lib/rep/functions.go

@@ -1,52 +0,0 @@
-package rep
-
-import (
-	"encoding/binary"
-	"encoding/json"
-	"net"
-	"path/filepath"
-	"time"
-
-	"git.crumpington.com/public/jldb/lib/errs"
-)
-
-// ----------------------------------------------------------------------------
-
-func lockFilePath(rootDir string) string {
-	return filepath.Join(rootDir, "lock")
-}
-
-func walRootDir(rootDir string) string {
-	return filepath.Join(rootDir, "wal")
-}
-
-func stateFilePath(rootDir string) string {
-	return filepath.Join(rootDir, "state")
-}
-
-// ----------------------------------------------------------------------------
-
-func sendJSON(
-	item any,
-	conn net.Conn,
-	timeout time.Duration,
-) error {
-
-	buf := bufPoolGet()
-	defer bufPoolPut(buf)
-
-	if err := json.NewEncoder(buf).Encode(item); err != nil {
-		return errs.Unexpected.WithErr(err)
-	}
-
-	sizeBuf := make([]byte, 2)
-	binary.LittleEndian.PutUint16(sizeBuf, uint16(buf.Len()))
-
-	conn.SetWriteDeadline(time.Now().Add(timeout))
-	buffers := net.Buffers{sizeBuf, buf.Bytes()}
-	if _, err := buffers.WriteTo(conn); err != nil {
-		return errs.IO.WithErr(err)
-	}
-
-	return nil
-}

lib/rep/http-client.go

@@ -1,10 +1,10 @@
 package rep
 
 import (
-	"encoding/binary"
 	"encoding/json"
-	"io"
 	"net"
+	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -14,166 +14,96 @@ import (
 )
 
 type client struct {
-	// Mutex-protected variables.
-	lock   sync.Mutex
-	closed bool
-	conn   net.Conn
+	client *http.Client
 
 	// The following are constant.
 	endpoint string
-	psk      []byte
+	pskBytes [64]byte
 	timeout  time.Duration
 
-	buf []byte
+	lock sync.Mutex
+	conn net.Conn
 }
 
 func newClient(endpoint, psk string, timeout time.Duration) *client {
-	b := make([]byte, 256)
-	copy(b, []byte(psk))
+	httpClient := &http.Client{
+		Timeout: timeout,
+	}
+
+	if !strings.HasSuffix(endpoint, "/") {
+		endpoint += "/"
+	}
 
 	return &client{
+		client:   httpClient,
 		endpoint: endpoint,
-		psk:      b,
+		pskBytes: pskToBytes(psk),
 		timeout:  timeout,
 	}
 }
 
 func (c *client) GetInfo() (info Info, err error) {
-	err = c.withConn(cmdGetInfo, func(conn net.Conn) error {
-		return c.recvJSON(&info, conn, c.timeout)
-	})
-	return info, err
+	req, err := http.NewRequest(http.MethodGet, c.endpoint+pathGetInfo, nil)
+	if err != nil {
+		return info, errs.Unexpected.WithErr(err)
+	}
+	req.SetBasicAuth("", string(c.pskBytes[:]))
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return info, errs.IO.WithErr(err)
+	}
+	defer resp.Body.Close()
+
+	if err := json.NewDecoder(resp.Body).Decode(&info); err != nil {
+		return info, errs.IO.WithErr(err)
+	}
+	return info, nil
 }
 
 func (c *client) RecvState(recv func(net.Conn) error) error {
-	return c.withConn(cmdSendState, recv)
+	err := c.dialConnect(c.endpoint + pathSendState)
+	if err != nil {
+		return err
+	}
+	defer c.conn.Close()
+
+	return recv(c.conn)
 }
 
 func (c *client) StreamWAL(w *wal.WAL) error {
-	return c.withConn(cmdStreamWAL, func(conn net.Conn) error {
-		return w.Recv(conn, c.timeout)
-	})
+	err := c.dialConnect(c.endpoint + pathStreamWAL)
+	if err != nil {
+		return err
+	}
+	defer c.conn.Close()
+
+	return w.Recv(c.conn, c.timeout)
 }
 
 func (c *client) Close() {
 	c.lock.Lock()
 	defer c.lock.Unlock()
-	c.closed = true
-
 	if c.conn != nil {
 		c.conn.Close()
-		c.conn = nil
 	}
 }
 
 // ----------------------------------------------------------------------------
 
-func (c *client) writeCmd(cmd byte) error {
-	c.conn.SetWriteDeadline(time.Now().Add(c.timeout))
-	if _, err := c.conn.Write([]byte{cmd}); err != nil {
-		return errs.IO.WithErr(err)
-	}
-	return nil
-}
-
-func (c *client) dial() error {
-	c.conn = nil
-
-	conn, err := httpconn.Dial(c.endpoint)
+func (c *client) dialConnect(endpoint string) error {
+	conn, err := httpconn.Dial(endpoint)
 	if err != nil {
 		return err
 	}
 
 	conn.SetWriteDeadline(time.Now().Add(c.timeout))
-	if _, err := conn.Write(c.psk); err != nil {
-		conn.Close()
+	if _, err := conn.Write(c.pskBytes[:]); err != nil {
 		return errs.IO.WithErr(err)
 	}
 
+	c.lock.Lock()
+	defer c.lock.Unlock()
 	c.conn = conn
 	return nil
 }
-
-func (c *client) withConn(cmd byte, fn func(net.Conn) error) error {
-	conn, err := c.getConn(cmd)
-	if err != nil {
-		return err
-	}
-
-	if err := fn(conn); err != nil {
-		conn.Close()
-		return err
-	}
-	return nil
-}
-
-func (c *client) getConn(cmd byte) (net.Conn, error) {
-	c.lock.Lock()
-	defer c.lock.Unlock()
-
-	if c.closed {
-		return nil, errs.IO.WithErr(io.EOF)
-	}
-
-	dialed := false
-
-	if c.conn == nil {
-		if err := c.dial(); err != nil {
-			return nil, err
-		}
-		dialed = true
-	}
-
-	if err := c.writeCmd(cmd); err != nil {
-		if dialed {
-			c.conn = nil
-			return nil, err
-		}
-
-		if err := c.dial(); err != nil {
-			return nil, err
-		}
-
-		if err := c.writeCmd(cmd); err != nil {
-			return nil, err
-		}
-	}
-
-	return c.conn, nil
-}
-
-func (c *client) recvJSON(
-	item any,
-	conn net.Conn,
-	timeout time.Duration,
-) error {
-
-	if cap(c.buf) < 2 {
-		c.buf = make([]byte, 0, 1024)
-	}
-	buf := c.buf[:2]
-
-	conn.SetReadDeadline(time.Now().Add(timeout))
-
-	if _, err := io.ReadFull(conn, buf); err != nil {
-		return errs.IO.WithErr(err)
-	}
-
-	size := binary.LittleEndian.Uint16(buf)
-
-	if cap(buf) < int(size) {
-		buf = make([]byte, size)
-		c.buf = buf
-	}
-	buf = buf[:size]
-
-	if _, err := io.ReadFull(conn, buf); err != nil {
-		return errs.IO.WithErr(err)
-	}
-
-	if err := json.Unmarshal(buf, item); err != nil {
-		return errs.Unexpected.WithErr(err)
-	}
-
-	return nil
-}

lib/rep/http-handler-util.go

@@ -0,0 +1,54 @@
+package rep
+
+import (
+	"crypto/subtle"
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"time"
+
+	"git.crumpington.com/public/jldb/lib/httpconn"
+)
+
+func (rep *Replicator) handlerLogf(pattern string, args ...any) {
+	log.Printf("[HTTP-HANDLER] "+pattern, args...)
+}
+
+// checkBasicAuth tests whether the caller has provided the appropriate basic auth
+// header. The caller should provide the PSK as the basic-auth password.
+func (rep *Replicator) checkBasicAuth(w http.ResponseWriter, r *http.Request) bool {
+	_, pwd, _ := r.BasicAuth()
+	if subtle.ConstantTimeCompare([]byte(pwd), rep.pskBytes[:]) != 1 {
+		rep.handlerLogf("PSK mismatch.")
+		http.Error(w, "not authorized", http.StatusUnauthorized)
+		return false
+	}
+	return true
+}
+
+// acceptConnect accepts a CONNECT request and checks the PSK.
+func (rep *Replicator) acceptConnect(w http.ResponseWriter, r *http.Request) net.Conn {
+	conn, err := httpconn.Accept(w, r)
+	if err != nil {
+		rep.handlerLogf("Failed to accept connection: %s", err)
+		return nil
+	}
+
+	psk := [64]byte{}
+
+	conn.SetReadDeadline(time.Now().Add(rep.conf.NetTimeout))
+	if _, err := io.ReadFull(conn, psk[:]); err != nil {
+		conn.Close()
+		rep.handlerLogf("Failed to read PSK: %v", err)
+		return nil
+	}
+
+	if subtle.ConstantTimeCompare(psk[:], rep.pskBytes[:]) != 1 {
+		conn.Close()
+		rep.handlerLogf("PSK mismatch.")
+		return nil
+	}
+
+	return conn
+}

lib/rep/http-handler.go

@@ -1,82 +1,69 @@
 package rep
 
 import (
-	"crypto/subtle"
-	"log"
+	"encoding/json"
 	"net/http"
-	"time"
-
-	"git.crumpington.com/public/jldb/lib/httpconn"
+	"path"
 )
 
 const (
-	cmdGetInfo   = 10
-	cmdSendState = 20
-	cmdStreamWAL = 30
+	pathGetInfo   = "get-info"
+	pathSendState = "send-state"
+	pathStreamWAL = "stream-wal"
 )
 
-// ---------------------------------------------------------------------------
-
 func (rep *Replicator) Handle(w http.ResponseWriter, r *http.Request) {
-	logf := func(pattern string, args ...any) {
-		log.Printf("[HTTP-HANDLER] "+pattern, args...)
+	// We'll handle two types of requests: HTTP GET requests for JSON, or
+	// streaming requets for state or wall.
+
+	base := path.Base(r.URL.Path)
+	switch base {
+	case pathGetInfo:
+		rep.handleGetInfo(w, r)
+	case pathSendState:
+		rep.handleSendState(w, r)
+	case pathStreamWAL:
+		rep.handleStreamWAL(w, r)
+	default:
+		http.Error(w, "not found", http.StatusNotFound)
+	}
 }
 
-	conn, err := httpconn.Accept(w, r)
-	if err != nil {
-		logf("Failed to accept connection: %s", err)
+func (rep *Replicator) handleGetInfo(w http.ResponseWriter, r *http.Request) {
+	if !rep.checkBasicAuth(w, r) {
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+
+	if err := json.NewEncoder(w).Encode(rep.Info()); err != nil {
+		rep.handlerLogf("Failed to send info: %s", err)
+	}
+}
+
+func (rep *Replicator) handleSendState(w http.ResponseWriter, r *http.Request) {
+	conn := rep.acceptConnect(w, r)
+	if conn == nil {
 		return
 	}
 	defer conn.Close()
 
-	psk := make([]byte, 256)
-
-	conn.SetReadDeadline(time.Now().Add(rep.conf.NetTimeout))
-	if _, err := conn.Read(psk); err != nil {
-		logf("Failed to read PSK: %v", err)
-		return
-	}
-
-	expected := rep.pskBytes
-	if subtle.ConstantTimeCompare(expected, psk) != 1 {
-		logf("PSK mismatch.")
-		return
-	}
-
-	cmd := make([]byte, 1)
-
-	for {
-		conn.SetReadDeadline(time.Now().Add(rep.conf.NetTimeout))
-		if _, err := conn.Read(cmd); err != nil {
-			logf("Read failed: %v", err)
-			return
-		}
-
-		switch cmd[0] {
-
-		case cmdGetInfo:
-
-			if err := sendJSON(rep.Info(), conn, rep.conf.NetTimeout); err != nil {
-				logf("Failed to send info: %s", err)
-				return
-			}
-
-		case cmdSendState:
-
 	if err := rep.sendState(conn); err != nil {
 		if !rep.stopped() {
-					logf("Failed to send state: %s", err)
+			rep.handlerLogf("Failed to send state: %s", err)
+		}
 	}
-				return
 }
 
-		case cmdStreamWAL:
+func (rep *Replicator) handleStreamWAL(w http.ResponseWriter, r *http.Request) {
+	conn := rep.acceptConnect(w, r)
+	if conn == nil {
+		return
+	}
+	defer conn.Close()
 
 	err := rep.wal.Send(conn, rep.conf.NetTimeout)
 	if !rep.stopped() {
-				logf("Failed when sending WAL: %s", err)
-			}
-			return
-		}
+		rep.handlerLogf("Failed when streaming WAL: %s", err)
 	}
 }

lib/rep/paths.go

@@ -0,0 +1,17 @@
+package rep
+
+import (
+	"path/filepath"
+)
+
+func lockFilePath(rootDir string) string {
+	return filepath.Join(rootDir, "lock")
+}
+
+func walRootDir(rootDir string) string {
+	return filepath.Join(rootDir, "wal")
+}
+
+func stateFilePath(rootDir string) string {
+	return filepath.Join(rootDir, "state")
+}

lib/rep/pools.go

@@ -1,21 +0,0 @@
-package rep
-
-import (
-	"bytes"
-	"sync"
-)
-
-var bufPool = sync.Pool{
-	New: func() any {
-		return &bytes.Buffer{}
-	},
-}
-
-func bufPoolGet() *bytes.Buffer {
-	return bufPool.Get().(*bytes.Buffer)
-}
-
-func bufPoolPut(b *bytes.Buffer) {
-	b.Reset()
-	bufPool.Put(b)
-}

lib/rep/psk.go

@@ -0,0 +1,16 @@
+package rep
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+)
+
+func pskToBytes(in string) [64]byte {
+	b := sha256.Sum256([]byte(in))
+	dst := [64]byte{}
+	i := hex.Encode(dst[:], b[:])
+	if i != 64 {
+		panic(i)
+	}
+	return dst
+}

lib/rep/replicator-open.go

@@ -27,9 +27,7 @@ func (rep *Replicator) loadConfigDefaults() {
 	}
 
 	rep.conf = conf
-
-	rep.pskBytes = make([]byte, 256)
-	copy(rep.pskBytes, []byte(conf.ReplicationPSK))
+	rep.pskBytes = pskToBytes(conf.ReplicationPSK)
 }
 
 func (rep *Replicator) initDirectories() error {

lib/rep/replicator-walrecvr.go

@@ -30,9 +30,8 @@ func (rep *Replicator) runWALRecvrOnce() {
 		log.Printf("[WAL-RECVR] "+pattern, args...)
 	}
 
-	if err := rep.client.StreamWAL(rep.wal); err != nil {
+	err := rep.client.StreamWAL(rep.wal)
 	if !rep.stopped() {
 		logf("Recv failed: %v", err)
 	}
 }
-}

lib/rep/replicator.go

@@ -60,7 +60,8 @@ type Replicator struct {
 	conf Config
 
 	lockFile *os.File
-	pskBytes []byte
+	pskBytes [64]byte // 64 ascii characters. See pskToBytes.
+
 	wal *wal.WAL
 
 	appendNotify chan struct{}

lib/rep/testapp_test.go

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"git.crumpington.com/public/jldb/lib/errs"
 	"git.crumpington.com/public/jldb/lib/wal"
 )
 
@@ -83,7 +84,7 @@ func newApp(t *testing.T, id int64, conf Config) *TestApp {
 		Apply:           a.apply,
 	}, conf)
 	if err != nil {
-		t.Fatal(err)
+		t.Fatal(errs.FmtDetails(err))
 	}
 
 	return a