Do not set explicit com parameters for the tty, instead use the exisiting

ones and onl change what the user requests.  Do not artifically limit the
baudrates.

prodding and ok by deraadt.

1 files changed, 67 insertions, 40 deletions

diff --git a/sbin/ldattach/ldattach.c b/sbin/ldattach/ldattach.c
index 9f5a9f75a80..eb8ae9a1eef 100644
--- a/sbin/ldattach/ldattach.c
+++ b/sbin/ldattach/ldattach.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldattach.c,v 1.2 2007/11/03 15:33:08 deraadt Exp $	*/
+/*	$OpenBSD: ldattach.c,v 1.3 2007/11/13 19:32:34 mbalmer Exp $	*/
 
 /*
  * Copyright (c) 2007 Marc Balmer <mbalmer@openbsd.org>
@@ -22,6 +22,7 @@
  */
 
 #include <sys/ioctl.h>
+#include <sys/limits.h>
 #include <sys/ttycom.h>
 
 #include <err.h>
@@ -57,11 +58,11 @@ main(int argc, char *argv[])
 	struct termios tty;
 	struct tstamps tstamps;
 	const char *errstr;
-	tcflag_t cflag = HUPCL | CS8;
 	sigset_t sigset;
 	pid_t ppid;
-	int ch, fd, ldisc, nodaemon = 0, parity = 0;
-	speed_t speed = B4800;
+	int ch, fd, ldisc, nodaemon = 0;
+	int  bits = 0, parity = 0, flowcl = 0, hupcl = 1;
+	speed_t speed = 0;
 	char devn[32], *dev, *disc;
 
 	tstamps.ts_set = tstamps.ts_clr = 0;
@@ -72,32 +73,25 @@ main(int argc, char *argv[])
 	while ((ch = getopt(argc, argv, "7dehmos:t:")) != -1) {
 		switch (ch) {
 		case '7':
-			cflag &= ~CS8;
-			cflag |= CS7;
+			bits = 7;
 			break;
 		case 'd':
 			nodaemon = 1;
 			break;
 		case 'e':
-			if (parity != 0)
-				parity = 0;	/* -o -e */
-			else
-				parity = -1;	/* even */
+			parity = 'e';
 			break;
 		case 'h':
-			cflag |= CRTSCTS;
+			flowcl = 1;
 			break;
 		case 'm':
-			cflag &= ~HUPCL;
+			hupcl = 0;
 			break;
 		case 'o':
-			if (parity != 0)
-				parity = 0;	/* -e -o */
-			else
-				parity = 1;	/* odd */
+			parity = 'o';
 			break;
 		case 's':
-			speed = (speed_t)strtonum(optarg, 50, 230400, &errstr);
+			speed = (speed_t)strtonum(optarg, 0, UINT_MAX, &errstr);
 			if (errstr) {
 				if (ppid != 1)
 					errx(1,  "speed is %s: %s", errstr,
@@ -141,41 +135,60 @@ main(int argc, char *argv[])
 		    "%s%s", _PATH_DEV, dev);
 		dev = devn;
 	}
-	syslog(LOG_INFO, "attach %s on %s", disc, dev);
-	if ((fd = open(dev, O_RDWR)) < 0)
-		goto bail_out;
 
-	if (!strcmp(disc, "slip"))
+	if (!strcmp(disc, "slip")) {
+		bits = 8;		/* make sure we use 8 databits */
 		ldisc = SLIPDISC;
-	else if (!strcmp(disc, "nmea"))
+	} else if (!strcmp(disc, "nmea")) {
 		ldisc = NMEADISC;
-	else {
+		if (speed == 0)
+			speed = B4800;	/* default is 4800 baud for nmea */
+	} else {
 		syslog(LOG_ERR, "unknown line discipline %s", disc);
 		goto bail_out;
 	}
 
-	switch (parity) {
-	case -1:	/* even parity */
-		cflag |= PARENB;
-		break;
-	case 1:		/* odd parity */
-		cflag |= PARENB | PARODD;
-		break;
-	}
+	syslog(LOG_INFO, "attach %s on %s", disc, dev);
+	if ((fd = open(dev, O_RDWR)) < 0)
+		goto bail_out;
 
-	tty.c_cflag = CREAD | cflag;
-	tty.c_iflag = 0;
-	tty.c_lflag = 0;
-	tty.c_oflag = 0;
-	tty.c_cc[VMIN] = 1;
-	tty.c_cc[VTIME] = 0;
-	cfsetspeed(&tty, speed);
-	if (tcsetattr(fd, TCSADRAIN, &tty) < 0) {
+	/*
+	 * Get the current line attributes, modify only values that are
+	 * either requested on the command line or that are needed by
+	 * the line discipline (e.g. nmea has a default baudrate of
+	 * 4800 instead of 9600).
+	 */
+	if (tcgetattr(fd, &tty) < 0) {
 		if (ppid != 1)
-			warnx("tcsetattr");
+			warnx("tcgetattr");
 		goto bail_out;
 	}
 
+
+	if (bits == 7) {
+		tty.c_cflag &= ~CS8;
+		tty.c_cflag |= CS7;
+	} else if (bits == 8) {
+		tty.c_cflag &= ~CS7;
+		tty.c_cflag |= CS8;
+	}
+
+	if (parity != 0)
+		tty.c_cflag |= PARENB;
+	if (parity == 'o')
+		tty.c_cflag |= PARODD;
+	else
+		tty.c_cflag &= ~PARODD;
+
+	if (flowcl)
+		tty.c_cflag |= CRTSCTS;
+
+	if (hupcl == 0)
+		tty.c_cflag &= ~HUPCL;
+
+	if (speed != 0)
+		cfsetspeed(&tty, speed);
+
 	/* setup common to all line disciplines */
 	if (ioctl(fd, TIOCSDTR, 0) < 0)
 		warn("TIOCSDTR");
@@ -193,6 +206,20 @@ main(int argc, char *argv[])
 			goto bail_out;
 		}
 		break;
+	case SLIPDISC:
+		tty.c_iflag = 0;
+		tty.c_lflag = 0;
+		tty.c_oflag = 0;
+		tty.c_cc[VMIN] = 1;
+		tty.c_cc[VTIME] = 0;
+		break;
+	}
+
+	/* finally set the line attributes */
+	if (tcsetattr(fd, TCSADRAIN, &tty) < 0) {
+		if (ppid != 1)
+			warnx("tcsetattr");
+		goto bail_out;
 	}
 
 	if (!nodaemon && daemon(0, 0))