/*
 * Copyright (c) 2001, Adam Dunkels.
 * Copyright (c) 2009, 2010 Joakim Eriksson, Niclas Finne, Dogan Yazar.
 * 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 of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This file is part of the uIP TCP/IP stack.
 *
 *
 */

 /* Below define allows importing saved output into Wireshark as "Raw IP" packet type */
#define WIRESHARK_IMPORT_FORMAT 1

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <err.h>

int verbose = 1;
int make = 1;
const char *ipaddr;
const char *netmask;
int slipfd = 0;
FILE *inslip = NULL;
uint16_t basedelay=0,delaymsec=0;
uint32_t startsec,startmsec,delaystartsec,delaystartmsec;
int timestamp = 0, flowcontrol=0;
unsigned int vnet_hdr=0;
const char *siodev = NULL;
const char *host = NULL;
const char *port = NULL;
#define VNET_HDR_LENGTH 10

int ssystem(const char *fmt, ...)
     __attribute__((__format__ (__printf__, 1, 2)));
void write_to_serial(int outfd, void *inbuf, int len);

int devopen(const char *dev, int flags);
void stty_telos(int fd);

int get_slipfd();
void slip_send(int fd, unsigned char c);
void slip_send_char(int fd, unsigned char c);

//#define PROGRESS(s) fprintf(stderr, s)
#define PROGRESS(s) do { } while (0)

char tundev[1024] = { "" };

int
ssystem(const char *fmt, ...) __attribute__((__format__ (__printf__, 1, 2)));

int
ssystem(const char *fmt, ...)
{
  char cmd[128];
  va_list ap;
  va_start(ap, fmt);
  vsnprintf(cmd, sizeof(cmd), fmt, ap);
  va_end(ap);
  printf("%s\n", cmd);
  fflush(stdout);
  return system(cmd);
}

#define SLIP_END     0300
#define SLIP_ESC     0333
#define SLIP_ESC_END 0334
#define SLIP_ESC_ESC 0335


/* get sockaddr, IPv4 or IPv6: */
void *
get_in_addr(struct sockaddr *sa)
{
  if(sa->sa_family == AF_INET) {
    return &(((struct sockaddr_in*)sa)->sin_addr);
  }
  return &(((struct sockaddr_in6*)sa)->sin6_addr);
}
void
stamptime(void)
{
  static long startsecs=0,startmsecs=0;
  long secs,msecs;
  struct timeval tv;
  time_t t;
  struct tm *tmp;
  char timec[20];

  gettimeofday(&tv, NULL) ;
  msecs=tv.tv_usec/1000;
  secs=tv.tv_sec;
  if (startsecs) {
    secs -=startsecs;
    msecs-=startmsecs;
    if (msecs<0) {secs--;msecs+=1000;}
    fprintf(stderr,"%04lu.%03lu ", secs, msecs);
  } else {
    startsecs=secs;
    startmsecs=msecs;
    t=time(NULL);
    tmp=localtime(&t);
    strftime(timec,sizeof(timec),"%T",tmp);
//    fprintf(stderr,"\n%s.%03lu ",timec,msecs);
    fprintf(stderr,"\n%s ",timec);
  }
}

int
is_sensible_string(const unsigned char *s, int len)
{
  int i;
  for(i = 1; i < len; i++) {
    if(s[i] == 0 || s[i] == '\r' || s[i] == '\n' || s[i] == '\t') {
      continue;
    } else if(s[i] < ' ' || '~' < s[i]) {
      return 0;
    }
  }
  return 1;
}

/*
 * Read from serial, when we have a packet write it to tun. No output
 * buffering, input buffered by stdio.
 */
void
serial_to_tun(FILE *inslip, int outfd)
{
  static struct {
    unsigned char vnet_header[VNET_HDR_LENGTH];
    unsigned char inbuf[2000];
  } uip = { .vnet_header = { 0 } };
  static int inbufptr = 0;
  int ret,i;
  unsigned char c;

#ifdef linux
  ret = fread(&c, 1, 1, inslip);
  if(ret == -1 || ret == 0) {
    if (get_slipfd()) return;
    err(1, "serial_to_tun: read");
  }
  goto after_fread;
#endif

 read_more:
  if(inbufptr >= sizeof(uip.inbuf)) {
     if(timestamp) stamptime();
     fprintf(stderr, "*** dropping large %d byte packet\n",inbufptr);
	 inbufptr = 0;
  }
  ret = fread(&c, 1, 1, inslip);
#ifdef linux
 after_fread:
#endif
  if(ret == -1 && errno == -EINTR) {
    /* Can be QEMU or other restarting, retry */
    ret = 0;
  }
  if(ret == -1) {
    err(1, "serial_to_tun: read");
  }
  if(ret == 0) {
    clearerr(inslip);
    return;
  }
  /*  fprintf(stderr, ".");*/
  switch(c) {
  case SLIP_END:
    if(inbufptr > 0) {
      if(uip.inbuf[0] == '!') {
	if(uip.inbuf[1] == 'M') {
	  /* Read gateway MAC address and autoconfigure tap0 interface */
	  char macs[24];
	  int i, pos;
	  for(i = 0, pos = 0; i < 16; i++) {
	    macs[pos++] = uip.inbuf[2 + i];
	    if((i & 1) == 1 && i < 14) {
	      macs[pos++] = ':';
	    }
	  }
          if(timestamp) stamptime();
	  macs[pos] = '\0';
//	  printf("*** Gateway's MAC address: %s\n", macs);
	  fprintf(stderr,"*** Gateway's MAC address: %s\n", macs);
	  if (make) {
	    if (timestamp) stamptime();
	    ssystem("ifconfig %s down", tundev);
	    if (timestamp) stamptime();
	    ssystem("ifconfig %s hw ether %s", tundev, &macs[6]);
	    if (timestamp) stamptime();
	    ssystem("ifconfig %s up", tundev);
	  }
	}
      } else if(uip.inbuf[0] == '?') {
	if(uip.inbuf[1] == 'P') {
          /* Prefix info requested */
          struct in6_addr addr;
	  int i;
	  char *s = strchr(ipaddr, '/');
	  if(s != NULL) {
	    *s = '\0';
	  }
          inet_pton(AF_INET6, ipaddr, &addr);
          if(timestamp) stamptime();
          fprintf(stderr,"*** Address:%s => %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
 //         printf("*** Address:%s => %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
		 ipaddr,
		 addr.s6_addr[0], addr.s6_addr[1],
		 addr.s6_addr[2], addr.s6_addr[3],
		 addr.s6_addr[4], addr.s6_addr[5],
		 addr.s6_addr[6], addr.s6_addr[7]);
	  slip_send(slipfd, '!');
	  slip_send(slipfd, 'P');
	  for(i = 0; i < 8; i++) {
	    /* need to call the slip_send_char for stuffing */
	    slip_send_char(slipfd, addr.s6_addr[i]);
	  }
	  slip_send(slipfd, SLIP_END);
        }
#define DEBUG_LINE_MARKER '\r'
      } else if(uip.inbuf[0] == DEBUG_LINE_MARKER) {
	fwrite(uip.inbuf + 1, inbufptr - 1, 1, stdout);
      } else if(is_sensible_string(uip.inbuf, inbufptr)) {
        if(verbose==1) {   /* strings already echoed below for verbose>1 */
          if (timestamp) stamptime();
          fwrite(uip.inbuf, inbufptr, 1, stdout);
        }
      } else {
        if(verbose>2) {
          if (timestamp) stamptime();
          printf("%s: Packet from SLIP of length %d - write TUN\n",
		 tundev, inbufptr);
          if (verbose>4) {
#if WIRESHARK_IMPORT_FORMAT
            printf("%s: 0000", tundev);
	    if (vnet_hdr) {
	      for(i = 0; i < sizeof(uip.vnet_header); i++)
		printf(" %02x",uip.vnet_header[i]);
	    }
	    for(i = 0; i < inbufptr; i++)
	      printf(" %02x",uip.inbuf[i]);
#else
            printf("         ");
	    if (vnet_hdr) {
	      for(i = 0; i < sizeof(uip.vnet_header); i++) {
		printf("%02x", uip.vnet_header[i]);
		if((i & 3) == 3) printf(" ");
		if((i & 15) == 15) printf("\n%s:          ", tundev);
	      }
	    }
            for(i = 0; i < inbufptr; i++) {
              printf("%02x", uip.inbuf[i]);
              if((i & 3) == 3) printf(" ");
              if((i & 15) == 15) printf("\n%s:          ", tundev);
            }
#endif
            printf("\n");
          }
        }
	unsigned count_errs = 0;
	struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 };
	size_t total_size = inbufptr;
	if (vnet_hdr)
	  total_size += sizeof(uip.vnet_header);

	while(1) {
	  if (vnet_hdr) {
	    if (write(outfd, (void *) &uip, total_size) == total_size)
	      break;
	  } else {
	    if(write(outfd, (void *) uip.inbuf, total_size) == total_size)
	      break;
	  }
	  if(count_errs > 10) {
	    err(1, "serial_to_tun: write");
	    break;
	  }
	  count_errs++;
	  if (0)
	    fprintf(stderr, "DEBUG: retrying %d\n", count_errs);
	  nanosleep(&ts, NULL);
	}
      }
      inbufptr = 0;
    }
    break;

  case SLIP_ESC:
    if(fread(&c, 1, 1, inslip) != 1) {
      clearerr(inslip);
      /* Put ESC back and give up! */
      ungetc(SLIP_ESC, inslip);
      return;
    }

    switch(c) {
    case SLIP_ESC_END:
      c = SLIP_END;
      break;
    case SLIP_ESC_ESC:
      c = SLIP_ESC;
      break;
    }
    /* FALLTHROUGH */
  default:
    uip.inbuf[inbufptr++] = c;

    /* Echo lines as they are received for verbose=2,3,5+ */
    /* Echo all printable characters for verbose==4 */
    if((verbose==2) || (verbose==3) || (verbose>4)) {
      if(c=='\n') {
        if(is_sensible_string(uip.inbuf, inbufptr)) {
          if (timestamp) stamptime();
          fwrite(uip.inbuf, inbufptr, 1, stdout);
        }
      }
    } else if(verbose==4) {
      if(c == 0 || c == '\r' || c == '\n' || c == '\t' || (c >= ' ' && c <= '~')) {
	fwrite(&c, 1, 1, stdout);
        if(c=='\n') if(timestamp) stamptime();
      }
    }

    break;
  }

  goto read_more;
}

unsigned char slip_buf[3028];
int slip_end, slip_begin;

static void flush_neighbors(const char *tundev)
{
	ssystem("ip neigh flush dev %s", tundev);
}

int
get_slipfd()
{
  const int start_i = 20;
  int status, i, fd = -1;
  struct timeval sleep_for = {
    .tv_sec = 0,       /* seconds */
    .tv_usec = 200000  /* microseconds */
  };

  /* Try to acquire slipfd a few times */
  for (i = start_i; i > 0; --i) {
    if (i != start_i) {
      select(0, NULL, NULL, NULL, &sleep_for);
    }

    if(host != NULL) {
      struct addrinfo hints, *servinfo, *p;
      int rv;
      char s[INET6_ADDRSTRLEN];

      if(port == NULL) {
        port = "60001";
      }

      memset(&hints, 0, sizeof hints);
      hints.ai_family = AF_UNSPEC;
      hints.ai_socktype = SOCK_STREAM;

      if((rv = getaddrinfo(host, port, &hints, &servinfo)) != 0) {
        fprintf(stderr, "getaddrinfo: %s", gai_strerror(rv));
        continue;
      }

      /* loop through all the results and connect to the first we can */
      for(p = servinfo; p != NULL; p = p->ai_next) {
        if((fd = socket(p->ai_family, p->ai_socktype,
                            p->ai_protocol)) == -1) {
          perror("client: socket");
          continue;
        }

        if(connect(fd, p->ai_addr, p->ai_addrlen) == -1) {
          close(fd);
          perror("client: connect");
          continue;
        }
        break;
      }

      if(p == NULL) {
        fprintf(stderr, "can't connect to ``%s:%s''\n", host, port);
        continue;
      }

      fcntl(fd, F_SETFL, O_NONBLOCK);

      inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr),
                s, sizeof(s));
      fprintf(stderr, "slip connected to ``%s:%s''\n", s, port);

      /* all done with this structure */
      freeaddrinfo(servinfo);

    } else {
      if(siodev != NULL) {
        fd = devopen(siodev, O_RDWR | O_NONBLOCK);
        if(fd == -1) {
          fprintf(stderr, "can't open siodev ``%s''\n", siodev);
          continue;
        }
      } else {
        static const char *siodevs[] = {
          "ttyUSB0", "cuaU0", "ucom0" /* linux, fbsd6, fbsd5 */
        };
        int i;
        for(i = 0; i < 3; i++) {
          siodev = siodevs[i];
          fd = devopen(siodev, O_RDWR | O_NONBLOCK);
          if(fd != -1) {
            break;
          }
        }
        if(fd == -1) {
          fprintf(stderr, "can't open siodev\n");
          continue;
        }
      }
      if (timestamp) stamptime();
      if (siodev[0] != '/') {
        fprintf(stderr, "********SLIP started on ``/dev/%s''\n", siodev);
      } else {
        fprintf(stderr, "********SLIP started on ``%s''\n", siodev);
      }
      stty_telos(fd);
    }

    slip_send(fd, SLIP_END);
    inslip = fdopen(fd, "r");
    if(inslip == NULL) {
      printf("get_slipfd: fdopen failed\n");
      continue;
    }

    slipfd = fd;

    printf("slipfd and inslip reopened\n");
    flush_neighbors(tundev);
    return 1;
  }

  return 0;
}

void
slip_send_char(int fd, unsigned char c)
{
  switch(c) {
  case SLIP_END:
    slip_send(fd, SLIP_ESC);
    slip_send(fd, SLIP_ESC_END);
    break;
  case SLIP_ESC:
    slip_send(fd, SLIP_ESC);
    slip_send(fd, SLIP_ESC_ESC);
    break;
  default:
    slip_send(fd, c);
    break;
  }
}

void
slip_send(int fd, unsigned char c)
{
  if(slip_end >= sizeof(slip_buf)) {
    err(1, "slip_send overflow");
  }
  slip_buf[slip_end] = c;
  slip_end++;
}

int
slip_empty()
{
  return slip_end == 0;
}

void
slip_flushbuf(int fd)
{
  int n;

  if(slip_empty()) {
    return;
  }

slip_flushbuf_try_again:
  n = write(fd, slip_buf + slip_begin, (slip_end - slip_begin));

  if(n == -1 && errno != EAGAIN) {
    if (get_slipfd()) goto slip_flushbuf_try_again;
    err(1, "slip_flushbuf write failed");
  } else if(n == -1) {
    PROGRESS("Q");		/* Outqueueis full! */
  } else {
    slip_begin += n;
    if(slip_begin == slip_end) {
      slip_begin = slip_end = 0;
    }
  }
}

void
write_to_serial(int outfd, void *inbuf, int len)
{
  u_int8_t *p = inbuf;
  int i;

  if(verbose>2) {
    if (timestamp) stamptime();
    printf("%s: Packet from TUN of length %d - write SLIP\n", tundev, len);
    if (verbose>4) {
#if WIRESHARK_IMPORT_FORMAT
      printf("%s: 0000", tundev);
	  for(i = 0; i < len; i++) printf(" %02x", p[i]);
#else
      printf("         ");
      for(i = 0; i < len; i++) {
        printf("%02x", p[i]);
        if((i & 3) == 3) printf(" ");
        if((i & 15) == 15) printf("\n%s:         ", tundev);
      }
#endif
      printf("\n");
    }
  }

  /* It would be ``nice'' to send a SLIP_END here but it's not
   * really necessary.
   */
  /* slip_send(outfd, SLIP_END); */
  if (vnet_hdr)  {
    /* We don't even parse the VNET header, we just skip it */
    i = VNET_HDR_LENGTH;
  } else {
    i = 0;
  }

  for(; i < len; i++) {
    switch(p[i]) {
    case SLIP_END:
      slip_send(outfd, SLIP_ESC);
      slip_send(outfd, SLIP_ESC_END);
      break;
    case SLIP_ESC:
      slip_send(outfd, SLIP_ESC);
      slip_send(outfd, SLIP_ESC_ESC);
      break;
    default:
      slip_send(outfd, p[i]);
      break;
    }
  }
  slip_send(outfd, SLIP_END);
  PROGRESS("t");
}


/*
 * Read from tun, write to slip.
 */
int
tun_to_serial(int infd, int outfd)
{
  struct {
    unsigned char inbuf[2000];
  } uip;
  int size;

  if((size = read(infd, uip.inbuf, 2000)) == -1) err(1, "tun_to_serial: read");

  write_to_serial(outfd, uip.inbuf, size);
  return size;
}

#ifndef BAUDRATE
#define BAUDRATE B115200
#endif
speed_t b_rate = BAUDRATE;

void
stty_telos(int fd)
{
  struct termios tty;
  speed_t speed = b_rate;
  int i;

  if(tcflush(fd, TCIOFLUSH) == -1) err(1, "tcflush");

  if(tcgetattr(fd, &tty) == -1) err(1, "tcgetattr");

  cfmakeraw(&tty);

  /* Nonblocking read. */
  tty.c_cc[VTIME] = 0;
  tty.c_cc[VMIN] = 0;
  if (flowcontrol)
    tty.c_cflag |= CRTSCTS;
  else
    tty.c_cflag &= ~CRTSCTS;
  tty.c_cflag &= ~HUPCL;
  tty.c_cflag &= ~CLOCAL;

  cfsetispeed(&tty, speed);
  cfsetospeed(&tty, speed);

  if(tcsetattr(fd, TCSAFLUSH, &tty) == -1) err(1, "tcsetattr");

#if 1
  /* Nonblocking read and write. */
  /* if(fcntl(fd, F_SETFL, O_NONBLOCK) == -1) err(1, "fcntl"); */

  tty.c_cflag |= CLOCAL;
  if(tcsetattr(fd, TCSAFLUSH, &tty) == -1) err(1, "tcsetattr");

  i = TIOCM_DTR;

  //if(ioctl(fd, TIOCMBIS, &i) == -1) err(1, "ioctl");
#endif

  usleep(10*1000);		/* Wait for hardware 10ms. */

  /* Flush input and output buffers. */
  if(tcflush(fd, TCIOFLUSH) == -1) err(1, "tcflush");
}

int
devopen_readlink(const char *dev, int flags)
{
  int fd = open(dev, flags);
  /* Failed to open, maybe its a symlink? Try readlink. */
  if (fd < 0) {
    const int buf_size = 255;
    char buf[buf_size];
    int i;
    i = readlink(dev, buf, buf_size);
    if (i < 0 || i >= buf_size) {
      return fd; /* We failed to readlink, return original error code. */
    }
    buf[i] = '\0';
    if (verbose > 2) {
      printf("Trying to open: '%s'\n", buf);
    }
    return open(buf, flags);
  }
  return fd;
}

int
devopen(const char *dev, int flags)
{
  if (dev[0] != '/') {
	  char t[1024];
	  strcpy(t, "/dev/");
	  strncat(t, dev, sizeof(t) - 5);
	  return devopen_readlink(t, flags);
  } else {
	  return devopen_readlink(dev, flags);
  }
}

#ifdef linux
#include <linux/if.h>
#include <linux/if_tun.h>

int
tun_alloc(char *dev, int tap, int make)
{
  struct ifreq ifr;
  int fd, err;

  if (!make)
    return devopen(dev, O_RDWR);
  
  if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
    return -1;
  }

  memset(&ifr, 0, sizeof(ifr));

  /* Flags: IFF_TUN   - TUN device (no Ethernet headers)
   *        IFF_TAP   - TAP device
   *
   *        IFF_NO_PI - Do not provide packet information
   */
  ifr.ifr_flags = (tap ? IFF_TAP : IFF_TUN) | IFF_NO_PI;
  if(*dev != 0)
    strncpy(ifr.ifr_name, dev, IFNAMSIZ);

  if((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ) {
    close(fd);
    return err;
  }
  strcpy(dev, ifr.ifr_name);
  return fd;
}
#else
int
tun_alloc(char *dev, int tap, int make)
{
  return devopen(dev, O_RDWR);
}
#endif

void
cleanup(void)
{
  if (ipaddr == NULL) {
    /* no configuration was done in this case by ifconf, we let the
     * user take care of it */
    return;
  }
#ifndef __APPLE__
  if (make) {
    if (timestamp) stamptime();
    ssystem("ifconfig %s down", tundev);
#ifndef linux
    ssystem("sysctl -w net.ipv6.conf.all.forwarding=1");
#endif
    /* ssystem("arp -d %s", ipaddr); */
    if (timestamp) stamptime();
    ssystem("netstat -nr"
	    " | awk '{ if ($2 == \"%s\") print \"route delete -net \"$1; }'"
	    " | sh",
	    tundev);
  }
#else
  if (make) {
    char *  itfaddr = strdup(ipaddr);
    char *  prefix = index(itfaddr, '/');
    if (timestamp) stamptime();
    ssystem("ifconfig %s inet6 %s remove", tundev, ipaddr);
    if (timestamp) stamptime();
    ssystem("ifconfig %s down", tundev);
    if ( prefix != NULL ) *prefix = '\0';
    ssystem("route delete -inet6 %s", itfaddr);
    free(itfaddr);
  }
#endif
}

void
sigcleanup(int signo)
{
  fprintf(stderr, "signal %d\n", signo);
  exit(0);			/* exit(0) will call cleanup() */
}

static int got_sigalarm;

void
sigalarm(int signo)
{
  got_sigalarm = 1;
  return;
}

void
sigalarm_reset()
{
#ifdef linux
#define TIMEOUT (997*1000)
#else
#define TIMEOUT (2451*1000)
#endif
  ualarm(TIMEOUT, TIMEOUT);
  got_sigalarm = 0;
}

void
ifconf(const char *tundev, const char *ipaddr, int tap)
{
  if (!make)
    return;
  if (ipaddr == NULL) {
    /* No ipaddr; the user will do it manually */
    return;
  }
#ifdef linux
  if (timestamp) stamptime();
  if (!tap) {
	  ssystem("ifconfig %s inet `hostname` up", tundev);
	  ssystem("ifconfig %s add %s", tundev, ipaddr);
  } else {
	  ssystem("ifconfig %s up", tundev);
	  ssystem("ip -6 route add 2001:db8::/64 dev %s", tundev);
	  ssystem("ip -6 addr add 2001:db8::2/64 dev %s", tundev);
	  ssystem("ip route add 192.0.2.0/24 dev %s", tundev);
	  ssystem("ip addr add 192.0.2.2/24 dev %s", tundev);
  }
  if (timestamp) stamptime();

/* radvd needs a link local address for routing */
#if 0
/* fe80::1/64 is good enough */
  ssystem("ifconfig %s add fe80::1/64", tundev);
#elif 1
/* Generate a link local address a la sixxs/aiccu */
/* First a full parse, stripping off the prefix length */
  if (!tap) {
    char lladdr[40];
    char c, *ptr=(char *)ipaddr;
    uint16_t digit,ai,a[8],cc,scc,i;
    for(ai=0; ai<8; ai++) {
      a[ai]=0;
    }
    ai=0;
    cc=scc=0;
    while(c=*ptr++) {
      if(c=='/') break;
      if(c==':') {
	if(cc)
	  scc = ai;
	cc = 1;
	if(++ai>7) break;
      } else {
	cc=0;
	digit = c-'0';
	if (digit > 9)
	  digit = 10 + (c & 0xdf) - 'A';
	a[ai] = (a[ai] << 4) + digit;
      }
    }
    /* Get # elided and shift what's after to the end */
    cc=8-ai;
    for(i=0;i<cc;i++) {
      if ((8-i-cc) <= scc) {
	a[7-i] = 0;
      } else {
	a[7-i] = a[8-i-cc];
	a[8-i-cc]=0;
      }
    }
    sprintf(lladdr,"fe80::%x:%x:%x:%x",a[1]&0xfefd,a[2],a[3],a[7]);
    if (timestamp) stamptime();
    ssystem("ifconfig %s add %s/64", tundev, lladdr);
  }
#endif /* link local */
#elif defined(__APPLE__)
  {
	char * itfaddr = strdup(ipaddr);
	char * prefix = index(itfaddr, '/');
	if ( prefix != NULL ) {
		*prefix = '\0';
		prefix++;
	} else {
		prefix = "64";
	}
    if (timestamp) stamptime();
    ssystem("ifconfig %s inet6 up", tundev );
    if (timestamp) stamptime();
    ssystem("ifconfig %s inet6 %s add", tundev, ipaddr );
    if (timestamp) stamptime();
    ssystem("sysctl -w net.inet6.ip6.forwarding=1");
    free(itfaddr);
  }
#else
  if (timestamp) stamptime();
  ssystem("ifconfig %s inet `hostname` %s up", tundev, ipaddr);
  if (timestamp) stamptime();
  ssystem("sysctl -w net.inet.ip.forwarding=1");
#endif /* !linux */

  if (timestamp) stamptime();
  ssystem("ifconfig %s\n", tundev);
}

int
main(int argc, char **argv)
{
  int c;
  int tunfd, maxfd;
  int ret;
  fd_set rset, wset;
  const char *prog;
  int baudrate = -2;
  int tap = 0;
  slipfd = 0;

  prog = argv[0];
  setvbuf(stdout, NULL, _IOLBF, 0); /* Line buffered output. */

  while((c = getopt(argc, argv, "B:HNxLhs:t:v::d::a:p:T")) != -1) {
    switch(c) {
    case 'B':
      baudrate = atoi(optarg);
      break;

    case 'H':
      flowcontrol=1;
      break;

    case 'L':
      timestamp=1;
      break;

    case 'x':
      make=0;
      break;

    case 'N':
      vnet_hdr=1;
      break;

    case 's':
      if(strncmp("/dev/", optarg, 5) == 0) {
	siodev = optarg + 5;
      } else {
	siodev = optarg;
      }
      break;

    case 't':
      if(strncmp("/dev/", optarg, 5) == 0) {
	strncpy(tundev, optarg + 5, sizeof(tundev));
      } else {
	strncpy(tundev, optarg, sizeof(tundev));
      }
      break;

    case 'a':
      host = optarg;
      break;

    case 'p':
      port = optarg;
      break;

    case 'd':
      basedelay = 10;
      if (optarg) basedelay = atoi(optarg);
      break;

    case 'v':
      verbose = 2;
      if (optarg) verbose = atoi(optarg);
      break;

    case 'T':
      tap = 1;
      break;

    case '?':
    case 'h':
    default:
fprintf(stderr,"usage:  %s [options] [ipaddress]\n", prog);
fprintf(stderr,"example: tunslip6 -L -v2 -s ttyUSB1 2001:db8::1/64\n");
fprintf(stderr,"Options are:\n");
#ifndef __APPLE__
fprintf(stderr," -B baudrate    9600,19200,38400,57600,115200 (default),230400,460800,921600\n");
#else
fprintf(stderr," -B baudrate    9600,19200,38400,57600,115200 (default),230400\n");
#endif
fprintf(stderr," -H             Hardware CTS/RTS flow control (default disabled)\n");
fprintf(stderr," -L             Log output format (adds time stamps)\n");
fprintf(stderr," -s siodev      Serial device (default /dev/ttyUSB0)\n");
fprintf(stderr," -T             Make tap interface (default is tun interface)\n");
fprintf(stderr," -x             Reuse tun device instead of creating a new one;\n"
               "                likewise do not attempt to configure the device\n");
fprintf(stderr," -N             add (and remove) a VNET header\n");
fprintf(stderr," -t tundev      Name of interface (default tap0 or tun0)\n");
fprintf(stderr," -v[level]      Verbosity level\n");
fprintf(stderr,"    -v0         No messages\n");
fprintf(stderr,"    -v1         Encapsulated SLIP debug messages (default)\n");
fprintf(stderr,"    -v2         Printable strings after they are received\n");
fprintf(stderr,"    -v3         Printable strings and SLIP packet notifications\n");
fprintf(stderr,"    -v4         All printable characters as they are received\n");
fprintf(stderr,"    -v5         All SLIP packets in hex\n");
fprintf(stderr,"    -v          Equivalent to -v3\n");
fprintf(stderr," -d[basedelay]  Minimum delay between outgoing SLIP packets.\n");
fprintf(stderr,"                Actual delay is basedelay*(#6LowPAN fragments) milliseconds.\n");
fprintf(stderr,"                -d is equivalent to -d10.\n");
fprintf(stderr," -a serveraddr  \n");
fprintf(stderr," -p serverport  \n");
exit(1);
      break;
    }
  }
  argc -= (optind - 1);
  argv += (optind - 1);

  if(argc > 3) {
    err(1, "usage: %s [-B baudrate] [-N] [-x] [-H] [-L] [-s siodev] [-t tundev] [-T] [-v verbosity] [-d delay] [-a serveraddress] [-p serverport] [ipaddress]", prog);
  }
  if (argc == 2) 
    ipaddr = argv[1];
  else
    ipaddr = NULL;

  switch(baudrate) {
  case -2:
    break;			/* Use default. */
  case 9600:
    b_rate = B9600;
    break;
  case 19200:
    b_rate = B19200;
    break;
  case 38400:
    b_rate = B38400;
    break;
  case 57600:
    b_rate = B57600;
    break;
  case 115200:
    b_rate = B115200;
    break;
  case 230400:
    b_rate = B230400;
    break;
#ifndef __APPLE__
  case 460800:
    b_rate = B460800;
    break;
  case 921600:
    b_rate = B921600;
    break;
#endif
  default:
    err(1, "unknown baudrate %d", baudrate);
    break;
  }

  if(*tundev == '\0') {
    /* Use default. */
    if(tap) {
      strcpy(tundev, "tap0");
    } else {
      strcpy(tundev, "tun0");
    }
  }

  get_slipfd();

  tunfd = tun_alloc(tundev, tap, make);
  if(tunfd == -1) err(1, "main: open");
  if (timestamp) stamptime();
  fprintf(stderr, "opened %s device ``/dev/%s''\n",
          tap ? "tap" : "tun", tundev);

  atexit(cleanup);
  signal(SIGHUP, sigcleanup);
  signal(SIGTERM, sigcleanup);
  signal(SIGINT, sigcleanup);
  signal(SIGALRM, sigalarm);
  ifconf(tundev, ipaddr, tap);

  while(1) {
    maxfd = 0;
    FD_ZERO(&rset);
    FD_ZERO(&wset);

/* do not send IPA all the time... - add get MAC later... */
/*     if(got_sigalarm) { */
/*       /\* Send "?IPA". *\/ */
/*       slip_send(slipfd, '?'); */
/*       slip_send(slipfd, 'I'); */
/*       slip_send(slipfd, 'P'); */
/*       slip_send(slipfd, 'A'); */
/*       slip_send(slipfd, SLIP_END); */
/*       got_sigalarm = 0; */
/*     } */

    if(!slip_empty()) {		/* Anything to flush? */
      FD_SET(slipfd, &wset);
    }

    FD_SET(slipfd, &rset);	/* Read from slip ASAP! */
    if(slipfd > maxfd) maxfd = slipfd;

    /* We only have one packet at a time queued for slip output. */
    if(slip_empty()) {
      FD_SET(tunfd, &rset);
      if(tunfd > maxfd) maxfd = tunfd;
    }

    ret = select(maxfd + 1, &rset, &wset, NULL, NULL);
    if(ret == -1 && errno != EINTR) {
      err(1, "select");
    } else if(ret > 0) {
      if(FD_ISSET(slipfd, &rset)) {
        serial_to_tun(inslip, tunfd);
      }

      if(FD_ISSET(slipfd, &wset)) {
	slip_flushbuf(slipfd);
	sigalarm_reset();
      }

      /* Optional delay between outgoing packets */
      /* Base delay times number of 6lowpan fragments to be sent */
      if(delaymsec) {
       struct timeval tv;
       int dmsec;
       gettimeofday(&tv, NULL) ;
       dmsec=(tv.tv_sec-delaystartsec)*1000+tv.tv_usec/1000-delaystartmsec;
       if(dmsec<0) delaymsec=0;
       if(dmsec>delaymsec) delaymsec=0;
      }
      if(delaymsec==0) {
        int size;
        if(slip_empty() && FD_ISSET(tunfd, &rset)) {
          size=tun_to_serial(tunfd, slipfd);
          slip_flushbuf(slipfd);
          sigalarm_reset();
          if(basedelay) {
            struct timeval tv;
            gettimeofday(&tv, NULL) ;
 //         delaymsec=basedelay*(1+(size/120));//multiply by # of 6lowpan packets?
            delaymsec=basedelay;
            delaystartsec =tv.tv_sec;
            delaystartmsec=tv.tv_usec/1000;
          }
        }
      }
    }
  }
}