added real_ip and cloudflare_real_ip middlewares, fixed that some middlewares does not work properly

internal/net/http/middleware/x_forwarded.go

@@ -0,0 +1,44 @@
+package middleware
+
+import (
+	"net"
+	"strings"
+)
+
+var AddXForwarded = &Middleware{
+	rewrite: func(req *Request) {
+		clientIP, _, err := net.SplitHostPort(req.RemoteAddr)
+		if err == nil {
+			req.Header.Set("X-Forwarded-For", clientIP)
+		} else {
+			req.Header.Del("X-Forwarded-For")
+		}
+		req.Header.Set("X-Forwarded-Host", req.Host)
+		if req.TLS == nil {
+			req.Header.Set("X-Forwarded-Proto", "http")
+		} else {
+			req.Header.Set("X-Forwarded-Proto", "https")
+		}
+	},
+}
+
+var SetXForwarded = &Middleware{
+	rewrite: func(req *Request) {
+		clientIP, _, err := net.SplitHostPort(req.RemoteAddr)
+		if err == nil {
+			prior := req.Header["X-Forwarded-For"]
+			if len(prior) > 0 {
+				clientIP = strings.Join(prior, ", ") + ", " + clientIP
+			}
+			req.Header.Set("X-Forwarded-For", clientIP)
+		} else {
+			req.Header.Del("X-Forwarded-For")
+		}
+		req.Header.Set("X-Forwarded-Host", req.Host)
+		if req.TLS == nil {
+			req.Header.Set("X-Forwarded-Proto", "http")
+		} else {
+			req.Header.Set("X-Forwarded-Proto", "https")
+		}
+	},
+}