41
42
fork(), setuid(), geteuid(),
42
43
setsid(), chdir(), dup2(),
43
44
STDERR_FILENO, execv() */
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit() */
45
#include <stdlib.h> /* free(), EXIT_FAILURE, strtoul(),
46
realloc(), EXIT_SUCCESS, malloc(),
46
48
#include <stdlib.h> /* getenv() */
47
49
#include <dirent.h> /* opendir(), readdir(), closedir() */
48
#include <inttypes.h> /* intmax_t, strtoimax() */
49
50
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
51
52
sig_atomic_t interrupted_by_signal = 0;
53
const char usplash_name[] = "/sbin/usplash";
55
static void termination_handler(int signum){
56
if(interrupted_by_signal){
54
static void termination_handler(__attribute__((unused))int signum){
59
55
interrupted_by_signal = 1;
60
signal_received = signum;
63
static bool usplash_write(int *fifo_fd_r,
64
const char *cmd, const char *arg){
58
static bool usplash_write(const char *cmd, const char *arg){
66
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
67
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
60
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
61
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
73
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
68
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
69
if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
72
}while(fifo_fd == -1);
80
74
const char *cmd_line;
81
75
size_t cmd_line_len;
82
76
char *cmd_line_alloc = NULL;
85
cmd_line_len = strlen(cmd) + 1;
79
cmd_line_len = strlen(cmd);
88
82
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
83
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
91
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
96
90
cmd_line = cmd_line_alloc;
97
91
cmd_line_len = (size_t)ret + 1;
100
94
size_t written = 0;
102
while(written < cmd_line_len){
103
sret = write(*fifo_fd_r, cmd_line + written,
96
while(not interrupted_by_signal and written < cmd_line_len){
97
sret = write(fifo_fd, cmd_line + written,
104
98
cmd_line_len - written);
107
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
108
free(cmd_line_alloc);
100
if(errno != EINTR or interrupted_by_signal){
103
free(cmd_line_alloc);
112
110
written += (size_t)sret;
114
112
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){
119
/* Create prompt string */
120
char *makeprompt(void){
123
const char *const cryptsource = getenv("cryptsource");
124
const char *const crypttarget = getenv("crypttarget");
125
const char prompt_start[] = "Enter passphrase to unlock the disk";
127
if(cryptsource == NULL){
128
if(crypttarget == NULL){
129
ret = asprintf(&prompt, "%s: ", prompt_start);
131
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
135
if(crypttarget == NULL){
136
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
138
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
139
cryptsource, crypttarget);
148
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
125
int main(__attribute__((unused))int argc,
126
__attribute__((unused))char **argv){
129
bool an_error_occured = false;
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);
158
/* Find usplash process */
159
pid_t usplash_pid = 0;
151
160
char *cmdline = NULL;
152
161
size_t cmdline_len = 0;
153
DIR *proc_dir = opendir("/proc");
154
if(proc_dir == NULL){
159
for(struct dirent *proc_ent = readdir(proc_dir);
161
proc_ent = readdir(proc_dir)){
166
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
167
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
168
or tmpmax != (pid_t)tmpmax){
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)){
173
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
169
175
/* Not a process */
175
/* Find the executable name by doing readlink() on the
176
/proc/<pid>/exe link */
177
char exe_target[sizeof(usplash_name)];
179
/* create file name string */
181
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
184
goto fail_find_usplash;
187
/* Check that it refers to a symlink owned by root:root */
188
struct stat exe_stat;
189
ret = lstat(exe_link, &exe_stat);
197
goto fail_find_usplash;
199
if(not S_ISLNK(exe_stat.st_mode)
200
or exe_stat.st_uid != 0
201
or exe_stat.st_gid != 0){
206
sret = readlink(exe_link, exe_target, sizeof(exe_target));
209
/* Compare executable name */
210
if((sret != ((ssize_t)sizeof(exe_target)-1))
211
or (memcmp(usplash_name, exe_target,
212
sizeof(exe_target)-1) != 0)){
217
/* Read and save the command line of usplash in "cmdline" */
219
/* Open /proc/<pid>/cmdline */
178
/* Find the executable name by doing readlink() on the
179
/proc/<pid>/exe link */
180
char exe_target[sizeof(usplash_name)];
222
char *cmdline_filename;
223
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
182
/* create file name string */
184
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
226
186
perror("asprintf");
227
goto fail_find_usplash;
229
cl_fd = open(cmdline_filename, O_RDONLY);
230
free(cmdline_filename);
233
goto fail_find_usplash;
192
/* Check that it refers to a symlink owned by root:root */
193
struct stat exe_stat;
194
ret = lstat(exe_link, &exe_stat);
202
if(not S_ISLNK(exe_stat.st_mode)
203
or exe_stat.st_uid != 0
204
or exe_stat.st_gid != 0){
209
sret = readlink(exe_link, exe_target, sizeof(exe_target));
236
size_t cmdline_allocated = 0;
238
const size_t blocksize = 1024;
240
/* Allocate more space? */
241
if(cmdline_len + blocksize > cmdline_allocated){
242
tmp = realloc(cmdline, cmdline_allocated + blocksize);
246
goto fail_find_usplash;
215
if((sret == ((ssize_t)sizeof(exe_target)-1))
216
and (memcmp(usplash_name, exe_target,
217
sizeof(exe_target)-1) == 0)){
219
/* Read and save the command line of usplash in "cmdline" */
221
/* Open /proc/<pid>/cmdline */
224
char *cmdline_filename;
225
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
233
cl_fd = open(cmdline_filename, O_RDONLY);
236
free(cmdline_filename);
241
free(cmdline_filename);
249
cmdline_allocated += blocksize;
252
sret = read(cl_fd, cmdline + cmdline_len,
253
cmdline_allocated - cmdline_len);
243
size_t cmdline_allocated = 0;
245
const size_t blocksize = 1024;
247
if(cmdline_len + blocksize > cmdline_allocated){
248
tmp = realloc(cmdline, cmdline_allocated + blocksize);
257
cmdline_allocated += blocksize;
259
sret = read(cl_fd, cmdline + cmdline_len,
260
cmdline_allocated - cmdline_len);
268
cmdline_len += (size_t)sret;
257
goto fail_find_usplash;
259
cmdline_len += (size_t)sret;
264
goto fail_find_usplash;
267
/* Close directory */
268
ret = closedir(proc_dir);
271
goto fail_find_usplash;
274
*cmdline_r = cmdline;
275
*cmdline_len_r = cmdline_len;
282
if(proc_dir != NULL){
284
275
closedir(proc_dir);
290
int main(__attribute__((unused))int argc,
291
__attribute__((unused))char **argv){
298
pid_t usplash_pid = -1;
299
bool usplash_accessed = false;
301
char *prompt = makeprompt();
306
/* Find usplash process */
307
char *cmdline = NULL;
308
size_t cmdline_len = 0;
309
usplash_pid = find_usplash(&cmdline, &cmdline_len);
310
277
if(usplash_pid == 0){
314
282
/* Set up the signal handler */
317
285
new_action = { .sa_handler = termination_handler,
319
287
sigemptyset(&new_action.sa_mask);
320
ret = sigaddset(&new_action.sa_mask, SIGINT);
325
ret = sigaddset(&new_action.sa_mask, SIGHUP);
330
ret = sigaddset(&new_action.sa_mask, SIGTERM);
288
sigaddset(&new_action.sa_mask, SIGINT);
289
sigaddset(&new_action.sa_mask, SIGHUP);
290
sigaddset(&new_action.sa_mask, SIGTERM);
335
291
ret = sigaction(SIGINT, NULL, &old_action);
342
297
if(old_action.sa_handler != SIG_IGN){
343
298
ret = sigaction(SIGINT, &new_action, NULL);
351
305
ret = sigaction(SIGHUP, NULL, &old_action);
358
311
if(old_action.sa_handler != SIG_IGN){
359
312
ret = sigaction(SIGHUP, &new_action, NULL);
367
319
ret = sigaction(SIGTERM, NULL, &old_action);
374
325
if(old_action.sa_handler != SIG_IGN){
375
326
ret = sigaction(SIGTERM, &new_action, NULL);
385
usplash_accessed = true;
386
335
/* Write command to FIFO */
387
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
389
perror("usplash_write");
394
if(interrupted_by_signal){
398
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
400
perror("usplash_write");
405
if(interrupted_by_signal){
336
if(not interrupted_by_signal){
337
if(not usplash_write("TIMEOUT", "0")
338
and (errno != EINTR)){
339
perror("usplash_write");
340
an_error_occured = true;
343
if(not interrupted_by_signal and not an_error_occured){
344
if(not usplash_write("INPUTQUIET", prompt)
345
and (errno != EINTR)){
346
perror("usplash_write");
347
an_error_occured = true;
412
/* Read reply from usplash */
414
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
415
if(outfifo_fd == -1){
422
if(interrupted_by_signal){
427
size_t buf_allocated = 0;
428
const size_t blocksize = 1024;
430
/* Allocate more space */
431
if(buf_len + blocksize > buf_allocated){
432
char *tmp = realloc(buf, buf_allocated + blocksize);
352
/* This is not really a loop; while() is used to be able to "break"
353
out of it; those breaks are marked "Big" */
354
while(not interrupted_by_signal and not an_error_occured){
361
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
434
363
if(errno != EINTR){
365
an_error_occured = true;
368
if(interrupted_by_signal){
372
}while(fifo_fd == -1);
373
if(interrupted_by_signal or an_error_occured){
378
size_t buf_allocated = 0;
379
const size_t blocksize = 1024;
381
if(buf_len + blocksize > buf_allocated){
382
char *tmp = realloc(buf, buf_allocated + blocksize);
435
384
perror("realloc");
440
buf_allocated += blocksize;
442
sret = read(outfifo_fd, buf + buf_len,
443
buf_allocated - buf_len);
448
TEMP_FAILURE_RETRY(close(outfifo_fd));
451
if(interrupted_by_signal){
455
buf_len += (size_t)sret;
457
ret = close(outfifo_fd);
466
if(interrupted_by_signal){
470
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
472
perror("usplash_write");
477
if(interrupted_by_signal){
481
ret = close(fifo_fd);
490
/* Print password to stdout */
492
while(written < buf_len){
494
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
503
if(interrupted_by_signal){
506
written += (size_t)sret;
511
if(interrupted_by_signal){
524
/* If usplash was never accessed, we can stop now */
525
if(not usplash_accessed){
531
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
532
if(ret == -1 and errno != EINTR){
538
/* Close output FIFO */
539
if(outfifo_fd != -1){
540
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
385
an_error_occured = true;
389
buf_allocated += blocksize;
392
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
396
an_error_occured = true;
399
if(interrupted_by_signal){
404
if(interrupted_by_signal or an_error_occured){
408
buf_len += (size_t)sret;
411
if(interrupted_by_signal or an_error_occured){
415
if(not usplash_write("TIMEOUT", "15")
416
and (errno != EINTR)){
417
perror("usplash_write");
418
an_error_occured = true;
420
if(interrupted_by_signal or an_error_occured){
424
/* Print password to stdout */
426
while(written < buf_len){
428
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
432
an_error_occured = true;
435
if(interrupted_by_signal){
440
if(interrupted_by_signal or an_error_occured){
443
written += (size_t)sret;
446
if(not interrupted_by_signal and not an_error_occured){
451
} /* end of non-loop while() */
453
/* If we got here, an error or interrupt must have happened */
546
455
/* Create argc and argv for new usplash*/
547
456
int cmdline_argc = 0;