glibc/nscd/nscd_gethst_r.c

297 lines
7.7 KiB
C

/* Copyright (C) 1998-2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/nameser.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include "nscd-client.h"
#include "nscd_proto.h"
int __nss_not_use_nscd_hosts;
static int nscd_gethst_r (const char *key, size_t keylen, request_type type,
struct hostent *resultbuf, char *buffer,
size_t buflen, int *h_errnop) internal_function;
int
__nscd_gethostbyname_r (const char *name, struct hostent *resultbuf,
char *buffer, size_t buflen, int *h_errnop)
{
request_type reqtype;
reqtype = (_res.options & RES_USE_INET6) ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
buffer, buflen, h_errnop);
}
int
__nscd_gethostbyname2_r (const char *name, int af, struct hostent *resultbuf,
char *buffer, size_t buflen, int *h_errnop)
{
request_type reqtype;
reqtype = af == AF_INET6 ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
buffer, buflen, h_errnop);
}
int
__nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type,
struct hostent *resultbuf, char *buffer, size_t buflen,
int *h_errnop)
{
request_type reqtype;
if (!((len == INADDRSZ && type == AF_INET)
|| (len == IN6ADDRSZ && type == AF_INET6)))
/* LEN and TYPE do not match. */
return -1;
reqtype = type == AF_INET6 ? GETHOSTBYADDRv6 : GETHOSTBYADDR;
return nscd_gethst_r (addr, len, reqtype, resultbuf, buffer, buflen,
h_errnop);
}
/* Create a socket connected to a name. */
int
__nscd_open_socket (void)
{
struct sockaddr_un addr;
int sock;
int saved_errno = errno;
sock = __socket (PF_UNIX, SOCK_STREAM, 0);
if (sock < 0)
{
__set_errno (saved_errno);
return -1;
}
addr.sun_family = AF_UNIX;
strcpy (addr.sun_path, _PATH_NSCDSOCKET);
if (__connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
{
__close (sock);
__set_errno (saved_errno);
return -1;
}
return sock;
}
static int
internal_function
nscd_gethst_r (const char *key, size_t keylen, request_type type,
struct hostent *resultbuf, char *buffer, size_t buflen,
int *h_errnop)
{
int sock = __nscd_open_socket ();
hst_response_header hst_resp;
request_header req;
ssize_t nbytes;
struct iovec vec[4];
int result = -1;
if (sock == -1)
{
__nss_not_use_nscd_group = 1;
return -1;
}
req.version = NSCD_VERSION;
req.type = type;
req.key_len = keylen;
vec[0].iov_base = &req;
vec[0].iov_len = sizeof (request_header);
vec[1].iov_base = (void *) key;
vec[1].iov_len = req.key_len;
nbytes = TEMP_FAILURE_RETRY (__writev (sock, vec, 2));
if ((size_t) nbytes != sizeof (request_header) + req.key_len)
goto out;
nbytes = TEMP_FAILURE_RETRY (__read (sock, &hst_resp,
sizeof (hst_response_header)));
if (__builtin_expect (nbytes != sizeof (hst_response_header), 0))
goto out;
if (hst_resp.found == -1)
{
/* The daemon does not cache this database. */
__nss_not_use_nscd_hosts = 1;
goto out;
}
if (hst_resp.found == 1)
{
uint32_t *aliases_len;
char *cp = buffer;
uintptr_t align1;
uintptr_t align2;
size_t total_len;
ssize_t cnt;
char *ignore;
int n;
/* A first check whether the buffer is sufficiently large is possible. */
/* Now allocate the buffer the array for the group members. We must
align the pointer and the base of the h_addr_list pointers. */
align1 = ((__alignof__ (char *) - (cp - ((char *) 0)))
& (__alignof__ (char *) - 1));
align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp.h_name_len)
- ((char *) 0)))
& (__alignof__ (char *) - 1));
if (buflen < (align1 + hst_resp.h_name_len + align2
+ ((hst_resp.h_aliases_cnt + hst_resp.h_addr_list_cnt + 2)
* sizeof (char *))
+ hst_resp.h_addr_list_cnt * (type == AF_INET
? INADDRSZ : IN6ADDRSZ)))
{
no_room:
__set_errno (ERANGE);
result = ERANGE;
goto out;
}
cp += align1;
/* Prepare the result as far as we can. */
resultbuf->h_aliases = (char **) cp;
cp += (hst_resp.h_aliases_cnt + 1) * sizeof (char *);
resultbuf->h_addr_list = (char **) cp;
cp += (hst_resp.h_addr_list_cnt + 1) * sizeof (char *);
resultbuf->h_name = cp;
cp += hst_resp.h_name_len + align2;
vec[0].iov_base = resultbuf->h_name;
vec[0].iov_len = hst_resp.h_name_len;
aliases_len = alloca (hst_resp.h_aliases_cnt * sizeof (uint32_t));
vec[1].iov_base = aliases_len;
vec[1].iov_len = hst_resp.h_aliases_cnt * sizeof (uint32_t);
total_len = (hst_resp.h_name_len
+ hst_resp.h_aliases_cnt * sizeof (uint32_t));
n = 2;
if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
{
vec[2].iov_base = cp;
vec[2].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;
for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt)
{
resultbuf->h_addr_list[cnt] = cp;
cp += INADDRSZ;
}
resultbuf->h_addrtype = AF_INET;
resultbuf->h_length = INADDRSZ;
total_len += hst_resp.h_addr_list_cnt * INADDRSZ;
n = 3;
}
else
{
if (hst_resp.h_length == INADDRSZ)
{
ignore = alloca (hst_resp.h_addr_list_cnt * INADDRSZ);
vec[2].iov_base = ignore;
vec[2].iov_len = hst_resp.h_addr_list_cnt * INADDRSZ;
total_len += hst_resp.h_addr_list_cnt * INADDRSZ;
n = 3;
}
vec[n].iov_base = cp;
vec[n].iov_len = hst_resp.h_addr_list_cnt * IN6ADDRSZ;
for (cnt = 0; cnt < hst_resp.h_addr_list_cnt; ++cnt)
{
resultbuf->h_addr_list[cnt] = cp;
cp += IN6ADDRSZ;
}
resultbuf->h_addrtype = AF_INET6;
resultbuf->h_length = IN6ADDRSZ;
total_len += hst_resp.h_addr_list_cnt * IN6ADDRSZ;
++n;
}
resultbuf->h_addr_list[cnt] = NULL;
if ((size_t) TEMP_FAILURE_RETRY (__readv (sock, vec, n)) != total_len)
goto out;
/* Now we also can read the aliases. */
total_len = 0;
for (cnt = 0; cnt < hst_resp.h_aliases_cnt; ++cnt)
{
resultbuf->h_aliases[cnt] = cp;
cp += aliases_len[cnt];
total_len += aliases_len[cnt];
}
resultbuf->h_aliases[cnt] = NULL;
/* See whether this would exceed the buffer capacity. */
if (cp > buffer + buflen)
goto no_room;
/* And finally read the aliases. */
if ((size_t) TEMP_FAILURE_RETRY (__read (sock, resultbuf->h_aliases[0],
total_len)) == total_len)
result = 0;
}
else
{
/* Store the error number. */
*h_errnop = hst_resp.error;
/* The `errno' to some value != ERANGE. */
__set_errno (ENOENT);
result = ENOENT;
}
out:
__close (sock);
return result;
}