84 lines
2.2 KiB
Go
84 lines
2.2 KiB
Go
package middleware
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import (
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"strconv"
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"time"
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"github.com/miekg/dns"
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)
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// ResponseRecorder is a type of ResponseWriter that captures
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// the rcode code written to it and also the size of the message
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// written in the response. A rcode code does not have
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// to be written, however, in which case 0 must be assumed.
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// It is best to have the constructor initialize this type
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// with that default status code.
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type ResponseRecorder struct {
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dns.ResponseWriter
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rcode int
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size int
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msg *dns.Msg
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start time.Time
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}
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// NewResponseRecorder makes and returns a new responseRecorder,
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// which captures the DNS rcode from the ResponseWriter
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// and also the length of the response message written through it.
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func NewResponseRecorder(w dns.ResponseWriter) *ResponseRecorder {
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return &ResponseRecorder{
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ResponseWriter: w,
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rcode: 0,
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msg: nil,
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start: time.Now(),
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}
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}
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// WriteMsg records the status code and calls the
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// underlying ResponseWriter's WriteMsg method.
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func (r *ResponseRecorder) WriteMsg(res *dns.Msg) error {
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r.rcode = res.Rcode
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// We may get called multiple times (axfr for instance).
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// Save the last message, but add the sizes.
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r.size += res.Len()
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r.msg = res
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return r.ResponseWriter.WriteMsg(res)
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}
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// Write is a wrapper that records the size of the message that gets written.
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func (r *ResponseRecorder) Write(buf []byte) (int, error) {
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n, err := r.ResponseWriter.Write(buf)
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if err == nil {
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r.size += n
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}
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return n, err
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}
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// Size returns the size.
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func (r *ResponseRecorder) Size() int {
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return r.size
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}
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// Rcode returns the rcode.
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func (r *ResponseRecorder) Rcode() string {
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if rcode, ok := dns.RcodeToString[r.rcode]; ok {
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return rcode
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}
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return "RCODE" + strconv.Itoa(r.rcode)
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}
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// Start returns the start time of the ResponseRecorder.
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func (r *ResponseRecorder) Start() time.Time {
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return r.start
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}
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// Msg returns the written message from the ResponseRecorder.
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func (r *ResponseRecorder) Msg() *dns.Msg {
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return r.msg
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}
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// Hijack implements dns.Hijacker. It simply wraps the underlying
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// ResponseWriter's Hijack method if there is one, or returns an error.
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func (r *ResponseRecorder) Hijack() {
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r.ResponseWriter.Hijack()
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return
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}
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