Added session duration metrics with device analytics along with device

analytics metrics in the DB to aggregate and DeviceID abuse prevention

internal/data/db.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 
 package data
 

internal/data/device_analytics.sql.go

@@ -0,0 +1,50 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.29.0
+// source: device_analytics.sql
+
+package data
+
+import (
+	"context"
+)
+
+const setDeviceAnalytics = `-- name: SetDeviceAnalytics :one
+INSERT INTO device_analytics (
+  device_id, os, arch, term, colorterm
+) VALUES (
+  ?1, ?2, ?3, ?4, ?5
+)
+ON CONFLICT DO
+UPDATE SET
+  os = EXCLUDED.os, arch = EXCLUDED.arch, term = EXCLUDED.term, colorterm = EXCLUDED.colorterm
+WHERE device_id = EXCLUDED.device_id
+RETURNING device_id, os, arch, term, colorterm
+`
+
+type SetDeviceAnalyticsParams struct {
+	DeviceID  string
+	Os        *string
+	Arch      *string
+	Term      *string
+	Colorterm *string
+}
+
+func (q *Queries) SetDeviceAnalytics(ctx context.Context, arg SetDeviceAnalyticsParams) (DeviceAnalytic, error) {
+	row := q.db.QueryRowContext(ctx, setDeviceAnalytics,
+		arg.DeviceID,
+		arg.Os,
+		arg.Arch,
+		arg.Term,
+		arg.Colorterm,
+	)
+	var i DeviceAnalytic
+	err := row.Scan(
+		&i.DeviceID,
+		&i.Os,
+		&i.Arch,
+		&i.Term,
+		&i.Colorterm,
+	)
+	return i, err
+}

internal/data/frequencies.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: frequencies.sql
 
 package data

internal/data/members.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: members.sql
 
 package data

internal/data/messages.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: messages.sql
 
 package data

internal/data/models.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 
 package data
 
@@ -14,6 +14,14 @@ type BlockedUser struct {
 	BlockedUserID  snowflake.ID
 }
 
+type DeviceAnalytic struct {
+	DeviceID  string
+	Os        *string
+	Arch      *string
+	Term      *string
+	Colorterm *string
+}
+
 type Frequency struct {
 	ID        snowflake.ID
 	NetworkID snowflake.ID

internal/data/networks.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: networks.sql
 
 package data

internal/data/notifications.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: notifications.sql
 
 package data

internal/data/trusted_and_blocked_users.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: trusted_and_blocked_users.sql
 
 package data

internal/data/users.sql.go

@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.28.0
+//   sqlc v1.29.0
 // source: users.sql
 
 package data

internal/server/api/api.go

@@ -5,10 +5,12 @@ import (
 	"context"
 	"crypto/ed25519"
 	"database/sql"
+	"encoding/binary"
 	"fmt"
 	"log/slog"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/kyren223/eko/internal/data"
 	"github.com/kyren223/eko/internal/packet"
@@ -34,7 +36,7 @@ func SendMessage(ctx context.Context, sess *session.Session, request *packet.Sen
 
 	if len(request.Content) > packet.MaxMessageBytes {
 		return &packet.Error{Error: fmt.Sprintf(
-			"message conent must not exceed %v bytes",
+			"message content must not exceed %v bytes",
 			packet.MaxMessageBytes,
 		)}
 	}
@@ -1647,7 +1649,57 @@ func sendInitialAuthPackets(ctx context.Context, sess *session.Session) bool {
 	return success
 }
 
+var (
+	ipDeviceID map[uint32]string = map[uint32]string{}
+	deviceIdMu sync.Mutex
+)
+
 func DeviceAnalytics(ctx context.Context, sess *session.Session, request *packet.DeviceAnalytics) packet.Payload {
-	// TODO: implement this
-	return &ErrNotImplemented
+	const DeviceIdLength = 64
+
+	if len(request.DeviceID) != DeviceIdLength {
+		return &packet.Error{Error: fmt.Sprintf(
+			"DeviceID must be exactly %v bytes", DeviceIdLength,
+		)}
+	}
+
+	for _, c := range request.DeviceID {
+		if (c < '0' || c > '9') && (c < 'a' || c > 'f') {
+			return &packet.Error{
+				Error: "DeviceID must be all lowercase hexadecimal",
+			}
+		}
+	}
+
+	ip := binary.BigEndian.Uint32(sess.Addr().IP.To4())
+	deviceIdMu.Lock()
+	if deviceId, ok := ipDeviceID[ip]; ok {
+		if request.DeviceID != deviceId {
+			slog.WarnContext(ctx, "device ID mismatch", "existing_device_id", deviceId, "request_device_id", request.DeviceID)
+			request.DeviceID = deviceId
+			// Override the request to use the known ID
+			// This avoids abuse
+		}
+	} else {
+		ipDeviceID[ip] = request.DeviceID
+	}
+	deviceIdMu.Unlock()
+
+	if !IsValidAnalytics(ctx, request) {
+		// This is either malicious or we should actually add new variations
+		// In either case the client shouldn't need a response
+		return nil
+	}
+
+	sess.SetAnalytics(request)
+	queries := data.New(db)
+	queries.SetDeviceAnalytics(ctx, data.SetDeviceAnalyticsParams{
+		DeviceID:  request.DeviceID,
+		Os:        &request.OS,
+		Arch:      &request.Arch,
+		Term:      &request.Term,
+		Colorterm: &request.Colorterm,
+	})
+
+	return nil
 }

internal/server/api/helpers.go

@@ -3,6 +3,7 @@ package api
 import (
 	"context"
 	"log/slog"
+	"slices"
 	"strings"
 	"time"
 
@@ -190,3 +191,38 @@ func getNotifications(ctx context.Context, userId snowflake.ID) (packet.Notifica
 	}
 	return items, nil
 }
+
+var (
+	ValidOs        = []string{"linux", "darwin", "windows", "android", ""}
+	ValidArch      = []string{"amd64", "arm64", "386", ""}
+	ValidTerm      = []string{"xterm-256color", "tmux-256color", "xterm-ghostty", "xterm-kitty", "alacritty", "foot", "xterm", ""}
+	ValidColorterm = []string{"truecolor", "24bit", ""}
+)
+
+func IsValidAnalytics(ctx context.Context, analytics *packet.DeviceAnalytics) bool {
+	if analytics == nil {
+		return false
+	}
+
+	if !slices.Contains(ValidOs, analytics.OS) {
+		slog.WarnContext(ctx, "unrecognized analytics value", "os", analytics.OS, "analytics", analytics)
+		return false
+	}
+
+	if !slices.Contains(ValidArch, analytics.Arch) {
+		slog.WarnContext(ctx, "unrecognized analytics value", "arch", analytics.Arch, "analytics", analytics)
+		return false
+	}
+
+	if !slices.Contains(ValidTerm, analytics.Term) {
+		slog.WarnContext(ctx, "unrecognized analytics value", "term", analytics.Term, "analytics", analytics)
+		return false
+	}
+
+	if !slices.Contains(ValidColorterm, analytics.Colorterm) {
+		slog.WarnContext(ctx, "unrecognized analytics value", "colorterm", analytics.Colorterm, "analytics", analytics)
+		return false
+	}
+
+	return true
+}

internal/server/api/migrations/20250717130820_device_analytics.sql

@@ -0,0 +1,11 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS device_analytics (
+    device_id TEXT PRIMARY KEY,
+    os TEXT,
+    arch TEXT,
+    term TEXT,
+    colorterm TEXT
+);
+
+-- +goose Down
+DROP TABLE IF EXISTS device_analytics;

internal/server/metrics/metrics.go

@@ -55,3 +55,10 @@ var UsersActive = promauto.NewGauge(prometheus.GaugeOpts{
 	Name:      "users_active_total",
 	Help:      "The total number of active users",
 })
+
+var SessionDuration = promauto.NewHistogramVec(prometheus.HistogramOpts{
+	Namespace:                   namespace,
+	Name:                        "session_duration_seconds",
+	Help:                        "The duration in seconds of an authenticated session",
+	NativeHistogramBucketFactor: 1.00271,
+}, []string{"os", "arch", "term", "colorterm"})

internal/server/server.go

@@ -276,8 +276,10 @@ func (server *server) handleConnection(conn net.Conn) {
 	sess := session.NewSession(server, addr, cancel, &writerWg)
 	go func() {
 		<-ctx.Done()
-		// Remove session after cancellation
 		if sess.IsAuthenticated() {
+			server.handleSessionMetrics(ctx, sess)
+
+			// Remove session after cancellation
 			sameAddress := addr.String() == server.Session(sess.ID()).Addr().String()
 			// false if the user signed in from a different connection
 			if sameAddress {
@@ -680,3 +682,17 @@ func formatIPv4(ip uint32) string {
 	n = strconv.AppendUint(n, uint64(ip&0xFF), 10)
 	return string(n)
 }
+
+func (s *server) handleSessionMetrics(ctx context.Context, sess *session.Session) {
+	duration := sess.Duration()
+	analytics := sess.Analytics()
+	if api.IsValidAnalytics(ctx, analytics) {
+		metrics.SessionDuration.WithLabelValues(
+			analytics.OS, analytics.Arch, analytics.Term, analytics.Colorterm,
+		).Observe(duration.Seconds())
+	} else {
+		metrics.SessionDuration.WithLabelValues(
+			"", "", "", "",
+		).Observe(duration.Seconds())
+	}
+}

internal/server/session/session.go

@@ -52,6 +52,8 @@ type Session struct {
 	pubKey        ed25519.PublicKey
 	id            snowflake.ID
 	rl            rate.Limiter
+	start         time.Time
+	analytics     *packet.DeviceAnalytics
 
 	mu sync.RWMutex
 }
@@ -77,6 +79,8 @@ func NewSession(
 		challengeMu:   sync.Mutex{},
 		isTosAccepted: false,
 		rl:            rate.NewLimiter(DefaultRate, DefaultLimit),
+		start:         time.Time{},
+		analytics:     nil,
 		mu:            sync.RWMutex{},
 	}
 	return session
@@ -130,6 +134,26 @@ func (s *Session) Promote(userId snowflake.ID, pubKey ed25519.PublicKey) {
 	s.pubKey = pubKey
 	s.rl.SetLimit(AuthenticatedLimit)
 	s.rl.SetRate(AuthenticatedRate)
+	s.start = time.Now().UTC()
+}
+
+func (s *Session) Duration() time.Duration {
+	assert.Assert(s.IsAuthenticated(), "tried accessing session duration in an authenticated session")
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return time.Since(s.start)
+}
+
+func (s *Session) Analytics() *packet.DeviceAnalytics {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.analytics
+}
+
+func (s *Session) SetAnalytics(analytics *packet.DeviceAnalytics) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.analytics = analytics
 }
 
 func (s *Session) Manager() SessionManager {

query/device_analytics.sql

@@ -0,0 +1,11 @@
+-- name: SetDeviceAnalytics :one
+INSERT INTO device_analytics (
+  device_id, os, arch, term, colorterm
+) VALUES (
+  @device_id, @os, @arch, @term, @colorterm
+)
+ON CONFLICT DO
+UPDATE SET
+  os = EXCLUDED.os, arch = EXCLUDED.arch, term = EXCLUDED.term, colorterm = EXCLUDED.colorterm
+WHERE device_id = EXCLUDED.device_id
+RETURNING *;

sqlc.yml

@@ -9,6 +9,8 @@ sql:
         out: "./internal/data/"
         emit_pointers_for_null_types: true
         overrides:
+          - column: "device_analytics.device_id"
+            go_type: "string"
           - column: "users.public_key"
             go_type: "crypto/ed25519.PublicKey"
           - column: "trusted_users.trusted_public_key"