"errors"
"fmt"
"golang.org/x/text/encoding/charmap"
+ "golang.org/x/time/rate"
"io"
"log"
"log/slog"
NetInterface string
Port int
+ rateLimiters map[string]*rate.Limiter
+
handlers map[TranType]HandlerFunc
Config Config
server := Server{
handlers: make(map[TranType]HandlerFunc),
outbox: make(chan Transaction),
+ rateLimiters: make(map[string]*rate.Limiter),
FS: &OSFileStore{},
ChatMgr: NewMemChatManager(),
ClientMgr: NewMemClientMgr(),
)
if err != nil {
- s.Logger.Error("file transfer error", "reason", err)
+ s.Logger.Error("file transfer error", "err", err)
}
}()
}
}
}
+// perIPRateLimit controls how frequently an IP address can connect before being throttled.
+// 0.5 = 1 connection every 2 seconds
+const perIPRateLimit = rate.Limit(0.5)
+
func (s *Server) Serve(ctx context.Context, ln net.Listener) error {
for {
select {
}
go func() {
+ ipAddr := strings.Split(conn.RemoteAddr().(*net.TCPAddr).String(), ":")[0]
+
connCtx := context.WithValue(ctx, contextKeyReq, requestCtx{
remoteAddr: conn.RemoteAddr().String(),
})
- s.Logger.Info("Connection established", "addr", conn.RemoteAddr())
+ s.Logger.Info("Connection established", "ip", ipAddr)
defer conn.Close()
+ // Check if we have an existing rate limit for the IP and create one if we do not.
+ rl, ok := s.rateLimiters[ipAddr]
+ if !ok {
+ rl = rate.NewLimiter(perIPRateLimit, 1)
+ s.rateLimiters[ipAddr] = rl
+ }
+
+ // Check if the rate limit is exceeded and close the connection if so.
+ if !rl.Allow() {
+ s.Logger.Info("Rate limit exceeded", "RemoteAddr", conn.RemoteAddr())
+ conn.Close()
+ return
+ }
+
if err := s.handleNewConnection(connCtx, conn, conn.RemoteAddr().String()); err != nil {
if err == io.EOF {
s.Logger.Info("Client disconnected", "RemoteAddr", conn.RemoteAddr())
// registerWithTrackers runs every trackerUpdateFrequency seconds to update the server's tracker entry on all configured
// trackers.
func (s *Server) registerWithTrackers(ctx context.Context) {
- ticker := time.NewTicker(trackerUpdateFrequency * time.Second)
- defer ticker.Stop()
-
for {
- select {
- case <-ctx.Done():
- return
- case <-ticker.C:
- if s.Config.EnableTrackerRegistration {
+ if s.Config.EnableTrackerRegistration {
+ for _, t := range s.Config.Trackers {
tr := &TrackerRegistration{
UserCount: len(s.ClientMgr.List()),
PassID: s.TrackerPassID,
}
binary.BigEndian.PutUint16(tr.Port[:], uint16(s.Port))
- for _, t := range s.Config.Trackers {
- if err := register(&RealDialer{}, t, tr); err != nil {
- s.Logger.Error(fmt.Sprintf("Unable to register with tracker %v", t), "error", err)
- }
+ // Check the tracker string for a password. This is janky but avoids a breaking change to the Config
+ // Trackers field.
+ splitAddr := strings.Split(":", t)
+ if len(splitAddr) == 3 {
+ tr.Password = splitAddr[2]
+ }
+
+ if err := register(&RealDialer{}, t, tr); err != nil {
+ s.Logger.Error(fmt.Sprintf("Unable to register with tracker %v", t), "error", err)
}
}
}
+ // Using time.Ticker with for/select would be more idiomatic, but it's super annoying that it doesn't tick on
+ // first pass. Revist, maybe.
+ // https://github.com/golang/go/issues/17601
+ time.Sleep(trackerUpdateFrequency * time.Second)
}
-
}
const (
return err
}
- c.Logger.Info("Login failed", "clientVersion", fmt.Sprintf("%x", c.Version))
+ c.Logger.Info("Incorrect login")
return nil
}
"Name", string(fileTransfer.ClientConn.UserName),
)
- fullPath, err := ReadPath(s.Config.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
+ fullPath, err := ReadPath(fileTransfer.FileRoot, fileTransfer.FilePath, fileTransfer.FileName)
if err != nil {
return err
}
switch fileTransfer.Type {
case BannerDownload:
if _, err := io.Copy(rwc, bytes.NewBuffer(s.Banner)); err != nil {
- return fmt.Errorf("error sending Banner: %w", err)
+ return fmt.Errorf("banner download: %w", err)
}
case FileDownload:
s.Stats.Increment(StatDownloadCounter, StatDownloadsInProgress)
err = UploadHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
if err != nil {
- return fmt.Errorf("file upload error: %w", err)
+ return fmt.Errorf("file upload: %w", err)
}
case FolderDownload:
err = DownloadFolderHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
if err != nil {
- return fmt.Errorf("file upload error: %w", err)
+ return fmt.Errorf("folder download: %w", err)
}
case FolderUpload:
err = UploadFolderHandler(rwc, fullPath, fileTransfer, s.FS, rLogger, s.Config.PreserveResourceForks)
if err != nil {
- return fmt.Errorf("file upload error: %w", err)
+ return fmt.Errorf("folder upload: %w", err)
}
}
return nil
git.r.bdr.sh / rbdr / mobius / blobdiff