Finally document the interfaces found in libutil. While being here,

also add the missing declaration of forkpty() to libutil.h.

Btw., the calling interface for login(3) is crude.  Some better
abstraction is needed, perhaps similar to logwtmp(3).

2.2 candidate, but i'll wait for the spelling police first. :)

7 files changed, 425 insertions, 2 deletions

diff --git a/lib/libutil/Makefile b/lib/libutil/Makefile
index 0ad1151..e5f7063 100644
--- a/lib/libutil/Makefile
+++ b/lib/libutil/Makefile
@@ -5,7 +5,8 @@ SHLIB_MAJOR= 2
 SHLIB_MINOR= 1
 CFLAGS+=-DLIBC_SCCS -I${.CURDIR} -I/sys
 SRCS=	login.c login_tty.c logout.c logwtmp.c pty.c setproctitle.c
-MAN3+=	setproctitle.3
+MAN3+=	login.3 login_tty.3 logout.3 logwtmp.3 pty.3 setproctitle.3
+MLINKS+= pty.3 openpty.3  pty.3 forkpty.3
 
 beforeinstall:
 	${INSTALL} -C -o ${BINOWN} -g ${BINGRP} -m 444 ${.CURDIR}/libutil.h \
diff --git a/lib/libutil/libutil.h b/lib/libutil/libutil.h
index 3f32d7a..05acf60 100644
--- a/lib/libutil/libutil.h
+++ b/lib/libutil/libutil.h
@@ -18,7 +18,7 @@
  * 5. Modifications may be freely made to this file providing the above
  *    conditions are met.
  *
- * $Id$
+ * $Id: libutil.h,v 1.1 1996/01/01 08:27:37 peter Exp $
  */
 
 #ifndef _LIBUTIL_H_
@@ -39,6 +39,8 @@ int	logout __P((char *line));
 void	logwtmp __P((char *line, char *name, char *host));
 int	openpty __P((int *amaster, int *aslave, char *name,
 		     struct termios *termp, struct winsize *winp));
+int	forkpty __P((int *amaster, char *name,
+		     struct termios *termp, struct winsize *winp));
 __END_DECLS
 
 #endif /* !_LIBUTIL_H_ */
diff --git a/lib/libutil/login.3 b/lib/libutil/login.3
new file mode 100644
index 0000000..dd326b0
--- /dev/null
+++ b/lib/libutil/login.3
@@ -0,0 +1,69 @@
+.\" 
+.\" Copyright (c) 1996 Joerg Wunsch
+.\" 
+.\" All rights reserved.
+.\" 
+.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
+.\" 
+.\" $Id$
+.\" "
+.Dd December 29, 1996
+.Os
+.Dt LOGIN 3
+.Sh NAME
+.Nm login
+.Nd "log a new login record to the utmp and wtmp files"
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <utmp.h>
+.Fd #include <libutil.h>
+.Ft void
+.Fn login "struct utmp *ut"
+.Pp
+Link with
+.Va -lutil
+on the
+.Xr cc 1
+command line.
+.Sh DESCRIPTION
+The function
+.Nm login
+records the
+.Ar ut
+entry being passed into the appropriate slot of the
+.Xr utmp 5
+file (according to the controlling terminal of the calling process),
+and appends it to the
+.Xr wtmp 5
+file.  The calling process must have permission to write to both files.
+.Sh RETURN VALUES
+None.
+.Sh SEE ALSO
+.Xr logout 3 ,
+.Xr ttyslot 3 ,
+.Xr utmp 5 ,
+.Xr wtmp 5
+.Sh BUGS
+The interface provided by
+.Nm login
+is rather crude.  The caller must know about the details of a
+.Va struct utmp .
+Some better abstraction needs to be worked out.
diff --git a/lib/libutil/login_tty.3 b/lib/libutil/login_tty.3
new file mode 100644
index 0000000..c9367b2
--- /dev/null
+++ b/lib/libutil/login_tty.3
@@ -0,0 +1,66 @@
+.\" 
+.\" Copyright (c) 1996 Joerg Wunsch
+.\" 
+.\" All rights reserved.
+.\" 
+.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
+.\" 
+.\" $Id$
+.\" "
+.Dd December 29, 1996
+.Os
+.Dt LOGIN_TTY 3
+.Sh NAME
+.Nm login_tty
+.Nd prepare a tty for a new login session
+.Sh SYNOPSIS
+.Fd #include <libutil.h>
+.Ft int
+.Fn login_tty "int fd"
+.Pp
+Link with
+.Va -lutil
+on the
+.Xr cc 1
+command line.
+.Sh DESCRIPTION
+The function
+.Nm login_tty
+prepares a terminal for a new login session.  The filedescriptor
+.Ar fd
+passed to
+.Nm login_tty
+must be opened for reading and writing on a terminal device.  It will be
+made the controlling terminal for the calling process, after allocating
+a new session with
+.Xr setsid 2 .
+This terminal device will also be made the standard input, standard output,
+and standard error output of the calling process.
+.Sh RETURN VALUES
+.Nm Login_tty
+returns -1 if it could not make the device referenced by
+.Ar fd
+the controlling terminal of the calling process, and 0 otherwise.
+.Sh SEE ALSO
+.Xr dup2 2 ,
+.Xr ioctl 2 ,
+.Xr setsid 2 ,
+.Xr tty 4
diff --git a/lib/libutil/logout.3 b/lib/libutil/logout.3
new file mode 100644
index 0000000..b4c768c
--- /dev/null
+++ b/lib/libutil/logout.3
@@ -0,0 +1,70 @@
+.\" 
+.\" Copyright (c) 1996 Joerg Wunsch
+.\" 
+.\" All rights reserved.
+.\" 
+.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
+.\" 
+.\" $Id$
+.\" "
+.Dd December 29, 1996
+.Os
+.Dt LOGOUT 3
+.Sh NAME
+.Nm logout
+.Nd remove an entry from the utmp file
+.Sh SYNOPSIS
+.Fd #include <libutil.h>
+.Ft int
+.Fn logout "char *line"
+.Pp
+Link with
+.Va -lutil
+on the
+.Xr cc 1
+command line.
+.Sh DESCRIPTION
+The function
+.Nm logout
+searches the
+.Xr utmp 5
+file for the slot described by
+.Ar line
+(usually a tty name).  If such a slot could be found, it will be updated
+with a record where the
+.Em name
+and
+.Em host
+fields are empty, and the timestamp field is updated to the current time.
+.Sh RETURN VALUES
+.Nm Logout
+returns 1 if the slot described by
+.Ar line
+has been found and updated, 0 otherwise.
+.Sh SEE ALSO
+.Xr login 3 ,
+.Xr utmp 5 ,
+.Xr wtmp 5
+.Sh BUGS
+The calling interface of
+.Nm logout
+is incosistent with that of
+.Xr login 3 .
diff --git a/lib/libutil/logwtmp.3 b/lib/libutil/logwtmp.3
new file mode 100644
index 0000000..3a9a05c
--- /dev/null
+++ b/lib/libutil/logwtmp.3
@@ -0,0 +1,72 @@
+.\" 
+.\" Copyright (c) 1996 Joerg Wunsch
+.\" 
+.\" All rights reserved.
+.\" 
+.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
+.\" 
+.\" $Id$
+.\" "
+.Dd December 29, 1996
+.Os
+.Dt LOGWTMP 3
+.Sh NAME
+.Nm logwtmp
+.Nd append a new record to the wtmp file
+.Sh SYNOPSIS
+.Fd #include <libutil.h>
+.Ft void
+.Fn logwtmp "char *line" "char *name" "char *host"
+.Pp
+Link with
+.Va -lutil
+on the
+.Xr cc 1
+command line.
+.Sh DESCRIPTION
+The function
+.Nm logwtmp
+tries to append a new record to the
+.Xr wtmp 5
+file, using the provided arguments
+.Ar line ,
+.Ar name ,
+and
+.Ar host ,
+and the current time.
+.Pp
+If the length of the hostname string
+.Ar host
+is longer than what would fit into the hostname field of the
+.Xr wtmp 5
+file, it will first be attempted to convert it into a numerical IP
+address using
+.Xr gethostbyname 3 .
+Failing this, the hostname will be recorded as
+.Qq invalid hostname .
+.Pp
+The calling process must have permission to write to both files.
+.Sh RETURN VALUES
+None.
+.Sh SEE ALSO
+.Xr gethostbyname 3 ,
+.Xr login 3 ,
+.Xr wtmp 5
diff --git a/lib/libutil/pty.3 b/lib/libutil/pty.3
new file mode 100644
index 0000000..4af344d
--- /dev/null
+++ b/lib/libutil/pty.3
@@ -0,0 +1,143 @@
+.\" 
+.\" Copyright (c) 1996 Joerg Wunsch
+.\" 
+.\" All rights reserved.
+.\" 
+.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
+.\" 
+.\" $Id$
+.\" "
+.Dd December 29, 1996
+.Os
+.Dt PTY 3
+.Sh NAME
+.Nm openpty, forkpty
+.Nd auxiliary functions to obtain a pseudo-terminal
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <sys/ioctl.h>
+.Fd #include <termios.h>
+.Fd #include <libutil.h>
+.Ft int
+.Fn openpty "int *amaster" "int *aslave" "char *name" "struct termios *termp" "struct winsize *winp"
+.Ft int
+.Fn forkpty "int *amaster" "char *name" "struct termios *termp" "struct winsize *winp"
+.Pp
+Link with
+.Va -lutil
+on the
+.Xr cc 1
+command line.
+.Sh DESCRIPTION
+The function
+.Nm openpty
+attempts to obtain the next available pseudo-terminal from the system (see
+.Xr pty 4 ) .
+If it successfully found one, it subsequently tries to change the
+ownership of the slave device to the real UID of the current process,
+the group membership to the group
+.Dq tty
+(if such a group exists in the system), the access permissions for
+reading and writing by the owner, and for writing by the group, and to
+invalidate any current use of the line by calling
+.Xr revoke 2 .
+.Pp
+If the argument
+.Ar name
+is not
+.Dv NULL ,
+.Nm openpty
+copies the pathname of the slave pty to this area.  The caller is
+responsible to allocate the required space in this array.
+.Pp
+If the arguments
+.Ar termp
+or
+.Ar winp
+are not
+.Dv NULL ,
+.Nm openpty
+initializes the termios and window size settings from the structures
+these argument point to, respectively.
+.Pp
+Upon return, the open filedescriptors for the master and slave side
+of the pty are returned in the locations pointed to by
+.Ar amaster
+and
+.Ar aslave ,
+respectively.
+.Pp
+.Nm Forkpty
+first calls
+.Xr openpty 3
+to obtain the next available pseudo-terminal from the system.  Upon success,
+it forks off a new process.  In the child process, it closes the descriptor
+for the master side of the pty, and calls
+.Xr login_tty 3
+for the slave pty.  In the parent process, it closes the descriptor for the
+slave side of the pty.  The arguments
+.Ar amaster ,
+.Ar name ,
+.Ar termp ,
+and
+.Ar winp
+have the same meaning as described for
+.Nm openpty .
+.Sh RETURN VALUES
+.Nm Openpty
+returns 0 on success, or -1 on failure.
+.Pp
+.Nm Forkpty
+returns -1 on failure, 0 in the slave process, and the process ID of the
+slave process in the parent process.
+.Sh ERRORS
+On failure,
+.Nm openpty
+will set the global variable
+.Dv errno
+to
+.Er ENOENT .
+.Pp
+In addition to this,
+.Nm forkpty
+may set it to any value as described for
+.Xr fork 2 .
+.Sh SEE ALSO
+.Xr chmod 2 ,
+.Xr chown 2 ,
+.Xr fork 2 ,
+.Xr getuid 2 ,
+.Xr open 2 ,
+.Xr revoke 2 ,
+.Xr login_tty 3 ,
+.Xr termios 3 ,
+.Xr pty 4 ,
+.Xr group 5
+.Sh BUGS
+The calling process must have an effective UID of super-user in order
+to perform all the intended actions.  No notification will occur if
+.Nm openpty
+or
+.Nm forkpty
+failed to proceed with one of the described steps, as long as they could
+at least allocate the pty at all (and create the new process in the case
+of
+.Nm forkpty ) .