Function realIPFromHdrs

proxy/serverhttps.go:326–345

realIPFromHdrs extracts the actual client's IP address from the first suitable r's header. It returns an error if r doesn't contain any information about real client's IP address. Current headers priority is: 1. [httphdr.CFConnectingIP] 2. [httphdr.TrueClientIP] 3. [httphdr.XRealIP] 4. [httphdr.X

(r *http.Request)

//  3. [httphdr.XRealIP]
//  4. [httphdr.XForwardedFor]
func realIPFromHdrs(r *http.Request) (realIP netip.Addr, err error) {
	for _, h := range []string{
		httphdr.CFConnectingIP,
		httphdr.TrueClientIP,
		httphdr.XRealIP,
	} {
		realIP, err = netip.ParseAddr(strings.TrimSpace(r.Header.Get(h)))
		if err == nil {
			return realIP, nil
		}
	}

	xff := r.Header.Get(httphdr.XForwardedFor)
	firstComma := strings.IndexByte(xff, ',')
	if firstComma > 0 {
		xff = xff[:firstComma]
	}

	return netip.ParseAddr(strings.TrimSpace(xff))
}

// remoteAddr returns the real client's address and the IP address of the latest
// proxy server if any.