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- Committer: Teddy Hogeborn
- Date: 2009-02-23 11:52:42 UTC
- Revision ID: teddy@fukt.bsnet.se-20090223115242-5930ewin7m4o6zpr
* README (The Plugin System): Improve wording.
added
removed
plugins.d/splashy.c
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,
29
30
SIG_IGN, kill(), SIGKILL */
30
31
#include <stddef.h> /* NULL */
31
32
#include <stdlib.h> /* getenv() */
32
#include <stdio.h> /* asprintf() */
33
#include <stdio.h> /* asprintf(), perror() */
33
34
#include <stdlib.h> /* EXIT_FAILURE, free(),
34
35
EXIT_SUCCESS */
35
36
#include <sys/types.h> /* pid_t, DIR, struct dirent,
40
41
#include <iso646.h> /* not, or, and */
41
42
#include <unistd.h> /* readlink(), fork(), execl(),
42
43
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit(),
44
pause() */
44
STDOUT_FILENO, _exit() */
45
45
#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 */
52
#include <error.h> /* error() */
46
#include <errno.h> /* errno */
53
47
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
54
48
WEXITSTATUS() */
55
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
56
EX_UNAVAILABLE */
57
49
58
50
sig_atomic_t interrupted_by_signal = 0;
59
int signal_received;
60
51
61
static void termination_handler(int signum){
62
if(interrupted_by_signal){
63
return;
64
}
52
static void termination_handler(__attribute__((unused))int signum){
65
53
interrupted_by_signal = 1;
66
signal_received = signum;
67
54
}
68
55
69
56
int main(__attribute__((unused))int argc,
70
57
__attribute__((unused))char **argv){
71
58
int ret = 0;
59
60
/* Create prompt string */
72
61
char *prompt = NULL;
73
DIR *proc_dir = NULL;
74
pid_t splashy_pid = 0;
75
pid_t splashy_command_pid = 0;
76
int exitstatus = EXIT_FAILURE;
77
78
/* Create prompt string */
79
62
{
80
63
const char *const cryptsource = getenv("cryptsource");
81
64
const char *const crypttarget = getenv("crypttarget");
98
81
}
99
82
}
100
83
if(ret == -1){
101
prompt = NULL;
102
exitstatus = EX_OSERR;
103
goto failure;
84
return EXIT_FAILURE;
104
85
}
105
86
}
106
87
107
88
/* Find splashy process */
89
pid_t splashy_pid = 0;
108
90
{
109
91
const char splashy_name[] = "/sbin/splashy";
110
proc_dir = opendir("/proc");
92
DIR *proc_dir = opendir("/proc");
111
93
if(proc_dir == NULL){
112
int e = errno;
113
error(0, errno, "opendir");
114
switch(e){
115
case EACCES:
116
case ENOTDIR:
117
case ELOOP:
118
case ENOENT:
119
default:
120
exitstatus = EX_OSFILE;
121
break;
122
case ENAMETOOLONG:
123
case EMFILE:
124
case ENFILE:
125
case ENOMEM:
126
exitstatus = EX_OSERR;
127
break;
128
}
129
goto failure;
94
free(prompt);
95
perror("opendir");
96
return EXIT_FAILURE;
130
97
}
131
98
for(struct dirent *proc_ent = readdir(proc_dir);
132
99
proc_ent != NULL;
152
119
char *exe_link;
153
120
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
154
121
if(ret == -1){
155
error(0, errno, "asprintf");
156
exitstatus = EX_OSERR;
157
goto failure;
122
perror("asprintf");
123
free(prompt);
124
closedir(proc_dir);
125
return EXIT_FAILURE;
158
126
}
159
127
160
128
/* Check that it refers to a symlink owned by root:root */
165
133
free(exe_link);
166
134
continue;
167
135
}
168
int e = errno;
169
error(0, errno, "lstat");
136
perror("lstat");
170
137
free(exe_link);
171
switch(e){
172
case EACCES:
173
case ENOTDIR:
174
case ELOOP:
175
default:
176
exitstatus = EX_OSFILE;
177
break;
178
case ENAMETOOLONG:
179
exitstatus = EX_OSERR;
180
break;
181
}
182
goto failure;
138
free(prompt);
139
closedir(proc_dir);
140
return EXIT_FAILURE;
183
141
}
184
142
if(not S_ISLNK(exe_stat.st_mode)
185
143
or exe_stat.st_uid != 0
199
157
}
200
158
}
201
159
closedir(proc_dir);
202
proc_dir = NULL;
203
160
}
204
161
if(splashy_pid == 0){
205
exitstatus = EX_UNAVAILABLE;
206
goto failure;
162
free(prompt);
163
return EXIT_FAILURE;
207
164
}
208
165
209
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/* Set up the signal handler */
212
169
new_action = { .sa_handler = termination_handler,
213
170
.sa_flags = 0 };
214
171
sigemptyset(&new_action.sa_mask);
215
ret = sigaddset(&new_action.sa_mask, SIGINT);
216
if(ret == -1){
217
error(0, errno, "sigaddset");
218
exitstatus = EX_OSERR;
219
goto failure;
220
}
221
ret = sigaddset(&new_action.sa_mask, SIGHUP);
222
if(ret == -1){
223
error(0, errno, "sigaddset");
224
exitstatus = EX_OSERR;
225
goto failure;
226
}
227
ret = sigaddset(&new_action.sa_mask, SIGTERM);
228
if(ret == -1){
229
error(0, errno, "sigaddset");
230
exitstatus = EX_OSERR;
231
goto failure;
232
}
172
sigaddset(&new_action.sa_mask, SIGINT);
173
sigaddset(&new_action.sa_mask, SIGHUP);
174
sigaddset(&new_action.sa_mask, SIGTERM);
233
175
ret = sigaction(SIGINT, NULL, &old_action);
234
176
if(ret == -1){
235
error(0, errno, "sigaction");
236
exitstatus = EX_OSERR;
237
goto failure;
177
perror("sigaction");
178
free(prompt);
179
return EXIT_FAILURE;
238
180
}
239
181
if(old_action.sa_handler != SIG_IGN){
240
182
ret = sigaction(SIGINT, &new_action, NULL);
241
183
if(ret == -1){
242
error(0, errno, "sigaction");
243
exitstatus = EX_OSERR;
244
goto failure;
184
perror("sigaction");
185
free(prompt);
186
return EXIT_FAILURE;
245
187
}
246
188
}
247
189
ret = sigaction(SIGHUP, NULL, &old_action);
248
190
if(ret == -1){
249
error(0, errno, "sigaction");
250
exitstatus = EX_OSERR;
251
goto failure;
191
perror("sigaction");
192
free(prompt);
193
return EXIT_FAILURE;
252
194
}
253
195
if(old_action.sa_handler != SIG_IGN){
254
196
ret = sigaction(SIGHUP, &new_action, NULL);
255
197
if(ret == -1){
256
error(0, errno, "sigaction");
257
exitstatus = EX_OSERR;
258
goto failure;
198
perror("sigaction");
199
free(prompt);
200
return EXIT_FAILURE;
259
201
}
260
202
}
261
203
ret = sigaction(SIGTERM, NULL, &old_action);
262
204
if(ret == -1){
263
error(0, errno, "sigaction");
264
exitstatus = EX_OSERR;
265
goto failure;
205
perror("sigaction");
206
free(prompt);
207
return EXIT_FAILURE;
266
208
}
267
209
if(old_action.sa_handler != SIG_IGN){
268
210
ret = sigaction(SIGTERM, &new_action, NULL);
269
211
if(ret == -1){
270
error(0, errno, "sigaction");
271
exitstatus = EX_OSERR;
272
goto failure;
212
perror("sigaction");
213
free(prompt);
214
return EXIT_FAILURE;
273
215
}
274
216
}
275
217
}
276
218
277
if(interrupted_by_signal){
278
goto failure;
279
}
280
281
219
/* Fork off the splashy command to prompt for password */
282
splashy_command_pid = fork();
283
if(splashy_command_pid != 0 and interrupted_by_signal){
284
goto failure;
285
}
286
if(splashy_command_pid == -1){
287
error(0, errno, "fork");
288
exitstatus = EX_OSERR;
289
goto failure;
290
}
291
/* Child */
292
if(splashy_command_pid == 0){
293
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){
294
231
const char splashy_command[] = "/sbin/splashy_update";
295
execl(splashy_command, splashy_command, prompt, (char *)NULL);
296
int e = errno;
297
error(0, errno, "execl");
298
switch(e){
299
case EACCES:
300
case ENOENT:
301
case ENOEXEC:
302
case EINVAL:
303
_exit(EX_UNAVAILABLE);
304
case ENAMETOOLONG:
305
case E2BIG:
306
case ENOMEM:
307
case EFAULT:
308
case EIO:
309
case EMFILE:
310
case ENFILE:
311
case ETXTBSY:
312
default:
313
_exit(EX_OSERR);
314
case ENOTDIR:
315
case ELOOP:
316
case EISDIR:
317
case ELIBBAD:
318
case EPERM:
319
_exit(EX_OSFILE);
232
ret = execl(splashy_command, splashy_command, prompt,
233
(char *)NULL);
234
if(not interrupted_by_signal){
235
perror("execl");
320
236
}
237
free(prompt);
238
_exit(EXIT_FAILURE);
321
239
}
322
free(prompt);
323
_exit(EXIT_FAILURE);
324
240
}
325
241
326
242
/* Parent */
327
243
free(prompt);
328
prompt = NULL;
329
330
if(interrupted_by_signal){
331
goto failure;
332
}
333
244
334
245
/* Wait for command to complete */
335
{
246
if(not interrupted_by_signal and splashy_command_pid != 0){
336
247
int status;
337
do {
338
ret = waitpid(splashy_command_pid, &status, 0);
339
} while(ret == -1 and errno == EINTR
340
and not interrupted_by_signal);
341
if(interrupted_by_signal){
342
goto failure;
343
}
248
ret = waitpid(splashy_command_pid, &status, 0);
344
249
if(ret == -1){
345
error(0, errno, "waitpid");
250
if(errno != EINTR){
251
perror("waitpid");
252
}
346
253
if(errno == ECHILD){
347
254
splashy_command_pid = 0;
348
255
}
349
256
} else {
350
257
/* The child process has exited */
351
258
splashy_command_pid = 0;
352
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
259
if(not interrupted_by_signal and WIFEXITED(status)
260
and WEXITSTATUS(status)==0){
353
261
return EXIT_SUCCESS;
354
262
}
355
263
}
356
264
}
357
358
failure:
359
360
free(prompt);
361
362
if(proc_dir != NULL){
363
TEMP_FAILURE_RETRY(closedir(proc_dir));
364
}
365
366
if(splashy_command_pid != 0){
367
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
368
369
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
370
sleep(2);
371
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
372
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
373
sleep(1);
374
}
375
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
376
if(new_splashy_pid == 0){
377
/* Child; will become new splashy process */
378
379
/* Make the effective user ID (root) the only user ID instead of
380
the real user ID (_mandos) */
381
ret = setuid(geteuid());
382
if(ret == -1){
383
error(0, errno, "setuid");
384
}
385
386
setsid();
387
ret = chdir("/");
388
if(ret == -1){
389
error(0, errno, "chdir");
390
}
391
/* if(fork() != 0){ */
392
/* _exit(EXIT_SUCCESS); */
393
/* } */
394
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
395
if(ret == -1){
396
error(0, errno, "dup2");
397
_exit(EX_OSERR);
398
}
399
400
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
401
{
402
int e = errno;
403
error(0, errno, "execl");
404
switch(e){
405
case EACCES:
406
case ENOENT:
407
case ENOEXEC:
408
default:
409
_exit(EX_UNAVAILABLE);
410
case ENAMETOOLONG:
411
case E2BIG:
412
case ENOMEM:
413
_exit(EX_OSERR);
414
case ENOTDIR:
415
case ELOOP:
416
_exit(EX_OSFILE);
417
}
418
}
419
}
420
}
421
422
if(interrupted_by_signal){
423
struct sigaction signal_action;
424
sigemptyset(&signal_action.sa_mask);
425
signal_action.sa_handler = SIG_DFL;
426
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
427
&signal_action, NULL));
428
if(ret == -1){
429
error(0, errno, "sigaction");
430
}
431
do {
432
ret = raise(signal_received);
433
} while(ret != 0 and errno == EINTR);
434
if(ret != 0){
435
error(0, errno, "raise");
436
abort();
437
}
438
TEMP_FAILURE_RETRY(pause());
439
}
440
441
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;
442
304
}
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