69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
package main
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import (
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"net/http"
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"net"
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"encoding/base32"
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"strings"
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"flag"
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"log"
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)
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// define tld
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var tld = flag.String("tld", "mesh.cat", "The top level domain for our network")
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// domainFromIP derives a meshname subdomain for the authoritative DNS server address
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func domainFromIP(target net.IP) string {
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host := strings.ToLower(base32.StdEncoding.EncodeToString(target)[0:26])
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domain := host + "." + *tld
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return domain
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}
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// handle HTTP requests
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func handler(w http.ResponseWriter, r *http.Request) {
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// parse query parameters
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params := r.URL.Query()
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ipParam := params.Get("ip")
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// check if the "ip" query parameter is set to "true"
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showIP := ipParam == "true"
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// get client's ip address
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ip, port, err := net.SplitHostPort(r.RemoteAddr)
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_, _ = port, err
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// check if we're behind a reverse proxy
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xForwardedFor := r.Header.Get("X-Forwarded-For")
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if xForwardedFor != "" {
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ip = xForwardedFor
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}
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parsedIP := net.ParseIP(ip)
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// return domain for IPv6 only
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if parsedIP.To4() == nil {
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if (showIP) {
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w.Write([]byte(ip + "\n"))
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} else {
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w.Write([]byte(domainFromIP(parsedIP) + "\n"))
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}
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log.Println(showIP)
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log.Println(ip)
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} else {
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// set the response status code to 422
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w.WriteHeader(http.StatusUnprocessableEntity)
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w.Write([]byte("ipv4 not supported\n"))
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}
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}
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func main() {
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// define path
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http.HandleFunc("/", handler)
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// define ip address
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address := flag.String("address", "[::0]", "The interface address to listen on")
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// define port
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port := flag.String("port", "8008", "The port to listen on")
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// parse the command-line arguments
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flag.Parse()
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// construct listening address
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listenAddr := *address + ":" + *port
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print("Listening on address: ", listenAddr, "\n")
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// start server
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http.ListenAndServe(listenAddr, nil)
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}
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