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- Committer: Teddy Hogeborn
- Date: 2009-09-08 04:41:37 UTC
- Revision ID: teddy@fukt.bsnet.se-20090908044137-4cxubotvn4etoxxl
* plugins.d/mandos-client.c (main): Bug fix: Check result of setgid().
Bug fix: If taking down network
interface, do not drop privileges
completely; save them and reassert
privileges when needed.
Bug fix: If taking down network
interface, do not drop privileges
completely; save them and reassert
privileges when needed.
- files removed:
- DBUS-API
- 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 © 2010-2016 Teddy Hogeborn
6
* Copyright © 2010-2016 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
__attribute__((nonnull (2, 3)))
158
bool exec_and_wait(pid_t *pid_return, const char *path,
159
const char * const *argv, bool interruptable,
160
bool daemonize){
161
int status;
162
int ret;
163
pid_t pid;
164
pid = fork();
165
if(pid == -1){
166
error_plus(0, errno, "fork");
167
return false;
168
}
169
if(pid == 0){
170
/* Child */
171
if(daemonize){
172
if(not become_a_daemon()){
173
_exit(EX_OSERR);
174
}
175
}
176
177
char **new_argv = NULL;
178
char **tmp;
179
int i = 0;
180
for (; argv[i]!=NULL; i++){
181
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
182
if(tmp == NULL){
183
error_plus(0, errno, "realloc");
184
free(new_argv);
185
_exit(EX_OSERR);
186
}
187
new_argv = tmp;
188
new_argv[i] = strdup(argv[i]);
189
}
190
new_argv[i] = NULL;
191
192
execv(path, (char *const *)new_argv);
193
error_plus(0, errno, "execv");
194
_exit(EXIT_FAILURE);
195
}
196
if(pid_return != NULL){
197
*pid_return = pid;
198
}
199
do {
200
ret = waitpid(pid, &status, 0);
201
} while(ret == -1 and errno == EINTR
202
and ((not interrupted_by_signal)
203
or (not interruptable)));
204
if(interrupted_by_signal and interruptable){
205
return false;
206
}
207
if(ret == -1){
208
error_plus(0, errno, "waitpid");
209
return false;
210
}
211
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
212
return true;
213
}
214
return false;
215
}
216
217
__attribute__((nonnull))
218
int is_plymouth(const struct dirent *proc_entry){
219
int ret;
220
{
221
uintmax_t proc_id;
222
char *tmp;
223
errno = 0;
224
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
225
226
if(errno != 0 or *tmp != '\0'
227
or proc_id != (uintmax_t)((pid_t)proc_id)){
228
return 0;
229
}
230
}
231
char exe_target[sizeof(plymouthd_path)];
232
char *exe_link;
233
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
234
if(ret == -1){
235
error_plus(0, errno, "asprintf");
236
return 0;
237
}
238
239
struct stat exe_stat;
240
ret = lstat(exe_link, &exe_stat);
241
if(ret == -1){
242
free(exe_link);
243
if(errno != ENOENT){
244
error_plus(0, errno, "lstat");
245
}
246
return 0;
247
}
248
249
if(not S_ISLNK(exe_stat.st_mode)
250
or exe_stat.st_uid != 0
251
or exe_stat.st_gid != 0){
252
free(exe_link);
253
return 0;
254
}
255
256
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
257
free(exe_link);
258
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
259
(memcmp(plymouthd_path, exe_target,
260
sizeof(plymouthd_path)-1) != 0)){
261
return 0;
262
}
263
return 1;
264
}
265
266
pid_t get_pid(void){
267
int ret;
268
uintmax_t proc_id = 0;
269
FILE *pidfile = fopen(plymouth_pid, "r");
270
/* Try the new pid file location */
271
if(pidfile != NULL){
272
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
273
if(ret != 1){
274
proc_id = 0;
275
}
276
fclose(pidfile);
277
}
278
/* Try the old pid file location */
279
if(proc_id == 0){
280
pidfile = fopen(plymouth_pid, "r");
281
if(pidfile != NULL){
282
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
283
if(ret != 1){
284
proc_id = 0;
285
}
286
fclose(pidfile);
287
}
288
}
289
/* Look for a plymouth process */
290
if(proc_id == 0){
291
struct dirent **direntries = NULL;
292
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
293
if(ret == -1){
294
error_plus(0, errno, "scandir");
295
}
296
if(ret > 0){
297
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &proc_id);
298
if(ret < 0){
299
error_plus(0, errno, "sscanf");
300
}
301
}
302
/* scandir might preallocate for this variable (man page unclear).
303
even if ret == 0, therefore we need to free it. */
304
free(direntries);
305
}
306
pid_t pid;
307
pid = (pid_t)proc_id;
308
if((uintmax_t)pid == proc_id){
309
return pid;
310
}
311
312
return 0;
313
}
314
315
const char * const * getargv(pid_t pid){
316
int cl_fd;
317
char *cmdline_filename;
318
ssize_t sret;
319
int ret;
320
321
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
322
(uintmax_t)pid);
323
if(ret == -1){
324
error_plus(0, errno, "asprintf");
325
return NULL;
326
}
327
328
/* Open /proc/<pid>/cmdline */
329
cl_fd = open(cmdline_filename, O_RDONLY);
330
free(cmdline_filename);
331
if(cl_fd == -1){
332
error_plus(0, errno, "open");
333
return NULL;
334
}
335
336
size_t cmdline_allocated = 0;
337
size_t cmdline_len = 0;
338
char *cmdline = NULL;
339
char *tmp;
340
const size_t blocksize = 1024;
341
do {
342
/* Allocate more space? */
343
if(cmdline_len + blocksize > cmdline_allocated){
344
tmp = realloc(cmdline, cmdline_allocated + blocksize);
345
if(tmp == NULL){
346
error_plus(0, errno, "realloc");
347
free(cmdline);
348
close(cl_fd);
349
return NULL;
350
}
351
cmdline = tmp;
352
cmdline_allocated += blocksize;
353
}
354
355
/* Read data */
356
sret = read(cl_fd, cmdline + cmdline_len,
357
cmdline_allocated - cmdline_len);
358
if(sret == -1){
359
error_plus(0, errno, "read");
360
free(cmdline);
361
close(cl_fd);
362
return NULL;
363
}
364
cmdline_len += (size_t)sret;
365
} while(sret != 0);
366
ret = close(cl_fd);
367
if(ret == -1){
368
error_plus(0, errno, "close");
369
free(cmdline);
370
return NULL;
371
}
372
373
/* we got cmdline and cmdline_len, ignore rest... */
374
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
375
* sizeof(char *)); /* Get number of args */
376
if(argv == NULL){
377
error_plus(0, errno, "argv = malloc()");
378
free(cmdline);
379
return NULL;
380
}
381
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
382
return (const char * const *)argv;
383
}
384
385
int main(__attribute__((unused))int argc,
386
__attribute__((unused))char **argv){
387
char *prompt;
388
char *prompt_arg;
389
pid_t plymouth_command_pid;
390
int ret;
391
bool bret;
392
393
/* test -x /bin/plymouth */
394
ret = access(plymouth_path, X_OK);
395
if(ret == -1){
396
/* Plymouth is probably not installed. Don't print an error
397
message, just exit. */
398
exit(EX_UNAVAILABLE);
399
}
400
401
{ /* Add signal handlers */
402
struct sigaction old_action,
403
new_action = { .sa_handler = termination_handler,
404
.sa_flags = 0 };
405
sigemptyset(&new_action.sa_mask);
406
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
407
*sig != 0; sig++){
408
ret = sigaddset(&new_action.sa_mask, *sig);
409
if(ret == -1){
410
error_plus(EX_OSERR, errno, "sigaddset");
411
}
412
ret = sigaction(*sig, NULL, &old_action);
413
if(ret == -1){
414
error_plus(EX_OSERR, errno, "sigaction");
415
}
416
if(old_action.sa_handler != SIG_IGN){
417
ret = sigaction(*sig, &new_action, NULL);
418
if(ret == -1){
419
error_plus(EX_OSERR, errno, "sigaction");
420
}
421
}
422
}
423
}
424
425
/* plymouth --ping */
426
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
427
(const char *[])
428
{ plymouth_path, "--ping", NULL },
429
true, false);
430
if(not bret){
431
if(interrupted_by_signal){
432
kill_and_wait(plymouth_command_pid);
433
exit(EXIT_FAILURE);
434
}
435
/* Plymouth is probably not running. Don't print an error
436
message, just exit. */
437
exit(EX_UNAVAILABLE);
438
}
439
440
prompt = makeprompt();
441
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
442
free(prompt);
443
if(ret == -1){
444
error_plus(EX_OSERR, errno, "asprintf");
445
}
446
447
/* plymouth ask-for-password --prompt="$prompt" */
448
bret = exec_and_wait(&plymouth_command_pid,
449
plymouth_path, (const char *[])
450
{ plymouth_path, "ask-for-password",
451
prompt_arg, NULL },
452
true, false);
453
free(prompt_arg);
454
if(bret){
455
exit(EXIT_SUCCESS);
456
}
457
if(not interrupted_by_signal){
458
/* exec_and_wait failed for some other reason */
459
exit(EXIT_FAILURE);
460
}
461
kill_and_wait(plymouth_command_pid);
462
463
const char * const *plymouthd_argv;
464
pid_t pid = get_pid();
465
if(pid == 0){
466
error_plus(0, 0, "plymouthd pid not found");
467
plymouthd_argv = plymouthd_default_argv;
468
} else {
469
plymouthd_argv = getargv(pid);
470
}
471
472
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
473
{ plymouth_path, "quit", NULL },
474
false, false);
475
if(not bret){
476
exit(EXIT_FAILURE);
477
}
478
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
479
false, true);
480
if(not bret){
481
exit(EXIT_FAILURE);
482
}
483
exec_and_wait(NULL, plymouth_path, (const char *[])
484
{ plymouth_path, "show-splash", NULL },
485
false, false);
486
exit(EXIT_FAILURE);
487
}
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