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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
|
/***
This file is part of systemd.
Copyright 2016 Lennart Poettering
systemd 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.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <nss.h>
#include "sd-bus.h"
#include "bus-common-errors.h"
#include "env-util.h"
#include "macro.h"
#include "nss-util.h"
#include "signal-util.h"
#include "string-util.h"
#include "user-util.h"
#include "util.h"
#ifndef NOBODY_USER_NAME
#define NOBODY_USER_NAME "nobody"
#endif
#ifndef NOBODY_GROUP_NAME
#define NOBODY_GROUP_NAME "nobody"
#endif
static const struct passwd root_passwd = {
.pw_name = (char*) "root",
.pw_passwd = (char*) "x", /* see shadow file */
.pw_uid = 0,
.pw_gid = 0,
.pw_gecos = (char*) "Super User",
.pw_dir = (char*) "/root",
.pw_shell = (char*) "/bin/sh",
};
static const struct passwd nobody_passwd = {
.pw_name = (char*) NOBODY_USER_NAME,
.pw_passwd = (char*) "*", /* locked */
.pw_uid = 65534,
.pw_gid = 65534,
.pw_gecos = (char*) "User Nobody",
.pw_dir = (char*) "/",
.pw_shell = (char*) "/sbin/nologin",
};
static const struct group root_group = {
.gr_name = (char*) "root",
.gr_gid = 0,
.gr_passwd = (char*) "x", /* see shadow file */
.gr_mem = (char*[]) { NULL },
};
static const struct group nobody_group = {
.gr_name = (char*) NOBODY_GROUP_NAME,
.gr_gid = 65534,
.gr_passwd = (char*) "*", /* locked */
.gr_mem = (char*[]) { NULL },
};
NSS_GETPW_PROTOTYPES(systemd);
NSS_GETGR_PROTOTYPES(systemd);
enum nss_status _nss_systemd_getpwnam_r(
const char *name,
struct passwd *pwd,
char *buffer, size_t buflen,
int *errnop) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
uint32_t translated;
size_t l;
int r;
BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
assert(name);
assert(pwd);
if (!valid_user_group_name(name)) {
r = -EINVAL;
goto fail;
}
/* Synthesize entries for the root and nobody users, in case they are missing in /etc/passwd */
if (streq(name, root_passwd.pw_name)) {
*pwd = root_passwd;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (streq(name, nobody_passwd.pw_name)) {
*pwd = nobody_passwd;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
/* Make sure that we don't go in circles when allocating a dynamic UID by checking our own database */
if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
goto not_found;
r = sd_bus_open_system(&bus);
if (r < 0)
goto fail;
r = sd_bus_call_method(bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"LookupDynamicUserByName",
&error,
&reply,
"s",
name);
if (r < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
goto not_found;
goto fail;
}
r = sd_bus_message_read(reply, "u", &translated);
if (r < 0)
goto fail;
l = strlen(name);
if (buflen < l+1) {
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
memcpy(buffer, name, l+1);
pwd->pw_name = buffer;
pwd->pw_uid = (uid_t) translated;
pwd->pw_gid = (uid_t) translated;
pwd->pw_gecos = (char*) "Dynamic User";
pwd->pw_passwd = (char*) "*"; /* locked */
pwd->pw_dir = (char*) "/";
pwd->pw_shell = (char*) "/sbin/nologin";
*errnop = 0;
return NSS_STATUS_SUCCESS;
not_found:
*errnop = 0;
return NSS_STATUS_NOTFOUND;
fail:
*errnop = -r;
return NSS_STATUS_UNAVAIL;
}
enum nss_status _nss_systemd_getpwuid_r(
uid_t uid,
struct passwd *pwd,
char *buffer, size_t buflen,
int *errnop) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
const char *translated;
size_t l;
int r;
BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
if (!uid_is_valid(uid)) {
r = -EINVAL;
goto fail;
}
/* Synthesize data for the root user and for nobody in case they are missing from /etc/passwd */
if (uid == root_passwd.pw_uid) {
*pwd = root_passwd;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (uid == nobody_passwd.pw_uid) {
*pwd = nobody_passwd;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (uid <= SYSTEM_UID_MAX)
goto not_found;
if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
goto not_found;
r = sd_bus_open_system(&bus);
if (r < 0)
goto fail;
r = sd_bus_call_method(bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"LookupDynamicUserByUID",
&error,
&reply,
"u",
(uint32_t) uid);
if (r < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
goto not_found;
goto fail;
}
r = sd_bus_message_read(reply, "s", &translated);
if (r < 0)
goto fail;
l = strlen(translated) + 1;
if (buflen < l) {
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
memcpy(buffer, translated, l);
pwd->pw_name = buffer;
pwd->pw_uid = uid;
pwd->pw_gid = uid;
pwd->pw_gecos = (char*) "Dynamic User";
pwd->pw_passwd = (char*) "*"; /* locked */
pwd->pw_dir = (char*) "/";
pwd->pw_shell = (char*) "/sbin/nologin";
*errnop = 0;
return NSS_STATUS_SUCCESS;
not_found:
*errnop = 0;
return NSS_STATUS_NOTFOUND;
fail:
*errnop = -r;
return NSS_STATUS_UNAVAIL;
}
enum nss_status _nss_systemd_getgrnam_r(
const char *name,
struct group *gr,
char *buffer, size_t buflen,
int *errnop) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
uint32_t translated;
size_t l;
int r;
BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
assert(name);
assert(gr);
if (!valid_user_group_name(name)) {
r = -EINVAL;
goto fail;
}
/* Synthesize records for root and nobody, in case they are missing form /etc/group */
if (streq(name, root_group.gr_name)) {
*gr = root_group;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (streq(name, nobody_group.gr_name)) {
*gr = nobody_group;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
goto not_found;
r = sd_bus_open_system(&bus);
if (r < 0)
goto fail;
r = sd_bus_call_method(bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"LookupDynamicUserByName",
&error,
&reply,
"s",
name);
if (r < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
goto not_found;
goto fail;
}
r = sd_bus_message_read(reply, "u", &translated);
if (r < 0)
goto fail;
l = sizeof(char*) + strlen(name) + 1;
if (buflen < l) {
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
memzero(buffer, sizeof(char*));
strcpy(buffer + sizeof(char*), name);
gr->gr_name = buffer + sizeof(char*);
gr->gr_gid = (gid_t) translated;
gr->gr_passwd = (char*) "*"; /* locked */
gr->gr_mem = (char**) buffer;
*errnop = 0;
return NSS_STATUS_SUCCESS;
not_found:
*errnop = 0;
return NSS_STATUS_NOTFOUND;
fail:
*errnop = -r;
return NSS_STATUS_UNAVAIL;
}
enum nss_status _nss_systemd_getgrgid_r(
gid_t gid,
struct group *gr,
char *buffer, size_t buflen,
int *errnop) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
const char *translated;
size_t l;
int r;
BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
if (!gid_is_valid(gid)) {
r = -EINVAL;
goto fail;
}
/* Synthesize records for root and nobody, in case they are missing from /etc/group */
if (gid == root_group.gr_gid) {
*gr = root_group;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (gid == nobody_group.gr_gid) {
*gr = nobody_group;
*errnop = 0;
return NSS_STATUS_SUCCESS;
}
if (gid <= SYSTEM_GID_MAX)
goto not_found;
if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
goto not_found;
r = sd_bus_open_system(&bus);
if (r < 0)
goto fail;
r = sd_bus_call_method(bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"LookupDynamicUserByUID",
&error,
&reply,
"u",
(uint32_t) gid);
if (r < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
goto not_found;
goto fail;
}
r = sd_bus_message_read(reply, "s", &translated);
if (r < 0)
goto fail;
l = sizeof(char*) + strlen(translated) + 1;
if (buflen < l) {
*errnop = ENOMEM;
return NSS_STATUS_TRYAGAIN;
}
memzero(buffer, sizeof(char*));
strcpy(buffer + sizeof(char*), translated);
gr->gr_name = buffer + sizeof(char*);
gr->gr_gid = gid;
gr->gr_passwd = (char*) "*"; /* locked */
gr->gr_mem = (char**) buffer;
*errnop = 0;
return NSS_STATUS_SUCCESS;
not_found:
*errnop = 0;
return NSS_STATUS_NOTFOUND;
fail:
*errnop = -r;
return NSS_STATUS_UNAVAIL;
}
|
