Expose trusted proxy list and counter configuration for realip middleware (#1535)

go.mod

@@ -171,3 +171,5 @@ replace github.com/getlantern/systray => github.com/netbirdio/systray v0.0.0-202
 replace golang.zx2c4.com/wireguard => github.com/netbirdio/wireguard-go v0.0.0-20240105182236-6c340dd55aed
 
 replace github.com/cloudflare/circl => github.com/cunicu/circl v0.0.0-20230801113412-fec58fc7b5f6
+
+replace github.com/grpc-ecosystem/go-grpc-middleware/v2 => github.com/surik/go-grpc-middleware/v2 v2.0.0-20240206110057-98a38fc1f86f

go.sum

@@ -286,8 +286,6 @@ github.com/gopherjs/gopherjs v0.0.0-20220410123724-9e86199038b0 h1:fWY+zXdWhvWnd
 github.com/gopherjs/gopherjs v0.0.0-20220410123724-9e86199038b0/go.mod h1:pRRIvn/QzFLrKfvEz3qUuEhtE/zLCWfreZ6J5gM2i+k=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
-github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.2-0.20240202184442-37827591b26c h1:Kvw2BIua5WGDnknpnODn9K74PYWLhhqt8G3l0chyzEI=
-github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.2-0.20240202184442-37827591b26c/go.mod h1:w9Y7gY31krpLmrVU5ZPG9H7l9fZuRu5/3R3S3FMtVQ4=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
 github.com/hashicorp/go-secure-stdlib/base62 v0.1.2 h1:ET4pqyjiGmY09R5y+rSd70J2w45CtbWDNvGqWp/R3Ng=
 github.com/hashicorp/go-secure-stdlib/base62 v0.1.2/go.mod h1:EdWO6czbmthiwZ3/PUsDV+UD1D5IRU4ActiaWGwt0Yw=
@@ -519,6 +517,8 @@ github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o
 github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/surik/go-grpc-middleware/v2 v2.0.0-20240206110057-98a38fc1f86f h1:J+egXEDkpg/vOYYzPO5IwF8OufGb7g+KcwEF1AWIzhQ=
+github.com/surik/go-grpc-middleware/v2 v2.0.0-20240206110057-98a38fc1f86f/go.mod h1:w9Y7gY31krpLmrVU5ZPG9H7l9fZuRu5/3R3S3FMtVQ4=
 github.com/things-go/go-socks5 v0.0.4 h1:jMQjIc+qhD4z9cITOMnBiwo9dDmpGuXmBlkRFrl/qD0=
 github.com/things-go/go-socks5 v0.0.4/go.mod h1:sh4K6WHrmHZpjxLTCHyYtXYH8OUuD+yZun41NomR1IQ=
 github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=

management/cmd/management.go

@@ -15,6 +15,7 @@ import (
 	"net/url"
 	"os"
 	"path"
+	"slices"
 	"strings"
 	"time"
 
@@ -170,21 +171,31 @@ var (
 
 			turnManager := server.NewTimeBasedAuthSecretsManager(peersUpdateManager, config.TURNConfig)
 
-			trustedPeers := config.TrustedHTTPProxies
+			trustedPeers := config.ReverseProxy.TrustedPeers
-			if len(trustedPeers) == 0 {
+			defaultTrustedPeers := []netip.Prefix{netip.MustParsePrefix("0.0.0.0/0"), netip.MustParsePrefix("::/0")}
-				trustedPeers = []netip.Prefix{netip.MustParsePrefix("0.0.0.0/0")}
+			if len(trustedPeers) == 0 || slices.Equal[[]netip.Prefix](trustedPeers, defaultTrustedPeers) {
+				log.Warn("TrustedPeers are configured to default value '0.0.0.0/0', '::/0'. This allows connection IP spoofing.")
+				trustedPeers = defaultTrustedPeers
+			}
+			trustedHTTPProxies := config.ReverseProxy.TrustedHTTPProxies
+			trustedProxiesCount := config.ReverseProxy.TrustedHTTPProxiesCount
+			if len(trustedHTTPProxies) > 0 && trustedProxiesCount > 0 {
+				log.Warn("TrustedHTTPProxies and TrustedHTTPProxiesCount both are configured. " +
+					"This is not recommended way to extract X-Forwarded-For. Consider using one of these options.")
+			}
+			realipOpts := realip.Opts{
+				TrustedPeers:        trustedPeers,
+				TrustedProxies:      trustedHTTPProxies,
+				TrustedProxiesCount: trustedProxiesCount,
+				Headers:             []string{realip.XForwardedFor, realip.XRealIp},
 			}
-			headers := []string{realip.XForwardedFor, realip.XRealIp}
 			gRPCOpts := []grpc.ServerOption{
 				grpc.KeepaliveEnforcementPolicy(kaep),
 				grpc.KeepaliveParams(kasp),
-				grpc.ChainUnaryInterceptor(
+				grpc.ChainUnaryInterceptor(realip.UnaryServerInterceptorOpts(realipOpts)),
-					realip.UnaryServerInterceptor(trustedPeers, headers),
+				grpc.ChainStreamInterceptor(realip.StreamServerInterceptorOpts(realipOpts)),
-				),
-				grpc.ChainStreamInterceptor(
-					realip.StreamServerInterceptor(trustedPeers, headers),
-				),
 			}
+
 			var certManager *autocert.Manager
 			var tlsConfig *tls.Config
 			tlsEnabled := false

management/server/config.go

@@ -41,8 +41,6 @@ type Config struct {
 
 	HttpConfig *HttpServerConfig
 
-	TrustedHTTPProxies []netip.Prefix
-
 	IdpManagerConfig *idp.Config
 
 	DeviceAuthorizationFlow *DeviceAuthorizationFlow
@@ -50,6 +48,8 @@ type Config struct {
 	PKCEAuthorizationFlow *PKCEAuthorizationFlow
 
 	StoreConfig StoreConfig
+
+	ReverseProxy ReverseProxy
 }
 
 // GetAuthAudiences returns the audience from the http config and device authorization flow config
@@ -146,6 +146,27 @@ type StoreConfig struct {
 	Engine StoreEngine
 }
 
+// ReverseProxy contains reverse proxy configuration in front of management.
+type ReverseProxy struct {
+	// TrustedHTTPProxies represents a list of trusted HTTP proxies by their IP prefixes.
+	// When extracting the real IP address from request headers, the middleware will verify
+	// if the peer's address falls within one of these trusted IP prefixes.
+	TrustedHTTPProxies []netip.Prefix
+
+	// TrustedHTTPProxiesCount specifies the count of trusted HTTP proxies between the internet
+	// and the server. When using the trusted proxy count method to extract the real IP address,
+	// the middleware will search the X-Forwarded-For IP list from the rightmost by this count
+	// minus one.
+	TrustedHTTPProxiesCount uint
+
+	// TrustedPeers represents a list of trusted peers by their IP prefixes.
+	// These peers are considered trustworthy by the gRPC server operator,
+	// and the middleware will attempt to extract the real IP address from
+	// request headers if the peer's address falls within one of these
+	// trusted IP prefixes.
+	TrustedPeers []netip.Prefix
+}
+
 // validateURL validates input http url
 func validateURL(httpURL string) bool {
 	_, err := url.ParseRequestURI(httpURL)