From ba8bf0e9d535f1c9a4848a243ac1d5c700fbb3e6 Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Wed, 20 Jul 2016 11:55:03 +0200
Subject: [PATCH] NMT: Fix autoanswer

If phone does not support autoanswer, the MTX proceeds with regular ringing.
---
 src/nmt/nmt.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-------
 src/nmt/nmt.h |  2 ++
 2 files changed, 67 insertions(+), 9 deletions(-)

diff --git a/src/nmt/nmt.c b/src/nmt/nmt.c
index 295ffed..15200b0 100644
--- a/src/nmt/nmt.c
+++ b/src/nmt/nmt.c
@@ -75,6 +75,8 @@ const char *nmt_state_name(enum nmt_state state)
 		return "MT CALL CHANNEL";
 	case STATE_MT_IDENT:
 		return "MT CALL IDENT";
+	case STATE_MT_AUTOANSWER:
+		return "MT CALL AUTOANSWER";
 	case STATE_MT_RINGING:
 		return "MT CALL RINGING";
 	case STATE_MT_COMPLETE:
@@ -810,7 +812,7 @@ static void tx_mo_complete(nmt_t *nmt, frame_t *frame)
 	if (++nmt->tx_frame_count <= 4) {
 		set_line_signal(nmt, frame, 6);
 		if (nmt->tx_frame_count == 1)
-			PDEBUG(DNMT, DEBUG_INFO, "Send 'addess complete'.\n");
+			PDEBUG(DNMT, DEBUG_INFO, "Send 'address complete'.\n");
 	} else {
 		if (nmt->compandor) {
 			set_line_signal(nmt, frame, 5);
@@ -937,11 +939,19 @@ static void rx_mt_ident(nmt_t *nmt, frame_t *frame)
 		nmt_value2digits(frame->ms_password, nmt->subscriber.password, 3);
 		PDEBUG(DNMT, DEBUG_INFO, "Received identity (password %s).\n", nmt->subscriber.password);
 		if (nmt->dms_call) {
-			nmt_new_state(nmt, STATE_MT_COMPLETE);
+			nmt_new_state(nmt, STATE_MT_AUTOANSWER);
+			nmt->wait_autoanswer = 1;
 			nmt->tx_frame_count = 0;
 		} else {
 			nmt_new_state(nmt, STATE_MT_RINGING);
-			nmt->tx_frame_count = 0;
+			/* start with caller ID before ringing */
+			if (nmt->send_callerid) {
+				nmt->tx_frame_count = 4;
+				nmt->tx_callerid_count = 1;
+			} else {
+				nmt->tx_frame_count = 0;
+				nmt->tx_callerid_count = 0;
+			}
 			timer_start(&nmt->timer, RINGING_TO);
 			call_in_alerting(nmt->sender.callref);
 		}
@@ -951,6 +961,49 @@ static void rx_mt_ident(nmt_t *nmt, frame_t *frame)
 	}
 }
 
+static void tx_mt_autoanswer(nmt_t *nmt, frame_t *frame)
+{
+	/* first we need to wait for autoanswer */
+	if (nmt->wait_autoanswer) {
+		frame->index = NMT_MESSAGE_6;
+		return;
+	}
+	if (++nmt->tx_frame_count == 1)
+		PDEBUG(DNMT, DEBUG_INFO, "Send 'autoanswer order'.\n");
+	set_line_signal(nmt, frame, 12);
+	if (nmt->tx_frame_count == 4) {
+		PDEBUG(DNMT, DEBUG_INFO, "No reaction to autoanswer, proceed with ringing.\n");
+		nmt_new_state(nmt, STATE_MT_RINGING);
+		nmt->tx_frame_count = 0;
+		nmt->tx_callerid_count = 0;
+		timer_start(&nmt->timer, RINGING_TO);
+		call_in_alerting(nmt->sender.callref);
+	}
+}
+
+static void rx_mt_autoanswer(nmt_t *nmt, frame_t *frame)
+{
+	switch (frame->index) {
+	case NMT_MESSAGE_15: /* idle */
+		nmt->wait_autoanswer = 0;
+		break;
+	case NMT_MESSAGE_13a: /* line signal */
+		if (!match_channel(nmt, frame))
+			break;
+		if (!match_subscriber(nmt, frame))
+			break;
+		if ((frame->line_signal & 0xf) != 12)
+			break;
+		PDEBUG(DNMT, DEBUG_INFO, "Received acknowlege to autoanswer.\n");
+		nmt_new_state(nmt, STATE_MT_COMPLETE);
+		nmt->tx_frame_count = 0;
+		call_in_answer(nmt->sender.callref, &nmt->subscriber.country);
+		break;
+	default:
+		PDEBUG(DNMT, DEBUG_DEBUG, "Dropping message %s in state %s\n", nmt_frame_name(frame->index), nmt_state_name(nmt->state));
+	}
+}
+
 static void tx_mt_ringing(nmt_t *nmt, frame_t *frame)
 {
 	set_line_signal(nmt, frame, 9);
@@ -967,6 +1020,8 @@ static void rx_mt_ringing(nmt_t *nmt, frame_t *frame)
 {
 	switch (frame->index) {
 	case NMT_MESSAGE_13a: /* line signal */
+		if (!match_channel(nmt, frame))
+			break;
 		if (!match_subscriber(nmt, frame))
 			break;
 		if ((frame->line_signal & 0xf) != 14)
@@ -984,12 +1039,7 @@ static void rx_mt_ringing(nmt_t *nmt, frame_t *frame)
 static void tx_mt_complete(nmt_t *nmt, frame_t *frame)
 {
 	++nmt->tx_frame_count;
-	if (nmt->dms_call) {
-		if (nmt->tx_frame_count == 1)
-			PDEBUG(DNMT, DEBUG_INFO, "Send 'autoanswer'.\n");
-		set_line_signal(nmt, frame, 12);
-	} else
-	if (nmt->compandor) {
+	if (nmt->compandor && !nmt->dms_call) {
 		if (nmt->tx_frame_count == 1)
 			PDEBUG(DNMT, DEBUG_INFO, "Send 'compandor in'.\n");
 		set_line_signal(nmt, frame, 5);
@@ -1274,6 +1324,9 @@ void nmt_receive_frame(nmt_t *nmt, const char *bits, double quality, double leve
 	case STATE_MT_IDENT:
 		rx_mt_ident(nmt, &frame);
 		break;
+	case STATE_MT_AUTOANSWER:
+		rx_mt_autoanswer(nmt, &frame);
+		break;
 	case STATE_MT_RINGING:
 		rx_mt_ringing(nmt, &frame);
 		break;
@@ -1352,6 +1405,9 @@ const char *nmt_get_frame(nmt_t *nmt)
 	case STATE_MT_IDENT:
 		tx_mt_ident(nmt, &frame);
 		break;
+	case STATE_MT_AUTOANSWER:
+		tx_mt_autoanswer(nmt, &frame);
+		break;
 	case STATE_MT_RINGING:
 		tx_mt_ringing(nmt, &frame);
 		break;
diff --git a/src/nmt/nmt.h b/src/nmt/nmt.h
index 8b5b9a4..cd7ff24 100644
--- a/src/nmt/nmt.h
+++ b/src/nmt/nmt.h
@@ -31,6 +31,7 @@ enum nmt_state {
 	STATE_MT_PAGING,	/* paging mobile phone */
 	STATE_MT_CHANNEL,	/* assigning traffic channel */
 	STATE_MT_IDENT,		/* waiting for identity */
+	STATE_MT_AUTOANSWER,	/* sending autoanswer, waiting for reply */
 	STATE_MT_RINGING,	/* mobile phone is ringing, waiting for answer */
 	STATE_MT_COMPLETE,	/* mobile phone has answered, completing call */
 	STATE_ACTIVE,		/* during active call */
@@ -79,6 +80,7 @@ typedef struct nmt {
 
 	/* sender's states */
 	enum nmt_state		state;
+	int			wait_autoanswer;	/* wait for frame 15 before we can send autoanswer */
 	enum nmt_active_state	active_state;
 	nmt_subscriber_t	subscriber;		/* current subscriber */
 	struct timer		timer;