glibc/nis/nss_nisplus/nisplus-alias.c

338 lines
7.7 KiB
C

/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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 <atomic.h>
#include <nss.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
#include <aliases.h>
#include <libc-lock.h>
#include <rpcsvc/nis.h>
#include "nss-nisplus.h"
__libc_lock_define_initialized (static, lock)
static nis_result *result;
static u_long next_entry;
static nis_name tablename_val;
static size_t 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)
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[] = "mail_aliases.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;
}
static int
_nss_nisplus_parse_aliasent (nis_result *result, unsigned long entry,
struct aliasent *alias, char *buffer,
size_t buflen, int *errnop)
{
if (result == NULL)
return 0;
if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
|| __type_of (&NIS_RES_OBJECT (result)[entry]) != NIS_ENTRY_OBJ
|| strcmp (NIS_RES_OBJECT (result)[entry].EN_data.en_type,
"mail_aliases") != 0
|| NIS_RES_OBJECT (result)[entry].EN_data.en_cols.en_cols_len < 2)
return 0;
if (NISENTRYLEN (entry, 1, result) >= buflen)
{
/* The line is too long for our buffer. */
no_more_room:
*errnop = ERANGE;
return -1;
}
char *cp = __stpncpy (buffer, NISENTRYVAL (entry, 1, result),
NISENTRYLEN (entry, 1, result));
*cp = '\0';
char *first_unused = cp + 1;
size_t room_left = buflen - (first_unused - buffer);
alias->alias_local = 0;
alias->alias_members_len = 0;
if (NISENTRYLEN (entry, 0, result) >= room_left)
goto no_more_room;
cp = __stpncpy (first_unused, NISENTRYVAL (entry, 0, result),
NISENTRYLEN (entry, 0, result));
*cp = '\0';
alias->alias_name = first_unused;
/* Terminate the line for any case. */
cp = strpbrk (alias->alias_name, "#\n");
if (cp != NULL)
*cp = '\0';
size_t len = strlen (alias->alias_name) + 1;
first_unused += len;
room_left -= len;
/* 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)
goto no_more_room;
first_unused += adjust;
room_left -= adjust;
alias->alias_members = (char **) first_unused;
char *line = buffer;
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 *);
alias->alias_members[alias->alias_members_len] = line;
while (*line != '\0' && *line != ',')
++line;
if (line != alias->alias_members[alias->alias_members_len])
{
*line++ = '\0';
++alias->alias_members_len;
}
else if (*line == ',')
++line;
}
return alias->alias_members_len == 0 ? 0 : 1;
}
static enum nss_status
internal_setaliasent (void)
{
enum nss_status status;
int err;
if (result != NULL)
{
nis_freeresult (result);
result = NULL;
}
if (_nss_create_tablename (&err) != NSS_STATUS_SUCCESS)
return NSS_STATUS_UNAVAIL;
next_entry = 0;
result = nis_list (tablename_val, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
if (result == NULL)
{
status = NSS_STATUS_TRYAGAIN;
__set_errno (ENOMEM);
}
else
{
status = niserr2nss (result->status);
if (status != NSS_STATUS_SUCCESS)
{
nis_freeresult (result);
result = NULL;
}
}
return status;
}
enum nss_status
_nss_nisplus_setaliasent (void)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_setaliasent ();
__libc_lock_unlock (lock);
return status;
}
enum nss_status
_nss_nisplus_endaliasent (void)
{
__libc_lock_lock (lock);
if (result != NULL)
{
nis_freeresult (result);
result = NULL;
}
next_entry = 0;
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
static enum nss_status
internal_nisplus_getaliasent_r (struct aliasent *alias,
char *buffer, size_t buflen, int *errnop)
{
int parse_res;
if (result == NULL)
{
enum nss_status status;
status = internal_setaliasent ();
if (result == NULL || status != NSS_STATUS_SUCCESS)
return status;
}
/* Get the next entry until we found a correct one. */
do
{
if (next_entry >= result->objects.objects_len)
return NSS_STATUS_NOTFOUND;
parse_res = _nss_nisplus_parse_aliasent (result, next_entry, alias,
buffer, buflen, errnop);
if (parse_res == -1)
return NSS_STATUS_TRYAGAIN;
++next_entry;
}
while (!parse_res);
return NSS_STATUS_SUCCESS;
}
enum nss_status
_nss_nisplus_getaliasent_r (struct aliasent *result, char *buffer,
size_t buflen, int *errnop)
{
int status;
__libc_lock_lock (lock);
status = internal_nisplus_getaliasent_r (result, buffer, buflen, errnop);
__libc_lock_unlock (lock);
return status;
}
enum nss_status
_nss_nisplus_getaliasbyname_r (const char *name, struct aliasent *alias,
char *buffer, size_t buflen, int *errnop)
{
int parse_res;
if (tablename_val == NULL)
{
__libc_lock_lock (lock);
enum nss_status status = _nss_create_tablename (errnop);
__libc_lock_unlock (lock);
if (status != NSS_STATUS_SUCCESS)
return status;
}
if (name == NULL)
{
*errnop = EINVAL;
return NSS_STATUS_UNAVAIL;
}
char buf[strlen (name) + 9 + tablename_len];
int olderr = errno;
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)
{
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
if (__glibc_unlikely (niserr2nss (result->status) != NSS_STATUS_SUCCESS))
{
enum nss_status status = niserr2nss (result->status);
nis_freeresult (result);
return status;
}
parse_res = _nss_nisplus_parse_aliasent (result, 0, alias,
buffer, buflen, errnop);
/* We do not need the lookup result anymore. */
nis_freeresult (result);
if (__glibc_unlikely (parse_res < 1))
{
__set_errno (olderr);
if (parse_res == -1)
return NSS_STATUS_TRYAGAIN;
else
return NSS_STATUS_NOTFOUND;
}
return NSS_STATUS_SUCCESS;
}