1
/* -*- coding: utf-8 -*- */
3
* Plymouth - Read a password from Plymouth and output it
5
* Copyright © 2010-2014 Teddy Hogeborn
6
* Copyright © 2010-2014 Björn Påhlsson
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.
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.
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/>.
22
* Contact the authors at <mandos@recompile.se>.
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction(),
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_RDONLY */
32
#include <iso646.h> /* and, or, not*/
33
#include <sys/types.h> /* size_t, ssize_t, pid_t, struct
35
#include <sys/wait.h> /* waitpid() */
36
#include <stddef.h> /* NULL */
37
#include <string.h> /* strchr(), memcmp() */
38
#include <stdio.h> /* asprintf(), perror(), fopen(),
39
fscanf(), vasprintf(), fprintf(),
41
#include <unistd.h> /* close(), readlink(), read(),
42
fork(), setsid(), chdir(), dup2(),
43
STDERR_FILENO, execv(), access() */
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit(),
47
#include <dirent.h> /* scandir(), alphasort() */
48
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
49
#include <sys/stat.h> /* struct stat, lstat() */
50
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
51
#include <error.h> /* error() */
52
#include <errno.h> /* TEMP_FAILURE_RETRY */
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
56
sig_atomic_t interrupted_by_signal = 0;
58
/* Used by Ubuntu 11.04 (Natty Narwahl) */
59
const char plymouth_old_pid[] = "/dev/.initramfs/plymouth.pid";
60
/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
61
const char plymouth_pid[] = "/run/initramfs/plymouth.pid";
63
const char plymouth_path[] = "/bin/plymouth";
64
const char plymouthd_path[] = "/sbin/plymouthd";
65
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
67
"--attach-to-session",
70
static void termination_handler(__attribute__((unused))int signum){
71
if(interrupted_by_signal){
74
interrupted_by_signal = 1;
77
/* Function to use when printing errors */
78
__attribute__((format (gnu_printf, 3, 4)))
79
void error_plus(int status, int errnum, const char *formatstring,
85
va_start(ap, formatstring);
86
ret = vasprintf(&text, formatstring, ap);
88
fprintf(stderr, "Mandos plugin %s: ",
89
program_invocation_short_name);
90
vfprintf(stderr, formatstring, ap);
91
fprintf(stderr, ": ");
92
fprintf(stderr, "%s\n", strerror(errnum));
93
error(status, errno, "vasprintf while printing error");
96
fprintf(stderr, "Mandos plugin ");
97
error(status, errnum, "%s", text);
101
/* Create prompt string */
102
char *makeprompt(void){
105
const char *const cryptsource = getenv("cryptsource");
106
const char *const crypttarget = getenv("crypttarget");
107
const char prompt_start[] = "Unlocking the disk";
108
const char prompt_end[] = "Enter passphrase";
110
if(cryptsource == NULL){
111
if(crypttarget == NULL){
112
ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
114
ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
115
crypttarget, prompt_end);
118
if(crypttarget == NULL){
119
ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
122
ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
123
cryptsource, crypttarget, prompt_end);
132
void kill_and_wait(pid_t pid){
133
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
134
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
137
bool become_a_daemon(void){
138
int ret = setuid(geteuid());
140
error_plus(0, errno, "setuid");
146
error_plus(0, errno, "chdir");
149
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
151
error_plus(0, errno, "dup2");
157
__attribute__((nonnull (2, 3)))
158
bool exec_and_wait(pid_t *pid_return, const char *path,
159
const char * const *argv, bool interruptable,
166
error_plus(0, errno, "fork");
172
if(not become_a_daemon()){
177
char **new_argv = NULL;
180
for (; argv[i]!=NULL; i++){
181
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
183
error_plus(0, errno, "realloc");
188
new_argv[i] = strdup(argv[i]);
192
execv(path, (char *const *)new_argv);
193
error_plus(0, errno, "execv");
196
if(pid_return != NULL){
200
ret = waitpid(pid, &status, 0);
201
} while(ret == -1 and errno == EINTR
202
and ((not interrupted_by_signal)
203
or (not interruptable)));
204
if(interrupted_by_signal and interruptable){
208
error_plus(0, errno, "waitpid");
211
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
217
__attribute__((nonnull))
218
int is_plymouth(const struct dirent *proc_entry){
224
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
226
if(errno != 0 or *tmp != '\0'
227
or proc_id != (uintmax_t)((pid_t)proc_id)){
231
char exe_target[sizeof(plymouthd_path)];
233
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
235
error_plus(0, errno, "asprintf");
239
struct stat exe_stat;
240
ret = lstat(exe_link, &exe_stat);
244
error_plus(0, errno, "lstat");
249
if(not S_ISLNK(exe_stat.st_mode)
250
or exe_stat.st_uid != 0
251
or exe_stat.st_gid != 0){
256
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
258
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
259
(memcmp(plymouthd_path, exe_target,
260
sizeof(plymouthd_path)-1) != 0)){
268
uintmax_t proc_id = 0;
269
FILE *pidfile = fopen(plymouth_pid, "r");
270
/* Try the new pid file location */
272
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
278
/* Try the old pid file location */
280
pidfile = fopen(plymouth_pid, "r");
282
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
289
/* Look for a plymouth process */
291
struct dirent **direntries = NULL;
292
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
294
error_plus(0, errno, "scandir");
297
ret = sscanf(direntries[0]->d_name, "%" SCNuMAX, &proc_id);
299
error_plus(0, errno, "sscanf");
302
/* scandir might preallocate for this variable (man page unclear).
303
even if ret == 0, therefore we need to free it. */
307
pid = (pid_t)proc_id;
308
if((uintmax_t)pid == proc_id){
315
const char * const * getargv(pid_t pid){
317
char *cmdline_filename;
321
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
324
error_plus(0, errno, "asprintf");
328
/* Open /proc/<pid>/cmdline */
329
cl_fd = open(cmdline_filename, O_RDONLY);
330
free(cmdline_filename);
332
error_plus(0, errno, "open");
336
size_t cmdline_allocated = 0;
337
size_t cmdline_len = 0;
338
char *cmdline = NULL;
340
const size_t blocksize = 1024;
342
/* Allocate more space? */
343
if(cmdline_len + blocksize > cmdline_allocated){
344
tmp = realloc(cmdline, cmdline_allocated + blocksize);
346
error_plus(0, errno, "realloc");
352
cmdline_allocated += blocksize;
356
sret = read(cl_fd, cmdline + cmdline_len,
357
cmdline_allocated - cmdline_len);
359
error_plus(0, errno, "read");
364
cmdline_len += (size_t)sret;
368
error_plus(0, errno, "close");
373
/* we got cmdline and cmdline_len, ignore rest... */
374
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
375
* sizeof(char *)); /* Get number of args */
377
error_plus(0, errno, "argv = malloc()");
381
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
382
return (const char * const *)argv;
385
int main(__attribute__((unused))int argc,
386
__attribute__((unused))char **argv){
389
pid_t plymouth_command_pid;
393
/* test -x /bin/plymouth */
394
ret = access(plymouth_path, X_OK);
396
/* Plymouth is probably not installed. Don't print an error
397
message, just exit. */
398
exit(EX_UNAVAILABLE);
401
{ /* Add signal handlers */
402
struct sigaction old_action,
403
new_action = { .sa_handler = termination_handler,
405
sigemptyset(&new_action.sa_mask);
406
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
408
ret = sigaddset(&new_action.sa_mask, *sig);
410
error_plus(EX_OSERR, errno, "sigaddset");
412
ret = sigaction(*sig, NULL, &old_action);
414
error_plus(EX_OSERR, errno, "sigaction");
416
if(old_action.sa_handler != SIG_IGN){
417
ret = sigaction(*sig, &new_action, NULL);
419
error_plus(EX_OSERR, errno, "sigaction");
425
/* plymouth --ping */
426
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
428
{ plymouth_path, "--ping", NULL },
431
if(interrupted_by_signal){
432
kill_and_wait(plymouth_command_pid);
435
/* Plymouth is probably not running. Don't print an error
436
message, just exit. */
437
exit(EX_UNAVAILABLE);
440
prompt = makeprompt();
441
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
444
error_plus(EX_OSERR, errno, "asprintf");
447
/* plymouth ask-for-password --prompt="$prompt" */
448
bret = exec_and_wait(&plymouth_command_pid,
449
plymouth_path, (const char *[])
450
{ plymouth_path, "ask-for-password",
457
if(not interrupted_by_signal){
458
/* exec_and_wait failed for some other reason */
461
kill_and_wait(plymouth_command_pid);
463
const char * const *plymouthd_argv;
464
pid_t pid = get_pid();
466
error_plus(0, 0, "plymouthd pid not found");
467
plymouthd_argv = plymouthd_default_argv;
469
plymouthd_argv = getargv(pid);
472
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
473
{ plymouth_path, "quit", NULL },
478
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
483
exec_and_wait(NULL, plymouth_path, (const char *[])
484
{ plymouth_path, "show-splash", NULL },
added
removed
plugins.d/plymouth.c
