[PATCH] openbsc[master]: bsc: Create minimal SI6 rest octets

[Holger Freyther]

Hello Jenkins Builder,

I'd like you to reexamine a change.  Please visit

    https://gerrit.osmocom.org/71

to look at the new patch set (#2).

bsc: Create minimal SI6 rest octets

In GSM R99 SI6 has mandatory SI6 rest octets and so far we did
not include them. Add minimal support to generate the right band
indicator.

Target a slightly older version of the SI6 rest octets as we neither
support MBMS nor Random bit stream but should include the band
indicator.

Change-Id: I417a40eb91f42a3416b4e07bb9fb4d7a01aaa36b
Fixes: OS#1698
Related: OS#1725
---
M openbsc/include/openbsc/rest_octets.h
M openbsc/src/libbsc/rest_octets.c
M openbsc/src/libbsc/system_information.c
3 files changed, 43 insertions(+), 1 deletion(-)


  git pull ssh://gerrit.osmocom.org:29418/openbsc refs/changes/71/71/2

diff --git a/openbsc/include/openbsc/rest_octets.h b/openbsc/include/openbsc/rest_octets.h
index 32b9963..91413b5 100644
--- a/openbsc/include/openbsc/rest_octets.h
+++ b/openbsc/include/openbsc/rest_octets.h
@@ -12,6 +12,7 @@
 int rest_octets_si1(uint8_t *data, uint8_t *nch_pos, int is1800_net);
 int rest_octets_si2quater(uint8_t *data, const struct osmo_earfcn_si2q *e,
 			  const uint16_t *u, const uint16_t *sc, size_t u_len);
+int rest_octets_si6(uint8_t *data, bool is1800_net);
 
 struct gsm48_si_selection_params {
 	uint16_t penalty_time:5,
diff --git a/openbsc/src/libbsc/rest_octets.c b/openbsc/src/libbsc/rest_octets.c
index aa286e5..065fb7b 100644
--- a/openbsc/src/libbsc/rest_octets.c
+++ b/openbsc/src/libbsc/rest_octets.c
@@ -450,6 +450,45 @@
 	return bv.data_len;
 }
 
+
+/* GSM 04.18 ETSI TS 101 503 V8.27.0 (2006-05)
+
+<SI6 rest octets> ::=
+{L | H <PCH and NCH info>}
+{L | H <VBS/VGCS options : bit(2)>}
+{ < DTM_support : bit == L > I < DTM_support : bit == H >
+< RAC : bit (8) >
+< MAX_LAPDm : bit (3) > }
+< Band indicator >
+{ L | H < GPRS_MS_TXPWR_MAX_CCH : bit (5) > }
+<implicit spare >;
+*/
+int rest_octets_si6(uint8_t *data, bool is1800_net)
+{
+	struct bitvec bv;
+
+	memset(&bv, 0, sizeof(bv));
+	bv.data = data;
+	bv.data_len = 1;
+
+	/* no PCH/NCH info */
+	bitvec_set_bit(&bv, L);
+	/* no VBS/VGCS options */
+	bitvec_set_bit(&bv, L);
+	/* no DTM_support */
+	bitvec_set_bit(&bv, L);
+	/* band indicator */
+	if (is1800_net)
+		bitvec_set_bit(&bv, L);
+	else
+		bitvec_set_bit(&bv, H);
+	/* no GPRS_MS_TXPWR_MAX_CCH */
+	bitvec_set_bit(&bv, L);
+
+	bitvec_spare_padding(&bv, (bv.data_len * 8) - 1);
+	return bv.data_len;
+}
+
 /* GPRS Mobile Allocation as per TS 04.60 Chapter 12.10a:
    < GPRS Mobile Allocation IE > ::=
      < HSN : bit (6) >
diff --git a/openbsc/src/libbsc/system_information.c b/openbsc/src/libbsc/system_information.c
index bf20394..d40bbaf 100644
--- a/openbsc/src/libbsc/system_information.c
+++ b/openbsc/src/libbsc/system_information.c
@@ -905,6 +905,7 @@
 {
 	struct gsm48_system_information_type_6 *si6;
 	int l2_plen = 11;
+	int rc;
 
 	memset(output, GSM_MACBLOCK_PADDING, GSM_MACBLOCK_LEN);
 
@@ -935,8 +936,9 @@
 	gsm48_set_dtx(&si6->cell_options, bts->dtxu, bts->dtxu, false);
 
 	/* SI6 Rest Octets: 10.5.2.35a: PCH / NCH info, VBS/VGCS options */
+	rc = rest_octets_si6(si6->rest_octets, is_dcs_net(bts));
 
-	return l2_plen;
+	return l2_plen + rc;
 }
 
 static struct gsm48_si13_info si13_default = {

-- 
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I417a40eb91f42a3416b4e07bb9fb4d7a01aaa36b
Gerrit-PatchSet: 2
Gerrit-Project: openbsc
Gerrit-Branch: master
Gerrit-Owner: Holger Freyther <holger at freyther.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: Max <msuraev at sysmocom.de>