Add disable-inactive-user config option

This can be used to automatically disable users if they don't
actively use the bouncer for a while.

cmd/soju/main.go

@@ -91,6 +91,7 @@ func loadConfig() (*config.Server, *soju.Config, error) {
 		AcceptProxyIPs:            raw.AcceptProxyIPs,
 		MaxUserNetworks:           raw.MaxUserNetworks,
 		UpstreamUserIPs:           raw.UpstreamUserIPs,
+		DisableInactiveUsersDelay: raw.DisableInactiveUsersDelay,
 		MOTD:                      motd,
 	}
 	return raw, cfg, nil

config/config.go

@@ -5,6 +5,8 @@ import (
 	"net"
 	"os"
 	"strconv"
+	"strings"
+	"time"
 
 	"git.sr.ht/~emersion/go-scfg"
 )
@@ -32,6 +34,18 @@ var loopbackIPs = IPSet{
 	},
 }
 
+func parseDuration(s string) (time.Duration, error) {
+	if !strings.HasSuffix(s, "d") {
+		return 0, fmt.Errorf("missing 'd' suffix in duration")
+	}
+	s = strings.TrimSuffix(s, "d")
+	v, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0, fmt.Errorf("invalid duration: %v", err)
+	}
+	return time.Duration(v * 24 * float64(time.Hour)), nil
+}
+
 type TLS struct {
 	CertPath, KeyPath string
 }
@@ -59,6 +73,7 @@ type Server struct {
 
 	MaxUserNetworks           int
 	UpstreamUserIPs           []*net.IPNet
+	DisableInactiveUsersDelay time.Duration
 }
 
 func Defaults() *Server {
@@ -180,6 +195,18 @@ func parse(cfg scfg.Block) (*Server, error) {
 				}
 				srv.UpstreamUserIPs = append(srv.UpstreamUserIPs, n)
 			}
+		case "disable-inactive-user":
+			var durStr string
+			if err := d.ParseParams(&durStr); err != nil {
+				return nil, err
+			}
+			dur, err := parseDuration(durStr)
+			if err != nil {
+				return nil, fmt.Errorf("directive %q: %v", d.Name, err)
+			} else if dur < 0 {
+				return nil, fmt.Errorf("directive %q: duration must be positive", d.Name)
+			}
+			srv.DisableInactiveUsersDelay = dur
 		default:
 			return nil, fmt.Errorf("unknown directive %q", d.Name)
 		}

database/database.go

@@ -20,6 +20,7 @@ type Database interface {
 	GetUser(ctx context.Context, username string) (*User, error)
 	StoreUser(ctx context.Context, user *User) error
 	DeleteUser(ctx context.Context, id int64) error
+	ListInactiveUsernames(ctx context.Context, limit time.Time) ([]string, error)
 
 	ListNetworks(ctx context.Context, userID int64) ([]Network, error)
 	StoreNetwork(ctx context.Context, userID int64, network *Network) error

database/postgres.go

@@ -354,6 +354,33 @@ func (db *PostgresDB) GetUser(ctx context.Context, username string) (*User, erro
 	return user, nil
 }
 
+func (db *PostgresDB) ListInactiveUsernames(ctx context.Context, limit time.Time) ([]string, error) {
+	ctx, cancel := context.WithTimeout(ctx, postgresQueryTimeout)
+	defer cancel()
+
+	rows, err := db.db.QueryContext(ctx,
+		`SELECT username FROM "User" WHERE COALESCE(downstream_interacted_at, created_at) < $1`,
+		limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var usernames []string
+	for rows.Next() {
+		var username string
+		if err := rows.Scan(&username); err != nil {
+			return nil, err
+		}
+		usernames = append(usernames, username)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return usernames, nil
+}
+
 func (db *PostgresDB) StoreUser(ctx context.Context, user *User) error {
 	ctx, cancel := context.WithTimeout(ctx, postgresQueryTimeout)
 	defer cancel()

database/sqlite.go

@@ -445,6 +445,33 @@ func (db *SqliteDB) GetUser(ctx context.Context, username string) (*User, error)
 	return user, nil
 }
 
+func (db *SqliteDB) ListInactiveUsernames(ctx context.Context, limit time.Time) ([]string, error) {
+	ctx, cancel := context.WithTimeout(ctx, sqliteQueryTimeout)
+	defer cancel()
+
+	rows, err := db.db.QueryContext(ctx,
+		"SELECT username FROM User WHERE coalesce(downstream_interacted_at, created_at) < ?",
+		sqliteTime{limit})
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var usernames []string
+	for rows.Next() {
+		var username string
+		if err := rows.Scan(&username); err != nil {
+			return nil, err
+		}
+		usernames = append(usernames, username)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return usernames, nil
+}
+
 func (db *SqliteDB) StoreUser(ctx context.Context, user *User) error {
 	ctx, cancel := context.WithTimeout(ctx, sqliteQueryTimeout)
 	defer cancel()

doc/soju.1.scd

@@ -170,6 +170,15 @@ The following directives are supported:
 	This can be useful to avoid having the whole bouncer banned from an upstream
 	network because of one malicious user.
 
+*disable-inactive-user* <duration>
+	Disable inactive users after the specified duration.
+
+	A user is inactive when the last downstream connection is closed.
+
+	The duration is a positive decimal number followed by the unit "d" (days).
+	For instance, "30d" disables users 30 days after they last disconnect from
+	the bouncer.
+
 # IRC SERVICE
 
 soju exposes an IRC service called *BouncerServ* to manage the bouncer.

server.go

@@ -141,6 +141,7 @@ type Config struct {
 	MaxUserNetworks           int
 	MOTD                      string
 	UpstreamUserIPs           []*net.IPNet
+	DisableInactiveUsersDelay time.Duration
 }
 
 type Server struct {
@@ -151,6 +152,7 @@ type Server struct {
 	config atomic.Value // *Config
 	db     database.Database
 	stopWG sync.WaitGroup
+	stopCh chan struct{}
 
 	lock      sync.Mutex
 	listeners map[net.Listener]struct{}
@@ -178,6 +180,7 @@ func NewServer(db database.Database) *Server {
 		db:        db,
 		listeners: make(map[net.Listener]struct{}),
 		users:     make(map[string]*user),
+		stopCh:    make(chan struct{}),
 	}
 	srv.config.Store(&Config{
 		Hostname:        "localhost",
@@ -216,6 +219,12 @@ func (s *Server) Start() error {
 	}
 	s.lock.Unlock()
 
+	s.stopWG.Add(1)
+	go func() {
+		defer s.stopWG.Done()
+		s.disableInactiveUsersLoop()
+	}()
+
 	return nil
 }
 
@@ -343,6 +352,8 @@ func (s *Server) sendWebPush(ctx context.Context, sub *webpush.Subscription, vap
 func (s *Server) Shutdown() {
 	s.Logger.Printf("shutting down server")
 
+	close(s.stopCh)
+
 	s.lock.Lock()
 	s.shutdown = true
 	for ln := range s.listeners {
@@ -547,3 +558,88 @@ func (s *Server) Stats() *ServerStats {
 	stats.Upstreams = s.metrics.upstreams.Value()
 	return &stats
 }
+
+func (s *Server) disableInactiveUsersLoop() {
+	ticker := time.NewTicker(4 * time.Hour)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-s.stopCh:
+			return
+		case <-ticker.C:
+		}
+
+		if err := s.disableInactiveUsers(context.TODO()); err != nil {
+			s.Logger.Printf("failed to disable inactive users: %v", err)
+		}
+	}
+}
+
+func (s *Server) disableInactiveUsers(ctx context.Context) error {
+	delay := s.Config().DisableInactiveUsersDelay
+	if delay == 0 {
+		return nil
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, time.Minute)
+	defer cancel()
+
+	usernames, err := s.db.ListInactiveUsernames(ctx, time.Now().Add(-delay))
+	if err != nil {
+		return fmt.Errorf("failed to list inactive users: %v", err)
+	} else if len(usernames) == 0 {
+		return nil
+	}
+
+	// Filter out users with active downstream connections
+	var users []*user
+	s.lock.Lock()
+	for _, username := range usernames {
+		u := s.users[username]
+		if u == nil {
+			// TODO: disable the user in the DB
+			continue
+		}
+
+		if n := u.numDownstreamConns.Load(); n > 0 {
+			continue
+		}
+
+		users = append(users, u)
+	}
+	s.lock.Unlock()
+
+	if len(users) == 0 {
+		return nil
+	}
+
+	s.Logger.Printf("found %v inactive users", len(users))
+	for _, u := range users {
+		done := make(chan error, 1)
+		enabled := false
+		event := eventUserUpdate{
+			enabled: &enabled,
+			done:    done,
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case u.events <- event:
+			// Event was sent, let's wait for the reply
+		}
+
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case err := <-done:
+			if err != nil {
+				return err
+			} else {
+				s.Logger.Printf("deleted inactive user %q", u.Username)
+			}
+		}
+	}
+
+	return nil
+}

user.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"sort"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	"git.sr.ht/~emersion/soju/xirc"
@@ -503,6 +504,8 @@ type user struct {
 	events chan event
 	done   chan struct{}
 
+	numDownstreamConns atomic.Int64
+
 	networks        []*network
 	downstreamConns []*downstreamConn
 	msgStore        msgstore.Store
@@ -715,6 +718,7 @@ func (u *user) run() {
 			}
 
 			u.downstreamConns = append(u.downstreamConns, dc)
+			u.numDownstreamConns.Add(1)
 
 			dc.forEachNetwork(func(network *network) {
 				if network.lastError != nil {
@@ -734,6 +738,7 @@ func (u *user) run() {
 			for i := range u.downstreamConns {
 				if u.downstreamConns[i] == dc {
 					u.downstreamConns = append(u.downstreamConns[:i], u.downstreamConns[i+1:]...)
+					u.numDownstreamConns.Add(-1)
 					break
 				}
 			}