Add Configuration.RemoteAddrHeadersForce as requested at #1567 and change RemoteAddrHeaders from map to string slice

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HISTORY.md

@@ -375,6 +375,8 @@ Other Improvements:
 
 ![DBUG routes](https://iris-go.com/images/v12.2.0-dbug2.png?v=0)
 
+- Add `Configuration.RemoteAddrHeadersForce bool` to force `Context.RemoteAddr() string` to return the first entry of request headers as a fallback instead of the `Request.RemoteAddr` one, as requested at: [1567#issuecomment-663972620](https://github.com/kataras/iris/issues/1567#issuecomment-663972620).
+
 - Fix [#1569#issuecomment-663739177](https://github.com/kataras/iris/issues/1569#issuecomment-663739177).
 
 - Fix [#1564](https://github.com/kataras/iris/issues/1564).
@@ -516,6 +518,7 @@ New Context Methods:
 
 Breaking Changes:
 
+- `Configuration.RemoteAddrHeaders` from `map[string]bool` to `[]string`. If you used `With(out)RemoteAddrHeader` then you are ready to proceed without any code changes for that one.
 - `ctx.Gzip(boolean)` replaced with `ctx.CompressWriter(boolean) error`.
 - `ctx.GzipReader(boolean) error` replaced with `ctx.CompressReader(boolean) error`.
 - `iris.Gzip` and `iris.GzipReader` replaced with `iris.Compression` (middleware).

_examples/configuration/from-toml-file/configs/iris.tml

@@ -4,6 +4,6 @@ FireMethodNotAllowed = true
 DisableBodyConsumptionOnUnmarshal = false
 TimeFormat = "Mon, 01 Jan 2006 15:04:05 GMT"
 Charset = "utf-8"
-
+RemoteAddrHeaders = ["X-Real-Ip", "X-Forwarded-For", "CF-Connecting-IP"]
 [Other]
 	MyServerName = "iris"

_examples/configuration/from-yaml-file/configs/iris.yml

@@ -9,8 +9,8 @@ SSLProxyHeaders:
 HostProxyHeaders:
   X-Host: true
 RemoteAddrHeaders:
-  X-Real-Ip: true
-  X-Forwarded-For: true
-  CF-Connecting-IP: true
+  - X-Real-Ip
+  - X-Forwarded-For
+  - CF-Connecting-IP
 Other:
   Addr: :8080

configuration.go

@@ -351,48 +351,38 @@ func WithPostMaxMemory(limit int64) Configurator {
 	}
 }
 
-// WithRemoteAddrHeader enables or adds a new or existing request header name
+// WithRemoteAddrHeader adds a new request header name
 // that can be used to validate the client's real IP.
-//
-// By-default no "X-" header is consired safe to be used for retrieving the
-// client's IP address, because those headers can manually change by
-// the client. But sometimes are useful e.g., when behind a proxy
-// you want to enable the "X-Forwarded-For" or when cloudflare
-// you want to enable the "CF-Connecting-IP", inneed you
-// can allow the `ctx.RemoteAddr()` to use any header
-// that the client may sent.
-//
-// Defaults to an empty map but an example usage is:
-// WithRemoteAddrHeader("X-Forwarded-For", "CF-Connecting-IP")
-//
-// Look `context.RemoteAddr()` for more.
 func WithRemoteAddrHeader(header ...string) Configurator {
 	return func(app *Application) {
-		if app.config.RemoteAddrHeaders == nil {
-			app.config.RemoteAddrHeaders = make(map[string]bool)
+		for _, h := range header {
+			exists := false
+			for _, v := range app.config.RemoteAddrHeaders {
+				if v == h {
+					exists = true
+				}
 			}
 
-		for _, k := range header {
-			app.config.RemoteAddrHeaders[k] = true
+			if !exists {
+				app.config.RemoteAddrHeaders = append(app.config.RemoteAddrHeaders, h)
+			}
 		}
 	}
 }
 
-// WithoutRemoteAddrHeader disables an existing request header name
+// WithoutRemoteAddrHeader removes an existing request header name
 // that can be used to validate and parse the client's real IP.
 //
-//
-// Keep note that RemoteAddrHeaders is already defaults to an empty map
-// so you don't have to call this Configurator if you didn't
-// add allowed headers via configuration or via `WithRemoteAddrHeader` before.
-//
 // Look `context.RemoteAddr()` for more.
 func WithoutRemoteAddrHeader(headerName string) Configurator {
 	return func(app *Application) {
-		if app.config.RemoteAddrHeaders == nil {
-			app.config.RemoteAddrHeaders = make(map[string]bool)
+		tmp := app.config.RemoteAddrHeaders[:0]
+		for _, v := range app.config.RemoteAddrHeaders {
+			if v != headerName {
+				tmp = append(tmp, v)
 			}
-		app.config.RemoteAddrHeaders[headerName] = false
+		}
+		app.config.RemoteAddrHeaders = tmp
 	}
 }
 
@@ -783,21 +773,27 @@ type Configuration struct {
 	// that can be valid to parse the client's IP based on.
 	// By-default no "X-" header is consired safe to be used for retrieving the
 	// client's IP address, because those headers can manually change by
-	// the client. But sometimes are useful e.g., when behind a proxy
+	// the client. But sometimes are useful e.g. when behind a proxy
 	// you want to enable the "X-Forwarded-For" or when cloudflare
-	// you want to enable the "CF-Connecting-IP", inneed you
+	// you want to enable the "CF-Connecting-IP", indeed you
 	// can allow the `ctx.RemoteAddr()` to use any header
 	// that the client may sent.
 	//
-	// Defaults to an empty map but an example usage is:
+	// Defaults to an empty slice but an example usage is:
 	// RemoteAddrHeaders {
-	//	"X-Real-Ip":             true,
-	//  "X-Forwarded-For":       true,
-	// 	"CF-Connecting-IP": 	 true,
+	//	"X-Real-Ip",
+	//  "X-Forwarded-For",
+	// 	"CF-Connecting-IP",
 	//	}
 	//
 	// Look `context.RemoteAddr()` for more.
-	RemoteAddrHeaders map[string]bool `json:"remoteAddrHeaders,omitempty" yaml:"RemoteAddrHeaders" toml:"RemoteAddrHeaders"`
+	RemoteAddrHeaders []string `json:"remoteAddrHeaders,omitempty" yaml:"RemoteAddrHeaders" toml:"RemoteAddrHeaders"`
+	// RemoteAddrHeadersForce forces the `Context.RemoteAddr()` method
+	// to return the first entry of a request header as a fallback,
+	// even if that IP is a part of the `RemoteAddrPrivateSubnets` list.
+	// The default behavior, if a remote address is part of the `RemoteAddrPrivateSubnets`,
+	// is to retrieve the IP from the `Request.RemoteAddr` field instead.
+	RemoteAddrHeadersForce bool `json:"remoteAddrHeadersForce,omitempty" yaml:"RemoteAddrHeadersForce" toml:"RemoteAddrHeadersForce"`
 	// RemoteAddrPrivateSubnets defines the private sub-networks.
 	// They are used to be compared against
 	// IP Addresses fetched through `RemoteAddrHeaders` or `Context.Request.RemoteAddr`.
@@ -960,10 +956,15 @@ func (c Configuration) GetViewDataContextKey() string {
 }
 
 // GetRemoteAddrHeaders returns the RemoteAddrHeaders field.
-func (c Configuration) GetRemoteAddrHeaders() map[string]bool {
+func (c Configuration) GetRemoteAddrHeaders() []string {
 	return c.RemoteAddrHeaders
 }
 
+// GetRemoteAddrHeadersForce returns RemoteAddrHeadersForce field.
+func (c Configuration) GetRemoteAddrHeadersForce() bool {
+	return c.RemoteAddrHeadersForce
+}
+
 // GetSSLProxyHeaders returns the SSLProxyHeaders field.
 func (c Configuration) GetSSLProxyHeaders() map[string]string {
 	return c.SSLProxyHeaders
@@ -1102,12 +1103,11 @@ func WithConfiguration(c Configuration) Configurator {
 		}
 
 		if v := c.RemoteAddrHeaders; len(v) > 0 {
-			if main.RemoteAddrHeaders == nil {
-				main.RemoteAddrHeaders = make(map[string]bool, len(v))
-			}
-			for key, value := range v {
-				main.RemoteAddrHeaders[key] = value
+			main.RemoteAddrHeaders = v
 		}
+
+		if v := c.RemoteAddrHeadersForce; v {
+			main.RemoteAddrHeadersForce = v
 		}
 
 		if v := c.RemoteAddrPrivateSubnets; len(v) > 0 {
@@ -1171,7 +1171,8 @@ func DefaultConfiguration() Configuration {
 		VersionContextKey:      "iris.api.version",
 		ViewLayoutContextKey:   "iris.viewLayout",
 		ViewDataContextKey:     "iris.viewData",
-		RemoteAddrHeaders:    make(map[string]bool),
+		RemoteAddrHeaders:      nil,
+		RemoteAddrHeadersForce: false,
 		RemoteAddrPrivateSubnets: []netutil.IPRange{
 			{
 				Start: net.ParseIP("10.0.0.0"),

configuration_test.go

@@ -154,9 +154,9 @@ DisableBodyConsumptionOnUnmarshal: true
 TimeFormat: "Mon, 02 Jan 2006 15:04:05 GMT"
 Charset: "utf-8"
 RemoteAddrHeaders:
-  X-Real-Ip: true
-  X-Forwarded-For: true
-  CF-Connecting-IP: true
+  - X-Real-Ip
+  - X-Forwarded-For
+  - CF-Connecting-IP
 HostProxyHeaders:
   X-Host: true
 SSLProxyHeaders:
@@ -210,19 +210,19 @@ Other:
 		t.Fatalf("error on TestConfigurationYAML: Expected RemoteAddrHeaders to be filled")
 	}
 
-	expectedRemoteAddrHeaders := map[string]bool{
-		"X-Real-Ip":        true,
-		"X-Forwarded-For":  true,
-		"CF-Connecting-IP": true,
+	expectedRemoteAddrHeaders := []string{
+		"X-Real-Ip",
+		"X-Forwarded-For",
+		"CF-Connecting-IP",
 	}
 
 	if expected, got := len(c.RemoteAddrHeaders), len(expectedRemoteAddrHeaders); expected != got {
 		t.Fatalf("error on TestConfigurationYAML: Expected RemoteAddrHeaders' len(%d) and got(%d), len is not the same", expected, got)
 	}
 
-	for k, v := range c.RemoteAddrHeaders {
-		if expected, got := expectedRemoteAddrHeaders[k], v; expected != got {
-			t.Fatalf("error on TestConfigurationYAML: Expected RemoteAddrHeaders[%s] = %t but got %t", k, expected, got)
+	for i, v := range c.RemoteAddrHeaders {
+		if expected, got := expectedRemoteAddrHeaders[i], v; expected != got {
+			t.Fatalf("error on TestConfigurationYAML: Expected RemoteAddrHeaders[%d] = %s but got %s", i, expected, got)
 		}
 	}
 
@@ -285,10 +285,7 @@ DisableBodyConsumptionOnUnmarshal = true
 TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
 Charset = "utf-8"
 
-[RemoteAddrHeaders]
-    X-Real-Ip = true
-    X-Forwarded-For = true
-    CF-Connecting-IP = true
+RemoteAddrHeaders = ["X-Real-Ip", "X-Forwarded-For", "CF-Connecting-IP"]
 
 [Other]
 	# Indentation (tabs and/or spaces) is allowed but not required
@@ -337,19 +334,19 @@ Charset = "utf-8"
 		t.Fatalf("error on TestConfigurationTOML: Expected RemoteAddrHeaders to be filled")
 	}
 
-	expectedRemoteAddrHeaders := map[string]bool{
-		"X-Real-Ip":        true,
-		"X-Forwarded-For":  true,
-		"CF-Connecting-IP": true,
+	expectedRemoteAddrHeaders := []string{
+		"X-Real-Ip",
+		"X-Forwarded-For",
+		"CF-Connecting-IP",
 	}
 
 	if expected, got := len(c.RemoteAddrHeaders), len(expectedRemoteAddrHeaders); expected != got {
 		t.Fatalf("error on TestConfigurationTOML: Expected RemoteAddrHeaders' len(%d) and got(%d), len is not the same", expected, got)
 	}
 
-	for k, v := range c.RemoteAddrHeaders {
-		if expected, got := expectedRemoteAddrHeaders[k], v; expected != got {
-			t.Fatalf("error on TestConfigurationTOML: Expected RemoteAddrHeaders[%s] = %t but got %t", k, expected, got)
+	for i, got := range c.RemoteAddrHeaders {
+		if expected := expectedRemoteAddrHeaders[i]; expected != got {
+			t.Fatalf("error on TestConfigurationTOML: Expected RemoteAddrHeaders[%d] = %s but got %s", i, expected, got)
 		}
 	}
 

context/configuration.go

@@ -57,7 +57,9 @@ type ConfigurationReadOnly interface {
 	GetViewDataContextKey() string
 
 	// GetRemoteAddrHeaders returns RemoteAddrHeaders field.
-	GetRemoteAddrHeaders() map[string]bool
+	GetRemoteAddrHeaders() []string
+	// GetRemoteAddrHeadersForce returns RemoteAddrHeadersForce field.
+	GetRemoteAddrHeadersForce() bool
 	// GetRemoteAddrPrivateSubnets returns the RemoteAddrPrivateSubnets field.
 	GetRemoteAddrPrivateSubnets() []netutil.IPRange
 	// GetSSLProxyHeaders returns the SSLProxyHeaders field.

context/context.go

@@ -803,27 +803,41 @@ func (ctx *Context) FullRequestURI() string {
 // Based on allowed headers names that can be modified from Configuration.RemoteAddrHeaders.
 //
 // If parse based on these headers fail then it will return the Request's `RemoteAddr` field
-// which is filled by the server before the HTTP handler.
+// which is filled by the server before the HTTP handler,
+// unless the Configuration.RemoteAddrHeadersForce was set to true
+// which will force this method to return the first IP from RemoteAddrHeaders
+// even if it's part of a private network.
 //
 // Look `Configuration.RemoteAddrHeaders`,
+//		`Configuration.RemoteAddrHeadersForce`,
 //      `Configuration.WithRemoteAddrHeader(...)`,
 //      `Configuration.WithoutRemoteAddrHeader(...)` and
 //      `Configuration.RemoteAddrPrivateSubnets` for more.
 func (ctx *Context) RemoteAddr() string {
-	remoteHeaders := ctx.app.ConfigurationReadOnly().GetRemoteAddrHeaders()
+	if remoteHeaders := ctx.app.ConfigurationReadOnly().GetRemoteAddrHeaders(); len(remoteHeaders) > 0 {
 		privateSubnets := ctx.app.ConfigurationReadOnly().GetRemoteAddrPrivateSubnets()
 
-	for headerName, enabled := range remoteHeaders {
-		if !enabled {
-			continue
-		}
-
+		for _, headerName := range remoteHeaders {
 			ipAddresses := strings.Split(ctx.GetHeader(headerName), ",")
 			if ip, ok := netutil.GetIPAddress(ipAddresses, privateSubnets); ok {
 				return ip
 			}
 		}
 
+		if ctx.app.ConfigurationReadOnly().GetRemoteAddrHeadersForce() {
+			for _, headerName := range remoteHeaders {
+				// return the first valid IP,
+				//  even if it's a part of a private network.
+				ipAddresses := strings.Split(ctx.GetHeader(headerName), ",")
+				for _, addr := range ipAddresses {
+					if ip, _, err := net.SplitHostPort(addr); err == nil {
+						return ip
+					}
+				}
+			}
+		}
+	}
+
 	addr := strings.TrimSpace(ctx.request.RemoteAddr)
 	if addr != "" {
 		// if addr has port use the net.SplitHostPort otherwise(error occurs) take as it is