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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
- debian/source
- debian/upstream
- network-hooks.d
- plugin-helpers
- files modified:
- .bzrignore
added
removed
plugins.d/plymouth.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Plymouth - Read a password from Plymouth and output it
4
*
5
* Copyright © 2010-2018 Teddy Hogeborn
6
* Copyright © 2010-2018 Björn Påhlsson
7
*
8
* This file is part of Mandos.
9
*
10
* Mandos is free software: you can redistribute it and/or modify it
11
* under the terms of the GNU General Public License as published by
12
* the Free Software Foundation, either version 3 of the License, or
13
* (at your option) any later version.
14
*
15
* Mandos is distributed in the hope that it will be useful, but
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
* General Public License for more details.
19
*
20
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
22
*
23
* Contact the authors at <mandos@recompile.se>.
24
*/
25
26
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction(),
30
kill(), SIG_IGN */
31
#include <stdbool.h> /* bool, false, true */
32
#include <fcntl.h> /* open(), O_RDONLY */
33
#include <iso646.h> /* and, or, not*/
34
#include <sys/types.h> /* size_t, ssize_t, pid_t, struct
35
dirent, waitpid() */
36
#include <sys/wait.h> /* waitpid() */
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strchr(), memcmp() */
39
#include <stdio.h> /* asprintf(), perror(), fopen(),
40
fscanf(), vasprintf(), fprintf(),
41
vfprintf() */
42
#include <unistd.h> /* close(), readlink(), read(),
43
fork(), setsid(), chdir(), dup2(),
44
STDERR_FILENO, execv(), access() */
45
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit(),
47
getenv() */
48
#include <dirent.h> /* scandir(), alphasort() */
49
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
50
#include <sys/stat.h> /* struct stat, lstat() */
51
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
#include <error.h> /* error() */
53
#include <errno.h> /* TEMP_FAILURE_RETRY */
54
#include <argz.h> /* argz_count(), argz_extract() */
55
#include <stdarg.h> /* va_list, va_start(), ... */
56
57
sig_atomic_t interrupted_by_signal = 0;
58
59
/* Used by Ubuntu 11.04 (Natty Narwahl) */
60
const char plymouth_old_old_pid[] = "/dev/.initramfs/plymouth.pid";
61
/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
62
const char plymouth_old_pid[] = "/run/initramfs/plymouth.pid";
63
/* Used by Debian 9 (stretch) */
64
const char plymouth_pid[] = "/run/plymouth/pid";
65
66
const char plymouth_path[] = "/bin/plymouth";
67
const char plymouthd_path[] = "/sbin/plymouthd";
68
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
69
"--mode=boot",
70
"--attach-to-session",
71
NULL };
72
73
static void termination_handler(__attribute__((unused))int signum){
74
if(interrupted_by_signal){
75
return;
76
}
77
interrupted_by_signal = 1;
78
}
79
80
/* Function to use when printing errors */
81
__attribute__((format (gnu_printf, 3, 4)))
82
void error_plus(int status, int errnum, const char *formatstring,
83
...){
84
va_list ap;
85
char *text;
86
int ret;
87
88
va_start(ap, formatstring);
89
ret = vasprintf(&text, formatstring, ap);
90
if(ret == -1){
91
fprintf(stderr, "Mandos plugin %s: ",
92
program_invocation_short_name);
93
vfprintf(stderr, formatstring, ap);
94
fprintf(stderr, ": ");
95
fprintf(stderr, "%s\n", strerror(errnum));
96
error(status, errno, "vasprintf while printing error");
97
return;
98
}
99
fprintf(stderr, "Mandos plugin ");
100
error(status, errnum, "%s", text);
101
free(text);
102
}
103
104
/* Create prompt string */
105
char *makeprompt(void){
106
int ret = 0;
107
char *prompt;
108
const char *const cryptsource = getenv("cryptsource");
109
const char *const crypttarget = getenv("crypttarget");
110
const char prompt_start[] = "Unlocking the disk";
111
const char prompt_end[] = "Enter passphrase";
112
113
if(cryptsource == NULL){
114
if(crypttarget == NULL){
115
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
116
} else {
117
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
118
crypttarget, prompt_end);
119
}
120
} else {
121
if(crypttarget == NULL){
122
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
123
prompt_end);
124
} else {
125
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
126
cryptsource, crypttarget, prompt_end);
127
}
128
}
129
if(ret == -1){
130
return NULL;
131
}
132
return prompt;
133
}
134
135
void kill_and_wait(pid_t pid){
136
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
137
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
138
}
139
140
bool become_a_daemon(void){
141
int ret = setuid(geteuid());
142
if(ret == -1){
143
error_plus(0, errno, "setuid");
144
}
145
146
setsid();
147
ret = chdir("/");
148
if(ret == -1){
149
error_plus(0, errno, "chdir");
150
return false;
151
}
152
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
153
if(ret == -1){
154
error_plus(0, errno, "dup2");
155
return false;
156
}
157
return true;
158
}
159
160
__attribute__((nonnull (2, 3)))
161
bool exec_and_wait(pid_t *pid_return, const char *path,
162
const char * const *argv, bool interruptable,
163
bool daemonize){
164
int status;
165
int ret;
166
pid_t pid;
167
pid = fork();
168
if(pid == -1){
169
error_plus(0, errno, "fork");
170
return false;
171
}
172
if(pid == 0){
173
/* Child */
174
if(daemonize){
175
if(not become_a_daemon()){
176
_exit(EX_OSERR);
177
}
178
}
179
180
char **new_argv = malloc(sizeof(const char *));
181
if(new_argv == NULL){
182
error_plus(0, errno, "malloc");
183
_exit(EX_OSERR);
184
}
185
char **tmp;
186
int i = 0;
187
for (; argv[i] != NULL; i++){
188
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 2));
189
if(tmp == NULL){
190
error_plus(0, errno, "realloc");
191
free(new_argv);
192
_exit(EX_OSERR);
193
}
194
new_argv = tmp;
195
new_argv[i] = strdup(argv[i]);
196
}
197
new_argv[i] = NULL;
198
199
execv(path, (char *const *)new_argv);
200
error_plus(0, errno, "execv");
201
_exit(EXIT_FAILURE);
202
}
203
if(pid_return != NULL){
204
*pid_return = pid;
205
}
206
do {
207
ret = waitpid(pid, &status, 0);
208
} while(ret == -1 and errno == EINTR
209
and ((not interrupted_by_signal)
210
or (not interruptable)));
211
if(interrupted_by_signal and interruptable){
212
return false;
213
}
214
if(ret == -1){
215
error_plus(0, errno, "waitpid");
216
return false;
217
}
218
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
219
return true;
220
}
221
return false;
222
}
223
224
__attribute__((nonnull))
225
int is_plymouth(const struct dirent *proc_entry){
226
int ret;
227
{
228
uintmax_t proc_id;
229
char *tmp;
230
errno = 0;
231
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
232
233
if(errno != 0 or *tmp != '\0'
234
or proc_id != (uintmax_t)((pid_t)proc_id)){
235
return 0;
236
}
237
}
238
char exe_target[sizeof(plymouthd_path)];
239
char *exe_link;
240
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
241
if(ret == -1){
242
error_plus(0, errno, "asprintf");
243
return 0;
244
}
245
246
struct stat exe_stat;
247
ret = lstat(exe_link, &exe_stat);
248
if(ret == -1){
249
free(exe_link);
250
if(errno != ENOENT){
251
error_plus(0, errno, "lstat");
252
}
253
return 0;
254
}
255
256
if(not S_ISLNK(exe_stat.st_mode)
257
or exe_stat.st_uid != 0
258
or exe_stat.st_gid != 0){
259
free(exe_link);
260
return 0;
261
}
262
263
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
264
free(exe_link);
265
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
266
(memcmp(plymouthd_path, exe_target,
267
sizeof(plymouthd_path)-1) != 0)){
268
return 0;
269
}
270
return 1;
271
}
272
273
pid_t get_pid(void){
274
int ret;
275
uintmax_t proc_id = 0;
276
FILE *pidfile = fopen(plymouth_pid, "r");
277
/* Try the new pid file location */
278
if(pidfile != NULL){
279
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
280
if(ret != 1){
281
proc_id = 0;
282
}
283
fclose(pidfile);
284
}
285
/* Try the old pid file location */
286
if(proc_id == 0){
287
pidfile = fopen(plymouth_old_pid, "r");
288
if(pidfile != NULL){
289
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
290
if(ret != 1){
291
proc_id = 0;
292
}
293
fclose(pidfile);
294
}
295
}
296
/* Try the old old pid file location */
297
if(proc_id == 0){
298
pidfile = fopen(plymouth_old_old_pid, "r");
299
if(pidfile != NULL){
300
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
301
if(ret != 1){
302
proc_id = 0;
303
}
304
fclose(pidfile);
305
}
306
}
307
/* Look for a plymouth process */
308
if(proc_id == 0){
309
struct dirent **direntries = NULL;
310
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
311
if(ret == -1){
312
error_plus(0, errno, "scandir");
313
}
314
if(ret > 0){
315
for(int i = ret-1; i >= 0; i--){
316
if(proc_id == 0){
317
ret = sscanf(direntries[i]->d_name, "%" SCNuMAX, &proc_id);
318
if(ret < 0){
319
error_plus(0, errno, "sscanf");
320
}
321
}
322
free(direntries[i]);
323
}
324
}
325
/* scandir might preallocate for this variable (man page unclear).
326
even if ret == 0, therefore we need to free it. */
327
free(direntries);
328
}
329
pid_t pid;
330
pid = (pid_t)proc_id;
331
if((uintmax_t)pid == proc_id){
332
return pid;
333
}
334
335
return 0;
336
}
337
338
char **getargv(pid_t pid){
339
int cl_fd;
340
char *cmdline_filename;
341
ssize_t sret;
342
int ret;
343
344
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
345
(uintmax_t)pid);
346
if(ret == -1){
347
error_plus(0, errno, "asprintf");
348
return NULL;
349
}
350
351
/* Open /proc/<pid>/cmdline */
352
cl_fd = open(cmdline_filename, O_RDONLY);
353
free(cmdline_filename);
354
if(cl_fd == -1){
355
error_plus(0, errno, "open");
356
return NULL;
357
}
358
359
size_t cmdline_allocated = 0;
360
size_t cmdline_len = 0;
361
char *cmdline = NULL;
362
char *tmp;
363
const size_t blocksize = 1024;
364
do {
365
/* Allocate more space? */
366
if(cmdline_len + blocksize > cmdline_allocated){
367
tmp = realloc(cmdline, cmdline_allocated + blocksize);
368
if(tmp == NULL){
369
error_plus(0, errno, "realloc");
370
free(cmdline);
371
close(cl_fd);
372
return NULL;
373
}
374
cmdline = tmp;
375
cmdline_allocated += blocksize;
376
}
377
378
/* Read data */
379
sret = read(cl_fd, cmdline + cmdline_len,
380
cmdline_allocated - cmdline_len);
381
if(sret == -1){
382
error_plus(0, errno, "read");
383
free(cmdline);
384
close(cl_fd);
385
return NULL;
386
}
387
cmdline_len += (size_t)sret;
388
} while(sret != 0);
389
ret = close(cl_fd);
390
if(ret == -1){
391
error_plus(0, errno, "close");
392
free(cmdline);
393
return NULL;
394
}
395
396
/* we got cmdline and cmdline_len, ignore rest... */
397
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
398
* sizeof(char *)); /* Get number of args */
399
if(argv == NULL){
400
error_plus(0, errno, "argv = malloc()");
401
free(cmdline);
402
return NULL;
403
}
404
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
405
return argv;
406
}
407
408
int main(__attribute__((unused))int argc,
409
__attribute__((unused))char **argv){
410
char *prompt;
411
char *prompt_arg;
412
pid_t plymouth_command_pid;
413
int ret;
414
bool bret;
415
416
/* test -x /bin/plymouth */
417
ret = access(plymouth_path, X_OK);
418
if(ret == -1){
419
/* Plymouth is probably not installed. Don't print an error
420
message, just exit. */
421
exit(EX_UNAVAILABLE);
422
}
423
424
{ /* Add signal handlers */
425
struct sigaction old_action,
426
new_action = { .sa_handler = termination_handler,
427
.sa_flags = 0 };
428
sigemptyset(&new_action.sa_mask);
429
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
430
*sig != 0; sig++){
431
ret = sigaddset(&new_action.sa_mask, *sig);
432
if(ret == -1){
433
error_plus(EX_OSERR, errno, "sigaddset");
434
}
435
ret = sigaction(*sig, NULL, &old_action);
436
if(ret == -1){
437
error_plus(EX_OSERR, errno, "sigaction");
438
}
439
if(old_action.sa_handler != SIG_IGN){
440
ret = sigaction(*sig, &new_action, NULL);
441
if(ret == -1){
442
error_plus(EX_OSERR, errno, "sigaction");
443
}
444
}
445
}
446
}
447
448
/* plymouth --ping */
449
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
450
(const char *[])
451
{ plymouth_path, "--ping", NULL },
452
true, false);
453
if(not bret){
454
if(interrupted_by_signal){
455
kill_and_wait(plymouth_command_pid);
456
exit(EXIT_FAILURE);
457
}
458
/* Plymouth is probably not running. Don't print an error
459
message, just exit. */
460
exit(EX_UNAVAILABLE);
461
}
462
463
prompt = makeprompt();
464
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
465
free(prompt);
466
if(ret == -1){
467
error_plus(EX_OSERR, errno, "asprintf");
468
}
469
470
/* plymouth ask-for-password --prompt="$prompt" */
471
bret = exec_and_wait(&plymouth_command_pid,
472
plymouth_path, (const char *[])
473
{ plymouth_path, "ask-for-password",
474
prompt_arg, NULL },
475
true, false);
476
free(prompt_arg);
477
if(bret){
478
exit(EXIT_SUCCESS);
479
}
480
if(not interrupted_by_signal){
481
/* exec_and_wait failed for some other reason */
482
exit(EXIT_FAILURE);
483
}
484
kill_and_wait(plymouth_command_pid);
485
486
char **plymouthd_argv = NULL;
487
pid_t pid = get_pid();
488
if(pid == 0){
489
error_plus(0, 0, "plymouthd pid not found");
490
} else {
491
plymouthd_argv = getargv(pid);
492
}
493
494
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
495
{ plymouth_path, "quit", NULL },
496
false, false);
497
if(not bret){
498
if(plymouthd_argv != NULL){
499
free(*plymouthd_argv);
500
free(plymouthd_argv);
501
}
502
exit(EXIT_FAILURE);
503
}
504
bret = exec_and_wait(NULL, plymouthd_path,
505
(plymouthd_argv != NULL)
506
? (const char * const *)plymouthd_argv
507
: plymouthd_default_argv,
508
false, true);
509
if(plymouthd_argv != NULL){
510
free(*plymouthd_argv);
511
free(plymouthd_argv);
512
}
513
if(not bret){
514
exit(EXIT_FAILURE);
515
}
516
exec_and_wait(NULL, plymouth_path, (const char *[])
517
{ plymouth_path, "show-splash", NULL },
518
false, false);
519
exit(EXIT_FAILURE);
520
}
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