customizable client ip extractor

context.go

@@ -729,6 +729,10 @@ func (c *Context) ShouldBindBodyWith(obj interface{}, bb binding.BindingBody) (e
 // X-Real-IP and X-Forwarded-For in order to work properly with reverse-proxies such us: nginx or haproxy.
 // Use X-Forwarded-For before X-Real-Ip as nginx uses X-Real-Ip with the proxy's IP.
 func (c *Context) ClientIP() string {
+	if c.engine.ClientIPExtractor != nil {
+		// if you don't trust your proxies, you can define your own extractor for client IP
+		return c.engine.ClientIPExtractor(c.Request)
+	}
 	if c.engine.ForwardedByClientIP {
 		clientIP := c.requestHeader("X-Forwarded-For")
 		clientIP = strings.TrimSpace(strings.Split(clientIP, ",")[0])

context_test.go

@@ -1416,6 +1416,14 @@ func TestContextClientIP(t *testing.T) {
 	// no port
 	c.Request.RemoteAddr = "50.50.50.50"
 	assert.Empty(t, c.ClientIP())
+
+	// custome client IP extractor
+	c.engine.ClientIPExtractor = func(req *http.Request) string {
+		clientIP := c.requestHeader("My-Client-IP")
+		return clientIP
+	}
+	c.Request.Header.Set("My-Client-IP", "10.10.10.10")
+	assert.Equal(t, "10.10.10.10", c.ClientIP())
 }
 
 func TestContextContentType(t *testing.T) {

gin.go

@@ -83,6 +83,9 @@ type Engine struct {
 	HandleMethodNotAllowed bool
 	ForwardedByClientIP    bool
 
+	// Custom extractor for extracting client IP from request
+	ClientIPExtractor func(*http.Request) string
+
 	// #726 #755 If enabled, it will thrust some headers starting with
 	// 'X-AppEngine...' for better integration with that PaaS.
 	AppEngine bool