From d831805fc7660d2f7c6195c98d0070c0a644680f Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <zecke@selfish.org>
Date: Wed, 28 Oct 2009 14:23:39 +0100
Subject: [PATCH] [lchan] Keep track which SAPIs has been established with the
 BTS

Keep track of which SAPIs have been established either by the
BTS (from the MS) or by us. This can be used by the on-waves
BSC code to figure out if a new request should be made.
---
 openbsc/include/openbsc/gsm_data.h | 8 ++++++++
 openbsc/src/abis_rsl.c             | 4 ++++
 openbsc/src/chan_alloc.c           | 3 +++
 3 files changed, 15 insertions(+)

diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index 927c3284..94a70818 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -131,6 +131,11 @@ struct gsm_loc_updating_operation {
 #define MAX_A5_KEY_LEN	(128/8)
 #define RSL_ENC_ALG_A5(x)	(x+1)
 
+/* is the data link established? who established it? */
+#define LCHAN_SAPI_UNUSED	0
+#define LCHAN_SAPI_MS		1
+#define LCHAN_SAPI_NET		2
+
 struct gsm_lchan {
 	/* The TS that we're part of */
 	struct gsm_bts_trx_ts *ts;
@@ -160,6 +165,9 @@ struct gsm_lchan {
 
 	struct timer_list T3101;
 
+	/* Established data link layer services */
+	u_int8_t sapis[8];
+
 	/*
 	 * Operations that have a state and might be pending
 	 */
diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c
index a4764f5f..acd41dd6 100644
--- a/openbsc/src/abis_rsl.c
+++ b/openbsc/src/abis_rsl.c
@@ -1294,6 +1294,7 @@ static int abis_rsl_rx_rll(struct msgb *msg)
 	case RSL_MT_EST_IND:
 		DEBUGPC(DRLL, "ESTABLISH INDICATION\n");
 		/* lchan is established, stop T3101 */
+		msg->lchan->sapis[rllh->link_id & 0x7] = LCHAN_SAPI_MS;
 		bsc_del_timer(&msg->lchan->T3101);
 		if (msgb_l2len(msg) > 
 		    sizeof(struct abis_rsl_common_hdr) + sizeof(*rllh) &&
@@ -1304,12 +1305,14 @@ static int abis_rsl_rx_rll(struct msgb *msg)
 		break;
 	case RSL_MT_EST_CONF:
 		DEBUGPC(DRLL, "ESTABLISH CONFIRM\n");
+		msg->lchan->sapis[rllh->link_id & 0x7] = LCHAN_SAPI_NET;
 		rll_indication(msg->lchan, rllh->link_id,
 				  BSC_RLLR_IND_EST_CONF);
 		break;
 	case RSL_MT_REL_IND:
 		/* BTS informs us of having received  DISC from MS */
 		DEBUGPC(DRLL, "RELEASE INDICATION\n");
+		msg->lchan->sapis[rllh->link_id & 0x7] = LCHAN_SAPI_UNUSED;
 		rll_indication(msg->lchan, rllh->link_id,
 				  BSC_RLLR_IND_REL_IND);
 		/* we can now releae the channel on the BTS/Abis side */
@@ -1321,6 +1324,7 @@ static int abis_rsl_rx_rll(struct msgb *msg)
 		/* BTS informs us of having received UA from MS,
 		 * in response to DISC that we've sent earlier */
 		DEBUGPC(DRLL, "RELEASE CONFIRMATION\n");
+		msg->lchan->sapis[rllh->link_id & 0x7] = LCHAN_SAPI_UNUSED;
 		/* we can now releae the channel on the BTS/Abis side */
 		/* FIXME: officially we need to start T3111 and wait for
 		 * some grace period */
diff --git a/openbsc/src/chan_alloc.c b/openbsc/src/chan_alloc.c
index 541c6c35..7464aa96 100644
--- a/openbsc/src/chan_alloc.c
+++ b/openbsc/src/chan_alloc.c
@@ -212,6 +212,9 @@ struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type)
 		lchan->type = type;
 		lchan->use_count = 0;
 
+		/* clear sapis */
+		memset(lchan->sapis, 0, sizeof(lchan->sapis));
+
 		/* Configure the time and start it so it will be closed */
 		lchan->release_timer.cb = auto_release_channel;
 		lchan->release_timer.data = lchan;