[9fans] Roaming Plan9 terminal (laptop) network configuration

[9fans] Roaming Plan9 terminal (laptop) network configuration

[tad]

I just threw the attached little script together
to make network configuration easy for any number of
roaming ethernet (non-dhcp and dhcp) configurations.

1) edit /rc/bin/termrc, comment out the 'ip/ipconfig'
   line, and replace it with an invocation of
   '/rc/bin/netconfig'.

2) netconfig will prompt you to enter a system name,
   If you just hit return, it will default to DHCP.

   the system name you enter must exist in your ndb
   database (/lib/ndb/local, probably) looking
   something like this:

	ipnet=home-net ip=192.168.100.0 ipmask=255.255.255.0
		dnsdomain=cs.bell-labs.com
		dnsdomain=research.bell-labs.com
		dns=135.1.1.150
		ipgw=192.168.100.105
		dns=135.1.1.150

	#
	# ipgw and ipmask set here so /rc/bin/netconfig can
	# find them. (I don't currently know a better way
	# to get from the sysname to the network record above)
	#
	ip=192.168.100.103 sys=think ether=0060973ff2ae
		ipgw=192.168.100.105
		ipmask=255.255.255.0
		dom=think.lackawanna.net

   Note that you don't need the separate 'home-net' entry,
   you could have put the dnsdomain and dns server entries
   in the 'sys=think' entry.

--------------- /rc/bin/netconfig ------------------

#!/bin/rc

fn run {
	echo $*
	eval $*
}

fn try {
	ip=`{ndb/query sys $1 ip}
	if(~ $#ip 0) {
		echo no ip address for $1
		echo fail
	}
	ipgw=`{ndb/query sys $1 ipgw}
	if(~ $#ipgw 0) {
		echo warning: no ip gateway for $1 >[1=2]
		gw=''
	}
	if not
		gw='-g'$ipgw

	ipmask=`{ndb/query sys $1 ipmask}
	if(~ $#ipmask 0) {
		echo no ip mask for $1 >[1=2]
		echo fail
	}

	run ip/ipconfig $gw ether /net/ether0 add $ip $ipmask >[1=2]

	echo ok
}

while() {
	echo -n 'system name [dhcp]: '
	x=`{read}

	if(~ $#x 0) {
		echo ip/ipconfig -dD
		exit
	}

	ok=`{try $x}
	if(~ $ok ok)
		exit
}