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- Committer: Teddy Hogeborn
- Date: 2008-09-21 14:05:44 UTC
- mfrom: (24.1.103 mandos)
- Revision ID: teddy@fukt.bsnet.se-20080921140544-e9qo7alcl0bne2mn
Merge.
- files added:
- debian/mandos-client.config
- files removed:
- DBUS-API
- debian/source
- files modified:
- .bzrignore
added
removed
plugins.d/usplash.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Usplash - Read a password from usplash and output it
4
*
5
* Copyright © 2008-2011 Teddy Hogeborn
6
* Copyright © 2008-2011 Björn Påhlsson
7
*
8
* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
10
* published by the Free Software Foundation, either version 3 of the
11
* License, or (at your option) any later version.
12
*
13
* This program is distributed in the hope that it will be useful, but
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
* General Public License for more details.
17
*
18
* You should have received a copy of the GNU General Public License
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
21
*
22
* Contact the authors at <mandos@fukt.bsnet.se>.
23
*/
24
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction(),
29
SIG_IGN, kill(), SIGKILL */
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
32
#include <iso646.h> /* and, or, not*/
33
#include <errno.h> /* errno, EINTR */
34
#include <error.h>
35
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
36
dirent */
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strlen(), memcmp() */
39
#include <stdio.h> /* asprintf()*/
40
#include <unistd.h> /* close(), write(), readlink(),
41
read(), STDOUT_FILENO, sleep(),
42
fork(), setuid(), geteuid(),
43
setsid(), chdir(), dup2(),
44
STDERR_FILENO, execv() */
45
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit(),
47
getenv() */
48
#include <dirent.h> /* opendir(), readdir(), closedir() */
49
#include <inttypes.h> /* intmax_t, strtoimax() */
50
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
51
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
#include <argz.h> /* argz_count(), argz_extract() */
53
54
sig_atomic_t interrupted_by_signal = 0;
55
int signal_received;
56
const char usplash_name[] = "/sbin/usplash";
57
58
static void termination_handler(int signum){
59
if(interrupted_by_signal){
60
return;
61
}
62
interrupted_by_signal = 1;
63
signal_received = signum;
64
}
65
66
static bool usplash_write(int *fifo_fd_r,
67
const char *cmd, const char *arg){
68
/*
69
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
70
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
71
* SEE ALSO
72
* usplash_write(8)
73
*/
74
int ret;
75
if(*fifo_fd_r == -1){
76
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
77
if(ret == -1){
78
return false;
79
}
80
*fifo_fd_r = ret;
81
}
82
83
const char *cmd_line;
84
size_t cmd_line_len;
85
char *cmd_line_alloc = NULL;
86
if(arg == NULL){
87
cmd_line = cmd;
88
cmd_line_len = strlen(cmd) + 1;
89
} else {
90
do {
91
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
92
if(ret == -1){
93
int e = errno;
94
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
95
errno = e;
96
return false;
97
}
98
} while(ret == -1);
99
cmd_line = cmd_line_alloc;
100
cmd_line_len = (size_t)ret + 1;
101
}
102
103
size_t written = 0;
104
ssize_t sret = 0;
105
while(written < cmd_line_len){
106
sret = write(*fifo_fd_r, cmd_line + written,
107
cmd_line_len - written);
108
if(sret == -1){
109
int e = errno;
110
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
111
free(cmd_line_alloc);
112
errno = e;
113
return false;
114
}
115
written += (size_t)sret;
116
}
117
free(cmd_line_alloc);
118
119
return true;
120
}
121
122
/* Create prompt string */
123
char *makeprompt(void){
124
int ret = 0;
125
char *prompt;
126
const char *const cryptsource = getenv("cryptsource");
127
const char *const crypttarget = getenv("crypttarget");
128
const char prompt_start[] = "Enter passphrase to unlock the disk";
129
130
if(cryptsource == NULL){
131
if(crypttarget == NULL){
132
ret = asprintf(&prompt, "%s: ", prompt_start);
133
} else {
134
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
135
crypttarget);
136
}
137
} else {
138
if(crypttarget == NULL){
139
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
140
} else {
141
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
142
cryptsource, crypttarget);
143
}
144
}
145
if(ret == -1){
146
return NULL;
147
}
148
return prompt;
149
}
150
151
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
152
int ret = 0;
153
ssize_t sret = 0;
154
char *cmdline = NULL;
155
size_t cmdline_len = 0;
156
DIR *proc_dir = opendir("/proc");
157
if(proc_dir == NULL){
158
error(0, errno, "opendir");
159
return -1;
160
}
161
errno = 0;
162
for(struct dirent *proc_ent = readdir(proc_dir);
163
proc_ent != NULL;
164
proc_ent = readdir(proc_dir)){
165
pid_t pid;
166
{
167
intmax_t tmpmax;
168
char *tmp;
169
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
170
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
171
or tmpmax != (pid_t)tmpmax){
172
/* Not a process */
173
errno = 0;
174
continue;
175
}
176
pid = (pid_t)tmpmax;
177
}
178
/* Find the executable name by doing readlink() on the
179
/proc/<pid>/exe link */
180
char exe_target[sizeof(usplash_name)];
181
{
182
/* create file name string */
183
char *exe_link;
184
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
185
if(ret == -1){
186
error(0, errno, "asprintf");
187
goto fail_find_usplash;
188
}
189
190
/* Check that it refers to a symlink owned by root:root */
191
struct stat exe_stat;
192
ret = lstat(exe_link, &exe_stat);
193
if(ret == -1){
194
if(errno == ENOENT){
195
free(exe_link);
196
continue;
197
}
198
error(0, errno, "lstat");
199
free(exe_link);
200
goto fail_find_usplash;
201
}
202
if(not S_ISLNK(exe_stat.st_mode)
203
or exe_stat.st_uid != 0
204
or exe_stat.st_gid != 0){
205
free(exe_link);
206
continue;
207
}
208
209
sret = readlink(exe_link, exe_target, sizeof(exe_target));
210
free(exe_link);
211
}
212
/* Compare executable name */
213
if((sret != ((ssize_t)sizeof(exe_target)-1))
214
or (memcmp(usplash_name, exe_target,
215
sizeof(exe_target)-1) != 0)){
216
/* Not it */
217
continue;
218
}
219
/* Found usplash */
220
/* Read and save the command line of usplash in "cmdline" */
221
{
222
/* Open /proc/<pid>/cmdline */
223
int cl_fd;
224
{
225
char *cmdline_filename;
226
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
227
proc_ent->d_name);
228
if(ret == -1){
229
error(0, errno, "asprintf");
230
goto fail_find_usplash;
231
}
232
cl_fd = open(cmdline_filename, O_RDONLY);
233
free(cmdline_filename);
234
if(cl_fd == -1){
235
error(0, errno, "open");
236
goto fail_find_usplash;
237
}
238
}
239
size_t cmdline_allocated = 0;
240
char *tmp;
241
const size_t blocksize = 1024;
242
do {
243
/* Allocate more space? */
244
if(cmdline_len + blocksize > cmdline_allocated){
245
tmp = realloc(cmdline, cmdline_allocated + blocksize);
246
if(tmp == NULL){
247
error(0, errno, "realloc");
248
close(cl_fd);
249
goto fail_find_usplash;
250
}
251
cmdline = tmp;
252
cmdline_allocated += blocksize;
253
}
254
/* Read data */
255
sret = read(cl_fd, cmdline + cmdline_len,
256
cmdline_allocated - cmdline_len);
257
if(sret == -1){
258
error(0, errno, "read");
259
close(cl_fd);
260
goto fail_find_usplash;
261
}
262
cmdline_len += (size_t)sret;
263
} while(sret != 0);
264
ret = close(cl_fd);
265
if(ret == -1){
266
error(0, errno, "close");
267
goto fail_find_usplash;
268
}
269
}
270
/* Close directory */
271
ret = closedir(proc_dir);
272
if(ret == -1){
273
error(0, errno, "closedir");
274
goto fail_find_usplash;
275
}
276
/* Success */
277
*cmdline_r = cmdline;
278
*cmdline_len_r = cmdline_len;
279
return pid;
280
}
281
282
fail_find_usplash:
283
284
free(cmdline);
285
if(proc_dir != NULL){
286
int e = errno;
287
closedir(proc_dir);
288
errno = e;
289
}
290
return 0;
291
}
292
293
int main(__attribute__((unused))int argc,
294
__attribute__((unused))char **argv){
295
int ret = 0;
296
ssize_t sret;
297
int fifo_fd = -1;
298
int outfifo_fd = -1;
299
char *buf = NULL;
300
size_t buf_len = 0;
301
pid_t usplash_pid = -1;
302
bool usplash_accessed = false;
303
int status = EXIT_FAILURE; /* Default failure exit status */
304
305
char *prompt = makeprompt();
306
if(prompt == NULL){
307
status = EX_OSERR;
308
goto failure;
309
}
310
311
/* Find usplash process */
312
char *cmdline = NULL;
313
size_t cmdline_len = 0;
314
usplash_pid = find_usplash(&cmdline, &cmdline_len);
315
if(usplash_pid == 0){
316
status = EX_UNAVAILABLE;
317
goto failure;
318
}
319
320
/* Set up the signal handler */
321
{
322
struct sigaction old_action,
323
new_action = { .sa_handler = termination_handler,
324
.sa_flags = 0 };
325
sigemptyset(&new_action.sa_mask);
326
ret = sigaddset(&new_action.sa_mask, SIGINT);
327
if(ret == -1){
328
error(0, errno, "sigaddset");
329
status = EX_OSERR;
330
goto failure;
331
}
332
ret = sigaddset(&new_action.sa_mask, SIGHUP);
333
if(ret == -1){
334
error(0, errno, "sigaddset");
335
status = EX_OSERR;
336
goto failure;
337
}
338
ret = sigaddset(&new_action.sa_mask, SIGTERM);
339
if(ret == -1){
340
error(0, errno, "sigaddset");
341
status = EX_OSERR;
342
goto failure;
343
}
344
ret = sigaction(SIGINT, NULL, &old_action);
345
if(ret == -1){
346
if(errno != EINTR){
347
error(0, errno, "sigaction");
348
status = EX_OSERR;
349
}
350
goto failure;
351
}
352
if(old_action.sa_handler != SIG_IGN){
353
ret = sigaction(SIGINT, &new_action, NULL);
354
if(ret == -1){
355
if(errno != EINTR){
356
error(0, errno, "sigaction");
357
status = EX_OSERR;
358
}
359
goto failure;
360
}
361
}
362
ret = sigaction(SIGHUP, NULL, &old_action);
363
if(ret == -1){
364
if(errno != EINTR){
365
error(0, errno, "sigaction");
366
status = EX_OSERR;
367
}
368
goto failure;
369
}
370
if(old_action.sa_handler != SIG_IGN){
371
ret = sigaction(SIGHUP, &new_action, NULL);
372
if(ret == -1){
373
if(errno != EINTR){
374
error(0, errno, "sigaction");
375
status = EX_OSERR;
376
}
377
goto failure;
378
}
379
}
380
ret = sigaction(SIGTERM, NULL, &old_action);
381
if(ret == -1){
382
if(errno != EINTR){
383
error(0, errno, "sigaction");
384
status = EX_OSERR;
385
}
386
goto failure;
387
}
388
if(old_action.sa_handler != SIG_IGN){
389
ret = sigaction(SIGTERM, &new_action, NULL);
390
if(ret == -1){
391
if(errno != EINTR){
392
error(0, errno, "sigaction");
393
status = EX_OSERR;
394
}
395
goto failure;
396
}
397
}
398
}
399
400
usplash_accessed = true;
401
/* Write command to FIFO */
402
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
403
if(errno != EINTR){
404
error(0, errno, "usplash_write");
405
status = EX_OSERR;
406
}
407
goto failure;
408
}
409
410
if(interrupted_by_signal){
411
goto failure;
412
}
413
414
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
415
if(errno != EINTR){
416
error(0, errno, "usplash_write");
417
status = EX_OSERR;
418
}
419
goto failure;
420
}
421
422
if(interrupted_by_signal){
423
goto failure;
424
}
425
426
free(prompt);
427
prompt = NULL;
428
429
/* Read reply from usplash */
430
/* Open FIFO */
431
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
432
if(outfifo_fd == -1){
433
if(errno != EINTR){
434
error(0, errno, "open");
435
status = EX_OSERR;
436
}
437
goto failure;
438
}
439
440
if(interrupted_by_signal){
441
goto failure;
442
}
443
444
/* Read from FIFO */
445
size_t buf_allocated = 0;
446
const size_t blocksize = 1024;
447
do {
448
/* Allocate more space */
449
if(buf_len + blocksize > buf_allocated){
450
char *tmp = realloc(buf, buf_allocated + blocksize);
451
if(tmp == NULL){
452
if(errno != EINTR){
453
error(0, errno, "realloc");
454
status = EX_OSERR;
455
}
456
goto failure;
457
}
458
buf = tmp;
459
buf_allocated += blocksize;
460
}
461
sret = read(outfifo_fd, buf + buf_len,
462
buf_allocated - buf_len);
463
if(sret == -1){
464
if(errno != EINTR){
465
error(0, errno, "read");
466
status = EX_OSERR;
467
}
468
TEMP_FAILURE_RETRY(close(outfifo_fd));
469
goto failure;
470
}
471
if(interrupted_by_signal){
472
break;
473
}
474
475
buf_len += (size_t)sret;
476
} while(sret != 0);
477
ret = close(outfifo_fd);
478
if(ret == -1){
479
if(errno != EINTR){
480
error(0, errno, "close");
481
status = EX_OSERR;
482
}
483
goto failure;
484
}
485
outfifo_fd = -1;
486
487
if(interrupted_by_signal){
488
goto failure;
489
}
490
491
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
492
if(errno != EINTR){
493
error(0, errno, "usplash_write");
494
status = EX_OSERR;
495
}
496
goto failure;
497
}
498
499
if(interrupted_by_signal){
500
goto failure;
501
}
502
503
ret = close(fifo_fd);
504
if(ret == -1){
505
if(errno != EINTR){
506
error(0, errno, "close");
507
status = EX_OSERR;
508
}
509
goto failure;
510
}
511
fifo_fd = -1;
512
513
/* Print password to stdout */
514
size_t written = 0;
515
while(written < buf_len){
516
do {
517
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
518
if(sret == -1){
519
if(errno != EINTR){
520
error(0, errno, "write");
521
status = EX_OSERR;
522
}
523
goto failure;
524
}
525
} while(sret == -1);
526
527
if(interrupted_by_signal){
528
goto failure;
529
}
530
written += (size_t)sret;
531
}
532
free(buf);
533
buf = NULL;
534
535
if(interrupted_by_signal){
536
goto failure;
537
}
538
539
free(cmdline);
540
return EXIT_SUCCESS;
541
542
failure:
543
544
free(buf);
545
546
free(prompt);
547
548
/* If usplash was never accessed, we can stop now */
549
if(not usplash_accessed){
550
return status;
551
}
552
553
/* Close FIFO */
554
if(fifo_fd != -1){
555
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
556
if(ret == -1 and errno != EINTR){
557
error(0, errno, "close");
558
}
559
fifo_fd = -1;
560
}
561
562
/* Close output FIFO */
563
if(outfifo_fd != -1){
564
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
565
if(ret == -1){
566
error(0, errno, "close");
567
}
568
}
569
570
/* Create argv for new usplash*/
571
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
572
* sizeof(char *)); /* Count args */
573
if(cmdline_argv == NULL){
574
error(0, errno, "malloc");
575
return status;
576
}
577
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
578
579
/* Kill old usplash */
580
kill(usplash_pid, SIGTERM);
581
sleep(2);
582
while(kill(usplash_pid, 0) == 0){
583
kill(usplash_pid, SIGKILL);
584
sleep(1);
585
}
586
587
pid_t new_usplash_pid = fork();
588
if(new_usplash_pid == 0){
589
/* Child; will become new usplash process */
590
591
/* Make the effective user ID (root) the only user ID instead of
592
the real user ID (_mandos) */
593
ret = setuid(geteuid());
594
if(ret == -1){
595
error(0, errno, "setuid");
596
}
597
598
setsid();
599
ret = chdir("/");
600
if(ret == -1){
601
error(0, errno, "chdir");
602
_exit(EX_OSERR);
603
}
604
/* if(fork() != 0){ */
605
/* _exit(EXIT_SUCCESS); */
606
/* } */
607
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
608
if(ret == -1){
609
error(0, errno, "dup2");
610
_exit(EX_OSERR);
611
}
612
613
execv(usplash_name, cmdline_argv);
614
if(not interrupted_by_signal){
615
error(0, errno, "execv");
616
}
617
free(cmdline);
618
free(cmdline_argv);
619
_exit(EX_OSERR);
620
}
621
free(cmdline);
622
free(cmdline_argv);
623
sleep(2);
624
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
625
if(errno != EINTR){
626
error(0, errno, "usplash_write");
627
}
628
}
629
630
/* Close FIFO (again) */
631
if(fifo_fd != -1){
632
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
633
if(ret == -1 and errno != EINTR){
634
error(0, errno, "close");
635
}
636
fifo_fd = -1;
637
}
638
639
if(interrupted_by_signal){
640
struct sigaction signal_action = { .sa_handler = SIG_DFL };
641
sigemptyset(&signal_action.sa_mask);
642
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
643
&signal_action, NULL));
644
if(ret == -1){
645
error(0, errno, "sigaction");
646
}
647
do {
648
ret = raise(signal_received);
649
} while(ret != 0 and errno == EINTR);
650
if(ret != 0){
651
error(0, errno, "raise");
652
abort();
653
}
654
TEMP_FAILURE_RETRY(pause());
655
}
656
657
return status;
658
}
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