glibc/nis/nss_nisplus/nisplus-initgroups.c

149 lines
3.7 KiB
C

/* Copyright (C) 1997-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <atomic.h>
#include <nss.h>
#include <grp.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <libc-lock.h>
#include <rpcsvc/nis.h>
#include "nss-nisplus.h"
#include "nisplus-parser.h"
#include <libnsl.h>
#include <nis_intern.h>
#include <nis_xdr.h>
#define NISOBJVAL(col, obj) \
((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
#define NISOBJLEN(col, obj) \
((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
extern nis_name grp_tablename_val attribute_hidden;
extern size_t grp_tablename_len attribute_hidden;
extern enum nss_status _nss_grp_create_tablename (int *errnop);
enum nss_status
_nss_nisplus_initgroups_dyn (const char *user, gid_t group, long int *start,
long int *size, gid_t **groupsp, long int limit,
int *errnop)
{
if (grp_tablename_val == NULL)
{
enum nss_status status = _nss_grp_create_tablename (errnop);
if (status != NSS_STATUS_SUCCESS)
return status;
}
nis_result *result;
char buf[strlen (user) + 12 + grp_tablename_len];
snprintf (buf, sizeof (buf), "[members=%s],%s", user, grp_tablename_val);
result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | ALL_RESULTS, 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;
}
if (NIS_RES_NUMOBJ (result) == 0)
{
errout:
nis_freeresult (result);
return NSS_STATUS_NOTFOUND;
}
gid_t *groups = *groupsp;
nis_object *obj = NIS_RES_OBJECT (result);
for (unsigned int cnt = 0; cnt < NIS_RES_NUMOBJ (result); ++cnt, ++obj)
{
if (__type_of (obj) != NIS_ENTRY_OBJ
|| strcmp (obj->EN_data.en_type, "group_tbl") != 0
|| obj->EN_data.en_cols.en_cols_len < 4)
continue;
char *numstr = NISOBJVAL (2, obj);
size_t len = NISOBJLEN (2, obj);
if (len == 0 || numstr[0] == '\0')
continue;
gid_t gid;
char *endp;
if (__glibc_unlikely (numstr[len - 1] != '\0'))
{
char numstrbuf[len + 1];
memcpy (numstrbuf, numstr, len);
numstrbuf[len] = '\0';
gid = strtoul (numstrbuf, &endp, 10);
if (*endp)
continue;
}
else
{
gid = strtoul (numstr, &endp, 10);
if (*endp)
continue;
}
if (gid == group)
continue;
/* Insert this group. */
if (*start == *size)
{
/* Need a bigger buffer. */
long int newsize;
if (limit > 0 && *size == limit)
/* We reached the maximum. */
break;
if (limit <= 0)
newsize = 2 * *size;
else
newsize = MIN (limit, 2 * *size);
gid_t *newgroups = realloc (groups, newsize * sizeof (*groups));
if (newgroups == NULL)
goto errout;
*groupsp = groups = newgroups;
*size = newsize;
}
groups[*start] = gid;
*start += 1;
}
nis_freeresult (result);
return NSS_STATUS_SUCCESS;
}