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/* $OpenBSD: gethostnamadr.c,v 1.11 2014/03/26 18:13:15 eric Exp $ */
/*
* Copyright (c) 2012,2013 Eric Faurot <eric@openbsd.org>
*
* 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <asr.h>
#include <errno.h>
#include <resolv.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
static int _gethostbyname(const char *, int, struct hostent *, char *, size_t,
int *);
static int _fillhostent(const struct hostent *, struct hostent *, char *,
size_t);
static struct hostent _hostent;
static char _entbuf[4096];
static char *_empty[] = { NULL, };
static int
_fillhostent(const struct hostent *h, struct hostent *r, char *buf, size_t len)
{
char **ptr, *end, *pos;
size_t n, i;
int naliases, naddrs;
bzero(buf, len);
bzero(r, sizeof(*r));
r->h_aliases = _empty;
r->h_addr_list = _empty;
end = buf + len;
ptr = (char **)ALIGN(buf);
if ((char *)ptr >= end)
return (ERANGE);
for (naliases = 0; h->h_aliases[naliases]; naliases++)
;
for (naddrs = 0; h->h_addr_list[naddrs]; naddrs++)
;
pos = (char *)(ptr + (naliases + 1) + (naddrs + 1));
if (pos >= end)
return (ERANGE);
r->h_name = NULL;
r->h_addrtype = h->h_addrtype;
r->h_length = h->h_length;
r->h_aliases = ptr;
r->h_addr_list = ptr + naliases + 1;
n = strlcpy(pos, h->h_name, end - pos);
if (n >= end - pos)
return (ERANGE);
r->h_name = pos;
pos += n + 1;
for (i = 0; i < naliases; i++) {
n = strlcpy(pos, h->h_aliases[i], end - pos);
if (n >= end - pos)
return (ERANGE);
r->h_aliases[i] = pos;
pos += n + 1;
}
pos = (char *)ALIGN(pos);
if (pos >= end)
return (ERANGE);
for (i = 0; i < naddrs; i++) {
if (r->h_length > end - pos)
return (ERANGE);
memmove(pos, h->h_addr_list[i], r->h_length);
r->h_addr_list[i] = pos;
pos += r->h_length;
}
return (0);
}
static int
_gethostbyname(const char *name, int af, struct hostent *ret, char *buf,
size_t buflen, int *h_errnop)
{
struct asr_query *as;
struct asr_result ar;
int r;
if (af == -1)
as = gethostbyname_async(name, NULL);
else
as = gethostbyname2_async(name, af, NULL);
if (as == NULL)
return (errno);
asr_run_sync(as, &ar);
errno = ar.ar_errno;
*h_errnop = ar.ar_h_errno;
if (ar.ar_hostent == NULL)
return (0);
r = _fillhostent(ar.ar_hostent, ret, buf, buflen);
free(ar.ar_hostent);
return (r);
}
struct hostent *
gethostbyname(const char *name)
{
struct hostent *h;
res_init();
if (_res.options & RES_USE_INET6 &&
(h = gethostbyname2(name, AF_INET6)))
return (h);
return gethostbyname2(name, AF_INET);
}
struct hostent *
gethostbyname2(const char *name, int af)
{
int r;
res_init();
r = _gethostbyname(name, af, &_hostent, _entbuf, sizeof(_entbuf),
&h_errno);
if (r) {
h_errno = NETDB_INTERNAL;
errno = r;
}
if (h_errno)
return (NULL);
return (&_hostent);
}
struct hostent *
gethostbyaddr(const void *addr, socklen_t len, int af)
{
struct asr_query *as;
struct asr_result ar;
int r;
res_init();
as = gethostbyaddr_async(addr, len, af, NULL);
if (as == NULL) {
h_errno = NETDB_INTERNAL;
return (NULL);
}
asr_run_sync(as, &ar);
errno = ar.ar_errno;
h_errno = ar.ar_h_errno;
if (ar.ar_hostent == NULL)
return (NULL);
r = _fillhostent(ar.ar_hostent, &_hostent, _entbuf, sizeof(_entbuf));
free(ar.ar_hostent);
if (r) {
h_errno = NETDB_INTERNAL;
errno = r;
return (NULL);
}
return (&_hostent);
}
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