50 lines
1.2 KiB
Go
50 lines
1.2 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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type Chaos struct {
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Next middleware.Handler
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Version string
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Authors map[string]bool // get randomization for free \o/
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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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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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