/* Copyright (C) 1997-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@suse.de>, 1997.
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, see
<http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <atomic.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <nss.h>
#include <string.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <rpcsvc/nis.h>
#include <libc-lock.h>
#include "nss-nisplus.h"
__libc_lock_define_initialized (static, lock)
static nis_result *result;
static nis_name tablename_val;
static u_long tablename_len;
#define NISENTRYVAL(idx, col, res) \
(NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
#define NISENTRYLEN(idx, col, res) \
(NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
/* Get implementation for some internal functions. */
#include <resolv/resolv-internal.h>
#include <resolv/mapv4v6addr.h>
static int
_nss_nisplus_parse_hostent (nis_result *result, int af, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int flags)
{
unsigned int i;
char *first_unused = buffer;
size_t room_left = buflen;
if (result == NULL)
return 0;
if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
|| __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ
|| strcmp (NIS_RES_OBJECT (result)[0].EN_data.en_type, "hosts_tbl") != 0
|| NIS_RES_OBJECT (result)[0].EN_data.en_cols.en_cols_len < 4)
return 0;
char *data = first_unused;
if (room_left < (af != AF_INET || (flags & AI_V4MAPPED) != 0
? IN6ADDRSZ : INADDRSZ))
{
no_more_room:
*errnop = ERANGE;
return -1;
}
/* Parse address. */
if (af != AF_INET6
&& inet_pton (AF_INET, NISENTRYVAL (0, 2, result), data) > 0)
{
assert ((flags & AI_V4MAPPED) == 0 || af != AF_UNSPEC);
if (flags & AI_V4MAPPED)
{
map_v4v6_address (data, data);
host->h_addrtype = AF_INET6;
host->h_length = IN6ADDRSZ;
}
else
{
host->h_addrtype = AF_INET;
host->h_length = INADDRSZ;
}
}
else if (af != AF_INET
&& inet_pton (AF_INET6, NISENTRYVAL (0, 2, result), data) > 0)
{
host->h_addrtype = AF_INET6;
host->h_length = IN6ADDRSZ;
}
else
/* Illegal address: ignore line. */
return 0;
first_unused += host->h_length;
room_left -= host->h_length;
if (NISENTRYLEN (0, 0, result) + 1 > room_left)
goto no_more_room;
host->h_name = first_unused;
first_unused = __stpncpy (first_unused, NISENTRYVAL (0, 0, result),
NISENTRYLEN (0, 0, result));
*first_unused++ = '\0';
room_left -= NISENTRYLEN (0, 0, result) + 1;
char *line = first_unused;
/* When this is a call to gethostbyname4_r we do not need the aliases. */
if (af != AF_UNSPEC)
{
/* XXX Rewrite at some point to allocate the array first and then
copy the strings. It is wasteful to first concatenate the strings
to just split them again later. */
for (i = 0; i < NIS_RES_NUMOBJ (result); ++i)
{
if (strcmp (NISENTRYVAL (i, 1, result), host->h_name) != 0)
{
if (NISENTRYLEN (i, 1, result) + 2 > room_left)
goto no_more_room;
*first_unused++ = ' ';
first_unused = __stpncpy (first_unused,
NISENTRYVAL (i, 1, result),
NISENTRYLEN (i, 1, result));
*first_unused = '\0';
room_left -= NISENTRYLEN (i, 1, result) + 1;
}
}
*first_unused++ = '\0';
}
/* Adjust the pointer so it is aligned for
storing pointers. */
size_t adjust = ((__alignof__ (char *)
- (first_unused - (char *) 0) % __alignof__ (char *))
% __alignof__ (char *));
if (room_left < adjust + 3 * sizeof (char *))
goto no_more_room;
first_unused += adjust;
room_left -= adjust;
host->h_addr_list = (char **) first_unused;
room_left -= 3 * sizeof (char *);
host->h_addr_list[0] = data;
host->h_addr_list[1] = NULL;
host->h_aliases = &host->h_addr_list[2];
/* When this is a call to gethostbyname4_r we do not need the aliases. */
if (af != AF_UNSPEC)
{
i = 0;
while (*line != '\0')
{
/* Skip leading blanks. */
while (isspace (*line))
++line;
if (*line == '\0')
break;
if (room_left < sizeof (char *))
goto no_more_room;
room_left -= sizeof (char *);
host->h_aliases[i++] = line;
while (*line != '\0' && *line != ' ')
++line;
if (*line == ' ')
*line++ = '\0';
}
host->h_aliases[i] = NULL;
}
return 1;
}
static enum nss_status
_nss_create_tablename (int *errnop)
{
if (tablename_val == NULL)
{
const char *local_dir = nis_local_directory ();
size_t local_dir_len = strlen (local_dir);
static const char prefix[] = "hosts.org_dir.";
char *p = malloc (sizeof (prefix) + local_dir_len);
if (p == NULL)
{
*errnop = errno;
return NSS_STATUS_TRYAGAIN;
}
memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
tablename_len = sizeof (prefix) - 1 + local_dir_len;
atomic_write_barrier ();
tablename_val = p;
}
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nisplus_sethostent (int stayopen)
{
enum nss_status status = NSS_STATUS_SUCCESS;
int err;
__libc_lock_lock (lock);
if (result != NULL)
{
nis_freeresult (result);
result = NULL;
}
if (tablename_val == NULL)
status = _nss_create_tablename (&err);
__libc_lock_unlock (lock);
return status;
}
enum nss_status
_nss_nisplus_endhostent (void)
{
__libc_lock_lock (lock);
if (result != NULL)
{
nis_freeresult (result);
result = NULL;
}
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
static enum nss_status
internal_nisplus_gethostent_r (struct hostent *host, char *buffer,
size_t buflen, int *errnop, int *herrnop)
{
int parse_res;
/* Get the next entry until we found a correct one. */
do
{
nis_result *saved_res;
if (result == NULL)
{
saved_res = NULL;
if (tablename_val == NULL)
{
enum nss_status status = _nss_create_tablename (errnop);
if (status != NSS_STATUS_SUCCESS)
return status;
}
result = nis_first_entry (tablename_val);
if (result == NULL)
{
*errnop = errno;
return NSS_STATUS_TRYAGAIN;
}
if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
{
enum nss_status retval = niserr2nss (result->status);
if (retval == NSS_STATUS_TRYAGAIN)
{
*herrnop = NETDB_INTERNAL;
*errnop = errno;
}
return retval;
}
}
else
{
saved_res = result;
result = nis_next_entry (tablename_val, &result->cookie);
if (result == NULL)
{
*errnop = errno;
return NSS_STATUS_TRYAGAIN;
}
if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
{
enum nss_status retval= niserr2nss (result->status);
nis_freeresult (result);
result = saved_res;
if (retval == NSS_STATUS_TRYAGAIN)
{
*herrnop = NETDB_INTERNAL;
*errnop = errno;
}
return retval;
}
}
if (res_use_inet6 ())
parse_res = _nss_nisplus_parse_hostent (result, AF_INET6, host, buffer,
buflen, errnop, AI_V4MAPPED);
else
parse_res = _nss_nisplus_parse_hostent (result, AF_INET, host, buffer,
buflen, errnop, 0);
if (parse_res == -1)
{
nis_freeresult (result);
result = saved_res;
*herrnop = NETDB_INTERNAL;
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
if (saved_res != NULL)
nis_freeresult (saved_res);
} while (!parse_res);
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nisplus_gethostent_r (struct hostent *result, char *buffer,
size_t buflen, int *errnop, int *herrnop)
{
int status;
__libc_lock_lock (lock);
status = internal_nisplus_gethostent_r (result, buffer, buflen, errnop,
herrnop);
__libc_lock_unlock (lock);
return status;
}
static enum nss_status
get_tablename (int *herrnop)
{
__libc_lock_lock (lock);
enum nss_status status = _nss_create_tablename (herrnop);
__libc_lock_unlock (lock);
if (status != NSS_STATUS_SUCCESS)
*herrnop = NETDB_INTERNAL;
return status;
}
static enum nss_status
internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int flags)
{
if (tablename_val == NULL)
{
enum nss_status status = get_tablename (herrnop);
if (status != NSS_STATUS_SUCCESS)
return status;
}
if (name == NULL)
{
*errnop = EINVAL;
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_NOTFOUND;
}
char buf[strlen (name) + 10 + tablename_len];
int olderr = errno;
/* Search at first in the alias list, and use the correct name
for the next search. */
snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
if (result != NULL)
{
/* If we did not find it, try it as original name. But if the
database is correct, we should find it in the first case, too. */
char *bufptr = buf;
size_t buflen = sizeof (buf);
if ((result->status == NIS_SUCCESS || result->status == NIS_S_SUCCESS)
&& __type_of (result->objects.objects_val) == NIS_ENTRY_OBJ
&& strcmp (result->objects.objects_val->EN_data.en_type,
"hosts_tbl") == 0
&& result->objects.objects_val->EN_data.en_cols.en_cols_len >= 3)
{
/* We need to allocate a new buffer since there is no
guarantee the returned alias name has a length limit. */
name = NISENTRYVAL(0, 0, result);
size_t buflen = strlen (name) + 10 + tablename_len;
bufptr = alloca (buflen);
}
snprintf (bufptr, buflen, "[cname=%s],%s", name, tablename_val);
nis_freeresult (result);
result = nis_list (bufptr, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
}
if (result == NULL)
{
*errnop = ENOMEM;
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
int retval = niserr2nss (result->status);
if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))
{
if (retval == NSS_STATUS_TRYAGAIN)
{
*errnop = errno;
*herrnop = TRY_AGAIN;
}
else
{
__set_errno (olderr);
*herrnop = NETDB_INTERNAL;
}
nis_freeresult (result);
return retval;
}
int parse_res = _nss_nisplus_parse_hostent (result, af, host, buffer,
buflen, errnop, flags);
nis_freeresult (result);
if (parse_res > 0)
return NSS_STATUS_SUCCESS;
*herrnop = NETDB_INTERNAL;
if (parse_res == -1)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
__set_errno (olderr);
return NSS_STATUS_NOTFOUND;
}
enum nss_status
_nss_nisplus_gethostbyname2_r (const char *name, int af, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int *herrnop)
{
if (af != AF_INET && af != AF_INET6)
{
*herrnop = HOST_NOT_FOUND;
return NSS_STATUS_NOTFOUND;
}
return internal_gethostbyname2_r (name, af, host, buffer, buflen, errnop,
herrnop,
(res_use_inet6 () ? AI_V4MAPPED : 0));
}
enum nss_status
_nss_nisplus_gethostbyname_r (const char *name, struct hostent *host,
char *buffer, size_t buflen, int *errnop,
int *h_errnop)
{
if (res_use_inet6 ())
{
enum nss_status status;
status = internal_gethostbyname2_r (name, AF_INET6, host, buffer,
buflen, errnop, h_errnop,
AI_V4MAPPED);
if (status == NSS_STATUS_SUCCESS)
return status;
}
return internal_gethostbyname2_r (name, AF_INET, host, buffer,
buflen, errnop, h_errnop, 0);
}
enum nss_status
_nss_nisplus_gethostbyaddr_r (const void *addr, socklen_t addrlen, int af,
struct hostent *host, char *buffer,
size_t buflen, int *errnop, int *herrnop)
{
if (tablename_val == NULL)
{
enum nss_status status = get_tablename (herrnop);
if (status != NSS_STATUS_SUCCESS)
return status;
}
if (addr == NULL)
return NSS_STATUS_NOTFOUND;
char buf[24 + tablename_len];
int retval, parse_res;
int olderr = errno;
snprintf (buf, sizeof (buf), "[addr=%s],%s",
inet_ntoa (*(const struct in_addr *) addr), tablename_val);
nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
if (result == NULL)
{
__set_errno (ENOMEM);
return NSS_STATUS_TRYAGAIN;
}
retval = niserr2nss (result->status);
if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))
{
if (retval == NSS_STATUS_TRYAGAIN)
{
*errnop = errno;
*herrnop = NETDB_INTERNAL;
}
else
__set_errno (olderr);
nis_freeresult (result);
return retval;
}
parse_res = _nss_nisplus_parse_hostent (result, af, host,
buffer, buflen, errnop,
(res_use_inet6 ()
? AI_V4MAPPED : 0));
nis_freeresult (result);
if (parse_res > 0)
return NSS_STATUS_SUCCESS;
*herrnop = NETDB_INTERNAL;
if (parse_res == -1)
{
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
__set_errno (olderr);
return NSS_STATUS_NOTFOUND;
}
enum nss_status
_nss_nisplus_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
char *buffer, size_t buflen, int *errnop,
int *herrnop, int32_t *ttlp)
{
struct hostent host;
enum nss_status status = internal_gethostbyname2_r (name, AF_UNSPEC, &host,
buffer, buflen,
errnop, herrnop, 0);
if (__glibc_likely (status == NSS_STATUS_SUCCESS))
{
if (*pat == NULL)
{
uintptr_t pad = (-(uintptr_t) buffer
% __alignof__ (struct gaih_addrtuple));
buffer += pad;
buflen = buflen > pad ? buflen - pad : 0;
if (__glibc_unlikely (buflen < sizeof (struct gaih_addrtuple)))
{
free (result);
*errnop = ERANGE;
*herrnop = NETDB_INTERNAL;
return NSS_STATUS_TRYAGAIN;
}
}
(*pat)->next = NULL;
(*pat)->name = host.h_name;
(*pat)->family = host.h_addrtype;
memcpy ((*pat)->addr, host.h_addr_list[0], host.h_length);
(*pat)->scopeid = 0;
assert (host.h_addr_list[1] == NULL);
}
return status;
}