diff options
| author | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 16:08:12 -0400 |
|---|---|---|
| committer | Jacob McDonnell <jacob@jacobmcdonnell.com> | 2026-04-25 16:08:12 -0400 |
| commit | b9cde963555b6519c5dbd34a39dee3418f593437 (patch) | |
| tree | 453accad3c3286e3416d4160de4a87223aff684c /static/freebsd/man9/accf_dns.9 | |
| parent | 5cb84ec742fd33f78c8022863fadaa8d0d93e176 (diff) | |
feat: Added FreeBSD man pages
Diffstat (limited to 'static/freebsd/man9/accf_dns.9')
| -rw-r--r-- | static/freebsd/man9/accf_dns.9 | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/static/freebsd/man9/accf_dns.9 b/static/freebsd/man9/accf_dns.9 new file mode 100644 index 00000000..00b7bcf1 --- /dev/null +++ b/static/freebsd/man9/accf_dns.9 @@ -0,0 +1,80 @@ +.\" +.\" Copyright (c) 2008 David Malone +.\" +.\" 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 other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES +.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. +.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, +.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF +.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" " +.Dd July 16, 2008 +.Dt ACCF_DNS 9 +.Os +.Sh NAME +.Nm accf_dns +.Nd buffer incoming DNS requests until the whole first request is present +.Sh SYNOPSIS +.Cd options INET +.Cd options ACCEPT_FILTER_DNS +.Pp +In +.Xr rc.conf 5 : +.Cd kld_list="accf_dns" +.Sh DESCRIPTION +This is a filter to be placed on a socket that will be using +.Fn accept +to receive incoming connections. +.Pp +It prevents the application from receiving the connected descriptor via +.Fn accept +until a whole DNS request is available on the socket. +It does this by reading the first two bytes of the request, +to determine its size, +and waiting until the required amount of data is available to be read. +.Pp +The +.Fa ACCEPT_FILTER_DNS +kernel option is also a module that can be enabled at runtime via +.Xr kldload 8 +if the INET option has been compiled into the kernel. +.Sh EXAMPLES +If the +.Nm +module is available in the kernel, +the following code will enable the DNS accept filter +on a socket +.Fa sok . +.Bd -literal -offset 0i + struct accept_filter_arg afa; + + bzero(&afa, sizeof(afa)); + strcpy(afa.af_name, "dnsready"); + setsockopt(sok, SOL_SOCKET, SO_ACCEPTFILTER, &afa, sizeof(afa)); +.Ed +.Sh SEE ALSO +.Xr setsockopt 2 , +.Xr accept_filter 9 , +.Xr accf_data 9 , +.Xr accf_http 9 +.Sh HISTORY +The accept filter mechanism was introduced in +.Fx 4.0 . +.Sh AUTHORS +This manual page and the filter were written by +.An David Malone . |
