freebsd/share/man/man4/ngatmbase.4

.\"
.\" Copyright (c) 2004
.\"	Hartmut Brandt.
.\" 	All rights reserved.
.\"
.\" Author: Hartmut Brandt <harti@FreeBSD.org>
.\"
.\" 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.
.\"
.\" $FreeBSD$
.\"
.\" ngatmbase(4) man page
.\"
.Dd August 24, 2004
.Dt NGATMBASE 4
.Os
.Sh NAME
.Nm ngatmbase
.Nd netgraph ATM utility module
.Sh SYNOPSIS
.In netnatm/unimsg.h
.In netgraph/atm/ngatmbase.h
.Ft "struct mbuf *"
.Fn uni_msg_pack_mbuf "struct uni_msg *msg" "void *hdr" "size_t len"
.Ft "struct uni_msg *"
.Fn uni_msg_alloc "size_t len"
.Ft "struct uni_msg *"
.Fn uni_msg_build "void *buf" ...
.Ft void
.Fn uni_msg_destroy "struct uni_msg *msg"
.Ft int
.Fn uni_msg_unpack_mbuf "struct mbuf *m" "struct uni_msg *msgp"
.Sh DESCRIPTION
This module provides utility functions for the handling of signalling
messages to the NgATM modules.
.Pp
The
.Fn uni_msg_pack_mbuf
function
packs a message into one or several
.Vt mbuf Ns s
optionally prepending a header.
The header is given by its address
.Fa hdr
and length
.Fa len .
If
.Fa hdr
is
.Dv NULL
or
.Fa len
equals 0, no header is prepended.
Either
.Fa msg
or
.Fa hdr
may be
.Dv NULL
but not both.
The
.Fn uni_msg_pack_mbuf
function
returns a pointer to the allocated
.Vt mbuf
chain or
.Dv NULL
in the case of an error.
.Pp
The
.Fn uni_msg_alloc
function
allocates a new message with space for at least
.Fa len
bytes.
In the case of an error
.Dv NULL
is returned.
.Pp
The
.Fn uni_msg_build
function constructs a message from pieces.
Each piece is given by a pair of
arguments, the first of type
.Vt "void *"
and the second a
.Vt size_t .
The list of pieces must be terminated by
.Po Vt "void *" Pc Ns Dv NULL .
.Pp
The
.Fn uni_msg_destroy
function
destroyes the messages and frees all the messages's memory.
.Pp
The
.Fn uni_msg_unpack_mbuf
function
unpacks an
.Vt mbuf
chain info a
.Vt uni_msg .
A pointer to the newly allocated message is stored in
.Fa msgp
and 0 is returned.
In the case of an error (either when no packet header is found
in the first mbuf or memory cannot be allocated) the function
returns an appropriate error code.
.Sh SEE ALSO
.Xr ng_ccatm 4 ,
.Xr ng_sscfu 4 ,
.Xr ng_sscop 4 ,
.Xr ng_uni 4
.Sh AUTHORS
.An Harti Brandt Aq harti@FreeBSD.org