/*--------------------------------*-C-*---------------------------------*
 * File:	netdisp.c
 */
/*{{{ notes: */
/*----------------------------------------------------------------------*
 * 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.
 *
 * Copyright 1996	Chuck Blake <cblake@BBN.COM>
 *
 * You can do what you like with this source code as long as you don't try
 * to make money out of it and you include an unaltered copy of this
 * message (including the copyright).
 *
 * As usual, the author accepts no responsibility for anything, nor does
 * he guarantee anything whatsoever.
 *----------------------------------------------------------------------*/
/*}}} */
#include "config.h"
#include "feature.h"

/* compile an empty file if this option is disabled. */
#ifndef DISPLAY_IS_IP
/* char * network_display (const char * display) { return display; } */
#endif
#ifdef DISPLAY_IS_IP
/*{{{ includes */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

/* On Solaris link with -lsocket and -lnsl */
#include <sys/types.h>
#include <sys/socket.h>

/* these next two are probably only on Sun (not Solaris) */
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#ifdef HAVE_SYS_BYTEORDER_H
#include <sys/byteorder.h>
#endif

#ifdef TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_arp.h>
/*}}} */
/* extern functions referenced */
/* extern variables referenced */
/* extern variables declared here */
/* local variables */
/* local functions referenced */

/*----------------------------------------------------------------------*/
/* return a pointer to a static buffer */
char *
network_display (const char *display)
{
  static char ipaddress[32] = "";
  char buffer[1024], *rval = NULL;
  struct ifconf ifc;
  struct ifreq *ifr;
  int i, skfd;

  if (display[0] != ':' && strncmp (display, "unix:", 5))
    return 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";

	      sprintf (ipaddress, "%d.%d.%d.%d%s",
		       (int) ((addr >> 030) & 0xFF),
		       (int) ((addr >> 020) & 0xFF),
		       (int) ((addr >> 010) & 0xFF),
		       (int) (addr & 0xFF), colon);

	      rval = ipaddress;
	      break;
	    }
	}
    }

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