accf_data (9)

Leading comments

Copyright (c) 2000 Alfred Perlstein

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modification, are permitted provided that the following conditions
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(The comments found at the beginning of the groff file "man9/accf_data.9freebsd".)

NAME

accf_data - buffer incoming connections until data arrives

SYNOPSIS

options INET
options ACCEPT_FILTER_DATA
kldload accf_data

DESCRIPTION

This is a filter to be placed on a socket that will be using Fn accept to receive incoming connections.

It prevents the application from receiving the connected descriptor via Fn accept until data arrives on the connection.

The Fa ACCEPT_FILTER_DATA kernel option is also a module that can be enabled at runtime via kldload(8) if the INET option has been compiled into the kernel.

EXAMPLES

Assuming ACCEPT_FILTER_DATA has been included in the kernel config file or the ifconfig module has been loaded, this will enable the data accept filter on the socket Fa sok .

        struct accept_filter_arg afa;

        bzero(&afa, sizeof(afa));
        strcpy(afa.af_name, "dataready");
        setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa));

SEE ALSO

setsockopt(2), accept_filter9, accf_dns9 accf_http9

HISTORY

The accept filter mechanism and the accf_data filter were introduced in Fx 4.0 .

AUTHORS

This manual page and the filter were written by An Alfred Perlstein .