| 1 | package forward |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "net" |
| 8 | "testing" |
| 9 | "time" |
| 10 | |
| 11 | "golang.org/x/crypto/ssh" |
| 12 | |
| 13 | "reasonix/internal/remote/sshtest" |
| 14 | ) |
| 15 | |
| 16 | // dialSSHClient connects to the sshtest server as a real ssh client. |
| 17 | func dialSSHClient(t *testing.T, srv *sshtest.Server) *ssh.Client { |
| 18 | t.Helper() |
| 19 | cfg := &ssh.ClientConfig{ |
| 20 | User: "test", |
| 21 | HostKeyCallback: ssh.InsecureIgnoreHostKey(), |
| 22 | Timeout: 5 * time.Second, |
| 23 | } |
| 24 | cl, err := ssh.Dial("tcp", srv.Addr, cfg) |
| 25 | if err != nil { |
| 26 | t.Fatalf("ssh dial: %v", err) |
| 27 | } |
| 28 | t.Cleanup(func() { cl.Close() }) |
| 29 | return cl |
| 30 | } |
| 31 | |
| 32 | // echoServer starts a local TCP echo server for -L target testing. |
| 33 | func echoServer(t *testing.T) string { |
| 34 | t.Helper() |
| 35 | ln, err := net.Listen("tcp", "127.0.0.1:0") |
| 36 | if err != nil { |
| 37 | t.Fatal(err) |
| 38 | } |
| 39 | t.Cleanup(func() { ln.Close() }) |
| 40 | go func() { |
| 41 | for { |
| 42 | c, err := ln.Accept() |
| 43 | if err != nil { |
| 44 | return |
| 45 | } |
| 46 | go func() { _, _ = io.Copy(c, c); c.Close() }() |
| 47 | } |
| 48 | }() |
| 49 | return ln.Addr().String() |
| 50 | } |
| 51 | |
| 52 | func TestLocalForwardEndToEnd(t *testing.T) { |
| 53 | srv := sshtest.Start(t, sshtest.Options{}) |
| 54 | cl := dialSSHClient(t, srv) |
| 55 | target := echoServer(t) |
| 56 | |
| 57 | set := NewSet(nil) |
| 58 | defer set.Close() |
| 59 | if err := set.Attach(cl); err != nil { |
| 60 | t.Fatalf("attach: %v", err) |
| 61 | } |
| 62 | bound, err := set.Add(Spec{Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: target}) |
| 63 | if err != nil { |
| 64 | t.Fatalf("add local forward: %v", err) |
| 65 | } |
| 66 | if bound == "" { |
| 67 | t.Fatal("no bound address") |
| 68 | } |
| 69 | |
| 70 | conn, err := net.Dial("tcp", bound) |
| 71 | if err != nil { |
| 72 | t.Fatalf("dial forward: %v", err) |
| 73 | } |
| 74 | defer conn.Close() |
| 75 | if _, err := conn.Write([]byte("ping")); err != nil { |
| 76 | t.Fatal(err) |
| 77 | } |
| 78 | buf := make([]byte, 4) |
| 79 | _ = conn.SetReadDeadline(time.Now().Add(5 * time.Second)) |
| 80 | if _, err := io.ReadFull(conn, buf); err != nil { |
| 81 | t.Fatalf("read echo: %v", err) |
| 82 | } |
| 83 | if string(buf) != "ping" { |
| 84 | t.Fatalf("echo = %q, want ping", buf) |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | func TestLocalListenerPersistsAcrossReattach(t *testing.T) { |
| 89 | srv := sshtest.Start(t, sshtest.Options{}) |
| 90 | target := echoServer(t) |
| 91 | |
| 92 | set := NewSet(nil) |
| 93 | defer set.Close() |
| 94 | cl1 := dialSSHClient(t, srv) |
| 95 | if err := set.Attach(cl1); err != nil { |
| 96 | t.Fatal(err) |
| 97 | } |
| 98 | bound, err := set.Add(Spec{Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: target}) |
| 99 | if err != nil { |
| 100 | t.Fatal(err) |
| 101 | } |
| 102 | |
| 103 | // Simulate a connection drop then reconnect on a new client. |
| 104 | set.Detach() |
| 105 | cl2 := dialSSHClient(t, srv) |
| 106 | if err := set.Attach(cl2); err != nil { |
| 107 | t.Fatal(err) |
| 108 | } |
| 109 | |
| 110 | // The bound address must be unchanged (listener stayed open). |
| 111 | entries := set.List() |
| 112 | if len(entries) != 1 || entries[0].BoundAddr != bound { |
| 113 | t.Fatalf("bound address changed across reattach: %+v (was %s)", entries, bound) |
| 114 | } |
| 115 | |
| 116 | // And traffic works again through the new connection. |
| 117 | conn, err := net.Dial("tcp", bound) |
| 118 | if err != nil { |
| 119 | t.Fatalf("dial after reattach: %v", err) |
| 120 | } |
| 121 | defer conn.Close() |
| 122 | _, _ = conn.Write([]byte("pong")) |
| 123 | buf := make([]byte, 4) |
| 124 | _ = conn.SetReadDeadline(time.Now().Add(5 * time.Second)) |
| 125 | if _, err := io.ReadFull(conn, buf); err != nil { |
| 126 | t.Fatalf("read echo after reattach: %v", err) |
| 127 | } |
| 128 | if string(buf) != "pong" { |
| 129 | t.Fatalf("echo = %q", buf) |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | func TestDuplicateForwardRejected(t *testing.T) { |
| 134 | set := NewSet(nil) |
| 135 | defer set.Close() |
| 136 | spec := Spec{Name: "web", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: "svc:80"} |
| 137 | if _, err := set.Add(spec); err != nil { |
| 138 | t.Fatal(err) |
| 139 | } |
| 140 | if _, err := set.Add(spec); !errors.Is(err, ErrDuplicateForward) { |
| 141 | t.Fatalf("second add err = %v, want ErrDuplicateForward", err) |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | func TestReplaceSwapsLiveForwardAfterReplacementStarts(t *testing.T) { |
| 146 | srv := sshtest.Start(t, sshtest.Options{}) |
| 147 | cl := dialSSHClient(t, srv) |
| 148 | firstTarget := echoServer(t) |
| 149 | secondTarget := echoServer(t) |
| 150 | set := NewSet(nil) |
| 151 | defer set.Close() |
| 152 | if err := set.Attach(cl); err != nil { |
| 153 | t.Fatal(err) |
| 154 | } |
| 155 | firstBound, err := set.Add(Spec{Name: "serve", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: firstTarget}) |
| 156 | if err != nil { |
| 157 | t.Fatal(err) |
| 158 | } |
| 159 | secondBound, err := set.Replace(Spec{Name: "serve", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: secondTarget}) |
| 160 | if err != nil { |
| 161 | t.Fatal(err) |
| 162 | } |
| 163 | if firstBound == secondBound { |
| 164 | t.Fatalf("replacement reused old listener %q", firstBound) |
| 165 | } |
| 166 | entries := set.List() |
| 167 | if len(entries) != 1 || entries[0].Spec.TargetAddr != secondTarget || !entries[0].Up { |
| 168 | t.Fatalf("replacement registry = %+v", entries) |
| 169 | } |
| 170 | if conn, err := net.DialTimeout("tcp", firstBound, 100*time.Millisecond); err == nil { |
| 171 | _ = conn.Close() |
| 172 | t.Fatalf("old listener %q is still accepting", firstBound) |
| 173 | } |
| 174 | conn, err := net.Dial("tcp", secondBound) |
| 175 | if err != nil { |
| 176 | t.Fatalf("dial replacement: %v", err) |
| 177 | } |
| 178 | _ = conn.Close() |
| 179 | } |
| 180 | |
| 181 | func TestReplaceFailurePreservesExistingForward(t *testing.T) { |
| 182 | srv := sshtest.Start(t, sshtest.Options{}) |
| 183 | cl := dialSSHClient(t, srv) |
| 184 | target := echoServer(t) |
| 185 | occupied, err := net.Listen("tcp", "127.0.0.1:0") |
| 186 | if err != nil { |
| 187 | t.Fatal(err) |
| 188 | } |
| 189 | defer occupied.Close() |
| 190 | set := NewSet(nil) |
| 191 | defer set.Close() |
| 192 | if err := set.Attach(cl); err != nil { |
| 193 | t.Fatal(err) |
| 194 | } |
| 195 | bound, err := set.Add(Spec{Name: "serve", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: target}) |
| 196 | if err != nil { |
| 197 | t.Fatal(err) |
| 198 | } |
| 199 | if _, err := set.Replace(Spec{Name: "serve", Direction: Local, BindAddr: occupied.Addr().String(), TargetAddr: "other:80"}); err == nil { |
| 200 | t.Fatal("Replace unexpectedly bound an occupied address") |
| 201 | } |
| 202 | entries := set.List() |
| 203 | if len(entries) != 1 || entries[0].BoundAddr != bound || entries[0].Spec.TargetAddr != target || !entries[0].Up { |
| 204 | t.Fatalf("failed replacement disturbed existing forward: %+v", entries) |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | func TestReplaceWhileDetachedPreservesExistingForward(t *testing.T) { |
| 209 | set := NewSet(nil) |
| 210 | defer set.Close() |
| 211 | old := Spec{Name: "serve", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: "old:80"} |
| 212 | if _, err := set.Add(old); err != nil { |
| 213 | t.Fatal(err) |
| 214 | } |
| 215 | if _, err := set.Replace(Spec{Name: "serve", Direction: Local, BindAddr: "127.0.0.1:0", TargetAddr: "new:80"}); !errors.Is(err, ErrNotAttached) { |
| 216 | t.Fatalf("Replace error = %v, want ErrNotAttached", err) |
| 217 | } |
| 218 | entries := set.List() |
| 219 | if len(entries) != 1 || entries[0].Spec.TargetAddr != old.TargetAddr { |
| 220 | t.Fatalf("detached replacement disturbed old forward: %+v", entries) |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | func TestBindBusyReported(t *testing.T) { |
| 225 | srv := sshtest.Start(t, sshtest.Options{}) |
| 226 | cl := dialSSHClient(t, srv) |
| 227 | // Occupy a port. |
| 228 | occupied, err := net.Listen("tcp", "127.0.0.1:0") |
| 229 | if err != nil { |
| 230 | t.Fatal(err) |
| 231 | } |
| 232 | defer occupied.Close() |
| 233 | busyAddr := occupied.Addr().String() |
| 234 | |
| 235 | set := NewSet(nil) |
| 236 | defer set.Close() |
| 237 | if err := set.Attach(cl); err != nil { |
| 238 | t.Fatal(err) |
| 239 | } |
| 240 | _, err = set.Add(Spec{Direction: Local, BindAddr: busyAddr, TargetAddr: "svc:80"}) |
| 241 | if err == nil { |
| 242 | t.Fatal("expected bind-busy error") |
| 243 | } |
| 244 | if !errors.Is(err, ErrBindBusy) { |
| 245 | t.Fatalf("err = %v, want ErrBindBusy", err) |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | func TestRemoteForwardEndToEnd(t *testing.T) { |
| 250 | srv := sshtest.Start(t, sshtest.Options{}) |
| 251 | cl := dialSSHClient(t, srv) |
| 252 | target := echoServer(t) |
| 253 | |
| 254 | events := make(chan Event, 8) |
| 255 | set := NewSet(func(e Event) { events <- e }) |
| 256 | defer set.Close() |
| 257 | if err := set.Attach(cl); err != nil { |
| 258 | t.Fatal(err) |
| 259 | } |
| 260 | // -R: sshtest listens on its side and forwards back to our local target. |
| 261 | if _, err := set.Add(Spec{Direction: Remote, BindAddr: "127.0.0.1:0", TargetAddr: target}); err != nil { |
| 262 | t.Fatalf("add remote forward: %v", err) |
| 263 | } |
| 264 | |
| 265 | // Find the remote bound address from the registry. |
| 266 | var bound string |
| 267 | deadline := time.After(5 * time.Second) |
| 268 | for bound == "" { |
| 269 | select { |
| 270 | case <-deadline: |
| 271 | t.Fatal("remote forward never came up") |
| 272 | default: |
| 273 | } |
| 274 | for _, e := range set.List() { |
| 275 | if e.Up { |
| 276 | bound = e.BoundAddr |
| 277 | } |
| 278 | } |
| 279 | if bound == "" { |
| 280 | time.Sleep(20 * time.Millisecond) |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | conn, err := net.Dial("tcp", bound) |
| 285 | if err != nil { |
| 286 | t.Fatalf("dial remote-forward bind: %v", err) |
| 287 | } |
| 288 | defer conn.Close() |
| 289 | _, _ = conn.Write([]byte("rrrr")) |
| 290 | buf := make([]byte, 4) |
| 291 | _ = conn.SetReadDeadline(time.Now().Add(5 * time.Second)) |
| 292 | if _, err := io.ReadFull(conn, buf); err != nil { |
| 293 | t.Fatalf("read echo via -R: %v", err) |
| 294 | } |
| 295 | if string(buf) != "rrrr" { |
| 296 | t.Fatalf("echo = %q", buf) |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | // A remote listener that dies under an attached Set must clear Up. Leaving the |
| 301 | // entry marked Up with a dead BoundAddr makes credential-proxy ensure reuse the |
| 302 | // stale port and the remote serve dials connection refused forever. |
| 303 | func TestRemoteForwardAcceptExitMarksDown(t *testing.T) { |
| 304 | srv := sshtest.Start(t, sshtest.Options{}) |
| 305 | cl := dialSSHClient(t, srv) |
| 306 | target := echoServer(t) |
| 307 | |
| 308 | set := NewSet(nil) |
| 309 | defer set.Close() |
| 310 | if err := set.Attach(cl); err != nil { |
| 311 | t.Fatal(err) |
| 312 | } |
| 313 | if _, err := set.Add(Spec{Name: "cred", Direction: Remote, BindAddr: "127.0.0.1:0", TargetAddr: target}); err != nil { |
| 314 | t.Fatalf("add remote forward: %v", err) |
| 315 | } |
| 316 | deadline := time.After(5 * time.Second) |
| 317 | for { |
| 318 | entries := set.List() |
| 319 | if len(entries) == 1 && entries[0].Up && entries[0].BoundAddr != "" { |
| 320 | break |
| 321 | } |
| 322 | select { |
| 323 | case <-deadline: |
| 324 | t.Fatalf("remote forward never came up: %+v", entries) |
| 325 | case <-time.After(20 * time.Millisecond): |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | // Close the SSH client without Detach: Accept returns, and the registry |
| 330 | // must not keep advertising the dead listener as Up. |
| 331 | _ = cl.Close() |
| 332 | deadline = time.After(5 * time.Second) |
| 333 | for { |
| 334 | entries := set.List() |
| 335 | if len(entries) == 1 && !entries[0].Up { |
| 336 | return |
| 337 | } |
| 338 | select { |
| 339 | case <-deadline: |
| 340 | t.Fatalf("dead remote forward still Up: %+v", entries) |
| 341 | case <-time.After(20 * time.Millisecond): |
| 342 | } |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | var _ = fmt.Sprintf |
| 347 |