+
+ /*
+ * Set device for non-blocking reads.
+ */
+ if ((initfdflags = fcntl(fd, F_GETFL)) == -1
+ || fcntl(fd, F_SETFL, initfdflags | O_NONBLOCK) == -1) {
+ syslog(LOG_WARNING, "Couldn't set device to non-blocking mode: %m");
+ }
+}
+
+#if 0
+/*
+ * transfer_ppp - make the device on fd `fd' take over the PPP interface
+ * unit that we are using.
+ */
+void
+transfer_ppp(fd)
+ int fd;
+{
+ int x, prevdisc;
+
+ if (fd == ppp_fd)
+ return; /* we can't get here */
+
+ /* Reset non-blocking mode on ppp_fd. */
+ if (initfdflags != -1 && fcntl(ppp_fd, F_SETFL, initfdflags) < 0)
+ syslog(LOG_WARNING, "Couldn't restore device fd flags: %m");
+ initfdflags = -1;
+
+ /*
+ * Prime the old ppp device to relinquish the unit.
+ */
+ if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) < 0) {
+ syslog(LOG_ERR, "ioctl(transfer ppp unit): %m");
+ die(1);
+ }
+
+ /*
+ * Save the old line discipline of fd, and set it to PPP.
+ */
+ if (ioctl(fd, TIOCGETD, &prevdisc) < 0) {
+ syslog(LOG_ERR, "ioctl(TIOCGETD): %m");
+ die(1);
+ }
+ x = PPPDISC;
+ if (ioctl(fd, TIOCSETD, &x) < 0) {
+ syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
+ die(1);
+ }
+
+ /*
+ * Set the old ppp device back to its previous discipline,
+ */
+ ioctl(ppp_fd, TIOCSETD, &initdisc);
+ initdisc = prevdisc;
+
+ /*
+ * Check that we got the same unit again.
+ */
+ if (ioctl(fd, PPPIOCGUNIT, &x) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
+ die(1);
+ }
+ if (x != ifunit) {
+ syslog(LOG_ERR, "transfer_ppp failed: wanted unit %d, got %d",
+ ifunit, x);
+ die(1);
+ }
+
+ ppp_fd = fd;
+
+ /*
+ * Set device for non-blocking reads.
+ */
+ if ((initfdflags = fcntl(fd, F_GETFL)) == -1
+ || fcntl(fd, F_SETFL, initfdflags | O_NONBLOCK) == -1) {
+ syslog(LOG_WARNING, "Couldn't set device to non-blocking mode: %m");
+ }
+}
+#endif
+
+/*
+ * restore_loop - reattach the ppp unit to the loopback.
+ */
+void
+restore_loop()
+{
+ int x;
+
+ /*
+ * Transfer the ppp interface back to the loopback.
+ */
+ if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) < 0) {
+ syslog(LOG_ERR, "ioctl(transfer ppp unit): %m");
+ die(1);
+ }
+ x = PPPDISC;
+ if (ioctl(loop_slave, TIOCSETD, &x) < 0) {
+ syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
+ die(1);
+ }
+
+ /*
+ * Check that we got the same unit again.
+ */
+ if (ioctl(loop_slave, PPPIOCGUNIT, &x) < 0) {
+ syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
+ die(1);
+ }
+ if (x != ifunit) {
+ syslog(LOG_ERR, "transfer_ppp failed: wanted unit %d, got %d",
+ ifunit, x);
+ die(1);
+ }
+ ppp_fd = loop_slave;