/share/man/man9/accf_data.9

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26.\" $FreeBSD$
27.\" "
28.Dd November 15, 2000
29.Dt ACCF_DATA 9
30.Os
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_dns 9
71.Xr accf_http 9
72.Sh HISTORY
73The accept filter mechanism and the
74accf_data filter were introduced in
75.Fx 4.0 .
76.Sh AUTHORS
77This manual page and the filter were written by
78.An Alfred Perlstein .