MT#56861 support DTMF injection with kernel mode

Add a flag to inhibit kernel mode while DTMF injection is active. Tie in
DTMF playback trigger function: Remove stream from kernel, set inhibit
flag, play DTMF, then unset inhibit flag when all events have been
injected.

Change-Id: I533ec95a676bc7edf4dd973217f8d9499f1e22b6

daemon/call_interfaces.c

@@ -3262,6 +3262,9 @@ const char *call_play_dtmf_ng(bencode_item_t *input, bencode_item_t *output) {
 		// XXX fall back to generating a secondary stream
 
 found:
+		monologue->dtmf_injection_active = 1;
+		dialogue_unkernelize(monologue, "DTMF playback");
+
 		for (GList *k = monologue->subscribers.head; k; k = k->next) {
 			struct call_subscription *cs = k->data;
 			struct call_monologue *dialogue = cs->monologue;

daemon/codec.c

@@ -1665,6 +1665,8 @@ static int handler_func_passthrough(struct codec_handler *h, struct media_packet
 		codec_calc_lost(mp->ssrc_in, ntohs(mp->rtp->seq_num));
 	}
 
+	mp->media->monologue->dtmf_injection_active = 0;
+
 	__buffer_delay_raw(h->delay_buffer, h, codec_add_raw_packet, mp, h->source_pt.clock_rate);
 
 	return 0;
@@ -2435,6 +2437,9 @@ static int handler_func_passthrough_ssrc(struct codec_handler *h, struct media_p
 
 			add_packet_fn = codec_add_raw_packet_dup;
 		}
+		else if (!ch->dtmf_events.length)
+			mp->media->monologue->dtmf_injection_active = 0;
+
 		obj_put(&ch->h);
 	}
 

daemon/media_socket.c

@@ -2479,6 +2479,9 @@ static void media_packet_kernel_check(struct packet_handler_ctx *phc) {
 		return;
 	}
 
+	if (phc->mp.media->monologue->dtmf_injection_active)
+		return;
+
 	mutex_lock(&phc->mp.stream->in_lock);
 	kernelize(phc->mp.stream);
 	mutex_unlock(&phc->mp.stream->in_lock);

include/call.h

@@ -538,6 +538,7 @@ struct call_monologue {
 
 	unsigned int		rec_forwarding:1;
 	unsigned int		inject_dtmf:1;
+	unsigned int		dtmf_injection_active:1;
 	unsigned int		detect_dtmf:1;
 };