3
3
* Plymouth - Read a password from Plymouth and output it
5
* Copyright © 2010 Teddy Hogeborn
6
* Copyright © 2010 Björn Påhlsson
5
* Copyright © 2010-2014 Teddy Hogeborn
6
* Copyright © 2010-2014 Björn Påhlsson
8
8
* This program is free software: you can redistribute it and/or
9
9
* modify it under the terms of the GNU General Public License as
19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
22
* Contact the authors at <mandos@recompile.se>.
25
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
36
36
#include <stddef.h> /* NULL */
37
37
#include <string.h> /* strchr(), memcmp() */
38
38
#include <stdio.h> /* asprintf(), perror(), fopen(),
39
fscanf(), vasprintf(), fprintf(),
40
41
#include <unistd.h> /* close(), readlink(), read(),
41
42
fork(), setsid(), chdir(), dup2(),
42
43
STDERR_FILENO, execv(), access() */
50
51
#include <error.h> /* error() */
51
52
#include <errno.h> /* TEMP_FAILURE_RETRY */
52
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
54
56
sig_atomic_t interrupted_by_signal = 0;
55
const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
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";
56
63
const char plymouth_path[] = "/bin/plymouth";
57
64
const char plymouthd_path[] = "/sbin/plymouthd";
58
65
const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
60
67
"--attach-to-session",
66
70
static void termination_handler(__attribute__((unused))int signum){
70
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);
73
101
/* Create prompt string */
74
102
char *makeprompt(void){
109
137
bool become_a_daemon(void){
110
138
int ret = setuid(geteuid());
112
error(0, errno, "setuid");
140
error_plus(0, errno, "setuid");
116
144
ret = chdir("/");
118
error(0, errno, "chdir");
146
error_plus(0, errno, "chdir");
121
149
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
123
error(0, errno, "dup2");
151
error_plus(0, errno, "dup2");
157
__attribute__((nonnull (2, 3)))
129
158
bool exec_and_wait(pid_t *pid_return, const char *path,
130
const char **argv, bool interruptable,
159
const char * const *argv, bool interruptable,
137
error(0, errno, "fork");
166
error_plus(0, errno, "fork");
151
180
for (; argv[i]!=NULL; i++){
152
181
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
154
error(0, errno, "realloc");
183
error_plus(0, errno, "realloc");
161
190
new_argv[i] = NULL;
163
192
execv(path, (char *const *)new_argv);
164
error(0, errno, "execv");
193
error_plus(0, errno, "execv");
165
194
_exit(EXIT_FAILURE);
167
196
if(pid_return != NULL){
179
error(0, errno, "waitpid");
208
error_plus(0, errno, "waitpid");
182
211
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
217
__attribute__((nonnull))
188
218
int is_plymouth(const struct dirent *proc_entry){
194
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
224
proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
196
226
if(errno != 0 or *tmp != '\0'
197
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
227
or proc_id != (uintmax_t)((pid_t)proc_id)){
201
char exe_target[sizeof(plymouth_path)];
231
char exe_target[sizeof(plymouthd_path)];
203
233
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
205
error(0, errno, "asprintf");
235
error_plus(0, errno, "asprintf");
226
256
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
228
if((sret != (ssize_t)sizeof(plymouth_path)-1) or
229
(memcmp(plymouth_path, exe_target,
230
sizeof(plymouth_path)-1) != 0)){
258
if((sret != (ssize_t)sizeof(plymouthd_path)-1) or
259
(memcmp(plymouthd_path, exe_target,
260
sizeof(plymouthd_path)-1) != 0)){
236
266
pid_t get_pid(void){
268
uintmax_t proc_id = 0;
238
269
FILE *pidfile = fopen(plymouth_pid, "r");
239
uintmax_t maxvalue = 0;
270
/* Try the new pid file location */
240
271
if(pidfile != NULL){
241
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
272
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
248
struct dirent **direntries;
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;
249
292
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
250
sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
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. */
253
pid = (pid_t)maxvalue;
254
if((uintmax_t)pid == maxvalue){
307
pid = (pid_t)proc_id;
308
if((uintmax_t)pid == proc_id){
261
const char **getargv(pid_t pid){
315
const char * const * getargv(pid_t pid){
263
317
char *cmdline_filename;
267
321
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
270
error(0, errno, "asprintf");
324
error_plus(0, errno, "asprintf");
289
343
if(cmdline_len + blocksize > cmdline_allocated){
290
344
tmp = realloc(cmdline, cmdline_allocated + blocksize);
292
error(0, errno, "realloc");
346
error_plus(0, errno, "realloc");
302
356
sret = read(cl_fd, cmdline + cmdline_len,
303
357
cmdline_allocated - cmdline_len);
305
error(0, errno, "read");
359
error_plus(0, errno, "read");
320
374
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
321
375
* sizeof(char *)); /* Get number of args */
322
376
if(argv == NULL){
323
error(0, errno, "argv = malloc()");
377
error_plus(0, errno, "argv = malloc()");
327
381
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
328
return (const char **)argv;
382
return (const char * const *)argv;
331
385
int main(__attribute__((unused))int argc,
353
407
*sig != 0; sig++){
354
408
ret = sigaddset(&new_action.sa_mask, *sig);
356
error(EX_OSERR, errno, "sigaddset");
410
error_plus(EX_OSERR, errno, "sigaddset");
358
412
ret = sigaction(*sig, NULL, &old_action);
360
error(EX_OSERR, errno, "sigaction");
414
error_plus(EX_OSERR, errno, "sigaction");
362
416
if(old_action.sa_handler != SIG_IGN){
363
417
ret = sigaction(*sig, &new_action, NULL);
365
error(EX_OSERR, errno, "sigaction");
419
error_plus(EX_OSERR, errno, "sigaction");
387
441
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
390
error(EX_OSERR, errno, "asprintf");
444
error_plus(EX_OSERR, errno, "asprintf");
393
447
/* plymouth ask-for-password --prompt="$prompt" */
407
461
kill_and_wait(plymouth_command_pid);
409
const char **plymouthd_argv;
463
const char * const *plymouthd_argv;
410
464
pid_t pid = get_pid();
412
error(0, 0, "plymouthd pid not found");
466
error_plus(0, 0, "plymouthd pid not found");
413
467
plymouthd_argv = plymouthd_default_argv;
415
469
plymouthd_argv = getargv(pid);