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// 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 (
"crypto/tls"
"fmt"
"net"
"net/http"
"net/url"
"os"
"strings"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"golang.org/x/net/context"
"golang.org/x/net/websocket"
"gopkg.in/fatih/set.v0"
)
// 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 (srv *Server) WebsocketHandler(allowedOrigins string) http.Handler {
return websocket.Server{
Handshake: wsHandshakeValidator(strings.Split(allowedOrigins, ",")),
Handler: func(conn *websocket.Conn) {
srv.ServeCodec(NewJSONCodec(conn), OptionMethodInvocation|OptionSubscriptions)
},
}
}
// 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)}
}
// 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(*websocket.Config, *http.Request) error {
origins := set.New()
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.List()) == 0 {
origins.Add("http://localhost")
if hostname, err := os.Hostname(); err == nil {
origins.Add("http://" + strings.ToLower(hostname))
}
}
glog.V(logger.Debug).Infof("Allowed origin(s) for WS RPC interface %v\n", origins.List())
f := func(cfg *websocket.Config, req *http.Request) error {
origin := strings.ToLower(req.Header.Get("Origin"))
if allowAllOrigins || origins.Has(origin) {
return nil
}
glog.V(logger.Debug).Infof("origin '%s' not allowed on WS-RPC interface\n", origin)
return fmt.Errorf("origin %s not allowed", origin)
}
return f
}
// 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) {
if origin == "" {
var err error
if origin, err = os.Hostname(); err != nil {
return nil, err
}
if strings.HasPrefix(endpoint, "wss") {
origin = "https://" + strings.ToLower(origin)
} else {
origin = "http://" + strings.ToLower(origin)
}
}
config, err := websocket.NewConfig(endpoint, origin)
if err != nil {
return nil, err
}
return newClient(ctx, func(ctx context.Context) (net.Conn, error) {
return wsDialContext(ctx, config)
})
}
func wsDialContext(ctx context.Context, config *websocket.Config) (*websocket.Conn, error) {
var conn net.Conn
var err error
switch config.Location.Scheme {
case "ws":
conn, err = dialContext(ctx, "tcp", wsDialAddress(config.Location))
case "wss":
dialer := contextDialer(ctx)
conn, err = tls.DialWithDialer(dialer, "tcp", wsDialAddress(config.Location), config.TlsConfig)
default:
err = websocket.ErrBadScheme
}
if err != nil {
return nil, err
}
ws, err := websocket.NewClient(config, conn)
if err != nil {
conn.Close()
return nil, err
}
return ws, err
}
var wsPortMap = map[string]string{"ws": "80", "wss": "443"}
func wsDialAddress(location *url.URL) string {
if _, ok := wsPortMap[location.Scheme]; ok {
if _, _, err := net.SplitHostPort(location.Host); err != nil {
return net.JoinHostPort(location.Host, wsPortMap[location.Scheme])
}
}
return location.Host
}
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