diff options
| -rw-r--r-- | cmd/derper/mesh.go | 1 | ||||
| -rw-r--r-- | derp/derphttp/derphttp_client.go | 40 | ||||
| -rw-r--r-- | derp/derphttp/mesh_client.go | 34 |
3 files changed, 43 insertions, 32 deletions
diff --git a/cmd/derper/mesh.go b/cmd/derper/mesh.go index acbd39f1b..60ee42aca 100644 --- a/cmd/derper/mesh.go +++ b/cmd/derper/mesh.go @@ -41,6 +41,7 @@ func startMeshWithHost(s *derp.Server, host string) error { return err } c.MeshKey = s.MeshKey() + c.WatchConnectionChanges = true // For meshed peers within a region, connect via VPC addresses. c.SetURLDialer(func(ctx context.Context, network, addr string) (net.Conn, error) { diff --git a/derp/derphttp/derphttp_client.go b/derp/derphttp/derphttp_client.go index 3bd314464..06abaeb14 100644 --- a/derp/derphttp/derphttp_client.go +++ b/derp/derphttp/derphttp_client.go @@ -56,6 +56,12 @@ type Client struct { MeshKey string // optional; for trusted clients IsProber bool // optional; for probers to optional declare themselves as such + // WatchConnectionChanges is whether the client wishes to subscribe to + // notifications about clients connecting & disconnecting. + // + // Only trusted connections (using MeshKey) are allowed to use this. + WatchConnectionChanges bool + // BaseContext, if non-nil, returns the base context to use for dialing a // new derp server. If nil, context.Background is used. // In either case, additional timeouts may be added to the base context. @@ -80,6 +86,7 @@ type Client struct { addrFamSelAtomic syncs.AtomicValue[AddressFamilySelector] mu sync.Mutex + started bool // true upon first connect, never transitions to false preferred bool canAckPings bool closed bool @@ -142,6 +149,15 @@ func NewClient(privateKey key.NodePrivate, serverURL string, logf logger.Logf) ( return c, nil } +// isStarted reports whether this client has been used yet. +// +// If if reports false, it may still have its exported fields configured. +func (c *Client) isStarted() bool { + c.mu.Lock() + defer c.mu.Unlock() + return c.started +} + // Connect connects or reconnects to the server, unless already connected. // It returns nil if there was already a good connection, or if one was made. func (c *Client) Connect(ctx context.Context) error { @@ -284,6 +300,7 @@ func useWebsockets() bool { func (c *Client) connect(ctx context.Context, caller string) (client *derp.Client, connGen int, err error) { c.mu.Lock() defer c.mu.Unlock() + c.started = true if c.closed { return nil, 0, ErrClientClosed } @@ -495,6 +512,13 @@ func (c *Client) connect(ctx context.Context, caller string) (client *derp.Clien } } + if c.WatchConnectionChanges { + if err := derpClient.WatchConnectionChanges(); err != nil { + go httpConn.Close() + return nil, 0, err + } + } + c.serverPubKey = derpClient.ServerPublicKey() c.client = derpClient c.netConn = tcpConn @@ -956,22 +980,6 @@ func (c *Client) NotePreferred(v bool) { } } -// WatchConnectionChanges sends a request to subscribe to -// notifications about clients connecting & disconnecting. -// -// Only trusted connections (using MeshKey) are allowed to use this. -func (c *Client) WatchConnectionChanges() error { - client, _, err := c.connect(c.newContext(), "derphttp.Client.WatchConnectionChanges") - if err != nil { - return err - } - err = client.WatchConnectionChanges() - if err != nil { - c.closeForReconnect(client) - } - return err -} - // ClosePeer asks the server to close target's TCP connection. // // Only trusted connections (using MeshKey) are allowed to use this. diff --git a/derp/derphttp/mesh_client.go b/derp/derphttp/mesh_client.go index 748598d6f..2793fd068 100644 --- a/derp/derphttp/mesh_client.go +++ b/derp/derphttp/mesh_client.go @@ -14,20 +14,30 @@ import ( "tailscale.com/types/logger" ) -// RunWatchConnectionLoop loops until ctx is done, sending WatchConnectionChanges and subscribing to -// connection changes. +// RunWatchConnectionLoop loops until ctx is done, sending +// WatchConnectionChanges and subscribing to connection changes. // -// If the server's public key is ignoreServerKey, RunWatchConnectionLoop returns. +// If the server's public key is ignoreServerKey, RunWatchConnectionLoop +// returns. // // Otherwise, the add and remove funcs are called as clients come & go. // -// infoLogf, if non-nil, is the logger to write periodic status -// updates about how many peers are on the server. Error log output is -// set to the c's logger, regardless of infoLogf's value. +// infoLogf, if non-nil, is the logger to write periodic status updates about +// how many peers are on the server. Error log output is set to the c's logger, +// regardless of infoLogf's value. // -// To force RunWatchConnectionLoop to return quickly, its ctx needs to -// be closed, and c itself needs to be closed. +// To force RunWatchConnectionLoop to return quickly, its ctx needs to be +// closed, and c itself needs to be closed. +// +// It is a fatal error to call this on an already-started Client withoutq having +// initialized Client.WatchConnectionChanges to true. func (c *Client) RunWatchConnectionLoop(ctx context.Context, ignoreServerKey key.NodePublic, infoLogf logger.Logf, add func(key.NodePublic, netip.AddrPort), remove func(key.NodePublic)) { + if !c.WatchConnectionChanges { + if c.isStarted() { + panic("invalid use of RunWatchConnectionLoop on already-started Client without setting Client.RunWatchConnectionLoop") + } + c.WatchConnectionChanges = true + } if infoLogf == nil { infoLogf = logger.Discard } @@ -101,14 +111,6 @@ func (c *Client) RunWatchConnectionLoop(ctx context.Context, ignoreServerKey key } for ctx.Err() == nil { - err := c.WatchConnectionChanges() - if err != nil { - clear() - logf("WatchConnectionChanges: %v", err) - sleep(retryInterval) - continue - } - if c.ServerPublicKey() == ignoreServerKey { logf("detected self-connect; ignoring host") return |