diff --git a/ipn/ipn_clone.go b/ipn/ipn_clone.go index 8a0a3c833..3d2670947 100644 --- a/ipn/ipn_clone.go +++ b/ipn/ipn_clone.go @@ -242,6 +242,7 @@ var _HTTPHandlerCloneNeedsRegeneration = HTTPHandler(struct { Proxy string Text string AcceptAppCaps []tailcfg.PeerCapability + Redirect string }{}) // Clone makes a deep copy of WebServerConfig. diff --git a/ipn/ipn_view.go b/ipn/ipn_view.go index 61d0dec23..ba5477a6d 100644 --- a/ipn/ipn_view.go +++ b/ipn/ipn_view.go @@ -896,12 +896,22 @@ func (v HTTPHandlerView) AcceptAppCaps() views.Slice[tailcfg.PeerCapability] { return views.SliceOf(v.ж.AcceptAppCaps) } +// Redirect, if not empty, is the target URL to redirect requests to. +// By default, we redirect with HTTP 302 (Found) status. +// If Redirect starts with ':', then we use that status instead. +// +// The target URL supports the following expansion variables: +// - ${HOST}: replaced with the request's Host header value +// - ${REQUEST_URI}: replaced with the request's full URI (path and query string) +func (v HTTPHandlerView) Redirect() string { return v.ж.Redirect } + // A compilation failure here means this code must be regenerated, with the command at the top of this file. var _HTTPHandlerViewNeedsRegeneration = HTTPHandler(struct { Path string Proxy string Text string AcceptAppCaps []tailcfg.PeerCapability + Redirect string }{}) // View returns a read-only view of WebServerConfig. diff --git a/ipn/ipnlocal/serve.go b/ipn/ipnlocal/serve.go index eb2c932c0..554761ed7 100644 --- a/ipn/ipnlocal/serve.go +++ b/ipn/ipnlocal/serve.go @@ -966,6 +966,19 @@ func (b *LocalBackend) addAppCapabilitiesHeader(r *httputil.ProxyRequest) error return nil } +// parseRedirectWithCode parses a redirect string that may optionally start with +// a HTTP redirect status code ("3xx:"). +// Returns the status code and the final redirect URL. +// If no code prefix is found, returns http.StatusFound (302). +func parseRedirectWithCode(redirect string) (code int, url string) { + if len(redirect) >= 4 && redirect[3] == ':' { + if statusCode, err := strconv.Atoi(redirect[:3]); err == nil && statusCode >= 300 && statusCode <= 399 { + return statusCode, redirect[4:] + } + } + return http.StatusFound, redirect +} + // serveWebHandler is an http.HandlerFunc that maps incoming requests to the // correct *http. func (b *LocalBackend) serveWebHandler(w http.ResponseWriter, r *http.Request) { @@ -979,6 +992,13 @@ func (b *LocalBackend) serveWebHandler(w http.ResponseWriter, r *http.Request) { io.WriteString(w, s) return } + if v := h.Redirect(); v != "" { + code, v := parseRedirectWithCode(v) + v = strings.ReplaceAll(v, "${HOST}", r.Host) + v = strings.ReplaceAll(v, "${REQUEST_URI}", r.RequestURI) + http.Redirect(w, r, v, code) + return + } if v := h.Path(); v != "" { b.serveFileOrDirectory(w, r, v, mountPoint) return diff --git a/ipn/ipnlocal/serve_test.go b/ipn/ipnlocal/serve_test.go index a72c50c1f..c3e5b2ff9 100644 --- a/ipn/ipnlocal/serve_test.go +++ b/ipn/ipnlocal/serve_test.go @@ -72,6 +72,41 @@ func TestExpandProxyArg(t *testing.T) { } } +func TestParseRedirectWithRedirectCode(t *testing.T) { + tests := []struct { + in string + wantCode int + wantURL string + }{ + {"301:https://example.com", 301, "https://example.com"}, + {"302:https://example.com", 302, "https://example.com"}, + {"303:/path", 303, "/path"}, + {"307:https://example.com/path?query=1", 307, "https://example.com/path?query=1"}, + {"308:https://example.com", 308, "https://example.com"}, + + {"https://example.com", 302, "https://example.com"}, + {"/path", 302, "/path"}, + {"http://example.com", 302, "http://example.com"}, + {"git://example.com", 302, "git://example.com"}, + + {"200:https://example.com", 302, "200:https://example.com"}, + {"404:https://example.com", 302, "404:https://example.com"}, + {"500:https://example.com", 302, "500:https://example.com"}, + {"30:https://example.com", 302, "30:https://example.com"}, + {"3:https://example.com", 302, "3:https://example.com"}, + {"3012:https://example.com", 302, "3012:https://example.com"}, + {"abc:https://example.com", 302, "abc:https://example.com"}, + {"301", 302, "301"}, + } + for _, tt := range tests { + gotCode, gotURL := parseRedirectWithCode(tt.in) + if gotCode != tt.wantCode || gotURL != tt.wantURL { + t.Errorf("parseRedirectWithCode(%q) = (%d, %q), want (%d, %q)", + tt.in, gotCode, gotURL, tt.wantCode, tt.wantURL) + } + } +} + func TestGetServeHandler(t *testing.T) { const serverName = "example.ts.net" conf1 := &ipn.ServeConfig{ @@ -1327,3 +1362,95 @@ func TestServeGRPCProxy(t *testing.T) { }) } } + +func TestServeHTTPRedirect(t *testing.T) { + b := newTestBackend(t) + + tests := []struct { + host string + path string + redirect string + reqURI string + wantCode int + wantLoc string + }{ + { + host: "hardcoded-root", + path: "/", + redirect: "https://example.com/", + reqURI: "/old", + wantCode: http.StatusFound, // 302 is the default + wantLoc: "https://example.com/", + }, + { + host: "template-host-and-uri", + path: "/", + redirect: "https://${HOST}${REQUEST_URI}", + reqURI: "/path?foo=bar", + wantCode: http.StatusFound, // 302 is the default + wantLoc: "https://template-host-and-uri/path?foo=bar", + }, + { + host: "custom-301", + path: "/", + redirect: "301:https://example.com/", + reqURI: "/old", + wantCode: http.StatusMovedPermanently, // 301 + wantLoc: "https://example.com/", + }, + { + host: "custom-307", + path: "/", + redirect: "307:https://example.com/new", + reqURI: "/old", + wantCode: http.StatusTemporaryRedirect, // 307 + wantLoc: "https://example.com/new", + }, + { + host: "custom-308", + path: "/", + redirect: "308:https://example.com/permanent", + reqURI: "/old", + wantCode: http.StatusPermanentRedirect, // 308 + wantLoc: "https://example.com/permanent", + }, + } + + for _, tt := range tests { + t.Run(tt.host, func(t *testing.T) { + conf := &ipn.ServeConfig{ + Web: map[ipn.HostPort]*ipn.WebServerConfig{ + ipn.HostPort(tt.host + ":80"): { + Handlers: map[string]*ipn.HTTPHandler{ + tt.path: {Redirect: tt.redirect}, + }, + }, + }, + } + if err := b.SetServeConfig(conf, ""); err != nil { + t.Fatal(err) + } + + req := &http.Request{ + Host: tt.host, + URL: &url.URL{Path: tt.path}, + RequestURI: tt.reqURI, + TLS: &tls.ConnectionState{ServerName: tt.host}, + } + req = req.WithContext(serveHTTPContextKey.WithValue(req.Context(), &serveHTTPContext{ + DestPort: 80, + SrcAddr: netip.MustParseAddrPort("1.2.3.4:1234"), + })) + + w := httptest.NewRecorder() + b.serveWebHandler(w, req) + + if w.Code != tt.wantCode { + t.Errorf("got status %d, want %d", w.Code, tt.wantCode) + } + if got := w.Header().Get("Location"); got != tt.wantLoc { + t.Errorf("got Location %q, want %q", got, tt.wantLoc) + } + }) + } +} diff --git a/ipn/serve.go b/ipn/serve.go index 3f674d9ed..2ac37a141 100644 --- a/ipn/serve.go +++ b/ipn/serve.go @@ -162,8 +162,17 @@ type HTTPHandler struct { AcceptAppCaps []tailcfg.PeerCapability `json:",omitempty"` // peer capabilities to forward in grant header, e.g. example.com/cap/mon + // Redirect, if not empty, is the target URL to redirect requests to. + // By default, we redirect with HTTP 302 (Found) status. + // If Redirect starts with ':', then we use that status instead. + // + // The target URL supports the following expansion variables: + // - ${HOST}: replaced with the request's Host header value + // - ${REQUEST_URI}: replaced with the request's full URI (path and query string) + Redirect string `json:",omitempty"` + // TODO(bradfitz): bool to not enumerate directories? TTL on mapping for - // temporary ones? Error codes? Redirects? + // temporary ones? Error codes? } // WebHandlerExists reports whether if the ServeConfig Web handler exists for