1.\" $NetBSD: ifwatchd.8,v 1.12 2002/04/16 07:28:09 wiz Exp $ 2.\" 3.\" Copyright (c) 2001-2002 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Martin Husemann <martin@NetBSD.ORG>. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd September 2, 2001 38.Os 39.Dt IFWATCHD 8 40.Sh NAME 41.Nm ifwatchd 42.Nd "watch for addresses added to or deleted from interfaces and call up/down-scripts for them" 43.Sh SYNOPSIS 44.Nm 45.Op Fl d Ar down-script 46.Op Fl h 47.Op Fl i 48.Op Fl u Ar up-script 49.Op Fl v 50.Ar ifname(s) 51.Sh DESCRIPTION 52.Nm 53is used to monitor dynamic interfaces (for example PPP interfaces) for address 54changes. Sometimes these interfaces are accompanied by a daemon program, which 55can take care of running any necessary scripts (like 56.Xr pppd 8 57or 58.Xr isdnd 8 ) , 59but sometimes the interfaces run completely autonomously (like 60.Xr pppoe 8 ) . 61.Pp 62.Nm 63provides a generic way to watch this type of changes. It works by monitoring 64the routing socket and interpreting 65.Ql RTM_NEWADDR 66.Pq address added 67and 68.Ql RTM_DELADDR 69.Pq address deleted 70messages. It does not need special privileges to do this. The scripts called 71for up or down events are run with the same user id as 72.Nm 73is run. 74.Pp 75The following options are available: 76.Bl -tag -width indent 77.It Fl d Ar down-script 78Specify the command to invoke on 79.Dq interface down 80events (or: deletion of an address from an interface). 81.It Fl h 82Show the synopsis. 83.It Fl i 84Inhibit a call to the up-script on startup for all watched interfaces 85already marked up. If this option is not given, 86.Nm 87will check all watched interfaces on startup whether they are already marked 88up and, if they are, call the up-script with appropriate parameters. 89.Pp 90Since ifwatchd typically is started late in the system boot sequence, some 91of the monitored interfaces may already have come up when it finally starts, 92but their up-scripts have not been called. By default 93.Nm 94calls them on startup to account for this (and make the scripts easier.) 95.It Fl u Ar up-script 96Specify the command to invoke on 97.Dq interface up 98events (or: addition of an address to an interface). 99.It Fl v 100Output verbose progress messages and flag errors ignored during normal 101operation. 102.It Ar ifname(s) 103The name of the interface to watch. Multiple interfaces may be specified. 104Events for other interfaces are ignored. 105.El 106.Sh EXAMPLES 107.Bd -literal -offset indent 108# ifwatchd -u /etc/ppp/ip-up -d /etc/ppp/ip-down pppoe0 109 110.Ed 111If your pppoe0 interface is your main connection to the internet, the typical 112use of the up/down scripts is to add and remove a default route. This is 113an example for an up script doing this: 114.Bd -literal -offset indent 115#! /bin/sh 116/sbin/route add default $5 117 118.Ed 119As described below the fifth command line parameter will contain the peer 120address of the pppoe link. The corresponding ip-down script is: 121.Bd -literal -offset indent 122#! /bin/sh 123/sbin/route delete default $5 124 125.Ed 126Note that this is not a good idea if you have pppoe0 configured to connect 127only on demand (via the link1 flag), but works well for all permanent connected 128cases. Use 129.Bd -literal -offset indent 130! /sbin/route add default -iface 0.0.0.1 131 132.Ed 133in your 134.Pa /etc/ifconfig.pppoe0 135file in the on-demand case. 136.Sh PARAMETERS PASSED TO SCRIPTS 137The invoked scripts get passed these parameters: 138.Bl -tag -width destination 139.It Ar ifname 140The name of the interface this change is for (this allows to share the same 141script for multiple interfaces watched and dispatching on the interface name 142in the script). 143.It Ar tty 144Dummy parameter for compatibility with 145.Xr pppd 8 146which will always be 147.Em /dev/null . 148.It Ar speed 149Dummy parameter for compatibility with 150.Xr pppd 8 151which will always be 152.Em 9600 . 153.It Ar address 154The new address if this is an up event, or the no longer valid old address 155if this is a down event. 156.Pp 157The format of the address depends on the address family, for IPv4 it is the 158usual dotted quad notation, for IPv6 the colon separated standard notation. 159.It Ar destination 160For point to point interfaces, this is the remote address of the interface. 161For other interfaces it is the broadcast address. 162.El 163.Sh SEE ALSO 164.Xr route 4 , 165.Xr ifconfig.if 5 , 166.Xr pppoe 8 , 167.Xr rc.d 8 , 168.Xr route 8 169.Sh HISTORY 170The 171.Nm 172utility appeared in 173.Nx 1.6 . 174.Sh AUTHORS 175The program was written by 176.An Martin Husemann Aq martin@netbsd.org . 177