Import code to generate RRLP ephemeris data from u-blox GPS receiver
taken from http://www.246tnt.com/files/rrlp-20091101.tar.bz2
diff --git a/rrlp-ephemeris/rrlp.c b/rrlp-ephemeris/rrlp.c
new file mode 100644
index 0000000..8b0d14a
--- /dev/null
+++ b/rrlp-ephemeris/rrlp.c
@@ -0,0 +1,599 @@
+/*
+ * 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 "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 */
+/* ---------------------------------------------------------------------{{{ */
+
+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;
+
+ /* FIXME: Check if info is in gps_ad */
+
+ rrlp_refloc = calloc(1, sizeof(*rrlp_refloc));
+ if (!rrlp_refloc)
+ return -ENOMEM;
+ rrlp_gps_ad->controlHeader.refLocation = rrlp_refloc;
+
+ /* FIXME */
+ {
+ uint8_t gps_loc[] = {
+ 0x80, /* Ellipsoid Point with altitude */
+ 0x48, 0x0f, 0x93, /* 50.667778 N */
+ 0x03, 0x47, 0x87, /* 4.611667 E */
+ 0x00, 0x72, /* 114m */
+ };
+ uint8_t *b = malloc(sizeof(gps_loc));
+ memcpy(b, gps_loc, sizeof(gps_loc));
+ rrlp_refloc->threeDLocation.buf = b;
+ rrlp_refloc->threeDLocation.size = sizeof(gps_loc);
+ }
+
+ return 0;
+}
+
+static int
+_rrlp_add_reference_time(
+ struct GPS_AssistData *rrlp_gps_ad,
+ struct gps_assist_data *gps_ad)
+{
+ struct ReferenceTime *rrlp_reftime;
+
+ /* FIXME: Check if info is in gps_ad */
+
+ rrlp_reftime = calloc(1, sizeof(*rrlp_reftime));
+ if (!rrlp_reftime)
+ return -ENOMEM;
+ rrlp_gps_ad->controlHeader.referenceTime = rrlp_reftime;
+
+ /* FIXME */
+// rrlp_reftime.gpsTime.gpsTOW23b = g_gps_tow / 80; /* 23 bits */
+// rrlp_reftime.gpsTime.gpsWeek = g_gps_week & 0x3ff; /* 10 bits */
+
+ 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++) {
+ // 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;
+ }
+
+ return 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;
+}
+
+/* }}} */
+