/* Virtual BTS layer 1 primitive handling and interface * * Copyright (C) 2015 Harald Welte * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern int vbts_sched_start(struct gsm_bts *bts); /** * Callback to handle incoming messages from the MS. * The incoming message should be GSM_TAP encapsulated. * TODO: implement all channels */ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg) { struct gsmtap_hdr *gh = msgb_l1(msg); uint32_t fn = ntohl(gh->frame_number); // frame number of the rcv msg uint16_t arfcn = ntohs(gh->arfcn); // arfcn of the cell we currently camp on uint8_t gsmtap_chantype = gh->sub_type; // gsmtap channel type uint8_t signal_dbm = gh->signal_dbm; // signal strength, 63 is best uint8_t snr = gh->snr_db; // signal noise ratio, 63 is best uint8_t subslot = gh->sub_slot; // multiframe subslot to send msg in (tch -> 0-26, bcch/ccch -> 0-51) uint8_t timeslot = gh->timeslot; // tdma timeslot to send in (0-7) uint8_t rsl_chantype; // rsl chan type (8.58, 9.3.1) uint8_t link_id; // rsl link id tells if this is an ssociated or dedicated link uint8_t chan_nr; // encoded rsl channel type, timeslot and mf subslot struct phy_link *plink = (struct phy_link *)vui->priv; // TODO: is there more than one physical instance? Where do i get the corresponding pinst number? Maybe gsmtap_hdr->antenna? struct phy_instance *pinst = phy_instance_by_num(plink, 0); struct l1sched_trx *l1t = &pinst->u.virt.sched; struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, timeslot); struct osmo_phsap_prim l1sap; memset(&l1sap, 0, sizeof(l1sap)); // get rid of l1 gsmtap hdr msg->l2h = msgb_pull(msg, sizeof(*gh)); // convert gsmtap chan to rsl chan and link id chantype_gsmtap2rsl(gsmtap_chantype, &rsl_chantype, &link_id); chan_nr = rsl_enc_chan_nr(rsl_chantype, subslot, timeslot); // Generally ignore all msgs that are either not received with the right arfcn... if((arfcn & GSMTAP_ARFCN_MASK) != l1t->trx->arfcn) { LOGP(LOGL_NOTICE, DL1P, "Ignore incoming msg - msg arfcn=%d not equal trx arfcn=%d!\n", arfcn & GSMTAP_ARFCN_MASK, l1t->trx->arfcn); goto nomessage; } // ... or not uplink if(!(arfcn & GSMTAP_ARFCN_F_UPLINK)) { LOGP(LOGL_NOTICE, DL1P, "Ignore incoming msg - no uplink flag.\n"); goto nomessage; } // switch case with removed acch flag switch (gsmtap_chantype & ~GSMTAP_CHANNEL_ACCH & 0xff) { case GSMTAP_CHANNEL_RACH: // generate primitive for upper layer // see 04.08 - 3.3.1.3.1: the IMMEDIATE_ASSIGNMENT coming back from the network has to be // sent with the same ra reference as in the CHANNEL_REQUEST that was received osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_PH_RACH, PRIM_OP_INDICATION, msg); l1sap.u.rach_ind.chan_nr = chan_nr; l1sap.u.rach_ind.ra = msgb_pull_u8(msg); // directly after gh hdr comes ra l1sap.u.rach_ind.acc_delay = 0; // probably not used in virt um l1sap.u.rach_ind.is_11bit = 0; // We dont use that l1sap.u.rach_ind.fn = fn; l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_NONE; // FIXME: what comes here break; case GSMTAP_CHANNEL_TCH_F: case GSMTAP_CHANNEL_TCH_H: #if(0) // TODO: handle msgs on TCH that neither FACCH nor TCH/ACCH if(!facch && ! tch_acch) { osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_INDICATION, msg); } #endif case GSMTAP_CHANNEL_SDCCH4: case GSMTAP_CHANNEL_SDCCH8: osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_PH_DATA, PRIM_OP_INDICATION, msg); l1sap.u.data.chan_nr = chan_nr; l1sap.u.data.link_id = link_id; l1sap.u.data.fn = fn; l1sap.u.data.rssi = 0; // Radio Signal Strength Indicator. Best -> 0. l1sap.u.data.ber10k = 0; // Bit Error Rate in 0.01%. Best -> 0. l1sap.u.data.ta_offs_qbits = 0; // Burst time of arrival in quarter bits. Probably used for Timing Advance calc. Best -> 0. l1sap.u.data.lqual_cb = 10 * signal_dbm; // Link quality in centiBel = 10 * db. l1sap.u.data.pdch_presence_info = PRES_INFO_UNKNOWN; break; case GSMTAP_CHANNEL_AGCH: case GSMTAP_CHANNEL_PCH: case GSMTAP_CHANNEL_BCCH: LOGP(LOGL_NOTICE, DL1P, "Ignore incoming msg - channel type downlink only!\n"); goto nomessage; case GSMTAP_CHANNEL_SDCCH: case GSMTAP_CHANNEL_CCCH: case GSMTAP_CHANNEL_PACCH: case GSMTAP_CHANNEL_PDCH: case GSMTAP_CHANNEL_PTCCH: case GSMTAP_CHANNEL_CBCH51: case GSMTAP_CHANNEL_CBCH52: LOGP(LOGL_NOTICE, DL1P, "Ignore incoming msg - channel type not supported!\n"); goto nomessage; default: LOGP(LOGL_NOTICE, DL1P, "Ignore incoming msg - channel type unknown.\n"); goto nomessage; } /* forward primitive, forwarded msg will not be freed */ l1sap_up(pinst->trx, &l1sap); DEBUGP(DL1P, "Message forwarded to layer 2.\n"); return; // handle memory deallocation nomessage: talloc_free(msg); } /* called by common part once OML link is established */ int bts_model_oml_estab(struct gsm_bts *bts) { return 0; } /* called by bts_main to initialize physical link */ int bts_model_phy_link_open(struct phy_link *plink) { struct phy_instance *pinst; //OSMO_ASSERT(plink->type == PHY_LINK_T_VIRTUAL); if (plink->u.virt.virt_um) virt_um_destroy(plink->u.virt.virt_um); phy_link_state_set(plink, PHY_LINK_CONNECTING); if (!plink->u.virt.bts_mcast_group) { plink->u.virt.bts_mcast_group = DEFAULT_BTS_MCAST_GROUP; } if (!plink->u.virt.bts_mcast_port) { plink->u.virt.bts_mcast_port = DEFAULT_BTS_MCAST_PORT; } if (!plink->u.virt.ms_mcast_group) { plink->u.virt.ms_mcast_group = DEFAULT_MS_MCAST_GROUP; } if (!plink->u.virt.ms_mcast_port) { plink->u.virt.ms_mcast_port = DEFAULT_MS_MCAST_PORT; } plink->u.virt.virt_um = virt_um_init(plink, plink->u.virt.ms_mcast_group, plink->u.virt.ms_mcast_port, plink->u.virt.bts_mcast_group, plink->u.virt.bts_mcast_port, virt_um_rcv_cb); // set back reference to plink plink->u.virt.virt_um->priv = plink; if (!plink->u.virt.virt_um) { phy_link_state_set(plink, PHY_LINK_SHUTDOWN); return -1; } /* iterate over list of PHY instances and initialize the * scheduler */ llist_for_each_entry(pinst, &plink->instances, list) { trx_sched_init(&pinst->u.virt.sched, pinst->trx); /* Only start the scheduler for the transceiver on c0. If we have multiple tranceivers, CCCH is always on C0 and has to be auto active */ /* Other trx are activated via oml by a PRIM_INFO_MODIFY / PRIM_INFO_ACTIVATE */ if (pinst->trx == pinst->trx->bts->c0) { vbts_sched_start(pinst->trx->bts); // init lapdm layer 3 callback for the trx on timeslot 0 == BCCH lchan_init_lapdm(&pinst->trx->ts[0].lchan[CCCH_LCHAN]); /* This is probably the wrong location to set the ccch to active... the oml link def. needs to be reworked and fixed. */ pinst->trx->ts[0].lchan[CCCH_LCHAN].rel_act_kind = LCHAN_REL_ACT_OML; lchan_set_state(&pinst->trx->ts[0].lchan[CCCH_LCHAN], LCHAN_S_ACTIVE); } } /* this will automatically update the MO state of all associated * TRX objects */ phy_link_state_set(plink, PHY_LINK_CONNECTED); return 0; } /* * primitive handling */ /* enable ciphering */ static int l1if_set_ciphering(struct gsm_lchan *lchan, uint8_t chan_nr, int downlink) { struct gsm_bts_trx *trx = lchan->ts->trx; struct phy_instance *pinst = trx_phy_instance(trx); struct l1sched_trx *sched = &pinst->u.virt.sched; /* ciphering already enabled in both directions */ if (lchan->ciph_state == LCHAN_CIPH_RXTX_CONF) return -EINVAL; if (!downlink) { /* set uplink */ trx_sched_set_cipher(sched, chan_nr, 0, lchan->encr.alg_id - 1, lchan->encr.key, lchan->encr.key_len); lchan->ciph_state = LCHAN_CIPH_RX_CONF; } else { /* set downlink and also set uplink, if not already */ if (lchan->ciph_state != LCHAN_CIPH_RX_CONF) { trx_sched_set_cipher(sched, chan_nr, 0, lchan->encr.alg_id - 1, lchan->encr.key, lchan->encr.key_len); } trx_sched_set_cipher(sched, chan_nr, 1, lchan->encr.alg_id - 1, lchan->encr.key, lchan->encr.key_len); lchan->ciph_state = LCHAN_CIPH_RXTX_CONF; } return 0; } static int mph_info_chan_confirm(struct gsm_bts_trx *trx, uint8_t chan_nr, enum osmo_mph_info_type type, uint8_t cause) { struct osmo_phsap_prim l1sap; memset(&l1sap, 0, sizeof(l1sap)); osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_MPH_INFO, PRIM_OP_CONFIRM, NULL); l1sap.u.info.type = type; l1sap.u.info.u.act_cnf.chan_nr = chan_nr; l1sap.u.info.u.act_cnf.cause = cause; return l1sap_up(trx, &l1sap); } int l1if_mph_time_ind(struct gsm_bts *bts, uint32_t fn) { struct osmo_phsap_prim l1sap; memset(&l1sap, 0, sizeof(l1sap)); osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_MPH_INFO, PRIM_OP_INDICATION, NULL); l1sap.u.info.type = PRIM_INFO_TIME; l1sap.u.info.u.time_ind.fn = fn; if (!bts->c0) return -EINVAL; return l1sap_up(bts->c0, &l1sap); } static void l1if_fill_meas_res(struct osmo_phsap_prim *l1sap, uint8_t chan_nr, float ta, float ber, float rssi) { memset(l1sap, 0, sizeof(*l1sap)); osmo_prim_init(&l1sap->oph, SAP_GSM_PH, PRIM_MPH_INFO, PRIM_OP_INDICATION, NULL); l1sap->u.info.type = PRIM_INFO_MEAS; l1sap->u.info.u.meas_ind.chan_nr = chan_nr; l1sap->u.info.u.meas_ind.ta_offs_qbits = (int16_t)(ta * 4); l1sap->u.info.u.meas_ind.ber10k = (unsigned int)(ber * 10000); l1sap->u.info.u.meas_ind.inv_rssi = (uint8_t)(rssi * -1); } int l1if_process_meas_res(struct gsm_bts_trx *trx, uint8_t tn, uint32_t fn, uint8_t chan_nr, int n_errors, int n_bits_total, float rssi, float toa) { struct gsm_lchan *lchan = &trx->ts[tn].lchan[l1sap_chan2ss(chan_nr)]; struct osmo_phsap_prim l1sap; /* 100% BER is n_bits_total is 0 */ float ber = n_bits_total == 0 ? 1.0 : (float)n_errors / (float)n_bits_total; LOGP(DMEAS, LOGL_DEBUG, "RX L1 frame %s fn=%u chan_nr=0x%02x MS pwr=%ddBm rssi=%.1f dBFS " "ber=%.2f%% (%d/%d bits) L1_ta=%d rqd_ta=%d toa=%.2f\n", gsm_lchan_name(lchan), fn, chan_nr, ms_pwr_dbm(lchan->ts->trx->bts->band, lchan->ms_power), rssi, ber * 100, n_errors, n_bits_total, lchan->meas.l1_info[1], lchan->rqd_ta, toa); l1if_fill_meas_res(&l1sap, chan_nr, lchan->rqd_ta + toa, ber, rssi); return l1sap_up(trx, &l1sap); } /* primitive from common part */ int bts_model_l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap) { struct phy_instance *pinst = trx_phy_instance(trx); struct l1sched_trx *sched = &pinst->u.virt.sched; struct msgb *msg = l1sap->oph.msg; uint8_t chan_nr; uint8_t tn, ss; int rc = 0; struct gsm_lchan *lchan; switch (OSMO_PRIM_HDR(&l1sap->oph)) { case OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_REQUEST): if (!msg) break; /* put data into scheduler's queue */ return trx_sched_ph_data_req(sched, l1sap); case OSMO_PRIM(PRIM_TCH, PRIM_OP_REQUEST): if (!msg) break; /* put data into scheduler's queue */ return trx_sched_tch_req(sched, l1sap); case OSMO_PRIM(PRIM_MPH_INFO, PRIM_OP_REQUEST): switch (l1sap->u.info.type) { case PRIM_INFO_ACT_CIPH: chan_nr = l1sap->u.info.u.ciph_req.chan_nr; tn = L1SAP_CHAN2TS(chan_nr); ss = l1sap_chan2ss(chan_nr); lchan = &trx->ts[tn].lchan[ss]; if (l1sap->u.info.u.ciph_req.uplink) l1if_set_ciphering(lchan, chan_nr, 0); if (l1sap->u.info.u.ciph_req.downlink) l1if_set_ciphering(lchan, chan_nr, 1); break; case PRIM_INFO_ACTIVATE: case PRIM_INFO_DEACTIVATE: case PRIM_INFO_MODIFY: chan_nr = l1sap->u.info.u.act_req.chan_nr; tn = L1SAP_CHAN2TS(chan_nr); ss = l1sap_chan2ss(chan_nr); lchan = &trx->ts[tn].lchan[ss]; // we receive a channel activation request from the bsc e.g. as a response to a channel req on rach if (l1sap->u.info.type == PRIM_INFO_ACTIVATE) { if ((chan_nr & 0x80)) { LOGP(DL1C, LOGL_ERROR, "Cannot activate" " chan_nr 0x%02x\n", chan_nr); break; } /* activate dedicated channel */ trx_sched_set_lchan(sched, chan_nr, LID_DEDIC, 1); /* activate associated channel */ trx_sched_set_lchan(sched, chan_nr, LID_SACCH, 1); /* set mode */ trx_sched_set_mode(sched, chan_nr, lchan->rsl_cmode, lchan->tch_mode, lchan->tch.amr_mr.num_modes, lchan->tch.amr_mr.bts_mode[0].mode, lchan->tch.amr_mr.bts_mode[1].mode, lchan->tch.amr_mr.bts_mode[2].mode, lchan->tch.amr_mr.bts_mode[3].mode, amr_get_initial_mode(lchan), (lchan->ho.active == 1)); /* init lapdm */ lchan_init_lapdm(lchan); /* set lchan active */ lchan_set_state(lchan, LCHAN_S_ACTIVE); /* set initial ciphering */ l1if_set_ciphering(lchan, chan_nr, 0); l1if_set_ciphering(lchan, chan_nr, 1); if (lchan->encr.alg_id) lchan->ciph_state = LCHAN_CIPH_RXTX_CONF; else lchan->ciph_state = LCHAN_CIPH_NONE; /* confirm */ mph_info_chan_confirm(trx, chan_nr, PRIM_INFO_ACTIVATE, 0); break; } if (l1sap->u.info.type == PRIM_INFO_MODIFY) { /* change mode */ trx_sched_set_mode(sched, chan_nr, lchan->rsl_cmode, lchan->tch_mode, lchan->tch.amr_mr.num_modes, lchan->tch.amr_mr.bts_mode[0].mode, lchan->tch.amr_mr.bts_mode[1].mode, lchan->tch.amr_mr.bts_mode[2].mode, lchan->tch.amr_mr.bts_mode[3].mode, amr_get_initial_mode(lchan), 0); break; } if ((chan_nr & 0x80)) { LOGP(DL1C, LOGL_ERROR, "Cannot deactivate " "chan_nr 0x%02x\n", chan_nr); break; } /* deactivate associated channel */ trx_sched_set_lchan(sched, chan_nr, 0x40, 0); if (!l1sap->u.info.u.act_req.sacch_only) { /* set lchan inactive */ lchan_set_state(lchan, LCHAN_S_NONE); /* deactivate dedicated channel */ trx_sched_set_lchan(sched, chan_nr, 0x00, 0); /* confirm only on dedicated channel */ mph_info_chan_confirm(trx, chan_nr, PRIM_INFO_DEACTIVATE, 0); lchan->ciph_state = 0; /* FIXME: do this in common/\*.c */ } break; default: LOGP(DL1C, LOGL_NOTICE, "unknown MPH-INFO.req %d\n", l1sap->u.info.type); rc = -EINVAL; goto done; } break; default: LOGP(DL1C, LOGL_NOTICE, "unknown prim %d op %d\n", l1sap->oph.primitive, l1sap->oph.operation); rc = -EINVAL; goto done; } done: if (msg) msgb_free(msg); return rc; }