ccch: Stop following assignment requests and sending LUs

Make the ccch_scan only look at the immediate assignment
but do not follow it. The old behavior was dangerous as
it could interfere with the real receiver of the channel.

diff --git a/src/host/layer23/src/misc/app_ccch_scan.c b/src/host/layer23/src/misc/app_ccch_scan.c
index 0fe83b1..b4e4b6f 100644 (file)
--- a/src/host/layer23/src/misc/app_ccch_scan.c
+++ b/src/host/layer23/src/misc/app_ccch_scan.c
@@ -182,35 +182,15 @@ static void dump_bcch(struct osmocom_ms *ms, uint8_t tc, const uint8_t *data)
 }
 
 
-/* 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)
+/**
+ * This method used to send a l1ctl_tx_dm_est_req_h0 or
+ * a l1ctl_tx_dm_est_req_h1 to the layer1 to follow this
+ * assignment. The code has been removed.
+ */
+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)
@@ -231,10 +211,6 @@ static int gsm48_rx_imm_ass(struct msgb *msg, struct osmocom_ms *ms)
                        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;
@@ -261,19 +237,10 @@ static int gsm48_rx_imm_ass(struct msgb *msg, struct osmocom_ms *ms)
                                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;
+       return 0;
 }
 
 int gsm48_rx_ccch(struct msgb *msg, struct osmocom_ms *ms)
@@ -291,7 +258,7 @@ int gsm48_rx_ccch(struct msgb *msg, struct osmocom_ms *ms)
                /* FIXME: implement decoding of paging request */
                break;
        case GSM48_MT_RR_IMM_ASS:
-               rc = gsm48_rx_imm_ass(msg, ms);
+               LOGP(DRR, LOGL_NOTICE, "Immediate assignment.\n");
                break;
        default:
                LOGP(DRR, LOGL_NOTICE, "unknown PCH/AGCH type 0x%02x\n",