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- Committer: Teddy Hogeborn
- Date: 2008-09-08 18:54:47 UTC
- Revision ID: teddy@fukt.bsnet.se-20080908185447-dm2ertwxa20qbckf
* INSTALL: Even better text.
- 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
* Passprompt - 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
perror("lstat");
197
free(exe_link);
198
free(prompt);
199
closedir(proc_dir);
200
return EXIT_FAILURE;
201
}
202
if(not S_ISLNK(exe_stat.st_mode)
203
or exe_stat.st_uid != 0
204
or exe_stat.st_gid != 0){
205
free(exe_link);
206
continue;
207
}
208
209
sret = readlink(exe_link, exe_target, sizeof(exe_target));
210
free(exe_link);
211
if(sret == -1){
212
continue;
213
}
214
}
215
if((sret == ((ssize_t)sizeof(exe_target)-1))
216
and (memcmp(usplash_name, exe_target,
217
sizeof(exe_target)-1) == 0)){
218
usplash_pid = pid;
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
perror("asprintf");
229
free(prompt);
230
closedir(proc_dir);
231
return EXIT_FAILURE;
232
}
233
cl_fd = open(cmdline_filename, O_RDONLY);
234
if(cl_fd == -1){
235
perror("open");
236
free(cmdline_filename);
237
free(prompt);
238
closedir(proc_dir);
239
return EXIT_FAILURE;
240
}
241
free(cmdline_filename);
242
}
243
size_t cmdline_allocated = 0;
244
char *tmp;
245
const size_t blocksize = 1024;
246
do{
247
if(cmdline_len + blocksize > cmdline_allocated){
248
tmp = realloc(cmdline, cmdline_allocated + blocksize);
249
if(tmp == NULL){
250
perror("realloc");
251
free(cmdline);
252
free(prompt);
253
closedir(proc_dir);
254
return EXIT_FAILURE;
255
}
256
cmdline = tmp;
257
cmdline_allocated += blocksize;
258
}
259
sret = read(cl_fd, cmdline + cmdline_len,
260
cmdline_allocated - cmdline_len);
261
if(sret == -1){
262
perror("read");
263
free(cmdline);
264
free(prompt);
265
closedir(proc_dir);
266
return EXIT_FAILURE;
267
}
268
cmdline_len += (size_t)sret;
269
} while(sret != 0);
270
close(cl_fd);
271
}
272
break;
273
}
274
}
275
closedir(proc_dir);
276
}
277
if(usplash_pid == 0){
278
free(prompt);
279
return EXIT_FAILURE;
280
}
281
282
/* Set up the signal handler */
283
{
284
struct sigaction old_action,
285
new_action = { .sa_handler = termination_handler,
286
.sa_flags = 0 };
287
sigemptyset(&new_action.sa_mask);
288
sigaddset(&new_action.sa_mask, SIGINT);
289
sigaddset(&new_action.sa_mask, SIGHUP);
290
sigaddset(&new_action.sa_mask, SIGTERM);
291
ret = sigaction(SIGINT, NULL, &old_action);
292
if(ret == -1){
293
perror("sigaction");
294
free(prompt);
295
return EXIT_FAILURE;
296
}
297
if(old_action.sa_handler != SIG_IGN){
298
ret = sigaction(SIGINT, &new_action, NULL);
299
if(ret == -1){
300
perror("sigaction");
301
free(prompt);
302
return EXIT_FAILURE;
303
}
304
}
305
ret = sigaction(SIGHUP, NULL, &old_action);
306
if(ret == -1){
307
perror("sigaction");
308
free(prompt);
309
return EXIT_FAILURE;
310
}
311
if(old_action.sa_handler != SIG_IGN){
312
ret = sigaction(SIGHUP, &new_action, NULL);
313
if(ret == -1){
314
perror("sigaction");
315
free(prompt);
316
return EXIT_FAILURE;
317
}
318
}
319
ret = sigaction(SIGTERM, NULL, &old_action);
320
if(ret == -1){
321
perror("sigaction");
322
free(prompt);
323
return EXIT_FAILURE;
324
}
325
if(old_action.sa_handler != SIG_IGN){
326
ret = sigaction(SIGTERM, &new_action, NULL);
327
if(ret == -1){
328
perror("sigaction");
329
free(prompt);
330
return EXIT_FAILURE;
331
}
332
}
333
}
334
335
/* Write command to FIFO */
336
if(not interrupted_by_signal){
337
if(not usplash_write("TIMEOUT", "0")
338
and (errno != EINTR)){
339
perror("usplash_write");
340
an_error_occured = true;
341
}
342
}
343
if(not interrupted_by_signal and not an_error_occured){
344
if(not usplash_write("INPUTQUIET", prompt)
345
and (errno != EINTR)){
346
perror("usplash_write");
347
an_error_occured = true;
348
}
349
}
350
free(prompt);
351
352
/* This is not really a loop; while() is used to be able to "break"
353
out of it; those breaks are marked "Big" */
354
while(not interrupted_by_signal and not an_error_occured){
355
char *buf = NULL;
356
size_t buf_len = 0;
357
358
/* Open FIFO */
359
int fifo_fd;
360
do{
361
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
362
if(fifo_fd == -1){
363
if(errno != EINTR){
364
perror("open");
365
an_error_occured = true;
366
break;
367
}
368
if(interrupted_by_signal){
369
break;
370
}
371
}
372
}while(fifo_fd == -1);
373
if(interrupted_by_signal or an_error_occured){
374
break; /* Big */
375
}
376
377
/* Read from FIFO */
378
size_t buf_allocated = 0;
379
const size_t blocksize = 1024;
380
do{
381
if(buf_len + blocksize > buf_allocated){
382
char *tmp = realloc(buf, buf_allocated + blocksize);
383
if(tmp == NULL){
384
perror("realloc");
385
an_error_occured = true;
386
break;
387
}
388
buf = tmp;
389
buf_allocated += blocksize;
390
}
391
do{
392
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
393
if(sret == -1){
394
if(errno != EINTR){
395
perror("read");
396
an_error_occured = true;
397
break;
398
}
399
if(interrupted_by_signal){
400
break;
401
}
402
}
403
}while(sret == -1);
404
if(interrupted_by_signal or an_error_occured){
405
break;
406
}
407
408
buf_len += (size_t)sret;
409
}while(sret != 0);
410
close(fifo_fd);
411
if(interrupted_by_signal or an_error_occured){
412
break; /* Big */
413
}
414
415
if(not usplash_write("TIMEOUT", "15")
416
and (errno != EINTR)){
417
perror("usplash_write");
418
an_error_occured = true;
419
}
420
if(interrupted_by_signal or an_error_occured){
421
break; /* Big */
422
}
423
424
/* Print password to stdout */
425
size_t written = 0;
426
while(written < buf_len){
427
do{
428
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
429
if(sret == -1){
430
if(errno != EINTR){
431
perror("write");
432
an_error_occured = true;
433
break;
434
}
435
if(interrupted_by_signal){
436
break;
437
}
438
}
439
}while(sret == -1);
440
if(interrupted_by_signal or an_error_occured){
441
break;
442
}
443
written += (size_t)sret;
444
}
445
free(buf);
446
if(not interrupted_by_signal and not an_error_occured){
447
free(cmdline);
448
return EXIT_SUCCESS;
449
}
450
break; /* Big */
451
} /* end of non-loop while() */
452
453
/* If we got here, an error or interrupt must have happened */
454
455
/* Create argc and argv for new usplash*/
456
int cmdline_argc = 0;
457
char **cmdline_argv = malloc(sizeof(char *));
458
{
459
size_t position = 0;
460
while(position < cmdline_len){
461
char **tmp = realloc(cmdline_argv,
462
(sizeof(char *)
463
* (size_t)(cmdline_argc + 2)));
464
if(tmp == NULL){
465
perror("realloc");
466
free(cmdline_argv);
467
return EXIT_FAILURE;
468
}
469
cmdline_argv = tmp;
470
cmdline_argv[cmdline_argc] = cmdline + position;
471
cmdline_argc++;
472
position += strlen(cmdline + position) + 1;
473
}
474
cmdline_argv[cmdline_argc] = NULL;
475
}
476
/* Kill old usplash */
477
kill(usplash_pid, SIGTERM);
478
sleep(2);
479
while(kill(usplash_pid, 0) == 0){
480
kill(usplash_pid, SIGKILL);
481
sleep(1);
482
}
483
pid_t new_usplash_pid = fork();
484
if(new_usplash_pid == 0){
485
/* Child; will become new usplash process */
486
487
/* Make the effective user ID (root) the only user ID instead of
488
the real user ID (mandos) */
489
ret = setuid(geteuid());
490
if(ret == -1){
491
perror("setuid");
492
}
493
494
setsid();
495
ret = chdir("/");
496
/* if(fork() != 0){ */
497
/* _exit(EXIT_SUCCESS); */
498
/* } */
499
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
500
if(ret == -1){
501
perror("dup2");
502
_exit(EXIT_FAILURE);
503
}
504
505
execv(usplash_name, cmdline_argv);
506
if(not interrupted_by_signal){
507
perror("execv");
508
}
509
free(cmdline);
510
free(cmdline_argv);
511
_exit(EXIT_FAILURE);
512
}
513
free(cmdline);
514
free(cmdline_argv);
515
sleep(2);
516
if(not usplash_write("PULSATE", NULL)
517
and (errno != EINTR)){
518
perror("usplash_write");
519
}
520
521
return EXIT_FAILURE;
522
}
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