From 5bba65e978c6064278cee3f5d88f02f30791fa80 Mon Sep 17 00:00:00 2001
From: Maisem Ali <maisem@tailscale.com>
Date: Mon, 30 Jan 2023 10:53:58 -0800
Subject: [PATCH] net/memnet: rename from net/nettest

This is just #cleanup to resolve a TODO

Also add a package doc.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
---
 control/controlbase/conn_test.go         | 10 +++++-----
 control/controlbase/handshake_test.go    | 14 +++++++-------
 control/controlbase/interop_test.go      |  6 +++---
 derp/derp_test.go                        |  6 +++---
 net/{nettest => memnet}/conn.go          |  2 +-
 net/{nettest => memnet}/conn_test.go     |  2 +-
 net/{nettest => memnet}/listener.go      |  2 +-
 net/{nettest => memnet}/listener_test.go |  2 +-
 net/memnet/memnet.go                     |  8 ++++++++
 net/{nettest => memnet}/pipe.go          | 10 +++++-----
 net/{nettest => memnet}/pipe_test.go     |  2 +-
 ssh/tailssh/tailssh_test.go              |  4 ++--
 tsnet/tsnet.go                           |  5 ++---
 13 files changed, 40 insertions(+), 33 deletions(-)
 rename net/{nettest => memnet}/conn.go (99%)
 rename net/{nettest => memnet}/conn_test.go (95%)
 rename net/{nettest => memnet}/listener.go (99%)
 rename net/{nettest => memnet}/listener_test.go (97%)
 create mode 100644 net/memnet/memnet.go
 rename net/{nettest => memnet}/pipe.go (94%)
 rename net/{nettest => memnet}/pipe_test.go (99%)

diff --git a/control/controlbase/conn_test.go b/control/controlbase/conn_test.go
index 17eaae617..079c57c6e 100644
--- a/control/controlbase/conn_test.go
+++ b/control/controlbase/conn_test.go
@@ -21,7 +21,7 @@
 
 	chp "golang.org/x/crypto/chacha20poly1305"
 	"golang.org/x/net/nettest"
-	tsnettest "tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/types/key"
 )
 
@@ -82,7 +82,7 @@ func (c *bufferedWriteConn) Write(bs []byte) (int, error) {
 // Noise frames at once and decode each in turn without making another
 // syscall.
 func TestFastPath(t *testing.T) {
-	s1, s2 := tsnettest.NewConn("noise", 128000)
+	s1, s2 := memnet.NewConn("noise", 128000)
 	b := &bufferedWriteConn{s1, bufio.NewWriterSize(s1, 10000), false}
 	client, server := pairWithConns(t, b, s2)
 
@@ -175,7 +175,7 @@ func (c readerConn) Read(bs []byte) (int, error) { return c.r.Read(bs) }
 // Check that the receiver can handle not being able to read an entire
 // frame in a single syscall.
 func TestDataTrickle(t *testing.T) {
-	s1, s2 := tsnettest.NewConn("noise", 128000)
+	s1, s2 := memnet.NewConn("noise", 128000)
 	client, server := pairWithConns(t, s1, readerConn{s2, iotest.OneByteReader(s2)})
 	serverReads := sinkReads(server)
 
@@ -199,7 +199,7 @@ func TestConnStd(t *testing.T) {
 	// they're not on our Conn due to cipher security.
 	t.Skip("not all tests can pass on this Conn, see https://github.com/golang/go/issues/46977")
 	nettest.TestConn(t, func() (c1 net.Conn, c2 net.Conn, stop func(), err error) {
-		s1, s2 := tsnettest.NewConn("noise", 4096)
+		s1, s2 := memnet.NewConn("noise", 4096)
 		controlKey := key.NewMachine()
 		machineKey := key.NewMachine()
 		serverErr := make(chan error, 1)
@@ -412,6 +412,6 @@ func pairWithConns(t *testing.T, clientConn, serverConn net.Conn) (*Conn, *Conn)
 }
 
 func pair(t *testing.T) (*Conn, *Conn) {
-	s1, s2 := tsnettest.NewConn("noise", 128000)
+	s1, s2 := memnet.NewConn("noise", 128000)
 	return pairWithConns(t, s1, s2)
 }
diff --git a/control/controlbase/handshake_test.go b/control/controlbase/handshake_test.go
index a84f730e7..e4400c95d 100644
--- a/control/controlbase/handshake_test.go
+++ b/control/controlbase/handshake_test.go
@@ -11,13 +11,13 @@
 	"testing"
 	"time"
 
-	tsnettest "tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/types/key"
 )
 
 func TestHandshake(t *testing.T) {
 	var (
-		clientConn, serverConn = tsnettest.NewConn("noise", 128000)
+		clientConn, serverConn = memnet.NewConn("noise", 128000)
 		serverKey              = key.NewMachine()
 		clientKey              = key.NewMachine()
 		server                 *Conn
@@ -66,7 +66,7 @@ func TestNoReuse(t *testing.T) {
 	)
 	for i := 0; i < 10; i++ {
 		var (
-			clientRaw, serverRaw = tsnettest.NewConn("noise", 128000)
+			clientRaw, serverRaw = memnet.NewConn("noise", 128000)
 			clientBuf, serverBuf bytes.Buffer
 			clientConn           = &readerConn{clientRaw, io.TeeReader(clientRaw, &clientBuf)}
 			serverConn           = &readerConn{serverRaw, io.TeeReader(serverRaw, &serverBuf)}
@@ -164,7 +164,7 @@ func TestTampering(t *testing.T) {
 	// Tamper with every byte of the client initiation message.
 	for i := 0; i < 101; i++ {
 		var (
-			clientConn, serverRaw = tsnettest.NewConn("noise", 128000)
+			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, i, 0}}
 			serverKey             = key.NewMachine()
 			clientKey             = key.NewMachine()
@@ -192,7 +192,7 @@ func TestTampering(t *testing.T) {
 	// Tamper with every byte of the server response message.
 	for i := 0; i < 51; i++ {
 		var (
-			clientRaw, serverConn = tsnettest.NewConn("noise", 128000)
+			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, i, 0}}
 			serverKey             = key.NewMachine()
 			clientKey             = key.NewMachine()
@@ -217,7 +217,7 @@ func TestTampering(t *testing.T) {
 	// Tamper with every byte of the first server>client transport message.
 	for i := 0; i < 30; i++ {
 		var (
-			clientRaw, serverConn = tsnettest.NewConn("noise", 128000)
+			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, 51 + i, 0}}
 			serverKey             = key.NewMachine()
 			clientKey             = key.NewMachine()
@@ -258,7 +258,7 @@ func TestTampering(t *testing.T) {
 	// Tamper with every byte of the first client>server transport message.
 	for i := 0; i < 30; i++ {
 		var (
-			clientConn, serverRaw = tsnettest.NewConn("noise", 128000)
+			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, 101 + i, 0}}
 			serverKey             = key.NewMachine()
 			clientKey             = key.NewMachine()
diff --git a/control/controlbase/interop_test.go b/control/controlbase/interop_test.go
index d980b2198..c41fbf4dd 100644
--- a/control/controlbase/interop_test.go
+++ b/control/controlbase/interop_test.go
@@ -11,14 +11,14 @@
 	"net"
 	"testing"
 
-	tsnettest "tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/types/key"
 )
 
 // Can a reference Noise IK client talk to our server?
 func TestInteropClient(t *testing.T) {
 	var (
-		s1, s2      = tsnettest.NewConn("noise", 128000)
+		s1, s2      = memnet.NewConn("noise", 128000)
 		controlKey  = key.NewMachine()
 		machineKey  = key.NewMachine()
 		serverErr   = make(chan error, 2)
@@ -66,7 +66,7 @@ func TestInteropClient(t *testing.T) {
 // Can our client talk to a reference Noise IK server?
 func TestInteropServer(t *testing.T) {
 	var (
-		s1, s2      = tsnettest.NewConn("noise", 128000)
+		s1, s2      = memnet.NewConn("noise", 128000)
 		controlKey  = key.NewMachine()
 		machineKey  = key.NewMachine()
 		clientErr   = make(chan error, 2)
diff --git a/derp/derp_test.go b/derp/derp_test.go
index ed950ea28..ac2521f8e 100644
--- a/derp/derp_test.go
+++ b/derp/derp_test.go
@@ -25,7 +25,7 @@
 
 	"go4.org/mem"
 	"golang.org/x/time/rate"
-	"tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 )
@@ -235,9 +235,9 @@ func TestSendFreeze(t *testing.T) {
 	// Then cathy stops processing messages.
 	// That should not interfere with alice talking to bob.
 
-	newClient := func(ctx context.Context, name string, k key.NodePrivate) (c *Client, clientConn nettest.Conn) {
+	newClient := func(ctx context.Context, name string, k key.NodePrivate) (c *Client, clientConn memnet.Conn) {
 		t.Helper()
-		c1, c2 := nettest.NewConn(name, 1024)
+		c1, c2 := memnet.NewConn(name, 1024)
 		go s.Accept(ctx, c1, bufio.NewReadWriter(bufio.NewReader(c1), bufio.NewWriter(c1)), name)
 
 		brw := bufio.NewReadWriter(bufio.NewReader(c2), bufio.NewWriter(c2))
diff --git a/net/nettest/conn.go b/net/memnet/conn.go
similarity index 99%
rename from net/nettest/conn.go
rename to net/memnet/conn.go
index 0365464b3..fb7776e61 100644
--- a/net/nettest/conn.go
+++ b/net/memnet/conn.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"net"
diff --git a/net/nettest/conn_test.go b/net/memnet/conn_test.go
similarity index 95%
rename from net/nettest/conn_test.go
rename to net/memnet/conn_test.go
index 9fb7f3e8a..743ce5248 100644
--- a/net/nettest/conn_test.go
+++ b/net/memnet/conn_test.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"net"
diff --git a/net/nettest/listener.go b/net/memnet/listener.go
similarity index 99%
rename from net/nettest/listener.go
rename to net/memnet/listener.go
index 0d39f490a..f6ac809bd 100644
--- a/net/nettest/listener.go
+++ b/net/memnet/listener.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"context"
diff --git a/net/nettest/listener_test.go b/net/memnet/listener_test.go
similarity index 97%
rename from net/nettest/listener_test.go
rename to net/memnet/listener_test.go
index 9696a83be..73b67841a 100644
--- a/net/nettest/listener_test.go
+++ b/net/memnet/listener_test.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"context"
diff --git a/net/memnet/memnet.go b/net/memnet/memnet.go
new file mode 100644
index 000000000..c8799bc17
--- /dev/null
+++ b/net/memnet/memnet.go
@@ -0,0 +1,8 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package memnet implements an in-memory network implementation.
+// It is useful for dialing and listening on in-memory addresses
+// in tests and other situations where you don't want to use the
+// network.
+package memnet
diff --git a/net/nettest/pipe.go b/net/memnet/pipe.go
similarity index 94%
rename from net/nettest/pipe.go
rename to net/memnet/pipe.go
index 133b3cb89..471635083 100644
--- a/net/nettest/pipe.go
+++ b/net/memnet/pipe.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"bytes"
@@ -216,10 +216,10 @@ func (p *Pipe) Block() error {
 	p.blocked = true
 
 	if closed {
-		return fmt.Errorf("nettest.Pipe(%q).Block: closed", p.name)
+		return fmt.Errorf("memnet.Pipe(%q).Block: closed", p.name)
 	}
 	if blocked {
-		return fmt.Errorf("nettest.Pipe(%q).Block: already blocked", p.name)
+		return fmt.Errorf("memnet.Pipe(%q).Block: already blocked", p.name)
 	}
 	p.cnd.Broadcast()
 	return nil
@@ -234,10 +234,10 @@ func (p *Pipe) Unblock() error {
 	p.blocked = false
 
 	if closed {
-		return fmt.Errorf("nettest.Pipe(%q).Block: closed", p.name)
+		return fmt.Errorf("memnet.Pipe(%q).Block: closed", p.name)
 	}
 	if !blocked {
-		return fmt.Errorf("nettest.Pipe(%q).Block: already unblocked", p.name)
+		return fmt.Errorf("memnet.Pipe(%q).Block: already unblocked", p.name)
 	}
 	p.cnd.Broadcast()
 	return nil
diff --git a/net/nettest/pipe_test.go b/net/memnet/pipe_test.go
similarity index 99%
rename from net/nettest/pipe_test.go
rename to net/memnet/pipe_test.go
index f6252c713..a86d65388 100644
--- a/net/nettest/pipe_test.go
+++ b/net/memnet/pipe_test.go
@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-package nettest
+package memnet
 
 import (
 	"errors"
diff --git a/ssh/tailssh/tailssh_test.go b/ssh/tailssh/tailssh_test.go
index 2dec08ea7..2c0710003 100644
--- a/ssh/tailssh/tailssh_test.go
+++ b/ssh/tailssh/tailssh_test.go
@@ -32,7 +32,7 @@
 	gossh "github.com/tailscale/golang-x-crypto/ssh"
 	"tailscale.com/ipn/ipnlocal"
 	"tailscale.com/ipn/store/mem"
-	"tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/net/tsdial"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tempfork/gliderlabs/ssh"
@@ -429,7 +429,7 @@ func TestSSHAuthFlow(t *testing.T) {
 	src, dst := must.Get(netip.ParseAddrPort("100.100.100.101:2231")), must.Get(netip.ParseAddrPort("100.100.100.102:22"))
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			sc, dc := nettest.NewTCPConn(src, dst, 1024)
+			sc, dc := memnet.NewTCPConn(src, dst, 1024)
 			s.lb = tc.state
 			sshUser := "alice"
 			if tc.sshUser != "" {
diff --git a/tsnet/tsnet.go b/tsnet/tsnet.go
index b1a7b9259..a905a4d64 100644
--- a/tsnet/tsnet.go
+++ b/tsnet/tsnet.go
@@ -34,7 +34,7 @@
 	"tailscale.com/logpolicy"
 	"tailscale.com/logtail"
 	"tailscale.com/logtail/filch"
-	"tailscale.com/net/nettest"
+	"tailscale.com/net/memnet"
 	"tailscale.com/net/tsdial"
 	"tailscale.com/smallzstd"
 	"tailscale.com/types/logger"
@@ -380,8 +380,7 @@ func (s *Server) start() (reterr error) {
 
 	// Create an in-process listener.
 	// nettest.Listen provides a in-memory pipe based implementation for net.Conn.
-	// TODO(maisem): Rename nettest package to remove "test".
-	lal := nettest.Listen("local-tailscaled.sock:80")
+	lal := memnet.Listen("local-tailscaled.sock:80")
 	s.localAPIListener = lal
 	s.localClient = &tailscale.LocalClient{Dial: lal.Dial}
 	go func() {