/*--------------------------------*-C-*---------------------------------*
 * File:	netdisp.C
 *----------------------------------------------------------------------*
 *
 * All portions of code are copyright by their respective author/s.
 * Copyright (c) 1996      Chuck Blake <cblake@BBN.COM>
 *				- original version
 * Copyright (c) 1997      mj olesen <olesen@me.queensu.ca>
 * Copyright (c) 1997,1998 Oezguer Kesim <kesim@math.fu-berlin.de>
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *----------------------------------------------------------------------*/
/*----------------------------------------------------------------------*
 * support for resolving the actual IP number of the host for remote
 * DISPLAYs.  When the display is local (i.e. :0), we add support for
 * sending the first non-loopback interface IP number as the DISPLAY
 * instead of just sending the incorrect ":0".  This way telnet/rlogin
 * shells can actually get the correct information into DISPLAY for
 * xclients.
 *----------------------------------------------------------------------*/

#include "../config.h"		/* NECESSARY */
#include "rxvt.h"		/* NECESSARY */

#ifdef DISPLAY_IS_IP
#include "netdisp.h"

/*----------------------------------------------------------------------*/
/* return NULL a pointer to buffer which may be freed */
char           *
rxvt_network_display (const char *display)
{
  char            buffer[1024], *rval = NULL;
  struct ifconf   ifc;
  struct ifreq   *ifr;
  int             i, skfd;

  if (display[0] != ':' && strncmp (display, "unix:", 5))
    return (char *) display;		/* nothing to do */

  ifc.ifc_len = sizeof (buffer);	/* Get names of all ifaces */
  ifc.ifc_buf = buffer;

  if ((skfd = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
    {
      perror ("socket");
      return NULL;
    }
  if (ioctl (skfd, SIOCGIFCONF, &ifc) < 0)
    {
      perror ("SIOCGIFCONF");
      close (skfd);
      return NULL;
    }
  for (i = 0, ifr = ifc.ifc_req;
       i < (ifc.ifc_len / sizeof (struct ifreq));
       i++, ifr++)
    {
      struct ifreq    ifr2;

      strcpy (ifr2.ifr_name, ifr->ifr_name);
      if (ioctl (skfd, SIOCGIFADDR, &ifr2) >= 0)
        {
          unsigned long   addr;
          struct sockaddr_in *p_addr;

          p_addr = (struct sockaddr_in *)& (ifr2.ifr_addr);
          addr = htonl ((unsigned long)p_addr->sin_addr.s_addr);

          /*
           * not "0.0.0.0" or "127.0.0.1" - so format the address
           */
          if (addr && addr != 0x7F000001)
            {
              char           *colon = strchr (display, ':');

              if (colon == NULL)
                colon = ":0.0";

              rval = rxvt_malloc (strlen (colon) + 16);
              sprintf (rval, "%d.%d.%d.%d%s",
                      (int) ((addr >> 030) & 0xFF),
                      (int) ((addr >> 020) & 0xFF),
                      (int) ((addr >> 010) & 0xFF),
                      (int) (addr & 0xFF), colon);
              break;
            }
        }
    }

  close (skfd);
  return rval;
}
#endif				/* DISPLAY_IS_IP */
/*----------------------- end-of-file (C source) -----------------------*/