Add support for application/dtmf SIP INFO dtmf handling. Yep, another

way of handling DTMF in SIP. Totally undocumented, but implemented
in enough devices so we have to support it. 

Code by sergee, small changes by oej.

Closes issue #11049


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89278 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -796,6 +796,7 @@ struct sip_auth {
 #define SIP_DTMF_INBAND		(1 << 16)	/*!< DP: DTMF Support: Inband audio, only for ULAW/ALAW - "inband" */
 #define SIP_DTMF_INFO		(2 << 16)	/*!< DP: DTMF Support: SIP Info messages - "info" */
 #define SIP_DTMF_AUTO		(3 << 16)	/*!< DP: DTMF Support: AUTO switch between rfc2833 and in-band DTMF */
+#define SIP_DTMF_SHORTINFO      (4 << 16)       /*!< DP: DTMF Support: SIP Info messages - "info" - short variant */
 /* NAT settings - see nat2str() */
 #define SIP_NAT			(3 << 18)	/*!< DP: four settings, uses two bits */
@@ -1742,7 +1743,7 @@ static int add_header(struct sip_request *req, const char *var, const char *valu
 static int add_header_contentLength(struct sip_request *req, int len);
 static int add_line(struct sip_request *req, const char *line);
 static int add_text(struct sip_request *req, const char *text);
-static int add_digit(struct sip_request *req, char digit, unsigned int duration);
+static int add_digit(struct sip_request *req, char digit, unsigned int duration, int mode);
 static int add_vidupdate(struct sip_request *req);
 static void add_route(struct sip_request *req, struct sip_route *route);
 static int copy_header(struct sip_request *req, const struct sip_request *orig, const char *field);
@@ -4385,6 +4386,7 @@ static int sip_senddigit_end(struct ast_channel *ast, char digit, unsigned int d
 	sip_pvt_lock(p);
 	switch (ast_test_flag(&p->flags[0], SIP_DTMF)) {
 	case SIP_DTMF_INFO:
+	case SIP_DTMF_SHORTINFO:
 		transmit_info_with_digit(p, digit, duration);
 		break;
 	case SIP_DTMF_RFC2833:
@@ -4550,7 +4552,7 @@ static struct ast_channel *sip_new(struct sip_pvt *i, int state, const char *tit
 	}
 	sip_pvt_lock(i);
-	tmp->tech = ast_test_flag(&i->flags[0], SIP_DTMF) == SIP_DTMF_INFO ?  &sip_tech_info : &sip_tech;
+	tmp->tech = ( ast_test_flag(&i->flags[0], SIP_DTMF) == SIP_DTMF_INFO || ast_test_flag(&i->flags[0], SIP_DTMF) == SIP_DTMF_SHORTINFO) ?  &sip_tech_info : &sip_tech;
 	/* Select our native format based on codec preference until we receive
 	   something from another device to the contrary. */
@@ -6763,16 +6765,35 @@ static int add_text(struct sip_request *req, const char *text)
 	return 0;
 }
-/*! \brief Add DTMF INFO tone to sip message */
-/* Always adds default duration 250 ms, regardless of what came in over the line */
-static int add_digit(struct sip_request *req, char digit, unsigned int duration)
+/*! \brief Add DTMF INFO tone to sip message 
+	Mode = 	0 for application/dtmf-relay (Cisco)
+		1 for application/dtmf
+*/
+static int add_digit(struct sip_request *req, char digit, unsigned int duration, int mode)
 {
 	char tmp[256];
-
-	snprintf(tmp, sizeof(tmp), "Signal=%c\r\nDuration=%u\r\n", digit, duration);
-	add_header(req, "Content-Type", "application/dtmf-relay");
-	add_header_contentLength(req, strlen(tmp));
-	add_line(req, tmp);
+	int event;
+	if (mode) {
+		/* Application/dtmf short version used by some implementations */
+		if (digit == '*')
+			event = 10;
+		else if (digit == '#')
+			event = 11;
+		else if ((digit >= 'A') && (digit <= 'D'))
+			event = 12 + digit - 'A';
+		else
+			event = atoi(&digit);
+		snprintf(tmp, sizeof(tmp), "%d\r\n", event);
+		add_header(req, "Content-Type", "application/dtmf");
+		add_header_contentLength(req, strlen(tmp));
+		add_line(req, tmp);
+	} else {
+		/* Application/dtmf-relay as documented by Cisco */
+		snprintf(tmp, sizeof(tmp), "Signal=%c\r\nDuration=%u\r\n", digit, duration);
+		add_header(req, "Content-Type", "application/dtmf-relay");
+		add_header_contentLength(req, strlen(tmp));
+		add_line(req, tmp);
+	}
 	return 0;
 }
@@ -8479,7 +8500,7 @@ static int transmit_info_with_digit(struct sip_pvt *p, const char digit, unsigne
 	struct sip_request req;
 	reqprep(&req, p, SIP_INFO, 0, 1);
-	add_digit(&req, digit, duration);
+	add_digit(&req, digit, duration, (ast_test_flag(&p->flags[0], SIP_DTMF) == SIP_DTMF_SHORTINFO));
 	return send_request(p, &req, XMIT_RELIABLE, p->ocseq);
 }
@@ -10944,6 +10965,7 @@ static void  print_group(int fd, ast_group_t group, int crlf)
 static struct _map_x_s dtmfstr[] = {
 	{ SIP_DTMF_RFC2833,     "rfc2833" },
 	{ SIP_DTMF_INFO,        "info" },
+	{ SIP_DTMF_SHORTINFO,   "shortinfo" },
 	{ SIP_DTMF_INBAND,      "inband" },
 	{ SIP_DTMF_AUTO,        "auto" },
 	{ -1,                   NULL }, /* terminator */
@@ -12333,6 +12355,49 @@ static void handle_request_info(struct sip_pvt *p, struct sip_request *req)
 		}
 		transmit_response(p, "200 OK", req);
 		return;
+	} else if (!strcasecmp(c, "application/dtmf")) {
+		unsigned int duration = 0;
+
+		get_msg_text(buf, sizeof(buf), req);
+		duration = 100; /* 100 ms */
+
+		if (!p->owner) {	/* not a PBX call */	
+			transmit_response(p, "481 Call leg/transaction does not exist", req);
+			sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
+			return;
+		}
+
+		if (ast_strlen_zero(buf)) {
+			transmit_response(p, "200 OK", req);
+			return;
+		}
+		event = atoi(buf);
+		if (event == 16) {
+			/* send a FLASH event */
+			struct ast_frame f = { AST_FRAME_CONTROL, AST_CONTROL_FLASH, };
+			ast_queue_frame(p->owner, &f);
+			if (sipdebug)
+				ast_verbose("* DTMF-relay event received: FLASH\n");
+		} else {
+			/* send a DTMF event */
+			struct ast_frame f = { AST_FRAME_DTMF, };
+			if (event < 10) {
+				f.subclass = '0' + event;
+			} else if (event < 11) {
+				f.subclass = '*';
+			} else if (event < 12) {
+				f.subclass = '#';
+			} else if (event < 16) {
+				f.subclass = 'A' + (event - 12);
+			}
+			f.len = duration;
+			ast_queue_frame(p->owner, &f);
+			if (sipdebug)
+				ast_verbose("* DTMF-relay event received: %c\n", f.subclass);
+		}
+		transmit_response(p, "200 OK", req);
+		return;
+
 	} else if (!strcasecmp(c, "application/media_control+xml")) {
 		/* Eh, we'll just assume it's a fast picture update for now */
 		if (p->owner)
@@ -17086,6 +17151,8 @@ static int handle_common_options(struct ast_flags *flags, struct ast_flags *mask
 			ast_set_flag(&flags[0], SIP_DTMF_RFC2833);
 		else if (!strcasecmp(v->value, "info"))
 			ast_set_flag(&flags[0], SIP_DTMF_INFO);
+		else if (!strcasecmp(v->value, "shortinfo"))
+			ast_set_flag(&flags[0], SIP_DTMF_SHORTINFO);
 		else if (!strcasecmp(v->value, "auto"))
 			ast_set_flag(&flags[0], SIP_DTMF_AUTO);
 		else {
@@ -18774,6 +18841,10 @@ static int sip_dtmfmode(struct ast_channel *chan, void *data)
 		ast_clear_flag(&p->flags[0], SIP_DTMF);
 		ast_set_flag(&p->flags[0], SIP_DTMF_INFO);
 		p->jointnoncodeccapability &= ~AST_RTP_DTMF;
+	} else if (!strcasecmp(mode,"shortinfo")) {
+		ast_clear_flag(&p->flags[0], SIP_DTMF);
+		ast_set_flag(&p->flags[0], SIP_DTMF_SHORTINFO);
+		p->jointnoncodeccapability &= ~AST_RTP_DTMF;
 	} else if (!strcasecmp(mode,"rfc2833")) {
 		ast_clear_flag(&p->flags[0], SIP_DTMF);
 		ast_set_flag(&p->flags[0], SIP_DTMF_RFC2833);

configs/sip.conf.sample

@@ -126,7 +126,8 @@ srvlookup=yes			; Enable DNS SRV lookups on outbound calls
 				; a valid phone number
 ;dtmfmode = rfc2833		; Set default dtmfmode for sending DTMF. Default: rfc2833
 				; Other options: 
-				; info : SIP INFO messages
+				; info : SIP INFO messages (application/dtmf-relay)
+				; shortinfo : SIP INFO messages (application/dtmf)
 				; inband : Inband audio (requires 64 kbit codec -alaw, ulaw)
 				; auto : Use rfc2833 if offered, inband otherwise