interface.c

Serveez是一个服务器框架

  /* this is for WinNT... */
  else if (Method == IPAPI_METHOD)
    {
      /* Use of the IPHelper-API here. */
      GetIfTable = (GetIfTableProc) 
	GetProcAddress (WSockHandle, "GetIfTable");
      if (!GetIfTable)
	{
	  printf ("GetProcAddress (GetIfTable): %s\n", SYS_ERROR);
	  FreeLibrary (WSockHandle);
	  return;
	}

      GetIpAddrTable = (GetIpAddrTableProc) 
	GetProcAddress (WSockHandle, "GetIpAddrTable");
      if (!GetIpAddrTable)
	{
	  printf ("GetProcAddress (GetIpAddrTable): %s\n", SYS_ERROR);
	  FreeLibrary (WSockHandle);
	  return;
	}

      ifTableSize = sizeof (MIB_IFTABLE);
      ifTable = (PMIB_IFTABLE) svz_malloc (ifTableSize);
      GetIfTable (ifTable, &ifTableSize, FALSE);
      ifTable = (PMIB_IFTABLE) svz_realloc (ifTable, ifTableSize);
      if (GetIfTable (ifTable, &ifTableSize, FALSE) != NO_ERROR)
	{
	  printf ("GetIfTable: %s\n", SYS_ERROR);
	  FreeLibrary (WSockHandle);
	  svz_free (ifTable);
	  return;
	}
  
      ipTableSize = sizeof (MIB_IPADDRTABLE);
      ipTable = (PMIB_IPADDRTABLE) svz_malloc (ipTableSize);
      GetIpAddrTable (ipTable, &ipTableSize, FALSE);
      ipTable = (PMIB_IPADDRTABLE) svz_realloc (ipTable, ipTableSize);
      if (GetIpAddrTable (ipTable, &ipTableSize, FALSE) != NO_ERROR)
	{
	  printf ("GetIpAddrTable: %s\n", SYS_ERROR);
	  FreeLibrary (WSockHandle);
	  svz_free (ipTable);
	  svz_free (ifTable);
	  return;
	}
      
      for (n = 0; n < ipTable->dwNumEntries; n++)
	{
	  for (i = 0; i < ifTable->dwNumEntries; i++)
	    {
	      if (ifTable->table[i].dwIndex == ipTable->table[n].dwIndex)
		{
		  ifTable->table[i].bDescr[ifTable->table[i].dwDescrLen] = 0;
		  svz_interface_add (ipTable->table[n].dwIndex, 
				     (char *) ifTable->table[i].bDescr,
				     ipTable->table[n].dwAddr);
		  break;
		}
	    }
	  if (i == ifTable->dwNumEntries)
	    {
	      svz_interface_add (ipTable->table[n].dwIndex, NULL,
				 ipTable->table[n].dwAddr);
	    }
	}

      svz_free (ipTable);
      svz_free (ifTable);
      FreeLibrary (WSockHandle);
    }
  else
    {
      printf ("Neither IPHlpApi.dll nor WSock32.WsControl found...\n");
    }
}

#else /* not __MINGW32__ */

/*
 * Collect all available network interfaces and put them into the list
 * @var{svz_interfaces}. This is useful in order to @code{bind()} server
 * sockets to specific network interfaces. Thus you can make certain 
 * services accessible from "outside" or "inside" a network installation
 * only.
 */
void
svz_interface_collect (void)
{
  int numreqs = 16;
  struct ifconf ifc;
  struct ifreq *ifr;
  struct ifreq ifr2;
  int n;
  int fd;

  /* Get a socket out of the Internet Address Family. */
  if ((fd = socket (AF_INET, SOCK_STREAM, 0)) < 0) 
    {
      perror ("socket");
      return;
    }

  /* Collect information. */
  ifc.ifc_buf = NULL;
  for (;;) 
    {
      ifc.ifc_len = sizeof (struct ifreq) * numreqs;
      ifc.ifc_buf = svz_realloc (ifc.ifc_buf, ifc.ifc_len);

      /*
       * On newer AIXes we cannot use SIOCGICONF anymore, although it is
       * present. The data structure returned is bogus. Using OSIOCGIFCONF.
       */
#if defined (OSIOCGIFCONF)
      if (ioctl (fd, OSIOCGIFCONF, &ifc) < 0)
	{
	  perror ("OSIOCGIFCONF");
	  close (fd);
	  svz_free (ifc.ifc_buf);
	  return;	  
	}
#else /* OSIOCGIFCONF */
      if (ioctl (fd, SIOCGIFCONF, &ifc) < 0) 
	{
	  perror ("SIOCGIFCONF");
	  close (fd);
	  svz_free (ifc.ifc_buf);
	  return;
	}
#endif /* OSIOCGIFCONF */

      if ((unsigned) ifc.ifc_len == sizeof (struct ifreq) * numreqs) 
	{
	  /* Assume it overflowed and try again. */
	  numreqs += 10;
	  continue;
	}
      break;
    }

  ifr = ifc.ifc_req;
  for (n = 0; n < ifc.ifc_len; n += sizeof (struct ifreq), ifr++)
    {
      /*
       * On AIX (and perhaps others) you get interfaces that are not AF_INET
       * from the first `ioctl ()', so filter here again.
       */
#if defined (__FreeBSD__)
      if ((ifr->ifr_phys & 0xFFFF0000) == 0)
#elif defined (__NetBSD__)
      if (((long) ifr->ifr_data & 0xFFFF0000) != 0)
#else
      if (ifr->ifr_addr.sa_family != AF_INET)
#endif
	continue;

      strcpy (ifr2.ifr_name, ifr->ifr_name);
      ifr2.ifr_addr.sa_family = AF_INET;
      if (ioctl (fd, SIOCGIFADDR, &ifr2) == 0)
	{
	  static int index = 0;

	  /* 
	   * The following cast looks bogus. ifr2.ifr_addr is a
	   * (struct sockaddr), but we know that we deal with a 
	   * (struct sockaddr_in) here. Since you cannot cast structures
	   * in C, I cast addresses just to get a (struct sockaddr_in) in 
	   * the end ...
	   */
#ifdef ifr_ifindex
	  index = ifr->ifr_ifindex;
#else
	  index++;
#endif
	  svz_interface_add (index, ifr->ifr_name, 
			     (*(struct sockaddr_in *) 
			      (void *) &ifr2.ifr_addr).sin_addr.s_addr);
	}
    }
  
  close (fd);
  svz_free (ifc.ifc_buf);
}

#endif /* not __MINGW32__ */

#else /* not ENABLE_IFLIST */

void
svz_interface_collect (void)
{
  printf ("\n"
	  "Sorry, the list of local interfaces is not available. If you\n"
	  "know how to get such a list on your OS, please contact\n"
	  "Raimund Jacob <[e-mail]>. Thanks.\n\n");
}

#endif /* not ENABLE_IFLIST */

/*
 * Print the text representation of all the network interfaces.
 */
void
svz_interface_list (void)
{
  unsigned long n;
  svz_interface_t *ifc;

  printf ("--- list of local interfaces you can start ip services on ---\n");

  /* any interfaces at all ? */
  if (!svz_interfaces)
    return;

  for (n = 0; n < svz_vector_length (svz_interfaces); n++)
    {
      ifc = svz_vector_get (svz_interfaces, n);

      /* interface with description */
      if (ifc->description)
	{
	  printf ("%40s: %s\n", ifc->description, 
		  svz_inet_ntoa (ifc->ipaddr));
	}
      else
	{
	  /* interface with interface # only */
	  printf ("%31s%09lu: %s\n", "interface # ",
		  ifc->index, svz_inet_ntoa (ifc->ipaddr));
	}
    }
}

/*
 * Add a network interface to the current list of known interfaces. Drop
 * duplicate entries.
 */
int
svz_interface_add (int index, char *desc, unsigned long addr)
{
  char *p;
  unsigned long n;
  svz_interface_t *ifc;

  /* Check if there is such an interface already. */
  if (svz_interfaces == NULL)
    {
      svz_interfaces = svz_vector_create (sizeof (svz_interface_t));
    }
  else
    {
      for (n = 0; n < svz_vector_length (svz_interfaces); n++)
	{
	  ifc = svz_vector_get (svz_interfaces, n);
	  if (ifc->ipaddr == addr)
	    return -1;
	}
    }

  /* Actually add this interface. */
  ifc = svz_malloc (sizeof (svz_interface_t));
  ifc->index = index;
  ifc->ipaddr = addr;
  ifc->description = svz_strdup (desc);

  /* Delete trailing white space characters. */
  p = ifc->description + strlen (ifc->description) - 1;
  while (p > ifc->description && 
	 (*p == '\n' || *p == '\r' || *p == '\t' || *p == ' '))
    *p-- = '\0';

  svz_vector_add (svz_interfaces, ifc);
  svz_free (ifc);
  return 0;
}

/*
 * This function returns the interface structure for the given IP address
 * @var{addr} if any. Returns @code{NULL} otherwise.
 */
svz_interface_t *
svz_interface_get (unsigned long addr)
{
  svz_interface_t *ifc;
  int n;

  svz_vector_foreach (svz_interfaces, ifc, n)
    {
      if (ifc->ipaddr == addr)
	return ifc;
    }
  return NULL;
}

/*
 * The following function returns a network interface structure for a given
 * interface name (e.g. eth0). If no such interface exists it returns 
 * @code{NULL}.
 */
svz_interface_t *
svz_interface_search (char *desc)
{
  svz_interface_t *ifc;
  int n;

  svz_vector_foreach (svz_interfaces, ifc, n)
    if (!strcmp (ifc->description, desc))
      return ifc;
  return NULL;
}

/*
 * Free the network interface list.
 */
int
svz_interface_free (void)
{
  unsigned long n;
  svz_interface_t *ifc;

  if (svz_interfaces)
    {
      svz_vector_foreach (svz_interfaces, ifc, n)
	{
	  ifc = svz_vector_get (svz_interfaces, n);
	  if (ifc->description)
	    svz_free (ifc->description);
	}
      svz_vector_destroy (svz_interfaces);
      svz_interfaces = NULL;
      return 0;
    }
  return -1;
}