exp/ssh: add simple tcpip.go functional tests

R=rsc, agl, n13m3y3r, bradfitz
CC=golang-dev
https://golang.org/cl/5385041

src/pkg/exp/ssh/tcpip_func_test.go

+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ssh
+
+// direct-tcpip functional tests
+
+import (
+	"net"
+	"net/http"
+	"testing"
+)
+
+func TestTCPIPHTTP(t *testing.T) {
+	if *sshuser == "" {
+		t.Log("ssh.user not defined, skipping test")
+		return
+	}
+	// google.com will generate at least one redirect, possibly three
+	// depending on your location.
+	doTest(t, "http://google.com")
+}
+
+func TestTCPIPHTTPS(t *testing.T) {
+	if *sshuser == "" {
+		t.Log("ssh.user not defined, skipping test")
+		return
+	}
+	doTest(t, "https://encrypted.google.com/")
+}
+
+func doTest(t *testing.T, url string) {
+	config := &ClientConfig{
+		User: *sshuser,
+		Auth: []ClientAuth{
+			ClientAuthPassword(password(*sshpass)),
+		},
+	}
+	conn, err := Dial("tcp", "localhost:22", config)
+	if err != nil {
+		t.Fatalf("Unable to connect: %s", err)
+	}
+	defer conn.Close()
+	tr := &http.Transport{
+		Dial: func(n, addr string) (net.Conn, error) {
+			return conn.Dial(n, addr)
+		},
+	}
+	client := &http.Client{
+		Transport: tr,
+	}
+	resp, err := client.Get(url)
+	if err != nil {
+		t.Fatalf("unable to proxy: %s", err)
+	}
+	// got a body without error
+	t.Log(resp)
+}