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 // not defined on HP-UX for example
00131 #ifndef CTRL
00132 # define CTRL(x) ((x) & 037)
00133 #endif
00134 
00135 #define TTY_GROUP "tty"
00136 
00138 // private functions //
00140 
00141 #ifdef HAVE_UTEMPTER
00142 class KProcess_Utmp : public KProcess
00143 {
00144 public:
00145    int commSetupDoneC()
00146    {
00147      dup2(cmdFd, 0);
00148      dup2(cmdFd, 1);
00149      dup2(cmdFd, 3);
00150      return 1;
00151    }
00152    int cmdFd;
00153 };
00154 #endif
00155 
00156 #define BASE_CHOWN "kgrantpty"
00157 
00158 
00159 
00161 // private data //
00163 
00164 struct KPtyPrivate {
00165    KPtyPrivate() :
00166      xonXoff(false),
00167      masterFd(-1), slaveFd(-1)
00168    {
00169      memset(&winSize, 0, sizeof(winSize));
00170      winSize.ws_row = 24;
00171      winSize.ws_col = 80;
00172    }
00173 
00174    bool xonXoff : 1;
00175    bool utf8    : 1;
00176    int masterFd;
00177    int slaveFd;
00178    struct winsize winSize;
00179 
00180    QCString ttyName;
00181 };
00182 
00184 // public member functions //
00186 
00187 KPty::KPty()
00188 {
00189   d = new KPtyPrivate;
00190 }
00191 
00192 KPty::~KPty()
00193 {
00194   close();
00195   delete d;
00196 }
00197 
00198 bool KPty::open()
00199 {
00200   if (d->masterFd >= 0)
00201     return true;
00202 
00203   QCString ptyName;
00204 
00205   // Find a master pty that we can open ////////////////////////////////
00206 
00207   // Because not all the pty animals are created equal, they want to
00208   // be opened by several different methods.
00209 
00210   // We try, as we know them, one by one.
00211 
00212 #if defined(HAVE_PTSNAME) && defined(HAVE_GRANTPT)
00213 #ifdef _AIX
00214   d->masterFd = ::open("/dev/ptc",O_RDWR);
00215 #else
00216   d->masterFd = ::open("/dev/ptmx",O_RDWR);
00217 #endif
00218   if (d->masterFd >= 0)
00219   {
00220     char *ptsn = ptsname(d->masterFd);
00221     if (ptsn) {
00222         grantpt(d->masterFd);
00223         d->ttyName = ptsn;
00224         goto gotpty;
00225     } else {
00226        ::close(d->masterFd);
00227        d->masterFd = -1;
00228     }
00229   }
00230 #endif
00231 
00232   // Linux device names, FIXME: Trouble on other systems?
00233   for (const char* s3 = "pqrstuvwxyzabcdefghijklmno"; *s3; s3++)
00234   {
00235     for (const char* s4 = "0123456789abcdefghijklmnopqrstuvwxyz"; *s4; s4++)
00236     {
00237       ptyName.sprintf("/dev/pty%c%c", *s3, *s4);
00238       d->ttyName.sprintf("/dev/tty%c%c", *s3, *s4);
00239 
00240       d->masterFd = ::open(ptyName.data(), O_RDWR);
00241       if (d->masterFd >= 0)
00242       {
00243 #ifdef __sun
00244         /* Need to check the process group of the pty.
00245          * If it exists, then the slave pty is in use,
00246          * and we need to get another one.
00247          */
00248         int pgrp_rtn;
00249         if (ioctl(d->masterFd, TIOCGPGRP, &pgrp_rtn) == 0 || errno != EIO) {
00250           ::close(d->masterFd);
00251           d->masterFd = -1;
00252           continue;
00253         }
00254 #endif /* sun */
00255         if (!access(d->ttyName.data(),R_OK|W_OK)) // checks availability based on permission bits
00256         {
00257           if (!geteuid())
00258           {
00259             struct group* p = getgrnam(TTY_GROUP);
00260             if (!p)
00261               p = getgrnam("wheel");
00262             gid_t gid = p ? p->gr_gid : getgid ();
00263 
00264             chown(d->ttyName.data(), getuid(), gid);
00265             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IWGRP);
00266           }
00267           goto gotpty;
00268         }
00269         ::close(d->masterFd);
00270         d->masterFd = -1;
00271       }
00272     }
00273   }
00274 
00275   kdWarning(175) << "Can't open a pseudo teletype" << endl;
00276   return false;
00277 
00278  gotpty:
00279   struct stat st;
00280   if (stat(d->ttyName.data(), &st))
00281     return false; // this just cannot happen ... *cough*  Yeah right, I just
00282                   // had it happen when pty #349 was allocated.  I guess
00283                   // there was some sort of leak?  I only had a few open.
00284   if (((st.st_uid != getuid()) ||
00285        (st.st_mode & (S_IRGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH))) &&
00286       !chownpty(true))
00287   {
00288     kdWarning(175)
00289       << "chownpty failed for device " << ptyName << "::" << d->ttyName
00290       << "\nThis means the communication can be eavesdropped." << endl;
00291   }
00292 
00293 #ifdef BSD
00294   revoke(d->ttyName.data());
00295 #endif
00296 
00297 #ifdef HAVE_UNLOCKPT
00298   unlockpt(d->masterFd);
00299 #endif
00300 
00301   d->slaveFd = ::open(d->ttyName.data(), O_RDWR | O_NOCTTY);
00302   if (d->slaveFd < 0)
00303   {
00304     kdWarning(175) << "Can't open slave pseudo teletype" << endl;
00305     ::close(d->masterFd);
00306     d->masterFd = -1;
00307     return false;
00308   }
00309 
00310 #if (defined(__svr4__) || defined(__sgi__))
00311   // Solaris
00312   ioctl(d->slaveFd, I_PUSH, "ptem");
00313   ioctl(d->slaveFd, I_PUSH, "ldterm");
00314 #endif
00315 
00316     // set xon/xoff & control keystrokes
00317   // without the '::' some version of HP-UX thinks, this declares
00318   // the struct in this class, in this method, and fails to find
00319   // the correct tc[gs]etattr
00320   struct ::termios ttmode;
00321 
00322   _tcgetattr(d->slaveFd, &ttmode);
00323 
00324   if (!d->xonXoff)
00325     ttmode.c_iflag &= ~(IXOFF | IXON);
00326   else
00327     ttmode.c_iflag |= (IXOFF | IXON);
00328 
00329 #ifdef IUTF8
00330   if (!d->utf8)
00331     ttmode.c_iflag &= ~IUTF8;
00332   else
00333     ttmode.c_iflag |= IUTF8;
00334 #endif
00335 
00336   ttmode.c_cc[VINTR] = CTRL('C' - '@');
00337   ttmode.c_cc[VQUIT] = CTRL('\\' - '@');
00338   ttmode.c_cc[VERASE] = 0177;
00339 
00340   _tcsetattr(d->slaveFd, &ttmode);
00341 
00342   // set screen size
00343   ioctl(d->slaveFd, TIOCSWINSZ, (char *)&d->winSize);
00344 
00345   fcntl(d->masterFd, F_SETFD, FD_CLOEXEC);
00346   fcntl(d->slaveFd, F_SETFD, FD_CLOEXEC);
00347 
00348   return true;
00349 }
00350 
00351 void KPty::close()
00352 {
00353    if (d->masterFd < 0)
00354       return;
00355    // don't bother resetting unix98 pty, it will go away after closing master anyway.
00356    if (memcmp(d->ttyName.data(), "/dev/pts/", 9)) {
00357       if (!geteuid()) {
00358          struct stat st;
00359          if (!stat(d->ttyName.data(), &st)) {
00360             chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
00361             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
00362      }
00363       } else {
00364          fcntl(d->masterFd, F_SETFD, 0);
00365          chownpty(false);
00366       }
00367    }
00368    ::close(d->slaveFd);
00369    ::close(d->masterFd);
00370    d->masterFd = d->slaveFd = -1;
00371 }
00372 
00373 void KPty::setCTty()
00374 {
00375     // Setup job control //////////////////////////////////
00376 
00377     // Become session leader, process group leader,
00378     // and get rid of the old controlling terminal.
00379     setsid();
00380 
00381     // make our slave pty the new controlling terminal.
00382 #ifdef TIOCSCTTY
00383     ioctl(d->slaveFd, TIOCSCTTY, 0);
00384 #else
00385     // SVR4 hack: the first tty opened after setsid() becomes controlling tty
00386     ::close(::open(d->ttyName, O_WRONLY, 0));
00387 #endif
00388 
00389     // make our new process group the foreground group on the pty
00390     int pgrp = getpid();
00391 #if defined(_POSIX_VERSION) || defined(__svr4__)
00392     tcsetpgrp (d->slaveFd, pgrp);
00393 #elif defined(TIOCSPGRP)
00394     ioctl(d->slaveFd, TIOCSPGRP, (char *)&pgrp);
00395 #endif
00396 }
00397 
00398 void KPty::login(const char *user, const char *remotehost)
00399 {
00400 #ifdef HAVE_UTEMPTER
00401     KProcess_Utmp utmp;
00402     utmp.cmdFd = d->masterFd;
00403     utmp << "/usr/sbin/utempter" << "-a" << d->ttyName << "";
00404     utmp.start(KProcess::Block);
00405     Q_UNUSED(user);
00406     Q_UNUSED(remotehost);
00407 #elif defined(USE_LOGIN)
00408     const char *str_ptr;
00409     struct utmp l_struct;
00410     memset(&l_struct, 0, sizeof(struct utmp));
00411     // note: strncpy without terminators _is_ correct here. man 4 utmp
00412 
00413     if (user)
00414       strncpy(l_struct.ut_name, user, UT_NAMESIZE);
00415 
00416     if (remotehost)
00417       strncpy(l_struct.ut_host, remotehost, UT_HOSTSIZE);
00418 
00419 # ifndef __GLIBC__
00420     str_ptr = d->ttyName.data();
00421     if (!memcmp(str_ptr, "/dev/", 5))
00422         str_ptr += 5;
00423     strncpy(l_struct.ut_line, str_ptr, UT_LINESIZE);
00424 # endif
00425 
00426     // Handle 64-bit time_t properly, where it may be larger
00427     // than the integral type of ut_time.
00428     {
00429         time_t ut_time_temp;
00430         time(&ut_time_temp);
00431         l_struct.ut_time=ut_time_temp;
00432     }
00433 
00434     ::login(&l_struct);
00435 #else
00436     Q_UNUSED(user);
00437     Q_UNUSED(remotehost);
00438 #endif
00439 }
00440 
00441 void KPty::logout()
00442 {
00443 #ifdef HAVE_UTEMPTER
00444     KProcess_Utmp utmp;
00445     utmp.cmdFd = d->masterFd;
00446     utmp << "/usr/sbin/utempter" << "-d" << d->ttyName;
00447     utmp.start(KProcess::Block);
00448 #elif defined(USE_LOGIN)
00449     const char *str_ptr = d->ttyName.data();
00450     if (!memcmp(str_ptr, "/dev/", 5))
00451         str_ptr += 5;
00452 # ifdef __GLIBC__
00453     else {
00454         const char *sl_ptr = strrchr(str_ptr, '/');
00455         if (sl_ptr)
00456             str_ptr = sl_ptr + 1;
00457     }
00458 # endif
00459     ::logout(str_ptr);
00460 #endif
00461 }
00462 
00463 void KPty::setWinSize(int lines, int columns)
00464 {
00465   d->winSize.ws_row = (unsigned short)lines;
00466   d->winSize.ws_col = (unsigned short)columns;
00467   if (d->masterFd >= 0)
00468     ioctl( d->masterFd, TIOCSWINSZ, (char *)&d->winSize );
00469 }
00470 
00471 void KPty::setXonXoff(bool useXonXoff)
00472 {
00473   d->xonXoff = useXonXoff;
00474   if (d->masterFd >= 0) {
00475     // without the '::' some version of HP-UX thinks, this declares
00476     // the struct in this class, in this method, and fails to find
00477     // the correct tc[gs]etattr
00478     struct ::termios ttmode;
00479 
00480     _tcgetattr(d->masterFd, &ttmode);
00481 
00482     if (!useXonXoff)
00483       ttmode.c_iflag &= ~(IXOFF | IXON);
00484     else
00485       ttmode.c_iflag |= (IXOFF | IXON);
00486 
00487     _tcsetattr(d->masterFd, &ttmode);
00488   }
00489 }
00490 
00491 void KPty::setUtf8Mode(bool useUtf8)
00492 {
00493   d->utf8 = useUtf8;
00494   if (d->masterFd >= 0) {
00495     // without the '::' some version of HP-UX thinks, this declares
00496     // the struct in this class, in this method, and fails to find
00497     // the correct tc[gs]etattr
00498     struct ::termios ttmode;
00499 
00500 #ifdef IUTF8
00501     _tcgetattr(d->masterFd, &ttmode);
00502 
00503     if (!useUtf8)
00504       ttmode.c_iflag &= ~IUTF8;
00505     else
00506       ttmode.c_iflag |= IUTF8;
00507 
00508     _tcsetattr(d->masterFd, &ttmode);
00509 #endif
00510   }
00511 }
00512 
00513 const char *KPty::ttyName() const
00514 {
00515     return d->ttyName.data();
00516 }
00517 
00518 int KPty::masterFd() const
00519 {
00520     return d->masterFd;
00521 }
00522 
00523 int KPty::slaveFd() const
00524 {
00525     return d->slaveFd;
00526 }
00527 
00528 // private
00529 bool KPty::chownpty(bool grant)
00530 {
00531   KProcess proc;
00532   proc << locate("exe", BASE_CHOWN) << (grant?"--grant":"--revoke") << QString::number(d->masterFd);
00533   return proc.start(KProcess::Block) && proc.normalExit() && !proc.exitStatus();
00534 }
00535 
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