path: root/rpc/comms/comms.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// go-ethereum 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 comms

import (
    "io"
    "net"

    "fmt"
    "strings"

    "strconv"

    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/rpc/codec"
    "github.com/ethereum/go-ethereum/rpc/shared"
)

const (
    maxHttpSizeReqLength = 1024 * 1024 // 1MB
)

var (
    // List with all API's which are offered over the in proc interface by default
    DefaultInProcApis = shared.AllApis

    // List with all API's which are offered over the IPC interface by default
    DefaultIpcApis = shared.AllApis

    // List with API's which are offered over thr HTTP/RPC interface by default
    DefaultHttpRpcApis = strings.Join([]string{
        shared.DbApiName, shared.EthApiName, shared.NetApiName, shared.Web3ApiName,
    }, ",")
)

type EthereumClient interface {
    // Close underlaying connection
    Close()
    // Send request
    Send(interface{}) error
    // Receive response
    Recv() (interface{}, error)
    // List with modules this client supports
    SupportedModules() (map[string]string, error)
}

func handle(id int, conn net.Conn, api shared.EthereumApi, c codec.Codec) {
    codec := c.New(conn)

    for {
        requests, isBatch, err := codec.ReadRequest()
        if err == io.EOF {
            codec.Close()
            return
        } else if err != nil {
            codec.Close()
            glog.V(logger.Debug).Infof("Closed IPC Conn %06d recv err - %v\n", id, err)
            return
        }

        if isBatch {
            responses := make([]*interface{}, len(requests))
            responseCount := 0
            for _, req := range requests {
                res, err := api.Execute(req)
                if req.Id != nil {
                    rpcResponse := shared.NewRpcResponse(req.Id, req.Jsonrpc, res, err)
                    responses[responseCount] = rpcResponse
                    responseCount += 1
                }
            }

            err = codec.WriteResponse(responses[:responseCount])
            if err != nil {
                codec.Close()
                glog.V(logger.Debug).Infof("Closed IPC Conn %06d send err - %v\n", id, err)
                return
            }
        } else {
            var rpcResponse interface{}
            res, err := api.Execute(requests[0])

            rpcResponse = shared.NewRpcResponse(requests[0].Id, requests[0].Jsonrpc, res, err)
            err = codec.WriteResponse(rpcResponse)
            if err != nil {
                codec.Close()
                glog.V(logger.Debug).Infof("Closed IPC Conn %06d send err - %v\n", id, err)
                return
            }
        }
    }
}

// Endpoint must be in the form of:
// ${protocol}:${path}
// e.g. ipc:/tmp/geth.ipc
//      rpc:localhost:8545
func ClientFromEndpoint(endpoint string, c codec.Codec) (EthereumClient, error) {
    if strings.HasPrefix(endpoint, "ipc:") {
        cfg := IpcConfig{
            Endpoint: endpoint[4:],
        }
        return NewIpcClient(cfg, codec.JSON)
    }

    if strings.HasPrefix(endpoint, "rpc:") {
        parts := strings.Split(endpoint, ":")
        addr := "http://localhost"
        port := uint(8545)
        if len(parts) >= 3 {
            addr = parts[1] + ":" + parts[2]
        }

        if len(parts) >= 4 {
            p, err := strconv.Atoi(parts[3])

            if err != nil {
                return nil, err
            }
            port = uint(p)
        }

        cfg := HttpConfig{
            ListenAddress: addr,
            ListenPort:    port,
        }

        return NewHttpClient(cfg, codec.JSON), nil
    }

    return nil, fmt.Errorf("Invalid endpoint")
}