Copyright (c) 2000 Alfred Perlstein All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or ...
NAMEaccf_data - buffer incoming connections until data arrives
DESCRIPTIONThis is a filter to be placed on a socket that will be using Fn accept to receive incoming connections.
It prevents the application from receiving the connected descriptor via Fn accept until data arrives on the connection.
The Fa 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.
EXAMPLESAssuming ACCEPT_FILTER_DATA has been included in the kernel config file or the sysctl Cm net.inet.tcp.syncookies module has been loaded, this will enable the data accept filter on the socket Fa sok .
struct accept_filter_arg afa; bzero(&afa, sizeof(afa)); strcpy(afa.af_name, "dataready"); setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa));