1
/* -*- coding: utf-8 -*- */
3
* Plymouth - Read a password from Plymouth and output it
5
* Copyright © 2010-2022 Teddy Hogeborn
6
* Copyright © 2010-2022 Björn Påhlsson
8
* This file is part of Mandos.
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.
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.
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/>.
23
* Contact the authors at <mandos@recompile.se>.
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,
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(),
43
#include <stdarg.h> /* va_list, va_start(), vfprintf() */
44
#include <errno.h> /* program_invocation_short_name,
45
errno, ENOMEM, EINTR, ENOENT,
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(),
64
#include <iso646.h> /* not, and, or */
65
#include <sysexits.h> /* EX_OSERR, EX_USAGE,
67
#include <stdint.h> /* SIZE_MAX */
68
#include <dirent.h> /* struct dirent, scandir(),
70
#include <inttypes.h> /* uintmax_t, strtoumax(), SCNuMAX,
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() */
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>";
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";
87
const char plymouth_path[] = "/bin/plymouth";
88
const char plymouthd_path[] = "/sbin/plymouthd";
89
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
91
"--attach-to-session",
95
static void termination_handler(__attribute__((unused))int signum){
96
if(interrupted_by_signal){
99
interrupted_by_signal = 1;
102
__attribute__((format (gnu_printf, 2, 3), nonnull))
103
int fprintf_plus(FILE *stream, const char *format, ...){
105
va_start (ap, format);
106
fprintf(stream, "Mandos plugin %s: ", program_invocation_short_name);
107
return vfprintf(stream, format, ap);
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,
118
va_start(ap, formatstring);
119
ret = vasprintf(&text, formatstring, ap);
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");
129
fprintf(stderr, "Mandos plugin ");
130
error(status, errnum, "%s", text);
134
/* Create prompt string */
135
char *makeprompt(void){
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";
143
if(cryptsource == NULL){
144
if(crypttarget == NULL){
145
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
147
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
148
crypttarget, prompt_end);
151
if(crypttarget == NULL){
152
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
155
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
156
cryptsource, crypttarget, prompt_end);
165
void kill_and_wait(pid_t pid){
166
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
167
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
170
bool become_a_daemon(void){
171
int ret = setuid(geteuid());
173
error_plus(0, errno, "setuid");
179
error_plus(0, errno, "chdir");
182
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
184
error_plus(0, errno, "dup2");
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,
198
for(const char * const *arg = argv; *arg != NULL; arg++){
199
fprintf_plus(stderr, "exec_and_wait arg: %s\n", *arg);
201
fprintf_plus(stderr, "exec_and_wait end of args\n");
206
error_plus(0, errno, "fork");
212
if(not become_a_daemon()){
217
char **new_argv = malloc(sizeof(const char *));
218
if(new_argv == NULL){
219
error_plus(0, errno, "malloc");
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 *));
229
if(((size_t)i + 2) > (SIZE_MAX / sizeof(const char *))){
234
tmp = realloc(new_argv, ((size_t)i + 2) * sizeof(const char *));
238
error_plus(0, errno, "reallocarray");
243
new_argv[i] = strdup(argv[i]);
247
execv(path, (char *const *)new_argv);
248
error_plus(0, errno, "execv");
251
if(pid_return != NULL){
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){
261
fprintf_plus(stderr, "Interrupted by signal\n");
266
error_plus(0, errno, "waitpid");
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",
278
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
284
__attribute__((nonnull))
285
int is_plymouth(const struct dirent *proc_entry){
291
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
293
if(errno != 0 or *tmp != '\0'
294
or proc_id != (uintmax_t)((pid_t)proc_id)){
298
char exe_target[sizeof(plymouthd_path)];
300
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
302
error_plus(0, errno, "asprintf");
306
struct stat exe_stat;
307
ret = lstat(exe_link, &exe_stat);
311
error_plus(0, errno, "lstat");
316
if(not S_ISLNK(exe_stat.st_mode)
317
or exe_stat.st_uid != 0
318
or exe_stat.st_gid != 0){
323
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
325
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
326
(memcmp(plymouthd_path, exe_target,
327
sizeof(plymouthd_path)-1) != 0)){
335
uintmax_t proc_id = 0;
336
FILE *pidfile = fopen(plymouth_pid, "r");
337
/* Try the new pid file location */
339
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
345
/* Try the old pid file location */
347
pidfile = fopen(plymouth_old_pid, "r");
349
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
356
/* Try the old old pid file location */
358
pidfile = fopen(plymouth_old_old_pid, "r");
360
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
367
/* Look for a plymouth process */
369
struct dirent **direntries = NULL;
370
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
372
error_plus(0, errno, "scandir");
375
for(int i = ret-1; i >= 0; i--){
377
ret = sscanf(direntries[i]->d_name, "%" SCNuMAX, &proc_id);
379
error_plus(0, errno, "sscanf");
385
/* scandir might preallocate for this variable (man page unclear).
386
even if ret == 0, therefore we need to free it. */
390
pid = (pid_t)proc_id;
391
if((uintmax_t)pid == proc_id){
398
char **getargv(pid_t pid){
400
char *cmdline_filename;
404
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
407
error_plus(0, errno, "asprintf");
411
/* Open /proc/<pid>/cmdline */
412
cl_fd = open(cmdline_filename, O_RDONLY);
413
free(cmdline_filename);
415
error_plus(0, errno, "open");
419
size_t cmdline_allocated = 0;
420
size_t cmdline_len = 0;
421
char *cmdline = NULL;
423
const size_t blocksize = 1024;
425
/* Allocate more space? */
426
if(cmdline_len + blocksize > cmdline_allocated){
427
tmp = realloc(cmdline, cmdline_allocated + blocksize);
429
error_plus(0, errno, "realloc");
435
cmdline_allocated += blocksize;
439
sret = read(cl_fd, cmdline + cmdline_len,
440
cmdline_allocated - cmdline_len);
442
error_plus(0, errno, "read");
447
cmdline_len += (size_t)sret;
451
error_plus(0, errno, "close");
456
/* we got cmdline and cmdline_len, ignore rest... */
457
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
458
* sizeof(char *)); /* Get number of args */
460
error_plus(0, errno, "argv = malloc()");
464
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
468
int main(__attribute__((unused))int argc,
469
__attribute__((unused))char **argv){
472
pid_t plymouth_command_pid;
477
struct argp_option options[] = {
478
{ .name = "prompt", .key = 128, .arg = "PROMPT",
479
.doc = "The prompt to show" },
480
{ .name = "debug", .key = 129,
481
.doc = "Debug mode" },
485
__attribute__((nonnull(3)))
486
error_t parse_opt (int key, char *arg, __attribute__((unused))
487
struct argp_state *state){
490
case 128: /* --prompt */
493
fprintf_plus(stderr, "Custom prompt \"%s\"\n", prompt);
496
case 129: /* --debug */
500
return ARGP_ERR_UNKNOWN;
505
struct argp argp = { .options = options, .parser = parse_opt,
507
.doc = "Mandos plymouth -- Read and"
508
" output a password" };
509
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, NULL, NULL);
516
error_plus(0, errno, "argp_parse");
519
error_plus(0, errno, "argp_parse");
524
/* test -x /bin/plymouth */
525
ret = access(plymouth_path, X_OK);
527
/* Plymouth is probably not installed. Don't print an error
528
message, just exit. */
530
fprintf_plus(stderr, "Plymouth (%s) not found\n",
533
exit(EX_UNAVAILABLE);
536
{ /* Add signal handlers */
537
struct sigaction old_action,
538
new_action = { .sa_handler = termination_handler,
540
sigemptyset(&new_action.sa_mask);
541
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
543
ret = sigaddset(&new_action.sa_mask, *sig);
545
error_plus(EX_OSERR, errno, "sigaddset");
547
ret = sigaction(*sig, NULL, &old_action);
549
error_plus(EX_OSERR, errno, "sigaction");
551
if(old_action.sa_handler != SIG_IGN){
552
ret = sigaction(*sig, &new_action, NULL);
554
error_plus(EX_OSERR, errno, "sigaction");
560
/* plymouth --ping */
561
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
563
{ plymouth_path, "--ping", NULL },
566
if(interrupted_by_signal){
567
kill_and_wait(plymouth_command_pid);
570
/* Plymouth is probably not running. Don't print an error
571
message, just exit. */
573
fprintf_plus(stderr, "Plymouth not running\n");
575
exit(EX_UNAVAILABLE);
579
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
581
char *made_prompt = makeprompt();
582
ret = asprintf(&prompt_arg, "--prompt=%s", made_prompt);
586
error_plus(EX_OSERR, errno, "asprintf");
589
/* plymouth ask-for-password --prompt="$prompt" */
591
fprintf_plus(stderr, "Prompting for password via Plymouth\n");
593
bret = exec_and_wait(&plymouth_command_pid,
594
plymouth_path, (const char *[])
595
{ plymouth_path, "ask-for-password",
602
if(not interrupted_by_signal){
603
/* exec_and_wait failed for some other reason */
606
kill_and_wait(plymouth_command_pid);
608
char **plymouthd_argv = NULL;
609
pid_t pid = get_pid();
611
error_plus(0, 0, "plymouthd pid not found");
613
plymouthd_argv = getargv(pid);
616
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
617
{ plymouth_path, "quit", NULL },
620
if(plymouthd_argv != NULL){
621
free(*plymouthd_argv);
622
free(plymouthd_argv);
626
bret = exec_and_wait(NULL, plymouthd_path,
627
(plymouthd_argv != NULL)
628
? (const char * const *)plymouthd_argv
629
: plymouthd_default_argv,
631
if(plymouthd_argv != NULL){
632
free(*plymouthd_argv);
633
free(plymouthd_argv);
638
exec_and_wait(NULL, plymouth_path, (const char *[])
639
{ plymouth_path, "show-splash", NULL },
added
removed
plugins.d/plymouth.c
