external/bsd/dhcpcd/dist/dhcpcd-hooks/20-resolv.conf

   1 # Generate /etc/resolv.conf
   2 # Support resolvconf(8) if available
   3 # We can merge other dhcpcd resolv.conf files into one like resolvconf,
   4 # but resolvconf is preferred as other applications like VPN clients
   5 # can readily hook into it.
   6 # Also, resolvconf can configure local nameservers such as bind
   7 # or dnsmasq. This is important as the libc resolver isn't that powerful.
   8
   9 resolv_conf_dir="$state_dir/resolv.conf"
  10
  11 build_resolv_conf()
  12 {
  13         local cf="$state_dir/resolv.conf.$interface"
  14         local interfaces= header= search= srvs= servers= x=
  15
  16         # Build a list of interfaces
  17         interfaces=$(list_interfaces "$resolv_conf_dir")
  18
  19         # Build the resolv.conf
  20         if [ -n "$interfaces" ]; then
  21                 # Build the header
  22                 for x in ${interfaces}; do
  23                         header="$header${header:+, }$x"
  24                 done
  25
  26                 # Build the search list
  27                 domain=$(cd "$resolv_conf_dir"; \
  28                         key_get_value "domain " ${interfaces})
  29                 search=$(cd "$resolv_conf_dir"; \
  30                         key_get_value "search " ${interfaces})
  31                 set -- ${domain}
  32                 unset domain
  33                 if [ -n "$2" ]; then
  34                         search="$search $@"
  35                 elif [ -n "$1" ]; then
  36                         domain="domain $1\n"
  37                 fi
  38                 [ -n "$search" ] && search="search $(uniqify $search)\n"
  39
  40                 # Build the nameserver list
  41                 srvs=$(cd "$resolv_conf_dir"; \
  42                         key_get_value "nameserver " ${interfaces})
  43                 for x in $(uniqify ${srvs}); do
  44                         servers="${servers}nameserver $x\n"
  45                 done
  46         fi
  47         header="$signature_base${header:+ $from }$header"
  48
  49         # Assemble resolv.conf using our head and tail files
  50         [ -f "$cf" ] && rm -f "$cf"
  51         [ -d "$resolv_conf_dir" ] || mkdir -p "$resolv_conf_dir"
  52         echo "$header" > "$cf"
  53         if [ -f /etc/resolv.conf.head ]; then
  54                 cat /etc/resolv.conf.head >> "$cf"
  55         else
  56                 echo "# /etc/resolv.conf.head can replace this line" >> "$cf"
  57         fi
  58         printf "$domain$search$servers" >> "$cf"
  59         if [ -f /etc/resolv.conf.tail ]; then
  60                 cat /etc/resolv.conf.tail >> "$cf"
  61         else
  62                 echo "# /etc/resolv.conf.tail can replace this line" >> "$cf"
  63         fi
  64         cat "$cf" > /etc/resolv.conf
  65         chmod 644 /etc/resolv.conf
  66         rm -f "$cf"
  67 }
  68
  69 add_resolv_conf()
  70 {
  71         local x= conf="$signature\n"
  72
  73         # If we don't have any configuration, remove it
  74         if [ -z "$new_domain_name_servers" -a \
  75                 -z "$new_domain_name" -a \
  76                 -z "$new_domain_search" ]; then
  77                 remove_resolv_conf
  78                 return $?
  79         fi
  80
  81         if [ -n "$new_domain_name" ]; then
  82                 set -- $new_domain_name
  83                 new_domain_name="$1"
  84                 conf="${conf}domain $new_domain_name\n"
  85                 # Support RFC violating search in domain
  86                 if [ -z "$new_domain_search" -a -n "$2" ]; then
  87                         new_domain_search="$@"
  88                 fi
  89         fi
  90         if [ -n "$new_domain_search" ]; then
  91                 conf="${conf}search $new_domain_search\n"
  92         fi
  93         for x in ${new_domain_name_servers}; do
  94                 conf="${conf}nameserver $x\n"
  95         done
  96         if type resolvconf >/dev/null 2>&1; then
  97                 [ -n "$metric" ] && export IF_METRIC="$metric"
  98                 printf "$conf" | resolvconf -a "$interface"
  99                 return $?
 100         fi
 101
 102         if [ -e "$resolv_conf_dir/$interface" ]; then
 103                 rm -f "$resolv_conf_dir/$interface"
 104         fi
 105         [ -d "$resolv_conf_dir" ] || mkdir -p "$resolv_conf_dir"
 106         printf "$conf" > "$resolv_conf_dir/$interface"
 107         build_resolv_conf
 108 }
 109
 110 remove_resolv_conf()
 111 {
 112         if type resolvconf >/dev/null 2>&1; then
 113                 resolvconf -d "$interface" -f
 114         else
 115                 if [ -e "$resolv_conf_dir/$interface" ]; then
 116                         rm -f "$resolv_conf_dir/$interface"
 117                 fi
 118                 build_resolv_conf
 119         fi
 120 }
 121
 122 case "$reason" in
 123 BOUND|INFORM|REBIND|REBOOT|RENEW|TIMEOUT|STATIC)        add_resolv_conf;;
 124 PREINIT|EXPIRE|FAIL|IPV4LL|NAK|NOCARRIER|RELEASE|STOP)  remove_resolv_conf;;
 125 esac