Change in osmo-bts[master]: cbch: Implement support for DEFAULT message

[Harald Welte]

Harald Welte has uploaded this change for review. ( https://gerrit.osmocom.org/14100


Change subject: cbch: Implement support for DEFAULT message
......................................................................

cbch: Implement support for DEFAULT message

The BSC can not only send us each to-be-sent message separately, but
it can also configure a DEFAULT message, which is then to be sent
instead of the NULL message.  Let's add support for this

Change-Id: I65a79215b54155d128c26d2ca11ff9ff3ed2cdba
Closes: OS#4013
---
M include/osmo-bts/gsm_data_shared.h
M src/common/cbch.c
2 files changed, 38 insertions(+), 13 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/00/14100/1

diff --git a/include/osmo-bts/gsm_data_shared.h b/include/osmo-bts/gsm_data_shared.h
index 72d9710..6974e62 100644
--- a/include/osmo-bts/gsm_data_shared.h
+++ b/include/osmo-bts/gsm_data_shared.h
@@ -737,6 +737,7 @@
 	struct {
 		struct llist_head queue;	/* list of struct smscb_msg */
 		struct smscb_msg *cur_msg;	/* current SMS-CB */
+		struct smscb_msg *default_msg;	/* default broadcast message; NULL if none */
 	} smscb_state;
 
 	float min_qual_rach;	/* minimum quality for RACH bursts */
diff --git a/src/common/cbch.c b/src/common/cbch.c
index 817489f..185386a 100644
--- a/src/common/cbch.c
+++ b/src/common/cbch.c
@@ -101,9 +101,14 @@
 		block_type->lb = 0;
 
 	if (block_nr == 4) {
-		/* delete any fully-transmitted normal message (or superseded default) */
-		talloc_free(bts->smscb_state.cur_msg);
-		bts->smscb_state.cur_msg = NULL;
+		if (msg != bts->smscb_state.default_msg) {
+			DEBUGPGT(DLSMS, g_time, "deleting fully-transmitted message %p\n", msg);
+			/* delete any fully-transmitted normal message (or superseded default) */
+			talloc_free(bts->smscb_state.cur_msg);
+			bts->smscb_state.cur_msg = NULL;
+		} else {
+			DEBUGPGT(DLSMS, g_time, "keeping fully-transmitted default message %p\n", msg);
+		}
 	}
 
 	return block_type->lb;
@@ -160,16 +165,25 @@
 	case RSL_CB_CMD_TYPE_SCHEDULE:
 	case RSL_CB_CMD_TYPE_NULL:
 		/* def_bcast is ignored as per Section 9.3.41 of 3GPP TS 48.058 */
+		llist_add_tail(&scm->list, &bts->smscb_state.queue);
+		/* FIXME: limit queue size and optionally send CBCH LOAD Information (overflow) via RSL */
 		break;
 	case RSL_CB_CMD_TYPE_DEFAULT:
-		/* use def_bcast, ignore command  */
-		/* def_bcast == 0: normal mess */
+		/* old default msg will be free'd in get_smscb_block() if it is currently in transit
+		 * and we set a new default_msg here */
+		if (bts->smscb_state.cur_msg && bts->smscb_state.cur_msg == bts->smscb_state.default_msg)
+			talloc_free(bts->smscb_state.cur_msg);
+		if (cmd_type.def_bcast == RSL_CB_CMD_DEFBCAST_NORMAL)
+			/* def_bcast == 0: normal message */
+			bts->smscb_state.default_msg = scm;
+		else {
+			/* def_bcast == 1: NULL message */
+			bts->smscb_state.default_msg = NULL;
+			talloc_free(scm);
+		}
 		break;
 	}
 
-	llist_add_tail(&scm->list, &bts->smscb_state.queue);
-	/* FIXME: limit queue size and optionally send CBCH LOAD Information (overflow) via RSL */
-
 	return 0;
 }
 
@@ -178,13 +192,23 @@
 	struct smscb_msg *msg;
 
 	msg = llist_first_entry_or_null(&bts->smscb_state.queue, struct smscb_msg, list);
-	if (!msg) {
-		/* FIXME: send CBCH LOAD Information (underflow) via RSL */
-		return NULL;
+	if (msg) {
+		llist_del(&msg->list);
+		DEBUGP(DLSMS, "%s: Dequeued msg\n", __func__);
+		return msg;
 	}
 
-	llist_del(&msg->list);
-	return msg;
+	/* FIXME: send CBCH LOAD Information (underflow) via RSL */
+
+	/* choose the default message, if any */
+	msg = bts->smscb_state.default_msg;
+	if (msg) {
+		DEBUGP(DLSMS, "%s: Using default msg\n", __func__);
+		return msg;
+	}
+
+	DEBUGP(DLSMS, "%s: No queued msg nor default\n", __func__);
+	return NULL;
 }
 
 /* call-back from bts model specific code when it wants to obtain a CBCH

-- 
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Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I65a79215b54155d128c26d2ca11ff9ff3ed2cdba
Gerrit-Change-Number: 14100
Gerrit-PatchSet: 1
Gerrit-Owner: Harald Welte <laforge at gnumonks.org>
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