mgcp: Make it possible to drop RTCP packets coming from the BTS/Net

The ip.access nanoBTS appears to send quite broken NTP timestamps in
the RTCP messages might confuse equipment that uses the sender report
of the BTS. Make it easy to experiment by adding an option to drop RTCP.

4 files changed, 56 insertions, 2 deletions

diff --git a/openbsc/include/openbsc/mgcp.h b/openbsc/include/openbsc/mgcp.h
index 4619572d0..751943ada 100644
--- a/openbsc/include/openbsc/mgcp.h
+++ b/openbsc/include/openbsc/mgcp.h
@@ -114,6 +114,8 @@ struct mgcp_trunk_config {
 	int audio_payload;
 	int audio_loop;
 
+	int omit_rtcp;
+
 	/* spec handling */
 	int force_realloc;
 
diff --git a/openbsc/src/libmgcp/mgcp_network.c b/openbsc/src/libmgcp/mgcp_network.c
index ab4d0e391..6f3f8d519 100644
--- a/openbsc/src/libmgcp/mgcp_network.c
+++ b/openbsc/src/libmgcp/mgcp_network.c
@@ -212,7 +212,7 @@ static int send_to(struct mgcp_endpoint *endp, int dest, int is_rtp,
 				     &endp->taps[MGCP_TAP_NET_OUT], buf, rc);
 			return udp_send(endp->net_end.rtp.fd, &endp->net_end.addr,
 					endp->net_end.rtp_port, buf, rc);
-		} else {
+		} else if (!tcfg->omit_rtcp) {
 			return udp_send(endp->net_end.rtcp.fd, &endp->net_end.addr,
 					endp->net_end.rtcp_port, buf, rc);
 		}
@@ -225,7 +225,7 @@ static int send_to(struct mgcp_endpoint *endp, int dest, int is_rtp,
 				     &endp->taps[MGCP_TAP_BTS_OUT], buf, rc);
 			return udp_send(endp->bts_end.rtp.fd, &endp->bts_end.addr,
 					endp->bts_end.rtp_port, buf, rc);
-		} else {
+		} else if (!tcfg->omit_rtcp) {
 			return udp_send(endp->bts_end.rtcp.fd, &endp->bts_end.addr,
 					endp->bts_end.rtcp_port, buf, rc);
 		}
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index c87635dff..ac7dea19a 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -850,6 +850,7 @@ struct mgcp_config *mgcp_config_alloc(void)
 	cfg->trunk.trunk_type = MGCP_TRUNK_VIRTUAL;
 	cfg->trunk.audio_name = talloc_strdup(cfg, "AMR/8000");
 	cfg->trunk.audio_payload = 126;
+	cfg->trunk.omit_rtcp = 0;
 
 	INIT_LLIST_HEAD(&cfg->trunks);
 
@@ -872,6 +873,7 @@ struct mgcp_trunk_config *mgcp_trunk_alloc(struct mgcp_config *cfg, int nr)
 	trunk->audio_name = talloc_strdup(cfg, "AMR/8000");
 	trunk->audio_payload = 126;
 	trunk->number_endpoints = 33;
+	trunk->omit_rtcp = 0;
 	llist_add_tail(&trunk->entry, &cfg->trunks);
 	return trunk;
 }
diff --git a/openbsc/src/libmgcp/mgcp_vty.c b/openbsc/src/libmgcp/mgcp_vty.c
index 7309f502d..787dad282 100644
--- a/openbsc/src/libmgcp/mgcp_vty.c
+++ b/openbsc/src/libmgcp/mgcp_vty.c
@@ -82,6 +82,10 @@ static int config_write_mgcp(struct vty *vty)
 			g_cfg->net_ports.range_start, g_cfg->net_ports.range_end, VTY_NEWLINE);
 
 	vty_out(vty, "  rtp ip-dscp %d%s", g_cfg->endp_dscp, VTY_NEWLINE);
+	if (g_cfg->trunk.omit_rtcp)
+		vty_out(vty, "  rtcp-omit%s", VTY_NEWLINE);
+	else
+		vty_out(vty, "  no rtcp-omit%s", VTY_NEWLINE);
 	if (g_cfg->trunk.audio_payload != -1)
 		vty_out(vty, "  sdp audio-payload number %d%s",
 			g_cfg->trunk.audio_payload, VTY_NEWLINE);
@@ -368,6 +372,24 @@ DEFUN(cfg_mgcp_number_endp,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_mgcp_omit_rtcp,
+      cfg_mgcp_omit_rtcp_cmd,
+      "rtcp-omit",
+      "Drop RTCP packets in both directions")
+{
+	g_cfg->trunk.omit_rtcp = 1;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_mgcp_no_omit_rtcp,
+      cfg_mgcp_no_omit_rtcp_cmd,
+      "no rtcp-omit",
+      NO_STR "Drop RTCP packets in both directions")
+{
+	g_cfg->trunk.omit_rtcp = 0;
+	return CMD_SUCCESS;
+}
+
 #define CALL_AGENT_STR "Callagent information\n"
 DEFUN(cfg_mgcp_agent_addr,
       cfg_mgcp_agent_addr_cmd,
@@ -454,6 +476,10 @@ static int config_write_trunk(struct vty *vty)
 			trunk->audio_name, VTY_NEWLINE);
 		vty_out(vty, "  loop %d%s",
 			trunk->audio_loop, VTY_NEWLINE);
+		if (trunk->omit_rtcp)
+			vty_out(vty, "  rtcp-omit%s", VTY_NEWLINE);
+		else
+			vty_out(vty, "  no rtcp-omit%s", VTY_NEWLINE);
 	}
 
 	return CMD_SUCCESS;
@@ -503,6 +529,26 @@ DEFUN(cfg_trunk_loop,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_trunk_omit_rtcp,
+      cfg_trunk_omit_rtcp_cmd,
+      "rtcp-omit",
+      "Drop RTCP packets in both directions")
+{
+	struct mgcp_trunk_config *trunk = vty->index;
+	trunk->omit_rtcp = 1;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_trunk_no_omit_rtcp,
+      cfg_trunk_no_omit_rtcp_cmd,
+      "no rtcp-omit",
+      "Drop RTCP packets in both directions")
+{
+	struct mgcp_trunk_config *trunk = vty->index;
+	trunk->omit_rtcp = 0;
+	return CMD_SUCCESS;
+}
+
 DEFUN(loop_endp,
       loop_endp_cmd,
       "loop-endpoint <0-64> NAME (0|1)",
@@ -731,6 +777,8 @@ int mgcp_vty_init(void)
 	install_element(MGCP_NODE, &cfg_mgcp_sdp_payload_name_cmd_old);
 	install_element(MGCP_NODE, &cfg_mgcp_loop_cmd);
 	install_element(MGCP_NODE, &cfg_mgcp_number_endp_cmd);
+	install_element(MGCP_NODE, &cfg_mgcp_omit_rtcp_cmd);
+	install_element(MGCP_NODE, &cfg_mgcp_no_omit_rtcp_cmd);
 
 	install_element(MGCP_NODE, &cfg_mgcp_trunk_cmd);
 	install_node(&trunk_node, config_write_trunk);
@@ -742,6 +790,8 @@ int mgcp_vty_init(void)
 	install_element(TRUNK_NODE, &cfg_trunk_payload_number_cmd_old);
 	install_element(TRUNK_NODE, &cfg_trunk_payload_name_cmd_old);
 	install_element(TRUNK_NODE, &cfg_trunk_loop_cmd);
+	install_element(TRUNK_NODE, &cfg_trunk_omit_rtcp_cmd);
+	install_element(TRUNK_NODE, &cfg_trunk_no_omit_rtcp_cmd);
 
 	return 0;
 }