diff options
Diffstat (limited to 'openbsc/src/libiu/iu.c')
| -rw-r--r-- | openbsc/src/libiu/iu.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/openbsc/src/libiu/iu.c b/openbsc/src/libiu/iu.c new file mode 100644 index 000000000..56b6ec1d3 --- /dev/null +++ b/openbsc/src/libiu/iu.c @@ -0,0 +1,483 @@ +#include <stdint.h> +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include <osmocom/core/select.h> +#include <osmocom/core/prim.h> +#include <osmocom/core/talloc.h> +#include <osmocom/core/logging.h> +#include <osmocom/core/application.h> +#include <osmocom/vty/logging.h> + +#include <osmocom/gsm/gsm48.h> +#include <osmocom/gprs/gprs_msgb.h> + +#include <osmocom/sigtran/sua.h> +#include <osmocom/sigtran/sccp_sap.h> + +#include <openbsc/gprs_sgsn.h> +#include <openbsc/iu.h> +#include <openbsc/debug.h> + +#include <pdp.h> + +#include <osmocom/ranap/ranap_ies_defs.h> +#include <osmocom/ranap/ranap_common.h> +#include <osmocom/ranap/ranap_common_cn.h> +#include <osmocom/ranap/ranap_msg_factory.h> + +#include <asn1c/asn1helpers.h> + +int asn1_xer_print = 1; +void *talloc_asn1_ctx; + + +iu_recv_cb_t global_iu_recv_cb = NULL; +iu_event_cb_t global_iu_event_cb = NULL; + +static LLIST_HEAD(ue_conn_ctx_list); + +struct ue_conn_ctx *ue_conn_ctx_alloc(struct osmo_sua_link *link, uint32_t conn_id) +{ + struct ue_conn_ctx *ctx = talloc_zero(NULL, struct ue_conn_ctx); + + ctx->link = link; + ctx->conn_id = conn_id; + llist_add(&ctx->list, &ue_conn_ctx_list); + + return ctx; +} + +struct ue_conn_ctx *ue_conn_ctx_find(struct osmo_sua_link *link, + uint32_t conn_id) +{ + struct ue_conn_ctx *ctx; + + llist_for_each_entry(ctx, &ue_conn_ctx_list, list) { + if (ctx->link == link && ctx->conn_id == conn_id) + return ctx; + } + return NULL; +} + +/*********************************************************************** + * RANAP handling + ***********************************************************************/ + +static int iu_rab_act(struct ue_conn_ctx *ue_ctx, struct msgb *msg) +{ + struct osmo_scu_prim *prim; + + /* wrap RANAP message in SCCP N-DATA.req */ + prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim)); + prim->u.data.conn_id = ue_ctx->conn_id; + osmo_prim_init(&prim->oph, + SCCP_SAP_USER, + OSMO_SCU_PRIM_N_DATA, + PRIM_OP_REQUEST, + msg); + return osmo_sua_user_link_down(ue_ctx->link, &prim->oph); +} + +int iu_rab_act_cs(struct ue_conn_ctx *ue_ctx, uint32_t rtp_ip, uint16_t rtp_port) +{ + struct msgb *msg; + + /* FIXME: Generate unique RAB ID per UE */ + msg = ranap_new_msg_rab_assign_voice(1, rtp_ip, rtp_port); + msg->l2h = msg->data; + return iu_rab_act(ue_ctx, msg); +} + +int iu_rab_act_ps(struct sgsn_pdp_ctx *pdp) +{ + struct msgb *msg; + struct sgsn_mm_ctx *mm = pdp->mm; + struct ue_conn_ctx *uectx; + uint32_t ggsn_ip; + + uectx = mm->iu.ue_ctx; + + /* Get the IP address for ggsn user plane */ + memcpy(&ggsn_ip, pdp->lib->gsnru.v, pdp->lib->gsnru.l); + ggsn_ip = htonl(ggsn_ip); + + /* FIXME: Generate unique RAB ID per UE */ + msg = ranap_new_msg_rab_assign_data(1, ggsn_ip, pdp->lib->teid_own); + msg->l2h = msg->data; + return iu_rab_act(uectx, msg); +} + +int iu_rab_deact(struct ue_conn_ctx *ue_ctx, uint8_t rab_id) +{ + /* FIXME */ + return -1; +} + +int iu_tx_sec_mode_cmd(struct ue_conn_ctx *uectx, struct gsm_auth_tuple *tp, + int send_ck) +{ + struct osmo_scu_prim *prim; + struct msgb *msg; + uint8_t ik[16]; + uint8_t ck[16]; + unsigned int i; + + /* C5 function to derive IK from Kc */ + for (i = 0; i < 4; i++) + ik[i] = tp->kc[i] ^ tp->kc[i+4]; + memcpy(ik+4, tp->kc, 8); + for (i = 12; i < 16; i++) + ik[i] = ik[i-12]; + + if (send_ck) { + /* C4 function to derive CK from Kc */ + memcpy(ck, tp->kc, 8); + memcpy(ck+8, tp->kc, 8); + } + + /* crate RANAP message */ + msg = ranap_new_msg_sec_mod_cmd(ik, send_ck? ck : NULL); + msg->l2h = msg->data; + /* wrap RANAP message in SCCP N-DATA.req */ + prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim)); + prim->u.data.conn_id = uectx->conn_id; + osmo_prim_init(&prim->oph, SCCP_SAP_USER, + OSMO_SCU_PRIM_N_DATA, + PRIM_OP_REQUEST, msg); + osmo_sua_user_link_down(uectx->link, &prim->oph); + + return 0; +} + +static int ranap_handle_co_initial_ue(void *ctx, RANAP_InitialUE_MessageIEs_t *ies) +{ + struct gprs_ra_id ra_id; + uint16_t sai; + struct msgb *msg = msgb_alloc(256, "RANAP->NAS"); + + ranap_parse_lai(&ra_id, &ies->lai); + sai = asn1str_to_u16(&ies->sai.sAC); + msgb_gmmh(msg) = msgb_put(msg, ies->nas_pdu.size); + memcpy(msgb_gmmh(msg), ies->nas_pdu.buf, ies->nas_pdu.size); + + /* Feed into the MM layer */ + msg->dst = ctx; + global_iu_recv_cb(msg, &ra_id, &sai); + + return 0; +} + +static int ranap_handle_co_dt(void *ctx, RANAP_DirectTransferIEs_t *ies) +{ + struct gprs_ra_id _ra_id, *ra_id = NULL; + uint16_t _sai, *sai = NULL; + struct msgb *msg = msgb_alloc(256, "RANAP->NAS"); + + if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_LAI_PRESENT) { + ranap_parse_lai(&_ra_id, &ies->lai); + ra_id = &_ra_id; + if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_RAC_PRESENT) { + _ra_id.rac = asn1str_to_u8(&ies->rac); + } + if (ies->presenceMask & DIRECTTRANSFERIES_RANAP_SAI_PRESENT) { + _sai = asn1str_to_u16(&ies->sai.sAC); + sai = &_sai; + } + } + + msgb_gmmh(msg) = msgb_put(msg, ies->nas_pdu.size); + memcpy(msgb_gmmh(msg), ies->nas_pdu.buf, ies->nas_pdu.size); + + /* Feed into the MM/CC/SMS-CP layer */ + msg->dst = ctx; + global_iu_recv_cb(msg, ra_id, sai); + + return 0; +} + +static int ranap_handle_co_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies) +{ + if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT) + LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n", + ranap_cause_str(&ies->cause)); + else + LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n"); + + return 0; +} + +int iu_tx(struct msgb *msg, uint8_t sapi) +{ + struct ue_conn_ctx *uectx = msg->dst; + struct osmo_scu_prim *prim; + + LOGP(DRANAP, LOGL_INFO, "Transmitting L3 Message as RANAP DT (SUA link %p conn_id %u)\n", + uectx->link, uectx->conn_id); + + msg = ranap_new_msg_dt(sapi, msg->data, msgb_length(msg)); + msg->l2h = msg->data; + prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim)); + prim->u.data.conn_id = uectx->conn_id; + osmo_prim_init(&prim->oph, SCCP_SAP_USER, + OSMO_SCU_PRIM_N_DATA, + PRIM_OP_REQUEST, msg); + osmo_sua_user_link_down(uectx->link, &prim->oph); + return 0; +} + +static int ranap_handle_co_iu_rel_req(struct ue_conn_ctx *ctx, RANAP_Iu_ReleaseRequestIEs_t *ies) +{ + struct msgb *msg; + struct osmo_scu_prim *prim; + + LOGP(DRANAP, LOGL_INFO, "Received Iu Release Request, Sending Release Command\n"); + msg = ranap_new_msg_iu_rel_cmd(&ies->cause); + msg->l2h = msg->data; + prim = (struct osmo_scu_prim *) msgb_push(msg, sizeof(*prim)); + prim->u.data.conn_id = ctx->conn_id; + osmo_prim_init(&prim->oph, SCCP_SAP_USER, + OSMO_SCU_PRIM_N_DATA, + PRIM_OP_REQUEST, msg); + osmo_sua_user_link_down(ctx->link, &prim->oph); + return 0; +} + +static int ranap_handle_co_rab_ass_resp(struct ue_conn_ctx *ctx, RANAP_RAB_AssignmentResponseIEs_t *ies) +{ + int rc = -1; + + LOGP(DRANAP, LOGL_INFO, "RAB Asignment Response:"); + if (ies->presenceMask & RAB_ASSIGNMENTRESPONSEIES_RANAP_RAB_SETUPORMODIFIEDLIST_PRESENT) { + /* TODO: Iterate over list of SetupOrModifiedList IEs and handle each one */ + RANAP_IE_t *ranap_ie = ies->raB_SetupOrModifiedList.raB_SetupOrModifiedList_ies.list.array[0]; + RANAP_RAB_SetupOrModifiedItemIEs_t setup_ies; + + rc = ranap_decode_rab_setupormodifieditemies_fromlist(&setup_ies, &ranap_ie->value); + if (rc) { + LOGP(DRANAP, LOGL_ERROR, "Error in ranap_decode_rab_setupormodifieditemies()\n"); + return rc; + } + + rc = global_iu_event_cb(ctx, IU_EVENT_RAB_ASSIGN, &setup_ies); + + ranap_free_rab_setupormodifieditemies(&setup_ies); + } + + LOGPC(DRANAP, LOGL_INFO, "\n"); + + return rc; +} + +/* Entry point for connection-oriented RANAP message */ +static void cn_ranap_handle_co(void *ctx, ranap_message *message) +{ + int rc; + + LOGP(DRANAP, LOGL_NOTICE, "handle_co(dir=%u, proc=%u)\n", message->direction, message->procedureCode); + + switch (message->direction) { + case RANAP_RANAP_PDU_PR_initiatingMessage: + switch (message->procedureCode) { + case RANAP_ProcedureCode_id_InitialUE_Message: + rc = ranap_handle_co_initial_ue(ctx, &message->msg.initialUE_MessageIEs); + break; + case RANAP_ProcedureCode_id_DirectTransfer: + rc = ranap_handle_co_dt(ctx, &message->msg.directTransferIEs); + break; + case RANAP_ProcedureCode_id_ErrorIndication: + rc = ranap_handle_co_err_ind(ctx, &message->msg.errorIndicationIEs); + break; + case RANAP_ProcedureCode_id_Iu_ReleaseRequest: + /* Iu Release Request */ + rc = ranap_handle_co_iu_rel_req(ctx, &message->msg.iu_ReleaseRequestIEs); + break; + default: + rc = -1; + break; + } + break; + case RANAP_RANAP_PDU_PR_successfulOutcome: + switch (message->procedureCode) { + case RANAP_ProcedureCode_id_SecurityModeControl: + /* Security Mode Complete */ + LOGP(DRANAP, LOGL_NOTICE, "FIXME: Handle security mode complete\n"); + rc = global_iu_event_cb(ctx, IU_EVENT_SECURITY_MODE_COMPLETE, NULL); + break; + case RANAP_ProcedureCode_id_Iu_Release: + /* Iu Release Complete */ + LOGP(DRANAP, LOGL_NOTICE, "FIXME: Handle Iu release complete\n"); + rc = global_iu_event_cb(ctx, IU_EVENT_IU_RELEASE, NULL); + break; + default: + rc = -1; + break; + } + case RANAP_RANAP_PDU_PR_outcome: + switch (message->procedureCode) { + case RANAP_ProcedureCode_id_RAB_Assignment: + /* RAB Assignment Response */ + rc = ranap_handle_co_rab_ass_resp(ctx, &message->msg.raB_AssignmentResponseIEs); + break; + } + case RANAP_RANAP_PDU_PR_unsuccessfulOutcome: + default: + rc = -1; + break; + } + + if (rc) { + LOGP(DRANAP, LOGL_ERROR, "Error in cn_ranap_handle_co (%d)\n", + rc); + /* TODO handling of the error? */ + } +} + +static int ranap_handle_cl_reset_req(void *ctx, RANAP_ResetIEs_t *ies) +{ + /* FIXME: send reset response */ + return -1; +} + +static int ranap_handle_cl_err_ind(void *ctx, RANAP_ErrorIndicationIEs_t *ies) +{ + if (ies->presenceMask & ERRORINDICATIONIES_RANAP_CAUSE_PRESENT) + LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication (%s)\n", + ranap_cause_str(&ies->cause)); + else + LOGP(DRANAP, LOGL_ERROR, "Rx Error Indication\n"); + + return 0; +} + +/* Entry point for connection-less RANAP message */ +static void cn_ranap_handle_cl(void *ctx, ranap_message *message) +{ + int rc; + + switch (message->direction) { + case RANAP_RANAP_PDU_PR_initiatingMessage: + switch (message->procedureCode) { + case RANAP_ProcedureCode_id_Reset: + /* received reset.req, send reset.resp */ + rc = ranap_handle_cl_reset_req(ctx, &message->msg.resetIEs); + break; + case RANAP_ProcedureCode_id_ErrorIndication: + rc = ranap_handle_cl_err_ind(ctx, &message->msg.errorIndicationIEs); + break; + default: + rc = -1; + break; + } + break; + case RANAP_RANAP_PDU_PR_successfulOutcome: + case RANAP_RANAP_PDU_PR_unsuccessfulOutcome: + case RANAP_RANAP_PDU_PR_outcome: + default: + rc = -1; + break; + } + + if (rc) { + LOGP(DRANAP, LOGL_ERROR, "Error in cn_ranap_handle_cl (%d)\n", + rc); + /* TODO handling of the error? */ + } +} + +/*********************************************************************** + * + ***********************************************************************/ + +int tx_unitdata(struct osmo_sua_link *link); +int tx_conn_req(struct osmo_sua_link *link, uint32_t conn_id); + +struct osmo_prim_hdr *make_conn_req(uint32_t conn_id); +struct osmo_prim_hdr *make_dt1_req(uint32_t conn_id, const uint8_t *data, unsigned int len); + +struct osmo_prim_hdr *make_conn_resp(struct osmo_scu_connect_param *param) +{ + struct msgb *msg = msgb_alloc(1024, "conn_resp"); + struct osmo_scu_prim *prim; + + prim = (struct osmo_scu_prim *) msgb_put(msg, sizeof(*prim)); + osmo_prim_init(&prim->oph, SCCP_SAP_USER, + OSMO_SCU_PRIM_N_CONNECT, + PRIM_OP_RESPONSE, msg); + memcpy(&prim->u.connect, param, sizeof(prim->u.connect)); + return &prim->oph; +} + +static int sccp_sap_up(struct osmo_prim_hdr *oph, void *link) +{ + struct osmo_scu_prim *prim = (struct osmo_scu_prim *) oph; + struct osmo_prim_hdr *resp = NULL; + int rc; + struct ue_conn_ctx *ue; + + printf("sccp_sap_up(%s)\n", osmo_scu_prim_name(oph)); + + switch (OSMO_PRIM_HDR(oph)) { + case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_CONFIRM): + /* confirmation of outbound connection */ + rc = -1; + break; + case OSMO_PRIM(OSMO_SCU_PRIM_N_CONNECT, PRIM_OP_INDICATION): + /* indication of new inbound connection request*/ + printf("N-CONNECT.ind(X->%u)\n", prim->u.connect.conn_id); + if (/* prim->u.connect.called_addr.ssn != OSMO_SCCP_SSN_RANAP || */ + !msgb_l2(oph->msg) || msgb_l2len(oph->msg) == 0) { + LOGP(DGPRS, LOGL_NOTICE, "Received invalid N-CONNECT.ind\n"); + return 0; + } + ue = ue_conn_ctx_alloc(link, prim->u.connect.conn_id); + /* first ensure the local SUA/SCCP socket is ACTIVE */ + resp = make_conn_resp(&prim->u.connect); + osmo_sua_user_link_down(link, resp); + /* then handle the RANAP payload */ + rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg)); + break; + case OSMO_PRIM(OSMO_SCU_PRIM_N_DISCONNECT, PRIM_OP_INDICATION): + /* indication of disconnect */ + printf("N-DISCONNECT.ind(%u)\n", prim->u.disconnect.conn_id); + ue = ue_conn_ctx_find(link, prim->u.disconnect.conn_id); + rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg)); + break; + case OSMO_PRIM(OSMO_SCU_PRIM_N_DATA, PRIM_OP_INDICATION): + /* connection-oriented data received */ + printf("N-DATA.ind(%u, %s)\n", prim->u.data.conn_id, + osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); + /* resolve UE context */ + ue = ue_conn_ctx_find(link, prim->u.data.conn_id); + rc = ranap_cn_rx_co(cn_ranap_handle_co, ue, msgb_l2(oph->msg), msgb_l2len(oph->msg)); + break; + case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): + /* connection-less data received */ + printf("N-UNITDATA.ind(%s)\n", + osmo_hexdump(msgb_l2(oph->msg), msgb_l2len(oph->msg))); + rc = ranap_cn_rx_cl(cn_ranap_handle_cl, link, msgb_l2(oph->msg), msgb_l2len(oph->msg)); + break; + default: + rc = -1; + break; + } + + msgb_free(oph->msg); + return rc; +} + +int iu_init(void *ctx, const char *listen_addr, uint16_t listen_port, + iu_recv_cb_t iu_recv_cb, iu_event_cb_t iu_event_cb) +{ + struct osmo_sua_user *user; + talloc_asn1_ctx = talloc_named_const(ctx, 1, "asn1"); + + global_iu_recv_cb = iu_recv_cb; + global_iu_event_cb = iu_event_cb; + osmo_sua_set_log_area(DSUA); + user = osmo_sua_user_create(ctx, sccp_sap_up, ctx); + return osmo_sua_server_listen(user, listen_addr, listen_port); +} + |