#!/bin/sh

Action=GENERATE
SipDomain=""
HostMax=0
ExitStatus=0


showUsage() {
    cat <<USAGE

Usage:
    
    sipx-dns <sip-domain> <server-name>[/<ipaddr>]...

    Output DNS records in BIND format for sipX services.  The output is
    printed on the standard output; it can be captured in a file and 
    editted into the zone file for your domain.

      sip-domain   
          Is the domain that will be used as the domain part of your SIP
          addresses.  Typically, this will be your top level domain name
          (example.com).

      server-name  

          This is the fully qualified name of a sipX server in your domain
          (sipx.example.com).

          May also include the IP address (sipx.example.com/10.1.1.10).  If
          the address is given, then the A record for the host name will be
          generated; if not, then you must supply that record.

          The PTR records for reverse (address to name) lookups are not
          generated.  They are nice to have for system management, but sipX
          does not need them.
USAGE
}

validateFullName() {
    case ${1} in 
        *.*)
            echo ${1}
            break
            ;;
        *.)
            echo ${1} | sed 's/.$//'
            break
            ;;
        *)
            echo "'${1}' is not a fully qualified name." 1>&2
            showUsage
            exit 1
            ;;
    esac
}

while [ $# -ne 0 ]
do
    case ${1} in
        -h|-\?|--help)
            showUsage
            exit 0
            ;;

        ##
        ## handle the 'end of options' marker
        ##
        --)
            ;;

        ##
        ## handle an unknown switch
        ##
        -*)
            echo "Unrecognized option '${1}'" 1>&2
            showUsage
            exit 1
            ;;

        *)
            if [ -z "${SipDomain}" ]
            then
                SipDomain=`validateFullName ${1}`
            else
                ClusterHosts[${HostMax}]=${1}
                HostMax=$(($HostMax + 1))
            fi
            ;;
    esac           

    shift # always consume 1
done

HostMax=$(($HostMax - 1))

if [ $HostMax -eq -1 ]
then
    echo "Must specify servers" 1>&2
    showUsage
    exit 1
fi

for host in `seq 0 $HostMax`
  do
  thishost=${ClusterHosts[$host]}
  case $thishost in
      */*)
          hostname=`echo $thishost | cut -d / -f 1`
          Host[$host]=`validateFullName $hostname`
          Addr[$host]=`echo $thishost | cut -d / -f 2`
          ;;
      *)
          Host[$host]=`validateFullName $thishost`
          Addr[$host]=""
          ;;
  esac
done

cat <<EOF
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; sipX Servers for SIP domain '$SipDomain'
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
EOF

for host in `seq 0 $HostMax`
do
  if [ -n "${Addr[$host]}" ]
  then
      cat <<EOF
${Host[$host]}.	IN	A	${Addr[$host]}
EOF
  fi
done

cat <<EOF

$SipDomain.		IN	NAPTR	2 0 "s" "SIP+D2T" "" _sip._tcp.$SipDomain.
$SipDomain.		IN	NAPTR	2 0 "s" "SIP+D2U" "" _sip._udp.$SipDomain.

EOF

for host in `seq 0 $HostMax`
do
  server=${Host[$host]}
cat <<EOF
_sip._tcp.$SipDomain.	IN	SRV	1 0 5060 $server.
EOF
done

for host in `seq 0 $HostMax`
do
  server=${Host[$host]}
cat <<EOF
_sip._udp.$SipDomain.	IN	SRV	1 0 5060 $server.
EOF
done

if [ $HostMax -gt 0 ]
then
    rr=5070
    Name[$rr]="registry/redirect"

    ap=5080
    Name[$ap]="authorization"

    for host in `seq 0 $HostMax`
      do
      server=${Host[$host]}
      for service in rr ap
        do
        cat <<EOF

; $server routing for ${Name[${!service}]} service
_sip._tcp.$service.$server.	IN	SRV	1   0 ${!service} $server.
_sip._udp.$service.$server.	IN	SRV	3   0 ${!service} $server.
EOF
        for backuphost in `seq 0 $HostMax`
          do
          backup=${Host[$backuphost]}
          if [ "$server" != "$backup" ] 
              then
              cat <<EOF
_sip._tcp.$service.$server.	IN	SRV	2 100 ${!service} $backup.
_sip._udp.$service.$server.	IN	SRV	4 100 ${!service} $backup.
EOF
          fi
        done
      done
    done
fi

cat <<EOF

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

EOF

exit