/*
 * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de. All rights reserved.
 * Copyright 2010, Jérôme Duval, korli@users.berlios.de. All rights reserved.
 * Distributed under the terms of the MIT License.
 */

#include <pty.h>

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>


int
openpty(int* _master, int* _slave, char* name, struct termios* termAttrs,
        struct winsize* windowSize)
{
        int master = posix_openpt(O_RDWR);
        if (master < 0)
        return -1;

        int slave;
        const char *ttyName;
        if (grantpt(master) != 0 || unlockpt(master) != 0
                || (ttyName = ptsname(master)) == NULL
                || (slave = open(ttyName, O_RDWR | O_NOCTTY)) < 0) {
                close(master);
                return -1;
        }

        if ((termAttrs != NULL && tcsetattr(master, TCSANOW, termAttrs) != 0)
                || (windowSize != NULL
                        && ioctl(master, TIOCSWINSZ, windowSize, sizeof(winsize)) != 0)) {
                close(slave);
                close(master);
                return -1;
        }

        *_master = master;
        *_slave = slave;

        if (name != NULL)
                strcpy(name, ttyName);

        return 0;
}


int
login_tty(int fd)
{
        setsid();

        if (ioctl(fd, TIOCSCTTY, NULL) != 0)
                return -1;

        dup2(fd, 0);
        dup2(fd, 1);
        dup2(fd, 2);

        close(fd);
        return 0;
}


pid_t
forkpty(int* _master, char* name, struct termios* termAttrs,
        struct winsize* windowSize)
{
        int master, slave;
        if (openpty(&master, &slave, name, termAttrs, windowSize) != 0)
                return -1;

        int pid = fork();
        if (pid < 0) {
                close(master);
                close(slave);
                return -1;
        }
        // child
        if (pid == 0) {
                close(master);
                return login_tty(slave);
        }

        // parent
        close (slave);
        *_master = master;
        return pid;
}