37
36
#include <stddef.h> /* NULL */
38
37
#include <string.h> /* strlen(), memcmp() */
39
#include <stdio.h> /* asprintf(), perror(), sscanf() */
38
#include <stdio.h> /* asprintf(), perror() */
40
39
#include <unistd.h> /* close(), write(), readlink(),
41
40
read(), STDOUT_FILENO, sleep(),
42
41
fork(), setuid(), geteuid(),
43
42
setsid(), chdir(), dup2(),
44
43
STDERR_FILENO, execv() */
45
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit() */
47
#include <stdlib.h> /* getenv() */
45
EXIT_SUCCESS, malloc(), _exit(),
48
47
#include <dirent.h> /* opendir(), readdir(), closedir() */
49
#include <inttypes.h> /* intmax_t, SCNdMAX */
48
#include <inttypes.h> /* intmax_t, strtoimax() */
50
49
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
50
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
52
sig_atomic_t interrupted_by_signal = 0;
54
const char usplash_name[] = "/sbin/usplash";
54
static void termination_handler(__attribute__((unused))int signum){
56
static void termination_handler(int signum){
57
if(interrupted_by_signal){
55
60
interrupted_by_signal = 1;
61
signal_received = signum;
58
static bool usplash_write(const char *cmd, const char *arg){
64
static bool usplash_write(int *fifo_fd_r,
65
const char *cmd, const char *arg){
60
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
61
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
67
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
68
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
68
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
69
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
74
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
72
}while(fifo_fd == -1);
74
81
const char *cmd_line;
75
82
size_t cmd_line_len;
76
83
char *cmd_line_alloc = NULL;
79
cmd_line_len = strlen(cmd);
86
cmd_line_len = strlen(cmd) + 1;
82
89
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
83
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
92
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
90
97
cmd_line = cmd_line_alloc;
91
98
cmd_line_len = (size_t)ret + 1;
94
101
size_t written = 0;
96
while(not interrupted_by_signal and written < cmd_line_len){
97
sret = write(fifo_fd, cmd_line + written,
103
while(written < cmd_line_len){
104
sret = write(*fifo_fd_r, cmd_line + written,
98
105
cmd_line_len - written);
100
if(errno != EINTR or interrupted_by_signal){
103
free(cmd_line_alloc);
108
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
109
free(cmd_line_alloc);
110
113
written += (size_t)sret;
112
115
free(cmd_line_alloc);
114
ret = close(fifo_fd);
115
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
119
if(interrupted_by_signal){
120
/* Create prompt string */
121
char *makeprompt(void){
124
const char *const cryptsource = getenv("cryptsource");
125
const char *const crypttarget = getenv("crypttarget");
126
const char prompt_start[] = "Enter passphrase to unlock the disk";
128
if(cryptsource == NULL){
129
if(crypttarget == NULL){
130
ret = asprintf(&prompt, "%s: ", prompt_start);
132
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
136
if(crypttarget == NULL){
137
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
139
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
140
cryptsource, crypttarget);
149
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
152
char *cmdline = NULL;
153
size_t cmdline_len = 0;
154
DIR *proc_dir = opendir("/proc");
155
if(proc_dir == NULL){
160
for(struct dirent *proc_ent = readdir(proc_dir);
162
proc_ent = readdir(proc_dir)){
167
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
168
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
169
or tmpmax != (pid_t)tmpmax){
176
/* Find the executable name by doing readlink() on the
177
/proc/<pid>/exe link */
178
char exe_target[sizeof(usplash_name)];
180
/* create file name string */
182
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
185
goto fail_find_usplash;
188
/* Check that it refers to a symlink owned by root:root */
189
struct stat exe_stat;
190
ret = lstat(exe_link, &exe_stat);
198
goto fail_find_usplash;
200
if(not S_ISLNK(exe_stat.st_mode)
201
or exe_stat.st_uid != 0
202
or exe_stat.st_gid != 0){
207
sret = readlink(exe_link, exe_target, sizeof(exe_target));
210
/* Compare executable name */
211
if((sret != ((ssize_t)sizeof(exe_target)-1))
212
or (memcmp(usplash_name, exe_target,
213
sizeof(exe_target)-1) != 0)){
218
/* Read and save the command line of usplash in "cmdline" */
220
/* Open /proc/<pid>/cmdline */
223
char *cmdline_filename;
224
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
228
goto fail_find_usplash;
230
cl_fd = open(cmdline_filename, O_RDONLY);
231
free(cmdline_filename);
234
goto fail_find_usplash;
237
size_t cmdline_allocated = 0;
239
const size_t blocksize = 1024;
241
/* Allocate more space? */
242
if(cmdline_len + blocksize > cmdline_allocated){
243
tmp = realloc(cmdline, cmdline_allocated + blocksize);
247
goto fail_find_usplash;
250
cmdline_allocated += blocksize;
253
sret = read(cl_fd, cmdline + cmdline_len,
254
cmdline_allocated - cmdline_len);
258
goto fail_find_usplash;
260
cmdline_len += (size_t)sret;
265
goto fail_find_usplash;
268
/* Close directory */
269
ret = closedir(proc_dir);
272
goto fail_find_usplash;
275
*cmdline_r = cmdline;
276
*cmdline_len_r = cmdline_len;
283
if(proc_dir != NULL){
125
291
int main(__attribute__((unused))int argc,
126
292
__attribute__((unused))char **argv){
129
bool an_error_occured = false;
299
pid_t usplash_pid = -1;
300
bool usplash_accessed = false;
301
int status = EXIT_FAILURE; /* Default failure exit status */
131
/* Create prompt string */
134
const char *const cryptsource = getenv("cryptsource");
135
const char *const crypttarget = getenv("crypttarget");
136
const char prompt_start[] = "Enter passphrase to unlock the disk";
138
if(cryptsource == NULL){
139
if(crypttarget == NULL){
140
ret = asprintf(&prompt, "%s: ", prompt_start);
142
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
146
if(crypttarget == NULL){
147
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
149
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
150
cryptsource, crypttarget);
303
char *prompt = makeprompt();
158
309
/* Find usplash process */
159
pid_t usplash_pid = 0;
160
310
char *cmdline = NULL;
161
311
size_t cmdline_len = 0;
162
const char usplash_name[] = "/sbin/usplash";
164
DIR *proc_dir = opendir("/proc");
165
if(proc_dir == NULL){
170
for(struct dirent *proc_ent = readdir(proc_dir);
172
proc_ent = readdir(proc_dir)){
177
ret = sscanf(proc_ent->d_name, "%" SCNdMAX "%n", &tmpmax,
179
if(ret < 1 or tmpmax != (pid_t)tmpmax
180
or proc_ent->d_name[numchars] != '\0'){
186
/* Find the executable name by doing readlink() on the
187
/proc/<pid>/exe link */
188
char exe_target[sizeof(usplash_name)];
190
/* create file name string */
192
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
200
/* Check that it refers to a symlink owned by root:root */
201
struct stat exe_stat;
202
ret = lstat(exe_link, &exe_stat);
214
if(not S_ISLNK(exe_stat.st_mode)
215
or exe_stat.st_uid != 0
216
or exe_stat.st_gid != 0){
221
sret = readlink(exe_link, exe_target, sizeof(exe_target));
224
if((sret == ((ssize_t)sizeof(exe_target)-1))
225
and (memcmp(usplash_name, exe_target,
226
sizeof(exe_target)-1) == 0)){
228
/* Read and save the command line of usplash in "cmdline" */
230
/* Open /proc/<pid>/cmdline */
233
char *cmdline_filename;
234
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
242
cl_fd = open(cmdline_filename, O_RDONLY);
245
free(cmdline_filename);
250
free(cmdline_filename);
252
size_t cmdline_allocated = 0;
254
const size_t blocksize = 1024;
256
if(cmdline_len + blocksize > cmdline_allocated){
257
tmp = realloc(cmdline, cmdline_allocated + blocksize);
266
cmdline_allocated += blocksize;
268
sret = read(cl_fd, cmdline + cmdline_len,
269
cmdline_allocated - cmdline_len);
277
cmdline_len += (size_t)sret;
312
usplash_pid = find_usplash(&cmdline, &cmdline_len);
286
313
if(usplash_pid == 0){
314
status = EX_UNAVAILABLE;
291
318
/* Set up the signal handler */
294
321
new_action = { .sa_handler = termination_handler,
296
323
sigemptyset(&new_action.sa_mask);
297
sigaddset(&new_action.sa_mask, SIGINT);
298
sigaddset(&new_action.sa_mask, SIGHUP);
299
sigaddset(&new_action.sa_mask, SIGTERM);
324
ret = sigaddset(&new_action.sa_mask, SIGINT);
330
ret = sigaddset(&new_action.sa_mask, SIGHUP);
336
ret = sigaddset(&new_action.sa_mask, SIGTERM);
300
342
ret = sigaction(SIGINT, NULL, &old_action);
306
350
if(old_action.sa_handler != SIG_IGN){
307
351
ret = sigaction(SIGINT, &new_action, NULL);
314
360
ret = sigaction(SIGHUP, NULL, &old_action);
320
368
if(old_action.sa_handler != SIG_IGN){
321
369
ret = sigaction(SIGHUP, &new_action, NULL);
328
378
ret = sigaction(SIGTERM, NULL, &old_action);
334
386
if(old_action.sa_handler != SIG_IGN){
335
387
ret = sigaction(SIGTERM, &new_action, NULL);
398
usplash_accessed = true;
344
399
/* Write command to FIFO */
345
if(not interrupted_by_signal){
346
if(not usplash_write("TIMEOUT", "0")
347
and (errno != EINTR)){
348
perror("usplash_write");
349
an_error_occured = true;
352
if(not interrupted_by_signal and not an_error_occured){
353
if(not usplash_write("INPUTQUIET", prompt)
354
and (errno != EINTR)){
355
perror("usplash_write");
356
an_error_occured = true;
400
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
402
perror("usplash_write");
408
if(interrupted_by_signal){
412
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
414
perror("usplash_write");
420
if(interrupted_by_signal){
361
/* This is not really a loop; while() is used to be able to "break"
362
out of it; those breaks are marked "Big" */
363
while(not interrupted_by_signal and not an_error_occured){
370
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
427
/* Read reply from usplash */
429
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
430
if(outfifo_fd == -1){
438
if(interrupted_by_signal){
443
size_t buf_allocated = 0;
444
const size_t blocksize = 1024;
446
/* Allocate more space */
447
if(buf_len + blocksize > buf_allocated){
448
char *tmp = realloc(buf, buf_allocated + blocksize);
372
450
if(errno != EINTR){
374
an_error_occured = true;
377
if(interrupted_by_signal){
381
}while(fifo_fd == -1);
382
if(interrupted_by_signal or an_error_occured){
387
size_t buf_allocated = 0;
388
const size_t blocksize = 1024;
390
if(buf_len + blocksize > buf_allocated){
391
char *tmp = realloc(buf, buf_allocated + blocksize);
393
451
perror("realloc");
394
an_error_occured = true;
398
buf_allocated += blocksize;
401
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
405
an_error_occured = true;
408
if(interrupted_by_signal){
413
if(interrupted_by_signal or an_error_occured){
417
buf_len += (size_t)sret;
420
if(interrupted_by_signal or an_error_occured){
424
if(not usplash_write("TIMEOUT", "15")
425
and (errno != EINTR)){
426
perror("usplash_write");
427
an_error_occured = true;
429
if(interrupted_by_signal or an_error_occured){
433
/* Print password to stdout */
435
while(written < buf_len){
437
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
441
an_error_occured = true;
444
if(interrupted_by_signal){
449
if(interrupted_by_signal or an_error_occured){
452
written += (size_t)sret;
455
if(not interrupted_by_signal and not an_error_occured){
460
} /* end of non-loop while() */
462
/* If we got here, an error or interrupt must have happened */
457
buf_allocated += blocksize;
459
sret = read(outfifo_fd, buf + buf_len,
460
buf_allocated - buf_len);
466
TEMP_FAILURE_RETRY(close(outfifo_fd));
469
if(interrupted_by_signal){
473
buf_len += (size_t)sret;
475
ret = close(outfifo_fd);
485
if(interrupted_by_signal){
489
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
491
perror("usplash_write");
497
if(interrupted_by_signal){
501
ret = close(fifo_fd);
511
/* Print password to stdout */
513
while(written < buf_len){
515
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
525
if(interrupted_by_signal){
528
written += (size_t)sret;
533
if(interrupted_by_signal){
546
/* If usplash was never accessed, we can stop now */
547
if(not usplash_accessed){
553
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
554
if(ret == -1 and errno != EINTR){
560
/* Close output FIFO */
561
if(outfifo_fd != -1){
562
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
464
568
/* Create argc and argv for new usplash*/
465
569
int cmdline_argc = 0;