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- Committer: Teddy Hogeborn
- Date: 2014-05-13 06:06:28 UTC
- mfrom: (237.7.231 trunk)
- Revision ID: teddy@recompile.se-20140513060628-9wpzoh97hape9ub8
Merge from trunk.
- files added:
- DBUS-API
- debian/source
- debian/upstream
- network-hooks.d
- files renamed:
- mandos-list => mandos-ctl
- 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 © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
5
* Copyright © 2008-2014 Teddy Hogeborn
6
* Copyright © 2008-2014 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 <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
22
* Contact the authors at <mandos@recompile.se>.
24
23
*/
25
24
26
#define _GNU_SOURCE /* asprintf() */
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
27
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
27
sigemptyset(), sigaddset(), SIGINT,
29
28
SIGHUP, SIGTERM, sigaction,
30
29
SIG_IGN, kill(), SIGKILL */
31
30
#include <stddef.h> /* NULL */
32
31
#include <stdlib.h> /* getenv() */
33
#include <stdio.h> /* asprintf(), perror(), sscanf() */
32
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
33
fprintf() */
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
40
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
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
#include <string.h> /* memcmp() */
45
#include <errno.h> /* errno */
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() */
46
54
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
47
55
WEXITSTATUS() */
56
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
57
EX_UNAVAILABLE */
58
#include <stdarg.h> /* va_list, va_start(), ... */
48
59
49
60
sig_atomic_t interrupted_by_signal = 0;
50
51
static void termination_handler(__attribute__((unused))int signum){
61
int signal_received;
62
63
/* Function to use when printing errors */
64
__attribute__((format (gnu_printf, 3, 4)))
65
void error_plus(int status, int errnum, const char *formatstring,
66
...){
67
va_list ap;
68
char *text;
69
int ret;
70
71
va_start(ap, formatstring);
72
ret = vasprintf(&text, formatstring, ap);
73
if(ret == -1){
74
fprintf(stderr, "Mandos plugin %s: ",
75
program_invocation_short_name);
76
vfprintf(stderr, formatstring, ap);
77
fprintf(stderr, ": ");
78
fprintf(stderr, "%s\n", strerror(errnum));
79
error(status, errno, "vasprintf while printing error");
80
return;
81
}
82
fprintf(stderr, "Mandos plugin ");
83
error(status, errnum, "%s", text);
84
free(text);
85
}
86
87
88
static void termination_handler(int signum){
89
if(interrupted_by_signal){
90
return;
91
}
52
92
interrupted_by_signal = 1;
93
signal_received = signum;
53
94
}
54
95
55
96
int main(__attribute__((unused))int argc,
56
97
__attribute__((unused))char **argv){
57
98
int ret = 0;
99
char *prompt = NULL;
100
DIR *proc_dir = NULL;
101
pid_t splashy_pid = 0;
102
pid_t splashy_command_pid = 0;
103
int exitstatus = EXIT_FAILURE;
58
104
59
105
/* Create prompt string */
60
char *prompt = NULL;
61
106
{
62
107
const char *const cryptsource = getenv("cryptsource");
63
108
const char *const crypttarget = getenv("crypttarget");
80
125
}
81
126
}
82
127
if(ret == -1){
83
return EXIT_FAILURE;
128
prompt = NULL;
129
exitstatus = EX_OSERR;
130
goto failure;
84
131
}
85
132
}
86
133
87
134
/* Find splashy process */
88
pid_t splashy_pid = 0;
89
135
{
90
136
const char splashy_name[] = "/sbin/splashy";
91
DIR *proc_dir = opendir("/proc");
137
proc_dir = opendir("/proc");
92
138
if(proc_dir == NULL){
93
free(prompt);
94
perror("opendir");
95
return EXIT_FAILURE;
139
int e = errno;
140
error_plus(0, errno, "opendir");
141
switch(e){
142
case EACCES:
143
case ENOTDIR:
144
case ELOOP:
145
case ENOENT:
146
default:
147
exitstatus = EX_OSFILE;
148
break;
149
case ENAMETOOLONG:
150
case EMFILE:
151
case ENFILE:
152
case ENOMEM:
153
exitstatus = EX_OSERR;
154
break;
155
}
156
goto failure;
96
157
}
97
158
for(struct dirent *proc_ent = readdir(proc_dir);
98
159
proc_ent != NULL;
99
160
proc_ent = readdir(proc_dir)){
100
161
pid_t pid;
101
/* In the GNU C library, pid_t is always int */
102
ret = sscanf(proc_ent->d_name, "%d", &pid);
103
if(ret != 1){
104
/* Not a process */
105
continue;
162
{
163
intmax_t tmpmax;
164
char *tmp;
165
errno = 0;
166
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
167
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
168
or tmpmax != (pid_t)tmpmax){
169
/* Not a process */
170
continue;
171
}
172
pid = (pid_t)tmpmax;
106
173
}
107
174
/* Find the executable name by doing readlink() on the
108
175
/proc/<pid>/exe link */
112
179
char *exe_link;
113
180
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
114
181
if(ret == -1){
115
perror("asprintf");
116
free(prompt);
117
closedir(proc_dir);
118
return EXIT_FAILURE;
182
error_plus(0, errno, "asprintf");
183
exitstatus = EX_OSERR;
184
goto failure;
119
185
}
120
186
121
187
/* Check that it refers to a symlink owned by root:root */
126
192
free(exe_link);
127
193
continue;
128
194
}
129
perror("lstat");
195
int e = errno;
196
error_plus(0, errno, "lstat");
130
197
free(exe_link);
131
free(prompt);
132
closedir(proc_dir);
133
return EXIT_FAILURE;
198
switch(e){
199
case EACCES:
200
case ENOTDIR:
201
case ELOOP:
202
default:
203
exitstatus = EX_OSFILE;
204
break;
205
case ENAMETOOLONG:
206
exitstatus = EX_OSERR;
207
break;
208
}
209
goto failure;
134
210
}
135
211
if(not S_ISLNK(exe_stat.st_mode)
136
212
or exe_stat.st_uid != 0
150
226
}
151
227
}
152
228
closedir(proc_dir);
229
proc_dir = NULL;
153
230
}
154
231
if(splashy_pid == 0){
155
free(prompt);
156
return EXIT_FAILURE;
232
exitstatus = EX_UNAVAILABLE;
233
goto failure;
157
234
}
158
235
159
236
/* Set up the signal handler */
162
239
new_action = { .sa_handler = termination_handler,
163
240
.sa_flags = 0 };
164
241
sigemptyset(&new_action.sa_mask);
165
sigaddset(&new_action.sa_mask, SIGINT);
166
sigaddset(&new_action.sa_mask, SIGHUP);
167
sigaddset(&new_action.sa_mask, SIGTERM);
242
ret = sigaddset(&new_action.sa_mask, SIGINT);
243
if(ret == -1){
244
error_plus(0, errno, "sigaddset");
245
exitstatus = EX_OSERR;
246
goto failure;
247
}
248
ret = sigaddset(&new_action.sa_mask, SIGHUP);
249
if(ret == -1){
250
error_plus(0, errno, "sigaddset");
251
exitstatus = EX_OSERR;
252
goto failure;
253
}
254
ret = sigaddset(&new_action.sa_mask, SIGTERM);
255
if(ret == -1){
256
error_plus(0, errno, "sigaddset");
257
exitstatus = EX_OSERR;
258
goto failure;
259
}
168
260
ret = sigaction(SIGINT, NULL, &old_action);
169
261
if(ret == -1){
170
perror("sigaction");
171
free(prompt);
172
return EXIT_FAILURE;
262
error_plus(0, errno, "sigaction");
263
exitstatus = EX_OSERR;
264
goto failure;
173
265
}
174
266
if(old_action.sa_handler != SIG_IGN){
175
267
ret = sigaction(SIGINT, &new_action, NULL);
176
268
if(ret == -1){
177
perror("sigaction");
178
free(prompt);
179
return EXIT_FAILURE;
269
error_plus(0, errno, "sigaction");
270
exitstatus = EX_OSERR;
271
goto failure;
180
272
}
181
273
}
182
274
ret = sigaction(SIGHUP, NULL, &old_action);
183
275
if(ret == -1){
184
perror("sigaction");
185
free(prompt);
186
return EXIT_FAILURE;
276
error_plus(0, errno, "sigaction");
277
exitstatus = EX_OSERR;
278
goto failure;
187
279
}
188
280
if(old_action.sa_handler != SIG_IGN){
189
281
ret = sigaction(SIGHUP, &new_action, NULL);
190
282
if(ret == -1){
191
perror("sigaction");
192
free(prompt);
193
return EXIT_FAILURE;
283
error_plus(0, errno, "sigaction");
284
exitstatus = EX_OSERR;
285
goto failure;
194
286
}
195
287
}
196
288
ret = sigaction(SIGTERM, NULL, &old_action);
197
289
if(ret == -1){
198
perror("sigaction");
199
free(prompt);
200
return EXIT_FAILURE;
290
error_plus(0, errno, "sigaction");
291
exitstatus = EX_OSERR;
292
goto failure;
201
293
}
202
294
if(old_action.sa_handler != SIG_IGN){
203
295
ret = sigaction(SIGTERM, &new_action, NULL);
204
296
if(ret == -1){
205
perror("sigaction");
206
free(prompt);
207
return EXIT_FAILURE;
297
error_plus(0, errno, "sigaction");
298
exitstatus = EX_OSERR;
299
goto failure;
208
300
}
209
301
}
210
302
}
211
303
304
if(interrupted_by_signal){
305
goto failure;
306
}
307
212
308
/* Fork off the splashy command to prompt for password */
213
pid_t splashy_command_pid = 0;
214
if(not interrupted_by_signal){
215
splashy_command_pid = fork();
216
if(splashy_command_pid == -1){
217
if(not interrupted_by_signal){
218
perror("fork");
219
}
220
return EXIT_FAILURE;
221
}
222
/* Child */
223
if(splashy_command_pid == 0){
309
splashy_command_pid = fork();
310
if(splashy_command_pid != 0 and interrupted_by_signal){
311
goto failure;
312
}
313
if(splashy_command_pid == -1){
314
error_plus(0, errno, "fork");
315
exitstatus = EX_OSERR;
316
goto failure;
317
}
318
/* Child */
319
if(splashy_command_pid == 0){
320
if(not interrupted_by_signal){
224
321
const char splashy_command[] = "/sbin/splashy_update";
225
ret = execl(splashy_command, splashy_command, prompt,
226
(char *)NULL);
227
if(not interrupted_by_signal){
228
perror("execl");
322
execl(splashy_command, splashy_command, prompt, (char *)NULL);
323
int e = errno;
324
error_plus(0, errno, "execl");
325
switch(e){
326
case EACCES:
327
case ENOENT:
328
case ENOEXEC:
329
case EINVAL:
330
_exit(EX_UNAVAILABLE);
331
case ENAMETOOLONG:
332
case E2BIG:
333
case ENOMEM:
334
case EFAULT:
335
case EIO:
336
case EMFILE:
337
case ENFILE:
338
case ETXTBSY:
339
default:
340
_exit(EX_OSERR);
341
case ENOTDIR:
342
case ELOOP:
343
case EISDIR:
344
#ifdef ELIBBAD
345
case ELIBBAD: /* Linux only */
346
#endif
347
case EPERM:
348
_exit(EX_OSFILE);
229
349
}
230
free(prompt);
231
_exit(EXIT_FAILURE);
232
350
}
351
free(prompt);
352
_exit(EXIT_FAILURE);
233
353
}
234
354
235
355
/* Parent */
236
356
free(prompt);
357
prompt = NULL;
358
359
if(interrupted_by_signal){
360
goto failure;
361
}
237
362
238
363
/* Wait for command to complete */
239
if(not interrupted_by_signal and splashy_command_pid != 0){
364
{
240
365
int status;
241
ret = waitpid(splashy_command_pid, &status, 0);
366
do {
367
ret = waitpid(splashy_command_pid, &status, 0);
368
} while(ret == -1 and errno == EINTR
369
and not interrupted_by_signal);
370
if(interrupted_by_signal){
371
goto failure;
372
}
242
373
if(ret == -1){
243
if(errno != EINTR){
244
perror("waitpid");
245
}
374
error_plus(0, errno, "waitpid");
246
375
if(errno == ECHILD){
247
376
splashy_command_pid = 0;
248
377
}
249
378
} else {
250
379
/* The child process has exited */
251
380
splashy_command_pid = 0;
252
if(not interrupted_by_signal and WIFEXITED(status)
253
and WEXITSTATUS(status)==0){
381
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
254
382
return EXIT_SUCCESS;
255
383
}
256
384
}
257
385
}
258
kill(splashy_pid, SIGTERM);
259
if(interrupted_by_signal and splashy_command_pid != 0){
260
kill(splashy_command_pid, SIGTERM);
261
}
262
sleep(2);
263
while(kill(splashy_pid, 0) == 0){
264
kill(splashy_pid, SIGKILL);
265
sleep(1);
266
}
267
pid_t new_splashy_pid = fork();
268
if(new_splashy_pid == 0){
269
/* Child; will become new splashy process */
270
271
/* Make the effective user ID (root) the only user ID instead of
272
the real user ID (mandos) */
273
ret = setuid(geteuid());
274
if(ret == -1){
275
perror("setuid");
276
}
277
278
setsid();
279
ret = chdir("/");
280
/* if(fork() != 0){ */
281
/* _exit(EXIT_SUCCESS); */
282
/* } */
283
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
284
if(ret == -1){
285
perror("dup2");
286
_exit(EXIT_FAILURE);
287
}
288
289
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
290
if(not interrupted_by_signal){
291
perror("execl");
292
}
293
_exit(EXIT_FAILURE);
294
}
295
296
return EXIT_FAILURE;
386
387
failure:
388
389
free(prompt);
390
391
if(proc_dir != NULL){
392
TEMP_FAILURE_RETRY(closedir(proc_dir));
393
}
394
395
if(splashy_command_pid != 0){
396
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
397
398
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
399
sleep(2);
400
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
401
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
402
sleep(1);
403
}
404
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
405
if(new_splashy_pid == 0){
406
/* Child; will become new splashy process */
407
408
/* Make the effective user ID (root) the only user ID instead of
409
the real user ID (_mandos) */
410
ret = setuid(geteuid());
411
if(ret == -1){
412
error_plus(0, errno, "setuid");
413
}
414
415
setsid();
416
ret = chdir("/");
417
if(ret == -1){
418
error_plus(0, errno, "chdir");
419
}
420
/* if(fork() != 0){ */
421
/* _exit(EXIT_SUCCESS); */
422
/* } */
423
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
424
if(ret == -1){
425
error_plus(0, errno, "dup2");
426
_exit(EX_OSERR);
427
}
428
429
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
430
{
431
int e = errno;
432
error_plus(0, errno, "execl");
433
switch(e){
434
case EACCES:
435
case ENOENT:
436
case ENOEXEC:
437
default:
438
_exit(EX_UNAVAILABLE);
439
case ENAMETOOLONG:
440
case E2BIG:
441
case ENOMEM:
442
_exit(EX_OSERR);
443
case ENOTDIR:
444
case ELOOP:
445
_exit(EX_OSFILE);
446
}
447
}
448
}
449
}
450
451
if(interrupted_by_signal){
452
struct sigaction signal_action;
453
sigemptyset(&signal_action.sa_mask);
454
signal_action.sa_handler = SIG_DFL;
455
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
456
&signal_action, NULL));
457
if(ret == -1){
458
error_plus(0, errno, "sigaction");
459
}
460
do {
461
ret = raise(signal_received);
462
} while(ret != 0 and errno == EINTR);
463
if(ret != 0){
464
error_plus(0, errno, "raise");
465
abort();
466
}
467
TEMP_FAILURE_RETRY(pause());
468
}
469
470
return exitstatus;
297
471
}
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