Provided by: freebsd-manpages_12.0-1_all
accf_data — buffer incoming connections until data arrives
options INET options ACCEPT_FILTER_DATA kldload 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. 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.
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));
setsockopt(2), accept_filter(9), accf_dns(9), accf_http(9)
The accept filter mechanism and the accf_data filter were introduced in FreeBSD 4.0.
This manual page and the filter were written by Alfred Perlstein.