6445a3f2f0
Make the CH middleware actually work. Needs a bit of a hack to route the fake version.bind and friends zone to the correct handler. Fiddle with the order in directive.go so that CH queries get logged as well. Secondly add class rewriting to the rewrite middleware handler and also log the class by default.
55 lines
1.3 KiB
Go
55 lines
1.3 KiB
Go
package chaos
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import (
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"os"
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"github.com/miekg/coredns/middleware"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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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 middleware.Handler
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Version string
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Authors map[string]bool
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}
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func (c Chaos) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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state := middleware.State{W: w, Req: r}
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if state.QClass() != dns.ClassCHAOS || state.QType() != dns.TypeTXT {
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return c.Next.ServeDNS(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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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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