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- Committer: Teddy Hogeborn
- Date: 2009-02-09 19:33:46 UTC
- mfrom: (24.1.135 mandos)
- Revision ID: teddy@fukt.bsnet.se-20090209193346-5insyr1rsisor8dj
Merge from Björn:
* plugins.d/mandos-client.c (mc): Initialize globally.
(main): Better handling of signals.
* plugins.d/mandos-client.c (mc): Initialize globally.
(main): Better handling of signals.
- files removed:
- DBUS-API
- debian/source
- files modified:
- .bzrignore
added
removed
plugins.d/splashy.c
2
2
/*
3
3
* Splashy - Read a password from splashy and output it
4
4
*
5
* Copyright © 2008-2011 Teddy Hogeborn
6
* Copyright © 2008-2011 Björn Påhlsson
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
7
7
*
8
8
* This program is free software: you can redistribute it and/or
9
9
* modify it under the terms of the GNU General Public License as
19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
21
21
*
22
* Contact the authors at <mandos@recompile.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,
29
30
SIG_IGN, kill(), SIGKILL */
30
31
#include <stddef.h> /* NULL */
31
32
#include <stdlib.h> /* getenv() */
32
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
33
fprintf() */
33
#include <stdio.h> /* asprintf(), perror(), sscanf() */
34
34
#include <stdlib.h> /* EXIT_FAILURE, free(),
35
35
EXIT_SUCCESS */
36
36
#include <sys/types.h> /* pid_t, DIR, struct dirent,
37
37
ssize_t */
38
38
#include <dirent.h> /* opendir(), readdir(), closedir() */
39
#include <inttypes.h> /* intmax_t, strtoimax() */
39
#include <inttypes.h> /* intmax_t, SCNdMAX */
40
40
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
41
41
#include <iso646.h> /* not, or, and */
42
42
#include <unistd.h> /* readlink(), fork(), execl(),
43
43
sleep(), dup2() STDERR_FILENO,
44
STDOUT_FILENO, _exit(),
45
pause() */
46
#include <string.h> /* memcmp(), strerror() */
47
#include <errno.h> /* errno, EACCES, ENOTDIR, ELOOP,
48
ENOENT, ENAMETOOLONG, EMFILE,
49
ENFILE, ENOMEM, ENOEXEC, EINVAL,
50
E2BIG, EFAULT, EIO, ETXTBSY,
51
EISDIR, ELIBBAD, EPERM, EINTR,
52
ECHILD */
53
#include <error.h> /* error() */
44
STDOUT_FILENO, _exit() */
45
#include <string.h> /* memcmp() */
46
#include <errno.h> /* errno */
54
47
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
55
48
WEXITSTATUS() */
56
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
57
EX_UNAVAILABLE */
58
#include <stdarg.h> /* va_list, va_start(), ... */
59
49
60
50
sig_atomic_t interrupted_by_signal = 0;
61
int signal_received;
62
63
/* Function to use when printing errors */
64
void error_plus(int status, int errnum, const char *formatstring,
65
...){
66
va_list ap;
67
char *text;
68
int ret;
69
70
va_start(ap, formatstring);
71
ret = vasprintf(&text, formatstring, ap);
72
if (ret == -1){
73
fprintf(stderr, "Mandos plugin %s: ",
74
program_invocation_short_name);
75
vfprintf(stderr, formatstring, ap);
76
fprintf(stderr, ": ");
77
fprintf(stderr, "%s\n", strerror(errnum));
78
error(status, errno, "vasprintf while printing error");
79
return;
80
}
81
fprintf(stderr, "Mandos plugin ");
82
error(status, errnum, "%s", text);
83
free(text);
84
}
85
86
87
static void termination_handler(int signum){
88
if(interrupted_by_signal){
89
return;
90
}
51
52
static void termination_handler(__attribute__((unused))int signum){
91
53
interrupted_by_signal = 1;
92
signal_received = signum;
93
54
}
94
55
95
56
int main(__attribute__((unused))int argc,
96
57
__attribute__((unused))char **argv){
97
58
int ret = 0;
59
60
/* Create prompt string */
98
61
char *prompt = NULL;
99
DIR *proc_dir = NULL;
100
pid_t splashy_pid = 0;
101
pid_t splashy_command_pid = 0;
102
int exitstatus = EXIT_FAILURE;
103
104
/* Create prompt string */
105
62
{
106
63
const char *const cryptsource = getenv("cryptsource");
107
64
const char *const crypttarget = getenv("crypttarget");
124
81
}
125
82
}
126
83
if(ret == -1){
127
prompt = NULL;
128
exitstatus = EX_OSERR;
129
goto failure;
84
return EXIT_FAILURE;
130
85
}
131
86
}
132
87
133
88
/* Find splashy process */
89
pid_t splashy_pid = 0;
134
90
{
135
91
const char splashy_name[] = "/sbin/splashy";
136
proc_dir = opendir("/proc");
92
DIR *proc_dir = opendir("/proc");
137
93
if(proc_dir == NULL){
138
int e = errno;
139
error_plus(0, errno, "opendir");
140
switch(e){
141
case EACCES:
142
case ENOTDIR:
143
case ELOOP:
144
case ENOENT:
145
default:
146
exitstatus = EX_OSFILE;
147
break;
148
case ENAMETOOLONG:
149
case EMFILE:
150
case ENFILE:
151
case ENOMEM:
152
exitstatus = EX_OSERR;
153
break;
154
}
155
goto failure;
94
free(prompt);
95
perror("opendir");
96
return EXIT_FAILURE;
156
97
}
157
98
for(struct dirent *proc_ent = readdir(proc_dir);
158
99
proc_ent != NULL;
160
101
pid_t pid;
161
102
{
162
103
intmax_t tmpmax;
163
char *tmp;
164
errno = 0;
165
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
166
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
167
or tmpmax != (pid_t)tmpmax){
104
int numchars;
105
ret = sscanf(proc_ent->d_name, "%" SCNdMAX "%n", &tmpmax,
106
&numchars);
107
if(ret < 1 or tmpmax != (pid_t)tmpmax
108
or proc_ent->d_name[numchars] != '\0'){
168
109
/* Not a process */
169
110
continue;
170
111
}
178
119
char *exe_link;
179
120
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
180
121
if(ret == -1){
181
error_plus(0, errno, "asprintf");
182
exitstatus = EX_OSERR;
183
goto failure;
122
perror("asprintf");
123
free(prompt);
124
closedir(proc_dir);
125
return EXIT_FAILURE;
184
126
}
185
127
186
128
/* Check that it refers to a symlink owned by root:root */
191
133
free(exe_link);
192
134
continue;
193
135
}
194
int e = errno;
195
error_plus(0, errno, "lstat");
136
perror("lstat");
196
137
free(exe_link);
197
switch(e){
198
case EACCES:
199
case ENOTDIR:
200
case ELOOP:
201
default:
202
exitstatus = EX_OSFILE;
203
break;
204
case ENAMETOOLONG:
205
exitstatus = EX_OSERR;
206
break;
207
}
208
goto failure;
138
free(prompt);
139
closedir(proc_dir);
140
return EXIT_FAILURE;
209
141
}
210
142
if(not S_ISLNK(exe_stat.st_mode)
211
143
or exe_stat.st_uid != 0
225
157
}
226
158
}
227
159
closedir(proc_dir);
228
proc_dir = NULL;
229
160
}
230
161
if(splashy_pid == 0){
231
exitstatus = EX_UNAVAILABLE;
232
goto failure;
162
free(prompt);
163
return EXIT_FAILURE;
233
164
}
234
165
235
166
/* Set up the signal handler */
238
169
new_action = { .sa_handler = termination_handler,
239
170
.sa_flags = 0 };
240
171
sigemptyset(&new_action.sa_mask);
241
ret = sigaddset(&new_action.sa_mask, SIGINT);
242
if(ret == -1){
243
error_plus(0, errno, "sigaddset");
244
exitstatus = EX_OSERR;
245
goto failure;
246
}
247
ret = sigaddset(&new_action.sa_mask, SIGHUP);
248
if(ret == -1){
249
error_plus(0, errno, "sigaddset");
250
exitstatus = EX_OSERR;
251
goto failure;
252
}
253
ret = sigaddset(&new_action.sa_mask, SIGTERM);
254
if(ret == -1){
255
error_plus(0, errno, "sigaddset");
256
exitstatus = EX_OSERR;
257
goto failure;
258
}
172
sigaddset(&new_action.sa_mask, SIGINT);
173
sigaddset(&new_action.sa_mask, SIGHUP);
174
sigaddset(&new_action.sa_mask, SIGTERM);
259
175
ret = sigaction(SIGINT, NULL, &old_action);
260
176
if(ret == -1){
261
error_plus(0, errno, "sigaction");
262
exitstatus = EX_OSERR;
263
goto failure;
177
perror("sigaction");
178
free(prompt);
179
return EXIT_FAILURE;
264
180
}
265
181
if(old_action.sa_handler != SIG_IGN){
266
182
ret = sigaction(SIGINT, &new_action, NULL);
267
183
if(ret == -1){
268
error_plus(0, errno, "sigaction");
269
exitstatus = EX_OSERR;
270
goto failure;
184
perror("sigaction");
185
free(prompt);
186
return EXIT_FAILURE;
271
187
}
272
188
}
273
189
ret = sigaction(SIGHUP, NULL, &old_action);
274
190
if(ret == -1){
275
error_plus(0, errno, "sigaction");
276
exitstatus = EX_OSERR;
277
goto failure;
191
perror("sigaction");
192
free(prompt);
193
return EXIT_FAILURE;
278
194
}
279
195
if(old_action.sa_handler != SIG_IGN){
280
196
ret = sigaction(SIGHUP, &new_action, NULL);
281
197
if(ret == -1){
282
error_plus(0, errno, "sigaction");
283
exitstatus = EX_OSERR;
284
goto failure;
198
perror("sigaction");
199
free(prompt);
200
return EXIT_FAILURE;
285
201
}
286
202
}
287
203
ret = sigaction(SIGTERM, NULL, &old_action);
288
204
if(ret == -1){
289
error_plus(0, errno, "sigaction");
290
exitstatus = EX_OSERR;
291
goto failure;
205
perror("sigaction");
206
free(prompt);
207
return EXIT_FAILURE;
292
208
}
293
209
if(old_action.sa_handler != SIG_IGN){
294
210
ret = sigaction(SIGTERM, &new_action, NULL);
295
211
if(ret == -1){
296
error_plus(0, errno, "sigaction");
297
exitstatus = EX_OSERR;
298
goto failure;
212
perror("sigaction");
213
free(prompt);
214
return EXIT_FAILURE;
299
215
}
300
216
}
301
217
}
302
218
303
if(interrupted_by_signal){
304
goto failure;
305
}
306
307
219
/* Fork off the splashy command to prompt for password */
308
splashy_command_pid = fork();
309
if(splashy_command_pid != 0 and interrupted_by_signal){
310
goto failure;
311
}
312
if(splashy_command_pid == -1){
313
error_plus(0, errno, "fork");
314
exitstatus = EX_OSERR;
315
goto failure;
316
}
317
/* Child */
318
if(splashy_command_pid == 0){
319
if(not interrupted_by_signal){
220
pid_t splashy_command_pid = 0;
221
if(not interrupted_by_signal){
222
splashy_command_pid = fork();
223
if(splashy_command_pid == -1){
224
if(not interrupted_by_signal){
225
perror("fork");
226
}
227
return EXIT_FAILURE;
228
}
229
/* Child */
230
if(splashy_command_pid == 0){
320
231
const char splashy_command[] = "/sbin/splashy_update";
321
execl(splashy_command, splashy_command, prompt, (char *)NULL);
322
int e = errno;
323
error_plus(0, errno, "execl");
324
switch(e){
325
case EACCES:
326
case ENOENT:
327
case ENOEXEC:
328
case EINVAL:
329
_exit(EX_UNAVAILABLE);
330
case ENAMETOOLONG:
331
case E2BIG:
332
case ENOMEM:
333
case EFAULT:
334
case EIO:
335
case EMFILE:
336
case ENFILE:
337
case ETXTBSY:
338
default:
339
_exit(EX_OSERR);
340
case ENOTDIR:
341
case ELOOP:
342
case EISDIR:
343
#ifdef ELIBBAD
344
case ELIBBAD: /* Linux only */
345
#endif
346
case EPERM:
347
_exit(EX_OSFILE);
232
ret = execl(splashy_command, splashy_command, prompt,
233
(char *)NULL);
234
if(not interrupted_by_signal){
235
perror("execl");
348
236
}
237
free(prompt);
238
_exit(EXIT_FAILURE);
349
239
}
350
free(prompt);
351
_exit(EXIT_FAILURE);
352
240
}
353
241
354
242
/* Parent */
355
243
free(prompt);
356
prompt = NULL;
357
358
if(interrupted_by_signal){
359
goto failure;
360
}
361
244
362
245
/* Wait for command to complete */
363
{
246
if(not interrupted_by_signal and splashy_command_pid != 0){
364
247
int status;
365
do {
366
ret = waitpid(splashy_command_pid, &status, 0);
367
} while(ret == -1 and errno == EINTR
368
and not interrupted_by_signal);
369
if(interrupted_by_signal){
370
goto failure;
371
}
248
ret = waitpid(splashy_command_pid, &status, 0);
372
249
if(ret == -1){
373
error_plus(0, errno, "waitpid");
250
if(errno != EINTR){
251
perror("waitpid");
252
}
374
253
if(errno == ECHILD){
375
254
splashy_command_pid = 0;
376
255
}
377
256
} else {
378
257
/* The child process has exited */
379
258
splashy_command_pid = 0;
380
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
259
if(not interrupted_by_signal and WIFEXITED(status)
260
and WEXITSTATUS(status)==0){
381
261
return EXIT_SUCCESS;
382
262
}
383
263
}
384
264
}
385
386
failure:
387
388
free(prompt);
389
390
if(proc_dir != NULL){
391
TEMP_FAILURE_RETRY(closedir(proc_dir));
392
}
393
394
if(splashy_command_pid != 0){
395
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
396
397
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
398
sleep(2);
399
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
400
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
401
sleep(1);
402
}
403
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
404
if(new_splashy_pid == 0){
405
/* Child; will become new splashy process */
406
407
/* Make the effective user ID (root) the only user ID instead of
408
the real user ID (_mandos) */
409
ret = setuid(geteuid());
410
if(ret == -1){
411
error_plus(0, errno, "setuid");
412
}
413
414
setsid();
415
ret = chdir("/");
416
if(ret == -1){
417
error_plus(0, errno, "chdir");
418
}
419
/* if(fork() != 0){ */
420
/* _exit(EXIT_SUCCESS); */
421
/* } */
422
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
423
if(ret == -1){
424
error_plus(0, errno, "dup2");
425
_exit(EX_OSERR);
426
}
427
428
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
429
{
430
int e = errno;
431
error_plus(0, errno, "execl");
432
switch(e){
433
case EACCES:
434
case ENOENT:
435
case ENOEXEC:
436
default:
437
_exit(EX_UNAVAILABLE);
438
case ENAMETOOLONG:
439
case E2BIG:
440
case ENOMEM:
441
_exit(EX_OSERR);
442
case ENOTDIR:
443
case ELOOP:
444
_exit(EX_OSFILE);
445
}
446
}
447
}
448
}
449
450
if(interrupted_by_signal){
451
struct sigaction signal_action;
452
sigemptyset(&signal_action.sa_mask);
453
signal_action.sa_handler = SIG_DFL;
454
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
455
&signal_action, NULL));
456
if(ret == -1){
457
error_plus(0, errno, "sigaction");
458
}
459
do {
460
ret = raise(signal_received);
461
} while(ret != 0 and errno == EINTR);
462
if(ret != 0){
463
error_plus(0, errno, "raise");
464
abort();
465
}
466
TEMP_FAILURE_RETRY(pause());
467
}
468
469
return exitstatus;
265
kill(splashy_pid, SIGTERM);
266
if(interrupted_by_signal and splashy_command_pid != 0){
267
kill(splashy_command_pid, SIGTERM);
268
}
269
sleep(2);
270
while(kill(splashy_pid, 0) == 0){
271
kill(splashy_pid, SIGKILL);
272
sleep(1);
273
}
274
pid_t new_splashy_pid = fork();
275
if(new_splashy_pid == 0){
276
/* Child; will become new splashy process */
277
278
/* Make the effective user ID (root) the only user ID instead of
279
the real user ID (_mandos) */
280
ret = setuid(geteuid());
281
if(ret == -1){
282
perror("setuid");
283
}
284
285
setsid();
286
ret = chdir("/");
287
/* if(fork() != 0){ */
288
/* _exit(EXIT_SUCCESS); */
289
/* } */
290
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
291
if(ret == -1){
292
perror("dup2");
293
_exit(EXIT_FAILURE);
294
}
295
296
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
297
if(not interrupted_by_signal){
298
perror("execl");
299
}
300
_exit(EXIT_FAILURE);
301
}
302
303
return EXIT_FAILURE;
470
304
}
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