1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
/*
* 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"
#if HAVE_PTHREAD
static pthread_mutex_t pw_mc_ctx_mutex = PTHREAD_MUTEX_INITIALIZER;
static struct sss_cli_mc_ctx pw_mc_ctx = SSS_CLI_MC_CTX_INITIALIZER(&pw_mc_ctx_mutex);
#else
static struct sss_cli_mc_ctx pw_mc_ctx = SSS_CLI_MC_CTX_INITIALIZER;
#endif
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;
const size_t strs_offset = offsetof(struct sss_mc_pwd_data, strs);
size_t data_size;
ret = sss_nss_mc_get_ctx("passwd", &pw_mc_ctx);
if (ret) {
return ret;
}
/* Get max size of data table. */
data_size = 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 mmapped region and
* it's value is not MC_INVALID_VAL, then the cache is
* probably corrupted. */
while (MC_SLOT_WITHIN_BOUNDS(slot, data_size)) {
/* free record from previous iteration */
free(rec);
rec = NULL;
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;
}
data = (struct sss_mc_pwd_data *)rec->data;
rec_name = (char *)data + data->name;
/* Integrity check
* - data->name cannot point outside strings
* - all strings must be within copy of record
* - rec_name is a zero-terminated string */
if (data->name < strs_offset
|| data->name >= strs_offset + data->strs_len
|| data->strs_len > rec->len) {
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, data_size)) {
ret = ENOENT;
goto done;
}
ret = sss_nss_mc_parse_result(rec, result, buffer, buflen);
done:
free(rec);
__sync_sub_and_fetch(&pw_mc_ctx.active_threads, 1);
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) {
ret = EINVAL;
goto done;
}
/* 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 mmapped region and
* it's value is not MC_INVALID_VAL, then the cache is
* probably corrupted. */
while (MC_SLOT_WITHIN_BOUNDS(slot, pw_mc_ctx.dt_size)) {
/* free record from previous iteration */
free(rec);
rec = NULL;
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);
__sync_sub_and_fetch(&pw_mc_ctx.active_threads, 1);
return ret;
}
|
