1.\" 2.\" Copyright (c) 2000 Alfred Perlstein 3.\" 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" " 28.Dd November 15, 2000 29.Os 30.Dt ACCF_DATA 9 31.Sh NAME 32.Nm accf_data 33.Nd buffer incoming connections until data arrives 34.Sh SYNOPSIS 35.Nm options INET 36.Nm options ACCEPT_FILTER_DATA 37.Nm kldload 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.Pp 47The 48.Fa ACCEPT_FILTER_DATA 49kernel option is also a module that can be enabled at runtime via 50.Xr kldload 8 51if the INET option has been compiled into the kernel. 52.Sh EXAMPLES 53Assuming ACCEPT_FILTER_DATA has been included in the kernel config 54file or the 55.Nm 56module 57has been loaded, this will enable the data accept filter 58on the socket 59.Fa sok . 60.Bd -literal -offset 0i 61 struct accept_filter_arg afa; 62 63 bzero(&afa, sizeof(afa)); 64 strcpy(afa.af_name, "dataready"); 65 setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa)); 66.Ed 67.Sh SEE ALSO 68.Xr setsockopt 2 , 69.Xr accept_filter 9 , 70.Xr accf_http 9 71.Sh HISTORY 72The accept filter mechanism and the 73accf_data filter were introduced in 74.Fx 4.0 . 75.Sh AUTHORS 76This manual page and the filter were written by 77.An Alfred Perlstein . 78