3
3
* Splashy - Read a password from splashy and output it
5
* Copyright © 2008-2017 Teddy Hogeborn
6
* Copyright © 2008-2017 Björn Påhlsson
8
* This file is part of Mandos.
10
* Mandos is free software: you can redistribute it and/or modify it
11
* under the terms of the GNU General Public License as published by
12
* the Free Software Foundation, either version 3 of the License, or
13
* (at your option) any later version.
15
* Mandos is distributed in the hope that it will be useful, but
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
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.
13
* This program is distributed in the hope that it will be useful, but
16
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
16
* General Public License for more details.
20
18
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
23
* Contact the authors at <mandos@recompile.se>.
22
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
26
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
26
#define _GNU_SOURCE /* asprintf() */
27
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
28
sigemptyset(), sigaddset(), SIGINT,
29
29
SIGHUP, SIGTERM, sigaction,
30
30
SIG_IGN, kill(), SIGKILL */
31
31
#include <stddef.h> /* NULL */
32
32
#include <stdlib.h> /* getenv() */
33
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
35
#include <stdlib.h> /* EXIT_FAILURE, free(),
33
#include <stdio.h> /* asprintf(), perror() */
34
#include <stdlib.h> /* EXIT_FAILURE, free(), strtoul(),
37
36
#include <sys/types.h> /* pid_t, DIR, struct dirent,
39
38
#include <dirent.h> /* opendir(), readdir(), closedir() */
40
#include <inttypes.h> /* intmax_t, strtoimax() */
41
39
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
42
40
#include <iso646.h> /* not, or, and */
43
41
#include <unistd.h> /* readlink(), fork(), execl(),
44
42
sleep(), dup2() STDERR_FILENO,
45
STDOUT_FILENO, _exit(),
47
#include <string.h> /* memcmp(), strerror() */
48
#include <errno.h> /* errno, EACCES, ENOTDIR, ELOOP,
49
ENOENT, ENAMETOOLONG, EMFILE,
50
ENFILE, ENOMEM, ENOEXEC, EINVAL,
51
E2BIG, EFAULT, EIO, ETXTBSY,
52
EISDIR, ELIBBAD, EPERM, EINTR,
54
#include <error.h> /* error() */
43
STDOUT_FILENO, _exit() */
44
#include <string.h> /* memcmp() */
45
#include <errno.h> /* errno */
55
46
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
57
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
59
#include <stdarg.h> /* va_list, va_start(), ... */
61
49
sig_atomic_t interrupted_by_signal = 0;
64
/* Function to use when printing errors */
65
__attribute__((format (gnu_printf, 3, 4)))
66
void error_plus(int status, int errnum, const char *formatstring,
72
va_start(ap, formatstring);
73
ret = vasprintf(&text, formatstring, ap);
75
fprintf(stderr, "Mandos plugin %s: ",
76
program_invocation_short_name);
77
vfprintf(stderr, formatstring, ap);
78
fprintf(stderr, ": ");
79
fprintf(stderr, "%s\n", strerror(errnum));
80
error(status, errno, "vasprintf while printing error");
83
fprintf(stderr, "Mandos plugin ");
84
error(status, errnum, "%s", text);
89
static void termination_handler(int signum){
90
if(interrupted_by_signal){
51
static void termination_handler(__attribute__((unused))int signum){
93
52
interrupted_by_signal = 1;
94
signal_received = signum;
97
55
int main(__attribute__((unused))int argc,
98
56
__attribute__((unused))char **argv){
59
/* Create prompt string */
100
60
char *prompt = NULL;
101
DIR *proc_dir = NULL;
102
pid_t splashy_pid = 0;
103
pid_t splashy_command_pid = 0;
104
int exitstatus = EXIT_FAILURE;
106
/* Create prompt string */
108
62
const char *const cryptsource = getenv("cryptsource");
109
63
const char *const crypttarget = getenv("crypttarget");
240
156
new_action = { .sa_handler = termination_handler,
242
158
sigemptyset(&new_action.sa_mask);
243
ret = sigaddset(&new_action.sa_mask, SIGINT);
245
error_plus(0, errno, "sigaddset");
246
exitstatus = EX_OSERR;
249
ret = sigaddset(&new_action.sa_mask, SIGHUP);
251
error_plus(0, errno, "sigaddset");
252
exitstatus = EX_OSERR;
255
ret = sigaddset(&new_action.sa_mask, SIGTERM);
257
error_plus(0, errno, "sigaddset");
258
exitstatus = EX_OSERR;
159
sigaddset(&new_action.sa_mask, SIGINT);
160
sigaddset(&new_action.sa_mask, SIGHUP);
161
sigaddset(&new_action.sa_mask, SIGTERM);
261
162
ret = sigaction(SIGINT, NULL, &old_action);
263
error_plus(0, errno, "sigaction");
264
exitstatus = EX_OSERR;
267
168
if(old_action.sa_handler != SIG_IGN){
268
169
ret = sigaction(SIGINT, &new_action, NULL);
270
error_plus(0, errno, "sigaction");
271
exitstatus = EX_OSERR;
275
176
ret = sigaction(SIGHUP, NULL, &old_action);
277
error_plus(0, errno, "sigaction");
278
exitstatus = EX_OSERR;
281
182
if(old_action.sa_handler != SIG_IGN){
282
183
ret = sigaction(SIGHUP, &new_action, NULL);
284
error_plus(0, errno, "sigaction");
285
exitstatus = EX_OSERR;
289
190
ret = sigaction(SIGTERM, NULL, &old_action);
291
error_plus(0, errno, "sigaction");
292
exitstatus = EX_OSERR;
295
196
if(old_action.sa_handler != SIG_IGN){
296
197
ret = sigaction(SIGTERM, &new_action, NULL);
298
error_plus(0, errno, "sigaction");
299
exitstatus = EX_OSERR;
305
if(interrupted_by_signal){
309
206
/* Fork off the splashy command to prompt for password */
310
splashy_command_pid = fork();
311
if(splashy_command_pid != 0 and interrupted_by_signal){
314
if(splashy_command_pid == -1){
315
error_plus(0, errno, "fork");
316
exitstatus = EX_OSERR;
320
if(splashy_command_pid == 0){
321
if(not interrupted_by_signal){
207
pid_t splashy_command_pid = 0;
208
if(not interrupted_by_signal){
209
splashy_command_pid = fork();
210
if(splashy_command_pid == -1){
211
if(not interrupted_by_signal){
217
if(splashy_command_pid == 0){
322
218
const char splashy_command[] = "/sbin/splashy_update";
323
execl(splashy_command, splashy_command, prompt, (char *)NULL);
325
error_plus(0, errno, "execl");
331
_exit(EX_UNAVAILABLE);
346
case ELIBBAD: /* Linux only */
219
ret = execl(splashy_command, splashy_command, prompt,
221
if(not interrupted_by_signal){
360
if(interrupted_by_signal){
364
232
/* Wait for command to complete */
233
if(not interrupted_by_signal and splashy_command_pid != 0){
368
ret = waitpid(splashy_command_pid, &status, 0);
369
} while(ret == -1 and errno == EINTR
370
and not interrupted_by_signal);
371
if(interrupted_by_signal){
235
ret = waitpid(splashy_command_pid, &status, 0);
375
error_plus(0, errno, "waitpid");
376
240
if(errno == ECHILD){
377
241
splashy_command_pid = 0;
380
244
/* The child process has exited */
381
245
splashy_command_pid = 0;
382
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
246
if(not interrupted_by_signal and WIFEXITED(status)
247
and WEXITSTATUS(status)==0){
383
248
return EXIT_SUCCESS;
392
if(proc_dir != NULL){
393
TEMP_FAILURE_RETRY(closedir(proc_dir));
396
if(splashy_command_pid != 0){
397
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
399
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
401
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
402
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
405
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
406
if(new_splashy_pid == 0){
407
/* Child; will become new splashy process */
409
/* Make the effective user ID (root) the only user ID instead of
410
the real user ID (_mandos) */
411
ret = setuid(geteuid());
413
error_plus(0, errno, "setuid");
419
error_plus(0, errno, "chdir");
421
/* if(fork() != 0){ */
422
/* _exit(EXIT_SUCCESS); */
424
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
426
error_plus(0, errno, "dup2");
430
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
433
error_plus(0, errno, "execl");
439
_exit(EX_UNAVAILABLE);
452
if(interrupted_by_signal){
453
struct sigaction signal_action;
454
sigemptyset(&signal_action.sa_mask);
455
signal_action.sa_handler = SIG_DFL;
456
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
457
&signal_action, NULL));
459
error_plus(0, errno, "sigaction");
462
ret = raise(signal_received);
463
} while(ret != 0 and errno == EINTR);
465
error_plus(0, errno, "raise");
468
TEMP_FAILURE_RETRY(pause());
252
kill(splashy_pid, SIGTERM);
253
if(interrupted_by_signal and splashy_command_pid != 0){
254
kill(splashy_command_pid, SIGTERM);
257
while(kill(splashy_pid, 0) == 0){
258
kill(splashy_pid, SIGKILL);
261
pid_t new_splashy_pid = fork();
262
if(new_splashy_pid == 0){
263
/* Child; will become new splashy process */
265
/* Make the effective user ID (root) the only user ID instead of
266
the real user ID (mandos) */
267
ret = setuid(geteuid());
274
/* if(fork() != 0){ */
275
/* _exit(EXIT_SUCCESS); */
277
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
283
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
284
if(not interrupted_by_signal){