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3
* Usplash - Read a password from usplash and output it
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* Copyright © 2008,2009 Teddy Hogeborn
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* Copyright © 2008,2009 Björn Påhlsson
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* This program is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful, but
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* Copyright © 2008-2017 Teddy Hogeborn
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* Copyright © 2008-2017 Björn Påhlsson
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* This file is part of Mandos.
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* Mandos is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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* Mandos is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
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* Contact the authors at <mandos@fukt.bsnet.se>.
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* Contact the authors at <mandos@recompile.se>.
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#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
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#include <sys/types.h> /* size_t, ssize_t, pid_t, DIR, struct
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#include <stddef.h> /* NULL */
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#include <string.h> /* strlen(), memcmp() */
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#include <stdio.h> /* asprintf()*/
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#include <string.h> /* strlen(), memcmp(), strerror() */
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#include <stdio.h> /* asprintf(), vasprintf(), vprintf(),
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#include <unistd.h> /* close(), write(), readlink(),
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read(), STDOUT_FILENO, sleep(),
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fork(), setuid(), geteuid(),
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#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
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#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
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#include <argz.h> /* argz_count(), argz_extract() */
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#include <stdarg.h> /* va_list, va_start(), ... */
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sig_atomic_t interrupted_by_signal = 0;
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int signal_received;
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const char usplash_name[] = "/sbin/usplash";
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/* Function to use when printing errors */
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__attribute__((format (gnu_printf, 3, 4)))
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void error_plus(int status, int errnum, const char *formatstring,
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va_start(ap, formatstring);
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ret = vasprintf(&text, formatstring, ap);
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fprintf(stderr, "Mandos plugin %s: ",
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program_invocation_short_name);
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vfprintf(stderr, formatstring, ap);
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fprintf(stderr, ": ");
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fprintf(stderr, "%s\n", strerror(errnum));
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error(status, errno, "vasprintf while printing error");
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fprintf(stderr, "Mandos plugin ");
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error(status, errnum, "%s", text);
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static void termination_handler(int signum){
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if(interrupted_by_signal){
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size_t cmdline_len = 0;
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DIR *proc_dir = opendir("/proc");
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if(proc_dir == NULL){
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error(0, errno, "opendir");
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error_plus(0, errno, "opendir");
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ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
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error(0, errno, "asprintf");
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error_plus(0, errno, "asprintf");
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goto fail_find_usplash;
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ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
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proc_ent->d_name);
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error(0, errno, "asprintf");
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error_plus(0, errno, "asprintf");
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goto fail_find_usplash;
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cl_fd = open(cmdline_filename, O_RDONLY);
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free(cmdline_filename);
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error(0, errno, "open");
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error_plus(0, errno, "open");
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goto fail_find_usplash;
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if(cmdline_len + blocksize > cmdline_allocated){
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tmp = realloc(cmdline, cmdline_allocated + blocksize);
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error(0, errno, "realloc");
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error_plus(0, errno, "realloc");
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goto fail_find_usplash;
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sret = read(cl_fd, cmdline + cmdline_len,
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cmdline_allocated - cmdline_len);
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error(0, errno, "read");
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error_plus(0, errno, "read");
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goto fail_find_usplash;
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} while(sret != 0);
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ret = close(cl_fd);
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error(0, errno, "close");
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error_plus(0, errno, "close");
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goto fail_find_usplash;
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/* Close directory */
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ret = closedir(proc_dir);
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error(0, errno, "closedir");
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error_plus(0, errno, "closedir");
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goto fail_find_usplash;
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sigemptyset(&new_action.sa_mask);
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ret = sigaddset(&new_action.sa_mask, SIGINT);
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error(0, errno, "sigaddset");
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error_plus(0, errno, "sigaddset");
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status = EX_OSERR;
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ret = sigaddset(&new_action.sa_mask, SIGHUP);
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error(0, errno, "sigaddset");
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error_plus(0, errno, "sigaddset");
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status = EX_OSERR;
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ret = sigaddset(&new_action.sa_mask, SIGTERM);
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error(0, errno, "sigaddset");
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error_plus(0, errno, "sigaddset");
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status = EX_OSERR;
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ret = sigaction(SIGINT, NULL, &old_action);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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ret = sigaction(SIGINT, &new_action, NULL);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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ret = sigaction(SIGHUP, NULL, &old_action);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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ret = sigaction(SIGHUP, &new_action, NULL);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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ret = sigaction(SIGTERM, NULL, &old_action);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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ret = sigaction(SIGTERM, &new_action, NULL);
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if(errno != EINTR){
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error(0, errno, "sigaction");
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error_plus(0, errno, "sigaction");
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status = EX_OSERR;
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/* Write command to FIFO */
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if(not usplash_write(&fifo_fd, "TIMEOUT", "0")){
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if(errno != EINTR){
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error(0, errno, "usplash_write");
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error_plus(0, errno, "usplash_write");
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status = EX_OSERR;
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if(not usplash_write(&fifo_fd, "INPUTQUIET", prompt)){
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if(errno != EINTR){
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error(0, errno, "usplash_write");
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error_plus(0, errno, "usplash_write");
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status = EX_OSERR;
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477
char *tmp = realloc(buf, buf_allocated + blocksize);
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479
if(errno != EINTR){
453
error(0, errno, "realloc");
480
error_plus(0, errno, "realloc");
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status = EX_OSERR;
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buf_allocated - buf_len);
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491
if(errno != EINTR){
465
error(0, errno, "read");
492
error_plus(0, errno, "read");
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493
status = EX_OSERR;
468
TEMP_FAILURE_RETRY(close(outfifo_fd));
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498
if(interrupted_by_signal){
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if(not usplash_write(&fifo_fd, "TIMEOUT", "15")){
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519
if(errno != EINTR){
493
error(0, errno, "usplash_write");
520
error_plus(0, errno, "usplash_write");
494
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status = EX_OSERR;
517
544
sret = write(STDOUT_FILENO, buf + written, buf_len - written);
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546
if(errno != EINTR){
520
error(0, errno, "write");
547
error_plus(0, errno, "write");
521
548
status = EX_OSERR;
554
581
if(fifo_fd != -1){
555
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
582
ret = close(fifo_fd);
556
583
if(ret == -1 and errno != EINTR){
557
error(0, errno, "close");
584
error_plus(0, errno, "close");
562
589
/* Close output FIFO */
563
590
if(outfifo_fd != -1){
564
ret = (int)TEMP_FAILURE_RETRY(close(outfifo_fd));
591
ret = close(outfifo_fd);
566
error(0, errno, "close");
593
error_plus(0, errno, "close");
570
597
/* Create argv for new usplash*/
571
char **cmdline_argv = malloc(argz_count(cmdline, cmdline_len)
598
char **cmdline_argv = malloc((argz_count(cmdline, cmdline_len) + 1)
572
599
* sizeof(char *)); /* Count args */
573
600
if(cmdline_argv == NULL){
574
error(0, errno, "malloc");
601
error_plus(0, errno, "malloc");
577
604
argz_extract(cmdline, cmdline_len, cmdline_argv); /* Create argv */
592
619
the real user ID (_mandos) */
593
620
ret = setuid(geteuid());
595
error(0, errno, "setuid");
622
error_plus(0, errno, "setuid");
599
626
ret = chdir("/");
601
error(0, errno, "chdir");
628
error_plus(0, errno, "chdir");
604
631
/* if(fork() != 0){ */
607
634
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
609
error(0, errno, "dup2");
636
error_plus(0, errno, "dup2");
613
640
execv(usplash_name, cmdline_argv);
614
641
if(not interrupted_by_signal){
615
error(0, errno, "execv");
642
error_plus(0, errno, "execv");
618
645
free(cmdline_argv);
624
651
if(not usplash_write(&fifo_fd, "PULSATE", NULL)){
625
652
if(errno != EINTR){
626
error(0, errno, "usplash_write");
653
error_plus(0, errno, "usplash_write");
630
657
/* Close FIFO (again) */
631
658
if(fifo_fd != -1){
632
ret = (int)TEMP_FAILURE_RETRY(close(fifo_fd));
659
ret = close(fifo_fd);
633
660
if(ret == -1 and errno != EINTR){
634
error(0, errno, "close");
661
error_plus(0, errno, "close");
642
669
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
643
670
&signal_action, NULL));
645
error(0, errno, "sigaction");
672
error_plus(0, errno, "sigaction");
648
675
ret = raise(signal_received);
649
676
} while(ret != 0 and errno == EINTR);
651
error(0, errno, "raise");
678
error_plus(0, errno, "raise");
654
681
TEMP_FAILURE_RETRY(pause());