+ if_is_up = 0;
+
+ memset (&ifr, '\0', sizeof (ifr));
+ strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+ if (ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
+ if (! ok_error (errno))
+ error("ioctl (SIOCGIFFLAGS): %m(%d)", errno);
+ return 0;
+ }
+
+ ifr.ifr_flags &= ~IFF_UP;
+ ifr.ifr_flags |= IFF_POINTOPOINT;
+ if (ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
+ if (! ok_error (errno))
+ error("ioctl(SIOCSIFFLAGS): %m(%d)", errno);
+ return 0;
+ }
+ return 1;
+}
+
+/********************************************************************
+ *
+ * sifaddr - Config the interface IP addresses and netmask.
+ */
+
+int sifaddr (int unit, u_int32_t our_adr, u_int32_t his_adr,
+ u_int32_t net_mask)
+{
+ struct ifreq ifr;
+ struct rtentry rt;
+
+ memset (&ifr, '\0', sizeof (ifr));
+ memset (&rt, '\0', sizeof (rt));
+
+ SET_SA_FAMILY (ifr.ifr_addr, AF_INET);
+ SET_SA_FAMILY (ifr.ifr_dstaddr, AF_INET);
+ SET_SA_FAMILY (ifr.ifr_netmask, AF_INET);
+
+ strlcpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+/*
+ * Set our IP address
+ */
+ ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = our_adr;
+ if (ioctl(sock_fd, SIOCSIFADDR, (caddr_t) &ifr) < 0) {
+ if (errno != EEXIST) {
+ if (! ok_error (errno))
+ error("ioctl(SIOCSIFADDR): %m(%d)", errno);
+ }
+ else {
+ warn("ioctl(SIOCSIFADDR): Address already exists");
+ }
+ return (0);
+ }
+/*
+ * Set the gateway address
+ */
+ ((struct sockaddr_in *) &ifr.ifr_dstaddr)->sin_addr.s_addr = his_adr;
+ if (ioctl(sock_fd, SIOCSIFDSTADDR, (caddr_t) &ifr) < 0) {
+ if (! ok_error (errno))
+ error("ioctl(SIOCSIFDSTADDR): %m(%d)", errno);
+ return (0);
+ }
+/*
+ * Set the netmask.
+ * For recent kernels, force the netmask to 255.255.255.255.
+ */
+ if (kernel_version >= KVERSION(2,1,16))
+ net_mask = ~0L;
+ if (net_mask != 0) {
+ ((struct sockaddr_in *) &ifr.ifr_netmask)->sin_addr.s_addr = net_mask;
+ if (ioctl(sock_fd, SIOCSIFNETMASK, (caddr_t) &ifr) < 0) {
+ if (! ok_error (errno))
+ error("ioctl(SIOCSIFNETMASK): %m(%d)", errno);
+ return (0);
+ }
+ }
+/*
+ * Add the device route
+ */
+ if (kernel_version < KVERSION(2,1,16)) {
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ rt.rt_dev = ifname;
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = 0L;
+ ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr = his_adr;
+ rt.rt_flags = RTF_UP | RTF_HOST;
+
+ if (kernel_version > KVERSION(2,1,0)) {
+ SET_SA_FAMILY (rt.rt_genmask, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_genmask)->sin_addr.s_addr = -1L;
+ }
+
+ if (ioctl(sock_fd, SIOCADDRT, &rt) < 0) {
+ if (! ok_error (errno))
+ error("ioctl(SIOCADDRT) device route: %m(%d)", errno);
+ return (0);
+ }
+ }
+ return 1;
+}
+
+/********************************************************************
+ *
+ * cifaddr - Clear the interface IP addresses, and delete routes
+ * through the interface if possible.
+ */
+
+int cifaddr (int unit, u_int32_t our_adr, u_int32_t his_adr)
+{
+ struct rtentry rt;
+
+ if (kernel_version < KVERSION(2,1,16)) {
+/*
+ * Delete the route through the device
+ */
+ memset (&rt, '\0', sizeof (rt));
+
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+ SET_SA_FAMILY (rt.rt_gateway, AF_INET);
+ rt.rt_dev = ifname;
+
+ ((struct sockaddr_in *) &rt.rt_gateway)->sin_addr.s_addr = 0;
+ ((struct sockaddr_in *) &rt.rt_dst)->sin_addr.s_addr = his_adr;
+ rt.rt_flags = RTF_UP | RTF_HOST;
+
+ if (kernel_version > KVERSION(2,1,0)) {
+ SET_SA_FAMILY (rt.rt_genmask, AF_INET);
+ ((struct sockaddr_in *) &rt.rt_genmask)->sin_addr.s_addr = -1L;
+ }
+
+ if (ioctl(sock_fd, SIOCDELRT, &rt) < 0 && errno != ESRCH) {
+ if (still_ppp() && ! ok_error (errno))
+ error("ioctl(SIOCDELRT) device route: %m(%d)", errno);
+ return (0);
+ }
+ }
+ return 1;
+}
+
+/*
+ * get_pty - get a pty master/slave pair and chown the slave side
+ * to the uid given. Assumes slave_name points to >= 16 bytes of space.
+ */
+int
+get_pty(master_fdp, slave_fdp, slave_name, uid)
+ int *master_fdp;
+ int *slave_fdp;
+ char *slave_name;
+ int uid;
+{
+ int i, mfd, sfd = -1;
+ char pty_name[16];
+ struct termios tios;
+
+#ifdef TIOCGPTN
+ /*
+ * Try the unix98 way first.
+ */
+ mfd = open("/dev/ptmx", O_RDWR);
+ if (mfd >= 0) {
+ int ptn;
+ if (ioctl(mfd, TIOCGPTN, &ptn) >= 0) {
+ slprintf(pty_name, sizeof(pty_name), "/dev/pts/%d", ptn);
+ chmod(pty_name, S_IRUSR | S_IWUSR);
+#ifdef TIOCSPTLCK
+ ptn = 0;
+ if (ioctl(mfd, TIOCSPTLCK, &ptn) < 0)
+ warn("Couldn't unlock pty slave %s: %m", pty_name);
+#endif
+ if ((sfd = open(pty_name, O_RDWR)) < 0)
+ warn("Couldn't open pty slave %s: %m", pty_name);
+ }
+ }
+#endif /* TIOCGPTN */
+
+ if (sfd < 0) {
+ /* the old way - scan through the pty name space */
+ for (i = 0; i < 64; ++i) {
+ slprintf(pty_name, sizeof(pty_name), "/dev/pty%c%x",
+ 'p' + i / 16, i % 16);
+ mfd = open(pty_name, O_RDWR, 0);
+ if (mfd >= 0) {
+ pty_name[5] = 't';
+ sfd = open(pty_name, O_RDWR | O_NOCTTY, 0);
+ if (sfd >= 0) {
+ fchown(sfd, uid, -1);
+ fchmod(sfd, S_IRUSR | S_IWUSR);
+ break;
+ }
+ close(mfd);
+ }
+ }
+ }
+
+ if (sfd < 0)
+ return 0;
+
+ strlcpy(slave_name, pty_name, 16);
+ *master_fdp = mfd;
+ *slave_fdp = sfd;
+ if (tcgetattr(sfd, &tios) == 0) {
+ tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB);
+ tios.c_cflag |= CS8 | CREAD;
+ tios.c_iflag = IGNPAR | CLOCAL;
+ tios.c_oflag = 0;
+ tios.c_lflag = 0;
+ if (tcsetattr(sfd, TCSAFLUSH, &tios) < 0)
+ warn("couldn't set attributes on pty: %m");
+ } else
+ warn("couldn't get attributes on pty: %m");
+
+ return 1;
+}
+
+/********************************************************************
+ *
+ * open_loopback - open the device we use for getting packets
+ * in demand mode. Under Linux, we use a pty master/slave pair.
+ */
+int
+open_ppp_loopback(void)
+{
+ int flags;
+
+ if (new_style_driver) {
+ /* allocate ourselves a ppp unit */
+ ifunit = -1;
+ if (ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit) < 0)
+ fatal("Couldn't create PPP unit: %m");
+ set_flags(ppp_dev_fd, SC_LOOP_TRAFFIC);
+ set_kdebugflag(kdebugflag);
+ ppp_fd = -1;
+ return ppp_dev_fd;
+ }
+
+ if (!get_pty(&master_fd, &slave_fd, loop_name, 0))
+ fatal("No free pty for loopback");
+ SYSDEBUG(("using %s for loopback", loop_name));
+
+ set_ppp_fd(slave_fd);
+
+ flags = fcntl(master_fd, F_GETFL);
+ if (flags == -1 ||
+ fcntl(master_fd, F_SETFL, flags | O_NONBLOCK) == -1)
+ warn("couldn't set master loopback to nonblock: %m(%d)", errno);
+
+ flags = fcntl(ppp_fd, F_GETFL);
+ if (flags == -1 ||
+ fcntl(ppp_fd, F_SETFL, flags | O_NONBLOCK) == -1)
+ warn("couldn't set slave loopback to nonblock: %m(%d)", errno);
+
+ if (ioctl(ppp_fd, TIOCSETD, &ppp_disc) < 0)
+ fatal("ioctl(TIOCSETD): %m(%d)", errno);
+/*
+ * Find out which interface we were given.
+ */
+ if (ioctl(ppp_fd, PPPIOCGUNIT, &ifunit) < 0)
+ fatal("ioctl(PPPIOCGUNIT): %m(%d)", errno);