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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 <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
24
*/
25
26
#define _GNU_SOURCE /* asprintf() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction(),
30
SIG_IGN, kill(), SIGKILL */
31
#include <stdbool.h> /* bool, false, true */
32
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
33
#include <iso646.h> /* and, or, not*/
34
#include <errno.h> /* errno, EINTR */
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(), perror() */
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, strtoul(),
46
realloc(), EXIT_SUCCESS, malloc(),
47
_exit() */
48
#include <stdlib.h> /* getenv() */
49
#include <dirent.h> /* opendir(), readdir(), closedir() */
50
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
51
52
sig_atomic_t interrupted_by_signal = 0;
53
54
static void termination_handler(__attribute__((unused))int signum){
55
interrupted_by_signal = 1;
56
}
57
58
static bool usplash_write(const char *cmd, const char *arg){
59
/*
60
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
61
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
62
* SEE ALSO
63
* usplash_write(8)
64
*/
65
int ret;
66
int fifo_fd;
67
do{
68
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
69
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
70
return false;
71
}
72
}while(fifo_fd == -1);
73
74
const char *cmd_line;
75
size_t cmd_line_len;
76
char *cmd_line_alloc = NULL;
77
if(arg == NULL){
78
cmd_line = cmd;
79
cmd_line_len = strlen(cmd);
80
}else{
81
do{
82
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
83
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
84
int e = errno;
85
close(fifo_fd);
86
errno = e;
87
return false;
88
}
89
}while(ret == -1);
90
cmd_line = cmd_line_alloc;
91
cmd_line_len = (size_t)ret + 1;
92
}
93
94
size_t written = 0;
95
ssize_t sret = 0;
96
while(not interrupted_by_signal and written < cmd_line_len){
97
sret = write(fifo_fd, cmd_line + written,
98
cmd_line_len - written);
99
if(sret == -1){
100
if(errno != EINTR or interrupted_by_signal){
101
int e = errno;
102
close(fifo_fd);
103
free(cmd_line_alloc);
104
errno = e;
105
return false;
106
} else {
107
continue;
108
}
109
}
110
written += (size_t)sret;
111
}
112
free(cmd_line_alloc);
113
do{
114
ret = close(fifo_fd);
115
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
116
return false;
117
}
118
}while(ret == -1);
119
if(interrupted_by_signal){
120
return false;
121
}
122
return true;
123
}
124
125
int main(__attribute__((unused))int argc,
126
__attribute__((unused))char **argv){
127
int ret = 0;
128
ssize_t sret;
129
bool an_error_occured = false;
130
131
/* Create prompt string */
132
char *prompt = NULL;
133
{
134
const char *const cryptsource = getenv("cryptsource");
135
const char *const crypttarget = getenv("crypttarget");
136
const char prompt_start[] = "Enter passphrase to unlock the disk";
137
138
if(cryptsource == NULL){
139
if(crypttarget == NULL){
140
ret = asprintf(&prompt, "%s: ", prompt_start);
141
} else {
142
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
143
crypttarget);
144
}
145
} else {
146
if(crypttarget == NULL){
147
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
148
} else {
149
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
150
cryptsource, crypttarget);
151
}
152
}
153
if(ret == -1){
154
return EXIT_FAILURE;
155
}
156
}
157
158
/* Find usplash process */
159
pid_t usplash_pid = 0;
160
char *cmdline = NULL;
161
size_t cmdline_len = 0;
162
const char usplash_name[] = "/sbin/usplash";
163
{
164
DIR *proc_dir = opendir("/proc");
165
if(proc_dir == NULL){
166
free(prompt);
167
perror("opendir");
168
return EXIT_FAILURE;
169
}
170
for(struct dirent *proc_ent = readdir(proc_dir);
171
proc_ent != NULL;
172
proc_ent = readdir(proc_dir)){
173
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
174
if(pid == 0){
175
/* Not a process */
176
continue;
177
}
178
/* Find the executable name by doing readlink() on the
179
/proc/<pid>/exe link */
180
char exe_target[sizeof(usplash_name)];
181
{
182
/* create file name string */
183
char *exe_link;
184
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
185
if(ret == -1){
186
perror("asprintf");
187
free(prompt);
188
closedir(proc_dir);
189
return EXIT_FAILURE;
190
}
191
192
/* Check that it refers to a symlink owned by root:root */
193
struct stat exe_stat;
194
ret = lstat(exe_link, &exe_stat);
195
if(ret == -1){
196
if(errno == ENOENT){
197
free(exe_link);
198
continue;
199
}
200
perror("lstat");
201
free(exe_link);
202
free(prompt);
203
closedir(proc_dir);
204
return EXIT_FAILURE;
205
}
206
if(not S_ISLNK(exe_stat.st_mode)
207
or exe_stat.st_uid != 0
208
or exe_stat.st_gid != 0){
209
free(exe_link);
210
continue;
211
}
212
213
sret = readlink(exe_link, exe_target, sizeof(exe_target));
214
free(exe_link);
215
}
216
if((sret == ((ssize_t)sizeof(exe_target)-1))
217
and (memcmp(usplash_name, exe_target,
218
sizeof(exe_target)-1) == 0)){
219
usplash_pid = pid;
220
/* Read and save the command line of usplash in "cmdline" */
221
{
222
/* Open /proc/<pid>/cmdline */
223
int cl_fd;
224
{
225
char *cmdline_filename;
226
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
227
proc_ent->d_name);
228
if(ret == -1){
229
perror("asprintf");
230
free(prompt);
231
closedir(proc_dir);
232
return EXIT_FAILURE;
233
}
234
cl_fd = open(cmdline_filename, O_RDONLY);
235
if(cl_fd == -1){
236
perror("open");
237
free(cmdline_filename);
238
free(prompt);
239
closedir(proc_dir);
240
return EXIT_FAILURE;
241
}
242
free(cmdline_filename);
243
}
244
size_t cmdline_allocated = 0;
245
char *tmp;
246
const size_t blocksize = 1024;
247
do{
248
if(cmdline_len + blocksize > cmdline_allocated){
249
tmp = realloc(cmdline, cmdline_allocated + blocksize);
250
if(tmp == NULL){
251
perror("realloc");
252
free(cmdline);
253
free(prompt);
254
closedir(proc_dir);
255
return EXIT_FAILURE;
256
}
257
cmdline = tmp;
258
cmdline_allocated += blocksize;
259
}
260
sret = read(cl_fd, cmdline + cmdline_len,
261
cmdline_allocated - cmdline_len);
262
if(sret == -1){
263
perror("read");
264
free(cmdline);
265
free(prompt);
266
closedir(proc_dir);
267
return EXIT_FAILURE;
268
}
269
cmdline_len += (size_t)sret;
270
} while(sret != 0);
271
close(cl_fd);
272
}
273
break;
274
}
275
}
276
closedir(proc_dir);
277
}
278
if(usplash_pid == 0){
279
free(prompt);
280
return EXIT_FAILURE;
281
}
282
283
/* Set up the signal handler */
284
{
285
struct sigaction old_action,
286
new_action = { .sa_handler = termination_handler,
287
.sa_flags = 0 };
288
sigemptyset(&new_action.sa_mask);
289
sigaddset(&new_action.sa_mask, SIGINT);
290
sigaddset(&new_action.sa_mask, SIGHUP);
291
sigaddset(&new_action.sa_mask, SIGTERM);
292
ret = sigaction(SIGINT, NULL, &old_action);
293
if(ret == -1){
294
perror("sigaction");
295
free(prompt);
296
return EXIT_FAILURE;
297
}
298
if(old_action.sa_handler != SIG_IGN){
299
ret = sigaction(SIGINT, &new_action, NULL);
300
if(ret == -1){
301
perror("sigaction");
302
free(prompt);
303
return EXIT_FAILURE;
304
}
305
}
306
ret = sigaction(SIGHUP, NULL, &old_action);
307
if(ret == -1){
308
perror("sigaction");
309
free(prompt);
310
return EXIT_FAILURE;
311
}
312
if(old_action.sa_handler != SIG_IGN){
313
ret = sigaction(SIGHUP, &new_action, NULL);
314
if(ret == -1){
315
perror("sigaction");
316
free(prompt);
317
return EXIT_FAILURE;
318
}
319
}
320
ret = sigaction(SIGTERM, NULL, &old_action);
321
if(ret == -1){
322
perror("sigaction");
323
free(prompt);
324
return EXIT_FAILURE;
325
}
326
if(old_action.sa_handler != SIG_IGN){
327
ret = sigaction(SIGTERM, &new_action, NULL);
328
if(ret == -1){
329
perror("sigaction");
330
free(prompt);
331
return EXIT_FAILURE;
332
}
333
}
334
}
335
336
/* Write command to FIFO */
337
if(not interrupted_by_signal){
338
if(not usplash_write("TIMEOUT", "0")
339
and (errno != EINTR)){
340
perror("usplash_write");
341
an_error_occured = true;
342
}
343
}
344
if(not interrupted_by_signal and not an_error_occured){
345
if(not usplash_write("INPUTQUIET", prompt)
346
and (errno != EINTR)){
347
perror("usplash_write");
348
an_error_occured = true;
349
}
350
}
351
free(prompt);
352
353
/* This is not really a loop; while() is used to be able to "break"
354
out of it; those breaks are marked "Big" */
355
while(not interrupted_by_signal and not an_error_occured){
356
char *buf = NULL;
357
size_t buf_len = 0;
358
359
/* Open FIFO */
360
int fifo_fd;
361
do{
362
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
363
if(fifo_fd == -1){
364
if(errno != EINTR){
365
perror("open");
366
an_error_occured = true;
367
break;
368
}
369
if(interrupted_by_signal){
370
break;
371
}
372
}
373
}while(fifo_fd == -1);
374
if(interrupted_by_signal or an_error_occured){
375
break; /* Big */
376
}
377
378
/* Read from FIFO */
379
size_t buf_allocated = 0;
380
const size_t blocksize = 1024;
381
do{
382
if(buf_len + blocksize > buf_allocated){
383
char *tmp = realloc(buf, buf_allocated + blocksize);
384
if(tmp == NULL){
385
perror("realloc");
386
an_error_occured = true;
387
break;
388
}
389
buf = tmp;
390
buf_allocated += blocksize;
391
}
392
do{
393
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
394
if(sret == -1){
395
if(errno != EINTR){
396
perror("read");
397
an_error_occured = true;
398
break;
399
}
400
if(interrupted_by_signal){
401
break;
402
}
403
}
404
}while(sret == -1);
405
if(interrupted_by_signal or an_error_occured){
406
break;
407
}
408
409
buf_len += (size_t)sret;
410
}while(sret != 0);
411
close(fifo_fd);
412
if(interrupted_by_signal or an_error_occured){
413
break; /* Big */
414
}
415
416
if(not usplash_write("TIMEOUT", "15")
417
and (errno != EINTR)){
418
perror("usplash_write");
419
an_error_occured = true;
420
}
421
if(interrupted_by_signal or an_error_occured){
422
break; /* Big */
423
}
424
425
/* Print password to stdout */
426
size_t written = 0;
427
while(written < buf_len){
428
do{
429
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
430
if(sret == -1){
431
if(errno != EINTR){
432
perror("write");
433
an_error_occured = true;
434
break;
435
}
436
if(interrupted_by_signal){
437
break;
438
}
439
}
440
}while(sret == -1);
441
if(interrupted_by_signal or an_error_occured){
442
break;
443
}
444
written += (size_t)sret;
445
}
446
free(buf);
447
if(not interrupted_by_signal and not an_error_occured){
448
free(cmdline);
449
return EXIT_SUCCESS;
450
}
451
break; /* Big */
452
} /* end of non-loop while() */
453
454
/* If we got here, an error or interrupt must have happened */
455
456
/* Create argc and argv for new usplash*/
457
int cmdline_argc = 0;
458
char **cmdline_argv = malloc(sizeof(char *));
459
{
460
size_t position = 0;
461
while(position < cmdline_len){
462
char **tmp = realloc(cmdline_argv,
463
(sizeof(char *)
464
* (size_t)(cmdline_argc + 2)));
465
if(tmp == NULL){
466
perror("realloc");
467
free(cmdline_argv);
468
return EXIT_FAILURE;
469
}
470
cmdline_argv = tmp;
471
cmdline_argv[cmdline_argc] = cmdline + position;
472
cmdline_argc++;
473
position += strlen(cmdline + position) + 1;
474
}
475
cmdline_argv[cmdline_argc] = NULL;
476
}
477
/* Kill old usplash */
478
kill(usplash_pid, SIGTERM);
479
sleep(2);
480
while(kill(usplash_pid, 0) == 0){
481
kill(usplash_pid, SIGKILL);
482
sleep(1);
483
}
484
pid_t new_usplash_pid = fork();
485
if(new_usplash_pid == 0){
486
/* Child; will become new usplash process */
487
488
/* Make the effective user ID (root) the only user ID instead of
489
the real user ID (mandos) */
490
ret = setuid(geteuid());
491
if(ret == -1){
492
perror("setuid");
493
}
494
495
setsid();
496
ret = chdir("/");
497
/* if(fork() != 0){ */
498
/* _exit(EXIT_SUCCESS); */
499
/* } */
500
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
501
if(ret == -1){
502
perror("dup2");
503
_exit(EXIT_FAILURE);
504
}
505
506
execv(usplash_name, cmdline_argv);
507
if(not interrupted_by_signal){
508
perror("execv");
509
}
510
free(cmdline);
511
free(cmdline_argv);
512
_exit(EXIT_FAILURE);
513
}
514
free(cmdline);
515
free(cmdline_argv);
516
sleep(2);
517
if(not usplash_write("PULSATE", NULL)
518
and (errno != EINTR)){
519
perror("usplash_write");
520
}
521
522
return EXIT_FAILURE;
523
}
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