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/*
* System Security Services Daemon. NSS client interface
*
* Copyright (C) Simo Sorce 2011
*
* 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/>.
*/
/* PASSWD 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"
struct sss_cli_mc_ctx pw_mc_ctx = { false, -1, 0, NULL, 0, NULL, 0, NULL, 0 };
static errno_t sss_nss_mc_parse_result(struct sss_mc_rec *rec,
struct passwd *result,
char *buffer, size_t buflen)
{
struct sss_mc_pwd_data *data;
time_t expire;
void *cookie;
int ret;
/* additional checks before filling result*/
expire = rec->expire;
if (expire < time(NULL)) {
/* entry is now invalid */
return EINVAL;
}
data = (struct sss_mc_pwd_data *)rec->data;
if (data->strs_len > buflen) {
return ERANGE;
}
/* fill in glibc provided structs */
/* copy in buffer */
memcpy(buffer, data->strs, data->strs_len);
/* fill in passwd */
result->pw_uid = data->uid;
result->pw_gid = data->gid;
cookie = NULL;
ret = sss_nss_str_ptr_from_buffer(&result->pw_name, &cookie,
buffer, data->strs_len);
if (ret) {
return ret;
}
ret = sss_nss_str_ptr_from_buffer(&result->pw_passwd, &cookie,
buffer, data->strs_len);
if (ret) {
return ret;
}
ret = sss_nss_str_ptr_from_buffer(&result->pw_gecos, &cookie,
buffer, data->strs_len);
if (ret) {
return ret;
}
ret = sss_nss_str_ptr_from_buffer(&result->pw_dir, &cookie,
buffer, data->strs_len);
if (ret) {
return ret;
}
ret = sss_nss_str_ptr_from_buffer(&result->pw_shell, &cookie,
buffer, data->strs_len);
if (ret) {
return ret;
}
if (cookie != NULL) {
return EINVAL;
}
return 0;
}
errno_t sss_nss_mc_getpwnam(const char *name, size_t name_len,
struct passwd *result,
char *buffer, size_t buflen)
{
struct sss_mc_rec *rec = NULL;
struct sss_mc_pwd_data *data;
char *rec_name;
uint32_t hash;
uint32_t slot;
int ret;
size_t strs_offset;
uint8_t *max_addr;
ret = sss_nss_mc_get_ctx("passwd", &pw_mc_ctx);
if (ret) {
return ret;
}
/* Get max address of data table. */
max_addr = pw_mc_ctx.data_table + pw_mc_ctx.dt_size;
/* hashes are calculated including the NULL terminator */
hash = sss_nss_mc_hash(&pw_mc_ctx, name, name_len + 1);
slot = pw_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, pw_mc_ctx.dt_size)) {
ret = sss_nss_mc_get_record(&pw_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;
}
strs_offset = offsetof(struct sss_mc_pwd_data, strs);
data = (struct sss_mc_pwd_data *)rec->data;
/* Integrity check
* - name_len cannot be longer than all strings
* - data->name cannot point outside strings
* - all strings must be within data_table */
if (name_len > data->strs_len
|| (data->name + name_len) > (strs_offset + data->strs_len)
|| (uint8_t *)data->strs + data->strs_len > max_addr) {
ret = ENOENT;
goto done;
}
rec_name = (char *)data + data->name;
if (strcmp(name, rec_name) == 0) {
break;
}
slot = sss_nss_mc_next_slot_with_hash(rec, hash);
}
if (!MC_SLOT_WITHIN_BOUNDS(slot, pw_mc_ctx.dt_size)) {
ret = ENOENT;
goto done;
}
ret = sss_nss_mc_parse_result(rec, result, buffer, buflen);
done:
free(rec);
return ret;
}
errno_t sss_nss_mc_getpwuid(uid_t uid,
struct passwd *result,
char *buffer, size_t buflen)
{
struct sss_mc_rec *rec = NULL;
struct sss_mc_pwd_data *data;
char uidstr[11];
uint32_t hash;
uint32_t slot;
int len;
int ret;
ret = sss_nss_mc_get_ctx("passwd", &pw_mc_ctx);
if (ret) {
return ret;
}
len = snprintf(uidstr, 11, "%ld", (long)uid);
if (len > 10) {
return EINVAL;
}
/* hashes are calculated including the NULL terminator */
hash = sss_nss_mc_hash(&pw_mc_ctx, uidstr, len+1);
slot = pw_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, pw_mc_ctx.dt_size)) {
ret = sss_nss_mc_get_record(&pw_mc_ctx, slot, &rec);
if (ret) {
goto done;
}
/* check record matches what we are searching for */
if (hash != rec->hash2) {
/* if uid hash does not match we can skip this immediately */
slot = sss_nss_mc_next_slot_with_hash(rec, hash);
continue;
}
data = (struct sss_mc_pwd_data *)rec->data;
if (uid == data->uid) {
break;
}
slot = sss_nss_mc_next_slot_with_hash(rec, hash);
}
if (!MC_SLOT_WITHIN_BOUNDS(slot, pw_mc_ctx.dt_size)) {
ret = ENOENT;
goto done;
}
ret = sss_nss_mc_parse_result(rec, result, buffer, buflen);
done:
free(rec);
return ret;
}
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