aboutsummaryrefslogtreecommitdiffstats
path: root/rpc/http.go
blob: 882aff7eae2240552d16591d33b6d6a2b08cc8be (plain) (blame)
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
package rpc

import (
    "encoding/json"
    "fmt"
    "io"
    "io/ioutil"
    "net/http"

    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/xeth"
    "github.com/rs/cors"
)

var rpclogger = logger.NewLogger("RPC")
var rpclistener *StoppableTCPListener

const (
    jsonrpcver       = "2.0"
    maxSizeReqLength = 1024 * 1024 // 1MB
)

func Start(pipe *xeth.XEth, config RpcConfig) error {
    if rpclistener != nil {
        if fmt.Sprintf("%s:%d", config.ListenAddress, config.ListenPort) != rpclistener.Addr().String() {
            return fmt.Errorf("RPC service already running on %s ", rpclistener.Addr().String())
        }
        return nil // RPC service already running on given host/port
    }

    l, err := NewStoppableTCPListener(fmt.Sprintf("%s:%d", config.ListenAddress, config.ListenPort))
    if err != nil {
        rpclogger.Errorf("Can't listen on %s:%d: %v", config.ListenAddress, config.ListenPort, err)
        return err
    }
    rpclistener = l

    var handler http.Handler
    if len(config.CorsDomain) > 0 {
        var opts cors.Options
        opts.AllowedMethods = []string{"POST"}
        opts.AllowedOrigins = []string{config.CorsDomain}

        c := cors.New(opts)
        handler = NewStoppableHandler(c.Handler(JSONRPC(pipe)), l.stop)
    } else {
        handler = JSONRPC(pipe)
    }

    go http.Serve(l, handler)

    return nil
}

func Stop() error {
    if rpclistener != nil {
        rpclistener.Stop()
        rpclistener = nil
    }

    return nil
}

// JSONRPC returns a handler that implements the Ethereum JSON-RPC API.
func JSONRPC(pipe *xeth.XEth) http.Handler {
    api := NewEthereumApi(pipe)

    return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
        w.Header().Set("Content-Type", "application/json")

        // Limit request size to resist DoS
        if req.ContentLength > maxSizeReqLength {
            jsonerr := &RpcErrorObject{-32700, "Request too large"}
            send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
            return
        }

        // Read request body
        defer req.Body.Close()
        body, err := ioutil.ReadAll(req.Body)
        if err != nil {
            jsonerr := &RpcErrorObject{-32700, "Could not read request body"}
            send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
        }

        // Try to parse the request as a single
        var reqSingle RpcRequest
        if err := json.Unmarshal(body, &reqSingle); err == nil {
            response := RpcResponse(api, &reqSingle)
            send(w, &response)
            return
        }

        // Try to parse the request to batch
        var reqBatch []RpcRequest
        if err := json.Unmarshal(body, &reqBatch); err == nil {
            // Build response batch
            resBatch := make([]*interface{}, len(reqBatch))
            for i, request := range reqBatch {
                response := RpcResponse(api, &request)
                resBatch[i] = response
            }
            send(w, resBatch)
            return
        }

        // Not a batch or single request, error
        jsonerr := &RpcErrorObject{-32600, "Could not decode request"}
        send(w, &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: nil, Error: jsonerr})
    })
}

func RpcResponse(api *EthereumApi, request *RpcRequest) *interface{} {
    var reply, response interface{}
    reserr := api.GetRequestReply(request, &reply)
    switch reserr.(type) {
    case nil:
        response = &RpcSuccessResponse{Jsonrpc: jsonrpcver, Id: request.Id, Result: reply}
    case *NotImplementedError:
        jsonerr := &RpcErrorObject{-32601, reserr.Error()}
        response = &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: request.Id, Error: jsonerr}
    case *DecodeParamError, *InsufficientParamsError, *ValidationError, *InvalidTypeError:
        jsonerr := &RpcErrorObject{-32602, reserr.Error()}
        response = &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: request.Id, Error: jsonerr}
    default:
        jsonerr := &RpcErrorObject{-32603, reserr.Error()}
        response = &RpcErrorResponse{Jsonrpc: jsonrpcver, Id: request.Id, Error: jsonerr}
    }

    glog.V(logger.Detail).Infof("Generated response: %T %s", response, response)
    return &response
}

func send(writer io.Writer, v interface{}) (n int, err error) {
    var payload []byte
    payload, err = json.MarshalIndent(v, "", "\t")
    if err != nil {
        rpclogger.Fatalln("Error marshalling JSON", err)
        return 0, err
    }
    glog.V(logger.Detail).Infof("Sending payload: %s", payload)

    return writer.Write(payload)
}