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- Committer: Teddy Hogeborn
- Date: 2024-11-17 16:53:00 UTC
- mto: This revision was merged to the branch mainline in revision 412.
- Revision ID: teddy@recompile.se-20241117165300-02hxm96s8cj9528e
mandos: Avoid closing configured server network socket
If we are passed a pre-created created network socket as a file
descriptor, we must avoid later closing it (when stdin, stdout and
stderr are dup2()ed over with /dev/null) by making sure that the
network file descriptor is not 0, 1, or 2, by creating a new file
descriptor if necessary.
However, when we create a new file descriptor we must check that the
new file descriptor is not 0, 1, or 2 either, and try again until we
get a suitable file descriptor.
If we are passed a pre-created created network socket as a file
descriptor, we must avoid later closing it (when stdin, stdout and
stderr are dup2()ed over with /dev/null) by making sure that the
network file descriptor is not 0, 1, or 2, by creating a new file
descriptor if necessary.
However, when we create a new file descriptor we must check that the
new file descriptor is not 0, 1, or 2 either, and try again until we
get a suitable file descriptor.
- files added:
- DBUS-API
- debian/source
- debian/tests
- debian/upstream
- dracut-module
- network-hooks.d
- plugin-helpers
- files removed:
- initramfs-tools-hook-conf
- files modified:
- .bzrignore
added
removed
plugins.d/plymouth.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Plymouth - Read a password from Plymouth and output it
4
*
5
* Copyright © 2010-2022 Teddy Hogeborn
6
* Copyright © 2010-2022 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 /* program_invocation_short_name,
27
vasprintf(), asprintf(),
28
TEMP_FAILURE_RETRY() */
29
#include <sys/types.h> /* sig_atomic_t, pid_t, setuid(),
30
geteuid(), setsid() */
31
#include <argp.h> /* argp_program_version,
32
argp_program_bug_address,
33
struct argp_option,
34
struct argp_state,
35
ARGP_ERR_UNKNOWN, struct argp,
36
argp_parse(), ARGP_IN_ORDER */
37
#include <stddef.h> /* NULL, size_t */
38
#include <stdbool.h> /* bool, false, true */
39
#include <stdio.h> /* FILE, fprintf(), vfprintf(),
40
vasprintf(), stderr, asprintf(),
41
fopen(), fscanf(), fclose(),
42
sscanf() */
43
#include <stdarg.h> /* va_list, va_start(), vfprintf() */
44
#include <errno.h> /* program_invocation_short_name,
45
errno, ENOMEM, EINTR, ENOENT,
46
error_t, EINVAL */
47
#include <string.h> /* strerror(), strdup(), memcmp() */
48
#include <error.h> /* error() */
49
#include <stdlib.h> /* free(), getenv(), malloc(),
50
reallocarray(), realloc(),
51
EXIT_FAILURE, EXIT_SUCCESS */
52
#include <unistd.h> /* TEMP_FAILURE_RETRY(), setuid(),
53
geteuid(), setsid(), chdir(),
54
dup2(), STDERR_FILENO,
55
STDOUT_FILENO, fork(), _exit(),
56
execv(), ssize_t, readlink(),
57
close(), read(), access(), X_OK */
58
#include <signal.h> /* kill(), SIGTERM, struct sigaction,
59
sigemptyset(), SIGINT, SIGHUP,
60
sigaddset(), SIG_IGN */
61
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
62
WEXITSTATUS(), WIFSIGNALED(),
63
WTERMSIG() */
64
#include <iso646.h> /* not, and, or */
65
#include <sysexits.h> /* EX_OSERR, EX_USAGE,
66
EX_UNAVAILABLE */
67
#include <stdint.h> /* SIZE_MAX */
68
#include <dirent.h> /* struct dirent, scandir(),
69
alphasort() */
70
#include <inttypes.h> /* uintmax_t, strtoumax(), SCNuMAX,
71
PRIuMAX */
72
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK() */
73
#include <fcntl.h> /* open(), O_RDONLY */
74
#include <argz.h> /* argz_count(), argz_extract() */
75
76
sig_atomic_t interrupted_by_signal = 0;
77
const char *argp_program_version = "plymouth " VERSION;
78
const char *argp_program_bug_address = "<mandos@recompile.se>";
79
80
/* Used by Ubuntu 11.04 (Natty Narwahl) */
81
const char plymouth_old_old_pid[] = "/dev/.initramfs/plymouth.pid";
82
/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
83
const char plymouth_old_pid[] = "/run/initramfs/plymouth.pid";
84
/* Used by Debian 9 (stretch) */
85
const char plymouth_pid[] = "/run/plymouth/pid";
86
87
const char plymouth_path[] = "/bin/plymouth";
88
const char plymouthd_path[] = "/sbin/plymouthd";
89
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
90
"--mode=boot",
91
"--attach-to-session",
92
NULL };
93
bool debug = false;
94
95
static void termination_handler(__attribute__((unused))int signum){
96
if(interrupted_by_signal){
97
return;
98
}
99
interrupted_by_signal = 1;
100
}
101
102
__attribute__((format (gnu_printf, 2, 3), nonnull))
103
int fprintf_plus(FILE *stream, const char *format, ...){
104
va_list ap;
105
va_start (ap, format);
106
fprintf(stream, "Mandos plugin %s: ", program_invocation_short_name);
107
return vfprintf(stream, format, ap);
108
}
109
110
/* Function to use when printing errors */
111
__attribute__((format (gnu_printf, 3, 4)))
112
void error_plus(int status, int errnum, const char *formatstring,
113
...){
114
va_list ap;
115
char *text;
116
int ret;
117
118
va_start(ap, formatstring);
119
ret = vasprintf(&text, formatstring, ap);
120
if(ret == -1){
121
fprintf(stderr, "Mandos plugin %s: ",
122
program_invocation_short_name);
123
vfprintf(stderr, formatstring, ap);
124
fprintf(stderr, ": ");
125
fprintf(stderr, "%s\n", strerror(errnum));
126
error(status, errno, "vasprintf while printing error");
127
return;
128
}
129
fprintf(stderr, "Mandos plugin ");
130
error(status, errnum, "%s", text);
131
free(text);
132
}
133
134
/* Create prompt string */
135
char *makeprompt(void){
136
int ret = 0;
137
char *prompt;
138
const char *const cryptsource = getenv("cryptsource");
139
const char *const crypttarget = getenv("crypttarget");
140
const char prompt_start[] = "Unlocking the disk";
141
const char prompt_end[] = "Enter passphrase";
142
143
if(cryptsource == NULL){
144
if(crypttarget == NULL){
145
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
146
} else {
147
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
148
crypttarget, prompt_end);
149
}
150
} else {
151
if(crypttarget == NULL){
152
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
153
prompt_end);
154
} else {
155
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
156
cryptsource, crypttarget, prompt_end);
157
}
158
}
159
if(ret == -1){
160
return NULL;
161
}
162
return prompt;
163
}
164
165
void kill_and_wait(pid_t pid){
166
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
167
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
168
}
169
170
bool become_a_daemon(void){
171
int ret = setuid(geteuid());
172
if(ret == -1){
173
error_plus(0, errno, "setuid");
174
}
175
176
setsid();
177
ret = chdir("/");
178
if(ret == -1){
179
error_plus(0, errno, "chdir");
180
return false;
181
}
182
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
183
if(ret == -1){
184
error_plus(0, errno, "dup2");
185
return false;
186
}
187
return true;
188
}
189
190
__attribute__((nonnull (2, 3)))
191
bool exec_and_wait(pid_t *pid_return, const char *path,
192
const char * const * const argv, bool interruptable,
193
bool daemonize){
194
int status;
195
int ret;
196
pid_t pid;
197
if(debug){
198
for(const char * const *arg = argv; *arg != NULL; arg++){
199
fprintf_plus(stderr, "exec_and_wait arg: %s\n", *arg);
200
}
201
fprintf_plus(stderr, "exec_and_wait end of args\n");
202
}
203
204
pid = fork();
205
if(pid == -1){
206
error_plus(0, errno, "fork");
207
return false;
208
}
209
if(pid == 0){
210
/* Child */
211
if(daemonize){
212
if(not become_a_daemon()){
213
_exit(EX_OSERR);
214
}
215
}
216
217
char **new_argv = malloc(sizeof(const char *));
218
if(new_argv == NULL){
219
error_plus(0, errno, "malloc");
220
_exit(EX_OSERR);
221
}
222
char **tmp;
223
int i = 0;
224
for (; argv[i] != NULL; i++){
225
#if defined(__GLIBC_PREREQ) and __GLIBC_PREREQ(2, 26)
226
tmp = reallocarray(new_argv, ((size_t)i + 2),
227
sizeof(const char *));
228
#else
229
if(((size_t)i + 2) > (SIZE_MAX / sizeof(const char *))){
230
/* overflow */
231
tmp = NULL;
232
errno = ENOMEM;
233
} else {
234
tmp = realloc(new_argv, ((size_t)i + 2) * sizeof(const char *));
235
}
236
#endif
237
if(tmp == NULL){
238
error_plus(0, errno, "reallocarray");
239
free(new_argv);
240
_exit(EX_OSERR);
241
}
242
new_argv = tmp;
243
new_argv[i] = strdup(argv[i]);
244
}
245
new_argv[i] = NULL;
246
247
execv(path, (char *const *)new_argv);
248
error_plus(0, errno, "execv");
249
_exit(EXIT_FAILURE);
250
}
251
if(pid_return != NULL){
252
*pid_return = pid;
253
}
254
do {
255
ret = waitpid(pid, &status, 0);
256
} while(ret == -1 and errno == EINTR
257
and ((not interrupted_by_signal)
258
or (not interruptable)));
259
if(interrupted_by_signal and interruptable){
260
if(debug){
261
fprintf_plus(stderr, "Interrupted by signal\n");
262
}
263
return false;
264
}
265
if(ret == -1){
266
error_plus(0, errno, "waitpid");
267
return false;
268
}
269
if(debug){
270
if(WIFEXITED(status)){
271
fprintf_plus(stderr, "exec_and_wait exited: %d\n",
272
WEXITSTATUS(status));
273
} else if(WIFSIGNALED(status)) {
274
fprintf_plus(stderr, "exec_and_wait signaled: %d\n",
275
WTERMSIG(status));
276
}
277
}
278
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
279
return true;
280
}
281
return false;
282
}
283
284
__attribute__((nonnull))
285
int is_plymouth(const struct dirent *proc_entry){
286
int ret;
287
{
288
uintmax_t proc_id;
289
char *tmp;
290
errno = 0;
291
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
292
293
if(errno != 0 or *tmp != '\0'
294
or proc_id != (uintmax_t)((pid_t)proc_id)){
295
return 0;
296
}
297
}
298
char exe_target[sizeof(plymouthd_path)];
299
char *exe_link;
300
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
301
if(ret == -1){
302
error_plus(0, errno, "asprintf");
303
return 0;
304
}
305
306
struct stat exe_stat;
307
ret = lstat(exe_link, &exe_stat);
308
if(ret == -1){
309
free(exe_link);
310
if(errno != ENOENT){
311
error_plus(0, errno, "lstat");
312
}
313
return 0;
314
}
315
316
if(not S_ISLNK(exe_stat.st_mode)
317
or exe_stat.st_uid != 0
318
or exe_stat.st_gid != 0){
319
free(exe_link);
320
return 0;
321
}
322
323
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
324
free(exe_link);
325
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
326
(memcmp(plymouthd_path, exe_target,
327
sizeof(plymouthd_path)-1) != 0)){
328
return 0;
329
}
330
return 1;
331
}
332
333
pid_t get_pid(void){
334
int ret;
335
uintmax_t proc_id = 0;
336
FILE *pidfile = fopen(plymouth_pid, "r");
337
/* Try the new pid file location */
338
if(pidfile != NULL){
339
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
340
if(ret != 1){
341
proc_id = 0;
342
}
343
fclose(pidfile);
344
}
345
/* Try the old pid file location */
346
if(proc_id == 0){
347
pidfile = fopen(plymouth_old_pid, "r");
348
if(pidfile != NULL){
349
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
350
if(ret != 1){
351
proc_id = 0;
352
}
353
fclose(pidfile);
354
}
355
}
356
/* Try the old old pid file location */
357
if(proc_id == 0){
358
pidfile = fopen(plymouth_old_old_pid, "r");
359
if(pidfile != NULL){
360
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
361
if(ret != 1){
362
proc_id = 0;
363
}
364
fclose(pidfile);
365
}
366
}
367
/* Look for a plymouth process */
368
if(proc_id == 0){
369
struct dirent **direntries = NULL;
370
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
371
if(ret == -1){
372
error_plus(0, errno, "scandir");
373
}
374
if(ret > 0){
375
const int num_entries = ret;
376
for(int i = 0; i < num_entries; i++){
377
if(proc_id == 0){
378
ret = sscanf(direntries[i]->d_name, "%" SCNuMAX, &proc_id);
379
if(ret < 0){
380
error_plus(0, errno, "sscanf");
381
}
382
}
383
free(direntries[i]);
384
}
385
}
386
/* scandir might preallocate for this variable (man page unclear).
387
even if ret == 0, therefore we need to free it. */
388
free(direntries);
389
}
390
pid_t pid;
391
pid = (pid_t)proc_id;
392
if((uintmax_t)pid == proc_id){
393
return pid;
394
}
395
396
return 0;
397
}
398
399
char **getargv(pid_t pid){
400
int cl_fd;
401
char *cmdline_filename;
402
ssize_t sret;
403
int ret;
404
405
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
406
(uintmax_t)pid);
407
if(ret == -1){
408
error_plus(0, errno, "asprintf");
409
return NULL;
410
}
411
412
/* Open /proc/<pid>/cmdline */
413
cl_fd = open(cmdline_filename, O_RDONLY);
414
free(cmdline_filename);
415
if(cl_fd == -1){
416
error_plus(0, errno, "open");
417
return NULL;
418
}
419
420
size_t cmdline_allocated = 0;
421
size_t cmdline_len = 0;
422
char *cmdline = NULL;
423
char *tmp;
424
const size_t blocksize = 1024;
425
do {
426
/* Allocate more space? */
427
if(cmdline_len + blocksize > cmdline_allocated){
428
tmp = realloc(cmdline, cmdline_allocated + blocksize);
429
if(tmp == NULL){
430
error_plus(0, errno, "realloc");
431
free(cmdline);
432
close(cl_fd);
433
return NULL;
434
}
435
cmdline = tmp;
436
cmdline_allocated += blocksize;
437
}
438
439
/* Read data */
440
sret = read(cl_fd, cmdline + cmdline_len,
441
cmdline_allocated - cmdline_len);
442
if(sret == -1){
443
error_plus(0, errno, "read");
444
free(cmdline);
445
close(cl_fd);
446
return NULL;
447
}
448
cmdline_len += (size_t)sret;
449
} while(sret != 0);
450
ret = close(cl_fd);
451
if(ret == -1){
452
error_plus(0, errno, "close");
453
free(cmdline);
454
return NULL;
455
}
456
457
/* we got cmdline and cmdline_len, ignore rest... */
458
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
459
* sizeof(char *)); /* Get number of args */
460
if(argv == NULL){
461
error_plus(0, errno, "argv = malloc()");
462
free(cmdline);
463
return NULL;
464
}
465
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
466
return argv;
467
}
468
469
int main(__attribute__((unused))int argc,
470
__attribute__((unused))char **argv){
471
char *prompt = NULL;
472
char *prompt_arg;
473
pid_t plymouth_command_pid;
474
int ret;
475
bool bret;
476
477
{
478
struct argp_option options[] = {
479
{ .name = "prompt", .key = 128, .arg = "PROMPT",
480
.doc = "The prompt to show" },
481
{ .name = "debug", .key = 129,
482
.doc = "Debug mode" },
483
{ .name = NULL }
484
};
485
486
__attribute__((nonnull(3)))
487
error_t parse_opt (int key, char *arg, __attribute__((unused))
488
struct argp_state *state){
489
errno = 0;
490
switch (key){
491
case 128: /* --prompt */
492
prompt = arg;
493
if(debug){
494
fprintf_plus(stderr, "Custom prompt \"%s\"\n", prompt);
495
}
496
break;
497
case 129: /* --debug */
498
debug = true;
499
break;
500
default:
501
return ARGP_ERR_UNKNOWN;
502
}
503
return errno;
504
}
505
506
struct argp argp = { .options = options, .parser = parse_opt,
507
.args_doc = "",
508
.doc = "Mandos plymouth -- Read and"
509
" output a password" };
510
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, NULL, NULL);
511
switch(ret){
512
case 0:
513
break;
514
case ENOMEM:
515
default:
516
errno = ret;
517
error_plus(0, errno, "argp_parse");
518
return EX_OSERR;
519
case EINVAL:
520
error_plus(0, errno, "argp_parse");
521
return EX_USAGE;
522
}
523
}
524
525
/* test -x /bin/plymouth */
526
ret = access(plymouth_path, X_OK);
527
if(ret == -1){
528
/* Plymouth is probably not installed. Don't print an error
529
message, just exit. */
530
if(debug){
531
fprintf_plus(stderr, "Plymouth (%s) not found\n",
532
plymouth_path);
533
}
534
exit(EX_UNAVAILABLE);
535
}
536
537
{ /* Add signal handlers */
538
struct sigaction old_action,
539
new_action = { .sa_handler = termination_handler,
540
.sa_flags = 0 };
541
sigemptyset(&new_action.sa_mask);
542
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
543
*sig != 0; sig++){
544
ret = sigaddset(&new_action.sa_mask, *sig);
545
if(ret == -1){
546
error_plus(EX_OSERR, errno, "sigaddset");
547
}
548
ret = sigaction(*sig, NULL, &old_action);
549
if(ret == -1){
550
error_plus(EX_OSERR, errno, "sigaction");
551
}
552
if(old_action.sa_handler != SIG_IGN){
553
ret = sigaction(*sig, &new_action, NULL);
554
if(ret == -1){
555
error_plus(EX_OSERR, errno, "sigaction");
556
}
557
}
558
}
559
}
560
561
/* plymouth --ping */
562
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
563
(const char *[])
564
{ plymouth_path, "--ping", NULL },
565
true, false);
566
if(not bret){
567
if(interrupted_by_signal){
568
kill_and_wait(plymouth_command_pid);
569
exit(EXIT_FAILURE);
570
}
571
/* Plymouth is probably not running. Don't print an error
572
message, just exit. */
573
if(debug){
574
fprintf_plus(stderr, "Plymouth not running\n");
575
}
576
exit(EX_UNAVAILABLE);
577
}
578
579
if(prompt != NULL){
580
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
581
} else {
582
char *made_prompt = makeprompt();
583
ret = asprintf(&prompt_arg, "--prompt=%s", made_prompt);
584
free(made_prompt);
585
}
586
if(ret == -1){
587
error_plus(EX_OSERR, errno, "asprintf");
588
}
589
590
/* plymouth ask-for-password --prompt="$prompt" */
591
if(debug){
592
fprintf_plus(stderr, "Prompting for password via Plymouth\n");
593
}
594
bret = exec_and_wait(&plymouth_command_pid,
595
plymouth_path, (const char *[])
596
{ plymouth_path, "ask-for-password",
597
prompt_arg, NULL },
598
true, false);
599
free(prompt_arg);
600
if(bret){
601
exit(EXIT_SUCCESS);
602
}
603
if(not interrupted_by_signal){
604
/* exec_and_wait failed for some other reason */
605
exit(EXIT_FAILURE);
606
}
607
kill_and_wait(plymouth_command_pid);
608
609
char **plymouthd_argv = NULL;
610
pid_t pid = get_pid();
611
if(pid == 0){
612
error_plus(0, 0, "plymouthd pid not found");
613
} else {
614
plymouthd_argv = getargv(pid);
615
}
616
617
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
618
{ plymouth_path, "quit", NULL },
619
false, false);
620
if(not bret){
621
if(plymouthd_argv != NULL){
622
free(*plymouthd_argv);
623
free(plymouthd_argv);
624
}
625
exit(EXIT_FAILURE);
626
}
627
bret = exec_and_wait(NULL, plymouthd_path,
628
(plymouthd_argv != NULL)
629
? (const char * const *)plymouthd_argv
630
: plymouthd_default_argv,
631
false, true);
632
if(plymouthd_argv != NULL){
633
free(*plymouthd_argv);
634
free(plymouthd_argv);
635
}
636
if(not bret){
637
exit(EXIT_FAILURE);
638
}
639
exec_and_wait(NULL, plymouth_path, (const char *[])
640
{ plymouth_path, "show-splash", NULL },
641
false, false);
642
exit(EXIT_FAILURE);
643
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0