code dup: join [rsl_]lchan_lookup() from libbsc and osmo-bts
lchan_lookup in abis_rsl.c and rsl_lchan_lookup() from osmo-bts rsl.c are the
same code, except for the log context, which is only set in abis_rsl.c.
Factor out the common code to rsl_lchan_lookup() in gsm_data_shared.c.
Openbsc and osmo-bts each define their own DRSL log constant, so add an int *rc
return code argument and keep the logging part in abis_rsl.c's thin lchan_lookup()
wrapper. Incidentally, this also removes code dup for logging.
To avoid duplicate symbols, the rsl_lchan_lookup() implementation needs to be
removed from osmo-bts, so older osmo-bts git revisions will not build with
this.
Change-Id: Ie89bc5bb9110a0e539d37991dedac6f913211b48
diff --git a/openbsc/src/libcommon/gsm_data_shared.c b/openbsc/src/libcommon/gsm_data_shared.c
index 07bb64d..2fc5690 100644
--- a/openbsc/src/libcommon/gsm_data_shared.c
+++ b/openbsc/src/libcommon/gsm_data_shared.c
@@ -612,3 +612,52 @@
return lchan;
}
+
+/* determine logical channel based on TRX and channel number IE */
+struct gsm_lchan *rsl_lchan_lookup(struct gsm_bts_trx *trx, uint8_t chan_nr,
+ int *rc)
+{
+ uint8_t ts_nr = chan_nr & 0x07;
+ uint8_t cbits = chan_nr >> 3;
+ uint8_t lch_idx;
+ struct gsm_bts_trx_ts *ts = &trx->ts[ts_nr];
+ bool ok = true;
+
+ if (rc)
+ *rc = -EINVAL;
+
+ if (cbits == 0x01) {
+ lch_idx = 0; /* TCH/F */
+ if (ts->pchan != GSM_PCHAN_TCH_F &&
+ ts->pchan != GSM_PCHAN_PDCH &&
+ ts->pchan != GSM_PCHAN_TCH_F_PDCH)
+ ok = false;
+ } else if ((cbits & 0x1e) == 0x02) {
+ lch_idx = cbits & 0x1; /* TCH/H */
+ if (ts->pchan != GSM_PCHAN_TCH_H)
+ ok = false;
+ } else if ((cbits & 0x1c) == 0x04) {
+ lch_idx = cbits & 0x3; /* SDCCH/4 */
+ if (ts->pchan != GSM_PCHAN_CCCH_SDCCH4 &&
+ ts->pchan != GSM_PCHAN_CCCH_SDCCH4_CBCH)
+ ok = false;
+ } else if ((cbits & 0x18) == 0x08) {
+ lch_idx = cbits & 0x7; /* SDCCH/8 */
+ if (ts->pchan != GSM_PCHAN_SDCCH8_SACCH8C &&
+ ts->pchan != GSM_PCHAN_SDCCH8_SACCH8C_CBCH)
+ ok = false;
+ } else if (cbits == 0x10 || cbits == 0x11 || cbits == 0x12) {
+ lch_idx = 0;
+ if (ts->pchan != GSM_PCHAN_CCCH &&
+ ts->pchan != GSM_PCHAN_CCCH_SDCCH4 &&
+ ts->pchan != GSM_PCHAN_CCCH_SDCCH4_CBCH)
+ ok = false;
+ /* FIXME: we should not return first sdcch4 !!! */
+ } else
+ return NULL;
+
+ if (rc && ok)
+ *rc = 0;
+
+ return &ts->lchan[lch_idx];
+}