feat(vless): IP restriction

app/policy/config.go

@@ -27,6 +27,9 @@ func defaultPolicy() *Policy {
 		Buffer: &Policy_Buffer{
 			Connection: p.Buffer.PerConnection,
 		},
+		Restriction: &Policy_Restriction{
+			MaxIPs: p.Restriction.MaxIPs,
+		},
 	}
 }
 
@@ -58,6 +61,11 @@ func (p *Policy) overrideWith(another *Policy) {
 			Connection: another.Buffer.Connection,
 		}
 	}
+	if another.Restriction != nil {
+		p.Restriction = &Policy_Restriction{
+			MaxIPs: another.Restriction.MaxIPs,
+		}
+	}
 }
 
 // ToCorePolicy converts this Policy to policy.Session.
@@ -77,6 +85,9 @@ func (p *Policy) ToCorePolicy() policy.Session {
 	if p.Buffer != nil {
 		cp.Buffer.PerConnection = p.Buffer.Connection
 	}
+	if p.Restriction != nil {
+		cp.Restriction.MaxIPs = p.Restriction.MaxIPs
+	}
 	return cp
 }
 

app/policy/config.proto

@@ -29,9 +29,14 @@ message Policy {
     int32 connection = 1;
   }
 
+  message Restriction {
+    int32 maxIPs = 1;
+  }
+
   Timeout timeout = 1;
   Stats stats = 2;
   Buffer buffer = 3;
+  Restriction restriction = 4;
 }
 
 message SystemPolicy {

app/proxyman/inbound/worker.go

@@ -18,6 +18,7 @@ import (
 	"github.com/xtls/xray-core/features/stats"
 	"github.com/xtls/xray-core/proxy"
 	"github.com/xtls/xray-core/transport/internet"
+	"github.com/xtls/xray-core/transport/internet/restriction"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tcp"
 	"github.com/xtls/xray-core/transport/internet/udp"
@@ -32,6 +33,8 @@ type worker interface {
 }
 
 type tcpWorker struct {
+	sync.Mutex
+
 	address         net.Address
 	port            net.Port
 	proxy           proxy.Inbound
@@ -42,6 +45,7 @@ type tcpWorker struct {
 	sniffingConfig  *proxyman.SniffingConfig
 	uplinkCounter   stats.Counter
 	downlinkCounter stats.Counter
+	ipLimitPool     map[session.ID]*restriction.UserMaxIp
 
 	hub internet.Listener
 
@@ -104,9 +108,22 @@ func (w *tcpWorker) callback(conn stat.Connection) {
 	}
 	ctx = session.ContextWithContent(ctx, content)
 
-	if err := w.proxy.Process(ctx, net.Network_TCP, conn, w.dispatcher); err != nil {
+	// Add this IP address to the pool for futher IP limit check
+	w.Lock()
+	w.ipLimitPool[sid] = &restriction.UserMaxIp{
+		IpAddress: net.IP(conn.RemoteAddr().Network()),
+	}
+	w.Unlock()
+
+	if err := w.proxy.Process(ctx, net.Network_TCP, conn, w.dispatcher, &w.ipLimitPool, w.ipLimitPool[sid]); err != nil {
 		newError("connection ends").Base(err).WriteToLog(session.ExportIDToError(ctx))
 	}
+
+	// Deletes the IP address from the pool after the connection ends
+	w.Lock()
+	delete(w.ipLimitPool, sid)
+	w.Unlock()
+
 	cancel()
 	conn.Close()
 }
@@ -116,6 +133,9 @@ func (w *tcpWorker) Proxy() proxy.Inbound {
 }
 
 func (w *tcpWorker) Start() error {
+	if len(w.ipLimitPool) == 0 {
+		w.ipLimitPool = make(map[session.ID]*restriction.UserMaxIp)
+	}
 	ctx := context.Background()
 	hub, err := internet.ListenTCP(ctx, w.address, w.port, w.stream, func(conn stat.Connection) {
 		go w.callback(conn)
@@ -244,6 +264,7 @@ type udpWorker struct {
 	sniffingConfig  *proxyman.SniffingConfig
 	uplinkCounter   stats.Counter
 	downlinkCounter stats.Counter
+	ipLimitPool     map[session.ID]*restriction.UserMaxIp
 
 	checker    *task.Periodic
 	activeConn map[connID]*udpConn
@@ -326,9 +347,23 @@ func (w *udpWorker) callback(b *buf.Buffer, source net.Destination, originalDest
 				content.SniffingRequest.RouteOnly = w.sniffingConfig.RouteOnly
 			}
 			ctx = session.ContextWithContent(ctx, content)
-			if err := w.proxy.Process(ctx, net.Network_UDP, conn, w.dispatcher); err != nil {
+
+			// Add this IP address to the pool for futher IP limit check
+			w.Lock()
+			w.ipLimitPool[sid] = &restriction.UserMaxIp{
+				IpAddress: net.IP(conn.RemoteAddr().Network()),
+			}
+			w.Unlock()
+
+			if err := w.proxy.Process(ctx, net.Network_UDP, conn, w.dispatcher, &w.ipLimitPool, w.ipLimitPool[sid]); err != nil {
 				newError("connection ends").Base(err).WriteToLog(session.ExportIDToError(ctx))
 			}
+
+			// Deletes the IP address from the pool after the connection ends
+			w.Lock()
+			delete(w.ipLimitPool, sid)
+			w.Unlock()
+
 			conn.Close()
 			// conn not removed by checker TODO may be lock worker here is better
 			if !conn.inactive {
@@ -379,6 +414,9 @@ func (w *udpWorker) clean() error {
 }
 
 func (w *udpWorker) Start() error {
+	if len(w.ipLimitPool) == 0 {
+		w.ipLimitPool = make(map[session.ID]*restriction.UserMaxIp)
+	}
 	w.activeConn = make(map[connID]*udpConn, 16)
 	ctx := context.Background()
 	h, err := udp.ListenUDP(ctx, w.address, w.port, w.stream, udp.HubCapacity(256))
@@ -478,7 +516,7 @@ func (w *dsWorker) callback(conn stat.Connection) {
 	}
 	ctx = session.ContextWithContent(ctx, content)
 
-	if err := w.proxy.Process(ctx, net.Network_UNIX, conn, w.dispatcher); err != nil {
+	if err := w.proxy.Process(ctx, net.Network_UNIX, conn, w.dispatcher, nil, nil); err != nil {
 		newError("connection ends").Base(err).WriteToLog(session.ExportIDToError(ctx))
 	}
 	cancel()

features/policy/policy.go

@@ -35,6 +35,12 @@ type Buffer struct {
 	PerConnection int32
 }
 
+// Buffer contains settings for restriction such as ip restriction.
+type Restriction struct {
+	// Maximum allowed ips, -1 for unlimited
+	MaxIPs int32
+}
+
 // SystemStats contains stat policy settings on system level.
 type SystemStats struct {
 	// Whether or not to enable stat counter for uplink traffic in inbound handlers.
@@ -55,9 +61,10 @@ type System struct {
 
 // Session is session based settings for controlling Xray requests. It contains various settings (or limits) that may differ for different users in the context.
 type Session struct {
-	Timeouts Timeout // Timeout settings
-	Stats    Stats
-	Buffer   Buffer
+	Timeouts    Timeout // Timeout settings
+	Stats       Stats
+	Buffer      Buffer
+	Restriction Restriction
 }
 
 // Manager is a feature that provides Policy for the given user by its id or level.
@@ -109,6 +116,12 @@ func defaultBufferPolicy() Buffer {
 	}
 }
 
+func defaultRestrictionPolicy() Restriction {
+	return Restriction{
+		MaxIPs: -1,
+	}
+}
+
 // SessionDefault returns the Policy when user is not specified.
 func SessionDefault() Session {
 	return Session{
@@ -124,7 +137,8 @@ func SessionDefault() Session {
 			UserUplink:   false,
 			UserDownlink: false,
 		},
-		Buffer: defaultBufferPolicy(),
+		Buffer:      defaultBufferPolicy(),
+		Restriction: defaultRestrictionPolicy(),
 	}
 }
 

infra/conf/common.go

@@ -231,8 +231,8 @@ func (list *PortList) UnmarshalJSON(data []byte) error {
 }
 
 type User struct {
-	EmailString string `json:"email"`
-	LevelByte   byte   `json:"level"`
+	EmailString   string `json:"email"`
+	LevelByte     byte   `json:"level"`
 }
 
 func (v *User) Build() *protocol.User {

infra/conf/policy.go

@@ -12,6 +12,7 @@ type Policy struct {
 	StatsUserUplink   bool    `json:"statsUserUplink"`
 	StatsUserDownlink bool    `json:"statsUserDownlink"`
 	BufferSize        *int32  `json:"bufferSize"`
+	MaxIPs            *int32  `json:"maxIPs"`
 }
 
 func (t *Policy) Build() (*policy.Policy, error) {
@@ -47,6 +48,12 @@ func (t *Policy) Build() (*policy.Policy, error) {
 		}
 	}
 
+	if t.MaxIPs != nil {
+		p.Restriction = &policy.Policy_Restriction{
+			MaxIPs: (*t.MaxIPs),
+		}
+	}
+
 	return p, nil
 }
 

proxy/dokodemo/dokodemo.go

@@ -18,6 +18,7 @@ import (
 	"github.com/xtls/xray-core/core"
 	"github.com/xtls/xray-core/features/policy"
 	"github.com/xtls/xray-core/features/routing"
+	"github.com/xtls/xray-core/transport/internet/restriction"
 	"github.com/xtls/xray-core/transport/internet/stat"
 )
 
@@ -76,7 +77,7 @@ type hasHandshakeAddress interface {
 }
 
 // Process implements proxy.Inbound.
-func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn stat.Connection, dispatcher routing.Dispatcher) error {
+func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn stat.Connection, dispatcher routing.Dispatcher, _ *map[session.ID]*restriction.UserMaxIp, _ *restriction.UserMaxIp) error {
 	newError("processing connection from: ", conn.RemoteAddr()).AtDebug().WriteToLog(session.ExportIDToError(ctx))
 	dest := net.Destination{
 		Network: network,

proxy/proxy.go

@@ -26,6 +26,7 @@ import (
 	"github.com/xtls/xray-core/transport"
 	"github.com/xtls/xray-core/transport/internet"
 	"github.com/xtls/xray-core/transport/internet/reality"
+	"github.com/xtls/xray-core/transport/internet/restriction"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
 )
@@ -60,7 +61,7 @@ type Inbound interface {
 	Network() []net.Network
 
 	// Process processes a connection of given network. If necessary, the Inbound can dispatch the connection to an Outbound.
-	Process(context.Context, net.Network, stat.Connection, routing.Dispatcher) error
+	Process(context.Context, net.Network, stat.Connection, routing.Dispatcher, *map[session.ID]*restriction.UserMaxIp, *restriction.UserMaxIp) error
 }
 
 // An Outbound process outbound connections.

proxy/trojan/server.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/xtls/xray-core/common"
@@ -22,6 +23,7 @@ import (
 	"github.com/xtls/xray-core/features/policy"
 	"github.com/xtls/xray-core/features/routing"
 	"github.com/xtls/xray-core/transport/internet/reality"
+	"github.com/xtls/xray-core/transport/internet/restriction"
 	"github.com/xtls/xray-core/transport/internet/stat"
 	"github.com/xtls/xray-core/transport/internet/tls"
 	"github.com/xtls/xray-core/transport/internet/udp"
@@ -35,6 +37,8 @@ func init() {
 
 // Server is an inbound connection handler that handles messages in trojan protocol.
 type Server struct {
+	sync.Mutex
+
 	policyManager policy.Manager
 	validator     *Validator
 	fallbacks     map[string]map[string]map[string]*Fallback // or nil
@@ -131,7 +135,7 @@ func (s *Server) Network() []net.Network {
 }
 
 // Process implements proxy.Inbound.Process().
-func (s *Server) Process(ctx context.Context, network net.Network, conn stat.Connection, dispatcher routing.Dispatcher) error {
+func (s *Server) Process(ctx context.Context, network net.Network, conn stat.Connection, dispatcher routing.Dispatcher, usrIpRstrct *map[session.ID]*restriction.UserMaxIp, connIp *restriction.UserMaxIp) error {
 	sid := session.ExportIDToError(ctx)
 
 	iConn := conn
@@ -219,6 +223,29 @@ func (s *Server) Process(ctx context.Context, network net.Network, conn stat.Con
 	inbound.User = user
 	sessionPolicy = s.policyManager.ForLevel(user.Level)
 
+	if sessionPolicy.Restriction.MaxIPs > 0 {
+		addr := conn.RemoteAddr().(*net.TCPAddr)
+
+		uniqueIps := make(map[string]bool)
+
+		s.Lock()
+		// Iterate through the connections and find unique used IP addresses withing last 30 seconds.
+		for _, conn := range *usrIpRstrct {
+			if conn.User == user.Email && !conn.IpAddress.Equal(addr.IP) && ((time.Now().Unix() - conn.Time) < 30) {
+				uniqueIps[conn.IpAddress.String()] = true
+			}
+		}
+		s.Unlock()
+
+		if len(uniqueIps) >= int(sessionPolicy.Restriction.MaxIPs) {
+			return newError("User ", user, " has exceeded their allowed IPs.").AtWarning()
+		}
+
+		connIp.IpAddress = addr.IP
+		connIp.User = user.Email
+		connIp.Time = time.Now().Unix()
+	}
+
 	if destination.Network == net.Network_UDP { // handle udp request
 		return s.handleUDPPayload(ctx, &PacketReader{Reader: clientReader}, &PacketWriter{Writer: conn}, dispatcher)
 	}