v0.19.0 use updated config and toml packages, dep update, minor fixes

internal/session/proxy.go

@@ -29,10 +29,8 @@ func (p *Proxy) CreateSession(remoteAddr string, metadata map[string]any) *Sessi
 	metadata["instance_id"] = p.instanceID
 
 	// Create session with instance-scoped source
-	session := p.manager.CreateSession(remoteAddr, p.instanceID, metadata)
-	session.InstanceID = p.instanceID
-
-	return session
+	// Set identity before publishing the session to concurrent snapshot readers.
+	return p.manager.createSession(remoteAddr, p.instanceID, p.instanceID, metadata)
 }
 
 // GetSession retrieves a session if it belongs to this instance
@@ -79,4 +77,4 @@ func (p *Proxy) UpdateActivity(sessionID string) bool {
 // GetInstanceID returns the instance ID this proxy is bound to
 func (p *Proxy) GetInstanceID() string {
 	return p.instanceID
-}
+}

internal/session/session.go

@@ -4,6 +4,7 @@ import (
 	"crypto/rand"
 	"encoding/base64"
 	"fmt"
+	"maps"
 	"sync"
 	"time"
 
@@ -59,7 +60,12 @@ func NewManager(maxIdleTime time.Duration) *Manager {
 
 // CreateSession creates and stores a new session for a connection
 func (m *Manager) CreateSession(remoteAddr string, source string, metadata map[string]any) *Session {
+	return m.createSession(remoteAddr, source, "", metadata)
+}
+
+func (m *Manager) createSession(remoteAddr, source, instanceID string, metadata map[string]any) *Session {
 	session := &Session{
+		InstanceID:   instanceID,
 		ID:           generateSessionID(),
 		RemoteAddr:   remoteAddr,
 		CreatedAt:    time.Now(),
@@ -127,7 +133,7 @@ func (m *Manager) GetActiveSessions() []*Session {
 
 	sessions := make([]*Session, 0, len(m.sessions))
 	for _, session := range m.sessions {
-		sessions = append(sessions, session)
+		sessions = append(sessions, snapshotSession(session))
 	}
 	return sessions
 }
@@ -139,7 +145,7 @@ func (m *Manager) GetSessionCount() int {
 	return len(m.sessions)
 }
 
-// GetSessionsBySource returns all sessions matching a specific source type
+// GetSessionsBySource returns snapshots of sessions matching a specific source type.
 func (m *Manager) GetSessionsBySource(source string) []*Session {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -147,13 +153,13 @@ func (m *Manager) GetSessionsBySource(source string) []*Session {
 	var sessions []*Session
 	for _, session := range m.sessions {
 		if session.Source == source {
-			sessions = append(sessions, session)
+			sessions = append(sessions, snapshotSession(session))
 		}
 	}
 	return sessions
 }
 
-// GetActiveSessionsBySource returns all active sessions for a given source
+// GetActiveSessionsBySource returns snapshots of active sessions for a given source.
 func (m *Manager) GetActiveSessionsBySource(source string) []*Session {
 	m.mu.RLock()
 	defer m.mu.RUnlock()
@@ -163,12 +169,20 @@ func (m *Manager) GetActiveSessionsBySource(source string) []*Session {
 
 	for _, session := range m.sessions {
 		if session.Source == source && now.Sub(session.LastActivity) < m.maxIdleTime {
-			sessions = append(sessions, session)
+			sessions = append(sessions, snapshotSession(session))
 		}
 	}
 	return sessions
 }
 
+// Call under m.mu. Metadata values are immutable after session creation; copy
+// the top-level map so readers cannot add or remove entries in stored metadata.
+func snapshotSession(session *Session) *Session {
+	snapshot := *session
+	snapshot.Metadata = maps.Clone(session.Metadata)
+	return &snapshot
+}
+
 // GetStats returns statistics about the session manager
 func (m *Manager) GetStats() map[string]any {
 	m.mu.RLock()
@@ -291,4 +305,4 @@ func generateSessionID() string {
 		return fmt.Sprintf("session_%d", time.Now().UnixNano())
 	}
 	return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(b)
-}
+}

internal/session/snapshot_test.go

@@ -0,0 +1,45 @@
+package session
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestSessionSnapshotsDoNotRaceActivityUpdates(t *testing.T) {
+	m := NewManager(time.Minute)
+	defer m.Stop()
+	proxy := NewProxy(m, "source")
+	stored := proxy.CreateSession("remote", map[string]any{"label": "original"})
+	readers := []func() []*Session{
+		m.GetActiveSessions,
+		func() []*Session { return m.GetSessionsBySource("source") },
+		func() []*Session { return m.GetActiveSessionsBySource("source") },
+	}
+	var wg sync.WaitGroup
+	wg.Go(func() {
+		for range 1000 {
+			proxy.UpdateActivity(stored.ID)
+		}
+	})
+	for _, read := range readers {
+		for range 100 {
+			snapshots := read()
+			if len(snapshots) != 1 || snapshots[0] == stored || snapshots[0].InstanceID != "source" {
+				t.Errorf("invalid snapshot: %+v", snapshots)
+				break
+			}
+			snapshot := snapshots[0]
+			before := snapshot.LastActivity
+			proxy.UpdateActivity(stored.ID)
+			if !snapshot.LastActivity.Equal(before) {
+				t.Error("activity update changed an earlier snapshot")
+			}
+			snapshot.Metadata["label"] = "changed"
+		}
+	}
+	wg.Wait()
+	if stored.Metadata["label"] != "original" {
+		t.Fatal("snapshot metadata aliases the stored map")
+	}
+}