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- Committer: Björn Påhlsson
- Date: 2008-08-24 23:40:11 UTC
- mfrom: (102 mandos)
- mto: (237.7.1 mandos) (24.1.154 mandos)
- mto: This revision was merged to the branch mainline in revision 107.
- Revision ID: belorn@braxen-20080824234011-vb6j0ekivqripwhk
Merge.
- files added:
- plugins.d/usplash
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- files renamed:
- plugins.d/mandos-client.c => plugins.d/password-request.c
- plugins.d/mandos-client.xml => plugins.d/password-request.xml
- files modified:
- Makefile
added
removed
plugins.d/splashy.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Splashy - Read a password from splashy and output it
4
*
5
* Copyright © 2008-2011 Teddy Hogeborn
6
* Copyright © 2008-2011 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() */
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction,
29
SIG_IGN, kill(), SIGKILL */
30
#include <stddef.h> /* NULL */
31
#include <stdlib.h> /* getenv() */
32
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(), fprintf() */
33
#include <stdlib.h> /* EXIT_FAILURE, free(),
34
EXIT_SUCCESS */
35
#include <sys/types.h> /* pid_t, DIR, struct dirent,
36
ssize_t */
37
#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
#include <unistd.h> /* readlink(), fork(), execl(),
42
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit(),
44
pause() */
45
#include <string.h> /* memcmp(), strerror() */
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() */
53
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
54
WEXITSTATUS() */
55
#include <sysexits.h> /* EX_OSERR, EX_OSFILE,
56
EX_UNAVAILABLE */
57
#include <stdarg.h> /* va_list, va_start(), ... */
58
59
sig_atomic_t interrupted_by_signal = 0;
60
int signal_received;
61
62
/* Function to use when printing errors */
63
void error_plus(int status, int errnum, const char *formatstring, ...){
64
va_list ap;
65
char *text;
66
int ret;
67
68
va_start(ap, formatstring);
69
ret = vasprintf(&text, formatstring, ap);
70
if (ret == -1){
71
fprintf(stderr, "Mandos plugin %s: ", program_invocation_short_name);
72
vfprintf(stderr, formatstring, ap);
73
fprintf(stderr, ": ");
74
fprintf(stderr, "%s\n", strerror(errnum));
75
error(status, errno, "vasprintf while printing error");
76
return;
77
}
78
fprintf(stderr, "Mandos plugin ");
79
error(status, errnum, "%s", text);
80
free(text);
81
}
82
83
84
static void termination_handler(int signum){
85
if(interrupted_by_signal){
86
return;
87
}
88
interrupted_by_signal = 1;
89
signal_received = signum;
90
}
91
92
int main(__attribute__((unused))int argc,
93
__attribute__((unused))char **argv){
94
int ret = 0;
95
char *prompt = NULL;
96
DIR *proc_dir = NULL;
97
pid_t splashy_pid = 0;
98
pid_t splashy_command_pid = 0;
99
int exitstatus = EXIT_FAILURE;
100
101
/* Create prompt string */
102
{
103
const char *const cryptsource = getenv("cryptsource");
104
const char *const crypttarget = getenv("crypttarget");
105
const char *const prompt_start = "getpass "
106
"Enter passphrase to unlock the disk";
107
108
if(cryptsource == NULL){
109
if(crypttarget == NULL){
110
ret = asprintf(&prompt, "%s: ", prompt_start);
111
} else {
112
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
113
crypttarget);
114
}
115
} else {
116
if(crypttarget == NULL){
117
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
118
} else {
119
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
120
cryptsource, crypttarget);
121
}
122
}
123
if(ret == -1){
124
prompt = NULL;
125
exitstatus = EX_OSERR;
126
goto failure;
127
}
128
}
129
130
/* Find splashy process */
131
{
132
const char splashy_name[] = "/sbin/splashy";
133
proc_dir = opendir("/proc");
134
if(proc_dir == NULL){
135
int e = errno;
136
error_plus(0, errno, "opendir");
137
switch(e){
138
case EACCES:
139
case ENOTDIR:
140
case ELOOP:
141
case ENOENT:
142
default:
143
exitstatus = EX_OSFILE;
144
break;
145
case ENAMETOOLONG:
146
case EMFILE:
147
case ENFILE:
148
case ENOMEM:
149
exitstatus = EX_OSERR;
150
break;
151
}
152
goto failure;
153
}
154
for(struct dirent *proc_ent = readdir(proc_dir);
155
proc_ent != NULL;
156
proc_ent = readdir(proc_dir)){
157
pid_t pid;
158
{
159
intmax_t tmpmax;
160
char *tmp;
161
errno = 0;
162
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
163
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
164
or tmpmax != (pid_t)tmpmax){
165
/* Not a process */
166
continue;
167
}
168
pid = (pid_t)tmpmax;
169
}
170
/* Find the executable name by doing readlink() on the
171
/proc/<pid>/exe link */
172
char exe_target[sizeof(splashy_name)];
173
ssize_t sret;
174
{
175
char *exe_link;
176
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
177
if(ret == -1){
178
error_plus(0, errno, "asprintf");
179
exitstatus = EX_OSERR;
180
goto failure;
181
}
182
183
/* Check that it refers to a symlink owned by root:root */
184
struct stat exe_stat;
185
ret = lstat(exe_link, &exe_stat);
186
if(ret == -1){
187
if(errno == ENOENT){
188
free(exe_link);
189
continue;
190
}
191
int e = errno;
192
error_plus(0, errno, "lstat");
193
free(exe_link);
194
switch(e){
195
case EACCES:
196
case ENOTDIR:
197
case ELOOP:
198
default:
199
exitstatus = EX_OSFILE;
200
break;
201
case ENAMETOOLONG:
202
exitstatus = EX_OSERR;
203
break;
204
}
205
goto failure;
206
}
207
if(not S_ISLNK(exe_stat.st_mode)
208
or exe_stat.st_uid != 0
209
or exe_stat.st_gid != 0){
210
free(exe_link);
211
continue;
212
}
213
214
sret = readlink(exe_link, exe_target, sizeof(exe_target));
215
free(exe_link);
216
}
217
if((sret == ((ssize_t)sizeof(exe_target)-1))
218
and (memcmp(splashy_name, exe_target,
219
sizeof(exe_target)-1) == 0)){
220
splashy_pid = pid;
221
break;
222
}
223
}
224
closedir(proc_dir);
225
proc_dir = NULL;
226
}
227
if(splashy_pid == 0){
228
exitstatus = EX_UNAVAILABLE;
229
goto failure;
230
}
231
232
/* Set up the signal handler */
233
{
234
struct sigaction old_action,
235
new_action = { .sa_handler = termination_handler,
236
.sa_flags = 0 };
237
sigemptyset(&new_action.sa_mask);
238
ret = sigaddset(&new_action.sa_mask, SIGINT);
239
if(ret == -1){
240
error_plus(0, errno, "sigaddset");
241
exitstatus = EX_OSERR;
242
goto failure;
243
}
244
ret = sigaddset(&new_action.sa_mask, SIGHUP);
245
if(ret == -1){
246
error_plus(0, errno, "sigaddset");
247
exitstatus = EX_OSERR;
248
goto failure;
249
}
250
ret = sigaddset(&new_action.sa_mask, SIGTERM);
251
if(ret == -1){
252
error_plus(0, errno, "sigaddset");
253
exitstatus = EX_OSERR;
254
goto failure;
255
}
256
ret = sigaction(SIGINT, NULL, &old_action);
257
if(ret == -1){
258
error_plus(0, errno, "sigaction");
259
exitstatus = EX_OSERR;
260
goto failure;
261
}
262
if(old_action.sa_handler != SIG_IGN){
263
ret = sigaction(SIGINT, &new_action, NULL);
264
if(ret == -1){
265
error_plus(0, errno, "sigaction");
266
exitstatus = EX_OSERR;
267
goto failure;
268
}
269
}
270
ret = sigaction(SIGHUP, NULL, &old_action);
271
if(ret == -1){
272
error_plus(0, errno, "sigaction");
273
exitstatus = EX_OSERR;
274
goto failure;
275
}
276
if(old_action.sa_handler != SIG_IGN){
277
ret = sigaction(SIGHUP, &new_action, NULL);
278
if(ret == -1){
279
error_plus(0, errno, "sigaction");
280
exitstatus = EX_OSERR;
281
goto failure;
282
}
283
}
284
ret = sigaction(SIGTERM, NULL, &old_action);
285
if(ret == -1){
286
error_plus(0, errno, "sigaction");
287
exitstatus = EX_OSERR;
288
goto failure;
289
}
290
if(old_action.sa_handler != SIG_IGN){
291
ret = sigaction(SIGTERM, &new_action, NULL);
292
if(ret == -1){
293
error_plus(0, errno, "sigaction");
294
exitstatus = EX_OSERR;
295
goto failure;
296
}
297
}
298
}
299
300
if(interrupted_by_signal){
301
goto failure;
302
}
303
304
/* Fork off the splashy command to prompt for password */
305
splashy_command_pid = fork();
306
if(splashy_command_pid != 0 and interrupted_by_signal){
307
goto failure;
308
}
309
if(splashy_command_pid == -1){
310
error_plus(0, errno, "fork");
311
exitstatus = EX_OSERR;
312
goto failure;
313
}
314
/* Child */
315
if(splashy_command_pid == 0){
316
if(not interrupted_by_signal){
317
const char splashy_command[] = "/sbin/splashy_update";
318
execl(splashy_command, splashy_command, prompt, (char *)NULL);
319
int e = errno;
320
error_plus(0, errno, "execl");
321
switch(e){
322
case EACCES:
323
case ENOENT:
324
case ENOEXEC:
325
case EINVAL:
326
_exit(EX_UNAVAILABLE);
327
case ENAMETOOLONG:
328
case E2BIG:
329
case ENOMEM:
330
case EFAULT:
331
case EIO:
332
case EMFILE:
333
case ENFILE:
334
case ETXTBSY:
335
default:
336
_exit(EX_OSERR);
337
case ENOTDIR:
338
case ELOOP:
339
case EISDIR:
340
#ifdef ELIBBAD
341
case ELIBBAD: /* Linux only */
342
#endif
343
case EPERM:
344
_exit(EX_OSFILE);
345
}
346
}
347
free(prompt);
348
_exit(EXIT_FAILURE);
349
}
350
351
/* Parent */
352
free(prompt);
353
prompt = NULL;
354
355
if(interrupted_by_signal){
356
goto failure;
357
}
358
359
/* Wait for command to complete */
360
{
361
int status;
362
do {
363
ret = waitpid(splashy_command_pid, &status, 0);
364
} while(ret == -1 and errno == EINTR
365
and not interrupted_by_signal);
366
if(interrupted_by_signal){
367
goto failure;
368
}
369
if(ret == -1){
370
error_plus(0, errno, "waitpid");
371
if(errno == ECHILD){
372
splashy_command_pid = 0;
373
}
374
} else {
375
/* The child process has exited */
376
splashy_command_pid = 0;
377
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
378
return EXIT_SUCCESS;
379
}
380
}
381
}
382
383
failure:
384
385
free(prompt);
386
387
if(proc_dir != NULL){
388
TEMP_FAILURE_RETRY(closedir(proc_dir));
389
}
390
391
if(splashy_command_pid != 0){
392
TEMP_FAILURE_RETRY(kill(splashy_command_pid, SIGTERM));
393
394
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGTERM));
395
sleep(2);
396
while(TEMP_FAILURE_RETRY(kill(splashy_pid, 0)) == 0){
397
TEMP_FAILURE_RETRY(kill(splashy_pid, SIGKILL));
398
sleep(1);
399
}
400
pid_t new_splashy_pid = (pid_t)TEMP_FAILURE_RETRY(fork());
401
if(new_splashy_pid == 0){
402
/* Child; will become new splashy process */
403
404
/* Make the effective user ID (root) the only user ID instead of
405
the real user ID (_mandos) */
406
ret = setuid(geteuid());
407
if(ret == -1){
408
error_plus(0, errno, "setuid");
409
}
410
411
setsid();
412
ret = chdir("/");
413
if(ret == -1){
414
error_plus(0, errno, "chdir");
415
}
416
/* if(fork() != 0){ */
417
/* _exit(EXIT_SUCCESS); */
418
/* } */
419
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace stdout */
420
if(ret == -1){
421
error_plus(0, errno, "dup2");
422
_exit(EX_OSERR);
423
}
424
425
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
426
{
427
int e = errno;
428
error_plus(0, errno, "execl");
429
switch(e){
430
case EACCES:
431
case ENOENT:
432
case ENOEXEC:
433
default:
434
_exit(EX_UNAVAILABLE);
435
case ENAMETOOLONG:
436
case E2BIG:
437
case ENOMEM:
438
_exit(EX_OSERR);
439
case ENOTDIR:
440
case ELOOP:
441
_exit(EX_OSFILE);
442
}
443
}
444
}
445
}
446
447
if(interrupted_by_signal){
448
struct sigaction signal_action;
449
sigemptyset(&signal_action.sa_mask);
450
signal_action.sa_handler = SIG_DFL;
451
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
452
&signal_action, NULL));
453
if(ret == -1){
454
error_plus(0, errno, "sigaction");
455
}
456
do {
457
ret = raise(signal_received);
458
} while(ret != 0 and errno == EINTR);
459
if(ret != 0){
460
error_plus(0, errno, "raise");
461
abort();
462
}
463
TEMP_FAILURE_RETRY(pause());
464
}
465
466
return exitstatus;
467
}
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