go-ethereum/rpc/endpoints.go

// Copyright 2018 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 (
	"fmt"
	"net"

	"github.com/ethereum/go-ethereum/log"
)

// isModuleAvailable enforces that requested api modules (eg. via --rpcapi) are actually
// available API services. If an invalid module is given (ie API "foo" wanted which does not exist),
// then log.Crit is used to cause program to exit, logging the invalid module and a list of available
// API service names.
func isModuleAvailable(module string, apis []API) (err error) {
	for _, api := range apis {
		if module == api.Namespace {
			return nil
		}
	}
	// Module did not find a matching api namespace: this is an invalid module.
	// Collect list of available modules for user debugging.
	available := []string{}
outer:
	for _, api := range apis {

		// Only include unique api names
		for _, av := range available {
			if av == api.Namespace {
				continue outer
			}
		}
		available = append(available, api.Namespace)
	}
	return fmt.Errorf("invalid api module: module=%s available=%v", module, available)
}

// StartHTTPEndpoint starts the HTTP RPC endpoint, configured with cors/vhosts/modules
func StartHTTPEndpoint(endpoint string, apis []API, modules []string, cors []string, vhosts []string, timeouts HTTPTimeouts) (net.Listener, *Server, error) {
	// Generate the whitelist based on the allowed modules
	whitelist := make(map[string]bool)
	for _, module := range modules {

		// Ensure the requested module is actually available.
		if err := isModuleAvailable(module, apis); err != nil {
			return nil, nil, err
		}
		whitelist[module] = true
	}
	// Register all the APIs exposed by the services
	handler := NewServer()
	for _, api := range apis {
		if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
				return nil, nil, err
			}
			log.Debug("HTTP registered", "namespace", api.Namespace)
		}
	}
	// All APIs registered, start the HTTP listener
	var (
		listener net.Listener
		err      error
	)
	if listener, err = net.Listen("tcp", endpoint); err != nil {
		return nil, nil, err
	}
	go NewHTTPServer(cors, vhosts, timeouts, handler).Serve(listener)
	return listener, handler, err
}

// StartWSEndpoint starts a websocket endpoint
func StartWSEndpoint(endpoint string, apis []API, modules []string, wsOrigins []string, exposeAll bool) (net.Listener, *Server, error) {

	// Generate the whitelist based on the allowed modules
	whitelist := make(map[string]bool)
	for _, module := range modules {

		// Ensure the requested module is actually available.
		if err := isModuleAvailable(module, apis); err != nil {
			return nil, nil, err
		}
		whitelist[module] = true
	}
	// Register all the APIs exposed by the services
	handler := NewServer()
	for _, api := range apis {
		if exposeAll || whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
			if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
				return nil, nil, err
			}
			log.Debug("WebSocket registered", "service", api.Service, "namespace", api.Namespace)
		}
	}
	// All APIs registered, start the HTTP listener
	var (
		listener net.Listener
		err      error
	)
	if listener, err = net.Listen("tcp", endpoint); err != nil {
		return nil, nil, err
	}
	go NewWSServer(wsOrigins, handler).Serve(listener)
	return listener, handler, err

}

// StartIPCEndpoint starts an IPC endpoint.
func StartIPCEndpoint(ipcEndpoint string, apis []API) (net.Listener, *Server, error) {
	// Register all the APIs exposed by the services.
	handler := NewServer()
	for _, api := range apis {
		if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
			return nil, nil, err
		}
		log.Debug("IPC registered", "namespace", api.Namespace)
	}
	// All APIs registered, start the IPC listener.
	listener, err := ipcListen(ipcEndpoint)
	if err != nil {
		return nil, nil, err
	}
	go handler.ServeListener(listener)
	return listener, handler, nil
}