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
Reviewed-on: https://gerrit.osmocom.org/71
Tested-by: Jenkins Builder
Reviewed-by: Max <msuraev@sysmocom.de>
Reviewed-by: Holger Freyther <holger@freyther.de>
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) >