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