kpty/kpty.cpp

   1 /*
   2
   3    This file is part of the KDE libraries
   4    Copyright (C) 2002 Waldo Bastian <bastian@kde.org>
   5    Copyright (C) 2002-2003,2007-2008 Oswald Buddenhagen <ossi@kde.org>
   6
   7    This library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Library General Public
   9    License as published by the Free Software Foundation; either
  10    version 2 of the License, or (at your option) any later version.
  11
  12    This library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Library General Public License for more details.
  16
  17    You should have received a copy of the GNU Library General Public License
  18    along with this library; see the file COPYING.LIB.  If not, write to
  19    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.
  21 */
  22
  23 #include "kpty_p.h"
  24
  25 #include <config.h>
  26
  27 #ifdef __sgi
  28 #define __svr4__
  29 #endif
  30
  31 #ifdef __osf__
  32 #define _OSF_SOURCE
  33 #include <float.h>
  34 #endif
  35
  36 #ifdef _AIX
  37 #define _ALL_SOURCE
  38 #endif
  39
  40 // __USE_XOPEN isn't defined by default in ICC
  41 // (needed for ptsname(), grantpt() and unlockpt())
  42 #ifdef __INTEL_COMPILER
  43 #  ifndef __USE_XOPEN
  44 #    define __USE_XOPEN
  45 #  endif
  46 #endif
  47
  48 #include <sys/types.h>
  49 #include <sys/ioctl.h>
  50 #include <sys/time.h>
  51 #include <sys/resource.h>
  52 #include <sys/stat.h>
  53 #include <sys/param.h>
  54
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <time.h>
  58 #include <stdlib.h>
  59 #include <stdio.h>
  60 #include <string.h>
  61 #include <unistd.h>
  62 #include <grp.h>
  63
  64 #if defined(HAVE_PTY_H)
  65 # include <pty.h>
  66 #endif
  67
  68 #ifdef HAVE_LIBUTIL_H
  69 # include <libutil.h>
  70 #elif defined(HAVE_UTIL_H)
  71 # include <util.h>
  72 #endif
  73
  74 #ifdef HAVE_UTEMPTER
  75 extern "C" {
  76 # include <utempter.h>
  77 }
  78 #else
  79 # include <utmp.h>
  80 # ifdef HAVE_UTMPX
  81 #  include <utmpx.h>
  82 # endif
  83 # if !defined(_PATH_UTMPX) && defined(_UTMPX_FILE)
  84 #  define _PATH_UTMPX _UTMPX_FILE
  85 # endif
  86 # if !defined(_PATH_WTMPX) && defined(_WTMPX_FILE)
  87 #  define _PATH_WTMPX _WTMPX_FILE
  88 # endif
  89 #endif
  90
  91 /* for HP-UX (some versions) the extern C is needed, and for other
  92    platforms it doesn't hurt */
  93 extern "C" {
  94 #include <termios.h>
  95 #if defined(HAVE_TERMIO_H)
  96 # include <termio.h> // struct winsize on some systems
  97 #endif
  98 }
  99
 100 #if defined (_HPUX_SOURCE)
 101 # define _TERMIOS_INCLUDED
 102 # include <bsdtty.h>
 103 #endif
 104
 105 #ifdef HAVE_SYS_STROPTS_H
 106 # include <sys/stropts.h>       // Defines I_PUSH
 107 # define _NEW_TTY_CTRL
 108 #endif
 109
 110 #if defined (__FreeBSD__) || defined (__NetBSD__) || defined (__OpenBSD__) || defined (__bsdi__) || defined(__APPLE__) || defined (__DragonFly__)
 111 # define _tcgetattr(fd, ttmode) ioctl(fd, TIOCGETA, (char *)ttmode)
 112 #else
 113 # if defined(_HPUX_SOURCE) || defined(__Lynx__) || defined (__CYGWIN__)
 114 #  define _tcgetattr(fd, ttmode) tcgetattr(fd, ttmode)
 115 # else
 116 #  define _tcgetattr(fd, ttmode) ioctl(fd, TCGETS, (char *)ttmode)
 117 # endif
 118 #endif
 119
 120 #if defined (__FreeBSD__) || defined (__NetBSD__) || defined (__OpenBSD__) || defined (__bsdi__) || defined(__APPLE__) || defined (__DragonFly__)
 121 # define _tcsetattr(fd, ttmode) ioctl(fd, TIOCSETA, (char *)ttmode)
 122 #else
 123 # if defined(_HPUX_SOURCE) || defined(__CYGWIN__)
 124 #  define _tcsetattr(fd, ttmode) tcsetattr(fd, TCSANOW, ttmode)
 125 # else
 126 #  define _tcsetattr(fd, ttmode) ioctl(fd, TCSETS, (char *)ttmode)
 127 # endif
 128 #endif
 129
 130 #include <kdebug.h>
 131 #include <kstandarddirs.h>      // findExe
 132 #include <kde_file.h>
 133
 134 #include <QtCore/Q_PID>
 135
 136 #define TTY_GROUP "tty"
 137
 138 ///////////////////////
 139 // private functions //
 140 ///////////////////////
 141
 142 //////////////////
 143 // private data //
 144 //////////////////
 145
 146 KPtyPrivate::KPtyPrivate(KPty* parent) :
 147     masterFd(-1), slaveFd(-1), ownMaster(true), q_ptr(parent)
 148 {
 149 }
 150
 151 KPtyPrivate::~KPtyPrivate()
 152 {
 153 }
 154
 155 #ifndef HAVE_OPENPTY
 156 bool KPtyPrivate::chownpty(bool grant)
 157 {
 158     return !QProcess::execute(KStandardDirs::findExe("kgrantpty"),
 159         QStringList() << (grant?"--grant":"--revoke") << QString::number(masterFd));
 160 }
 161 #endif
 162
 163 /////////////////////////////
 164 // public member functions //
 165 /////////////////////////////
 166
 167 KPty::KPty() :
 168     d_ptr(new KPtyPrivate(this))
 169 {
 170 }
 171
 172 KPty::KPty(KPtyPrivate *d) :
 173     d_ptr(d)
 174 {
 175     d_ptr->q_ptr = this;
 176 }
 177
 178 KPty::~KPty()
 179 {
 180     close();
 181     delete d_ptr;
 182 }
 183
 184 bool KPty::open()
 185 {
 186   Q_D(KPty);
 187
 188   if (d->masterFd >= 0)
 189     return true;
 190
 191   d->ownMaster = true;
 192
 193   QByteArray ptyName;
 194
 195   // Find a master pty that we can open ////////////////////////////////
 196
 197   // Because not all the pty animals are created equal, they want to
 198   // be opened by several different methods.
 199
 200   // We try, as we know them, one by one.
 201
 202 #ifdef HAVE_OPENPTY
 203
 204   char ptsn[PATH_MAX];
 205   if (::openpty( &d->masterFd, &d->slaveFd, ptsn, 0, 0))
 206   {
 207     d->masterFd = -1;
 208     d->slaveFd = -1;
 209     kWarning(175) << "Can't open a pseudo teletype";
 210     return false;
 211   }
 212   d->ttyName = ptsn;
 213
 214 #else
 215
 216 #ifdef HAVE__GETPTY // irix
 217
 218   char *ptsn = _getpty(&d->masterFd, O_RDWR|O_NOCTTY, S_IRUSR|S_IWUSR, 0);
 219   if (ptsn) {
 220     d->ttyName = ptsn;
 221     goto grantedpt;
 222   }
 223
 224 #elif defined(HAVE_PTSNAME) || defined(TIOCGPTN)
 225
 226 #ifdef HAVE_POSIX_OPENPT
 227   d->masterFd = ::posix_openpt(O_RDWR|O_NOCTTY);
 228 #elif defined(HAVE_GETPT)
 229   d->masterFd = ::getpt();
 230 #elif defined(PTM_DEVICE)
 231   d->masterFd = KDE_open(PTM_DEVICE, O_RDWR|O_NOCTTY);
 232 #else
 233 # error No method to open a PTY master detected.
 234 #endif
 235   if (d->masterFd >= 0)
 236   {
 237 #ifdef HAVE_PTSNAME
 238     char *ptsn = ptsname(d->masterFd);
 239     if (ptsn) {
 240         d->ttyName = ptsn;
 241 #else
 242     int ptyno;
 243     if (!ioctl(d->masterFd, TIOCGPTN, &ptyno)) {
 244         char buf[32];
 245         sprintf(buf, "/dev/pts/%d", ptyno);
 246         d->ttyName = buf;
 247 #endif
 248 #ifdef HAVE_GRANTPT
 249         if (!grantpt(d->masterFd))
 250            goto grantedpt;
 251 #else
 252         goto gotpty;
 253 #endif
 254     }
 255     ::close(d->masterFd);
 256     d->masterFd = -1;
 257   }
 258 #endif // HAVE_PTSNAME || TIOCGPTN
 259
 260   // Linux device names, FIXME: Trouble on other systems?
 261   for (const char* s3 = "pqrstuvwxyzabcde"; *s3; s3++)
 262   {
 263     for (const char* s4 = "0123456789abcdef"; *s4; s4++)
 264     {
 265       ptyName = QString().sprintf("/dev/pty%c%c", *s3, *s4).toAscii();
 266       d->ttyName = QString().sprintf("/dev/tty%c%c", *s3, *s4).toAscii();
 267
 268       d->masterFd = KDE_open(ptyName.data(), O_RDWR);
 269       if (d->masterFd >= 0)
 270       {
 271 #ifdef Q_OS_SOLARIS
 272         /* Need to check the process group of the pty.
 273          * If it exists, then the slave pty is in use,
 274          * and we need to get another one.
 275          */
 276         int pgrp_rtn;
 277         if (ioctl(d->masterFd, TIOCGPGRP, &pgrp_rtn) == 0 || errno != EIO) {
 278           ::close(d->masterFd);
 279           d->masterFd = -1;
 280           continue;
 281         }
 282 #endif /* Q_OS_SOLARIS */
 283         if (!access(d->ttyName.data(),R_OK|W_OK)) // checks availability based on permission bits
 284         {
 285           if (!geteuid())
 286           {
 287             struct group* p = getgrnam(TTY_GROUP);
 288             if (!p)
 289               p = getgrnam("wheel");
 290             gid_t gid = p ? p->gr_gid : getgid ();
 291
 292             chown(d->ttyName.data(), getuid(), gid);
 293             chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IWGRP);
 294           }
 295           goto gotpty;
 296         }
 297         ::close(d->masterFd);
 298         d->masterFd = -1;
 299       }
 300     }
 301   }
 302
 303   kWarning(175) << "Can't open a pseudo teletype";
 304   return false;
 305
 306  gotpty:
 307   KDE_struct_stat st;
 308   if (KDE_stat(d->ttyName.data(), &st))
 309     return false; // this just cannot happen ... *cough*  Yeah right, I just
 310                   // had it happen when pty #349 was allocated.  I guess
 311                   // there was some sort of leak?  I only had a few open.
 312   if (((st.st_uid != getuid()) ||
 313        (st.st_mode & (S_IRGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH))) &&
 314       !d->chownpty(true))
 315   {
 316     kWarning(175)
 317       << "chownpty failed for device " << ptyName << "::" << d->ttyName
 318       << "\nThis means the communication can be eavesdropped." << endl;
 319   }
 320
 321  grantedpt:
 322
 323 #ifdef HAVE_REVOKE
 324   revoke(d->ttyName.data());
 325 #endif
 326
 327 #ifdef HAVE_UNLOCKPT
 328   unlockpt(d->masterFd);
 329 #elif defined(TIOCSPTLCK)
 330   int flag = 0;
 331   ioctl(d->masterFd, TIOCSPTLCK, &flag);
 332 #endif
 333
 334   d->slaveFd = KDE_open(d->ttyName.data(), O_RDWR | O_NOCTTY);
 335   if (d->slaveFd < 0)
 336   {
 337     kWarning(175) << "Can't open slave pseudo teletype";
 338     ::close(d->masterFd);
 339     d->masterFd = -1;
 340     return false;
 341   }
 342
 343 #if (defined(__svr4__) || defined(__sgi__))
 344   // Solaris
 345   ioctl(d->slaveFd, I_PUSH, "ptem");
 346   ioctl(d->slaveFd, I_PUSH, "ldterm");
 347 #endif
 348
 349 #endif /* HAVE_OPENPTY */
 350
 351   fcntl(d->masterFd, F_SETFD, FD_CLOEXEC);
 352   fcntl(d->slaveFd, F_SETFD, FD_CLOEXEC);
 353
 354   return true;
 355 }
 356
 357 bool KPty::open(int fd)
 358 {
 359 #if !defined(HAVE_PTSNAME) && !defined(TIOCGPTN)
 360     kWarning(175) << "Unsupported attempt to open pty with fd" << fd;
 361     return false;
 362 #else
 363     Q_D(KPty);
 364
 365     if (d->masterFd >= 0) {
 366         kWarning(175) << "Attempting to open an already open pty";
 367         return false;
 368     }
 369
 370     d->ownMaster = false;
 371
 372 # ifdef HAVE_PTSNAME
 373     char *ptsn = ptsname(fd);
 374     if (ptsn) {
 375         d->ttyName = ptsn;
 376 # else
 377     int ptyno;
 378     if (!ioctl(fd, TIOCGPTN, &ptyno)) {
 379         char buf[32];
 380         sprintf(buf, "/dev/pts/%d", ptyno);
 381         d->ttyName = buf;
 382 # endif
 383     } else {
 384         kWarning(175) << "Failed to determine pty slave device for fd" << fd;
 385         return false;
 386     }
 387
 388     d->masterFd = fd;
 389     if (!openSlave()) {
 390         d->masterFd = -1;
 391         return false;
 392     }
 393
 394     return true;
 395 #endif
 396 }
 397
 398 void KPty::closeSlave()
 399 {
 400     Q_D(KPty);
 401
 402     if (d->slaveFd < 0)
 403         return;
 404     ::close(d->slaveFd);
 405     d->slaveFd = -1;
 406 }
 407
 408 bool KPty::openSlave()
 409 {
 410     Q_D(KPty);
 411
 412     if (d->slaveFd >= 0)
 413         return true;
 414     if (d->masterFd < 0) {
 415         kWarning(175) << "Attempting to open pty slave while master is closed";
 416         return false;
 417     }
 418     d->slaveFd = KDE_open(d->ttyName.data(), O_RDWR | O_NOCTTY);
 419     if (d->slaveFd < 0) {
 420         kWarning(175) << "Can't open slave pseudo teletype";
 421         return false;
 422     }
 423     fcntl(d->slaveFd, F_SETFD, FD_CLOEXEC);
 424     return true;
 425 }
 426
 427 void KPty::close()
 428 {
 429     Q_D(KPty);
 430
 431     if (d->masterFd < 0)
 432         return;
 433     closeSlave();
 434     if (d->ownMaster) {
 435 #ifndef HAVE_OPENPTY
 436         // don't bother resetting unix98 pty, it will go away after closing master anyway.
 437         if (memcmp(d->ttyName.data(), "/dev/pts/", 9)) {
 438             if (!geteuid()) {
 439                 struct stat st;
 440                 if (!stat(d->ttyName.data(), &st)) {
 441                     chown(d->ttyName.data(), 0, st.st_gid == getgid() ? 0 : -1);
 442                     chmod(d->ttyName.data(), S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
 443                 }
 444             } else {
 445                 fcntl(d->masterFd, F_SETFD, 0);
 446                 d->chownpty(false);
 447             }
 448         }
 449 #endif
 450         ::close(d->masterFd);
 451     }
 452     d->masterFd = -1;
 453 }
 454
 455 void KPty::setCTty()
 456 {
 457     Q_D(KPty);
 458
 459     // Setup job control //////////////////////////////////
 460
 461     // Become session leader, process group leader,
 462     // and get rid of the old controlling terminal.
 463     setsid();
 464
 465     // make our slave pty the new controlling terminal.
 466 #ifdef TIOCSCTTY
 467     ioctl(d->slaveFd, TIOCSCTTY, 0);
 468 #else
 469     // __svr4__ hack: the first tty opened after setsid() becomes controlling tty
 470     ::close(KDE_open(d->ttyName, O_WRONLY, 0));
 471 #endif
 472
 473     // make our new process group the foreground group on the pty
 474     int pgrp = getpid();
 475 #if defined(_POSIX_VERSION) || defined(__svr4__)
 476     tcsetpgrp(d->slaveFd, pgrp);
 477 #elif defined(TIOCSPGRP)
 478     ioctl(d->slaveFd, TIOCSPGRP, (char *)&pgrp);
 479 #endif
 480 }
 481
 482 void KPty::login(const char *user, const char *remotehost)
 483 {
 484 #ifdef HAVE_UTEMPTER
 485     Q_D(KPty);
 486
 487     addToUtmp(d->ttyName, remotehost, d->masterFd);
 488     Q_UNUSED(user);
 489 #else
 490 # ifdef HAVE_UTMPX
 491     struct utmpx l_struct;
 492 # else
 493     struct utmp l_struct;
 494 # endif
 495     memset(&l_struct, 0, sizeof(l_struct));
 496     // note: strncpy without terminators _is_ correct here. man 4 utmp
 497
 498     if (user)
 499       strncpy(l_struct.ut_name, user, sizeof(l_struct.ut_name));
 500
 501     if (remotehost) {
 502       strncpy(l_struct.ut_host, remotehost, sizeof(l_struct.ut_host));
 503 # ifdef HAVE_STRUCT_UTMP_UT_SYSLEN
 504       l_struct.ut_syslen = qMin(strlen(remotehost), sizeof(l_struct.ut_host));
 505 # endif
 506     }
 507
 508 # ifndef __GLIBC__
 509     Q_D(KPty);
 510     const char *str_ptr = d->ttyName.data();
 511     if (!memcmp(str_ptr, "/dev/", 5))
 512         str_ptr += 5;
 513     strncpy(l_struct.ut_line, str_ptr, sizeof(l_struct.ut_line));
 514 #  ifdef HAVE_STRUCT_UTMP_UT_ID
 515     strncpy(l_struct.ut_id,
 516             str_ptr + strlen(str_ptr) - sizeof(l_struct.ut_id),
 517             sizeof(l_struct.ut_id));
 518 #  endif
 519 # endif
 520
 521 # ifdef HAVE_UTMPX
 522     gettimeofday(&l_struct.ut_tv, 0);
 523 # else
 524     l_struct.ut_time = time(0);
 525 # endif
 526
 527 # ifdef HAVE_LOGIN
 528 #  ifdef HAVE_LOGINX
 529     ::loginx(&l_struct);
 530 #  else
 531     ::login(&l_struct);
 532 #  endif
 533 # else
 534 #  ifdef HAVE_STRUCT_UTMP_UT_TYPE
 535     l_struct.ut_type = USER_PROCESS;
 536 #  endif
 537 #  ifdef HAVE_STRUCT_UTMP_UT_PID
 538     l_struct.ut_pid = getpid();
 539 #   ifdef HAVE_STRUCT_UTMP_UT_SESSION
 540     l_struct.ut_session = getsid(0);
 541 #   endif
 542 #  endif
 543 #  ifdef HAVE_UTMPX
 544     utmpxname(_PATH_UTMPX);
 545     setutxent();
 546     pututxline(&l_struct);
 547     endutxent();
 548     updwtmpx(_PATH_WTMPX, &l_struct);
 549 #  else
 550     utmpname(_PATH_UTMP);
 551     setutent();
 552     pututline(&l_struct);
 553     endutent();
 554     updwtmp(_PATH_WTMP, &l_struct);
 555 #  endif
 556 # endif
 557 #endif
 558 }
 559
 560 void KPty::logout()
 561 {
 562 #ifdef HAVE_UTEMPTER
 563     Q_D(KPty);
 564
 565     removeLineFromUtmp(d->ttyName, d->masterFd);
 566 #else
 567     Q_D(KPty);
 568
 569     const char *str_ptr = d->ttyName.data();
 570     if (!memcmp(str_ptr, "/dev/", 5))
 571         str_ptr += 5;
 572 # ifdef __GLIBC__
 573     else {
 574         const char *sl_ptr = strrchr(str_ptr, '/');
 575         if (sl_ptr)
 576             str_ptr = sl_ptr + 1;
 577     }
 578 # endif
 579 # ifdef HAVE_LOGIN
 580 #  ifdef HAVE_LOGINX
 581     ::logoutx(str_ptr, 0, DEAD_PROCESS);
 582 #  else
 583     ::logout(str_ptr);
 584 #  endif
 585 # else
 586 #  ifdef HAVE_UTMPX
 587     struct utmpx l_struct, *ut;
 588 #  else
 589     struct utmp l_struct, *ut;
 590 #  endif
 591     memset(&l_struct, 0, sizeof(l_struct));
 592
 593     strncpy(l_struct.ut_line, str_ptr, sizeof(l_struct.ut_line));
 594
 595 #  ifdef HAVE_UTMPX
 596     utmpxname(_PATH_UTMPX);
 597     setutxent();
 598     if ((ut = getutxline(&l_struct))) {
 599 #  else
 600     utmpname(_PATH_UTMP);
 601     setutent();
 602     if ((ut = getutline(&l_struct))) {
 603 #  endif
 604         memset(ut->ut_name, 0, sizeof(*ut->ut_name));
 605         memset(ut->ut_host, 0, sizeof(*ut->ut_host));
 606 #  ifdef HAVE_STRUCT_UTMP_UT_SYSLEN
 607         ut->ut_syslen = 0;
 608 #  endif
 609 #  ifdef HAVE_STRUCT_UTMP_UT_TYPE
 610         ut->ut_type = DEAD_PROCESS;
 611 #  endif
 612 #  ifdef HAVE_UTMPX
 613         gettimeofday(&(ut->ut_tv), 0);
 614         pututxline(ut);
 615     }
 616     endutxent();
 617 #  else
 618         ut->ut_time = time(0);
 619         pututline(ut);
 620     }
 621     endutent();
 622 #  endif
 623 # endif
 624 #endif
 625 }
 626
 627 // XXX Supposedly, tc[gs]etattr do not work with the master on Solaris.
 628 // Please verify.
 629
 630 bool KPty::tcGetAttr(struct ::termios *ttmode) const
 631 {
 632     Q_D(const KPty);
 633
 634     return _tcgetattr(d->masterFd, ttmode) == 0;
 635 }
 636
 637 bool KPty::tcSetAttr(struct ::termios *ttmode)
 638 {
 639     Q_D(KPty);
 640
 641     return _tcsetattr(d->masterFd, ttmode) == 0;
 642 }
 643
 644 bool KPty::setWinSize(int lines, int columns)
 645 {
 646     Q_D(KPty);
 647
 648     struct winsize winSize;
 649     memset(&winSize, 0, sizeof(winSize));
 650     winSize.ws_row = (unsigned short)lines;
 651     winSize.ws_col = (unsigned short)columns;
 652     return ioctl(d->masterFd, TIOCSWINSZ, (char *)&winSize) == 0;
 653 }
 654
 655 bool KPty::setEcho(bool echo)
 656 {
 657     struct ::termios ttmode;
 658     if (!tcGetAttr(&ttmode))
 659         return false;
 660     if (!echo)
 661         ttmode.c_lflag &= ~ECHO;
 662     else
 663         ttmode.c_lflag |= ECHO;
 664     return tcSetAttr(&ttmode);
 665 }
 666
 667 const char *KPty::ttyName() const
 668 {
 669     Q_D(const KPty);
 670
 671     return d->ttyName.data();
 672 }
 673
 674 int KPty::masterFd() const
 675 {
 676     Q_D(const KPty);
 677
 678     return d->masterFd;
 679 }
 680
 681 int KPty::slaveFd() const
 682 {
 683     Q_D(const KPty);
 684
 685     return d->slaveFd;
 686 }