pkgsrc/net/pppd/patches/patch-az

$NetBSD: patch-az,v 1.3 2005/01/02 22:28:31 cube Exp $

--- pppd/sys-bsd.c.orig	2005-01-02 23:24:27.000000000 +0100
+++ pppd/sys-bsd.c
@@ -0,0 +1,2184 @@
+/*	NetBSD: sys-bsd.c,v 1.50 2004/12/05 04:16:22 christos Exp 	*/
+
+/*
+ * sys-bsd.c - System-dependent procedures for setting up
+ * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.)
+ *
+ * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The name "Carnegie Mellon University" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For permission or any legal
+ *    details, please contact
+ *      Office of Technology Transfer
+ *      Carnegie Mellon University
+ *      5000 Forbes Avenue
+ *      Pittsburgh, PA  15213-3890
+ *      (412) 268-4387, fax: (412) 268-7395
+ *      tech-transfer@andrew.cmu.edu
+ *
+ * 4. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by Computing Services
+ *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
+ *
+ * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
+ * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The name(s) of the authors of this software must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission.
+ *
+ * 4. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by Paul Mackerras
+ *     <paulus@samba.org>".
+ *
+ * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+#define RCSID	"Id: sys-bsd.c,v 1.47 2000/04/13 12:04:23 paulus Exp "
+#else
+__RCSID("NetBSD: sys-bsd.c,v 1.50 2004/12/05 04:16:22 christos Exp ");
+#endif
+#endif
+
+/*
+ * TODO:
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <signal.h>
+#include <vis.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#if defined(NetBSD1_2) || defined(__NetBSD_Version__)
+#include <util.h>
+#endif
+#ifdef PPP_FILTER
+#include <net/bpf.h>
+#endif
+
+#include <net/if.h>
+#include <net/ppp_defs.h>
+#include <net/if_ppp.h>
+#include <net/route.h>
+#include <net/if_dl.h>
+#include <netinet/in.h>
+#ifdef __KAME__
+#include <netinet6/in6_var.h>
+#include <netinet6/nd6.h>
+#endif
+#include <ifaddrs.h>
+
+#if RTM_VERSION >= 3
+#include <sys/param.h>
+#if defined(NetBSD) && (NetBSD >= 199703)
+#include <netinet/if_inarp.h>
+#else	/* NetBSD 1.2D or later */
+#ifdef __FreeBSD__
+#include <netinet/if_ether.h>
+#else
+#include <net/if_ether.h>
+#endif
+#endif
+#endif
+
+#include "pppd.h"
+#include "fsm.h"
+#include "ipcp.h"
+
+#ifdef RCSID
+static const char rcsid[] = RCSID;
+#endif
+
+static int initdisc = -1;	/* Initial TTY discipline for ppp_fd */
+static int initfdflags = -1;	/* Initial file descriptor flags for ppp_fd */
+static int ppp_fd = -1;		/* fd which is set to PPP discipline */
+static int rtm_seq;
+
+static int restore_term;	/* 1 => we've munged the terminal */
+static struct termios inittermios; /* Initial TTY termios */
+static struct winsize wsinfo;	/* Initial window size info */
+
+static int loop_slave = -1;
+static int loop_master;
+static char loop_name[20];
+
+static unsigned char inbuf[512]; /* buffer for chars read from loopback */
+
+static int sock_fd;		/* socket for doing interface ioctls */
+#ifdef INET6
+static int sock6_fd = -1;	/* socket for doing ipv6 interface ioctls */
+#endif /* INET6 */
+static int ttyfd = -1;		/* the file descriptor of the tty */
+
+static fd_set in_fds;		/* set of fds that wait_input waits for */
+static int max_in_fd;		/* highest fd set in in_fds */
+
+static int if_is_up;		/* the interface is currently up */
+static u_int32_t ifaddrs[2];	/* local and remote addresses we set */
+static u_int32_t default_route_gateway;	/* gateway addr for default route */
+static u_int32_t proxy_arp_addr;	/* remote addr for proxy arp */
+
+/* Prototypes for procedures local to this file. */
+static int get_flags __P((int));
+static void set_flags __P((int, int));
+static int dodefaultroute __P((u_int32_t, int));
+static int get_ether_addr __P((u_int32_t, struct sockaddr_dl *));
+static void restore_loop(void);	/* Transfer ppp unit back to loopback */
+
+
+/********************************************************************
+ *
+ * Functions to read and set the flags value in the device driver
+ */
+
+static int
+get_flags(fd)
+    int fd;
+{    
+    int flags;
+
+    if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &flags) == -1)
+	fatal("ioctl(PPPIOCGFLAGS): %m");
+
+    SYSDEBUG((LOG_DEBUG, "get flags = %x\n", flags));
+    return flags;
+}
+
+/********************************************************************/
+
+static void
+set_flags(fd, flags)
+    int fd, flags;
+{    
+    SYSDEBUG((LOG_DEBUG, "set flags = %x\n", flags));
+
+    if (ioctl(fd, PPPIOCSFLAGS, (caddr_t) &flags) == -1)
+	fatal("ioctl(PPPIOCSFLAGS, %x): %m", flags, errno);
+}
+
+/*
+ * sys_init - System-dependent initialization.
+ */
+void
+sys_init()
+{
+    /* Get an internet socket for doing socket ioctl's on. */
+    if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
+	fatal("Couldn't create IP socket: %m");
+
+#ifdef INET6
+    if ((sock6_fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+	/* check it at runtime */
+	sock6_fd = -1;
+    }
+#endif
+
+    FD_ZERO(&in_fds);
+    max_in_fd = 0;
+}
+
+/*
+ * sys_cleanup - restore any system state we modified before exiting:
+ * mark the interface down, delete default route and/or proxy arp entry.
+ * This should call die() because it's called from die().
+ */
+void
+sys_cleanup()
+{
+    struct ifreq ifr;
+
+    if (if_is_up) {
+	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	if (ioctl(sock_fd, SIOCGIFFLAGS, &ifr) >= 0
+	    && ((ifr.ifr_flags & IFF_UP) != 0)) {
+	    ifr.ifr_flags &= ~IFF_UP;
+	    ioctl(sock_fd, SIOCSIFFLAGS, &ifr);
+	}
+    }
+    if (ifaddrs[0] != 0)
+	cifaddr(0, ifaddrs[0], ifaddrs[1]);
+    if (default_route_gateway)
+	cifdefaultroute(0, 0, default_route_gateway);
+    if (proxy_arp_addr)
+	cifproxyarp(0, proxy_arp_addr);
+}
+
+/*
+ * sys_close - Clean up in a child process before execing.
+ */
+void
+sys_close()
+{
+    close(sock_fd);
+    if (loop_slave >= 0) {
+	close(loop_slave);
+	close(loop_master);
+    }
+}
+
+/*
+ * sys_check_options - check the options that the user specified
+ */
+int
+sys_check_options()
+{
+#ifndef CDTRCTS
+    if (crtscts == 2) {
+	warn("DTR/CTS flow control is not supported on this system");
+	return 0;
+    }
+#endif
+    return 1;
+}
+
+/*
+ * ppp_available - check whether the system has any ppp interfaces
+ * (in fact we check whether we can do an ioctl on ppp0).
+ */
+int
+ppp_available()
+{
+    struct if_clonereq ifcr;
+    char *cp, *buf;
+    int idx, s, ok;
+    extern char *no_ppp_msg;
+
+    (void)memset(&ifcr, 0, sizeof(ifcr));
+
+    if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
+	fatal("socket: %m");
+
+    if (ioctl(s, SIOCIFGCLONERS, &ifcr) == -1)
+	fatal("ioctl(get cloners): %m");
+
+    buf = malloc(ifcr.ifcr_total * IFNAMSIZ);
+    if (buf == NULL)
+	fatal("Unable to allocate cloner name buffer: %m");
+
+    ifcr.ifcr_count = ifcr.ifcr_total;
+    ifcr.ifcr_buffer = buf;
+
+    if (ioctl(s, SIOCIFGCLONERS, &ifcr) == -1)
+	fatal("ioctl(get cloners): %m");
+
+    /*
+     * In case some disappeared in the mean time, clamp it down.
+     */
+    if (ifcr.ifcr_count > ifcr.ifcr_total)
+	ifcr.ifcr_count = ifcr.ifcr_total;
+
+    for (cp = buf, idx = 0; idx < ifcr.ifcr_count; idx++, cp += IFNAMSIZ) {
+	if (strcmp(cp, "ppp") == 0)
+	    break;
+    }
+    free(buf);
+
+    if (idx == ifcr.ifcr_count) {
+	    /*
+	     * Try ppp0 directly, as before ppp was clonable.
+	     */
+	    struct ifreq ifr;
+	    (void)memset(&ifr, 0, sizeof(ifr));
+	    strlcpy(ifr.ifr_name, "ppp0", sizeof (ifr.ifr_name));
+	    ok = ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) != -1;
+    } else
+	    ok = 1;
+
+    (void)close(s);
+
+#ifdef __NetBSD__
+    no_ppp_msg = "\
+This system lacks kernel support for PPP.  To include PPP support\n\
+in the kernel, please read the ppp(4) manual page.\n";
+#else
+    no_ppp_msg = "\
+This system lacks kernel support for PPP.  To include PPP support\n\
+in the kernel, please follow the steps detailed in the README.bsd\n\
+file in the ppp-2.2 distribution.\n";
+#endif
+    return ok;
+}
+
+/*
+ * tty_establish_ppp - Turn the serial port into a ppp interface.
+ */
+int
+tty_establish_ppp(fd)
+    int fd;
+{
+    int pppdisc = PPPDISC;
+    int x;
+    ttyfd = fd;
+
+    if (demand) {
+	/*
+	 * Demand mode - prime the old ppp device to relinquish the unit.
+	 */
+	if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) < 0)
+	    fatal("ioctl(transfer ppp unit): %m");
+    }
+
+    /*
+     * Save the old line discipline of fd, and set it to PPP.
+     */
+    if (ioctl(fd, TIOCGETD, &initdisc) < 0)
+	fatal("ioctl(TIOCGETD): %m");
+    if (ioctl(fd, TIOCSETD, &pppdisc) < 0)
+	fatal("ioctl(TIOCSETD): %m");
+
+    if (!demand) {
+	/*
+	 * Find out which interface we were given.
+	 */
+	if (ioctl(fd, PPPIOCGUNIT, &ifunit) < 0)
+	    fatal("ioctl(PPPIOCGUNIT): %m");
+    } else {
+	/*
+	 * Check that we got the same unit again.
+	 */
+	if (ioctl(fd, PPPIOCGUNIT, &x) < 0)
+	    fatal("ioctl(PPPIOCGUNIT): %m");
+	if (x != ifunit)
+	    fatal("transfer_ppp failed: wanted unit %d, got %d", ifunit, x);
+	x = TTYDISC;
+	ioctl(loop_slave, TIOCSETD, &x);
+    }
+
+    ppp_fd = fd;
+
+    /*
+     * Enable debug in the driver if requested.
+     */
+    if (kdebugflag) {
+	x = get_flags(fd);
+	x |= (kdebugflag & 0xFF) * SC_DEBUG;
+	set_flags(fd, x);
+    }
+
+    /*
+     * Set device for non-blocking reads.
+     */
+    if ((initfdflags = fcntl(fd, F_GETFL)) == -1
+	|| fcntl(fd, F_SETFL, initfdflags | O_NONBLOCK) == -1) {
+	warn("Couldn't set device to non-blocking mode: %m");
+    }
+
+    return fd;
+}
+
+/*
+ * restore_loop - reattach the ppp unit to the loopback.
+ */
+static void
+restore_loop()
+{
+    int x;
+
+    /*
+     * Transfer the ppp interface back to the loopback.
+     */
+    if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) < 0)
+	fatal("ioctl(transfer ppp unit): %m");
+    x = PPPDISC;
+    if (ioctl(loop_slave, TIOCSETD, &x) < 0)
+	fatal("ioctl(TIOCSETD): %m");
+
+    /*
+     * Check that we got the same unit again.
+     */
+    if (ioctl(loop_slave, PPPIOCGUNIT, &x) < 0)
+	fatal("ioctl(PPPIOCGUNIT): %m");
+    if (x != ifunit)
+	fatal("transfer_ppp failed: wanted unit %d, got %d", ifunit, x);
+    ppp_fd = loop_slave;
+}
+
+
+/*
+ * Determine if the PPP connection should still be present.
+ */
+extern int hungup;
+
+/*
+ * tty_disestablish_ppp - Restore the serial port to normal operation.
+ * and reconnect the ppp unit to the loopback if in demand mode.
+ * This shouldn't call die() because it's called from die().
+ */
+void
+tty_disestablish_ppp(fd)
+    int fd;
+{
+    if (demand)
+	restore_loop();
+
+    if (!hungup) {
+
+
+	/* Flush the tty output buffer so that the TIOCSETD doesn't hang.  */
+	if (tcflush(fd, TCIOFLUSH) < 0)
+	    warn("tcflush failed: %m");
+
+	/* Restore old line discipline. */
+	if (initdisc >= 0 && ioctl(fd, TIOCSETD, &initdisc) < 0)
+	    error("ioctl(TIOCSETD): %m");
+	initdisc = -1;
+
+	/* Reset non-blocking mode on fd. */
+	if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) < 0)
+	    warn("Couldn't restore device fd flags: %m");
+    }
+    initfdflags = -1;
+
+    if (fd == ppp_fd)
+	ppp_fd = -1;
+}
+
+/*
+ * cfg_bundle - configure the existing bundle.
+ * Used in demand mode.
+ */
+void
+cfg_bundle(mrru, mtru, rssn, tssn)
+    int mrru, mtru, rssn, tssn;
+{
+    abort();
+#ifdef notyet
+    int flags;
+    struct ifreq ifr;
+
+    if (!new_style_driver)
+	return;
+
+    /* set the mrru, mtu and flags */
+    if (ioctl(ppp_dev_fd, PPPIOCSMRRU, &mrru) < 0)
+	error("Couldn't set MRRU: %m");
+    flags = get_flags(ppp_dev_fd);
+    flags &= ~(SC_MP_SHORTSEQ | SC_MP_XSHORTSEQ);
+    flags |= (rssn? SC_MP_SHORTSEQ: 0) | (tssn? SC_MP_XSHORTSEQ: 0)
+	    | (mrru? SC_MULTILINK: 0);
+
+    set_flags(ppp_dev_fd, flags);
+
+    /* connect up the channel */
+    if (ioctl(ppp_fd, PPPIOCCONNECT, &ifunit) < 0)
+	fatal("Couldn't attach to PPP unit %d: %m", ifunit);
+    add_fd(ppp_dev_fd);
+#endif
+}
+
+/*
+ * make_new_bundle - create a new PPP unit (i.e. a bundle)
+ * and connect our channel to it.  This should only get called
+ * if `multilink' was set at the time establish_ppp was called.
+ * In demand mode this uses our existing bundle instead of making
+ * a new one.
+ */
+void
+make_new_bundle(mrru, mtru, rssn, tssn)
+    int mrru, mtru, rssn, tssn;
+{
+    abort();
+#ifdef notyet
+    if (!new_style_driver)
+	return;
+
+    /* make us a ppp unit */
+    if (make_ppp_unit() < 0)
+	die(1);
+
+    /* set the mrru, mtu and flags */
+    cfg_bundle(mrru, mtru, rssn, tssn);
+#endif
+}
+
+/*
+ * bundle_attach - attach our link to a given PPP unit.
+ * We assume the unit is controlled by another pppd.
+ */
+int
+bundle_attach(ifnum)
+	int ifnum;
+{
+    abort();
+#ifdef notyet
+    if (!new_style_driver)
+	return -1;
+
+    if (ioctl(ppp_dev_fd, PPPIOCATTACH, &ifnum) < 0) {
+	if (errno == ENXIO)
+	    return 0;	/* doesn't still exist */
+	fatal("Couldn't attach to interface unit %d: %m\n", ifnum);
+    }
+    if (ioctl(ppp_fd, PPPIOCCONNECT, &ifnum) < 0)
+	fatal("Couldn't connect to interface unit %d: %m", ifnum);
+    set_flags(ppp_dev_fd, get_flags(ppp_dev_fd) | SC_MULTILINK);
+
+    ifunit = ifnum;
+#endif
+    return 1;
+}
+
+/*
+ * destroy_bundle - tell the driver to destroy our bundle.
+ */
+void destroy_bundle(void)
+{
+#if notyet
+	if (ppp_dev_fd >= 0) {
+		close(ppp_dev_fd);
+		remove_fd(ppp_dev_fd);
+		ppp_dev_fd = -1;
+	}
+#endif
+}
+
+
+/*
+ * Check whether the link seems not to be 8-bit clean.
+ */
+void
+clean_check()
+{
+    int x;
+    char *s;
+
+    if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == 0) {
+	s = NULL;
+	switch (~x & (SC_RCV_B7_0|SC_RCV_B7_1|SC_RCV_EVNP|SC_RCV_ODDP)) {
+	case SC_RCV_B7_0:
+	    s = "bit 7 set to 1";
+	    break;
+	case SC_RCV_B7_1:
+	    s = "bit 7 set to 0";
+	    break;
+	case SC_RCV_EVNP:
+	    s = "odd parity";
+	    break;
+	case SC_RCV_ODDP:
+	    s = "even parity";
+	    break;
+	}
+	if (s != NULL) {
+	    struct ppp_rawin win;
+	    char buf[4 * sizeof(win.buf) + 1];
+	    int i;
+	    warn("Serial link is not 8-bit clean:");
+	    warn("All received characters had %s", s);
+	    if (ioctl(ppp_fd, PPPIOCGRAWIN, &win) == -1) {
+		warn("ioctl(PPPIOCGRAWIN): %s", strerror(errno));
+		return;
+	    }
+	    for (i = 0; i < sizeof(win.buf); i++)
+		win.buf[i] = win.buf[i] & 0x7f;
+	    strvisx(buf, (char *)win.buf, win.count, VIS_CSTYLE);
+	    warn("Last %d characters were: %s", (int)win.count, buf);
+	}
+    }
+}
+
+/*
+ * 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.
+ *
+ * For *BSD, we assume that speed_t values numerically equal bits/second.
+ */
+void
+set_up_tty(fd, local)
+    int fd, local;
+{
+    struct termios tios;
+
+    if (tcgetattr(fd, &tios) < 0)
+	fatal("tcgetattr: %m");
+
+    if (!restore_term) {
+	inittermios = tios;
+	ioctl(fd, TIOCGWINSZ, &wsinfo);
+    }
+
+    tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
+    if (crtscts > 0 && !local) {
+        if (crtscts == 2) {
+#ifdef CDTRCTS
+            tios.c_cflag |= CDTRCTS;
+#endif
+	} else
+	    tios.c_cflag |= CRTSCTS;
+    } else if (crtscts < 0) {
+	tios.c_cflag &= ~CRTSCTS;
+#ifdef CDTRCTS
+	tios.c_cflag &= ~CDTRCTS;
+#endif
+    }
+
+    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 |= IXON | IXOFF;
+	tios.c_cc[VSTOP] = 0x13;	/* DC3 = XOFF = ^S */
+	tios.c_cc[VSTART] = 0x11;	/* DC1 = XON  = ^Q */
+    }
+
+    if (inspeed) {
+	cfsetospeed(&tios, inspeed);
+	cfsetispeed(&tios, inspeed);
+    } else {
+	inspeed = cfgetospeed(&tios);
+	/*
+	 * We can't proceed if the serial port speed is 0,
+	 * since that implies that the serial port is disabled.
+	 */
+	if (inspeed == 0)
+	    fatal("Baud rate for %s is 0; need explicit baud rate", devnam);
+    }
+    baud_rate = inspeed;
+
+    if (tcsetattr(fd, TCSAFLUSH, &tios) < 0)
+	fatal("tcsetattr: %m");
+
+    restore_term = 1;
+}
+
+/*
+ * restore_tty - restore the terminal to the saved settings.
+ */
+void
+restore_tty(fd)
+    int fd;
+{
+    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)
+		warn("tcsetattr: %m");
+	ioctl(fd, TIOCSWINSZ, &wsinfo);
+	restore_term = 0;
+    }
+}
+
+/*
+ * setdtr - control the DTR line on the serial port.
+ * This is called from die(), so it shouldn't call die().
+ */
+void
+setdtr(fd, on)
+int fd, on;
+{
+    int modembits = TIOCM_DTR;
+
+    ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
+}
+
+#ifdef INET6
+/*
+ * sif6addr - Config the interface with an IPv6 link-local address
+ */
+int
+sif6addr(unit, our_eui64, his_eui64)
+    int unit;
+    eui64_t our_eui64, his_eui64;
+{
+#ifdef __KAME__
+    int ifindex;
+    struct in6_aliasreq addreq6;
+
+    if (sock6_fd < 0) {
+	fatal("No IPv6 socket available");
+	/*NOTREACHED*/
+    }
+
+    /* actually, this part is not kame local - RFC2553 conformant */
+    ifindex = if_nametoindex(ifname);
+    if (ifindex == 0) {
+	error("sifaddr6: no interface %s", ifname);
+	return 0;
+    }
+
+    memset(&addreq6, 0, sizeof(addreq6));
+    strlcpy(addreq6.ifra_name, ifname, sizeof(addreq6.ifra_name));
+
+    /* my addr */
+    addreq6.ifra_addr.sin6_family = AF_INET6;
+    addreq6.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
+    addreq6.ifra_addr.sin6_addr.s6_addr[0] = 0xfe;
+    addreq6.ifra_addr.sin6_addr.s6_addr[1] = 0x80;
+    memcpy(&addreq6.ifra_addr.sin6_addr.s6_addr[8], &our_eui64,
+	sizeof(our_eui64));
+    /* KAME ifindex hack */
+    *(u_int16_t *)&addreq6.ifra_addr.sin6_addr.s6_addr[2] = htons(ifindex);
+
+    /* his addr */
+    addreq6.ifra_dstaddr.sin6_family = AF_INET6;
+    addreq6.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
+    addreq6.ifra_dstaddr.sin6_addr.s6_addr[0] = 0xfe;
+    addreq6.ifra_dstaddr.sin6_addr.s6_addr[1] = 0x80;
+    memcpy(&addreq6.ifra_dstaddr.sin6_addr.s6_addr[8], &his_eui64,
+	sizeof(our_eui64));
+    /* KAME ifindex hack */
+    *(u_int16_t *)&addreq6.ifra_dstaddr.sin6_addr.s6_addr[2] = htons(ifindex);
+
+    /* prefix mask: 128bit */
+    addreq6.ifra_prefixmask.sin6_family = AF_INET6;
+    addreq6.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
+    memset(&addreq6.ifra_prefixmask.sin6_addr, 0xff,
+	sizeof(addreq6.ifra_prefixmask.sin6_addr));
+
+    /* address lifetime (infty) */
+    addreq6.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
+    addreq6.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
+
+    if (ioctl(sock6_fd, SIOCAIFADDR_IN6, &addreq6) < 0) {
+	error("sif6addr: ioctl(SIOCAIFADDR_IN6): %m");
+	return 0;
+    }
+
+    return 1;
+#else
+    struct in6_ifreq ifr6;
+    struct ifreq ifr;
+    struct in6_rtmsg rt6;
+
+    if (sock6_fd < 0) {
+	fatal("No IPv6 socket available");
+	/*NOTREACHED*/
+    }
+
+    memset(&ifr, 0, sizeof (ifr));
+    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+    if (ioctl(sock6_fd, SIOCGIFINDEX, (caddr_t) &ifr) < 0) {
+	error("sif6addr: ioctl(SIOCGIFINDEX): %m");
+	return 0;
+    }
+    
+    /* Local interface */
+    memset(&ifr6, 0, sizeof(ifr6));
+    IN6_LLADDR_FROM_EUI64(ifr6.ifr6_addr, our_eui64);
+    ifr6.ifr6_ifindex = ifindex;
+    ifr6.ifr6_prefixlen = 10;
+
+    if (ioctl(sock6_fd, SIOCSIFADDR, &ifr6) < 0) {
+	error("sif6addr: ioctl(SIOCSIFADDR): %m");
+	return 0;
+    }
+    
+    /* Route to remote host */
+    memset(&rt6, 0, sizeof(rt6));
+    IN6_LLADDR_FROM_EUI64(rt6.rtmsg_dst, his_eui64);
+    rt6.rtmsg_flags = RTF_UP | RTF_HOST;
+    rt6.rtmsg_dst_len = 128;
+    rt6.rtmsg_ifindex = ifr.ifr_ifindex;
+    rt6.rtmsg_metric = 1;
+    
+    if (ioctl(sock6_fd, SIOCADDRT, &rt6) < 0) {
+	error("sif6addr: ioctl(SIOCADDRT): %m");
+	return 0;
+    }
+
+    return 1;
+#endif
+}
+
+
+/*
+ * cif6addr - Remove IPv6 address from interface
+ */
+int
+cif6addr(unit, our_eui64, his_eui64)
+    int unit;
+    eui64_t our_eui64, his_eui64;
+{
+#ifdef __KAME__
+    int ifindex;
+    struct in6_ifreq delreq6;
+
+    if (sock6_fd < 0) {
+	fatal("No IPv6 socket available");
+	/*NOTREACHED*/
+    }
+
+    /* actually, this part is not kame local - RFC2553 conformant */
+    ifindex = if_nametoindex(ifname);
+    if (ifindex == 0) {
+	error("cifaddr6: no interface %s", ifname);
+	return 0;
+    }
+
+    memset(&delreq6, 0, sizeof(delreq6));
+    strlcpy(delreq6.ifr_name, ifname, sizeof(delreq6.ifr_name));
+
+    /* my addr */
+    delreq6.ifr_ifru.ifru_addr.sin6_family = AF_INET6;
+    delreq6.ifr_ifru.ifru_addr.sin6_len = sizeof(struct sockaddr_in6);
+    delreq6.ifr_ifru.ifru_addr.sin6_addr.s6_addr[0] = 0xfe;
+    delreq6.ifr_ifru.ifru_addr.sin6_addr.s6_addr[1] = 0x80;
+    memcpy(&delreq6.ifr_ifru.ifru_addr.sin6_addr.s6_addr[8], &our_eui64,
+	sizeof(our_eui64));
+    /* KAME ifindex hack */
+    *(u_int16_t *)&delreq6.ifr_ifru.ifru_addr.sin6_addr.s6_addr[2] =
+	htons(ifindex);
+
+    if (ioctl(sock6_fd, SIOCDIFADDR_IN6, &delreq6) < 0) {
+	error("cif6addr: ioctl(SIOCDIFADDR_IN6): %m");
+	return 0;
+    }
+
+    return 1;
+#else
+    struct ifreq ifr;
+    struct in6_ifreq ifr6;
+
+    if (sock6_fd < 0) {
+	fatal("No IPv6 socket available");
+	/*NOTREACHED*/
+    }
+
+    memset(&ifr, 0, sizeof(ifr));
+    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+    if (ioctl(sock6_fd, SIOCGIFINDEX, (caddr_t) &ifr) < 0) {
+	error("cif6addr: ioctl(SIOCGIFINDEX): %m");
+	return 0;
+    }
+    
+    memset(&ifr6, 0, sizeof(ifr6));
+    IN6_LLADDR_FROM_EUI64(ifr6.ifr6_addr, our_eui64);
+    ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+    ifr6.ifr6_prefixlen = 10;
+
+    if (ioctl(sock6_fd, SIOCDIFADDR, &ifr6) < 0) {
+	if (errno != EADDRNOTAVAIL) {
+	    if (! ok_error (errno))
+		error("cif6addr: ioctl(SIOCDIFADDR): %m");
+	}
+        else {
+	    warn("cif6addr: ioctl(SIOCDIFADDR): No such address");
+	}
+        return (0);
+    }
+    return 1;
+#endif
+}
+#endif /* INET6 */
+
+/*
+ * get_pty - get a pty master/slave pair and chown the slave side
+ * to the uid given.  Assumes slave_name points to >= 12 bytes of space.
+ */
+int
+get_pty(master_fdp, slave_fdp, slave_name, uid)
+    int *master_fdp;
+    int *slave_fdp;
+    char *slave_name;
+    int uid;
+{
+    struct termios tios;
+
+    if (openpty(master_fdp, slave_fdp, slave_name, NULL, NULL) < 0)
+	return 0;
+
+    fchown(*slave_fdp, uid, -1);
+    fchmod(*slave_fdp, S_IRUSR | S_IWUSR);
+    if (tcgetattr(*slave_fdp, &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(*slave_fdp, TCSAFLUSH, &tios) < 0)
+	    warn("couldn't set attributes on pty: %m");
+    } else
+	warn("couldn't get attributes on pty: %m");
+
+    return 1;
+}
+
+
+/*
+ * open_ppp_loopback - open the device we use for getting
+ * packets in demand mode, and connect it to a ppp interface.
+ * Here we use a pty.
+ */
+int
+open_ppp_loopback()
+{
+    int flags;
+    struct termios tios;
+    int pppdisc = PPPDISC;
+
+    if (openpty(&loop_master, &loop_slave, loop_name, NULL, NULL) < 0)
+	fatal("No free pty for loopback");
+    SYSDEBUG(("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)
+	    warn("couldn't set attributes on loopback: %m");
+    }
+
+    if ((flags = fcntl(loop_master, F_GETFL)) != -1) 
+	if (fcntl(loop_master, F_SETFL, flags | O_NONBLOCK) == -1)
+	    warn("couldn't set loopback to nonblock: %m");
+
+    ppp_fd = loop_slave;
+    if (ioctl(ppp_fd, TIOCSETD, &pppdisc) < 0)
+	fatal("ioctl(TIOCSETD): %m");
+
+    /*
+     * Find out which interface we were given.
+     */
+    if (ioctl(ppp_fd, PPPIOCGUNIT, &ifunit) < 0)
+	fatal("ioctl(PPPIOCGUNIT): %m");
+
+    /*
+     * Enable debug in the driver if requested.
+     */
+    if (kdebugflag) {
+	flags = get_flags(ppp_fd);
+	flags |= (kdebugflag & 0xFF) * SC_DEBUG;
+	set_flags(ppp_fd, flags);
+    }
+
+    return loop_master;
+}
+
+
+/*
+ * output - Output PPP packet.
+ */
+void
+output(unit, p, len)
+    int unit;
+    u_char *p;
+    int len;
+{
+    if (debug)
+	dbglog("sent %P", p, len);
+
+    if (write(ttyfd, p, len) < 0) {
+	if (errno != EIO)
+	    error("write: %m");
+    }
+}
+
+
+/*
+ * wait_input - wait until there is data available,
+ * for the length of time specified by *timo (indefinite
+ * if timo is NULL).
+ */
+void
+wait_input(timo)
+    struct timeval *timo;
+{
+    fd_set ready;
+    int n;
+
+    ready = in_fds;
+    n = select(max_in_fd + 1, &ready, NULL, &ready, timo);
+    if (n < 0 && errno != EINTR)
+	fatal("select: %m");
+}
+
+
+/*
+ * add_fd - add an fd to the set that wait_input waits for.
+ */
+void add_fd(fd)
+    int fd;
+{
+    if (fd >= FD_SETSIZE)
+	fatal("descriptor too big");
+    FD_SET(fd, &in_fds);
+    if (fd > max_in_fd)
+	max_in_fd = fd;
+}
+
+/*
+ * remove_fd - remove an fd from the set that wait_input waits for.
+ */
+void remove_fd(fd)
+    int fd;
+{
+    FD_CLR(fd, &in_fds);
+}
+
+#if 0
+/*
+ * wait_loop_output - wait until there is data available on the
+ * loopback, for the length of time specified by *timo (indefinite
+ * if timo is NULL).
+ */
+void
+wait_loop_output(timo)
+    struct timeval *timo;
+{
+    fd_set ready;
+    int n;
+
+    FD_ZERO(&ready);
+    if (loop_master >= FD_SETSIZE)
+	fatal("descriptor too big");
+    FD_SET(loop_master, &ready);
+    n = select(loop_master + 1, &ready, NULL, &ready, timo);
+    if (n < 0 && errno != EINTR)
+	fatal("select: %m");
+}
+
+
+/*
+ * wait_time - wait for a given length of time or until a
+ * signal is received.
+ */
+void
+wait_time(timo)
+    struct timeval *timo;
+{
+    int n;
+
+    n = select(0, NULL, NULL, NULL, timo);
+    if (n < 0 && errno != EINTR)
+	fatal("select: %m");
+}
+#endif
+
+
+/*
+ * read_packet - get a PPP packet from the serial device.
+ */
+int
+read_packet(buf)
+    u_char *buf;
+{
+    int len;
+
+    if ((len = read(ttyfd, buf, PPP_MTU + PPP_HDRLEN)) < 0) {
+	if (errno == EWOULDBLOCK || errno == EINTR)
+	    return -1;
+	fatal("read: %m");
+    }
+    return len;
+}
+
+
+/*
+ * get_loop_output - read characters from the loopback, form them
+ * into frames, and detect when we want to bring the real link up.
+ * Return value is 1 if we need to bring up the link, 0 otherwise.
+ */
+int
+get_loop_output()
+{
+    int rv = 0;
+    int n;
+
+    while ((n = read(loop_master, inbuf, sizeof(inbuf))) >= 0) {
+	if (loop_chars(inbuf, n))
+	    rv = 1;
+    }
+
+    if (n == 0)
+	fatal("eof on loopback");
+    if (errno != EWOULDBLOCK)
+	fatal("read from loopback: %m");
+
+    return rv;
+}
+
+
+/*
+ * netif_set_mtu - set the MTU on the PPP network interface.
+ */
+void
+netif_set_mtu(unit, mtu)
+    int unit, mtu;
+{
+    struct ifreq ifr;
+
+    SYSDEBUG((LOG_DEBUG, "netif_set_mtu: mtu = %d\n", mtu));
+
+    memset(&ifr, '\0', sizeof (ifr));
+    strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+    ifr.ifr_mtu = mtu;
+	
+    if (ifunit >= 0 && ioctl(sock_fd, SIOCSIFMTU, (caddr_t) &ifr) < 0)
+	fatal("ioctl(SIOCSIFMTU): %m");
+}
+
+/*
+ * netif_get_mtu - get the MTU on the PPP network interface.
+ */
+int
+netif_get_mtu(int unit)
+{
+    struct ifreq ifr;
+
+    memset (&ifr, '\0', sizeof (ifr));
+    strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+
+    if (ifunit >= 0 && ioctl(sock_fd, SIOCGIFMTU, (caddr_t) &ifr) < 0) {
+	error("ioctl(SIOCGIFMTU): %m (line %d)", __LINE__);
+	return 0;
+    }
+    return ifr.ifr_mtu;
+}
+
+
+/*
+ * tty_send_config - configure the transmit characteristics of
+ * the ppp interface.
+ */
+void
+tty_send_config(mtu, asyncmap, pcomp, accomp)
+    int mtu;
+    u_int32_t asyncmap;
+    int pcomp, accomp;
+{
+    u_int x;
+#if 0
+    /* Linux code does not do anything with the mtu here */
+    ifnet_set_mtu(-1, mtu);
+#endif
+
+    if (ioctl(ppp_fd, PPPIOCSASYNCMAP, (caddr_t) &asyncmap) < 0)
+	fatal("ioctl(PPPIOCSASYNCMAP): %m");
+
+    x = get_flags(ppp_fd);
+    x = pcomp? x | SC_COMP_PROT: x &~ SC_COMP_PROT;
+    x = accomp? x | SC_COMP_AC: x &~ SC_COMP_AC;
+    x = sync_serial ? x | SC_SYNC : x & ~SC_SYNC;
+    set_flags(ppp_fd, x);
+}
+
+
+/*
+ * ppp_set_xaccm - set the extended transmit ACCM for the interface.
+ */
+void
+tty_set_xaccm(accm)
+    ext_accm accm;
+{
+    if (ioctl(ppp_fd, PPPIOCSXASYNCMAP, accm) < 0 && errno != ENOTTY)
+	warn("ioctl(set extended ACCM): %m");
+}
+
+
+/*
+ * ppp_recv_config - configure the receive-side characteristics of
+ * the ppp interface.
+ */
+void
+tty_recv_config(mru, asyncmap, pcomp, accomp)
+    int mru;
+    u_int32_t asyncmap;
+    int pcomp, accomp;
+{
+    int x;
+
+    if (ioctl(ppp_fd, PPPIOCSMRU, (caddr_t) &mru) < 0)
+	fatal("ioctl(PPPIOCSMRU): %m");
+    if (ioctl(ppp_fd, PPPIOCSRASYNCMAP, (caddr_t) &asyncmap) < 0)
+	fatal("ioctl(PPPIOCSRASYNCMAP): %m");
+    x = get_flags(ppp_fd);
+    x = !accomp? x | SC_REJ_COMP_AC: x &~ SC_REJ_COMP_AC;
+    set_flags(ppp_fd, x);
+}
+
+/*
+ * ccp_test - ask kernel whether a given compression method
+ * is acceptable for use.  Returns 1 if the method and parameters
+ * are OK, 0 if the method is known but the parameters are not OK
+ * (e.g. code size should be reduced), or -1 if the method is unknown.
+ */
+int
+ccp_test(unit, opt_ptr, opt_len, for_transmit)
+    int unit, opt_len, for_transmit;
+    u_char *opt_ptr;
+{
+    struct ppp_option_data data;
+
+    data.ptr = opt_ptr;
+    data.length = opt_len;
+    data.transmit = for_transmit;
+    if (ioctl(ttyfd, PPPIOCSCOMPRESS, (caddr_t) &data) >= 0)
+	return 1;
+    return (errno == ENOBUFS)? 0: -1;
+}
+
+/*
+ * ccp_flags_set - inform kernel about the current state of CCP.
+ */
+void
+ccp_flags_set(unit, isopen, isup)
+    int unit, isopen, isup;
+{
+    int x;
+
+    x = get_flags(ppp_fd);
+    x = isopen? x | SC_CCP_OPEN: x &~ SC_CCP_OPEN;
+    x = isup? x | SC_CCP_UP: x &~ SC_CCP_UP;
+    set_flags(ppp_fd, x);
+}
+
+/*
+ * ccp_fatal_error - returns 1 if decompression was disabled as a
+ * result of an error detected after decompression of a packet,
+ * 0 otherwise.  This is necessary because of patent nonsense.
+ */
+int
+ccp_fatal_error(unit)
+    int unit;
+{
+    int x;
+
+    x = get_flags(ppp_fd);
+    return x & SC_DC_FERROR;
+}
+
+/*
+ * get_idle_time - return how long the link has been idle.
+ */
+int
+get_idle_time(u, ip)
+    int u;
+    struct ppp_idle *ip;
+{
+    return ioctl(ppp_fd, PPPIOCGIDLE, ip) >= 0;
+}
+
+/*
+ * get_ppp_stats - return statistics for the link.
+ */
+int
+get_ppp_stats(u, stats)
+    int u;
+    struct pppd_stats *stats;
+{
+    struct ifpppstatsreq req;
+
+    memset (&req, 0, sizeof (req));
+    strlcpy(req.ifr_name, ifname, sizeof(req.ifr_name));
+    if (ioctl(sock_fd, SIOCGPPPSTATS, &req) < 0) {
+	error("Couldn't get PPP statistics: %m");
+	return 0;
+    }
+    stats->bytes_in = req.stats.p.ppp_ibytes;
+    stats->bytes_out = req.stats.p.ppp_obytes;
+    return 1;
+}
+
+
+#ifdef PPP_FILTER
+/*
+ * set_filters - transfer the pass and active filters to the kernel.
+ */
+int
+set_filters(pass_in, pass_out, active_in, active_out)
+    struct bpf_program *pass_in, *pass_out, *active_in, *active_out;
+{
+    int ret = 1;
+
+    if (pass_in->bf_len > 0) {
+	if (ioctl(ppp_fd, PPPIOCSIPASS, pass_in) < 0) {
+	    error("Couldn't set pass-filter-in in kernel: %m");
+	    ret = 0;
+	}
+    }
+
+    if (pass_out->bf_len > 0) {
+	if (ioctl(ppp_fd, PPPIOCSOPASS, pass_out) < 0) {
+	    error("Couldn't set pass-filter-out in kernel: %m");
+	    ret = 0;
+	}
+    }
+
+    if (active_in->bf_len > 0) {
+	if (ioctl(ppp_fd, PPPIOCSIACTIVE, active_in) < 0) {
+	    error("Couldn't set active-filter-in in kernel: %m");
+	    ret = 0;
+	}
+    }
+
+    if (active_out->bf_len > 0) {
+	if (ioctl(ppp_fd, PPPIOCSOACTIVE, active_out) < 0) {
+	    error("Couldn't set active-filter-out in kernel: %m");
+	    ret = 0;
+	}
+    }
+
+    return ret;
+}
+#endif
+
+/*
+ * sifvjcomp - config tcp header compression
+ */
+int
+sifvjcomp(u, vjcomp, cidcomp, maxcid)
+    int u, vjcomp, cidcomp, maxcid;
+{
+    u_int x;
+
+    x = get_flags(ppp_fd);
+    x = vjcomp ? x | SC_COMP_TCP: x &~ SC_COMP_TCP;
+    x = cidcomp? x & ~SC_NO_TCP_CCID: x | SC_NO_TCP_CCID;
+    set_flags(ppp_fd, x);
+    if (vjcomp && ioctl(ppp_fd, PPPIOCSMAXCID, (caddr_t) &maxcid) < 0) {
+	error("ioctl(PPPIOCSMAXCID): %m");
+	return 0;
+    }
+    return 1;
+}
+
+/*
+ * sifup - Config the interface up and enable IP packets to pass.
+ */
+int
+sifup(u)
+    int u;
+{
+    struct ifreq ifr;
+
+    strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+    if (ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
+	error("ioctl (SIOCGIFFLAGS): %m");
+	return 0;
+    }
+    ifr.ifr_flags |= IFF_UP;
+    if (ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
+	error("ioctl(SIOCSIFFLAGS): %m");
+	return 0;
+    }
+    if_is_up = 1;
+    return 1;
+}
+
+/*
+ * sifnpmode - Set the mode for handling packets for a given NP.
+ */
+int
+sifnpmode(u, proto, mode)
+    int u;
+    int proto;
+    enum NPmode mode;
+{
+    struct npioctl npi;
+
+    npi.protocol = proto;
+    npi.mode = mode;
+    if (ioctl(ppp_fd, PPPIOCSNPMODE, &npi) < 0) {
+	error("ioctl(set NP %d mode to %d): %m", proto, mode);
+	return 0;
+    }
+    return 1;
+}
+
+/*
+ * sifdown - Config the interface down and disable IP.
+ */
+int
+sifdown(u)
+    int u;
+{
+    struct ifreq ifr;
+    int rv;
+    struct npioctl npi;
+
+    rv = 1;
+    npi.protocol = PPP_IP;
+    npi.mode = NPMODE_ERROR;
+    ioctl(ppp_fd, PPPIOCSNPMODE, (caddr_t) &npi);
+    /* ignore errors, because ppp_fd might have been closed by now. */
+
+    strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
+    if (ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
+	error("ioctl (SIOCGIFFLAGS): %m");
+	rv = 0;
+    } else {
+	ifr.ifr_flags &= ~IFF_UP;
+	if (ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
+	    error("ioctl(SIOCSIFFLAGS): %m");
+	    rv = 0;
+	} else
+	    if_is_up = 0;
+    }
+    return rv;
+}
+
+/*
+ * SET_SA_FAMILY - set the sa_family field of a struct sockaddr,
+ * if it exists.
+ */
+#define SET_SA_FAMILY(addr, family)		\
+    BZERO((char *) &(addr), sizeof(addr));	\
+    addr.sa_family = (family); 			\
+    addr.sa_len = sizeof(addr);
+
+/*
+ * sifaddr - Config the interface IP addresses and netmask.
+ */
+int
+sifaddr(u, o, h, m)
+    int u;
+    u_int32_t o, h, m;
+{
+    struct ifaliasreq ifra;
+    struct ifreq ifr;
+
+    strlcpy(ifra.ifra_name, ifname, sizeof(ifra.ifra_name));
+    SET_SA_FAMILY(ifra.ifra_addr, AF_INET);
+    ((struct sockaddr_in *) &ifra.ifra_addr)->sin_addr.s_addr = o;
+    SET_SA_FAMILY(ifra.ifra_broadaddr, AF_INET);
+    ((struct sockaddr_in *) &ifra.ifra_broadaddr)->sin_addr.s_addr = h;
+    if (m != 0) {
+	SET_SA_FAMILY(ifra.ifra_mask, AF_INET);
+	((struct sockaddr_in *) &ifra.ifra_mask)->sin_addr.s_addr = m;
+    } else
+	BZERO(&ifra.ifra_mask, sizeof(ifra.ifra_mask));
+    BZERO(&ifr, sizeof(ifr));
+    strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+    if (ioctl(sock_fd, SIOCDIFADDR, (caddr_t) &ifr) < 0) {
+	if (errno != EADDRNOTAVAIL)
+	    warn("Couldn't remove interface address: %m");
+    }
+    if (ioctl(sock_fd, SIOCAIFADDR, (caddr_t) &ifra) < 0) {
+	if (errno != EEXIST) {
+	    error("Couldn't set interface address: %m");
+	    return 0;
+	}
+	warn("Couldn't set interface address: Address %I already exists", o);
+    }
+    ifaddrs[0] = o;
+    ifaddrs[1] = h;
+    return 1;
+}
+
+/*
+ * cifaddr - Clear the interface IP addresses, and delete routes
+ * through the interface if possible.
+ */
+int
+cifaddr(u, o, h)
+    int u;
+    u_int32_t o, h;
+{
+    struct ifaliasreq ifra;
+
+    ifaddrs[0] = 0;
+    strlcpy(ifra.ifra_name, ifname, sizeof(ifra.ifra_name));
+    SET_SA_FAMILY(ifra.ifra_addr, AF_INET);
+    ((struct sockaddr_in *) &ifra.ifra_addr)->sin_addr.s_addr = o;
+    SET_SA_FAMILY(ifra.ifra_broadaddr, AF_INET);
+    ((struct sockaddr_in *) &ifra.ifra_broadaddr)->sin_addr.s_addr = h;
+    BZERO(&ifra.ifra_mask, sizeof(ifra.ifra_mask));
+    if (ioctl(sock_fd, SIOCDIFADDR, (caddr_t) &ifra) < 0) {
+	if (errno != EADDRNOTAVAIL)
+	    warn("Couldn't delete interface address: %m");
+	return 0;
+    }
+    return 1;
+}
+
+/*
+ * sifdefaultroute - assign a default route through the address given.
+ */
+int
+sifdefaultroute(u, l, g)
+    int u;
+    u_int32_t l, g;
+{
+    return dodefaultroute(g, 's');
+}
+
+/*
+ * cifdefaultroute - delete a default route through the address given.
+ */
+int
+cifdefaultroute(u, l, g)
+    int u;
+    u_int32_t l, g;
+{
+    return dodefaultroute(g, 'c');
+}
+
+/********************************************************************
+ *
+ * sipxfaddr - Config the interface IPX networknumber
+ */
+
+int sipxfaddr (int unit, unsigned long int network, unsigned char * node )
+{
+    int    result = 1;
+
+#ifdef IPX_CHANGE
+    int    skfd;
+    struct ifreq         ifr;
+    struct sockaddr_ipx *sipx = (struct sockaddr_ipx *) &ifr.ifr_addr;
+
+    skfd = socket (AF_IPX, SOCK_DGRAM, 0);
+    if (skfd < 0) {
+	if (! ok_error (errno))
+	    dbglog("socket(AF_IPX): %m (line %d)", __LINE__);
+	result = 0;
+    }
+    else {
+	memset (&ifr, '\0', sizeof (ifr));
+	strlcpy (ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+
+	memcpy (sipx->sipx_node, node, IPX_NODE_LEN);
+	sipx->sipx_family  = AF_IPX;
+	sipx->sipx_port    = 0;
+	sipx->sipx_network = htonl (network);
+	sipx->sipx_type    = IPX_FRAME_ETHERII;
+	sipx->sipx_action  = IPX_CRTITF;
+/*
+ *  Set the IPX device
+ */
+	if (ioctl(skfd, SIOCSIFADDR, (caddr_t) &ifr) < 0) {
+	    result = 0;
+	    if (errno != EEXIST) {
+		if (! ok_error (errno))
+		    dbglog("ioctl(SIOCSIFADDR, CRTITF): %m (line %d)", __LINE__);
+	    }
+	    else {
+		warn("ioctl(SIOCSIFADDR, CRTITF): Address already exists");
+	    }
+	}
+	close (skfd);
+    }
+#endif
+    return result;
+}
+
+/********************************************************************
+ *
+ * cipxfaddr - Clear the information for the IPX network. The IPX routes
+ *	       are removed and the device is no longer able to pass IPX
+ *	       frames.
+ */
+
+int cipxfaddr (int unit)
+{
+    int    result = 1;
+
+#ifdef IPX_CHANGE
+    int    skfd;
+    struct ifreq         ifr;
+    struct sockaddr_ipx *sipx = (struct sockaddr_ipx *) &ifr.ifr_addr;
+
+    skfd = socket (AF_IPX, SOCK_DGRAM, 0);
+    if (skfd < 0) {
+	if (! ok_error (errno))
+	    dbglog("socket(AF_IPX): %m (line %d)", __LINE__);
+	result = 0;
+    }
+    else {
+	memset (&ifr, '\0', sizeof (ifr));
+	strlcpy (ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+
+	sipx->sipx_type    = IPX_FRAME_ETHERII;
+	sipx->sipx_action  = IPX_DLTITF;
+	sipx->sipx_family  = AF_IPX;
+/*
+ *  Set the IPX device
+ */
+	if (ioctl(skfd, SIOCSIFADDR, (caddr_t) &ifr) < 0) {
+	    if (! ok_error (errno))
+		info("ioctl(SIOCSIFADDR, IPX_DLTITF): %m (line %d)", __LINE__);
+	    result = 0;
+	}
+	close (skfd);
+    }
+#endif
+    return result;
+}
+
+/*
+ * dodefaultroute - talk to a routing socket to add/delete a default route.
+ */
+static int
+dodefaultroute(g, cmd)
+    u_int32_t g;
+    int cmd;
+{
+    int routes;
+    struct {
+	struct rt_msghdr	hdr;
+	struct sockaddr_in	dst;
+	struct sockaddr_in	gway;
+	struct sockaddr_in	netmask;
+	struct sockaddr_in	genmask;
+	struct sockaddr_dl	ifp;
+    } rtmsg;
+
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+	error("Couldn't %s default route: socket: %m",
+	    cmd == 's' ? "add" : "delete");
+	return 0;
+    }
+
+    memset(&rtmsg, 0, sizeof(rtmsg));
+
+    rtmsg.hdr.rtm_type = cmd == 's' ? RTM_ADD : RTM_DELETE;
+    rtmsg.hdr.rtm_flags = RTF_UP | RTF_GATEWAY | RTF_STATIC;
+    rtmsg.hdr.rtm_version = RTM_VERSION;
+    rtmsg.hdr.rtm_seq = ++rtm_seq;
+    rtmsg.hdr.rtm_addrs =
+	RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_GENMASK | RTA_IFP;
+
+    rtmsg.dst.sin_len = sizeof(rtmsg.dst);
+    rtmsg.dst.sin_family = AF_INET;
+    rtmsg.dst.sin_addr.s_addr = 0;
+
+    rtmsg.gway.sin_len = sizeof(rtmsg.gway);
+    rtmsg.gway.sin_family = AF_INET;
+    rtmsg.gway.sin_addr.s_addr = g;
+
+    rtmsg.netmask.sin_len = sizeof(rtmsg.netmask);
+    rtmsg.netmask.sin_family = AF_INET;
+    rtmsg.netmask.sin_addr.s_addr = 0;
+
+    rtmsg.genmask.sin_len = sizeof(rtmsg.genmask);
+    rtmsg.genmask.sin_family = AF_INET;
+    rtmsg.genmask.sin_addr.s_addr = 0;
+
+    rtmsg.ifp.sdl_family = AF_LINK;
+    rtmsg.ifp.sdl_len = sizeof(rtmsg.ifp);
+    link_addr(ifname, &rtmsg.ifp);
+
+    rtmsg.hdr.rtm_msglen = sizeof(rtmsg);
+
+    if (write(routes, &rtmsg, sizeof(rtmsg)) < 0) {
+	error("Couldn't %s default route: %m",
+	    cmd == 's' ? "add" : "delete");
+	close(routes);
+	return 0;
+    }
+
+    close(routes);
+    default_route_gateway = (cmd == 's') ? g : 0;
+    return 1;
+}
+
+#if RTM_VERSION >= 3
+
+/*
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+static struct {
+    struct rt_msghdr		hdr;
+    struct sockaddr_inarp	dst;
+    struct sockaddr_dl		hwa;
+    char			extra[128];
+} arpmsg;
+
+static int arpmsg_valid;
+
+int
+sifproxyarp(unit, hisaddr)
+    int unit;
+    u_int32_t hisaddr;
+{
+    int routes;
+
+    /*
+     * Get the hardware address of an interface on the same subnet
+     * as our local address.
+     */
+    memset(&arpmsg, 0, sizeof(arpmsg));
+    if (!get_ether_addr(hisaddr, &arpmsg.hwa)) {
+	error("Cannot determine ethernet address for proxy ARP");
+	return 0;
+    }
+
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+	error("Couldn't add proxy arp entry: socket: %m");
+	return 0;
+    }
+
+    arpmsg.hdr.rtm_type = RTM_ADD;
+    arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC;
+    arpmsg.hdr.rtm_version = RTM_VERSION;
+    arpmsg.hdr.rtm_seq = ++rtm_seq;
+    arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
+    arpmsg.hdr.rtm_inits = RTV_EXPIRE;
+    arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp);
+    arpmsg.dst.sin_family = AF_INET;
+    arpmsg.dst.sin_addr.s_addr = hisaddr;
+    arpmsg.dst.sin_other = SIN_PROXY;
+
+    arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
+	+ arpmsg.hwa.sdl_len;
+    if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
+	error("Couldn't add proxy arp entry: %m");
+	close(routes);
+	return 0;
+    }
+
+    close(routes);
+    arpmsg_valid = 1;
+    proxy_arp_addr = hisaddr;
+    return 1;
+}
+
+/*
+ * cifproxyarp - Delete the proxy ARP entry for the peer.
+ */
+int
+cifproxyarp(unit, hisaddr)
+    int unit;
+    u_int32_t hisaddr;
+{
+    int routes;
+
+    if (!arpmsg_valid)
+	return 0;
+    arpmsg_valid = 0;
+
+    arpmsg.hdr.rtm_type = RTM_DELETE;
+    arpmsg.hdr.rtm_seq = ++rtm_seq;
+
+    if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
+	error("Couldn't delete proxy arp entry: socket: %m");
+	return 0;
+    }
+
+    if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
+	error("Couldn't delete proxy arp entry: %m");
+	close(routes);
+	return 0;
+    }
+
+    close(routes);
+    proxy_arp_addr = 0;
+    return 1;
+}
+
+#else	/* RTM_VERSION */
+
+/*
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+int
+sifproxyarp(unit, hisaddr)
+    int unit;
+    u_int32_t hisaddr;
+{
+    struct arpreq arpreq;
+    struct {
+	struct sockaddr_dl	sdl;
+	char			space[128];
+    } dls;
+
+    BZERO(&arpreq, sizeof(arpreq));
+
+    /*
+     * Get the hardware address of an interface on the same subnet
+     * as our local address.
+     */
+    if (!get_ether_addr(hisaddr, &dls.sdl)) {
+	error("Cannot determine ethernet address for proxy ARP");
+	return 0;
+    }
+
+    arpreq.arp_ha.sa_len = sizeof(struct sockaddr);
+    arpreq.arp_ha.sa_family = AF_UNSPEC;
+    BCOPY(LLADDR(&dls.sdl), arpreq.arp_ha.sa_data, dls.sdl.sdl_alen);
+    SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
+    ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
+    arpreq.arp_flags = ATF_PERM | ATF_PUBL;
+    if (ioctl(sock_fd, SIOCSARP, (caddr_t)&arpreq) < 0) {
+	error("Couldn't add proxy arp entry: %m");
+	return 0;
+    }
+
+    proxy_arp_addr = hisaddr;
+    return 1;
+}
+
+/*
+ * cifproxyarp - Delete the proxy ARP entry for the peer.
+ */
+int
+cifproxyarp(unit, hisaddr)
+    int unit;
+    u_int32_t hisaddr;
+{
+    struct arpreq arpreq;
+
+    BZERO(&arpreq, sizeof(arpreq));
+    SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
+    ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
+    if (ioctl(sock_fd, SIOCDARP, (caddr_t)&arpreq) < 0) {
+	warn("Couldn't delete proxy arp entry: %m");
+	return 0;
+    }
+    proxy_arp_addr = 0;
+    return 1;
+}
+#endif	/* RTM_VERSION */
+
+
+/*
+ * get_ether_addr - get the hardware address of an interface on the
+ * the same subnet as ipaddr.
+ */
+static int
+get_ether_addr(ipaddr, hwaddr)
+    u_int32_t ipaddr;
+    struct sockaddr_dl *hwaddr;
+{
+    u_int32_t ina, mask;
+    struct sockaddr_dl *dla;
+    struct ifaddrs *ifap, *ifa, *ifp;
+
+    /*
+     * Scan through looking for an interface with an Internet
+     * address on the same subnet as `ipaddr'.
+     */
+    if (getifaddrs(&ifap) != 0) {
+	error("getifaddrs: %m");
+	return 0;
+    }
+
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+	if (ifa->ifa_addr->sa_family != AF_INET)
+	    continue;
+	ina = ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr.s_addr;
+	/*
+	 * Check that the interface is up, and not point-to-point
+	 * or loopback.
+	 */
+	if ((ifa->ifa_flags &
+	     (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|IFF_LOOPBACK|IFF_NOARP))
+	     != (IFF_UP|IFF_BROADCAST))
+	    continue;
+	/*
+	 * Get its netmask and check that it's on the right subnet.
+	 */
+	mask = ((struct sockaddr_in *) ifa->ifa_netmask)->sin_addr.s_addr;
+	if ((ipaddr & mask) != (ina & mask))
+	    continue;
+	break;
+    }
+
+    if (!ifa) {
+	freeifaddrs(ifap);
+	return 0;
+    }
+    info("found interface %s for proxy arp", ifa->ifa_name);
+
+    ifp = ifa;
+
+    /*
+     * Now scan through again looking for a link-level address
+     * for this interface.
+     */
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+	if (strcmp(ifp->ifa_name, ifa->ifa_name) != 0)
+	    continue;
+	if (ifa->ifa_addr->sa_family != AF_LINK)
+	    continue;
+	/*
+	 * Found the link-level address - copy it out
+	 */
+	dla = (struct sockaddr_dl *) ifa->ifa_addr;
+	BCOPY(dla, hwaddr, dla->sdl_len);
+	freeifaddrs(ifap);
+	return 1;
+    }
+
+    freeifaddrs(ifap);
+    return 0;
+}
+
+/*
+ * get_if_hwaddr - get the hardware address for the specified
+ * network interface device.
+ */
+int
+get_if_hwaddr(addr, name)
+    u_char *addr;
+    char *name;
+{
+    struct ifreq ifreq;
+    struct sockaddr_dl *sdl = (struct sockaddr_dl *) &ifreq.ifr_addr;
+    int fd;
+
+    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+	return 0;
+    (void)memset(sdl, 0, sizeof(*sdl));
+    sdl->sdl_family = AF_LINK;
+    (void)strlcpy(ifreq.ifr_name, name, sizeof(ifreq.ifr_name));
+    if (ioctl(fd, SIOCGIFADDR, &ifreq) == -1) {
+	(void)close(fd);
+	return 0;
+    }
+    (void)close(fd);
+    (void)memcpy(addr, LLADDR(sdl), sdl->sdl_alen);
+    return sdl->sdl_nlen;
+}
+
+/*
+ * get_first_ethernet - return the name of the first ethernet-style
+ * interface on this system.
+ */
+char *
+get_first_ethernet()
+{
+    static char ifname[IFNAMSIZ];
+    struct ifaddrs *ifap, *ifa;
+
+    /*
+     * Scan through the system's network interfaces.
+     */
+    if (getifaddrs(&ifap) != 0) {
+	warn("getifaddrs: %m");
+	return NULL;
+    }
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+	/*
+	 * Check the interface's internet address.
+	 */
+	if (ifa->ifa_addr->sa_family != AF_INET)
+	    continue;
+	/*
+	 * Check that the interface is up, and not point-to-point or loopback.
+	 */
+	if ((ifa->ifa_flags & (IFF_UP|IFF_POINTOPOINT|IFF_LOOPBACK))
+	    != IFF_UP) {
+	    strlcpy(ifname, ifa->ifa_name, sizeof(ifname));
+	    freeifaddrs(ifap);
+	    return ifname;
+	}
+    }
+    freeifaddrs(ifap);
+    return NULL;
+}
+
+/*
+ * Return user specified netmask, modified by any mask we might determine
+ * for address `addr' (in network byte order).
+ * Here we scan through the system's list of interfaces, looking for
+ * any non-point-to-point interfaces which might appear to be on the same
+ * network as `addr'.  If we find any, we OR in their netmask to the
+ * user-specified netmask.
+ */
+u_int32_t
+GetMask(addr)
+    u_int32_t addr;
+{
+    u_int32_t mask, nmask, ina;
+    struct ifaddrs *ifap, *ifa;
+
+    addr = ntohl(addr);
+    if (IN_CLASSA(addr))	/* determine network mask for address class */
+	nmask = IN_CLASSA_NET;
+    else if (IN_CLASSB(addr))
+	nmask = IN_CLASSB_NET;
+    else
+	nmask = IN_CLASSC_NET;
+    /* class D nets are disallowed by bad_ip_adrs */
+    mask = netmask | htonl(nmask);
+
+    /*
+     * Scan through the system's network interfaces.
+     */
+    if (getifaddrs(&ifap) != 0) {
+	warn("getifaddrs: %m");
+	return 0;
+    }
+
+    for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
+	/*
+	 * Check the interface's internet address.
+	 */
+	if (ifa->ifa_addr->sa_family != AF_INET)
+	    continue;
+	ina = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
+	if ((ntohl(ina) & nmask) != (addr & nmask))
+	    continue;
+	/*
+	 * Check that the interface is up, and not point-to-point or loopback.
+	 */
+	if ((ifa->ifa_flags & (IFF_UP|IFF_POINTOPOINT|IFF_LOOPBACK)) != IFF_UP)
+	    continue;
+	/*
+	 * Get its netmask and OR it into our mask.
+	 */
+	mask |= ((struct sockaddr_in *)&ifa->ifa_netmask)->sin_addr.s_addr;
+    }
+
+    freeifaddrs(ifap);
+    return mask;
+}
+
+/*
+ * have_route_to - determine if the system has any route to
+ * a given IP address.
+ * For demand mode to work properly, we have to ignore routes
+ * through our own interface.
+ */
+int have_route_to(u_int32_t addr)
+{
+    return -1;
+}
+
+/*
+ * Use the hostid as part of the random number seed.
+ */
+int
+get_host_seed()
+{
+    return gethostid();
+}
+
+#if 0
+/*
+ * lock - create a lock file for the named lock device
+ */
+#define	LOCK_PREFIX	"/var/spool/lock/LCK.."
+
+static char *lock_file;		/* name of lock file created */
+
+int
+lock(dev)
+    char *dev;
+{
+    char hdb_lock_buffer[12];
+    int fd, pid, n;
+    char *p;
+    size_t l;
+
+    if ((p = strrchr(dev, '/')) != NULL)
+	dev = p + 1;
+    l = strlen(LOCK_PREFIX) + strlen(dev) + 1;
+    lock_file = malloc(l);
+    if (lock_file == NULL)
+	novm("lock file name");
+    slprintf(lock_file, l, "%s%s", LOCK_PREFIX, dev);
+
+    while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0) {
+	if (errno == EEXIST
+	    && (fd = open(lock_file, O_RDONLY, 0)) >= 0) {
+	    /* Read the lock file to find out who has the device locked */
+	    n = read(fd, hdb_lock_buffer, 11);
+	    if (n <= 0) {
+		error("Can't read pid from lock file %s", lock_file);
+		close(fd);
+	    } else {
+		hdb_lock_buffer[n] = 0;
+		pid = atoi(hdb_lock_buffer);
+		if (kill(pid, 0) == -1 && errno == ESRCH) {
+		    /* pid no longer exists - remove the lock file */
+		    if (unlink(lock_file) == 0) {
+			close(fd);
+			notice("Removed stale lock on %s (pid %d)",
+			       dev, pid);
+			continue;
+		    } else
+			warn("Couldn't remove stale lock on %s",
+			       dev);
+		} else
+		    notice("Device %s is locked by pid %d",
+			   dev, pid);
+	    }
+	    close(fd);
+	} else
+	    error("Can't create lock file %s: %m", lock_file);
+	free(lock_file);
+	lock_file = NULL;
+	return -1;
+    }
+
+    slprintf(hdb_lock_buffer, sizeof(hdb_lock_buffer), "%10d\n", getpid());
+    write(fd, hdb_lock_buffer, 11);
+
+    close(fd);
+    return 0;
+}
+
+/*
+ * unlock - remove our lockfile
+ */
+void
+unlock()
+{
+    if (lock_file) {
+	unlink(lock_file);
+	free(lock_file);
+	lock_file = NULL;
+    }
+}
+#endif