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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
- 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 © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 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
53
sig_atomic_t interrupted_by_signal = 0;
54
int signal_received;
55
const char usplash_name[] = "/sbin/usplash";
56
57
static void termination_handler(int signum){
58
if(interrupted_by_signal){
59
return;
60
}
61
interrupted_by_signal = 1;
62
signal_received = signum;
63
}
64
65
static bool usplash_write(int *fifo_fd_r,
66
const char *cmd, const char *arg){
67
/*
68
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
69
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
70
* SEE ALSO
71
* usplash_write(8)
72
*/
73
int ret;
74
if(*fifo_fd_r == -1){
75
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
76
if(ret == -1){
77
return false;
78
}
79
*fifo_fd_r = ret;
80
}
81
82
const char *cmd_line;
83
size_t cmd_line_len;
84
char *cmd_line_alloc = NULL;
85
if(arg == NULL){
86
cmd_line = cmd;
87
cmd_line_len = strlen(cmd) + 1;
88
} else {
89
do {
90
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
91
if(ret == -1){
92
int e = errno;
93
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
94
errno = e;
95
return false;
96
}
97
} while(ret == -1);
98
cmd_line = cmd_line_alloc;
99
cmd_line_len = (size_t)ret + 1;
100
}
101
102
size_t written = 0;
103
ssize_t sret = 0;
104
while(written < cmd_line_len){
105
sret = write(*fifo_fd_r, cmd_line + written,
106
cmd_line_len - written);
107
if(sret == -1){
108
int e = errno;
109
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
110
free(cmd_line_alloc);
111
errno = e;
112
return false;
113
}
114
written += (size_t)sret;
115
}
116
free(cmd_line_alloc);
117
118
return true;
119
}
120
121
/* Create prompt string */
122
char *makeprompt(void){
123
int ret = 0;
124
char *prompt;
125
const char *const cryptsource = getenv("cryptsource");
126
const char *const crypttarget = getenv("crypttarget");
127
const char prompt_start[] = "Enter passphrase to unlock the disk";
128
129
if(cryptsource == NULL){
130
if(crypttarget == NULL){
131
ret = asprintf(&prompt, "%s: ", prompt_start);
132
} else {
133
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
134
crypttarget);
135
}
136
} else {
137
if(crypttarget == NULL){
138
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
139
} else {
140
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
141
cryptsource, crypttarget);
142
}
143
}
144
if(ret == -1){
145
return NULL;
146
}
147
return prompt;
148
}
149
150
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
151
int ret = 0;
152
ssize_t sret = 0;
153
char *cmdline = NULL;
154
size_t cmdline_len = 0;
155
DIR *proc_dir = opendir("/proc");
156
if(proc_dir == NULL){
157
error(0, errno, "opendir");
158
return -1;
159
}
160
errno = 0;
161
for(struct dirent *proc_ent = readdir(proc_dir);
162
proc_ent != NULL;
163
proc_ent = readdir(proc_dir)){
164
pid_t pid;
165
{
166
intmax_t tmpmax;
167
char *tmp;
168
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
169
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
170
or tmpmax != (pid_t)tmpmax){
171
/* Not a process */
172
errno = 0;
173
continue;
174
}
175
pid = (pid_t)tmpmax;
176
}
177
/* Find the executable name by doing readlink() on the
178
/proc/<pid>/exe link */
179
char exe_target[sizeof(usplash_name)];
180
{
181
/* create file name string */
182
char *exe_link;
183
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
184
if(ret == -1){
185
error(0, errno, "asprintf");
186
goto fail_find_usplash;
187
}
188
189
/* Check that it refers to a symlink owned by root:root */
190
struct stat exe_stat;
191
ret = lstat(exe_link, &exe_stat);
192
if(ret == -1){
193
if(errno == ENOENT){
194
free(exe_link);
195
continue;
196
}
197
error(0, errno, "lstat");
198
free(exe_link);
199
goto fail_find_usplash;
200
}
201
if(not S_ISLNK(exe_stat.st_mode)
202
or exe_stat.st_uid != 0
203
or exe_stat.st_gid != 0){
204
free(exe_link);
205
continue;
206
}
207
208
sret = readlink(exe_link, exe_target, sizeof(exe_target));
209
free(exe_link);
210
}
211
/* Compare executable name */
212
if((sret != ((ssize_t)sizeof(exe_target)-1))
213
or (memcmp(usplash_name, exe_target,
214
sizeof(exe_target)-1) != 0)){
215
/* Not it */
216
continue;
217
}
218
/* Found usplash */
219
/* Read and save the command line of usplash in "cmdline" */
220
{
221
/* Open /proc/<pid>/cmdline */
222
int cl_fd;
223
{
224
char *cmdline_filename;
225
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
226
proc_ent->d_name);
227
if(ret == -1){
228
error(0, errno, "asprintf");
229
goto fail_find_usplash;
230
}
231
cl_fd = open(cmdline_filename, O_RDONLY);
232
free(cmdline_filename);
233
if(cl_fd == -1){
234
error(0, errno, "open");
235
goto fail_find_usplash;
236
}
237
}
238
size_t cmdline_allocated = 0;
239
char *tmp;
240
const size_t blocksize = 1024;
241
do {
242
/* Allocate more space? */
243
if(cmdline_len + blocksize > cmdline_allocated){
244
tmp = realloc(cmdline, cmdline_allocated + blocksize);
245
if(tmp == NULL){
246
error(0, errno, "realloc");
247
close(cl_fd);
248
goto fail_find_usplash;
249
}
250
cmdline = tmp;
251
cmdline_allocated += blocksize;
252
}
253
/* Read data */
254
sret = read(cl_fd, cmdline + cmdline_len,
255
cmdline_allocated - cmdline_len);
256
if(sret == -1){
257
error(0, errno, "read");
258
close(cl_fd);
259
goto fail_find_usplash;
260
}
261
cmdline_len += (size_t)sret;
262
} while(sret != 0);
263
ret = close(cl_fd);
264
if(ret == -1){
265
error(0, errno, "close");
266
goto fail_find_usplash;
267
}
268
}
269
/* Close directory */
270
ret = closedir(proc_dir);
271
if(ret == -1){
272
error(0, errno, "closedir");
273
goto fail_find_usplash;
274
}
275
/* Success */
276
*cmdline_r = cmdline;
277
*cmdline_len_r = cmdline_len;
278
return pid;
279
}
280
281
fail_find_usplash:
282
283
free(cmdline);
284
if(proc_dir != NULL){
285
int e = errno;
286
closedir(proc_dir);
287
errno = e;
288
}
289
return 0;
290
}
291
292
int main(__attribute__((unused))int argc,
293
__attribute__((unused))char **argv){
294
int ret = 0;
295
ssize_t sret;
296
int fifo_fd = -1;
297
int outfifo_fd = -1;
298
char *buf = NULL;
299
size_t buf_len = 0;
300
pid_t usplash_pid = -1;
301
bool usplash_accessed = false;
302
int status = EXIT_FAILURE; /* Default failure exit status */
303
304
char *prompt = makeprompt();
305
if(prompt == NULL){
306
status = EX_OSERR;
307
goto failure;
308
}
309
310
/* Find usplash process */
311
char *cmdline = NULL;
312
size_t cmdline_len = 0;
313
usplash_pid = find_usplash(&cmdline, &cmdline_len);
314
if(usplash_pid == 0){
315
status = EX_UNAVAILABLE;
316
goto failure;
317
}
318
319
/* Set up the signal handler */
320
{
321
struct sigaction old_action,
322
new_action = { .sa_handler = termination_handler,
323
.sa_flags = 0 };
324
sigemptyset(&new_action.sa_mask);
325
ret = sigaddset(&new_action.sa_mask, SIGINT);
326
if(ret == -1){
327
error(0, errno, "sigaddset");
328
status = EX_OSERR;
329
goto failure;
330
}
331
ret = sigaddset(&new_action.sa_mask, SIGHUP);
332
if(ret == -1){
333
error(0, errno, "sigaddset");
334
status = EX_OSERR;
335
goto failure;
336
}
337
ret = sigaddset(&new_action.sa_mask, SIGTERM);
338
if(ret == -1){
339
error(0, errno, "sigaddset");
340
status = EX_OSERR;
341
goto failure;
342
}
343
ret = sigaction(SIGINT, NULL, &old_action);
344
if(ret == -1){
345
if(errno != EINTR){
346
error(0, errno, "sigaction");
347
status = EX_OSERR;
348
}
349
goto failure;
350
}
351
if(old_action.sa_handler != SIG_IGN){
352
ret = sigaction(SIGINT, &new_action, NULL);
353
if(ret == -1){
354
if(errno != EINTR){
355
error(0, errno, "sigaction");
356
status = EX_OSERR;
357
}
358
goto failure;
359
}
360
}
361
ret = sigaction(SIGHUP, NULL, &old_action);
362
if(ret == -1){
363
if(errno != EINTR){
364
error(0, errno, "sigaction");
365
status = EX_OSERR;
366
}
367
goto failure;
368
}
369
if(old_action.sa_handler != SIG_IGN){
370
ret = sigaction(SIGHUP, &new_action, NULL);
371
if(ret == -1){
372
if(errno != EINTR){
373
error(0, errno, "sigaction");
374
status = EX_OSERR;
375
}
376
goto failure;
377
}
378
}
379
ret = sigaction(SIGTERM, NULL, &old_action);
380
if(ret == -1){
381
if(errno != EINTR){
382
error(0, errno, "sigaction");
383
status = EX_OSERR;
384
}
385
goto failure;
386
}
387
if(old_action.sa_handler != SIG_IGN){
388
ret = sigaction(SIGTERM, &new_action, NULL);
389
if(ret == -1){
390
if(errno != EINTR){
391
error(0, errno, "sigaction");
392
status = EX_OSERR;
393
}
394
goto failure;
395
}
396
}
397
}
398
399
usplash_accessed = true;
400
/* Write command to FIFO */
401
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
402
if(errno != EINTR){
403
error(0, errno, "usplash_write");
404
status = EX_OSERR;
405
}
406
goto failure;
407
}
408
409
if(interrupted_by_signal){
410
goto failure;
411
}
412
413
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
414
if(errno != EINTR){
415
error(0, errno, "usplash_write");
416
status = EX_OSERR;
417
}
418
goto failure;
419
}
420
421
if(interrupted_by_signal){
422
goto failure;
423
}
424
425
free(prompt);
426
prompt = NULL;
427
428
/* Read reply from usplash */
429
/* Open FIFO */
430
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
431
if(outfifo_fd == -1){
432
if(errno != EINTR){
433
error(0, errno, "open");
434
status = EX_OSERR;
435
}
436
goto failure;
437
}
438
439
if(interrupted_by_signal){
440
goto failure;
441
}
442
443
/* Read from FIFO */
444
size_t buf_allocated = 0;
445
const size_t blocksize = 1024;
446
do {
447
/* Allocate more space */
448
if(buf_len + blocksize > buf_allocated){
449
char *tmp = realloc(buf, buf_allocated + blocksize);
450
if(tmp == NULL){
451
if(errno != EINTR){
452
error(0, errno, "realloc");
453
status = EX_OSERR;
454
}
455
goto failure;
456
}
457
buf = tmp;
458
buf_allocated += blocksize;
459
}
460
sret = read(outfifo_fd, buf + buf_len,
461
buf_allocated - buf_len);
462
if(sret == -1){
463
if(errno != EINTR){
464
error(0, errno, "read");
465
status = EX_OSERR;
466
}
467
TEMP_FAILURE_RETRY(close(outfifo_fd));
468
goto failure;
469
}
470
if(interrupted_by_signal){
471
break;
472
}
473
474
buf_len += (size_t)sret;
475
} while(sret != 0);
476
ret = close(outfifo_fd);
477
if(ret == -1){
478
if(errno != EINTR){
479
error(0, errno, "close");
480
status = EX_OSERR;
481
}
482
goto failure;
483
}
484
outfifo_fd = -1;
485
486
if(interrupted_by_signal){
487
goto failure;
488
}
489
490
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
491
if(errno != EINTR){
492
error(0, errno, "usplash_write");
493
status = EX_OSERR;
494
}
495
goto failure;
496
}
497
498
if(interrupted_by_signal){
499
goto failure;
500
}
501
502
ret = close(fifo_fd);
503
if(ret == -1){
504
if(errno != EINTR){
505
error(0, errno, "close");
506
status = EX_OSERR;
507
}
508
goto failure;
509
}
510
fifo_fd = -1;
511
512
/* Print password to stdout */
513
size_t written = 0;
514
while(written < buf_len){
515
do {
516
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
517
if(sret == -1){
518
if(errno != EINTR){
519
error(0, errno, "write");
520
status = EX_OSERR;
521
}
522
goto failure;
523
}
524
} while(sret == -1);
525
526
if(interrupted_by_signal){
527
goto failure;
528
}
529
written += (size_t)sret;
530
}
531
free(buf);
532
buf = NULL;
533
534
if(interrupted_by_signal){
535
goto failure;
536
}
537
538
free(cmdline);
539
return EXIT_SUCCESS;
540
541
failure:
542
543
free(buf);
544
545
free(prompt);
546
547
/* If usplash was never accessed, we can stop now */
548
if(not usplash_accessed){
549
return status;
550
}
551
552
/* Close FIFO */
553
if(fifo_fd != -1){
554
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
555
if(ret == -1 and errno != EINTR){
556
error(0, errno, "close");
557
}
558
fifo_fd = -1;
559
}
560
561
/* Close output FIFO */
562
if(outfifo_fd != -1){
563
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
564
if(ret == -1){
565
error(0, errno, "close");
566
}
567
}
568
569
/* Create argc and argv for new usplash*/
570
int cmdline_argc = 0;
571
char **cmdline_argv = malloc(sizeof(char *));
572
{
573
size_t position = 0;
574
while(position < cmdline_len){
575
char **tmp = realloc(cmdline_argv,
576
(sizeof(char *)
577
* (size_t)(cmdline_argc + 2)));
578
if(tmp == NULL){
579
error(0, errno, "realloc");
580
free(cmdline_argv);
581
return status;
582
}
583
cmdline_argv = tmp;
584
cmdline_argv[cmdline_argc] = cmdline + position;
585
cmdline_argc++;
586
position += strlen(cmdline + position) + 1;
587
}
588
cmdline_argv[cmdline_argc] = NULL;
589
}
590
/* Kill old usplash */
591
kill(usplash_pid, SIGTERM);
592
sleep(2);
593
while(kill(usplash_pid, 0) == 0){
594
kill(usplash_pid, SIGKILL);
595
sleep(1);
596
}
597
598
pid_t new_usplash_pid = fork();
599
if(new_usplash_pid == 0){
600
/* Child; will become new usplash process */
601
602
/* Make the effective user ID (root) the only user ID instead of
603
the real user ID (_mandos) */
604
ret = setuid(geteuid());
605
if(ret == -1){
606
error(0, errno, "setuid");
607
}
608
609
setsid();
610
ret = chdir("/");
611
if(ret == -1){
612
error(0, errno, "chdir");
613
_exit(EX_OSERR);
614
}
615
/* if(fork() != 0){ */
616
/* _exit(EXIT_SUCCESS); */
617
/* } */
618
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
619
if(ret == -1){
620
error(0, errno, "dup2");
621
_exit(EX_OSERR);
622
}
623
624
execv(usplash_name, cmdline_argv);
625
if(not interrupted_by_signal){
626
error(0, errno, "execv");
627
}
628
free(cmdline);
629
free(cmdline_argv);
630
_exit(EX_OSERR);
631
}
632
free(cmdline);
633
free(cmdline_argv);
634
sleep(2);
635
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
636
if(errno != EINTR){
637
error(0, errno, "usplash_write");
638
}
639
}
640
641
/* Close FIFO (again) */
642
if(fifo_fd != -1){
643
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
644
if(ret == -1 and errno != EINTR){
645
error(0, errno, "close");
646
}
647
fifo_fd = -1;
648
}
649
650
if(interrupted_by_signal){
651
struct sigaction signal_action = { .sa_handler = SIG_DFL };
652
sigemptyset(&signal_action.sa_mask);
653
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
654
&signal_action, NULL));
655
if(ret == -1){
656
error(0, errno, "sigaction");
657
}
658
do {
659
ret = raise(signal_received);
660
} while(ret != 0 and errno == EINTR);
661
if(ret != 0){
662
error(0, errno, "raise");
663
abort();
664
}
665
TEMP_FAILURE_RETRY(pause());
666
}
667
668
return status;
669
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0