kdecore Library API Documentation

kpty.cpp

00001 /*
00002 
00003    This file is part of the KDE libraries
00004    Copyright (C) 1997-2002 The Konsole Developers
00005    Copyright (C) 2002 Waldo Bastian <bastian@kde.org>
00006    Copyright (C) 2002-2003 Oswald Buddenhagen <ossi@kde.org>
00007 
00008    This library is free software; you can redistribute it and/or
00009    modify it under the terms of the GNU Library General Public
00010    License as published by the Free Software Foundation; either
00011    version 2 of the License, or (at your option) any later version.
00012 
00013    This library is distributed in the hope that it will be useful,
00014    but WITHOUT ANY WARRANTY; without even the implied warranty of
00015    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016    Library General Public License for more details.
00017 
00018    You should have received a copy of the GNU Library General Public License
00019    along with this library; see the file COPYING.LIB.  If not, write to
00020    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
00021    Boston, MA 02111-1307, USA.
00022 */
00023 
00024 #include <config.h>
00025 
00026 #include "kpty.h"
00027 #include "kprocess.h"
00028 
00029 #ifdef __sgi
00030 #define __svr4__
00031 #endif
00032 
00033 #ifdef __osf__
00034 #define _OSF_SOURCE
00035 #include <float.h>
00036 #endif
00037 
00038 #ifdef _AIX
00039 #define _ALL_SOURCE
00040 #endif
00041 
00042 // __USE_XOPEN isn't defined by default in ICC
00043 // (needed for ptsname(), grantpt() and unlockpt())
00044 #ifdef __INTEL_COMPILER
00045 #  ifndef __USE_XOPEN
00046 #    define __USE_XOPEN
00047 #  endif
00048 #endif
00049 
00050 #include <sys/types.h>
00051 #include <sys/ioctl.h>
00052 #include <sys/time.h>
00053 #include <sys/resource.h>
00054 #include <sys/stat.h>
00055 #include <sys/param.h>
00056 
00057 #ifdef HAVE_SYS_STROPTS_H
00058 # include <sys/stropts.h>   // Defines I_PUSH
00059 # define _NEW_TTY_CTRL
00060 #endif
00061 
00062 #include <errno.h>
00063 #include <fcntl.h>
00064 #include <time.h>
00065 #include <stdlib.h>
00066 #include <stdio.h>
00067 #include <string.h>
00068 #include <unistd.h>
00069 #include <grp.h>
00070 
00071 #ifdef HAVE_LIBUTIL_H
00072 # include <libutil.h>
00073 # define USE_LOGIN
00074 #elif defined(HAVE_UTIL_H)
00075 # include <util.h>
00076 # define USE_LOGIN
00077 #endif
00078 
00079 #ifdef USE_LOGIN
00080 # include <utmp.h>
00081 #endif
00082 
00083 #ifdef HAVE_TERMIOS_H
00084 /* for HP-UX (some versions) the extern C is needed, and for other
00085    platforms it doesn't hurt */
00086 extern "C" {
00087 # include <termios.h>
00088 }
00089 #endif
00090 
00091 #if !defined(__osf__)
00092 # ifdef HAVE_TERMIO_H
00093 /* needed at least on AIX */
00094 #  include <termio.h>
00095 # endif
00096 #endif
00097 
00098 #if defined (__FreeBSD__) || defined (__NetBSD__) || defined (__OpenBSD__) || defined (__bsdi__) || defined(__APPLE__)
00099 # define _tcgetattr(fd, ttmode) ioctl(fd, TIOCGETA, (char *)ttmode)
00100 #else
00101 # if defined(_HPUX_SOURCE) || defined(__Lynx__)
00102 #  define _tcgetattr(fd, ttmode) tcgetattr(fd, ttmode)
00103 # else
00104 #  define _tcgetattr(fd, ttmode) ioctl(fd, TCGETS, (char *)ttmode)
00105 # endif
00106 #endif
00107 
00108 #if defined (__FreeBSD__) || defined (__NetBSD__) || defined (__OpenBSD__) || defined (__bsdi__) || defined(__APPLE__)
00109 # define _tcsetattr(fd, ttmode) ioctl(fd, TIOCSETA, (char *)ttmode)
00110 #else
00111 # ifdef _HPUX_SOURCE
00112 #  define _tcsetattr(fd, ttmode) tcsetattr(fd, TCSANOW, ttmode)
00113 # else
00114 #  define _tcsetattr(fd, ttmode) ioctl(fd, TCSETS, (char *)ttmode)
00115 # endif
00116 #endif
00117 
00118 #if defined (_HPUX_SOURCE)
00119 # define _TERMIOS_INCLUDED
00120 # include <bsdtty.h>
00121 #endif
00122 
00123 #if defined(HAVE_PTY_H)
00124 # include <pty.h>
00125 #endif
00126 
00127 #include <kdebug.h>
00128 #include <kstandarddirs.h>  // locate
00129 
00130 #define TTY_GROUP "tty"
00131 
00133 // private functions //
00135 
00136 #ifdef HAVE_UTEMPTER
00137 class KProcess_Utmp : public KProcess
00138 {
00139 public:
00140    int commSetupDoneC()
00141    {
00142      dup2(cmdFd, 0);
00143      dup2(cmdFd, 1);
00144      dup2(cmdFd, 3);
00145      return 1;
00146    }
00147    int cmdFd;
00148 };
00149 #endif
00150 
00151 #define BASE_CHOWN "kgrantpty"
00152 
00153 
00154 
00156 // private data //
00158 
00159 struct KPtyPrivate {
00160    KPtyPrivate() : 
00161      xonXoff(false),
00162      masterFd(-1), slaveFd(-1)
00163    { 
00164      memset(&winSize, 0, sizeof(winSize));
00165      winSize.ws_row = 24;
00166      winSize.ws_col = 80;
00167    }
00168 
00169    bool xonXoff : 1;
00170    int masterFd;
00171    int slaveFd;
00172    struct winsize winSize;
00173 
00174    QCString ttyName;
00175 };
00176 
00178 // public member functions //
00180 
00181 KPty::KPty()
00182 {
00183   d = new KPtyPrivate;
00184 }
00185 
00186 KPty::~KPty()
00187 {
00188   close();
00189   delete d;
00190 }
00191   
00192 bool KPty::open()
00193 {
00194   if (d->masterFd >= 0)
00195     return true;
00196 
00197   QCString ptyName;
00198 
00199   // Find a master pty that we can open ////////////////////////////////
00200 
00201   // Because not all the pty animals are created equal, they want to
00202   // be opened by several different methods.
00203 
00204   // We try, as we know them, one by one.
00205 
00206 #if defined(HAVE_PTSNAME) && defined(HAVE_GRANTPT)
00207 #ifdef _AIX
00208   d->masterFd = ::open("/dev/ptc",O_RDWR);
00209 #else
00210   d->masterFd = ::open("/dev/ptmx",O_RDWR);
00211 #endif
00212   if (d->masterFd >= 0)
00213   {
00214     char *ptsn = ptsname(d->masterFd);
00215     if (ptsn) {
00216         grantpt(d->masterFd);
00217         d->ttyName = ptsn;
00218         goto gotpty;
00219     } else {
00220        ::close(d->masterFd);
00221        d->masterFd = -1;
00222     }
00223   }
00224 #endif
00225 
00226   // Linux device names, FIXME: Trouble on other systems?
00227   for (const char* s3 = "pqrstuvwxyzabcdefghijklmno"; *s3; s3++)
00228   { 
00229     for (const char* s4 = "0123456789abcdefghijklmnopqrstuvwxyz"; *s4; s4++)
00230     { 
00231       ptyName.sprintf("/dev/pty%c%c", *s3, *s4);
00232       d->ttyName.sprintf("/dev/tty%c%c", *s3, *s4);
00233          
00234       d->masterFd = ::open(ptyName.data(), O_RDWR);
00235       if (d->masterFd >= 0)
00236       {
00237 #ifdef __sun
00238         /* Need to check the process group of the pty.
00239          * If it exists, then the slave pty is in use,
00240          * and we need to get another one.
00241          */
00242         int pgrp_rtn;
00243         if (ioctl(d->masterFd, TIOCGPGRP, &pgrp_rtn) == 0 || errno != EIO) {
00244           ::close(d->masterFd);
00245           d->masterFd = -1;
00246           continue;
00247         }
00248 #endif /* sun */
00249         if (!access(d->ttyName.data(),R_OK|W_OK)) // checks availability based on permission bits
00250         {
00251           if (!geteuid())
00252           {
00253             struct group* p = getgrnam(TTY_GROUP);
00254             if (!p)
00255               p = getgrnam("wheel");
00256             gid_t gid = p ? p->gr_gid : getgid ();
00257 
00258             chown(d->ttyName.data(), getuid(), gid);
00259             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IWGRP);
00260           }
00261           goto gotpty;
00262         }
00263         ::close(d->masterFd);
00264         d->masterFd = -1;
00265       }
00266     }
00267   }
00268 
00269   kdWarning(175) << "Can't open a pseudo teletype" << endl;
00270   return false;
00271 
00272  gotpty:
00273   struct stat st;
00274   if (stat(d->ttyName.data(), &st))
00275     return false; // this just cannot happen ... *cough*
00276   if (((st.st_uid != getuid()) ||
00277        (st.st_mode & (S_IRGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH))) &&
00278       !chownpty(true))
00279   {
00280     kdWarning(175)
00281       << "chownpty failed for device " << ptyName << "::" << d->ttyName
00282       << "\nThis means the communication can be eavesdropped." << endl;
00283   }
00284 
00285 #ifdef BSD
00286   revoke(d->ttyName.data());
00287 #endif
00288 
00289 #ifdef HAVE_UNLOCKPT
00290   unlockpt(d->masterFd);
00291 #endif
00292 
00293   d->slaveFd = ::open(d->ttyName.data(), O_RDWR);
00294   if (d->slaveFd < 0)
00295   {
00296     kdWarning(175) << "Can't open slave pseudo teletype" << endl;
00297     ::close(d->masterFd);
00298     d->masterFd = -1;
00299     return false;
00300   }
00301 
00302 #if (defined(__svr4__) || defined(__sgi__))
00303   // Solaris
00304   ioctl(d->slaveFd, I_PUSH, "ptem");
00305   ioctl(d->slaveFd, I_PUSH, "ldterm");
00306 #endif
00307 
00308     // set xon/xoff & control keystrokes
00309   // without the '::' some version of HP-UX thinks, this declares
00310   // the struct in this class, in this method, and fails to find 
00311   // the correct tc[gs]etattr 
00312   struct ::termios ttmode;
00313 
00314   _tcgetattr(d->slaveFd, &ttmode);
00315 
00316   if (!d->xonXoff)
00317     ttmode.c_iflag &= ~(IXOFF | IXON);
00318   else
00319     ttmode.c_iflag |= (IXOFF | IXON);
00320 
00321   ttmode.c_cc[VINTR] = CTRL('C' - '@');
00322   ttmode.c_cc[VQUIT] = CTRL('\\' - '@');
00323   ttmode.c_cc[VERASE] = 0177;
00324 
00325   _tcsetattr(d->slaveFd, &ttmode);
00326 
00327   // set screen size
00328   ioctl(d->slaveFd, TIOCSWINSZ, (char *)&d->winSize);
00329 
00330   fcntl(d->masterFd, F_SETFD, FD_CLOEXEC);
00331   fcntl(d->slaveFd, F_SETFD, FD_CLOEXEC);
00332 
00333   return true;
00334 }
00335 
00336 void KPty::close()
00337 {
00338    if (d->masterFd < 0)
00339       return;
00340    // don't bother resetting unix98 pty, it will go away after closing master anyway.
00341    if (memcmp(d->ttyName.data(), "/dev/pts/", 9)) {
00342       if (!geteuid()) {
00343          struct stat st;
00344          if (!stat(d->ttyName.data(), &st)) {
00345             chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
00346             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
00347      }
00348       } else {
00349          fcntl(d->masterFd, F_SETFD, 0);
00350          chownpty(false);
00351       }
00352    }
00353    ::close(d->slaveFd);
00354    ::close(d->masterFd);
00355    d->masterFd = d->slaveFd = -1;
00356 }
00357 
00358 void KPty::setCTty()
00359 {
00360     // Setup job control //////////////////////////////////
00361 
00362     // Become session leader, process group leader,
00363     // and get rid of the old controlling terminal.
00364     setsid();
00365 
00366     // make our slave pty the new controlling terminal.
00367 #ifdef TIOCSCTTY
00368     ioctl(d->slaveFd, TIOCSCTTY, 0);
00369 #else
00370     // SVR4 hack: the first tty opened after setsid() becomes controlling tty
00371     ::close(::open(d->ttyName, O_WRONLY, 0));
00372 #endif
00373 
00374     // make our new process group the foreground group on the pty
00375     int pgrp = getpid();
00376 #if defined(_POSIX_VERSION) || defined(__svr4__)
00377     tcsetpgrp (d->slaveFd, pgrp);
00378 #elif defined(TIOCSPGRP)
00379     ioctl(d->slaveFd, TIOCSPGRP, (char *)&pgrp);
00380 #endif
00381 }
00382 
00383 void KPty::login(const char *user, const char *remotehost)
00384 {
00385 #ifdef HAVE_UTEMPTER
00386     KProcess_Utmp utmp;
00387     utmp.cmdFd = d->masterFd;
00388     utmp << "/usr/sbin/utempter" << "-a" << d->ttyName << "";
00389     utmp.start(KProcess::Block);
00390     Q_UNUSED(user);
00391     Q_UNUSED(remotehost);
00392 #elif defined(USE_LOGIN)
00393     const char *str_ptr;
00394     struct utmp l_struct;
00395     memset(&l_struct, 0, sizeof(struct utmp));
00396     // note: strncpy without terminators _is_ correct here. man 4 utmp
00397 
00398     if (user)
00399       strncpy(l_struct.ut_name, user, UT_NAMESIZE);
00400 
00401     if (remotehost)
00402       strncpy(l_struct.ut_host, remotehost, UT_HOSTSIZE);
00403 
00404 # ifndef __GLIBC__
00405     str_ptr = d->ttyName.data();
00406     if (!memcmp(str_ptr, "/dev/", 5))
00407         str_ptr += 5;
00408     strncpy(l_struct.ut_line, str_ptr, UT_LINESIZE);
00409 # endif
00410 
00411     // Handle 64-bit time_t properly, where it may be larger
00412     // than the integral type of ut_time. 
00413     {
00414         time_t ut_time_temp;
00415         time(&ut_time_temp);
00416         l_struct.ut_time=ut_time_temp;
00417     }
00418 
00419     ::login(&l_struct);
00420 #else
00421     Q_UNUSED(user);
00422     Q_UNUSED(remotehost);
00423 #endif
00424 }
00425 
00426 void KPty::logout()
00427 {
00428 #ifdef HAVE_UTEMPTER
00429     KProcess_Utmp utmp;
00430     utmp.cmdFd = d->masterFd;
00431     utmp << "/usr/sbin/utempter" << "-d" << d->ttyName;
00432     utmp.start(KProcess::Block);
00433 #elif defined(USE_LOGIN)
00434     const char *str_ptr = d->ttyName.data();
00435     if (!memcmp(str_ptr, "/dev/", 5))
00436         str_ptr += 5;
00437 # ifdef __GLIBC__
00438     else {
00439         const char *sl_ptr = strrchr(str_ptr, '/');
00440         if (sl_ptr)
00441             str_ptr = sl_ptr + 1;
00442     }
00443 # endif
00444     ::logout(str_ptr);
00445 #endif
00446 }
00447 
00448 void KPty::setWinSize(int lines, int columns)
00449 {
00450   d->winSize.ws_row = (unsigned short)lines;
00451   d->winSize.ws_col = (unsigned short)columns;
00452   if (d->masterFd >= 0)
00453     ioctl( d->masterFd, TIOCSWINSZ, (char *)&d->winSize );
00454 }
00455   
00456 void KPty::setXonXoff(bool useXonXoff)
00457 {
00458   d->xonXoff = useXonXoff;
00459   if (d->masterFd >= 0) {
00460     // without the '::' some version of HP-UX thinks, this declares
00461     // the struct in this class, in this method, and fails to find 
00462     // the correct tc[gs]etattr 
00463     struct ::termios ttmode;
00464 
00465     _tcgetattr(d->masterFd, &ttmode);
00466 
00467     if (!useXonXoff)
00468       ttmode.c_iflag &= ~(IXOFF | IXON);
00469     else
00470       ttmode.c_iflag |= (IXOFF | IXON);
00471 
00472     _tcsetattr(d->masterFd, &ttmode);
00473   }
00474 }
00475 
00476 const char *KPty::ttyName() const
00477 {
00478     return d->ttyName.data();
00479 }
00480 
00481 int KPty::masterFd() const
00482 {
00483     return d->masterFd;
00484 }
00485 
00486 int KPty::slaveFd() const
00487 {
00488     return d->slaveFd;
00489 }
00490 
00491 // private
00492 bool KPty::chownpty(bool grant)
00493 {
00494   KProcess proc;
00495   proc << locate("exe", BASE_CHOWN) << (grant?"--grant":"--revoke") << QString::number(d->masterFd);
00496   return proc.start(KProcess::Block) && proc.normalExit() && !proc.exitStatus();
00497 }
00498 
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This file is part of the documentation for kdecore Library Version 3.2.0.
Documentation copyright © 1996-2004 the KDE developers.
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