/* Virtual BTS layer 1 primitive handling and interface * * Copyright (C) 2015-2017 Harald Welte * Copyright (C) 2017 Sebastian Stumpf * * 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 #include #include "virtual_um.h" extern int vbts_sched_start(struct gsm_bts *bts); static struct phy_instance *phy_instance_by_arfcn(struct phy_link *plink, uint16_t arfcn) { struct phy_instance *pinst; llist_for_each_entry(pinst, &plink->instances, list) { if (pinst->trx && pinst->trx->arfcn == arfcn) return pinst; } return NULL; } static 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); /** * 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 phy_link *plink = (struct phy_link *)vui->priv; struct phy_instance *pinst; if (!msg) { pinst = phy_instance_by_num(plink, 0); bts_shutdown(pinst->trx->bts, "VirtPHY read socket died\n"); return; } 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 in dBm */ //uint8_t snr = gh->snr_db; /* signal noise ratio in dB */ 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 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); /* ... or not uplink */ if (!(arfcn & GSMTAP_ARFCN_F_UPLINK)) { LOGPFN(DL1P, LOGL_NOTICE, fn, "Ignoring incoming msg - no uplink flag\n"); goto nomessage; } /* Generally ignore all msgs that are either not received with the right ARFCN... */ pinst = phy_instance_by_arfcn(plink, arfcn & GSMTAP_ARFCN_MASK); if (!pinst) 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; /* TODO: 11bit RACH */ 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; l1sap.u.rach_ind.fn = fn; /* we don't really know which RACH burst type the virtual MS is using, as this field is not * part of information present in the GSMTAP header. So we simply report all of them as 0 */ l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_ACCESS_0; l1sap.u.rach_ind.lqual_cb = 10 * signal_dbm; /* Link quality in centiBel = 10 * dB. */ break; case GSMTAP_CHANNEL_TCH_F: case GSMTAP_CHANNEL_TCH_H: /* This is TCH signalling, for voice frames see GSMTAP_CHANNEL_VOICE */ case GSMTAP_CHANNEL_SDCCH4: case GSMTAP_CHANNEL_SDCCH8: case GSMTAP_CHANNEL_PACCH: case GSMTAP_CHANNEL_PDCH: case GSMTAP_CHANNEL_PTCCH: 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_256bits = 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_BOTH; l1if_process_meas_res(pinst->trx, timeslot, fn, chan_nr, 0, 0, 0, 0); break; case GSMTAP_CHANNEL_VOICE_F: case GSMTAP_CHANNEL_VOICE_H: /* the first byte indicates the type of voice codec (gsmtap_um_voice_type) */ msg->l2h = msgb_pull(msg, 1); osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_INDICATION, msg); l1sap.u.tch.chan_nr = chan_nr; l1sap.u.tch.fn = fn; l1sap.u.tch.rssi = 0; /* Radio Signal Strength Indicator. Best -> 0 */ l1sap.u.tch.ber10k = 0; /* Bit Error Rate in 0.01%. Best -> 0 */ l1sap.u.tch.ta_offs_256bits = 0; /* Burst time of arrival in quarter bits. Probably used for Timing Advance calc. Best -> 0 */ l1sap.u.tch.lqual_cb = 10 * signal_dbm; /* Link quality in centiBel = 10 * dB. */ l1if_process_meas_res(pinst->trx, timeslot, fn, chan_nr, 0, 0, 0, 0); break; case GSMTAP_CHANNEL_AGCH: case GSMTAP_CHANNEL_PCH: case GSMTAP_CHANNEL_BCCH: LOGPFN(DL1P, LOGL_NOTICE, fn, "Ignore incoming msg - channel type downlink only!\n"); goto nomessage; case GSMTAP_CHANNEL_SDCCH: case GSMTAP_CHANNEL_CCCH: case GSMTAP_CHANNEL_CBCH51: case GSMTAP_CHANNEL_CBCH52: LOGPFN(DL1P, LOGL_NOTICE, fn, "Ignore incoming msg - channel type not supported!\n"); goto nomessage; default: LOGPFN(DL1P, LOGL_NOTICE, fn, "Ignore incoming msg - channel type unknown\n"); goto nomessage; } /* forward primitive, lsap takes ownership of the msgb. */ l1sap_up(pinst->trx, &l1sap); DEBUGPFN(DL1P, fn, "Message forwarded to layer 2.\n"); return; nomessage: talloc_free(msg); } /* called by common part once OML link is established */ int bts_model_oml_estab(struct gsm_bts *bts) { struct phy_instance *pinst = trx_phy_instance(bts->c0); if (vbts_sched_start(pinst->trx->bts) < 0) return -ENOLINK; 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); 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, plink->u.virt.ttl, plink->u.virt.mcast_dev, virt_um_rcv_cb); if (!plink->u.virt.virt_um) { phy_link_state_set(plink, PHY_LINK_SHUTDOWN); return -1; } /* set back reference to plink */ plink->u.virt.virt_um->priv = plink; /* iterate over list of PHY instances and initialize the scheduler */ llist_for_each_entry(pinst, &plink->instances, list) { if (pinst->trx == NULL) continue; trx_sched_init(pinst->trx); } /* 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) { /* ciphering already enabled in both directions */ if (lchan->ciph_state == LCHAN_CIPH_RXTX_CONF) return -EINVAL; if (!downlink) { /* set uplink */ trx_sched_set_cipher(lchan, chan_nr, false); 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(lchan, chan_nr, false); trx_sched_set_cipher(lchan, chan_nr, true); 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, uint32_t fn) { 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_256bits = (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); l1sap->u.info.u.meas_ind.fn = fn; } static 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; LOGPLCFN(lchan, fn, DMEAS, LOGL_DEBUG, "RX L1 frame chan_nr=0x%02x MS pwr=%ddBm rssi=%.1f dBFS " "ber=%.2f%% (%d/%d bits) L1_ta=%d ta_ctrl.current=%d toa=%.2f\n", chan_nr, ms_pwr_dbm(lchan->ts->trx->bts->band, lchan->ms_power_ctrl.max), rssi, ber * 100, n_errors, n_bits_total, lchan->meas.l1_info.ta, lchan->ta_ctrl.current, toa); l1if_fill_meas_res(&l1sap, chan_nr, lchan->ta_ctrl.current + toa, ber, rssi, fn); 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 msgb *msg = l1sap->oph.msg; uint8_t chan_nr; 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(trx, l1sap); case OSMO_PRIM(PRIM_TCH, PRIM_OP_REQUEST): if (!msg) break; /* put data into scheduler's queue */ return trx_sched_tch_req(trx, l1sap); case OSMO_PRIM(PRIM_MPH_INFO, PRIM_OP_REQUEST): if (l1sap->u.info.type == PRIM_INFO_ACT_CIPH) chan_nr = l1sap->u.info.u.ciph_req.chan_nr; else /* u.act_req used by PRIM_INFO_{ACTIVATE,DEACTIVATE,MODIFY} */ chan_nr = l1sap->u.info.u.act_req.chan_nr; lchan = get_lchan_by_chan_nr(trx, chan_nr); if (OSMO_UNLIKELY(lchan == NULL)) { LOGP(DL1C, LOGL_ERROR, "Rx MPH-INFO.req (type=0x%02x) for non-existent lchan (%s)\n", l1sap->u.info.type, rsl_chan_nr_str(chan_nr)); rc = -ENODEV; break; } switch (l1sap->u.info.type) { case PRIM_INFO_ACT_CIPH: 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: if ((chan_nr & 0xE0) == 0x80) { LOGPLCHAN(lchan, DL1C, LOGL_ERROR, "Cannot activate" " channel %s\n", rsl_chan_nr_str(chan_nr)); rc = -EPERM; break; } /* activate dedicated channel */ trx_sched_set_lchan(lchan, chan_nr, LID_DEDIC, true); /* activate associated channel */ trx_sched_set_lchan(lchan, chan_nr, LID_SACCH, true); /* set mode */ trx_sched_set_mode(lchan->ts, chan_nr, lchan->rsl_cmode, lchan->tch_mode, lchan->tch.amr_mr.num_modes, lchan->tch.amr_mr.mode[0].mode, lchan->tch.amr_mr.mode[1].mode, lchan->tch.amr_mr.mode[2].mode, lchan->tch.amr_mr.mode[3].mode, amr_get_initial_mode(lchan), (lchan->ho.active == HANDOVER_ENABLED || rsl_chan_rt_is_asci(lchan->rsl_chan_rt))); /* 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; case PRIM_INFO_MODIFY: /* change mode */ trx_sched_set_mode(lchan->ts, chan_nr, lchan->rsl_cmode, lchan->tch_mode, lchan->tch.amr_mr.num_modes, lchan->tch.amr_mr.mode[0].mode, lchan->tch.amr_mr.mode[1].mode, lchan->tch.amr_mr.mode[2].mode, lchan->tch.amr_mr.mode[3].mode, amr_get_initial_mode(lchan), 0); break; case PRIM_INFO_DEACTIVATE: if ((chan_nr & 0xE0) == 0x80) { LOGPLCHAN(lchan, DL1C, LOGL_ERROR, "Cannot deactivate" " channel %s\n", rsl_chan_nr_str(chan_nr)); rc = -EPERM; break; } /* deactivate associated channel */ trx_sched_set_lchan(lchan, chan_nr, LID_SACCH, false); 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(lchan, chan_nr, LID_DEDIC, false); /* 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; }