#!/bin/sh
#------------------------------------------------------------------------------
# /etc/rc.d/resolvconf-common - common functions operating on resolv.conf
#
# Last Update:  $Id$
#------------------------------------------------------------------------------

. /etc/boot.d/base-helper

resolvconf_no=/etc/resolv.conf
resolvconf_yes=/etc/resolv.dnsmasq
resolvconf_backup=/var/run/resolv.conf.orig
resolvconf_peerdns=/var/run/resolv.conf.peerdns

# takes a lock on the resolv.conf
# $1 = caller
resolvconf_lock()
{
    sync_lock_resource resolvconf $1
}

# release a lock on the resolv.conf
# $1 = caller
resolvconf_unlock()
{
    sync_unlock_resource resolvconf $1
}

# $1 = caller
resolvconf_generate()
{
    {
        echo "# overridden by peer DNS servers"
        local caller dns
        while read caller dns
        do
            echo "# $caller"
            echo "nameserver $dns"
        done < $resolvconf_peerdns
    } > $resolvconf
}

# $1 = source of the DNS servers (circuit name)
# $2... = DNS servers to add
# return = 1 if default resolv.conf has been overridden, 0 otherwise
resolvconf_addpeerdns()
{
    local caller=$1
    eval local $(grep "^OPT_DNS=" /etc/rc.cfg)
    : ${OPT_DNS:=no}
    eval local resolvconf=\$resolvconf_${OPT_DNS}
    shift
    local rc=0

    resolvconf_lock $caller

    if [ ! -s $resolvconf_peerdns ]
    then
        cp -a $resolvconf $resolvconf_backup
        rc=1
    fi

    for dns
    do
        echo "$caller $dns"
    done >> $resolvconf_peerdns
    resolvconf_generate $caller

    resolvconf_unlock $caller
    return $rc
}

# $1 = source of the DNS servers (circuit name)
# return = 1 if default resolv.conf has been restored, 0 otherwise
resolvconf_removepeerdns()
{
    local caller=$1
    eval local $(grep "^OPT_DNS=" /etc/rc.cfg)
    : ${OPT_DNS:=no}
    eval local resolvconf=\$resolvconf_${OPT_DNS}
    shift
    local rc=0

    resolvconf_lock $caller

    sed -i "/^$caller /d" $resolvconf_peerdns 2>/dev/null
    if [ -s $resolvconf_peerdns ]
    then
        resolvconf_generate
    elif [ -f $resolvconf_backup ]
    then
        mv $resolvconf_backup $resolvconf
        rc=1
    fi

    resolvconf_unlock $caller
    return $rc
}