pcu_sock: use PCU_IF_SAPI_AGCH_2 instead PCU_IF_SAPI_AGCH

In PCUIF v.11 we use PCU_IF_SAPI_AGCH_2 exclusively. We use this SAPI
to transfer IMMEDIATE ASSIGNMENT messages for uplink and downlink. In
both cases we send a confirmation back to the PCU. For details see
coresponding patch in osmo-pcu.git (see Depends)

CAUTION: This patch breaks compatibility to current master osmo-pcu (See
also "Depends")

Related: OS#5927
Depends: osmo-pcu.git I9effdcec1da91a6e2e7a7c41f95d3300ad1bb292
Depends: osmo-ttcn3-hacks.git Iec00d8144dfb2cd8bcee9093c96a3cc98aea6458
Change-Id: I29858fa20ad8bd0aefe81a5c40ad77a2559a8c10

6 files changed, 47 insertions, 8 deletions

diff --git a/include/osmo-bts/bts.h b/include/osmo-bts/bts.h
index b2dd024e..d3329355 100644
--- a/include/osmo-bts/bts.h
+++ b/include/osmo-bts/bts.h
@@ -442,4 +442,11 @@ struct gsm_lchan *gsm_bts_get_cbch(struct gsm_bts *bts);
 
 int bts_set_c0_pwr_red(struct gsm_bts *bts, const uint8_t red);
 
+/* Context information to be put in the control buffer (db) of the AGCH msg
+ * buffer */
+struct bts_agch_msg_cb {
+	uint32_t msg_id;
+	bool confirm;
+} __attribute__ ((packed));
+
 #endif /* _BTS_H */
diff --git a/include/osmo-bts/pcu_if.h b/include/osmo-bts/pcu_if.h
index 4b375606..3563c5ba 100644
--- a/include/osmo-bts/pcu_if.h
+++ b/include/osmo-bts/pcu_if.h
@@ -23,7 +23,7 @@ int pcu_tx_rach_ind(uint8_t bts_nr, uint8_t trx_nr, uint8_t ts_nr,
 int pcu_tx_time_ind(uint32_t fn);
 int pcu_tx_interf_ind(const struct gsm_bts_trx *trx, uint32_t fn);
 int pcu_tx_pag_req(const uint8_t *identity_lv, uint8_t chan_needed);
-int pcu_tx_pch_data_cnf(uint32_t msg_id);
+int pcu_tx_data_cnf(uint32_t msg_id, uint8_t sapi);
 int pcu_tx_susp_req(struct gsm_lchan *lchan, uint32_t tlli, const uint8_t *ra_id, uint8_t cause);
 int pcu_sock_send(struct msgb *msg);
 
diff --git a/include/osmo-bts/pcuif_proto.h b/include/osmo-bts/pcuif_proto.h
index 498d9d44..b47dc75a 100644
--- a/include/osmo-bts/pcuif_proto.h
+++ b/include/osmo-bts/pcuif_proto.h
@@ -36,6 +36,7 @@
 #define PCU_IF_SAPI_PRACH	0x06	/* packet random access channel */
 #define PCU_IF_SAPI_PTCCH	0x07	/* packet TA control channel */
 #define PCU_IF_SAPI_PCH_2	0x08	/* assignment on PCH (confirmed using message id) */
+#define PCU_IF_SAPI_AGCH_2	0x09	/* assignment on AGCH (confirmed using message id) */
 
 /* flags */
 #define PCU_IF_FLAG_ACTIVE	(1 << 0)/* BTS is active */
@@ -235,6 +236,18 @@ struct gsm_pcu_if_pch {
 	bool confirm;
 } __attribute__((packed));
 
+/* Struct to send a (confirmed) IMMEDIATE ASSIGNMENT message via AGCH. The struct is sent as a data request
+ * (data_req) under SAPI PCU_IF_SAPI_AGCH_2. */
+struct gsm_pcu_if_agch {
+	/* message id as reference for confirmation */
+	uint32_t msg_id;
+	/* GSM mac-block (with immediate assignment message) */
+	uint8_t data[GSM_MACBLOCK_LEN];
+	/* Set to true in case the receiving end must send a confirmation
+	 * when the MAC block (data) has been sent. */
+	bool confirm;
+} __attribute__((packed));
+
 struct gsm_pcu_if {
 	/* context based information */
 	uint8_t		msg_type;	/* message type */
diff --git a/src/common/bts.c b/src/common/bts.c
index 0f2a0191..3cd91e7e 100644
--- a/src/common/bts.c
+++ b/src/common/bts.c
@@ -47,6 +47,7 @@
 #include <osmo-bts/bts_sm.h>
 #include <osmo-bts/dtx_dl_amr_fsm.h>
 #include <osmo-bts/pcuif_proto.h>
+#include <osmo-bts/pcu_if.h>
 #include <osmo-bts/rsl.h>
 #include <osmo-bts/oml.h>
 #include <osmo-bts/signal.h>
@@ -729,6 +730,7 @@ int bts_ccch_copy_msg(struct gsm_bts *bts, uint8_t *out_buf, struct gsm_time *gt
 	struct msgb *msg = NULL;
 	int rc = 0;
 	int is_empty = 1;
+	const struct bts_agch_msg_cb *msg_cb;
 
 	/* Do queue house keeping.
 	 * This needs to be done every time a CCCH message is requested, since
@@ -759,6 +761,11 @@ int bts_ccch_copy_msg(struct gsm_bts *bts, uint8_t *out_buf, struct gsm_time *gt
 
 	rate_ctr_inc2(bts->ctrs, BTS_CTR_AGCH_SENT);
 
+	/* Confirm sending of the AGCH message towards the PCU */
+	msg_cb = (struct bts_agch_msg_cb *) msg->cb;
+	if (msg_cb->confirm)
+		pcu_tx_data_cnf(msg_cb->msg_id, PCU_IF_SAPI_AGCH_2);
+
 	/* Copy AGCH message */
 	memcpy(out_buf, msgb_l3(msg), msgb_l3len(msg));
 	rc = msgb_l3len(msg);
diff --git a/src/common/paging.c b/src/common/paging.c
index 9738bd64..0d3877d9 100644
--- a/src/common/paging.c
+++ b/src/common/paging.c
@@ -734,7 +734,7 @@ int paging_gen_msg(struct paging_state *ps, uint8_t *out_buf, struct gsm_time *g
 							GSM_MACBLOCK_LEN);
 			/* send a confirmation back (if required) */
 			if (pr[num_pr]->u.macblock.confirm)
-				pcu_tx_pch_data_cnf(pr[num_pr]->u.macblock.msg_id);
+				pcu_tx_data_cnf(pr[num_pr]->u.macblock.msg_id, PCU_IF_SAPI_PCH_2);
 			talloc_free(pr[num_pr]);
 			return GSM_MACBLOCK_LEN;
 		}
diff --git a/src/common/pcu_sock.c b/src/common/pcu_sock.c
index 333937ad..e1004641 100644
--- a/src/common/pcu_sock.c
+++ b/src/common/pcu_sock.c
@@ -60,6 +60,7 @@ static const char *sapi_string[] = {
 	[PCU_IF_SAPI_PRACH] =	"PRACH",
 	[PCU_IF_SAPI_PTCCH] = 	"PTCCH",
 	[PCU_IF_SAPI_PCH_2] =	"PCH_2",
+	[PCU_IF_SAPI_AGCH_2] =	"AGCH_2",
 };
 
 /*
@@ -618,7 +619,7 @@ int pcu_tx_pag_req(const uint8_t *identity_lv, uint8_t chan_needed)
 	return pcu_sock_send(msg);
 }
 
-int pcu_tx_pch_data_cnf(uint32_t msg_id)
+int pcu_tx_data_cnf(uint32_t msg_id, uint8_t sapi)
 {
 	struct gsm_bts *bts;
 	struct msgb *msg;
@@ -634,7 +635,7 @@ int pcu_tx_pch_data_cnf(uint32_t msg_id)
 		return -ENOMEM;
 	pcu_prim = (struct gsm_pcu_if *) msg->data;
 	pcu_prim->u.data_cnf2 = (struct gsm_pcu_if_data_cnf) {
-		.sapi = PCU_IF_SAPI_PCH_2,
+		.sapi = sapi,
 		.msg_id = msg_id,
 	};
 
@@ -688,19 +689,30 @@ static int pcu_rx_data_req(struct gsm_bts *bts, uint8_t msg_type,
 					 gsm_pcu_if_pch->imsi, gsm_pcu_if_pch->confirm, gsm_pcu_if_pch->data);
 		break;
 	}
-	case PCU_IF_SAPI_AGCH:
-		msg = msgb_alloc(data_req->len, "pcu_agch");
+	case PCU_IF_SAPI_AGCH_2:
+	{
+		const struct gsm_pcu_if_agch *gsm_pcu_if_agch;
+		struct bts_agch_msg_cb *msg_cb;
+
+		gsm_pcu_if_agch = (struct gsm_pcu_if_agch *)data_req->data;
+
+		msg = msgb_alloc(GSM_MACBLOCK_LEN, "pcu_agch");
 		if (!msg) {
 			rc = -ENOMEM;
 			break;
 		}
-		msg->l3h = msgb_put(msg, data_req->len);
-		memcpy(msg->l3h, data_req->data, data_req->len);
+		msg->l3h = msgb_put(msg, GSM_MACBLOCK_LEN);
+		memcpy(msg->l3h, gsm_pcu_if_agch->data, GSM_MACBLOCK_LEN);
+
+		msg_cb = (struct bts_agch_msg_cb *) msg->cb;
+		msg_cb->confirm = gsm_pcu_if_agch->confirm;
+		msg_cb->msg_id = gsm_pcu_if_agch->msg_id;
 		if (bts_agch_enqueue(bts, msg) < 0) {
 			msgb_free(msg);
 			rc = -EIO;
 		}
 		break;
+	}
 	case PCU_IF_SAPI_PDTCH:
 	case PCU_IF_SAPI_PTCCH:
 		trx = gsm_bts_trx_num(bts, data_req->trx_nr);