v1.0.0

features/policy/policy.go

@@ -0,0 +1,151 @@
+package policy
+
+import (
+	"context"
+	"runtime"
+	"time"
+
+	"github.com/xtls/xray-core/v1/common/platform"
+	"github.com/xtls/xray-core/v1/features"
+)
+
+// Timeout contains limits for connection timeout.
+type Timeout struct {
+	// Timeout for handshake phase in a connection.
+	Handshake time.Duration
+	// Timeout for connection being idle, i.e., there is no egress or ingress traffic in this connection.
+	ConnectionIdle time.Duration
+	// Timeout for an uplink only connection, i.e., the downlink of the connection has been closed.
+	UplinkOnly time.Duration
+	// Timeout for an downlink only connection, i.e., the uplink of the connection has been closed.
+	DownlinkOnly time.Duration
+}
+
+// Stats contains settings for stats counters.
+type Stats struct {
+	// Whether or not to enable stat counter for user uplink traffic.
+	UserUplink bool
+	// Whether or not to enable stat counter for user downlink traffic.
+	UserDownlink bool
+}
+
+// Buffer contains settings for internal buffer.
+type Buffer struct {
+	// Size of buffer per connection, in bytes. -1 for unlimited buffer.
+	PerConnection 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.
+	InboundUplink bool
+	// Whether or not to enable stat counter for downlink traffic in inbound handlers.
+	InboundDownlink bool
+	// Whether or not to enable stat counter for uplink traffic in outbound handlers.
+	OutboundUplink bool
+	// Whether or not to enable stat counter for downlink traffic in outbound handlers.
+	OutboundDownlink bool
+}
+
+// System contains policy settings at system level.
+type System struct {
+	Stats  SystemStats
+	Buffer Buffer
+}
+
+// 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
+}
+
+// Manager is a feature that provides Policy for the given user by its id or level.
+//
+// xray:api:stable
+type Manager interface {
+	features.Feature
+
+	// ForLevel returns the Session policy for the given user level.
+	ForLevel(level uint32) Session
+
+	// ForSystem returns the System policy for Xray system.
+	ForSystem() System
+}
+
+// ManagerType returns the type of Manager interface. Can be used to implement common.HasType.
+//
+// xray:api:stable
+func ManagerType() interface{} {
+	return (*Manager)(nil)
+}
+
+var defaultBufferSize int32
+
+func init() {
+	const key = "xray.ray.buffer.size"
+	const defaultValue = -17
+	size := platform.EnvFlag{
+		Name:    key,
+		AltName: platform.NormalizeEnvName(key),
+	}.GetValueAsInt(defaultValue)
+
+	switch size {
+	case 0:
+		defaultBufferSize = -1 // For pipe to use unlimited size
+	case defaultValue: // Env flag not defined. Use default values per CPU-arch.
+		switch runtime.GOARCH {
+		case "arm", "mips", "mipsle":
+			defaultBufferSize = 0
+		case "arm64", "mips64", "mips64le":
+			defaultBufferSize = 4 * 1024 // 4k cache for low-end devices
+		default:
+			defaultBufferSize = 512 * 1024
+		}
+	default:
+		defaultBufferSize = int32(size) * 1024 * 1024
+	}
+}
+
+func defaultBufferPolicy() Buffer {
+	return Buffer{
+		PerConnection: defaultBufferSize,
+	}
+}
+
+// SessionDefault returns the Policy when user is not specified.
+func SessionDefault() Session {
+	return Session{
+		Timeouts: Timeout{
+			// Align Handshake timeout with nginx client_header_timeout
+			// So that this value will not indicate server identity
+			Handshake:      time.Second * 60,
+			ConnectionIdle: time.Second * 300,
+			UplinkOnly:     time.Second * 1,
+			DownlinkOnly:   time.Second * 1,
+		},
+		Stats: Stats{
+			UserUplink:   false,
+			UserDownlink: false,
+		},
+		Buffer: defaultBufferPolicy(),
+	}
+}
+
+type policyKey int32
+
+const (
+	bufferPolicyKey policyKey = 0
+)
+
+func ContextWithBufferPolicy(ctx context.Context, p Buffer) context.Context {
+	return context.WithValue(ctx, bufferPolicyKey, p)
+}
+
+func BufferPolicyFromContext(ctx context.Context) Buffer {
+	pPolicy := ctx.Value(bufferPolicyKey)
+	if pPolicy == nil {
+		return defaultBufferPolicy()
+	}
+	return pPolicy.(Buffer)
+}