fc667b98e0
* Fix EDNS0 compliance Do SizeAndDo in the server (ScrubWriter) and remove all uses of this from the plugins. Also *always* do it. This is to get into compliance for https://dnsflagday.net/. The pkg/edns0 now exports the EDNS0 options we understand; this is exported to allow plugins add things there. The *rewrite* plugin used this to add custom EDNS0 option codes that the server needs to understand. This also needs a new release of miekg/dns because it triggered a race-condition that was basicly there forever. See: * https://github.com/miekg/dns/issues/857 * https://github.com/miekg/dns/pull/859 Running a test instance and pointing the https://ednscomp.isc.org/ednscomp to it shows the tests are now fixed: ~~~ EDNS Compliance Tester Checking: 'miek.nl' as at 2018-12-01T17:53:15Z miek.nl. @147.75.204.203 (drone.coredns.io.): dns=ok edns=ok edns1=ok edns@512=ok ednsopt=ok edns1opt=ok do=ok ednsflags=ok docookie=ok edns512tcp=ok optlist=ok miek.nl. @2604:1380:2002:a000::1 (drone.coredns.io.): dns=ok edns=ok edns1=ok edns@512=ok ednsopt=ok edns1opt=ok do=ok ednsflags=ok docookie=ok edns512tcp=ok optlist=ok All Ok Codes ok - test passed. ~~~ Signed-off-by: Miek Gieben <miek@miek.nl> Signed-off-by: Miek Gieben <miek@miek.nl> * typos in comments Signed-off-by: Miek Gieben <miek@miek.nl>
61 lines
1.5 KiB
Go
61 lines
1.5 KiB
Go
// Package chaos implements a plugin that answer to 'CH version.bind TXT' type queries.
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package chaos
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import (
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"context"
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"os"
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"github.com/coredns/coredns/plugin"
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"github.com/coredns/coredns/request"
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"github.com/miekg/dns"
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)
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// Chaos allows CoreDNS to reply to CH TXT queries and return author or
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// version information.
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type Chaos struct {
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Next plugin.Handler
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Version string
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Authors map[string]bool
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}
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// ServeDNS implements the plugin.Handler interface.
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func (c Chaos) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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state := request.Request{W: w, Req: r}
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if state.QClass() != dns.ClassCHAOS || state.QType() != dns.TypeTXT {
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return plugin.NextOrFailure(c.Name(), c.Next, ctx, w, r)
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}
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m := new(dns.Msg)
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m.SetReply(r)
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hdr := dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeTXT, Class: dns.ClassCHAOS, Ttl: 0}
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switch state.Name() {
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default:
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return c.Next.ServeDNS(ctx, w, r)
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case "authors.bind.":
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for a := range c.Authors {
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m.Answer = append(m.Answer, &dns.TXT{Hdr: hdr, Txt: []string{trim(a)}})
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}
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case "version.bind.", "version.server.":
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m.Answer = []dns.RR{&dns.TXT{Hdr: hdr, Txt: []string{trim(c.Version)}}}
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case "hostname.bind.", "id.server.":
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hostname, err := os.Hostname()
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if err != nil {
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hostname = "localhost"
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}
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m.Answer = []dns.RR{&dns.TXT{Hdr: hdr, Txt: []string{trim(hostname)}}}
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}
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w.WriteMsg(m)
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return 0, nil
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}
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// Name implements the Handler interface.
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func (c Chaos) Name() string { return "chaos" }
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func trim(s string) string {
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if len(s) < 256 {
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return s
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}
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return s[:255]
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}
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