1
/* -*- coding: utf-8 -*- */
3
* Plymouth - Read a password from Plymouth and output it
5
* Copyright © 2010-2019 Teddy Hogeborn
6
* Copyright © 2010-2019 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 /* asprintf(), TEMP_FAILURE_RETRY() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction(),
31
#include <stdbool.h> /* bool, false, true */
32
#include <fcntl.h> /* open(), O_RDONLY */
33
#include <iso646.h> /* and, or, not*/
34
#include <sys/types.h> /* size_t, ssize_t, pid_t, struct
36
#include <sys/wait.h> /* waitpid() */
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strchr(), memcmp() */
39
#include <stdio.h> /* asprintf(), perror(), fopen(),
40
fscanf(), vasprintf(), fprintf(),
42
#include <unistd.h> /* close(), readlink(), read(),
43
fork(), setsid(), chdir(), dup2(),
44
STDERR_FILENO, execv(), access() */
45
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit(),
47
getenv(), reallocarray() */
48
#include <dirent.h> /* scandir(), alphasort() */
49
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
50
#include <sys/stat.h> /* struct stat, lstat() */
51
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
#include <error.h> /* error() */
53
#include <errno.h> /* TEMP_FAILURE_RETRY */
54
#include <argz.h> /* argz_count(), argz_extract() */
55
#include <stdarg.h> /* va_list, va_start(), ... */
58
sig_atomic_t interrupted_by_signal = 0;
59
const char *argp_program_version = "plymouth " VERSION;
60
const char *argp_program_bug_address = "<mandos@recompile.se>";
62
/* Used by Ubuntu 11.04 (Natty Narwahl) */
63
const char plymouth_old_old_pid[] = "/dev/.initramfs/plymouth.pid";
64
/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
65
const char plymouth_old_pid[] = "/run/initramfs/plymouth.pid";
66
/* Used by Debian 9 (stretch) */
67
const char plymouth_pid[] = "/run/plymouth/pid";
69
const char plymouth_path[] = "/bin/plymouth";
70
const char plymouthd_path[] = "/sbin/plymouthd";
71
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
73
"--attach-to-session",
77
static void termination_handler(__attribute__((unused))int signum){
78
if(interrupted_by_signal){
81
interrupted_by_signal = 1;
84
__attribute__((format (gnu_printf, 2, 3), nonnull))
85
int fprintf_plus(FILE *stream, const char *format, ...){
87
va_start (ap, format);
88
fprintf(stream, "Mandos plugin %s: ", program_invocation_short_name);
89
return vfprintf(stream, format, ap);
92
/* Function to use when printing errors */
93
__attribute__((format (gnu_printf, 3, 4)))
94
void error_plus(int status, int errnum, const char *formatstring,
100
va_start(ap, formatstring);
101
ret = vasprintf(&text, formatstring, ap);
103
fprintf(stderr, "Mandos plugin %s: ",
104
program_invocation_short_name);
105
vfprintf(stderr, formatstring, ap);
106
fprintf(stderr, ": ");
107
fprintf(stderr, "%s\n", strerror(errnum));
108
error(status, errno, "vasprintf while printing error");
111
fprintf(stderr, "Mandos plugin ");
112
error(status, errnum, "%s", text);
116
/* Create prompt string */
117
char *makeprompt(void){
120
const char *const cryptsource = getenv("cryptsource");
121
const char *const crypttarget = getenv("crypttarget");
122
const char prompt_start[] = "Unlocking the disk";
123
const char prompt_end[] = "Enter passphrase";
125
if(cryptsource == NULL){
126
if(crypttarget == NULL){
127
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
129
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
130
crypttarget, prompt_end);
133
if(crypttarget == NULL){
134
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
137
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
138
cryptsource, crypttarget, prompt_end);
147
void kill_and_wait(pid_t pid){
148
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
149
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
152
bool become_a_daemon(void){
153
int ret = setuid(geteuid());
155
error_plus(0, errno, "setuid");
161
error_plus(0, errno, "chdir");
164
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
166
error_plus(0, errno, "dup2");
172
__attribute__((nonnull (2, 3)))
173
bool exec_and_wait(pid_t *pid_return, const char *path,
174
const char * const * const argv, bool interruptable,
180
for(const char * const *arg = argv; *arg != NULL; arg++){
181
fprintf_plus(stderr, "exec_and_wait arg: %s\n", *arg);
183
fprintf_plus(stderr, "exec_and_wait end of args\n");
188
error_plus(0, errno, "fork");
194
if(not become_a_daemon()){
199
char **new_argv = malloc(sizeof(const char *));
200
if(new_argv == NULL){
201
error_plus(0, errno, "malloc");
206
for (; argv[i] != NULL; i++){
207
#if defined(__GLIBC_PREREQ) and __GLIBC_PREREQ(2, 26)
208
tmp = reallocarray(new_argv, ((size_t)i + 2),
209
sizeof(const char *));
211
if(((size_t)i + 2) > (SIZE_MAX / sizeof(const char *))){
216
tmp = realloc(new_argv, ((size_t)i + 2) * sizeof(const char *));
220
error_plus(0, errno, "reallocarray");
225
new_argv[i] = strdup(argv[i]);
229
execv(path, (char *const *)new_argv);
230
error_plus(0, errno, "execv");
233
if(pid_return != NULL){
237
ret = waitpid(pid, &status, 0);
238
} while(ret == -1 and errno == EINTR
239
and ((not interrupted_by_signal)
240
or (not interruptable)));
241
if(interrupted_by_signal and interruptable){
243
fprintf_plus(stderr, "Interrupted by signal\n");
248
error_plus(0, errno, "waitpid");
252
if(WIFEXITED(status)){
253
fprintf_plus(stderr, "exec_and_wait exited: %d\n",
254
WEXITSTATUS(status));
255
} else if(WIFSIGNALED(status)) {
256
fprintf_plus(stderr, "exec_and_wait signaled: %d\n",
260
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
266
__attribute__((nonnull))
267
int is_plymouth(const struct dirent *proc_entry){
273
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
275
if(errno != 0 or *tmp != '\0'
276
or proc_id != (uintmax_t)((pid_t)proc_id)){
280
char exe_target[sizeof(plymouthd_path)];
282
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
284
error_plus(0, errno, "asprintf");
288
struct stat exe_stat;
289
ret = lstat(exe_link, &exe_stat);
293
error_plus(0, errno, "lstat");
298
if(not S_ISLNK(exe_stat.st_mode)
299
or exe_stat.st_uid != 0
300
or exe_stat.st_gid != 0){
305
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
307
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
308
(memcmp(plymouthd_path, exe_target,
309
sizeof(plymouthd_path)-1) != 0)){
317
uintmax_t proc_id = 0;
318
FILE *pidfile = fopen(plymouth_pid, "r");
319
/* Try the new pid file location */
321
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
327
/* Try the old pid file location */
329
pidfile = fopen(plymouth_old_pid, "r");
331
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
338
/* Try the old old pid file location */
340
pidfile = fopen(plymouth_old_old_pid, "r");
342
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
349
/* Look for a plymouth process */
351
struct dirent **direntries = NULL;
352
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
354
error_plus(0, errno, "scandir");
357
for(int i = ret-1; i >= 0; i--){
359
ret = sscanf(direntries[i]->d_name, "%" SCNuMAX, &proc_id);
361
error_plus(0, errno, "sscanf");
367
/* scandir might preallocate for this variable (man page unclear).
368
even if ret == 0, therefore we need to free it. */
372
pid = (pid_t)proc_id;
373
if((uintmax_t)pid == proc_id){
380
char **getargv(pid_t pid){
382
char *cmdline_filename;
386
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
389
error_plus(0, errno, "asprintf");
393
/* Open /proc/<pid>/cmdline */
394
cl_fd = open(cmdline_filename, O_RDONLY);
395
free(cmdline_filename);
397
error_plus(0, errno, "open");
401
size_t cmdline_allocated = 0;
402
size_t cmdline_len = 0;
403
char *cmdline = NULL;
405
const size_t blocksize = 1024;
407
/* Allocate more space? */
408
if(cmdline_len + blocksize > cmdline_allocated){
409
tmp = realloc(cmdline, cmdline_allocated + blocksize);
411
error_plus(0, errno, "realloc");
417
cmdline_allocated += blocksize;
421
sret = read(cl_fd, cmdline + cmdline_len,
422
cmdline_allocated - cmdline_len);
424
error_plus(0, errno, "read");
429
cmdline_len += (size_t)sret;
433
error_plus(0, errno, "close");
438
/* we got cmdline and cmdline_len, ignore rest... */
439
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
440
* sizeof(char *)); /* Get number of args */
442
error_plus(0, errno, "argv = malloc()");
446
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
450
int main(__attribute__((unused))int argc,
451
__attribute__((unused))char **argv){
454
pid_t plymouth_command_pid;
459
struct argp_option options[] = {
460
{ .name = "prompt", .key = 128, .arg = "PROMPT",
461
.doc = "The prompt to show" },
462
{ .name = "debug", .key = 129,
463
.doc = "Debug mode" },
467
__attribute__((nonnull(3)))
468
error_t parse_opt (int key, char *arg, __attribute__((unused))
469
struct argp_state *state){
472
case 128: /* --prompt */
475
fprintf_plus(stderr, "Custom prompt \"%s\"\n", prompt);
478
case 129: /* --debug */
482
return ARGP_ERR_UNKNOWN;
487
struct argp argp = { .options = options, .parser = parse_opt,
489
.doc = "Mandos plymouth -- Read and"
490
" output a password" };
491
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, NULL, NULL);
498
error_plus(0, errno, "argp_parse");
501
error_plus(0, errno, "argp_parse");
506
/* test -x /bin/plymouth */
507
ret = access(plymouth_path, X_OK);
509
/* Plymouth is probably not installed. Don't print an error
510
message, just exit. */
512
fprintf_plus(stderr, "Plymouth (%s) not found\n",
515
exit(EX_UNAVAILABLE);
518
{ /* Add signal handlers */
519
struct sigaction old_action,
520
new_action = { .sa_handler = termination_handler,
522
sigemptyset(&new_action.sa_mask);
523
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
525
ret = sigaddset(&new_action.sa_mask, *sig);
527
error_plus(EX_OSERR, errno, "sigaddset");
529
ret = sigaction(*sig, NULL, &old_action);
531
error_plus(EX_OSERR, errno, "sigaction");
533
if(old_action.sa_handler != SIG_IGN){
534
ret = sigaction(*sig, &new_action, NULL);
536
error_plus(EX_OSERR, errno, "sigaction");
542
/* plymouth --ping */
543
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
545
{ plymouth_path, "--ping", NULL },
548
if(interrupted_by_signal){
549
kill_and_wait(plymouth_command_pid);
552
/* Plymouth is probably not running. Don't print an error
553
message, just exit. */
555
fprintf_plus(stderr, "Plymouth not running\n");
557
exit(EX_UNAVAILABLE);
561
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
563
char *made_prompt = makeprompt();
564
ret = asprintf(&prompt_arg, "--prompt=%s", made_prompt);
568
error_plus(EX_OSERR, errno, "asprintf");
571
/* plymouth ask-for-password --prompt="$prompt" */
573
fprintf_plus(stderr, "Prompting for password via Plymouth\n");
575
bret = exec_and_wait(&plymouth_command_pid,
576
plymouth_path, (const char *[])
577
{ plymouth_path, "ask-for-password",
584
if(not interrupted_by_signal){
585
/* exec_and_wait failed for some other reason */
588
kill_and_wait(plymouth_command_pid);
590
char **plymouthd_argv = NULL;
591
pid_t pid = get_pid();
593
error_plus(0, 0, "plymouthd pid not found");
595
plymouthd_argv = getargv(pid);
598
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
599
{ plymouth_path, "quit", NULL },
602
if(plymouthd_argv != NULL){
603
free(*plymouthd_argv);
604
free(plymouthd_argv);
608
bret = exec_and_wait(NULL, plymouthd_path,
609
(plymouthd_argv != NULL)
610
? (const char * const *)plymouthd_argv
611
: plymouthd_default_argv,
613
if(plymouthd_argv != NULL){
614
free(*plymouthd_argv);
615
free(plymouthd_argv);
620
exec_and_wait(NULL, plymouth_path, (const char *[])
621
{ plymouth_path, "show-splash", NULL },
added
removed
plugins.d/plymouth.c
