accf_data(9freebsd)

accf_data9freebsd

Buffer incoming connections until data arrives

Usage

options INET

options ACCEPT_FILTER_DATA

kldload accf_data

Overview

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

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

The 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 accf_data module has been loaded, this will enable the data accept filter on the socket sok.

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

Releases

9 releases since Debian 5.0 (Lenny); the text changed 6 times.

  1. 5.0
  2. 6.0
  3. 7
  4. 8
  5. 9
  6. 10
  7. 11–13

History

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

Authors

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

From freebsd-manpages 12.2-2 in Debian 13 (Trixie). Parsed by carta from the page's mdoc source.