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- Committer: Teddy Hogeborn
- Date: 2009-02-15 09:28:06 UTC
- mto: (237.4.2 mandos-pipe-ipc) (24.1.137 mandos) (299.1.1 release) (300.1.1 release) (301.1.1 release)
- mto: This revision was merged to the branch mainline in revision 252.
- Revision ID: teddy@fukt.bsnet.se-20090215092806-l0uq42v3j1rq3gmi
* INSTALL: Changed "Python 2.4" to "Python 2.5".
* mandos.lsm: - '' -
* mandos.lsm: - '' -
- 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
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* <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(), vfprintf() */
40
#include <unistd.h> /* close(), readlink(), read(),
41
fork(), setsid(), chdir(), dup2(),
42
STDERR_FILENO, execv(), access() */
43
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
44
EXIT_SUCCESS, malloc(), _exit(),
45
getenv() */
46
#include <dirent.h> /* scandir(), alphasort() */
47
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
48
#include <sys/stat.h> /* struct stat, lstat() */
49
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
50
#include <error.h> /* error() */
51
#include <errno.h> /* TEMP_FAILURE_RETRY */
52
#include <argz.h> /* argz_count(), argz_extract() */
53
#include <stdarg.h> /* va_list, va_start(), ... */
54
55
sig_atomic_t interrupted_by_signal = 0;
56
const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
57
const char plymouth_path[] = "/bin/plymouth";
58
const char plymouthd_path[] = "/sbin/plymouthd";
59
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
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"--mode=boot",
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"--attach-to-session",
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"--pid-file="
63
"/dev/.initramfs/"
64
"plymouth.pid",
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NULL };
66
67
static void termination_handler(__attribute__((unused))int signum){
68
if(interrupted_by_signal){
69
return;
70
}
71
interrupted_by_signal = 1;
72
}
73
74
/* Function to use when printing errors */
75
void error_plus(int status, int errnum, const char *formatstring, ...){
76
va_list ap;
77
char *text;
78
int ret;
79
80
va_start(ap, formatstring);
81
ret = vasprintf(&text, formatstring, ap);
82
if (ret == -1){
83
fprintf(stderr, "Mandos plugin %s: ", program_invocation_short_name);
84
vfprintf(stderr, formatstring, ap);
85
fprintf(stderr, ": ");
86
fprintf(stderr, "%s\n", strerror(errnum));
87
error(status, errno, "vasprintf while printing error");
88
return;
89
}
90
fprintf(stderr, "Mandos plugin ");
91
error(status, errnum, "%s", text);
92
free(text);
93
}
94
95
/* Create prompt string */
96
char *makeprompt(void){
97
int ret = 0;
98
char *prompt;
99
const char *const cryptsource = getenv("cryptsource");
100
const char *const crypttarget = getenv("crypttarget");
101
const char prompt_start[] = "Unlocking the disk";
102
const char prompt_end[] = "Enter passphrase";
103
104
if(cryptsource == NULL){
105
if(crypttarget == NULL){
106
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
107
} else {
108
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
109
crypttarget, prompt_end);
110
}
111
} else {
112
if(crypttarget == NULL){
113
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
114
prompt_end);
115
} else {
116
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
117
cryptsource, crypttarget, prompt_end);
118
}
119
}
120
if(ret == -1){
121
return NULL;
122
}
123
return prompt;
124
}
125
126
void kill_and_wait(pid_t pid){
127
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
128
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
129
}
130
131
bool become_a_daemon(void){
132
int ret = setuid(geteuid());
133
if(ret == -1){
134
error_plus(0, errno, "setuid");
135
}
136
137
setsid();
138
ret = chdir("/");
139
if(ret == -1){
140
error_plus(0, errno, "chdir");
141
return false;
142
}
143
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
144
if(ret == -1){
145
error_plus(0, errno, "dup2");
146
return false;
147
}
148
return true;
149
}
150
151
bool exec_and_wait(pid_t *pid_return, const char *path,
152
const char **argv, bool interruptable,
153
bool daemonize){
154
int status;
155
int ret;
156
pid_t pid;
157
pid = fork();
158
if(pid == -1){
159
error_plus(0, errno, "fork");
160
return false;
161
}
162
if(pid == 0){
163
/* Child */
164
if(daemonize){
165
if(not become_a_daemon()){
166
_exit(EX_OSERR);
167
}
168
}
169
170
char **new_argv = NULL;
171
char **tmp;
172
int i = 0;
173
for (; argv[i]!=NULL; i++){
174
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
175
if (tmp == NULL){
176
error_plus(0, errno, "realloc");
177
free(new_argv);
178
_exit(EX_OSERR);
179
}
180
new_argv = tmp;
181
new_argv[i] = strdup(argv[i]);
182
}
183
new_argv[i] = NULL;
184
185
execv(path, (char *const *)new_argv);
186
error_plus(0, errno, "execv");
187
_exit(EXIT_FAILURE);
188
}
189
if(pid_return != NULL){
190
*pid_return = pid;
191
}
192
do {
193
ret = waitpid(pid, &status, 0);
194
} while(ret == -1 and errno == EINTR
195
and ((not interrupted_by_signal)
196
or (not interruptable)));
197
if(interrupted_by_signal and interruptable){
198
return false;
199
}
200
if(ret == -1){
201
error_plus(0, errno, "waitpid");
202
return false;
203
}
204
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
205
return true;
206
}
207
return false;
208
}
209
210
int is_plymouth(const struct dirent *proc_entry){
211
int ret;
212
{
213
uintmax_t maxvalue;
214
char *tmp;
215
errno = 0;
216
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
217
218
if(errno != 0 or *tmp != '\0'
219
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
220
return 0;
221
}
222
}
223
char exe_target[sizeof(plymouthd_path)];
224
char *exe_link;
225
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
226
if(ret == -1){
227
error_plus(0, errno, "asprintf");
228
return 0;
229
}
230
231
struct stat exe_stat;
232
ret = lstat(exe_link, &exe_stat);
233
if(ret == -1){
234
free(exe_link);
235
if(errno != ENOENT){
236
error_plus(0, errno, "lstat");
237
}
238
return 0;
239
}
240
241
if(not S_ISLNK(exe_stat.st_mode)
242
or exe_stat.st_uid != 0
243
or exe_stat.st_gid != 0){
244
free(exe_link);
245
return 0;
246
}
247
248
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
249
free(exe_link);
250
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
251
(memcmp(plymouthd_path, exe_target,
252
sizeof(plymouthd_path)-1) != 0)){
253
return 0;
254
}
255
return 1;
256
}
257
258
pid_t get_pid(void){
259
int ret;
260
FILE *pidfile = fopen(plymouth_pid, "r");
261
uintmax_t maxvalue = 0;
262
if(pidfile != NULL){
263
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
264
if(ret != 1){
265
maxvalue = 0;
266
}
267
fclose(pidfile);
268
}
269
if(maxvalue == 0){
270
struct dirent **direntries = NULL;
271
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
272
if (ret == -1){
273
error_plus(0, errno, "scandir");
274
}
275
if (ret > 0){
276
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
277
if (ret < 0){
278
error_plus(0, errno, "sscanf");
279
}
280
}
281
/* scandir might preallocate for this variable (man page unclear).
282
even if ret == 0, we need to free it. */
283
free(direntries);
284
}
285
pid_t pid;
286
pid = (pid_t)maxvalue;
287
if((uintmax_t)pid == maxvalue){
288
return pid;
289
}
290
291
return 0;
292
}
293
294
const char **getargv(pid_t pid){
295
int cl_fd;
296
char *cmdline_filename;
297
ssize_t sret;
298
int ret;
299
300
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
301
(uintmax_t)pid);
302
if(ret == -1){
303
error_plus(0, errno, "asprintf");
304
return NULL;
305
}
306
307
/* Open /proc/<pid>/cmdline */
308
cl_fd = open(cmdline_filename, O_RDONLY);
309
free(cmdline_filename);
310
if(cl_fd == -1){
311
error_plus(0, errno, "open");
312
return NULL;
313
}
314
315
size_t cmdline_allocated = 0;
316
size_t cmdline_len = 0;
317
char *cmdline = NULL;
318
char *tmp;
319
const size_t blocksize = 1024;
320
do {
321
/* Allocate more space? */
322
if(cmdline_len + blocksize > cmdline_allocated){
323
tmp = realloc(cmdline, cmdline_allocated + blocksize);
324
if(tmp == NULL){
325
error_plus(0, errno, "realloc");
326
free(cmdline);
327
close(cl_fd);
328
return NULL;
329
}
330
cmdline = tmp;
331
cmdline_allocated += blocksize;
332
}
333
334
/* Read data */
335
sret = read(cl_fd, cmdline + cmdline_len,
336
cmdline_allocated - cmdline_len);
337
if(sret == -1){
338
error_plus(0, errno, "read");
339
free(cmdline);
340
close(cl_fd);
341
return NULL;
342
}
343
cmdline_len += (size_t)sret;
344
} while(sret != 0);
345
ret = close(cl_fd);
346
if(ret == -1){
347
error_plus(0, errno, "close");
348
free(cmdline);
349
return NULL;
350
}
351
352
/* we got cmdline and cmdline_len, ignore rest... */
353
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
354
* sizeof(char *)); /* Get number of args */
355
if(argv == NULL){
356
error_plus(0, errno, "argv = malloc()");
357
free(cmdline);
358
return NULL;
359
}
360
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
361
return (const char **)argv;
362
}
363
364
int main(__attribute__((unused))int argc,
365
__attribute__((unused))char **argv){
366
char *prompt;
367
char *prompt_arg;
368
pid_t plymouth_command_pid;
369
int ret;
370
bool bret;
371
372
/* test -x /bin/plymouth */
373
ret = access(plymouth_path, X_OK);
374
if(ret == -1){
375
/* Plymouth is probably not installed. Don't print an error
376
message, just exit. */
377
exit(EX_UNAVAILABLE);
378
}
379
380
{ /* Add signal handlers */
381
struct sigaction old_action,
382
new_action = { .sa_handler = termination_handler,
383
.sa_flags = 0 };
384
sigemptyset(&new_action.sa_mask);
385
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
386
*sig != 0; sig++){
387
ret = sigaddset(&new_action.sa_mask, *sig);
388
if(ret == -1){
389
error_plus(EX_OSERR, errno, "sigaddset");
390
}
391
ret = sigaction(*sig, NULL, &old_action);
392
if(ret == -1){
393
error_plus(EX_OSERR, errno, "sigaction");
394
}
395
if(old_action.sa_handler != SIG_IGN){
396
ret = sigaction(*sig, &new_action, NULL);
397
if(ret == -1){
398
error_plus(EX_OSERR, errno, "sigaction");
399
}
400
}
401
}
402
}
403
404
/* plymouth --ping */
405
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
406
(const char *[])
407
{ plymouth_path, "--ping", NULL },
408
true, false);
409
if(not bret){
410
if(interrupted_by_signal){
411
kill_and_wait(plymouth_command_pid);
412
exit(EXIT_FAILURE);
413
}
414
/* Plymouth is probably not running. Don't print an error
415
message, just exit. */
416
exit(EX_UNAVAILABLE);
417
}
418
419
prompt = makeprompt();
420
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
421
free(prompt);
422
if(ret == -1){
423
error_plus(EX_OSERR, errno, "asprintf");
424
}
425
426
/* plymouth ask-for-password --prompt="$prompt" */
427
bret = exec_and_wait(&plymouth_command_pid,
428
plymouth_path, (const char *[])
429
{ plymouth_path, "ask-for-password",
430
prompt_arg, NULL },
431
true, false);
432
free(prompt_arg);
433
if(bret){
434
exit(EXIT_SUCCESS);
435
}
436
if(not interrupted_by_signal){
437
/* exec_and_wait failed for some other reason */
438
exit(EXIT_FAILURE);
439
}
440
kill_and_wait(plymouth_command_pid);
441
442
const char **plymouthd_argv;
443
pid_t pid = get_pid();
444
if(pid == 0){
445
error_plus(0, 0, "plymouthd pid not found");
446
plymouthd_argv = plymouthd_default_argv;
447
} else {
448
plymouthd_argv = getargv(pid);
449
}
450
451
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
452
{ plymouth_path, "quit", NULL },
453
false, false);
454
if(not bret){
455
exit(EXIT_FAILURE);
456
}
457
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
458
false, true);
459
if(not bret){
460
exit(EXIT_FAILURE);
461
}
462
exec_and_wait(NULL, plymouth_path, (const char *[])
463
{ plymouth_path, "show-splash", NULL },
464
false, false);
465
exit(EXIT_FAILURE);
466
}
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