#!/bin/sh -
#
#	$OpenBSD: netstart,v 1.45 1998/10/28 19:17:10 millert Exp $

# Returns true if $1 contains only alphanumerics
isalphanumeric() {
	local _n
	_n=$1
	while [ ${#_n} != 0 ]; do
		case $_n in
			[A-Za-z0-9]*)	;;
			*)		return 1;;
		esac
		_n=${_n#?}
	done
	return 0
}

# /etc/myname contains my symbolic name
#
hostname=`cat /etc/myname`
hostname $hostname
if [ -f /etc/defaultdomain ]; then
	domainname `cat /etc/defaultdomain`
fi

# pick up option configuration
. /etc/rc.conf

# Configure the IP filter before configuring network interfaces
if [ X"${ipfilter}" = X"YES" -a -f "${ipfilter_rules}" ]; then
	echo 'configuring IP filter'
	ipf -Fa -f ${ipfilter_rules} -E
else
	ipfilter=NO
fi

# set the address for the loopback interface
ifconfig lo0 inet localhost

# use loopback, not the wire
route -n add -host $hostname localhost
route -n add -net 127 127.0.0.1 -reject

# configure all of the non-loopback interfaces which we know about.
# do this by reading /etc/hostname.* files, where * is the name
# of a given interface.
#
# these files are formatted like the following, but with no # at the
# beginning of the line
#
# addr_family hostname netmask broadcast_addr options
# dest dest_addr
#
# OR
#
# dhcp 
#
# addr_family is the address family of the interface, generally inet
# hostname is the host name that belongs to the interface, in /etc/hosts.
# netmask is the network mask for the interface.
# broadcast_addr is the broadcast address for the interface
# options are misc. options to ifconfig for the interface.
#
# dest is simply the string "dest" (no quotes, though) if the interface
# has a "destination" (i.e. it's a point-to-point link, like SLIP).
# dest_addr is the hostname of the other end of the link, in /etc/hosts
#
# dhcp is simply the string "dhcp" (no quotes, though) if the interface
# is to be configured using DHCP.  See dhclient(8) and dhclient.conf(5)
# for details.
#
# the only required contents of the file are the addr_family field
# and the hostname.

(
    for hn in /etc/hostname.*; do
	# Strip off /etc/hostname. prefix
	if=${hn#/etc/hostname.}

	# Interface names must be alphanumeric only.  We check to avoid
	# configuring backup or temp files, and to catch the "*" case.
	if ! isalphanumeric "$if"; then
	    continue
	fi

	# Now parse the hostname.* file
        (
            read af name mask bcaddr extras
            read dt dtaddr

	    # check to see if device should be configure by dhcp
	    if [ "$af" = "dhcp" ]; then
		ifconfig $if $extras down
		cmd="/sbin/dhclient $if";
	    else
		if [ ! -n "$name" ]; then
		    echo "/etc/hostname.$if: invalid network configuration file"
		    exit
		fi

		cmd="ifconfig $if $af $name "
		if [ "${dt}" = "dest" ]; then cmd="$cmd $dtaddr"; fi
		if [ -n "$mask" ]; then cmd="$cmd netmask $mask"; fi
		if [ -n "$bcaddr" -a "X$bcaddr" != "XNONE" ]; then
		    cmd="$cmd broadcast $bcaddr";
		fi
		cmd="$cmd $extras";
	    fi

	    $cmd
        ) < /etc/hostname.$if
    done
)

# /etc/mygate, if it exists, contains the name of my gateway host
# that name must be in /etc/hosts.
if [ -f /etc/mygate ]; then
	route -n add -host default `cat /etc/mygate`

	# default multicast route for hosts with a gateway
	route -n add -net 224.0.0.0 -interface default
else
	# default multicast route
	route -n add -net 224.0.0.0 -interface $hostname
fi

# Configure NAT after configuring network interfaces
if [ "${ipnat}" = "YES" -a "${ipfilter}" = "YES" -a -f "${ipnat_rules}" ]; then
	echo 'configuring NAT'
	ipnat -CF -f ${ipnat_rules}
else
	ipnat=NO
fi