/*
 * Virtual terminal [aka TeletYpe] interface routine.
 * Copyright (C) 1997, 98 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#include <zebra.h>

#include "linklist.h"
#include "thread.h"
#include "buffer.h"
#include "version.h"
#include "command.h"
#include "sockunion.h"
#include "memory.h"
#include "str.h"
#include "log.h"
#include "prefix.h"
#include "filter.h"
#include "vty.h"
#include "privs.h"

/* Vty events */
enum event 
{
  VTY_SERV,
  VTY_READ,
  VTY_WRITE,
  VTY_TIMEOUT_RESET,
#ifdef VTYSH
  VTYSH_SERV,
  VTYSH_READ
#endif /* VTYSH */
};

static void vty_event (enum event, int, struct vty *);

/* Extern host structure from command.c */
extern struct host host;

/* Vector which store each vty structure. */
static vector vtyvec;

/* Vty timeout value. */
static unsigned long vty_timeout_val = VTY_TIMEOUT_DEFAULT;

/* Vty access-class command */
static char *vty_accesslist_name = NULL;

/* Vty access-calss for IPv6. */
static char *vty_ipv6_accesslist_name = NULL;

/* VTY server thread. */
vector Vvty_serv_thread;

/* Current directory. */
char *vty_cwd = NULL;

/* Configure lock. */
static int vty_config;

/* Login password check. */
static int no_password_check = 0;

/* Integrated configuration file path */
char integrate_default[] = SYSCONFDIR INTEGRATE_DEFAULT_CONFIG;


/* VTY standard output function. */
int
vty_out (struct vty *vty, const char *format, ...)
{
  va_list args;
  int len = 0;
  int size = 1024;
  char buf[1024];
  char *p = NULL;
  
  va_start (args, format);

  if (vty_shell (vty))
    vprintf (format, args);
  else
    {
      /* Try to write to initial buffer.  */
      len = vsnprintf (buf, sizeof buf, format, args);

      /* Initial buffer is not enough.  */
      if (len < 0 || len >= size)
	{
	  while (1)
	    {
	      if (len > -1)
		size = len + 1;
	      else
		size = size * 2;

	      p = XREALLOC (MTYPE_VTY_OUT_BUF, p, size);
	      if (! p)
		return -1;

	      len = vsnprintf (p, size, format, args);

	      if (len > -1 && len < size)
		break;
	    }
	}

      /* When initial buffer is enough to store all output.  */
      if (! p)
	p = buf;

      /* Pointer p must point out buffer. */
      if (vty_shell_serv (vty))
	write (vty->fd, (u_char *) p, len);
      else
	buffer_write (vty->obuf, (u_char *) p, len);

      /* If p is not different with buf, it is allocated buffer.  */
      if (p != buf)
	XFREE (MTYPE_VTY_OUT_BUF, p);
    }

  va_end (args);

  return len;
}

int
vty_log_out (struct vty *vty, const char *proto_str, const char *format,
	     va_list va)
{
  int len;
  char buf[1024];

  snprintf (buf, sizeof buf, "%s: ", proto_str);
  write (vty->fd, buf, strlen (proto_str) + 2);

  len = vsnprintf (buf, sizeof buf, format, va);
  if (len < 0)
    return -1;
  write (vty->fd, (u_char *)buf, len);

  snprintf (buf, sizeof buf, "\r\n");
  write (vty->fd, buf, 2);

  return len;
}

/* Output current time to the vty. */
void
vty_time_print (struct vty *vty, int cr)
{
  time_t clock;
  struct tm *tm;
#define TIME_BUF 25
  char buf [TIME_BUF];
  int ret;
  
  time (&clock);
  tm = localtime (&clock);

  ret = strftime (buf, TIME_BUF, "%Y/%m/%d %H:%M:%S", tm);
  if (ret == 0)
    {
      zlog (NULL, LOG_INFO, "strftime error");
      return;
    }
  if (cr)
    vty_out (vty, "%s\n", buf);
  else
    vty_out (vty, "%s ", buf);

  return;
}

/* Say hello to vty interface. */
void
vty_hello (struct vty *vty)
{
  if (host.motd)
    vty_out (vty, host.motd);
}

/* Put out prompt and wait input from user. */
static void
vty_prompt (struct vty *vty)
{
  struct utsname names;
  const char*hostname;

  if (vty->type == VTY_TERM)
    {
      hostname = host.name;
      if (!hostname)
	{
	  uname (&names);
	  hostname = names.nodename;
	}
      vty_out (vty, cmd_prompt (vty->node), hostname);
    }
}

/* Send WILL TELOPT_ECHO to remote server. */
void
vty_will_echo (struct vty *vty)
{
  char cmd[] = { IAC, WILL, TELOPT_ECHO, '\0' };
  vty_out (vty, "%s", cmd);
}

/* Make suppress Go-Ahead telnet option. */
static void
vty_will_suppress_go_ahead (struct vty *vty)
{
  char cmd[] = { IAC, WILL, TELOPT_SGA, '\0' };
  vty_out (vty, "%s", cmd);
}

/* Make don't use linemode over telnet. */
static void
vty_dont_linemode (struct vty *vty)
{
  char cmd[] = { IAC, DONT, TELOPT_LINEMODE, '\0' };
  vty_out (vty, "%s", cmd);
}

/* Use window size. */
static void
vty_do_window_size (struct vty *vty)
{
  char cmd[] = { IAC, DO, TELOPT_NAWS, '\0' };
  vty_out (vty, "%s", cmd);
}

#if 0 /* Currently not used. */
/* Make don't use lflow vty interface. */
static void
vty_dont_lflow_ahead (struct vty *vty)
{
  char cmd[] = { IAC, DONT, TELOPT_LFLOW, '\0' };
  vty_out (vty, "%s", cmd);
}
#endif /* 0 */

/* Allocate new vty struct. */
struct vty *
vty_new ()
{
  struct vty *new = XCALLOC (MTYPE_VTY, sizeof (struct vty));

  new->obuf = (struct buffer *) buffer_new (100);
  new->buf = XCALLOC (MTYPE_VTY, VTY_BUFSIZ);
  new->max = VTY_BUFSIZ;
  new->sb_buffer = NULL;

  return new;
}

/* Authentication of vty */
static void
vty_auth (struct vty *vty, char *buf)
{
  char *passwd = NULL;
  enum node_type next_node = 0;
  int fail;
  char *crypt (const char *, const char *);

  switch (vty->node)
    {
    case AUTH_NODE:
      if (host.encrypt)
	passwd = host.password_encrypt;
      else
	passwd = host.password;
      if (host.advanced)
	next_node = host.enable ? VIEW_NODE : ENABLE_NODE;
      else
	next_node = VIEW_NODE;
      break;
    case AUTH_ENABLE_NODE:
      if (host.encrypt)
	passwd = host.enable_encrypt;
      else
	passwd = host.enable;
      next_node = ENABLE_NODE;
      break;
    }

  if (passwd)
    {
      if (host.encrypt)
	fail = strcmp (crypt(buf, passwd), passwd);
      else
	fail = strcmp (buf, passwd);
    }
  else
    fail = 1;

  if (! fail)
    {
      vty->fail = 0;
      vty->node = next_node;	/* Success ! */
    }
  else
    {
      vty->fail++;
      if (vty->fail >= 3)
	{
	  if (vty->node == AUTH_NODE)
	    {
	      vty_out (vty, "%% Bad passwords, too many failures!%s", VTY_NEWLINE);
	      vty->status = VTY_CLOSE;
	    }
	  else			
	    {
	      /* AUTH_ENABLE_NODE */
	      vty->fail = 0;
	      vty_out (vty, "%% Bad enable passwords, too many failures!%s", VTY_NEWLINE);
	      vty->node = VIEW_NODE;
	    }
	}
    }
}

/* Command execution over the vty interface. */
int
vty_command (struct vty *vty, char *buf)
{
  int ret;
  vector vline;

  /* Split readline string up into the vector */
  vline = cmd_make_strvec (buf);

  if (vline == NULL)
    return CMD_SUCCESS;

  ret = cmd_execute_command (vline, vty, NULL);

  if (ret != CMD_SUCCESS)
    switch (ret)
      {
      case CMD_WARNING:
	if (vty->type == VTY_FILE)
	  vty_out (vty, "Warning...%s", VTY_NEWLINE);
	break;
      case CMD_ERR_AMBIGUOUS:
	vty_out (vty, "%% Ambiguous command.%s", VTY_NEWLINE);
	break;
      case CMD_ERR_NO_MATCH:
	vty_out (vty, "%% Unknown command.%s", VTY_NEWLINE);
	break;
      case CMD_ERR_INCOMPLETE:
	vty_out (vty, "%% Command incomplete.%s", VTY_NEWLINE);
	break;
      }
  cmd_free_strvec (vline);

  return ret;
}

char telnet_backward_char = 0x08;
char telnet_space_char = ' ';

/* Basic function to write buffer to vty. */
static void
vty_write (struct vty *vty, char *buf, size_t nbytes)
{
  if ((vty->node == AUTH_NODE) || (vty->node == AUTH_ENABLE_NODE))
    return;

  /* Should we do buffering here ?  And make vty_flush (vty) ? */
  buffer_write (vty->obuf, (u_char *)buf, nbytes);
}

/* Ensure length of input buffer.  Is buffer is short, double it. */
static void
vty_ensure (struct vty *vty, int length)
{
  if (vty->max <= length)
    {
      vty->max *= 2;
      vty->buf = XREALLOC (MTYPE_VTY, vty->buf, vty->max);
    }
}

/* Basic function to insert character into vty. */
static void
vty_self_insert (struct vty *vty, char c)
{
  int i;
  int length;

  vty_ensure (vty, vty->length + 1);
  length = vty->length - vty->cp;
  memmove (&vty->buf[vty->cp + 1], &vty->buf[vty->cp], length);
  vty->buf[vty->cp] = c;

  vty_write (vty, &vty->buf[vty->cp], length + 1);
  for (i = 0; i < length; i++)
    vty_write (vty, &telnet_backward_char, 1);

  vty->cp++;
  vty->length++;
}

/* Self insert character 'c' in overwrite mode. */
static void
vty_self_insert_overwrite (struct vty *vty, char c)
{
  vty_ensure (vty, vty->length + 1);
  vty->buf[vty->cp++] = c;

  if (vty->cp > vty->length)
    vty->length++;

  if ((vty->node == AUTH_NODE) || (vty->node == AUTH_ENABLE_NODE))
    return;

  vty_write (vty, &c, 1);
}

/* Insert a word into vty interface with overwrite mode. */
static void
vty_insert_word_overwrite (struct vty *vty, char *str)
{
  int len = strlen (str);
  vty_write (vty, str, len);
  strcpy (&vty->buf[vty->cp], str);
  vty->cp += len;
  vty->length = vty->cp;
}

/* Forward character. */
static void
vty_forward_char (struct vty *vty)
{
  if (vty->cp < vty->length)
    {
      vty_write (vty, &vty->buf[vty->cp], 1);
      vty->cp++;
    }
}

/* Backward character. */
static void
vty_backward_char (struct vty *vty)
{
  if (vty->cp > 0)
    {
      vty->cp--;
      vty_write (vty, &telnet_backward_char, 1);
    }
}

/* Move to the beginning of the line. */
static void
vty_beginning_of_line (struct vty *vty)
{
  while (vty->cp)
    vty_backward_char (vty);
}

/* Move to the end of the line. */
static void
vty_end_of_line (struct vty *vty)
{
  while (vty->cp < vty->length)
    vty_forward_char (vty);
}

static void vty_kill_line_from_beginning (struct vty *);
static void vty_redraw_line (struct vty *);

/* Print command line history.  This function is called from
   vty_next_line and vty_previous_line. */
static void
vty_history_print (struct vty *vty)
{
  int length;

  vty_kill_line_from_beginning (vty);

  /* Get previous line from history buffer */
  length = strlen (vty->hist[vty->hp]);
  memcpy (vty->buf, vty->hist[vty->hp], length);
  vty->cp = vty->length = length;

  /* Redraw current line */
  vty_redraw_line (vty);
}

/* Show next command line history. */
void
vty_next_line (struct vty *vty)
{
  int try_index;

  if (vty->hp == vty->hindex)
    return;

  /* Try is there history exist or not. */
  try_index = vty->hp;
  if (try_index == (VTY_MAXHIST - 1))
    try_index = 0;
  else
    try_index++;

  /* If there is not history return. */
  if (vty->hist[try_index] == NULL)
    return;
  else
    vty->hp = try_index;

  vty_history_print (vty);
}

/* Show previous command line history. */
void
vty_previous_line (struct vty *vty)
{
  int try_index;

  try_index = vty->hp;
  if (try_index == 0)
    try_index = VTY_MAXHIST - 1;
  else
    try_index--;

  if (vty->hist[try_index] == NULL)
    return;
  else
    vty->hp = try_index;

  vty_history_print (vty);
}

/* This function redraw all of the command line character. */
static void
vty_redraw_line (struct vty *vty)
{
  vty_write (vty, vty->buf, vty->length);
  vty->cp = vty->length;
}

/* Forward word. */
static void
vty_forward_word (struct vty *vty)
{
  while (vty->cp != vty->length && vty->buf[vty->cp] != ' ')
    vty_forward_char (vty);
  
  while (vty->cp != vty->length && vty->buf[vty->cp] == ' ')
    vty_forward_char (vty);
}

/* Backward word without skipping training space. */
static void
vty_backward_pure_word (struct vty *vty)
{
  while (vty->cp > 0 && vty->buf[vty->cp - 1] != ' ')
    vty_backward_char (vty);
}

/* Backward word. */
static void
vty_backward_word (struct vty *vty)
{
  while (vty->cp > 0 && vty->buf[vty->cp - 1] == ' ')
    vty_backward_char (vty);

  while (vty->cp > 0 && vty->buf[vty->cp - 1] != ' ')
    vty_backward_char (vty);
}

/* When '^D' is typed at the beginning of the line we move to the down
   level. */
static void
vty_down_level (struct vty *vty)
{
  vty_out (vty, "%s", VTY_NEWLINE);
  config_exit (NULL, vty, 0, NULL);
  vty_prompt (vty);
  vty->cp = 0;
}

/* When '^Z' is received from vty, move down to the enable mode. */
void
vty_end_config (struct vty *vty)
{
  vty_out (vty, "%s", VTY_NEWLINE);

  switch (vty->node)
    {
    case VIEW_NODE:
    case ENABLE_NODE:
      /* Nothing to do. */
      break;
    case CONFIG_NODE:
    case INTERFACE_NODE:
    case ZEBRA_NODE:
    case RIP_NODE:
    case RIPNG_NODE:
    case BGP_NODE:
    case BGP_VPNV4_NODE:
    case BGP_IPV4_NODE:
    case BGP_IPV4M_NODE:
    case BGP_IPV6_NODE:
    case RMAP_NODE:
    case OSPF_NODE:
    case OSPF6_NODE:
    case KEYCHAIN_NODE:
    case KEYCHAIN_KEY_NODE:
    case MASC_NODE:
    case VTY_NODE:
      vty_config_unlock (vty);
      vty->node = ENABLE_NODE;
      break;
    default:
      /* Unknown node, we have to ignore it. */
      break;
    }

  vty_prompt (vty);
  vty->cp = 0;
}

/* Delete a charcter at the current point. */
static void
vty_delete_char (struct vty *vty)
{
  int i;
  int size;

  if (vty->node == AUTH_NODE || vty->node == AUTH_ENABLE_NODE)
    return;

  if (vty->length == 0)
    {
      vty_down_level (vty);
      return;
    }

  if (vty->cp == vty->length)
    return;			/* completion need here? */

  size = vty->length - vty->cp;

  vty->length--;
  memmove (&vty->buf[vty->cp], &vty->buf[vty->cp + 1], size - 1);
  vty->buf[vty->length] = '\0';

  vty_write (vty, &vty->buf[vty->cp], size - 1);
  vty_write (vty, &telnet_space_char, 1);

  for (i = 0; i < size; i++)
    vty_write (vty, &telnet_backward_char, 1);
}

/* Delete a character before the point. */
static void
vty_delete_backward_char (struct vty *vty)
{
  if (vty->cp == 0)
    return;

  vty_backward_char (vty);
  vty_delete_char (vty);
}

/* Kill rest of line from current point. */
static void
vty_kill_line (struct vty *vty)
{
  int i;
  int size;

  size = vty->length - vty->cp;
  
  if (size == 0)
    return;

  for (i = 0; i < size; i++)
    vty_write (vty, &telnet_space_char, 1);
  for (i = 0; i < size; i++)
    vty_write (vty, &telnet_backward_char, 1);

  memset (&vty->buf[vty->cp], 0, size);
  vty->length = vty->cp;
}

/* Kill line from the beginning. */
static void
vty_kill_line_from_beginning (struct vty *vty)
{
  vty_beginning_of_line (vty);
  vty_kill_line (vty);
}

/* Delete a word before the point. */
static void
vty_forward_kill_word (struct vty *vty)
{
  while (vty->cp != vty->length && vty->buf[vty->cp] == ' ')
    vty_delete_char (vty);
  while (vty->cp != vty->length && vty->buf[vty->cp] != ' ')
    vty_delete_char (vty);
}

/* Delete a word before the point. */
static void
vty_backward_kill_word (struct vty *vty)
{
  while (vty->cp > 0 && vty->buf[vty->cp - 1] == ' ')
    vty_delete_backward_char (vty);
  while (vty->cp > 0 && vty->buf[vty->cp - 1] != ' ')
    vty_delete_backward_char (vty);
}

/* Transpose chars before or at the point. */
static void
vty_transpose_chars (struct vty *vty)
{
  char c1, c2;

  /* If length is short or point is near by the beginning of line then
     return. */
  if (vty->length < 2 || vty->cp < 1)
    return;

  /* In case of point is located at the end of the line. */
  if (vty->cp == vty->length)
    {
      c1 = vty->buf[vty->cp - 1];
      c2 = vty->buf[vty->cp - 2];

      vty_backward_char (vty);
      vty_backward_char (vty);
      vty_self_insert_overwrite (vty, c1);
      vty_self_insert_overwrite (vty, c2);
    }
  else
    {
      c1 = vty->buf[vty->cp];
      c2 = vty->buf[vty->cp - 1];

      vty_backward_char (vty);
      vty_self_insert_overwrite (vty, c1);
      vty_self_insert_overwrite (vty, c2);
    }
}

/* Do completion at vty interface. */
static void
vty_complete_command (struct vty *vty)
{
  int i;
  int ret;
  char **matched = NULL;
  vector vline;

  if (vty->node == AUTH_NODE || vty->node == AUTH_ENABLE_NODE)
    return;

  vline = cmd_make_strvec (vty->buf);
  if (vline == NULL)
    return;

  /* In case of 'help \t'. */
  if (isspace ((int) vty->buf[vty->length - 1]))
    vector_set (vline, '\0');

  matched = cmd_complete_command (vline, vty, &ret);
  
  cmd_free_strvec (vline);

  vty_out (vty, "%s", VTY_NEWLINE);
  switch (ret)
    {
    case CMD_ERR_AMBIGUOUS:
      vty_out (vty, "%% Ambiguous command.%s", VTY_NEWLINE);
      vty_prompt (vty);
      vty_redraw_line (vty);
      break;
    case CMD_ERR_NO_MATCH:
      /* vty_out (vty, "%% There is no matched command.%s", VTY_NEWLINE); */
      vty_prompt (vty);
      vty_redraw_line (vty);
      break;
    case CMD_COMPLETE_FULL_MATCH:
      vty_prompt (vty);
      vty_redraw_line (vty);
      vty_backward_pure_word (vty);
      vty_insert_word_overwrite (vty, matched[0]);
      vty_self_insert (vty, ' ');
      XFREE (MTYPE_TMP, matched[0]);
      break;
    case CMD_COMPLETE_MATCH:
      vty_prompt (vty);
      vty_redraw_line (vty);
      vty_backward_pure_word (vty);
      vty_insert_word_overwrite (vty, matched[0]);
      XFREE (MTYPE_TMP, matched[0]);
      vector_only_index_free (matched);
      return;
      break;
    case CMD_COMPLETE_LIST_MATCH:
      for (i = 0; matched[i] != NULL; i++)
	{
	  if (i != 0 && ((i % 6) == 0))
	    vty_out (vty, "%s", VTY_NEWLINE);
	  vty_out (vty, "%-10s ", matched[i]);
	  XFREE (MTYPE_TMP, matched[i]);
	}
      vty_out (vty, "%s", VTY_NEWLINE);

      vty_prompt (vty);
      vty_redraw_line (vty);
      break;
    case CMD_ERR_NOTHING_TODO:
      vty_prompt (vty);
      vty_redraw_line (vty);
      break;
    default:
      break;
    }
  if (matched)
    vector_only_index_free (matched);
}

void
vty_describe_fold (struct vty *vty, int cmd_width,
                 int desc_width, struct desc *desc)
{
  char *buf, *cmd, *p;
  int pos;

  cmd = desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd;

  if (desc_width <= 0)
    {
      vty_out (vty, "  %-*s  %s%s", cmd_width, cmd, desc->str, VTY_NEWLINE);
      return;
    }

  buf = XCALLOC (MTYPE_TMP, strlen (desc->str) + 1);

  for (p = desc->str; strlen (p) > desc_width; p += pos + 1)
    {
      for (pos = desc_width; pos > 0; pos--)
      if (*(p + pos) == ' ')
        break;

      if (pos == 0)
      break;

      strncpy (buf, p, pos);
      buf[pos] = '\0';
      vty_out (vty, "  %-*s  %s%s", cmd_width, cmd, buf, VTY_NEWLINE);

      cmd = "";
    }

  vty_out (vty, "  %-*s  %s%s", cmd_width, cmd, p, VTY_NEWLINE);

  XFREE (MTYPE_TMP, buf);
}

/* Describe matched command function. */
static void
vty_describe_command (struct vty *vty)
{
  int ret;
  vector vline;
  vector describe;
  int i, width, desc_width;
  struct desc *desc, *desc_cr = NULL;

  vline = cmd_make_strvec (vty->buf);

  /* In case of '> ?'. */
  if (vline == NULL)
    {
      vline = vector_init (1);
      vector_set (vline, '\0');
    }
  else 
    if (isspace ((int) vty->buf[vty->length - 1]))
      vector_set (vline, '\0');

  describe = cmd_describe_command (vline, vty, &ret);

  vty_out (vty, "%s", VTY_NEWLINE);

  /* Ambiguous error. */
  switch (ret)
    {
    case CMD_ERR_AMBIGUOUS:
      cmd_free_strvec (vline);
      vty_out (vty, "%% Ambiguous command.%s", VTY_NEWLINE);
      vty_prompt (vty);
      vty_redraw_line (vty);
      return;
      break;
    case CMD_ERR_NO_MATCH:
      cmd_free_strvec (vline);
      vty_out (vty, "%% There is no matched command.%s", VTY_NEWLINE);
      vty_prompt (vty);
      vty_redraw_line (vty);
      return;
      break;
    }  

  /* Get width of command string. */
  width = 0;
  for (i = 0; i < vector_max (describe); i++)
    if ((desc = vector_slot (describe, i)) != NULL)
      {
	int len;

	if (desc->cmd[0] == '\0')
	  continue;

	len = strlen (desc->cmd);
	if (desc->cmd[0] == '.')
	  len--;

	if (width < len)
	  width = len;
      }

  /* Get width of description string. */
  desc_width = vty->width - (width + 6);

  /* Print out description. */
  for (i = 0; i < vector_max (describe); i++)
    if ((desc = vector_slot (describe, i)) != NULL)
      {
	if (desc->cmd[0] == '\0')
	  continue;
	
	if (strcmp (desc->cmd, "<cr>") == 0)
	  {
	    desc_cr = desc;
	    continue;
	  }

	if (!desc->str)
	  vty_out (vty, "  %-s%s",
		   desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd,
		   VTY_NEWLINE);
	else if (desc_width >= strlen (desc->str))
	  vty_out (vty, "  %-*s  %s%s", width,
		   desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd,
		   desc->str, VTY_NEWLINE);
	else
	  vty_describe_fold (vty, width, desc_width, desc);

#if 0
	vty_out (vty, "  %-*s %s%s", width
		 desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd,
		 desc->str ? desc->str : "", VTY_NEWLINE);
#endif /* 0 */
      }

  if ((desc = desc_cr))
    {
      if (!desc->str)
	vty_out (vty, "  %-s%s",
		 desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd,
		 VTY_NEWLINE);
      else if (desc_width >= strlen (desc->str))
	vty_out (vty, "  %-*s  %s%s", width,
		 desc->cmd[0] == '.' ? desc->cmd + 1 : desc->cmd,
		 desc->str, VTY_NEWLINE);
      else
	vty_describe_fold (vty, width, desc_width, desc);
    }

  cmd_free_strvec (vline);
  vector_free (describe);

  vty_prompt (vty);
  vty_redraw_line (vty);
}

void
vty_clear_buf (struct vty *vty)
{
  memset (vty->buf, 0, vty->max);
}

/* ^C stop current input and do not add command line to the history. */
static void
vty_stop_input (struct vty *vty)
{
  vty->cp = vty->length = 0;
  vty_clear_buf (vty);
  vty_out (vty, "%s", VTY_NEWLINE);

  switch (vty->node)
    {
    case VIEW_NODE:
    case ENABLE_NODE:
      /* Nothing to do. */
      break;
    case CONFIG_NODE:
    case INTERFACE_NODE:
    case ZEBRA_NODE:
    case RIP_NODE:
    case RIPNG_NODE:
    case BGP_NODE:
    case RMAP_NODE:
    case OSPF_NODE:
    case OSPF6_NODE:
    case KEYCHAIN_NODE:
    case KEYCHAIN_KEY_NODE:
    case MASC_NODE:
    case VTY_NODE:
      vty_config_unlock (vty);
      vty->node = ENABLE_NODE;
      break;
    default:
      /* Unknown node, we have to ignore it. */
      break;
    }
  vty_prompt (vty);

  /* Set history pointer to the latest one. */
  vty->hp = vty->hindex;
}

/* Add current command line to the history buffer. */
static void
vty_hist_add (struct vty *vty)
{
  int index;

  if (vty->length == 0)
    return;

  index = vty->hindex ? vty->hindex - 1 : VTY_MAXHIST - 1;

  /* Ignore the same string as previous one. */
  if (vty->hist[index])
    if (strcmp (vty->buf, vty->hist[index]) == 0)
      {
      vty->hp = vty->hindex;
      return;
      }

  /* Insert history entry. */
  if (vty->hist[vty->hindex])
    XFREE (MTYPE_VTY_HIST, vty->hist[vty->hindex]);
  vty->hist[vty->hindex] = XSTRDUP (MTYPE_VTY_HIST, vty->buf);

  /* History index rotation. */
  vty->hindex++;
  if (vty->hindex == VTY_MAXHIST)
    vty->hindex = 0;

  vty->hp = vty->hindex;
}

/* #define TELNET_OPTION_DEBUG */

/* Get telnet window size. */
static int
vty_telnet_option (struct vty *vty, unsigned char *buf, int nbytes)
{
#ifdef TELNET_OPTION_DEBUG
  int i;

  for (i = 0; i < nbytes; i++)
    {
      switch (buf[i])
	{
	case IAC:
	  vty_out (vty, "IAC ");
	  break;
	case WILL:
	  vty_out (vty, "WILL ");
	  break;
	case WONT:
	  vty_out (vty, "WONT ");
	  break;
	case DO:
	  vty_out (vty, "DO ");
	  break;
	case DONT:
	  vty_out (vty, "DONT ");
	  break;
	case SB:
	  vty_out (vty, "SB ");
	  break;
	case SE:
	  vty_out (vty, "SE ");
	  break;
	case TELOPT_ECHO:
	  vty_out (vty, "TELOPT_ECHO %s", VTY_NEWLINE);
	  break;
	case TELOPT_SGA:
	  vty_out (vty, "TELOPT_SGA %s", VTY_NEWLINE);
	  break;
	case TELOPT_NAWS:
	  vty_out (vty, "TELOPT_NAWS %s", VTY_NEWLINE);
	  break;
	default:
	  vty_out (vty, "%x ", buf[i]);
	  break;
	}
    }
  vty_out (vty, "%s", VTY_NEWLINE);

#endif /* TELNET_OPTION_DEBUG */

  switch (buf[0])
    {
    case SB:
      buffer_reset(vty->sb_buffer);
      vty->iac_sb_in_progress = 1;
      return 0;
      break;
    case SE: 
      {
	char *buffer;
	int length;

	if (!vty->iac_sb_in_progress)
	  return 0;

	buffer = (char *)vty->sb_buffer->head->data;
	length = vty->sb_buffer->length;

	if (buffer == NULL)
	  return 0;

	if (buffer[0] == '\0')
	  {
	    vty->iac_sb_in_progress = 0;
	    return 0;
	  }
	switch (buffer[0])
	  {
	  case TELOPT_NAWS:
	    if (length < 5)
	      break;
	    vty->width = buffer[2];
	    vty->height = vty->lines >= 0 ? vty->lines : buffer[4];
	    break;
	  }
	vty->iac_sb_in_progress = 0;
	return 0;
	break;
      }
    default:
      break;
    }
  return 1;
}

/* Execute current command line. */
static int
vty_execute (struct vty *vty)
{
  int ret;

  ret = CMD_SUCCESS;

  switch (vty->node)
    {
    case AUTH_NODE:
    case AUTH_ENABLE_NODE:
      vty_auth (vty, vty->buf);
      break;
    default:
      ret = vty_command (vty, vty->buf);
      if (vty->type == VTY_TERM)
	vty_hist_add (vty);
      break;
    }

  /* Clear command line buffer. */
  vty->cp = vty->length = 0;
  vty_clear_buf (vty);

  if (vty->status != VTY_CLOSE 
      && vty->status != VTY_START
      && vty->status != VTY_CONTINUE)
    vty_prompt (vty);

  return ret;
}

#define CONTROL(X)  ((X) - '@')
#define VTY_NORMAL     0
#define VTY_PRE_ESCAPE 1
#define VTY_ESCAPE     2

/* Escape character command map. */
static void
vty_escape_map (unsigned char c, struct vty *vty)
{
  switch (c)
    {
    case ('A'):
      vty_previous_line (vty);
      break;
    case ('B'):
      vty_next_line (vty);
      break;
    case ('C'):
      vty_forward_char (vty);
      break;
    case ('D'):
      vty_backward_char (vty);
      break;
    default:
      break;
    }

  /* Go back to normal mode. */
  vty->escape = VTY_NORMAL;
}

/* Quit print out to the buffer. */
static void
vty_buffer_reset (struct vty *vty)
{
  buffer_reset (vty->obuf);
  vty_prompt (vty);
  vty_redraw_line (vty);
}

/* Read data via vty socket. */
static int
vty_read (struct thread *thread)
{
  int i;
  int nbytes;
  unsigned char buf[VTY_READ_BUFSIZ];

  int vty_sock = THREAD_FD (thread);
  struct vty *vty = THREAD_ARG (thread);
  vty->t_read = NULL;

  /* Read raw data from socket */
  nbytes = read (vty->fd, buf, VTY_READ_BUFSIZ);
  if (nbytes <= 0)
    vty->status = VTY_CLOSE;

  for (i = 0; i < nbytes; i++) 
    {
      if (buf[i] == IAC)
	{
	  if (!vty->iac)
	    {
	      vty->iac = 1;
	      continue;
	    }
	  else
	    {
	      vty->iac = 0;
	    }
	}
      
      if (vty->iac_sb_in_progress && !vty->iac)
	{
	    buffer_putc(vty->sb_buffer, buf[i]);
	    continue;
	}

      if (vty->iac)
	{
	  /* In case of telnet command */
	  int ret = 0;
	  if (vty->iac_sb_in_progress)
	    ret = vty_telnet_option (vty, buf + i, nbytes - i);
	  vty->iac = 0;
	  i += ret;
	  continue;
	}
	        

      if (vty->status == VTY_MORE)
	{
	  switch (buf[i])
	    {
	    case CONTROL('C'):
	    case 'q':
	    case 'Q':
	      if (vty->output_func)
		(*vty->output_func) (vty, 1);
	      vty_buffer_reset (vty);
	      break;
#if 0 /* More line does not work for "show ip bgp".  */
	    case '\n':
	    case '\r':
	      vty->status = VTY_MORELINE;
	      break;
#endif
	    default:
	      if (vty->output_func)
		(*vty->output_func) (vty, 0);
	      break;
	    }
	  continue;
	}

      /* Escape character. */
      if (vty->escape == VTY_ESCAPE)
	{
	  vty_escape_map (buf[i], vty);
	  continue;
	}

      /* Pre-escape status. */
      if (vty->escape == VTY_PRE_ESCAPE)
	{
	  switch (buf[i])
	    {
	    case '[':
	      vty->escape = VTY_ESCAPE;
	      break;
	    case 'b':
	      vty_backward_word (vty);
	      vty->escape = VTY_NORMAL;
	      break;
	    case 'f':
	      vty_forward_word (vty);
	      vty->escape = VTY_NORMAL;
	      break;
	    case 'd':
	      vty_forward_kill_word (vty);
	      vty->escape = VTY_NORMAL;
	      break;
	    case CONTROL('H'):
	    case 0x7f:
	      vty_backward_kill_word (vty);
	      vty->escape = VTY_NORMAL;
	      break;
	    default:
	      vty->escape = VTY_NORMAL;
	      break;
	    }
	  continue;
	}

      switch (buf[i])
	{
	case CONTROL('A'):
	  vty_beginning_of_line (vty);
	  break;
	case CONTROL('B'):
	  vty_backward_char (vty);
	  break;
	case CONTROL('C'):
	  vty_stop_input (vty);
	  break;
	case CONTROL('D'):
	  vty_delete_char (vty);
	  break;
	case CONTROL('E'):
	  vty_end_of_line (vty);
	  break;
	case CONTROL('F'):
	  vty_forward_char (vty);
	  break;
	case CONTROL('H'):
	case 0x7f:
	  vty_delete_backward_char (vty);
	  break;
	case CONTROL('K'):
	  vty_kill_line (vty);
	  break;
	case CONTROL('N'):
	  vty_next_line (vty);
	  break;
	case CONTROL('P'):
	  vty_previous_line (vty);
	  break;
	case CONTROL('T'):
	  vty_transpose_chars (vty);
	  break;
	case CONTROL('U'):
	  vty_kill_line_from_beginning (vty);
	  break;
	case CONTROL('W'):
	  vty_backward_kill_word (vty);
	  break;
	case CONTROL('Z'):
	  vty_end_config (vty);
	  break;
	case '\n':
	case '\r':
	  vty_out (vty, "%s", VTY_NEWLINE);
	  vty_execute (vty);
	  break;
	case '\t':
	  vty_complete_command (vty);
	  break;
	case '?':
	  if (vty->node == AUTH_NODE || vty->node == AUTH_ENABLE_NODE)
	    vty_self_insert (vty, buf[i]);
	  else
	    vty_describe_command (vty);
	  break;
	case '\033':
	  if (i + 1 < nbytes && buf[i + 1] == '[')
	    {
	      vty->escape = VTY_ESCAPE;
	      i++;
	    }
	  else
	    vty->escape = VTY_PRE_ESCAPE;
	  break;
	default:
	  if (buf[i] > 31 && buf[i] < 127)
	    vty_self_insert (vty, buf[i]);
	  break;
	}
    }

  /* Check status. */
  if (vty->status == VTY_CLOSE)
    vty_close (vty);
  else
    {
      vty_event (VTY_WRITE, vty_sock, vty);
      vty_event (VTY_READ, vty_sock, vty);
    }
  return 0;
}

/* Flush buffer to the vty. */
static int
vty_flush (struct thread *thread)
{
  int erase;
  int dont_more;
  int vty_sock = THREAD_FD (thread);
  struct vty *vty = THREAD_ARG (thread);
  vty->t_write = NULL;

  /* Tempolary disable read thread. */
  if (vty->lines == 0)
    if (vty->t_read)
      {
	thread_cancel (vty->t_read);
	vty->t_read = NULL;
      }

  /* Function execution continue. */
  if (vty->status == VTY_START || vty->status == VTY_CONTINUE)
    {
      if (vty->status == VTY_CONTINUE)
	erase = 1;
      else
	erase = 0;

      if (vty->output_func == NULL)
	dont_more = 1;
      else
	dont_more = 0;

      if (vty->lines == 0)
	{
	  erase = 0;
	  dont_more = 1;
	}

      buffer_flush_vty_all (vty->obuf, vty->fd, erase, dont_more);

      if (vty->status == VTY_CLOSE)
	{
	  vty_close (vty);
	  return 0;
	}

      if (vty->output_func == NULL)
	{
	  vty->status = VTY_NORMAL;
	  vty_prompt (vty);
	  vty_event (VTY_WRITE, vty_sock, vty);
	}
      else
	vty->status = VTY_MORE;

      if (vty->lines == 0)
	{
	  if (vty->output_func == NULL)
	    vty_event (VTY_READ, vty_sock, vty);
	  else
	    {
	      if (vty->output_func)
		(*vty->output_func) (vty, 0);
	      vty_event (VTY_WRITE, vty_sock, vty);
	    }
	}
    }
  else
    {
      if (vty->status == VTY_MORE || vty->status == VTY_MORELINE)
	erase = 1;
      else
	erase = 0;

      if (vty->lines == 0)
	buffer_flush_window (vty->obuf, vty->fd, vty->width, 25, 0, 1);
      else if (vty->status == VTY_MORELINE)
	buffer_flush_window (vty->obuf, vty->fd, vty->width, 1, erase, 0);
      else
	buffer_flush_window (vty->obuf, vty->fd, vty->width,
			     vty->lines >= 0 ? vty->lines : vty->height,
			     erase, 0);
  
      if (buffer_empty (vty->obuf))
	{
	  if (vty->status == VTY_CLOSE)
	    vty_close (vty);
	  else
	    {
	      vty->status = VTY_NORMAL;
	  
	      if (vty->lines == 0)
		vty_event (VTY_READ, vty_sock, vty);
	    }
	}
      else
	{
	  vty->status = VTY_MORE;

	  if (vty->lines == 0)
	    vty_event (VTY_WRITE, vty_sock, vty);
	}
    }

  return 0;
}

/* Create new vty structure. */
struct vty *
vty_create (int vty_sock, union sockunion *su)
{
  struct vty *vty;

  /* Allocate new vty structure and set up default values. */
  vty = vty_new ();
  vty->fd = vty_sock;
  vty->type = VTY_TERM;
  vty->address = sockunion_su2str (su);
  if (no_password_check)
    {
      if (host.advanced)
	vty->node = ENABLE_NODE;
      else
	vty->node = VIEW_NODE;
    }
  else
    vty->node = AUTH_NODE;
  vty->fail = 0;
  vty->cp = 0;
  vty_clear_buf (vty);
  vty->length = 0;
  memset (vty->hist, 0, sizeof (vty->hist));
  vty->hp = 0;
  vty->hindex = 0;
  vector_set_index (vtyvec, vty_sock, vty);
  vty->status = VTY_NORMAL;
  vty->v_timeout = vty_timeout_val;
  if (host.lines >= 0)
    vty->lines = host.lines;
  else
    vty->lines = -1;
  vty->iac = 0;
  vty->iac_sb_in_progress = 0;
  vty->sb_buffer = buffer_new (1024);

  if (! no_password_check)
    {
      /* Vty is not available if password isn't set. */
      if (host.password == NULL && host.password_encrypt == NULL)
	{
	  vty_out (vty, "Vty password is not set.%s", VTY_NEWLINE);
	  vty->status = VTY_CLOSE;
	  vty_close (vty);
	  return NULL;
	}
    }

  /* Say hello to the world. */
  vty_hello (vty);
  if (! no_password_check)
    vty_out (vty, "%sUser Access Verification%s%s", VTY_NEWLINE, VTY_NEWLINE, VTY_NEWLINE);

  /* Setting up terminal. */
  vty_will_echo (vty);
  vty_will_suppress_go_ahead (vty);

  vty_dont_linemode (vty);
  vty_do_window_size (vty);
  /* vty_dont_lflow_ahead (vty); */

  vty_prompt (vty);

  /* Add read/write thread. */
  vty_event (VTY_WRITE, vty_sock, vty);
  vty_event (VTY_READ, vty_sock, vty);

  return vty;
}

/* Accept connection from the network. */
static int
vty_accept (struct thread *thread)
{
  int vty_sock;
  struct vty *vty;
  union sockunion su;
  int ret;
  unsigned int on;
  int accept_sock;
  struct prefix *p = NULL;
  struct access_list *acl = NULL;

  accept_sock = THREAD_FD (thread);

  /* We continue hearing vty socket. */
  vty_event (VTY_SERV, accept_sock, NULL);

  memset (&su, 0, sizeof (union sockunion));

  /* We can handle IPv4 or IPv6 socket. */
  vty_sock = sockunion_accept (accept_sock, &su);
  if (vty_sock < 0)
    {
      zlog_warn ("can't accept vty socket : %s", strerror (errno));
      return -1;
    }

  p = sockunion2hostprefix (&su);

  /* VTY's accesslist apply. */
  if (p->family == AF_INET && vty_accesslist_name)
    {
      if ((acl = access_list_lookup (AFI_IP, vty_accesslist_name)) &&
	  (access_list_apply (acl, p) == FILTER_DENY))
	{
	  char *buf;
	  zlog (NULL, LOG_INFO, "Vty connection refused from %s",
		(buf = sockunion_su2str (&su)));
	  free (buf);
	  close (vty_sock);
	  
	  /* continue accepting connections */
	  vty_event (VTY_SERV, accept_sock, NULL);
	  
	  prefix_free (p);

	  return 0;
	}
    }

#ifdef HAVE_IPV6
  /* VTY's ipv6 accesslist apply. */
  if (p->family == AF_INET6 && vty_ipv6_accesslist_name)
    {
      if ((acl = access_list_lookup (AFI_IP6, vty_ipv6_accesslist_name)) &&
	  (access_list_apply (acl, p) == FILTER_DENY))
	{
	  char *buf;
	  zlog (NULL, LOG_INFO, "Vty connection refused from %s",
		(buf = sockunion_su2str (&su)));
	  free (buf);
	  close (vty_sock);
	  
	  /* continue accepting connections */
	  vty_event (VTY_SERV, accept_sock, NULL);
	  
	  prefix_free (p);

	  return 0;
	}
    }
#endif /* HAVE_IPV6 */
  
  prefix_free (p);

  on = 1;
  ret = setsockopt (vty_sock, IPPROTO_TCP, TCP_NODELAY, 
		    (char *) &on, sizeof (on));
  if (ret < 0)
    zlog (NULL, LOG_INFO, "can't set sockopt to vty_sock : %s", 
	  strerror (errno));

  vty = vty_create (vty_sock, &su);

  return 0;
}

#if defined(HAVE_IPV6) && !defined(NRL)
void
vty_serv_sock_addrinfo (const char *hostname, unsigned short port)
{
  int ret;
  struct addrinfo req;
  struct addrinfo *ainfo;
  struct addrinfo *ainfo_save;
  int sock;
  char port_str[BUFSIZ];

  memset (&req, 0, sizeof (struct addrinfo));
  req.ai_flags = AI_PASSIVE;
  req.ai_family = AF_UNSPEC;
  req.ai_socktype = SOCK_STREAM;
  sprintf (port_str, "%d", port);
  port_str[sizeof (port_str) - 1] = '\0';

  ret = getaddrinfo (hostname, port_str, &req, &ainfo);

  if (ret != 0)
    {
      fprintf (stderr, "getaddrinfo failed: %s\n", gai_strerror (ret));
      exit (1);
    }

  ainfo_save = ainfo;

  do
    {
      if (ainfo->ai_family != AF_INET
#ifdef HAVE_IPV6
	  && ainfo->ai_family != AF_INET6
#endif /* HAVE_IPV6 */
	  )
	continue;

      sock = socket (ainfo->ai_family, ainfo->ai_socktype, ainfo->ai_protocol);
      if (sock < 0)
	continue;

      sockopt_reuseaddr (sock);
      sockopt_reuseport (sock);

      ret = bind (sock, ainfo->ai_addr, ainfo->ai_addrlen);
      if (ret < 0)
	{
	  close (sock);	/* Avoid sd leak. */
	continue;
	}

      ret = listen (sock, 3);
      if (ret < 0) 
	{
	  close (sock);	/* Avoid sd leak. */
	continue;
	}

      vty_event (VTY_SERV, sock, NULL);
    }
  while ((ainfo = ainfo->ai_next) != NULL);

  freeaddrinfo (ainfo_save);
}
#endif /* HAVE_IPV6 && ! NRL */

/* Make vty server socket. */
void
vty_serv_sock_family (const char* addr, unsigned short port, int family)
{
  int ret;
  union sockunion su;
  int accept_sock;
  void* naddr=NULL;

  memset (&su, 0, sizeof (union sockunion));
  su.sa.sa_family = family;
  if(addr)
    switch(family)
    {
      case AF_INET:
        naddr=&su.sin.sin_addr;
#ifdef HAVE_IPV6
      case AF_INET6:
        naddr=&su.sin6.sin6_addr;
#endif	
    }

  if(naddr)
    switch(inet_pton(family,addr,naddr))
    {
      case -1:
        zlog_err("bad address %s",addr);
	naddr=NULL;
	break;
      case 0:
        zlog_err("error translating address %s: %s",addr,strerror(errno));
	naddr=NULL;
    }

  /* Make new socket. */
  accept_sock = sockunion_stream_socket (&su);
  if (accept_sock < 0)
    return;

  /* This is server, so reuse address. */
  sockopt_reuseaddr (accept_sock);
  sockopt_reuseport (accept_sock);

  /* Bind socket to universal address and given port. */
  ret = sockunion_bind (accept_sock, &su, port, naddr);
  if (ret < 0)
    {
      zlog_warn("can't bind socket");
      close (accept_sock);	/* Avoid sd leak. */
      return;
    }

  /* Listen socket under queue 3. */
  ret = listen (accept_sock, 3);
  if (ret < 0) 
    {
      zlog (NULL, LOG_WARNING, "can't listen socket");
      close (accept_sock);	/* Avoid sd leak. */
      return;
    }

  /* Add vty server event. */
  vty_event (VTY_SERV, accept_sock, NULL);
}

#ifdef VTYSH
/* For sockaddr_un. */
#include <sys/un.h>

/* VTY shell UNIX domain socket. */
void
vty_serv_un (char *path)
{
  int ret;
  int sock, len;
  struct sockaddr_un serv;
  mode_t old_mask;
  struct zprivs_ids_t ids;
  
  /* First of all, unlink existing socket */
  unlink (path);

  /* Set umask */
  old_mask = umask (0007);

  /* Make UNIX domain socket. */
  sock = socket (AF_UNIX, SOCK_STREAM, 0);
  if (sock < 0)
    {
      perror ("sock");
      return;
    }

  /* Make server socket. */
  memset (&serv, 0, sizeof (struct sockaddr_un));
  serv.sun_family = AF_UNIX;
  strncpy (serv.sun_path, path, strlen (path));
#ifdef HAVE_SUN_LEN
  len = serv.sun_len = SUN_LEN(&serv);
#else
  len = sizeof (serv.sun_family) + strlen (serv.sun_path);
#endif /* HAVE_SUN_LEN */

  ret = bind (sock, (struct sockaddr *) &serv, len);
  if (ret < 0)
    {
      perror ("bind");
      close (sock);	/* Avoid sd leak. */
      return;
    }

  ret = listen (sock, 5);
  if (ret < 0)
    {
      perror ("listen");
      close (sock);	/* Avoid sd leak. */
      return;
    }

  umask (old_mask);

  zprivs_get_ids(&ids);
  
  if (ids.gid_vty > 0)
    {
      /* set group of socket */
      if ( chown (path, -1, ids.gid_vty) )
        {
          zlog_err ("vty_serv_un: could chown socket, %s",
                     strerror (errno) );
        }
    }

  vty_event (VTYSH_SERV, sock, NULL);
}

/* #define VTYSH_DEBUG 1 */

static int
vtysh_accept (struct thread *thread)
{
  int accept_sock;
  int sock;
  int client_len;
  struct sockaddr_un client;
  struct vty *vty;
  
  accept_sock = THREAD_FD (thread);

  vty_event (VTYSH_SERV, accept_sock, NULL);

  memset (&client, 0, sizeof (struct sockaddr_un));
  client_len = sizeof (struct sockaddr_un);

  sock = accept (accept_sock, (struct sockaddr *) &client, &client_len);

  if (sock < 0)
    {
      zlog_warn ("can't accept vty socket : %s", strerror (errno));
      return -1;
    }

#ifdef VTYSH_DEBUG
  printf ("VTY shell accept\n");
#endif /* VTYSH_DEBUG */

  vty = vty_new ();
  vty->fd = sock;
  vty->type = VTY_SHELL_SERV;
  vty->node = VIEW_NODE;

  vty_event (VTYSH_READ, sock, vty);

  return 0;
}

static int
vtysh_read (struct thread *thread)
{
  int ret;
  int sock;
  int nbytes;
  struct vty *vty;
  unsigned char buf[VTY_READ_BUFSIZ];
  u_char header[4] = {0, 0, 0, 0};

  sock = THREAD_FD (thread);
  vty = THREAD_ARG (thread);
  vty->t_read = NULL;

  nbytes = read (sock, buf, VTY_READ_BUFSIZ);
  if (nbytes <= 0)
    {
      vty_close (vty);
#ifdef VTYSH_DEBUG
      printf ("close vtysh\n");
#endif /* VTYSH_DEBUG */
      return 0;
    }

#ifdef VTYSH_DEBUG
  printf ("line: %s\n", buf);
#endif /* VTYSH_DEBUG */

  vty_ensure (vty, nbytes);
  memcpy (vty->buf, buf, nbytes);
  
  /* Pass this line to parser. */
  ret = vty_execute (vty);

  vty_clear_buf (vty);

  /* Return result. */
#ifdef VTYSH_DEBUG
  printf ("result: %d\n", ret);
  printf ("vtysh node: %d\n", vty->node);
#endif /* VTYSH_DEBUG */

  header[3] = ret;
  write (vty->fd, header, 4);

  vty_event (VTYSH_READ, sock, vty);

  return 0;
}
#endif /* VTYSH */

/* Determine address family to bind. */
void
vty_serv_sock (const char *addr, unsigned short port, char *path)
{
  /* If port is set to 0, do not listen on TCP/IP at all! */
  if (port)
    {

#ifdef HAVE_IPV6
#ifdef NRL
      vty_serv_sock_family (addr, port, AF_INET);
      vty_serv_sock_family (addr, port, AF_INET6);
#else /* ! NRL */
      vty_serv_sock_addrinfo (addr, port);
#endif /* NRL*/
#else /* ! HAVE_IPV6 */
      vty_serv_sock_family (addr,port, AF_INET);
#endif /* HAVE_IPV6 */
    }

#ifdef VTYSH
  vty_serv_un (path);
#endif /* VTYSH */
}

/* Close vty interface. */
void
vty_close (struct vty *vty)
{
  int i;

  /* Cancel threads.*/
  if (vty->t_read)
    thread_cancel (vty->t_read);
  if (vty->t_write)
    thread_cancel (vty->t_write);
  if (vty->t_timeout)
    thread_cancel (vty->t_timeout);
  if (vty->t_output)
    thread_cancel (vty->t_output);

  /* Flush buffer. */
  if (! buffer_empty (vty->obuf))
    buffer_flush_all (vty->obuf, vty->fd);

  /* Free input buffer. */
  buffer_free (vty->obuf);

  /* Free SB buffer. */
  if (vty->sb_buffer)
    buffer_free (vty->sb_buffer);

  /* Free command history. */
  for (i = 0; i < VTY_MAXHIST; i++)
    if (vty->hist[i])
      XFREE (MTYPE_VTY_HIST, vty->hist[i]);

  /* Unset vector. */
  vector_unset (vtyvec, vty->fd);

  /* Close socket. */
  if (vty->fd > 0)
    close (vty->fd);

  if (vty->address)
    XFREE (0, vty->address);
  if (vty->buf)
    XFREE (MTYPE_VTY, vty->buf);

  /* Check configure. */
  vty_config_unlock (vty);

  /* OK free vty. */
  XFREE (MTYPE_VTY, vty);
}

/* When time out occur output message then close connection. */
static int
vty_timeout (struct thread *thread)
{
  struct vty *vty;

  vty = THREAD_ARG (thread);
  vty->t_timeout = NULL;
  vty->v_timeout = 0;

  /* Clear buffer*/
  buffer_reset (vty->obuf);
  vty_out (vty, "%sVty connection is timed out.%s", VTY_NEWLINE, VTY_NEWLINE);

  /* Close connection. */
  vty->status = VTY_CLOSE;
  vty_close (vty);

  return 0;
}

/* Read up configuration file from file_name. */
static void
vty_read_file (FILE *confp)
{
  int ret;
  struct vty *vty;

  vty = vty_new ();
  vty->fd = 0;			/* stdout */
  vty->type = VTY_TERM;
  vty->node = CONFIG_NODE;
  
  /* Execute configuration file */
  ret = config_from_file (vty, confp);

  if ( !((ret == CMD_SUCCESS) || (ret == CMD_ERR_NOTHING_TODO)) ) 
    {
      switch (ret)
       {
         case CMD_ERR_AMBIGUOUS:
           fprintf (stderr, "Ambiguous command.\n");
           break;
         case CMD_ERR_NO_MATCH:
           fprintf (stderr, "There is no such command.\n");
           break;
       }
      fprintf (stderr, "Error occured during reading below line.\n%s\n", 
	       vty->buf);
      vty_close (vty);
      exit (1);
    }

  vty_close (vty);
}

FILE *
vty_use_backup_config (char *fullpath)
{
  char *fullpath_sav, *fullpath_tmp;
  FILE *ret = NULL;
  struct stat buf;
  int tmp, sav;
  int c;
  char buffer[512];
  
  fullpath_sav = malloc (strlen (fullpath) + strlen (CONF_BACKUP_EXT) + 1);
  strcpy (fullpath_sav, fullpath);
  strcat (fullpath_sav, CONF_BACKUP_EXT);
  if (stat (fullpath_sav, &buf) == -1)
    {
      free (fullpath_sav);
      return NULL;
    }

  fullpath_tmp = malloc (strlen (fullpath) + 8);
  sprintf (fullpath_tmp, "%s.XXXXXX", fullpath);
  
  /* Open file to configuration write. */
  tmp = mkstemp (fullpath_tmp);
  if (tmp < 0)
    {
      free (fullpath_sav);
      free (fullpath_tmp);
      return NULL;
    }

  sav = open (fullpath_sav, O_RDONLY);
  if (sav < 0)
    {
      free (fullpath_sav);
      free (fullpath_tmp);
      unlink (fullpath_tmp);
      return NULL;
    }
  
  while((c = read (sav, buffer, 512)) > 0)
    write (tmp, buffer, c);
  
  close (sav);
  close (tmp);
  
  if (link (fullpath_tmp, fullpath) == 0)
    ret = fopen (fullpath, "r");

  unlink (fullpath_tmp);
  
  free (fullpath_sav);
  free (fullpath_tmp);
  return fopen (fullpath, "r");
}

/* Read up configuration file from file_name. */
void
vty_read_config (char *config_file,
		 char *config_current_dir,
		 char *config_default_dir)
{
  char cwd[MAXPATHLEN];
  FILE *confp = NULL;
  char *fullpath;

  /* If -f flag specified. */
  if (config_file != NULL)
    {
      if (! IS_DIRECTORY_SEP (config_file[0]))
	{
	  getcwd (cwd, MAXPATHLEN);
	  fullpath = XMALLOC (MTYPE_TMP, 
			      strlen (cwd) + strlen (config_file) + 2);
	  sprintf (fullpath, "%s/%s", cwd, config_file);
	}
      else
	fullpath = config_file;

      confp = fopen (fullpath, "r");

      if (confp == NULL)
	{
	  confp = vty_use_backup_config (fullpath);
	  if (confp)
	    fprintf (stderr, "WARNING: using backup configuration file!\n");
	  else
	    {
	      fprintf (stderr, "can't open configuration file [%s]\n", 
		       config_file);
	      exit(1);
	    }
	}
    }
  else
    {
      /* Relative path configuration file open. */
      if (config_current_dir)
	{
	  confp = fopen (config_current_dir, "r");
	  if (confp == NULL)
	    {
	      confp = vty_use_backup_config (config_current_dir);
	      if (confp)
		fprintf (stderr, "WARNING: using backup configuration file!\n");
	    }
	}

      /* If there is no relative path exists, open system default file. */
      if (confp == NULL)
	{
#ifdef VTYSH
	  int ret;
	  struct stat conf_stat;

	  /* !!!!PLEASE LEAVE!!!!
	     This is NEEDED for use with vtysh -b, or else you can get
	     a real configuration food fight with a lot garbage in the
	     merged configuration file it creates coming from the per
	     daemon configuration files.  This also allows the daemons
	     to start if there default configuration file is not
	     present or ignore them, as needed when using vtysh -b to
	     configure the daemons at boot - MAG */

	  /* Stat for vtysh Zebra.conf, if found startup and wait for
	     boot configuration */

	  if ( strstr(config_default_dir, "vtysh") == NULL)
	    {
	      ret = stat (integrate_default, &conf_stat);
	      if (ret >= 0)
		{
		  return;
		}
	    }
#endif /* VTYSH */

	  confp = fopen (config_default_dir, "r");
	  if (confp == NULL)
	    {
	      confp = vty_use_backup_config (config_default_dir);
	      if (confp)
		{
		  fprintf (stderr, "WARNING: using backup configuration file!\n");
		  fullpath = config_default_dir;
		}
	      else
		{
		  fprintf (stderr, "can't open configuration file [%s]\n",
			   config_default_dir);
		  exit (1);
		}
	    }      
	  else
	    fullpath = config_default_dir;
	}
      else
	{
	  /* Rleative path configuration file. */
	  getcwd (cwd, MAXPATHLEN);
	  fullpath = XMALLOC (MTYPE_TMP, 
			      strlen (cwd) + strlen (config_current_dir) + 2);
	  sprintf (fullpath, "%s/%s", cwd, config_current_dir);
	}  
    }  
  vty_read_file (confp);

  fclose (confp);

  host_config_set (fullpath);
}

/* Small utility function which output log to the VTY. */
void
vty_log (const char *proto_str, const char *format, va_list va)
{
  int i;
  struct vty *vty;

  for (i = 0; i < vector_max (vtyvec); i++)
    if ((vty = vector_slot (vtyvec, i)) != NULL)
      if (vty->monitor)
	vty_log_out (vty, proto_str, format, va);
}

int
vty_config_lock (struct vty *vty)
{
  if (vty_config == 0)
    {
      vty->config = 1;
      vty_config = 1;
    }
  return vty->config;
}

int
vty_config_unlock (struct vty *vty)
{
  if (vty_config == 1 && vty->config == 1)
    {
      vty->config = 0;
      vty_config = 0;
    }
  return vty->config;
}

/* Master of the threads. */
static struct thread_master *master;

static void
vty_event (enum event event, int sock, struct vty *vty)
{
  struct thread *vty_serv_thread;

  switch (event)
    {
    case VTY_SERV:
      vty_serv_thread = thread_add_read (master, vty_accept, vty, sock);
      vector_set_index (Vvty_serv_thread, sock, vty_serv_thread);
      break;
#ifdef VTYSH
    case VTYSH_SERV:
      thread_add_read (master, vtysh_accept, vty, sock);
      break;
    case VTYSH_READ:
      thread_add_read (master, vtysh_read, vty, sock);
      break;
#endif /* VTYSH */
    case VTY_READ:
      vty->t_read = thread_add_read (master, vty_read, vty, sock);

      /* Time out treatment. */
      if (vty->v_timeout)
	{
	  if (vty->t_timeout)
	    thread_cancel (vty->t_timeout);
	  vty->t_timeout = 
	    thread_add_timer (master, vty_timeout, vty, vty->v_timeout);
	}
      break;
    case VTY_WRITE:
      if (! vty->t_write)
	vty->t_write = thread_add_write (master, vty_flush, vty, sock);
      break;
    case VTY_TIMEOUT_RESET:
      if (vty->t_timeout)
	{
	  thread_cancel (vty->t_timeout);
	  vty->t_timeout = NULL;
	}
      if (vty->v_timeout)
	{
	  vty->t_timeout = 
	    thread_add_timer (master, vty_timeout, vty, vty->v_timeout);
	}
      break;
    }
}

DEFUN (config_who,
       config_who_cmd,
       "who",
       "Display who is on vty\n")
{
  int i;
  struct vty *v;

  for (i = 0; i < vector_max (vtyvec); i++)
    if ((v = vector_slot (vtyvec, i)) != NULL)
      vty_out (vty, "%svty[%d] connected from %s.%s",
	       v->config ? "*" : " ",
	       i, v->address, VTY_NEWLINE);
  return CMD_SUCCESS;
}

/* Move to vty configuration mode. */
DEFUN (line_vty,
       line_vty_cmd,
       "line vty",
       "Configure a terminal line\n"
       "Virtual terminal\n")
{
  vty->node = VTY_NODE;
  return CMD_SUCCESS;
}

/* Set time out value. */
int
exec_timeout (struct vty *vty, char *min_str, char *sec_str)
{
  unsigned long timeout = 0;

  /* min_str and sec_str are already checked by parser.  So it must be
     all digit string. */
  if (min_str)
    {
      timeout = strtol (min_str, NULL, 10);
      timeout *= 60;
    }
  if (sec_str)
    timeout += strtol (sec_str, NULL, 10);

  vty_timeout_val = timeout;
  vty->v_timeout = timeout;
  vty_event (VTY_TIMEOUT_RESET, 0, vty);


  return CMD_SUCCESS;
}

DEFUN (exec_timeout_min,
       exec_timeout_min_cmd,
       "exec-timeout <0-35791>",
       "Set timeout value\n"
       "Timeout value in minutes\n")
{
  return exec_timeout (vty, argv[0], NULL);
}

DEFUN (exec_timeout_sec,
       exec_timeout_sec_cmd,
       "exec-timeout <0-35791> <0-2147483>",
       "Set the EXEC timeout\n"
       "Timeout in minutes\n"
       "Timeout in seconds\n")
{
  return exec_timeout (vty, argv[0], argv[1]);
}

DEFUN (no_exec_timeout,
       no_exec_timeout_cmd,
       "no exec-timeout",
       NO_STR
       "Set the EXEC timeout\n")
{
  return exec_timeout (vty, NULL, NULL);
}

/* Set vty access class. */
DEFUN (vty_access_class,
       vty_access_class_cmd,
       "access-class WORD",
       "Filter connections based on an IP access list\n"
       "IP access list\n")
{
  if (vty_accesslist_name)
    XFREE(MTYPE_VTY, vty_accesslist_name);

  vty_accesslist_name = XSTRDUP(MTYPE_VTY, argv[0]);

  return CMD_SUCCESS;
}

/* Clear vty access class. */
DEFUN (no_vty_access_class,
       no_vty_access_class_cmd,
       "no access-class [WORD]",
       NO_STR
       "Filter connections based on an IP access list\n"
       "IP access list\n")
{
  if (! vty_accesslist_name || (argc && strcmp(vty_accesslist_name, argv[0])))
    {
      vty_out (vty, "Access-class is not currently applied to vty%s",
	       VTY_NEWLINE);
      return CMD_WARNING;
    }

  XFREE(MTYPE_VTY, vty_accesslist_name);

  vty_accesslist_name = NULL;

  return CMD_SUCCESS;
}

#ifdef HAVE_IPV6
/* Set vty access class. */
DEFUN (vty_ipv6_access_class,
       vty_ipv6_access_class_cmd,
       "ipv6 access-class WORD",
       IPV6_STR
       "Filter connections based on an IP access list\n"
       "IPv6 access list\n")
{
  if (vty_ipv6_accesslist_name)
    XFREE(MTYPE_VTY, vty_ipv6_accesslist_name);

  vty_ipv6_accesslist_name = XSTRDUP(MTYPE_VTY, argv[0]);

  return CMD_SUCCESS;
}

/* Clear vty access class. */
DEFUN (no_vty_ipv6_access_class,
       no_vty_ipv6_access_class_cmd,
       "no ipv6 access-class [WORD]",
       NO_STR
       IPV6_STR
       "Filter connections based on an IP access list\n"
       "IPv6 access list\n")
{
  if (! vty_ipv6_accesslist_name ||
      (argc && strcmp(vty_ipv6_accesslist_name, argv[0])))
    {
      vty_out (vty, "IPv6 access-class is not currently applied to vty%s",
	       VTY_NEWLINE);
      return CMD_WARNING;
    }

  XFREE(MTYPE_VTY, vty_ipv6_accesslist_name);

  vty_ipv6_accesslist_name = NULL;

  return CMD_SUCCESS;
}
#endif /* HAVE_IPV6 */

/* vty login. */
DEFUN (vty_login,
       vty_login_cmd,
       "login",
       "Enable password checking\n")
{
  no_password_check = 0;
  return CMD_SUCCESS;
}

DEFUN (no_vty_login,
       no_vty_login_cmd,
       "no login",
       NO_STR
       "Enable password checking\n")
{
  no_password_check = 1;
  return CMD_SUCCESS;
}

DEFUN (service_advanced_vty,
       service_advanced_vty_cmd,
       "service advanced-vty",
       "Set up miscellaneous service\n"
       "Enable advanced mode vty interface\n")
{
  host.advanced = 1;
  return CMD_SUCCESS;
}

DEFUN (no_service_advanced_vty,
       no_service_advanced_vty_cmd,
       "no service advanced-vty",
       NO_STR
       "Set up miscellaneous service\n"
       "Enable advanced mode vty interface\n")
{
  host.advanced = 0;
  return CMD_SUCCESS;
}

DEFUN (terminal_monitor,
       terminal_monitor_cmd,
       "terminal monitor",
       "Set terminal line parameters\n"
       "Copy debug output to the current terminal line\n")
{
  vty->monitor = 1;
  return CMD_SUCCESS;
}

DEFUN (terminal_no_monitor,
       terminal_no_monitor_cmd,
       "terminal no monitor",
       "Set terminal line parameters\n"
       NO_STR
       "Copy debug output to the current terminal line\n")
{
  vty->monitor = 0;
  return CMD_SUCCESS;
}

DEFUN (show_history,
       show_history_cmd,
       "show history",
       SHOW_STR
       "Display the session command history\n")
{
  int index;

  for (index = vty->hindex + 1; index != vty->hindex;)
    {
      if (index == VTY_MAXHIST)
	{
	  index = 0;
	  continue;
	}

      if (vty->hist[index] != NULL)
	vty_out (vty, "  %s%s", vty->hist[index], VTY_NEWLINE);

      index++;
    }

  return CMD_SUCCESS;
}

/* Display current configuration. */
int
vty_config_write (struct vty *vty)
{
  vty_out (vty, "line vty%s", VTY_NEWLINE);

  if (vty_accesslist_name)
    vty_out (vty, " access-class %s%s",
	     vty_accesslist_name, VTY_NEWLINE);

  if (vty_ipv6_accesslist_name)
    vty_out (vty, " ipv6 access-class %s%s",
	     vty_ipv6_accesslist_name, VTY_NEWLINE);

  /* exec-timeout */
  if (vty_timeout_val != VTY_TIMEOUT_DEFAULT)
    vty_out (vty, " exec-timeout %ld %ld%s", 
	     vty_timeout_val / 60,
	     vty_timeout_val % 60, VTY_NEWLINE);

  /* login */
  if (no_password_check)
    vty_out (vty, " no login%s", VTY_NEWLINE);

  vty_out (vty, "!%s", VTY_NEWLINE);

  return CMD_SUCCESS;
}

struct cmd_node vty_node =
{
  VTY_NODE,
  "%s(config-line)# ",
};

/* Reset all VTY status. */
void
vty_reset ()
{
  int i;
  struct vty *vty;
  struct thread *vty_serv_thread;

  for (i = 0; i < vector_max (vtyvec); i++)
    if ((vty = vector_slot (vtyvec, i)) != NULL)
      {
	buffer_reset (vty->obuf);
	vty->status = VTY_CLOSE;
	vty_close (vty);
      }

  for (i = 0; i < vector_max (Vvty_serv_thread); i++)
    if ((vty_serv_thread = vector_slot (Vvty_serv_thread, i)) != NULL)
      {
	thread_cancel (vty_serv_thread);
	vector_slot (Vvty_serv_thread, i) = NULL;
        close (i);
      }

  vty_timeout_val = VTY_TIMEOUT_DEFAULT;

  if (vty_accesslist_name)
    {
      XFREE(MTYPE_VTY, vty_accesslist_name);
      vty_accesslist_name = NULL;
    }

  if (vty_ipv6_accesslist_name)
    {
      XFREE(MTYPE_VTY, vty_ipv6_accesslist_name);
      vty_ipv6_accesslist_name = NULL;
    }
}

/* for ospf6d easy temprary reload function */
/* vty_reset + close accept socket */
void
vty_finish ()
{
  int i;
  struct vty *vty;
  struct thread *vty_serv_thread;

  for (i = 0; i < vector_max (vtyvec); i++)
    if ((vty = vector_slot (vtyvec, i)) != NULL)
      {
	buffer_reset (vty->obuf);
	vty->status = VTY_CLOSE;
	vty_close (vty);
      }

  for (i = 0; i < vector_max (Vvty_serv_thread); i++)
    if ((vty_serv_thread = vector_slot (Vvty_serv_thread, i)) != NULL)
      {
	thread_cancel (vty_serv_thread);
	vector_slot (Vvty_serv_thread, i) = NULL;
        close (i);
      }

  vty_timeout_val = VTY_TIMEOUT_DEFAULT;

  if (vty_accesslist_name)
    {
      XFREE(MTYPE_VTY, vty_accesslist_name);
      vty_accesslist_name = NULL;
    }

  if (vty_ipv6_accesslist_name)
    {
      XFREE(MTYPE_VTY, vty_ipv6_accesslist_name);
      vty_ipv6_accesslist_name = NULL;
    }
}

void
vty_save_cwd ()
{
  char cwd[MAXPATHLEN];
  char *c;

  c = getcwd (cwd, MAXPATHLEN);

  if (!c)
    {
      chdir (SYSCONFDIR);
      getcwd (cwd, MAXPATHLEN);
    }

  vty_cwd = XMALLOC (MTYPE_TMP, strlen (cwd) + 1);
  strcpy (vty_cwd, cwd);
}

char *
vty_get_cwd ()
{
  return vty_cwd;
}

int
vty_shell (struct vty *vty)
{
  return vty->type == VTY_SHELL ? 1 : 0;
}

int
vty_shell_serv (struct vty *vty)
{
  return vty->type == VTY_SHELL_SERV ? 1 : 0;
}

void
vty_init_vtysh ()
{
  vtyvec = vector_init (VECTOR_MIN_SIZE);
}

/* Install vty's own commands like `who' command. */
void
vty_init (struct thread_master *master_thread)
{
  /* For further configuration read, preserve current directory. */
  vty_save_cwd ();

  vtyvec = vector_init (VECTOR_MIN_SIZE);

  master = master_thread;

  /* Initilize server thread vector. */
  Vvty_serv_thread = vector_init (VECTOR_MIN_SIZE);

  /* Install bgp top node. */
  install_node (&vty_node, vty_config_write);

  install_element (VIEW_NODE, &config_who_cmd);
  install_element (VIEW_NODE, &show_history_cmd);
  install_element (ENABLE_NODE, &config_who_cmd);
  install_element (CONFIG_NODE, &line_vty_cmd);
  install_element (CONFIG_NODE, &service_advanced_vty_cmd);
  install_element (CONFIG_NODE, &no_service_advanced_vty_cmd);
  install_element (CONFIG_NODE, &show_history_cmd);
  install_element (ENABLE_NODE, &terminal_monitor_cmd);
  install_element (ENABLE_NODE, &terminal_no_monitor_cmd);
  install_element (ENABLE_NODE, &show_history_cmd);

  install_default (VTY_NODE);
  install_element (VTY_NODE, &exec_timeout_min_cmd);
  install_element (VTY_NODE, &exec_timeout_sec_cmd);
  install_element (VTY_NODE, &no_exec_timeout_cmd);
  install_element (VTY_NODE, &vty_access_class_cmd);
  install_element (VTY_NODE, &no_vty_access_class_cmd);
  install_element (VTY_NODE, &vty_login_cmd);
  install_element (VTY_NODE, &no_vty_login_cmd);
#ifdef HAVE_IPV6
  install_element (VTY_NODE, &vty_ipv6_access_class_cmd);
  install_element (VTY_NODE, &no_vty_ipv6_access_class_cmd);
#endif /* HAVE_IPV6 */
}