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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
- network-hooks.d
- 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 © 2008-2012 Teddy Hogeborn
6
* Copyright © 2008-2012 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@recompile.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
__attribute__((format (gnu_printf, 3, 4)))
62
void error_plus(int status, int errnum, const char *formatstring,
63
...){
64
va_list ap;
65
char *text;
66
int ret;
67
68
va_start(ap, formatstring);
69
ret = vasprintf(&text, formatstring, ap);
70
if (ret == -1){
71
fprintf(stderr, "Mandos plugin %s: ",
72
program_invocation_short_name);
73
vfprintf(stderr, formatstring, ap);
74
fprintf(stderr, ": ");
75
fprintf(stderr, "%s\n", strerror(errnum));
76
error(status, errno, "vasprintf while printing error");
77
return;
78
}
79
fprintf(stderr, "Mandos plugin ");
80
error(status, errnum, "%s", text);
81
free(text);
82
}
83
84
static void termination_handler(int signum){
85
if(interrupted_by_signal){
86
return;
87
}
88
interrupted_by_signal = 1;
89
signal_received = signum;
90
}
91
92
static bool usplash_write(int *fifo_fd_r,
93
const char *cmd, const char *arg){
94
/*
95
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
96
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
97
* SEE ALSO
98
* usplash_write(8)
99
*/
100
int ret;
101
if(*fifo_fd_r == -1){
102
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
103
if(ret == -1){
104
return false;
105
}
106
*fifo_fd_r = ret;
107
}
108
109
const char *cmd_line;
110
size_t cmd_line_len;
111
char *cmd_line_alloc = NULL;
112
if(arg == NULL){
113
cmd_line = cmd;
114
cmd_line_len = strlen(cmd) + 1;
115
} else {
116
do {
117
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
118
if(ret == -1){
119
int e = errno;
120
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
121
errno = e;
122
return false;
123
}
124
} while(ret == -1);
125
cmd_line = cmd_line_alloc;
126
cmd_line_len = (size_t)ret + 1;
127
}
128
129
size_t written = 0;
130
ssize_t sret = 0;
131
while(written < cmd_line_len){
132
sret = write(*fifo_fd_r, cmd_line + written,
133
cmd_line_len - written);
134
if(sret == -1){
135
int e = errno;
136
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
137
free(cmd_line_alloc);
138
errno = e;
139
return false;
140
}
141
written += (size_t)sret;
142
}
143
free(cmd_line_alloc);
144
145
return true;
146
}
147
148
/* Create prompt string */
149
char *makeprompt(void){
150
int ret = 0;
151
char *prompt;
152
const char *const cryptsource = getenv("cryptsource");
153
const char *const crypttarget = getenv("crypttarget");
154
const char prompt_start[] = "Enter passphrase to unlock the disk";
155
156
if(cryptsource == NULL){
157
if(crypttarget == NULL){
158
ret = asprintf(&prompt, "%s: ", prompt_start);
159
} else {
160
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
161
crypttarget);
162
}
163
} else {
164
if(crypttarget == NULL){
165
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
166
} else {
167
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
168
cryptsource, crypttarget);
169
}
170
}
171
if(ret == -1){
172
return NULL;
173
}
174
return prompt;
175
}
176
177
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
178
int ret = 0;
179
ssize_t sret = 0;
180
char *cmdline = NULL;
181
size_t cmdline_len = 0;
182
DIR *proc_dir = opendir("/proc");
183
if(proc_dir == NULL){
184
error_plus(0, errno, "opendir");
185
return -1;
186
}
187
errno = 0;
188
for(struct dirent *proc_ent = readdir(proc_dir);
189
proc_ent != NULL;
190
proc_ent = readdir(proc_dir)){
191
pid_t pid;
192
{
193
intmax_t tmpmax;
194
char *tmp;
195
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
196
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
197
or tmpmax != (pid_t)tmpmax){
198
/* Not a process */
199
errno = 0;
200
continue;
201
}
202
pid = (pid_t)tmpmax;
203
}
204
/* Find the executable name by doing readlink() on the
205
/proc/<pid>/exe link */
206
char exe_target[sizeof(usplash_name)];
207
{
208
/* create file name string */
209
char *exe_link;
210
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
211
if(ret == -1){
212
error_plus(0, errno, "asprintf");
213
goto fail_find_usplash;
214
}
215
216
/* Check that it refers to a symlink owned by root:root */
217
struct stat exe_stat;
218
ret = lstat(exe_link, &exe_stat);
219
if(ret == -1){
220
if(errno == ENOENT){
221
free(exe_link);
222
continue;
223
}
224
error_plus(0, errno, "lstat");
225
free(exe_link);
226
goto fail_find_usplash;
227
}
228
if(not S_ISLNK(exe_stat.st_mode)
229
or exe_stat.st_uid != 0
230
or exe_stat.st_gid != 0){
231
free(exe_link);
232
continue;
233
}
234
235
sret = readlink(exe_link, exe_target, sizeof(exe_target));
236
free(exe_link);
237
}
238
/* Compare executable name */
239
if((sret != ((ssize_t)sizeof(exe_target)-1))
240
or (memcmp(usplash_name, exe_target,
241
sizeof(exe_target)-1) != 0)){
242
/* Not it */
243
continue;
244
}
245
/* Found usplash */
246
/* Read and save the command line of usplash in "cmdline" */
247
{
248
/* Open /proc/<pid>/cmdline */
249
int cl_fd;
250
{
251
char *cmdline_filename;
252
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
253
proc_ent->d_name);
254
if(ret == -1){
255
error_plus(0, errno, "asprintf");
256
goto fail_find_usplash;
257
}
258
cl_fd = open(cmdline_filename, O_RDONLY);
259
free(cmdline_filename);
260
if(cl_fd == -1){
261
error_plus(0, errno, "open");
262
goto fail_find_usplash;
263
}
264
}
265
size_t cmdline_allocated = 0;
266
char *tmp;
267
const size_t blocksize = 1024;
268
do {
269
/* Allocate more space? */
270
if(cmdline_len + blocksize > cmdline_allocated){
271
tmp = realloc(cmdline, cmdline_allocated + blocksize);
272
if(tmp == NULL){
273
error_plus(0, errno, "realloc");
274
close(cl_fd);
275
goto fail_find_usplash;
276
}
277
cmdline = tmp;
278
cmdline_allocated += blocksize;
279
}
280
/* Read data */
281
sret = read(cl_fd, cmdline + cmdline_len,
282
cmdline_allocated - cmdline_len);
283
if(sret == -1){
284
error_plus(0, errno, "read");
285
close(cl_fd);
286
goto fail_find_usplash;
287
}
288
cmdline_len += (size_t)sret;
289
} while(sret != 0);
290
ret = close(cl_fd);
291
if(ret == -1){
292
error_plus(0, errno, "close");
293
goto fail_find_usplash;
294
}
295
}
296
/* Close directory */
297
ret = closedir(proc_dir);
298
if(ret == -1){
299
error_plus(0, errno, "closedir");
300
goto fail_find_usplash;
301
}
302
/* Success */
303
*cmdline_r = cmdline;
304
*cmdline_len_r = cmdline_len;
305
return pid;
306
}
307
308
fail_find_usplash:
309
310
free(cmdline);
311
if(proc_dir != NULL){
312
int e = errno;
313
closedir(proc_dir);
314
errno = e;
315
}
316
return 0;
317
}
318
319
int main(__attribute__((unused))int argc,
320
__attribute__((unused))char **argv){
321
int ret = 0;
322
ssize_t sret;
323
int fifo_fd = -1;
324
int outfifo_fd = -1;
325
char *buf = NULL;
326
size_t buf_len = 0;
327
pid_t usplash_pid = -1;
328
bool usplash_accessed = false;
329
int status = EXIT_FAILURE; /* Default failure exit status */
330
331
char *prompt = makeprompt();
332
if(prompt == NULL){
333
status = EX_OSERR;
334
goto failure;
335
}
336
337
/* Find usplash process */
338
char *cmdline = NULL;
339
size_t cmdline_len = 0;
340
usplash_pid = find_usplash(&cmdline, &cmdline_len);
341
if(usplash_pid == 0){
342
status = EX_UNAVAILABLE;
343
goto failure;
344
}
345
346
/* Set up the signal handler */
347
{
348
struct sigaction old_action,
349
new_action = { .sa_handler = termination_handler,
350
.sa_flags = 0 };
351
sigemptyset(&new_action.sa_mask);
352
ret = sigaddset(&new_action.sa_mask, SIGINT);
353
if(ret == -1){
354
error_plus(0, errno, "sigaddset");
355
status = EX_OSERR;
356
goto failure;
357
}
358
ret = sigaddset(&new_action.sa_mask, SIGHUP);
359
if(ret == -1){
360
error_plus(0, errno, "sigaddset");
361
status = EX_OSERR;
362
goto failure;
363
}
364
ret = sigaddset(&new_action.sa_mask, SIGTERM);
365
if(ret == -1){
366
error_plus(0, errno, "sigaddset");
367
status = EX_OSERR;
368
goto failure;
369
}
370
ret = sigaction(SIGINT, NULL, &old_action);
371
if(ret == -1){
372
if(errno != EINTR){
373
error_plus(0, errno, "sigaction");
374
status = EX_OSERR;
375
}
376
goto failure;
377
}
378
if(old_action.sa_handler != SIG_IGN){
379
ret = sigaction(SIGINT, &new_action, NULL);
380
if(ret == -1){
381
if(errno != EINTR){
382
error_plus(0, errno, "sigaction");
383
status = EX_OSERR;
384
}
385
goto failure;
386
}
387
}
388
ret = sigaction(SIGHUP, NULL, &old_action);
389
if(ret == -1){
390
if(errno != EINTR){
391
error_plus(0, errno, "sigaction");
392
status = EX_OSERR;
393
}
394
goto failure;
395
}
396
if(old_action.sa_handler != SIG_IGN){
397
ret = sigaction(SIGHUP, &new_action, NULL);
398
if(ret == -1){
399
if(errno != EINTR){
400
error_plus(0, errno, "sigaction");
401
status = EX_OSERR;
402
}
403
goto failure;
404
}
405
}
406
ret = sigaction(SIGTERM, NULL, &old_action);
407
if(ret == -1){
408
if(errno != EINTR){
409
error_plus(0, errno, "sigaction");
410
status = EX_OSERR;
411
}
412
goto failure;
413
}
414
if(old_action.sa_handler != SIG_IGN){
415
ret = sigaction(SIGTERM, &new_action, NULL);
416
if(ret == -1){
417
if(errno != EINTR){
418
error_plus(0, errno, "sigaction");
419
status = EX_OSERR;
420
}
421
goto failure;
422
}
423
}
424
}
425
426
usplash_accessed = true;
427
/* Write command to FIFO */
428
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
429
if(errno != EINTR){
430
error_plus(0, errno, "usplash_write");
431
status = EX_OSERR;
432
}
433
goto failure;
434
}
435
436
if(interrupted_by_signal){
437
goto failure;
438
}
439
440
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
441
if(errno != EINTR){
442
error_plus(0, errno, "usplash_write");
443
status = EX_OSERR;
444
}
445
goto failure;
446
}
447
448
if(interrupted_by_signal){
449
goto failure;
450
}
451
452
free(prompt);
453
prompt = NULL;
454
455
/* Read reply from usplash */
456
/* Open FIFO */
457
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
458
if(outfifo_fd == -1){
459
if(errno != EINTR){
460
error_plus(0, errno, "open");
461
status = EX_OSERR;
462
}
463
goto failure;
464
}
465
466
if(interrupted_by_signal){
467
goto failure;
468
}
469
470
/* Read from FIFO */
471
size_t buf_allocated = 0;
472
const size_t blocksize = 1024;
473
do {
474
/* Allocate more space */
475
if(buf_len + blocksize > buf_allocated){
476
char *tmp = realloc(buf, buf_allocated + blocksize);
477
if(tmp == NULL){
478
if(errno != EINTR){
479
error_plus(0, errno, "realloc");
480
status = EX_OSERR;
481
}
482
goto failure;
483
}
484
buf = tmp;
485
buf_allocated += blocksize;
486
}
487
sret = read(outfifo_fd, buf + buf_len,
488
buf_allocated - buf_len);
489
if(sret == -1){
490
if(errno != EINTR){
491
error_plus(0, errno, "read");
492
status = EX_OSERR;
493
}
494
TEMP_FAILURE_RETRY(close(outfifo_fd));
495
goto failure;
496
}
497
if(interrupted_by_signal){
498
break;
499
}
500
501
buf_len += (size_t)sret;
502
} while(sret != 0);
503
ret = close(outfifo_fd);
504
if(ret == -1){
505
if(errno != EINTR){
506
error_plus(0, errno, "close");
507
status = EX_OSERR;
508
}
509
goto failure;
510
}
511
outfifo_fd = -1;
512
513
if(interrupted_by_signal){
514
goto failure;
515
}
516
517
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
518
if(errno != EINTR){
519
error_plus(0, errno, "usplash_write");
520
status = EX_OSERR;
521
}
522
goto failure;
523
}
524
525
if(interrupted_by_signal){
526
goto failure;
527
}
528
529
ret = close(fifo_fd);
530
if(ret == -1){
531
if(errno != EINTR){
532
error_plus(0, errno, "close");
533
status = EX_OSERR;
534
}
535
goto failure;
536
}
537
fifo_fd = -1;
538
539
/* Print password to stdout */
540
size_t written = 0;
541
while(written < buf_len){
542
do {
543
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
544
if(sret == -1){
545
if(errno != EINTR){
546
error_plus(0, errno, "write");
547
status = EX_OSERR;
548
}
549
goto failure;
550
}
551
} while(sret == -1);
552
553
if(interrupted_by_signal){
554
goto failure;
555
}
556
written += (size_t)sret;
557
}
558
free(buf);
559
buf = NULL;
560
561
if(interrupted_by_signal){
562
goto failure;
563
}
564
565
free(cmdline);
566
return EXIT_SUCCESS;
567
568
failure:
569
570
free(buf);
571
572
free(prompt);
573
574
/* If usplash was never accessed, we can stop now */
575
if(not usplash_accessed){
576
return status;
577
}
578
579
/* Close FIFO */
580
if(fifo_fd != -1){
581
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
582
if(ret == -1 and errno != EINTR){
583
error_plus(0, errno, "close");
584
}
585
fifo_fd = -1;
586
}
587
588
/* Close output FIFO */
589
if(outfifo_fd != -1){
590
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
591
if(ret == -1){
592
error_plus(0, errno, "close");
593
}
594
}
595
596
/* Create argv for new usplash*/
597
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
598
* sizeof(char *)); /* Count args */
599
if(cmdline_argv == NULL){
600
error_plus(0, errno, "malloc");
601
return status;
602
}
603
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
604
605
/* Kill old usplash */
606
kill(usplash_pid, SIGTERM);
607
sleep(2);
608
while(kill(usplash_pid, 0) == 0){
609
kill(usplash_pid, SIGKILL);
610
sleep(1);
611
}
612
613
pid_t new_usplash_pid = fork();
614
if(new_usplash_pid == 0){
615
/* Child; will become new usplash process */
616
617
/* Make the effective user ID (root) the only user ID instead of
618
the real user ID (_mandos) */
619
ret = setuid(geteuid());
620
if(ret == -1){
621
error_plus(0, errno, "setuid");
622
}
623
624
setsid();
625
ret = chdir("/");
626
if(ret == -1){
627
error_plus(0, errno, "chdir");
628
_exit(EX_OSERR);
629
}
630
/* if(fork() != 0){ */
631
/* _exit(EXIT_SUCCESS); */
632
/* } */
633
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
634
if(ret == -1){
635
error_plus(0, errno, "dup2");
636
_exit(EX_OSERR);
637
}
638
639
execv(usplash_name, cmdline_argv);
640
if(not interrupted_by_signal){
641
error_plus(0, errno, "execv");
642
}
643
free(cmdline);
644
free(cmdline_argv);
645
_exit(EX_OSERR);
646
}
647
free(cmdline);
648
free(cmdline_argv);
649
sleep(2);
650
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
651
if(errno != EINTR){
652
error_plus(0, errno, "usplash_write");
653
}
654
}
655
656
/* Close FIFO (again) */
657
if(fifo_fd != -1){
658
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
659
if(ret == -1 and errno != EINTR){
660
error_plus(0, errno, "close");
661
}
662
fifo_fd = -1;
663
}
664
665
if(interrupted_by_signal){
666
struct sigaction signal_action = { .sa_handler = SIG_DFL };
667
sigemptyset(&signal_action.sa_mask);
668
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
669
&signal_action, NULL));
670
if(ret == -1){
671
error_plus(0, errno, "sigaction");
672
}
673
do {
674
ret = raise(signal_received);
675
} while(ret != 0 and errno == EINTR);
676
if(ret != 0){
677
error_plus(0, errno, "raise");
678
abort();
679
}
680
TEMP_FAILURE_RETRY(pause());
681
}
682
683
return status;
684
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0