32
31
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
33
32
#include <iso646.h> /* and, or, not*/
34
33
#include <errno.h> /* errno, EINTR */
35
35
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
37
37
#include <stddef.h> /* NULL */
38
#include <string.h> /* strlen(), memcmp() */
39
#include <stdio.h> /* asprintf(), perror() */
38
#include <string.h> /* strlen(), memcmp(), strerror() */
39
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(), fprintf() */
40
40
#include <unistd.h> /* close(), write(), readlink(),
41
41
read(), STDOUT_FILENO, sleep(),
42
42
fork(), setuid(), geteuid(),
43
43
setsid(), chdir(), dup2(),
44
44
STDERR_FILENO, execv() */
45
45
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
46
EXIT_SUCCESS, malloc(), _exit() */
47
#include <stdlib.h> /* getenv() */
46
EXIT_SUCCESS, malloc(), _exit(),
48
48
#include <dirent.h> /* opendir(), readdir(), closedir() */
49
49
#include <inttypes.h> /* intmax_t, strtoimax() */
50
50
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
51
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
52
#include <argz.h> /* argz_count(), argz_extract() */
53
#include <stdarg.h> /* va_list, va_start(), ... */
52
55
sig_atomic_t interrupted_by_signal = 0;
54
static void termination_handler(__attribute__((unused))int signum){
57
const char usplash_name[] = "/sbin/usplash";
59
/* Function to use when printing errors */
60
void error_plus(int status, int errnum, const char *formatstring, ...){
65
va_start(ap, formatstring);
66
ret = vasprintf(&text, formatstring, ap);
68
fprintf(stderr, "Mandos plugin %s: ", program_invocation_short_name);
69
vfprintf(stderr, formatstring, ap);
70
fprintf(stderr, ": ");
71
fprintf(stderr, "%s\n", strerror(errnum));
72
error(status, errno, "vasprintf while printing error");
75
fprintf(stderr, "Mandos plugin ");
76
error(status, errnum, "%s", text);
80
static void termination_handler(int signum){
81
if(interrupted_by_signal){
55
84
interrupted_by_signal = 1;
85
signal_received = signum;
58
static bool usplash_write(const char *cmd, const char *arg){
88
static bool usplash_write(int *fifo_fd_r,
89
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"
91
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
92
* 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)){
98
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
72
}while(fifo_fd == -1);
74
105
const char *cmd_line;
75
106
size_t cmd_line_len;
76
107
char *cmd_line_alloc = NULL;
79
cmd_line_len = strlen(cmd);
110
cmd_line_len = strlen(cmd) + 1;
82
113
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
83
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
116
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
90
121
cmd_line = cmd_line_alloc;
91
122
cmd_line_len = (size_t)ret + 1;
94
125
size_t written = 0;
96
while(not interrupted_by_signal and written < cmd_line_len){
97
sret = write(fifo_fd, cmd_line + written,
127
while(written < cmd_line_len){
128
sret = write(*fifo_fd_r, cmd_line + written,
98
129
cmd_line_len - written);
100
if(errno != EINTR or interrupted_by_signal){
103
free(cmd_line_alloc);
132
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
133
free(cmd_line_alloc);
110
137
written += (size_t)sret;
112
139
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){
144
/* Create prompt string */
145
char *makeprompt(void){
148
const char *const cryptsource = getenv("cryptsource");
149
const char *const crypttarget = getenv("crypttarget");
150
const char prompt_start[] = "Enter passphrase to unlock the disk";
152
if(cryptsource == NULL){
153
if(crypttarget == NULL){
154
ret = asprintf(&prompt, "%s: ", prompt_start);
156
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
160
if(crypttarget == NULL){
161
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
163
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
164
cryptsource, crypttarget);
173
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
176
char *cmdline = NULL;
177
size_t cmdline_len = 0;
178
DIR *proc_dir = opendir("/proc");
179
if(proc_dir == NULL){
180
error_plus(0, errno, "opendir");
184
for(struct dirent *proc_ent = readdir(proc_dir);
186
proc_ent = readdir(proc_dir)){
191
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
192
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
193
or tmpmax != (pid_t)tmpmax){
200
/* Find the executable name by doing readlink() on the
201
/proc/<pid>/exe link */
202
char exe_target[sizeof(usplash_name)];
204
/* create file name string */
206
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
208
error_plus(0, errno, "asprintf");
209
goto fail_find_usplash;
212
/* Check that it refers to a symlink owned by root:root */
213
struct stat exe_stat;
214
ret = lstat(exe_link, &exe_stat);
220
error_plus(0, errno, "lstat");
222
goto fail_find_usplash;
224
if(not S_ISLNK(exe_stat.st_mode)
225
or exe_stat.st_uid != 0
226
or exe_stat.st_gid != 0){
231
sret = readlink(exe_link, exe_target, sizeof(exe_target));
234
/* Compare executable name */
235
if((sret != ((ssize_t)sizeof(exe_target)-1))
236
or (memcmp(usplash_name, exe_target,
237
sizeof(exe_target)-1) != 0)){
242
/* Read and save the command line of usplash in "cmdline" */
244
/* Open /proc/<pid>/cmdline */
247
char *cmdline_filename;
248
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
251
error_plus(0, errno, "asprintf");
252
goto fail_find_usplash;
254
cl_fd = open(cmdline_filename, O_RDONLY);
255
free(cmdline_filename);
257
error_plus(0, errno, "open");
258
goto fail_find_usplash;
261
size_t cmdline_allocated = 0;
263
const size_t blocksize = 1024;
265
/* Allocate more space? */
266
if(cmdline_len + blocksize > cmdline_allocated){
267
tmp = realloc(cmdline, cmdline_allocated + blocksize);
269
error_plus(0, errno, "realloc");
271
goto fail_find_usplash;
274
cmdline_allocated += blocksize;
277
sret = read(cl_fd, cmdline + cmdline_len,
278
cmdline_allocated - cmdline_len);
280
error_plus(0, errno, "read");
282
goto fail_find_usplash;
284
cmdline_len += (size_t)sret;
288
error_plus(0, errno, "close");
289
goto fail_find_usplash;
292
/* Close directory */
293
ret = closedir(proc_dir);
295
error_plus(0, errno, "closedir");
296
goto fail_find_usplash;
299
*cmdline_r = cmdline;
300
*cmdline_len_r = cmdline_len;
307
if(proc_dir != NULL){
125
315
int main(__attribute__((unused))int argc,
126
316
__attribute__((unused))char **argv){
129
bool an_error_occured = false;
323
pid_t usplash_pid = -1;
324
bool usplash_accessed = false;
325
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);
327
char *prompt = makeprompt();
158
333
/* Find usplash process */
159
pid_t usplash_pid = 0;
160
334
char *cmdline = NULL;
161
335
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)){
178
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
179
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
180
or tmpmax != (pid_t)tmpmax){
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;
336
usplash_pid = find_usplash(&cmdline, &cmdline_len);
286
337
if(usplash_pid == 0){
338
status = EX_UNAVAILABLE;
291
342
/* Set up the signal handler */
294
345
new_action = { .sa_handler = termination_handler,
296
347
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);
348
ret = sigaddset(&new_action.sa_mask, SIGINT);
350
error_plus(0, errno, "sigaddset");
354
ret = sigaddset(&new_action.sa_mask, SIGHUP);
356
error_plus(0, errno, "sigaddset");
360
ret = sigaddset(&new_action.sa_mask, SIGTERM);
362
error_plus(0, errno, "sigaddset");
300
366
ret = sigaction(SIGINT, NULL, &old_action);
369
error_plus(0, errno, "sigaction");
306
374
if(old_action.sa_handler != SIG_IGN){
307
375
ret = sigaction(SIGINT, &new_action, NULL);
378
error_plus(0, errno, "sigaction");
314
384
ret = sigaction(SIGHUP, NULL, &old_action);
387
error_plus(0, errno, "sigaction");
320
392
if(old_action.sa_handler != SIG_IGN){
321
393
ret = sigaction(SIGHUP, &new_action, NULL);
396
error_plus(0, errno, "sigaction");
328
402
ret = sigaction(SIGTERM, NULL, &old_action);
405
error_plus(0, errno, "sigaction");
334
410
if(old_action.sa_handler != SIG_IGN){
335
411
ret = sigaction(SIGTERM, &new_action, NULL);
414
error_plus(0, errno, "sigaction");
422
usplash_accessed = true;
344
423
/* 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;
424
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
426
error_plus(0, errno, "usplash_write");
432
if(interrupted_by_signal){
436
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
438
error_plus(0, errno, "usplash_write");
444
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);
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);
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 */
464
/* Create argc and argv for new usplash*/
465
int cmdline_argc = 0;
466
char **cmdline_argv = malloc(sizeof(char *));
469
while(position < cmdline_len){
470
char **tmp = realloc(cmdline_argv,
472
* (size_t)(cmdline_argc + 2)));
451
/* Read reply from usplash */
453
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
454
if(outfifo_fd == -1){
456
error_plus(0, errno, "open");
462
if(interrupted_by_signal){
467
size_t buf_allocated = 0;
468
const size_t blocksize = 1024;
470
/* Allocate more space */
471
if(buf_len + blocksize > buf_allocated){
472
char *tmp = realloc(buf, buf_allocated + blocksize);
479
cmdline_argv[cmdline_argc] = cmdline + position;
481
position += strlen(cmdline + position) + 1;
483
cmdline_argv[cmdline_argc] = NULL;
475
error_plus(0, errno, "realloc");
481
buf_allocated += blocksize;
483
sret = read(outfifo_fd, buf + buf_len,
484
buf_allocated - buf_len);
487
error_plus(0, errno, "read");
490
TEMP_FAILURE_RETRY(close(outfifo_fd));
493
if(interrupted_by_signal){
497
buf_len += (size_t)sret;
499
ret = close(outfifo_fd);
502
error_plus(0, errno, "close");
509
if(interrupted_by_signal){
513
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
515
error_plus(0, errno, "usplash_write");
521
if(interrupted_by_signal){
525
ret = close(fifo_fd);
528
error_plus(0, errno, "close");
535
/* Print password to stdout */
537
while(written < buf_len){
539
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
542
error_plus(0, errno, "write");
549
if(interrupted_by_signal){
552
written += (size_t)sret;
557
if(interrupted_by_signal){
570
/* If usplash was never accessed, we can stop now */
571
if(not usplash_accessed){
577
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
578
if(ret == -1 and errno != EINTR){
579
error_plus(0, errno, "close");
584
/* Close output FIFO */
585
if(outfifo_fd != -1){
586
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
588
error_plus(0, errno, "close");
592
/* Create argv for new usplash*/
593
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
594
* sizeof(char *)); /* Count args */
595
if(cmdline_argv == NULL){
596
error_plus(0, errno, "malloc");
599
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
485
601
/* Kill old usplash */
486
602
kill(usplash_pid, SIGTERM);