31
31
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
32
32
#include <iso646.h> /* and, or, not*/
33
33
#include <errno.h> /* errno, EINTR */
34
35
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
36
37
#include <stddef.h> /* NULL */
37
#include <string.h> /* strlen(), memcmp() */
38
#include <stdio.h> /* asprintf(), perror() */
38
#include <string.h> /* strlen(), memcmp(), strerror() */
39
#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
39
41
#include <unistd.h> /* close(), write(), readlink(),
40
42
read(), STDOUT_FILENO, sleep(),
41
43
fork(), setuid(), geteuid(),
42
44
setsid(), chdir(), dup2(),
43
45
STDERR_FILENO, execv() */
44
46
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit() */
46
#include <stdlib.h> /* getenv() */
47
EXIT_SUCCESS, malloc(), _exit(),
47
49
#include <dirent.h> /* opendir(), readdir(), closedir() */
48
50
#include <inttypes.h> /* intmax_t, strtoimax() */
49
51
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
52
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
53
#include <argz.h> /* argz_count(), argz_extract() */
54
#include <stdarg.h> /* va_list, va_start(), ... */
51
56
sig_atomic_t interrupted_by_signal = 0;
53
static void termination_handler(__attribute__((unused))int signum){
58
const char usplash_name[] = "/sbin/usplash";
60
/* Function to use when printing errors */
61
__attribute__((format (gnu_printf, 3, 4)))
62
void error_plus(int status, int errnum, const char *formatstring,
68
va_start(ap, formatstring);
69
ret = vasprintf(&text, formatstring, ap);
71
fprintf(stderr, "Mandos plugin %s: ",
72
program_invocation_short_name);
73
vfprintf(stderr, formatstring, ap);
74
fprintf(stderr, ": ");
75
fprintf(stderr, "%s\n", strerror(errnum));
76
error(status, errno, "vasprintf while printing error");
79
fprintf(stderr, "Mandos plugin ");
80
error(status, errnum, "%s", text);
84
static void termination_handler(int signum){
85
if(interrupted_by_signal){
54
88
interrupted_by_signal = 1;
89
signal_received = signum;
57
static bool usplash_write(const char *cmd, const char *arg){
92
static bool usplash_write(int *fifo_fd_r,
93
const char *cmd, const char *arg){
59
* usplash_write("TIMEOUT", "15") will write "TIMEOUT 15\0"
60
* usplash_write("PULSATE", NULL) will write "PULSATE\0"
95
* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
96
* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
67
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
68
if((fifo_fd == -1) and (errno != EINTR or interrupted_by_signal)){
101
if(*fifo_fd_r == -1){
102
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
71
} while(fifo_fd == -1);
73
109
const char *cmd_line;
74
110
size_t cmd_line_len;
75
111
char *cmd_line_alloc = NULL;
78
cmd_line_len = strlen(cmd);
114
cmd_line_len = strlen(cmd) + 1;
81
117
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
82
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
120
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
93
129
size_t written = 0;
95
while(not interrupted_by_signal and written < cmd_line_len){
96
sret = write(fifo_fd, cmd_line + written,
131
while(written < cmd_line_len){
132
sret = write(*fifo_fd_r, cmd_line + written,
97
133
cmd_line_len - written);
99
if(errno != EINTR or interrupted_by_signal){
102
free(cmd_line_alloc);
136
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
137
free(cmd_line_alloc);
109
141
written += (size_t)sret;
111
143
free(cmd_line_alloc);
113
ret = close(fifo_fd);
114
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
118
if(interrupted_by_signal){
148
/* Create prompt string */
149
char *makeprompt(void){
152
const char *const cryptsource = getenv("cryptsource");
153
const char *const crypttarget = getenv("crypttarget");
154
const char prompt_start[] = "Enter passphrase to unlock the disk";
156
if(cryptsource == NULL){
157
if(crypttarget == NULL){
158
ret = asprintf(&prompt, "%s: ", prompt_start);
160
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
164
if(crypttarget == NULL){
165
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
167
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
168
cryptsource, crypttarget);
177
pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
180
char *cmdline = NULL;
181
size_t cmdline_len = 0;
182
DIR *proc_dir = opendir("/proc");
183
if(proc_dir == NULL){
184
error_plus(0, errno, "opendir");
188
for(struct dirent *proc_ent = readdir(proc_dir);
190
proc_ent = readdir(proc_dir)){
195
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
196
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
197
or tmpmax != (pid_t)tmpmax){
204
/* Find the executable name by doing readlink() on the
205
/proc/<pid>/exe link */
206
char exe_target[sizeof(usplash_name)];
208
/* create file name string */
210
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
212
error_plus(0, errno, "asprintf");
213
goto fail_find_usplash;
216
/* Check that it refers to a symlink owned by root:root */
217
struct stat exe_stat;
218
ret = lstat(exe_link, &exe_stat);
224
error_plus(0, errno, "lstat");
226
goto fail_find_usplash;
228
if(not S_ISLNK(exe_stat.st_mode)
229
or exe_stat.st_uid != 0
230
or exe_stat.st_gid != 0){
235
sret = readlink(exe_link, exe_target, sizeof(exe_target));
238
/* Compare executable name */
239
if((sret != ((ssize_t)sizeof(exe_target)-1))
240
or (memcmp(usplash_name, exe_target,
241
sizeof(exe_target)-1) != 0)){
246
/* Read and save the command line of usplash in "cmdline" */
248
/* Open /proc/<pid>/cmdline */
251
char *cmdline_filename;
252
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
255
error_plus(0, errno, "asprintf");
256
goto fail_find_usplash;
258
cl_fd = open(cmdline_filename, O_RDONLY);
259
free(cmdline_filename);
261
error_plus(0, errno, "open");
262
goto fail_find_usplash;
265
size_t cmdline_allocated = 0;
267
const size_t blocksize = 1024;
269
/* Allocate more space? */
270
if(cmdline_len + blocksize > cmdline_allocated){
271
tmp = realloc(cmdline, cmdline_allocated + blocksize);
273
error_plus(0, errno, "realloc");
275
goto fail_find_usplash;
278
cmdline_allocated += blocksize;
281
sret = read(cl_fd, cmdline + cmdline_len,
282
cmdline_allocated - cmdline_len);
284
error_plus(0, errno, "read");
286
goto fail_find_usplash;
288
cmdline_len += (size_t)sret;
292
error_plus(0, errno, "close");
293
goto fail_find_usplash;
296
/* Close directory */
297
ret = closedir(proc_dir);
299
error_plus(0, errno, "closedir");
300
goto fail_find_usplash;
303
*cmdline_r = cmdline;
304
*cmdline_len_r = cmdline_len;
311
if(proc_dir != NULL){
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319
int main(__attribute__((unused))int argc,
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320
__attribute__((unused))char **argv){
128
bool an_error_occured = false;
327
pid_t usplash_pid = -1;
328
bool usplash_accessed = false;
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int status = EXIT_FAILURE; /* Default failure exit status */
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/* Create prompt string */
133
const char *const cryptsource = getenv("cryptsource");
134
const char *const crypttarget = getenv("crypttarget");
135
const char prompt_start[] = "Enter passphrase to unlock the disk";
137
if(cryptsource == NULL){
138
if(crypttarget == NULL){
139
ret = asprintf(&prompt, "%s: ", prompt_start);
141
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
145
if(crypttarget == NULL){
146
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
148
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
149
cryptsource, crypttarget);
331
char *prompt = makeprompt();
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337
/* Find usplash process */
158
pid_t usplash_pid = 0;
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338
char *cmdline = NULL;
160
339
size_t cmdline_len = 0;
161
const char usplash_name[] = "/sbin/usplash";
163
DIR *proc_dir = opendir("/proc");
164
if(proc_dir == NULL){
169
for(struct dirent *proc_ent = readdir(proc_dir);
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proc_ent = readdir(proc_dir)){
177
tmpmax = strtoimax(proc_ent->d_name, &tmp, 10);
178
if(errno != 0 or tmp == proc_ent->d_name or *tmp != '\0'
179
or tmpmax != (pid_t)tmpmax){
185
/* Find the executable name by doing readlink() on the
186
/proc/<pid>/exe link */
187
char exe_target[sizeof(usplash_name)];
189
/* create file name string */
191
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
199
/* Check that it refers to a symlink owned by root:root */
200
struct stat exe_stat;
201
ret = lstat(exe_link, &exe_stat);
213
if(not S_ISLNK(exe_stat.st_mode)
214
or exe_stat.st_uid != 0
215
or exe_stat.st_gid != 0){
220
sret = readlink(exe_link, exe_target, sizeof(exe_target));
223
if((sret == ((ssize_t)sizeof(exe_target)-1))
224
and (memcmp(usplash_name, exe_target,
225
sizeof(exe_target)-1) == 0)){
227
/* Read and save the command line of usplash in "cmdline" */
229
/* Open /proc/<pid>/cmdline */
232
char *cmdline_filename;
233
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
241
cl_fd = open(cmdline_filename, O_RDONLY);
244
free(cmdline_filename);
249
free(cmdline_filename);
251
size_t cmdline_allocated = 0;
253
const size_t blocksize = 1024;
255
if(cmdline_len + blocksize > cmdline_allocated){
256
tmp = realloc(cmdline, cmdline_allocated + blocksize);
265
cmdline_allocated += blocksize;
267
sret = read(cl_fd, cmdline + cmdline_len,
268
cmdline_allocated - cmdline_len);
276
cmdline_len += (size_t)sret;
340
usplash_pid = find_usplash(&cmdline, &cmdline_len);
285
341
if(usplash_pid == 0){
342
status = EX_UNAVAILABLE;
290
346
/* Set up the signal handler */
293
349
new_action = { .sa_handler = termination_handler,
295
351
sigemptyset(&new_action.sa_mask);
296
sigaddset(&new_action.sa_mask, SIGINT);
297
sigaddset(&new_action.sa_mask, SIGHUP);
298
sigaddset(&new_action.sa_mask, SIGTERM);
352
ret = sigaddset(&new_action.sa_mask, SIGINT);
354
error_plus(0, errno, "sigaddset");
358
ret = sigaddset(&new_action.sa_mask, SIGHUP);
360
error_plus(0, errno, "sigaddset");
364
ret = sigaddset(&new_action.sa_mask, SIGTERM);
366
error_plus(0, errno, "sigaddset");
299
370
ret = sigaction(SIGINT, NULL, &old_action);
373
error_plus(0, errno, "sigaction");
305
378
if(old_action.sa_handler != SIG_IGN){
306
379
ret = sigaction(SIGINT, &new_action, NULL);
382
error_plus(0, errno, "sigaction");
313
388
ret = sigaction(SIGHUP, NULL, &old_action);
391
error_plus(0, errno, "sigaction");
319
396
if(old_action.sa_handler != SIG_IGN){
320
397
ret = sigaction(SIGHUP, &new_action, NULL);
400
error_plus(0, errno, "sigaction");
327
406
ret = sigaction(SIGTERM, NULL, &old_action);
409
error_plus(0, errno, "sigaction");
333
414
if(old_action.sa_handler != SIG_IGN){
334
415
ret = sigaction(SIGTERM, &new_action, NULL);
418
error_plus(0, errno, "sigaction");
426
usplash_accessed = true;
343
427
/* Write command to FIFO */
344
if(not interrupted_by_signal){
345
if(not usplash_write("TIMEOUT", "0")
346
and (errno != EINTR)){
347
perror("usplash_write");
348
an_error_occured = true;
351
if(not interrupted_by_signal and not an_error_occured){
352
if(not usplash_write("INPUTQUIET", prompt)
353
and (errno != EINTR)){
354
perror("usplash_write");
355
an_error_occured = true;
428
if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
430
error_plus(0, errno, "usplash_write");
436
if(interrupted_by_signal){
440
if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
442
error_plus(0, errno, "usplash_write");
448
if(interrupted_by_signal){
360
/* This is not really a loop; while() is used to be able to "break"
361
out of it; those breaks are marked "Big" */
362
while(not interrupted_by_signal and not an_error_occured){
369
fifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
373
an_error_occured = true;
376
if(interrupted_by_signal){
380
} while(fifo_fd == -1);
381
if(interrupted_by_signal or an_error_occured){
386
size_t buf_allocated = 0;
387
const size_t blocksize = 1024;
389
if(buf_len + blocksize > buf_allocated){
390
char *tmp = realloc(buf, buf_allocated + blocksize);
393
an_error_occured = true;
397
buf_allocated += blocksize;
400
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
404
an_error_occured = true;
407
if(interrupted_by_signal){
412
if(interrupted_by_signal or an_error_occured){
416
buf_len += (size_t)sret;
419
if(interrupted_by_signal or an_error_occured){
423
if(not usplash_write("TIMEOUT", "15")
424
and (errno != EINTR)){
425
perror("usplash_write");
426
an_error_occured = true;
428
if(interrupted_by_signal or an_error_occured){
432
/* Print password to stdout */
434
while(written < buf_len){
436
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
440
an_error_occured = true;
443
if(interrupted_by_signal){
448
if(interrupted_by_signal or an_error_occured){
451
written += (size_t)sret;
454
if(not interrupted_by_signal and not an_error_occured){
459
} /* end of non-loop while() */
461
/* If we got here, an error or interrupt must have happened */
463
/* Create argc and argv for new usplash*/
464
int cmdline_argc = 0;
465
char **cmdline_argv = malloc(sizeof(char *));
468
while(position < cmdline_len){
469
char **tmp = realloc(cmdline_argv,
471
* (size_t)(cmdline_argc + 2)));
455
/* Read reply from usplash */
457
outfifo_fd = open("/dev/.initramfs/usplash_outfifo", O_RDONLY);
458
if(outfifo_fd == -1){
460
error_plus(0, errno, "open");
466
if(interrupted_by_signal){
471
size_t buf_allocated = 0;
472
const size_t blocksize = 1024;
474
/* Allocate more space */
475
if(buf_len + blocksize > buf_allocated){
476
char *tmp = realloc(buf, buf_allocated + blocksize);
478
cmdline_argv[cmdline_argc] = cmdline + position;
480
position += strlen(cmdline + position) + 1;
482
cmdline_argv[cmdline_argc] = NULL;
479
error_plus(0, errno, "realloc");
485
buf_allocated += blocksize;
487
sret = read(outfifo_fd, buf + buf_len,
488
buf_allocated - buf_len);
491
error_plus(0, errno, "read");
494
TEMP_FAILURE_RETRY(close(outfifo_fd));
497
if(interrupted_by_signal){
501
buf_len += (size_t)sret;
503
ret = close(outfifo_fd);
506
error_plus(0, errno, "close");
513
if(interrupted_by_signal){
517
if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
519
error_plus(0, errno, "usplash_write");
525
if(interrupted_by_signal){
529
ret = close(fifo_fd);
532
error_plus(0, errno, "close");
539
/* Print password to stdout */
541
while(written < buf_len){
543
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
546
error_plus(0, errno, "write");
553
if(interrupted_by_signal){
556
written += (size_t)sret;
561
if(interrupted_by_signal){
574
/* If usplash was never accessed, we can stop now */
575
if(not usplash_accessed){
581
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
582
if(ret == -1 and errno != EINTR){
583
error_plus(0, errno, "close");
588
/* Close output FIFO */
589
if(outfifo_fd != -1){
590
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
592
error_plus(0, errno, "close");
596
/* Create argv for new usplash*/
597
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
598
* sizeof(char *)); /* Count args */
599
if(cmdline_argv == NULL){
600
error_plus(0, errno, "malloc");
603
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
484
605
/* Kill old usplash */
485
606
kill(usplash_pid, SIGTERM);
496
618
the real user ID (_mandos) */
497
619
ret = setuid(geteuid());
621
error_plus(0, errno, "setuid");
503
625
ret = chdir("/");
627
error_plus(0, errno, "chdir");
504
630
/* if(fork() != 0){ */
505
631
/* _exit(EXIT_SUCCESS); */
507
633
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
635
error_plus(0, errno, "dup2");
513
639
execv(usplash_name, cmdline_argv);
514
640
if(not interrupted_by_signal){
641
error_plus(0, errno, "execv");
518
644
free(cmdline_argv);
522
648
free(cmdline_argv);
524
if(not usplash_write("PULSATE", NULL)
525
and (errno != EINTR)){
526
perror("usplash_write");
650
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
652
error_plus(0, errno, "usplash_write");
656
/* Close FIFO (again) */
658
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
659
if(ret == -1 and errno != EINTR){
660
error_plus(0, errno, "close");
665
if(interrupted_by_signal){
666
struct sigaction signal_action = { .sa_handler = SIG_DFL };
667
sigemptyset(&signal_action.sa_mask);
668
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
669
&signal_action, NULL));
671
error_plus(0, errno, "sigaction");
674
ret = raise(signal_received);
675
} while(ret != 0 and errno == EINTR);
677
error_plus(0, errno, "raise");
680
TEMP_FAILURE_RETRY(pause());