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