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- Committer: Björn Påhlsson
- Date: 2008-08-09 15:36:06 UTC
- mto: (24.1.154 mandos) (237.4.3 mandos-release)
- mto: This revision was merged to the branch mainline in revision 54.
- Revision ID: belorn@braxen-20080809153606-v1uexn8v9veinjvw
Added more header file comments
fixed a small perror bug
fixed a small perror bug
- files added:
- network-protocol.txt
- files removed:
- .bzr-builddeb
- debian
- debian/po
- files renamed:
- plugin-runner.c => mandos-client.c
- plugin-runner.xml => mandos-client.xml
- 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/usplash.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Usplash - Read a password from usplash 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 <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
24
*/
25
26
#define _GNU_SOURCE /* asprintf() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction(),
30
SIG_IGN, kill(), SIGKILL */
31
#include <stdbool.h> /* bool, false, true */
32
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
33
#include <iso646.h> /* and, or, not*/
34
#include <errno.h> /* errno, EINTR */
35
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
36
dirent */
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strlen(), memcmp() */
39
#include <stdio.h> /* asprintf(), perror(), sscanf() */
40
#include <unistd.h> /* close(), write(), readlink(),
41
read(), STDOUT_FILENO, sleep(),
42
fork(), setuid(), geteuid(),
43
setsid(), chdir(), dup2(),
44
STDERR_FILENO, execv() */
45
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit() */
47
#include <stdlib.h> /* getenv() */
48
#include <dirent.h> /* opendir(), readdir(), closedir() */
49
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
50
51
sig_atomic_t interrupted_by_signal = 0;
52
53
static void termination_handler(__attribute__((unused))int signum){
54
interrupted_by_signal = 1;
55
}
56
57
static bool usplash_write(const char *cmd, const char *arg){
58
/*
59
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
60
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
61
* SEE ALSO
62
* usplash_write(8)
63
*/
64
int ret;
65
int fifo_fd;
66
do{
67
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
68
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
69
return false;
70
}
71
}while(fifo_fd == -1);
72
73
const char *cmd_line;
74
size_t cmd_line_len;
75
char *cmd_line_alloc = NULL;
76
if(arg == NULL){
77
cmd_line = cmd;
78
cmd_line_len = strlen(cmd);
79
}else{
80
do{
81
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
82
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
83
int e = errno;
84
close(fifo_fd);
85
errno = e;
86
return false;
87
}
88
}while(ret == -1);
89
cmd_line = cmd_line_alloc;
90
cmd_line_len = (size_t)ret + 1;
91
}
92
93
size_t written = 0;
94
ssize_t sret = 0;
95
while(not interrupted_by_signal and written < cmd_line_len){
96
sret = write(fifo_fd, cmd_line + written,
97
cmd_line_len - written);
98
if(sret == -1){
99
if(errno != EINTR or interrupted_by_signal){
100
int e = errno;
101
close(fifo_fd);
102
free(cmd_line_alloc);
103
errno = e;
104
return false;
105
} else {
106
continue;
107
}
108
}
109
written += (size_t)sret;
110
}
111
free(cmd_line_alloc);
112
do{
113
ret = close(fifo_fd);
114
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
115
return false;
116
}
117
}while(ret == -1);
118
if(interrupted_by_signal){
119
return false;
120
}
121
return true;
122
}
123
124
int main(__attribute__((unused))int argc,
125
__attribute__((unused))char **argv){
126
int ret = 0;
127
ssize_t sret;
128
bool an_error_occured = false;
129
130
/* Create prompt string */
131
char *prompt = NULL;
132
{
133
const char *const cryptsource = getenv("cryptsource");
134
const char *const crypttarget = getenv("crypttarget");
135
const char prompt_start[] = "Enter passphrase to unlock the disk";
136
137
if(cryptsource == NULL){
138
if(crypttarget == NULL){
139
ret = asprintf(&prompt, "%s: ", prompt_start);
140
} else {
141
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
142
crypttarget);
143
}
144
} else {
145
if(crypttarget == NULL){
146
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
147
} else {
148
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
149
cryptsource, crypttarget);
150
}
151
}
152
if(ret == -1){
153
return EXIT_FAILURE;
154
}
155
}
156
157
/* Find usplash process */
158
pid_t usplash_pid = 0;
159
char *cmdline = NULL;
160
size_t cmdline_len = 0;
161
const char usplash_name[] = "/sbin/usplash";
162
{
163
DIR *proc_dir = opendir("/proc");
164
if(proc_dir == NULL){
165
free(prompt);
166
perror("opendir");
167
return EXIT_FAILURE;
168
}
169
for(struct dirent *proc_ent = readdir(proc_dir);
170
proc_ent != NULL;
171
proc_ent = readdir(proc_dir)){
172
pid_t pid;
173
/* In the GNU C library, pid_t is always int */
174
ret = sscanf(proc_ent->d_name, "%d", &pid);
175
if(ret != 1){
176
/* Not a process */
177
continue;
178
}
179
/* Find the executable name by doing readlink() on the
180
/proc/<pid>/exe link */
181
char exe_target[sizeof(usplash_name)];
182
{
183
/* create file name string */
184
char *exe_link;
185
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
186
if(ret == -1){
187
perror("asprintf");
188
free(prompt);
189
closedir(proc_dir);
190
return EXIT_FAILURE;
191
}
192
193
/* Check that it refers to a symlink owned by root:root */
194
struct stat exe_stat;
195
ret = lstat(exe_link, &exe_stat);
196
if(ret == -1){
197
if(errno == ENOENT){
198
free(exe_link);
199
continue;
200
}
201
perror("lstat");
202
free(exe_link);
203
free(prompt);
204
closedir(proc_dir);
205
return EXIT_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(usplash_name, exe_target,
219
sizeof(exe_target)-1) == 0)){
220
usplash_pid = pid;
221
/* Read and save the command line of usplash in "cmdline" */
222
{
223
/* Open /proc/<pid>/cmdline */
224
int cl_fd;
225
{
226
char *cmdline_filename;
227
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
228
proc_ent->d_name);
229
if(ret == -1){
230
perror("asprintf");
231
free(prompt);
232
closedir(proc_dir);
233
return EXIT_FAILURE;
234
}
235
cl_fd = open(cmdline_filename, O_RDONLY);
236
if(cl_fd == -1){
237
perror("open");
238
free(cmdline_filename);
239
free(prompt);
240
closedir(proc_dir);
241
return EXIT_FAILURE;
242
}
243
free(cmdline_filename);
244
}
245
size_t cmdline_allocated = 0;
246
char *tmp;
247
const size_t blocksize = 1024;
248
do{
249
if(cmdline_len + blocksize > cmdline_allocated){
250
tmp = realloc(cmdline, cmdline_allocated + blocksize);
251
if(tmp == NULL){
252
perror("realloc");
253
free(cmdline);
254
free(prompt);
255
closedir(proc_dir);
256
return EXIT_FAILURE;
257
}
258
cmdline = tmp;
259
cmdline_allocated += blocksize;
260
}
261
sret = read(cl_fd, cmdline + cmdline_len,
262
cmdline_allocated - cmdline_len);
263
if(sret == -1){
264
perror("read");
265
free(cmdline);
266
free(prompt);
267
closedir(proc_dir);
268
return EXIT_FAILURE;
269
}
270
cmdline_len += (size_t)sret;
271
} while(sret != 0);
272
close(cl_fd);
273
}
274
break;
275
}
276
}
277
closedir(proc_dir);
278
}
279
if(usplash_pid == 0){
280
free(prompt);
281
return EXIT_FAILURE;
282
}
283
284
/* Set up the signal handler */
285
{
286
struct sigaction old_action,
287
new_action = { .sa_handler = termination_handler,
288
.sa_flags = 0 };
289
sigemptyset(&new_action.sa_mask);
290
sigaddset(&new_action.sa_mask, SIGINT);
291
sigaddset(&new_action.sa_mask, SIGHUP);
292
sigaddset(&new_action.sa_mask, SIGTERM);
293
ret = sigaction(SIGINT, NULL, &old_action);
294
if(ret == -1){
295
perror("sigaction");
296
free(prompt);
297
return EXIT_FAILURE;
298
}
299
if(old_action.sa_handler != SIG_IGN){
300
ret = sigaction(SIGINT, &new_action, NULL);
301
if(ret == -1){
302
perror("sigaction");
303
free(prompt);
304
return EXIT_FAILURE;
305
}
306
}
307
ret = sigaction(SIGHUP, NULL, &old_action);
308
if(ret == -1){
309
perror("sigaction");
310
free(prompt);
311
return EXIT_FAILURE;
312
}
313
if(old_action.sa_handler != SIG_IGN){
314
ret = sigaction(SIGHUP, &new_action, NULL);
315
if(ret == -1){
316
perror("sigaction");
317
free(prompt);
318
return EXIT_FAILURE;
319
}
320
}
321
ret = sigaction(SIGTERM, NULL, &old_action);
322
if(ret == -1){
323
perror("sigaction");
324
free(prompt);
325
return EXIT_FAILURE;
326
}
327
if(old_action.sa_handler != SIG_IGN){
328
ret = sigaction(SIGTERM, &new_action, NULL);
329
if(ret == -1){
330
perror("sigaction");
331
free(prompt);
332
return EXIT_FAILURE;
333
}
334
}
335
}
336
337
/* Write command to FIFO */
338
if(not interrupted_by_signal){
339
if(not usplash_write("TIMEOUT", "0")
340
and (errno != EINTR)){
341
perror("usplash_write");
342
an_error_occured = true;
343
}
344
}
345
if(not interrupted_by_signal and not an_error_occured){
346
if(not usplash_write("INPUTQUIET", prompt)
347
and (errno != EINTR)){
348
perror("usplash_write");
349
an_error_occured = true;
350
}
351
}
352
free(prompt);
353
354
/* This is not really a loop; while() is used to be able to "break"
355
out of it; those breaks are marked "Big" */
356
while(not interrupted_by_signal and not an_error_occured){
357
char *buf = NULL;
358
size_t buf_len = 0;
359
360
/* Open FIFO */
361
int fifo_fd;
362
do{
363
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
364
if(fifo_fd == -1){
365
if(errno != EINTR){
366
perror("open");
367
an_error_occured = true;
368
break;
369
}
370
if(interrupted_by_signal){
371
break;
372
}
373
}
374
}while(fifo_fd == -1);
375
if(interrupted_by_signal or an_error_occured){
376
break; /* Big */
377
}
378
379
/* Read from FIFO */
380
size_t buf_allocated = 0;
381
const size_t blocksize = 1024;
382
do{
383
if(buf_len + blocksize > buf_allocated){
384
char *tmp = realloc(buf, buf_allocated + blocksize);
385
if(tmp == NULL){
386
perror("realloc");
387
an_error_occured = true;
388
break;
389
}
390
buf = tmp;
391
buf_allocated += blocksize;
392
}
393
do{
394
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
395
if(sret == -1){
396
if(errno != EINTR){
397
perror("read");
398
an_error_occured = true;
399
break;
400
}
401
if(interrupted_by_signal){
402
break;
403
}
404
}
405
}while(sret == -1);
406
if(interrupted_by_signal or an_error_occured){
407
break;
408
}
409
410
buf_len += (size_t)sret;
411
}while(sret != 0);
412
close(fifo_fd);
413
if(interrupted_by_signal or an_error_occured){
414
break; /* Big */
415
}
416
417
if(not usplash_write("TIMEOUT", "15")
418
and (errno != EINTR)){
419
perror("usplash_write");
420
an_error_occured = true;
421
}
422
if(interrupted_by_signal or an_error_occured){
423
break; /* Big */
424
}
425
426
/* Print password to stdout */
427
size_t written = 0;
428
while(written < buf_len){
429
do{
430
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
431
if(sret == -1){
432
if(errno != EINTR){
433
perror("write");
434
an_error_occured = true;
435
break;
436
}
437
if(interrupted_by_signal){
438
break;
439
}
440
}
441
}while(sret == -1);
442
if(interrupted_by_signal or an_error_occured){
443
break;
444
}
445
written += (size_t)sret;
446
}
447
free(buf);
448
if(not interrupted_by_signal and not an_error_occured){
449
free(cmdline);
450
return EXIT_SUCCESS;
451
}
452
break; /* Big */
453
} /* end of non-loop while() */
454
455
/* If we got here, an error or interrupt must have happened */
456
457
/* Create argc and argv for new usplash*/
458
int cmdline_argc = 0;
459
char **cmdline_argv = malloc(sizeof(char *));
460
{
461
size_t position = 0;
462
while(position < cmdline_len){
463
char **tmp = realloc(cmdline_argv,
464
(sizeof(char *)
465
* (size_t)(cmdline_argc + 2)));
466
if(tmp == NULL){
467
perror("realloc");
468
free(cmdline_argv);
469
return EXIT_FAILURE;
470
}
471
cmdline_argv = tmp;
472
cmdline_argv[cmdline_argc] = cmdline + position;
473
cmdline_argc++;
474
position += strlen(cmdline + position) + 1;
475
}
476
cmdline_argv[cmdline_argc] = NULL;
477
}
478
/* Kill old usplash */
479
kill(usplash_pid, SIGTERM);
480
sleep(2);
481
while(kill(usplash_pid, 0) == 0){
482
kill(usplash_pid, SIGKILL);
483
sleep(1);
484
}
485
pid_t new_usplash_pid = fork();
486
if(new_usplash_pid == 0){
487
/* Child; will become new usplash process */
488
489
/* Make the effective user ID (root) the only user ID instead of
490
the real user ID (_mandos) */
491
ret = setuid(geteuid());
492
if(ret == -1){
493
perror("setuid");
494
}
495
496
setsid();
497
ret = chdir("/");
498
/* if(fork() != 0){ */
499
/* _exit(EXIT_SUCCESS); */
500
/* } */
501
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
502
if(ret == -1){
503
perror("dup2");
504
_exit(EXIT_FAILURE);
505
}
506
507
execv(usplash_name, cmdline_argv);
508
if(not interrupted_by_signal){
509
perror("execv");
510
}
511
free(cmdline);
512
free(cmdline_argv);
513
_exit(EXIT_FAILURE);
514
}
515
free(cmdline);
516
free(cmdline_argv);
517
sleep(2);
518
if(not usplash_write("PULSATE", NULL)
519
and (errno != EINTR)){
520
perror("usplash_write");
521
}
522
523
return EXIT_FAILURE;
524
}
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