1.\" $NetBSD: accf_data.9,v 1.5 2010/04/11 21:32:10 wiz Exp $ 2.\" 3.\" Copyright (c) 2000 Alfred Perlstein 4.\" 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" $FreeBSD: src/share/man/man9/accf_data.9,v 1.8 2005/01/18 20:52:51 ru Exp $ 28.\" " 29.Dd August 10, 2008 30.Dt ACCF_DATA 9 31.Os 32.Sh NAME 33.Nm accf_data 34.Nd buffer incoming connections until data arrives 35.Sh SYNOPSIS 36.Cd "options INET" 37.Cd "pseudo-device accf_data" 38.Sh DESCRIPTION 39This is a filter to be placed on a socket that will be using 40.Fn accept 41to receive incoming connections. 42.Pp 43It prevents the application from receiving the connected descriptor via 44.Fn accept 45until data arrives on the connection. 46.Sh EXAMPLES 47If the 48.Nm 49accept filter is present in the kernel configuration, 50this will enable the data accept filter 51on the socket 52.Fa sok . 53.Bd -literal -offset 0i 54 struct accept_filter_arg afa; 55 56 bzero(\*[Am]afa, sizeof(afa)); 57 strcpy(afa.af_name, "dataready"); 58 setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, \*[Am]afa, sizeof(afa)); 59.Ed 60.Sh SEE ALSO 61.Xr setsockopt 2 , 62.Xr accept_filter 9 , 63.Xr accf_http 9 64.Sh HISTORY 65The accept filter mechanism and the 66.Nm 67filter were introduced in 68.Fx 4.0 . 69They were ported to 70.Nx 71by Coyote Point Systems and appeared in 72.Nx 5.0 . 73.Sh AUTHORS 74This manual page and the filter were written by 75.An Alfred Perlstein . 76