From 5bcbb2980be0c565088e8cdabddb0fb2d08e1fad Mon Sep 17 00:00:00 2001 From: Felix Lange Date: Thu, 20 Jan 2022 12:45:07 +0100 Subject: [PATCH] rpc: add PeerInfo (#24255) This replaces the sketchy and undocumented string context keys for HTTP requests with a defined interface. Using string keys with context is discouraged because they may clash with keys created by other packages. We added these keys to make connection metadata available in the signer, so this change also updates signer/core to use the new PeerInfo API. --- rpc/client.go | 52 +++++++++++++---------------------------- rpc/http.go | 30 ++++++++++++++---------- rpc/http_test.go | 36 ++++++++++++++++++++++++++++ rpc/json.go | 5 ++++ rpc/server.go | 35 +++++++++++++++++++++++++++ rpc/server_test.go | 2 +- rpc/testservice_test.go | 4 ++++ rpc/types.go | 2 ++ rpc/websocket.go | 20 +++++++++++++--- rpc/websocket_test.go | 35 +++++++++++++++++++++++++++ signer/core/api.go | 26 +++++++++++---------- 11 files changed, 183 insertions(+), 64 deletions(-) diff --git a/rpc/client.go b/rpc/client.go index e43760c22c..d55af75545 100644 --- a/rpc/client.go +++ b/rpc/client.go @@ -58,12 +58,6 @@ const ( maxClientSubscriptionBuffer = 20000 ) -const ( - httpScheme = "http" - wsScheme = "ws" - ipcScheme = "ipc" -) - // BatchElem is an element in a batch request. type BatchElem struct { Method string @@ -80,7 +74,7 @@ type BatchElem struct { // Client represents a connection to an RPC server. type Client struct { idgen func() ID // for subscriptions - scheme string // connection type: http, ws or ipc + isHTTP bool // connection type: http, ws or ipc services *serviceRegistry idCounter uint32 @@ -115,11 +109,9 @@ type clientConn struct { } func (c *Client) newClientConn(conn ServerCodec) *clientConn { - ctx := context.WithValue(context.Background(), clientContextKey{}, c) - // Http connections have already set the scheme - if !c.isHTTP() && c.scheme != "" { - ctx = context.WithValue(ctx, "scheme", c.scheme) - } + ctx := context.Background() + ctx = context.WithValue(ctx, clientContextKey{}, c) + ctx = context.WithValue(ctx, peerInfoContextKey{}, conn.peerInfo()) handler := newHandler(ctx, conn, c.idgen, c.services) return &clientConn{conn, handler} } @@ -145,7 +137,7 @@ func (op *requestOp) wait(ctx context.Context, c *Client) (*jsonrpcMessage, erro select { case <-ctx.Done(): // Send the timeout to dispatch so it can remove the request IDs. - if !c.isHTTP() { + if !c.isHTTP { select { case c.reqTimeout <- op: case <-c.closing: @@ -212,18 +204,10 @@ func newClient(initctx context.Context, connect reconnectFunc) (*Client, error) } func initClient(conn ServerCodec, idgen func() ID, services *serviceRegistry) *Client { - scheme := "" - switch conn.(type) { - case *httpConn: - scheme = httpScheme - case *websocketCodec: - scheme = wsScheme - case *jsonCodec: - scheme = ipcScheme - } + _, isHTTP := conn.(*httpConn) c := &Client{ + isHTTP: isHTTP, idgen: idgen, - scheme: scheme, services: services, writeConn: conn, close: make(chan struct{}), @@ -236,7 +220,7 @@ func initClient(conn ServerCodec, idgen func() ID, services *serviceRegistry) *C reqSent: make(chan error, 1), reqTimeout: make(chan *requestOp), } - if !c.isHTTP() { + if !isHTTP { go c.dispatch(conn) } return c @@ -267,7 +251,7 @@ func (c *Client) SupportedModules() (map[string]string, error) { // Close closes the client, aborting any in-flight requests. func (c *Client) Close() { - if c.isHTTP() { + if c.isHTTP { return } select { @@ -281,7 +265,7 @@ func (c *Client) Close() { // This method only works for clients using HTTP, it doesn't have // any effect for clients using another transport. func (c *Client) SetHeader(key, value string) { - if !c.isHTTP() { + if !c.isHTTP { return } conn := c.writeConn.(*httpConn) @@ -315,7 +299,7 @@ func (c *Client) CallContext(ctx context.Context, result interface{}, method str } op := &requestOp{ids: []json.RawMessage{msg.ID}, resp: make(chan *jsonrpcMessage, 1)} - if c.isHTTP() { + if c.isHTTP { err = c.sendHTTP(ctx, op, msg) } else { err = c.send(ctx, op, msg) @@ -378,7 +362,7 @@ func (c *Client) BatchCallContext(ctx context.Context, b []BatchElem) error { } var err error - if c.isHTTP() { + if c.isHTTP { err = c.sendBatchHTTP(ctx, op, msgs) } else { err = c.send(ctx, op, msgs) @@ -417,7 +401,7 @@ func (c *Client) Notify(ctx context.Context, method string, args ...interface{}) } msg.ID = nil - if c.isHTTP() { + if c.isHTTP { return c.sendHTTP(ctx, op, msg) } return c.send(ctx, op, msg) @@ -450,12 +434,12 @@ func (c *Client) Subscribe(ctx context.Context, namespace string, channel interf // Check type of channel first. chanVal := reflect.ValueOf(channel) if chanVal.Kind() != reflect.Chan || chanVal.Type().ChanDir()&reflect.SendDir == 0 { - panic("first argument to Subscribe must be a writable channel") + panic(fmt.Sprintf("channel argument of Subscribe has type %T, need writable channel", channel)) } if chanVal.IsNil() { panic("channel given to Subscribe must not be nil") } - if c.isHTTP() { + if c.isHTTP { return nil, ErrNotificationsUnsupported } @@ -509,8 +493,8 @@ func (c *Client) send(ctx context.Context, op *requestOp, msg interface{}) error } func (c *Client) write(ctx context.Context, msg interface{}, retry bool) error { - // The previous write failed. Try to establish a new connection. if c.writeConn == nil { + // The previous write failed. Try to establish a new connection. if err := c.reconnect(ctx); err != nil { return err } @@ -657,7 +641,3 @@ func (c *Client) read(codec ServerCodec) { c.readOp <- readOp{msgs, batch} } } - -func (c *Client) isHTTP() bool { - return c.scheme == httpScheme -} diff --git a/rpc/http.go b/rpc/http.go index 32f4e7d90a..9c5a5cc0f2 100644 --- a/rpc/http.go +++ b/rpc/http.go @@ -48,11 +48,18 @@ type httpConn struct { headers http.Header } -// httpConn is treated specially by Client. +// httpConn implements ServerCodec, but it is treated specially by Client +// and some methods don't work. The panic() stubs here exist to ensure +// this special treatment is correct. + func (hc *httpConn) writeJSON(context.Context, interface{}) error { panic("writeJSON called on httpConn") } +func (hc *httpConn) peerInfo() PeerInfo { + panic("peerInfo called on httpConn") +} + func (hc *httpConn) remoteAddr() string { return hc.url } @@ -236,20 +243,19 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) { http.Error(w, err.Error(), code) return } + + // Create request-scoped context. + connInfo := PeerInfo{Transport: "http", RemoteAddr: r.RemoteAddr} + connInfo.HTTP.Version = r.Proto + connInfo.HTTP.Host = r.Host + connInfo.HTTP.Origin = r.Header.Get("Origin") + connInfo.HTTP.UserAgent = r.Header.Get("User-Agent") + ctx := r.Context() + ctx = context.WithValue(ctx, peerInfoContextKey{}, connInfo) + // All checks passed, create a codec that reads directly from the request body // until EOF, writes the response to w, and orders the server to process a // single request. - ctx := r.Context() - ctx = context.WithValue(ctx, "remote", r.RemoteAddr) - ctx = context.WithValue(ctx, "scheme", r.Proto) - ctx = context.WithValue(ctx, "local", r.Host) - if ua := r.Header.Get("User-Agent"); ua != "" { - ctx = context.WithValue(ctx, "User-Agent", ua) - } - if origin := r.Header.Get("Origin"); origin != "" { - ctx = context.WithValue(ctx, "Origin", origin) - } - w.Header().Set("content-type", contentType) codec := newHTTPServerConn(r, w) defer codec.close() diff --git a/rpc/http_test.go b/rpc/http_test.go index 97f8d44c39..c84d7705f2 100644 --- a/rpc/http_test.go +++ b/rpc/http_test.go @@ -162,3 +162,39 @@ func TestHTTPErrorResponse(t *testing.T) { t.Error("unexpected error message", errMsg) } } + +func TestHTTPPeerInfo(t *testing.T) { + s := newTestServer() + defer s.Stop() + ts := httptest.NewServer(s) + defer ts.Close() + + c, err := Dial(ts.URL) + if err != nil { + t.Fatal(err) + } + c.SetHeader("user-agent", "ua-testing") + c.SetHeader("origin", "origin.example.com") + + // Request peer information. + var info PeerInfo + if err := c.Call(&info, "test_peerInfo"); err != nil { + t.Fatal(err) + } + + if info.RemoteAddr == "" { + t.Error("RemoteAddr not set") + } + if info.Transport != "http" { + t.Errorf("wrong Transport %q", info.Transport) + } + if info.HTTP.Version != "HTTP/1.1" { + t.Errorf("wrong HTTP.Version %q", info.HTTP.Version) + } + if info.HTTP.UserAgent != "ua-testing" { + t.Errorf("wrong HTTP.UserAgent %q", info.HTTP.UserAgent) + } + if info.HTTP.Origin != "origin.example.com" { + t.Errorf("wrong HTTP.Origin %q", info.HTTP.UserAgent) + } +} diff --git a/rpc/json.go b/rpc/json.go index 1daee3db82..6024f1e7dc 100644 --- a/rpc/json.go +++ b/rpc/json.go @@ -198,6 +198,11 @@ func NewCodec(conn Conn) ServerCodec { return NewFuncCodec(conn, enc.Encode, dec.Decode) } +func (c *jsonCodec) peerInfo() PeerInfo { + // This returns "ipc" because all other built-in transports have a separate codec type. + return PeerInfo{Transport: "ipc", RemoteAddr: c.remote} +} + func (c *jsonCodec) remoteAddr() string { return c.remote } diff --git a/rpc/server.go b/rpc/server.go index 64e078a7fd..e2d5c03835 100644 --- a/rpc/server.go +++ b/rpc/server.go @@ -145,3 +145,38 @@ func (s *RPCService) Modules() map[string]string { } return modules } + +// PeerInfo contains information about the remote end of the network connection. +// +// This is available within RPC method handlers through the context. Call +// PeerInfoFromContext to get information about the client connection related to +// the current method call. +type PeerInfo struct { + // Transport is name of the protocol used by the client. + // This can be "http", "ws" or "ipc". + Transport string + + // Address of client. This will usually contain the IP address and port. + RemoteAddr string + + // Addditional information for HTTP and WebSocket connections. + HTTP struct { + // Protocol version, i.e. "HTTP/1.1". This is not set for WebSocket. + Version string + // Header values sent by the client. + UserAgent string + Origin string + Host string + } +} + +type peerInfoContextKey struct{} + +// PeerInfoFromContext returns information about the client's network connection. +// Use this with the context passed to RPC method handler functions. +// +// The zero value is returned if no connection info is present in ctx. +func PeerInfoFromContext(ctx context.Context) PeerInfo { + info, _ := ctx.Value(peerInfoContextKey{}).(PeerInfo) + return info +} diff --git a/rpc/server_test.go b/rpc/server_test.go index 6a2b09e449..c692a071cf 100644 --- a/rpc/server_test.go +++ b/rpc/server_test.go @@ -45,7 +45,7 @@ func TestServerRegisterName(t *testing.T) { t.Fatalf("Expected service calc to be registered") } - wantCallbacks := 9 + wantCallbacks := 10 if len(svc.callbacks) != wantCallbacks { t.Errorf("Expected %d callbacks for service 'service', got %d", wantCallbacks, len(svc.callbacks)) } diff --git a/rpc/testservice_test.go b/rpc/testservice_test.go index 62afc1df44..253e263289 100644 --- a/rpc/testservice_test.go +++ b/rpc/testservice_test.go @@ -80,6 +80,10 @@ func (s *testService) EchoWithCtx(ctx context.Context, str string, i int, args * return echoResult{str, i, args} } +func (s *testService) PeerInfo(ctx context.Context) PeerInfo { + return PeerInfoFromContext(ctx) +} + func (s *testService) Sleep(ctx context.Context, duration time.Duration) { time.Sleep(duration) } diff --git a/rpc/types.go b/rpc/types.go index ca52d474d9..959e383723 100644 --- a/rpc/types.go +++ b/rpc/types.go @@ -40,8 +40,10 @@ type API struct { // a RPC session. Implementations must be go-routine safe since the codec can be called in // multiple go-routines concurrently. type ServerCodec interface { + peerInfo() PeerInfo readBatch() (msgs []*jsonrpcMessage, isBatch bool, err error) close() + jsonWriter } diff --git a/rpc/websocket.go b/rpc/websocket.go index 5571324af8..28380d8aa4 100644 --- a/rpc/websocket.go +++ b/rpc/websocket.go @@ -60,7 +60,7 @@ func (s *Server) WebsocketHandler(allowedOrigins []string) http.Handler { log.Debug("WebSocket upgrade failed", "err", err) return } - codec := newWebsocketCodec(conn) + codec := newWebsocketCodec(conn, r.Host, r.Header) s.ServeCodec(codec, 0) }) } @@ -197,7 +197,7 @@ func DialWebsocketWithDialer(ctx context.Context, endpoint, origin string, diale } return nil, hErr } - return newWebsocketCodec(conn), nil + return newWebsocketCodec(conn, endpoint, header), nil }) } @@ -235,12 +235,13 @@ func wsClientHeaders(endpoint, origin string) (string, http.Header, error) { type websocketCodec struct { *jsonCodec conn *websocket.Conn + info PeerInfo wg sync.WaitGroup pingReset chan struct{} } -func newWebsocketCodec(conn *websocket.Conn) ServerCodec { +func newWebsocketCodec(conn *websocket.Conn, host string, req http.Header) ServerCodec { conn.SetReadLimit(wsMessageSizeLimit) conn.SetPongHandler(func(appData string) error { conn.SetReadDeadline(time.Time{}) @@ -250,7 +251,16 @@ func newWebsocketCodec(conn *websocket.Conn) ServerCodec { jsonCodec: NewFuncCodec(conn, conn.WriteJSON, conn.ReadJSON).(*jsonCodec), conn: conn, pingReset: make(chan struct{}, 1), + info: PeerInfo{ + Transport: "ws", + RemoteAddr: conn.RemoteAddr().String(), + }, } + // Fill in connection details. + wc.info.HTTP.Host = host + wc.info.HTTP.Origin = req.Get("Origin") + wc.info.HTTP.UserAgent = req.Get("User-Agent") + // Start pinger. wc.wg.Add(1) go wc.pingLoop() return wc @@ -261,6 +271,10 @@ func (wc *websocketCodec) close() { wc.wg.Wait() } +func (wc *websocketCodec) peerInfo() PeerInfo { + return wc.info +} + func (wc *websocketCodec) writeJSON(ctx context.Context, v interface{}) error { err := wc.jsonCodec.writeJSON(ctx, v) if err == nil { diff --git a/rpc/websocket_test.go b/rpc/websocket_test.go index cf83b621f1..8659f798e4 100644 --- a/rpc/websocket_test.go +++ b/rpc/websocket_test.go @@ -117,6 +117,41 @@ func TestWebsocketLargeCall(t *testing.T) { } } +func TestWebsocketPeerInfo(t *testing.T) { + var ( + s = newTestServer() + ts = httptest.NewServer(s.WebsocketHandler([]string{"origin.example.com"})) + tsurl = "ws:" + strings.TrimPrefix(ts.URL, "http:") + ) + defer s.Stop() + defer ts.Close() + + ctx := context.Background() + c, err := DialWebsocket(ctx, tsurl, "origin.example.com") + if err != nil { + t.Fatal(err) + } + + // Request peer information. + var connInfo PeerInfo + if err := c.Call(&connInfo, "test_peerInfo"); err != nil { + t.Fatal(err) + } + + if connInfo.RemoteAddr == "" { + t.Error("RemoteAddr not set") + } + if connInfo.Transport != "ws" { + t.Errorf("wrong Transport %q", connInfo.Transport) + } + if connInfo.HTTP.UserAgent != "Go-http-client/1.1" { + t.Errorf("wrong HTTP.UserAgent %q", connInfo.HTTP.UserAgent) + } + if connInfo.HTTP.Origin != "origin.example.com" { + t.Errorf("wrong HTTP.Origin %q", connInfo.HTTP.UserAgent) + } +} + // This test checks that client handles WebSocket ping frames correctly. func TestClientWebsocketPing(t *testing.T) { t.Parallel() diff --git a/signer/core/api.go b/signer/core/api.go index 48b54b8f43..f06fbeb76d 100644 --- a/signer/core/api.go +++ b/signer/core/api.go @@ -33,6 +33,7 @@ import ( "github.com/ethereum/go-ethereum/common/hexutil" "github.com/ethereum/go-ethereum/internal/ethapi" "github.com/ethereum/go-ethereum/log" + "github.com/ethereum/go-ethereum/rpc" "github.com/ethereum/go-ethereum/signer/core/apitypes" "github.com/ethereum/go-ethereum/signer/storage" ) @@ -188,23 +189,24 @@ func StartClefAccountManager(ksLocation string, nousb, lightKDF bool, scpath str // MetadataFromContext extracts Metadata from a given context.Context func MetadataFromContext(ctx context.Context) Metadata { + info := rpc.PeerInfoFromContext(ctx) + m := Metadata{"NA", "NA", "NA", "", ""} // batman - if v := ctx.Value("remote"); v != nil { - m.Remote = v.(string) - } - if v := ctx.Value("scheme"); v != nil { - m.Scheme = v.(string) - } - if v := ctx.Value("local"); v != nil { - m.Local = v.(string) + if info.Transport != "" { + if info.Transport == "http" { + m.Scheme = info.HTTP.Version + } + m.Scheme = info.Transport } - if v := ctx.Value("Origin"); v != nil { - m.Origin = v.(string) + if info.RemoteAddr != "" { + m.Remote = info.RemoteAddr } - if v := ctx.Value("User-Agent"); v != nil { - m.UserAgent = v.(string) + if info.HTTP.Host != "" { + m.Local = info.HTTP.Host } + m.Origin = info.HTTP.Origin + m.UserAgent = info.HTTP.UserAgent return m }