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
|
/*
* 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/>.
*/
/* GROUP 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 gr_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 group *result,
char *buffer, size_t buflen)
{
struct sss_mc_grp_data *data;
time_t expire;
void *cookie;
char *membuf;
size_t memsize;
int ret;
int i;
/* additional checks before filling result*/
expire = rec->expire;
if (expire < time(NULL)) {
/* entry is now invalid */
return EINVAL;
}
data = (struct sss_mc_grp_data *)rec->data;
memsize = (data->members + 1) * sizeof(char *);
if (data->strs_len + memsize > buflen) {
return ERANGE;
}
/* fill in glibc provided structs */
/* copy in buffer */
membuf = buffer + memsize;
memcpy(membuf, data->strs, data->strs_len);
/* fill in group */
result->gr_gid = data->gid;
result->gr_mem = (char **)buffer;
result->gr_mem[data->members] = NULL;
cookie = NULL;
ret = sss_nss_str_ptr_from_buffer(&result->gr_name, &cookie,
membuf, data->strs_len);
if (ret) {
return ret;
}
ret = sss_nss_str_ptr_from_buffer(&result->gr_passwd, &cookie,
membuf, data->strs_len);
if (ret) {
return ret;
}
for (i = 0; i < data->members; i++) {
ret = sss_nss_str_ptr_from_buffer(&result->gr_mem[i], &cookie,
membuf, data->strs_len);
if (ret) {
return ret;
}
}
if (cookie != NULL) {
return EINVAL;
}
return 0;
}
errno_t sss_nss_mc_getgrnam(const char *name, size_t name_len,
struct group *result,
char *buffer, size_t buflen)
{
struct sss_mc_rec *rec = NULL;
struct sss_mc_grp_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("group", &gr_mc_ctx);
if (ret) {
return ret;
}
/* Get max address of data table. */
max_addr = gr_mc_ctx.data_table + gr_mc_ctx.dt_size;
/* hashes are calculated including the NULL terminator */
hash = sss_nss_mc_hash(&gr_mc_ctx, name, name_len + 1);
slot = gr_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, gr_mc_ctx.dt_size)) {
ret = sss_nss_mc_get_record(&gr_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 = rec->next;
continue;
}
strs_offset = offsetof(struct sss_mc_grp_data, strs);
data = (struct sss_mc_grp_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 = rec->next;
}
if (!MC_SLOT_WITHIN_BOUNDS(slot, gr_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_getgrgid(gid_t gid,
struct group *result,
char *buffer, size_t buflen)
{
struct sss_mc_rec *rec = NULL;
struct sss_mc_grp_data *data;
char gidstr[11];
uint32_t hash;
uint32_t slot;
int len;
int ret;
ret = sss_nss_mc_get_ctx("group", &gr_mc_ctx);
if (ret) {
return ret;
}
len = snprintf(gidstr, 11, "%ld", (long)gid);
if (len > 10) {
return EINVAL;
}
/* hashes are calculated including the NULL terminator */
hash = sss_nss_mc_hash(&gr_mc_ctx, gidstr, len+1);
slot = gr_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, gr_mc_ctx.dt_size)) {
ret = sss_nss_mc_get_record(&gr_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 = rec->next;
continue;
}
data = (struct sss_mc_grp_data *)rec->data;
if (gid == data->gid) {
break;
}
slot = rec->next;
}
if (!MC_SLOT_WITHIN_BOUNDS(slot, gr_mc_ctx.dt_size)) {
ret = ENOENT;
goto done;
}
ret = sss_nss_mc_parse_result(rec, result, buffer, buflen);
done:
free(rec);
return ret;
}
|
