94 lines
1.8 KiB
Go
94 lines
1.8 KiB
Go
package dns64
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import (
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"net"
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"github.com/coredns/coredns/core/dnsserver"
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"github.com/coredns/coredns/plugin"
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clog "github.com/coredns/coredns/plugin/pkg/log"
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"github.com/coredns/coredns/plugin/pkg/upstream"
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"github.com/caddyserver/caddy"
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)
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const pluginName = "dns64"
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var log = clog.NewWithPlugin(pluginName)
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func init() { plugin.Register(pluginName, setup) }
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func setup(c *caddy.Controller) error {
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dns64, err := dns64Parse(c)
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if err != nil {
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return plugin.Error(pluginName, err)
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}
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dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
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dns64.Next = next
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return dns64
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})
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return nil
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}
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func dns64Parse(c *caddy.Controller) (*DNS64, error) {
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_, defaultPref, _ := net.ParseCIDR("64:ff9b::/96")
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dns64 := &DNS64{
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Upstream: upstream.New(),
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Prefix: defaultPref,
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}
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for c.Next() {
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args := c.RemainingArgs()
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if len(args) == 1 {
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pref, err := parsePrefix(c, args[0])
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if err != nil {
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return nil, err
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}
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dns64.Prefix = pref
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continue
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}
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if len(args) > 0 {
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return nil, c.ArgErr()
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}
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for c.NextBlock() {
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switch c.Val() {
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case "prefix":
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if !c.NextArg() {
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return nil, c.ArgErr()
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}
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pref, err := parsePrefix(c, c.Val())
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if err != nil {
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return nil, err
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}
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dns64.Prefix = pref
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case "translate_all":
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dns64.TranslateAll = true
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default:
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return nil, c.Errf("unknown property '%s'", c.Val())
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}
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}
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}
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return dns64, nil
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}
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func parsePrefix(c *caddy.Controller, addr string) (*net.IPNet, error) {
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_, pref, err := net.ParseCIDR(addr)
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if err != nil {
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return nil, err
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}
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// Test for valid prefix
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n, total := pref.Mask.Size()
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if total != 128 {
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return nil, c.Errf("invalid netmask %d IPv6 address: %q", total, pref)
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}
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if n%8 != 0 || n < 32 || n > 96 {
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return nil, c.Errf("invalid prefix length %q", pref)
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}
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return pref, nil
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}
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