xref: /freebsd/share/man/man9/accf_data.9 (revision 069ac184)
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2.\" Copyright (c) 2000 Alfred Perlstein
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26.Dd November 15, 2000
27.Dt ACCF_DATA 9
28.Os
29.Sh NAME
30.Nm accf_data
31.Nd buffer incoming connections until data arrives
32.Sh SYNOPSIS
33.Nm options INET
34.Nm options ACCEPT_FILTER_DATA
35.Nm kldload accf_data
36.Sh DESCRIPTION
37This is a filter to be placed on a socket that will be using
38.Fn accept
39to receive incoming connections.
40.Pp
41It prevents the application from receiving the connected descriptor via
42.Fn accept
43until data arrives on the connection.
44.Pp
45The
46.Fa ACCEPT_FILTER_DATA
47kernel option is also a module that can be enabled at runtime via
48.Xr kldload 8
49if the INET option has been compiled into the kernel.
50.Sh EXAMPLES
51Assuming ACCEPT_FILTER_DATA has been included in the kernel config
52file or the
53.Nm
54module
55has been loaded, this will enable the data accept filter
56on the socket
57.Fa sok .
58.Bd -literal -offset 0i
59	struct accept_filter_arg afa;
60
61	bzero(&afa, sizeof(afa));
62	strcpy(afa.af_name, "dataready");
63	setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa));
64.Ed
65.Sh SEE ALSO
66.Xr setsockopt 2 ,
67.Xr accept_filter 9 ,
68.Xr accf_dns 9 ,
69.Xr accf_http 9
70.Sh HISTORY
71The accept filter mechanism and the
72accf_data filter were introduced in
73.Fx 4.0 .
74.Sh AUTHORS
75This manual page and the filter were written by
76.An Alfred Perlstein .
77