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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, Gunnar Beutner <gbeutner@serenityos.org>
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <errno.h>
#include <fcntl.h>
#include <pty.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
int openpty(int* amaster, int* aslave, char* name, const struct termios* termp, const struct winsize* winp)
{
*amaster = posix_openpt(O_RDWR);
if (*amaster < 0) {
return -1;
}
if (grantpt(*amaster) < 0) {
int error = errno;
close(*amaster);
errno = error;
return -1;
}
if (unlockpt(*amaster) < 0) {
int error = errno;
close(*amaster);
errno = error;
return -1;
}
char tty_name[32];
int rc = ptsname_r(*amaster, tty_name, sizeof(tty_name));
if (rc < 0) {
int error = errno;
close(*amaster);
errno = error;
return -1;
}
if (name) {
/* The spec doesn't say how large name has to be. Good luck. */
[[maybe_unused]] auto rc = strlcpy(name, tty_name, 128);
}
*aslave = open(tty_name, O_RDWR | O_NOCTTY);
if (*aslave < 0) {
int error = errno;
close(*amaster);
errno = error;
return -1;
}
if (termp) {
if (tcsetattr(*aslave, TCSAFLUSH, termp) == -1) {
int error = errno;
close(*aslave);
close(*amaster);
errno = error;
return -1;
}
}
if (winp) {
if (ioctl(*aslave, TIOCGWINSZ, winp) == -1) {
int error = errno;
close(*aslave);
close(*amaster);
errno = error;
return -1;
}
}
return 0;
}
pid_t forkpty(int* amaster, char* name, const struct termios* termp, const struct winsize* winp)
{
int master;
int slave;
if (openpty(&master, &slave, name, termp, winp) < 0)
return -1;
pid_t pid = fork();
if (pid < 0) {
close(master);
close(slave);
return -1;
}
*amaster = master;
if (pid == 0) {
close(master);
if (login_tty(slave) < 0)
_exit(1);
return 0;
}
close(slave);
return pid;
}
int login_tty(int fd)
{
setsid();
close(0);
close(1);
close(2);
int rc = dup2(fd, 0);
if (rc < 0)
return rc;
rc = dup2(fd, 1);
if (rc < 0)
return -1;
rc = dup2(fd, 2);
if (rc < 0)
return rc;
rc = close(fd);
if (rc < 0)
return rc;
rc = ioctl(0, TIOCSCTTY);
if (rc < 0)
return rc;
return 0;
}
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