diff --git a/core/dnsserver/zdirectives.go b/core/dnsserver/zdirectives.go index 0420672f0..75c79f3e8 100644 --- a/core/dnsserver/zdirectives.go +++ b/core/dnsserver/zdirectives.go @@ -26,6 +26,7 @@ var Directives = []string{ "errors", "log", "dnstap", + "any", "chaos", "loadbalance", "cache", diff --git a/core/plugin/zplugin.go b/core/plugin/zplugin.go index 8eab63498..e9d350894 100644 --- a/core/plugin/zplugin.go +++ b/core/plugin/zplugin.go @@ -4,6 +4,7 @@ package plugin import ( // Include all plugins. + _ "github.com/coredns/coredns/plugin/any" _ "github.com/coredns/coredns/plugin/auto" _ "github.com/coredns/coredns/plugin/autopath" _ "github.com/coredns/coredns/plugin/bind" diff --git a/plugin.cfg b/plugin.cfg index 7a941a5ec..5acb88c09 100644 --- a/plugin.cfg +++ b/plugin.cfg @@ -35,6 +35,7 @@ prometheus:metrics errors:errors log:log dnstap:dnstap +any:any chaos:chaos loadbalance:loadbalance cache:cache diff --git a/plugin/any/OWNERS b/plugin/any/OWNERS new file mode 100644 index 000000000..eee46f686 --- /dev/null +++ b/plugin/any/OWNERS @@ -0,0 +1,4 @@ +reviewers: + - miekg +approvers: + - miekg diff --git a/plugin/any/README.md b/plugin/any/README.md new file mode 100644 index 000000000..1abc97803 --- /dev/null +++ b/plugin/any/README.md @@ -0,0 +1,36 @@ + +# any + +## Name + +*any* - give a minimal response to ANY queries. + +## Description + +*any* basically blocks ANY queries by responding to them with a short HINFO reply. See [RFC +8482](https://tools.ietf.org/html/rfc8482) for details. + +## Syntax + +~~~ txt +any +~~~ + +## Examples + +~~~ corefile +example.org { + whoami + any +} +~~~ + +A `dig +nocmd ANY example.org +noall +answer` now returns: + +~~~ txt +example.org. 8482 IN HINFO "ANY obsoleted" "See RFC 8482" +~~~ + +## Also See + +[RFC 8482](https://tools.ietf.org/html/rfc8482). diff --git a/plugin/any/any.go b/plugin/any/any.go new file mode 100644 index 000000000..9a05e37b2 --- /dev/null +++ b/plugin/any/any.go @@ -0,0 +1,32 @@ +package any + +import ( + "context" + + "github.com/coredns/coredns/plugin" + + "github.com/miekg/dns" +) + +// Any is a plugin that returns a HINFO reply to ANY queries. +type Any struct { + Next plugin.Handler +} + +// ServeDNS implements the plugin.Handler interface. +func (a Any) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) { + if r.Question[0].Qtype != dns.TypeANY { + return plugin.NextOrFailure(a.Name(), a.Next, ctx, w, r) + } + + m := new(dns.Msg) + m.SetReply(r) + hdr := dns.RR_Header{Name: r.Question[0].Name, Ttl: 8482, Class: dns.ClassINET, Rrtype: dns.TypeHINFO} + m.Answer = []dns.RR{&dns.HINFO{Hdr: hdr, Cpu: "ANY obsoleted", Os: "See RFC 8482"}} + + w.WriteMsg(m) + return 0, nil +} + +// Name implements the Handler interface. +func (a Any) Name() string { return "any" } diff --git a/plugin/any/any_test.go b/plugin/any/any_test.go new file mode 100644 index 000000000..85df7d672 --- /dev/null +++ b/plugin/any/any_test.go @@ -0,0 +1,28 @@ +package any + +import ( + "context" + "testing" + + "github.com/coredns/coredns/plugin/pkg/dnstest" + "github.com/coredns/coredns/plugin/test" + + "github.com/miekg/dns" +) + +func TestAny(t *testing.T) { + req := new(dns.Msg) + req.SetQuestion("example.org.", dns.TypeANY) + a := &Any{} + + rec := dnstest.NewRecorder(&test.ResponseWriter{}) + _, err := a.ServeDNS(context.TODO(), rec, req) + + if err != nil { + t.Errorf("Expected no error, but got %q", err) + } + + if rec.Msg.Answer[0].(*dns.HINFO).Cpu != "ANY obsoleted" { + t.Errorf("Expected HINFO, but got %q", rec.Msg.Answer[0].(*dns.HINFO).Cpu) + } +} diff --git a/plugin/any/setup.go b/plugin/any/setup.go new file mode 100644 index 000000000..de4697a82 --- /dev/null +++ b/plugin/any/setup.go @@ -0,0 +1,26 @@ +package any + +import ( + "github.com/coredns/coredns/core/dnsserver" + "github.com/coredns/coredns/plugin" + + "github.com/mholt/caddy" +) + +func init() { + caddy.RegisterPlugin("any", caddy.Plugin{ + ServerType: "dns", + Action: setup, + }) +} + +func setup(c *caddy.Controller) error { + a := Any{} + + dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler { + a.Next = next + return a + }) + + return nil +}