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- Committer: Teddy Hogeborn
- Date: 2008-09-23 18:52:33 UTC
- Revision ID: teddy@fukt.bsnet.se-20080923185233-a6zir2neltxk2qvd
* debian/mandos-client.lintian-overrides: Ignore setuid
"plugins.d/splashy".
"plugins.d/splashy".
- files added:
- debian/mandos-client.config
- files removed:
- DBUS-API
- debian/source
- debian/tests
- debian/upstream
- network-hooks.d
- plugin-helpers
- files modified:
- .bzrignore
added
removed
plugins.d/splashy.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Splashy - Read a password from splashy and output it
4
*
5
* Copyright © 2008-2018 Teddy Hogeborn
6
* Copyright © 2008-2018 Björn Påhlsson
7
*
8
* This file is part of Mandos.
9
*
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.
14
*
15
* Mandos is distributed in the hope that it will be useful, but
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
* General Public License for more details.
19
*
20
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
22
*
23
* Contact the authors at <mandos@recompile.se>.
24
*/
25
26
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
1
#define _GNU_SOURCE /* asprintf() */
27
2
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction,
30
SIG_IGN, kill(), SIGKILL */
3
sigemptyset(), sigaddset(),
4
sigaction, SIGINT, SIG_IGN, SIGHUP,
5
SIGTERM, kill(), SIGKILL */
31
6
#include <stddef.h> /* NULL */
32
7
#include <stdlib.h> /* getenv() */
33
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
34
fprintf() */
35
#include <stdlib.h> /* EXIT_FAILURE, free(),
36
EXIT_SUCCESS */
8
#include <stdio.h> /* asprintf(), perror() */
9
#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS,
10
strtoul(), free() */
37
11
#include <sys/types.h> /* pid_t, DIR, struct dirent,
38
12
ssize_t */
39
13
#include <dirent.h> /* opendir(), readdir(), closedir() */
40
#include <inttypes.h> /* intmax_t, strtoimax() */
41
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
42
#include <iso646.h> /* not, or, and */
43
14
#include <unistd.h> /* readlink(), fork(), execl(),
44
sleep(), dup2() STDERR_FILENO,
45
STDOUT_FILENO, _exit(),
46
pause() */
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,
53
ECHILD */
54
#include <error.h> /* error() */
15
_exit */
16
#include <string.h> /* memcmp() */
17
#include <iso646.h> /* and */
18
#include <errno.h> /* errno */
55
19
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
56
20
WEXITSTATUS() */
57
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
58
EX_UNAVAILABLE */
59
#include <stdarg.h> /* va_list, va_start(), ... */
60
21
61
22
sig_atomic_t interrupted_by_signal = 0;
62
int signal_received;
63
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,
67
...){
68
va_list ap;
69
char *text;
70
int ret;
71
72
va_start(ap, formatstring);
73
ret = vasprintf(&text, formatstring, ap);
74
if(ret == -1){
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");
81
return;
82
}
83
fprintf(stderr, "Mandos plugin ");
84
error(status, errnum, "%s", text);
85
free(text);
86
}
87
88
89
static void termination_handler(int signum){
90
if(interrupted_by_signal){
91
return;
92
}
23
24
static void termination_handler(__attribute__((unused))int signum){
93
25
interrupted_by_signal = 1;
94
signal_received = signum;
95
26
}
96
27
97
int main(__attribute__((unused))int argc,
98
__attribute__((unused))char **argv){
28
int main(__attribute__((unused))int argc, char **argv){
99
29
int ret = 0;
30
31
/* Create prompt string */
100
32
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;
105
106
/* Create prompt string */
107
33
{
108
34
const char *const cryptsource = getenv("cryptsource");
109
35
const char *const crypttarget = getenv("crypttarget");
126
52
}
127
53
}
128
54
if(ret == -1){
129
prompt = NULL;
130
exitstatus = EX_OSERR;
131
goto failure;
55
return EXIT_FAILURE;
132
56
}
133
57
}
134
58
135
59
/* Find splashy process */
60
pid_t splashy_pid = 0;
136
61
{
137
62
const char splashy_name[] = "/sbin/splashy";
138
proc_dir = opendir("/proc");
63
DIR *proc_dir = opendir("/proc");
139
64
if(proc_dir == NULL){
140
int e = errno;
141
error_plus(0, errno, "opendir");
142
switch(e){
143
case EACCES:
144
case ENOTDIR:
145
case ELOOP:
146
case ENOENT:
147
default:
148
exitstatus = EX_OSFILE;
149
break;
150
case ENAMETOOLONG:
151
case EMFILE:
152
case ENFILE:
153
case ENOMEM:
154
exitstatus = EX_OSERR;
155
break;
156
}
157
goto failure;
65
free(prompt);
66
perror("opendir");
67
return EXIT_FAILURE;
158
68
}
159
69
for(struct dirent *proc_ent = readdir(proc_dir);
160
70
proc_ent != NULL;
161
71
proc_ent = readdir(proc_dir)){
162
pid_t pid;
163
{
164
intmax_t tmpmax;
165
char *tmp;
166
errno = 0;
167
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
168
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
169
or tmpmax != (pid_t)tmpmax){
170
/* Not a process */
171
continue;
172
}
173
pid = (pid_t)tmpmax;
72
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
73
if(pid == 0){
74
/* Not a process */
75
continue;
174
76
}
175
77
/* Find the executable name by doing readlink() on the
176
78
/proc/<pid>/exe link */
79
char *exe_link;
80
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
81
if(ret == -1){
82
perror("asprintf");
83
free(prompt);
84
closedir(proc_dir);
85
return EXIT_FAILURE;
86
}
177
87
char exe_target[sizeof(splashy_name)];
178
ssize_t sret;
179
{
180
char *exe_link;
181
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
182
if(ret == -1){
183
error_plus(0, errno, "asprintf");
184
exitstatus = EX_OSERR;
185
goto failure;
186
}
187
188
/* Check that it refers to a symlink owned by root:root */
189
struct stat exe_stat;
190
ret = lstat(exe_link, &exe_stat);
191
if(ret == -1){
192
if(errno == ENOENT){
193
free(exe_link);
194
continue;
195
}
196
int e = errno;
197
error_plus(0, errno, "lstat");
198
free(exe_link);
199
switch(e){
200
case EACCES:
201
case ENOTDIR:
202
case ELOOP:
203
default:
204
exitstatus = EX_OSFILE;
205
break;
206
case ENAMETOOLONG:
207
exitstatus = EX_OSERR;
208
break;
209
}
210
goto failure;
211
}
212
if(not S_ISLNK(exe_stat.st_mode)
213
or exe_stat.st_uid != 0
214
or exe_stat.st_gid != 0){
215
free(exe_link);
216
continue;
217
}
218
219
sret = readlink(exe_link, exe_target, sizeof(exe_target));
220
free(exe_link);
221
}
88
ssize_t sret = readlink(exe_link, exe_target,
89
sizeof(exe_target));
222
90
if((sret == ((ssize_t)sizeof(exe_target)-1))
223
91
and (memcmp(splashy_name, exe_target,
224
92
sizeof(exe_target)-1) == 0)){
227
95
}
228
96
}
229
97
closedir(proc_dir);
230
proc_dir = NULL;
231
98
}
232
99
if(splashy_pid == 0){
233
exitstatus = EX_UNAVAILABLE;
234
goto failure;
100
free(prompt);
101
return EXIT_FAILURE;
235
102
}
236
103
237
104
/* Set up the signal handler */
240
107
new_action = { .sa_handler = termination_handler,
241
108
.sa_flags = 0 };
242
109
sigemptyset(&new_action.sa_mask);
243
ret = sigaddset(&new_action.sa_mask, SIGINT);
244
if(ret == -1){
245
error_plus(0, errno, "sigaddset");
246
exitstatus = EX_OSERR;
247
goto failure;
248
}
249
ret = sigaddset(&new_action.sa_mask, SIGHUP);
250
if(ret == -1){
251
error_plus(0, errno, "sigaddset");
252
exitstatus = EX_OSERR;
253
goto failure;
254
}
255
ret = sigaddset(&new_action.sa_mask, SIGTERM);
256
if(ret == -1){
257
error_plus(0, errno, "sigaddset");
258
exitstatus = EX_OSERR;
259
goto failure;
260
}
110
sigaddset(&new_action.sa_mask, SIGINT);
111
sigaddset(&new_action.sa_mask, SIGHUP);
112
sigaddset(&new_action.sa_mask, SIGTERM);
261
113
ret = sigaction(SIGINT, NULL, &old_action);
262
114
if(ret == -1){
263
error_plus(0, errno, "sigaction");
264
exitstatus = EX_OSERR;
265
goto failure;
115
perror("sigaction");
116
free(prompt);
117
return EXIT_FAILURE;
266
118
}
267
if(old_action.sa_handler != SIG_IGN){
119
if (old_action.sa_handler != SIG_IGN){
268
120
ret = sigaction(SIGINT, &new_action, NULL);
269
121
if(ret == -1){
270
error_plus(0, errno, "sigaction");
271
exitstatus = EX_OSERR;
272
goto failure;
122
perror("sigaction");
123
free(prompt);
124
return EXIT_FAILURE;
273
125
}
274
126
}
275
127
ret = sigaction(SIGHUP, NULL, &old_action);
276
128
if(ret == -1){
277
error_plus(0, errno, "sigaction");
278
exitstatus = EX_OSERR;
279
goto failure;
129
perror("sigaction");
130
free(prompt);
131
return EXIT_FAILURE;
280
132
}
281
if(old_action.sa_handler != SIG_IGN){
133
if (old_action.sa_handler != SIG_IGN){
282
134
ret = sigaction(SIGHUP, &new_action, NULL);
283
135
if(ret == -1){
284
error_plus(0, errno, "sigaction");
285
exitstatus = EX_OSERR;
286
goto failure;
136
perror("sigaction");
137
free(prompt);
138
return EXIT_FAILURE;
287
139
}
288
140
}
289
141
ret = sigaction(SIGTERM, NULL, &old_action);
290
142
if(ret == -1){
291
error_plus(0, errno, "sigaction");
292
exitstatus = EX_OSERR;
293
goto failure;
143
perror("sigaction");
144
free(prompt);
145
return EXIT_FAILURE;
294
146
}
295
if(old_action.sa_handler != SIG_IGN){
147
if (old_action.sa_handler != SIG_IGN){
296
148
ret = sigaction(SIGTERM, &new_action, NULL);
297
149
if(ret == -1){
298
error_plus(0, errno, "sigaction");
299
exitstatus = EX_OSERR;
300
goto failure;
150
perror("sigaction");
151
free(prompt);
152
return EXIT_FAILURE;
301
153
}
302
154
}
303
155
}
304
156
305
if(interrupted_by_signal){
306
goto failure;
307
}
308
309
157
/* Fork off the splashy command to prompt for password */
310
splashy_command_pid = fork();
311
if(splashy_command_pid != 0 and interrupted_by_signal){
312
goto failure;
313
}
314
if(splashy_command_pid == -1){
315
error_plus(0, errno, "fork");
316
exitstatus = EX_OSERR;
317
goto failure;
318
}
319
/* Child */
320
if(splashy_command_pid == 0){
321
if(not interrupted_by_signal){
158
pid_t splashy_command_pid = 0;
159
if(not interrupted_by_signal){
160
splashy_command_pid = fork();
161
if(splashy_command_pid == -1){
162
if(not interrupted_by_signal){
163
perror("fork");
164
}
165
return EXIT_FAILURE;
166
}
167
/* Child */
168
if(splashy_command_pid == 0){
322
169
const char splashy_command[] = "/sbin/splashy_update";
323
execl(splashy_command, splashy_command, prompt, (char *)NULL);
324
int e = errno;
325
error_plus(0, errno, "execl");
326
switch(e){
327
case EACCES:
328
case ENOENT:
329
case ENOEXEC:
330
case EINVAL:
331
_exit(EX_UNAVAILABLE);
332
case ENAMETOOLONG:
333
case E2BIG:
334
case ENOMEM:
335
case EFAULT:
336
case EIO:
337
case EMFILE:
338
case ENFILE:
339
case ETXTBSY:
340
default:
341
_exit(EX_OSERR);
342
case ENOTDIR:
343
case ELOOP:
344
case EISDIR:
345
#ifdef ELIBBAD
346
case ELIBBAD: /* Linux only */
347
#endif
348
case EPERM:
349
_exit(EX_OSFILE);
170
ret = execl(splashy_command, splashy_command, prompt,
171
(char *)NULL);
172
if(not interrupted_by_signal and errno != ENOENT){
173
/* Don't report "File not found", since splashy might not be
174
installed. */
175
perror("execl");
350
176
}
177
free(prompt);
178
return EXIT_FAILURE;
351
179
}
352
free(prompt);
353
_exit(EXIT_FAILURE);
354
180
}
355
181
356
182
/* Parent */
357
183
free(prompt);
358
prompt = NULL;
359
360
if(interrupted_by_signal){
361
goto failure;
362
}
363
184
364
185
/* Wait for command to complete */
365
{
366
int status;
367
do {
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){
372
goto failure;
373
}
374
if(ret == -1){
375
error_plus(0, errno, "waitpid");
376
if(errno == ECHILD){
377
splashy_command_pid = 0;
378
}
379
} else {
380
/* The child process has exited */
381
splashy_command_pid = 0;
382
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
383
return EXIT_SUCCESS;
384
}
385
}
386
}
387
388
failure:
389
390
free(prompt);
391
392
if(proc_dir != NULL){
393
TEMP_FAILURE_RETRY(closedir(proc_dir));
394
}
395
396
if(splashy_command_pid != 0){
397
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
398
399
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
400
sleep(2);
401
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
402
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
186
int status;
187
while(not interrupted_by_signal){
188
waitpid(splashy_command_pid, &status, 0);
189
if(not interrupted_by_signal
190
and WIFEXITED(status) and WEXITSTATUS(status)==0){
191
return EXIT_SUCCESS;
192
}
193
}
194
kill(splashy_pid, SIGTERM);
195
if(interrupted_by_signal){
196
kill(splashy_command_pid, SIGTERM);
197
}
198
199
pid_t new_splashy_pid = fork();
200
if(new_splashy_pid == 0){
201
while(kill(splashy_pid, 0)){
202
sleep(2);
203
kill(splashy_pid, SIGKILL);
403
204
sleep(1);
404
205
}
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 */
408
409
/* Make the effective user ID (root) the only user ID instead of
410
the real user ID (_mandos) */
411
ret = setuid(geteuid());
412
if(ret == -1){
413
error_plus(0, errno, "setuid");
414
}
415
416
setsid();
417
ret = chdir("/");
418
if(ret == -1){
419
error_plus(0, errno, "chdir");
420
}
421
/* if(fork() != 0){ */
422
/* _exit(EXIT_SUCCESS); */
423
/* } */
424
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
425
if(ret == -1){
426
error_plus(0, errno, "dup2");
427
_exit(EX_OSERR);
428
}
429
430
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
431
{
432
int e = errno;
433
error_plus(0, errno, "execl");
434
switch(e){
435
case EACCES:
436
case ENOENT:
437
case ENOEXEC:
438
default:
439
_exit(EX_UNAVAILABLE);
440
case ENAMETOOLONG:
441
case E2BIG:
442
case ENOMEM:
443
_exit(EX_OSERR);
444
case ENOTDIR:
445
case ELOOP:
446
_exit(EX_OSFILE);
447
}
448
}
449
}
450
}
451
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));
206
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
458
207
if(ret == -1){
459
error_plus(0, errno, "sigaction");
460
}
461
do {
462
ret = raise(signal_received);
463
} while(ret != 0 and errno == EINTR);
464
if(ret != 0){
465
error_plus(0, errno, "raise");
466
abort();
467
}
468
TEMP_FAILURE_RETRY(pause());
208
perror("dup2");
209
_exit(EXIT_FAILURE);
210
}
211
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
469
212
}
470
213
471
return exitstatus;
214
return EXIT_FAILURE;
472
215
}
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