cirros-testvm/src-cirros/src/usr/bin/parse-interfaces

   1 #!/bin/sh
   2
   3 ENABLE=yes
   4 NAME=Ethernet
   5 IPADDRESS=192.168.1.20
   6 CIDRLEN=
   7 NETWORK=192.168.1.0
   8 NETMASK=255.255.255.0
   9 GATEWAY=192.168.1.1
  10 BROADCAST=
  11 DHCP=no
  12 CIDRLEN=24
  13 NETWORK=192.168.1.0
  14
  15 netinfo() {
  16    local ipaddr=$1 netmask=$2 oifs=${IFS} mask=255
  17    local ipb1 ipb2 ipb3 ipb4 nmb1 nmb2 nmb3 nmb4
  18    IFS=.
  19    set -- ${ipaddr}; ipb1=${1}; ipb2=${2}; ipb3=${3}; ipb4=${4}
  20    set -- ${netmask}; nmb1=${1}; nmb2=${2}; nmb3=${3}; nmb4=${4}
  21    IFS=$SaveIFS
  22
  23    local network bcast
  24    network=$(($ipb1 & $nmb1)).$(($ipb2 & $nmb2)).$(($ipb3 & $nmb3)).$(($ipb4 & $nmb4))
  25    bcast=$(($ipb1 | ($mask ^ $nmb1))).$(($ipb2 | ($mask ^ $nmb2))).$(($ipb3 | ($mask ^ $nmb3))).$(($ipb4 | ($mask ^ $nmb4)))
  26
  27    _RET_NETWORK=${network}
  28    _RET_BCAST=${bcast}
  29 }
  30
  31 iface="${1:-eth0}"
  32 file=${2:-/etc/network/interfaces}
  33 [ "$file" = "-" ] || exec <"$file"
  34
  35 hash="#"
  36 cur_iface=""
  37 found=0
  38 while read line; do
  39         line=${line%%${hash}*}
  40         [ -n "$line" ] || continue
  41         set -- ${line}
  42         case $1 in
  43                 auto) [ "$2" = "$iface" ] && ENABLE=yes;;
  44                 iface)
  45                         [ "$2" = "$iface" ] || continue;
  46                         # if its not static, let the default path handle
  47                         [ "$4" = "static" ] || { DHCP=yes; continue; }
  48                         cur_iface=$2
  49                         found=1
  50                         ;;
  51                 *)
  52                         [ "$cur_iface" = "$iface" ] || continue;
  53                         case $1 in
  54                                 address) IPADDRESS=${2};;
  55                                 netmask) NETMASK=${2};;
  56                                 gateway) GATEWAY=${2};;
  57                                 address) IPADDRESS=${2};;
  58                         esac
  59                         ;;
  60         esac
  61 done
  62
  63 [ -n "$IPADDRESS" -a -n "$NETMASK" ] && netinfo "$IPADDRESS" "$NETMASK" &&
  64         BROADCAST=${_RET_BCAST}
  65
  66 cat <<EOF
  67 # this file was written by: $0 $iface $file
  68 # some short experimentation shows that you must define
  69 # ENABLE NAME CIDRLEN NETWORK and DHCP to get working DHCP
  70 ENABLE=$ENABLE
  71 NAME=Ethernet
  72 IPADDRESS=$IPADDRESS
  73 NETMASK=$NETMASK
  74 GATEWAY=$GATEWAY
  75 BROADCAST=$BROADCAST
  76 DHCP=$DHCP
  77 # the following are not set right, but not believed to matter
  78 CIDRLEN=$CIDRLEN;
  79 NETWORK=$NETWORK
  80 EOF