resolv/hostent.h

/*	$NetBSD: hostent.h,v 1.2 2013/08/27 09:56:12 christos Exp $	*/

/*-
 * Copyright (c) 2013 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */
#ifndef NETD_RESOLV_HOSTENT_H
#define NETD_RESOLV_HOSTENT_H

#include <netdb.h>
#include <stdio.h>

struct getnamaddr {
    struct hostent* hp;
    char* buf;
    size_t buflen;
};

// /etc/hosts lookup
int _hf_gethtbyaddr(const unsigned char* uaddr, int len, int af, getnamaddr* info);
int _hf_gethtbyname2(const char* name, int af, getnamaddr* info);
hostent* netbsd_gethostent_r(FILE*, struct hostent*, char*, size_t, int*);

// Reserved padding for remapping IPv4 address to NAT64 synthesis IPv6 address
static const char NAT64_PAD[NS_IN6ADDRSZ - NS_INADDRSZ] = {};

#define HENT_ARRAY(dst, anum, ptr, len) do {     \
        size_t _len = (anum + 1) * sizeof(*dst); \
        if (_len > len) goto nospc;              \
        dst = (char**) ptr;                      \
        ptr += _len;                             \
        len -= _len;                             \
    } while (0)

#define HENT_COPY(dst, src, slen, ptr, len) do { \
        if ((size_t) slen > len) goto nospc;     \
        memcpy(ptr, src, (size_t) slen);         \
        dst = ptr;                               \
        ptr += slen;                             \
        len -= slen;                             \
    } while (0)

#define HENT_SCOPY(dst, src, ptr, len) do {  \
        size_t _len = strlen(src) + 1;       \
        HENT_COPY(dst, src, _len, ptr, len); \
    } while (0)

#endif  // NETD_RESOLV_HOSTENT_H