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- Committer: Teddy Hogeborn
- Date: 2009-01-06 22:54:01 UTC
- Revision ID: teddy@fukt.bsnet.se-20090106225401-7l9f7s3hw9eissra
* mandos (main): Try to find non-privileged user+group in pairs, so
that mismatched pairs are never used.
that mismatched pairs are never used.
- files removed:
- dbus-mandos.conf
- files renamed:
- mandos-ctl => mandos-list
- files modified:
- INSTALL
added
removed
plugins.d/splashy.c
1
1
/* -*- coding: utf-8 -*- */
2
2
/*
3
* Splashy - Read a password from splashy and output it
3
* Passprompt - Read a password from splashy and output it
4
4
*
5
5
* Copyright © 2008,2009 Teddy Hogeborn
6
6
* Copyright © 2008,2009 Björn Påhlsson
19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
21
21
*
22
* Contact the authors at <mandos@fukt.bsnet.se>.
22
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
23
24
*/
24
25
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
26
#define _GNU_SOURCE /* asprintf() */
26
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
28
sigemptyset(), sigaddset(), SIGINT,
28
29
SIGHUP, SIGTERM, sigaction,
30
31
#include <stddef.h> /* NULL */
31
32
#include <stdlib.h> /* getenv() */
32
33
#include <stdio.h> /* asprintf(), perror() */
33
#include <stdlib.h> /* EXIT_FAILURE, free(),
34
#include <stdlib.h> /* EXIT_FAILURE, free(), strtoul(),
34
35
EXIT_SUCCESS */
35
36
#include <sys/types.h> /* pid_t, DIR, struct dirent,
36
37
ssize_t */
37
38
#include <dirent.h> /* opendir(), readdir(), closedir() */
38
#include <inttypes.h> /* intmax_t, strtoimax() */
39
39
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
40
40
#include <iso646.h> /* not, or, and */
41
41
#include <unistd.h> /* readlink(), fork(), execl(),
42
42
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit(),
44
pause() */
43
STDOUT_FILENO, _exit() */
45
44
#include <string.h> /* memcmp() */
46
#include <errno.h> /* errno, EACCES, ENOTDIR, ELOOP,
47
ENOENT, ENAMETOOLONG, EMFILE,
48
ENFILE, ENOMEM, ENOEXEC, EINVAL,
49
E2BIG, EFAULT, EIO, ETXTBSY,
50
EISDIR, ELIBBAD, EPERM, EINTR,
51
ECHILD */
45
#include <errno.h> /* errno */
52
46
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
53
47
WEXITSTATUS() */
54
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
55
EX_UNAVAILABLE */
56
48
57
49
sig_atomic_t interrupted_by_signal = 0;
58
int signal_received;
59
50
60
static void termination_handler(int signum){
61
if(interrupted_by_signal){
62
return;
63
}
51
static void termination_handler(__attribute__((unused))int signum){
64
52
interrupted_by_signal = 1;
65
signal_received = signum;
66
53
}
67
54
68
55
int main(__attribute__((unused))int argc,
69
56
__attribute__((unused))char **argv){
70
57
int ret = 0;
58
59
/* Create prompt string */
71
60
char *prompt = NULL;
72
DIR *proc_dir = NULL;
73
pid_t splashy_pid = 0;
74
pid_t splashy_command_pid = 0;
75
int exitstatus = EXIT_FAILURE;
76
77
/* Create prompt string */
78
61
{
79
62
const char *const cryptsource = getenv("cryptsource");
80
63
const char *const crypttarget = getenv("crypttarget");
97
80
}
98
81
}
99
82
if(ret == -1){
100
prompt = NULL;
101
exitstatus = EX_OSERR;
102
goto failure;
83
return EXIT_FAILURE;
103
84
}
104
85
}
105
86
106
87
/* Find splashy process */
88
pid_t splashy_pid = 0;
107
89
{
108
90
const char splashy_name[] = "/sbin/splashy";
109
proc_dir = opendir("/proc");
91
DIR *proc_dir = opendir("/proc");
110
92
if(proc_dir == NULL){
111
int e = errno;
93
free(prompt);
112
94
perror("opendir");
113
switch(e){
114
case EACCES:
115
case ENOTDIR:
116
case ELOOP:
117
case ENOENT:
118
default:
119
exitstatus = EX_OSFILE;
120
break;
121
case ENAMETOOLONG:
122
case EMFILE:
123
case ENFILE:
124
case ENOMEM:
125
exitstatus = EX_OSERR;
126
break;
127
}
128
goto failure;
95
return EXIT_FAILURE;
129
96
}
130
97
for(struct dirent *proc_ent = readdir(proc_dir);
131
98
proc_ent != NULL;
132
99
proc_ent = readdir(proc_dir)){
133
pid_t pid;
134
{
135
intmax_t tmpmax;
136
char *tmp;
137
errno = 0;
138
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
139
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
140
or tmpmax != (pid_t)tmpmax){
141
/* Not a process */
142
continue;
143
}
144
pid = (pid_t)tmpmax;
100
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
101
if(pid == 0){
102
/* Not a process */
103
continue;
145
104
}
146
105
/* Find the executable name by doing readlink() on the
147
106
/proc/<pid>/exe link */
152
111
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
153
112
if(ret == -1){
154
113
perror("asprintf");
155
exitstatus = EX_OSERR;
156
goto failure;
114
free(prompt);
115
closedir(proc_dir);
116
return EXIT_FAILURE;
157
117
}
158
118
159
119
/* Check that it refers to a symlink owned by root:root */
160
120
struct stat exe_stat;
161
121
ret = lstat(exe_link, &exe_stat);
162
122
if(ret == -1){
163
if(errno == ENOENT){
164
free(exe_link);
165
continue;
166
}
167
int e = errno;
168
123
perror("lstat");
169
124
free(exe_link);
170
switch(e){
171
case EACCES:
172
case ENOTDIR:
173
case ELOOP:
174
default:
175
exitstatus = EX_OSFILE;
176
break;
177
case ENAMETOOLONG:
178
exitstatus = EX_OSERR;
179
break;
180
}
181
goto failure;
125
free(prompt);
126
closedir(proc_dir);
127
return EXIT_FAILURE;
182
128
}
183
129
if(not S_ISLNK(exe_stat.st_mode)
184
130
or exe_stat.st_uid != 0
198
144
}
199
145
}
200
146
closedir(proc_dir);
201
proc_dir = NULL;
202
147
}
203
148
if(splashy_pid == 0){
204
exitstatus = EX_UNAVAILABLE;
205
goto failure;
149
free(prompt);
150
return EXIT_FAILURE;
206
151
}
207
152
208
153
/* Set up the signal handler */
211
156
new_action = { .sa_handler = termination_handler,
212
157
.sa_flags = 0 };
213
158
sigemptyset(&new_action.sa_mask);
214
ret = sigaddset(&new_action.sa_mask, SIGINT);
215
if(ret == -1){
216
perror("sigaddset");
217
exitstatus = EX_OSERR;
218
goto failure;
219
}
220
ret = sigaddset(&new_action.sa_mask, SIGHUP);
221
if(ret == -1){
222
perror("sigaddset");
223
exitstatus = EX_OSERR;
224
goto failure;
225
}
226
ret = sigaddset(&new_action.sa_mask, SIGTERM);
227
if(ret == -1){
228
perror("sigaddset");
229
exitstatus = EX_OSERR;
230
goto failure;
231
}
159
sigaddset(&new_action.sa_mask, SIGINT);
160
sigaddset(&new_action.sa_mask, SIGHUP);
161
sigaddset(&new_action.sa_mask, SIGTERM);
232
162
ret = sigaction(SIGINT, NULL, &old_action);
233
163
if(ret == -1){
234
164
perror("sigaction");
235
exitstatus = EX_OSERR;
236
goto failure;
165
free(prompt);
166
return EXIT_FAILURE;
237
167
}
238
168
if(old_action.sa_handler != SIG_IGN){
239
169
ret = sigaction(SIGINT, &new_action, NULL);
240
170
if(ret == -1){
241
171
perror("sigaction");
242
exitstatus = EX_OSERR;
243
goto failure;
172
free(prompt);
173
return EXIT_FAILURE;
244
174
}
245
175
}
246
176
ret = sigaction(SIGHUP, NULL, &old_action);
247
177
if(ret == -1){
248
178
perror("sigaction");
249
exitstatus = EX_OSERR;
250
goto failure;
179
free(prompt);
180
return EXIT_FAILURE;
251
181
}
252
182
if(old_action.sa_handler != SIG_IGN){
253
183
ret = sigaction(SIGHUP, &new_action, NULL);
254
184
if(ret == -1){
255
185
perror("sigaction");
256
exitstatus = EX_OSERR;
257
goto failure;
186
free(prompt);
187
return EXIT_FAILURE;
258
188
}
259
189
}
260
190
ret = sigaction(SIGTERM, NULL, &old_action);
261
191
if(ret == -1){
262
192
perror("sigaction");
263
exitstatus = EX_OSERR;
264
goto failure;
193
free(prompt);
194
return EXIT_FAILURE;
265
195
}
266
196
if(old_action.sa_handler != SIG_IGN){
267
197
ret = sigaction(SIGTERM, &new_action, NULL);
268
198
if(ret == -1){
269
199
perror("sigaction");
270
exitstatus = EX_OSERR;
271
goto failure;
200
free(prompt);
201
return EXIT_FAILURE;
272
202
}
273
203
}
274
204
}
275
205
276
if(interrupted_by_signal){
277
goto failure;
278
}
279
280
206
/* Fork off the splashy command to prompt for password */
281
splashy_command_pid = fork();
282
if(splashy_command_pid != 0 and interrupted_by_signal){
283
goto failure;
284
}
285
if(splashy_command_pid == -1){
286
perror("fork");
287
exitstatus = EX_OSERR;
288
goto failure;
289
}
290
/* Child */
291
if(splashy_command_pid == 0){
292
if(not interrupted_by_signal){
207
pid_t splashy_command_pid = 0;
208
if(not interrupted_by_signal){
209
splashy_command_pid = fork();
210
if(splashy_command_pid == -1){
211
if(not interrupted_by_signal){
212
perror("fork");
213
}
214
return EXIT_FAILURE;
215
}
216
/* Child */
217
if(splashy_command_pid == 0){
293
218
const char splashy_command[] = "/sbin/splashy_update";
294
execl(splashy_command, splashy_command, prompt, (char *)NULL);
295
int e = errno;
296
perror("execl");
297
switch(e){
298
case EACCES:
299
case ENOENT:
300
case ENOEXEC:
301
case EINVAL:
302
_exit(EX_UNAVAILABLE);
303
case ENAMETOOLONG:
304
case E2BIG:
305
case ENOMEM:
306
case EFAULT:
307
case EIO:
308
case EMFILE:
309
case ENFILE:
310
case ETXTBSY:
311
default:
312
_exit(EX_OSERR);
313
case ENOTDIR:
314
case ELOOP:
315
case EISDIR:
316
case ELIBBAD:
317
case EPERM:
318
_exit(EX_OSFILE);
219
ret = execl(splashy_command, splashy_command, prompt,
220
(char *)NULL);
221
if(not interrupted_by_signal){
222
perror("execl");
319
223
}
224
free(prompt);
225
_exit(EXIT_FAILURE);
320
226
}
321
free(prompt);
322
_exit(EXIT_FAILURE);
323
227
}
324
228
325
229
/* Parent */
326
230
free(prompt);
327
prompt = NULL;
328
329
if(interrupted_by_signal){
330
goto failure;
331
}
332
231
333
232
/* Wait for command to complete */
334
{
233
if(not interrupted_by_signal and splashy_command_pid != 0){
335
234
int status;
336
do {
337
ret = waitpid(splashy_command_pid, &status, 0);
338
} while(ret == -1 and errno == EINTR
339
and not interrupted_by_signal);
340
if(interrupted_by_signal){
341
goto failure;
342
}
235
ret = waitpid(splashy_command_pid, &status, 0);
343
236
if(ret == -1){
344
perror("waitpid");
237
if(errno != EINTR){
238
perror("waitpid");
239
}
345
240
if(errno == ECHILD){
346
241
splashy_command_pid = 0;
347
242
}
348
243
} else {
349
244
/* The child process has exited */
350
245
splashy_command_pid = 0;
351
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
246
if(not interrupted_by_signal and WIFEXITED(status)
247
and WEXITSTATUS(status)==0){
352
248
return EXIT_SUCCESS;
353
249
}
354
250
}
355
251
}
356
357
failure:
358
359
free(prompt);
360
361
if(proc_dir != NULL){
362
TEMP_FAILURE_RETRY(closedir(proc_dir));
363
}
364
365
if(splashy_command_pid != 0){
366
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
367
368
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
369
sleep(2);
370
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
371
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
372
sleep(1);
373
}
374
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
375
if(new_splashy_pid == 0){
376
/* Child; will become new splashy process */
377
378
/* Make the effective user ID (root) the only user ID instead of
379
the real user ID (_mandos) */
380
ret = setuid(geteuid());
381
if(ret == -1){
382
perror("setuid");
383
}
384
385
setsid();
386
ret = chdir("/");
387
if(ret == -1){
388
perror("chdir");
389
}
390
/* if(fork() != 0){ */
391
/* _exit(EXIT_SUCCESS); */
392
/* } */
393
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
394
if(ret == -1){
395
perror("dup2");
396
_exit(EX_OSERR);
397
}
398
399
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
400
{
401
int e = errno;
402
perror("execl");
403
switch(e){
404
case EACCES:
405
case ENOENT:
406
case ENOEXEC:
407
default:
408
_exit(EX_UNAVAILABLE);
409
case ENAMETOOLONG:
410
case E2BIG:
411
case ENOMEM:
412
_exit(EX_OSERR);
413
case ENOTDIR:
414
case ELOOP:
415
_exit(EX_OSFILE);
416
}
417
}
418
}
419
}
420
421
if(interrupted_by_signal){
422
struct sigaction signal_action;
423
sigemptyset(&signal_action.sa_mask);
424
signal_action.sa_handler = SIG_DFL;
425
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
426
&signal_action, NULL));
427
if(ret == -1){
428
perror("sigaction");
429
}
430
do {
431
ret = raise(signal_received);
432
} while(ret != 0 and errno == EINTR);
433
if(ret != 0){
434
perror("raise");
435
abort();
436
}
437
TEMP_FAILURE_RETRY(pause());
438
}
439
440
return exitstatus;
252
kill(splashy_pid, SIGTERM);
253
if(interrupted_by_signal and splashy_command_pid != 0){
254
kill(splashy_command_pid, SIGTERM);
255
}
256
sleep(2);
257
while(kill(splashy_pid, 0) == 0){
258
kill(splashy_pid, SIGKILL);
259
sleep(1);
260
}
261
pid_t new_splashy_pid = fork();
262
if(new_splashy_pid == 0){
263
/* Child; will become new splashy process */
264
265
/* Make the effective user ID (root) the only user ID instead of
266
the real user ID (mandos) */
267
ret = setuid(geteuid());
268
if(ret == -1){
269
perror("setuid");
270
}
271
272
setsid();
273
ret = chdir("/");
274
/* if(fork() != 0){ */
275
/* _exit(EXIT_SUCCESS); */
276
/* } */
277
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
278
if(ret == -1){
279
perror("dup2");
280
_exit(EXIT_FAILURE);
281
}
282
283
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
284
if(not interrupted_by_signal){
285
perror("execl");
286
}
287
_exit(EXIT_FAILURE);
288
}
289
290
return EXIT_FAILURE;
441
291
}
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Version: 2.0.2.dev0