external/bsd/dhcpcd/dist/dhcpcd-hooks/30-hostname

   1 # $NetBSD: 30-hostname,v 1.7 2015/08/21 10:39:00 roy Exp $
   2
   3 # Set the hostname from DHCP data if required
   4
   5 # A hostname can either be a short hostname or a FQDN.
   6 # hostname_fqdn=true
   7 # hostname_fqdn=false
   8 # hostname_fqdn=server
   9
  10 # A value of server means just what the server says, don't manipulate it.
  11 # This could lead to an inconsistent hostname on a DHCPv4 and DHCPv6 network
  12 # where the DHCPv4 hostname is short and the DHCPv6 has an FQDN.
  13 # DHCPv6 has no hostname option.
  14 # RFC4702 section 3.1 says FQDN should be prefered over hostname.
  15 #
  16 # As such, the default is hostname_fqdn=true so that a consistent hostname
  17 # is always assigned.
  18 : ${hostname_fqdn:=true}
  19
  20 # Some systems don't have hostname(1)
  21 _hostname()
  22 {
  23         local name=
  24
  25         if [ -z "$1" ]; then
  26                 if type hostname >/dev/null 2>&1; then
  27                         hostname
  28                 elif [ -r /proc/sys/kernel/hostname ]; then
  29                         read name </proc/sys/kernel/hostname && echo "$name"
  30                 elif sysctl kern.hostname >/dev/null 2>&1; then
  31                         sysctl -n kern.hostname
  32                 elif sysctl kernel.hostname >/dev/null 2>&1; then
  33                         sysctl -n kernel.hostname
  34                 else
  35                         return 1
  36                 fi
  37                 return $?
  38         fi
  39
  40         # Always prefer hostname(1) if we have it
  41         if type hostname >/dev/null 2>&1; then
  42                 hostname "$1"
  43         elif [ -w /proc/sys/kernel/hostname ]; then
  44                 echo "$1" >/proc/sys/kernel/hostname
  45         elif sysctl kern.hostname >/dev/null 2>&1; then
  46                 sysctl -w "kern.hostname=$1"
  47         elif sysctl kernel.hostname >/dev/null 2>&1; then
  48                 sysctl -w "kernel.hostname=$1"
  49         else
  50                 # We know this will fail, but it will now fail
  51                 # with an error to stdout
  52                 hostname "$1"
  53         fi
  54 }
  55
  56 need_hostname()
  57 {
  58         local hostname hfqdn=false hshort=false
  59
  60         case "$force_hostname" in
  61         [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|1) return 0;;
  62         esac
  63
  64         hostname="$(_hostname)"
  65         case "$hostname" in
  66         ""|"(none)"|localhost|localhost.localdomain) return 0;;
  67         esac
  68
  69         case "$hostname_fqdn" in
  70         [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|1)        hfqdn=true;;
  71         [Ss][Ee][Rr][Vv][Ee][Rr])               ;;
  72         *)                                      hshort=true;;
  73         esac
  74
  75         if [ -n "$old_fqdn" ]; then
  76                 if ${hfqdn} || ! ${hsort}; then
  77                         [ "$hostname" = "$old_fqdn" ]
  78                 else
  79                         [ "$hostname" = "${old_fqdn%%.*}" ]
  80                 fi
  81         elif [ -n "$old_host_name" ]; then
  82                 if ${hfqdn}; then
  83                         if [ -n "$old_domain_name" -a \
  84                             "$old_host_name" = "${old_host_name#*.}" ]
  85                         then
  86                                 [ "$hostname" = \
  87                                     "$old_host_name.$old_domain_name" ]
  88                         else
  89                                 [ "$hostname" = "$old_host_name" ]
  90                         fi
  91                 elif ${hshort}; then
  92                         [ "$hostname" = "${old_host_name%%.*}" ]
  93                 else
  94                         [ "$hostname" = "$old_host_name" ]
  95                 fi
  96         else
  97                 # No old hostname
  98                 false
  99         fi
 100 }
 101
 102 try_hostname()
 103 {
 104
 105         if valid_domainname "$1"; then
 106                 _hostname "$1"
 107         else
 108                 syslog err "Invalid hostname: $1"
 109         fi
 110 }
 111
 112 set_hostname()
 113 {
 114         local hfqdn=false hshort=false
 115
 116         need_hostname || return
 117
 118         case "$hostname_fqdn" in
 119         [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|1)        hfqdn=true;;
 120         "")                                     ;;
 121         *)                                      hshort=true;;
 122         esac
 123
 124         if [ -n "$new_fqdn" ]; then
 125                 if ${hfqdn} || ! ${hshort}; then
 126                         try_hostname "$new_fqdn"
 127                 else
 128                         try_hostname "${new_fqdn%%.*}"
 129                 fi
 130         elif [ -n "$new_host_name" ]; then
 131                 if ${hfqdn}; then
 132                         if [ -n "$new_domain_name" -a \
 133                             "$new_host_name" = "${new_host_name#*.}" ]
 134                         then
 135                                 try_hostname "$new_host_name.$new_domain_name"
 136                         else
 137                                 try_hostname "$new_host_name"
 138                         fi
 139                 elif ${hshort}; then
 140                         try_hostname "${new_host_name%%.*}"
 141                 else
 142                         try_hostname "$new_host_name"
 143                 fi
 144         fi
 145 }
 146
 147 # For ease of use, map DHCP6 names onto our DHCP4 names
 148 case "$reason" in
 149 BOUND6|RENEW6|REBIND6|REBOOT6|INFORM6)
 150         new_fqdn="$new_dhcp6_fqdn"
 151         old_fqdn="$old_dhcp6_fqdn"
 152         ;;
 153 esac
 154
 155 if $if_up; then
 156         set_hostname
 157 fi