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 */
50
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
52
sig_atomic_t interrupted_by_signal = 0;
54
const char usplash_name[] = "/sbin/usplash";
56
static void termination_handler(int signum){
57
if(interrupted_by_signal){
54
static void termination_handler(__attribute__((unused))int signum){
60
55
interrupted_by_signal = 1;
61
signal_received = signum;
64
static bool usplash_write(int *fifo_fd_r,
65
const char *cmd, const char *arg){
58
static bool usplash_write(const char *cmd, const char *arg){
67
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
68
* 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"
74
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);
81
74
const char *cmd_line;
82
75
size_t cmd_line_len;
83
76
char *cmd_line_alloc = NULL;
86
cmd_line_len = strlen(cmd) + 1;
79
cmd_line_len = strlen(cmd);
89
82
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));
97
90
cmd_line = cmd_line_alloc;
98
91
cmd_line_len = (size_t)ret + 1;
101
94
size_t written = 0;
103
while(written < cmd_line_len){
104
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,
105
98
cmd_line_len - written);
108
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
109
free(cmd_line_alloc);
100
if(errno != EINTR or interrupted_by_signal){
103
free(cmd_line_alloc);
113
110
written += (size_t)sret;
115
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){
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){
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;
152
160
char *cmdline = NULL;
153
161
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){
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);
170
175
/* Not a process */
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 */
178
/* Find the executable name by doing readlink() on the
179
/proc/<pid>/exe link */
180
char exe_target[sizeof(usplash_name)];
223
char *cmdline_filename;
224
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
182
/* create file name string */
184
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
227
186
perror("asprintf");
228
goto fail_find_usplash;
230
cl_fd = open(cmdline_filename, O_RDONLY);
231
free(cmdline_filename);
234
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);
206
if(not S_ISLNK(exe_stat.st_mode)
207
or exe_stat.st_uid != 0
208
or exe_stat.st_gid != 0){
213
sret = readlink(exe_link, exe_target, sizeof(exe_target));
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;
216
if((sret == ((ssize_t)sizeof(exe_target)-1))
217
and (memcmp(usplash_name, exe_target,
218
sizeof(exe_target)-1) == 0)){
220
/* Read and save the command line of usplash in "cmdline" */
222
/* Open /proc/<pid>/cmdline */
225
char *cmdline_filename;
226
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
234
cl_fd = open(cmdline_filename, O_RDONLY);
237
free(cmdline_filename);
242
free(cmdline_filename);
250
cmdline_allocated += blocksize;
253
sret = read(cl_fd, cmdline + cmdline_len,
254
cmdline_allocated - cmdline_len);
244
size_t cmdline_allocated = 0;
246
const size_t blocksize = 1024;
248
if(cmdline_len + blocksize > cmdline_allocated){
249
tmp = realloc(cmdline, cmdline_allocated + blocksize);
258
cmdline_allocated += blocksize;
260
sret = read(cl_fd, cmdline + cmdline_len,
261
cmdline_allocated - cmdline_len);
269
cmdline_len += (size_t)sret;
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){
285
276
closedir(proc_dir);
291
int main(__attribute__((unused))int argc,
292
__attribute__((unused))char **argv){
299
pid_t usplash_pid = -1;
300
bool usplash_accessed = false;
301
int status = EXIT_FAILURE; /* Default failure exit status */
303
char *prompt = makeprompt();
309
/* Find usplash process */
310
char *cmdline = NULL;
311
size_t cmdline_len = 0;
312
usplash_pid = find_usplash(&cmdline, &cmdline_len);
313
278
if(usplash_pid == 0){
314
status = EX_UNAVAILABLE;
318
283
/* Set up the signal handler */
321
286
new_action = { .sa_handler = termination_handler,
323
288
sigemptyset(&new_action.sa_mask);
324
ret = sigaddset(&new_action.sa_mask, SIGINT);
330
ret = sigaddset(&new_action.sa_mask, SIGHUP);
336
ret = sigaddset(&new_action.sa_mask, SIGTERM);
289
sigaddset(&new_action.sa_mask, SIGINT);
290
sigaddset(&new_action.sa_mask, SIGHUP);
291
sigaddset(&new_action.sa_mask, SIGTERM);
342
292
ret = sigaction(SIGINT, NULL, &old_action);
350
298
if(old_action.sa_handler != SIG_IGN){
351
299
ret = sigaction(SIGINT, &new_action, NULL);
360
306
ret = sigaction(SIGHUP, NULL, &old_action);
368
312
if(old_action.sa_handler != SIG_IGN){
369
313
ret = sigaction(SIGHUP, &new_action, NULL);
378
320
ret = sigaction(SIGTERM, NULL, &old_action);
386
326
if(old_action.sa_handler != SIG_IGN){
387
327
ret = sigaction(SIGTERM, &new_action, NULL);
398
usplash_accessed = true;
399
336
/* Write command to FIFO */
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){
337
if(not interrupted_by_signal){
338
if(not usplash_write("TIMEOUT", "0")
339
and (errno != EINTR)){
340
perror("usplash_write");
341
an_error_occured = true;
344
if(not interrupted_by_signal and not an_error_occured){
345
if(not usplash_write("INPUTQUIET", prompt)
346
and (errno != EINTR)){
347
perror("usplash_write");
348
an_error_occured = true;
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);
353
/* This is not really a loop; while() is used to be able to "break"
354
out of it; those breaks are marked "Big" */
355
while(not interrupted_by_signal and not an_error_occured){
362
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
450
364
if(errno != EINTR){
366
an_error_occured = true;
369
if(interrupted_by_signal){
373
}while(fifo_fd == -1);
374
if(interrupted_by_signal or an_error_occured){
379
size_t buf_allocated = 0;
380
const size_t blocksize = 1024;
382
if(buf_len + blocksize > buf_allocated){
383
char *tmp = realloc(buf, buf_allocated + blocksize);
451
385
perror("realloc");
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));
386
an_error_occured = true;
390
buf_allocated += blocksize;
393
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
397
an_error_occured = true;
400
if(interrupted_by_signal){
405
if(interrupted_by_signal or an_error_occured){
409
buf_len += (size_t)sret;
412
if(interrupted_by_signal or an_error_occured){
416
if(not usplash_write("TIMEOUT", "15")
417
and (errno != EINTR)){
418
perror("usplash_write");
419
an_error_occured = true;
421
if(interrupted_by_signal or an_error_occured){
425
/* Print password to stdout */
427
while(written < buf_len){
429
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
433
an_error_occured = true;
436
if(interrupted_by_signal){
441
if(interrupted_by_signal or an_error_occured){
444
written += (size_t)sret;
447
if(not interrupted_by_signal and not an_error_occured){
452
} /* end of non-loop while() */
454
/* If we got here, an error or interrupt must have happened */
568
456
/* Create argc and argv for new usplash*/
569
457
int cmdline_argc = 0;