Soumendra Ganguly: add os.login_tty() for *nix.

Signed-off-by: Soumendra Ganguly <soumendraganguly@gmail.com>
This commit is contained in:
Soumendra Ganguly 2020-12-17 03:23:48 -06:00
parent 67b769f515
commit ddc3219f3a
5 changed files with 241 additions and 14 deletions

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@ -990,6 +990,17 @@ as internal buffering of data.
.. versionadded:: 3.3
.. function:: login_tty(fd)
Prepare the tty of which fd is a file descriptor for a new login session.
Make the calling process a session leader; make the tty the controlling tty,
the stdin, the stdout, and the stderr of the calling process; close fd.
.. availability:: Unix.
.. versionadded:: 3.10
.. function:: lseek(fd, pos, how)
Set the current position of file descriptor *fd* to position *pos*, modified

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@ -0,0 +1 @@
Soumendra Ganguly: New function os.login_tty() for Unix.

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@ -3029,6 +3029,41 @@ os_openpty(PyObject *module, PyObject *Py_UNUSED(ignored))
#endif /* (defined(HAVE_OPENPTY) || defined(HAVE__GETPTY) || defined(HAVE_DEV_PTMX)) */
#if (defined(HAVE_LOGIN_TTY) || defined(HAVE_FALLBACK_LOGIN_TTY))
PyDoc_STRVAR(os_login_tty__doc__,
"login_tty($module, fd, /)\n"
"--\n"
"\n"
"Prepare the tty of which fd is a file descriptor for a new login session.\n"
"\n"
"Make the calling process a session leader; make the tty the\n"
"controlling tty, the stdin, the stdout, and the stderr of the\n"
"calling process; close fd.");
#define OS_LOGIN_TTY_METHODDEF \
{"login_tty", (PyCFunction)os_login_tty, METH_O, os_login_tty__doc__},
static PyObject *
os_login_tty_impl(PyObject *module, int fd);
static PyObject *
os_login_tty(PyObject *module, PyObject *arg)
{
PyObject *return_value = NULL;
int fd;
if (!_PyLong_FileDescriptor_Converter(arg, &fd)) {
goto exit;
}
return_value = os_login_tty_impl(module, fd);
exit:
return return_value;
}
#endif /* (defined(HAVE_LOGIN_TTY) || defined(HAVE_FALLBACK_LOGIN_TTY)) */
#if defined(HAVE_FORKPTY)
PyDoc_STRVAR(os_forkpty__doc__,
@ -8764,6 +8799,10 @@ exit:
#define OS_OPENPTY_METHODDEF
#endif /* !defined(OS_OPENPTY_METHODDEF) */
#ifndef OS_LOGIN_TTY_METHODDEF
#define OS_LOGIN_TTY_METHODDEF
#endif /* !defined(OS_LOGIN_TTY_METHODDEF) */
#ifndef OS_FORKPTY_METHODDEF
#define OS_FORKPTY_METHODDEF
#endif /* !defined(OS_FORKPTY_METHODDEF) */
@ -9163,4 +9202,4 @@ exit:
#ifndef OS_WAITSTATUS_TO_EXITCODE_METHODDEF
#define OS_WAITSTATUS_TO_EXITCODE_METHODDEF
#endif /* !defined(OS_WAITSTATUS_TO_EXITCODE_METHODDEF) */
/*[clinic end generated code: output=f3ec08afcd6cd8f8 input=a9049054013a1b77]*/
/*[clinic end generated code: output=f9f9bf32d1318d82 input=a9049054013a1b77]*/

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@ -7118,22 +7118,21 @@ error:
# define DEV_PTY_FILE "/dev/ptmx"
#endif
#if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) || defined(HAVE_DEV_PTMX)
#ifdef HAVE_PTY_H
#if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) || defined(HAVE_LOGIN_TTY) || defined(HAVE_DEV_PTMX)
#if defined(HAVE_PTY_H)
#include <pty.h>
#else
#ifdef HAVE_LIBUTIL_H
#if defined(HAVE_UTMP_H)
#include <utmp.h>
#endif /* HAVE_UTMP_H */
#elif defined(HAVE_LIBUTIL_H)
#include <libutil.h>
#else
#ifdef HAVE_UTIL_H
#elif defined(HAVE_UTIL_H)
#include <util.h>
#endif /* HAVE_UTIL_H */
#endif /* HAVE_LIBUTIL_H */
#endif /* HAVE_PTY_H */
#ifdef HAVE_STROPTS_H
#include <stropts.h>
#endif
#endif /* defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) || defined(HAVE_DEV_PTMX) */
#endif /* if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) || defined(HAVE_LOGIN_TTY) || defined(HAVE_DEV_PTMX) */
#if defined(HAVE_OPENPTY) || defined(HAVE__GETPTY) || defined(HAVE_DEV_PTMX)
@ -7235,6 +7234,84 @@ error:
}
#endif /* defined(HAVE_OPENPTY) || defined(HAVE__GETPTY) || defined(HAVE_DEV_PTMX) */
#if defined(HAVE_SETSID)
#if defined(TIOCSCTTY) || defined(HAVE_TTYNAME)
#define HAVE_FALLBACK_LOGIN_TTY 1
#endif /* defined(TIOCSCTTY) || defined(HAVE_TTYNAME) */
#endif /* HAVE_SETSID */
#if defined(HAVE_LOGIN_TTY) || defined(HAVE_FALLBACK_LOGIN_TTY)
/*[clinic input]
os.login_tty
fd: fildes
/
Prepare the tty of which fd is a file descriptor for a new login session.
Make the calling process a session leader; make the tty the
controlling tty, the stdin, the stdout, and the stderr of the
calling process; close fd.
[clinic start generated code]*/
static PyObject *
os_login_tty_impl(PyObject *module, int fd)
/*[clinic end generated code: output=495a79911b4cc1bc input=5f298565099903a2]*/
{
#if defined(HAVE_LOGIN_TTY)
if (login_tty(fd) == -1) {
return posix_error();
}
#else /* defined(HAVE_FALLBACK_LOGIN_TTY) */
/* Establish a new session. */
if (setsid() == -1) {
return posix_error();
}
/* The tty becomes the controlling terminal. */
#if defined(TIOCSCTTY)
if (ioctl(fd, TIOCSCTTY, (char *)NULL) == -1) {
return posix_error();
}
#else /* defined(HAVE_TTYNAME) */
/* Fallback method (archaic); from Advanced Programming in the UNIX(R)
* Environment, Third edition, 2013, Section 9.6 - Controlling Terminal:
* "Systems derived from UNIX System V allocate the controlling
* terminal for a session when the session leader opens the first
* terminal device that is not already associated with a session, as
* long as the call to open does not specify the O_NOCTTY flag." */
char *tmppath = ttyname(fd);
if (tmppath == NULL) {
return posix_error();
}
#define CLOSE_IF_NOT_FD(otherfd) \
if (fd != otherfd) { \
close(otherfd); \
} \
CLOSE_IF_NOT_FD(0);
CLOSE_IF_NOT_FD(1);
CLOSE_IF_NOT_FD(2);
int tmpfd = open(tmppath, O_RDWR);
if (tmpfd == -1) {
return posix_error();
}
close(tmpfd);
#endif /* defined(TIOCSCTTY) */
/* The tty becomes stdin/stdout/stderr */
if (dup2(fd, 0) == -1 || dup2(fd, 1) == -1 || dup2(fd, 2) == -1) {
return posix_error();
}
if (fd > 2) {
close(fd);
}
#endif /* defined(HAVE_LOGIN_TTY) */
Py_RETURN_NONE;
}
#endif /* defined(HAVE_LOGIN_TTY) || defined(HAVE_FALLBACK_LOGIN_TTY) */
#ifdef HAVE_FORKPTY
/*[clinic input]
@ -7271,8 +7348,9 @@ os_forkpty_impl(PyObject *module)
/* parent: release the import lock. */
PyOS_AfterFork_Parent();
}
if (pid == -1)
if (pid == -1) {
return posix_error();
}
return Py_BuildValue("(Ni)", PyLong_FromPid(pid), master_fd);
}
#endif /* HAVE_FORKPTY */
@ -7613,7 +7691,7 @@ os_initgroups_impl(PyObject *module, PyObject *oname, gid_t gid)
const char *username = PyBytes_AS_STRING(oname);
if (initgroups(username, gid) == -1)
return PyErr_SetFromErrno(PyExc_OSError);
return posix_error();
Py_RETURN_NONE;
}
@ -14652,6 +14730,7 @@ static PyMethodDef posix_methods[] = {
OS_SCHED_GETAFFINITY_METHODDEF
OS_OPENPTY_METHODDEF
OS_FORKPTY_METHODDEF
OS_LOGIN_TTY_METHODDEF
OS_GETEGID_METHODDEF
OS_GETEUID_METHODDEF
OS_GETGID_METHODDEF

101
configure vendored
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@ -8041,7 +8041,7 @@ sys/audioio.h sys/xattr.h sys/bsdtty.h sys/event.h sys/file.h sys/ioctl.h \
sys/kern_control.h sys/loadavg.h sys/lock.h sys/mkdev.h sys/modem.h \
sys/param.h sys/random.h sys/select.h sys/sendfile.h sys/socket.h sys/statvfs.h \
sys/stat.h sys/syscall.h sys/sys_domain.h sys/termio.h sys/time.h \
sys/times.h sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h pty.h \
sys/times.h sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h pty.h utmp.h \
libutil.h sys/resource.h netpacket/packet.h sysexits.h bluetooth.h \
linux/tipc.h linux/random.h spawn.h util.h alloca.h endian.h \
sys/endian.h sys/sysmacros.h linux/memfd.h linux/wait.h sys/memfd.h \
@ -12735,7 +12735,7 @@ $as_echo "no" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
# check for openpty and forkpty
# check for openpty, login_tty, and forkpty
for ac_func in openpty
do :
@ -12831,6 +12831,103 @@ fi
fi
fi
done
for ac_func in login_tty
do :
ac_fn_c_check_func "$LINENO" "login_tty" "ac_cv_func_login_tty"
if test "x$ac_cv_func_login_tty" = xyes; then :
cat >>confdefs.h <<_ACEOF
#define HAVE_LOGIN_TTY 1
_ACEOF
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for login_tty in -lutil" >&5
$as_echo_n "checking for login_tty in -lutil... " >&6; }
if ${ac_cv_lib_util_login_tty+:} false; then :
$as_echo_n "(cached) " >&6
else
ac_check_lib_save_LIBS=$LIBS
LIBS="-lutil $LIBS"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char login_tty ();
int
main ()
{
return login_tty ();
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_lib_util_login_tty=yes
else
ac_cv_lib_util_login_tty=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
LIBS=$ac_check_lib_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_util_login_tty" >&5
$as_echo "$ac_cv_lib_util_login_tty" >&6; }
if test "x$ac_cv_lib_util_login_tty" = xyes; then :
$as_echo "#define HAVE_LOGIN_TTY 1" >>confdefs.h
LIBS="$LIBS -lutil"
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for login_tty in -lbsd" >&5
$as_echo_n "checking for login_tty in -lbsd... " >&6; }
if ${ac_cv_lib_bsd_login_tty+:} false; then :
$as_echo_n "(cached) " >&6
else
ac_check_lib_save_LIBS=$LIBS
LIBS="-lbsd $LIBS"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
/* Override any GCC internal prototype to avoid an error.
Use char because int might match the return type of a GCC
builtin and then its argument prototype would still apply. */
#ifdef __cplusplus
extern "C"
#endif
char login_tty ();
int
main ()
{
return login_tty ();
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
ac_cv_lib_bsd_login_tty=yes
else
ac_cv_lib_bsd_login_tty=no
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
LIBS=$ac_check_lib_save_LIBS
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_bsd_login_tty" >&5
$as_echo "$ac_cv_lib_bsd_login_tty" >&6; }
if test "x$ac_cv_lib_bsd_login_tty" = xyes; then :
$as_echo "#define HAVE_LOGIN_TTY 1" >>confdefs.h
LIBS="$LIBS -lbsd"
fi
fi
fi
done