Revert "feat(): add CF-Connecting-IP (#908)" (#966)

This reverts commit cbaac31.

Author: VojtechVitek

middleware/realip.go

@@ -9,11 +9,9 @@ import (
 	"strings"
 )
 
-var defaultHeaders = []string{
-	"True-Client-IP", // Cloudflare Enterprise plan
-	"X-Real-IP",
-	"X-Forwarded-For",
-}
+var trueClientIP = http.CanonicalHeaderKey("True-Client-IP")
+var xForwardedFor = http.CanonicalHeaderKey("X-Forwarded-For")
+var xRealIP = http.CanonicalHeaderKey("X-Real-IP")
 
 // RealIP is a middleware that sets a http.Request's RemoteAddr to the results
 // of parsing either the True-Client-IP, X-Real-IP or the X-Forwarded-For headers
@@ -32,7 +30,7 @@ var defaultHeaders = []string{
 // how you're using RemoteAddr, vulnerable to an attack of some sort).
 func RealIP(h http.Handler) http.Handler {
 	fn := func(w http.ResponseWriter, r *http.Request) {
-		if rip := getRealIP(r, defaultHeaders); rip != "" {
+		if rip := realIP(r); rip != "" {
 			r.RemoteAddr = rip
 		}
 		h.ServeHTTP(w, r)
@@ -41,33 +39,22 @@ func RealIP(h http.Handler) http.Handler {
 	return http.HandlerFunc(fn)
 }
 
-// RealIPFromHeaders is a middleware that sets a http.Request's RemoteAddr to the results
-// of parsing the custom headers.
-//
-// usage:
-// r.Use(RealIPFromHeaders("CF-Connecting-IP"))
-func RealIPFromHeaders(headers ...string) func(http.Handler) http.Handler {
-	f := func(h http.Handler) http.Handler {
-		fn := func(w http.ResponseWriter, r *http.Request) {
-			if rip := getRealIP(r, headers); rip != "" {
-				r.RemoteAddr = rip
-			}
-			h.ServeHTTP(w, r)
-		}
-		return http.HandlerFunc(fn)
-	}
-	return f
-}
+func realIP(r *http.Request) string {
+	var ip string
 
-func getRealIP(r *http.Request, headers []string) string {
-	for _, header := range headers {
-		if ip := r.Header.Get(header); ip != "" {
-			ips := strings.Split(ip, ",")
-			if ips[0] == "" || net.ParseIP(ips[0]) == nil {
-				continue
-			}
-			return ips[0]
+	if tcip := r.Header.Get(trueClientIP); tcip != "" {
+		ip = tcip
+	} else if xrip := r.Header.Get(xRealIP); xrip != "" {
+		ip = xrip
+	} else if xff := r.Header.Get(xForwardedFor); xff != "" {
+		i := strings.Index(xff, ",")
+		if i == -1 {
+			i = len(xff)
 		}
+		ip = xff[:i]
+	}
+	if ip == "" || net.ParseIP(ip) == nil {
+		return ""
 	}
-	return ""
+	return ip
 }

middleware/realip_test.go

@@ -113,52 +113,3 @@ func TestInvalidIP(t *testing.T) {
 		t.Fatal("Invalid IP used.")
 	}
 }
-
-func TestCustomIPHeader(t *testing.T) {
-	var customHeaderKey = "X-CUSTOM-IP"
-	req, _ := http.NewRequest("GET", "/", nil)
-	req.Header.Add(customHeaderKey, "100.100.100.100")
-	w := httptest.NewRecorder()
-
-	r := chi.NewRouter()
-	r.Use(RealIPFromHeaders(customHeaderKey))
-
-	realIP := ""
-	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-		realIP = r.RemoteAddr
-		w.Write([]byte("Hello World"))
-	})
-	r.ServeHTTP(w, req)
-
-	if w.Code != 200 {
-		t.Fatal("Response Code should be 200")
-	}
-
-	if realIP != "100.100.100.100" {
-		t.Fatal("Test get real IP precedence error.")
-	}
-}
-
-func TestCustomIPHeaderWithoutDefault(t *testing.T) {
-	req, _ := http.NewRequest("GET", "/", nil)
-	req.Header.Add("X-REAL-IP", "100.100.100.100")
-	w := httptest.NewRecorder()
-
-	r := chi.NewRouter()
-	r.Use(RealIPFromHeaders("CF-Connecting-IP"))
-
-	realIP := ""
-	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-		realIP = r.RemoteAddr
-		w.Write([]byte("Hello World"))
-	})
-	r.ServeHTTP(w, req)
-
-	if w.Code != 200 {
-		t.Fatal("Response Code should be 200")
-	}
-
-	if realIP != "" {
-		t.Fatal("Invalid IP used.")
-	}
-}