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/*
* System Security Services Daemon. NSS client interface
*
* Authors:
* Lukas Slebodnik <lslebodn@redhat.com>
*
* Copyright (C) 2015 Red Hat
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* INITGROUPs database NSS interface using mmap cache */
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <sys/mman.h>
#include <time.h>
#include "nss_mc.h"
#include "util/util_safealign.h"
struct sss_cli_mc_ctx initgr_mc_ctx = { UNINITIALIZED, -1, 0, NULL, 0, NULL, 0,
NULL, 0, 0 };
static errno_t sss_nss_mc_parse_result(struct sss_mc_rec *rec,
long int *start, long int *size,
gid_t **groups, long int limit)
{
struct sss_mc_initgr_data *data;
time_t expire;
long int i;
uint32_t num_groups;
long int max_ret;
/* additional checks before filling result*/
expire = rec->expire;
if (expire < time(NULL)) {
/* entry is now invalid */
return EINVAL;
}
data = (struct sss_mc_initgr_data *)rec->data;
num_groups = data->num_groups;
max_ret = num_groups;
/* check we have enough space in the buffer */
if ((*size - *start) < num_groups) {
long int newsize;
gid_t *newgroups;
newsize = *size + num_groups;
if ((limit > 0) && (newsize > limit)) {
newsize = limit;
max_ret = newsize - *start;
}
newgroups = (gid_t *)realloc((*groups), newsize * sizeof(**groups));
if (!newgroups) {
return ENOMEM;
}
*groups = newgroups;
*size = newsize;
}
for (i = 0; i < max_ret; i++) {
SAFEALIGN_COPY_UINT32(&(*groups)[*start], data->gids + i, NULL);
*start += 1;
}
return 0;
}
errno_t sss_nss_mc_initgroups_dyn(const char *name, size_t name_len,
gid_t group, long int *start, long int *size,
gid_t **groups, long int limit)
{
struct sss_mc_rec *rec = NULL;
struct sss_mc_initgr_data *data;
char *rec_name;
uint32_t hash;
uint32_t slot;
int ret;
const size_t data_offset = offsetof(struct sss_mc_initgr_data, gids);
uint8_t *max_addr;
ret = sss_nss_mc_get_ctx("initgroups", &initgr_mc_ctx);
if (ret) {
return ret;
}
/* Get max address of data table. */
max_addr = initgr_mc_ctx.data_table + initgr_mc_ctx.dt_size;
/* hashes are calculated including the NULL terminator */
hash = sss_nss_mc_hash(&initgr_mc_ctx, name, name_len + 1);
slot = initgr_mc_ctx.hash_table[hash];
/* If slot is not within the bounds of mmaped region and
* it's value is not MC_INVALID_VAL, then the cache is
* probbably corrupted. */
while (MC_SLOT_WITHIN_BOUNDS(slot, initgr_mc_ctx.dt_size)) {
/* free record from previous iteration */
free(rec);
rec = NULL;
ret = sss_nss_mc_get_record(&initgr_mc_ctx, slot, &rec);
if (ret) {
goto done;
}
/* check record matches what we are searching for */
if (hash != rec->hash1) {
/* if name hash does not match we can skip this immediately */
slot = sss_nss_mc_next_slot_with_hash(rec, hash);
continue;
}
data = (struct sss_mc_initgr_data *)rec->data;
rec_name = (char *)data + data->name;
/* Integrity check
* - name_len cannot be longer than all strings or data
* - data->name cannot point outside strings
* - all data must be within data_table
* - name must be within data_table */
if (name_len > data->data_len
|| name_len > data->strs_len
|| (data->strs + name_len) > (data_offset + data->data_len)
|| (uint8_t *)data->gids + data->data_len > max_addr
|| (uint8_t *)rec_name + name_len > max_addr) {
ret = ENOENT;
goto done;
}
if (strcmp(name, rec_name) == 0) {
break;
}
slot = sss_nss_mc_next_slot_with_hash(rec, hash);
}
if (!MC_SLOT_WITHIN_BOUNDS(slot, initgr_mc_ctx.dt_size)) {
ret = ENOENT;
goto done;
}
ret = sss_nss_mc_parse_result(rec, start, size, groups, limit);
done:
free(rec);
__sync_sub_and_fetch(&initgr_mc_ctx.active_threads, 1);
return ret;
}
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