layer23: Rename layer23 to ccch_scan as discussed on the ml

1 files changed, 307 insertions, 0 deletions

diff --git a/src/host/layer23/src/misc/app_ccch_scan.c b/src/host/layer23/src/misc/app_ccch_scan.c
new file mode 100644
index 00000000..d54f7a3f
--- /dev/null
+++ b/src/host/layer23/src/misc/app_ccch_scan.c
@@ -0,0 +1,307 @@
+#include <stdint.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include <osmocore/msgb.h>
+#include <osmocore/rsl.h>
+#include <osmocore/tlv.h>
+#include <osmocore/gsm48_ie.h>
+#include <osmocore/protocol/gsm_04_08.h>
+
+#include <osmocom/bb/common/logging.h>
+#include <osmocom/bb/common/lapdm.h>
+#include <osmocom/bb/misc/rslms.h>
+#include <osmocom/bb/misc/layer3.h>
+#include <osmocom/bb/common/osmocom_data.h>
+#include <osmocom/bb/common/l1ctl.h>
+
+static struct {
+	int has_si1;
+	int ccch_mode;
+	int ccch_enabled;
+	int rach_count;
+	struct gsm_sysinfo_freq cell_arfcns[1024];
+} app_state;
+
+
+static void dump_bcch(struct osmocom_ms *ms, uint8_t tc, const uint8_t *data)
+{
+	struct gsm48_system_information_type_header *si_hdr;
+	si_hdr = (struct gsm48_system_information_type_header *) data;
+
+	/* GSM 05.02 §6.3.1.3 Mapping of BCCH data */
+	switch (si_hdr->system_information) {
+	case GSM48_MT_RR_SYSINFO_1:
+		fprintf(stderr, "\tSI1");
+#ifdef BCCH_TC_CHECK
+		if (tc != 0)
+			fprintf(stderr, " on wrong TC");
+#endif
+		if (!app_state.has_si1) {
+			struct gsm48_system_information_type_1 *si1 =
+				(struct gsm48_system_information_type_1 *)data;
+
+			gsm48_decode_freq_list(&app_state.cell_arfcns,
+			                       si1->cell_channel_description,
+					       sizeof(si1->cell_channel_description),
+					       0xff, 0x01);
+
+			app_state.has_si1 = 1;
+		}
+		break;
+	case GSM48_MT_RR_SYSINFO_2:
+		fprintf(stderr, "\tSI2");
+#ifdef BCCH_TC_CHECK
+		if (tc != 1)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_3:
+		fprintf(stderr, "\tSI3");
+#ifdef BCCH_TC_CHECK
+		if (tc != 2 && tc != 6)
+			fprintf(stderr, " on wrong TC");
+#endif
+		if (app_state.ccch_mode == CCCH_MODE_NONE) {
+			struct gsm48_system_information_type_3 *si3 =
+				(struct gsm48_system_information_type_3 *)data;
+
+			if (si3->control_channel_desc.ccch_conf == RSL_BCCH_CCCH_CONF_1_C)
+				app_state.ccch_mode = CCCH_MODE_COMBINED;
+			else
+				app_state.ccch_mode = CCCH_MODE_NON_COMBINED;
+
+			l1ctl_tx_ccch_mode_req(ms, app_state.ccch_mode);
+		}
+		break;
+	case GSM48_MT_RR_SYSINFO_4:
+		fprintf(stderr, "\tSI4");
+#ifdef BCCH_TC_CHECK
+		if (tc != 3 && tc != 7)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_5:
+		fprintf(stderr, "\tSI5");
+		break;
+	case GSM48_MT_RR_SYSINFO_6:
+		fprintf(stderr, "\tSI6");
+		break;
+	case GSM48_MT_RR_SYSINFO_7:
+		fprintf(stderr, "\tSI7");
+#ifdef BCCH_TC_CHECK
+		if (tc != 7)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_8:
+		fprintf(stderr, "\tSI8");
+#ifdef BCCH_TC_CHECK
+		if (tc != 3)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_9:
+		fprintf(stderr, "\tSI9");
+#ifdef BCCH_TC_CHECK
+		if (tc != 4)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_13:
+		fprintf(stderr, "\tSI13");
+#ifdef BCCH_TC_CHECK
+		if (tc != 4 && tc != 0)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_16:
+		fprintf(stderr, "\tSI16");
+#ifdef BCCH_TC_CHECK
+		if (tc != 6)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_17:
+		fprintf(stderr, "\tSI17");
+#ifdef BCCH_TC_CHECK
+		if (tc != 2)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_2bis:
+		fprintf(stderr, "\tSI2bis");
+#ifdef BCCH_TC_CHECK
+		if (tc != 5)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_2ter:
+		fprintf(stderr, "\tSI2ter");
+#ifdef BCCH_TC_CHECK
+		if (tc != 5 && tc != 4)
+			fprintf(stderr, " on wrong TC");
+#endif
+		break;
+	case GSM48_MT_RR_SYSINFO_5bis:
+		fprintf(stderr, "\tSI5bis");
+		break;
+	case GSM48_MT_RR_SYSINFO_5ter:
+		fprintf(stderr, "\tSI5ter");
+		break;
+	default:
+		fprintf(stderr, "\tUnknown SI");
+		break;
+	};
+
+	fprintf(stderr, "\n");
+}
+
+
+/* send location updating request * (as part of RSLms EST IND /
+   LAPDm SABME) */
+static int gsm48_tx_loc_upd_req(struct osmocom_ms *ms, uint8_t chan_nr)
+{
+	struct msgb *msg = msgb_alloc_headroom(256, 16, "loc_upd_req");
+	struct gsm48_hdr *gh;
+	struct gsm48_loc_upd_req *lu_r;
+
+	DEBUGP(DMM, "chan_nr=%u\n", chan_nr);
+
+	msg->l3h = msgb_put(msg, sizeof(*gh));
+	gh = (struct gsm48_hdr *) msg->l3h;
+	gh->proto_discr = GSM48_PDISC_MM;
+	gh->msg_type = GSM48_MT_MM_LOC_UPD_REQUEST;
+	lu_r = (struct gsm48_loc_upd_req *) msgb_put(msg, sizeof(*lu_r));
+	lu_r->type = GSM48_LUPD_IMSI_ATT;
+	lu_r->key_seq = 0;
+	/* FIXME: set LAI and CM1 */
+	/* FIXME: set MI */
+	lu_r->mi_len = 0;
+
+	return rslms_tx_rll_req_l3(ms, RSL_MT_EST_REQ, chan_nr, 0, msg);
+}
+
+static int gsm48_rx_imm_ass(struct msgb *msg, struct osmocom_ms *ms)
+{
+	struct gsm48_imm_ass *ia = msgb_l3(msg);
+	uint8_t ch_type, ch_subch, ch_ts;
+	int rv;
+
+	/* Discard packet TBF assignement */
+	if (ia->page_mode & 0xf0)
+		return 0;
+
+	/* FIXME: compare RA and GSM time with when we sent RACH req */
+
+	rsl_dec_chan_nr(ia->chan_desc.chan_nr, &ch_type, &ch_subch, &ch_ts);
+
+	if (!ia->chan_desc.h0.h) {
+		/* Non-hopping */
+		uint16_t arfcn;
+
+		arfcn = ia->chan_desc.h0.arfcn_low | (ia->chan_desc.h0.arfcn_high << 8);
+
+		DEBUGP(DRR, "GSM48 IMM ASS (ra=0x%02x, chan_nr=0x%02x, "
+			"ARFCN=%u, TS=%u, SS=%u, TSC=%u) ", ia->req_ref.ra,
+			ia->chan_desc.chan_nr, arfcn, ch_ts, ch_subch,
+			ia->chan_desc.h0.tsc);
+
+		/* request L1 to go to dedicated mode on assigned channel */
+		rv = l1ctl_tx_dm_est_req_h0(ms,
+			arfcn, ia->chan_desc.chan_nr, ia->chan_desc.h0.tsc,
+			GSM48_CMODE_SIGN);
+	} else {
+		/* Hopping */
+		uint8_t maio, hsn, ma_len;
+		uint16_t ma[64], arfcn;
+		int i, j, k;
+
+		hsn = ia->chan_desc.h1.hsn;
+		maio = ia->chan_desc.h1.maio_low | (ia->chan_desc.h1.maio_high << 2);
+
+		DEBUGP(DRR, "GSM48 IMM ASS (ra=0x%02x, chan_nr=0x%02x, "
+			"HSN=%u, MAIO=%u, TS=%u, SS=%u, TSC=%u) ", ia->req_ref.ra,
+			ia->chan_desc.chan_nr, hsn, maio, ch_ts, ch_subch,
+			ia->chan_desc.h1.tsc);
+
+		/* decode mobile allocation */
+		ma_len = 0;
+		for (i=1, j=0; i<=1024; i++) {
+			arfcn = i & 1023;
+			if (app_state.cell_arfcns[arfcn].mask & 0x01) {
+				k = ia->mob_alloc_len - (j>>3) - 1;
+				if (ia->mob_alloc[k] & (1 << (j&7))) {
+					ma[ma_len++] = arfcn;
+				}
+				j++;
+			}
+		}
+
+		/* request L1 to go to dedicated mode on assigned channel */
+		rv = l1ctl_tx_dm_est_req_h1(ms,
+			maio, hsn, ma, ma_len,
+			ia->chan_desc.chan_nr, ia->chan_desc.h1.tsc,
+			GSM48_CMODE_SIGN);
+	}
+
+	DEBUGPC(DRR, "\n");
+
+	rv = gsm48_tx_loc_upd_req(ms, ia->chan_desc.chan_nr);
+
+	return rv;
+}
+
+int gsm48_rx_ccch(struct msgb *msg, struct osmocom_ms *ms)
+{
+	struct gsm48_system_information_type_header *sih = msgb_l3(msg);
+	int rc = 0;
+
+	if (sih->rr_protocol_discriminator != GSM48_PDISC_RR)
+		LOGP(DRR, LOGL_ERROR, "PCH pdisc != RR\n");
+
+	switch (sih->system_information) {
+	case GSM48_MT_RR_PAG_REQ_1:
+	case GSM48_MT_RR_PAG_REQ_2:
+	case GSM48_MT_RR_PAG_REQ_3:
+		/* FIXME: implement decoding of paging request */
+		break;
+	case GSM48_MT_RR_IMM_ASS:
+		rc = gsm48_rx_imm_ass(msg, ms);
+		break;
+	default:
+		LOGP(DRR, LOGL_NOTICE, "unknown PCH/AGCH type 0x%02x\n",
+			sih->system_information);
+		rc = -EINVAL;
+	}
+
+	return rc;
+}
+
+int gsm48_rx_bcch(struct msgb *msg, struct osmocom_ms *ms)
+{
+	/* FIXME: we have lost the gsm frame time until here, need to store it
+	 * in some msgb context */
+	//dump_bcch(dl->time.tc, ccch->data);
+	dump_bcch(ms, 0, msg->l3h);
+
+	/* Req channel logic */
+	if (app_state.ccch_enabled && (app_state.rach_count < 2)) {
+		l1ctl_tx_rach_req(ms, app_state.rach_count, 0,
+			app_state.ccch_mode == CCCH_MODE_COMBINED);
+		app_state.rach_count++;
+	}
+
+	return 0;
+}
+
+void layer3_app_reset(void)
+{
+	/* Reset state */
+	app_state.has_si1 = 0;
+	app_state.ccch_mode = CCCH_MODE_NONE;
+	app_state.ccch_enabled = 0;
+	app_state.rach_count = 0;
+
+	memset(&app_state.cell_arfcns, 0x00, sizeof(app_state.cell_arfcns));
+}