Replace template-based SYSTEM INFORMATION with real implementation

Before this commit, OpenBSC used templates for the SYSTEM INFO
1, 2, 3, 4, 5 and 6 messages.  Those templates were patched in
various places to reflect the network config like ARFCN.

Now, we actually generate those SI messages ourselves, using
values from the configuration file, and even calculating neighbor
cell lists.

All bts'es that you have configured in OpenBSC will end up in
the neighbor cell list - which should be more than sufficient for
the current small-single-site networks.

1 files changed, 393 insertions, 0 deletions

diff --git a/openbsc/src/rest_octets.c b/openbsc/src/rest_octets.c
new file mode 100644
index 000000000..6efd47515
--- /dev/null
+++ b/openbsc/src/rest_octets.c
@@ -0,0 +1,393 @@
+/* GSM Mobile Radio Interface Layer 3 messages on the A-bis interface,
+ * rest octet handling according to
+ * 3GPP TS 04.08 version 7.21.0 Release 1998 / ETSI TS 100 940 V7.21.0 */
+
+/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/bitvec.h>
+#include <openbsc/rest_octets.h>
+
+/* generate SI1 rest octets */
+int rest_octets_si1(u_int8_t *data, u_int8_t *nch_pos)
+{
+	struct bitvec bv;
+
+	memset(&bv, 0, sizeof(bv));
+	bv.data = data;
+	bv.data_len = 2;
+
+	if (nch_pos) {
+		bitvec_set_bit(&bv, H);
+		bitvec_set_uint(&bv, *nch_pos, 5);
+	} else
+		bitvec_set_bit(&bv, L);
+
+	bitvec_spare_padding(&bv, 15);
+	return 0;
+}
+
+/* Append selection parameters to bitvec */
+static void append_selection_params(struct bitvec *bv,
+				    const struct gsm48_si_selection_params *sp)
+{
+	if (sp->present) {
+		bitvec_set_bit(bv, H);
+		bitvec_set_bit(bv, sp->cbq);
+		bitvec_set_uint(bv, sp->cell_resel_off, 6);
+		bitvec_set_uint(bv, sp->temp_offs, 3);
+		bitvec_set_uint(bv, sp->penalty_time, 5);
+	} else
+		bitvec_set_bit(bv, L);
+}
+
+/* Append power offset to bitvec */
+static void append_power_offset(struct bitvec *bv,
+				const struct gsm48_si_power_offset *po)
+{
+	if (po->present) {
+		bitvec_set_bit(bv, H);
+		bitvec_set_uint(bv, po->power_offset, 2);
+	} else
+		bitvec_set_bit(bv, L);
+}
+
+/* Append GPRS indicator to bitvec */
+static void append_gprs_ind(struct bitvec *bv,
+			    const struct gsm48_si3_gprs_ind *gi)
+{
+	if (gi->present) {
+		bitvec_set_bit(bv, H);
+		bitvec_set_uint(bv, gi->ra_colour, 3);
+		/* 0 == SI13 in BCCH Norm, 1 == SI13 sent on BCCH Ext */
+		bitvec_set_bit(bv, gi->si13_position);
+	} else
+		bitvec_set_bit(bv, L);
+}
+
+
+/* Generate SI3 Rest Octests (Chapter 10.5.2.34 / Table 10.4.72) */
+int rest_octets_si3(u_int8_t *data, const struct gsm48_si_ro_info *si3)
+{
+	struct bitvec bv;
+
+	memset(&bv, 0, sizeof(bv));
+	bv.data = data;
+	bv.data_len = 5;
+
+	/* Optional Selection Parameters */
+	append_selection_params(&bv, &si3->selection_params);
+
+	/* Optional Power Offset */
+	append_power_offset(&bv, &si3->power_offset);
+
+	/* Do we have a SI2ter on the BCCH? */
+	if (si3->si2ter_indicator)
+		bitvec_set_bit(&bv, H);
+	else
+		bitvec_set_bit(&bv, L);
+
+	/* Early Classmark Sending Control */
+	if (si3->early_cm_ctrl)
+		bitvec_set_bit(&bv, H);
+	else
+		bitvec_set_bit(&bv, L);
+
+	/* Do we have a SI Type 9 on the BCCH? */
+	if (si3->scheduling.present) {
+		bitvec_set_bit(&bv, H);
+		bitvec_set_uint(&bv, si3->scheduling.where, 3);
+	} else
+		bitvec_set_bit(&bv, L);
+
+	/* GPRS Indicator */
+	append_gprs_ind(&bv, &si3->gprs_ind);
+
+	return bitvec_spare_padding(&bv, (bv.data_len*8)-1);
+}
+
+static int append_lsa_params(struct bitvec *bv,
+			     const struct gsm48_lsa_params *lsa_params)
+{
+	/* FIXME */
+}
+
+/* Generate SI4 Rest Octets (Chapter 10.5.2.35) */
+int rest_octets_si4(u_int8_t *data, const struct gsm48_si_ro_info *si4)
+{
+	struct bitvec bv;
+
+	memset(&bv, 0, sizeof(bv));
+	bv.data = data;
+	bv.data_len = 11; /* FIXME: up to ? */
+
+	/* SI4 Rest Octets O */
+	append_selection_params(&bv, &si4->selection_params);
+	append_power_offset(&bv, &si4->power_offset);
+	append_gprs_ind(&bv, &si4->gprs_ind);
+
+	if (0 /* FIXME */) {
+		/* H and SI4 Rest Octets S */
+		bitvec_set_bit(&bv, H);
+
+		/* LSA Parameters */
+		if (si4->lsa_params.present) {
+			bitvec_set_bit(&bv, H);
+			append_lsa_params(&bv, &si4->lsa_params);
+		} else
+			bitvec_set_bit(&bv, L);
+
+		/* Cell Identity */
+		if (1) {
+			bitvec_set_bit(&bv, H);
+			bitvec_set_uint(&bv, si4->cell_id, 16);
+		} else
+			bitvec_set_bit(&bv, L);
+
+		/* LSA ID Information */
+		if (0) {
+			bitvec_set_bit(&bv, H);
+			/* FIXME */
+		} else
+			bitvec_set_bit(&bv, L);
+	} else {
+		/* L and break indicator */
+		bitvec_set_bit(&bv, L);
+		bitvec_set_bit(&bv, si4->break_ind ? H : L);
+	}
+
+	return 0;
+}
+
+/* GPRS Mobile Allocation as per TS 04.60 Chapter 12.10a:
+   < GPRS Mobile Allocation IE > ::=
+     < HSN : bit (6) >
+     { 0 | 1 < RFL number list : < RFL number list struct > > }
+     { 0 < MA_LENGTH : bit (6) >
+         < MA_BITMAP: bit (val(MA_LENGTH) + 1) >
+     | 1 { 0 | 1 <ARFCN index list : < ARFCN index list struct > > } } ;
+
+     < RFL number list struct > :: =
+       < RFL_NUMBER : bit (4) >
+       { 0 | 1 < RFL number list struct > } ;
+     < ARFCN index list struct > ::=
+       < ARFCN_INDEX : bit(6) >
+       { 0 | 1 < ARFCN index list struct > } ;
+ */
+static int append_gprs_mobile_alloc(struct bitvec *bv)
+{
+	/* Hopping Sequence Number */
+	bitvec_set_uint(bv, 0, 6);
+
+	if (0) {
+		/* We want to use a RFL number list */
+		bitvec_set_bit(bv, 1);
+		/* FIXME: RFL number list */
+	} else
+		bitvec_set_bit(bv, 0);
+
+	if (0) {
+		/* We want to use a MA_BITMAP */
+		bitvec_set_bit(bv, 0);
+		/* FIXME: MA_LENGTH, MA_BITMAP, ... */
+	} else {
+		bitvec_set_bit(bv, 1);
+		if (0) {
+			/* We want to provide an ARFCN index list */
+			bitvec_set_bit(bv, 1);
+			/* FIXME */
+		} else
+			bitvec_set_bit(bv, 0);
+	}
+	return 0;
+}
+
+static int encode_t3192(unsigned int t3192)
+{
+	if (t3192 == 0)
+		return 3;
+	else if (t3192 <= 80)
+		return 4;
+	else if (t3192 <= 120)
+		return 5;
+	else if (t3192 <= 160)
+		return 6;
+	else if (t3192 <= 200)
+		return 7;
+	else if (t3192 <= 500)
+		return 0;
+	else if (t3192 <= 1000)
+		return 1;
+	else if (t3192 <= 1500)
+		return 2;
+	else
+		return -EINVAL;
+}
+
+static int encode_drx_timer(unsigned int drx)
+{
+	if (drx == 0)
+		return 0;
+	else if (drx == 1)
+		return 1;
+	else if (drx == 2)
+		return 2;
+	else if (drx <= 4)
+		return 3;
+	else if (drx <= 8)
+		return 4;
+	else if (drx <= 16)
+		return 5;
+	else if (drx <= 32)
+		return 6;
+	else if (drx <= 64)
+		return 7;
+	else
+		return -EINVAL;
+}
+
+/* GPRS Cell Options as per TS 04.60 Chapter 12.24
+	< GPRS Cell Options IE > ::=
+		< NMO : bit(2) >
+		< T3168 : bit(3) >
+		< T3192 : bit(3) >
+		< DRX_TIMER_MAX: bit(3) >
+		< ACCESS_BURST_TYPE: bit >
+		< CONTROL_ACK_TYPE : bit >
+		< BS_CV_MAX: bit(4) >
+		{ 0 | 1 < PAN_DEC : bit(3) >
+			< PAN_INC : bit(3) >
+			< PAN_MAX : bit(3) >
+		{ 0 | 1 < Extension Length : bit(6) >
+			< bit (val(Extension Length) + 1
+			& { < Extension Information > ! { bit ** = <no string> } } ;
+	< Extension Information > ::=
+		{ 0 | 1 < EGPRS_PACKET_CHANNEL_REQUEST : bit >
+			< BEP_PERIOD : bit(4) > }
+		< PFC_FEATURE_MODE : bit >
+		< DTM_SUPPORT : bit >
+		<BSS_PAGING_COORDINATION: bit >
+		<spare bit > ** ;
+ */
+static int append_gprs_cell_opt(struct bitvec *bv, struct gprs_cell_options *gco)
+{
+	int t3192, drx_timer_max;
+
+	t3192 = encode_t3192(gco->t3192);
+	if (t3192 < 0)
+		return t3192;
+
+	drx_timer_max = encode_drx_timer(gco->drx_timer_max);
+	if (drx_timer_max < 0)
+		return drx_timer_max;
+
+	bitvec_set_uint(bv, gco->nmo, 2);
+	bitvec_set_uint(bv, gco->t3168 / 500, 3);
+	bitvec_set_uint(bv, t3192, 3);
+	bitvec_set_uint(bv, drx_timer_max, 3);
+	/* ACCESS_BURST_TYPE: Hard-code 8bit */
+	bitvec_set_bit(bv, 0);
+	/* CONTROL_ACK_TYPE: Hard-code to RLC/MAC control block */
+	bitvec_set_bit(bv, 1);
+	bitvec_set_uint(bv, gco->bs_cv_max, 4);
+
+	/* hard-code no PAN_{DEC,INC,MAX} */
+	bitvec_set_bit(bv, 0);
+
+	/* no extension information (EDGE) */
+	bitvec_set_bit(bv, 0);
+
+	return 0;
+}
+
+static void append_gprs_pwr_ctrl_pars(struct bitvec *bv,
+				      struct gprs_power_ctrl_pars *pcp)
+{
+	bitvec_set_uint(bv, pcp->alpha, 4);
+	bitvec_set_uint(bv, pcp->t_avg_w, 5);
+	bitvec_set_uint(bv, pcp->t_avg_t, 5);
+	bitvec_set_uint(bv, pcp->pc_meas_chan, 1);
+	bitvec_set_uint(bv, pcp->n_avg_i, 4);
+}
+
+/* Generate SI13 Rest Octests (Chapter 10.5.2.37b) */
+int rest_octets_si13(u_int8_t *data, const struct gsm48_si13_info *si13)
+{
+	struct bitvec bv;
+
+	memset(&bv, 0, sizeof(bv));
+	bv.data = data;
+	bv.data_len = 21;
+
+	if (0) {
+		/* No rest octets */
+		bitvec_set_bit(&bv, L);
+	} else {
+		bitvec_set_bit(&bv, H);
+		bitvec_set_uint(&bv, si13->bcch_change_mark, 3);
+		bitvec_set_uint(&bv, si13->si_change_field, 4);
+		if (0) {
+			bitvec_set_bit(&bv, 0);
+		} else {
+			bitvec_set_bit(&bv, 1);
+			bitvec_set_uint(&bv, si13->bcch_change_mark, 2);
+			append_gprs_mobile_alloc(&bv);
+		}
+		if (!si13->pbcch_present) {
+			/* PBCCH not present in cell */
+			bitvec_set_bit(&bv, 0);
+			bitvec_set_uint(&bv, si13->no_pbcch.rac, 8);
+			bitvec_set_bit(&bv, si13->no_pbcch.spgc_ccch_sup);
+			bitvec_set_uint(&bv, si13->no_pbcch.prio_acc_thr, 3);
+			bitvec_set_uint(&bv, si13->no_pbcch.net_ctrl_ord, 2);
+			append_gprs_cell_opt(&bv, &si13->cell_opts);
+			append_gprs_pwr_ctrl_pars(&bv, &si13->pwr_ctrl_pars);
+		} else {
+			/* PBCCH present in cell */
+			bitvec_set_bit(&bv, 1);
+			bitvec_set_uint(&bv, si13->pbcch.psi1_rep_per, 4);
+			/* PBCCH Descripiton */
+			bitvec_set_uint(&bv, si13->pbcch.pb, 4);
+			bitvec_set_uint(&bv, si13->pbcch.tsc, 3);
+			bitvec_set_uint(&bv, si13->pbcch.tn, 3);
+			switch (si13->pbcch.carrier_type) {
+			case PBCCH_BCCH:
+				bitvec_set_bit(&bv, 0);
+				bitvec_set_bit(&bv, 0);
+				break;
+			case PBCCH_ARFCN:
+				bitvec_set_bit(&bv, 0);
+				bitvec_set_bit(&bv, 1);
+				bitvec_set_uint(&bv, si13->pbcch.arfcn, 10);
+				break;
+			case PBCCH_MAIO:
+				bitvec_set_bit(&bv, 1);
+				bitvec_set_uint(&bv, si13->pbcch.maio, 6);
+				break;
+			}
+		}
+	}
+	return bitvec_spare_padding(&bv, (bv.data_len*8)-1);
+}