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- Committer: Björn Påhlsson
- Date: 2009-02-06 01:15:52 UTC
- mfrom: (299 mandos)
- mto: (24.1.154 mandos) (237.4.3 mandos-release)
- mto: This revision was merged to the branch mainline in revision 306.
- Revision ID: belorn@braxen-20090206011552-p07z71hj60jm7ncl
merge
- files removed:
- DBUS-API
- debian/source
- 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@fukt.bsnet.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
const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
58
const char plymouth_path[] = "/bin/plymouth";
59
const char plymouthd_path[] = "/sbin/plymouthd";
60
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
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"--mode=boot",
62
"--attach-to-session",
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"--pid-file="
64
"/dev/.initramfs/"
65
"plymouth.pid",
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NULL };
67
68
static void termination_handler(__attribute__((unused))int signum){
69
if(interrupted_by_signal){
70
return;
71
}
72
interrupted_by_signal = 1;
73
}
74
75
/* Function to use when printing errors */
76
void error_plus(int status, int errnum, const char *formatstring,
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...){
78
va_list ap;
79
char *text;
80
int ret;
81
82
va_start(ap, formatstring);
83
ret = vasprintf(&text, formatstring, ap);
84
if (ret == -1){
85
fprintf(stderr, "Mandos plugin %s: ",
86
program_invocation_short_name);
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vfprintf(stderr, formatstring, ap);
88
fprintf(stderr, ": ");
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fprintf(stderr, "%s\n", strerror(errnum));
90
error(status, errno, "vasprintf while printing error");
91
return;
92
}
93
fprintf(stderr, "Mandos plugin ");
94
error(status, errnum, "%s", text);
95
free(text);
96
}
97
98
/* Create prompt string */
99
char *makeprompt(void){
100
int ret = 0;
101
char *prompt;
102
const char *const cryptsource = getenv("cryptsource");
103
const char *const crypttarget = getenv("crypttarget");
104
const char prompt_start[] = "Unlocking the disk";
105
const char prompt_end[] = "Enter passphrase";
106
107
if(cryptsource == NULL){
108
if(crypttarget == NULL){
109
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
110
} else {
111
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
112
crypttarget, prompt_end);
113
}
114
} else {
115
if(crypttarget == NULL){
116
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
117
prompt_end);
118
} else {
119
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
120
cryptsource, crypttarget, prompt_end);
121
}
122
}
123
if(ret == -1){
124
return NULL;
125
}
126
return prompt;
127
}
128
129
void kill_and_wait(pid_t pid){
130
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
131
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
132
}
133
134
bool become_a_daemon(void){
135
int ret = setuid(geteuid());
136
if(ret == -1){
137
error_plus(0, errno, "setuid");
138
}
139
140
setsid();
141
ret = chdir("/");
142
if(ret == -1){
143
error_plus(0, errno, "chdir");
144
return false;
145
}
146
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
147
if(ret == -1){
148
error_plus(0, errno, "dup2");
149
return false;
150
}
151
return true;
152
}
153
154
bool exec_and_wait(pid_t *pid_return, const char *path,
155
const char **argv, bool interruptable,
156
bool daemonize){
157
int status;
158
int ret;
159
pid_t pid;
160
pid = fork();
161
if(pid == -1){
162
error_plus(0, errno, "fork");
163
return false;
164
}
165
if(pid == 0){
166
/* Child */
167
if(daemonize){
168
if(not become_a_daemon()){
169
_exit(EX_OSERR);
170
}
171
}
172
173
char **new_argv = NULL;
174
char **tmp;
175
int i = 0;
176
for (; argv[i]!=NULL; i++){
177
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
178
if (tmp == NULL){
179
error_plus(0, errno, "realloc");
180
free(new_argv);
181
_exit(EX_OSERR);
182
}
183
new_argv = tmp;
184
new_argv[i] = strdup(argv[i]);
185
}
186
new_argv[i] = NULL;
187
188
execv(path, (char *const *)new_argv);
189
error_plus(0, errno, "execv");
190
_exit(EXIT_FAILURE);
191
}
192
if(pid_return != NULL){
193
*pid_return = pid;
194
}
195
do {
196
ret = waitpid(pid, &status, 0);
197
} while(ret == -1 and errno == EINTR
198
and ((not interrupted_by_signal)
199
or (not interruptable)));
200
if(interrupted_by_signal and interruptable){
201
return false;
202
}
203
if(ret == -1){
204
error_plus(0, errno, "waitpid");
205
return false;
206
}
207
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
208
return true;
209
}
210
return false;
211
}
212
213
int is_plymouth(const struct dirent *proc_entry){
214
int ret;
215
{
216
uintmax_t maxvalue;
217
char *tmp;
218
errno = 0;
219
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
220
221
if(errno != 0 or *tmp != '\0'
222
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
223
return 0;
224
}
225
}
226
char exe_target[sizeof(plymouthd_path)];
227
char *exe_link;
228
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
229
if(ret == -1){
230
error_plus(0, errno, "asprintf");
231
return 0;
232
}
233
234
struct stat exe_stat;
235
ret = lstat(exe_link, &exe_stat);
236
if(ret == -1){
237
free(exe_link);
238
if(errno != ENOENT){
239
error_plus(0, errno, "lstat");
240
}
241
return 0;
242
}
243
244
if(not S_ISLNK(exe_stat.st_mode)
245
or exe_stat.st_uid != 0
246
or exe_stat.st_gid != 0){
247
free(exe_link);
248
return 0;
249
}
250
251
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
252
free(exe_link);
253
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
254
(memcmp(plymouthd_path, exe_target,
255
sizeof(plymouthd_path)-1) != 0)){
256
return 0;
257
}
258
return 1;
259
}
260
261
pid_t get_pid(void){
262
int ret;
263
FILE *pidfile = fopen(plymouth_pid, "r");
264
uintmax_t maxvalue = 0;
265
if(pidfile != NULL){
266
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
267
if(ret != 1){
268
maxvalue = 0;
269
}
270
fclose(pidfile);
271
}
272
if(maxvalue == 0){
273
struct dirent **direntries = NULL;
274
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
275
if (ret == -1){
276
error_plus(0, errno, "scandir");
277
}
278
if (ret > 0){
279
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
280
if (ret < 0){
281
error_plus(0, errno, "sscanf");
282
}
283
}
284
/* scandir might preallocate for this variable (man page unclear).
285
even if ret == 0, therefore we need to free it. */
286
free(direntries);
287
}
288
pid_t pid;
289
pid = (pid_t)maxvalue;
290
if((uintmax_t)pid == maxvalue){
291
return pid;
292
}
293
294
return 0;
295
}
296
297
const char **getargv(pid_t pid){
298
int cl_fd;
299
char *cmdline_filename;
300
ssize_t sret;
301
int ret;
302
303
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
304
(uintmax_t)pid);
305
if(ret == -1){
306
error_plus(0, errno, "asprintf");
307
return NULL;
308
}
309
310
/* Open /proc/<pid>/cmdline */
311
cl_fd = open(cmdline_filename, O_RDONLY);
312
free(cmdline_filename);
313
if(cl_fd == -1){
314
error_plus(0, errno, "open");
315
return NULL;
316
}
317
318
size_t cmdline_allocated = 0;
319
size_t cmdline_len = 0;
320
char *cmdline = NULL;
321
char *tmp;
322
const size_t blocksize = 1024;
323
do {
324
/* Allocate more space? */
325
if(cmdline_len + blocksize > cmdline_allocated){
326
tmp = realloc(cmdline, cmdline_allocated + blocksize);
327
if(tmp == NULL){
328
error_plus(0, errno, "realloc");
329
free(cmdline);
330
close(cl_fd);
331
return NULL;
332
}
333
cmdline = tmp;
334
cmdline_allocated += blocksize;
335
}
336
337
/* Read data */
338
sret = read(cl_fd, cmdline + cmdline_len,
339
cmdline_allocated - cmdline_len);
340
if(sret == -1){
341
error_plus(0, errno, "read");
342
free(cmdline);
343
close(cl_fd);
344
return NULL;
345
}
346
cmdline_len += (size_t)sret;
347
} while(sret != 0);
348
ret = close(cl_fd);
349
if(ret == -1){
350
error_plus(0, errno, "close");
351
free(cmdline);
352
return NULL;
353
}
354
355
/* we got cmdline and cmdline_len, ignore rest... */
356
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
357
* sizeof(char *)); /* Get number of args */
358
if(argv == NULL){
359
error_plus(0, errno, "argv = malloc()");
360
free(cmdline);
361
return NULL;
362
}
363
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
364
return (const char **)argv;
365
}
366
367
int main(__attribute__((unused))int argc,
368
__attribute__((unused))char **argv){
369
char *prompt;
370
char *prompt_arg;
371
pid_t plymouth_command_pid;
372
int ret;
373
bool bret;
374
375
/* test -x /bin/plymouth */
376
ret = access(plymouth_path, X_OK);
377
if(ret == -1){
378
/* Plymouth is probably not installed. Don't print an error
379
message, just exit. */
380
exit(EX_UNAVAILABLE);
381
}
382
383
{ /* Add signal handlers */
384
struct sigaction old_action,
385
new_action = { .sa_handler = termination_handler,
386
.sa_flags = 0 };
387
sigemptyset(&new_action.sa_mask);
388
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
389
*sig != 0; sig++){
390
ret = sigaddset(&new_action.sa_mask, *sig);
391
if(ret == -1){
392
error_plus(EX_OSERR, errno, "sigaddset");
393
}
394
ret = sigaction(*sig, NULL, &old_action);
395
if(ret == -1){
396
error_plus(EX_OSERR, errno, "sigaction");
397
}
398
if(old_action.sa_handler != SIG_IGN){
399
ret = sigaction(*sig, &new_action, NULL);
400
if(ret == -1){
401
error_plus(EX_OSERR, errno, "sigaction");
402
}
403
}
404
}
405
}
406
407
/* plymouth --ping */
408
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
409
(const char *[])
410
{ plymouth_path, "--ping", NULL },
411
true, false);
412
if(not bret){
413
if(interrupted_by_signal){
414
kill_and_wait(plymouth_command_pid);
415
exit(EXIT_FAILURE);
416
}
417
/* Plymouth is probably not running. Don't print an error
418
message, just exit. */
419
exit(EX_UNAVAILABLE);
420
}
421
422
prompt = makeprompt();
423
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
424
free(prompt);
425
if(ret == -1){
426
error_plus(EX_OSERR, errno, "asprintf");
427
}
428
429
/* plymouth ask-for-password --prompt="$prompt" */
430
bret = exec_and_wait(&plymouth_command_pid,
431
plymouth_path, (const char *[])
432
{ plymouth_path, "ask-for-password",
433
prompt_arg, NULL },
434
true, false);
435
free(prompt_arg);
436
if(bret){
437
exit(EXIT_SUCCESS);
438
}
439
if(not interrupted_by_signal){
440
/* exec_and_wait failed for some other reason */
441
exit(EXIT_FAILURE);
442
}
443
kill_and_wait(plymouth_command_pid);
444
445
const char **plymouthd_argv;
446
pid_t pid = get_pid();
447
if(pid == 0){
448
error_plus(0, 0, "plymouthd pid not found");
449
plymouthd_argv = plymouthd_default_argv;
450
} else {
451
plymouthd_argv = getargv(pid);
452
}
453
454
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
455
{ plymouth_path, "quit", NULL },
456
false, false);
457
if(not bret){
458
exit(EXIT_FAILURE);
459
}
460
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
461
false, true);
462
if(not bret){
463
exit(EXIT_FAILURE);
464
}
465
exec_and_wait(NULL, plymouth_path, (const char *[])
466
{ plymouth_path, "show-splash", NULL },
467
false, false);
468
exit(EXIT_FAILURE);
469
}
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