.\" $OpenBSD: ifstated.conf.5,v 1.16 2020/05/16 16:58:11 jmc Exp $ .\" .\" Copyright (c) 2005 Nikolay Sturm .\" Copyright (c) 2005 Marco Pfatschbacher .\" .\" 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: May 16 2020 $ .Dt IFSTATED.CONF 5 .Os .Sh NAME .Nm ifstated.conf .Nd Interface State daemon configuration file .Sh DESCRIPTION The .Xr ifstated 8 daemon runs commands in response to network state changes, which it determines by monitoring interface link state or running external tests. .Nm is the configuration file for this daemon. .Pp The .Nm config file is divided into the following main sections: .Bl -tag -width xxxx .It Sy Global Configuration Global settings for .Xr ifstated 8 . .It Sy Macros User-defined variables may be defined and used later, simplifying configuration. Macros must be defined before they are referenced in .Nm ifstated.conf . .It Sy State Definitions Definitions of states and transitions. .El .Sh GLOBAL CONFIGURATION .Bl -tag -width Ds .It Ic init-state Ar state Set the initial state to .Ar state instead of using the first state defined. .El .Sh MACROS Macros can be defined that will later be expanded in context. Macro names must start with a letter, digit, or underscore, and may contain any of those characters. Macros are not expanded inside quotes. .Pp Macro names may not be reserved words like, for example, .Ar state or .Ar run . Macros are referenced with a shell-like notation as .Em $macro . Macros are usually used to define tests for state transitions like interface link state or external tests. .Pp Currently an interface can have three different link states: .Pp .Bl -tag -width xxxxxxxx -compact .It Ar up The physical link of the interface is up. For .Xr carp 4 interfaces this equals the master state. .It Ar down The physical link of the interface is down. For .Xr carp 4 interfaces this equals the backup state. .It Ar unknown The physical link of the interface is unknown. This is because the interface driver does not provide information of the physical link state. For .Xr carp 4 interfaces this equals the init state. .El .Pp In contrast to link state tests, external tests must be run periodically to evaluate their status. The frequency at which an external test is run is set, in seconds, with the .Ar every keyword. .Pp For example: .Bd -literal -offset indent links_up = "em0.link.up && em1.link.up" net = '( "ping -q -c 1 -w 1 192.168.0.1 > /dev/null" every 10 && \e "ping -q -c 1 -w 1 192.168.0.2 > /dev/null" every 10 )' .Ed .Sh TESTS AND EVENTS .Xr ifstated 8 delegates the process of testing to libevent which associates a value with every test, in this case .Em true or .Em false . Whenever the value of a test associated with the current state changes, an event is triggered and the state's body is processed. .Sh STATE DEFINITIONS .Xr ifstated 8 operates on a finite state machine with states and transitions. .Pp Each state consists of an .Em init block and a body. The .Em init block is used to initialise the state and is executed each time the state is entered. The body of a state is only executed when that state is the current state and an event occurs. .Pp The action taken within a certain state is typically made dependent on the evaluation of one or more .Em if statements. Possible actions include executing commands using the .Em run statement, or triggering a state transition with the .Ar set-state keyword. It is also possible to write multiple nested .Em if blocks. .Pp For example: .Bd -literal -offset indent state one { init { run "logger -t ifstated entering state one" run "ifconfig -g carp -carpdemote" } if ! $net || urndis0.link.up set-state two if ! $links_up { run "ifconfig -g carp carpdemote" if urndis0.link.down set-state three } } .Ed .Sh GRAMMAR Syntax for .Nm in BNF: .Bd -literal grammar = entry grammar | entry entry = global_config | varset | action | state global_config = initstate initstate = "init-state" string varset = string "=" string action_list = action [ action_list ] action = "run" string | "set-state" string | "if" expr action_block action_block = "{" action_list "}" | action expr = "!" expr | expr "&&" expr | expr "||" expr | term term = if_test | ext_test | "(" expr ")" if_test = string ".link." ( "up" | "down" | "unknown" ) ext_test = string "every" number state = "state" string "{" stateopt_list "}" stateopt_list = stateopt [ stateopt_list ] stateopt = init | action init = "init" action_block .Ed .Sh FILES .Bl -tag -width /etc/examples/ifstated.conf -compact .It Pa /etc/ifstated.conf .Xr ifstated 8 configuration file. .It Pa /etc/examples/ifstated.conf Example configuration file. .El .Sh SEE ALSO .Xr carp 4 , .Xr pf 4 , .Xr ifstated 8 .Sh HISTORY The .Nm file format first appeared in .Ox 3.8 .