+/*
+ * List of valid speeds.
+ */
+struct speed {
+ int speed_int, speed_val;
+} speeds[] = {
+#ifdef B50
+ { 50, B50 },
+#endif
+#ifdef B75
+ { 75, B75 },
+#endif
+#ifdef B110
+ { 110, B110 },
+#endif
+#ifdef B134
+ { 134, B134 },
+#endif
+#ifdef B150
+ { 150, B150 },
+#endif
+#ifdef B200
+ { 200, B200 },
+#endif
+#ifdef B300
+ { 300, B300 },
+#endif
+#ifdef B600
+ { 600, B600 },
+#endif
+#ifdef B1200
+ { 1200, B1200 },
+#endif
+#ifdef B1800
+ { 1800, B1800 },
+#endif
+#ifdef B2000
+ { 2000, B2000 },
+#endif
+#ifdef B2400
+ { 2400, B2400 },
+#endif
+#ifdef B3600
+ { 3600, B3600 },
+#endif
+#ifdef B4800
+ { 4800, B4800 },
+#endif
+#ifdef B7200
+ { 7200, B7200 },
+#endif
+#ifdef B9600
+ { 9600, B9600 },
+#endif
+#ifdef B19200
+ { 19200, B19200 },
+#endif
+#ifdef B38400
+ { 38400, B38400 },
+#endif
+#ifdef EXTA
+ { 19200, EXTA },
+#endif
+#ifdef EXTB
+ { 38400, EXTB },
+#endif
+#ifdef B57600
+ { 57600, B57600 },
+#endif
+#ifdef B115200
+ { 115200, B115200 },
+#endif
+ { 0, 0 }
+};
+
+/*
+ * Translate from bits/second to a speed_t.
+ */
+int
+translate_speed(bps)
+ int bps;
+{
+ struct speed *speedp;
+
+ if (bps == 0)
+ return 0;
+ for (speedp = speeds; speedp->speed_int; speedp++)
+ if (bps == speedp->speed_int)
+ return speedp->speed_val;
+ syslog(LOG_WARNING, "speed %d not supported", bps);
+ return 0;
+}
+
+/*
+ * Translate from a speed_t to bits/second.
+ */
+int
+baud_rate_of(speed)
+ int speed;
+{
+ struct speed *speedp;
+
+ if (speed == 0)
+ return 0;
+ for (speedp = speeds; speedp->speed_int; speedp++)
+ if (speed == speedp->speed_val)
+ return speedp->speed_int;
+ return 0;
+}
+
+/*
+ * set_up_tty: Set up the serial port on `fd' for 8 bits, no parity,
+ * at the requested speed, etc. If `local' is true, set CLOCAL
+ * regardless of whether the modem option was specified.
+ */
+set_up_tty(fd, local)
+ int fd, local;
+{
+ int speed;
+ struct termios tios;
+
+ if (tcgetattr(fd, &tios) < 0) {
+ syslog(LOG_ERR, "tcgetattr: %m");
+ die(1);
+ }
+
+ if (!restore_term)
+ inittermios = tios;
+
+ tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
+ if (crtscts > 0)
+ tios.c_cflag |= CRTSCTS;
+ else if (crtscts < 0)
+ tios.c_cflag &= ~CRTSCTS;
+
+ tios.c_cflag |= CS8 | CREAD | HUPCL;
+ if (local || !modem)
+ tios.c_cflag |= CLOCAL;
+ tios.c_iflag = IGNBRK | IGNPAR;
+ tios.c_oflag = 0;
+ tios.c_lflag = 0;
+ tios.c_cc[VMIN] = 1;
+ tios.c_cc[VTIME] = 0;
+
+ if (crtscts == 2) {
+ tios.c_iflag |= IXOFF;
+ tios.c_cc[VSTOP] = 0x13; /* DC3 = XOFF = ^S */
+ tios.c_cc[VSTART] = 0x11; /* DC1 = XON = ^Q */
+ }
+
+ speed = translate_speed(inspeed);
+ if (speed) {
+ cfsetospeed(&tios, speed);
+ cfsetispeed(&tios, speed);
+ } else {
+ speed = cfgetospeed(&tios);
+ /*
+ * We can't proceed if the serial port speed is B0,
+ * since that implies that the serial port is disabled.
+ */
+ if (speed == B0) {
+ syslog(LOG_ERR, "Baud rate for %s is 0; need explicit baud rate",
+ devnam);
+ die(1);
+ }
+ }
+
+ if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
+ syslog(LOG_ERR, "tcsetattr: %m");
+ die(1);
+ }
+
+ baud_rate = inspeed = baud_rate_of(speed);
+ restore_term = 1;
+}
+
+/*
+ * restore_tty - restore the terminal to the saved settings.
+ */
+void
+restore_tty()
+{
+ if (restore_term) {
+ if (!default_device) {
+ /*
+ * Turn off echoing, because otherwise we can get into
+ * a loop with the tty and the modem echoing to each other.
+ * We presume we are the sole user of this tty device, so
+ * when we close it, it will revert to its defaults anyway.
+ */
+ inittermios.c_lflag &= ~(ECHO | ECHONL);
+ }
+ if (tcsetattr(fd, TCSAFLUSH, &inittermios) < 0)
+ if (errno != ENXIO)
+ syslog(LOG_WARNING, "tcsetattr: %m");
+ restore_term = 0;
+ }
+}
+
+/*
+ * setdtr - control the DTR line on the serial port.
+ * This is called from die(), so it shouldn't call die().
+ */
+setdtr(fd, on)
+int fd, on;
+{
+ int modembits = TIOCM_DTR;
+
+ ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
+}
+
+
+/*
+ * open_loopback - open the device we use for getting packets
+ * in demand mode. Here we use a pty.
+ */
+int
+open_loopback()
+{
+ int flags;
+ struct termios tios;
+ static char c1[] = "pqrstuvwxyzPQRST";
+ static char c2[] = "0123456789abcdef";
+ char *p1, *p2;
+
+ p1 = c1;
+ p2 = c2;
+ strcpy(loop_name, "/dev/ptyxx");
+ loop_slave = -1;
+ for (;;) {
+ loop_name[8] = *p1;
+ loop_name[9] = *p2;
+ if ((loop_master = open(loop_name, O_RDWR, 0)) >= 0) {
+ loop_name[5] = 't';
+ chown(loop_name, geteuid(), getegid());
+ chmod(loop_name, S_IRUSR|S_IWUSR);
+ if ((loop_slave = open(loop_name, O_RDWR, 0)) >= 0)
+ break;
+ close(loop_master);
+ loop_name[5] = 'p';
+ } else if (errno == ENOENT)
+ break;
+ if (*++p2 == 0) {
+ p2 = c2;
+ if (*++p1 == 0)
+ break;
+ }
+ }
+ if (loop_slave < 0) {
+ syslog(LOG_ERR, "No free pty for loopback");
+ die(1);
+ }
+ SYSDEBUG((LOG_DEBUG, "using %s for loopback", loop_name));
+ if (tcgetattr(loop_slave, &tios) == 0) {
+ tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB);
+ tios.c_cflag |= CS8 | CREAD;
+ tios.c_iflag = IGNPAR;
+ tios.c_oflag = 0;
+ tios.c_lflag = 0;
+ if (tcsetattr(loop_slave, TCSAFLUSH, &tios) < 0)
+ syslog(LOG_WARNING, "couldn't set attributes on loopback: %m");
+ }
+ if ((flags = fcntl(loop_slave, F_GETFL)) != -1)
+ if (fcntl(loop_slave, F_SETFL, flags | O_NONBLOCK) == -1)
+ syslog(LOG_WARNING, "couldn't set loopback to nonblock: %m");
+ if ((flags = fcntl(loop_master, F_GETFL)) != -1)
+ if (fcntl(loop_master, F_SETFL, flags | O_NONBLOCK) == -1)
+ syslog(LOG_WARNING, "couldn't set loopback(m) to nonblock: %m");
+ return loop_slave;
+}