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- Committer: Björn Påhlsson
- Date: 2008-09-20 03:31:01 UTC
- mto: (24.1.154 mandos) (237.4.3 mandos-release)
- mto: This revision was merged to the branch mainline in revision 203.
- Revision ID: belorn@braxen-20080920033101-f3f3mtozgq6fy8xl
fixed todo to reflect recent changes
- files added:
- etc-plugins.d-README
- files removed:
- NEWS
- 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 Teddy Hogeborn
6
* Copyright © 2008 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
while(not interrupted_by_signal and written < cmd_line_len){
96
ret = write(fifo_fd, cmd_line + written,
97
cmd_line_len - written);
98
if(ret == -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)ret;
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 = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
173
if(pid == 0){
174
/* Not a process */
175
continue;
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
perror("asprintf");
186
free(prompt);
187
closedir(proc_dir);
188
return EXIT_FAILURE;
189
}
190
191
/* Check that it refers to a symlink owned by root:root */
192
struct stat exe_stat;
193
ret = lstat(exe_link, &exe_stat);
194
if(ret == -1){
195
perror("lstat");
196
free(exe_link);
197
free(prompt);
198
closedir(proc_dir);
199
return EXIT_FAILURE;
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
if(sret == -1){
211
continue;
212
}
213
}
214
if((sret == ((ssize_t)sizeof(exe_target)-1))
215
and (memcmp(usplash_name, exe_target,
216
sizeof(exe_target)-1) == 0)){
217
usplash_pid = pid;
218
/* Read and save the command line of usplash in "cmdline" */
219
{
220
/* Open /proc/<pid>/cmdline */
221
int cl_fd;
222
{
223
char *cmdline_filename;
224
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
225
proc_ent->d_name);
226
if(ret == -1){
227
perror("asprintf");
228
free(prompt);
229
closedir(proc_dir);
230
return EXIT_FAILURE;
231
}
232
cl_fd = open(cmdline_filename, O_RDONLY);
233
if(cl_fd == -1){
234
perror("open");
235
free(cmdline_filename);
236
free(prompt);
237
closedir(proc_dir);
238
return EXIT_FAILURE;
239
}
240
free(cmdline_filename);
241
}
242
size_t cmdline_allocated = 0;
243
char *tmp;
244
const size_t blocksize = 1024;
245
do{
246
if(cmdline_len + blocksize > cmdline_allocated){
247
tmp = realloc(cmdline, cmdline_allocated + blocksize);
248
if(tmp == NULL){
249
perror("realloc");
250
free(cmdline);
251
free(prompt);
252
closedir(proc_dir);
253
return EXIT_FAILURE;
254
}
255
cmdline = tmp;
256
cmdline_allocated += blocksize;
257
}
258
sret = read(cl_fd, cmdline + cmdline_len,
259
cmdline_allocated - cmdline_len);
260
if(sret == -1){
261
perror("read");
262
free(cmdline);
263
free(prompt);
264
closedir(proc_dir);
265
return EXIT_FAILURE;
266
}
267
cmdline_len += (size_t)sret;
268
} while(sret != 0);
269
close(cl_fd);
270
}
271
break;
272
}
273
}
274
closedir(proc_dir);
275
}
276
if(usplash_pid == 0){
277
free(prompt);
278
return EXIT_FAILURE;
279
}
280
281
/* Set up the signal handler */
282
{
283
struct sigaction old_action,
284
new_action = { .sa_handler = termination_handler,
285
.sa_flags = 0 };
286
sigemptyset(&new_action.sa_mask);
287
sigaddset(&new_action.sa_mask, SIGINT);
288
sigaddset(&new_action.sa_mask, SIGHUP);
289
sigaddset(&new_action.sa_mask, SIGTERM);
290
ret = sigaction(SIGINT, NULL, &old_action);
291
if(ret == -1){
292
perror("sigaction");
293
free(prompt);
294
return EXIT_FAILURE;
295
}
296
if(old_action.sa_handler != SIG_IGN){
297
ret = sigaction(SIGINT, &new_action, NULL);
298
if(ret == -1){
299
perror("sigaction");
300
free(prompt);
301
return EXIT_FAILURE;
302
}
303
}
304
ret = sigaction(SIGHUP, NULL, &old_action);
305
if(ret == -1){
306
perror("sigaction");
307
free(prompt);
308
return EXIT_FAILURE;
309
}
310
if(old_action.sa_handler != SIG_IGN){
311
ret = sigaction(SIGHUP, &new_action, NULL);
312
if(ret == -1){
313
perror("sigaction");
314
free(prompt);
315
return EXIT_FAILURE;
316
}
317
}
318
ret = sigaction(SIGTERM, NULL, &old_action);
319
if(ret == -1){
320
perror("sigaction");
321
free(prompt);
322
return EXIT_FAILURE;
323
}
324
if(old_action.sa_handler != SIG_IGN){
325
ret = sigaction(SIGTERM, &new_action, NULL);
326
if(ret == -1){
327
perror("sigaction");
328
free(prompt);
329
return EXIT_FAILURE;
330
}
331
}
332
}
333
334
/* Write command to FIFO */
335
if(not interrupted_by_signal){
336
if(not usplash_write("TIMEOUT", "0")
337
and (errno != EINTR)){
338
perror("usplash_write");
339
an_error_occured = true;
340
}
341
}
342
if(not interrupted_by_signal and not an_error_occured){
343
if(not usplash_write("INPUTQUIET", prompt)
344
and (errno != EINTR)){
345
perror("usplash_write");
346
an_error_occured = true;
347
}
348
}
349
free(prompt);
350
351
/* This is not really a loop; while() is used to be able to "break"
352
out of it; those breaks are marked "Big" */
353
while(not interrupted_by_signal and not an_error_occured){
354
char *buf = NULL;
355
size_t buf_len = 0;
356
357
/* Open FIFO */
358
int fifo_fd;
359
do{
360
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
361
if(fifo_fd == -1){
362
if(errno != EINTR){
363
perror("open");
364
an_error_occured = true;
365
break;
366
}
367
if(interrupted_by_signal){
368
break;
369
}
370
}
371
}while(fifo_fd == -1);
372
if(interrupted_by_signal or an_error_occured){
373
break; /* Big */
374
}
375
376
/* Read from FIFO */
377
size_t buf_allocated = 0;
378
const size_t blocksize = 1024;
379
do{
380
if(buf_len + blocksize > buf_allocated){
381
char *tmp = realloc(buf, buf_allocated + blocksize);
382
if(tmp == NULL){
383
perror("realloc");
384
an_error_occured = true;
385
break;
386
}
387
buf = tmp;
388
buf_allocated += blocksize;
389
}
390
do{
391
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
392
if(sret == -1){
393
if(errno != EINTR){
394
perror("read");
395
an_error_occured = true;
396
break;
397
}
398
if(interrupted_by_signal){
399
break;
400
}
401
}
402
}while(sret == -1);
403
if(interrupted_by_signal or an_error_occured){
404
break;
405
}
406
407
buf_len += (size_t)sret;
408
}while(sret != 0);
409
close(fifo_fd);
410
if(interrupted_by_signal or an_error_occured){
411
break; /* Big */
412
}
413
414
if(not usplash_write("TIMEOUT", "15")
415
and (errno != EINTR)){
416
perror("usplash_write");
417
an_error_occured = true;
418
}
419
if(interrupted_by_signal or an_error_occured){
420
break; /* Big */
421
}
422
423
/* Print password to stdout */
424
size_t written = 0;
425
while(written < buf_len){
426
do{
427
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
428
if(sret == -1){
429
if(errno != EINTR){
430
perror("write");
431
an_error_occured = true;
432
break;
433
}
434
if(interrupted_by_signal){
435
break;
436
}
437
}
438
}while(sret == -1);
439
if(interrupted_by_signal or an_error_occured){
440
break;
441
}
442
written += (size_t)sret;
443
}
444
free(buf);
445
if(not interrupted_by_signal and not an_error_occured){
446
free(cmdline);
447
return EXIT_SUCCESS;
448
}
449
break; /* Big */
450
} /* end of non-loop while() */
451
452
/* If we got here, an error or interrupt must have happened */
453
454
/* Create argc and argv for new usplash*/
455
int cmdline_argc = 0;
456
char **cmdline_argv = malloc(sizeof(char *));
457
{
458
size_t position = 0;
459
while(position < cmdline_len){
460
char **tmp = realloc(cmdline_argv,
461
(sizeof(char *)
462
* (size_t)(cmdline_argc + 2)));
463
if(tmp == NULL){
464
perror("realloc");
465
free(cmdline_argv);
466
return EXIT_FAILURE;
467
}
468
cmdline_argv = tmp;
469
cmdline_argv[cmdline_argc] = cmdline + position;
470
cmdline_argc++;
471
position += strlen(cmdline + position) + 1;
472
}
473
cmdline_argv[cmdline_argc] = NULL;
474
}
475
/* Kill old usplash */
476
kill(usplash_pid, SIGTERM);
477
sleep(2);
478
while(kill(usplash_pid, 0) == 0){
479
kill(usplash_pid, SIGKILL);
480
sleep(1);
481
}
482
pid_t new_usplash_pid = fork();
483
if(new_usplash_pid == 0){
484
/* Child; will become new usplash process */
485
486
/* Make the effective user ID (root) the only user ID instead of
487
the real user ID (mandos) */
488
ret = setuid(geteuid());
489
if(ret == -1){
490
perror("setuid");
491
}
492
493
setsid();
494
ret = chdir("/");
495
/* if(fork() != 0){ */
496
/* _exit(EXIT_SUCCESS); */
497
/* } */
498
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
499
if(ret == -1){
500
perror("dup2");
501
_exit(EXIT_FAILURE);
502
}
503
504
execv(usplash_name, cmdline_argv);
505
if(not interrupted_by_signal){
506
perror("execv");
507
}
508
free(cmdline);
509
free(cmdline_argv);
510
_exit(EXIT_FAILURE);
511
}
512
free(cmdline);
513
free(cmdline_argv);
514
sleep(2);
515
if(not usplash_write("PULSATE", NULL)
516
and (errno != EINTR)){
517
perror("usplash_write");
518
}
519
520
return EXIT_FAILURE;
521
}
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