| /* gprs_bssgp_pcu.cpp |
| * |
| * Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version 2 |
| * of the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <osmocom/gprs/gprs_bssgp.h> |
| #include <osmocom/gprs/gprs_bssgp_rim.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/gsm/tlv.h> |
| #include <osmocom/gprs/gprs_ns.h> |
| #include <osmocom/core/prim.h> |
| |
| #include "gprs_debug.h" |
| #include "gprs_pcu.h" |
| #include "bts.h" |
| #include "gprs_ms.h" |
| #include "nacc_fsm.h" |
| |
| #define LOGPRIM(nsei, level, fmt, args...) \ |
| LOGP(DRIM, level, "(NSEI=%u) " fmt, nsei, ## args) |
| |
| static inline void gprs_ra_id_ci_to_cgi_ps(struct osmo_cell_global_id_ps *cgi_ps, |
| const struct gprs_ra_id *raid, uint16_t cid) |
| { |
| *cgi_ps = (struct osmo_cell_global_id_ps) { |
| .rai.lac.plmn.mcc = raid->mcc, |
| .rai.lac.plmn.mnc = raid->mnc, |
| .rai.lac.plmn.mnc_3_digits = raid->mnc_3_digits, |
| .rai.lac.lac = raid->lac, |
| .rai.rac = raid->rac, |
| .cell_identity = cid, |
| }; |
| } |
| |
| /* Mirror RIM routing information of a given PDU, see also 3GPP TS 48.018, section 8c.1.4.3 */ |
| static void mirror_rim_routing_info(struct bssgp_ran_information_pdu *to_pdu, |
| const struct bssgp_ran_information_pdu *from_pdu) |
| { |
| memcpy(&to_pdu->routing_info_dest, &from_pdu->routing_info_src, sizeof(to_pdu->routing_info_dest)); |
| memcpy(&to_pdu->routing_info_src, &from_pdu->routing_info_dest, sizeof(to_pdu->routing_info_src)); |
| } |
| |
| /* Format a RAN INFORMATION ERROR PDU */ |
| static void format_response_pdu_err(struct bssgp_ran_information_pdu *resp_pdu, |
| const struct bssgp_ran_information_pdu *req_pdu) |
| { |
| memset(resp_pdu, 0, sizeof(*resp_pdu)); |
| mirror_rim_routing_info(resp_pdu, req_pdu); |
| |
| resp_pdu->decoded.err_rim_cont = (struct bssgp_ran_inf_err_rim_cont) { |
| .app_id = BSSGP_RAN_INF_APP_ID_NACC, |
| .prot_ver = 1, |
| .err_pdu = req_pdu->rim_cont, |
| .err_pdu_len = req_pdu->rim_cont_len, |
| }; |
| |
| resp_pdu->decoded_present = true; |
| resp_pdu->rim_cont_iei = BSSGP_IE_RI_ERROR_RIM_COINTAINER; |
| } |
| |
| /* Check if the application ID in the request PDU is actually BSSGP_RAN_INF_APP_ID_NACC */ |
| static const enum bssgp_ran_inf_app_id *get_app_id(const struct bssgp_ran_information_pdu *pdu) |
| { |
| switch (pdu->rim_cont_iei) { |
| case BSSGP_IE_RI_REQ_RIM_CONTAINER: |
| return &pdu->decoded.req_rim_cont.app_id; |
| case BSSGP_IE_RI_RIM_CONTAINER: |
| return &pdu->decoded.rim_cont.app_id; |
| case BSSGP_IE_RI_APP_ERROR_RIM_CONT: |
| return &pdu->decoded.app_err_rim_cont.app_id; |
| case BSSGP_IE_RI_ACK_RIM_CONTAINER: |
| return &pdu->decoded.ack_rim_cont.app_id; |
| case BSSGP_IE_RI_ERROR_RIM_COINTAINER: |
| return &pdu->decoded.err_rim_cont.app_id; |
| default: |
| return NULL; |
| } |
| } |
| |
| /* Check if the application ID in the request PDU is of a certain type */ |
| static bool match_app_id(const struct bssgp_ran_information_pdu *pdu, enum bssgp_ran_inf_app_id exp_app_id) |
| { |
| const enum bssgp_ran_inf_app_id *app_id = get_app_id(pdu); |
| if (app_id && *app_id == exp_app_id) |
| return true; |
| return false; |
| } |
| |
| static int handle_ran_info_response_nacc(const struct bssgp_ran_inf_app_cont_nacc *nacc, struct gprs_rlcmac_bts *bts) |
| { |
| struct si_cache_value val; |
| struct si_cache_entry *entry; |
| struct llist_head *tmp; |
| int i; |
| |
| LOGP(DRIM, LOGL_INFO, "Rx RAN-INFO cell=%s type=%sBCCH num_si=%d\n", |
| osmo_cgi_ps_name(&nacc->reprt_cell), |
| nacc->type_psi ? "P" : "", nacc->num_si); |
| |
| val.type_psi = nacc->type_psi; |
| val.si_len = 0; |
| for (i = 0; i < nacc->num_si; i++) { |
| size_t len = val.type_psi ? BSSGP_RIM_PSI_LEN : BSSGP_RIM_SI_LEN; |
| memcpy(&val.si_buf[val.si_len], nacc->si[i], len); |
| val.si_len += len; |
| } |
| entry = si_cache_add(bts->pcu->si_cache, &nacc->reprt_cell, &val); |
| |
| llist_for_each(tmp, bts_ms_list(bts)) { |
| struct GprsMs *ms = llist_entry(tmp, typeof(*ms), list); |
| if (!ms->nacc) |
| continue; |
| if (ms->nacc->fi->state != NACC_ST_WAIT_REQUEST_SI) |
| continue; |
| if (osmo_cgi_ps_cmp(&nacc->reprt_cell, &ms->nacc->cgi_ps) != 0) |
| continue; |
| osmo_fsm_inst_dispatch(ms->nacc->fi, NACC_EV_RX_SI, entry); |
| } |
| return 0; |
| } |
| |
| static int handle_ran_info_response(const struct bssgp_ran_information_pdu *pdu, struct gprs_rlcmac_bts *bts) |
| { |
| const struct bssgp_ran_inf_rim_cont *ran_info = &pdu->decoded.rim_cont; |
| char ri_src_str[64]; |
| |
| if (ran_info->app_err) { |
| LOGP(DRIM, LOGL_ERROR, |
| "%s Rx RAN-INFO with an app error! cause: %s\n", |
| bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &pdu->routing_info_src), |
| bssgp_nacc_cause_str(ran_info->u.app_err_cont_nacc.nacc_cause)); |
| return -1; |
| } |
| |
| switch (pdu->decoded.rim_cont.app_id) { |
| case BSSGP_RAN_INF_APP_ID_NACC: |
| handle_ran_info_response_nacc(&ran_info->u.app_cont_nacc, bts); |
| break; |
| default: |
| LOGP(DRIM, LOGL_ERROR, "%s Rx RAN-INFO with unknown/wrong application ID %s received\n", |
| bssgp_rim_ri_name_buf(ri_src_str, sizeof(ri_src_str), &pdu->routing_info_src), |
| bssgp_ran_inf_app_id_str(pdu->decoded.rim_cont.app_id)); |
| return -1; |
| } |
| return 0; |
| } |
| |
| int handle_rim(struct osmo_bssgp_prim *bp) |
| { |
| struct msgb *msg = bp->oph.msg; |
| uint16_t nsei = msgb_nsei(msg); |
| struct bssgp_ran_information_pdu *pdu = &bp->u.rim_pdu; |
| struct bssgp_ran_information_pdu resp_pdu; |
| struct osmo_cell_global_id_ps dst_addr; |
| struct gprs_rlcmac_bts *bts; |
| |
| OSMO_ASSERT (bp->oph.sap == SAP_BSSGP_RIM); |
| |
| /* At the moment we only support GERAN, so we block all other network |
| * types here. */ |
| if (pdu->routing_info_dest.discr != BSSGP_RIM_ROUTING_INFO_GERAN) { |
| LOGPRIM(nsei, LOGL_ERROR, |
| "Only GERAN supported, destination cell is not a GERAN cell -- rejected.\n"); |
| return bssgp_tx_status(BSSGP_CAUSE_UNKN_RIM_AI, NULL, msg); |
| } |
| |
| /* Check if the RIM pdu is really addressed to this PCU. In case we |
| * receive a RIM PDU for a cell that is not parented by this PCU we |
| * are supposed to reject it with a BSSGP STATUS. |
| * see also: 3GPP TS 48.018, section 8c.3.1.2 */ |
| gprs_ra_id_ci_to_cgi_ps(&dst_addr, &pdu->routing_info_dest.geran.raid, |
| pdu->routing_info_dest.geran.cid); |
| bts = gprs_pcu_get_bts_by_cgi_ps(the_pcu, &dst_addr); |
| if (!bts) { |
| LOGPRIM(nsei, LOGL_ERROR, "Cell %s unknown to this pcu\n", |
| osmo_cgi_ps_name(&dst_addr)); |
| return bssgp_tx_status(BSSGP_CAUSE_UNKN_DST, NULL, msg); |
| } |
| |
| /* Check if the incoming RIM PDU is parseable, if not we must report |
| * an error to the controlling BSS 3GPP TS 48.018, 8c.3.4 and 8c.3.4.2 */ |
| if (!pdu->decoded_present) { |
| LOGPRIM(nsei, LOGL_ERROR, "Errornous RIM PDU received -- rejected.\n"); |
| format_response_pdu_err(&resp_pdu, pdu); |
| return 0; |
| } |
| |
| /* Check if the RIM container inside the incoming RIM PDU has the correct |
| * application ID */ |
| if (!match_app_id(pdu, BSSGP_RAN_INF_APP_ID_NACC)) { |
| LOGPRIM(nsei, LOGL_ERROR, "RIM PDU with unknown/wrong application ID received -- rejected.\n"); |
| format_response_pdu_err(&resp_pdu, pdu); |
| return 0; |
| } |
| |
| /* Handle incoming RIM container */ |
| switch (pdu->rim_cont_iei) { |
| case BSSGP_IE_RI_REQ_RIM_CONTAINER: |
| LOGPRIM(nsei, LOGL_NOTICE, "Responding to RAN INFORMATION REQUEST not yet implemented!\n"); |
| break; |
| case BSSGP_IE_RI_RIM_CONTAINER: |
| return handle_ran_info_response(pdu, bts); |
| case BSSGP_IE_RI_APP_ERROR_RIM_CONT: |
| case BSSGP_IE_RI_ACK_RIM_CONTAINER: |
| case BSSGP_IE_RI_ERROR_RIM_COINTAINER: |
| LOGPRIM(nsei, LOGL_ERROR, "RIM PDU not handled by this application\n"); |
| return -EINVAL; |
| default: |
| /* This should never happen. If the RIM PDU is parsed correctly, then the rim_cont_iei will |
| * be set to one of the cases above and if parsing fails this switch statement is guarded |
| * by the check on decoded_present above */ |
| OSMO_ASSERT(false); |
| } |
| |
| return 0; |
| } |