/*      NetBSD: sys-bsd.c,v 1.68 2013/06/24 20:43:48 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
*      [email protected]
*
* 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
*     <[email protected]>".
*
* 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 1.68 2013/06/24 20:43:48 christos Exp ");
#endif
#endif

/*
* TODO:
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#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_WITH_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>

#ifdef INET6

#define s6_addr32 __u6_addr.__u6_addr32 /* Non-standard */

#define IN6_SOCKADDR_FROM_EUI64(s, eui64) do { \
       (s)->sin6_family = AF_INET6; \
       (s)->sin6_addr.s6_addr32[0] = htonl(0xfe800000); \
       eui64_copy(eui64, (s)->sin6_addr.s6_addr32[2]); \
       } while(0)
#ifndef IN6_LLADDR_FROM_EUI64
#ifdef __KAME__
#define IN6_LLADDR_FROM_EUI64(sin6, eui64) do {                 \
       sin6.sin6_family = AF_INET6;                            \
       sin6.sin6_len = sizeof(struct sockaddr_in6);            \
       sin6.sin6_addr.s6_addr[0] = 0xfe;                       \
       sin6.sin6_addr.s6_addr[1] = 0x80;                       \
       eui64_copy(eui64, sin6.sin6_addr.s6_addr[8]);           \
} while (/*CONSTCOND*/0)
#define IN6_IFINDEX(sin6, ifindex)                              \
   /* KAME ifindex hack */                                     \
   *(u_int16_t *)&sin6.sin6_addr.s6_addr[2] = htons(ifindex)
#else
#define IN6_LLADDR_FROM_EUI64(sin6, eui64) do {                 \
       memset(&sin6.s6_addr, 0, sizeof(struct in6_addr));      \
       sin6.s6_addr16[0] = htons(0xfe80);                      \
       eui64_copy(eui64, sin6.s6_addr32[2]);                   \
} while (/*CONSTCOND*/0)
#endif /* __KAME__ */
#endif /* IN6_LLADDR_FROM_EUI64 */

#endif /* INET6 */

#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 "pppd-private.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 = -1;
static int doing_cleanup = 0;
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 */
#ifdef INET6
static int if6_is_up;           /* the interface is currently up */
#endif /* INET6 */
static u_int32_t ifaddrs[2];    /* local and remote addresses we set */
static u_int32_t default_route_gateway; /* gateway addr for default route */
#ifdef INET6
static eui64_t  default_route_gateway6; /* Gateway for default IPv6 route added */
#endif /* INET6 */
static u_int32_t proxy_arp_addr;        /* remote addr for proxy arp */

/* Prototypes for procedures local to this file. */
static int get_flags(int);
static void set_flags(int, int);
static int dodefaultroute(u_int32_t, int);
static int get_ether_addr(u_int32_t, struct sockaddr_dl *);
static void restore_loop(void); /* Transfer ppp unit back to loopback */
static int setifstate(int, int);


static void
set_queue_size(const char *fmt, int fd) {
#ifdef TIOCSQSIZE
   int oqsize, qsize = 32768;

   /* Only for ptys */
   if (ioctl(fd, TIOCGQSIZE, &oqsize) == -1)
       return;

   if (oqsize >= qsize)
       return;

   if (ioctl(fd, TIOCSQSIZE, &qsize) == -1)
       warn("%s: Cannot set tty queue size for %d from %d to %d", fmt, fd,
           oqsize, qsize);
   else
       notice("%s: Changed queue size of %d from %d to %d", fmt, fd, oqsize,
           qsize);
#endif
}

/********************************************************************
*
* Functions to read and set the flags value in the device driver
*/

static int
get_flags(int fd)
{
   int flags;

   if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &flags) == -1)
       fatal("%s: ioctl(PPPIOCGFLAGS): %m", __func__);

   SYSDEBUG((LOG_DEBUG, "get flags = %x\n", flags));
   return flags;
}

/********************************************************************/

static void
set_flags(int fd, int flags)
{
   SYSDEBUG((LOG_DEBUG, "set flags = %x\n", flags));

   if (ioctl(fd, PPPIOCSFLAGS, (caddr_t) &flags) == -1)
       fatal("%s: ioctl(PPPIOCSFLAGS, %x): %m", __func__, flags, errno);
}

/*
* sys_init - System-dependent initialization.
*/
void
sys_init(void)
{
   /* Get an internet socket for doing socket ioctl's on. */
   if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
       fatal("%s: Couldn't create IP socket: %m", __func__);

#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(void)
{
   struct ifreq ifr;

   doing_cleanup = 1;
   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);
#ifdef INET6
   if (default_route_gateway6.e32[0] != 0 || default_route_gateway6.e32[1] != 0)
       cif6defaultroute(0, default_route_gateway6, default_route_gateway6);
#endif
   if (proxy_arp_addr)
       cifproxyarp(0, proxy_arp_addr);
   doing_cleanup = 0;
}

/*
* sys_close - Clean up in a child process before execing.
*/
void
ppp_sys_close()
{
   if (sock_fd >= 0)
       close(sock_fd);
#ifdef INET6
   if (sock6_fd >= 0)
       close(sock6_fd);
#endif
   if (loop_slave >= 0)
       close(loop_slave);
   if (loop_master >= 0)
       close(loop_master);
}

/*
* sys_check_options - check the options that the user specified
*/
int
sys_check_options(void)
{
#ifndef CDTRCTS
   if (crtscts == 2) {
       warn("%s: DTR/CTS flow control is not supported on this system",
           __func__);
       return 0;
   }
#endif
   return 1;
}

/*
* ppp_check_kernel_support - check whether the system has any ppp interfaces
* (in fact we check whether we can create one)
*/
int
ppp_check_kernel_support(void)
{
   int s;
   extern char *no_ppp_msg;
   struct ifreq ifr;


   if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
       fatal("%s: socket: %m", __func__);

   (void)memset(&ifr, 0, sizeof(ifr));
   strlcpy(ifr.ifr_name, "ppp0", sizeof(ifr.ifr_name));
   if (ioctl(s, SIOCIFCREATE, &ifr) == -1) {
       int notmine = errno == EEXIST;
       (void)close(s);
       if (notmine)
           return 1;
       goto out;
   }
   (void)ioctl(s, SIOCIFDESTROY, &ifr);
   (void)close(s);
   return 1;

out:
   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";
   return 0;
}

/*
* tty_establish_ppp - Turn the serial port into a ppp interface.
*/
int
tty_establish_ppp(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("%s: ioctl(transfer ppp unit): %m", __func__);
   }

   set_queue_size(__func__, fd);
   /*
    * Save the old line discipline of fd, and set it to PPP.
    */
   if (ioctl(fd, TIOCGETD, &initdisc) < 0)
       fatal("%s: ioctl(TIOCGETD): %m", __func__);
   if (ioctl(fd, TIOCSETD, &pppdisc) < 0)
       fatal("%s: ioctl(TIOCSETD): %m", __func__);

   if (ioctl(fd, PPPIOCGUNIT, &x) < 0)
       fatal("%s: ioctl(PPPIOCGUNIT): %m", __func__);
   if (!demand) {
       /*
        * Find out which interface we were given.
        */
       ifunit = x;
   } else {
       /*
        * Check that we got the same unit again.
        */
       if (x != ifunit)
           fatal("%s: transfer_ppp failed: wanted unit %d, got %d",
               __func__, ifunit, x);
       x = TTYDISC;
       if (ioctl(loop_slave, TIOCSETD, &x) == -1)
           fatal("%s: ioctl(TIOCGETD): %m", __func__);
   }

   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("%s: Couldn't set device to non-blocking mode: %m", __func__);
   }

   return fd;
}

/*
* restore_loop - reattach the ppp unit to the loopback.
*/
static void
restore_loop(void)
{
   int x;

   set_queue_size(__func__, loop_slave);
   /*
    * Transfer the ppp interface back to the loopback.
    */
   if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) < 0)
       fatal("%s: ioctl(transfer ppp unit): %m", __func__);
   x = PPPDISC;
   if (ioctl(loop_slave, TIOCSETD, &x) < 0)
       fatal("%s: ioctl(TIOCSETD): %m", __func__);

   /*
    * Check that we got the same unit again.
    */
   if (ioctl(loop_slave, PPPIOCGUNIT, &x) < 0)
       fatal("%s: ioctl(PPPIOCGUNIT): %m", __func__);
   if (x != ifunit)
       fatal("%s: transfer_ppp failed: wanted unit %d, got %d", __func__,
           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 (!doing_cleanup && demand)
       restore_loop();

   if (!hungup || demand) {

       /* Flush the tty output buffer so that the TIOCSETD doesn't hang.  */
       if (tcflush(fd, TCIOFLUSH) < 0)
           if (!doing_cleanup)
               warn("%s: tcflush failed: %m", __func__);

       /* Restore old line discipline. */
       if (initdisc >= 0 && ioctl(fd, TIOCSETD, &initdisc) < 0)
           if (!doing_cleanup)
               error("%s: ioctl(TIOCSETD): %m", __func__);
       initdisc = -1;

       /* Reset non-blocking mode on fd. */
       if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) < 0)
           if (!doing_cleanup)
               warn("%s: Couldn't restore device fd flags: %m", __func__);
   }
   initfdflags = -1;

   if (fd == ppp_fd)
       ppp_fd = -1;
}

/*
* cfg_bundle - configure the existing bundle.
* Used in demand mode.
*/
void
cfg_bundle(int mrru, int mtru, int rssn, int 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("%s: Couldn't set MRRU: %m", __func__);
   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("%s: Couldn't attach to PPP unit %d: %m", __func__, 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(int mrru, int mtru, int rssn, int 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(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("%s: Couldn't attach to interface unit %d: %m", __func__, ifnum);
   }
   if (ioctl(ppp_fd, PPPIOCCONNECT, &ifnum) < 0)
       fatal("%s: Couldn't connect to interface unit %d: %m", __func__, 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(void)
{
   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("%s: Serial link is not 8-bit clean:", __func__);
           warn("%s: All received characters had %s", __func__, s);
           if (ioctl(ppp_fd, PPPIOCGRAWIN, &win) == -1) {
               warn("%s: ioctl(PPPIOCGRAWIN): %s", __func__, 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("%s: Last %d characters were: %s", __func__, (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(int fd, int local)
{
   struct termios tios;

   if (tcgetattr(fd, &tios) < 0)
       fatal("%s: tcgetattr: %m", __func__);

   if (!restore_term) {
       inittermios = tios;
       ioctl(fd, TIOCGWINSZ, &wsinfo);
   }

   set_queue_size(__func__, fd);

   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("%s: Baud rate for %s is 0; need explicit baud rate",
               __func__, devnam);
   }
   baud_rate = inspeed;

   if (tcsetattr(fd, TCSAFLUSH, &tios) < 0)
       fatal("%s: tcsetattr: %m", __func__);

   restore_term = 1;
}

/*
* restore_tty - restore the terminal to the saved settings.
*/
void
restore_tty(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("%s: tcsetattr: %m", __func__);
       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(int fd, int 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(int unit, eui64_t our_eui64, eui64_t his_eui64)
{
#ifdef __KAME__
   int ifindex;
   struct in6_aliasreq addreq6;

   if (sock6_fd < 0) {
       fatal("%s: No IPv6 socket available", __func__);
       /*NOTREACHED*/
   }

   /* actually, this part is not kame local - RFC2553 conformant */
   ifindex = if_nametoindex(ifname);
   if (ifindex == 0) {
       error("%s: sifaddr6: no interface %s", __func__, ifname);
       return 0;
   }

   memset(&addreq6, 0, sizeof(addreq6));
   strlcpy(addreq6.ifra_name, ifname, sizeof(addreq6.ifra_name));

   /* my addr */
   IN6_LLADDR_FROM_EUI64(addreq6.ifra_addr, our_eui64);
   IN6_IFINDEX(addreq6.ifra_addr, ifindex);

#ifdef notdef
   /* his addr */
   IN6_LLADDR_FROM_EUI64(addreq6.ifra_dstaddr, his_eui64);
   IN6_IFINDEX(addreq6.ifra_dstaddr, ifindex);
#endif

   /* prefix mask: 72bit */
   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) - sizeof(our_eui64));
   memset((char *)&addreq6.ifra_prefixmask.sin6_addr +
       sizeof(addreq6.ifra_prefixmask.sin6_addr) - sizeof(our_eui64), 0x00,
       sizeof(our_eui64));

   /* 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("%s: sif6addr: ioctl(SIOCAIFADDR_IN6): %m", __func__);
       return 0;
   }

   return 1;
#else
   struct in6_ifreq ifr6;
   struct ifreq ifr;
   struct in6_rtmsg rt6;

   if (sock6_fd < 0) {
       fatal("%s: No IPv6 socket available", __func__);
       /*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("%s: sif6addr: ioctl(SIOCGIFINDEX): %m", __func__);
       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("%s: sif6addr: ioctl(SIOCSIFADDR): %m", __func__);
       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;
   rt6.rtmsg_dst_len = 10;
   rt6.rtmsg_ifindex = ifr.ifr_ifindex;
   rt6.rtmsg_metric = 1;

   if (ioctl(sock6_fd, SIOCADDRT, &rt6) < 0) {
       error("%s: sif6addr: ioctl(SIOCADDRT): %m", __func__);
       return 0;
   }

   return 1;
#endif
}


/*
* cif6addr - Remove IPv6 address from interface
*/
int
cif6addr(int unit, eui64_t our_eui64, eui64_t his_eui64)
{
#ifdef __KAME__
   int ifindex;
   struct in6_ifreq delreq6;

   if (sock6_fd < 0) {
       fatal("%s: No IPv6 socket available", __func__);
       /*NOTREACHED*/
   }

   /* actually, this part is not kame local - RFC2553 conformant */
   ifindex = if_nametoindex(ifname);
   if (ifindex == 0) {
       error("%s: cifaddr6: no interface %s", __func__, ifname);
       return 0;
   }

   memset(&delreq6, 0, sizeof(delreq6));
   strlcpy(delreq6.ifr_name, ifname, sizeof(delreq6.ifr_name));

   /* my addr */
   IN6_LLADDR_FROM_EUI64(delreq6.ifr_ifru.ifru_addr, our_eui64);
   IN6_IFINDEX(delreq6.ifr_ifru.ifru_addr, ifindex);

   if (ioctl(sock6_fd, SIOCDIFADDR_IN6, &delreq6) < 0) {
       error("%s: cif6addr: ioctl(SIOCDIFADDR_IN6): %m", __func__);
       return 0;
   }

   return 1;
#else
   struct ifreq ifr;
   struct in6_ifreq ifr6;

   if (sock6_fd < 0) {
       fatal("%s: No IPv6 socket available", __func__);
       /*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("%s: cif6addr: ioctl(SIOCGIFINDEX): %m", __func__);
       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("%s: cif6addr: ioctl(SIOCDIFADDR): %m", __func__);
       }
       else {
           warn("%s: cif6addr: ioctl(SIOCDIFADDR): No such address", __func__);
       }
       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(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;

   set_queue_size(__func__, *master_fdp);
   set_queue_size(__func__, *slave_fdp);
   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 | CLOCAL;
       tios.c_iflag  = IGNPAR;
       tios.c_oflag  = 0;
       tios.c_lflag  = 0;
       if (tcsetattr(*slave_fdp, TCSAFLUSH, &tios) < 0)
           warn("%s: couldn't set attributes on pty: %m", __func__);
   } else
       warn("%s: couldn't get attributes on pty: %m", __func__);

   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(void)
{
   int flags;
   struct termios tios;
   int pppdisc = PPPDISC;

   if (openpty(&loop_master, &loop_slave, loop_name, NULL, NULL) < 0)
       fatal("%s: No free pty for loopback", __func__);
   SYSDEBUG(("using %s for loopback", loop_name));

   if (tcgetattr(loop_slave, &tios) == 0) {
       tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB);
       tios.c_cflag |= CS8 | CREAD | CLOCAL;
       tios.c_iflag = IGNPAR;
       tios.c_oflag = 0;
       tios.c_lflag = 0;
       if (tcsetattr(loop_slave, TCSAFLUSH, &tios) < 0)
           warn("%s: couldn't set attributes on loopback: %m", __func__);
   }

   flags = fcntl(loop_master, F_GETFL);
   if (flags == -1 || fcntl(loop_master, F_SETFL, flags | O_NONBLOCK) == -1)
           warn("%s: couldn't set master loopback to nonblock: %m", __func__);

   flags = fcntl(loop_slave, F_GETFL);
   if (flags == -1 || fcntl(loop_slave, F_SETFL, flags | O_NONBLOCK) == -1)
           warn("%s: couldn't set slave loopback to nonblock: %m", __func__);

   ppp_fd = loop_slave;
   if (ioctl(ppp_fd, TIOCSETD, &pppdisc) < 0)
       fatal("%s: ioctl(TIOCSETD): %m", __func__);

   /*
    * Find out which interface we were given.
    */
   if (ioctl(ppp_fd, PPPIOCGUNIT, &ifunit) < 0)
       fatal("%s: ioctl(PPPIOCGUNIT): %m", __func__);

   /*
    * 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(int unit, u_char *p, int len)
{
   if (debug)
       dbglog("sent %P", p, len);

   if (write(ttyfd, p, len) < 0) {
       if (errno != EIO)
           error("%s: write: %m", __func__);
   }
}


/*
* wait_input - wait until there is data available,
* for the length of time specified by *timo (indefinite
* if timo is NULL).
*/
void
wait_input(struct timeval *timo)
{
   fd_set ready, eready;
   int n;

   ready = in_fds;
   eready = in_fds;
   n = select(max_in_fd + 1, &ready, NULL, &eready, timo);
   if (n < 0 && errno != EINTR)
       fatal("%s: select: %m", __func__);
}


/*
* add_fd - add an fd to the set that wait_input waits for.
*/
void add_fd(int fd)
{
   if (fd >= FD_SETSIZE)
       fatal("%s: descriptor too big", __func__);
   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(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(struct timeval *timo)
{
   fd_set ready;
   int n;

   FD_ZERO(&ready);
   if (loop_master >= FD_SETSIZE)
       fatal("%s: descriptor too big", __func__);
   FD_SET(loop_master, &ready);
   n = select(loop_master + 1, &ready, NULL, &ready, timo);
   if (n < 0 && errno != EINTR)
       fatal("%s: select: %m", __func__);
}


/*
* wait_time - wait for a given length of time or until a
* signal is received.
*/
void
wait_time(struct timeval *timo)
{
   int n;

   n = select(0, NULL, NULL, NULL, timo);
   if (n < 0 && errno != EINTR)
       fatal("%s: select: %m", __func__);
}
#endif


/*
* read_packet - get a PPP packet from the serial device.
*/
int
read_packet(u_char *buf)
{
   int len;

   if ((len = read(ttyfd, buf, PPP_MTU + PPP_HDRLEN)) < 0) {
       if (errno == EWOULDBLOCK || errno == EINTR)
           return -1;
       fatal("%s: read: %m", __func__);
   }
   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(void)
{
   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("%s: eof on loopback", __func__);
   if (n == -1 && errno != EWOULDBLOCK)
       fatal("%s: read from loopback: %m", __func__);

   return rv;
}


/*
* ppp_set_mtu - set the MTU on the PPP network interface.
*/
void
ppp_set_mtu(int unit, int 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("%s: ioctl(SIOCSIFMTU): %m", __func__);
}

/*
* ppp_get_mtu - get the MTU on the PPP network interface.
*/
int
ppp_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("%s: ioctl(SIOCGIFMTU): %m", __func__);
       return 0;
   }
   return ifr.ifr_mtu;
}

/*
* tty_send_config - configure the transmit characteristics of
* the ppp interface.
*/
void
tty_send_config(int mtu, u_int32_t asyncmap, int pcomp, int 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("%s: ioctl(PPPIOCSASYNCMAP): %m", __func__);

   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 = ppp_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(ext_accm accm)
{
   if (ioctl(ppp_fd, PPPIOCSXASYNCMAP, accm) < 0 && errno != ENOTTY)
       warn("%s: ioctl(set extended ACCM): %m", __func__);
}


/*
* ppp_recv_config - configure the receive-side characteristics of
* the ppp interface.
*/
void
tty_recv_config(int mru, u_int32_t asyncmap, int pcomp, int accomp)
{
   int x;

   if (ioctl(ppp_fd, PPPIOCSMRU, (caddr_t) &mru) < 0)
       fatal("%s: ioctl(PPPIOCSMRU): %m", __func__);
   if (ioctl(ppp_fd, PPPIOCSRASYNCMAP, (caddr_t) &asyncmap) < 0)
       fatal("%s: ioctl(PPPIOCSRASYNCMAP): %m", __func__);
   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(int unit, u_char *opt_ptr, int opt_len, int for_transmit)
{
   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(int unit, int isopen, int 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(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(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(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("%s: Couldn't get PPP statistics: %m", __func__);
       return 0;
   }
   stats->bytes_in = req.stats.p.ppp_ibytes;
   stats->bytes_out = req.stats.p.ppp_obytes;
   stats->pkts_in = req.stats.p.ppp_ipackets;
   stats->pkts_out = req.stats.p.ppp_opackets;
   return 1;
}


#ifdef PPP_WITH_FILTER
/*
* set_filters - transfer the pass and active filters to the kernel.
*/
int
set_filters(struct bpf_program *pass_in, struct bpf_program *pass_out,
   struct bpf_program *active_in, struct bpf_program *active_out)
{
   int ret = 1;

   if (pass_in->bf_len > 0) {
       if (ioctl(ppp_fd, PPPIOCSIPASS, pass_in) < 0) {
           error("%s: Couldn't set pass-filter-in in kernel: %m", __func__);
           ret = 0;
       }
   }

   if (pass_out->bf_len > 0) {
       if (ioctl(ppp_fd, PPPIOCSOPASS, pass_out) < 0) {
           error("%s: Couldn't set pass-filter-out in kernel: %m", __func__);
           ret = 0;
       }
   }

   if (active_in->bf_len > 0) {
       if (ioctl(ppp_fd, PPPIOCSIACTIVE, active_in) < 0) {
           error("%s: Couldn't set active-filter-in in kernel: %m", __func__);
           ret = 0;
       }
   }

   if (active_out->bf_len > 0) {
       if (ioctl(ppp_fd, PPPIOCSOACTIVE, active_out) < 0) {
           error("%s: Couldn't set active-filter-out in kernel: %m", __func__);
           ret = 0;
       }
   }

   return ret;
}
#endif

/*
* sifvjcomp - config tcp header compression
*/
int
sifvjcomp(int u, int vjcomp, int cidcomp, int 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("%s: ioctl(PPPIOCSMAXCID): %m", __func__);
       return 0;
   }
   return 1;
}

/********************************************************************
*
* sifup - Config the interface up and enable IP packets to pass.
*/

int sifup(int u)
{
   int ret;

   if ((ret = setifstate(u, 1)))
       if_is_up++;

   return ret;
}

/********************************************************************
*
* sifdown - Disable the indicated protocol and config the interface
*           down if there are no remaining protocols.
*/

int sifdown (int u)
{
   if (if_is_up && --if_is_up > 0)
       return 1;

#ifdef INET6
   if (if6_is_up)
       return 1;
#endif /* INET6 */

   return setifstate(u, 0);
}

#ifdef INET6
/********************************************************************
*
* sif6up - Config the interface up for IPv6
*/

int sif6up(int u)
{
   int ret;

   if ((ret = setifstate(u, 1)))
       if6_is_up = 1;

   return ret;
}

/********************************************************************
*
* sif6down - Disable the IPv6CP protocol and config the interface
*            down if there are no remaining protocols.
*/

int sif6down (int u)
{
   if6_is_up = 0;

   if (if_is_up)
       return 1;

   return setifstate(u, 0);
}
#endif /* INET6 */

/********************************************************************
*
* setifstate - Config the interface up or down
*/

static int setifstate (int u, int state)
{
   struct ifreq ifr;

   strlcpy(ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
   if (ioctl(sock_fd, SIOCGIFFLAGS, (caddr_t) &ifr) < 0) {
       error("%s: ioctl (SIOCGIFFLAGS): %m", __func__);
       return 0;
   }
   if (state)
       ifr.ifr_flags |= IFF_UP;
   else
       ifr.ifr_flags &= ~IFF_UP;
   if (ioctl(sock_fd, SIOCSIFFLAGS, (caddr_t) &ifr) < 0) {
       error("%s: ioctl(SIOCSIFFLAGS): %m", __func__);
       return 0;
   }
   if_is_up = 1;
   return 1;
}

/*
* sifnpmode - Set the mode for handling packets for a given NP.
*/
int
sifnpmode(int u, int proto, enum NPmode mode)
{
   struct npioctl npi;

   npi.protocol = proto;
   npi.mode = mode;
   if (ioctl(ppp_fd, PPPIOCSNPMODE, &npi) < 0) {
       error("%s: ioctl(set NP %d mode to %d): %m", __func__, proto, mode);
       return 0;
   }
   return 1;
}

/*
* 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(int u, u_int32_t o, u_int32_t h, u_int32_t 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("%s: Couldn't remove interface address: %m", __func__);
   }
   if (ioctl(sock_fd, SIOCAIFADDR, (caddr_t) &ifra) < 0) {
       if (errno != EEXIST) {
           error("%s: Couldn't set interface address: %m", __func__);
           return 0;
       }
       warn("%s: Couldn't set interface address: Address %I already exists",
           __func__, 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(int u, u_int32_t o, u_int32_t 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 (!doing_cleanup && errno != EADDRNOTAVAIL)
           warn("%s: Couldn't delete interface address: %m", __func__);
       return 0;
   }
   return 1;
}

/*
* sifdefaultroute - assign a default route through the address given.
*/
int
sifdefaultroute(int u, u_int32_t l, u_int32_t g, bool replace)
{
   if (replace)
       dodefaultroute(g, 'c');
   return dodefaultroute(g, 's');
}

/*
* cifdefaultroute - delete a default route through the address given.
*/
int
cifdefaultroute(int u, u_int32_t l, u_int32_t g)
{
   return dodefaultroute(g, 'c');
}

/*
* dodefaultroute - talk to a routing socket to add/delete a default route.
*/
static int
dodefaultroute(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_dl      ifp;
   } rtmsg;

   if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
       if (!doing_cleanup)
           error("%s: Couldn't %s default route: socket: %m", __func__,
               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_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.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) {
       if (!doing_cleanup)
           error("%s: Couldn't %s default route: %m", __func__,
               cmd == 's' ? "add" : "delete");
       close(routes);
       return 0;
   }

   close(routes);
   default_route_gateway = (cmd == 's') ? g : 0;
   return 1;
}


#ifdef INET6
/*
* dodefaultroute - assign/clear a default route through the address given.
*/
static int
dodefaultroute6(int u, eui64_t l, eui64_t g, char cmd)
{
   struct {
       struct rt_msghdr rtm;
       struct sockaddr_in6 dst;
       struct sockaddr_in6 gw;
   } rmsg;
   static int seq;
   int rtsock;

#if defined(__USLC__)
   g = l;                      /* use the local address as gateway */
#endif
   memset(&rmsg, 0, sizeof(rmsg));

   rmsg.rtm.rtm_msglen = sizeof (rmsg);
   rmsg.rtm.rtm_version = RTM_VERSION;
   rmsg.rtm.rtm_type = cmd == 's' ? RTM_ADD : RTM_DELETE;
   rmsg.rtm.rtm_flags = RTF_GATEWAY;
   rmsg.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
   rmsg.rtm.rtm_pid = getpid();
   rmsg.rtm.rtm_seq = seq++;

   rmsg.dst.sin6_family = AF_INET6;

   rmsg.gw.sin6_family = AF_INET6;
   IN6_SOCKADDR_FROM_EUI64(&rmsg.gw, g);

   rtsock = socket(PF_ROUTE, SOCK_RAW, 0);

   if (rtsock < 0) {
       error("Can't %s default route: %m", cmd == 's' ? "add" : "remove");
       return 0;
   }

   if (write(rtsock, &rmsg, sizeof(rmsg)) < 0)
       error("Can't %s default route: %m", cmd == 's' ? "add" : "remove");

   close(rtsock);

   default_route_gateway6 = g;
   return 1;
}

/*
* sif6defaultroute - assign a default route through the address given.
*/
int
sif6defaultroute(int u, eui64_t l, eui64_t g)
{
       return dodefaultroute6(u, l, g, 's');
}

/*
* cif6defaultroute - delete a default route through the address given.
*/
int
cif6defaultroute(int u, eui64_t l, eui64_t g)
{
       return dodefaultroute6(u, l, g, 'c');
}

#endif

#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(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("%s: Cannot determine ethernet address for proxy ARP", __func__);
       return 0;
   }

   if ((routes = socket(PF_ROUTE, SOCK_RAW, AF_INET)) < 0) {
       error("%s: Couldn't add proxy arp entry: socket: %m", __func__);
       return 0;
   }

   arpmsg.hdr.rtm_type = RTM_ADD;
   arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC | RTF_LLDATA;
   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
       + RT_ROUNDUP(arpmsg.hwa.sdl_len);
   if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
       error("%s: Couldn't add proxy arp entry: %m", __func__);
       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(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) {
       if (!doing_cleanup)
           error("%s: Couldn't delete proxy arp entry: socket: %m", __func__);
       return 0;
   }

   if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
       if (!doing_cleanup)
           error("%s: Couldn't delete proxy arp entry: %m", __func__);
       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(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("%s: Cannot determine ethernet address for proxy ARP", __func__);
       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("%s: Couldn't add proxy arp entry: %m", __func__);
       return 0;
   }

   proxy_arp_addr = hisaddr;
   return 1;
}

/*
* cifproxyarp - Delete the proxy ARP entry for the peer.
*/
int
cifproxyarp(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("%s: Couldn't delete proxy arp entry: %m", __func__);
       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(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("%s: getifaddrs: %m", __func__);
       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(u_char *addr, char *name)
{

#define IFREQ_SAFE (sizeof(struct ifreq) + sizeof(struct sockaddr_dl))
   /* XXX sockaddr_dl is larger than the sockaddr in struct ifreq! */
   union {                             /* XXX */
       struct ifreq _ifreq;            /* XXX */
       char _X[IFREQ_SAFE];            /* XXX */
   } _ifreq_dontsmashstack = {0};      /* XXX */
#define ifreq_xxx _ifreq_dontsmashstack._ifreq                  /* XXX */

   struct sockaddr_dl *sdl = (struct sockaddr_dl *) &ifreq_xxx.ifr_addr;
   int fd;

   if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
       return 0;
   sdl->sdl_family = AF_LINK;
   (void)strlcpy(ifreq_xxx.ifr_name, name, sizeof(ifreq_xxx.ifr_name));
   if (ioctl(fd, SIOCGIFADDR, &ifreq_xxx) == -1) {
       (void)close(fd);
       return 0;
   }
   (void)close(fd);
   (void)memcpy(addr, LLADDR(sdl), sdl->sdl_alen);
   return sdl->sdl_nlen;
}

/*
* get_first_ether_hwaddr - get the hardware address for the first
* ethernet-style interface on this system.
*/
int
get_first_ether_hwaddr(u_char *addr)
{
       struct if_nameindex *if_ni, *i;
       struct ifreq ifreq;
       int ret, sock_fd;

       sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
       if (sock_fd < 0)
               return -1;

       if_ni = if_nameindex();
       if (!if_ni) {
               close(sock_fd);
               return -1;
       }

       ret = -1;

       for (i = if_ni; !(i->if_index == 0 && i->if_name == NULL); i++) {
               struct sockaddr_dl *sdl = (struct sockaddr_dl *)
                   &ifreq.ifr_addr;
               sdl->sdl_family = AF_LINK;
               strlcpy(ifreq.ifr_name, i->if_name, sizeof(ifreq.ifr_name));
               ret = ioctl(sock_fd, SIOCGIFADDR, &ifreq);
               if (ret >= 0 && sdl->sdl_family == AF_LINK) {
                       memcpy(addr, LLADDR(sdl), sdl->sdl_alen);
                       break;
               }
               ret = -1;
       }

       if_freenameindex(if_ni);
       close(sock_fd);

       return ret;
}

/*
* 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(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("%s: getifaddrs: %m", __func__);
       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(void)
{
   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(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("%s: Can't read pid from lock file %s", __func__,
                   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("%s: Removed stale lock on %s (pid %d)",
                           __func__, dev, pid);
                       continue;
                   } else
                       warn("%s: Couldn't remove stale lock on %s", __func__,
                           dev);
               } else
                   notice("%s: Device %s is locked by pid %d", __func__,
                          dev, pid);
           }
           close(fd);
       } else
           error("%s: Can't create lock file %s: %m", __func__, 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(void)
{
   if (lock_file) {
       unlink(lock_file);
       free(lock_file);
       lock_file = NULL;
   }
}
#endif


/********************************************************************
*
* get_time - Get current time, monotonic if possible.
*/
int
ppp_get_time(struct timeval *tv)
{
   return gettimeofday(tv, NULL);
}