1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
// 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 (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"mime"
"net"
"net/http"
"sync"
"time"
"github.com/rs/cors"
)
const (
maxHTTPRequestContentLength = 1024 * 128
)
var nullAddr, _ = net.ResolveTCPAddr("tcp", "127.0.0.1:0")
type httpConn struct {
client *http.Client
req *http.Request
closeOnce sync.Once
closed chan struct{}
}
// httpConn is treated specially by Client.
func (hc *httpConn) LocalAddr() net.Addr { return nullAddr }
func (hc *httpConn) RemoteAddr() net.Addr { return nullAddr }
func (hc *httpConn) SetReadDeadline(time.Time) error { return nil }
func (hc *httpConn) SetWriteDeadline(time.Time) error { return nil }
func (hc *httpConn) SetDeadline(time.Time) error { return nil }
func (hc *httpConn) Write([]byte) (int, error) { panic("Write called") }
func (hc *httpConn) Read(b []byte) (int, error) {
<-hc.closed
return 0, io.EOF
}
func (hc *httpConn) Close() error {
hc.closeOnce.Do(func() { close(hc.closed) })
return nil
}
// DialHTTP creates a new RPC clients that connection to an RPC server over HTTP.
func DialHTTP(endpoint string) (*Client, error) {
req, err := http.NewRequest("POST", endpoint, nil)
if err != nil {
return nil, err
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Accept", "application/json")
initctx := context.Background()
return newClient(initctx, func(context.Context) (net.Conn, error) {
return &httpConn{client: new(http.Client), req: req, closed: make(chan struct{})}, nil
})
}
func (c *Client) sendHTTP(ctx context.Context, op *requestOp, msg interface{}) error {
hc := c.writeConn.(*httpConn)
respBody, err := hc.doRequest(ctx, msg)
if err != nil {
return err
}
defer respBody.Close()
var respmsg jsonrpcMessage
if err := json.NewDecoder(respBody).Decode(&respmsg); err != nil {
return err
}
op.resp <- &respmsg
return nil
}
func (c *Client) sendBatchHTTP(ctx context.Context, op *requestOp, msgs []*jsonrpcMessage) error {
hc := c.writeConn.(*httpConn)
respBody, err := hc.doRequest(ctx, msgs)
if err != nil {
return err
}
defer respBody.Close()
var respmsgs []jsonrpcMessage
if err := json.NewDecoder(respBody).Decode(&respmsgs); err != nil {
return err
}
for i := 0; i < len(respmsgs); i++ {
op.resp <- &respmsgs[i]
}
return nil
}
func (hc *httpConn) doRequest(ctx context.Context, msg interface{}) (io.ReadCloser, error) {
body, err := json.Marshal(msg)
if err != nil {
return nil, err
}
req := hc.req.WithContext(ctx)
req.Body = ioutil.NopCloser(bytes.NewReader(body))
req.ContentLength = int64(len(body))
resp, err := hc.client.Do(req)
if err != nil {
return nil, err
}
return resp.Body, nil
}
// httpReadWriteNopCloser wraps a io.Reader and io.Writer with a NOP Close method.
type httpReadWriteNopCloser struct {
io.Reader
io.Writer
}
// Close does nothing and returns always nil
func (t *httpReadWriteNopCloser) Close() error {
return nil
}
// NewHTTPServer creates a new HTTP RPC server around an API provider.
//
// Deprecated: Server implements http.Handler
func NewHTTPServer(cors []string, srv *Server) *http.Server {
return &http.Server{Handler: newCorsHandler(srv, cors)}
}
// ServeHTTP serves JSON-RPC requests over HTTP.
func (srv *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if r.ContentLength > maxHTTPRequestContentLength {
http.Error(w,
fmt.Sprintf("content length too large (%d>%d)", r.ContentLength, maxHTTPRequestContentLength),
http.StatusRequestEntityTooLarge)
return
}
ct := r.Header.Get("content-type")
mt, _, err := mime.ParseMediaType(ct)
if err != nil || mt != "application/json" {
http.Error(w,
"invalid content type, only application/json is supported",
http.StatusUnsupportedMediaType)
return
}
w.Header().Set("content-type", "application/json")
// create a codec that reads direct from the request body until
// EOF and writes the response to w and order the server to process
// a single request.
codec := NewJSONCodec(&httpReadWriteNopCloser{r.Body, w})
defer codec.Close()
srv.ServeSingleRequest(codec, OptionMethodInvocation)
}
func newCorsHandler(srv *Server, allowedOrigins []string) http.Handler {
// disable CORS support if user has not specified a custom CORS configuration
if len(allowedOrigins) == 0 {
return srv
}
c := cors.New(cors.Options{
AllowedOrigins: allowedOrigins,
AllowedMethods: []string{"POST", "GET"},
MaxAge: 600,
AllowedHeaders: []string{"*"},
})
return c.Handler(srv)
}
|
