.\" $OpenBSD: relayd.8,v 1.24 2013/07/16 11:13:34 schwarze Exp $ .\" .\" Copyright (c) 2006 Pierre-Yves Ritschard .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: July 16 2013 $ .Dt RELAYD 8 .Os .Sh NAME .Nm relayd .Nd relay daemon .Sh SYNOPSIS .Nm .Op Fl dnv .Op Fl D Ar macro Ns = Ns Ar value .Op Fl f Ar file .Sh DESCRIPTION .Nm is a daemon to relay and dynamically redirect incoming connections to a target host. Its main purposes are to run as a load-balancer, application layer gateway, or transparent proxy. The daemon is able to monitor groups of hosts for availability, which is determined by checking for a specific service common to a host group. When availability is confirmed, layer 3 and/or layer 7 forwarding services are set up by .Nm . .Pp Layer 3 redirection happens at the packet level; to configure it, .Nm communicates with .Xr pf 4 . To allow .Nm to properly set up .Xr pf 4 rules, the following line is required in the filter section of .Xr pf.conf 5 : .Bd -literal -offset indent anchor "relayd/*" .Ed .Pp Layer 7 relaying happens at the application level and is handled by .Nm itself. Various application level filtering and protocol-specific load-balancing options are available for relays. .Pp .Nm works in terms of the following .Em entities : relays, protocols, redirections, and tables. A .Em relay represents a layer 7 load-balancing instance. Each instance translates to a listening TCP or UDP port. A .Em protocol defines which actions, if any, are taken on the packet payload as data crosses a relay. A .Em redirection represents a layer 3 load-balancing instance. Each instance translates to a .Xr pf 4 rdr-to rule being added. A .Em table represents a group of hosts which can be checked for availability using the same method. Each table contains at least one host. If a table is used in a layer 3 load-balancing instance, it will be mapped to a .Xr pf 4 table containing only those hosts which are up. .Pp All these entities can be configured in .Xr relayd.conf 5 , and .Xr relayctl 8 can be used to alter or report on the status of each entity. .Pp The options are as follows: .Bl -tag -width Ds .It Fl D Ar macro Ns = Ns Ar value Define .Ar macro to be set to .Ar value on the command line. Overrides the definition of .Ar macro in the configuration file. .It Fl d Do not daemonize. If this option is specified, .Nm will run in the foreground and log to .Em stderr . .It Fl f Ar file Specify an alternative configuration file. The default is .Pa /etc/relayd.conf . .It Fl n Configtest mode. Only check the configuration file for validity. .It Fl v Produce more verbose output. .El .Sh FILES .Bl -tag -width "/var/run/relayd.sockXX" -compact .It /etc/relayd.conf Default configuration file. .It /var/run/relayd.sock .Ux Ns -domain socket used for communication with .Xr relayctl 8 . .El .Sh SEE ALSO .Xr relayd.conf 5 , .Xr relayctl 8 .Sh HISTORY The .Nm program, formerly known as .Ic hoststated , first appeared in .Ox 4.1 . It was renamed to .Nm in .Ox 4.3 . .Sh AUTHORS .An -nosplit The .Nm program was written by .An Pierre-Yves Ritschard Aq Mt pyr@openbsd.org and .An Reyk Floeter Aq Mt reyk@openbsd.org .