From dbe8b148f4f578920d2597e0413a4172c02413af Mon Sep 17 00:00:00 2001
From: Stefan Knoblich <stkn@freeswitch.org>
Date: Fri, 3 Jul 2009 09:24:52 +0000
Subject: [PATCH] - WARNING - Add STATUS ENQUIRY message handling to
 ozmod_isdn, this is a bad hack because the current OpenZAP isdn stack is not
 stateful (the experimental rewritten version is...) and so we have to try to
 map OpenZAP channel states to ISDN states, which is not possible in all
 cases. This patch (as long as it sends the right answer) prevents sudden
 disconnects of (active) calls, caused by not responding to a STATUS ENQUIRY
 message from the other side. - WARNING -

git-svn-id: http://svn.openzap.org/svn/openzap/trunk@754 a93c3328-9c30-0410-af19-c9cd2b2d52af
---
 .../freetdm/src/ozmod/ozmod_isdn/ozmod_isdn.c | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/libs/freetdm/src/ozmod/ozmod_isdn/ozmod_isdn.c b/libs/freetdm/src/ozmod/ozmod_isdn/ozmod_isdn.c
index 192a4446a2..7aa23604fa 100644
--- a/libs/freetdm/src/ozmod/ozmod_isdn/ozmod_isdn.c
+++ b/libs/freetdm/src/ozmod/ozmod_isdn/ozmod_isdn.c
@@ -1013,6 +1013,61 @@ static L3INT zap_isdn_931_34(void *pvt, L2UCHAR *msg, L2INT mlen)
 			}
 			break;
 
+		case Q931mes_STATUS_ENQUIRY:
+			{
+				/*
+				 * !! HACK ALERT !!
+				 *
+				 * Map OpenZAP channel states to Q.931 states
+				 */
+				Q931ie_CallState state;
+				Q931ie_Cause cause;
+
+				gen->MesType = Q931mes_STATUS;
+				gen->CRVFlag = gen->CRVFlag ? 0 : 1;
+
+				state.CodStand  = Q931_CODING_ITU;	/* ITU-T */
+				state.CallState = Q931_U0;		/* Default: Null */
+
+				cause.IEId = Q931ie_CAUSE;
+				cause.Size = sizeof(Q931ie_Cause);
+				cause.CodStand = Q931_CODING_ITU;	/* ITU */
+				cause.Location = 1;	/* private network */
+				cause.Recom    = 1;	/* */
+				*cause.Diag    = '\0';
+
+				if(zchan) {
+					switch(zchan->state) {
+					case ZAP_CHANNEL_STATE_UP:
+						state.CallState = Q931_U10;	/* Active */
+						break;
+					case ZAP_CHANNEL_STATE_RING:
+						state.CallState = Q931_U6;	/* Call present */
+						break;
+					case ZAP_CHANNEL_STATE_DIALING:
+						state.CallState = Q931_U1;	/* Call initiated */
+						break;
+					case ZAP_CHANNEL_STATE_DIALTONE:
+						state.CallState = Q931_U25;	/* Overlap receiving */
+						break;
+
+					/* TODO: map missing states */
+
+					default:
+						state.CallState = Q931_U0;
+					}
+
+					cause.Value = 30;	/* response to STATUS ENQUIRY */
+				} else {
+					cause.Value = 98;	/* */
+				}
+
+				gen->CallState = Q931AppendIE((L3UCHAR *) gen, (L3UCHAR *) &state);
+				gen->Cause     = Q931AppendIE((L3UCHAR *) gen, (L3UCHAR *) &cause);
+				Q931Rx43(&isdn_data->q931, (L3UCHAR *) gen, gen->Size);
+			}
+			break;
+
 		default:
 			zap_log(ZAP_LOG_CRIT, "Received unhandled message %d (%#x)\n", (int)gen->MesType, (int)gen->MesType);
 			break;