rpc: migrated the RPC insterface to a new reflection based RPC layer

1 files changed, 368 insertions, 0 deletions

diff --git a/rpc/http.go b/rpc/http.go
new file mode 100644
index 000000000..e4b25bed8
--- /dev/null
+++ b/rpc/http.go
@@ -0,0 +1,368 @@
+// 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 (
+	"bufio"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"errors"
+	"sync"
+
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/url"
+
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"gopkg.in/fatih/set.v0"
+)
+
+const (
+	httpReadDeadLine = 60 * time.Second // wait max httpReadDeadeline for next request
+)
+
+var (
+	httpServerMu sync.Mutex   // prevent concurrent access to the httpListener and httpServer
+	httpListener net.Listener // listener for the http server
+	httpRPCServer *Server      // the node can only start 1 HTTP RPC server instance
+)
+
+// httpMessageStream is the glue between a HTTP connection which is message based
+// and the RPC codecs that expect json requests to be read from a stream. It will
+// parse HTTP messages and offer the bodies of these requests as a stream through
+// the Read method. This will require full control of the connection and thus need
+// a "hijacked" HTTP connection.
+type httpMessageStream struct {
+	conn             net.Conn          // TCP connection
+	rw               *bufio.ReadWriter // buffered where HTTP requests/responses are read/written from/to
+	currentReq       *http.Request     // pending request, codec can pass in a too small buffer for a single read
+					   // we need to keep track of the current requests if it was not read at once
+	payloadBytesRead int64             // number of bytes which are read from the current request
+	allowedOrigins   *set.Set          // allowed CORS domains
+	origin           string            // origin of this connection/request
+}
+
+// NewHttpMessageStream will create a new http message stream parser that can be
+// used by the codes in the RPC package. It will take full control of the given
+// connection and thus needs to be hijacked. It will read and write HTTP messages
+// from the passed rwbuf. The allowed origins are the RPC CORS domains the user has supplied.
+func NewHTTPMessageStream(c net.Conn, rwbuf *bufio.ReadWriter, initialReq *http.Request, allowdOrigins []string) *httpMessageStream {
+	r := &httpMessageStream{conn: c, rw: rwbuf, currentReq: initialReq, allowedOrigins: set.New()}
+	for _, origin := range allowdOrigins {
+		r.allowedOrigins.Add(origin)
+	}
+	return r
+}
+
+// handleOptionsRequest handles the HTTP preflight requests (OPTIONS) that browsers
+// make to enforce CORS rules. Only the POST method is allowed and the origin must
+// be on the rpccorsdomain list the user has specified.
+func (h *httpMessageStream) handleOptionsRequest(req *http.Request) error {
+	headers := req.Header
+
+	if !strings.EqualFold(req.Method, "OPTIONS") {
+		return fmt.Errorf("preflight aborted: %s!=OPTIONS", req.Method)
+	}
+
+	origin := headers.Get("Origin")
+	if origin == "" {
+		return fmt.Errorf("preflight aborted: empty origin")
+	}
+
+	responseHeaders := make(http.Header)
+	responseHeaders.Set("Access-Control-Allow-Methods", "POST")
+	if h.allowedOrigins.Has(origin) || h.allowedOrigins.Has("*") {
+		responseHeaders.Set("Access-Control-Allow-Origin", origin)
+	} else {
+		glog.V(logger.Info).Infof("origin '%s' not allowed", origin)
+	}
+	responseHeaders.Set("Access-Control-Allow-Headers", "Content-Type")
+	responseHeaders.Set("Date", string(httpTimestamp(time.Now())))
+	responseHeaders.Set("Content-Type", "text/plain; charset=utf-8")
+	responseHeaders.Set("Content-Length", "0")
+	responseHeaders.Set("Vary", "Origin")
+
+	defer h.rw.Flush()
+
+	if _, err := h.rw.WriteString("HTTP/1.1 200 OK\r\n"); err != nil {
+		glog.V(logger.Error).Infof("unable to write OPTIONS response: %v\n", err)
+		return err
+	}
+	if err := responseHeaders.Write(h.rw); err != nil {
+		glog.V(logger.Error).Infof("unable to write OPTIONS headers: %v\n", err)
+	}
+	if _, err := h.rw.WriteString("\r\n"); err != nil {
+		glog.V(logger.Error).Infof("unable to write OPTIONS response: %v\n", err)
+	}
+
+	return nil
+}
+
+// Read will read incoming HTTP requests and reads the body data from these requests
+// as an endless stream of data.
+func (h *httpMessageStream) Read(buf []byte) (n int, err error) {
+	h.conn.SetReadDeadline(time.Now().Add(httpReadDeadLine))
+	for {
+		// if the last request was read completely try to read the next request
+		if h.currentReq == nil {
+			if h.currentReq, err = http.ReadRequest(bufio.NewReader(h.rw)); err != nil {
+				return 0, err
+			}
+		}
+
+		// The "options" method is http specific and not interested for the RPC server.
+		// Handle it internally and wait for the next request.
+		if strings.EqualFold(h.currentReq.Method, "OPTIONS") {
+			if err = h.handleOptionsRequest(h.currentReq); err != nil {
+				glog.V(logger.Info).Infof("RPC/HTTP OPTIONS error: %v\n", err)
+				h.currentReq = nil
+				return 0, err
+			}
+
+			// processed valid request -> reset deadline
+			h.conn.SetReadDeadline(time.Now().Add(httpReadDeadLine))
+			h.currentReq = nil
+			continue
+		}
+
+		if strings.EqualFold(h.currentReq.Method, "POST") {
+			n, err := h.currentReq.Body.Read(buf)
+			h.payloadBytesRead += int64(n)
+
+			// entire payload read, read new request next time
+			if err == io.EOF || h.payloadBytesRead >= h.currentReq.ContentLength {
+				h.origin = h.currentReq.Header.Get("origin")
+				h.payloadBytesRead = 0
+				h.currentReq.Body.Close()
+				h.currentReq = nil
+				err = nil // io.EOF is not an error
+			} else if err != nil {
+				// unable to read body
+				h.currentReq.Body.Close()
+				h.currentReq = nil
+				h.payloadBytesRead = 0
+			}
+
+			// partial read of body
+			return n, err
+		}
+
+		h.currentReq = nil
+		return 0, fmt.Errorf("unsupported HTTP method '%s'", h.currentReq.Method)
+	}
+}
+
+// Write will create a HTTP response with the given payload and send it to the peer.
+func (h *httpMessageStream) Write(payload []byte) (int, error) {
+	defer h.rw.Flush()
+
+	responseHeaders := make(http.Header)
+	responseHeaders.Set("Content-Type", "application/json")
+	responseHeaders.Set("Content-Length", strconv.Itoa(len(payload)))
+	if h.origin != "" {
+		responseHeaders.Set("Access-Control-Allow-Origin", h.origin)
+	}
+
+	h.rw.WriteString("HTTP/1.1 200 OK\r\n")
+	responseHeaders.Write(h.rw)
+	h.rw.WriteString("\r\n")
+
+	return h.rw.Write(payload)
+}
+
+// Close will close the underlying TCP connection this instance has taken ownership over.
+func (h *httpMessageStream) Close() error {
+	h.rw.Flush()
+	return h.conn.Close()
+}
+
+// TimeFormat is the time format to use with time.Parse and time.Time.Format when
+// parsing or generating times in HTTP headers. It is like time.RFC1123 but hard
+// codes GMT as the time zone.
+const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
+
+// httpTimestamp formats the given t as specified in RFC1123.
+func httpTimestamp(t time.Time) []byte {
+	const days = "SunMonTueWedThuFriSat"
+	const months = "JanFebMarAprMayJunJulAugSepOctNovDec"
+
+	b := make([]byte, 0)
+	t = t.UTC()
+	yy, mm, dd := t.Date()
+	hh, mn, ss := t.Clock()
+	day := days[3 * t.Weekday():]
+	mon := months[3 * (mm - 1):]
+
+	return append(b,
+		day[0], day[1], day[2], ',', ' ',
+		byte('0' + dd / 10), byte('0' + dd % 10), ' ',
+		mon[0], mon[1], mon[2], ' ',
+		byte('0' + yy / 1000), byte('0' + (yy / 100) % 10), byte('0' + (yy / 10) % 10), byte('0' + yy % 10), ' ',
+		byte('0' + hh / 10), byte('0' + hh % 10), ':',
+		byte('0' + mn / 10), byte('0' + mn % 10), ':',
+		byte('0' + ss / 10), byte('0' + ss % 10), ' ',
+		'G', 'M', 'T')
+}
+
+// httpConnHijacker is a http.Handler implementation that will hijack the HTTP
+// connection,  wraps it in a HttpMessageStream that is then wrapped in a JSON
+// codec which will be served on the rpcServer.
+type httpConnHijacker struct {
+	corsdomains []string
+	rpcServer   *Server
+}
+
+// ServeHTTP will hijack the connection, wraps the captured connection in a
+// HttpMessageStream which is then used as codec.
+func (h *httpConnHijacker) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	hj, ok := w.(http.Hijacker)
+	if !ok {
+		http.Error(w, "webserver doesn't support hijacking", http.StatusInternalServerError)
+		return
+	}
+
+	conn, rwbuf, err := hj.Hijack()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	httpRequestStream := NewHTTPMessageStream(conn, rwbuf, req, h.corsdomains)
+
+	codec := NewJSONCodec(httpRequestStream)
+	go h.rpcServer.ServeCodec(codec)
+}
+
+// StartHTTP will start the JSONRPC HTTP RPC interface when its not yet running.
+func StartHTTP(address string, port int, corsdomains []string, apis []API) error {
+	httpServerMu.Lock()
+	defer httpServerMu.Unlock()
+
+	if httpRPCServer != nil {
+		return fmt.Errorf("HTTP RPC interface already started on %s", httpListener.Addr())
+	}
+
+	rpcServer := NewServer()
+
+	for _, api := range apis {
+		if err := rpcServer.RegisterName(api.Namespace, api.Service); err != nil {
+			return err
+		}
+	}
+
+	listener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", address, port))
+	if err != nil {
+		return err
+	}
+
+	httpServer := http.Server{Handler: &httpConnHijacker{corsdomains, rpcServer}}
+	go httpServer.Serve(listener)
+
+	httpListener = listener
+	httpRPCServer = rpcServer
+
+	return nil
+}
+
+// StopHTTP will stop the running HTTP interface. If it is not running an error will be returned.
+func StopHTTP() error {
+	httpServerMu.Lock()
+	defer httpServerMu.Unlock()
+
+	if httpRPCServer == nil {
+		return errors.New("HTTP RPC interface not started")
+	}
+
+	httpListener.Close()
+	httpRPCServer.Stop()
+
+	httpRPCServer = nil
+	httpListener = nil
+
+	return nil
+}
+
+// httpClient connects to a geth RPC server over HTTP.
+type httpClient struct {
+	endpoint *url.URL // HTTP-RPC server endpoint
+	lastRes  []byte   // HTTP requests are synchronous, store last response
+}
+
+// NewHTTPClient create a new RPC clients that connection to a geth RPC server
+// over HTTP.
+func NewHTTPClient(endpoint string) (*httpClient, error) {
+	url, err := url.Parse(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	return &httpClient{endpoint: url}, nil
+}
+
+// Send will serialize the given msg to JSON and sends it to the RPC server.
+// Since HTTP is synchronous the response is stored until Recv is called.
+func (client *httpClient) Send(msg interface{}) error {
+	var body []byte
+	var err error
+
+	client.lastRes = nil
+
+	if body, err = json.Marshal(msg); err != nil {
+		return err
+	}
+
+	httpReq, err := http.NewRequest("POST", client.endpoint.String(), bytes.NewBuffer(body))
+	if err != nil {
+		return err
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	httpClient := http.Client{}
+	resp, err := httpClient.Do(httpReq)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusOK {
+		client.lastRes, err = ioutil.ReadAll(resp.Body)
+		return err
+	}
+
+	return fmt.Errorf("unable to handle request")
+}
+
+// Recv will try to deserialize the last received response into the given msg.
+func (client *httpClient) Recv(msg interface{}) error {
+	return json.Unmarshal(client.lastRes, &msg)
+}
+
+// Close is not necessary for httpClient
+func (client *httpClient) Close() {
+}
+
+// SupportedModules will return the collection of offered RPC modules.
+func (client *httpClient) SupportedModules() (map[string]string, error) {
+	return SupportedModules(client)
+}