, and the outgoing body is changed.
 				</para>
+				<para>
+					If <emphasis>$avp(rtpp_bind_local)</emphasis> is set to a string,
+					its value is appended as <emphasis>l&lt;value&gt;</emphasis> to
+					the RTPProxy U/L command (for example, "[1:2:3]" for IPv6).
+					This applies to both <function>rtpproxy_offer()</function> and
+					<function>rtpproxy_answer()</function>.
+				</para>
 			<para>
 		This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
 		FAILURE_ROUTE, BRANCH_ROUTE.
@@ -1264,4 +1271,3 @@ $ opensips-cli -x mi rtpproxy_reload
 </section>
 
 </chapter>
-

modules/rtpproxy/rtpproxy.c

@@ -228,6 +228,9 @@ static str param3_name = str_init("rtpproxy_3");
 str param3_bavp_name = str_init("$bavp(5589967)");
 pv_spec_t param3_spec;
 static str late_name = str_init("late_negotiation");
+static str rtpp_bind_local_avp_name = str_init("$avp(rtpp_bind_local)");
+static pv_spec_t rtpp_bind_local_spec;
+static int rtpp_bind_local_avp_ok = 0;
 
 /* parameters name for event signaling */
 static str event_name = str_init("E_RTPPROXY_STATUS");
@@ -1304,6 +1307,14 @@ mod_init(void)
 			parse_bavp(&param3_bavp_name, &param3_spec) < 0)
 		LM_DBG("cannot parse bavps\n");
 
+	if (pv_parse_spec(&rtpp_bind_local_avp_name, &rtpp_bind_local_spec) != NULL &&
+			rtpp_bind_local_spec.type == PVT_AVP) {
+		rtpp_bind_local_avp_ok = 1;
+	} else {
+		LM_ERR("malformed rtpp_bind_local AVP definition\n");
+		rtpp_bind_local_avp_ok = 0;
+	}
+
 	if(rtpp_notify_socket.s) {
 		if (strncmp("tcp:", rtpp_notify_socket.s, 4) == 0) {
 				rtpp_notify_socket_un = 0;
@@ -3583,12 +3594,13 @@ static int rtpproxy_offer_answer(struct sip_msg *msg, struct rtpp_args *args,
 	char medianum_buf[20];
 	char buf[32], dbuf[128];
 	int medianum, media_multi;
-	str medianum_str, tmpstr1;
+	str medianum_str, tmpstr1, bind_local_val;
 	int c1p_altered;
 	int enable_dtmf_catch = 0;
 	int node_has_notification, node_has_dtmf_catch = 0;
 	int vcnt;
 	pv_value_t val;
+	pv_value_t bind_val;
 	char *adv_address = NULL;
 	struct dlg_cell * dlg;
 	str dtmf_tag = {0, 0}, timeout_tag = {0, 0};
@@ -3817,6 +3829,22 @@ static int rtpproxy_offer_answer(struct sip_msg *msg, struct rtpp_args *args,
 	medianum = 0;
 
 	opts.s.s[0] = (create == 0) ? 'L' : 'U';
+
+	bind_local_val.len = 0;
+	if (msg && rtpp_bind_local_avp_ok) {
+		if (pv_get_spec_value(msg, &rtpp_bind_local_spec, &bind_val) < 0) {
+			LM_ERR("cannot get rtpp_bind_local avp value\n");
+		} else if (!(bind_val.flags & PV_VAL_NULL)) {
+			if (bind_val.flags & PV_VAL_STR) {
+				bind_local_val = bind_val.rs;
+			} else if (bind_val.flags & PV_VAL_INT) {
+				bind_local_val.s = int2str(bind_val.ri, &bind_local_val.len);
+			} else {
+				bind_local_val.len = 0;
+			}
+		}
+	}
+
 	STR2IOVEC(args->callid, vup.vu[5]);
 	STR2IOVEC(args->from_tag, vup.vu[11]);
 	STR2IOVEC(args->to_tag, vup.vu[15]);
@@ -3994,6 +4022,13 @@ static int rtpproxy_offer_answer(struct sip_msg *msg, struct rtpp_args *args,
 					goto error;
 				}
 			}
+			if (bind_local_val.len > 0) {
+				if (append_opts(&m_opts, 'l') == -1 ||
+						append_opts_str(&m_opts, &bind_local_val) == -1) {
+					LM_ERR("out of pkg memory\n");
+					goto error;
+				}
+			}
 			STR2IOVEC(newip, vup.vu[7]);
 			STR2IOVEC(oldport, vup.vu[9]);
 			if (1 || media_multi) /* XXX netch: can't choose now*/