diff options
Diffstat (limited to 'src/common/l1sap.c')
| -rw-r--r-- | src/common/l1sap.c | 1082 |
1 files changed, 1082 insertions, 0 deletions
diff --git a/src/common/l1sap.c b/src/common/l1sap.c new file mode 100644 index 00000000..1cb752e3 --- /dev/null +++ b/src/common/l1sap.c @@ -0,0 +1,1082 @@ +/* L1 SAP primitives */ + +/* (C) 2011 by Harald Welte <laforge@gnumonks.org> + * (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> + * + * 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 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 <http://www.gnu.org/licenses/>. + * + */ + +#include <stdint.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> + +#include <sys/types.h> +#include <sys/stat.h> + +#include <osmocom/core/msgb.h> +#include <osmocom/gsm/l1sap.h> +#include <osmocom/core/gsmtap.h> +#include <osmocom/core/gsmtap_util.h> +#include <osmocom/core/utils.h> + +#include <osmocom/trau/osmo_ortp.h> + +#include <osmo-bts/logging.h> +#include <osmo-bts/gsm_data.h> +#include <osmo-bts/l1sap.h> +#include <osmo-bts/pcu_if.h> +#include <osmo-bts/measurement.h> +#include <osmo-bts/bts.h> +#include <osmo-bts/rsl.h> +#include <osmo-bts/bts_model.h> +#include <osmo-bts/handover.h> + +static int l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap); + +static const uint8_t fill_frame[GSM_MACBLOCK_LEN] = { + 0x03, 0x03, 0x01, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, + 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, 0x2B, + 0x2B, 0x2B, 0x2B +}; + +/* allocate a msgb containing a osmo_phsap_prim + optional l2 data + * in order to wrap femtobts header arround l2 data, there must be enough space + * in front and behind data pointer */ +struct msgb *l1sap_msgb_alloc(unsigned int l2_len) +{ + struct msgb *msg = msgb_alloc_headroom(512, 128, "l1sap_prim"); + + if (!msg) + return NULL; + + msg->l1h = msgb_put(msg, sizeof(struct osmo_phsap_prim)); + + return msg; +} + +static int l1sap_tx_ciph_req(struct gsm_bts_trx *trx, uint8_t chan_nr, + uint8_t downlink, uint8_t uplink) +{ + struct osmo_phsap_prim l1sap_ciph; + + osmo_prim_init(&l1sap_ciph.oph, SAP_GSM_PH, PRIM_MPH_INFO, + PRIM_OP_REQUEST, NULL); + l1sap_ciph.u.info.type = PRIM_INFO_ACT_CIPH; + l1sap_ciph.u.info.u.ciph_req.chan_nr = chan_nr; + l1sap_ciph.u.info.u.ciph_req.downlink = downlink; + l1sap_ciph.u.info.u.ciph_req.uplink = uplink; + + return l1sap_down(trx, &l1sap_ciph); +} + + +/* check if the message is a GSM48_MT_RR_CIPH_M_CMD, and if yes, enable + * uni-directional de-cryption on the uplink. We need this ugly layering + * violation as we have no way of passing down L3 metadata (RSL CIPHERING CMD) + * to this point in L1 */ +static int check_for_ciph_cmd(struct msgb *msg, struct gsm_lchan *lchan, + uint8_t chan_nr) +{ + + /* only do this if we are in the right state */ + switch (lchan->ciph_state) { + case LCHAN_CIPH_NONE: + break; + default: + return 0; + } + + /* First byte (Address Field) of LAPDm header) */ + if (msg->data[0] != 0x03) + return 0; + /* First byte (protocol discriminator) of RR */ + if ((msg->data[3] & 0xF) != GSM48_PDISC_RR) + return 0; + /* 2nd byte (msg type) of RR */ + if ((msg->data[4] & 0x3F) != GSM48_MT_RR_CIPH_M_CMD) + return 0; + + l1sap_tx_ciph_req(lchan->ts->trx, chan_nr, 0, 1); + + return 1; +} + +struct gsmtap_inst *gsmtap = NULL; +uint32_t gsmtap_sapi_mask = 0; +uint8_t gsmtap_sapi_acch = 0; + +const struct value_string gsmtap_sapi_names[] = { + { GSMTAP_CHANNEL_BCCH, "BCCH" }, + { GSMTAP_CHANNEL_CCCH, "CCCH" }, + { GSMTAP_CHANNEL_RACH, "RACH" }, + { GSMTAP_CHANNEL_AGCH, "AGCH" }, + { GSMTAP_CHANNEL_PCH, "PCH" }, + { GSMTAP_CHANNEL_SDCCH, "SDCCH" }, + { GSMTAP_CHANNEL_TCH_F, "TCH/F" }, + { GSMTAP_CHANNEL_TCH_H, "TCH/H" }, + { GSMTAP_CHANNEL_PACCH, "PACCH" }, + { GSMTAP_CHANNEL_PDCH, "PDTCH" }, + { GSMTAP_CHANNEL_PTCCH, "PTCCH" }, + { GSMTAP_CHANNEL_CBCH51,"CBCH" }, + { GSMTAP_CHANNEL_ACCH, "SACCH" }, + { 0, NULL } +}; + +/* send primitive as gsmtap */ +static int gsmtap_ph_data(struct osmo_phsap_prim *l1sap, uint8_t *chan_type, + uint8_t *tn, uint8_t *ss, uint32_t *fn, uint8_t **data, int *len) +{ + struct msgb *msg = l1sap->oph.msg; + uint8_t chan_nr, link_id; + + *data = msg->data + sizeof(struct osmo_phsap_prim); + *len = msg->len - sizeof(struct osmo_phsap_prim); + *fn = l1sap->u.data.fn; + *tn = L1SAP_CHAN2TS(l1sap->u.data.chan_nr); + chan_nr = l1sap->u.data.chan_nr; + link_id = l1sap->u.data.link_id; + + if (L1SAP_IS_CHAN_TCHF(chan_nr)) { + *chan_type = GSMTAP_CHANNEL_TCH_F; + } else if (L1SAP_IS_CHAN_TCHH(chan_nr)) { + *ss = L1SAP_CHAN2SS_TCHH(chan_nr); + *chan_type = GSMTAP_CHANNEL_TCH_H; + } else if (L1SAP_IS_CHAN_SDCCH4(chan_nr)) { + *ss = L1SAP_CHAN2SS_SDCCH4(chan_nr); + *chan_type = GSMTAP_CHANNEL_SDCCH; + } else if (L1SAP_IS_CHAN_SDCCH8(chan_nr)) { + *ss = L1SAP_CHAN2SS_SDCCH8(chan_nr); + *chan_type = GSMTAP_CHANNEL_SDCCH; + } else if (L1SAP_IS_CHAN_BCCH(chan_nr)) { + *chan_type = GSMTAP_CHANNEL_BCCH; + } else if (L1SAP_IS_CHAN_AGCH_PCH(chan_nr)) { +#warning Set BS_AG_BLKS_RES + /* The sapi depends on DSP configuration, not + * on the actual SYSTEM INFORMATION 3. */ + if (L1SAP_FN2CCCHBLOCK(*fn) >= 1) + *chan_type = GSMTAP_CHANNEL_PCH; + else + *chan_type = GSMTAP_CHANNEL_AGCH; + } + if (L1SAP_IS_LINK_SACCH(link_id)) + *chan_type |= GSMTAP_CHANNEL_ACCH; + + return 0; +} + +static int gsmtap_pdch(struct osmo_phsap_prim *l1sap, uint8_t *chan_type, + uint8_t *tn, uint8_t *ss, uint32_t *fn, uint8_t **data, int *len) +{ + struct msgb *msg = l1sap->oph.msg; + + *data = msg->data + sizeof(struct osmo_phsap_prim); + *len = msg->len - sizeof(struct osmo_phsap_prim); + *fn = l1sap->u.data.fn; + *tn = L1SAP_CHAN2TS(l1sap->u.data.chan_nr); + + if (L1SAP_IS_PTCCH(*fn)) { + *chan_type = GSMTAP_CHANNEL_PTCCH; + *ss = L1SAP_FN2PTCCHBLOCK(*fn); + if (l1sap->oph.primitive + == PRIM_OP_INDICATION) { + if ((*data[0]) == 7) + return -EINVAL; + (*data)++; + (*len)--; + } + } else + *chan_type = GSMTAP_CHANNEL_PACCH; + + return 0; +} + +static int gsmtap_ph_rach(struct osmo_phsap_prim *l1sap, uint8_t *chan_type, + uint8_t *tn, uint8_t *ss, uint32_t *fn, uint8_t **data, int *len) +{ + uint8_t chan_nr; + + *chan_type = GSMTAP_CHANNEL_RACH; + *fn = l1sap->u.rach_ind.fn; + *tn = L1SAP_CHAN2TS(l1sap->u.rach_ind.chan_nr); + chan_nr = l1sap->u.rach_ind.chan_nr; + if (L1SAP_IS_CHAN_TCHH(chan_nr)) + *ss = L1SAP_CHAN2SS_TCHH(chan_nr); + else if (L1SAP_IS_CHAN_SDCCH4(chan_nr)) + *ss = L1SAP_CHAN2SS_SDCCH4(chan_nr); + else if (L1SAP_IS_CHAN_SDCCH8(chan_nr)) + *ss = L1SAP_CHAN2SS_SDCCH8(chan_nr); + *data = &l1sap->u.rach_ind.ra; + *len = 1; + + return 0; +} + +static int to_gsmtap(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap) +{ + uint8_t *data; + int len; + uint8_t chan_type = 0, tn = 0, ss = 0; + uint32_t fn; + uint16_t uplink = GSMTAP_ARFCN_F_UPLINK; + int rc; + + if (!gsmtap) + return 0; + + switch (OSMO_PRIM_HDR(&l1sap->oph)) { + case OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_REQUEST): + uplink = 0; + /* fall through */ + case OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_INDICATION): + if (trx->ts[tn].pchan == GSM_PCHAN_PDCH) + rc = gsmtap_pdch(l1sap, &chan_type, &tn, &ss, &fn, &data, + &len); + else + rc = gsmtap_ph_data(l1sap, &chan_type, &tn, &ss, &fn, + &data, &len); + break; + case OSMO_PRIM(PRIM_PH_RACH, PRIM_OP_INDICATION): + rc = gsmtap_ph_rach(l1sap, &chan_type, &tn, &ss, &fn, &data, + &len); + break; + default: + rc = -ENOTSUP; + } + + if (rc) + return rc; + + if (len == 0) + return 0; + if ((chan_type & GSMTAP_CHANNEL_ACCH)) { + if (!gsmtap_sapi_acch) + return 0; + } else { + if (!((1 << (chan_type & 31)) & gsmtap_sapi_mask)) + return 0; + } + + gsmtap_send(gsmtap, trx->arfcn | uplink, tn, chan_type, ss, fn, 0, 0, + data, len); + + return 0; +} + +/* time information received from bts model */ +static int l1sap_info_time_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, + struct info_time_ind_param *info_time_ind) +{ + struct gsm_bts *bts = trx->bts; + struct gsm_bts_role_bts *btsb = bts->role; + + int frames_expired = info_time_ind->fn - btsb->gsm_time.fn; + + DEBUGP(DL1P, "MPH_INFO time ind %u\n", info_time_ind->fn); + + /* Update our data structures with the current GSM time */ + gsm_fn2gsmtime(&btsb->gsm_time, info_time_ind->fn); + + /* Update time on PCU interface */ + pcu_tx_time_ind(info_time_ind->fn); + + /* check if the measurement period of some lchan has ended + * and pre-compute the respective measurement */ + trx_meas_check_compute(trx, info_time_ind->fn - 1); + + /* increment number of RACH slots that have passed by since the + * last time indication */ + if (trx == bts->c0) { + unsigned int num_rach_per_frame; + /* 27 / 51 taken from TS 05.01 Figure 3 */ + if (bts->c0->ts[0].pchan == GSM_PCHAN_CCCH_SDCCH4) + num_rach_per_frame = 27; + else + num_rach_per_frame = 51; + + btsb->load.rach.total += frames_expired * num_rach_per_frame; + } + + return 0; +} + +/* measurement information received from bts model */ +static int l1sap_info_meas_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, + struct info_meas_ind_param *info_meas_ind) +{ + struct bts_ul_meas ulm; + struct gsm_lchan *lchan; + + DEBUGP(DL1P, "MPH_INFO meas ind chan_nr=%02x\n", + info_meas_ind->chan_nr); + + lchan = &trx->ts[L1SAP_CHAN2TS(info_meas_ind->chan_nr)] + .lchan[l1sap_chan2ss(info_meas_ind->chan_nr)]; + + /* in the GPRS case we are not interested in measurement + * processing. The PCU will take care of it */ + if (lchan->type == GSM_LCHAN_PDTCH) + return 0; + + memset(&ulm, 0, sizeof(ulm)); + ulm.ta_offs_qbits = info_meas_ind->ta_offs_qbits; + ulm.ber10k = info_meas_ind->ber10k; + ulm.inv_rssi = info_meas_ind->inv_rssi; + + lchan_new_ul_meas(lchan, &ulm); + + return 0; +} + +/* any L1 MPH_INFO indication prim recevied from bts model */ +static int l1sap_mph_info_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct mph_info_param *info) +{ + int rc = 0; + + switch (info->type) { + case PRIM_INFO_TIME: + rc = l1sap_info_time_ind(trx, l1sap, &info->u.time_ind); + break; + case PRIM_INFO_MEAS: + rc = l1sap_info_meas_ind(trx, l1sap, &info->u.meas_ind); + break; + default: + LOGP(DL1P, LOGL_NOTICE, "unknown MPH_INFO ind type %d\n", + info->type); + break; + } + + return rc; +} + +/* activation confirm received from bts model */ +static int l1sap_info_act_cnf(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, + struct info_act_cnf_param *info_act_cnf) +{ + struct gsm_lchan *lchan; + + LOGP(DL1P, LOGL_INFO, "activate confirm chan_nr=%02x trx=%d\n", + info_act_cnf->chan_nr, trx->nr); + + lchan = &trx->ts[L1SAP_CHAN2TS(info_act_cnf->chan_nr)] + .lchan[l1sap_chan2ss(info_act_cnf->chan_nr)]; + + if (info_act_cnf->cause) + rsl_tx_chan_act_nack(lchan, info_act_cnf->cause); + else + rsl_tx_chan_act_ack(lchan); + + return 0; +} + +/* activation confirm received from bts model */ +static int l1sap_info_rel_cnf(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, + struct info_act_cnf_param *info_act_cnf) +{ + struct gsm_lchan *lchan; + + LOGP(DL1P, LOGL_INFO, "deactivate confirm chan_nr=%02x trx=%d\n", + info_act_cnf->chan_nr, trx->nr); + + lchan = &trx->ts[L1SAP_CHAN2TS(info_act_cnf->chan_nr)] + .lchan[l1sap_chan2ss(info_act_cnf->chan_nr)]; + + rsl_tx_rf_rel_ack(lchan); + + return 0; +} + +/* any L1 MPH_INFO confirm prim recevied from bts model */ +static int l1sap_mph_info_cnf(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct mph_info_param *info) +{ + int rc = 0; + + switch (info->type) { + case PRIM_INFO_ACTIVATE: + rc = l1sap_info_act_cnf(trx, l1sap, &info->u.act_cnf); + break; + case PRIM_INFO_DEACTIVATE: + rc = l1sap_info_rel_cnf(trx, l1sap, &info->u.act_cnf); + break; + default: + LOGP(DL1P, LOGL_NOTICE, "unknown MPH_INFO cnf type %d\n", + info->type); + break; + } + + return rc; +} + +/* PH-RTS-IND prim recevied from bts model */ +static int l1sap_ph_rts_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct ph_data_param *rts_ind) +{ + struct msgb *msg = l1sap->oph.msg; + struct gsm_time g_time; + struct gsm_lchan *lchan; + uint8_t chan_nr, link_id; + uint8_t tn, ss; + uint32_t fn; + uint8_t *p, *si; + struct lapdm_entity *le; + struct osmo_phsap_prim pp; + int rc; + + chan_nr = rts_ind->chan_nr; + link_id = rts_ind->link_id; + fn = rts_ind->fn; + tn = L1SAP_CHAN2TS(chan_nr); + + gsm_fn2gsmtime(&g_time, fn); + + DEBUGP(DL1P, "Rx PH-RTS.ind %02u/%02u/%02u chan_nr=%d link_id=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr, link_id); + + if (trx->ts[tn].pchan == GSM_PCHAN_PDCH) { + if (L1SAP_IS_PTCCH(rts_ind->fn)) { + pcu_tx_rts_req(&trx->ts[tn], 1, fn, 1 /* ARFCN */, + L1SAP_FN2PTCCHBLOCK(fn)); + + return 0; + } + pcu_tx_rts_req(&trx->ts[tn], 0, fn, 0 /* ARFCN */, + L1SAP_FN2MACBLOCK(fn)); + + return 0; + } + + /* reuse PH-RTS.ind for PH-DATA.req */ + if (!msg) { + LOGP(DL1P, LOGL_FATAL, "RTS without msg to be reused. Please " + "fix!\n"); + abort(); + } + msgb_trim(msg, sizeof(*l1sap)); + osmo_prim_init(&l1sap->oph, SAP_GSM_PH, PRIM_PH_DATA, PRIM_OP_REQUEST, + msg); + msg->l2h = msg->l1h + sizeof(*l1sap); + + if (L1SAP_IS_CHAN_BCCH(chan_nr)) { + p = msgb_put(msg, GSM_MACBLOCK_LEN); + /* get them from bts->si_buf[] */ + si = bts_sysinfo_get(trx->bts, &g_time); + if (si) + memcpy(p, si, GSM_MACBLOCK_LEN); + else + memcpy(p, fill_frame, GSM_MACBLOCK_LEN); + } else if (!(chan_nr & 0x80)) { /* only TCH/F, TCH/H, SDCCH/4 and SDCCH/8 have C5 bit cleared */ + if (L1SAP_IS_CHAN_TCHH(chan_nr)) + ss = L1SAP_CHAN2SS_TCHH(chan_nr); /* TCH/H */ + else if (L1SAP_IS_CHAN_SDCCH4(chan_nr)) + ss = L1SAP_CHAN2SS_SDCCH4(chan_nr); /* SDCCH/4 */ + else if (L1SAP_IS_CHAN_SDCCH8(chan_nr)) + ss = L1SAP_CHAN2SS_SDCCH8(chan_nr); /* SDCCH/8 */ + else + ss = 0; /* TCH/F */ + lchan = &trx->ts[tn].lchan[ss]; + if (L1SAP_IS_LINK_SACCH(link_id)) { + p = msgb_put(msg, GSM_MACBLOCK_LEN); + /* L1-header, if not set/modified by layer 1 */ + p[0] = lchan->ms_power_ctrl.current; + p[1] = lchan->rqd_ta; + le = &lchan->lapdm_ch.lapdm_acch; + } else + le = &lchan->lapdm_ch.lapdm_dcch; + rc = lapdm_phsap_dequeue_prim(le, &pp); + if (rc < 0) { + if (L1SAP_IS_LINK_SACCH(link_id)) { + /* No SACCH data from LAPDM pending, send SACCH filling */ + uint8_t *si = lchan_sacch_get(lchan); + if (si) { + /* The +2 is empty space where the DSP inserts the L1 hdr */ + memcpy(p + 2, si, GSM_MACBLOCK_LEN - 2); + } else + memcpy(p + 2, fill_frame, GSM_MACBLOCK_LEN - 2); + } else if ((!L1SAP_IS_CHAN_TCHF(chan_nr) && !L1SAP_IS_CHAN_TCHH(chan_nr)) + || lchan->rsl_cmode == RSL_CMOD_SPD_SIGN) { + /* send fill frame only, if not TCH/x != Signalling, otherwise send empty frame */ + p = msgb_put(msg, GSM_MACBLOCK_LEN); + memcpy(p, fill_frame, GSM_MACBLOCK_LEN); + } /* else the message remains empty, so TCH frames are sent */ + } else { + /* The +2 is empty space where the DSP inserts the L1 hdr */ + if (L1SAP_IS_LINK_SACCH(link_id)) + memcpy(p + 2, pp.oph.msg->data + 2, GSM_MACBLOCK_LEN - 2); + else { + p = msgb_put(msg, GSM_MACBLOCK_LEN); + memcpy(p, pp.oph.msg->data, GSM_MACBLOCK_LEN); + /* check if it is a RR CIPH MODE CMD. if yes, enable RX ciphering */ + check_for_ciph_cmd(pp.oph.msg, lchan, chan_nr); + } + msgb_free(pp.oph.msg); + } + } else if (L1SAP_IS_CHAN_AGCH_PCH(chan_nr)) { + p = msgb_put(msg, GSM_MACBLOCK_LEN); +#warning "TODO: Yet another assumption that BS_AG_BLKS_RES=1" + /* if CCCH block is 0, it is AGCH */ + rc = bts_ccch_copy_msg(trx->bts, p, &g_time, + (L1SAP_FN2CCCHBLOCK(fn) < 1)); + if (rc <= 0) + memcpy(p, fill_frame, GSM_MACBLOCK_LEN); + } + + DEBUGP(DL1P, "Tx PH-DATA.req %02u/%02u/%02u chan_nr=%d link_id=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr, link_id); + + l1sap_down(trx, l1sap); + + /* don't free, because we forwarded data */ + return 1; +} + +static int check_acc_delay(struct ph_rach_ind_param *rach_ind, + struct gsm_bts_role_bts *btsb, uint8_t *acc_delay) +{ + *acc_delay = rach_ind->acc_delay; + return *acc_delay <= btsb->max_ta; +} + +/* special case where handover RACH is detected */ +static int l1sap_handover_rach(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct ph_rach_ind_param *rach_ind) +{ + struct gsm_lchan *lchan; + uint8_t chan_nr; + uint8_t tn, ss; + + chan_nr = rach_ind->chan_nr; + tn = L1SAP_CHAN2TS(chan_nr); + ss = l1sap_chan2ss(chan_nr); + lchan = &trx->ts[tn].lchan[ss]; + + handover_rach(lchan, rach_ind->ra, rach_ind->acc_delay); + + /* must return 0, so in case of msg at l1sap, it will be freed */ + return 0; +} + +/* TCH-RTS-IND prim recevied from bts model */ +static int l1sap_tch_rts_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct ph_tch_param *rts_ind) +{ + struct msgb *resp_msg; + struct osmo_phsap_prim *resp_l1sap, empty_l1sap; + struct gsm_time g_time; + struct gsm_lchan *lchan; + uint8_t chan_nr; + uint8_t tn, ss; + uint32_t fn; + + chan_nr = rts_ind->chan_nr; + fn = rts_ind->fn; + tn = L1SAP_CHAN2TS(chan_nr); + + gsm_fn2gsmtime(&g_time, fn); + + DEBUGP(DL1P, "Rx TCH-RTS.ind %02u/%02u/%02u chan_nr=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr); + + /* get timeslot and subslot */ + tn = L1SAP_CHAN2TS(chan_nr); + if (L1SAP_IS_CHAN_TCHH(chan_nr)) + ss = L1SAP_CHAN2SS_TCHH(chan_nr); /* TCH/H */ + else + ss = 0; /* TCH/F */ + lchan = &trx->ts[tn].lchan[ss]; + + if (!lchan->loopback && lchan->abis_ip.rtp_socket) { + osmo_rtp_socket_poll(lchan->abis_ip.rtp_socket); + /* FIXME: we _assume_ that we never miss TDMA + * frames and that we always get to this point + * for every to-be-transmitted voice frame. A + * better solution would be to compute + * rx_user_ts based on how many TDMA frames have + * elapsed since the last call */ + lchan->abis_ip.rtp_socket->rx_user_ts += GSM_RTP_DURATION; + } + /* get a msgb from the dl_tx_queue */ + resp_msg = msgb_dequeue(&lchan->dl_tch_queue); + if (!resp_msg) { + LOGP(DL1P, LOGL_DEBUG, "%s DL TCH Tx queue underrun\n", + gsm_lchan_name(lchan)); + resp_l1sap = &empty_l1sap; + } else { + resp_msg->l2h = resp_msg->data; + msgb_push(resp_msg, sizeof(*resp_l1sap)); + resp_msg->l1h = resp_msg->data; + resp_l1sap = msgb_l1sap_prim(resp_msg); + } + + memset(resp_l1sap, 0, sizeof(*resp_l1sap)); + osmo_prim_init(&resp_l1sap->oph, SAP_GSM_PH, PRIM_TCH, PRIM_OP_REQUEST, + resp_msg); + resp_l1sap->u.tch.chan_nr = chan_nr; + resp_l1sap->u.tch.fn = fn; + + DEBUGP(DL1P, "Tx TCH.req %02u/%02u/%02u chan_nr=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr); + + l1sap_down(trx, resp_l1sap); + + return 0; +} + +/* process radio link timeout counter S */ +static void radio_link_timeout(struct gsm_lchan *lchan, int bad_frame) +{ + struct gsm_bts_role_bts *btsb = lchan->ts->trx->bts->role; + + /* if link loss criterion already reached */ + if (lchan->s == 0) { + DEBUGP(DMEAS, "%s radio link counter S already 0.\n", + gsm_lchan_name(lchan)); + return; + } + + if (bad_frame) { + /* count down radio link counter S */ + lchan->s--; + DEBUGP(DMEAS, "%s counting down radio link counter S=%d\n", + gsm_lchan_name(lchan), lchan->s); + if (lchan->s == 0) + rsl_tx_conn_fail(lchan, RSL_ERR_RADIO_LINK_FAIL); + return; + } + + if (lchan->s < btsb->radio_link_timeout) { + /* count up radio link counter S */ + lchan->s += 2; + if (lchan->s > btsb->radio_link_timeout) + lchan->s = btsb->radio_link_timeout; + DEBUGP(DMEAS, "%s counting up radio link counter S=%d\n", + gsm_lchan_name(lchan), lchan->s); + } +} + +static inline int check_for_first_ciphrd(struct gsm_lchan *lchan, + uint8_t *data, int len) +{ + uint8_t n_s; + + /* if this is the first valid message after enabling Rx + * decryption, we have to enable Tx encryption */ + if (lchan->ciph_state != LCHAN_CIPH_RX_CONF) + return 0; + + /* HACK: check if it's an I frame, in order to + * ignore some still buffered/queued UI frames received + * before decryption was enabled */ + if (data[0] != 0x01) + return 0; + + if ((data[1] & 0x01) != 0) + return 0; + + n_s = data[1] >> 5; + if (lchan->ciph_ns != n_s) + return 0; + + return 1; +} + +/* public helper for the test */ +int bts_check_for_first_ciphrd(struct gsm_lchan *lchan, + uint8_t *data, int len) +{ + return check_for_first_ciphrd(lchan, data, len); +} + +/* DATA received from bts model */ +static int l1sap_ph_data_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct ph_data_param *data_ind) +{ + struct msgb *msg = l1sap->oph.msg; + struct gsm_time g_time; + struct gsm_lchan *lchan; + struct lapdm_entity *le; + uint8_t *data = msg->l2h; + int len = msgb_l2len(msg); + uint8_t chan_nr, link_id; + uint8_t tn, ss; + uint32_t fn; + int8_t rssi; + + rssi = data_ind->rssi; + chan_nr = data_ind->chan_nr; + link_id = data_ind->link_id; + fn = data_ind->fn; + tn = L1SAP_CHAN2TS(chan_nr); + ss = l1sap_chan2ss(chan_nr); + + gsm_fn2gsmtime(&g_time, fn); + + DEBUGP(DL1P, "Rx PH-DATA.ind %02u/%02u/%02u chan_nr=%d link_id=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr, link_id); + + if (trx->ts[tn].pchan == GSM_PCHAN_PDCH) { + if (len == 0) + return -EINVAL; + if (L1SAP_IS_PTCCH(fn)) { + pcu_tx_data_ind(&trx->ts[tn], 1, fn, + 0 /* ARFCN */, L1SAP_FN2PTCCHBLOCK(fn), + data, len, rssi); + + return 0; + } + /* drop incomplete UL block */ + if (data[0] != 7) + return 0; + /* PDTCH / PACCH frame handling */ + pcu_tx_data_ind(&trx->ts[tn], 0, fn, 0 /* ARFCN */, + L1SAP_FN2MACBLOCK(fn), data + 1, len - 1, rssi); + + return 0; + } + + lchan = &trx->ts[tn].lchan[ss]; + + /* bad frame */ + if (len == 0) { + if (L1SAP_IS_LINK_SACCH(link_id)) + radio_link_timeout(lchan, 1); + return -EINVAL; + } + + /* report first valid received frame to handover process */ + if (lchan->ho.active == HANDOVER_WAIT_FRAME) + handover_frame(lchan); + + if (L1SAP_IS_LINK_SACCH(link_id)) { + radio_link_timeout(lchan, 0); + le = &lchan->lapdm_ch.lapdm_acch; + /* save the SACCH L1 header in the lchan struct for RSL MEAS RES */ + if (len < 2) { + LOGP(DL1P, LOGL_NOTICE, "SACCH with size %u<2 !?!\n", + len); + return -EINVAL; + } + /* Some brilliant engineer decided that the ordering of + * fields on the Um interface is different from the + * order of fields in RLS. See TS 04.04 (Chapter 7.2) + * vs. TS 08.58 (Chapter 9.3.10). */ + lchan->meas.l1_info[0] = data[0] << 3; + lchan->meas.l1_info[0] |= ((data[0] >> 5) & 1) << 2; + lchan->meas.l1_info[1] = data[1]; + lchan->meas.flags |= LC_UL_M_F_L1_VALID; + + lchan_ms_pwr_ctrl(lchan, data[0] & 0x1f, data_ind->rssi); + } else + le = &lchan->lapdm_ch.lapdm_dcch; + + if (check_for_first_ciphrd(lchan, data, len)) + l1sap_tx_ciph_req(lchan->ts->trx, chan_nr, 1, 0); + + /* SDCCH, SACCH and FACCH all go to LAPDm */ + msgb_pull(msg, (msg->l2h - msg->data)); + msg->l1h = NULL; + lapdm_phsap_up(&l1sap->oph, le); + + /* don't free, because we forwarded data */ + return 1; +} + +/* TCH received from bts model */ +static int l1sap_tch_ind(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap, + struct ph_tch_param *tch_ind) +{ + struct msgb *msg = l1sap->oph.msg; + struct gsm_time g_time; + struct gsm_lchan *lchan; + uint8_t tn, ss, chan_nr; + uint32_t fn; + + chan_nr = tch_ind->chan_nr; + fn = tch_ind->fn; + tn = L1SAP_CHAN2TS(chan_nr); + if (L1SAP_IS_CHAN_TCHH(chan_nr)) + ss = L1SAP_CHAN2SS_TCHH(chan_nr); + else + ss = 0; + lchan = &trx->ts[tn].lchan[ss]; + + gsm_fn2gsmtime(&g_time, fn); + + DEBUGP(DL1P, "Rx TCH.ind %02u/%02u/%02u chan_nr=%d\n", + g_time.t1, g_time.t2, g_time.t3, chan_nr); + + msgb_pull(msg, sizeof(*l1sap)); + + /* hand msg to RTP code for transmission */ + if (lchan->abis_ip.rtp_socket) + osmo_rtp_send_frame(lchan->abis_ip.rtp_socket, + msg->data, msg->len, 160); + + /* if loopback is enabled, also queue received RTP data */ + if (lchan->loopback) { + struct msgb *tmp; + int count = 0; + + /* make sure the queue doesn't get too long */ + llist_for_each_entry(tmp, &lchan->dl_tch_queue, list) + count++; + while (count >= 1) { + tmp = msgb_dequeue(&lchan->dl_tch_queue); + msgb_free(tmp); + count--; + } + + msgb_enqueue(&lchan->dl_tch_queue, msg); + } + + return 0; +} + +/* RACH received from bts model */ +static int l1sap_ph_rach_ind(struct gsm_bts_trx *trx, + struct osmo_phsap_prim *l1sap, struct ph_rach_ind_param *rach_ind) +{ + struct gsm_bts *bts = trx->bts; + struct gsm_bts_role_bts *btsb = bts->role; + struct lapdm_channel *lc; + uint8_t acc_delay; + + DEBUGP(DL1P, "Rx PH-RA.ind"); + + lc = &trx->ts[0].lchan[4].lapdm_ch; + + /* check for under/overflow / sign */ + if (!check_acc_delay(rach_ind, btsb, &acc_delay)) { + LOGP(DL1C, LOGL_INFO, "ignoring RACH request %u > max_ta(%u)\n", + acc_delay, btsb->max_ta); + return 0; + } + + /* check for handover rach */ + if (!L1SAP_IS_CHAN_RACH(rach_ind->chan_nr)) + return l1sap_handover_rach(trx, l1sap, rach_ind); + + /* check for packet access */ + if (trx == bts->c0 && L1SAP_IS_PACKET_RACH(rach_ind->ra)) { + LOGP(DL1P, LOGL_INFO, "RACH for packet access\n"); + pcu_tx_rach_ind(bts, rach_ind->acc_delay << 2, + rach_ind->ra, rach_ind->fn); + return 0; + } + + LOGP(DL1P, LOGL_INFO, "RACH for RR access (toa=%d, ra=%d)\n", + rach_ind->acc_delay, rach_ind->ra); + lapdm_phsap_up(&l1sap->oph, &lc->lapdm_dcch); + + return 0; +} + +/* any L1 prim received from bts model */ +int l1sap_up(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap) +{ + struct msgb *msg = l1sap->oph.msg; + int rc = 0; + + switch (OSMO_PRIM_HDR(&l1sap->oph)) { + case OSMO_PRIM(PRIM_MPH_INFO, PRIM_OP_INDICATION): + rc = l1sap_mph_info_ind(trx, l1sap, &l1sap->u.info); + break; + case OSMO_PRIM(PRIM_MPH_INFO, PRIM_OP_CONFIRM): + rc = l1sap_mph_info_cnf(trx, l1sap, &l1sap->u.info); + break; + case OSMO_PRIM(PRIM_PH_RTS, PRIM_OP_INDICATION): + rc = l1sap_ph_rts_ind(trx, l1sap, &l1sap->u.data); + break; + case OSMO_PRIM(PRIM_TCH_RTS, PRIM_OP_INDICATION): + rc = l1sap_tch_rts_ind(trx, l1sap, &l1sap->u.tch); + break; + case OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_INDICATION): + to_gsmtap(trx, l1sap); + rc = l1sap_ph_data_ind(trx, l1sap, &l1sap->u.data); + break; + case OSMO_PRIM(PRIM_TCH, PRIM_OP_INDICATION): + rc = l1sap_tch_ind(trx, l1sap, &l1sap->u.tch); + break; + case OSMO_PRIM(PRIM_PH_RACH, PRIM_OP_INDICATION): + to_gsmtap(trx, l1sap); + rc = l1sap_ph_rach_ind(trx, l1sap, &l1sap->u.rach_ind); + break; + default: + LOGP(DL1P, LOGL_NOTICE, "unknown prim %d op %d\n", + l1sap->oph.primitive, l1sap->oph.operation); + break; + } + + /* Special return value '1' means: do not free */ + if (rc != 1) + msgb_free(msg); + + return rc; +} + +/* any L1 prim sent to bts model */ +static int l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap) +{ + if (OSMO_PRIM_HDR(&l1sap->oph) == + OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_REQUEST)) + to_gsmtap(trx, l1sap); + + return bts_model_l1sap_down(trx, l1sap); +} + +/* pcu (socket interface) sends us a data request primitive */ +int l1sap_pdch_req(struct gsm_bts_trx_ts *ts, int is_ptcch, uint32_t fn, + uint16_t arfcn, uint8_t block_nr, uint8_t *data, uint8_t len) +{ + struct msgb *msg; + struct osmo_phsap_prim *l1sap; + struct gsm_time g_time; + + gsm_fn2gsmtime(&g_time, fn); + + DEBUGP(DL1P, "TX packet data %02u/%02u/%02u is_ptcch=%d trx=%d ts=%d " + "block_nr=%d, arfcn=%d, len=%d\n", g_time.t1, g_time.t2, + g_time.t3, is_ptcch, ts->trx->nr, ts->nr, block_nr, arfcn, len); + + msg = l1sap_msgb_alloc(len); + l1sap = msgb_l1sap_prim(msg); + osmo_prim_init(&l1sap->oph, SAP_GSM_PH, PRIM_PH_DATA, PRIM_OP_REQUEST, + msg); + l1sap->u.data.chan_nr = 0x08 | ts->nr; + l1sap->u.data.link_id = 0x00; + l1sap->u.data.fn = fn; + msg->l2h = msgb_put(msg, len); + memcpy(msg->l2h, data, len); + + return l1sap_down(ts->trx, l1sap); +} + +/*! \brief call-back function for incoming RTP */ +void l1sap_rtp_rx_cb(struct osmo_rtp_socket *rs, const uint8_t *rtp_pl, + unsigned int rtp_pl_len) +{ + struct gsm_lchan *lchan = rs->priv; + struct msgb *msg, *tmp; + struct osmo_phsap_prim *l1sap; + int count = 0; + + msg = l1sap_msgb_alloc(rtp_pl_len); + if (!msg) + return; + memcpy(msgb_put(msg, rtp_pl_len), rtp_pl, rtp_pl_len); + msgb_pull(msg, sizeof(*l1sap)); + + + /* make sure the queue doesn't get too long */ + llist_for_each_entry(tmp, &lchan->dl_tch_queue, list) + count++; + while (count >= 2) { + tmp = msgb_dequeue(&lchan->dl_tch_queue); + msgb_free(tmp); + count--; + } + + msgb_enqueue(&lchan->dl_tch_queue, msg); +} + +static int l1sap_chan_act_dact_modify(struct gsm_bts_trx *trx, uint8_t chan_nr, + enum osmo_mph_info_type type, uint8_t sacch_only) +{ + struct osmo_phsap_prim l1sap; + + memset(&l1sap, 0, sizeof(l1sap)); + osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_MPH_INFO, PRIM_OP_REQUEST, + NULL); + l1sap.u.info.type = type; + l1sap.u.info.u.act_req.chan_nr = chan_nr; + l1sap.u.info.u.act_req.sacch_only = sacch_only; + + return l1sap_down(trx, &l1sap); +} + +int l1sap_chan_act(struct gsm_bts_trx *trx, uint8_t chan_nr, struct tlv_parsed *tp) +{ + struct gsm_bts_role_bts *btsb = trx->bts->role; + struct gsm_lchan *lchan = &trx->ts[L1SAP_CHAN2TS(chan_nr)] + .lchan[l1sap_chan2ss(chan_nr)]; + struct gsm48_chan_desc *cd; + int rc; + + LOGP(DL1P, LOGL_INFO, "activating channel chan_nr=%02x trx=%d\n", + chan_nr, trx->nr); + + /* osmo-pcu calls this without a valid 'tp' parameter, so we + * need to make sure ew don't crash here */ + if (tp && TLVP_PRESENT(tp, GSM48_IE_CHANDESC_2) && + TLVP_LEN(tp, GSM48_IE_CHANDESC_2) >= sizeof(*cd)) { + cd = (struct gsm48_chan_desc *) + TLVP_VAL(tp, GSM48_IE_CHANDESC_2); + + /* our L1 only supports one global TSC for all channels + * one one TRX, so we need to make sure not to activate + * channels with a different TSC!! */ + if (cd->h0.tsc != (lchan->ts->trx->bts->bsic & 7)) { + LOGP(DRSL, LOGL_ERROR, "lchan TSC %u != BSIC-TSC %u\n", + cd->h0.tsc, lchan->ts->trx->bts->bsic & 7); + return -RSL_ERR_SERV_OPT_UNIMPL; + } + } + + lchan->sacch_deact = 0; + lchan->s = btsb->radio_link_timeout; + + rc = l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_ACTIVATE, 0); + if (rc) + return -RSL_ERR_EQUIPMENT_FAIL; + return 0; +} + +int l1sap_chan_rel(struct gsm_bts_trx *trx, uint8_t chan_nr) +{ + LOGP(DL1P, LOGL_INFO, "deactivating channel chan_nr=%02x trx=%d\n", + chan_nr, trx->nr); + + return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_DEACTIVATE, + 0); +} + +int l1sap_chan_deact_sacch(struct gsm_bts_trx *trx, uint8_t chan_nr) +{ + struct gsm_lchan *lchan = &trx->ts[L1SAP_CHAN2TS(chan_nr)] + .lchan[l1sap_chan2ss(chan_nr)]; + + LOGP(DL1P, LOGL_INFO, "deactivating sacch chan_nr=%02x trx=%d\n", + chan_nr, trx->nr); + + lchan->sacch_deact = 1; + + return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_DEACTIVATE, + 1); +} + +int l1sap_chan_modify(struct gsm_bts_trx *trx, uint8_t chan_nr) +{ + LOGP(DL1P, LOGL_INFO, "modifying channel chan_nr=%02x trx=%d\n", + chan_nr, trx->nr); + + return l1sap_chan_act_dact_modify(trx, chan_nr, PRIM_INFO_MODIFY, 0); +} |