396 lines
13 KiB
Plaintext
396 lines
13 KiB
Plaintext
module BSSMAP_Emulation {
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import from SCCP_Emulation all;
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import from SCCPasp_Types all;
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import from BSSAP_Types all;
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import from BSSMAP_Templates all;
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import from MGCP_Types all;
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import from MGCP_Templates all;
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import from IPA_Emulation all;
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/* General "base class" component definition, of which specific implementations
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* derive themselves by means of the "extends" feature */
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type component BSSAP_ConnHdlr {
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/* port towards MSC Emulator core / SCCP connection dispatchar */
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port BSSAP_Conn_PT BSSAP;
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}
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/* Auxiliary primitive that can happen on the port between per-connection client and this dispatcher */
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type enumerated BSSAP_Conn_Prim {
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/* SCCP tell us that connection was released */
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MSC_CONN_PRIM_DISC_IND,
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/* we tell SCCP to release connection */
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MSC_CONN_PRIM_DISC_REQ
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}
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type record BSSAP_Conn_Req {
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SCCP_PAR_Address addr_peer,
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SCCP_PAR_Address addr_own,
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PDU_BSSAP bssap
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}
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/* port between individual per-connection components and this dispatcher */
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type port BSSAP_Conn_PT message {
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inout PDU_BSSAP, BSSAP_Conn_Prim, BSSAP_Conn_Req, MgcpCommand, MgcpResponse;
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} with { extension "internal" };
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/* represents a single BSSAP connection over SCCP */
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type record ConnectionData {
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/* reference to the instance of the per-connection component */
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BSSAP_ConnHdlr comp_ref,
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integer sccp_conn_id,
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/* most recent MGCP transaction ID (Used on MSC side) */
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MgcpTransId mgcp_trans_id optional,
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/* CIC that has been used for voice of this channel (BSC side) */
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integer cic optional
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}
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type component BSSMAP_Emulation_CT {
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/* SCCP port on the bottom side, using ASP primitives */
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port SCCPasp_PT SCCP;
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/* BSSAP port to the per-connection clients */
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port BSSAP_Conn_PT CLIENT;
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/* MGCP port */
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port IPA_MGCP_PT MGCP;
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/* use 16 as this is also the number of SCCP connections that SCCP_Emulation can handle */
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var ConnectionData ConnectionTable[16];
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var charstring g_bssmap_id;
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var integer g_next_e1_ts := 1;
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};
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private function f_conn_id_known(integer sccp_conn_id)
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runs on BSSMAP_Emulation_CT return boolean {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].sccp_conn_id == sccp_conn_id){
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return true;
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}
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}
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return false;
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}
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private function f_comp_known(BSSAP_ConnHdlr client)
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runs on BSSMAP_Emulation_CT return boolean {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].comp_ref == client) {
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return true;
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}
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}
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return false;
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}
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/* resolve component reference by connection ID */
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private function f_comp_by_conn_id(integer sccp_conn_id)
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runs on BSSMAP_Emulation_CT return BSSAP_ConnHdlr {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].sccp_conn_id == sccp_conn_id) {
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return ConnectionTable[i].comp_ref;
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}
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}
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log("BSSMAP Connection table not found by SCCP Connection ID ", sccp_conn_id);
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self.stop;
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}
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/* resolve component reference by CIC */
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private function f_comp_by_mgcp_tid(MgcpTransId tid)
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runs on BSSMAP_Emulation_CT return BSSAP_ConnHdlr {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].mgcp_trans_id == tid) {
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return ConnectionTable[i].comp_ref;
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}
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}
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log("BSSMAP Connection table not found by MGCP Transaction ID ", tid);
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self.stop;
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}
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private function f_comp_store_mgcp_tid(BSSAP_ConnHdlr client, MgcpTransId tid)
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runs on BSSMAP_Emulation_CT {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].comp_ref == client) {
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ConnectionTable[i].mgcp_trans_id := tid;
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return;
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}
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}
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log("BSSMAP Connection table not found by component ", client);
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self.stop;
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}
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private function f_comp_by_cic(integer cic)
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runs on BSSMAP_Emulation_CT return BSSAP_ConnHdlr {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].cic == cic) {
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return ConnectionTable[i].comp_ref;
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}
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}
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log("BSSMAP Connection table not found by CIC ", cic);
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self.stop;
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}
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private function f_comp_store_cic(BSSAP_ConnHdlr client, integer cic)
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runs on BSSMAP_Emulation_CT {
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var integer i;
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for (i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].comp_ref == client) {
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ConnectionTable[i].cic := cic;
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return;
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}
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}
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log("BSSMAP Connection table not found by component ", client);
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}
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/* resolve connection ID by component reference */
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private function f_conn_id_by_comp(BSSAP_ConnHdlr client)
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runs on BSSMAP_Emulation_CT return integer {
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for (var integer i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].comp_ref == client) {
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return ConnectionTable[i].sccp_conn_id;
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}
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}
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log("BSSMAP Connection table not found by component ", client);
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self.stop;
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}
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private function f_gen_conn_id()
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runs on BSSMAP_Emulation_CT return integer {
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var integer conn_id;
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do {
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conn_id := float2int(rnd()*SCCP_Emulation.tsp_max_ConnectionId);
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} while (f_conn_id_known(conn_id) == true);
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return conn_id;
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}
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private function f_conn_table_init()
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runs on BSSMAP_Emulation_CT {
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for (var integer i := 0; i < sizeof(ConnectionTable); i := i+1) {
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ConnectionTable[i].comp_ref := null;
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ConnectionTable[i].sccp_conn_id := -1;
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ConnectionTable[i].mgcp_trans_id := omit;
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ConnectionTable[i].cic := omit;
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}
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}
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private function f_conn_table_add(BSSAP_ConnHdlr comp_ref, integer sccp_conn_id)
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runs on BSSMAP_Emulation_CT {
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for (var integer i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].sccp_conn_id == -1) {
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ConnectionTable[i].comp_ref := comp_ref;
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ConnectionTable[i].sccp_conn_id := sccp_conn_id;
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log("Added conn table entry ", i, comp_ref, sccp_conn_id);
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return;
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}
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}
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log("BSSMAP Connection table full!");
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self.stop;
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}
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private function f_conn_table_del(integer sccp_conn_id)
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runs on BSSMAP_Emulation_CT {
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for (var integer i := 0; i < sizeof(ConnectionTable); i := i+1) {
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if (ConnectionTable[i].sccp_conn_id == sccp_conn_id) {
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log("Deleted conn table entry ", i,
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ConnectionTable[i].comp_ref, sccp_conn_id);
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ConnectionTable[i].sccp_conn_id := -1;
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ConnectionTable[i].comp_ref := null;
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}
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}
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log("BSSMAP Connection table attempt to delete non-existant ", sccp_conn_id);
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self.stop;
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}
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/* handle (optional) userData portion of various primitives and dispatch it to the client */
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private function f_handle_userData(BSSAP_ConnHdlr client, octetstring userdata)
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runs on BSSMAP_Emulation_CT {
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/* decode + send decoded BSSAP to client */
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var PDU_BSSAP bssap := dec_PDU_BSSAP(valueof(userdata));
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/* BSC Side: If this is an assignment command, store CIC */
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if (ischosen(bssap.pdu.bssmap.assignmentRequest) and
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ispresent(bssap.pdu.bssmap.assignmentRequest.circuitIdentityCode)) {
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var BSSMAP_IE_CircuitIdentityCode cic_ie :=
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bssap.pdu.bssmap.assignmentRequest.circuitIdentityCode;
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var integer cic := (oct2int(cic_ie.cicHigh) * 256) + oct2int(cic_ie.cicLow);
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f_comp_store_cic(client, cic);
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}
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CLIENT.send(bssap) to client;
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}
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/* call-back type, to be provided by specific implementation; called when new SCCP connection
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* arrives */
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type function BssmapCreateCallback(ASP_SCCP_N_CONNECT_ind conn_ind, charstring id)
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runs on BSSMAP_Emulation_CT return BSSAP_ConnHdlr;
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type function BssmapUnitdataCallback(PDU_BSSAP bssap)
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runs on BSSMAP_Emulation_CT return template PDU_BSSAP;
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type record BssmapOps {
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BssmapCreateCallback create_cb,
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BssmapUnitdataCallback unitdata_cb
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}
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function main(BssmapOps ops, charstring id) runs on BSSMAP_Emulation_CT {
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g_bssmap_id := id;
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f_conn_table_init();
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while (true) {
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var ASP_SCCP_N_UNITDATA_ind ud_ind;
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var ASP_SCCP_N_CONNECT_ind conn_ind;
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var ASP_SCCP_N_CONNECT_cfm conn_cfm;
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var ASP_SCCP_N_DATA_ind data_ind;
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var ASP_SCCP_N_DISCONNECT_ind disc_ind;
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var BSSAP_Conn_Req creq;
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var BSSAP_ConnHdlr vc_conn;
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var PDU_BSSAP bssap;
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var MgcpCommand mgcp_req;
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var MgcpResponse mgcp_resp;
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alt {
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/* SCCP -> Client: UNIT-DATA (connectionless SCCP) from a BSC */
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[] SCCP.receive(ASP_SCCP_N_UNITDATA_ind:?) -> value ud_ind {
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/* Connectionless Procedures like RESET */
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var template PDU_BSSAP resp;
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bssap := dec_PDU_BSSAP(ud_ind.userData);
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resp := ops.unitdata_cb.apply(bssap);
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if (isvalue(resp)) {
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var octetstring resp_ud := enc_PDU_BSSAP(valueof(resp));
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SCCP.send(t_ASP_N_UNITDATA_req(ud_ind.callingAddress,
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ud_ind.calledAddress, omit,
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omit, resp_ud, omit));
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}
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}
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/* SCCP -> Client: new connection from BSC */
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[] SCCP.receive(ASP_SCCP_N_CONNECT_ind:?) -> value conn_ind {
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vc_conn := ops.create_cb.apply(conn_ind, id);
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/* store mapping between client components and SCCP connectionId */
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f_conn_table_add(vc_conn, conn_ind.connectionId);
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/* handle user payload */
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f_handle_userData(vc_conn, conn_ind.userData);
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/* confirm connection establishment */
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SCCP.send(t_ASP_N_CONNECT_res(omit, omit, omit, omit, conn_ind.connectionId, omit));
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}
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/* SCCP -> Client: connection-oriented data in existing connection */
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[] SCCP.receive(ASP_SCCP_N_DATA_ind:?) -> value data_ind {
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vc_conn := f_comp_by_conn_id(data_ind.connectionId);
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if (ispresent(data_ind.userData)) {
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f_handle_userData(vc_conn, data_ind.userData);
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}
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}
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/* SCCP -> Client: disconnect of an existing connection */
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[] SCCP.receive(ASP_SCCP_N_DISCONNECT_ind:?) -> value disc_ind {
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vc_conn := f_comp_by_conn_id(disc_ind.connectionId);
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if (ispresent(disc_ind.userData)) {
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f_handle_userData(vc_conn, disc_ind.userData);
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}
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/* notify client about termination */
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var BSSAP_Conn_Prim prim := MSC_CONN_PRIM_DISC_IND;
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CLIENT.send(prim) to vc_conn;
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f_conn_table_del(disc_ind.connectionId);
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/* TOOD: return confirm to other side? */
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}
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/* SCCP -> Client: connection confirm for outbound connection */
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[] SCCP.receive(ASP_SCCP_N_CONNECT_cfm:?) -> value conn_cfm {
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/* handle user payload */
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if (ispresent(conn_cfm.userData)) {
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f_handle_userData(vc_conn, conn_cfm.userData);
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}
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}
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/* Disconnect request client -> SCCP */
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[] CLIENT.receive(BSSAP_Conn_Prim:MSC_CONN_PRIM_DISC_REQ) -> sender vc_conn {
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var integer conn_id := f_conn_id_by_comp(vc_conn);
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SCCP.send(t_ASP_N_DISCONNECT_req(omit, 0, omit, conn_id, omit));
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f_conn_table_del(conn_id);
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}
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/* BSSAP from client -> SCCP */
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[] CLIENT.receive(BSSAP_Conn_Req:?) -> value creq sender vc_conn {
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var integer conn_id;
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/* encode + send to dispatcher */
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var octetstring userdata := enc_PDU_BSSAP(creq.bssap);
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if (f_comp_known(vc_conn) == false) {
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/* unknown client, create new connection */
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conn_id := f_gen_conn_id();
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/* store mapping between client components and SCCP connectionId */
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f_conn_table_add(vc_conn, conn_id);
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SCCP.send(t_ASP_N_CONNECT_req(creq.addr_peer, creq.addr_own, omit, omit,
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userdata, conn_id, omit));
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} else {
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/* known client, send via existing connection */
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conn_id := f_conn_id_by_comp(vc_conn);
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SCCP.send(t_ASP_N_DATA_req(userdata, conn_id, omit));
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}
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}
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[] CLIENT.receive(PDU_BSSAP:?) -> value bssap sender vc_conn {
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var integer conn_id := f_conn_id_by_comp(vc_conn);
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/* encode + send it to dispatcher */
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var octetstring userdata := enc_PDU_BSSAP(bssap);
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SCCP.send(t_ASP_N_DATA_req(userdata, conn_id, omit));
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}
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/* Handling of MGCP in IPA SCCPLite case. This predates 3GPP AoIP
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* and uses a MGCP session in parallel to BSSAP. BSSAP uses CIC
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* as usual, and MGCP uses "CIC@mgw" endpoint naming, where CIC
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* is printed as hex string, e.g. a@mgw for CIC 10 */
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/* CLIENT -> MGCP */
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[] CLIENT.receive(MgcpCommand:?) -> value mgcp_req sender vc_conn {
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/* MGCP request from Handler (we're MSC) */
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/* store the transaction ID we've seen */
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f_comp_store_mgcp_tid(vc_conn, mgcp_req.line.trans_id);
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/* simply forward any MGCP from the client to the port */
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MGCP.send(mgcp_req);
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}
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[] CLIENT.receive(MgcpResponse:?) -> value mgcp_resp sender vc_conn {
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/* MGCP response from Handler (we're BSC/MGW) */
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/* simply forward any MGCP from the client to the port */
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MGCP.send(mgcp_resp);
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}
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/* MGCP -> CLIENT */
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[] MGCP.receive(MgcpCommand:?) -> value mgcp_req {
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/* MGCP request from network side (we're BSC/MGW) */
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/* Extract CIC from local part of endpoint name */
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var integer cic := f_mgcp_ep_extract_cic(mgcp_req.line.ep);
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/* Resolve the vc_conn by the CIC */
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vc_conn := f_comp_by_cic(cic);
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CLIENT.send(mgcp_req) to vc_conn;
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}
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[] MGCP.receive(MgcpResponse:?) -> value mgcp_resp {
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/* MGCP response from network side (we're MSC) */
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/* Resolve the vc_conn by the transaction ID */
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vc_conn := f_comp_by_mgcp_tid(mgcp_resp.line.trans_id);
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CLIENT.send(mgcp_resp) to vc_conn;
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}
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}
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}
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}
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private function f_mgcp_ep_extract_cic(charstring inp) return integer {
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var charstring local_part := regexp(inp, "(*)@*", 0);
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return hex2int(str2hex(local_part));
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}
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}
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