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- Committer: Teddy Hogeborn
- Date: 2008-09-24 23:12:49 UTC
- Revision ID: teddy@fukt.bsnet.se-20080924231249-0xhjl5ydrbcjvce7
* debian/mandos-client.lintian-overrides: Ignore setuid
"plugins.d/usplash".
"plugins.d/usplash".
- files added:
- debian/mandos-client.config
- files removed:
- NEWS
- 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 © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 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@fukt.bsnet.se>.
23
*/
24
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
1
#define _GNU_SOURCE /* asprintf() */
26
2
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction,
29
SIG_IGN, kill(), SIGKILL */
3
sigemptyset(), sigaddset(),
4
sigaction, SIGINT, SIG_IGN, SIGHUP,
5
SIGTERM, kill(), SIGKILL */
30
6
#include <stddef.h> /* NULL */
31
7
#include <stdlib.h> /* getenv() */
32
#include <stdio.h> /* asprintf() */
33
#include <stdlib.h> /* EXIT_FAILURE, free(),
34
EXIT_SUCCESS */
8
#include <stdio.h> /* asprintf(), perror() */
9
#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS,
10
strtoul(), free() */
35
11
#include <sys/types.h> /* pid_t, DIR, struct dirent,
36
12
ssize_t */
37
13
#include <dirent.h> /* opendir(), readdir(), closedir() */
38
#include <inttypes.h> /* intmax_t, strtoimax() */
39
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
40
#include <iso646.h> /* not, or, and */
41
14
#include <unistd.h> /* readlink(), fork(), execl(),
42
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit(),
44
pause() */
15
_exit */
45
16
#include <string.h> /* memcmp() */
46
#include <errno.h> /* errno, EACCES, ENOTDIR, ELOOP,
47
ENOENT, ENAMETOOLONG, EMFILE,
48
ENFILE, ENOMEM, ENOEXEC, EINVAL,
49
E2BIG, EFAULT, EIO, ETXTBSY,
50
EISDIR, ELIBBAD, EPERM, EINTR,
51
ECHILD */
52
#include <error.h> /* error() */
17
#include <iso646.h> /* and */
18
#include <errno.h> /* errno */
53
19
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
54
20
WEXITSTATUS() */
55
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
56
EX_UNAVAILABLE */
57
21
58
22
sig_atomic_t interrupted_by_signal = 0;
59
int signal_received;
60
23
61
static void termination_handler(int signum){
62
if(interrupted_by_signal){
63
return;
64
}
24
static void termination_handler(__attribute__((unused))int signum){
65
25
interrupted_by_signal = 1;
66
signal_received = signum;
67
26
}
68
27
69
28
int main(__attribute__((unused))int argc,
70
29
__attribute__((unused))char **argv){
71
30
int ret = 0;
31
32
/* Create prompt string */
72
33
char *prompt = NULL;
73
DIR *proc_dir = NULL;
74
pid_t splashy_pid = 0;
75
pid_t splashy_command_pid = 0;
76
int exitstatus = EXIT_FAILURE;
77
78
/* Create prompt string */
79
34
{
80
35
const char *const cryptsource = getenv("cryptsource");
81
36
const char *const crypttarget = getenv("crypttarget");
98
53
}
99
54
}
100
55
if(ret == -1){
101
prompt = NULL;
102
exitstatus = EX_OSERR;
103
goto failure;
56
return EXIT_FAILURE;
104
57
}
105
58
}
106
59
107
60
/* Find splashy process */
61
pid_t splashy_pid = 0;
108
62
{
109
63
const char splashy_name[] = "/sbin/splashy";
110
proc_dir = opendir("/proc");
64
DIR *proc_dir = opendir("/proc");
111
65
if(proc_dir == NULL){
112
int e = errno;
113
error(0, errno, "opendir");
114
switch(e){
115
case EACCES:
116
case ENOTDIR:
117
case ELOOP:
118
case ENOENT:
119
default:
120
exitstatus = EX_OSFILE;
121
break;
122
case ENAMETOOLONG:
123
case EMFILE:
124
case ENFILE:
125
case ENOMEM:
126
exitstatus = EX_OSERR;
127
break;
128
}
129
goto failure;
66
free(prompt);
67
perror("opendir");
68
return EXIT_FAILURE;
130
69
}
131
70
for(struct dirent *proc_ent = readdir(proc_dir);
132
71
proc_ent != NULL;
133
72
proc_ent = readdir(proc_dir)){
134
pid_t pid;
135
{
136
intmax_t tmpmax;
137
char *tmp;
138
errno = 0;
139
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
140
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
141
or tmpmax != (pid_t)tmpmax){
142
/* Not a process */
143
continue;
144
}
145
pid = (pid_t)tmpmax;
73
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
74
if(pid == 0){
75
/* Not a process */
76
continue;
146
77
}
147
78
/* Find the executable name by doing readlink() on the
148
79
/proc/<pid>/exe link */
152
83
char *exe_link;
153
84
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
154
85
if(ret == -1){
155
error(0, errno, "asprintf");
156
exitstatus = EX_OSERR;
157
goto failure;
158
}
159
160
/* Check that it refers to a symlink owned by root:root */
161
struct stat exe_stat;
162
ret = lstat(exe_link, &exe_stat);
163
if(ret == -1){
164
if(errno == ENOENT){
165
free(exe_link);
166
continue;
167
}
168
int e = errno;
169
error(0, errno, "lstat");
170
free(exe_link);
171
switch(e){
172
case EACCES:
173
case ENOTDIR:
174
case ELOOP:
175
default:
176
exitstatus = EX_OSFILE;
177
break;
178
case ENAMETOOLONG:
179
exitstatus = EX_OSERR;
180
break;
181
}
182
goto failure;
183
}
184
if(not S_ISLNK(exe_stat.st_mode)
185
or exe_stat.st_uid != 0
186
or exe_stat.st_gid != 0){
187
free(exe_link);
188
continue;
189
}
190
86
perror("asprintf");
87
free(prompt);
88
closedir(proc_dir);
89
return EXIT_FAILURE;
90
}
191
91
sret = readlink(exe_link, exe_target, sizeof(exe_target));
192
92
free(exe_link);
193
93
}
199
99
}
200
100
}
201
101
closedir(proc_dir);
202
proc_dir = NULL;
203
102
}
204
103
if(splashy_pid == 0){
205
exitstatus = EX_UNAVAILABLE;
206
goto failure;
104
free(prompt);
105
return EXIT_FAILURE;
207
106
}
208
107
209
108
/* Set up the signal handler */
212
111
new_action = { .sa_handler = termination_handler,
213
112
.sa_flags = 0 };
214
113
sigemptyset(&new_action.sa_mask);
215
ret = sigaddset(&new_action.sa_mask, SIGINT);
216
if(ret == -1){
217
error(0, errno, "sigaddset");
218
exitstatus = EX_OSERR;
219
goto failure;
220
}
221
ret = sigaddset(&new_action.sa_mask, SIGHUP);
222
if(ret == -1){
223
error(0, errno, "sigaddset");
224
exitstatus = EX_OSERR;
225
goto failure;
226
}
227
ret = sigaddset(&new_action.sa_mask, SIGTERM);
228
if(ret == -1){
229
error(0, errno, "sigaddset");
230
exitstatus = EX_OSERR;
231
goto failure;
232
}
114
sigaddset(&new_action.sa_mask, SIGINT);
115
sigaddset(&new_action.sa_mask, SIGHUP);
116
sigaddset(&new_action.sa_mask, SIGTERM);
233
117
ret = sigaction(SIGINT, NULL, &old_action);
234
118
if(ret == -1){
235
error(0, errno, "sigaction");
236
exitstatus = EX_OSERR;
237
goto failure;
119
perror("sigaction");
120
free(prompt);
121
return EXIT_FAILURE;
238
122
}
239
if(old_action.sa_handler != SIG_IGN){
123
if (old_action.sa_handler != SIG_IGN){
240
124
ret = sigaction(SIGINT, &new_action, NULL);
241
125
if(ret == -1){
242
error(0, errno, "sigaction");
243
exitstatus = EX_OSERR;
244
goto failure;
126
perror("sigaction");
127
free(prompt);
128
return EXIT_FAILURE;
245
129
}
246
130
}
247
131
ret = sigaction(SIGHUP, NULL, &old_action);
248
132
if(ret == -1){
249
error(0, errno, "sigaction");
250
exitstatus = EX_OSERR;
251
goto failure;
133
perror("sigaction");
134
free(prompt);
135
return EXIT_FAILURE;
252
136
}
253
if(old_action.sa_handler != SIG_IGN){
137
if (old_action.sa_handler != SIG_IGN){
254
138
ret = sigaction(SIGHUP, &new_action, NULL);
255
139
if(ret == -1){
256
error(0, errno, "sigaction");
257
exitstatus = EX_OSERR;
258
goto failure;
140
perror("sigaction");
141
free(prompt);
142
return EXIT_FAILURE;
259
143
}
260
144
}
261
145
ret = sigaction(SIGTERM, NULL, &old_action);
262
146
if(ret == -1){
263
error(0, errno, "sigaction");
264
exitstatus = EX_OSERR;
265
goto failure;
147
perror("sigaction");
148
free(prompt);
149
return EXIT_FAILURE;
266
150
}
267
if(old_action.sa_handler != SIG_IGN){
151
if (old_action.sa_handler != SIG_IGN){
268
152
ret = sigaction(SIGTERM, &new_action, NULL);
269
153
if(ret == -1){
270
error(0, errno, "sigaction");
271
exitstatus = EX_OSERR;
272
goto failure;
154
perror("sigaction");
155
free(prompt);
156
return EXIT_FAILURE;
273
157
}
274
158
}
275
159
}
276
160
277
if(interrupted_by_signal){
278
goto failure;
279
}
280
281
161
/* Fork off the splashy command to prompt for password */
282
splashy_command_pid = fork();
283
if(splashy_command_pid != 0 and interrupted_by_signal){
284
goto failure;
285
}
286
if(splashy_command_pid == -1){
287
error(0, errno, "fork");
288
exitstatus = EX_OSERR;
289
goto failure;
290
}
291
/* Child */
292
if(splashy_command_pid == 0){
293
if(not interrupted_by_signal){
162
pid_t splashy_command_pid = 0;
163
if(not interrupted_by_signal){
164
splashy_command_pid = fork();
165
if(splashy_command_pid == -1){
166
if(not interrupted_by_signal){
167
perror("fork");
168
}
169
return EXIT_FAILURE;
170
}
171
/* Child */
172
if(splashy_command_pid == 0){
294
173
const char splashy_command[] = "/sbin/splashy_update";
295
execl(splashy_command, splashy_command, prompt, (char *)NULL);
296
int e = errno;
297
error(0, errno, "execl");
298
switch(e){
299
case EACCES:
300
case ENOENT:
301
case ENOEXEC:
302
case EINVAL:
303
_exit(EX_UNAVAILABLE);
304
case ENAMETOOLONG:
305
case E2BIG:
306
case ENOMEM:
307
case EFAULT:
308
case EIO:
309
case EMFILE:
310
case ENFILE:
311
case ETXTBSY:
312
default:
313
_exit(EX_OSERR);
314
case ENOTDIR:
315
case ELOOP:
316
case EISDIR:
317
case ELIBBAD:
318
case EPERM:
319
_exit(EX_OSFILE);
174
ret = execl(splashy_command, splashy_command, prompt,
175
(char *)NULL);
176
if(not interrupted_by_signal and errno != ENOENT){
177
/* Don't report "File not found", since splashy might not be
178
installed. */
179
perror("execl");
320
180
}
181
free(prompt);
182
return EXIT_FAILURE;
321
183
}
322
free(prompt);
323
_exit(EXIT_FAILURE);
324
184
}
325
185
326
186
/* Parent */
327
187
free(prompt);
328
prompt = NULL;
329
330
if(interrupted_by_signal){
331
goto failure;
332
}
333
188
334
189
/* Wait for command to complete */
335
{
336
int status;
337
do {
338
ret = waitpid(splashy_command_pid, &status, 0);
339
} while(ret == -1 and errno == EINTR
340
and not interrupted_by_signal);
341
if(interrupted_by_signal){
342
goto failure;
343
}
344
if(ret == -1){
345
error(0, errno, "waitpid");
346
if(errno == ECHILD){
347
splashy_command_pid = 0;
348
}
349
} else {
350
/* The child process has exited */
351
splashy_command_pid = 0;
352
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
353
return EXIT_SUCCESS;
354
}
355
}
356
}
357
358
failure:
359
360
free(prompt);
361
362
if(proc_dir != NULL){
363
TEMP_FAILURE_RETRY(closedir(proc_dir));
364
}
365
366
if(splashy_command_pid != 0){
367
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
368
369
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
370
sleep(2);
371
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
372
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
190
int status;
191
while(not interrupted_by_signal){
192
waitpid(splashy_command_pid, &status, 0);
193
if(not interrupted_by_signal
194
and WIFEXITED(status) and WEXITSTATUS(status)==0){
195
return EXIT_SUCCESS;
196
}
197
}
198
kill(splashy_pid, SIGTERM);
199
if(interrupted_by_signal){
200
kill(splashy_command_pid, SIGTERM);
201
}
202
203
pid_t new_splashy_pid = fork();
204
if(new_splashy_pid == 0){
205
/* Child; will become new splashy process */
206
while(kill(splashy_pid, 0)){
207
sleep(2);
208
kill(splashy_pid, SIGKILL);
373
209
sleep(1);
374
210
}
375
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
376
if(new_splashy_pid == 0){
377
/* Child; will become new splashy process */
378
379
/* Make the effective user ID (root) the only user ID instead of
380
the real user ID (_mandos) */
381
ret = setuid(geteuid());
382
if(ret == -1){
383
error(0, errno, "setuid");
384
}
385
386
setsid();
387
ret = chdir("/");
388
if(ret == -1){
389
error(0, errno, "chdir");
390
}
391
/* if(fork() != 0){ */
392
/* _exit(EXIT_SUCCESS); */
393
/* } */
394
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
395
if(ret == -1){
396
error(0, errno, "dup2");
397
_exit(EX_OSERR);
398
}
399
400
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
401
{
402
int e = errno;
403
error(0, errno, "execl");
404
switch(e){
405
case EACCES:
406
case ENOENT:
407
case ENOEXEC:
408
default:
409
_exit(EX_UNAVAILABLE);
410
case ENAMETOOLONG:
411
case E2BIG:
412
case ENOMEM:
413
_exit(EX_OSERR);
414
case ENOTDIR:
415
case ELOOP:
416
_exit(EX_OSFILE);
417
}
418
}
419
}
420
}
421
422
if(interrupted_by_signal){
423
struct sigaction signal_action;
424
sigemptyset(&signal_action.sa_mask);
425
signal_action.sa_handler = SIG_DFL;
426
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
427
&signal_action, NULL));
211
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
428
212
if(ret == -1){
429
error(0, errno, "sigaction");
430
}
431
do {
432
ret = raise(signal_received);
433
} while(ret != 0 and errno == EINTR);
434
if(ret != 0){
435
error(0, errno, "raise");
436
abort();
437
}
438
TEMP_FAILURE_RETRY(pause());
213
perror("dup2");
214
_exit(EXIT_FAILURE);
215
}
216
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
439
217
}
440
218
441
return exitstatus;
219
return EXIT_FAILURE;
442
220
}
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Version: 2.0.2.dev0