Add dialtone_detect option for analog incoming calls.

For analog lines, enables Asterisk to use dialtone detection per channel
if an incoming call was hung up before it was answered.  If dialtone is
detected, the call is hung up.
no:       Disabled. (Default)
yes:      Look for dialtone for 10000 ms after answer.
<number>: Look for dialtone for the specified number of ms after answer.
always:   Look for dialtone for the entire call.  Dialtone may return
          if the far end hangs up first.

dialtone_detect=yes
dialtone_detect=5000
dialtone_detect=always

(closes issue ASTERISK-19316)
Reported by: Jeremy Pepper
Patch by: Jeremy Pepper
Tested by: rmudgett,Jeremy Pepper

Review: https://reviewboard.asterisk.org/r/1737/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@358344 65c4cc65-6c06-0410-ace0-fbb531ad65f3

3 files changed, 54 insertions, 4 deletions

diff --git a/CHANGES b/CHANGES
index 443f1acb0..10c179fba 100644
--- a/CHANGES
+++ b/CHANGES
@@ -73,6 +73,11 @@ Chan_local changes
  * Added a manager event "LocalBridge" for local channel call bridges between
    the two pseudo-channels created.
 
+Chan_dahdi changes
+------------------
+ * Added dialtone_detect option for analog ports to disconnect incoming
+   calls when dialtone is detected.
+
 Codec changes
 -------------
  * Codec lists may now be modified by the '!' character, to allow succinct
diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 21214bd88..d65bb122e 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -532,6 +532,7 @@ static inline int dahdi_wait_event(int fd)
 #define CIDCW_EXPIRE_SAMPLES			((500 * 8) / READ_SIZE) /*!< 500 ms */
 #define MIN_MS_SINCE_FLASH				((2000) )	/*!< 2000 ms */
 #define DEFAULT_RINGT 					((8000 * 8) / READ_SIZE) /*!< 8,000 ms */
+#define DEFAULT_DIALTONE_DETECT_TIMEOUT ((10000 * 8) / READ_SIZE) /*!< 10,000 ms */
 
 struct dahdi_pvt;
 
@@ -1167,6 +1168,12 @@ struct dahdi_pvt {
 	 * \note Set from the "waitfordialtone" value read in from chan_dahdi.conf
 	 */
 	int waitfordialtone;
+	/*!
+	 * \brief Number of frames to watch for dialtone in incoming calls
+	 * \note Set from the "dialtone_detect" value read in from chan_dahdi.conf
+	 */
+	int dialtone_detect;
+	int dialtone_scanning_time_elapsed;	/*!< Amount of audio scanned for dialtone, in frames */
 	struct timeval waitingfordt;			/*!< Time we started waiting for dialtone */
 	struct timeval flashtime;			/*!< Last flash-hook time */
 	/*! \brief Opaque DSP configuration structure. */
@@ -9250,7 +9257,7 @@ static struct ast_frame *dahdi_read(struct ast_channel *ast)
 		p->subs[idx].f.data.ptr = NULL;
 		p->subs[idx].f.datalen= 0;
 	}
-	if (p->dsp && (!p->ignoredtmf || p->callwaitcas || p->busydetect || p->callprogress || p->waitingfordt.tv_sec) && !idx) {
+	if (p->dsp && (!p->ignoredtmf || p->callwaitcas || p->busydetect || p->callprogress || p->waitingfordt.tv_sec || p->dialtone_detect) && !idx) {
 		/* Perform busy detection etc on the dahdi line */
 		int mute;
 
@@ -9264,10 +9271,24 @@ static struct ast_frame *dahdi_read(struct ast_channel *ast)
 		}
 
 		if (f) {
+			if ((p->dsp_features & DSP_FEATURE_WAITDIALTONE) && (p->dialtone_detect > 0)
+				&& !p->outgoing && ast_channel_state(ast) == AST_STATE_UP) {
+				if (++p->dialtone_scanning_time_elapsed >= p->dialtone_detect) {
+					p->dsp_features &= ~DSP_FEATURE_WAITDIALTONE;
+					ast_dsp_set_features(p->dsp, p->dsp_features);
+				}
+			}
 			if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass.integer == AST_CONTROL_BUSY)) {
 				if ((ast_channel_state(ast) == AST_STATE_UP) && !p->outgoing) {
-					/* Treat this as a "hangup" instead of a "busy" on the assumption that
-					   a busy */
+					/*
+					 * Treat this as a "hangup" instead of a "busy" on the
+					 * assumption that a busy means the incoming call went away.
+					 */
+					f = NULL;
+				}
+			} else if (p->dialtone_detect && !p->outgoing && f->frametype == AST_FRAME_VOICE) {
+				if ((ast_dsp_get_tstate(p->dsp) == DSP_TONE_STATE_DIALTONE) && (ast_dsp_get_tcount(p->dsp) > 9)) {
+					/* Dialtone detected on inbound call; hangup the channel */
 					f = NULL;
 				}
 			} else if (f->frametype == AST_FRAME_DTMF_BEGIN
@@ -9691,7 +9712,7 @@ static struct ast_channel *dahdi_new(struct dahdi_pvt *i, int state, int startpb
 			features |= DSP_FEATURE_BUSY_DETECT;
 		if ((i->callprogress & CALLPROGRESS_PROGRESS) && CANPROGRESSDETECT(i))
 			features |= DSP_FEATURE_CALL_PROGRESS;
-		if ((i->waitfordialtone) && CANPROGRESSDETECT(i))
+		if ((i->waitfordialtone || i->dialtone_detect) && CANPROGRESSDETECT(i))
 			features |= DSP_FEATURE_WAITDIALTONE;
 		if ((!i->outgoing && (i->callprogress & CALLPROGRESS_FAX_INCOMING)) ||
 			(i->outgoing && (i->callprogress & CALLPROGRESS_FAX_OUTGOING))) {
@@ -9737,6 +9758,8 @@ static struct ast_channel *dahdi_new(struct dahdi_pvt *i, int state, int startpb
 		}
 	}
 
+	i->dialtone_scanning_time_elapsed = 0;
+
 	if (state == AST_STATE_RING)
 		ast_channel_rings_set(tmp, 1);
 	ast_channel_tech_pvt_set(tmp, i);
@@ -12873,6 +12896,7 @@ static struct dahdi_pvt *mkintf(int channel, const struct dahdi_chan_conf *conf,
 		tmp->busy_cadence = conf->chan.busy_cadence;
 		tmp->callprogress = conf->chan.callprogress;
 		tmp->waitfordialtone = conf->chan.waitfordialtone;
+		tmp->dialtone_detect = conf->chan.dialtone_detect;
 		tmp->cancallforward = conf->chan.cancallforward;
 		tmp->dtmfrelax = conf->chan.dtmfrelax;
 		tmp->callwaiting = tmp->permcallwaiting;
@@ -17281,6 +17305,16 @@ static int process_dahdi(struct dahdi_chan_conf *confp, const char *cat, struct
 				confp->chan.callprogress |= CALLPROGRESS_PROGRESS;
 		} else if (!strcasecmp(v->name, "waitfordialtone")) {
 			confp->chan.waitfordialtone = atoi(v->value);
+		} else if (!strcasecmp(v->name, "dialtone_detect")) {
+			if (!strcasecmp(v->value, "always")) {
+				confp->chan.dialtone_detect = -1;
+			} else if (ast_true(v->value)) {
+				confp->chan.dialtone_detect = DEFAULT_DIALTONE_DETECT_TIMEOUT;
+			} else if (ast_false(v->value)) {
+				confp->chan.dialtone_detect = 0;
+			} else {
+				confp->chan.dialtone_detect = ast_strlen_zero(v->value) ? 0 : (8 * atoi(v->value)) / READ_SIZE;
+			}
 		} else if (!strcasecmp(v->name, "faxdetect")) {
 			confp->chan.callprogress &= ~CALLPROGRESS_FAX;
 			if (!strcasecmp(v->value, "incoming")) {
diff --git a/configs/chan_dahdi.conf.sample b/configs/chan_dahdi.conf.sample
index 10c55ca75..d83bba8d9 100644
--- a/configs/chan_dahdi.conf.sample
+++ b/configs/chan_dahdi.conf.sample
@@ -551,6 +551,17 @@ usecallerid=yes
 ; marking the line as once again available for use with outgoing calls.
 ;waitfordialtone=yes
 ;
+; For analog lines, enables Asterisk to use dialtone detection per channel
+; if an incoming call was hung up before it was answered.  If dialtone is
+; detected, the call is hung up.
+; no:       Disabled. (Default)
+; yes:      Look for dialtone for 10000 ms after answer.
+; <number>: Look for dialtone for the specified number of ms after answer.
+; always:   Look for dialtone for the entire call.  Dialtone may return
+;           if the far end hangs up first.
+;
+;dialtone_detect=no
+;
 ; The following option enables receiving MWI on FXO lines.  The default
 ; value is no.
 ; 	The mwimonitor can take the following values