Wait for wink before dialing when using E&M wink signaling

This patch adds a new dahdi_wait function to specifically wait for the wink
event. If the wink is not eventually received the channel is hung up. 

(closes issue #14434)
Reported by: araasch
Patches:
      emwinkmod uploaded by araasch (license 693)



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.1@207637 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_dahdi.c

@@ -223,6 +223,8 @@ static const char config[] = "chan_dahdi.conf";
 #define CALLPROGRESS_FAX_INCOMING	4
 #define CALLPROGRESS_FAX		(CALLPROGRESS_FAX_INCOMING | CALLPROGRESS_FAX_OUTGOING)
 
+#define OUTBOUND_EM_WINK_RX_TIMEOUT     10000   /*!< Default time to wait for wink on outbound E&M Wink start trunks in ms*/
+
 static char defaultcic[64] = "";
 static char defaultozz[64] = "";
 
@@ -320,6 +322,34 @@ static inline int dahdi_wait_event(int fd)
 	return j;
 }
 
+static char *event2str(int event);
+
+/*! \brief Waits for a wink from the far party with a timeout, returns 0 on wink received, -1 on timeout */
+static inline int dahdi_wait_for_wink(int dfd, int timeout_ms, int *hookcomplete_evt_rcvd)
+{
+	int res = 0;
+	while (timeout_ms > 0)
+	{
+		res = dahdi_get_event(dfd);
+		ast_debug(2, "Detected event: %s, timeout_ms %d\n", event2str(res), timeout_ms);
+		switch (res) {
+		case DAHDI_EVENT_NONE:
+			timeout_ms -= 100;
+			usleep(100000);
+			break;
+		case DAHDI_EVENT_HOOKCOMPLETE:
+			*hookcomplete_evt_rcvd = 1;
+			break;
+		case DAHDI_EVENT_WINKFLASH:
+			return 0;
+			break;
+		default:
+			break;
+        }
+	}
+	return -1; /* indicate timeout has elapsed */
+}
+
 /*! Chunk size to read -- we use 20ms chunks to make things happy. */
 #define READ_SIZE 160
 
@@ -2449,6 +2479,8 @@ static int dahdi_call(struct ast_channel *ast, char *rdest, int timeout)
 	char *s = NULL;
 #endif
 	char dest[256]; /* must be same length as p->dialdest */
+ 	/* flag for if we got a HOOKCOMPLETE event while waiting for the wink */
+	int em_w_hookcomplete_evt_rcvd = 0;
 	ast_mutex_lock(&p->lock);
 	ast_copy_string(dest, rdest, sizeof(dest));
 	ast_copy_string(p->dialdest, rdest, sizeof(p->dialdest));
@@ -2623,6 +2655,28 @@ static int dahdi_call(struct ast_channel *ast, char *rdest, int timeout)
 #ifdef HAVE_PRI
 		}
 #endif
+
+		/* If the outbound protocol is E&M Wink start, this code will wait for the wink
+		 * before proceeding. It waits for the wink to be detected with a timeout and
+		 * also detects and notes the HOOKCOMPLETE event which will come before the
+		 * WINKFLASH event in the normal operation of outbound E&M Wink trunks.
+		 */
+		if (mysig == SIG_EMWINK) {
+			if (dahdi_wait_for_wink(p->subs[SUB_REAL].dfd, OUTBOUND_EM_WINK_RX_TIMEOUT, &em_w_hookcomplete_evt_rcvd)) {
+				/* we never received a wink from the far side */
+				ast_log(LOG_WARNING, "Timer elapsed while waiting to receive a wink on an E&M Wink trunk\n");
+				/* put this channel on hook and exit */
+				res = dahdi_set_hook(p->subs[SUB_REAL].dfd, DAHDI_ONHOOK);
+				if (res < 0) {
+					ast_log(LOG_WARNING, "Unable to hangup channel: %s\n", strerror(errno));
+				} else {
+					ast_log(LOG_WARNING, "Stopping channel since we did not get a wink before timeout\n");
+				}
+				ast_mutex_unlock(&p->lock);
+				return -1;
+			}
+		}
+
 		ast_debug(1, "Dialing '%s'\n", c);
 		p->dop.op = DAHDI_DIAL_OP_REPLACE;
 
@@ -2690,7 +2744,7 @@ static int dahdi_call(struct ast_channel *ast, char *rdest, int timeout)
 			p->dop.dialstr[strlen(p->dop.dialstr)-2] = '\0';
 		} else
 			p->echobreak = 0;
-		if (!res) {
+		if (!res || em_w_hookcomplete_evt_rcvd) {
 			if (ioctl(p->subs[SUB_REAL].dfd, DAHDI_DIAL, &p->dop)) {
 				int saveerr = errno;