tdesu_pty.cpp

/*
 *
 * $Id$
 *
 * This file is part of the KDE project, module tdesu.
 * Copyright (C) 1999,2000 Geert Jansen <jansen@kde.org>
 *
 * This file contains code from TEShell.C of the KDE konsole.
 * Copyright (c) 1997,1998 by Lars Doelle <lars.doelle@on-line.de>
 *
 * This is free software; you can use this library under the GNU Library
 * General Public License, version 2. See the file "COPYING.LIB" for the
 * exact licensing terms.
 *
 * pty.cpp: Access to PTY's on different systems a la UNIX98.
 */
 
 
#ifndef _GNU_SOURCE
#define _GNU_SOURCE   /* Needed for getpt, ptsname in glibc 2.1.x systems */
#endif
 
#include <config.h>
 
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
 
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#if defined(__CYGWIN__)
#include <pty.h>
#endif
 
#include <tqglobal.h>
#include <tqcstring.h>
 
#include <kdebug.h>
#include <tdestandarddirs.h>
#include "tdesu_pty.h"
 
// stdlib.h is meant to declare the prototypes but doesn't :(
#ifndef __THROW
#define __THROW
#endif
 
#ifdef HAVE_GRANTPT
extern "C" int grantpt(int fd) __THROW;
#endif
 
#ifdef HAVE_PTSNAME
extern "C" char * ptsname(int fd) __THROW;
#endif
 
#ifdef HAVE_UNLOCKPT
extern "C" int unlockpt(int fd) __THROW;
#endif
 
#ifdef HAVE__GETPTY
extern "C" char *_getpty(int *, int, mode_t, int);
#endif
 
#ifdef HAVE_PTY_H
    #include <pty.h>
#endif
 
#include <termios.h>
 
#ifdef HAVE_LIBUTIL_H
    #include <libutil.h>
#elif defined(HAVE_UTIL_H)
    #include <util.h>
#endif
 
PTY::PTY()
{
    ptyfd = -1;
}
 
PTY::~PTY()
{
    if (ptyfd >= 0)
    close(ptyfd);
}
 
 
// Opens a pty master and returns its filedescriptor.
 
int PTY::getpt()
{
 
#if (defined(HAVE_GETPT) || defined(HAVE_POSIX_OPENPT)) && defined(HAVE_PTSNAME)
 
    // 1: UNIX98: preferred way
#ifdef HAVE_GETPT
    ptyfd = ::getpt();
#elif defined(HAVE_POSIX_OPENPT)
    ptyfd = ::posix_openpt(O_RDWR);
#endif
    ttyname = ::ptsname(ptyfd);
    return ptyfd;
 
#elif defined(HAVE_OPENPTY)
    // 2: BSD interface
    // More preferred than the linux hacks
    char name[30];
    int master_fd, slave_fd;
    if (openpty(&master_fd, &slave_fd, name, 0L, 0L) != -1)  {
    ttyname = name;
    name[5]='p';
    ptyname = name;
        close(slave_fd); // We don't need this yet // Yes, we do.
    ptyfd = master_fd;
    return ptyfd;
    }
    ptyfd = -1;
    kdDebug(900) << k_lineinfo << "Opening pty failed.\n";
    return -1;
 
#elif defined(HAVE__GETPTY)
    // 3: Irix interface
    int master_fd;
    ttyname = _getpty(&master_fd,O_RDWR,0600,0);
    if (ttyname)
    ptyfd = master_fd;
    else{
    ptyfd = -1;
    kdDebug(900) << k_lineinfo << "Opening pty failed.error" << errno << '\n';
    }
    return ptyfd;
 
#else
 
    // 4: Open terminal device directly
    // 4.1: Try /dev/ptmx first. (Linux w/ Unix98 PTYs, Solaris)
 
    ptyfd = open("/dev/ptmx", O_RDWR);
    if (ptyfd >= 0) {
    ptyname = "/dev/ptmx";
#ifdef HAVE_PTSNAME
    ttyname = ::ptsname(ptyfd);
    return ptyfd;
#elif defined (TIOCGPTN)
    int ptyno;
    if (ioctl(ptyfd, TIOCGPTN, &ptyno) == 0) {
        ttyname.sprintf("/dev/pts/%d", ptyno);
        return ptyfd;
    }
#endif
    close(ptyfd);
    }
 
    // 4.2: Try /dev/pty[p-e][0-f] (Linux w/o UNIX98 PTY's)
 
    for (const char *c1 = "pqrstuvwxyzabcde"; *c1 != '\0'; c1++)
    {
    for (const char *c2 = "0123456789abcdef"; *c2 != '\0'; c2++)
    {
        ptyname.sprintf("/dev/pty%c%c", *c1, *c2);
        ttyname.sprintf("/dev/tty%c%c", *c1, *c2);
        if (access(ptyname, F_OK) < 0)
        goto linux_out;
        ptyfd = open(ptyname, O_RDWR);
        if (ptyfd >= 0)
        return ptyfd;
    }
    }
linux_out:
 
    // 4.3: Try /dev/pty%d (SCO, Unixware)
 
    for (int i=0; i<256; i++)
    {
    ptyname.sprintf("/dev/ptyp%d", i);
    ttyname.sprintf("/dev/ttyp%d", i);
    if (access(ptyname, F_OK) < 0)
        break;
    ptyfd = open(ptyname, O_RDWR);
    if (ptyfd >= 0)
        return ptyfd;
    }
 
 
    // Other systems ??
    ptyfd = -1;
    kdDebug(900) << k_lineinfo << "Unknown system or all methods failed.\n";
    return -1;
 
#endif // HAVE_GETPT && HAVE_PTSNAME
 
}
 
 
int PTY::grantpt()
{
    if (ptyfd < 0)
    return -1;
 
#ifdef HAVE_GRANTPT
 
    return ::grantpt(ptyfd);
 
#elif defined(HAVE_OPENPTY)
 
    // the BSD openpty() interface chowns the devices properly for us,
    // no need to do this at all
    return 0;
 
#else
 
    // konsole_grantpty only does /dev/pty??
    if (ptyname.left(8) != "/dev/pty")
    return 0;
 
    // Use konsole_grantpty:
    if (TDEStandardDirs::findExe("konsole_grantpty").isEmpty())
    {
    kdError(900) << k_lineinfo << "konsole_grantpty not found.\n";
    return -1;
    }
 
    // As defined in konsole_grantpty.c
    const int pty_fileno = 3;
 
    pid_t pid;
    if ((pid = fork()) == -1)
    {
    kdError(900) << k_lineinfo << "fork(): " << perror << "\n";
    return -1;
    }
 
    if (pid)
    {
    // Parent: wait for child
    int ret;
    waitpid(pid, &ret, 0);
        if (WIFEXITED(ret) && !WEXITSTATUS(ret))
        return 0;
    kdError(900) << k_lineinfo << "konsole_grantpty returned with error: "
             << WEXITSTATUS(ret) << "\n";
    return -1;
    } else
    {
    // Child: exec konsole_grantpty
    if (ptyfd != pty_fileno && dup2(ptyfd, pty_fileno) < 0)
        _exit(1);
    execlp("konsole_grantpty", "konsole_grantpty", "--grant", (void *)0);
    kdError(900) << k_lineinfo << "exec(): " << perror << "\n";
    _exit(1);
    }
 
    // shut up, gcc
    return 0;
 
#endif // HAVE_GRANTPT
}
 
 
int PTY::unlockpt()
{
    if (ptyfd < 0)
    return -1;
 
#ifdef HAVE_UNLOCKPT
 
    // (Linux w/ glibc 2.1, Solaris, ...)
 
    return ::unlockpt(ptyfd);
 
#elif defined(TIOCSPTLCK)
 
    // Unlock pty (Linux w/ UNIX98 PTY's & glibc 2.0)
    int flag = 0;
    return ioctl(ptyfd, TIOCSPTLCK, &flag);
 
#else
 
    // Other systems (Linux w/o UNIX98 PTY's, ...)
    return 0;
 
#endif
 
}
 
 
TQCString PTY::ptsname()
{
    if (ptyfd < 0)
    return 0;
 
    return ttyname;
}