control/ts2021: rename from internal/noiseconn in prep for controlclient split

A following change will split out the controlclient.NoiseClient type
out, away from the rest of the controlclient package which is
relatively dependency heavy.

A question was where to move it, and whether to make a new (a fifth!)
package in the ts2021 dependency chain.

@creachadair and I brainstormed and decided to merge
internal/noiseconn and controlclient.NoiseClient into one package,
with names ts2021.Conn and ts2021.Client.

For ease of reviewing the subsequent PR, this is the first step that
just renames the internal/noiseconn package to control/ts2021.

Updates #17305

Change-Id: Ib5ea162dc1d336c1d805bdd9548d1702dd6e1468
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/k8s-operator/depaware.txt

@@ -690,6 +690,7 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/control/controlclient
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/ipn/localapi+
@@ -710,7 +711,6 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/client/web+
         tailscale.com/internal/client/tailscale                      from tailscale.com/cmd/k8s-operator+
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient
         tailscale.com/ipn                                            from tailscale.com/client/local+
         tailscale.com/ipn/conffile                                   from tailscale.com/ipn/ipnlocal+
      💣 tailscale.com/ipn/ipnauth                                    from tailscale.com/ipn/ipnlocal+

cmd/tailscale/cli/debug.go

@@ -31,10 +31,10 @@ import (
 	"golang.org/x/net/http2"
 	"tailscale.com/client/tailscale/apitype"
 	"tailscale.com/control/controlhttp"
+	"tailscale.com/control/ts2021"
 	"tailscale.com/feature"
 	_ "tailscale.com/feature/condregister/useproxy"
 	"tailscale.com/hostinfo"
-	"tailscale.com/internal/noiseconn"
 	"tailscale.com/ipn"
 	"tailscale.com/net/ace"
 	"tailscale.com/net/netmon"
@@ -1122,7 +1122,7 @@ func tryConnect(ctx context.Context, controlPublic key.MachinePublic, noiseDiale
 	}
 
 	// Now, create a Noise conn over the existing conn.
-	nc, err := noiseconn.New(conn.Conn, h2Transport, 0, nil)
+	nc, err := ts2021.New(conn.Conn, h2Transport, 0, nil)
 	if err != nil {
 		return fmt.Errorf("noiseconn.New: %w", err)
 	}

cmd/tailscale/depaware.txt

@@ -85,6 +85,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlhttp                            from tailscale.com/cmd/tailscale/cli
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
+        tailscale.com/control/ts2021                                 from tailscale.com/cmd/tailscale/cli
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck
@@ -105,7 +106,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
         tailscale.com/health/healthmsg                               from tailscale.com/cmd/tailscale/cli
         tailscale.com/hostinfo                                       from tailscale.com/client/web+
         tailscale.com/internal/client/tailscale                      from tailscale.com/cmd/tailscale/cli+
-        tailscale.com/internal/noiseconn                             from tailscale.com/cmd/tailscale/cli
         tailscale.com/ipn                                            from tailscale.com/client/local+
         tailscale.com/ipn/ipnstate                                   from tailscale.com/client/local+
         tailscale.com/kube/kubetypes                                 from tailscale.com/envknob

cmd/tailscaled/depaware-min.txt

@@ -45,6 +45,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/control/controlclient
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck+
@@ -60,7 +61,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/health                                         from tailscale.com/control/controlclient+
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/cmd/tailscaled+
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient
         tailscale.com/ipn                                            from tailscale.com/cmd/tailscaled+
         tailscale.com/ipn/conffile                                   from tailscale.com/cmd/tailscaled+
         tailscale.com/ipn/ipnauth                                    from tailscale.com/ipn/ipnext+

cmd/tailscaled/depaware-minbox.txt

@@ -65,6 +65,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient+
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/cmd/tailscale/cli+
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/net/netcheck+
@@ -82,7 +83,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/cmd/tailscaled+
         tailscale.com/internal/client/tailscale                      from tailscale.com/cmd/tailscale/cli
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient+
         tailscale.com/ipn                                            from tailscale.com/cmd/tailscaled+
         tailscale.com/ipn/conffile                                   from tailscale.com/cmd/tailscaled+
         tailscale.com/ipn/ipnauth                                    from tailscale.com/ipn/ipnext+

cmd/tailscaled/depaware.txt

@@ -255,6 +255,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/control/controlclient
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/cmd/tailscaled+
@@ -296,7 +297,6 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/health                                         from tailscale.com/control/controlclient+
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/client/web+
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient
         tailscale.com/ipn                                            from tailscale.com/client/local+
    W    tailscale.com/ipn/auditlog                                   from tailscale.com/cmd/tailscaled
         tailscale.com/ipn/conffile                                   from tailscale.com/cmd/tailscaled+

cmd/tsidp/depaware.txt

@@ -132,6 +132,7 @@ tailscale.com/cmd/tsidp dependencies: (generated by github.com/tailscale/depawar
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/control/controlclient
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/ipn/localapi+
@@ -152,7 +153,6 @@ tailscale.com/cmd/tsidp dependencies: (generated by github.com/tailscale/depawar
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/client/web+
         tailscale.com/internal/client/tailscale                      from tailscale.com/tsnet+
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient
         tailscale.com/ipn                                            from tailscale.com/client/local+
         tailscale.com/ipn/conffile                                   from tailscale.com/ipn/ipnlocal+
      💣 tailscale.com/ipn/ipnauth                                    from tailscale.com/ipn/ipnext+

control/controlclient/noise.go

@@ -18,8 +18,8 @@ import (
 
 	"golang.org/x/net/http2"
 	"tailscale.com/control/controlhttp"
+	"tailscale.com/control/ts2021"
 	"tailscale.com/health"
-	"tailscale.com/internal/noiseconn"
 	"tailscale.com/net/dnscache"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/tsdial"
@@ -50,7 +50,7 @@ type NoiseClient struct {
 
 	// sfDial ensures that two concurrent requests for a noise connection only
 	// produce one shared one between the two callers.
-	sfDial singleflight.Group[struct{}, *noiseconn.Conn]
+	sfDial singleflight.Group[struct{}, *ts2021.Conn]
 
 	dialer       *tsdial.Dialer
 	dnsCache     *dnscache.Resolver
@@ -72,9 +72,9 @@ type NoiseClient struct {
 	// mu only protects the following variables.
 	mu       sync.Mutex
 	closed   bool
-	last     *noiseconn.Conn // or nil
+	last     *ts2021.Conn // or nil
 	nextID   int
-	connPool map[int]*noiseconn.Conn // active connections not yet closed; see noiseconn.Conn.Close
+	connPool map[int]*ts2021.Conn // active connections not yet closed; see ts2021.Conn.Close
 }
 
 // NoiseOpts contains options for the NewNoiseClient function. All fields are
@@ -195,12 +195,12 @@ func (e contextErr) Unwrap() error {
 	return e.err
 }
 
-// getConn returns a noiseconn.Conn that can be used to make requests to the
+// getConn returns a ts2021.Conn that can be used to make requests to the
 // coordination server. It may return a cached connection or create a new one.
 // Dials are singleflighted, so concurrent calls to getConn may only dial once.
 // As such, context values may not be respected as there are no guarantees that
 // the context passed to getConn is the same as the context passed to dial.
-func (nc *NoiseClient) getConn(ctx context.Context) (*noiseconn.Conn, error) {
+func (nc *NoiseClient) getConn(ctx context.Context) (*ts2021.Conn, error) {
 	nc.mu.Lock()
 	if last := nc.last; last != nil && last.CanTakeNewRequest() {
 		nc.mu.Unlock()
@@ -214,7 +214,7 @@ func (nc *NoiseClient) getConn(ctx context.Context) (*noiseconn.Conn, error) {
 		// canceled. Instead, we have to additionally check that the context
 		// which was canceled is our context and retry if our context is still
 		// valid.
-		conn, err, _ := nc.sfDial.Do(struct{}{}, func() (*noiseconn.Conn, error) {
+		conn, err, _ := nc.sfDial.Do(struct{}{}, func() (*ts2021.Conn, error) {
 			c, err := nc.dial(ctx)
 			if err != nil {
 				if ctx.Err() != nil {
@@ -282,7 +282,7 @@ func (nc *NoiseClient) Close() error {
 
 // dial opens a new connection to tailcontrol, fetching the server noise key
 // if not cached.
-func (nc *NoiseClient) dial(ctx context.Context) (*noiseconn.Conn, error) {
+func (nc *NoiseClient) dial(ctx context.Context) (*ts2021.Conn, error) {
 	nc.mu.Lock()
 	connID := nc.nextID
 	nc.nextID++
@@ -352,7 +352,7 @@ func (nc *NoiseClient) dial(ctx context.Context) (*noiseconn.Conn, error) {
 		return nil, err
 	}
 
-	ncc, err := noiseconn.New(clientConn.Conn, nc.h2t, connID, nc.connClosed)
+	ncc, err := ts2021.New(clientConn.Conn, nc.h2t, connID, nc.connClosed)
 	if err != nil {
 		return nil, err
 	}

control/controlclient/noise_test.go

@@ -15,7 +15,7 @@ import (
 
 	"golang.org/x/net/http2"
 	"tailscale.com/control/controlhttp/controlhttpserver"
-	"tailscale.com/internal/noiseconn"
+	"tailscale.com/control/ts2021"
 	"tailscale.com/net/netmon"
 	"tailscale.com/net/tsdial"
 	"tailscale.com/tailcfg"
@@ -310,7 +310,7 @@ func (up *Upgrader) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		// https://httpwg.org/specs/rfc7540.html#rfc.section.4.1 (Especially not
 		// an HTTP/2 settings frame, which isn't of type 'T')
 		var notH2Frame [5]byte
-		copy(notH2Frame[:], noiseconn.EarlyPayloadMagic)
+		copy(notH2Frame[:], ts2021.EarlyPayloadMagic)
 		var lenBuf [4]byte
 		binary.BigEndian.PutUint32(lenBuf[:], uint32(len(earlyJSON)))
 		// These writes are all buffered by caller, so fine to do them

control/ts2021/conn.go

@@ -1,12 +1,10 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-// Package noiseconn contains an internal-only wrapper around controlbase.Conn
+// Package ts2021 handles the details of the Tailscale 2021 control protocol
-// that properly handles the early payload sent by the server before the HTTP/2
+// that are after (above) the Noise layer. In particular, the
-// session begins.
+// "tailcfg.EarlyNoise" message and the subsequent HTTP/2 connection.
-//
+package ts2021
-// See the documentation on the Conn type for more details.
-package noiseconn
 
 import (
 	"bytes"

tsnet/depaware.txt

@@ -128,6 +128,7 @@ tailscale.com/tsnet dependencies: (generated by github.com/tailscale/depaware)
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient
         tailscale.com/control/controlhttp/controlhttpcommon          from tailscale.com/control/controlhttp
         tailscale.com/control/controlknobs                           from tailscale.com/control/controlclient+
+        tailscale.com/control/ts2021                                 from tailscale.com/control/controlclient
         tailscale.com/derp                                           from tailscale.com/derp/derphttp+
         tailscale.com/derp/derpconst                                 from tailscale.com/derp/derphttp+
         tailscale.com/derp/derphttp                                  from tailscale.com/ipn/localapi+
@@ -148,7 +149,6 @@ tailscale.com/tsnet dependencies: (generated by github.com/tailscale/depaware)
         tailscale.com/health/healthmsg                               from tailscale.com/ipn/ipnlocal+
         tailscale.com/hostinfo                                       from tailscale.com/client/web+
         tailscale.com/internal/client/tailscale                      from tailscale.com/tsnet+
-        tailscale.com/internal/noiseconn                             from tailscale.com/control/controlclient
         tailscale.com/ipn                                            from tailscale.com/client/local+
         tailscale.com/ipn/conffile                                   from tailscale.com/ipn/ipnlocal+
      💣 tailscale.com/ipn/ipnauth                                    from tailscale.com/ipn/ipnext+