Rework events

events/event_stream_test.go

@@ -39,11 +39,7 @@ func (suite *EventStreamTestSuite) SetupTest() {
 }
 
 func (suite *EventStreamTestSuite) TestEventStart() {
-	evt := mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.1"),
-	}
+	evt := mtglib.NewEventStart("connID", net.ParseIP("10.0.0.1"))
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -52,10 +48,9 @@ func (suite *EventStreamTestSuite) TestEventStart() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventStart)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
-				suite.Equal(evt.ConnID, caught.ConnID)
 				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 			})
 	}
 
@@ -64,12 +59,7 @@ func (suite *EventStreamTestSuite) TestEventStart() {
 }
 
 func (suite *EventStreamTestSuite) TestEventConnectedToDC() {
-	evt := mtglib.EventConnectedToDC{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.1"),
-		DC:        3,
-	}
+	evt := mtglib.NewEventConnectedToDC("connID", net.ParseIP("10.0.0.1"), 3)
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -78,11 +68,10 @@ func (suite *EventStreamTestSuite) TestEventConnectedToDC() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventConnectedToDC)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
-				suite.Equal(evt.ConnID, caught.ConnID)
 				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
 				suite.Equal(evt.StreamID(), caught.StreamID())
 				suite.Equal(evt.DC, caught.DC)
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 			})
 	}
 
@@ -91,10 +80,7 @@ func (suite *EventStreamTestSuite) TestEventConnectedToDC() {
 }
 
 func (suite *EventStreamTestSuite) TestEventDomainFronting() {
-	evt := mtglib.EventDomainFronting{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	}
+	evt := mtglib.NewEventDomainFronting("connID")
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -103,9 +89,8 @@ func (suite *EventStreamTestSuite) TestEventDomainFronting() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventDomainFronting)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
-				suite.Equal(evt.ConnID, caught.ConnID)
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 			})
 	}
 
@@ -114,12 +99,7 @@ func (suite *EventStreamTestSuite) TestEventDomainFronting() {
 }
 
 func (suite *EventStreamTestSuite) TestEventTraffic() {
-	evt := mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   1024,
-		IsRead:    true,
-	}
+	evt := mtglib.NewEventTraffic("connID", 1024, true)
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -128,9 +108,8 @@ func (suite *EventStreamTestSuite) TestEventTraffic() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventTraffic)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
-				suite.Equal(evt.ConnID, caught.ConnID)
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 				suite.Equal(evt.Traffic, caught.Traffic)
 				suite.Equal(evt.IsRead, caught.IsRead)
 			})
@@ -141,10 +120,7 @@ func (suite *EventStreamTestSuite) TestEventTraffic() {
 }
 
 func (suite *EventStreamTestSuite) TestEventFinish() {
-	evt := mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	}
+	evt := mtglib.NewEventFinish("connID")
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -153,9 +129,8 @@ func (suite *EventStreamTestSuite) TestEventFinish() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventFinish)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
-				suite.Equal(evt.ConnID, caught.ConnID)
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 			})
 	}
 
@@ -164,9 +139,7 @@ func (suite *EventStreamTestSuite) TestEventFinish() {
 }
 
 func (suite *EventStreamTestSuite) TestEventConcurrencyLimited() {
-	evt := mtglib.EventConcurrencyLimited{
-		CreatedAt: time.Now(),
-	}
+	evt := mtglib.NewEventConcurrencyLimited()
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -175,7 +148,8 @@ func (suite *EventStreamTestSuite) TestEventConcurrencyLimited() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventConcurrencyLimited)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
+				suite.Empty(evt.StreamID())
 			})
 	}
 
@@ -184,10 +158,7 @@ func (suite *EventStreamTestSuite) TestEventConcurrencyLimited() {
 }
 
 func (suite *EventStreamTestSuite) TestEventIPBlocklisted() {
-	evt := mtglib.EventIPBlocklisted{
-		CreatedAt: time.Now(),
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	}
+	evt := mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10"))
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -196,8 +167,8 @@ func (suite *EventStreamTestSuite) TestEventIPBlocklisted() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventIPBlocklisted)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 				suite.Equal(evt.RemoteIP.String(), caught.RemoteIP.String())
 			})
 	}
@@ -207,10 +178,7 @@ func (suite *EventStreamTestSuite) TestEventIPBlocklisted() {
 }
 
 func (suite *EventStreamTestSuite) TestEventReplayAttack() {
-	evt := mtglib.EventReplayAttack{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-	}
+	evt := mtglib.NewEventReplayAttack("CONNID")
 
 	for _, v := range []*ObserverMock{suite.observerMock1, suite.observerMock2} {
 		v.
@@ -219,8 +187,8 @@ func (suite *EventStreamTestSuite) TestEventReplayAttack() {
 			Run(func(args mock.Arguments) {
 				caught := args.Get(0).(mtglib.EventReplayAttack)
 
-				suite.Equal(evt.CreatedAt, caught.CreatedAt)
 				suite.Equal(evt.StreamID(), caught.StreamID())
+				suite.Equal(evt.Timestamp(), caught.Timestamp())
 			})
 	}
 

events/noop_test.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"net"
 	"testing"
-	"time"
 
 	"github.com/9seconds/mtg/v2/events"
 	"github.com/9seconds/mtg/v2/mtglib"
@@ -20,42 +19,14 @@ type NoopTestSuite struct {
 
 func (suite *NoopTestSuite) SetupSuite() {
 	suite.testData = map[string]mtglib.Event{
-		"start": mtglib.EventStart{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-			RemoteIP:  net.ParseIP("127.0.0.1"),
-		},
-		"connected-to-dc": mtglib.EventConnectedToDC{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-			RemoteIP:  net.ParseIP("127.1.0.1"),
-			DC:        2,
-		},
-		"domain-fronting": mtglib.EventDomainFronting{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-		},
-		"traffic": mtglib.EventTraffic{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-			Traffic:   1000,
-			IsRead:    true,
-		},
-		"finish": mtglib.EventFinish{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-		},
-		"concurrency-limited": mtglib.EventConcurrencyLimited{
-			CreatedAt: time.Now(),
-		},
-		"ip-blacklisted": mtglib.EventIPBlocklisted{
-			RemoteIP:  net.ParseIP("10.0.0.10"),
-			CreatedAt: time.Now(),
-		},
-		"replay-attack": mtglib.EventReplayAttack{
-			CreatedAt: time.Now(),
-			ConnID:    "connID",
-		},
+		"start":               mtglib.NewEventStart("connID", net.ParseIP("127.0.0.1")),
+		"connected-to-dc":     mtglib.NewEventConnectedToDC("connID", net.ParseIP("127.1.0.1"), 2),
+		"domain-fronting":     mtglib.NewEventDomainFronting("connID"),
+		"traffic":             mtglib.NewEventTraffic("connID", 1000, true),
+		"finish":              mtglib.NewEventFinish("connID"),
+		"concurrency-limited": mtglib.NewEventConcurrencyLimited(),
+		"ip-blacklisted":      mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10")),
+		"replay-attack":       mtglib.NewEventReplayAttack("connID"),
 	}
 	suite.ctx = context.Background()
 }

mtglib/conns.go

@@ -6,27 +6,21 @@ import (
 	"io"
 	"net"
 	"sync"
-	"time"
 )
 
 type connTraffic struct {
 	net.Conn
 
-	connID string
-	stream EventStream
-	ctx    context.Context
+	streamID string
+	stream   EventStream
+	ctx      context.Context
 }
 
 func (c connTraffic) Read(b []byte) (int, error) {
 	n, err := c.Conn.Read(b)
 
 	if n > 0 {
-		c.stream.Send(c.ctx, EventTraffic{
-			CreatedAt: time.Now(),
-			ConnID:    c.connID,
-			Traffic:   uint(n),
-			IsRead:    true,
-		})
+		c.stream.Send(c.ctx, NewEventTraffic(c.streamID, uint(n), true))
 	}
 
 	return n, err // nolint: wrapcheck
@@ -36,12 +30,7 @@ func (c connTraffic) Write(b []byte) (int, error) {
 	n, err := c.Conn.Write(b)
 
 	if n > 0 {
-		c.stream.Send(c.ctx, EventTraffic{
-			CreatedAt: time.Now(),
-			ConnID:    c.connID,
-			Traffic:   uint(n),
-			IsRead:    false,
-		})
+		c.stream.Send(c.ctx, NewEventTraffic(c.streamID, uint(n), false))
 	}
 
 	return n, err // nolint: wrapcheck

mtglib/conns_internal_test.go

@@ -37,10 +37,10 @@ func (suite *ConnTrafficTestSuite) SetupTest() {
 	suite.eventStreamMock = &EventStreamMock{}
 	suite.connMock = &testlib.NetConnMock{}
 	suite.conn = connTraffic{
-		Conn:   suite.connMock,
-		connID: "CONNID",
-		ctx:    context.Background(),
-		stream: suite.eventStreamMock,
+		Conn:     suite.connMock,
+		streamID: "CONNID",
+		ctx:      context.Background(),
+		stream:   suite.eventStreamMock,
 	}
 }
 

mtglib/events.go

@@ -5,110 +5,133 @@ import (
 	"time"
 )
 
-type EventStart struct {
-	CreatedAt time.Time
-	ConnID    string
-	RemoteIP  net.IP
+type eventBase struct {
+	streamID  string
+	timestamp time.Time
 }
 
-func (e EventStart) StreamID() string {
-	return e.ConnID
+func (e eventBase) StreamID() string {
+	return e.streamID
 }
 
-func (e EventStart) Timestamp() time.Time {
-	return e.CreatedAt
+func (e eventBase) Timestamp() time.Time {
+	return e.timestamp
 }
 
-type EventConnectedToDC struct {
-	CreatedAt time.Time
-	ConnID    string
-	RemoteIP  net.IP
-	DC        int
-}
+type EventStart struct {
+	eventBase
 
-func (e EventConnectedToDC) StreamID() string {
-	return e.ConnID
+	RemoteIP net.IP
 }
 
-func (e EventConnectedToDC) Timestamp() time.Time {
-	return e.CreatedAt
-}
+type EventConnectedToDC struct {
+	eventBase
 
-type EventTraffic struct {
-	CreatedAt time.Time
-	ConnID    string
-	Traffic   uint
-	IsRead    bool
+	RemoteIP net.IP
+	DC       int
 }
 
-func (e EventTraffic) StreamID() string {
-	return e.ConnID
-}
+type EventTraffic struct {
+	eventBase
 
-func (e EventTraffic) Timestamp() time.Time {
-	return e.CreatedAt
+	Traffic uint
+	IsRead  bool
 }
 
 type EventFinish struct {
-	CreatedAt time.Time
-	ConnID    string
-}
-
-func (e EventFinish) StreamID() string {
-	return e.ConnID
-}
-
-func (e EventFinish) Timestamp() time.Time {
-	return e.CreatedAt
+	eventBase
 }
 
 type EventDomainFronting struct {
-	CreatedAt time.Time
-	ConnID    string
-}
-
-func (e EventDomainFronting) StreamID() string {
-	return e.ConnID
-}
-
-func (e EventDomainFronting) Timestamp() time.Time {
-	return e.CreatedAt
+	eventBase
 }
 
 type EventConcurrencyLimited struct {
-	CreatedAt time.Time
-}
-
-func (e EventConcurrencyLimited) StreamID() string {
-	return ""
-}
-
-func (e EventConcurrencyLimited) Timestamp() time.Time {
-	return e.CreatedAt
+	eventBase
 }
 
 type EventIPBlocklisted struct {
-	CreatedAt time.Time
-	RemoteIP  net.IP
-}
-
-func (e EventIPBlocklisted) StreamID() string {
-	return ""
-}
+	eventBase
 
-func (e EventIPBlocklisted) Timestamp() time.Time {
-	return e.CreatedAt
+	RemoteIP net.IP
 }
 
 type EventReplayAttack struct {
-	CreatedAt time.Time
-	ConnID    string
-}
-
-func (e EventReplayAttack) StreamID() string {
-	return e.ConnID
-}
-
-func (e EventReplayAttack) Timestamp() time.Time {
-	return e.CreatedAt
+	eventBase
+}
+
+func NewEventStart(streamID string, remoteIP net.IP) EventStart {
+	return EventStart{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+		RemoteIP: remoteIP,
+	}
+}
+
+func NewEventConnectedToDC(streamID string, remoteIP net.IP, dc int) EventConnectedToDC {
+	return EventConnectedToDC{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+		RemoteIP: remoteIP,
+		DC:       dc,
+	}
+}
+
+func NewEventTraffic(streamID string, traffic uint, isRead bool) EventTraffic {
+	return EventTraffic{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+		Traffic: traffic,
+		IsRead:  isRead,
+	}
+}
+
+func NewEventFinish(streamID string) EventFinish {
+	return EventFinish{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+	}
+}
+
+func NewEventDomainFronting(streamID string) EventDomainFronting {
+	return EventDomainFronting{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+	}
+}
+
+func NewEventConcurrencyLimited() EventConcurrencyLimited {
+	return EventConcurrencyLimited{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+		},
+	}
+}
+
+func NewEventIPBlocklisted(remoteIP net.IP) EventIPBlocklisted {
+	return EventIPBlocklisted{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+		},
+		RemoteIP: remoteIP,
+	}
+}
+
+func NewEventReplayAttack(streamID string) EventReplayAttack {
+	return EventReplayAttack{
+		eventBase: eventBase{
+			timestamp: time.Now(),
+			streamID:  streamID,
+		},
+	}
 }

mtglib/events_test.go

@@ -14,84 +14,56 @@ type EventsTestSuite struct {
 }
 
 func (suite *EventsTestSuite) TestEventStart() {
-	evt := mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	}
+	evt := mtglib.NewEventStart("CONNID", net.ParseIP("10.0.0.10"))
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventFinish() {
-	evt := mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-	}
+	evt := mtglib.NewEventFinish("CONNID")
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventConnectedToDC() {
-	evt := mtglib.EventConnectedToDC{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-		DC:        3,
-	}
+	evt := mtglib.NewEventConnectedToDC("CONNID", net.ParseIP("10.0.0.10"), 3)
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventTraffic() {
-	evt := mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-		Traffic:   3,
-		IsRead:    true,
-	}
+	evt := mtglib.NewEventTraffic("CONNID", 1000, true)
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventDomainFronting() {
-	evt := mtglib.EventDomainFronting{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-	}
+	evt := mtglib.NewEventDomainFronting("CONNID")
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventConcurrencyLimited() {
-	evt := mtglib.EventConcurrencyLimited{
-		CreatedAt: time.Now(),
-	}
+	evt := mtglib.NewEventConcurrencyLimited()
 
 	suite.Empty(evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventIPBlocklisted() {
-	evt := mtglib.EventIPBlocklisted{
-		CreatedAt: time.Now(),
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	}
+	evt := mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10"))
 
 	suite.Empty(evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)
 }
 
 func (suite *EventsTestSuite) TestEventReplayAttack() {
-	evt := mtglib.EventReplayAttack{
-		CreatedAt: time.Now(),
-		ConnID:    "CONNID",
-	}
+	evt := mtglib.NewEventReplayAttack("CONNID")
 
 	suite.Equal("CONNID", evt.StreamID())
 	suite.WithinDuration(time.Now(), evt.Timestamp(), 10*time.Millisecond)

mtglib/init.go

@@ -9,22 +9,66 @@ import (
 )
 
 var (
-	ErrSecretEmpty                    = errors.New("secret is empty")
-	ErrSecretInvalid                  = errors.New("secret is invalid")
-	ErrNetworkIsNotDefined            = errors.New("network is not defined")
-	ErrAntiReplayCacheIsNotDefined    = errors.New("anti-replay cache is not defined")
+	// ErrSecretEmpty is returned if you are trying to create a proxy
+	// but do not provide a secret.
+	ErrSecretEmpty = errors.New("secret is empty")
+
+	// ErrSecretInvalid is returned if you are trying to create a proxy
+	// but secret value is invalid (no host or payload are zeroes).
+	ErrSecretInvalid = errors.New("secret is invalid")
+
+	// ErrNetworkIsNotDefined is returned if you are trying to create a
+	// proxy but network value is undefined.
+	ErrNetworkIsNotDefined = errors.New("network is not defined")
+
+	// ErrAntiReplayCacheIsNotDefined is returned if you are trying to
+	// create a proxy but anti replay cache value is undefined.
+	ErrAntiReplayCacheIsNotDefined = errors.New("anti-replay cache is not defined")
+
+	// ErrTimeAttackDetectorIsNotDefined is returned if you are trying to
+	// create a proxy but time attack detector is not defined.
 	ErrTimeAttackDetectorIsNotDefined = errors.New("time attack detector is not defined")
-	ErrIPBlocklistIsNotDefined        = errors.New("ip blocklist is not defined")
-	ErrEventStreamIsNotDefined        = errors.New("event stream is not defined")
-	ErrLoggerIsNotDefined             = errors.New("logger is not defined")
+
+	// ErrIPBlocklistIsNotDefined is returned if you are trying to
+	// create a proxy but ip blocklist instance is not defined.
+	ErrIPBlocklistIsNotDefined = errors.New("ip blocklist is not defined")
+
+	// ErrEventStreamIsNotDefined is returned if you are trying to create a
+	// proxy but event stream instance is not defined.
+	ErrEventStreamIsNotDefined = errors.New("event stream is not defined")
+
+	// ErrLoggerIsNotDefined is returned if you are trying to
+	// create a proxy but logger is not defined.
+	ErrLoggerIsNotDefined = errors.New("logger is not defined")
 )
 
 const (
-	DefaultConcurrency        = 4096
-	DefaultBufferSize         = 16 * 1024 // 16 kib
+	// DefaultConcurrency is a default max count of simultaneously
+	// connected clients.
+	DefaultConcurrency = 4096
+
+	// DefaultBufferSize is a default size of a copy buffer.
+	DefaultBufferSize = 16 * 1024 // 16 kib
+
+	// DefaultDomainFrontingPort is a default port (HTTPS) to connect to in
+	// case of probe-resistance activity.
 	DefaultDomainFrontingPort = 443
-	DefaultIdleTimeout        = time.Minute
-	DefaultPreferIP           = "prefer-ipv6"
+
+	// DefaultIdleTimeout is a default timeout for closing a connection
+	// in case of idling.
+	DefaultIdleTimeout = time.Minute
+
+	// DefaultPreferIP is a default value for Telegram IP connectivity
+	// preference.
+	DefaultPreferIP = "prefer-ipv6"
+
+	// SecretKeyLength defines a length of the secret bytes used
+	// by Telegram and a proxy.
+	SecretKeyLength = 16
+
+	// ConnectionIDBytesLength defines a count of random bytes
+	// used to generate a stream/connection ids.
+	ConnectionIDBytesLength = 16
 )
 
 // Network defines a knowledge how to work with a network. It may sound
@@ -105,8 +149,24 @@ type IPBlocklist interface {
 	Contains(net.IP) bool
 }
 
+// Event is a data structure which is populated during mtg request
+// processing lifecycle. Each request popluates many events:
+//
+// 1. Client connected
+//
+// 2. Request is finished
+//
+// 3. Connection to Telegram server is established
+//
+// and so on. All these events are data structures but all of them
+// must conform the same interface.
 type Event interface {
+	// StreamID returns an identifier of the stream, connection,
+	// request, you name it. All events within the same stream returns
+	// the same stream id.
 	StreamID() string
+
+	// Timestamp returns a timestamp when this event was generated.
 	Timestamp() time.Time
 }
 

mtglib/proxy.go

@@ -53,18 +53,11 @@ func (p *Proxy) ServeConn(conn net.Conn) {
 		ctx.Close()
 	}()
 
-	p.eventStream.Send(ctx, EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    ctx.connID,
-		RemoteIP:  ctx.ClientIP(),
-	})
+	p.eventStream.Send(ctx, NewEventStart(ctx.streamID, ctx.ClientIP()))
 	ctx.logger.Info("Stream has been started")
 
 	defer func() {
-		p.eventStream.Send(ctx, EventFinish{
-			CreatedAt: time.Now(),
-			ConnID:    ctx.connID,
-		})
+		p.eventStream.Send(ctx, NewEventFinish(ctx.streamID))
 		ctx.logger.Info("Stream has been finished")
 	}()
 
@@ -109,10 +102,7 @@ func (p *Proxy) Serve(listener net.Listener) error {
 		if p.ipBlocklist.Contains(ipAddr) {
 			conn.Close()
 			logger.Info("ip was blacklisted")
-			p.eventStream.Send(p.ctx, EventIPBlocklisted{
-				CreatedAt: time.Now(),
-				RemoteIP:  ipAddr,
-			})
+			p.eventStream.Send(p.ctx, NewEventIPBlocklisted(ipAddr))
 
 			continue
 		}
@@ -125,9 +115,7 @@ func (p *Proxy) Serve(listener net.Listener) error {
 			return nil
 		case errors.Is(err, ants.ErrPoolOverload):
 			logger.Info("connection was concurrency limited")
-			p.eventStream.Send(p.ctx, EventConcurrencyLimited{
-				CreatedAt: time.Now(),
-			})
+			p.eventStream.Send(p.ctx, NewEventConcurrencyLimited())
 		}
 
 		select {
@@ -181,10 +169,7 @@ func (p *Proxy) doFakeTLSHandshake(ctx *streamContext) bool {
 
 	if p.antiReplayCache.SeenBefore(hello.SessionID) {
 		p.logger.Warning("replay attack has been detected!")
-		p.eventStream.Send(p.ctx, EventReplayAttack{
-			CreatedAt: time.Now(),
-			ConnID:    ctx.connID,
-		})
+		p.eventStream.Send(p.ctx, NewEventReplayAttack(ctx.streamID))
 		p.doDomainFronting(ctx, rewind)
 
 		return false
@@ -235,31 +220,23 @@ func (p *Proxy) doTelegramCall(ctx *streamContext) error {
 
 	ctx.telegramConn = obfuscated2.Conn{
 		Conn: connTraffic{
-			Conn:   conn,
-			connID: ctx.connID,
-			stream: p.eventStream,
-			ctx:    ctx,
+			Conn:     conn,
+			streamID: ctx.streamID,
+			stream:   p.eventStream,
+			ctx:      ctx,
 		},
 		Encryptor: encryptor,
 		Decryptor: decryptor,
 	}
 
-	p.eventStream.Send(ctx, EventConnectedToDC{
-		CreatedAt: time.Now(),
-		ConnID:    ctx.connID,
-		RemoteIP:  conn.RemoteAddr().(*net.TCPAddr).IP,
-		DC:        ctx.dc,
-	})
+	p.eventStream.Send(ctx,
+		NewEventConnectedToDC(ctx.streamID, conn.RemoteAddr().(*net.TCPAddr).IP, ctx.dc))
 
 	return nil
 }
 
 func (p *Proxy) doDomainFronting(ctx *streamContext, conn *connRewind) {
-	p.eventStream.Send(p.ctx, EventDomainFronting{
-		CreatedAt: time.Now(),
-		ConnID:    ctx.connID,
-	})
-
+	p.eventStream.Send(p.ctx, NewEventDomainFronting(ctx.streamID))
 	conn.Rewind()
 
 	frontConn, err := p.network.DialContext(ctx, "tcp", p.DomainFrontingAddress())
@@ -270,10 +247,10 @@ func (p *Proxy) doDomainFronting(ctx *streamContext, conn *connRewind) {
 	}
 
 	frontConn = connTraffic{
-		Conn:   frontConn,
-		ctx:    ctx,
-		connID: ctx.connID,
-		stream: p.eventStream,
+		Conn:     frontConn,
+		ctx:      ctx,
+		streamID: ctx.streamID,
+		stream:   p.eventStream,
 	}
 
 	rel := relay.AcquireRelay(ctx,

mtglib/secret.go

@@ -7,11 +7,7 @@ import (
 	"fmt"
 )
 
-const (
-	SecretKeyLength = 16
-
-	secretFakeTLSFirstByte byte = 0xee
-)
+const secretFakeTLSFirstByte byte = 0xee
 
 var secretEmptyKey [SecretKeyLength]byte
 

mtglib/stream_context.go

@@ -8,14 +8,12 @@ import (
 	"time"
 )
 
-const ConnectionIDBytesLength = 16
-
 type streamContext struct {
 	ctx          context.Context
 	ctxCancel    context.CancelFunc
 	clientConn   net.Conn
 	telegramConn net.Conn
-	connID       string
+	streamID     string
 	dc           int
 	logger       Logger
 }
@@ -64,10 +62,10 @@ func newStreamContext(ctx context.Context, logger Logger, clientConn net.Conn) *
 		ctx:        ctx,
 		ctxCancel:  cancel,
 		clientConn: clientConn,
-		connID:     base64.RawURLEncoding.EncodeToString(connIDBytes),
+		streamID:   base64.RawURLEncoding.EncodeToString(connIDBytes),
 	}
 	streamCtx.logger = logger.
-		BindStr("stream-id", streamCtx.connID).
+		BindStr("stream-id", streamCtx.streamID).
 		BindStr("client-ip", streamCtx.ClientIP().String())
 
 	return streamCtx

stats/prometheus_test.go

@@ -55,57 +55,39 @@ func (suite *PrometheusTestSuite) TearDownTest() {
 }
 
 func (suite *PrometheusTestSuite) TestTelegramPath() {
-	suite.prometheus.EventStart(mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	})
+	suite.prometheus.EventStart(
+		mtglib.NewEventStart("connID", net.ParseIP("10.0.0.10")))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err := suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_client_connections{ip_family="ipv4"} 1`)
 
-	suite.prometheus.EventConnectedToDC(mtglib.EventConnectedToDC{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.1"),
-		DC:        4,
-	})
+	suite.prometheus.EventConnectedToDC(
+		mtglib.NewEventConnectedToDC("connID", net.ParseIP("10.0.0.1"), 4))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_telegram_connections{dc="4",telegram_ip="10.0.0.1"} 1`)
 
-	suite.prometheus.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   200,
-		IsRead:    true,
-	})
+	suite.prometheus.EventTraffic(
+		mtglib.NewEventTraffic("connID", 200, true))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_telegram_traffic{dc="4",direction="to_client",telegram_ip="10.0.0.1"} 200`)
 
-	suite.prometheus.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   100,
-		IsRead:    false,
-	})
+	suite.prometheus.EventTraffic(
+		mtglib.NewEventTraffic("connID", 100, false))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_telegram_traffic{dc="4",direction="from_client",telegram_ip="10.0.0.1"} 100`)
 
-	suite.prometheus.EventFinish(mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.prometheus.EventFinish(mtglib.NewEventFinish("connID"))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
@@ -115,21 +97,15 @@ func (suite *PrometheusTestSuite) TestTelegramPath() {
 }
 
 func (suite *PrometheusTestSuite) TestDomainFrontingPath() {
-	suite.prometheus.EventStart(mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	})
+	suite.prometheus.EventStart(
+		mtglib.NewEventStart("connID", net.ParseIP("10.0.0.10")))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err := suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_client_connections{ip_family="ipv4"} 1`)
 
-	suite.prometheus.EventDomainFronting(mtglib.EventDomainFronting{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.prometheus.EventDomainFronting(mtglib.NewEventDomainFronting("connID"))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
@@ -137,34 +113,23 @@ func (suite *PrometheusTestSuite) TestDomainFrontingPath() {
 	suite.Contains(data, `mtg_domain_fronting 1`)
 	suite.Contains(data, `mtg_domain_fronting_connections{ip_family="ipv4"} 1`)
 
-	suite.prometheus.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   200,
-		IsRead:    true,
-	})
+	suite.prometheus.EventTraffic(
+		mtglib.NewEventTraffic("connID", 200, true))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_domain_fronting_traffic{direction="to_client"} 200`)
 
-	suite.prometheus.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   100,
-		IsRead:    false,
-	})
+	suite.prometheus.EventTraffic(
+		mtglib.NewEventTraffic("connID", 100, false))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
 	suite.NoError(err)
 	suite.Contains(data, `mtg_domain_fronting_traffic{direction="from_client"} 100`)
 
-	suite.prometheus.EventFinish(mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.prometheus.EventFinish(mtglib.NewEventFinish("connID"))
 	time.Sleep(100 * time.Millisecond)
 
 	data, err = suite.Get()
@@ -174,9 +139,7 @@ func (suite *PrometheusTestSuite) TestDomainFrontingPath() {
 }
 
 func (suite *PrometheusTestSuite) TestEventConcurrencyLimited() {
-	suite.prometheus.EventConcurrencyLimited(mtglib.EventConcurrencyLimited{
-		CreatedAt: time.Now(),
-	})
+	suite.prometheus.EventConcurrencyLimited(mtglib.NewEventConcurrencyLimited())
 
 	time.Sleep(100 * time.Millisecond)
 
@@ -186,10 +149,8 @@ func (suite *PrometheusTestSuite) TestEventConcurrencyLimited() {
 }
 
 func (suite *PrometheusTestSuite) TestEventIPBlocklisted() {
-	suite.prometheus.EventIPBlocklisted(mtglib.EventIPBlocklisted{
-		CreatedAt: time.Now(),
-		RemoteIP:  net.ParseIP("2001:db8::68"),
-	})
+	suite.prometheus.EventIPBlocklisted(
+		mtglib.NewEventIPBlocklisted(net.ParseIP("2001:db8::68")))
 
 	time.Sleep(100 * time.Millisecond)
 
@@ -199,10 +160,7 @@ func (suite *PrometheusTestSuite) TestEventIPBlocklisted() {
 }
 
 func (suite *PrometheusTestSuite) TestEventReplayAttack() {
-	suite.prometheus.EventReplayAttack(mtglib.EventReplayAttack{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.prometheus.EventReplayAttack(mtglib.NewEventReplayAttack("connID"))
 
 	time.Sleep(100 * time.Millisecond)
 

stats/statsd.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
-	"time"
 
 	"github.com/9seconds/mtg/v2/events"
 	"github.com/9seconds/mtg/v2/logger"
@@ -123,14 +122,10 @@ func (s statsdProcessor) EventReplayAttack(_ mtglib.EventReplayAttack) {
 }
 
 func (s statsdProcessor) Shutdown() {
-	now := time.Now()
 	events := make([]mtglib.EventFinish, 0, len(s.streams))
 
 	for k := range s.streams {
-		events = append(events, mtglib.EventFinish{
-			CreatedAt: now,
-			ConnID:    k,
-		})
+		events = append(events, mtglib.NewEventFinish(k))
 	}
 
 	for i := range events {

stats/statsd_test.go

@@ -105,48 +105,30 @@ func (suite *StatsdTestSuite) TearDownTest() {
 }
 
 func (suite *StatsdTestSuite) TestTelegramPath() {
-	suite.statsd.EventStart(mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	})
+	suite.statsd.EventStart(
+		mtglib.NewEventStart("connID", net.ParseIP("10.0.0.10")))
 	time.Sleep(statsdSleepTime)
 	suite.Equal("mtg.client_connections:+1|g|#ip_family:ipv4", suite.statsdServer.String())
 
-	suite.statsd.EventConnectedToDC(mtglib.EventConnectedToDC{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.1.0.10"),
-		DC:        2,
-	})
+	suite.statsd.EventConnectedToDC(
+		mtglib.NewEventConnectedToDC("connID", net.ParseIP("10.1.0.10"), 2))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		"mtg.telegram_connections:+1|g|#telegram_ip:10.1.0.10,dc:2")
 
-	suite.statsd.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   30,
-		IsRead:    true,
-	})
+	suite.statsd.EventTraffic(
+		mtglib.NewEventTraffic("connID", 30, true))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		"mtg.telegram_traffic:30|c|#telegram_ip:10.1.0.10,dc:2,direction:to_client")
 
-	suite.statsd.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   90,
-		IsRead:    false,
-	})
+	suite.statsd.EventTraffic(
+		mtglib.NewEventTraffic("connID", 90, false))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		"mtg.telegram_traffic:90|c|#telegram_ip:10.1.0.10,dc:2,direction:from_client")
 
-	suite.statsd.EventFinish(mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.statsd.EventFinish(mtglib.NewEventFinish("connID"))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		"mtg.telegram_connections:-1|g|#telegram_ip:10.1.0.10,dc:2")
@@ -158,47 +140,30 @@ func (suite *StatsdTestSuite) TestTelegramPath() {
 }
 
 func (suite *StatsdTestSuite) TestDomainFrontingPath() {
-	suite.statsd.EventStart(mtglib.EventStart{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	})
+	suite.statsd.EventStart(
+		mtglib.NewEventStart("connID", net.ParseIP("10.0.0.10")))
 	time.Sleep(statsdSleepTime)
 	suite.Equal("mtg.client_connections:+1|g|#ip_family:ipv4", suite.statsdServer.String())
 
-	suite.statsd.EventDomainFronting(mtglib.EventDomainFronting{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.statsd.EventDomainFronting(mtglib.NewEventDomainFronting("connID"))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(), "mtg.domain_fronting:1|c")
 	suite.Contains(suite.statsdServer.String(),
 		`mtg.domain_fronting_connections:+1|g|#ip_family:ipv4`)
 
-	suite.statsd.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   30,
-		IsRead:    true,
-	})
+	suite.statsd.EventTraffic(
+		mtglib.NewEventTraffic("connID", 30, true))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		`mtg.domain_fronting_traffic:30|c|#direction:to_client`)
 
-	suite.statsd.EventTraffic(mtglib.EventTraffic{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-		Traffic:   90,
-		IsRead:    false,
-	})
+	suite.statsd.EventTraffic(
+		mtglib.NewEventTraffic("connID", 90, false))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		`mtg.domain_fronting_traffic:90|c|#direction:from_client`)
 
-	suite.statsd.EventFinish(mtglib.EventFinish{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.statsd.EventFinish(mtglib.NewEventFinish("connID"))
 	time.Sleep(statsdSleepTime)
 	suite.Contains(suite.statsdServer.String(),
 		"mtg.domain_fronting_connections:-1|g|#ip_family:ipv4")
@@ -210,29 +175,22 @@ func (suite *StatsdTestSuite) TestDomainFrontingPath() {
 }
 
 func (suite *StatsdTestSuite) TestEventConcurrencyLimited() {
-	suite.statsd.EventConcurrencyLimited(mtglib.EventConcurrencyLimited{
-		CreatedAt: time.Now(),
-	})
+	suite.statsd.EventConcurrencyLimited(mtglib.NewEventConcurrencyLimited())
 
 	time.Sleep(statsdSleepTime)
 	suite.Equal("mtg.concurrency_limited:1|c", suite.statsdServer.String())
 }
 
 func (suite *StatsdTestSuite) TestEventIPBlocklisted() {
-	suite.statsd.EventIPBlocklisted(mtglib.EventIPBlocklisted{
-		CreatedAt: time.Now(),
-		RemoteIP:  net.ParseIP("10.0.0.10"),
-	})
+	suite.statsd.EventIPBlocklisted(
+		mtglib.NewEventIPBlocklisted(net.ParseIP("10.0.0.10")))
 
 	time.Sleep(statsdSleepTime)
 	suite.Equal("mtg.ip_blocklisted:1|c", suite.statsdServer.String())
 }
 
 func (suite *StatsdTestSuite) TestEventReplayAttack() {
-	suite.statsd.EventReplayAttack(mtglib.EventReplayAttack{
-		CreatedAt: time.Now(),
-		ConnID:    "connID",
-	})
+	suite.statsd.EventReplayAttack(mtglib.NewEventReplayAttack("connID"))
 
 	time.Sleep(statsdSleepTime)
 	suite.Equal("mtg.replay_attacks:1|c", suite.statsdServer.String())