Add the >optional< ability to sense PPP link bringups and call an authentication program

libexec/getty/gettytab.5

@@ -30,7 +30,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)gettytab.5	8.4 (Berkeley) 4/19/94
-.\"	$Id: gettytab.5,v 1.6 1996/05/05 19:01:08 joerg Exp $
+.\"	$Id: gettytab.5,v 1.7 1996/08/23 20:33:49 mpp Exp $
 .\" "
 .Dd April 19, 1994
 .Dt GETTYTAB 5
@@ -148,6 +148,7 @@ hangup line on last close
 .It "pe	bool	false	use printer (hard copy) erase algorithm"
 .It "pf	num	0	delay"
 between first prompt and following flush (seconds)
+.It "pp	str	unused	PPP authentication program"
 .It "ps	bool	false	line connected to a"
 .Tn MICOM
 port selector
@@ -356,8 +357,15 @@ implementation.
 does not check parity of input characters in
 .Dv RAW
 mode.
+.Pp
+If
+.Em \&pp
+string is specified and a PPP link bringup sequence is recognized,
+getty will invoke the program referenced by the pp option.  This
+can be used to handle incoming PPP calls.
 .Sh SEE ALSO
 .Xr login 1 ,
+.Xr ppplogin 8 ,
 .Xr gethostname 2 ,
 .Xr uname 2 ,
 .Xr termcap 5 ,

libexec/getty/gettytab.h

@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)gettytab.h	8.2 (Berkeley) 3/30/94
- *	$Id: gettytab.h,v 1.1.1.2 1996/04/13 15:33:09 joerg Exp $
+ *	$Id: gettytab.h,v 1.3 1996/05/05 19:01:09 joerg Exp $
  */
 
 /*
@@ -86,6 +86,7 @@ struct gettyflags {
 #define WE	gettystrs[22].value
 #define LN	gettystrs[23].value
 #define Lo	gettystrs[24].value
+#define PP	gettystrs[25].value
 
 /*
  * Numeric definitions.

libexec/getty/init.c

@@ -33,7 +33,7 @@
 
 #ifndef lint
 /*static char sccsid[] = "from: @(#)init.c	8.1 (Berkeley) 6/4/93";*/
-static char rcsid[] = "$Id: init.c,v 1.1.1.2 1996/04/13 15:33:10 joerg Exp $";
+static char rcsid[] = "$Id: init.c,v 1.3 1996/05/05 19:01:09 joerg Exp $";
 #endif /* not lint */
 
 /*
@@ -76,6 +76,7 @@ struct	gettystrs gettystrs[] = {
 	{ "we", &tmode.c_cc[VWERASE] },	/* word erase */
 	{ "ln", &tmode.c_cc[VLNEXT] },	/* literal next */
 	{ "Lo" },			/* locale for strftime() */
+	{ "pp" },			/* ppp login program */
 	{ 0 }
 };
 

libexec/getty/main.c

@@ -39,7 +39,7 @@ static char copyright[] =
 
 #ifndef lint
 /*static char sccsid[] = "from: @(#)main.c	8.1 (Berkeley) 6/20/93";*/
-static char rcsid[] = "$Id: main.c,v 1.9 1996/05/05 19:01:10 joerg Exp $";
+static char rcsid[] = "$Id: main.c,v 1.10 1996/05/07 16:42:26 ache Exp $";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -78,6 +78,16 @@ static char rcsid[] = "$Id: main.c,v 1.9 1996/05/05 19:01:10 joerg Exp $";
 #undef CTRL
 #define CTRL(x)  (x&037)
 
+/* defines for auto detection of incoming PPP calls (->PAP/CHAP) */
+
+#define PPP_FRAME           0x7e  /* PPP Framing character */
+#define PPP_STATION         0xff  /* "All Station" character */
+#define PPP_ESCAPE          0x7d  /* Escape Character */
+#define PPP_CONTROL         0x03  /* PPP Control Field */
+#define PPP_CONTROL_ESCAPED 0x23  /* PPP Control Field, escaped */
+#define PPP_LCP_HI          0xc0  /* LCP protocol - high byte */
+#define PPP_LCP_LOW         0x21  /* LCP protocol - low byte */
+
 struct termios tmode, omode;
 
 int crmod, digit, lower, upper;
@@ -172,6 +182,7 @@ main(argc, argv)
 	const char *tname;
 	int repcnt = 0, failopenlogged = 0;
 	struct rlimit limit;
+	int rval;
 
 	signal(SIGINT, SIG_IGN);
 	signal(SIGQUIT, SIG_IGN);
@@ -293,7 +304,11 @@ main(argc, argv)
 			signal(SIGALRM, dingdong);
 			alarm(TO);
 		}
-		if (getname()) {
+		if ((rval = getname()) == 2) {
+			execle(PP, "ppplogin", ttyn, (char *) 0, env);
+			syslog(LOG_ERR, "%s: %m", PP);
+			exit(1);
+		} else if (rval) {
 			register int i;
 
 			oflush();
@@ -345,7 +360,9 @@ getname()
 {
 	register int c;
 	register char *np;
-	char cs;
+	unsigned char cs;
+	int ppp_state;
+	int ppp_connection = 0;
 
 	/*
 	 * Interrupt may happen if we use CBREAK mode
@@ -374,6 +391,34 @@ getname()
 			exit(0);
 		if ((c = cs&0177) == 0)
 			return (0);
+
+		/* PPP detection state machine..
+		   Look for sequences:
+		   PPP_FRAME, PPP_STATION, PPP_ESCAPE, PPP_CONTROL_ESCAPED or
+		   PPP_FRAME, PPP_STATION, PPP_CONTROL (deviant from RFC)
+		   See RFC1662.
+		   Derived from code from Michael Hancock, <michaelh@cet.co.jp>
+		   and Erik 'PPP' Olson, <eriko@wrq.com>
+		 */
+
+		if (PP && (cs == PPP_FRAME)) {
+			ppp_state = 1;
+		} else if (ppp_state == 1 && cs == PPP_STATION) {
+			ppp_state = 2;
+		} else if (ppp_state == 2 && cs == PPP_ESCAPE) {
+			ppp_state = 3;
+		} else if ((ppp_state == 2 && cs == PPP_CONTROL)
+			|| (ppp_state == 3 && cs == PPP_CONTROL_ESCAPED)) {
+			ppp_state = 4;
+		} else if (ppp_state == 4 && cs == PPP_LCP_HI) {
+			ppp_state = 5;
+		} else if (ppp_state == 5 && cs == PPP_LCP_LOW) {
+			ppp_connection = 1;
+			break;
+		} else {
+			ppp_state = 0;
+		}
+
 		if (c == EOT || c == CTRL('d'))
 			exit(1);
 		if (c == '\r' || c == '\n' || np >= &name[sizeof name]) {
@@ -418,7 +463,7 @@ getname()
 		for (np = name; *np; np++)
 			if (isupper(*np))
 				*np = tolower(*np);
-	return (1);
+	return (1 + ppp_connection);
 }
 
 static void