meshname/whoami.go
2024-06-13 10:04:38 +00:00

33 lines
723 B
Go

package main
import (
"net/http"
"net"
"strings"
"encoding/base32"
)
// DomainFromIP derives a meshname subdomain for the authoritative DNS server address
func DomainFromIP(target net.IP) string {
host := strings.ToLower(base32.StdEncoding.EncodeToString(target)[0:26])
tld := ".mesh.cat"
domain := strings.Join([]string{host, tld}, "")
return domain
}
func handler(w http.ResponseWriter, r *http.Request) {
ip, port, err := net.SplitHostPort(r.RemoteAddr)
_, _ = port, err
parsedIP := net.ParseIP(ip)
// return domain for IPv6 only
if parsedIP.To4() == nil {
w.Write([]byte(DomainFromIP(parsedIP)))
}
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":3000", nil)
}