cloudflared/tunneldns/https_proxy.go at master · 4cecoder/cloudflared · GitHub

39 lines (31 loc) · 993 Bytes

package tunneldns

import (

"context"

"github.com/coredns/coredns/plugin"

"github.com/miekg/dns"

"github.com/pkg/errors"

)

// Upstream is a simplified interface for proxy destination

type Upstream interface {

Exchange(ctx context.Context, query *dns.Msg) (*dns.Msg, error)

}

// ProxyPlugin is a simplified DNS proxy using a generic upstream interface

type ProxyPlugin struct {

Upstreams []Upstream

Next plugin.Handler

}

// ServeDNS implements interface for CoreDNS plugin

func (p ProxyPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {

var reply *dns.Msg

var backendErr error

for _, upstream := range p.Upstreams {

reply, backendErr = upstream.Exchange(ctx, r)

if backendErr == nil {

w.WriteMsg(reply)

return 0, nil

}

return dns.RcodeServerFailure, errors.Wrap(backendErr, "failed to contact any of the upstreams")

}

// Name implements interface for CoreDNS plugin

func (p ProxyPlugin) Name() string { return "proxy" }

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