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 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));

SEE ALSO

     setsockopt(2), accept_filter(9), accf_dns(9), accf_http(9)

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.