From 223ae57d468fdcac451209a095047a07a5698212 Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Mon, 8 Sep 2014 21:05:11 +0200 Subject: [PATCH] rework PTY magic to fix stair-stepping on kfreebsd A pty slave we have got from openpty can only be used for one dpkg child, if we give it to a second child on kfreebsd setting TIOCSCTTY fails causing the output to be stair-stepped from now on. By switching the code to creating a master and opening a new slave in the child for each child we can fix this glitch, so that at least the master remains stable. Closes: 759684 --- apt-pkg/deb/dpkgpm.cc | 159 ++++++++++++++++++++++++++++-------------- apt-pkg/deb/dpkgpm.h | 1 + 2 files changed, 107 insertions(+), 53 deletions(-) diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc index 5411d9ee8..04a13a86c 100644 --- a/apt-pkg/deb/dpkgpm.cc +++ b/apt-pkg/deb/dpkgpm.cc @@ -59,8 +59,8 @@ class pkgDPkgPMPrivate { public: pkgDPkgPMPrivate() : stdin_is_dev_null(false), dpkgbuf_pos(0), - term_out(NULL), history_out(NULL), - progress(NULL), master(-1), slave(-1) + term_out(NULL), history_out(NULL), + progress(NULL), master(-1), slave(NULL) { dpkgbuf[0] = '\0'; } @@ -77,9 +77,9 @@ public: APT::Progress::PackageManager *progress; // pty stuff - struct termios tt; + struct termios tt; int master; - int slave; + char * slave; // signals sigset_t sigmask; @@ -510,7 +510,7 @@ bool pkgDPkgPM::RunScriptsWithPkgs(const char *Cnf) return result; } /*}}}*/ -// DPkgPM::DoStdin - Read stdin and pass to slave pty /*{{{*/ +// DPkgPM::DoStdin - Read stdin and pass to master pty /*{{{*/ // --------------------------------------------------------------------- /* */ @@ -1051,60 +1051,127 @@ void pkgDPkgPM::StartPtyMagic() { if (_config->FindB("Dpkg::Use-Pty", true) == false) { - d->master = d->slave = -1; + d->master = -1; + if (d->slave != NULL) + free(d->slave); + d->slave = NULL; return; } - // setup the pty and stuff - struct winsize win; - + _error->PushToStack(); // if tcgetattr for both stdin/stdout returns 0 (no error) // we do the pty magic - _error->PushToStack(); - if (tcgetattr(STDIN_FILENO, &d->tt) == 0 && - tcgetattr(STDOUT_FILENO, &d->tt) == 0) + if (tcgetattr(STDOUT_FILENO, &d->tt) == 0 && + tcgetattr(STDIN_FILENO, &d->tt) == 0) { - if (ioctl(STDOUT_FILENO, TIOCGWINSZ, (char *)&win) < 0) - { - _error->Errno("ioctl", _("ioctl(TIOCGWINSZ) failed")); - } else if (openpty(&d->master, &d->slave, NULL, &d->tt, &win) < 0) - { - _error->Errno("openpty", _("Can not write log (%s)"), _("Is /dev/pts mounted?")); - d->master = d->slave = -1; - } else { - struct termios rtt; - rtt = d->tt; - cfmakeraw(&rtt); - rtt.c_lflag &= ~ECHO; - rtt.c_lflag |= ISIG; + d->master = posix_openpt(O_RDWR | O_NOCTTY); + if (d->master == -1) + _error->Errno("posix_openpt", _("Can not write log (%s)"), _("Is /dev/pts mounted?")); + else if (unlockpt(d->master) == -1) + { + _error->Errno("unlockpt", "Unlocking the slave of master fd %d failed!", d->master); + close(d->master); + d->master = -1; + } + else + { + char const * const slave_name = ptsname(d->master); + if (slave_name == NULL) + { + _error->Errno("unlockpt", "Getting name for slave of master fd %d failed!", d->master); + close(d->master); + d->master = -1; + } + else + { + d->slave = strdup(slave_name); + if (d->slave == NULL) + { + _error->Errno("strdup", "Copying name %s for slave of master fd %d failed!", slave_name, d->master); + close(d->master); + d->master = -1; + } + struct winsize win; + if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) < 0) + _error->Errno("ioctl", "Getting TIOCGWINSZ from stdout failed!"); + if (ioctl(d->master, TIOCSWINSZ, &win) < 0) + _error->Errno("ioctl", "Setting TIOCSWINSZ for master fd %d failed!", d->master); + if (tcsetattr(d->master, TCSANOW, &d->tt) == -1) + _error->Errno("tcsetattr", "Setting in Start via TCSANOW for master fd %d failed!", d->master); + + struct termios raw_tt; + raw_tt = d->tt; + cfmakeraw(&raw_tt); + raw_tt.c_lflag &= ~ECHO; + raw_tt.c_lflag |= ISIG; // block SIGTTOU during tcsetattr to prevent a hang if // the process is a member of the background process group // http://www.opengroup.org/onlinepubs/000095399/functions/tcsetattr.html sigemptyset(&d->sigmask); sigaddset(&d->sigmask, SIGTTOU); sigprocmask(SIG_BLOCK,&d->sigmask, &d->original_sigmask); - tcsetattr(0, TCSAFLUSH, &rtt); - sigprocmask(SIG_SETMASK, &d->original_sigmask, 0); - } + if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw_tt) == -1) + _error->Errno("tcsetattr", "Setting in Start via TCSAFLUSH for stdout failed!"); + sigprocmask(SIG_SETMASK, &d->original_sigmask, NULL); + } } - // complain only if stdout is either a terminal (but still failed) or is an invalid + } + else + { + // complain only if stdout is either a terminal (but still failed) or is an invalid // descriptor otherwise we would complain about redirection to e.g. /dev/null as well. - else if (isatty(STDOUT_FILENO) == 1 || errno == EBADF) - _error->Errno("tcgetattr", _("Can not write log (%s)"), _("Is stdout a terminal?")); + if (isatty(STDOUT_FILENO) == 1 || errno == EBADF) + _error->Errno("tcgetattr", _("Can not write log (%s)"), _("Is stdout a terminal?")); + } - if (_error->PendingError() == true) - _error->DumpErrors(std::cerr); - _error->RevertToStack(); + if (_error->PendingError() == true) + { + if (d->master != -1) + { + close(d->master); + d->master = -1; + } + _error->DumpErrors(std::cerr); + } + _error->RevertToStack(); } +void pkgDPkgPM::SetupSlavePtyMagic() +{ + if(d->master == -1) + return; + + if (close(d->master) == -1) + _error->FatalE("close", "Closing master %d in child failed!", d->master); + if (setsid() == -1) + _error->FatalE("setsid", "Starting a new session for child failed!"); + + int const slaveFd = open(d->slave, O_RDWR); + if (slaveFd == -1) + _error->FatalE("open", _("Can not write log (%s)"), _("Is /dev/pts mounted?")); + if (ioctl(slaveFd, TIOCSCTTY, 0) < 0) + _error->FatalE("ioctl", "Setting TIOCSCTTY for slave fd %d failed!", slaveFd); + else + { + for (unsigned short i = 0; i < 3; ++i) + if (dup2(slaveFd, i) == -1) + _error->FatalE("dup2", "Dupping %d to %d in child failed!", slaveFd, i); + + if (tcsetattr(0, TCSANOW, &d->tt) < 0) + _error->FatalE("tcsetattr", "Setting in Setup via TCSANOW for slave fd %d failed!", slaveFd); + } +} void pkgDPkgPM::StopPtyMagic() { - if(d->slave > 0) - close(d->slave); + if (d->slave != NULL) + free(d->slave); + d->slave = NULL; if(d->master >= 0) { - tcsetattr(0, TCSAFLUSH, &d->tt); + if (tcsetattr(0, TCSAFLUSH, &d->tt) == -1) + _error->FatalE("tcsetattr", "Setting in Stop via TCSAFLUSH for stdin failed!"); close(d->master); + d->master = -1; } } @@ -1416,22 +1483,8 @@ bool pkgDPkgPM::GoNoABIBreak(APT::Progress::PackageManager *progress) pid_t Child = ExecFork(KeepFDs); if (Child == 0) { - // This is the child - if(d->slave >= 0 && d->master >= 0) - { - setsid(); - int res = ioctl(d->slave, TIOCSCTTY, 0); - if (res < 0) { - std::cerr << "ioctl(TIOCSCTTY) failed for fd: " - << d->slave << std::endl; - } else { - close(d->master); - dup2(d->slave, 0); - dup2(d->slave, 1); - dup2(d->slave, 2); - close(d->slave); - } - } + // This is the child + SetupSlavePtyMagic(); close(fd[0]); // close the read end of the pipe dpkgChrootDirectory(); diff --git a/apt-pkg/deb/dpkgpm.h b/apt-pkg/deb/dpkgpm.h index 859c74b46..2c1805015 100644 --- a/apt-pkg/deb/dpkgpm.h +++ b/apt-pkg/deb/dpkgpm.h @@ -110,6 +110,7 @@ class pkgDPkgPM : public pkgPackageManager // helper void BuildPackagesProgressMap(); void StartPtyMagic(); + void SetupSlavePtyMagic(); void StopPtyMagic(); // input processing -- 2.45.2