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 78
- compare with another revision
- download diff
- download tarball
- view history from revision 78
- Committer: Teddy Hogeborn
- Date: 2008-08-16 03:29:08 UTC
- Revision ID: teddy@fukt.bsnet.se-20080816032908-ihw7c05r2mnyk389
Add feature to specify custom environment variables for plugins.
* plugin-runner.c (plugin): New members "environ" and "envc" to
contain possible custom environment.
(getplugin): Return NULL on failure instead of doing exit(); all
callers changed.
(add_to_char_array): New helper function for "add_argument" and
"add_environment".
(addargument): Renamed to "add_argument". Return bool. Call
"add_to_char_array" to actually do things.
(add_environment): New; analogous to "add_argument".
(addcustomargument): Renamed to "add_to_argv" to avoid confusion
with "add_argument".
(main): New options "--global-envs" and "--envs-for" to specify
custom environment for plugins. Print environment for
plugins in debug mode. Use asprintf instead of strcpy and
strcat. Use execve() for plugins with custom environments.
Free environment for plugin when freeing plugin list.
* plugin-runner.c (plugin): New members "environ" and "envc" to
contain possible custom environment.
(getplugin): Return NULL on failure instead of doing exit(); all
callers changed.
(add_to_char_array): New helper function for "add_argument" and
"add_environment".
(addargument): Renamed to "add_argument". Return bool. Call
"add_to_char_array" to actually do things.
(add_environment): New; analogous to "add_argument".
(addcustomargument): Renamed to "add_to_argv" to avoid confusion
with "add_argument".
(main): New options "--global-envs" and "--envs-for" to specify
custom environment for plugins. Print environment for
plugins in debug mode. Use asprintf instead of strcpy and
strcat. Use execve() for plugins with custom environments.
Free environment for plugin when freeing plugin list.
- files added:
- network-protocol.txt
- files removed:
- .bzr-builddeb
- debian
- debian/po
- files renamed:
- plugins.d/mandos-client.c => plugins.d/password-request.c
- plugins.d/mandos-client.xml => plugins.d/password-request.xml
- files modified:
- Makefile
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