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- Committer: Teddy Hogeborn
- Date: 2009-09-08 04:41:37 UTC
- mto: (24.1.142 mandos) (237.12.2 mandos-persistent) (299.1.1 release) (300.1.1 release) (301.1.1 release)
- mto: This revision was merged to the branch mainline in revision 264.
- 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
- 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 Teddy Hogeborn
6
* Copyright © 2010 Björn Påhlsson
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*
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* 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
*
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* 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/>.
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*
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* 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 */
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#include <fcntl.h> /* open(), O_RDONLY */
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#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 */
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#include <string.h> /* strchr(), memcmp() */
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#include <stdio.h> /* asprintf(), perror(), fopen(),
39
fscanf() */
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() */
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#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
50
#include <error.h> /* error() */
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#include <errno.h> /* TEMP_FAILURE_RETRY */
52
#include <argz.h> /* argz_count(), argz_extract() */
53
54
sig_atomic_t interrupted_by_signal = 0;
55
const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
56
const char plymouth_path[] = "/bin/plymouth";
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const char plymouthd_path[] = "/sbin/plymouthd";
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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="
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"/dev/.initramfs/"
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"plymouth.pid",
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NULL };
65
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static void termination_handler(__attribute__((unused))int signum){
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if(interrupted_by_signal){
68
return;
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}
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interrupted_by_signal = 1;
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}
72
73
/* Create prompt string */
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char *makeprompt(void){
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int ret = 0;
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char *prompt;
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const char *const cryptsource = getenv("cryptsource");
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const char *const crypttarget = getenv("crypttarget");
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const char prompt_start[] = "Unlocking the disk";
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const char prompt_end[] = "Enter passphrase";
81
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if(cryptsource == NULL){
83
if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
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} else {
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ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
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crypttarget, prompt_end);
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}
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} else {
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if(crypttarget == NULL){
91
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
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prompt_end);
93
} else {
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ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
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cryptsource, crypttarget, prompt_end);
96
}
97
}
98
if(ret == -1){
99
return NULL;
100
}
101
return prompt;
102
}
103
104
void kill_and_wait(pid_t pid){
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TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
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TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
107
}
108
109
bool become_a_daemon(void){
110
int ret = setuid(geteuid());
111
if(ret == -1){
112
error(0, errno, "setuid");
113
}
114
115
setsid();
116
ret = chdir("/");
117
if(ret == -1){
118
error(0, errno, "chdir");
119
return false;
120
}
121
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
122
if(ret == -1){
123
error(0, errno, "dup2");
124
return false;
125
}
126
return true;
127
}
128
129
bool exec_and_wait(pid_t *pid_return, const char *path,
130
const char **argv, bool interruptable,
131
bool daemonize){
132
int status;
133
int ret;
134
pid_t pid;
135
pid = fork();
136
if(pid == -1){
137
error(0, errno, "fork");
138
return false;
139
}
140
if(pid == 0){
141
/* Child */
142
if(daemonize){
143
if(not become_a_daemon()){
144
_exit(EX_OSERR);
145
}
146
}
147
148
char **new_argv = NULL;
149
char **tmp;
150
int i = 0;
151
for (; argv[i]!=NULL; i++){
152
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
153
if (tmp == NULL){
154
error(0, errno, "realloc");
155
free(new_argv);
156
_exit(EX_OSERR);
157
}
158
new_argv = tmp;
159
new_argv[i] = strdup(argv[i]);
160
}
161
new_argv[i] = NULL;
162
163
execv(path, (char *const *)new_argv);
164
error(0, errno, "execv");
165
_exit(EXIT_FAILURE);
166
}
167
if(pid_return != NULL){
168
*pid_return = pid;
169
}
170
do {
171
ret = waitpid(pid, &status, 0);
172
} while(ret == -1 and errno == EINTR
173
and ((not interrupted_by_signal)
174
or (not interruptable)));
175
if(interrupted_by_signal and interruptable){
176
return false;
177
}
178
if(ret == -1){
179
error(0, errno, "waitpid");
180
return false;
181
}
182
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
183
return true;
184
}
185
return false;
186
}
187
188
int is_plymouth(const struct dirent *proc_entry){
189
int ret;
190
{
191
uintmax_t maxvalue;
192
char *tmp;
193
errno = 0;
194
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
195
196
if(errno != 0 or *tmp != '\0'
197
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
198
return 0;
199
}
200
}
201
char exe_target[sizeof(plymouth_path)];
202
char *exe_link;
203
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
204
if(ret == -1){
205
error(0, errno, "asprintf");
206
return 0;
207
}
208
209
struct stat exe_stat;
210
ret = lstat(exe_link, &exe_stat);
211
if(ret == -1){
212
free(exe_link);
213
if(errno != ENOENT){
214
error(0, errno, "lstat");
215
}
216
return 0;
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}
218
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if(not S_ISLNK(exe_stat.st_mode)
220
or exe_stat.st_uid != 0
221
or exe_stat.st_gid != 0){
222
free(exe_link);
223
return 0;
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}
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ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
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free(exe_link);
228
if((sret != (ssize_t)sizeof(plymouth_path)-1) or
229
(memcmp(plymouth_path, exe_target,
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sizeof(plymouth_path)-1) != 0)){
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return 0;
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}
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return 1;
234
}
235
236
pid_t get_pid(void){
237
int ret;
238
FILE *pidfile = fopen(plymouth_pid, "r");
239
uintmax_t maxvalue = 0;
240
if(pidfile != NULL){
241
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
242
if(ret != 1){
243
maxvalue = 0;
244
}
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fclose(pidfile);
246
}
247
if(maxvalue == 0){
248
struct dirent **direntries;
249
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
250
sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
251
}
252
pid_t pid;
253
pid = (pid_t)maxvalue;
254
if((uintmax_t)pid == maxvalue){
255
return pid;
256
}
257
258
return 0;
259
}
260
261
const char **getargv(pid_t pid){
262
int cl_fd;
263
char *cmdline_filename;
264
ssize_t sret;
265
int ret;
266
267
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
268
(uintmax_t)pid);
269
if(ret == -1){
270
error(0, errno, "asprintf");
271
return NULL;
272
}
273
274
/* Open /proc/<pid>/cmdline */
275
cl_fd = open(cmdline_filename, O_RDONLY);
276
free(cmdline_filename);
277
if(cl_fd == -1){
278
error(0, errno, "open");
279
return NULL;
280
}
281
282
size_t cmdline_allocated = 0;
283
size_t cmdline_len = 0;
284
char *cmdline = NULL;
285
char *tmp;
286
const size_t blocksize = 1024;
287
do {
288
/* Allocate more space? */
289
if(cmdline_len + blocksize > cmdline_allocated){
290
tmp = realloc(cmdline, cmdline_allocated + blocksize);
291
if(tmp == NULL){
292
error(0, errno, "realloc");
293
free(cmdline);
294
close(cl_fd);
295
return NULL;
296
}
297
cmdline = tmp;
298
cmdline_allocated += blocksize;
299
}
300
301
/* Read data */
302
sret = read(cl_fd, cmdline + cmdline_len,
303
cmdline_allocated - cmdline_len);
304
if(sret == -1){
305
error(0, errno, "read");
306
free(cmdline);
307
close(cl_fd);
308
return NULL;
309
}
310
cmdline_len += (size_t)sret;
311
} while(sret != 0);
312
ret = close(cl_fd);
313
if(ret == -1){
314
error(0, errno, "close");
315
free(cmdline);
316
return NULL;
317
}
318
319
/* we got cmdline and cmdline_len, ignore rest... */
320
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
321
* sizeof(char *)); /* Get number of args */
322
if(argv == NULL){
323
error(0, errno, "argv = malloc()");
324
free(cmdline);
325
return NULL;
326
}
327
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
328
return (const char **)argv;
329
}
330
331
int main(__attribute__((unused))int argc,
332
__attribute__((unused))char **argv){
333
char *prompt;
334
char *prompt_arg;
335
pid_t plymouth_command_pid;
336
int ret;
337
bool bret;
338
339
/* test -x /bin/plymouth */
340
ret = access(plymouth_path, X_OK);
341
if(ret == -1){
342
/* Plymouth is probably not installed. Don't print an error
343
message, just exit. */
344
exit(EX_UNAVAILABLE);
345
}
346
347
{ /* Add signal handlers */
348
struct sigaction old_action,
349
new_action = { .sa_handler = termination_handler,
350
.sa_flags = 0 };
351
sigemptyset(&new_action.sa_mask);
352
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
353
*sig != 0; sig++){
354
ret = sigaddset(&new_action.sa_mask, *sig);
355
if(ret == -1){
356
error(EX_OSERR, errno, "sigaddset");
357
}
358
ret = sigaction(*sig, NULL, &old_action);
359
if(ret == -1){
360
error(EX_OSERR, errno, "sigaction");
361
}
362
if(old_action.sa_handler != SIG_IGN){
363
ret = sigaction(*sig, &new_action, NULL);
364
if(ret == -1){
365
error(EX_OSERR, errno, "sigaction");
366
}
367
}
368
}
369
}
370
371
/* plymouth --ping */
372
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
373
(const char *[])
374
{ plymouth_path, "--ping", NULL },
375
true, false);
376
if(not bret){
377
if(interrupted_by_signal){
378
kill_and_wait(plymouth_command_pid);
379
exit(EXIT_FAILURE);
380
}
381
/* Plymouth is probably not running. Don't print an error
382
message, just exit. */
383
exit(EX_UNAVAILABLE);
384
}
385
386
prompt = makeprompt();
387
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
388
free(prompt);
389
if(ret == -1){
390
error(EX_OSERR, errno, "asprintf");
391
}
392
393
/* plymouth ask-for-password --prompt="$prompt" */
394
bret = exec_and_wait(&plymouth_command_pid,
395
plymouth_path, (const char *[])
396
{ plymouth_path, "ask-for-password",
397
prompt_arg, NULL },
398
true, false);
399
free(prompt_arg);
400
if(bret){
401
exit(EXIT_SUCCESS);
402
}
403
if(not interrupted_by_signal){
404
/* exec_and_wait failed for some other reason */
405
exit(EXIT_FAILURE);
406
}
407
kill_and_wait(plymouth_command_pid);
408
409
const char **plymouthd_argv;
410
pid_t pid = get_pid();
411
if(pid == 0){
412
error(0, 0, "plymouthd pid not found");
413
plymouthd_argv = plymouthd_default_argv;
414
} else {
415
plymouthd_argv = getargv(pid);
416
}
417
418
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
419
{ plymouth_path, "quit", NULL },
420
false, false);
421
if(not bret){
422
exit(EXIT_FAILURE);
423
}
424
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
425
false, true);
426
if(not bret){
427
exit(EXIT_FAILURE);
428
}
429
exec_and_wait(NULL, plymouth_path, (const char *[])
430
{ plymouth_path, "show-splash", NULL },
431
false, false);
432
exit(EXIT_FAILURE);
433
}
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