add support for CDTRCTS flow control

pppd/options.c

@@ -18,7 +18,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$Id: options.c,v 1.42 1998/03/26 04:46:06 paulus Exp $";
+static char rcsid[] = "$Id: options.c,v 1.43 1998/09/04 18:49:15 christos Exp $";
 #endif
 
 #include <ctype.h>
@@ -171,6 +171,7 @@ static int setdomain __P((char **));
 static int setnetmask __P((char **));
 static int setcrtscts __P((char **));
 static int setnocrtscts __P((char **));
+static int setcdtrcts __P((char **));
 static int setxonxoff __P((char **));
 static int setnodetach __P((char **));
 static int setupdetach __P((char **));
@@ -311,6 +312,9 @@ static struct cmd {
     {"crtscts", 0, setcrtscts},	/* set h/w flow control */
     {"nocrtscts", 0, setnocrtscts}, /* clear h/w flow control */
     {"-crtscts", 0, setnocrtscts}, /* clear h/w flow control */
+    {"cdtrcts", 0, setcdtrcts},  /* set alternate h/w flow control */
+    {"nocdtrcts", 0, setnocrtscts}, /* clear h/w flow control */
+    {"-cdtrcts", 0, setnocrtscts}, /* clear h/w flow control */
     {"xonxoff", 0, setxonxoff},	/* set s/w flow control */
     {"debug", 0, setdebug},	/* Increase debugging level */
     {"kdebug", 1, setkdebug},	/* Enable kernel-level debugging */
@@ -435,6 +439,7 @@ Usage: %s [ options ], where options are:\n\
 	auth		Require authentication from peer\n\
         connect <p>     Invoke shell command <p> to set up the serial line\n\
 	crtscts		Use hardware RTS/CTS flow control\n\
+	cdtrcts		Use hardware DTR/CTS flow control (if supported)\n\
 	defaultroute	Add default route through interface\n\
 	file <f>	Take options from file <f>\n\
 	modem		Use modem control lines\n\
@@ -1853,6 +1858,14 @@ setnocrtscts(argv)
     return (1);
 }
 
+static int
+setcdtrcts(argv)
+    char **argv;
+{
+    crtscts = 2;
+    return (1);
+}
+
 static int
 setxonxoff(argv)
     char **argv;

pppd/pppd.8

@@ -1,5 +1,5 @@
 .\" manual page [] for pppd 2.3
-.\" $Id: pppd.8,v 1.27 1998/03/31 04:31:08 paulus Exp $
+.\" $Id: pppd.8,v 1.28 1998/09/04 18:49:15 christos Exp $
 .\" SH section heading
 .\" SS subsection heading
 .\" LP paragraph
@@ -92,10 +92,29 @@ program to dial the modem and start the remote ppp session.  This
 option is privileged if the \fInoauth\fR option is used.
 .TP
 .B crtscts
-Use hardware flow control (i.e. RTS/CTS) to control the flow of data
-on the serial port.  If neither the \fIcrtscts\fR nor the
-\fInocrtscts\fR option is given, the hardware flow control setting
-for the serial port is left unchanged.
+Use hardware flow control (i.e. RTS/CTS) to control the flow of
+data on the serial port.  If neither the \fIcrtscts\fR, the
+\fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR option
+is given, the hardware flow control setting for the serial port is
+left unchanged.
+Some serial ports (such as Macintosh serial ports) lack a true
+RTS output. Such serial ports use this mode to impliment
+unidirectional flow control. The serial port will
+suspend transmission when requested by the modem (via CTS)
+but will be unable to request the modem stop sending to the
+computer. This mode retains the ability to use DTR as
+a modem control line.
+.TP
+.B cdtrcts
+Use a non-standard hardware flow control (i.e. DTR/CTS) to control
+the flow of data on the serial port.  If neither the \fIcrtscts\fR,
+the \fInocrtscts\fR, the \fIcdtrcts\fR nor the \fInocdtrcts\fR
+option is given, the hardware flow control setting for the serial
+port is left unchanged.
+Some serial ports (such as Macintosh serial ports) lack a true
+RTS output. Such serial ports use this mode to impliment true
+bi-directional flow control. The sacrafice is that this flow
+control mode does not permit using DTR as a modem control line.
 .TP
 .B defaultroute
 Add a default route to the system routing tables, using the peer as
@@ -469,10 +488,14 @@ should only be required if the peer is buggy and gets confused by
 requests from pppd for CCP negotiation.
 .TP
 .B nocrtscts
-Disable hardware flow control (i.e. RTS/CTS) on the serial port.  If
-neither the \fIcrtscts\fR nor the \fInocrtscts\fR option is given,
-the hardware flow control setting for the serial port is left
-unchanged.
+Disable hardware flow control (i.e. RTS/CTS) on the serial port.
+If neither the \fIcrtscts\fR nor the \fInocrtscts\fR nor the
+\fIcdtrcts\fR nor the \fInodtrcts\fR option is given, the hardware
+flow control setting for the serial port is left unchanged.
+.TP
+.B nodtrcts
+This option is a synonym for \fInocrtscts\fR. Either of these options will
+disable both forms of hardware flow control.
 .TP
 .B nodefaultroute
 Disable the \fIdefaultroute\fR option.  The system administrator who

pppd/sys-bsd.c

@@ -21,7 +21,7 @@
  */
 
 #ifndef lint
-static char rcsid[] = "$Id: sys-bsd.c,v 1.32 1998/09/02 20:58:13 christos Exp $";
+static char rcsid[] = "$Id: sys-bsd.c,v 1.33 1998/09/04 18:49:16 christos Exp $";
 /*	$NetBSD: sys-bsd.c,v 1.1.1.3 1997/09/26 18:53:04 christos Exp $	*/
 #endif
 
@@ -385,10 +385,22 @@ set_up_tty(fd, local)
     }
 
     tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
-    if (crtscts > 0 && !local)
+    if (crtscts > 0 && !local) {
+        if (crtscts == 2) {
+#ifdef CDTRCTS
+            tios.c_cflag |= CDTRCTS;
+#else
+	    syslog(LOG_ERR, "System does not support DTR/CTS flow control");
+	    die(1);
+#endif
+	} else
 	    tios.c_cflag |= CRTSCTS;
-    else if (crtscts < 0)
+    } else if (crtscts < 0) {
 	tios.c_cflag &= ~CRTSCTS;
+#ifdef CDTRCTS
+	tios.c_cflag &= ~CDTRCTS;
+#endif
+    }
 
     tios.c_cflag |= CS8 | CREAD | HUPCL;
     if (local || !modem)