accf_data
—
buffer incoming connections until data arrives
options INET
pseudo-device accf_data
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.
If the accf_data
accept filter is present in the kernel
configuration, 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));
The accept filter mechanism and the accf_data
filter
were introduced in FreeBSD 4.0. They were ported to
NetBSD by Coyote Point Systems and appeared in
NetBSD 5.0.
This manual page and the filter were written by Alfred
Perlstein.