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- Committer: Teddy Hogeborn
- Date: 2009-09-17 14:21:18 UTC
- Revision ID: teddy@fukt.bsnet.se-20090917142118-6wto8m380jhiot68
Merge from release branch.
- 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@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
void error_plus(int status, int errnum, const char *formatstring,
79
...){
80
va_list ap;
81
char *text;
82
int ret;
83
84
va_start(ap, formatstring);
85
ret = vasprintf(&text, formatstring, ap);
86
if (ret == -1){
87
fprintf(stderr, "Mandos plugin %s: ",
88
program_invocation_short_name);
89
vfprintf(stderr, formatstring, ap);
90
fprintf(stderr, ": ");
91
fprintf(stderr, "%s\n", strerror(errnum));
92
error(status, errno, "vasprintf while printing error");
93
return;
94
}
95
fprintf(stderr, "Mandos plugin ");
96
error(status, errnum, "%s", text);
97
free(text);
98
}
99
100
/* Create prompt string */
101
char *makeprompt(void){
102
int ret = 0;
103
char *prompt;
104
const char *const cryptsource = getenv("cryptsource");
105
const char *const crypttarget = getenv("crypttarget");
106
const char prompt_start[] = "Unlocking the disk";
107
const char prompt_end[] = "Enter passphrase";
108
109
if(cryptsource == NULL){
110
if(crypttarget == NULL){
111
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
112
} else {
113
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
114
crypttarget, prompt_end);
115
}
116
} else {
117
if(crypttarget == NULL){
118
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
119
prompt_end);
120
} else {
121
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
122
cryptsource, crypttarget, prompt_end);
123
}
124
}
125
if(ret == -1){
126
return NULL;
127
}
128
return prompt;
129
}
130
131
void kill_and_wait(pid_t pid){
132
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
133
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
134
}
135
136
bool become_a_daemon(void){
137
int ret = setuid(geteuid());
138
if(ret == -1){
139
error_plus(0, errno, "setuid");
140
}
141
142
setsid();
143
ret = chdir("/");
144
if(ret == -1){
145
error_plus(0, errno, "chdir");
146
return false;
147
}
148
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
149
if(ret == -1){
150
error_plus(0, errno, "dup2");
151
return false;
152
}
153
return true;
154
}
155
156
bool exec_and_wait(pid_t *pid_return, const char *path,
157
const char **argv, bool interruptable,
158
bool daemonize){
159
int status;
160
int ret;
161
pid_t pid;
162
pid = fork();
163
if(pid == -1){
164
error_plus(0, errno, "fork");
165
return false;
166
}
167
if(pid == 0){
168
/* Child */
169
if(daemonize){
170
if(not become_a_daemon()){
171
_exit(EX_OSERR);
172
}
173
}
174
175
char **new_argv = NULL;
176
char **tmp;
177
int i = 0;
178
for (; argv[i]!=NULL; i++){
179
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
180
if (tmp == NULL){
181
error_plus(0, errno, "realloc");
182
free(new_argv);
183
_exit(EX_OSERR);
184
}
185
new_argv = tmp;
186
new_argv[i] = strdup(argv[i]);
187
}
188
new_argv[i] = NULL;
189
190
execv(path, (char *const *)new_argv);
191
error_plus(0, errno, "execv");
192
_exit(EXIT_FAILURE);
193
}
194
if(pid_return != NULL){
195
*pid_return = pid;
196
}
197
do {
198
ret = waitpid(pid, &status, 0);
199
} while(ret == -1 and errno == EINTR
200
and ((not interrupted_by_signal)
201
or (not interruptable)));
202
if(interrupted_by_signal and interruptable){
203
return false;
204
}
205
if(ret == -1){
206
error_plus(0, errno, "waitpid");
207
return false;
208
}
209
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
210
return true;
211
}
212
return false;
213
}
214
215
int is_plymouth(const struct dirent *proc_entry){
216
int ret;
217
{
218
uintmax_t maxvalue;
219
char *tmp;
220
errno = 0;
221
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
222
223
if(errno != 0 or *tmp != '\0'
224
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
225
return 0;
226
}
227
}
228
char exe_target[sizeof(plymouthd_path)];
229
char *exe_link;
230
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
231
if(ret == -1){
232
error_plus(0, errno, "asprintf");
233
return 0;
234
}
235
236
struct stat exe_stat;
237
ret = lstat(exe_link, &exe_stat);
238
if(ret == -1){
239
free(exe_link);
240
if(errno != ENOENT){
241
error_plus(0, errno, "lstat");
242
}
243
return 0;
244
}
245
246
if(not S_ISLNK(exe_stat.st_mode)
247
or exe_stat.st_uid != 0
248
or exe_stat.st_gid != 0){
249
free(exe_link);
250
return 0;
251
}
252
253
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
254
free(exe_link);
255
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
256
(memcmp(plymouthd_path, exe_target,
257
sizeof(plymouthd_path)-1) != 0)){
258
return 0;
259
}
260
return 1;
261
}
262
263
pid_t get_pid(void){
264
int ret;
265
uintmax_t maxvalue = 0;
266
FILE *pidfile = fopen(plymouth_pid, "r");
267
/* Try the new pid file location */
268
if(pidfile != NULL){
269
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
270
if(ret != 1){
271
maxvalue = 0;
272
}
273
fclose(pidfile);
274
}
275
/* Try the old pid file location */
276
if(maxvalue == 0){
277
pidfile = fopen(plymouth_pid, "r");
278
if(pidfile != NULL){
279
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
280
if(ret != 1){
281
maxvalue = 0;
282
}
283
fclose(pidfile);
284
}
285
}
286
/* Look for a plymouth process */
287
if(maxvalue == 0){
288
struct dirent **direntries = NULL;
289
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
290
if (ret == -1){
291
error_plus(0, errno, "scandir");
292
}
293
if (ret > 0){
294
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
295
if (ret < 0){
296
error_plus(0, errno, "sscanf");
297
}
298
}
299
/* scandir might preallocate for this variable (man page unclear).
300
even if ret == 0, therefore we need to free it. */
301
free(direntries);
302
}
303
pid_t pid;
304
pid = (pid_t)maxvalue;
305
if((uintmax_t)pid == maxvalue){
306
return pid;
307
}
308
309
return 0;
310
}
311
312
const char **getargv(pid_t pid){
313
int cl_fd;
314
char *cmdline_filename;
315
ssize_t sret;
316
int ret;
317
318
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
319
(uintmax_t)pid);
320
if(ret == -1){
321
error_plus(0, errno, "asprintf");
322
return NULL;
323
}
324
325
/* Open /proc/<pid>/cmdline */
326
cl_fd = open(cmdline_filename, O_RDONLY);
327
free(cmdline_filename);
328
if(cl_fd == -1){
329
error_plus(0, errno, "open");
330
return NULL;
331
}
332
333
size_t cmdline_allocated = 0;
334
size_t cmdline_len = 0;
335
char *cmdline = NULL;
336
char *tmp;
337
const size_t blocksize = 1024;
338
do {
339
/* Allocate more space? */
340
if(cmdline_len + blocksize > cmdline_allocated){
341
tmp = realloc(cmdline, cmdline_allocated + blocksize);
342
if(tmp == NULL){
343
error_plus(0, errno, "realloc");
344
free(cmdline);
345
close(cl_fd);
346
return NULL;
347
}
348
cmdline = tmp;
349
cmdline_allocated += blocksize;
350
}
351
352
/* Read data */
353
sret = read(cl_fd, cmdline + cmdline_len,
354
cmdline_allocated - cmdline_len);
355
if(sret == -1){
356
error_plus(0, errno, "read");
357
free(cmdline);
358
close(cl_fd);
359
return NULL;
360
}
361
cmdline_len += (size_t)sret;
362
} while(sret != 0);
363
ret = close(cl_fd);
364
if(ret == -1){
365
error_plus(0, errno, "close");
366
free(cmdline);
367
return NULL;
368
}
369
370
/* we got cmdline and cmdline_len, ignore rest... */
371
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
372
* sizeof(char *)); /* Get number of args */
373
if(argv == NULL){
374
error_plus(0, errno, "argv = malloc()");
375
free(cmdline);
376
return NULL;
377
}
378
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
379
return (const char **)argv;
380
}
381
382
int main(__attribute__((unused))int argc,
383
__attribute__((unused))char **argv){
384
char *prompt;
385
char *prompt_arg;
386
pid_t plymouth_command_pid;
387
int ret;
388
bool bret;
389
390
/* test -x /bin/plymouth */
391
ret = access(plymouth_path, X_OK);
392
if(ret == -1){
393
/* Plymouth is probably not installed. Don't print an error
394
message, just exit. */
395
exit(EX_UNAVAILABLE);
396
}
397
398
{ /* Add signal handlers */
399
struct sigaction old_action,
400
new_action = { .sa_handler = termination_handler,
401
.sa_flags = 0 };
402
sigemptyset(&new_action.sa_mask);
403
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
404
*sig != 0; sig++){
405
ret = sigaddset(&new_action.sa_mask, *sig);
406
if(ret == -1){
407
error_plus(EX_OSERR, errno, "sigaddset");
408
}
409
ret = sigaction(*sig, NULL, &old_action);
410
if(ret == -1){
411
error_plus(EX_OSERR, errno, "sigaction");
412
}
413
if(old_action.sa_handler != SIG_IGN){
414
ret = sigaction(*sig, &new_action, NULL);
415
if(ret == -1){
416
error_plus(EX_OSERR, errno, "sigaction");
417
}
418
}
419
}
420
}
421
422
/* plymouth --ping */
423
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
424
(const char *[])
425
{ plymouth_path, "--ping", NULL },
426
true, false);
427
if(not bret){
428
if(interrupted_by_signal){
429
kill_and_wait(plymouth_command_pid);
430
exit(EXIT_FAILURE);
431
}
432
/* Plymouth is probably not running. Don't print an error
433
message, just exit. */
434
exit(EX_UNAVAILABLE);
435
}
436
437
prompt = makeprompt();
438
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
439
free(prompt);
440
if(ret == -1){
441
error_plus(EX_OSERR, errno, "asprintf");
442
}
443
444
/* plymouth ask-for-password --prompt="$prompt" */
445
bret = exec_and_wait(&plymouth_command_pid,
446
plymouth_path, (const char *[])
447
{ plymouth_path, "ask-for-password",
448
prompt_arg, NULL },
449
true, false);
450
free(prompt_arg);
451
if(bret){
452
exit(EXIT_SUCCESS);
453
}
454
if(not interrupted_by_signal){
455
/* exec_and_wait failed for some other reason */
456
exit(EXIT_FAILURE);
457
}
458
kill_and_wait(plymouth_command_pid);
459
460
const char **plymouthd_argv;
461
pid_t pid = get_pid();
462
if(pid == 0){
463
error_plus(0, 0, "plymouthd pid not found");
464
plymouthd_argv = plymouthd_default_argv;
465
} else {
466
plymouthd_argv = getargv(pid);
467
}
468
469
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
470
{ plymouth_path, "quit", NULL },
471
false, false);
472
if(not bret){
473
exit(EXIT_FAILURE);
474
}
475
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
476
false, true);
477
if(not bret){
478
exit(EXIT_FAILURE);
479
}
480
exec_and_wait(NULL, plymouth_path, (const char *[])
481
{ plymouth_path, "show-splash", NULL },
482
false, false);
483
exit(EXIT_FAILURE);
484
}
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