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    int masterFd;
00176    int slaveFd;
00177    struct winsize winSize;
00178 
00179    QCString ttyName;
00180 };
00181 
00183 // public member functions //
00185 
00186 KPty::KPty()
00187 {
00188   d = new KPtyPrivate;
00189 }
00190 
00191 KPty::~KPty()
00192 {
00193   close();
00194   delete d;
00195 }
00196 
00197 bool KPty::open()
00198 {
00199   if (d->masterFd >= 0)
00200     return true;
00201 
00202   QCString ptyName;
00203 
00204   // Find a master pty that we can open ////////////////////////////////
00205 
00206   // Because not all the pty animals are created equal, they want to
00207   // be opened by several different methods.
00208 
00209   // We try, as we know them, one by one.
00210 
00211 #if defined(HAVE_PTSNAME) && defined(HAVE_GRANTPT)
00212 #ifdef _AIX
00213   d->masterFd = ::open("/dev/ptc",O_RDWR);
00214 #else
00215   d->masterFd = ::open("/dev/ptmx",O_RDWR);
00216 #endif
00217   if (d->masterFd >= 0)
00218   {
00219     char *ptsn = ptsname(d->masterFd);
00220     if (ptsn) {
00221         grantpt(d->masterFd);
00222         d->ttyName = ptsn;
00223         goto gotpty;
00224     } else {
00225        ::close(d->masterFd);
00226        d->masterFd = -1;
00227     }
00228   }
00229 #endif
00230 
00231   // Linux device names, FIXME: Trouble on other systems?
00232   for (const char* s3 = "pqrstuvwxyzabcdefghijklmno"; *s3; s3++)
00233   {
00234     for (const char* s4 = "0123456789abcdefghijklmnopqrstuvwxyz"; *s4; s4++)
00235     {
00236       ptyName.sprintf("/dev/pty%c%c", *s3, *s4);
00237       d->ttyName.sprintf("/dev/tty%c%c", *s3, *s4);
00238 
00239       d->masterFd = ::open(ptyName.data(), O_RDWR);
00240       if (d->masterFd >= 0)
00241       {
00242 #ifdef __sun
00243         /* Need to check the process group of the pty.
00244          * If it exists, then the slave pty is in use,
00245          * and we need to get another one.
00246          */
00247         int pgrp_rtn;
00248         if (ioctl(d->masterFd, TIOCGPGRP, &pgrp_rtn) == 0 || errno != EIO) {
00249           ::close(d->masterFd);
00250           d->masterFd = -1;
00251           continue;
00252         }
00253 #endif /* sun */
00254         if (!access(d->ttyName.data(),R_OK|W_OK)) // checks availability based on permission bits
00255         {
00256           if (!geteuid())
00257           {
00258             struct group* p = getgrnam(TTY_GROUP);
00259             if (!p)
00260               p = getgrnam("wheel");
00261             gid_t gid = p ? p->gr_gid : getgid ();
00262 
00263             chown(d->ttyName.data(), getuid(), gid);
00264             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IWGRP);
00265           }
00266           goto gotpty;
00267         }
00268         ::close(d->masterFd);
00269         d->masterFd = -1;
00270       }
00271     }
00272   }
00273 
00274   kdWarning(175) << "Can't open a pseudo teletype" << endl;
00275   return false;
00276 
00277  gotpty:
00278   struct stat st;
00279   if (stat(d->ttyName.data(), &st))
00280     return false; // this just cannot happen ... *cough*
00281   if (((st.st_uid != getuid()) ||
00282        (st.st_mode & (S_IRGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH))) &&
00283       !chownpty(true))
00284   {
00285     kdWarning(175)
00286       << "chownpty failed for device " << ptyName << "::" << d->ttyName
00287       << "\nThis means the communication can be eavesdropped." << endl;
00288   }
00289 
00290 #ifdef BSD
00291   revoke(d->ttyName.data());
00292 #endif
00293 
00294 #ifdef HAVE_UNLOCKPT
00295   unlockpt(d->masterFd);
00296 #endif
00297 
00298   d->slaveFd = ::open(d->ttyName.data(), O_RDWR | O_NOCTTY);
00299   if (d->slaveFd < 0)
00300   {
00301     kdWarning(175) << "Can't open slave pseudo teletype" << endl;
00302     ::close(d->masterFd);
00303     d->masterFd = -1;
00304     return false;
00305   }
00306 
00307 #if (defined(__svr4__) || defined(__sgi__))
00308   // Solaris
00309   ioctl(d->slaveFd, I_PUSH, "ptem");
00310   ioctl(d->slaveFd, I_PUSH, "ldterm");
00311 #endif
00312 
00313     // set xon/xoff & control keystrokes
00314   // without the '::' some version of HP-UX thinks, this declares
00315   // the struct in this class, in this method, and fails to find
00316   // the correct tc[gs]etattr
00317   struct ::termios ttmode;
00318 
00319   _tcgetattr(d->slaveFd, &ttmode);
00320 
00321   if (!d->xonXoff)
00322     ttmode.c_iflag &= ~(IXOFF | IXON);
00323   else
00324     ttmode.c_iflag |= (IXOFF | IXON);
00325 
00326   ttmode.c_cc[VINTR] = CTRL('C' - '@');
00327   ttmode.c_cc[VQUIT] = CTRL('\\' - '@');
00328   ttmode.c_cc[VERASE] = 0177;
00329 
00330   _tcsetattr(d->slaveFd, &ttmode);
00331 
00332   // set screen size
00333   ioctl(d->slaveFd, TIOCSWINSZ, (char *)&d->winSize);
00334 
00335   fcntl(d->masterFd, F_SETFD, FD_CLOEXEC);
00336   fcntl(d->slaveFd, F_SETFD, FD_CLOEXEC);
00337 
00338   return true;
00339 }
00340 
00341 void KPty::close()
00342 {
00343    if (d->masterFd < 0)
00344       return;
00345    // don't bother resetting unix98 pty, it will go away after closing master anyway.
00346    if (memcmp(d->ttyName.data(), "/dev/pts/", 9)) {
00347       if (!geteuid()) {
00348          struct stat st;
00349          if (!stat(d->ttyName.data(), &st)) {
00350             chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
00351             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
00352      }
00353       } else {
00354          fcntl(d->masterFd, F_SETFD, 0);
00355          chownpty(false);
00356       }
00357    }
00358    ::close(d->slaveFd);
00359    ::close(d->masterFd);
00360    d->masterFd = d->slaveFd = -1;
00361 }
00362 
00363 void KPty::setCTty()
00364 {
00365     // Setup job control //////////////////////////////////
00366 
00367     // Become session leader, process group leader,
00368     // and get rid of the old controlling terminal.
00369     setsid();
00370 
00371     // make our slave pty the new controlling terminal.
00372 #ifdef TIOCSCTTY
00373     ioctl(d->slaveFd, TIOCSCTTY, 0);
00374 #else
00375     // SVR4 hack: the first tty opened after setsid() becomes controlling tty
00376     ::close(::open(d->ttyName, O_WRONLY, 0));
00377 #endif
00378 
00379     // make our new process group the foreground group on the pty
00380     int pgrp = getpid();
00381 #if defined(_POSIX_VERSION) || defined(__svr4__)
00382     tcsetpgrp (d->slaveFd, pgrp);
00383 #elif defined(TIOCSPGRP)
00384     ioctl(d->slaveFd, TIOCSPGRP, (char *)&pgrp);
00385 #endif
00386 }
00387 
00388 void KPty::login(const char *user, const char *remotehost)
00389 {
00390 #ifdef HAVE_UTEMPTER
00391     KProcess_Utmp utmp;
00392     utmp.cmdFd = d->masterFd;
00393     utmp << "/usr/sbin/utempter" << "-a" << d->ttyName << "";
00394     utmp.start(KProcess::Block);
00395     Q_UNUSED(user);
00396     Q_UNUSED(remotehost);
00397 #elif defined(USE_LOGIN)
00398     const char *str_ptr;
00399     struct utmp l_struct;
00400     memset(&l_struct, 0, sizeof(struct utmp));
00401     // note: strncpy without terminators _is_ correct here. man 4 utmp
00402 
00403     if (user)
00404       strncpy(l_struct.ut_name, user, UT_NAMESIZE);
00405 
00406     if (remotehost)
00407       strncpy(l_struct.ut_host, remotehost, UT_HOSTSIZE);
00408 
00409 # ifndef __GLIBC__
00410     str_ptr = d->ttyName.data();
00411     if (!memcmp(str_ptr, "/dev/", 5))
00412         str_ptr += 5;
00413     strncpy(l_struct.ut_line, str_ptr, UT_LINESIZE);
00414 # endif
00415 
00416     // Handle 64-bit time_t properly, where it may be larger
00417     // than the integral type of ut_time.
00418     {
00419         time_t ut_time_temp;
00420         time(&ut_time_temp);
00421         l_struct.ut_time=ut_time_temp;
00422     }
00423 
00424     ::login(&l_struct);
00425 #else
00426     Q_UNUSED(user);
00427     Q_UNUSED(remotehost);
00428 #endif
00429 }
00430 
00431 void KPty::logout()
00432 {
00433 #ifdef HAVE_UTEMPTER
00434     KProcess_Utmp utmp;
00435     utmp.cmdFd = d->masterFd;
00436     utmp << "/usr/sbin/utempter" << "-d" << d->ttyName;
00437     utmp.start(KProcess::Block);
00438 #elif defined(USE_LOGIN)
00439     const char *str_ptr = d->ttyName.data();
00440     if (!memcmp(str_ptr, "/dev/", 5))
00441         str_ptr += 5;
00442 # ifdef __GLIBC__
00443     else {
00444         const char *sl_ptr = strrchr(str_ptr, '/');
00445         if (sl_ptr)
00446             str_ptr = sl_ptr + 1;
00447     }
00448 # endif
00449     ::logout(str_ptr);
00450 #endif
00451 }
00452 
00453 void KPty::setWinSize(int lines, int columns)
00454 {
00455   d->winSize.ws_row = (unsigned short)lines;
00456   d->winSize.ws_col = (unsigned short)columns;
00457   if (d->masterFd >= 0)
00458     ioctl( d->masterFd, TIOCSWINSZ, (char *)&d->winSize );
00459 }
00460 
00461 void KPty::setXonXoff(bool useXonXoff)
00462 {
00463   d->xonXoff = useXonXoff;
00464   if (d->masterFd >= 0) {
00465     // without the '::' some version of HP-UX thinks, this declares
00466     // the struct in this class, in this method, and fails to find
00467     // the correct tc[gs]etattr
00468     struct ::termios ttmode;
00469 
00470     _tcgetattr(d->masterFd, &ttmode);
00471 
00472     if (!useXonXoff)
00473       ttmode.c_iflag &= ~(IXOFF | IXON);
00474     else
00475       ttmode.c_iflag |= (IXOFF | IXON);
00476 
00477     _tcsetattr(d->masterFd, &ttmode);
00478   }
00479 }
00480 
00481 const char *KPty::ttyName() const
00482 {
00483     return d->ttyName.data();
00484 }
00485 
00486 int KPty::masterFd() const
00487 {
00488     return d->masterFd;
00489 }
00490 
00491 int KPty::slaveFd() const
00492 {
00493     return d->slaveFd;
00494 }
00495 
00496 // private
00497 bool KPty::chownpty(bool grant)
00498 {
00499   KProcess proc;
00500   proc << locate("exe", BASE_CHOWN) << (grant?"--grant":"--revoke") << QString::number(d->masterFd);
00501   return proc.start(KProcess::Block) && proc.normalExit() && !proc.exitStatus();
00502 }
00503 
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This file is part of the documentation for kdecore Library Version 3.3.2.
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