To get this branch, use:
bzr branch
http://bzr.recompile.se/loggerhead/mandos/trunk
« back to all changes in this revision
Viewing changes to plugins.d/usplash.c
- browse files at revision 177
- compare with another revision
- download diff
- download tarball
- view history from revision 177
- Committer: Teddy Hogeborn
- Date: 2008-09-07 09:36:35 UTC
- Revision ID: teddy@fukt.bsnet.se-20080907093635-yg1y272yv53dijhp
* Makefile (CONFDIR): Changed to be the same ("/etc/mandos") in both a
/usr/local install and a package install.
(KEYDIR): Changed /usr/local install value to be "/etc/mandos/keys".
(INITRAMFSTOOLS): Use $(DESTDIR) in /usr/local value too.
* initramfs-tools-hook: Look in "/etc/mandos/keys" too.
/usr/local install and a package install.
(KEYDIR): Changed /usr/local install value to be "/etc/mandos/keys".
(INITRAMFSTOOLS): Use $(DESTDIR) in /usr/local value too.
* initramfs-tools-hook: Look in "/etc/mandos/keys" too.
- files added:
- etc-plugins.d-README
- files removed:
- .bzr-builddeb
- debian
- debian/po
- 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(), strerror() */
39
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
40
fprintf() */
41
#include <unistd.h> /* close(), write(), readlink(),
42
read(), STDOUT_FILENO, sleep(),
43
fork(), setuid(), geteuid(),
44
setsid(), chdir(), dup2(),
45
STDERR_FILENO, execv() */
46
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
47
EXIT_SUCCESS, malloc(), _exit(),
48
getenv() */
49
#include <dirent.h> /* opendir(), readdir(), closedir() */
50
#include <inttypes.h> /* intmax_t, strtoimax() */
51
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
52
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
55
56
sig_atomic_t interrupted_by_signal = 0;
57
int signal_received;
58
const char usplash_name[] = "/sbin/usplash";
59
60
/* Function to use when printing errors */
61
void error_plus(int status, int errnum, const char *formatstring,
62
...){
63
va_list ap;
64
char *text;
65
int ret;
66
67
va_start(ap, formatstring);
68
ret = vasprintf(&text, formatstring, ap);
69
if (ret == -1){
70
fprintf(stderr, "Mandos plugin %s: ",
71
program_invocation_short_name);
72
vfprintf(stderr, formatstring, ap);
73
fprintf(stderr, ": ");
74
fprintf(stderr, "%s\n", strerror(errnum));
75
error(status, errno, "vasprintf while printing error");
76
return;
77
}
78
fprintf(stderr, "Mandos plugin ");
79
error(status, errnum, "%s", text);
80
free(text);
81
}
82
83
static void termination_handler(int signum){
84
if(interrupted_by_signal){
85
return;
86
}
87
interrupted_by_signal = 1;
88
signal_received = signum;
89
}
90
91
static bool usplash_write(int *fifo_fd_r,
92
const char *cmd, const char *arg){
93
/*
94
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
95
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
96
* SEE ALSO
97
* usplash_write(8)
98
*/
99
int ret;
100
if(*fifo_fd_r == -1){
101
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
102
if(ret == -1){
103
return false;
104
}
105
*fifo_fd_r = ret;
106
}
107
108
const char *cmd_line;
109
size_t cmd_line_len;
110
char *cmd_line_alloc = NULL;
111
if(arg == NULL){
112
cmd_line = cmd;
113
cmd_line_len = strlen(cmd) + 1;
114
} else {
115
do {
116
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
117
if(ret == -1){
118
int e = errno;
119
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
120
errno = e;
121
return false;
122
}
123
} while(ret == -1);
124
cmd_line = cmd_line_alloc;
125
cmd_line_len = (size_t)ret + 1;
126
}
127
128
size_t written = 0;
129
ssize_t sret = 0;
130
while(written < cmd_line_len){
131
sret = write(*fifo_fd_r, cmd_line + written,
132
cmd_line_len - written);
133
if(sret == -1){
134
int e = errno;
135
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
136
free(cmd_line_alloc);
137
errno = e;
138
return false;
139
}
140
written += (size_t)sret;
141
}
142
free(cmd_line_alloc);
143
144
return true;
145
}
146
147
/* Create prompt string */
148
char *makeprompt(void){
149
int ret = 0;
150
char *prompt;
151
const char *const cryptsource = getenv("cryptsource");
152
const char *const crypttarget = getenv("crypttarget");
153
const char prompt_start[] = "Enter passphrase to unlock the disk";
154
155
if(cryptsource == NULL){
156
if(crypttarget == NULL){
157
ret = asprintf(&prompt, "%s: ", prompt_start);
158
} else {
159
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
160
crypttarget);
161
}
162
} else {
163
if(crypttarget == NULL){
164
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
165
} else {
166
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
167
cryptsource, crypttarget);
168
}
169
}
170
if(ret == -1){
171
return NULL;
172
}
173
return prompt;
174
}
175
176
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
177
int ret = 0;
178
ssize_t sret = 0;
179
char *cmdline = NULL;
180
size_t cmdline_len = 0;
181
DIR *proc_dir = opendir("/proc");
182
if(proc_dir == NULL){
183
error_plus(0, errno, "opendir");
184
return -1;
185
}
186
errno = 0;
187
for(struct dirent *proc_ent = readdir(proc_dir);
188
proc_ent != NULL;
189
proc_ent = readdir(proc_dir)){
190
pid_t pid;
191
{
192
intmax_t tmpmax;
193
char *tmp;
194
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
195
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
196
or tmpmax != (pid_t)tmpmax){
197
/* Not a process */
198
errno = 0;
199
continue;
200
}
201
pid = (pid_t)tmpmax;
202
}
203
/* Find the executable name by doing readlink() on the
204
/proc/<pid>/exe link */
205
char exe_target[sizeof(usplash_name)];
206
{
207
/* create file name string */
208
char *exe_link;
209
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
210
if(ret == -1){
211
error_plus(0, errno, "asprintf");
212
goto fail_find_usplash;
213
}
214
215
/* Check that it refers to a symlink owned by root:root */
216
struct stat exe_stat;
217
ret = lstat(exe_link, &exe_stat);
218
if(ret == -1){
219
if(errno == ENOENT){
220
free(exe_link);
221
continue;
222
}
223
error_plus(0, errno, "lstat");
224
free(exe_link);
225
goto fail_find_usplash;
226
}
227
if(not S_ISLNK(exe_stat.st_mode)
228
or exe_stat.st_uid != 0
229
or exe_stat.st_gid != 0){
230
free(exe_link);
231
continue;
232
}
233
234
sret = readlink(exe_link, exe_target, sizeof(exe_target));
235
free(exe_link);
236
}
237
/* Compare executable name */
238
if((sret != ((ssize_t)sizeof(exe_target)-1))
239
or (memcmp(usplash_name, exe_target,
240
sizeof(exe_target)-1) != 0)){
241
/* Not it */
242
continue;
243
}
244
/* Found usplash */
245
/* Read and save the command line of usplash in "cmdline" */
246
{
247
/* Open /proc/<pid>/cmdline */
248
int cl_fd;
249
{
250
char *cmdline_filename;
251
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
252
proc_ent->d_name);
253
if(ret == -1){
254
error_plus(0, errno, "asprintf");
255
goto fail_find_usplash;
256
}
257
cl_fd = open(cmdline_filename, O_RDONLY);
258
free(cmdline_filename);
259
if(cl_fd == -1){
260
error_plus(0, errno, "open");
261
goto fail_find_usplash;
262
}
263
}
264
size_t cmdline_allocated = 0;
265
char *tmp;
266
const size_t blocksize = 1024;
267
do {
268
/* Allocate more space? */
269
if(cmdline_len + blocksize > cmdline_allocated){
270
tmp = realloc(cmdline, cmdline_allocated + blocksize);
271
if(tmp == NULL){
272
error_plus(0, errno, "realloc");
273
close(cl_fd);
274
goto fail_find_usplash;
275
}
276
cmdline = tmp;
277
cmdline_allocated += blocksize;
278
}
279
/* Read data */
280
sret = read(cl_fd, cmdline + cmdline_len,
281
cmdline_allocated - cmdline_len);
282
if(sret == -1){
283
error_plus(0, errno, "read");
284
close(cl_fd);
285
goto fail_find_usplash;
286
}
287
cmdline_len += (size_t)sret;
288
} while(sret != 0);
289
ret = close(cl_fd);
290
if(ret == -1){
291
error_plus(0, errno, "close");
292
goto fail_find_usplash;
293
}
294
}
295
/* Close directory */
296
ret = closedir(proc_dir);
297
if(ret == -1){
298
error_plus(0, errno, "closedir");
299
goto fail_find_usplash;
300
}
301
/* Success */
302
*cmdline_r = cmdline;
303
*cmdline_len_r = cmdline_len;
304
return pid;
305
}
306
307
fail_find_usplash:
308
309
free(cmdline);
310
if(proc_dir != NULL){
311
int e = errno;
312
closedir(proc_dir);
313
errno = e;
314
}
315
return 0;
316
}
317
318
int main(__attribute__((unused))int argc,
319
__attribute__((unused))char **argv){
320
int ret = 0;
321
ssize_t sret;
322
int fifo_fd = -1;
323
int outfifo_fd = -1;
324
char *buf = NULL;
325
size_t buf_len = 0;
326
pid_t usplash_pid = -1;
327
bool usplash_accessed = false;
328
int status = EXIT_FAILURE; /* Default failure exit status */
329
330
char *prompt = makeprompt();
331
if(prompt == NULL){
332
status = EX_OSERR;
333
goto failure;
334
}
335
336
/* Find usplash process */
337
char *cmdline = NULL;
338
size_t cmdline_len = 0;
339
usplash_pid = find_usplash(&cmdline, &cmdline_len);
340
if(usplash_pid == 0){
341
status = EX_UNAVAILABLE;
342
goto failure;
343
}
344
345
/* Set up the signal handler */
346
{
347
struct sigaction old_action,
348
new_action = { .sa_handler = termination_handler,
349
.sa_flags = 0 };
350
sigemptyset(&new_action.sa_mask);
351
ret = sigaddset(&new_action.sa_mask, SIGINT);
352
if(ret == -1){
353
error_plus(0, errno, "sigaddset");
354
status = EX_OSERR;
355
goto failure;
356
}
357
ret = sigaddset(&new_action.sa_mask, SIGHUP);
358
if(ret == -1){
359
error_plus(0, errno, "sigaddset");
360
status = EX_OSERR;
361
goto failure;
362
}
363
ret = sigaddset(&new_action.sa_mask, SIGTERM);
364
if(ret == -1){
365
error_plus(0, errno, "sigaddset");
366
status = EX_OSERR;
367
goto failure;
368
}
369
ret = sigaction(SIGINT, NULL, &old_action);
370
if(ret == -1){
371
if(errno != EINTR){
372
error_plus(0, errno, "sigaction");
373
status = EX_OSERR;
374
}
375
goto failure;
376
}
377
if(old_action.sa_handler != SIG_IGN){
378
ret = sigaction(SIGINT, &new_action, NULL);
379
if(ret == -1){
380
if(errno != EINTR){
381
error_plus(0, errno, "sigaction");
382
status = EX_OSERR;
383
}
384
goto failure;
385
}
386
}
387
ret = sigaction(SIGHUP, NULL, &old_action);
388
if(ret == -1){
389
if(errno != EINTR){
390
error_plus(0, errno, "sigaction");
391
status = EX_OSERR;
392
}
393
goto failure;
394
}
395
if(old_action.sa_handler != SIG_IGN){
396
ret = sigaction(SIGHUP, &new_action, NULL);
397
if(ret == -1){
398
if(errno != EINTR){
399
error_plus(0, errno, "sigaction");
400
status = EX_OSERR;
401
}
402
goto failure;
403
}
404
}
405
ret = sigaction(SIGTERM, NULL, &old_action);
406
if(ret == -1){
407
if(errno != EINTR){
408
error_plus(0, errno, "sigaction");
409
status = EX_OSERR;
410
}
411
goto failure;
412
}
413
if(old_action.sa_handler != SIG_IGN){
414
ret = sigaction(SIGTERM, &new_action, NULL);
415
if(ret == -1){
416
if(errno != EINTR){
417
error_plus(0, errno, "sigaction");
418
status = EX_OSERR;
419
}
420
goto failure;
421
}
422
}
423
}
424
425
usplash_accessed = true;
426
/* Write command to FIFO */
427
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
428
if(errno != EINTR){
429
error_plus(0, errno, "usplash_write");
430
status = EX_OSERR;
431
}
432
goto failure;
433
}
434
435
if(interrupted_by_signal){
436
goto failure;
437
}
438
439
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
440
if(errno != EINTR){
441
error_plus(0, errno, "usplash_write");
442
status = EX_OSERR;
443
}
444
goto failure;
445
}
446
447
if(interrupted_by_signal){
448
goto failure;
449
}
450
451
free(prompt);
452
prompt = NULL;
453
454
/* Read reply from usplash */
455
/* Open FIFO */
456
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
457
if(outfifo_fd == -1){
458
if(errno != EINTR){
459
error_plus(0, errno, "open");
460
status = EX_OSERR;
461
}
462
goto failure;
463
}
464
465
if(interrupted_by_signal){
466
goto failure;
467
}
468
469
/* Read from FIFO */
470
size_t buf_allocated = 0;
471
const size_t blocksize = 1024;
472
do {
473
/* Allocate more space */
474
if(buf_len + blocksize > buf_allocated){
475
char *tmp = realloc(buf, buf_allocated + blocksize);
476
if(tmp == NULL){
477
if(errno != EINTR){
478
error_plus(0, errno, "realloc");
479
status = EX_OSERR;
480
}
481
goto failure;
482
}
483
buf = tmp;
484
buf_allocated += blocksize;
485
}
486
sret = read(outfifo_fd, buf + buf_len,
487
buf_allocated - buf_len);
488
if(sret == -1){
489
if(errno != EINTR){
490
error_plus(0, errno, "read");
491
status = EX_OSERR;
492
}
493
TEMP_FAILURE_RETRY(close(outfifo_fd));
494
goto failure;
495
}
496
if(interrupted_by_signal){
497
break;
498
}
499
500
buf_len += (size_t)sret;
501
} while(sret != 0);
502
ret = close(outfifo_fd);
503
if(ret == -1){
504
if(errno != EINTR){
505
error_plus(0, errno, "close");
506
status = EX_OSERR;
507
}
508
goto failure;
509
}
510
outfifo_fd = -1;
511
512
if(interrupted_by_signal){
513
goto failure;
514
}
515
516
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
517
if(errno != EINTR){
518
error_plus(0, errno, "usplash_write");
519
status = EX_OSERR;
520
}
521
goto failure;
522
}
523
524
if(interrupted_by_signal){
525
goto failure;
526
}
527
528
ret = close(fifo_fd);
529
if(ret == -1){
530
if(errno != EINTR){
531
error_plus(0, errno, "close");
532
status = EX_OSERR;
533
}
534
goto failure;
535
}
536
fifo_fd = -1;
537
538
/* Print password to stdout */
539
size_t written = 0;
540
while(written < buf_len){
541
do {
542
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
543
if(sret == -1){
544
if(errno != EINTR){
545
error_plus(0, errno, "write");
546
status = EX_OSERR;
547
}
548
goto failure;
549
}
550
} while(sret == -1);
551
552
if(interrupted_by_signal){
553
goto failure;
554
}
555
written += (size_t)sret;
556
}
557
free(buf);
558
buf = NULL;
559
560
if(interrupted_by_signal){
561
goto failure;
562
}
563
564
free(cmdline);
565
return EXIT_SUCCESS;
566
567
failure:
568
569
free(buf);
570
571
free(prompt);
572
573
/* If usplash was never accessed, we can stop now */
574
if(not usplash_accessed){
575
return status;
576
}
577
578
/* Close FIFO */
579
if(fifo_fd != -1){
580
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
581
if(ret == -1 and errno != EINTR){
582
error_plus(0, errno, "close");
583
}
584
fifo_fd = -1;
585
}
586
587
/* Close output FIFO */
588
if(outfifo_fd != -1){
589
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
590
if(ret == -1){
591
error_plus(0, errno, "close");
592
}
593
}
594
595
/* Create argv for new usplash*/
596
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
597
* sizeof(char *)); /* Count args */
598
if(cmdline_argv == NULL){
599
error_plus(0, errno, "malloc");
600
return status;
601
}
602
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
603
604
/* Kill old usplash */
605
kill(usplash_pid, SIGTERM);
606
sleep(2);
607
while(kill(usplash_pid, 0) == 0){
608
kill(usplash_pid, SIGKILL);
609
sleep(1);
610
}
611
612
pid_t new_usplash_pid = fork();
613
if(new_usplash_pid == 0){
614
/* Child; will become new usplash process */
615
616
/* Make the effective user ID (root) the only user ID instead of
617
the real user ID (_mandos) */
618
ret = setuid(geteuid());
619
if(ret == -1){
620
error_plus(0, errno, "setuid");
621
}
622
623
setsid();
624
ret = chdir("/");
625
if(ret == -1){
626
error_plus(0, errno, "chdir");
627
_exit(EX_OSERR);
628
}
629
/* if(fork() != 0){ */
630
/* _exit(EXIT_SUCCESS); */
631
/* } */
632
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
633
if(ret == -1){
634
error_plus(0, errno, "dup2");
635
_exit(EX_OSERR);
636
}
637
638
execv(usplash_name, cmdline_argv);
639
if(not interrupted_by_signal){
640
error_plus(0, errno, "execv");
641
}
642
free(cmdline);
643
free(cmdline_argv);
644
_exit(EX_OSERR);
645
}
646
free(cmdline);
647
free(cmdline_argv);
648
sleep(2);
649
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
650
if(errno != EINTR){
651
error_plus(0, errno, "usplash_write");
652
}
653
}
654
655
/* Close FIFO (again) */
656
if(fifo_fd != -1){
657
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
658
if(ret == -1 and errno != EINTR){
659
error_plus(0, errno, "close");
660
}
661
fifo_fd = -1;
662
}
663
664
if(interrupted_by_signal){
665
struct sigaction signal_action = { .sa_handler = SIG_DFL };
666
sigemptyset(&signal_action.sa_mask);
667
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
668
&signal_action, NULL));
669
if(ret == -1){
670
error_plus(0, errno, "sigaction");
671
}
672
do {
673
ret = raise(signal_received);
674
} while(ret != 0 and errno == EINTR);
675
if(ret != 0){
676
error_plus(0, errno, "raise");
677
abort();
678
}
679
TEMP_FAILURE_RETRY(pause());
680
}
681
682
return status;
683
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0