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-rw-r--r--rpc/websocket.go175
1 files changed, 175 insertions, 0 deletions
diff --git a/rpc/websocket.go b/rpc/websocket.go
new file mode 100644
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+++ b/rpc/websocket.go
@@ -0,0 +1,175 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package rpc
+
+import (
+ "context"
+ "encoding/base64"
+ "fmt"
+ "net/http"
+ "net/url"
+ "os"
+ "strings"
+ "sync"
+
+ mapset "github.com/deckarep/golang-set"
+ "github.com/ava-labs/go-ethereum/log"
+ "github.com/gorilla/websocket"
+)
+
+const (
+ wsReadBuffer = 1024
+ wsWriteBuffer = 1024
+)
+
+var wsBufferPool = new(sync.Pool)
+
+// NewWSServer creates a new websocket RPC server around an API provider.
+//
+// Deprecated: use Server.WebsocketHandler
+func NewWSServer(allowedOrigins []string, srv *Server) *http.Server {
+ return &http.Server{Handler: srv.WebsocketHandler(allowedOrigins)}
+}
+
+// WebsocketHandler returns a handler that serves JSON-RPC to WebSocket connections.
+//
+// allowedOrigins should be a comma-separated list of allowed origin URLs.
+// To allow connections with any origin, pass "*".
+func (s *Server) WebsocketHandler(allowedOrigins []string) http.Handler {
+ var upgrader = websocket.Upgrader{
+ ReadBufferSize: wsReadBuffer,
+ WriteBufferSize: wsWriteBuffer,
+ WriteBufferPool: wsBufferPool,
+ CheckOrigin: wsHandshakeValidator(allowedOrigins),
+ }
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ conn, err := upgrader.Upgrade(w, r, nil)
+ if err != nil {
+ log.Debug("WebSocket upgrade failed", "err", err)
+ return
+ }
+ codec := newWebsocketCodec(conn)
+ s.ServeCodec(codec, OptionMethodInvocation|OptionSubscriptions)
+ })
+}
+
+// wsHandshakeValidator returns a handler that verifies the origin during the
+// websocket upgrade process. When a '*' is specified as an allowed origins all
+// connections are accepted.
+func wsHandshakeValidator(allowedOrigins []string) func(*http.Request) bool {
+ origins := mapset.NewSet()
+ allowAllOrigins := false
+
+ for _, origin := range allowedOrigins {
+ if origin == "*" {
+ allowAllOrigins = true
+ }
+ if origin != "" {
+ origins.Add(strings.ToLower(origin))
+ }
+ }
+ // allow localhost if no allowedOrigins are specified.
+ if len(origins.ToSlice()) == 0 {
+ origins.Add("http://localhost")
+ if hostname, err := os.Hostname(); err == nil {
+ origins.Add("http://" + strings.ToLower(hostname))
+ }
+ }
+ log.Debug(fmt.Sprintf("Allowed origin(s) for WS RPC interface %v", origins.ToSlice()))
+
+ f := func(req *http.Request) bool {
+ // Skip origin verification if no Origin header is present. The origin check
+ // is supposed to protect against browser based attacks. Browsers always set
+ // Origin. Non-browser software can put anything in origin and checking it doesn't
+ // provide additional security.
+ if _, ok := req.Header["Origin"]; !ok {
+ return true
+ }
+ // Verify origin against whitelist.
+ origin := strings.ToLower(req.Header.Get("Origin"))
+ if allowAllOrigins || origins.Contains(origin) {
+ return true
+ }
+ log.Warn("Rejected WebSocket connection", "origin", origin)
+ return false
+ }
+
+ return f
+}
+
+type wsHandshakeError struct {
+ err error
+ status string
+}
+
+func (e wsHandshakeError) Error() string {
+ s := e.err.Error()
+ if e.status != "" {
+ s += " (HTTP status " + e.status + ")"
+ }
+ return s
+}
+
+// DialWebsocket creates a new RPC client that communicates with a JSON-RPC server
+// that is listening on the given endpoint.
+//
+// The context is used for the initial connection establishment. It does not
+// affect subsequent interactions with the client.
+func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error) {
+ endpoint, header, err := wsClientHeaders(endpoint, origin)
+ if err != nil {
+ return nil, err
+ }
+ dialer := websocket.Dialer{
+ ReadBufferSize: wsReadBuffer,
+ WriteBufferSize: wsWriteBuffer,
+ WriteBufferPool: wsBufferPool,
+ }
+ return newClient(ctx, func(ctx context.Context) (ServerCodec, error) {
+ conn, resp, err := dialer.DialContext(ctx, endpoint, header)
+ if err != nil {
+ hErr := wsHandshakeError{err: err}
+ if resp != nil {
+ hErr.status = resp.Status
+ }
+ return nil, hErr
+ }
+ return newWebsocketCodec(conn), nil
+ })
+}
+
+func wsClientHeaders(endpoint, origin string) (string, http.Header, error) {
+ endpointURL, err := url.Parse(endpoint)
+ if err != nil {
+ return endpoint, nil, err
+ }
+ header := make(http.Header)
+ if origin != "" {
+ header.Add("origin", origin)
+ }
+ if endpointURL.User != nil {
+ b64auth := base64.StdEncoding.EncodeToString([]byte(endpointURL.User.String()))
+ header.Add("authorization", "Basic "+b64auth)
+ endpointURL.User = nil
+ }
+ return endpointURL.String(), header, nil
+}
+
+func newWebsocketCodec(conn *websocket.Conn) ServerCodec {
+ conn.SetReadLimit(maxRequestContentLength)
+ return newCodec(conn, conn.WriteJSON, conn.ReadJSON)
+}