Simple emulation of POSIX pty APIs posix_openpt(), ptsname(),

grantpt() and unlockpt() using /dev/ptm.  Man pages from FreeBSD.
OK kettenis@ deraadt@ beck@ ajacoutot@ naddy@

1 files changed, 128 insertions, 0 deletions

diff --git a/src/lib/libc/stdlib/posix_openpt.3 b/src/lib/libc/stdlib/posix_openpt.3
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+.\"     $OpenBSD: posix_openpt.3,v 1.1 2012/12/03 20:08:33 millert Exp $
+.\"
+.\" Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Portions of this software were developed under sponsorship from Snow
+.\" B.V., the Netherlands.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" Portions of this text are reprinted and reproduced in electronic form
+.\" from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology --
+.\" Portable Operating System Interface (POSIX), The Open Group Base
+.\" Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of
+.\" Electrical and Electronics Engineers, Inc and The Open Group.  In the
+.\" event of any discrepancy between this version and the original IEEE and
+.\" The Open Group Standard, the original IEEE and The Open Group Standard is
+.\" the referee document.  The original Standard can be obtained online at
+.\"     http://www.opengroup.org/unix/online.html.
+.\"
+.\" $FreeBSD: head/lib/libc/sys/posix_openpt.2 181905 2008-08-20 08:31:58Z ed $
+.\"
+.Dd $Mdocdate: December 3 2012 $
+.Dt POSIX_OPENPT 3
+.Os
+.Sh NAME
+.Nm posix_openpt
+.Nd "open a pseudo-terminal device"
+.Sh SYNOPSIS
+.In stdlib.h
+.In fcntl.h
+.Ft int
+.Fn posix_openpt "int oflag"
+.Sh DESCRIPTION
+The
+.Fn posix_openpt
+function allocates a new pseudo-terminal and establishes a connection
+with its master device.
+After the pseudo-terminal has been allocated, the slave device should
+have the proper permissions before it can be used (see
+.Xr grantpt 3 ) .
+The name of the slave device can be determined by calling
+.Xr ptsname 3 .
+.Pp
+The file status flags and file access modes of the open file description
+shall be set according to the value of
+.Fa oflag .
+Values for
+.Fa oflag
+are constructed by a bitwise-inclusive OR of flags from the following
+list, defined in
+.In fcntl.h :
+.Bl -tag -width ".Dv O_NOCTTY"
+.It Dv O_RDWR
+Open for reading and writing.
+.It Dv O_NOCTTY
+If set
+.Fn posix_openpt
+shall not cause the terminal device to become the controlling terminal
+for the process.
+.El
+.Pp
+The
+.Fn posix_openpt
+function shall fail when
+.Fa oflag
+contains other values.
+.Sh RETURN VALUES
+Upon successful completion, the
+.Fn posix_openpt
+function shall allocate a new pseudo-terminal device and return a
+non-negative integer representing a file descriptor, which is connected
+to its master device.
+Otherwise, -1 shall be returned and errno set to indicate the error.
+.Sh ERRORS
+The
+.Fn posix_openpt
+function shall fail if:
+.Bl -tag -width Er
+.It Bq Er EMFILE
+The per-process descriptor table is full.
+.It Bq Er ENFILE
+The system file table is full.
+.It Bq Er EINVAL
+The value of
+.Fa oflag
+is not valid.
+.El
+.Sh SEE ALSO
+.Xr ptsname 3 ,
+.Xr pty 4 ,
+.Xr tty 4
+.Sh STANDARDS
+The
+.Fn posix_openpt
+function conforms to
+.St -p1003.1-2001 .
+.Sh HISTORY
+The
+.Fn posix_openpt
+function appeared in
+.Ox 5.3 .
+.Sh CAVEATS
+The flag
+.Dv O_NOCTTY
+is included for compatibility; in
+.Ox ,
+opening a terminal does not cause it to become a process's controlling
+terminal.