diff options
Diffstat (limited to 'rrlp-ephemeris/rrlp.c')
-rw-r--r-- | rrlp-ephemeris/rrlp.c | 648 |
1 files changed, 648 insertions, 0 deletions
diff --git a/rrlp-ephemeris/rrlp.c b/rrlp-ephemeris/rrlp.c new file mode 100644 index 000000000..e60c3ab01 --- /dev/null +++ b/rrlp-ephemeris/rrlp.c @@ -0,0 +1,648 @@ +/* + * rrlp.c + * + * RRLP implementation + * + * + * Copyright (C) 2009 Sylvain Munaut <tnt@246tNt.com> + * + * 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, see <http://www.gnu.org/licenses/>. + */ + + +#include <errno.h> +#include <math.h> + +#include "gps.h" +#include "rrlp.h" + +#include <PDU.h> +#include <GPS-AssistData.h> +#include <NavigationModel.h> +#include <IonosphericModel.h> +#include <UTCModel.h> +#include <Almanac.h> +#include <RefLocation.h> +#include <ReferenceTime.h> + + +/* ------------------------------------------------------------------------ */ +/* RRLP Assistance request decoding */ +/* ---------------------------------------------------------------------{{{ */ +/* Decode and validate the assistance data request messages. + * See section 10.10 of + * . ETSI TS 149 031 V8.1.0 (2009-01) + * . 3GPP TS 49.031 version 8.1.0 Release 8 + */ + +/* Packed structure from 49.031 spec (RGA = Request GPS Assistance) */ + +#define RRLP_RGA0_ALMANAC (1<<0) +#define RRLP_RGA0_UTC_MODEL (1<<1) +#define RRLP_RGA0_IONO_MODEL (1<<2) +#define RRLP_RGA0_NAV_MODEL (1<<3) +#define RRLP_RGA0_DGPS (1<<4) +#define RRLP_RGA0_REF_LOC (1<<5) +#define RRLP_RGA0_REF_TIME (1<<6) +#define RRLP_RGA0_ACQ_ASSIST (1<<7) + +#define RRLP_RGA1_REALTIME_INT (1<<0) +#define RRLP_RGA1_EPH_EXT (1<<1) +#define RRLP_RGA1_EPH_EXT_CHECK (1<<2) + +struct rrlp_rga_hdr { + uint8_t items0; + uint8_t items1; +} __attribute__((packed)); + +struct rrlp_rga_eph_sv { + uint8_t sv_id; /* [7:6] reserved, [5:0] sv_id */ + uint8_t iode; /* latest eph in the MS memory in hours */ +} __attribute__((packed)); + +struct rrlp_rga_eph { + uint8_t wn_hi; /* [7:6] = wn[9:8] */ + uint8_t wn_lo; /* wn[7:0] */ + uint8_t toe; /* latest eph in the MS memory in hours */ + uint8_t nsat_tmtoe; /* [7:4] nstat, [3:0] T-Toe limit */ + struct rrlp_rga_eph_sv svs[0]; +} __attribute__((packed)); + +struct rrlp_rga_eph_ext { + uint8_t validity; /* in 4 hours units */ +} __attribute__((packed)); + +struct rrlp_rga_eph_ext_check { + /* weeks are in gps week modulo 4 */ + uint8_t wn_begin_end; /* [7:4] begin, [3:0] end */ + uint8_t tow_begin; + uint8_t tow_end; +} __attribute__((packed)); + + +/* Parsing function */ + +int +rrlp_decode_assistance_request( + struct rrlp_assist_req *ar, + void *req, int req_len) +{ + struct rrlp_rga_hdr *hdr = NULL; + struct rrlp_rga_eph *eph = NULL; + struct rrlp_rga_eph_ext *eph_ext = NULL; + struct rrlp_rga_eph_ext_check *eph_ext_check = NULL; + int p = 0; + + /* Reset */ + ar->req_elems = 0; + ar->eph_svs = 0; + + /* Parse message */ + hdr = req; + p += sizeof(struct rrlp_rga_hdr); + if (p > req_len) + return -1; + + if (hdr->items0 & RRLP_RGA0_NAV_MODEL) { + eph = req + p; + p += sizeof(struct rrlp_rga_eph); + if (p > req_len) + return -1; + p += (eph->nsat_tmtoe >> 4) * sizeof(struct rrlp_rga_eph_sv); + if (p > req_len) + return -1; + } + + if (hdr->items1 & RRLP_RGA1_EPH_EXT) { + eph_ext = req + p; + p += sizeof(struct rrlp_rga_eph_ext); + if (p > req_len) + return -1; + } + + if (hdr->items1 & RRLP_RGA1_EPH_EXT_CHECK) { + eph_ext_check = req + p; + p += sizeof(struct rrlp_rga_eph_ext_check); + if (p > req_len) + return -1; + } + + if (p != req_len) + return -2; /* not all bytes consumed ??? */ + + /* Print a warning for unsupported requests */ + if ((eph_ext != NULL) || + (eph_ext_check != NULL) || + (hdr->items0 & (RRLP_RGA0_DGPS | RRLP_RGA0_ACQ_ASSIST)) || + (hdr->items1 & RRLP_RGA1_REALTIME_INT)) { + fprintf(stderr, "[w] Unsupported assistance data requested, ignored ...\n"); + } + + /* Copy the request */ + if (hdr->items0 & RRLP_RGA0_ALMANAC) + ar->req_elems |= RRLP_AR_ALMANAC; + + if (hdr->items0 & RRLP_RGA0_UTC_MODEL) + ar->req_elems |= RRLP_AR_UTC_MODEL; + + if (hdr->items0 & RRLP_RGA0_IONO_MODEL) + ar->req_elems |= RRLP_AR_IONO_MODEL; + + if (hdr->items0 & RRLP_RGA0_REF_LOC) + ar->req_elems |= RRLP_AR_REF_LOC; + + if (hdr->items0 & RRLP_RGA0_REF_TIME) + ar->req_elems |= RRLP_AR_REF_TIME; + + if (hdr->items0 & RRLP_RGA0_NAV_MODEL) { + int i, n_svs = eph->nsat_tmtoe >> 4; + ar->req_elems |= RRLP_AR_EPHEMERIS; + for (i=0; i<n_svs; i++) + ar->eph_svs |= (1ULL << (eph->svs[i].sv_id - 1)); + } + + return 0; +} + +/* }}} */ + + +/* ------------------------------------------------------------------------ */ +/* RRLP elements fill */ +/* ---------------------------------------------------------------------{{{ */ + + /* Helpers */ + +static void +_ts_23_032_store_latitude(double lat, uint8_t *b) +{ + uint32_t x; + x = (uint32_t) floor(fabs(lat/90.0) * ((double)(1<<23))); + if (x >= (1<<23)) + x = (1<<23) - 1; + if (lat < 0.0) + x |= (1<<23); + b[0] = (x >> 16) & 0xff; + b[1] = (x >> 8) & 0xff; + b[2] = x & 0xff; +} + +static void +_ts_23_032_store_longitude(double lon, uint8_t *b) +{ + int32_t x; + x = floor((lon/360.0) * ((double)(1<<24))); + if (x >= (1<<23)) + x = 0x007fffff; + else if (x < -(1<<23)) + x = 0x00800000; + b[0] = (x >> 16) & 0xff; + b[1] = (x >> 8) & 0xff; + b[2] = x & 0xff; +} + +static void +_ts_23_032_store_altitude(double alt, uint8_t *b) +{ + int alt_i = (int)fabs(alt); + b[0] = ((alt_i >> 8) & 0x7f) | (alt<0.0 ? 0x80 : 0x00); + b[1] = alt_i & 0xff; +} + + + /* Fill methods */ + +static void +_rrlp_fill_navigation_model_element( + struct NavModelElement *rrlp_nme, + struct gps_ephemeris_sv *gps_eph_sv) +{ + struct UncompressedEphemeris *rrlp_eph; + + rrlp_nme->satStatus.present = SatStatus_PR_newSatelliteAndModelUC; + rrlp_nme->satelliteID = gps_eph_sv->sv_id; + + rrlp_eph = &rrlp_nme->satStatus.choice.newSatelliteAndModelUC; + + rrlp_eph->ephemCodeOnL2 = gps_eph_sv->code_on_l2; + rrlp_eph->ephemURA = gps_eph_sv->sv_ura; + rrlp_eph->ephemSVhealth = gps_eph_sv->sv_health; + rrlp_eph->ephemIODC = gps_eph_sv->iodc; + rrlp_eph->ephemL2Pflag = gps_eph_sv->l2_p_flag; + rrlp_eph->ephemTgd = gps_eph_sv->t_gd; + rrlp_eph->ephemToc = gps_eph_sv->t_oc; + rrlp_eph->ephemAF2 = gps_eph_sv->a_f2; + rrlp_eph->ephemAF1 = gps_eph_sv->a_f1; + rrlp_eph->ephemAF0 = gps_eph_sv->a_f0; + rrlp_eph->ephemCrs = gps_eph_sv->c_rs; + rrlp_eph->ephemDeltaN = gps_eph_sv->delta_n; + rrlp_eph->ephemM0 = gps_eph_sv->m_0; + rrlp_eph->ephemCuc = gps_eph_sv->c_uc; + rrlp_eph->ephemE = gps_eph_sv->e; + rrlp_eph->ephemCus = gps_eph_sv->c_us; + rrlp_eph->ephemAPowerHalf = gps_eph_sv->a_powhalf; + rrlp_eph->ephemToe = gps_eph_sv->t_oe; + rrlp_eph->ephemFitFlag = gps_eph_sv->fit_flag; + rrlp_eph->ephemAODA = gps_eph_sv->aodo; + rrlp_eph->ephemCic = gps_eph_sv->c_ic; + rrlp_eph->ephemOmegaA0 = gps_eph_sv->omega_0; + rrlp_eph->ephemCis = gps_eph_sv->c_is; + rrlp_eph->ephemI0 = gps_eph_sv->i_0; + rrlp_eph->ephemCrc = gps_eph_sv->c_rc; + rrlp_eph->ephemW = gps_eph_sv->w; + rrlp_eph->ephemOmegaADot = gps_eph_sv->omega_dot; + rrlp_eph->ephemIDot = gps_eph_sv->idot; + + rrlp_eph->ephemSF1Rsvd.reserved1 = gps_eph_sv->_rsvd1; + rrlp_eph->ephemSF1Rsvd.reserved2 = gps_eph_sv->_rsvd2; + rrlp_eph->ephemSF1Rsvd.reserved3 = gps_eph_sv->_rsvd3; + rrlp_eph->ephemSF1Rsvd.reserved4 = gps_eph_sv->_rsvd4; +} + +static void +_rrlp_fill_almanac_element( + struct AlmanacElement *rrlp_ae, + struct gps_almanac_sv *gps_alm_sv) +{ + rrlp_ae->satelliteID = gps_alm_sv->sv_id; + + rrlp_ae->almanacE = gps_alm_sv->e; + rrlp_ae->alamanacToa = gps_alm_sv->t_oa; + rrlp_ae->almanacKsii = gps_alm_sv->ksii; + rrlp_ae->almanacOmegaDot = gps_alm_sv->omega_dot; + rrlp_ae->almanacSVhealth = gps_alm_sv->sv_health; + rrlp_ae->almanacAPowerHalf = gps_alm_sv->a_powhalf; + rrlp_ae->almanacOmega0 = gps_alm_sv->omega_0; + rrlp_ae->almanacW = gps_alm_sv->w; + rrlp_ae->almanacM0 = gps_alm_sv->m_0; + rrlp_ae->almanacAF0 = gps_alm_sv->a_f0; + rrlp_ae->almanacAF1 = gps_alm_sv->a_f1; + +} + +static void +_rrlp_fill_ionospheric_model( + struct IonosphericModel *rrlp_iono, + struct gps_ionosphere_model *gps_iono) +{ + rrlp_iono->alfa0 = gps_iono->alpha_0; + rrlp_iono->alfa1 = gps_iono->alpha_1; + rrlp_iono->alfa2 = gps_iono->alpha_2; + rrlp_iono->alfa3 = gps_iono->alpha_3; + rrlp_iono->beta0 = gps_iono->beta_0; + rrlp_iono->beta1 = gps_iono->beta_1; + rrlp_iono->beta2 = gps_iono->beta_2; + rrlp_iono->beta3 = gps_iono->beta_3; +} + +static void +_rrlp_fill_utc_model( + struct UTCModel *rrlp_utc, + struct gps_utc_model *gps_utc) +{ + rrlp_utc->utcA1 = gps_utc->a1; + rrlp_utc->utcA0 = gps_utc->a0; + rrlp_utc->utcTot = gps_utc->t_ot; + rrlp_utc->utcWNt = gps_utc->wn_t & 0xff; + rrlp_utc->utcDeltaTls = gps_utc->delta_t_ls; + rrlp_utc->utcWNlsf = gps_utc->wn_lsf & 0xff; + rrlp_utc->utcDN = gps_utc->dn; + rrlp_utc->utcDeltaTlsf = gps_utc->delta_t_lsf; +} + +/* }}} */ + + +/* ------------------------------------------------------------------------ */ +/* RRLP Assistance PDU Generation */ +/* ---------------------------------------------------------------------{{{ */ + +struct PDU * +_rrlp_create_gps_assist_pdu(int refnum, struct GPS_AssistData **o_gps_ad) +{ + struct PDU *pdu; + struct GPS_AssistData *gps_ad; + + pdu = calloc(1, sizeof(*pdu)); + if (!pdu) + return NULL; + + gps_ad = calloc(1, sizeof(*gps_ad)); + if (!gps_ad) { + free(pdu); + return NULL; + } + + if (o_gps_ad) + *o_gps_ad = gps_ad; + + pdu->referenceNumber = refnum; + pdu->component.present = RRLP_Component_PR_assistanceData; + pdu->component.choice.assistanceData.gps_AssistData = gps_ad; + + return pdu; +} + +static int +_rrlp_add_ionospheric_model( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad) +{ + struct IonosphericModel *rrlp_iono; + + if (!(gps_ad->fields & GPS_FIELD_IONOSPHERE)) + return -EINVAL; + + rrlp_iono = calloc(1, sizeof(*rrlp_iono)); + if (!rrlp_iono) + return -ENOMEM; + rrlp_gps_ad->controlHeader.ionosphericModel = rrlp_iono; + + _rrlp_fill_ionospheric_model(rrlp_iono, &gps_ad->ionosphere); + + return 0; +} + +static int +_rrlp_add_utc_model( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad) +{ + struct UTCModel *rrlp_utc; + + if (!(gps_ad->fields & GPS_FIELD_UTC)) + return -EINVAL; + + rrlp_utc = calloc(1, sizeof(*rrlp_utc)); + if (!rrlp_utc) + return -ENOMEM; + rrlp_gps_ad->controlHeader.utcModel = rrlp_utc; + + _rrlp_fill_utc_model(rrlp_utc, &gps_ad->utc); + + return 0; +} + +static int +_rrlp_add_reference_location( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad) +{ + struct RefLocation *rrlp_refloc; + uint8_t *b; + + if (!(gps_ad->fields & GPS_FIELD_REFPOS)) + return -EINVAL; + + rrlp_refloc = calloc(1, sizeof(*rrlp_refloc)); + if (!rrlp_refloc) + return -ENOMEM; + rrlp_gps_ad->controlHeader.refLocation = rrlp_refloc; + + b = malloc(9); + + b[0] = 0x80; /* Ellipsoid Point with altitude */ + _ts_23_032_store_latitude(gps_ad->ref_pos.latitude, &b[1]); + _ts_23_032_store_longitude(gps_ad->ref_pos.longitude, &b[4]); + _ts_23_032_store_altitude(gps_ad->ref_pos.altitude, &b[7]); + + rrlp_refloc->threeDLocation.buf = b; + rrlp_refloc->threeDLocation.size = 9; + + return 0; +} + +static int +_rrlp_add_reference_time( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad) +{ + struct ReferenceTime *rrlp_reftime; + + if (!(gps_ad->fields & GPS_FIELD_REFTIME)) + return -EINVAL; + + rrlp_reftime = calloc(1, sizeof(*rrlp_reftime)); + if (!rrlp_reftime) + return -ENOMEM; + rrlp_gps_ad->controlHeader.referenceTime = rrlp_reftime; + + rrlp_reftime->gpsTime.gpsWeek = gps_ad->ref_time.wn & 0x3ff; /* 10b */ + rrlp_reftime->gpsTime.gpsTOW23b = + ((int)floor(gps_ad->ref_time.tow / 0.08)) & 0x7fffff; /* 23b */ + + return 0; +} + +static int +_rrlp_add_almanac( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad, int *start, int count) +{ + int i; + struct Almanac *rrlp_alm; + struct gps_almanac *gps_alm = &gps_ad->almanac; + + if (!(gps_ad->fields & GPS_FIELD_ALMANAC)) + return -EINVAL; + + rrlp_alm = calloc(1, sizeof(*rrlp_alm)); + if (!rrlp_alm) + return -ENOMEM; + rrlp_gps_ad->controlHeader.almanac = rrlp_alm; + + rrlp_alm->alamanacWNa = gps_alm->wna; + if (count == -1) + count = gps_alm->n_sv - *start; + for (i=*start; (i<*start+count) && (i<gps_alm->n_sv); i++) { + struct AlmanacElement *ae; + ae = calloc(1, sizeof(*ae)); + if (!ae) + return -ENOMEM; + _rrlp_fill_almanac_element(ae, &gps_alm->svs[i]); + ASN_SEQUENCE_ADD(&rrlp_alm->almanacList.list, ae); + } + + *start = i; + + return i < gps_alm->n_sv; +} + +static int +_rrlp_add_ephemeris( + struct GPS_AssistData *rrlp_gps_ad, + struct gps_assist_data *gps_ad, int *start, int count, uint64_t mask) +{ + int i, j; + struct NavigationModel *rrlp_nav; + struct gps_ephemeris *gps_eph = &gps_ad->ephemeris; + + if (!(gps_ad->fields & GPS_FIELD_EPHEMERIS)) + return -EINVAL; + + rrlp_nav = calloc(1, sizeof(*rrlp_nav)); + if (!rrlp_nav) + return -ENOMEM; + rrlp_gps_ad->controlHeader.navigationModel = rrlp_nav; + + if (count == -1) + count = gps_eph->n_sv - *start; + for (i=*start,j=0; (j<count) && (i<gps_eph->n_sv); i++) { + if (!(mask & (1ULL<<(gps_eph->svs[i].sv_id-1)))) + continue; + struct NavModelElement *nme; + nme = calloc(1, sizeof(*nme)); + if (!nme) + return -ENOMEM; + _rrlp_fill_navigation_model_element(nme, &gps_eph->svs[i]); + ASN_SEQUENCE_ADD(&rrlp_nav->navModelList.list, nme); + j++; + } + + *start = i; + + return i < gps_eph->n_sv; +} + + +#define MAX_PDUS 64 + +int +rrlp_gps_assist_pdus( + struct gps_assist_data *gps_ad, struct rrlp_assist_req *req, + void **o_pdu, int *o_len, int o_max_pdus) +{ + struct PDU *lst_pdu[MAX_PDUS]; + int lst_cnt = 0; + + struct PDU *rrlp_pdu = NULL; + struct GPS_AssistData *rrlp_gps_ad = NULL; + uint32_t re = req->req_elems; + int i, rv = 0; + + /* IonosphericModel, UTCModel, RefLocation, ReferenceTime */ + if (re & (RRLP_AR_IONO_MODEL | + RRLP_AR_UTC_MODEL | + RRLP_AR_REF_TIME | + RRLP_AR_REF_LOC)) + { + int pdu_has_data = 0; + + rrlp_pdu = _rrlp_create_gps_assist_pdu(1, &rrlp_gps_ad); + if (!rrlp_pdu) { + rv = -ENOMEM; + goto error; + } + + if (re & RRLP_AR_IONO_MODEL) + if (!_rrlp_add_ionospheric_model(rrlp_gps_ad, gps_ad)) + pdu_has_data = 1; + + if (re & RRLP_AR_UTC_MODEL) + if (!_rrlp_add_utc_model(rrlp_gps_ad, gps_ad)) + pdu_has_data = 1; + + if (re & RRLP_AR_REF_TIME) + if (!_rrlp_add_reference_time(rrlp_gps_ad, gps_ad)) + pdu_has_data = 1; + + if (re & RRLP_AR_REF_LOC) + if (!_rrlp_add_reference_location(rrlp_gps_ad, gps_ad)) + pdu_has_data = 1; + + if (pdu_has_data) { + lst_pdu[lst_cnt++] = rrlp_pdu; + rrlp_pdu = NULL; + } + } + + /* Almanac */ + if (re & RRLP_AR_ALMANAC) { + i = 0; + do { + if (!(gps_ad->fields & GPS_FIELD_ALMANAC)) + break; + + if (!rrlp_pdu) { + rrlp_pdu = _rrlp_create_gps_assist_pdu(1, &rrlp_gps_ad); + if (!rrlp_pdu) { + rv = -ENOMEM; + goto error; + } + } + + rv = _rrlp_add_almanac(rrlp_gps_ad, gps_ad, &i, 10); + if (rv < 0) + goto error; + + lst_pdu[lst_cnt++] = rrlp_pdu; + rrlp_pdu = NULL; + } while (rv); + } + + /* Ephemeris */ + if (re & RRLP_AR_EPHEMERIS) { + i = 0; + do { + if (!(gps_ad->fields & GPS_FIELD_EPHEMERIS)) + break; + + if (!rrlp_pdu) { + rrlp_pdu = _rrlp_create_gps_assist_pdu(1, &rrlp_gps_ad); + if (!rrlp_pdu) { + rv = -ENOMEM; + goto error; + } + } + + rv = _rrlp_add_ephemeris(rrlp_gps_ad, gps_ad, &i, 2, req->eph_svs); + + lst_pdu[lst_cnt++] = rrlp_pdu; + rrlp_pdu = NULL; + + } while (rv); + } + + /* Serialize & Release all PDUs */ + for (i=0; i<lst_cnt && i<o_max_pdus; i++) { + /* Pseudo segmentation flags */ + MoreAssDataToBeSent_t *mad = calloc(1, sizeof(*mad)); + *mad = (i == (lst_cnt-1)) ? + MoreAssDataToBeSent_noMoreMessages : + MoreAssDataToBeSent_moreMessagesOnTheWay; + lst_pdu[i]->component.choice.assistanceData.moreAssDataToBeSent = mad; + + /* Serialization */ + // asn_fprint(stdout, &asn_DEF_PDU, lst_pdu[i]); + rv = uper_encode_to_new_buffer(&asn_DEF_PDU, NULL, lst_pdu[i], &o_pdu[i]); + if (rv < 0) + goto error; + o_len[i] = rv; + } + + rv = lst_cnt; + + /* Release ASN.1 objects */ +error: + if (rrlp_pdu) + asn_DEF_PDU.free_struct(&asn_DEF_PDU, (void*)rrlp_pdu, 0); + + for (i=0; i<lst_cnt; i++) + asn_DEF_PDU.free_struct(&asn_DEF_PDU, lst_pdu[i], 0); + + return rv; +} + +/* }}} */ + |