lib/lwres/gethost.c

	gethost.c revision 499b34cea04a46823d003d4c0520c8b03e8513cb
/*
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: gethost.c,v 1.26 2001/01/09 21:59:17 bwelling Exp $ */

#include <config.h>

#include <sys/types.h>
#include <sys/socket.h>

#include <errno.h>
#include <string.h>

#include <lwres/netdb.h>

#include "assert_p.h"

#define LWRES_ALIGNBYTES (sizeof(char *) - 1)
#define LWRES_ALIGN(p) \
    (((unsigned long)(p) + LWRES_ALIGNBYTES) &~ LWRES_ALIGNBYTES)

static struct hostent *he = NULL;
static int copytobuf(struct hostent *, struct hostent *, char *, int);

struct hostent *
lwres_gethostbyname(const char *name) {

    if (he != NULL)
        lwres_freehostent(he);

    he = lwres_getipnodebyname(name, AF_INET, 0, &lwres_h_errno);
    return (he);
}

struct hostent *
lwres_gethostbyname2(const char *name, int af) {
    if (he != NULL)
        lwres_freehostent(he);

    he = lwres_getipnodebyname(name, af, 0, &lwres_h_errno);
    return (he);
}

struct hostent *
lwres_gethostbyaddr(const char *addr, int len, int type) {

    if (he != NULL)
        lwres_freehostent(he);

    he = lwres_getipnodebyaddr(addr, len, type, &lwres_h_errno);
    return (he);
}

struct hostent *
lwres_gethostent(void) {
    if (he != NULL)
        lwres_freehostent(he);

    return (NULL);
}

void
lwres_sethostent(int stayopen) {
    /*
     * Empty.
     */
    UNUSED(stayopen);
}

void
lwres_endhostent(void) {
    /*
     * Empty.
     */
}

struct hostent *
lwres_gethostbyname_r(const char *name, struct hostent *resbuf,
        char *buf, int buflen, int *error)
{
    struct hostent *he;
    int res;

    he = lwres_getipnodebyname(name, AF_INET, 0, error);
    if (he == NULL)
        return (NULL);
    res = copytobuf(he, resbuf, buf, buflen);
    lwres_freehostent(he);
    if (res != 0) {
        errno = ERANGE;
        return (NULL);
    }
    return (resbuf);
}

struct hostent  *
lwres_gethostbyaddr_r(const char *addr, int len, int type,
              struct hostent *resbuf, char *buf, int buflen,
              int *error)
{
    struct hostent *he;
    int res;

    he = lwres_getipnodebyaddr(addr, len, type, error);
    if (he == NULL)
        return (NULL);
    res = copytobuf(he, resbuf, buf, buflen);
    lwres_freehostent(he);
    if (res != 0) {
        errno = ERANGE;
        return (NULL);
    }
    return (resbuf);
}

struct hostent  *
lwres_gethostent_r(struct hostent *resbuf, char *buf, int buflen, int *error) {
    UNUSED(resbuf);
    UNUSED(buf);
    UNUSED(buflen);
    *error = 0;
    return (NULL);
}

void
lwres_sethostent_r(int stayopen) {
    /*
     * Empty.
     */
    UNUSED(stayopen);
}

void
lwres_endhostent_r(void) {
    /*
     * Empty.
     */
}

static int
copytobuf(struct hostent *he, struct hostent *hptr, char *buf, int buflen) {
        char *cp;
        char **ptr;
        int i, n;
        int nptr, len;

        /*
     * Find out the amount of space required to store the answer.
     */
        nptr = 2; /* NULL ptrs */
        len = (char *)LWRES_ALIGN(buf) - buf;
        for (i = 0; he->h_addr_list[i]; i++, nptr++) {
                len += he->h_length;
        }
        for (i = 0; he->h_aliases[i]; i++, nptr++) {
                len += strlen(he->h_aliases[i]) + 1;
        }
        len += strlen(he->h_name) + 1;
        len += nptr * sizeof(char*);

        if (len > buflen) {
                return (-1);
        }

        /*
     * Copy address size and type.
     */
        hptr->h_addrtype = he->h_addrtype;
        n = hptr->h_length = he->h_length;

        ptr = (char **)LWRES_ALIGN(buf);
        cp = (char *)LWRES_ALIGN(buf) + nptr * sizeof(char *);

        /*
     * Copy address list.
     */
        hptr->h_addr_list = ptr;
        for (i = 0; he->h_addr_list[i]; i++, ptr++) {
                memcpy(cp, he->h_addr_list[i], n);
                hptr->h_addr_list[i] = cp;
                cp += n;
        }
        hptr->h_addr_list[i] = NULL;
        ptr++;

        /*
     * Copy official name.
     */
        n = strlen(he->h_name) + 1;
        strcpy(cp, he->h_name);
        hptr->h_name = cp;
        cp += n;

        /*
     * Copy aliases.
     */
        hptr->h_aliases = ptr;
        for (i = 0; he->h_aliases[i]; i++) {
                n = strlen(he->h_aliases[i]) + 1;
                strcpy(cp, he->h_aliases[i]);
                hptr->h_aliases[i] = cp;
                cp += n;
        }
        hptr->h_aliases[i] = NULL;

        return (0);
}