1
#define _GNU_SOURCE /* asprintf() */
1
/* -*- coding: utf-8 -*- */
3
* Usplash - Read a password from usplash and output it
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
8
* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
10
* published by the Free Software Foundation, either version 3 of the
11
* License, or (at your option) any later version.
13
* This program is distributed in the hope that it will be useful, but
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
* General Public License for more details.
18
* You should have received a copy of the GNU General Public License
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
2
26
#include <signal.h> /* sig_atomic_t, struct sigaction,
3
sigemptyset(), sigaddset(),
4
sigaction, SIGINT, SIG_IGN, SIGHUP,
5
SIGTERM, kill(), SIGKILL */
27
sigemptyset(), sigaddset(), SIGINT,
28
SIGHUP, SIGTERM, sigaction(),
29
SIG_IGN, kill(), SIGKILL */
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_WRONLY, O_RDONLY */
32
#include <iso646.h> /* and, or, not*/
33
#include <errno.h> /* errno, EINTR */
34
#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
6
36
#include <stddef.h> /* NULL */
37
#include <string.h> /* strlen(), memcmp() */
38
#include <stdio.h> /* asprintf(), perror() */
39
#include <unistd.h> /* close(), write(), readlink(),
40
read(), STDOUT_FILENO, sleep(),
41
fork(), setuid(), geteuid(),
42
setsid(), chdir(), dup2(),
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STDERR_FILENO, execv() */
44
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
45
EXIT_SUCCESS, malloc(), _exit() */
7
46
#include <stdlib.h> /* getenv() */
8
#include <stdio.h> /* asprintf(), perror() */
9
#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS,
11
#include <sys/types.h> /* pid_t, DIR, struct dirent,
13
47
#include <dirent.h> /* opendir(), readdir(), closedir() */
14
#include <unistd.h> /* readlink(), fork(), execl(),
16
#include <string.h> /* memcmp() */
17
#include <iso646.h> /* and */
18
#include <stdbool.h> /* bool, false, true */
19
#include <errno.h> /* errno */
20
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
22
#include <fcntl.h> /* open(), O_RDONLY */
48
#include <inttypes.h> /* intmax_t, strtoimax() */
49
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
50
#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
24
52
sig_atomic_t interrupted_by_signal = 0;
54
const char usplash_name[] = "/sbin/usplash";
26
static void termination_handler(__attribute__((unused))int signum){
56
static void termination_handler(int signum){
57
if(interrupted_by_signal){
27
60
interrupted_by_signal = 1;
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signal_received = signum;
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static bool usplash_write(const char *cmd, const char *arg){
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static bool usplash_write(int *fifo_fd_r,
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const char *cmd, const char *arg){
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* usplash_write("TIMEOUT", "15"); -> "TIMEOUT 15\0"
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* usplash_write("PULSATE", NULL); -> "PULSATE\0"
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* usplash_write(&fd, "TIMEOUT", "15") will write "TIMEOUT 15\0"
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* usplash_write(&fd, "PULSATE", NULL) will write "PULSATE\0"
40
fifo_fd = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
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if(fifo_fd == -1 and (errno != EINTR or interrupted_by_signal)){
74
ret = open("/dev/.initramfs/usplash_fifo", O_WRONLY);
44
}while(fifo_fd == -1);
46
81
const char *cmd_line;
47
83
char *cmd_line_alloc = NULL;
50
ret = (int)strlen(cmd);
86
cmd_line_len = strlen(cmd) + 1;
53
89
ret = asprintf(&cmd_line_alloc, "%s %s", cmd, arg);
54
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
92
TEMP_FAILURE_RETRY(close(*fifo_fd_r));
61
97
cmd_line = cmd_line_alloc;
98
cmd_line_len = (size_t)ret + 1;
64
size_t cmd_line_len = (size_t)ret + 1;
65
101
size_t written = 0;
66
while(not interrupted_by_signal and written < cmd_line_len){
67
ret = write(fifo_fd, cmd_line + written,
68
cmd_line_len - written);
70
if(errno != EINTR or interrupted_by_signal){
103
while(written < cmd_line_len){
104
sret = write(*fifo_fd_r, cmd_line + written,
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cmd_line_len - written);
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TEMP_FAILURE_RETRY(close(*fifo_fd_r));
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free(cmd_line_alloc);
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written += (size_t)ret;
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written += (size_t)sret;
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115
free(cmd_line_alloc);
85
if(ret == -1 and (errno != EINTR or interrupted_by_signal)){
89
if(interrupted_by_signal){
95
int main(__attribute__((unused))int argc,
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__attribute__((unused))char **argv){
99
bool an_error_occured = false;
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/* Create prompt string */
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const char *const cryptsource = getenv("cryptsource");
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const char *const crypttarget = getenv("crypttarget");
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const char *const prompt_start = "Enter passphrase to unlock the disk";
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if(cryptsource == NULL){
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s: ", prompt_start);
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ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
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/* Find usplash process */
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pid_t usplash_pid = 0;
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/* Create prompt string */
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char *makeprompt(void){
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const char *const cryptsource = getenv("cryptsource");
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const char *const crypttarget = getenv("crypttarget");
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const char prompt_start[] = "Enter passphrase to unlock the disk";
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if(cryptsource == NULL){
129
if(crypttarget == NULL){
130
ret = asprintf(&prompt, "%s: ", prompt_start);
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ret = asprintf(&prompt, "%s (%s): ", prompt_start,
136
if(crypttarget == NULL){
137
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
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pid_t find_usplash(char **cmdline_r, size_t *cmdline_len_r){
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152
char *cmdline = NULL;
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153
size_t cmdline_len = 0;
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const char usplash_name[] = "/sbin/usplash";
134
DIR *proc_dir = opendir("/proc");
135
if(proc_dir == NULL){
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for(struct dirent *proc_ent = readdir(proc_dir);
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proc_ent = readdir(proc_dir)){
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pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
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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){
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170
/* Not a process */
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/* Find the executable name by doing readlink() on the
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/proc/<pid>/exe link */
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char exe_target[sizeof(usplash_name)];
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/* Find the executable name by doing readlink() on the
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/proc/<pid>/exe link */
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char exe_target[sizeof(usplash_name)];
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/* create file name string */
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ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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goto fail_find_usplash;
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/* Check that it refers to a symlink owned by root:root */
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struct stat exe_stat;
190
ret = lstat(exe_link, &exe_stat);
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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){
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sret = readlink(exe_link, exe_target, sizeof(exe_target));
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/* Compare executable name */
211
if((sret != ((ssize_t)sizeof(exe_target)-1))
212
or (memcmp(usplash_name, exe_target,
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sizeof(exe_target)-1) != 0)){
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/* Read and save the command line of usplash in "cmdline" */
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/* Open /proc/<pid>/cmdline */
153
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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char *cmdline_filename;
224
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
155
227
perror("asprintf");
160
sret = readlink(exe_link, exe_target, sizeof(exe_target));
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goto fail_find_usplash;
230
cl_fd = open(cmdline_filename, O_RDONLY);
231
free(cmdline_filename);
234
goto fail_find_usplash;
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if((sret == ((ssize_t)sizeof(exe_target)-1))
164
and (memcmp(usplash_name, exe_target,
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sizeof(exe_target)-1) == 0)){
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/* Read and save the command line of usplash in "cmdline" */
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/* Open /proc/<pid>/cmdline */
172
char *cmdline_filename;
173
ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
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cl_fd = open(cmdline_filename, O_RDONLY);
184
free(cmdline_filename);
189
free(cmdline_filename);
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;
191
size_t cmdline_allocated = 0;
193
const size_t blocksize = 1024;
195
if(cmdline_len + blocksize > cmdline_allocated){
196
tmp = realloc(cmdline, cmdline_allocated + blocksize);
205
cmdline_allocated += blocksize;
207
sret = read(cl_fd, cmdline + cmdline_len,
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cmdline_allocated - cmdline_len);
216
cmdline_len += (size_t)sret;
250
cmdline_allocated += blocksize;
253
sret = read(cl_fd, cmdline + cmdline_len,
254
cmdline_allocated - cmdline_len);
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goto fail_find_usplash;
260
cmdline_len += (size_t)sret;
265
goto fail_find_usplash;
268
/* Close directory */
269
ret = closedir(proc_dir);
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goto fail_find_usplash;
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*cmdline_r = cmdline;
276
*cmdline_len_r = cmdline_len;
283
if(proc_dir != NULL){
223
285
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);
225
313
if(usplash_pid == 0){
314
status = EX_UNAVAILABLE;
230
318
/* Set up the signal handler */
233
321
new_action = { .sa_handler = termination_handler,
235
323
sigemptyset(&new_action.sa_mask);
236
sigaddset(&new_action.sa_mask, SIGINT);
237
sigaddset(&new_action.sa_mask, SIGHUP);
238
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);
239
342
ret = sigaction(SIGINT, NULL, &old_action);
245
if (old_action.sa_handler != SIG_IGN){
350
if(old_action.sa_handler != SIG_IGN){
246
351
ret = sigaction(SIGINT, &new_action, NULL);
253
360
ret = sigaction(SIGHUP, NULL, &old_action);
259
if (old_action.sa_handler != SIG_IGN){
368
if(old_action.sa_handler != SIG_IGN){
260
369
ret = sigaction(SIGHUP, &new_action, NULL);
267
378
ret = sigaction(SIGTERM, NULL, &old_action);
273
if (old_action.sa_handler != SIG_IGN){
386
if(old_action.sa_handler != SIG_IGN){
274
387
ret = sigaction(SIGTERM, &new_action, NULL);
398
usplash_accessed = true;
283
399
/* Write command to FIFO */
284
if(not interrupted_by_signal){
285
if(not usplash_write("TIMEOUT", "0")
286
and (errno != EINTR)){
287
perror("usplash_write");
288
an_error_occured = true;
291
if(not interrupted_by_signal and not an_error_occured){
292
if(not usplash_write("INPUTQUIET", prompt)
293
and (errno != EINTR)){
294
perror("usplash_write");
295
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){
300
/* This is not really a loop; while() is used to be able to "break"
301
out of it; those breaks are marked "Big" */
302
while(not interrupted_by_signal and not an_error_occured){
309
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);
311
450
if(errno != EINTR){
313
an_error_occured = true;
316
if(interrupted_by_signal){
320
}while(fifo_fd == -1);
321
if(interrupted_by_signal or an_error_occured){
326
size_t buf_allocated = 0;
327
const size_t blocksize = 1024;
329
if(buf_len + blocksize > buf_allocated){
330
char *tmp = realloc(buf, buf_allocated + blocksize);
332
451
perror("realloc");
333
an_error_occured = true;
337
buf_allocated += blocksize;
340
sret = read(fifo_fd, buf + buf_len, buf_allocated - buf_len);
344
an_error_occured = true;
347
if(interrupted_by_signal){
352
if(interrupted_by_signal or an_error_occured){
356
buf_len += (size_t)sret;
359
if(interrupted_by_signal or an_error_occured){
363
if(not usplash_write("TIMEOUT", "15")
364
and (errno != EINTR)){
365
perror("usplash_write");
366
an_error_occured = true;
368
if(interrupted_by_signal or an_error_occured){
372
/* Print password to stdout */
376
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
380
an_error_occured = true;
383
if(interrupted_by_signal){
388
if(interrupted_by_signal or an_error_occured){
392
written += (size_t)sret;
393
}while(written < buf_len);
394
if(not interrupted_by_signal and not an_error_occured){
400
/* 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));
568
/* Create argc and argv for new usplash*/
402
569
int cmdline_argc = 0;
403
570
char **cmdline_argv = malloc(sizeof(char *));
404
/* Create argv and argc for new usplash*/
406
572
size_t position = 0;
407
573
while(position < cmdline_len){
408
574
char **tmp = realloc(cmdline_argv,
409
(sizeof(char *) * (size_t)(cmdline_argc + 2)));
576
* (size_t)(cmdline_argc + 2)));
411
578
perror("realloc");
412
579
free(cmdline_argv);
415
582
cmdline_argv = tmp;
416
583
cmdline_argv[cmdline_argc] = cmdline + position;