1 files changed, 162 insertions, 23 deletions
diff --git a/rpc/comms/http.go b/rpc/comms/http.go
index 108ba0c5f..c165aa27e 100644
--- a/rpc/comms/http.go
+++ b/rpc/comms/http.go
@@ -17,11 +17,16 @@
 package comms
 
 import (
+	"encoding/json"
 	"fmt"
+	"net"
 	"net/http"
 	"strings"
+	"sync"
+	"time"
 
 	"bytes"
+	"io"
 	"io/ioutil"
 
 	"github.com/ethereum/go-ethereum/logger"
@@ -31,10 +36,15 @@ import (
 	"github.com/rs/cors"
 )
 
+const (
+	serverIdleTimeout  = 10 * time.Second // idle keep-alive connections
+	serverReadTimeout  = 15 * time.Second // per-request read timeout
+	serverWriteTimeout = 15 * time.Second // per-request read timeout
+)
+
 var (
-	// main HTTP rpc listener
-	httpListener         *stoppableTCPListener
-	listenerStoppedError = fmt.Errorf("Listener has stopped")
+	httpServerMu sync.Mutex
+	httpServer   *stopServer
 )
 
 type HttpConfig struct {
@@ -43,42 +53,171 @@ type HttpConfig struct {
 	CorsDomain    string
 }
 
+// stopServer augments http.Server with idle connection tracking.
+// Idle keep-alive connections are shut down when Close is called.
+type stopServer struct {
+	*http.Server
+	l net.Listener
+	// connection tracking state
+	mu       sync.Mutex
+	shutdown bool // true when Stop has returned
+	idle     map[net.Conn]struct{}
+}
+
+type handler struct {
+	codec codec.Codec
+	api   shared.EthereumApi
+}
+
+// StartHTTP starts listening for RPC requests sent via HTTP.
 func StartHttp(cfg HttpConfig, codec codec.Codec, api shared.EthereumApi) error {
-	if httpListener != nil {
-		if fmt.Sprintf("%s:%d", cfg.ListenAddress, cfg.ListenPort) != httpListener.Addr().String() {
-			return fmt.Errorf("RPC service already running on %s ", httpListener.Addr().String())
+	httpServerMu.Lock()
+	defer httpServerMu.Unlock()
+
+	addr := fmt.Sprintf("%s:%d", cfg.ListenAddress, cfg.ListenPort)
+	if httpServer != nil {
+		if addr != httpServer.Addr {
+			return fmt.Errorf("RPC service already running on %s ", httpServer.Addr)
 		}
 		return nil // RPC service already running on given host/port
 	}
-
-	l, err := newStoppableTCPListener(fmt.Sprintf("%s:%d", cfg.ListenAddress, cfg.ListenPort))
+	// Set up the request handler, wrapping it with CORS headers if configured.
+	handler := http.Handler(&handler{codec, api})
+	if len(cfg.CorsDomain) > 0 {
+		opts := cors.Options{
+			AllowedMethods: []string{"POST"},
+			AllowedOrigins: strings.Split(cfg.CorsDomain, " "),
+		}
+		handler = cors.New(opts).Handler(handler)
+	}
+	// Start the server.
+	s, err := listenHTTP(addr, handler)
 	if err != nil {
 		glog.V(logger.Error).Infof("Can't listen on %s:%d: %v", cfg.ListenAddress, cfg.ListenPort, err)
 		return err
 	}
-	httpListener = l
+	httpServer = s
+	return nil
+}
 
-	var handler http.Handler
-	if len(cfg.CorsDomain) > 0 {
-		var opts cors.Options
-		opts.AllowedMethods = []string{"POST"}
-		opts.AllowedOrigins = strings.Split(cfg.CorsDomain, " ")
+func (h *handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
 
-		c := cors.New(opts)
-		handler = newStoppableHandler(c.Handler(gethHttpHandler(codec, api)), l.stop)
-	} else {
-		handler = newStoppableHandler(gethHttpHandler(codec, api), l.stop)
+	// Limit request size to resist DoS
+	if req.ContentLength > maxHttpSizeReqLength {
+		err := fmt.Errorf("Request too large")
+		response := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32700, err)
+		sendJSON(w, &response)
+		return
 	}
 
-	go http.Serve(l, handler)
+	defer req.Body.Close()
+	payload, err := ioutil.ReadAll(req.Body)
+	if err != nil {
+		err := fmt.Errorf("Could not read request body")
+		response := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32700, err)
+		sendJSON(w, &response)
+		return
+	}
 
-	return nil
+	c := h.codec.New(nil)
+	var rpcReq shared.Request
+	if err = c.Decode(payload, &rpcReq); err == nil {
+		reply, err := h.api.Execute(&rpcReq)
+		res := shared.NewRpcResponse(rpcReq.Id, rpcReq.Jsonrpc, reply, err)
+		sendJSON(w, &res)
+		return
+	}
+
+	var reqBatch []shared.Request
+	if err = c.Decode(payload, &reqBatch); err == nil {
+		resBatch := make([]*interface{}, len(reqBatch))
+		resCount := 0
+		for i, rpcReq := range reqBatch {
+			reply, err := h.api.Execute(&rpcReq)
+			if rpcReq.Id != nil { // this leaves nil entries in the response batch for later removal
+				resBatch[i] = shared.NewRpcResponse(rpcReq.Id, rpcReq.Jsonrpc, reply, err)
+				resCount += 1
+			}
+		}
+		// make response omitting nil entries
+		sendJSON(w, resBatch[:resCount])
+		return
+	}
+
+	// invalid request
+	err = fmt.Errorf("Could not decode request")
+	res := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32600, err)
+	sendJSON(w, res)
 }
 
+func sendJSON(w io.Writer, v interface{}) {
+	if glog.V(logger.Detail) {
+		if payload, err := json.MarshalIndent(v, "", "\t"); err == nil {
+			glog.Infof("Sending payload: %s", payload)
+		}
+	}
+	if err := json.NewEncoder(w).Encode(v); err != nil {
+		glog.V(logger.Error).Infoln("Error sending JSON:", err)
+	}
+}
+
+// Stop closes all active HTTP connections and shuts down the server.
 func StopHttp() {
-	if httpListener != nil {
-		httpListener.Stop()
-		httpListener = nil
+	httpServerMu.Lock()
+	defer httpServerMu.Unlock()
+	if httpServer != nil {
+		httpServer.Close()
+		httpServer = nil
+	}
+}
+
+func listenHTTP(addr string, h http.Handler) (*stopServer, error) {
+	l, err := net.Listen("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+	s := &stopServer{l: l, idle: make(map[net.Conn]struct{})}
+	s.Server = &http.Server{
+		Addr:         addr,
+		Handler:      h,
+		ReadTimeout:  serverReadTimeout,
+		WriteTimeout: serverWriteTimeout,
+		ConnState:    s.connState,
+	}
+	go s.Serve(l)
+	return s, nil
+}
+
+func (s *stopServer) connState(c net.Conn, state http.ConnState) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	// Close c immediately if we're past shutdown.
+	if s.shutdown {
+		if state != http.StateClosed {
+			c.Close()
+		}
+		return
+	}
+	if state == http.StateIdle {
+		s.idle[c] = struct{}{}
+	} else {
+		delete(s.idle, c)
+	}
+}
+
+func (s *stopServer) Close() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	// Shut down the acceptor. No new connections can be created.
+	s.l.Close()
+	// Drop all idle connections. Non-idle connections will be
+	// closed by connState as soon as they become idle.
+	s.shutdown = true
+	for c := range s.idle {
+		glog.V(logger.Detail).Infof("closing idle connection %v", c.RemoteAddr())
+		c.Close()
+		delete(s.idle, c)
 	}
 }