To get this branch, use:
bzr branch
http://bzr.recompile.se/loggerhead/mandos/release
« back to all changes in this revision
Viewing changes to plugins.d/usplash.c
- browse files at revision 170
- compare with another revision
- download diff
- download tarball
- view history from revision 170
- Committer: Teddy Hogeborn
- Date: 2008-09-06 16:11:50 UTC
- Revision ID: teddy@fukt.bsnet.se-20080906161150-1umb8yz6a29zxg28
* Makefile (install-client): Add "/etc/plugins.d/README".
(uninstall-client): Remove "/etc/plugins.d/README".
* etc-plugins.d-README: New file.
(uninstall-client): Remove "/etc/plugins.d/README".
* etc-plugins.d-README: New file.
- files added:
- etc-plugins.d-README
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- files renamed:
- plugins.d/mandos-client.c => plugins.d/password-request.c
- plugins.d/mandos-client.xml => plugins.d/password-request.xml
- 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(), fprintf() */
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
#include <stdarg.h> /* va_list, va_start(), ... */
54
55
sig_atomic_t interrupted_by_signal = 0;
56
int signal_received;
57
const char usplash_name[] = "/sbin/usplash";
58
59
/* Function to use when printing errors */
60
void error_plus(int status, int errnum, const char *formatstring, ...){
61
va_list ap;
62
char *text;
63
int ret;
64
65
va_start(ap, formatstring);
66
ret = vasprintf(&text, formatstring, ap);
67
if (ret == -1){
68
fprintf(stderr, "Mandos plugin %s: ", program_invocation_short_name);
69
vfprintf(stderr, formatstring, ap);
70
fprintf(stderr, ": ");
71
fprintf(stderr, "%s\n", strerror(errnum));
72
error(status, errno, "vasprintf while printing error");
73
return;
74
}
75
fprintf(stderr, "Mandos plugin ");
76
error(status, errnum, "%s", text);
77
free(text);
78
}
79
80
static void termination_handler(int signum){
81
if(interrupted_by_signal){
82
return;
83
}
84
interrupted_by_signal = 1;
85
signal_received = signum;
86
}
87
88
static bool usplash_write(int *fifo_fd_r,
89
const char *cmd, const char *arg){
90
/*
91
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
92
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
93
* SEE ALSO
94
* usplash_write(8)
95
*/
96
int ret;
97
if(*fifo_fd_r == -1){
98
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
99
if(ret == -1){
100
return false;
101
}
102
*fifo_fd_r = ret;
103
}
104
105
const char *cmd_line;
106
size_t cmd_line_len;
107
char *cmd_line_alloc = NULL;
108
if(arg == NULL){
109
cmd_line = cmd;
110
cmd_line_len = strlen(cmd) + 1;
111
} else {
112
do {
113
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
114
if(ret == -1){
115
int e = errno;
116
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
117
errno = e;
118
return false;
119
}
120
} while(ret == -1);
121
cmd_line = cmd_line_alloc;
122
cmd_line_len = (size_t)ret + 1;
123
}
124
125
size_t written = 0;
126
ssize_t sret = 0;
127
while(written < cmd_line_len){
128
sret = write(*fifo_fd_r, cmd_line + written,
129
cmd_line_len - written);
130
if(sret == -1){
131
int e = errno;
132
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
133
free(cmd_line_alloc);
134
errno = e;
135
return false;
136
}
137
written += (size_t)sret;
138
}
139
free(cmd_line_alloc);
140
141
return true;
142
}
143
144
/* Create prompt string */
145
char *makeprompt(void){
146
int ret = 0;
147
char *prompt;
148
const char *const cryptsource = getenv("cryptsource");
149
const char *const crypttarget = getenv("crypttarget");
150
const char prompt_start[] = "Enter passphrase to unlock the disk";
151
152
if(cryptsource == NULL){
153
if(crypttarget == NULL){
154
ret = asprintf(&prompt, "%s: ", prompt_start);
155
} else {
156
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
157
crypttarget);
158
}
159
} else {
160
if(crypttarget == NULL){
161
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
162
} else {
163
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
164
cryptsource, crypttarget);
165
}
166
}
167
if(ret == -1){
168
return NULL;
169
}
170
return prompt;
171
}
172
173
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
174
int ret = 0;
175
ssize_t sret = 0;
176
char *cmdline = NULL;
177
size_t cmdline_len = 0;
178
DIR *proc_dir = opendir("/proc");
179
if(proc_dir == NULL){
180
error_plus(0, errno, "opendir");
181
return -1;
182
}
183
errno = 0;
184
for(struct dirent *proc_ent = readdir(proc_dir);
185
proc_ent != NULL;
186
proc_ent = readdir(proc_dir)){
187
pid_t pid;
188
{
189
intmax_t tmpmax;
190
char *tmp;
191
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
192
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
193
or tmpmax != (pid_t)tmpmax){
194
/* Not a process */
195
errno = 0;
196
continue;
197
}
198
pid = (pid_t)tmpmax;
199
}
200
/* Find the executable name by doing readlink() on the
201
/proc/<pid>/exe link */
202
char exe_target[sizeof(usplash_name)];
203
{
204
/* create file name string */
205
char *exe_link;
206
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
207
if(ret == -1){
208
error_plus(0, errno, "asprintf");
209
goto fail_find_usplash;
210
}
211
212
/* Check that it refers to a symlink owned by root:root */
213
struct stat exe_stat;
214
ret = lstat(exe_link, &exe_stat);
215
if(ret == -1){
216
if(errno == ENOENT){
217
free(exe_link);
218
continue;
219
}
220
error_plus(0, errno, "lstat");
221
free(exe_link);
222
goto fail_find_usplash;
223
}
224
if(not S_ISLNK(exe_stat.st_mode)
225
or exe_stat.st_uid != 0
226
or exe_stat.st_gid != 0){
227
free(exe_link);
228
continue;
229
}
230
231
sret = readlink(exe_link, exe_target, sizeof(exe_target));
232
free(exe_link);
233
}
234
/* Compare executable name */
235
if((sret != ((ssize_t)sizeof(exe_target)-1))
236
or (memcmp(usplash_name, exe_target,
237
sizeof(exe_target)-1) != 0)){
238
/* Not it */
239
continue;
240
}
241
/* Found usplash */
242
/* Read and save the command line of usplash in "cmdline" */
243
{
244
/* Open /proc/<pid>/cmdline */
245
int cl_fd;
246
{
247
char *cmdline_filename;
248
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
249
proc_ent->d_name);
250
if(ret == -1){
251
error_plus(0, errno, "asprintf");
252
goto fail_find_usplash;
253
}
254
cl_fd = open(cmdline_filename, O_RDONLY);
255
free(cmdline_filename);
256
if(cl_fd == -1){
257
error_plus(0, errno, "open");
258
goto fail_find_usplash;
259
}
260
}
261
size_t cmdline_allocated = 0;
262
char *tmp;
263
const size_t blocksize = 1024;
264
do {
265
/* Allocate more space? */
266
if(cmdline_len + blocksize > cmdline_allocated){
267
tmp = realloc(cmdline, cmdline_allocated + blocksize);
268
if(tmp == NULL){
269
error_plus(0, errno, "realloc");
270
close(cl_fd);
271
goto fail_find_usplash;
272
}
273
cmdline = tmp;
274
cmdline_allocated += blocksize;
275
}
276
/* Read data */
277
sret = read(cl_fd, cmdline + cmdline_len,
278
cmdline_allocated - cmdline_len);
279
if(sret == -1){
280
error_plus(0, errno, "read");
281
close(cl_fd);
282
goto fail_find_usplash;
283
}
284
cmdline_len += (size_t)sret;
285
} while(sret != 0);
286
ret = close(cl_fd);
287
if(ret == -1){
288
error_plus(0, errno, "close");
289
goto fail_find_usplash;
290
}
291
}
292
/* Close directory */
293
ret = closedir(proc_dir);
294
if(ret == -1){
295
error_plus(0, errno, "closedir");
296
goto fail_find_usplash;
297
}
298
/* Success */
299
*cmdline_r = cmdline;
300
*cmdline_len_r = cmdline_len;
301
return pid;
302
}
303
304
fail_find_usplash:
305
306
free(cmdline);
307
if(proc_dir != NULL){
308
int e = errno;
309
closedir(proc_dir);
310
errno = e;
311
}
312
return 0;
313
}
314
315
int main(__attribute__((unused))int argc,
316
__attribute__((unused))char **argv){
317
int ret = 0;
318
ssize_t sret;
319
int fifo_fd = -1;
320
int outfifo_fd = -1;
321
char *buf = NULL;
322
size_t buf_len = 0;
323
pid_t usplash_pid = -1;
324
bool usplash_accessed = false;
325
int status = EXIT_FAILURE; /* Default failure exit status */
326
327
char *prompt = makeprompt();
328
if(prompt == NULL){
329
status = EX_OSERR;
330
goto failure;
331
}
332
333
/* Find usplash process */
334
char *cmdline = NULL;
335
size_t cmdline_len = 0;
336
usplash_pid = find_usplash(&cmdline, &cmdline_len);
337
if(usplash_pid == 0){
338
status = EX_UNAVAILABLE;
339
goto failure;
340
}
341
342
/* Set up the signal handler */
343
{
344
struct sigaction old_action,
345
new_action = { .sa_handler = termination_handler,
346
.sa_flags = 0 };
347
sigemptyset(&new_action.sa_mask);
348
ret = sigaddset(&new_action.sa_mask, SIGINT);
349
if(ret == -1){
350
error_plus(0, errno, "sigaddset");
351
status = EX_OSERR;
352
goto failure;
353
}
354
ret = sigaddset(&new_action.sa_mask, SIGHUP);
355
if(ret == -1){
356
error_plus(0, errno, "sigaddset");
357
status = EX_OSERR;
358
goto failure;
359
}
360
ret = sigaddset(&new_action.sa_mask, SIGTERM);
361
if(ret == -1){
362
error_plus(0, errno, "sigaddset");
363
status = EX_OSERR;
364
goto failure;
365
}
366
ret = sigaction(SIGINT, NULL, &old_action);
367
if(ret == -1){
368
if(errno != EINTR){
369
error_plus(0, errno, "sigaction");
370
status = EX_OSERR;
371
}
372
goto failure;
373
}
374
if(old_action.sa_handler != SIG_IGN){
375
ret = sigaction(SIGINT, &new_action, NULL);
376
if(ret == -1){
377
if(errno != EINTR){
378
error_plus(0, errno, "sigaction");
379
status = EX_OSERR;
380
}
381
goto failure;
382
}
383
}
384
ret = sigaction(SIGHUP, NULL, &old_action);
385
if(ret == -1){
386
if(errno != EINTR){
387
error_plus(0, errno, "sigaction");
388
status = EX_OSERR;
389
}
390
goto failure;
391
}
392
if(old_action.sa_handler != SIG_IGN){
393
ret = sigaction(SIGHUP, &new_action, NULL);
394
if(ret == -1){
395
if(errno != EINTR){
396
error_plus(0, errno, "sigaction");
397
status = EX_OSERR;
398
}
399
goto failure;
400
}
401
}
402
ret = sigaction(SIGTERM, NULL, &old_action);
403
if(ret == -1){
404
if(errno != EINTR){
405
error_plus(0, errno, "sigaction");
406
status = EX_OSERR;
407
}
408
goto failure;
409
}
410
if(old_action.sa_handler != SIG_IGN){
411
ret = sigaction(SIGTERM, &new_action, NULL);
412
if(ret == -1){
413
if(errno != EINTR){
414
error_plus(0, errno, "sigaction");
415
status = EX_OSERR;
416
}
417
goto failure;
418
}
419
}
420
}
421
422
usplash_accessed = true;
423
/* Write command to FIFO */
424
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
425
if(errno != EINTR){
426
error_plus(0, errno, "usplash_write");
427
status = EX_OSERR;
428
}
429
goto failure;
430
}
431
432
if(interrupted_by_signal){
433
goto failure;
434
}
435
436
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
437
if(errno != EINTR){
438
error_plus(0, errno, "usplash_write");
439
status = EX_OSERR;
440
}
441
goto failure;
442
}
443
444
if(interrupted_by_signal){
445
goto failure;
446
}
447
448
free(prompt);
449
prompt = NULL;
450
451
/* Read reply from usplash */
452
/* Open FIFO */
453
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
454
if(outfifo_fd == -1){
455
if(errno != EINTR){
456
error_plus(0, errno, "open");
457
status = EX_OSERR;
458
}
459
goto failure;
460
}
461
462
if(interrupted_by_signal){
463
goto failure;
464
}
465
466
/* Read from FIFO */
467
size_t buf_allocated = 0;
468
const size_t blocksize = 1024;
469
do {
470
/* Allocate more space */
471
if(buf_len + blocksize > buf_allocated){
472
char *tmp = realloc(buf, buf_allocated + blocksize);
473
if(tmp == NULL){
474
if(errno != EINTR){
475
error_plus(0, errno, "realloc");
476
status = EX_OSERR;
477
}
478
goto failure;
479
}
480
buf = tmp;
481
buf_allocated += blocksize;
482
}
483
sret = read(outfifo_fd, buf + buf_len,
484
buf_allocated - buf_len);
485
if(sret == -1){
486
if(errno != EINTR){
487
error_plus(0, errno, "read");
488
status = EX_OSERR;
489
}
490
TEMP_FAILURE_RETRY(close(outfifo_fd));
491
goto failure;
492
}
493
if(interrupted_by_signal){
494
break;
495
}
496
497
buf_len += (size_t)sret;
498
} while(sret != 0);
499
ret = close(outfifo_fd);
500
if(ret == -1){
501
if(errno != EINTR){
502
error_plus(0, errno, "close");
503
status = EX_OSERR;
504
}
505
goto failure;
506
}
507
outfifo_fd = -1;
508
509
if(interrupted_by_signal){
510
goto failure;
511
}
512
513
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
514
if(errno != EINTR){
515
error_plus(0, errno, "usplash_write");
516
status = EX_OSERR;
517
}
518
goto failure;
519
}
520
521
if(interrupted_by_signal){
522
goto failure;
523
}
524
525
ret = close(fifo_fd);
526
if(ret == -1){
527
if(errno != EINTR){
528
error_plus(0, errno, "close");
529
status = EX_OSERR;
530
}
531
goto failure;
532
}
533
fifo_fd = -1;
534
535
/* Print password to stdout */
536
size_t written = 0;
537
while(written < buf_len){
538
do {
539
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
540
if(sret == -1){
541
if(errno != EINTR){
542
error_plus(0, errno, "write");
543
status = EX_OSERR;
544
}
545
goto failure;
546
}
547
} while(sret == -1);
548
549
if(interrupted_by_signal){
550
goto failure;
551
}
552
written += (size_t)sret;
553
}
554
free(buf);
555
buf = NULL;
556
557
if(interrupted_by_signal){
558
goto failure;
559
}
560
561
free(cmdline);
562
return EXIT_SUCCESS;
563
564
failure:
565
566
free(buf);
567
568
free(prompt);
569
570
/* If usplash was never accessed, we can stop now */
571
if(not usplash_accessed){
572
return status;
573
}
574
575
/* Close FIFO */
576
if(fifo_fd != -1){
577
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
578
if(ret == -1 and errno != EINTR){
579
error_plus(0, errno, "close");
580
}
581
fifo_fd = -1;
582
}
583
584
/* Close output FIFO */
585
if(outfifo_fd != -1){
586
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
587
if(ret == -1){
588
error_plus(0, errno, "close");
589
}
590
}
591
592
/* Create argv for new usplash*/
593
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
594
* sizeof(char *)); /* Count args */
595
if(cmdline_argv == NULL){
596
error_plus(0, errno, "malloc");
597
return status;
598
}
599
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
600
601
/* Kill old usplash */
602
kill(usplash_pid, SIGTERM);
603
sleep(2);
604
while(kill(usplash_pid, 0) == 0){
605
kill(usplash_pid, SIGKILL);
606
sleep(1);
607
}
608
609
pid_t new_usplash_pid = fork();
610
if(new_usplash_pid == 0){
611
/* Child; will become new usplash process */
612
613
/* Make the effective user ID (root) the only user ID instead of
614
the real user ID (_mandos) */
615
ret = setuid(geteuid());
616
if(ret == -1){
617
error_plus(0, errno, "setuid");
618
}
619
620
setsid();
621
ret = chdir("/");
622
if(ret == -1){
623
error_plus(0, errno, "chdir");
624
_exit(EX_OSERR);
625
}
626
/* if(fork() != 0){ */
627
/* _exit(EXIT_SUCCESS); */
628
/* } */
629
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
630
if(ret == -1){
631
error_plus(0, errno, "dup2");
632
_exit(EX_OSERR);
633
}
634
635
execv(usplash_name, cmdline_argv);
636
if(not interrupted_by_signal){
637
error_plus(0, errno, "execv");
638
}
639
free(cmdline);
640
free(cmdline_argv);
641
_exit(EX_OSERR);
642
}
643
free(cmdline);
644
free(cmdline_argv);
645
sleep(2);
646
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
647
if(errno != EINTR){
648
error_plus(0, errno, "usplash_write");
649
}
650
}
651
652
/* Close FIFO (again) */
653
if(fifo_fd != -1){
654
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
655
if(ret == -1 and errno != EINTR){
656
error_plus(0, errno, "close");
657
}
658
fifo_fd = -1;
659
}
660
661
if(interrupted_by_signal){
662
struct sigaction signal_action = { .sa_handler = SIG_DFL };
663
sigemptyset(&signal_action.sa_mask);
664
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
665
&signal_action, NULL));
666
if(ret == -1){
667
error_plus(0, errno, "sigaction");
668
}
669
do {
670
ret = raise(signal_received);
671
} while(ret != 0 and errno == EINTR);
672
if(ret != 0){
673
error_plus(0, errno, "raise");
674
abort();
675
}
676
TEMP_FAILURE_RETRY(pause());
677
}
678
679
return status;
680
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0