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Feature: Finish a plain DNS proxy demo.
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,67 @@ | ||
| package main | ||
|
|
||
| import ( | ||
| "context" | ||
| "flag" | ||
|
|
||
| "github.com/miekg/dns" | ||
| "github.com/sirupsen/logrus" | ||
| "golang.org/x/sync/errgroup" | ||
| ) | ||
|
|
||
| var udpCli = &dns.Client{SingleInflight: true} | ||
| var tcpCli = &dns.Client{SingleInflight: true, Net: "tcp"} | ||
|
|
||
| var ( | ||
| flagListen = flag.String("listen", "[::]:5553", "Listening address") | ||
| flagUDPMaxBytes = flag.Int("udpMaxBytes", 1410, "Default DNS max message size on UDP.") | ||
| ) | ||
|
|
||
| // DNS Proxy Implementation Guidelines: https://tools.ietf.org/html/rfc5625 | ||
| // DNS query processing: https://tools.ietf.org/html/rfc1034#section-3.7 | ||
| // Happy Eyeballs: https://tools.ietf.org/html/rfc6555#section-5.4 and #section-6 | ||
| func handle(w dns.ResponseWriter, req *dns.Msg) { | ||
| // defer w.Close() | ||
| logrus.Infoln("Question:", &req.Question[0]) | ||
|
|
||
| req.RecursionDesired = true | ||
| // https://tools.ietf.org/html/rfc6891#section-6.2.5 | ||
| if e := req.IsEdns0(); e != nil { | ||
| if e.UDPSize() < uint16(*flagUDPMaxBytes) { | ||
| e.SetUDPSize(uint16(*flagUDPMaxBytes)) | ||
| } | ||
| } else { | ||
| req.SetEdns0(uint16(*flagUDPMaxBytes), false) | ||
| } | ||
|
|
||
| reply, rtt, err := udpCli.Exchange(req, "119.29.29.29:53") | ||
| if err != nil { | ||
| logrus.WithError(err).Error("UDP query failed.") | ||
| reply, rtt, err = tcpCli.Exchange(req, "119.29.29.29:53") | ||
| if err != nil { | ||
| logrus.WithError(err).Error("TCP query failed.") | ||
| } | ||
| } | ||
| if reply != nil { | ||
| logrus.Infof("Query RTT: %s", rtt) | ||
| // https://github.com/miekg/dns/issues/216 | ||
| reply.Compress = true | ||
| } else { | ||
| reply = new(dns.Msg) | ||
| reply.SetReply(req) | ||
| } | ||
|
|
||
| w.WriteMsg(reply) | ||
| } | ||
|
|
||
| func main() { | ||
| flag.Parse() | ||
| dns.HandleFunc(".", handle) | ||
| udpServer := &dns.Server{Addr: *flagListen, Net: "udp", ReusePort: true} | ||
| tcpServer := &dns.Server{Addr: *flagListen, Net: "tcp", ReusePort: true} | ||
|
|
||
| eg, _ := errgroup.WithContext(context.Background()) | ||
| eg.Go(udpServer.ListenAndServe) | ||
| eg.Go(tcpServer.ListenAndServe) | ||
| eg.Wait() | ||
| } |
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| Original file line number | Diff line number | Diff line change |
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| @@ -0,0 +1,10 @@ | ||
| module github.com/cherrot/gochinadns | ||
|
|
||
| require ( | ||
| github.com/miekg/dns v1.1.3 | ||
| github.com/sirupsen/logrus v1.3.0 | ||
| golang.org/x/crypto v0.0.0-20190103213133-ff983b9c42bc // indirect | ||
| golang.org/x/net v0.0.0-20190110200230-915654e7eabc // indirect | ||
| golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 | ||
| golang.org/x/sys v0.0.0-20190116161447-11f53e031339 // indirect | ||
| ) |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,19 @@ | ||
| github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= | ||
| github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ= | ||
| github.com/miekg/dns v1.1.3 h1:1g0r1IvskvgL8rR+AcHzUA+oFmGcQlaIm4IqakufeMM= | ||
| github.com/miekg/dns v1.1.3/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg= | ||
| github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= | ||
| github.com/sirupsen/logrus v1.3.0 h1:hI/7Q+DtNZ2kINb6qt/lS+IyXnHQe9e90POfeewL/ME= | ||
| github.com/sirupsen/logrus v1.3.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo= | ||
| github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME= | ||
| github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs= | ||
| golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4= | ||
| golang.org/x/crypto v0.0.0-20190103213133-ff983b9c42bc h1:F5tKCVGp+MUAHhKp5MZtGqAlGX3+oCsiL1Q629FL90M= | ||
| golang.org/x/crypto v0.0.0-20190103213133-ff983b9c42bc/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4= | ||
| golang.org/x/net v0.0.0-20190110200230-915654e7eabc h1:Yx9JGxI1SBhVLFjpAkWMaO1TF+xyqtHLjZpvQboJGiM= | ||
| golang.org/x/net v0.0.0-20190110200230-915654e7eabc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4= | ||
| golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 h1:YUO/7uOKsKeq9UokNS62b8FYywz3ker1l1vDZRCRefw= | ||
| golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= | ||
| golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= | ||
| golang.org/x/sys v0.0.0-20190116161447-11f53e031339 h1:g/Jesu8+QLnA0CPzF3E1pURg0Byr7i6jLoX5sqjcAh0= | ||
| golang.org/x/sys v0.0.0-20190116161447-11f53e031339/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= |