[RFC] script for binding ARP <-> IP pairs

[Xin LI]

Hi, Doug,

Doug Barton wrote:
> Xin LI wrote:
>> Hi,
>>
>> Here is a new rc.d startup script, which helps to bind static ARP
>> entries like this:
>>
>> 	static_arp_pairs="gw"
>> 	arp_gw="172.16.1.254 00:1c:58:6a:7a:4c"
>>
>> At the beginning I was inclined to add an "options" part for this script
>> which helps to set e.g. logging options for ARP but it looks that these
>> would be redundant, i.e., can be done with easy /etc/sysctl.conf.
>>
>> Comments?
> 
> This looks pretty good. My only suggestion would be to change the file
> name, $name and PROVIDE to static_arp (and then in your example above
> the second var would be static_arp_gw). I realize that currently we
> have a non-trivial number of legacy variables that don't match their
> related script names and/or $name, however going forward my preference
> would be that we not add any more examples of this. I also think it's
> a bit more descriptive of what you're doing in the script.

Thanks for your comments, I have put together the revised patch, along
with rc.conf.5 and defaults/rc.conf changes.

Cheers,
-- 
Xin LI <delphij at delphij.net>	http://www.delphij.net/
FreeBSD - The Power to Serve!
-------------- next part --------------
Index: etc/defaults/rc.conf
===================================================================
--- etc/defaults/rc.conf	(revision 196086)
+++ etc/defaults/rc.conf	(working copy)
@@ -357,6 +357,7 @@
 
 ### Network routing options: ###
 defaultrouter="NO"		# Set to default gateway (or NO).
+static_arp_pairs=""		# Set to static ARP list (or leave empty).
 static_routes=""		# Set to static route list (or leave empty).
 natm_static_routes=""		# Set to static route list for NATM (or leave empty).
 gateway_enable="NO"		# Set to YES if this host will be a gateway.
Index: etc/rc.d/Makefile
===================================================================
--- etc/rc.d/Makefile	(revision 196086)
+++ etc/rc.d/Makefile	(working copy)
@@ -32,7 +32,7 @@
 	random rarpd resolv rfcomm_pppd_server root \
 	route6d routed routing rpcbind rtadvd rwho \
 	savecore sdpd securelevel sendmail \
-	serial sppp statd swap1 \
+	serial static_arp sppp statd swap1 \
 	syscons sysctl syslogd \
 	timed tmp \
 	ugidfw \
Index: etc/rc.d/static_arp
===================================================================
--- etc/rc.d/static_arp	(revision 0)
+++ etc/rc.d/static_arp	(revision 0)
@@ -0,0 +1,70 @@
+#!/bin/sh
+#
+# Copyright (c) 2009  Xin LI <delphij at FreeBSD.org>
+# 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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
+#
+# Configure static ARP table
+#
+# $FreeBSD$
+#
+
+# PROVIDE: static_arp
+# REQUIRE: netif
+# KEYWORD: nojail
+
+. /etc/rc.subr
+
+name="static_arp"
+start_cmd="static_arp_start"
+stop_cmd="static_arp_stop"
+
+static_arp_start()
+{
+	if [ -n "${static_arp_pairs}" ]; then
+		echo -n 'Binding static ARP pair:'
+		for e in ${static_arp_pairs}; do
+			echo -n " ${e}"
+			eval arp_args=\$arp_${e}
+			arp -S ${arp_args} >/dev/null 2>&1
+		done
+		echo '.'
+	fi
+}
+
+static_arp_stop()
+{
+	if [ -n "${static_arp_pairs}" ]; then
+		echo -n 'Unbinding static ARP pair:'
+		for e in ${static_arp_pairs}; do
+			echo -n " ${e}"
+			eval arp_args=\$arp_${e}
+			arp_args=`echo ${arp_args} | sed -e s,..:..:..:..:..:..,,g`
+			arp -d ${arp_args} >/dev/null 2>&1
+		done
+		echo '.'
+	fi
+}
+
+load_rc_config $name
+run_rc_command "$1"
Index: share/man/man5/rc.conf.5
===================================================================
--- share/man/man5/rc.conf.5	(revision 196086)
+++ share/man/man5/rc.conf.5	(working copy)
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 10, 2009
+.Dd August 10, 2009
 .Dt RC.CONF 5
 .Os
 .Sh NAME
@@ -2227,6 +2227,23 @@
 .Pq Vt str
 The IPv6 equivalent of
 .Va defaultrouter .
+.It Va static_arp_pairs
+.Pq Vt str
+Set to the list of static ARP paris that are to be added at system
+boot time.
+For each whitespace separated
+.Ar element
+in the value, a
+.Va
+arp_ Ns Aq Ar element
+variable is assumed to exist whose contents will later be passed to a
+.Dq Nm arp Cm -S
+operation.
+For example
+.Bd -literal
+static_arp_pairs="gw"
+arp_gw="192.168.1.1 00:01:02:03:04:05"
+.Ed
 .It Va static_routes
 .Pq Vt str
 Set to the list of static routes that are to be added at system