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- Committer: Björn Påhlsson
- Date: 2008-09-08 22:10:20 UTC
- mfrom: (181 mandos)
- mto: (24.1.154 mandos) (237.4.3 mandos-release)
- mto: This revision was merged to the branch mainline in revision 186.
- Revision ID: belorn@braxen-20080908221020-wy79n1pc07uo6wpv
merge
- files added:
- etc-plugins.d-README
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- network-hooks.d
- 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 © 2010-2011 Teddy Hogeborn
6
* Copyright © 2010-2011 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@recompile.se>.
23
*/
24
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction(),
29
kill(), SIG_IGN */
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_RDONLY */
32
#include <iso646.h> /* and, or, not*/
33
#include <sys/types.h> /* size_t, ssize_t, pid_t, struct
34
dirent, waitpid() */
35
#include <sys/wait.h> /* waitpid() */
36
#include <stddef.h> /* NULL */
37
#include <string.h> /* strchr(), memcmp() */
38
#include <stdio.h> /* asprintf(), perror(), fopen(),
39
fscanf(), vasprintf(), fprintf(),
40
vfprintf() */
41
#include <unistd.h> /* close(), readlink(), read(),
42
fork(), setsid(), chdir(), dup2(),
43
STDERR_FILENO, execv(), access() */
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit(),
46
getenv() */
47
#include <dirent.h> /* scandir(), alphasort() */
48
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
49
#include <sys/stat.h> /* struct stat, lstat() */
50
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
51
#include <error.h> /* error() */
52
#include <errno.h> /* TEMP_FAILURE_RETRY */
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
55
56
sig_atomic_t interrupted_by_signal = 0;
57
58
/* Used by Ubuntu 11.04 (Natty Narwahl) */
59
const char plymouth_old_pid[] = "/dev/.initramfs/plymouth.pid";
60
/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
61
const char plymouth_pid[] = "/run/initramfs/plymouth.pid";
62
63
const char plymouth_path[] = "/bin/plymouth";
64
const char plymouthd_path[] = "/sbin/plymouthd";
65
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
66
"--mode=boot",
67
"--attach-to-session",
68
NULL };
69
70
static void termination_handler(__attribute__((unused))int signum){
71
if(interrupted_by_signal){
72
return;
73
}
74
interrupted_by_signal = 1;
75
}
76
77
/* Function to use when printing errors */
78
__attribute__((format (gnu_printf, 3, 4)))
79
void error_plus(int status, int errnum, const char *formatstring,
80
...){
81
va_list ap;
82
char *text;
83
int ret;
84
85
va_start(ap, formatstring);
86
ret = vasprintf(&text, formatstring, ap);
87
if (ret == -1){
88
fprintf(stderr, "Mandos plugin %s: ",
89
program_invocation_short_name);
90
vfprintf(stderr, formatstring, ap);
91
fprintf(stderr, ": ");
92
fprintf(stderr, "%s\n", strerror(errnum));
93
error(status, errno, "vasprintf while printing error");
94
return;
95
}
96
fprintf(stderr, "Mandos plugin ");
97
error(status, errnum, "%s", text);
98
free(text);
99
}
100
101
/* Create prompt string */
102
char *makeprompt(void){
103
int ret = 0;
104
char *prompt;
105
const char *const cryptsource = getenv("cryptsource");
106
const char *const crypttarget = getenv("crypttarget");
107
const char prompt_start[] = "Unlocking the disk";
108
const char prompt_end[] = "Enter passphrase";
109
110
if(cryptsource == NULL){
111
if(crypttarget == NULL){
112
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
113
} else {
114
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
115
crypttarget, prompt_end);
116
}
117
} else {
118
if(crypttarget == NULL){
119
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
120
prompt_end);
121
} else {
122
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
123
cryptsource, crypttarget, prompt_end);
124
}
125
}
126
if(ret == -1){
127
return NULL;
128
}
129
return prompt;
130
}
131
132
void kill_and_wait(pid_t pid){
133
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
134
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
135
}
136
137
bool become_a_daemon(void){
138
int ret = setuid(geteuid());
139
if(ret == -1){
140
error_plus(0, errno, "setuid");
141
}
142
143
setsid();
144
ret = chdir("/");
145
if(ret == -1){
146
error_plus(0, errno, "chdir");
147
return false;
148
}
149
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
150
if(ret == -1){
151
error_plus(0, errno, "dup2");
152
return false;
153
}
154
return true;
155
}
156
157
bool exec_and_wait(pid_t *pid_return, const char *path,
158
const char **argv, bool interruptable,
159
bool daemonize){
160
int status;
161
int ret;
162
pid_t pid;
163
pid = fork();
164
if(pid == -1){
165
error_plus(0, errno, "fork");
166
return false;
167
}
168
if(pid == 0){
169
/* Child */
170
if(daemonize){
171
if(not become_a_daemon()){
172
_exit(EX_OSERR);
173
}
174
}
175
176
char **new_argv = NULL;
177
char **tmp;
178
int i = 0;
179
for (; argv[i]!=NULL; i++){
180
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
181
if (tmp == NULL){
182
error_plus(0, errno, "realloc");
183
free(new_argv);
184
_exit(EX_OSERR);
185
}
186
new_argv = tmp;
187
new_argv[i] = strdup(argv[i]);
188
}
189
new_argv[i] = NULL;
190
191
execv(path, (char *const *)new_argv);
192
error_plus(0, errno, "execv");
193
_exit(EXIT_FAILURE);
194
}
195
if(pid_return != NULL){
196
*pid_return = pid;
197
}
198
do {
199
ret = waitpid(pid, &status, 0);
200
} while(ret == -1 and errno == EINTR
201
and ((not interrupted_by_signal)
202
or (not interruptable)));
203
if(interrupted_by_signal and interruptable){
204
return false;
205
}
206
if(ret == -1){
207
error_plus(0, errno, "waitpid");
208
return false;
209
}
210
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
211
return true;
212
}
213
return false;
214
}
215
216
int is_plymouth(const struct dirent *proc_entry){
217
int ret;
218
{
219
uintmax_t maxvalue;
220
char *tmp;
221
errno = 0;
222
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
223
224
if(errno != 0 or *tmp != '\0'
225
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
226
return 0;
227
}
228
}
229
char exe_target[sizeof(plymouthd_path)];
230
char *exe_link;
231
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
232
if(ret == -1){
233
error_plus(0, errno, "asprintf");
234
return 0;
235
}
236
237
struct stat exe_stat;
238
ret = lstat(exe_link, &exe_stat);
239
if(ret == -1){
240
free(exe_link);
241
if(errno != ENOENT){
242
error_plus(0, errno, "lstat");
243
}
244
return 0;
245
}
246
247
if(not S_ISLNK(exe_stat.st_mode)
248
or exe_stat.st_uid != 0
249
or exe_stat.st_gid != 0){
250
free(exe_link);
251
return 0;
252
}
253
254
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
255
free(exe_link);
256
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
257
(memcmp(plymouthd_path, exe_target,
258
sizeof(plymouthd_path)-1) != 0)){
259
return 0;
260
}
261
return 1;
262
}
263
264
pid_t get_pid(void){
265
int ret;
266
uintmax_t maxvalue = 0;
267
FILE *pidfile = fopen(plymouth_pid, "r");
268
/* Try the new pid file location */
269
if(pidfile != NULL){
270
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
271
if(ret != 1){
272
maxvalue = 0;
273
}
274
fclose(pidfile);
275
}
276
/* Try the old pid file location */
277
if(maxvalue == 0){
278
pidfile = fopen(plymouth_pid, "r");
279
if(pidfile != NULL){
280
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
281
if(ret != 1){
282
maxvalue = 0;
283
}
284
fclose(pidfile);
285
}
286
}
287
/* Look for a plymouth process */
288
if(maxvalue == 0){
289
struct dirent **direntries = NULL;
290
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
291
if (ret == -1){
292
error_plus(0, errno, "scandir");
293
}
294
if (ret > 0){
295
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
296
if (ret < 0){
297
error_plus(0, errno, "sscanf");
298
}
299
}
300
/* scandir might preallocate for this variable (man page unclear).
301
even if ret == 0, therefore we need to free it. */
302
free(direntries);
303
}
304
pid_t pid;
305
pid = (pid_t)maxvalue;
306
if((uintmax_t)pid == maxvalue){
307
return pid;
308
}
309
310
return 0;
311
}
312
313
const char **getargv(pid_t pid){
314
int cl_fd;
315
char *cmdline_filename;
316
ssize_t sret;
317
int ret;
318
319
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
320
(uintmax_t)pid);
321
if(ret == -1){
322
error_plus(0, errno, "asprintf");
323
return NULL;
324
}
325
326
/* Open /proc/<pid>/cmdline */
327
cl_fd = open(cmdline_filename, O_RDONLY);
328
free(cmdline_filename);
329
if(cl_fd == -1){
330
error_plus(0, errno, "open");
331
return NULL;
332
}
333
334
size_t cmdline_allocated = 0;
335
size_t cmdline_len = 0;
336
char *cmdline = NULL;
337
char *tmp;
338
const size_t blocksize = 1024;
339
do {
340
/* Allocate more space? */
341
if(cmdline_len + blocksize > cmdline_allocated){
342
tmp = realloc(cmdline, cmdline_allocated + blocksize);
343
if(tmp == NULL){
344
error_plus(0, errno, "realloc");
345
free(cmdline);
346
close(cl_fd);
347
return NULL;
348
}
349
cmdline = tmp;
350
cmdline_allocated += blocksize;
351
}
352
353
/* Read data */
354
sret = read(cl_fd, cmdline + cmdline_len,
355
cmdline_allocated - cmdline_len);
356
if(sret == -1){
357
error_plus(0, errno, "read");
358
free(cmdline);
359
close(cl_fd);
360
return NULL;
361
}
362
cmdline_len += (size_t)sret;
363
} while(sret != 0);
364
ret = close(cl_fd);
365
if(ret == -1){
366
error_plus(0, errno, "close");
367
free(cmdline);
368
return NULL;
369
}
370
371
/* we got cmdline and cmdline_len, ignore rest... */
372
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
373
* sizeof(char *)); /* Get number of args */
374
if(argv == NULL){
375
error_plus(0, errno, "argv = malloc()");
376
free(cmdline);
377
return NULL;
378
}
379
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
380
return (const char **)argv;
381
}
382
383
int main(__attribute__((unused))int argc,
384
__attribute__((unused))char **argv){
385
char *prompt;
386
char *prompt_arg;
387
pid_t plymouth_command_pid;
388
int ret;
389
bool bret;
390
391
/* test -x /bin/plymouth */
392
ret = access(plymouth_path, X_OK);
393
if(ret == -1){
394
/* Plymouth is probably not installed. Don't print an error
395
message, just exit. */
396
exit(EX_UNAVAILABLE);
397
}
398
399
{ /* Add signal handlers */
400
struct sigaction old_action,
401
new_action = { .sa_handler = termination_handler,
402
.sa_flags = 0 };
403
sigemptyset(&new_action.sa_mask);
404
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
405
*sig != 0; sig++){
406
ret = sigaddset(&new_action.sa_mask, *sig);
407
if(ret == -1){
408
error_plus(EX_OSERR, errno, "sigaddset");
409
}
410
ret = sigaction(*sig, NULL, &old_action);
411
if(ret == -1){
412
error_plus(EX_OSERR, errno, "sigaction");
413
}
414
if(old_action.sa_handler != SIG_IGN){
415
ret = sigaction(*sig, &new_action, NULL);
416
if(ret == -1){
417
error_plus(EX_OSERR, errno, "sigaction");
418
}
419
}
420
}
421
}
422
423
/* plymouth --ping */
424
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
425
(const char *[])
426
{ plymouth_path, "--ping", NULL },
427
true, false);
428
if(not bret){
429
if(interrupted_by_signal){
430
kill_and_wait(plymouth_command_pid);
431
exit(EXIT_FAILURE);
432
}
433
/* Plymouth is probably not running. Don't print an error
434
message, just exit. */
435
exit(EX_UNAVAILABLE);
436
}
437
438
prompt = makeprompt();
439
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
440
free(prompt);
441
if(ret == -1){
442
error_plus(EX_OSERR, errno, "asprintf");
443
}
444
445
/* plymouth ask-for-password --prompt="$prompt" */
446
bret = exec_and_wait(&plymouth_command_pid,
447
plymouth_path, (const char *[])
448
{ plymouth_path, "ask-for-password",
449
prompt_arg, NULL },
450
true, false);
451
free(prompt_arg);
452
if(bret){
453
exit(EXIT_SUCCESS);
454
}
455
if(not interrupted_by_signal){
456
/* exec_and_wait failed for some other reason */
457
exit(EXIT_FAILURE);
458
}
459
kill_and_wait(plymouth_command_pid);
460
461
const char **plymouthd_argv;
462
pid_t pid = get_pid();
463
if(pid == 0){
464
error_plus(0, 0, "plymouthd pid not found");
465
plymouthd_argv = plymouthd_default_argv;
466
} else {
467
plymouthd_argv = getargv(pid);
468
}
469
470
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
471
{ plymouth_path, "quit", NULL },
472
false, false);
473
if(not bret){
474
exit(EXIT_FAILURE);
475
}
476
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
477
false, true);
478
if(not bret){
479
exit(EXIT_FAILURE);
480
}
481
exec_and_wait(NULL, plymouth_path, (const char *[])
482
{ plymouth_path, "show-splash", NULL },
483
false, false);
484
exit(EXIT_FAILURE);
485
}
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