From 320960cf9d28474098dad11bd1042f2a58d87fac Mon Sep 17 00:00:00 2001
From: Keith <keith@rhizomatica.org>
Date: Sat, 13 May 2017 23:38:52 +0200
Subject: libmsc: Map SMPP command status to GSM 04.11 cause

Send SMS RP ERROR with a failure cause that relates to
the status returned by the ESME in the deliver_sm_resp.

Actual mapping array is limited as most phones I tested
don't seem to care about the failure cause anyway,
although some will display a different notification for
GSM411_RP_CAUSE_MO_NUM_UNASSIGNED

Change-Id: I61fb2d9ef4f2d2eabdc49b53d9966ad328d15e51
---
 openbsc/src/libmsc/smpp_openbsc.c | 43 +++++++++++++++++++++++++++++++++++----
 openbsc/src/libmsc/smpp_smsc.c    |  3 +--
 openbsc/src/libmsc/smpp_smsc.h    |  2 +-
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/openbsc/src/libmsc/smpp_openbsc.c b/openbsc/src/libmsc/smpp_openbsc.c
index 8111d92b1..f94968a3f 100644
--- a/openbsc/src/libmsc/smpp_openbsc.c
+++ b/openbsc/src/libmsc/smpp_openbsc.c
@@ -461,6 +461,37 @@ static void append_osmo_tlvs(tlv_t **req_tlv, const struct gsm_lchan *lchan)
 	}
 }
 
+struct {
+	uint32_t smpp_status_code;
+	uint8_t gsm411_cause;
+} smpp_to_gsm411_err_array[] = {
+
+	/* Seems like most phones don't care about the failure cause,
+	 * although some will display a different notification for
+	 * GSM411_RP_CAUSE_MO_NUM_UNASSIGNED
+	 * Some provoke a display of "Try again later"
+	 * while others a more definitive "Message sending failed"
+	 */
+
+	{ ESME_RSYSERR, 	GSM411_RP_CAUSE_MO_DEST_OUT_OF_ORDER	},
+	{ ESME_RINVDSTADR,	GSM411_RP_CAUSE_MO_NUM_UNASSIGNED	},
+	{ ESME_RMSGQFUL,	GSM411_RP_CAUSE_MO_CONGESTION		},
+	{ ESME_RINVSRCADR,	GSM411_RP_CAUSE_MO_SMS_REJECTED		},
+	{ ESME_RINVMSGID,	GSM411_RP_CAUSE_INV_TRANS_REF		}
+};
+
+static int smpp_to_gsm411_err(uint32_t smpp_status_code, int *gsm411_cause)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(smpp_to_gsm411_err_array); i++) {
+		if (smpp_to_gsm411_err_array[i].smpp_status_code != smpp_status_code)
+			continue;
+		*gsm411_cause = smpp_to_gsm411_err_array[i].gsm411_cause;
+		return 0;
+	}
+	return -1;
+}
+
 static void smpp_cmd_free(struct osmo_smpp_cmd *cmd)
 {
 	osmo_timer_del(&cmd->response_timer);
@@ -501,10 +532,11 @@ void smpp_cmd_ack(struct osmo_smpp_cmd *cmd)
 	smpp_cmd_free(cmd);
 }
 
-void smpp_cmd_err(struct osmo_smpp_cmd *cmd)
+void smpp_cmd_err(struct osmo_smpp_cmd *cmd, uint32_t status)
 {
 	struct gsm_subscriber_connection *conn;
 	struct gsm_trans *trans;
+	int gsm411_cause;
 
 	conn = connection_for_subscr(cmd->subscr);
 	if (!conn) {
@@ -520,14 +552,17 @@ void smpp_cmd_err(struct osmo_smpp_cmd *cmd)
 		return;
 	}
 
-	gsm411_send_rp_error(trans, cmd->sms->gsm411.msg_ref,
-			     GSM411_RP_CAUSE_MO_NET_OUT_OF_ORDER);
+	if (smpp_to_gsm411_err(status, &gsm411_cause) < 0)
+		gsm411_cause = GSM411_RP_CAUSE_MO_NET_OUT_OF_ORDER;
+
+	gsm411_send_rp_error(trans, cmd->sms->gsm411.msg_ref, gsm411_cause);
+
 	smpp_cmd_free(cmd);
 }
 
 static void smpp_deliver_sm_cb(void *data)
 {
-	smpp_cmd_err(data);
+	smpp_cmd_err(data, ESME_RSYSERR);
 }
 
 static int smpp_cmd_enqueue(struct osmo_esme *esme,
diff --git a/openbsc/src/libmsc/smpp_smsc.c b/openbsc/src/libmsc/smpp_smsc.c
index bd259186f..48a119261 100644
--- a/openbsc/src/libmsc/smpp_smsc.c
+++ b/openbsc/src/libmsc/smpp_smsc.c
@@ -681,11 +681,10 @@ static int smpp_handle_deliver_resp(struct osmo_esme *esme, struct msgb *msg)
 		return -1;
 	}
 
-	/* Map SMPP command status to GSM 04.11 cause? */
 	if (deliver_r.command_status == ESME_ROK)
 		smpp_cmd_ack(cmd);
 	else
-		smpp_cmd_err(cmd);
+		smpp_cmd_err(cmd, deliver_r.command_status);
 
 	LOGP(DSMPP, LOGL_INFO, "[%s] Rx DELIVER-SM RESP (%s)\n",
 		esme->system_id, get_value_string(smpp_status_strs,
diff --git a/openbsc/src/libmsc/smpp_smsc.h b/openbsc/src/libmsc/smpp_smsc.h
index b95a1f509..d8e82e421 100644
--- a/openbsc/src/libmsc/smpp_smsc.h
+++ b/openbsc/src/libmsc/smpp_smsc.h
@@ -97,7 +97,7 @@ struct osmo_smpp_cmd {
 struct osmo_smpp_cmd *smpp_cmd_find_by_seqnum(struct osmo_esme *esme,
 					      uint32_t sequence_number);
 void smpp_cmd_ack(struct osmo_smpp_cmd *cmd);
-void smpp_cmd_err(struct osmo_smpp_cmd *cmd);
+void smpp_cmd_err(struct osmo_smpp_cmd *cmd, uint32_t status);
 void smpp_cmd_flush_pending(struct osmo_esme *esme);
 
 struct smsc {
-- 
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