add param:confirm-blind-transfer var:confirm_blind_transfer that makes blind transfers keep the transferrer on the line until its confirmed that the call was completed or brings it back to the bridge. blind_transfer_ack app can be executed in the dp by the transferee to indicate sucess or fail or a sucessful bridge will automatically trigger a success

src/include/switch_types.h

@@ -887,6 +887,7 @@ typedef enum {
 	SWITCH_MESSAGE_INDICATE_SIGNAL_DATA,
 	SWITCH_MESSAGE_INDICATE_INFO,
 	SWITCH_MESSAGE_INDICATE_AUDIO_DATA,
+	SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE,
 	SWITCH_MESSAGE_INVALID
 } switch_core_session_message_types_t;
 
@@ -1216,6 +1217,7 @@ typedef enum {
 	CF_ZRTP_PASS,
 	CF_CHANNEL_SWAP,
 	CF_PICKUP,
+	CF_CONFIRM_BLIND_TRANSFER,
 	/* WARNING: DO NOT ADD ANY FLAGS BELOW THIS LINE */
 	/* IF YOU ADD NEW ONES CHECK IF THEY SHOULD PERSIST OR ZERO THEM IN switch_core_session.c switch_core_session_request_xml() */
 	CF_FLAG_MAX

src/mod/applications/mod_dptools/mod_dptools.c

@@ -4462,6 +4462,34 @@ static char *file_string_supported_formats[SWITCH_MAX_CODECS] = { 0 };
 /* /FILE STRING INTERFACE */
 
 
+SWITCH_STANDARD_APP(blind_transfer_ack_function)
+{
+	switch_channel_t *channel = switch_core_session_get_channel(session);
+	switch_bool_t val = 0;
+
+	if (data) {
+		val = switch_true((char *) val);
+	}
+
+	if (switch_channel_test_flag(channel, CF_CONFIRM_BLIND_TRANSFER)) {
+		switch_core_session_t *other_session;
+		const char *uuid = switch_channel_get_variable(channel, "blind_transfer_uuid");
+
+		switch_channel_clear_flag(channel, CF_CONFIRM_BLIND_TRANSFER);
+
+		if (!zstr(uuid) && (other_session = switch_core_session_locate(uuid))) {
+			switch_core_session_message_t msg = { 0 };			
+			msg.message_id = SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE;
+			msg.from = __FILE__;
+			msg.numeric_arg = val;
+			switch_core_session_receive_message(other_session, &msg);
+			switch_core_session_rwunlock(other_session);
+		}
+	}
+}
+
+
+
 
 #define SPEAK_DESC "Speak text to a channel via the tts interface"
 #define DISPLACE_DESC "Displace audio from a file to the channels input"
@@ -4541,6 +4569,8 @@ SWITCH_MODULE_LOAD_FUNCTION(mod_dptools_load)
 	SWITCH_ADD_API(api_interface, "strftime", "strftime", strftime_api_function, "<format_string>");
 	SWITCH_ADD_API(api_interface, "presence", "presence", presence_api_function, PRESENCE_USAGE);
 
+	SWITCH_ADD_APP(app_interface, "blind_transfer_ack", "", "", blind_transfer_ack_function, "[true|false]", SAF_NONE);
+
 	SWITCH_ADD_APP(app_interface, "bind_digit_action", "bind a key sequence or regex to an action", 
 				   "bind a key sequence or regex to an action", bind_digit_action_function, BIND_DIGIT_ACTION_USAGE, SAF_SUPPORT_NOMEDIA);
 

src/mod/endpoints/mod_sofia/mod_sofia.c

@@ -1653,6 +1653,28 @@ static switch_status_t sofia_receive_message(switch_core_session_t *session, swi
 			}
 		}
 		goto end;
+	case SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE:
+		{
+			const char *event = switch_channel_get_variable(channel, "sip_blind_transfer_event");
+			const char *uuid = switch_channel_get_variable(channel, "blind_transfer_uuid");
+			char *xdest;
+
+			if (event && uuid) {
+				nua_notify(tech_pvt->nh, NUTAG_NEWSUB(1), SIPTAG_CONTENT_TYPE_STR("message/sipfrag;version=2.0"),
+						   NUTAG_SUBSTATE(nua_substate_terminated),
+						   SIPTAG_SUBSCRIPTION_STATE_STR("terminated;reason=noresource"), 
+						   SIPTAG_PAYLOAD_STR(msg->numeric_arg ? "SIP/2.0 200 OK\r\n" : "SIP/2.0 403 Forbidden\r\n"), 
+						   SIPTAG_EVENT_STR(event), TAG_END());				
+
+				
+				if (!msg->numeric_arg) {
+					xdest = switch_core_session_sprintf(session, "intercept:%s", uuid);
+					switch_ivr_session_transfer(session, xdest, "inline", NULL);
+				}
+			}
+
+		}
+		goto end;
 	case SWITCH_MESSAGE_INDICATE_UNBRIDGE:
 		if (switch_rtp_ready(tech_pvt->rtp_session)) {
 			
@@ -5343,7 +5365,6 @@ static switch_status_t list_profile_gateway(const char *line, const char *cursor
 	return status;
 }
 
-
 SWITCH_STANDARD_APP(sofia_sla_function)
 {
 	private_object_t *tech_pvt;
@@ -5502,6 +5523,7 @@ SWITCH_MODULE_LOAD_FUNCTION(mod_sofia_load)
 	SWITCH_ADD_APP(app_interface, "sofia_sla", "private sofia sla function", 
 				   "private sofia sla function", sofia_sla_function, "<uuid>", SAF_NONE);
 
+
 	SWITCH_ADD_API(api_interface, "sofia", "Sofia Controls", sofia_function, "<cmd> <args>");
 	SWITCH_ADD_API(api_interface, "sofia_gateway_data", "Get data from a sofia gateway", sofia_gateway_data_function,
 				   "<gateway_name> [ivar|ovar|var] <name>");

src/mod/endpoints/mod_sofia/mod_sofia.h

@@ -264,6 +264,7 @@ typedef enum {
 	PFLAG_PRESENCE_MAP,
 	PFLAG_OPTIONS_RESPOND_503_ON_BUSY,
 	PFLAG_PRESENCE_DISABLE_EARLY,
+	PFLAG_CONFIRM_BLIND_TRANSFER,
 	/* No new flags below this line */
 	PFLAG_MAX
 } PFLAGS;

src/mod/endpoints/mod_sofia/sofia.c

@@ -3105,6 +3105,12 @@ switch_status_t reconfig_sofia(sofia_profile_t *profile)
 						} else {
 							sofia_clear_pflag(profile, PFLAG_LOG_AUTH_FAIL);
 						}
+					} else if (!strcasecmp(var, "confirm-blind-transfer")) {
+						if (switch_true(val)) {
+							sofia_set_pflag(profile, PFLAG_CONFIRM_BLIND_TRANSFER);
+						} else {
+							sofia_clear_pflag(profile, PFLAG_CONFIRM_BLIND_TRANSFER);
+						}
 					} else if (!strcasecmp(var, "presence-proto-lookup")) {
 						if (switch_true(val)) {
 							sofia_set_pflag(profile, PFLAG_PRESENCE_MAP);
@@ -3892,6 +3898,12 @@ switch_status_t config_sofia(int reload, char *profile_name)
 						} else {
 							sofia_clear_pflag(profile, PFLAG_LOG_AUTH_FAIL);
 						}
+					} else if (!strcasecmp(var, "confirm-blind-transfer")) {
+						if (switch_true(val)) {
+							sofia_set_pflag(profile, PFLAG_CONFIRM_BLIND_TRANSFER);
+						} else {
+							sofia_clear_pflag(profile, PFLAG_CONFIRM_BLIND_TRANSFER);
+						}
 					} else if (!strcasecmp(var, "presence-proto-lookup")) {
 						if (switch_true(val)) {
 							sofia_set_pflag(profile, PFLAG_PRESENCE_MAP);
@@ -7093,37 +7105,54 @@ void sofia_handle_sip_i_refer(nua_t *nua, sofia_profile_t *profile, nua_handle_t
 	if (exten) {
 		switch_channel_t *channel = switch_core_session_get_channel(session);
 		const char *br;
+		switch_core_session_t *b_session;
 
-		if ((br = switch_channel_get_variable(channel, SWITCH_SIGNAL_BOND_VARIABLE))) {
+		if ((br = switch_channel_get_variable(channel, SWITCH_SIGNAL_BOND_VARIABLE)) && (b_session = switch_core_session_locate(br))) {
-			switch_core_session_t *b_session;
 
-			if ((b_session = switch_core_session_locate(br))) {
+			const char *var;
-				switch_channel_t *b_channel = switch_core_session_get_channel(b_session);
+			switch_channel_t *b_channel = switch_core_session_get_channel(b_session);
-				switch_channel_set_variable(channel, "transfer_fallback_extension", from->a_user);
-				if (!zstr(full_ref_by)) {
-					switch_channel_set_variable(b_channel, SOFIA_SIP_HEADER_PREFIX "Referred-By", full_ref_by);
-				}
-				if (!zstr(full_ref_to)) {
-					switch_channel_set_variable(b_channel, SOFIA_REFER_TO_VARIABLE, full_ref_to);
-				}
 
-				if (switch_true(switch_channel_get_variable(channel, "recording_follow_transfer"))) {
+			switch_channel_set_variable(channel, "transfer_fallback_extension", from->a_user);
-					switch_core_media_bug_transfer_recordings(session, b_session);
+			if (!zstr(full_ref_by)) {
-				}
+				switch_channel_set_variable(b_channel, SOFIA_SIP_HEADER_PREFIX "Referred-By", full_ref_by);
+			}
 
-				switch_ivr_session_transfer(b_session, exten, NULL, NULL);
+			if (!zstr(full_ref_to)) {
-				switch_core_session_rwunlock(b_session);
+				switch_channel_set_variable(b_channel, SOFIA_REFER_TO_VARIABLE, full_ref_to);
+			}
+			
+			if (switch_true(switch_channel_get_variable(channel, "recording_follow_transfer"))) {
+				switch_core_media_bug_transfer_recordings(session, b_session);
 			}
 
 			switch_channel_set_variable(channel, SWITCH_ENDPOINT_DISPOSITION_VARIABLE, "BLIND_TRANSFER");
-			nua_notify(tech_pvt->nh, NUTAG_NEWSUB(1), SIPTAG_CONTENT_TYPE_STR("message/sipfrag;version=2.0"),
+			
-					   NUTAG_SUBSTATE(nua_substate_terminated),SIPTAG_SUBSCRIPTION_STATE_STR("terminated;reason=noresource"), SIPTAG_PAYLOAD_STR("SIP/2.0 200 OK\r\n"), SIPTAG_EVENT_STR(etmp), TAG_END());
+			if (((var = switch_channel_get_variable(channel, "confirm_blind_transfer")) && switch_true(var)) || 
+				sofia_test_pflag(profile, PFLAG_CONFIRM_BLIND_TRANSFER)) {
 
+				switch_channel_set_state_flag(b_channel, CF_CONFIRM_BLIND_TRANSFER);
+				switch_channel_set_variable(channel, "sip_blind_transfer_event", etmp);
+				switch_channel_set_variable(b_channel, "blind_transfer_uuid", switch_core_session_get_uuid(session));
+				switch_channel_set_variable(channel, "blind_transfer_uuid", switch_core_session_get_uuid(b_session));
+
+				switch_channel_set_variable(channel, "park_timeout", "600:blind_transfer");
+				switch_channel_set_state(channel, CS_PARK);
+			} else {
+				nua_notify(tech_pvt->nh, NUTAG_NEWSUB(1), SIPTAG_CONTENT_TYPE_STR("message/sipfrag;version=2.0"),
+						   NUTAG_SUBSTATE(nua_substate_terminated),
+						   SIPTAG_SUBSCRIPTION_STATE_STR("terminated;reason=noresource"), 
+						   SIPTAG_PAYLOAD_STR("SIP/2.0 200 OK\r\n"), SIPTAG_EVENT_STR(etmp), TAG_END());
+			}
+			
+			switch_ivr_session_transfer(b_session, exten, NULL, NULL);
+			switch_core_session_rwunlock(b_session);
 		} else {
 			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Cannot Blind Transfer 1 Legged calls\n");
 			switch_channel_set_variable(channel_a, SWITCH_ENDPOINT_DISPOSITION_VARIABLE, "ATTENDED_TRANSFER_ERROR");
 			nua_notify(tech_pvt->nh, NUTAG_NEWSUB(1), SIPTAG_CONTENT_TYPE_STR("message/sipfrag;version=2.0"),
-					   NUTAG_SUBSTATE(nua_substate_terminated),SIPTAG_SUBSCRIPTION_STATE_STR("terminated;reason=noresource"), SIPTAG_PAYLOAD_STR("SIP/2.0 403 Forbidden\r\n"), SIPTAG_EVENT_STR(etmp), TAG_END());
+					   NUTAG_SUBSTATE(nua_substate_terminated),
+					   SIPTAG_SUBSCRIPTION_STATE_STR("terminated;reason=noresource"), 
+					   SIPTAG_PAYLOAD_STR("SIP/2.0 403 Forbidden\r\n"), SIPTAG_EVENT_STR(etmp), TAG_END());
 		}
 	}
 

src/switch_core_session.c

@@ -640,6 +640,7 @@ static const char *message_names[] = {
 	"SIGNAL_DATA",
 	"INFO",
 	"AUDIO_DATA",
+	"BLIND_TRANSFER_RESPONSE",
 	"INVALID"
 };
 
@@ -722,6 +723,24 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_perform_receive_message(swit
 				break;
 			}
 		}
+
+
+		if (message->message_id == SWITCH_MESSAGE_INDICATE_BRIDGE &&
+			switch_channel_test_flag(session->channel, CF_CONFIRM_BLIND_TRANSFER)) {
+			switch_core_session_t *other_session;
+			const char *uuid = switch_channel_get_variable(session->channel, "blind_transfer_uuid");
+
+			switch_channel_clear_flag(session->channel, CF_CONFIRM_BLIND_TRANSFER);
+
+			if (!zstr(uuid) && (other_session = switch_core_session_locate(uuid))) {
+				switch_core_session_message_t msg = { 0 };			
+				msg.message_id = SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE;
+				msg.from = __FILE__;
+				msg.numeric_arg = 1;
+				switch_core_session_receive_message(other_session, &msg);
+				switch_core_session_rwunlock(other_session);
+			}
+		}
 	}
 
 

src/switch_core_state_machine.c

@@ -188,6 +188,7 @@ static void switch_core_standard_on_routing(switch_core_session_t *session)
 static void switch_core_standard_on_execute(switch_core_session_t *session)
 {
 	switch_caller_extension_t *extension;
+	const char *uuid;
 
 	switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "%s Standard EXECUTE\n", switch_channel_get_name(session->channel));
 
@@ -222,6 +223,25 @@ static void switch_core_standard_on_execute(switch_core_session_t *session)
 
 	}
 
+	if (switch_channel_ready(session->channel) && switch_channel_get_state(session->channel) == CS_EXECUTE && 
+		switch_channel_test_flag(session->channel, CF_CONFIRM_BLIND_TRANSFER) && 
+		(uuid = switch_channel_get_variable(session->channel, "blind_transfer_uuid"))) {
+		switch_core_session_t *other_session;
+
+		if ((other_session = switch_core_session_locate(uuid))) {
+			switch_core_session_message_t msg = { 0 };			
+			msg.message_id = SWITCH_MESSAGE_INDICATE_BLIND_TRANSFER_RESPONSE;
+			msg.from = __FILE__;
+			msg.numeric_arg = 0;
+			switch_core_session_receive_message(other_session, &msg);
+			switch_core_session_rwunlock(other_session);
+
+			switch_channel_set_variable(session->channel, "park_timeout", "10:blind_transfer");
+			switch_channel_set_state(session->channel, CS_PARK);
+			switch_channel_clear_flag(session->channel, CF_CONFIRM_BLIND_TRANSFER);
+		}
+	}
+	
 	if (switch_channel_ready(session->channel) && switch_channel_get_state(session->channel) == CS_EXECUTE) {
 		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_NOTICE, "%s has executed the last dialplan instruction, hanging up.\n",
 						  switch_channel_get_name(session->channel));