diff --git a/common/log/access.go b/common/log/access.go
new file mode 100644
index 00000000..5ea8bf39
--- /dev/null
+++ b/common/log/access.go
@@ -0,0 +1,15 @@
+package log
+
+type AccessStatus string
+
+const (
+	AccessAccepted = AccessStatus("accepted")
+	AccessRejected = AccessStatus("rejected")
+)
+
+type AccessMessage struct {
+	From   interface{}
+	To     interface{}
+	Status AccessStatus
+	Reason interface{}
+}
diff --git a/common/log/log.go b/common/log/log.go
new file mode 100644
index 00000000..361e1916
--- /dev/null
+++ b/common/log/log.go
@@ -0,0 +1,49 @@
+package log
+
+import (
+	"sync/atomic"
+	"unsafe"
+
+	"v2ray.com/core/common/serial"
+)
+
+type Message interface {
+	String() string
+}
+
+type Handler interface {
+	Handle(msg Message)
+}
+
+type noOpHandler byte
+
+func (noOpHandler) Handle(msg Message) {}
+
+type GeneralMessage struct {
+	Severity Severity
+	Content  interface{}
+}
+
+func (m *GeneralMessage) String() string {
+	return serial.Concat("[", m.Severity, "]: ", m.Content)
+}
+
+func Record(msg Message) {
+	h := (*Handler)(atomic.LoadPointer(&logHandler))
+	(*h).Handle(msg)
+}
+
+var (
+	logHandler unsafe.Pointer
+)
+
+func RegisterHandler(handler Handler) {
+	if handler == nil {
+		panic("Log handler is nil")
+	}
+	atomic.StorePointer(&logHandler, unsafe.Pointer(&handler))
+}
+
+func init() {
+	RegisterHandler(noOpHandler(0))
+}
diff --git a/common/log/log.pb.go b/common/log/log.pb.go
new file mode 100644
index 00000000..3aa9c986
--- /dev/null
+++ b/common/log/log.pb.go
@@ -0,0 +1,68 @@
+package log
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type Severity int32
+
+const (
+	Severity_Unknown Severity = 0
+	Severity_Error   Severity = 1
+	Severity_Warning Severity = 2
+	Severity_Info    Severity = 3
+	Severity_Debug   Severity = 4
+)
+
+var Severity_name = map[int32]string{
+	0: "Unknown",
+	1: "Error",
+	2: "Warning",
+	3: "Info",
+	4: "Debug",
+}
+var Severity_value = map[string]int32{
+	"Unknown": 0,
+	"Error":   1,
+	"Warning": 2,
+	"Info":    3,
+	"Debug":   4,
+}
+
+func (x Severity) String() string {
+	return proto.EnumName(Severity_name, int32(x))
+}
+func (Severity) EnumDescriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
+
+func init() {
+	proto.RegisterEnum("v2ray.core.common.log.Severity", Severity_name, Severity_value)
+}
+
+func init() { proto.RegisterFile("v2ray.com/core/common/log/log.proto", fileDescriptor0) }
+
+var fileDescriptor0 = []byte{
+	// 178 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x52, 0x2e, 0x33, 0x2a, 0x4a,
+	0xac, 0xd4, 0x4b, 0xce, 0xcf, 0xd5, 0x4f, 0xce, 0x2f, 0x4a, 0xd5, 0x4f, 0xce, 0xcf, 0xcd, 0xcd,
+	0xcf, 0xd3, 0xcf, 0xc9, 0x4f, 0x07, 0x61, 0xbd, 0x82, 0xa2, 0xfc, 0x92, 0x7c, 0x21, 0x51, 0x98,
+	0xa2, 0xa2, 0x54, 0x3d, 0x88, 0x02, 0xbd, 0x9c, 0xfc, 0x74, 0x2d, 0x17, 0x2e, 0x8e, 0xe0, 0xd4,
+	0xb2, 0xd4, 0xa2, 0xcc, 0x92, 0x4a, 0x21, 0x6e, 0x2e, 0xf6, 0xd0, 0xbc, 0xec, 0xbc, 0xfc, 0xf2,
+	0x3c, 0x01, 0x06, 0x21, 0x4e, 0x2e, 0x56, 0xd7, 0xa2, 0xa2, 0xfc, 0x22, 0x01, 0x46, 0x90, 0x78,
+	0x78, 0x62, 0x51, 0x5e, 0x66, 0x5e, 0xba, 0x00, 0x93, 0x10, 0x07, 0x17, 0x8b, 0x67, 0x5e, 0x5a,
+	0xbe, 0x00, 0x33, 0x48, 0x85, 0x4b, 0x6a, 0x52, 0x69, 0xba, 0x00, 0x8b, 0x93, 0x15, 0x97, 0x64,
+	0x72, 0x7e, 0xae, 0x1e, 0x56, 0x2b, 0x02, 0x18, 0xa3, 0x98, 0x73, 0xf2, 0xd3, 0x57, 0x31, 0x89,
+	0x86, 0x19, 0x05, 0x25, 0x56, 0xea, 0x39, 0x83, 0xa4, 0x9d, 0x21, 0xd2, 0x3e, 0xf9, 0xe9, 0x49,
+	0x6c, 0x60, 0xf7, 0x19, 0x03, 0x02, 0x00, 0x00, 0xff, 0xff, 0xfb, 0x69, 0xef, 0x0e, 0xc6, 0x00,
+	0x00, 0x00,
+}
diff --git a/common/log/log.proto b/common/log/log.proto
new file mode 100644
index 00000000..7e1d4de5
--- /dev/null
+++ b/common/log/log.proto
@@ -0,0 +1,16 @@
+syntax = "proto3";
+
+package v2ray.core.common.log;
+option csharp_namespace = "V2Ray.Core.Common.Log";
+option go_package = "log";
+option java_package = "com.v2ray.core.common.log";
+option java_multiple_files = true;
+
+enum Severity {
+  Unknown = 0;
+  Error = 1;
+  Warning = 2;
+  Info = 3;
+  Debug = 4;
+}
+
diff --git a/common/log/log_test.go b/common/log/log_test.go
new file mode 100644
index 00000000..f4ee096c
--- /dev/null
+++ b/common/log/log_test.go
@@ -0,0 +1,32 @@
+package log_test
+
+import (
+	"testing"
+
+	"v2ray.com/core/common/log"
+	"v2ray.com/core/common/net"
+	. "v2ray.com/ext/assert"
+)
+
+type testLogger struct {
+	value string
+}
+
+func (l *testLogger) Handle(msg log.Message) {
+	l.value = msg.String()
+}
+
+func TestLogRecord(t *testing.T) {
+	assert := With(t)
+
+	var logger testLogger
+	log.RegisterHandler(&logger)
+
+	ip := "8.8.8.8"
+	log.Record(&log.GeneralMessage{
+		Severity: log.Severity_Error,
+		Content:  net.ParseAddress(ip),
+	})
+
+	assert(logger.value, Equals, "[Error]: "+ip)
+}