external/bsd/dhcpcd/dist/dhcpcd-hooks/29-lookup-hostname

   1 # $NetBSD: 29-lookup-hostname,v 1.7 2014/12/09 20:21:05 roy Exp $
   2
   3 # Lookup the hostname in DNS if not set
   4
   5 lookup_hostname()
   6 {
   7         [ -z "$new_ip_address" ] && return 1
   8         local h=
   9         # Silly ISC programs love to send error text to stdout
  10         if type dig >/dev/null 2>&1; then
  11                 h=$(dig +short -x $new_ip_address)
  12                 if [ $? = 0 ]; then
  13                         echo "$h" | sed 's/\.$//'
  14                         return 0
  15                 fi
  16         elif type host >/dev/null 2>&1; then
  17                 h=$(host $new_ip_address)
  18                 if [ $? = 0 ]; then
  19                         echo "$h" \
  20                         | sed 's/.* domain name pointer \(.*\)./\1/'
  21                         return 0
  22                 fi
  23         elif type getent >/dev/null 2>&1; then
  24                 h=$(getent hosts $new_ip_address)
  25                 if [ $? = 0 ]; then
  26                         echo "$h" | sed 's/[^ ]* *\([^ ]*\).*/\1/'
  27                         return 0
  28                  fi
  29         fi
  30         return 1
  31 }
  32
  33 set_hostname()
  34 {
  35         if [ -z "$new_host_name" -a -z "$new_fqdn_name" ]; then
  36                 export new_host_name="$(lookup_hostname)"
  37         fi
  38 }
  39
  40 if $if_up; then
  41         set_hostname
  42 fi