getipnodebyaddr.c

来自「samba最新软件」· C语言 代码 · 共 75 行

/*
 * Copyright (c) 1999 Kungliga Tekniska H鰃skolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
RCSID("$Id: getipnodebyaddr.c 14773 2005-04-12 11:29:18Z lha $");
#endif

#include <roken.h>

/*
 * lookup `src, len' (address family `af') in DNS and return a pointer
 * to a malloced struct hostent or NULL.
 */

struct hostent * ROKEN_LIB_FUNCTION
getipnodebyaddr (const void *src, size_t len, int af, int *error_num)
{
    struct hostent *tmp;

    tmp = gethostbyaddr (src, len, af);
    if (tmp == NULL) {
	switch (h_errno) {
	case HOST_NOT_FOUND :
	case TRY_AGAIN :
	case NO_RECOVERY :
	    *error_num = h_errno;
	    break;
	case NO_DATA :
	    *error_num = NO_ADDRESS;
	    break;
	default :
	    *error_num = NO_RECOVERY;
	    break;
	}
	return NULL;
    }
    tmp = copyhostent (tmp);
    if (tmp == NULL) {
	*error_num = TRY_AGAIN;
	return NULL;
    }
    return tmp;
}