update the lchan name to always reflect VAMOS shadowness

Change gsm_lchan_name_compute() to a function that in-place updates the
lchan->name. That allows calling it numerous times with the talloc
handled internally. Rename it to lchan_update_name().

Add 'shadow' to lchan_update_name() and lchan_fsm_update_id() for VAMOS
shadow lchans, and also print the lchan index that it is a shadow for,
instead of the index in the lchan array.

When set_pchan_is() updates the VAMOSness of the lchans, call
lchan_fsm_update_id(). From lchan_fsm_update_id() also call
lchan_update_name().

This is a bit convoluted for legacy reasons. There are utility programs
and C tests using bts_trx.c but not lchan_fsm.c. lchan_update_name()
lives in gsm_data.c for that reason. This patch calls
lchan_update_name() from lchan_fsm_update_id() and not vice versa to
avoid having to add stubbed lchan_fsm_update_id() functions to all
utility programs and C tests.

We can't easily unify the lchan->name and lchan->fi->id without lots of
refactoring rippling through all those little utility programs and C
tests.

Change-Id: I7c2bae3b895a91f1b99b4147ecc0e3009cb7439a

include/osmocom/bsc/gsm_data.h

@@ -1008,7 +1008,7 @@ const char *gsm_lchant_name(enum gsm_chan_t c);
 const char *gsm_chreq_name(enum gsm_chreq_reason_t c);
 char *gsm_ts_name(const struct gsm_bts_trx_ts *ts);
 char *gsm_ts_and_pchan_name(const struct gsm_bts_trx_ts *ts);
-char *gsm_lchan_name_compute(void *ctx, const struct gsm_lchan *lchan);
+void lchan_update_name(struct gsm_lchan *lchan);
 
 static inline char *gsm_lchan_name(const struct gsm_lchan *lchan)
 {

include/osmocom/bsc/lchan_fsm.h

@@ -83,3 +83,4 @@ bool lchan_may_receive_data(struct gsm_lchan *lchan);
 void lchan_forget_conn(struct gsm_lchan *lchan);
 
 void lchan_fsm_skip_error(struct gsm_lchan *lchan);
+void lchan_fsm_update_id(struct gsm_lchan *lchan);

src/osmo-bsc/assignment_fsm.c

@@ -302,14 +302,15 @@ static void assignment_fsm_update_id(struct gsm_subscriber_connection *conn)
 		return;
 	}
 
-	osmo_fsm_inst_update_id_f(conn->assignment.fi, "%s_%u-%u-%u-%s%s%s-%u",
+	osmo_fsm_inst_update_id_f(conn->assignment.fi, "%s_%u-%u-%u-%s%s%s-%s%u",
 				  conn->fi->id,
 				  new_lchan->ts->trx->bts->nr, new_lchan->ts->trx->nr, new_lchan->ts->nr,
 				  gsm_pchan_id(new_lchan->ts->pchan_on_init),
 				  (new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? "" : "as",
 				  (new_lchan->ts->pchan_on_init == new_lchan->ts->pchan_is)? ""
 					  : gsm_pchan_id(new_lchan->ts->pchan_is),
-				  new_lchan->nr);
+				  new_lchan->vamos.is_secondary ? "shadow" : "",
+				  new_lchan->nr - (new_lchan->vamos.is_secondary ? new_lchan->ts->max_primary_lchans : 0));
 }
 
 static bool lchan_type_compat_with_mode(enum gsm_chan_t type, const struct channel_mode_and_rate *ch_mode_rate)

src/osmo-bsc/bts_trx.c

@@ -111,7 +111,7 @@ struct gsm_bts_trx *gsm_bts_trx_alloc(struct gsm_bts *bts)
 			lchan->nr = l;
 			lchan->type = GSM_LCHAN_NONE;
 
-			lchan->name = gsm_lchan_name_compute(trx, lchan);
+			lchan_update_name(lchan);
 		}
 	}
 

src/osmo-bsc/gsm_data.c

@@ -334,12 +334,15 @@ char *gsm_ts_and_pchan_name(const struct gsm_bts_trx_ts *ts)
 	return ts2str;
 }
 
-char *gsm_lchan_name_compute(void *ctx, const struct gsm_lchan *lchan)
+void lchan_update_name(struct gsm_lchan *lchan)
 {
 	struct gsm_bts_trx_ts *ts = lchan->ts;
-	return talloc_asprintf(ctx, "(bts=%d,trx=%d,ts=%d,ss=%d%s)",
-			       ts->trx->bts->nr, ts->trx->nr, ts->nr, lchan->nr,
-			       lchan->vamos.is_secondary ? "-VAMOS" : "");
+	if (lchan->name)
+		talloc_free(lchan->name);
+	lchan->name = talloc_asprintf(ts->trx, "(bts=%d,trx=%d,ts=%d,ss=%s%d)",
+				      ts->trx->bts->nr, ts->trx->nr, ts->nr,
+				      lchan->vamos.is_secondary ? "shadow" : "",
+				      lchan->nr - (lchan->vamos.is_secondary ? ts->max_primary_lchans : 0));
 }
 
 /* obtain the MO structure for a given object instance */

src/osmo-bsc/lchan_fsm.c

@@ -411,11 +411,16 @@ void lchan_mode_modify(struct gsm_lchan *lchan, struct lchan_modify_info *info)
 	}
 }
 
-static void lchan_fsm_update_id(struct gsm_lchan *lchan)
+void lchan_fsm_update_id(struct gsm_lchan *lchan)
 {
-	osmo_fsm_inst_update_id_f(lchan->fi, "%u-%u-%u-%s-%u",
+	lchan_update_name(lchan);
+	if (!lchan->fi)
+		return;
+	osmo_fsm_inst_update_id_f(lchan->fi, "%u-%u-%u-%s-%s%u",
 				  lchan->ts->trx->bts->nr, lchan->ts->trx->nr, lchan->ts->nr,
-				  gsm_pchan_id(lchan->ts->pchan_on_init), lchan->nr);
+				  gsm_pchan_id(lchan->ts->pchan_on_init),
+				  lchan->vamos.is_secondary ? "shadow" : "",
+				  lchan->nr - (lchan->vamos.is_secondary ? lchan->ts->max_primary_lchans : 0));
 	if (lchan->fi_rtp)
 		osmo_fsm_inst_update_id_f(lchan->fi_rtp, lchan->fi->id);
 }

src/osmo-bsc/timeslot_fsm.c

@@ -204,11 +204,14 @@ void ts_set_pchan_is(struct gsm_bts_trx_ts *ts, enum gsm_phys_chan_config pchan_
 				lchan->vamos.is_secondary = false;
 			else
 				lchan->vamos.is_secondary = true;
+			lchan_fsm_update_id(lchan);
 		}
 		break;
 	default:
-		ts_for_n_lchans(lchan, ts, ts->max_lchans_possible)
+		ts_for_n_lchans(lchan, ts, ts->max_lchans_possible) {
 			lchan->vamos.is_secondary = false;
+			lchan_fsm_update_id(lchan);
+		}
 		break;
 	}
 }