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- Committer: Teddy Hogeborn
- Date: 2012-01-15 21:02:37 UTC
- mfrom: (558 trunk)
- mto: (237.4.29 release)
- mto: This revision was merged to the branch mainline in revision 559.
- Revision ID: teddy@recompile.se-20120115210237-6mcl2zuoxyn5smr5
Merge from trunk.
- files added:
- DBUS-API
- debian/source
- 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 © 2008-2012 Teddy Hogeborn
6
* Copyright © 2008-2012 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, SCNdMAX */
39
#include <inttypes.h> /* intmax_t, strtoimax() */
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
#include <string.h> /* memcmp() */
46
#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() */
47
54
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
48
55
WEXITSTATUS() */
56
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
57
EX_UNAVAILABLE */
58
#include <stdarg.h> /* va_list, va_start(), ... */
49
59
50
60
sig_atomic_t interrupted_by_signal = 0;
51
52
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
}
53
92
interrupted_by_signal = 1;
93
signal_received = signum;
54
94
}
55
95
56
96
int main(__attribute__((unused))int argc,
57
97
__attribute__((unused))char **argv){
58
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;
59
104
60
105
/* Create prompt string */
61
char *prompt = NULL;
62
106
{
63
107
const char *const cryptsource = getenv("cryptsource");
64
108
const char *const crypttarget = getenv("crypttarget");
81
125
}
82
126
}
83
127
if(ret == -1){
84
return EXIT_FAILURE;
128
prompt = NULL;
129
exitstatus = EX_OSERR;
130
goto failure;
85
131
}
86
132
}
87
133
88
134
/* Find splashy process */
89
pid_t splashy_pid = 0;
90
135
{
91
136
const char splashy_name[] = "/sbin/splashy";
92
DIR *proc_dir = opendir("/proc");
137
proc_dir = opendir("/proc");
93
138
if(proc_dir == NULL){
94
free(prompt);
95
perror("opendir");
96
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;
97
157
}
98
158
for(struct dirent *proc_ent = readdir(proc_dir);
99
159
proc_ent != NULL;
101
161
pid_t pid;
102
162
{
103
163
intmax_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'){
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){
109
169
/* Not a process */
110
170
continue;
111
171
}
119
179
char *exe_link;
120
180
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
121
181
if(ret == -1){
122
perror("asprintf");
123
free(prompt);
124
closedir(proc_dir);
125
return EXIT_FAILURE;
182
error_plus(0, errno, "asprintf");
183
exitstatus = EX_OSERR;
184
goto failure;
126
185
}
127
186
128
187
/* Check that it refers to a symlink owned by root:root */
133
192
free(exe_link);
134
193
continue;
135
194
}
136
perror("lstat");
195
int e = errno;
196
error_plus(0, errno, "lstat");
137
197
free(exe_link);
138
free(prompt);
139
closedir(proc_dir);
140
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;
141
210
}
142
211
if(not S_ISLNK(exe_stat.st_mode)
143
212
or exe_stat.st_uid != 0
157
226
}
158
227
}
159
228
closedir(proc_dir);
229
proc_dir = NULL;
160
230
}
161
231
if(splashy_pid == 0){
162
free(prompt);
163
return EXIT_FAILURE;
232
exitstatus = EX_UNAVAILABLE;
233
goto failure;
164
234
}
165
235
166
236
/* Set up the signal handler */
169
239
new_action = { .sa_handler = termination_handler,
170
240
.sa_flags = 0 };
171
241
sigemptyset(&new_action.sa_mask);
172
sigaddset(&new_action.sa_mask, SIGINT);
173
sigaddset(&new_action.sa_mask, SIGHUP);
174
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
}
175
260
ret = sigaction(SIGINT, NULL, &old_action);
176
261
if(ret == -1){
177
perror("sigaction");
178
free(prompt);
179
return EXIT_FAILURE;
262
error_plus(0, errno, "sigaction");
263
exitstatus = EX_OSERR;
264
goto failure;
180
265
}
181
266
if(old_action.sa_handler != SIG_IGN){
182
267
ret = sigaction(SIGINT, &new_action, NULL);
183
268
if(ret == -1){
184
perror("sigaction");
185
free(prompt);
186
return EXIT_FAILURE;
269
error_plus(0, errno, "sigaction");
270
exitstatus = EX_OSERR;
271
goto failure;
187
272
}
188
273
}
189
274
ret = sigaction(SIGHUP, NULL, &old_action);
190
275
if(ret == -1){
191
perror("sigaction");
192
free(prompt);
193
return EXIT_FAILURE;
276
error_plus(0, errno, "sigaction");
277
exitstatus = EX_OSERR;
278
goto failure;
194
279
}
195
280
if(old_action.sa_handler != SIG_IGN){
196
281
ret = sigaction(SIGHUP, &new_action, NULL);
197
282
if(ret == -1){
198
perror("sigaction");
199
free(prompt);
200
return EXIT_FAILURE;
283
error_plus(0, errno, "sigaction");
284
exitstatus = EX_OSERR;
285
goto failure;
201
286
}
202
287
}
203
288
ret = sigaction(SIGTERM, NULL, &old_action);
204
289
if(ret == -1){
205
perror("sigaction");
206
free(prompt);
207
return EXIT_FAILURE;
290
error_plus(0, errno, "sigaction");
291
exitstatus = EX_OSERR;
292
goto failure;
208
293
}
209
294
if(old_action.sa_handler != SIG_IGN){
210
295
ret = sigaction(SIGTERM, &new_action, NULL);
211
296
if(ret == -1){
212
perror("sigaction");
213
free(prompt);
214
return EXIT_FAILURE;
297
error_plus(0, errno, "sigaction");
298
exitstatus = EX_OSERR;
299
goto failure;
215
300
}
216
301
}
217
302
}
218
303
304
if(interrupted_by_signal){
305
goto failure;
306
}
307
219
308
/* Fork off the splashy command to prompt for password */
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){
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){
231
321
const char splashy_command[] = "/sbin/splashy_update";
232
ret = execl(splashy_command, splashy_command, prompt,
233
(char *)NULL);
234
if(not interrupted_by_signal){
235
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);
236
349
}
237
free(prompt);
238
_exit(EXIT_FAILURE);
239
350
}
351
free(prompt);
352
_exit(EXIT_FAILURE);
240
353
}
241
354
242
355
/* Parent */
243
356
free(prompt);
357
prompt = NULL;
358
359
if(interrupted_by_signal){
360
goto failure;
361
}
244
362
245
363
/* Wait for command to complete */
246
if(not interrupted_by_signal and splashy_command_pid != 0){
364
{
247
365
int status;
248
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
}
249
373
if(ret == -1){
250
if(errno != EINTR){
251
perror("waitpid");
252
}
374
error_plus(0, errno, "waitpid");
253
375
if(errno == ECHILD){
254
376
splashy_command_pid = 0;
255
377
}
256
378
} else {
257
379
/* The child process has exited */
258
380
splashy_command_pid = 0;
259
if(not interrupted_by_signal and WIFEXITED(status)
260
and WEXITSTATUS(status)==0){
381
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
261
382
return EXIT_SUCCESS;
262
383
}
263
384
}
264
385
}
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;
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;
304
471
}
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