| 1 | package tunnelclient |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "net/http" |
| 8 | "net/http/httptest" |
| 9 | "testing" |
| 10 | "time" |
| 11 | |
| 12 | "golang.org/x/net/http2" |
| 13 | ) |
| 14 | |
| 15 | // fakeTunnelEdge accepts one registration, answers 101, then drives ONE h2 |
| 16 | // request over the inverted conn and returns the response body it read. |
| 17 | func fakeTunnelEdge(t *testing.T, wantToken, wantName string) (*httptest.Server, chan string) { |
| 18 | t.Helper() |
| 19 | got := make(chan string, 1) |
| 20 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 21 | if r.Header.Get("Authorization") != "Bearer "+wantToken || |
| 22 | r.Header.Get("Carlos-Tunnel-Name") != wantName { |
| 23 | http.Error(w, "unauthorized", http.StatusUnauthorized) |
| 24 | return |
| 25 | } |
| 26 | conn, bufrw, err := w.(http.Hijacker).Hijack() |
| 27 | if err != nil { |
| 28 | t.Errorf("hijack: %v", err) |
| 29 | return |
| 30 | } |
| 31 | fmt.Fprintf(bufrw, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: carlos-tunnel/1\r\nConnection: Upgrade\r\n\r\n") |
| 32 | bufrw.Flush() |
| 33 | cc, err := (&http2.Transport{}).NewClientConn(conn) |
| 34 | if err != nil { |
| 35 | t.Errorf("h2 client: %v", err) |
| 36 | return |
| 37 | } |
| 38 | req, _ := http.NewRequest("GET", "https://demo.example/hello", nil) |
| 39 | resp, err := cc.RoundTrip(req) |
| 40 | if err != nil { |
| 41 | t.Errorf("roundtrip over tunnel: %v", err) |
| 42 | got <- "" |
| 43 | return |
| 44 | } |
| 45 | body, _ := io.ReadAll(resp.Body) |
| 46 | got <- resp.Header.Get("X-From-Host") + ":" + string(body) |
| 47 | })) |
| 48 | return srv, got |
| 49 | } |
| 50 | |
| 51 | func TestDialAndServeInvertsConnection(t *testing.T) { |
| 52 | srv, got := fakeTunnelEdge(t, "sekrit", "pi-box") |
| 53 | defer srv.Close() |
| 54 | handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 55 | w.Header().Set("X-From-Host", r.Host) |
| 56 | fmt.Fprint(w, "pong") |
| 57 | }) |
| 58 | conn, err := Dial(context.Background(), srv.URL, "pi-box", "sekrit") |
| 59 | if err != nil { |
| 60 | t.Fatalf("Dial: %v", err) |
| 61 | } |
| 62 | go Serve(conn, handler) |
| 63 | if v := <-got; v != "demo.example:pong" { |
| 64 | t.Fatalf("over-tunnel response = %q, want demo.example:pong", v) |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | func TestDialRejectsNon101(t *testing.T) { |
| 69 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 70 | http.Error(w, "unauthorized", http.StatusUnauthorized) |
| 71 | })) |
| 72 | defer srv.Close() |
| 73 | if _, err := Dial(context.Background(), srv.URL, "pi-box", "wrong"); err == nil { |
| 74 | t.Fatal("want error on 401 handshake") |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | // A cancelled ctx must stop the loop from BOTH of its blocking positions: |
| 79 | // parked in backoff between dials (no edge at all), and parked in ServeConn on |
| 80 | // a live channel that is perfectly healthy. The second one is the load-bearing |
| 81 | // case — http2.Server.ServeConn has no stop signal of its own, so cancellation |
| 82 | // has to reach it by closing the conn — and it is what lets a test tear the |
| 83 | // fake host down deterministically instead of leaking a dialer for the rest of |
| 84 | // the run. |
| 85 | func TestLoopStopsOnContextCancel(t *testing.T) { |
| 86 | t.Run("while backing off", func(t *testing.T) { |
| 87 | // A server that is already gone: every dial is refused, so the loop |
| 88 | // spends essentially all of its time parked in wait(). |
| 89 | dead := httptest.NewServer(http.NotFoundHandler()) |
| 90 | url := dead.URL |
| 91 | dead.Close() |
| 92 | assertLoopReturns(t, url, nil) |
| 93 | }) |
| 94 | t.Run("while connected", func(t *testing.T) { |
| 95 | release := make(chan struct{}) |
| 96 | srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
| 97 | conn, bufrw, err := w.(http.Hijacker).Hijack() |
| 98 | if err != nil { |
| 99 | t.Errorf("hijack: %v", err) |
| 100 | return |
| 101 | } |
| 102 | fmt.Fprintf(bufrw, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: carlos-tunnel/1\r\nConnection: Upgrade\r\n\r\n") |
| 103 | bufrw.Flush() |
| 104 | // Hold the channel open from this side: the edge never hangs up, |
| 105 | // so the ONLY thing that can end ServeConn is cancellation |
| 106 | // closing the conn — which is the property under test. |
| 107 | <-release |
| 108 | conn.Close() |
| 109 | })) |
| 110 | // LIFO: release the fake edge's handler first, then shut it down. |
| 111 | defer srv.Close() |
| 112 | defer close(release) |
| 113 | assertLoopReturns(t, srv.URL, make(chan struct{}, 1)) |
| 114 | }) |
| 115 | } |
| 116 | |
| 117 | // assertLoopReturns runs Loop against url, waits for it to reach the state |
| 118 | // gate (connected, when connected is non-nil), cancels, and requires a prompt |
| 119 | // return. |
| 120 | func assertLoopReturns(t *testing.T, url string, connected chan struct{}) { |
| 121 | t.Helper() |
| 122 | ctx, cancel := context.WithCancel(context.Background()) |
| 123 | done := make(chan struct{}) |
| 124 | go func() { |
| 125 | defer close(done) |
| 126 | Loop(ctx, Config{ |
| 127 | URL: url, Name: "pi-box", Token: "sekrit", |
| 128 | Handler: http.NewServeMux(), |
| 129 | OnState: func(s string) { |
| 130 | if s == StateConnected && connected != nil { |
| 131 | select { |
| 132 | case connected <- struct{}{}: |
| 133 | default: |
| 134 | } |
| 135 | } |
| 136 | }, |
| 137 | Logf: func(string, ...any) {}, // the failing-dial case is noisy |
| 138 | }) |
| 139 | }() |
| 140 | if connected != nil { |
| 141 | select { |
| 142 | case <-connected: |
| 143 | case <-time.After(5 * time.Second): |
| 144 | cancel() |
| 145 | t.Fatal("loop never connected") |
| 146 | } |
| 147 | } |
| 148 | cancel() |
| 149 | select { |
| 150 | case <-done: |
| 151 | case <-time.After(5 * time.Second): |
| 152 | t.Fatal("Loop did not return after its context was cancelled") |
| 153 | } |
| 154 | } |
| 155 | |
amadan