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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:
- plugins.d/usplash
- files removed:
- common.ent
- files modified:
- .bzrignore
added
removed
plugins.d/usplash.c
1
#define _GNU_SOURCE /* asprintf() */
2
#include <signal.h> /* sig_atomic_t, struct sigaction,
3
sigemptyset(), sigaddset(), SIGINT,
4
SIGHUP, SIGTERM, sigaction(),
5
SIG_IGN, kill(), SIGKILL */
6
#include <stdbool.h> /* bool, false, true */
7
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
8
#include <iso646.h> /* and, or, not*/
9
#include <errno.h> /* errno, EINTR */
10
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
11
dirent */
12
#include <stddef.h> /* NULL */
13
#include <string.h> /* strlen(), memcmp() */
14
#include <stdio.h> /* asprintf(), perror() */
15
#include <unistd.h> /* close(), write(), readlink(),
16
read(), STDOUT_FILENO, sleep(),
17
fork(), setuid(), geteuid(),
18
setsid(), chdir(), dup2(),
19
STDERR_FILENO, execv() */
20
#include <stdlib.h> /* free(), EXIT_FAILURE, strtoul(),
21
realloc(), EXIT_SUCCESS, malloc(),
22
_exit() */
23
#include <stdlib.h> /* getenv() */
24
#include <dirent.h> /* opendir(), readdir(), closedir() */
25
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
26
27
sig_atomic_t interrupted_by_signal = 0;
28
29
static void termination_handler(__attribute__((unused))int signum){
30
interrupted_by_signal = 1;
31
}
32
33
static bool usplash_write(const char *cmd, const char *arg){
34
/*
35
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
36
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
37
* SEE ALSO
38
* usplash_write(8)
39
*/
40
int ret;
41
int fifo_fd;
42
do{
43
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
44
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
45
return false;
46
}
47
}while(fifo_fd == -1);
48
49
const char *cmd_line;
50
size_t cmd_line_len;
51
char *cmd_line_alloc = NULL;
52
if(arg == NULL){
53
cmd_line = cmd;
54
cmd_line_len = strlen(cmd);
55
}else{
56
do{
57
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
58
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
59
int e = errno;
60
close(fifo_fd);
61
errno = e;
62
return false;
63
}
64
}while(ret == -1);
65
cmd_line = cmd_line_alloc;
66
cmd_line_len = (size_t)ret + 1;
67
}
68
69
size_t written = 0;
70
while(not interrupted_by_signal and written < cmd_line_len){
71
ret = write(fifo_fd, cmd_line + written,
72
cmd_line_len - written);
73
if(ret == -1){
74
if(errno != EINTR or interrupted_by_signal){
75
int e = errno;
76
close(fifo_fd);
77
free(cmd_line_alloc);
78
errno = e;
79
return false;
80
} else {
81
continue;
82
}
83
}
84
written += (size_t)ret;
85
}
86
free(cmd_line_alloc);
87
do{
88
ret = close(fifo_fd);
89
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
90
return false;
91
}
92
}while(ret == -1);
93
if(interrupted_by_signal){
94
return false;
95
}
96
return true;
97
}
98
99
int main(__attribute__((unused))int argc,
100
__attribute__((unused))char **argv){
101
int ret = 0;
102
ssize_t sret;
103
bool an_error_occured = false;
104
105
/* Create prompt string */
106
char *prompt = NULL;
107
{
108
const char *const cryptsource = getenv("cryptsource");
109
const char *const crypttarget = getenv("crypttarget");
110
const char prompt_start[] = "Enter passphrase to unlock the disk";
111
112
if(cryptsource == NULL){
113
if(crypttarget == NULL){
114
ret = asprintf(&prompt, "%s: ", prompt_start);
115
} else {
116
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
117
crypttarget);
118
}
119
} else {
120
if(crypttarget == NULL){
121
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
122
} else {
123
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
124
cryptsource, crypttarget);
125
}
126
}
127
if(ret == -1){
128
return EXIT_FAILURE;
129
}
130
}
131
132
/* Find usplash process */
133
pid_t usplash_pid = 0;
134
char *cmdline = NULL;
135
size_t cmdline_len = 0;
136
const char usplash_name[] = "/sbin/usplash";
137
{
138
DIR *proc_dir = opendir("/proc");
139
if(proc_dir == NULL){
140
free(prompt);
141
perror("opendir");
142
return EXIT_FAILURE;
143
}
144
for(struct dirent *proc_ent = readdir(proc_dir);
145
proc_ent != NULL;
146
proc_ent = readdir(proc_dir)){
147
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
148
if(pid == 0){
149
/* Not a process */
150
continue;
151
}
152
/* Find the executable name by doing readlink() on the
153
/proc/<pid>/exe link */
154
char exe_target[sizeof(usplash_name)];
155
{
156
/* create file name string */
157
char *exe_link;
158
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
159
if(ret == -1){
160
perror("asprintf");
161
free(prompt);
162
closedir(proc_dir);
163
return EXIT_FAILURE;
164
}
165
166
/* Check that it refers to a symlink owned by root:root */
167
struct stat exe_stat;
168
ret = lstat(exe_link, &exe_stat);
169
if(ret == -1){
170
perror("lstat");
171
free(exe_link);
172
free(prompt);
173
closedir(proc_dir);
174
return EXIT_FAILURE;
175
}
176
if(not S_ISLNK(exe_stat.st_mode)
177
or exe_stat.st_uid != 0
178
or exe_stat.st_gid != 0){
179
free(exe_link);
180
continue;
181
}
182
183
sret = readlink(exe_link, exe_target, sizeof(exe_target));
184
free(exe_link);
185
if(sret == -1){
186
continue;
187
}
188
}
189
if((sret == ((ssize_t)sizeof(exe_target)-1))
190
and (memcmp(usplash_name, exe_target,
191
sizeof(exe_target)-1) == 0)){
192
usplash_pid = pid;
193
/* Read and save the command line of usplash in "cmdline" */
194
{
195
/* Open /proc/<pid>/cmdline */
196
int cl_fd;
197
{
198
char *cmdline_filename;
199
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
200
proc_ent->d_name);
201
if(ret == -1){
202
perror("asprintf");
203
free(prompt);
204
closedir(proc_dir);
205
return EXIT_FAILURE;
206
}
207
cl_fd = open(cmdline_filename, O_RDONLY);
208
if(cl_fd == -1){
209
perror("open");
210
free(cmdline_filename);
211
free(prompt);
212
closedir(proc_dir);
213
return EXIT_FAILURE;
214
}
215
free(cmdline_filename);
216
}
217
size_t cmdline_allocated = 0;
218
char *tmp;
219
const size_t blocksize = 1024;
220
do{
221
if(cmdline_len + blocksize > cmdline_allocated){
222
tmp = realloc(cmdline, cmdline_allocated + blocksize);
223
if(tmp == NULL){
224
perror("realloc");
225
free(cmdline);
226
free(prompt);
227
closedir(proc_dir);
228
return EXIT_FAILURE;
229
}
230
cmdline = tmp;
231
cmdline_allocated += blocksize;
232
}
233
sret = read(cl_fd, cmdline + cmdline_len,
234
cmdline_allocated - cmdline_len);
235
if(sret == -1){
236
perror("read");
237
free(cmdline);
238
free(prompt);
239
closedir(proc_dir);
240
return EXIT_FAILURE;
241
}
242
cmdline_len += (size_t)sret;
243
} while(sret != 0);
244
close(cl_fd);
245
}
246
break;
247
}
248
}
249
closedir(proc_dir);
250
}
251
if(usplash_pid == 0){
252
free(prompt);
253
return EXIT_FAILURE;
254
}
255
256
/* Set up the signal handler */
257
{
258
struct sigaction old_action,
259
new_action = { .sa_handler = termination_handler,
260
.sa_flags = 0 };
261
sigemptyset(&new_action.sa_mask);
262
sigaddset(&new_action.sa_mask, SIGINT);
263
sigaddset(&new_action.sa_mask, SIGHUP);
264
sigaddset(&new_action.sa_mask, SIGTERM);
265
ret = sigaction(SIGINT, NULL, &old_action);
266
if(ret == -1){
267
perror("sigaction");
268
free(prompt);
269
return EXIT_FAILURE;
270
}
271
if(old_action.sa_handler != SIG_IGN){
272
ret = sigaction(SIGINT, &new_action, NULL);
273
if(ret == -1){
274
perror("sigaction");
275
free(prompt);
276
return EXIT_FAILURE;
277
}
278
}
279
ret = sigaction(SIGHUP, NULL, &old_action);
280
if(ret == -1){
281
perror("sigaction");
282
free(prompt);
283
return EXIT_FAILURE;
284
}
285
if(old_action.sa_handler != SIG_IGN){
286
ret = sigaction(SIGHUP, &new_action, NULL);
287
if(ret == -1){
288
perror("sigaction");
289
free(prompt);
290
return EXIT_FAILURE;
291
}
292
}
293
ret = sigaction(SIGTERM, 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(SIGTERM, &new_action, NULL);
301
if(ret == -1){
302
perror("sigaction");
303
free(prompt);
304
return EXIT_FAILURE;
305
}
306
}
307
}
308
309
/* Write command to FIFO */
310
if(not interrupted_by_signal){
311
if(not usplash_write("TIMEOUT", "0")
312
and (errno != EINTR)){
313
perror("usplash_write");
314
an_error_occured = true;
315
}
316
}
317
if(not interrupted_by_signal and not an_error_occured){
318
if(not usplash_write("INPUTQUIET", prompt)
319
and (errno != EINTR)){
320
perror("usplash_write");
321
an_error_occured = true;
322
}
323
}
324
free(prompt);
325
326
/* This is not really a loop; while() is used to be able to "break"
327
out of it; those breaks are marked "Big" */
328
while(not interrupted_by_signal and not an_error_occured){
329
char *buf = NULL;
330
size_t buf_len = 0;
331
332
/* Open FIFO */
333
int fifo_fd;
334
do{
335
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
336
if(fifo_fd == -1){
337
if(errno != EINTR){
338
perror("open");
339
an_error_occured = true;
340
break;
341
}
342
if(interrupted_by_signal){
343
break;
344
}
345
}
346
}while(fifo_fd == -1);
347
if(interrupted_by_signal or an_error_occured){
348
break; /* Big */
349
}
350
351
/* Read from FIFO */
352
size_t buf_allocated = 0;
353
const size_t blocksize = 1024;
354
do{
355
if(buf_len + blocksize > buf_allocated){
356
char *tmp = realloc(buf, buf_allocated + blocksize);
357
if(tmp == NULL){
358
perror("realloc");
359
an_error_occured = true;
360
break;
361
}
362
buf = tmp;
363
buf_allocated += blocksize;
364
}
365
do{
366
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
367
if(sret == -1){
368
if(errno != EINTR){
369
perror("read");
370
an_error_occured = true;
371
break;
372
}
373
if(interrupted_by_signal){
374
break;
375
}
376
}
377
}while(sret == -1);
378
if(interrupted_by_signal or an_error_occured){
379
break;
380
}
381
382
buf_len += (size_t)sret;
383
}while(sret != 0);
384
close(fifo_fd);
385
if(interrupted_by_signal or an_error_occured){
386
break; /* Big */
387
}
388
389
if(not usplash_write("TIMEOUT", "15")
390
and (errno != EINTR)){
391
perror("usplash_write");
392
an_error_occured = true;
393
}
394
if(interrupted_by_signal or an_error_occured){
395
break; /* Big */
396
}
397
398
/* Print password to stdout */
399
size_t written = 0;
400
while(written < buf_len){
401
do{
402
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
403
if(sret == -1){
404
if(errno != EINTR){
405
perror("write");
406
an_error_occured = true;
407
break;
408
}
409
if(interrupted_by_signal){
410
break;
411
}
412
}
413
}while(sret == -1);
414
if(interrupted_by_signal or an_error_occured){
415
break;
416
}
417
written += (size_t)sret;
418
}
419
free(buf);
420
if(not interrupted_by_signal and not an_error_occured){
421
free(cmdline);
422
return EXIT_SUCCESS;
423
}
424
break; /* Big */
425
} /* end of non-loop while() */
426
427
/* If we got here, an error or interrupt must have happened */
428
429
/* Create argc and argv for new usplash*/
430
int cmdline_argc = 0;
431
char **cmdline_argv = malloc(sizeof(char *));
432
{
433
size_t position = 0;
434
while(position < cmdline_len){
435
char **tmp = realloc(cmdline_argv,
436
(sizeof(char *)
437
* (size_t)(cmdline_argc + 2)));
438
if(tmp == NULL){
439
perror("realloc");
440
free(cmdline_argv);
441
return EXIT_FAILURE;
442
}
443
cmdline_argv = tmp;
444
cmdline_argv[cmdline_argc] = cmdline + position;
445
cmdline_argc++;
446
position += strlen(cmdline + position) + 1;
447
}
448
cmdline_argv[cmdline_argc] = NULL;
449
}
450
/* Kill old usplash */
451
kill(usplash_pid, SIGTERM);
452
sleep(2);
453
while(kill(usplash_pid, 0) == 0){
454
kill(usplash_pid, SIGKILL);
455
sleep(1);
456
}
457
pid_t new_usplash_pid = fork();
458
if(new_usplash_pid == 0){
459
/* Child; will become new usplash process */
460
461
/* Make the effective user ID (root) the only user ID instead of
462
the real user ID (mandos) */
463
ret = setuid(geteuid());
464
if(ret == -1){
465
perror("setuid");
466
}
467
468
setsid();
469
ret = chdir("/");
470
/* if(fork() != 0){ */
471
/* _exit(EXIT_SUCCESS); */
472
/* } */
473
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
474
if(ret == -1){
475
perror("dup2");
476
_exit(EXIT_FAILURE);
477
}
478
479
execv(usplash_name, cmdline_argv);
480
if(not interrupted_by_signal){
481
perror("execv");
482
}
483
free(cmdline);
484
free(cmdline_argv);
485
_exit(EXIT_FAILURE);
486
}
487
free(cmdline);
488
free(cmdline_argv);
489
sleep(2);
490
if(not usplash_write("PULSATE", NULL)
491
and (errno != EINTR)){
492
perror("usplash_write");
493
}
494
495
return EXIT_FAILURE;
496
}
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