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- Committer: Teddy Hogeborn
- Date: 2008-09-06 17:24:58 UTC
- Revision ID: teddy@fukt.bsnet.se-20080906172458-2x5wlfkn7oqckt1y
* legalnotice.xml: Copy DocBook 4.4-formatted text from
<http://www.gnu.org/licenses/gpl-3.0.dbk>.
<http://www.gnu.org/licenses/gpl-3.0.dbk>.
- files added:
- etc-plugins.d-README
- files removed:
- .bzr-builddeb
- debian
- debian/po
- 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() */
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 <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
35
dirent */
36
#include <stddef.h> /* NULL */
37
#include <string.h> /* strlen(), memcmp() */
38
#include <stdio.h> /* asprintf(), perror() */
39
#include <unistd.h> /* close(), write(), readlink(),
40
read(), STDOUT_FILENO, sleep(),
41
fork(), setuid(), geteuid(),
42
setsid(), chdir(), dup2(),
43
STDERR_FILENO, execv() */
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit() */
46
#include <stdlib.h> /* getenv() */
47
#include <dirent.h> /* opendir(), readdir(), closedir() */
48
#include <inttypes.h> /* intmax_t, strtoimax() */
49
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
50
51
sig_atomic_t interrupted_by_signal = 0;
52
53
static void termination_handler(__attribute__((unused))int signum){
54
interrupted_by_signal = 1;
55
}
56
57
static bool usplash_write(const char *cmd, const char *arg){
58
/*
59
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
60
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
61
* SEE ALSO
62
* usplash_write(8)
63
*/
64
int ret;
65
int fifo_fd;
66
do {
67
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
68
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
69
return false;
70
}
71
} while(fifo_fd == -1);
72
73
const char *cmd_line;
74
size_t cmd_line_len;
75
char *cmd_line_alloc = NULL;
76
if(arg == NULL){
77
cmd_line = cmd;
78
cmd_line_len = strlen(cmd);
79
} else {
80
do {
81
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
82
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
83
int e = errno;
84
close(fifo_fd);
85
errno = e;
86
return false;
87
}
88
} while(ret == -1);
89
cmd_line = cmd_line_alloc;
90
cmd_line_len = (size_t)ret + 1;
91
}
92
93
size_t written = 0;
94
ssize_t sret = 0;
95
while(not interrupted_by_signal and written < cmd_line_len){
96
sret = write(fifo_fd, cmd_line + written,
97
cmd_line_len - written);
98
if(sret == -1){
99
if(errno != EINTR or interrupted_by_signal){
100
int e = errno;
101
close(fifo_fd);
102
free(cmd_line_alloc);
103
errno = e;
104
return false;
105
} else {
106
continue;
107
}
108
}
109
written += (size_t)sret;
110
}
111
free(cmd_line_alloc);
112
do {
113
ret = close(fifo_fd);
114
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
115
return false;
116
}
117
} while(ret == -1);
118
if(interrupted_by_signal){
119
return false;
120
}
121
return true;
122
}
123
124
int main(__attribute__((unused))int argc,
125
__attribute__((unused))char **argv){
126
int ret = 0;
127
ssize_t sret;
128
bool an_error_occured = false;
129
130
/* Create prompt string */
131
char *prompt = NULL;
132
{
133
const char *const cryptsource = getenv("cryptsource");
134
const char *const crypttarget = getenv("crypttarget");
135
const char prompt_start[] = "Enter passphrase to unlock the disk";
136
137
if(cryptsource == NULL){
138
if(crypttarget == NULL){
139
ret = asprintf(&prompt, "%s: ", prompt_start);
140
} else {
141
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
142
crypttarget);
143
}
144
} else {
145
if(crypttarget == NULL){
146
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
147
} else {
148
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
149
cryptsource, crypttarget);
150
}
151
}
152
if(ret == -1){
153
return EXIT_FAILURE;
154
}
155
}
156
157
/* Find usplash process */
158
pid_t usplash_pid = 0;
159
char *cmdline = NULL;
160
size_t cmdline_len = 0;
161
const char usplash_name[] = "/sbin/usplash";
162
{
163
DIR *proc_dir = opendir("/proc");
164
if(proc_dir == NULL){
165
free(prompt);
166
perror("opendir");
167
return EXIT_FAILURE;
168
}
169
for(struct dirent *proc_ent = readdir(proc_dir);
170
proc_ent != NULL;
171
proc_ent = readdir(proc_dir)){
172
pid_t pid;
173
{
174
intmax_t tmpmax;
175
char *tmp;
176
errno = 0;
177
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
178
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
179
or tmpmax != (pid_t)tmpmax){
180
/* Not a process */
181
continue;
182
}
183
pid = (pid_t)tmpmax;
184
}
185
/* Find the executable name by doing readlink() on the
186
/proc/<pid>/exe link */
187
char exe_target[sizeof(usplash_name)];
188
{
189
/* create file name string */
190
char *exe_link;
191
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
192
if(ret == -1){
193
perror("asprintf");
194
free(prompt);
195
closedir(proc_dir);
196
return EXIT_FAILURE;
197
}
198
199
/* Check that it refers to a symlink owned by root:root */
200
struct stat exe_stat;
201
ret = lstat(exe_link, &exe_stat);
202
if(ret == -1){
203
if(errno == ENOENT){
204
free(exe_link);
205
continue;
206
}
207
perror("lstat");
208
free(exe_link);
209
free(prompt);
210
closedir(proc_dir);
211
return EXIT_FAILURE;
212
}
213
if(not S_ISLNK(exe_stat.st_mode)
214
or exe_stat.st_uid != 0
215
or exe_stat.st_gid != 0){
216
free(exe_link);
217
continue;
218
}
219
220
sret = readlink(exe_link, exe_target, sizeof(exe_target));
221
free(exe_link);
222
}
223
if((sret == ((ssize_t)sizeof(exe_target)-1))
224
and (memcmp(usplash_name, exe_target,
225
sizeof(exe_target)-1) == 0)){
226
usplash_pid = pid;
227
/* Read and save the command line of usplash in "cmdline" */
228
{
229
/* Open /proc/<pid>/cmdline */
230
int cl_fd;
231
{
232
char *cmdline_filename;
233
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
234
proc_ent->d_name);
235
if(ret == -1){
236
perror("asprintf");
237
free(prompt);
238
closedir(proc_dir);
239
return EXIT_FAILURE;
240
}
241
cl_fd = open(cmdline_filename, O_RDONLY);
242
if(cl_fd == -1){
243
perror("open");
244
free(cmdline_filename);
245
free(prompt);
246
closedir(proc_dir);
247
return EXIT_FAILURE;
248
}
249
free(cmdline_filename);
250
}
251
size_t cmdline_allocated = 0;
252
char *tmp;
253
const size_t blocksize = 1024;
254
do {
255
if(cmdline_len + blocksize > cmdline_allocated){
256
tmp = realloc(cmdline, cmdline_allocated + blocksize);
257
if(tmp == NULL){
258
perror("realloc");
259
free(cmdline);
260
free(prompt);
261
closedir(proc_dir);
262
return EXIT_FAILURE;
263
}
264
cmdline = tmp;
265
cmdline_allocated += blocksize;
266
}
267
sret = read(cl_fd, cmdline + cmdline_len,
268
cmdline_allocated - cmdline_len);
269
if(sret == -1){
270
perror("read");
271
free(cmdline);
272
free(prompt);
273
closedir(proc_dir);
274
return EXIT_FAILURE;
275
}
276
cmdline_len += (size_t)sret;
277
} while(sret != 0);
278
close(cl_fd);
279
}
280
break;
281
}
282
}
283
closedir(proc_dir);
284
}
285
if(usplash_pid == 0){
286
free(prompt);
287
return EXIT_FAILURE;
288
}
289
290
/* Set up the signal handler */
291
{
292
struct sigaction old_action,
293
new_action = { .sa_handler = termination_handler,
294
.sa_flags = 0 };
295
sigemptyset(&new_action.sa_mask);
296
sigaddset(&new_action.sa_mask, SIGINT);
297
sigaddset(&new_action.sa_mask, SIGHUP);
298
sigaddset(&new_action.sa_mask, SIGTERM);
299
ret = sigaction(SIGINT, NULL, &old_action);
300
if(ret == -1){
301
perror("sigaction");
302
free(prompt);
303
return EXIT_FAILURE;
304
}
305
if(old_action.sa_handler != SIG_IGN){
306
ret = sigaction(SIGINT, &new_action, NULL);
307
if(ret == -1){
308
perror("sigaction");
309
free(prompt);
310
return EXIT_FAILURE;
311
}
312
}
313
ret = sigaction(SIGHUP, NULL, &old_action);
314
if(ret == -1){
315
perror("sigaction");
316
free(prompt);
317
return EXIT_FAILURE;
318
}
319
if(old_action.sa_handler != SIG_IGN){
320
ret = sigaction(SIGHUP, &new_action, NULL);
321
if(ret == -1){
322
perror("sigaction");
323
free(prompt);
324
return EXIT_FAILURE;
325
}
326
}
327
ret = sigaction(SIGTERM, NULL, &old_action);
328
if(ret == -1){
329
perror("sigaction");
330
free(prompt);
331
return EXIT_FAILURE;
332
}
333
if(old_action.sa_handler != SIG_IGN){
334
ret = sigaction(SIGTERM, &new_action, NULL);
335
if(ret == -1){
336
perror("sigaction");
337
free(prompt);
338
return EXIT_FAILURE;
339
}
340
}
341
}
342
343
/* Write command to FIFO */
344
if(not interrupted_by_signal){
345
if(not usplash_write("TIMEOUT", "0")
346
and (errno != EINTR)){
347
perror("usplash_write");
348
an_error_occured = true;
349
}
350
}
351
if(not interrupted_by_signal and not an_error_occured){
352
if(not usplash_write("INPUTQUIET", prompt)
353
and (errno != EINTR)){
354
perror("usplash_write");
355
an_error_occured = true;
356
}
357
}
358
free(prompt);
359
360
/* This is not really a loop; while() is used to be able to "break"
361
out of it; those breaks are marked "Big" */
362
while(not interrupted_by_signal and not an_error_occured){
363
char *buf = NULL;
364
size_t buf_len = 0;
365
366
/* Open FIFO */
367
int fifo_fd;
368
do {
369
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
370
if(fifo_fd == -1){
371
if(errno != EINTR){
372
perror("open");
373
an_error_occured = true;
374
break;
375
}
376
if(interrupted_by_signal){
377
break;
378
}
379
}
380
} while(fifo_fd == -1);
381
if(interrupted_by_signal or an_error_occured){
382
break; /* Big */
383
}
384
385
/* Read from FIFO */
386
size_t buf_allocated = 0;
387
const size_t blocksize = 1024;
388
do {
389
if(buf_len + blocksize > buf_allocated){
390
char *tmp = realloc(buf, buf_allocated + blocksize);
391
if(tmp == NULL){
392
perror("realloc");
393
an_error_occured = true;
394
break;
395
}
396
buf = tmp;
397
buf_allocated += blocksize;
398
}
399
do {
400
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
401
if(sret == -1){
402
if(errno != EINTR){
403
perror("read");
404
an_error_occured = true;
405
break;
406
}
407
if(interrupted_by_signal){
408
break;
409
}
410
}
411
} while(sret == -1);
412
if(interrupted_by_signal or an_error_occured){
413
break;
414
}
415
416
buf_len += (size_t)sret;
417
} while(sret != 0);
418
close(fifo_fd);
419
if(interrupted_by_signal or an_error_occured){
420
break; /* Big */
421
}
422
423
if(not usplash_write("TIMEOUT", "15")
424
and (errno != EINTR)){
425
perror("usplash_write");
426
an_error_occured = true;
427
}
428
if(interrupted_by_signal or an_error_occured){
429
break; /* Big */
430
}
431
432
/* Print password to stdout */
433
size_t written = 0;
434
while(written < buf_len){
435
do {
436
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
437
if(sret == -1){
438
if(errno != EINTR){
439
perror("write");
440
an_error_occured = true;
441
break;
442
}
443
if(interrupted_by_signal){
444
break;
445
}
446
}
447
} while(sret == -1);
448
if(interrupted_by_signal or an_error_occured){
449
break;
450
}
451
written += (size_t)sret;
452
}
453
free(buf);
454
if(not interrupted_by_signal and not an_error_occured){
455
free(cmdline);
456
return EXIT_SUCCESS;
457
}
458
break; /* Big */
459
} /* end of non-loop while() */
460
461
/* If we got here, an error or interrupt must have happened */
462
463
/* Create argc and argv for new usplash*/
464
int cmdline_argc = 0;
465
char **cmdline_argv = malloc(sizeof(char *));
466
{
467
size_t position = 0;
468
while(position < cmdline_len){
469
char **tmp = realloc(cmdline_argv,
470
(sizeof(char *)
471
* (size_t)(cmdline_argc + 2)));
472
if(tmp == NULL){
473
perror("realloc");
474
free(cmdline_argv);
475
return EXIT_FAILURE;
476
}
477
cmdline_argv = tmp;
478
cmdline_argv[cmdline_argc] = cmdline + position;
479
cmdline_argc++;
480
position += strlen(cmdline + position) + 1;
481
}
482
cmdline_argv[cmdline_argc] = NULL;
483
}
484
/* Kill old usplash */
485
kill(usplash_pid, SIGTERM);
486
sleep(2);
487
while(kill(usplash_pid, 0) == 0){
488
kill(usplash_pid, SIGKILL);
489
sleep(1);
490
}
491
pid_t new_usplash_pid = fork();
492
if(new_usplash_pid == 0){
493
/* Child; will become new usplash process */
494
495
/* Make the effective user ID (root) the only user ID instead of
496
the real user ID (_mandos) */
497
ret = setuid(geteuid());
498
if(ret == -1){
499
perror("setuid");
500
}
501
502
setsid();
503
ret = chdir("/");
504
/* if(fork() != 0){ */
505
/* _exit(EXIT_SUCCESS); */
506
/* } */
507
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
508
if(ret == -1){
509
perror("dup2");
510
_exit(EXIT_FAILURE);
511
}
512
513
execv(usplash_name, cmdline_argv);
514
if(not interrupted_by_signal){
515
perror("execv");
516
}
517
free(cmdline);
518
free(cmdline_argv);
519
_exit(EXIT_FAILURE);
520
}
521
free(cmdline);
522
free(cmdline_argv);
523
sleep(2);
524
if(not usplash_write("PULSATE", NULL)
525
and (errno != EINTR)){
526
perror("usplash_write");
527
}
528
529
return EXIT_FAILURE;
530
}
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